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libmdbx (empty) → 0.1.0.0

raw patch · 14 files changed

+29954/−0 lines, 14 filesdep +basedep +bytestringdep +libmdbxsetup-changed

Dependencies added: base, bytestring, libmdbx, mtl, store, string-interpolate, text

Files

+ ChangeLog.md view
@@ -0,0 +1,5 @@+### 0.1.0.0++* Initial release.+* Low level API.+* High level API.
+ LICENSE view
@@ -0,0 +1,30 @@+Copyright Francisco Vallarino (c) 2021++All rights reserved.++Redistribution and use in source and binary forms, with or without+modification, are permitted provided that the following conditions are met:++    * Redistributions of source code must retain the above copyright+      notice, this list of conditions and the following disclaimer.++    * Redistributions in binary form must reproduce the above+      copyright notice, this list of conditions and the following+      disclaimer in the documentation and/or other materials provided+      with the distribution.++    * Neither the name of Francisco Vallarino nor the names of other+      contributors may be used to endorse or promote products derived+      from this software without specific prior written permission.++THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ README.md view
@@ -0,0 +1,55 @@+# libmdbx-hs++A [libmdbx](https://github.com/erthink/libmdbx) wrapper, providing low level+access to its API plus a set of high level functions for common operations.++Excerpt from libmdbx's [documentation](https://github.com/erthink/libmdbx):++_**libmdbx** is an extremely fast, compact, powerful, embedded,+transactional [key-value database](https://en.wikipedia.org/wiki/Key-value_database),+with [permissive license](./LICENSE)._++_Historically, **libmdbx** is a deeply revised and extended descendant of the amazing+[Lightning Memory-Mapped Database](https://en.wikipedia.org/wiki/Lightning_Memory-Mapped_Database).+**libmdbx** inherits all benefits from _LMDB_, but resolves some issues and adds [a set of improvements](#improvements-beyond-lmdb)._++## Usage++### Low level interface++Using libmdbx low level interface involves the following steps:++- Opening an environment. This is the equivalent of a database.+- Opening a database. This is the equivalent of a table.+- Creating a transaction.+- Performing CRUD operations/using a cursor.+- Committing or aborting the transaction.++You can check [Hackage](https://hackage.haskell.org/package/libmdbx-hs/Mdbx-API.html)+for the low level interface or [libmdbx](https://erthink.github.io/libmdbx)+documentation for more details on internals.++### High level interface++Alternatively you can use the higher level interface which, although it provides+a more limited set of operations, takes care of transaction handling and makes+the common use cases really simple.++For the high level interface check [Hackage](https://hackage.haskell.org/package/libmdbx-hs/Mdbx-Database.html)+or the sample application [here](app/Main.hs).++### Common++In both scenarios, you will want to check [Hackage](https://hackage.haskell.org/package/libmdbx-hs/Mdbx-Types.html)+for information on how to make your data types compatible with libmdbx-hs.++## Dependencies++Source code for libmdbx is included in the repository and built with the rest of+the project, to avoid requiring a separate library install.++## License++libmdbx is licensed under the [The OpenLDAP Public License](https://github.com/erthink/libmdbx/blob/master/LICENSE).++libmdbx-hs is licensed under the [BSD-3 License](LICENSE).
+ Setup.hs view
@@ -0,0 +1,2 @@+import Distribution.Simple+main = defaultMain
+ app/Main.hs view
@@ -0,0 +1,60 @@+{-# LANGUAGE DeriveAnyClass #-}+{-# LANGUAGE DeriveGeneric #-}+{-# LANGUAGE DerivingVia #-}+{-# LANGUAGE FlexibleContexts #-}+{-# LANGUAGE OverloadedStrings #-}+{-# LANGUAGE QuasiQuotes #-}+{-# LANGUAGE StandaloneDeriving #-}+{-# LANGUAGE TypeApplications #-}++module Main where++import Control.Exception (bracket)+import Data.Store+import Data.String.Interpolate (i)+import Data.Text (Text)+import GHC.Generics++import Mdbx+import Mdbx.Store++data User = User {+  _username :: Text,+  _password :: Text+} deriving (Eq, Show, Generic, Store)++deriving via (MdbxItemStore User) instance MdbxItem User++openEnvDbi :: IO MdbxEnv+openEnvDbi = envOpen "./testdb" [MdbxNosubdir, MdbxCoalesce, MdbxLiforeclaim]++userKey :: User -> Text+userKey user = [i|user-#{_username user}|]++main :: IO ()+main = bracket openEnvDbi envClose $ \env -> do+  dbi <- dbiOpen env Nothing []+  putItems env dbi pairs+  getItems env dbi keys1 >>= print @[User]+  getItems env dbi keys2 >>= print @[User]+  getItems env dbi (_username <$> users) >>= print @[User]+  getRange env dbi range1 range2 >>= mapM_ (print @User)+  where+    keys1 = ["mark", "dale"] :: [Text]+    keys2 = ["john", "carl"] :: [Text]+    range1 = "user-user-327" :: Text+    range2 = "user-user-999" :: Text+    users = [+      User "mark" "hide",+      User "john" "test",+      User "ernest" "password",+      User "dale" "done",+      User "carl" "past",+      User "user-001" "test",+      User "user-101" "test",+      User "user-950" "test",+      User "user-327" "test",+      User "user-425" "test",+      User "user-897" "test"+      ]+    pairs = (\u -> (userKey u, u)) <$> users
+ app/Mdbx/Store.hs view
@@ -0,0 +1,33 @@+module Mdbx.Store (+  MdbxItemStore(..),+  fromMdbxStore,+  withMdbxStore+) where++import Data.ByteString.Unsafe (unsafeUseAsCStringLen, unsafePackCStringLen)+import Data.Coerce (coerce)+import Data.Store (Store, decodeIO, encode)+import Foreign.Ptr++import Mdbx++newtype MdbxItemStore a = MdbxItemStore {+  unwrapStore :: a+}++instance Store a => MdbxItem (MdbxItemStore a) where+  fromMdbxVal item = MdbxItemStore <$> fromMdbxStore item+  toMdbxVal item = withMdbxStore (unwrapStore item)++fromMdbxStore :: Store v => MdbxVal -> IO v+fromMdbxStore (MdbxVal size ptr) = do+  bs <- unsafePackCStringLen (castPtr ptr, fromIntegral size)+  decodeIO bs++withMdbxStore :: Store v => v -> (MdbxVal -> IO a) -> IO a+withMdbxStore val fn =+  unsafeUseAsCStringLen bsV $ \(ptrV, sizeV) -> do+    let mval = MdbxVal (fromIntegral sizeV) (castPtr ptrV)+    fn mval+  where+    bsV = encode val
+ cbits/libmdbx/mdbx.c view
@@ -0,0 +1,28730 @@+/*+ * Copyright 2015-2021 Leonid Yuriev <leo@yuriev.ru>+ * and other libmdbx authors: please see AUTHORS file.+ * All rights reserved.+ *+ * Redistribution and use in source and binary forms, with or without+ * modification, are permitted only as authorized by the OpenLDAP+ * Public License.+ *+ * A copy of this license is available in the file LICENSE in the+ * top-level directory of the distribution or, alternatively, at+ * <http://www.OpenLDAP.org/license.html>. */++#define MDBX_ALLOY 1+#define MDBX_BUILD_SOURCERY 5d07fd73c14d9bb29e5e409419ce7dd761ba3552e646f98a68540d43ea337946_v0_9_3_44_g0e0682f+#ifdef MDBX_CONFIG_H+#include MDBX_CONFIG_H+#endif++#define LIBMDBX_INTERNALS+#ifdef MDBX_TOOLS+#define MDBX_DEPRECATED+#endif /* MDBX_TOOLS */++/* *INDENT-OFF* */+/* clang-format off */++/* In case the MDBX_DEBUG is undefined set it corresponding to NDEBUG */+#ifndef MDBX_DEBUG+#   ifdef NDEBUG+#       define MDBX_DEBUG 0+#   else+#       define MDBX_DEBUG 1+#   endif+#endif++/* Undefine the NDEBUG if debugging is enforced by MDBX_DEBUG */+#if MDBX_DEBUG+#   undef NDEBUG+#endif++#ifdef MDBX_ALLOY+/* Amalgamated build */+#   define MDBX_INTERNAL_FUNC static+#   define MDBX_INTERNAL_VAR static+#else+/* Non-amalgamated build */+#   define MDBX_INTERNAL_FUNC+#   define MDBX_INTERNAL_VAR extern+#endif /* MDBX_ALLOY */++#ifndef MDBX_DISABLE_GNU_SOURCE+#define MDBX_DISABLE_GNU_SOURCE 0+#endif+#if MDBX_DISABLE_GNU_SOURCE+#undef _GNU_SOURCE+#elif (defined(__linux__) || defined(__gnu_linux__)) && !defined(_GNU_SOURCE)+#define _GNU_SOURCE+#endif++/*----------------------------------------------------------------------------*/++/* Should be defined before any includes */+#ifndef _FILE_OFFSET_BITS+#   define _FILE_OFFSET_BITS 64+#endif++#ifdef __APPLE__+#define _DARWIN_C_SOURCE+#endif++#ifdef _MSC_VER+#   if _MSC_FULL_VER < 190024234+        /* Actually libmdbx was not tested with compilers older than 19.00.24234 (Visual Studio 2015 Update 3).+         * But you could remove this #error and try to continue at your own risk.+         * In such case please don't rise up an issues related ONLY to old compilers.+         */+#       error "At least \"Microsoft C/C++ Compiler\" version 19.00.24234 (Visual Studio 2015 Update 3) is required."+#   endif+#   ifndef _CRT_SECURE_NO_WARNINGS+#       define _CRT_SECURE_NO_WARNINGS+#   endif+#if _MSC_VER > 1800+#   pragma warning(disable : 4464) /* relative include path contains '..' */+#endif+#if _MSC_VER > 1913+#   pragma warning(disable : 5045) /* Compiler will insert Spectre mitigation... */+#endif+#pragma warning(disable : 4710) /* 'xyz': function not inlined */+#pragma warning(disable : 4711) /* function 'xyz' selected for automatic inline expansion */+#pragma warning(disable : 4201) /* nonstandard extension used : nameless struct / union */+#pragma warning(disable : 4702) /* unreachable code */+#pragma warning(disable : 4706) /* assignment within conditional expression */+#pragma warning(disable : 4127) /* conditional expression is constant */+#pragma warning(disable : 4324) /* 'xyz': structure was padded due to alignment specifier */+#pragma warning(disable : 4310) /* cast truncates constant value */+#pragma warning(disable : 4820) /* bytes padding added after data member for alignment */+#pragma warning(disable : 4548) /* expression before comma has no effect; expected expression with side - effect */+#pragma warning(disable : 4366) /* the result of the unary '&' operator may be unaligned */+#pragma warning(disable : 4200) /* nonstandard extension used: zero-sized array in struct/union */+#pragma warning(disable : 4204) /* nonstandard extension used: non-constant aggregate initializer */+#pragma warning(disable : 4505) /* unreferenced local function has been removed */+#endif                          /* _MSC_VER (warnings) */++#include "mdbx.h"+/*+ * Copyright 2015-2021 Leonid Yuriev <leo@yuriev.ru>+ * and other libmdbx authors: please see AUTHORS file.+ * All rights reserved.+ *+ * Redistribution and use in source and binary forms, with or without+ * modification, are permitted only as authorized by the OpenLDAP+ * Public License.+ *+ * A copy of this license is available in the file LICENSE in the+ * top-level directory of the distribution or, alternatively, at+ * <http://www.OpenLDAP.org/license.html>.+ */++/* *INDENT-OFF* */+/* clang-format off */++#ifndef __GNUC_PREREQ+#   if defined(__GNUC__) && defined(__GNUC_MINOR__)+#       define __GNUC_PREREQ(maj, min) \+          ((__GNUC__ << 16) + __GNUC_MINOR__ >= ((maj) << 16) + (min))+#   else+#       define __GNUC_PREREQ(maj, min) (0)+#   endif+#endif /* __GNUC_PREREQ */++#ifndef __CLANG_PREREQ+#   ifdef __clang__+#       define __CLANG_PREREQ(maj,min) \+          ((__clang_major__ << 16) + __clang_minor__ >= ((maj) << 16) + (min))+#   else+#       define __CLANG_PREREQ(maj,min) (0)+#   endif+#endif /* __CLANG_PREREQ */++#ifndef __GLIBC_PREREQ+#   if defined(__GLIBC__) && defined(__GLIBC_MINOR__)+#       define __GLIBC_PREREQ(maj, min) \+          ((__GLIBC__ << 16) + __GLIBC_MINOR__ >= ((maj) << 16) + (min))+#   else+#       define __GLIBC_PREREQ(maj, min) (0)+#   endif+#endif /* __GLIBC_PREREQ */++#ifndef __has_warning+#   define __has_warning(x) (0)+#endif++#ifndef __has_include+#   define __has_include(x) (0)+#endif++#if __has_feature(thread_sanitizer)+#   define __SANITIZE_THREAD__ 1+#endif++#if __has_feature(address_sanitizer)+#   define __SANITIZE_ADDRESS__ 1+#endif++/*----------------------------------------------------------------------------*/++#ifndef __extern_C+#   ifdef __cplusplus+#       define __extern_C extern "C"+#   else+#       define __extern_C+#   endif+#endif /* __extern_C */++#if !defined(nullptr) && !defined(__cplusplus) || (__cplusplus < 201103L && !defined(_MSC_VER))+#   define nullptr NULL+#endif++/*----------------------------------------------------------------------------*/++#ifndef __always_inline+#   if defined(__GNUC__) || __has_attribute(__always_inline__)+#       define __always_inline __inline __attribute__((__always_inline__))+#   elif defined(_MSC_VER)+#       define __always_inline __forceinline+#   else+#       define __always_inline+#   endif+#endif /* __always_inline */++#ifndef __noinline+#   if defined(__GNUC__) || __has_attribute(__noinline__)+#       define __noinline __attribute__((__noinline__))+#   elif defined(_MSC_VER)+#       define __noinline __declspec(noinline)+#   else+#       define __noinline+#   endif+#endif /* __noinline */++#ifndef __must_check_result+#   if defined(__GNUC__) || __has_attribute(__warn_unused_result__)+#       define __must_check_result __attribute__((__warn_unused_result__))+#   else+#       define __must_check_result+#   endif+#endif /* __must_check_result */++#ifndef __maybe_unused+#   if defined(__GNUC__) || __has_attribute(__unused__)+#       define __maybe_unused __attribute__((__unused__))+#   else+#       define __maybe_unused+#   endif+#endif /* __maybe_unused */++#if !defined(__noop) && !defined(_MSC_VER)+#   define __noop(...) do {} while(0)+#endif /* __noop */++#ifndef __fallthrough+#  if defined(__cplusplus) && (__has_cpp_attribute(fallthrough) &&             \+     (!defined(__clang__) || __clang__ > 4)) || __cplusplus >= 201703L+#    define __fallthrough [[fallthrough]]+#  elif __GNUC_PREREQ(8, 0) && defined(__cplusplus) && __cplusplus >= 201103L+#    define __fallthrough [[fallthrough]]+#  elif __GNUC_PREREQ(7, 0) &&                                                 \+    (!defined(__LCC__) || (__LCC__ == 124 && __LCC_MINOR__ >= 12) ||           \+     (__LCC__ == 125 && __LCC_MINOR__ >= 5) || (__LCC__ >= 126))+#    define __fallthrough __attribute__((__fallthrough__))+#  elif defined(__clang__) && defined(__cplusplus) && __cplusplus >= 201103L &&\+    __has_feature(cxx_attributes) && __has_warning("-Wimplicit-fallthrough")+#    define __fallthrough [[clang::fallthrough]]+#  else+#    define __fallthrough+#  endif+#endif /* __fallthrough */++#ifndef __unreachable+#   if __GNUC_PREREQ(4,5) || __has_builtin(__builtin_unreachable)+#       define __unreachable() __builtin_unreachable()+#   elif defined(_MSC_VER)+#       define __unreachable() __assume(0)+#   else+#       define __unreachable() __noop()+#   endif+#endif /* __unreachable */++#ifndef __prefetch+#   if defined(__GNUC__) || defined(__clang__) || __has_builtin(__builtin_prefetch)+#       define __prefetch(ptr) __builtin_prefetch(ptr)+#   else+#       define __prefetch(ptr) __noop(ptr)+#   endif+#endif /* __prefetch */++#ifndef __nothrow+#   if defined(__cplusplus)+#       if __cplusplus < 201703L+#           define __nothrow throw()+#       else+#           define __nothrow noexcept(true)+#       endif /* __cplusplus */+#   elif defined(__GNUC__) || __has_attribute(__nothrow__)+#       define __nothrow __attribute__((__nothrow__))+#   elif defined(_MSC_VER) && defined(__cplusplus)+#       define __nothrow __declspec(nothrow)+#   else+#       define __nothrow+#   endif+#endif /* __nothrow */++#ifndef __hidden+#   if defined(__GNUC__) || __has_attribute(__visibility__)+#       define __hidden __attribute__((__visibility__("hidden")))+#   else+#       define __hidden+#   endif+#endif /* __hidden */++#ifndef __optimize+#   if defined(__OPTIMIZE__)+#       if (defined(__GNUC__) && !defined(__clang__)) || __has_attribute(__optimize__)+#           define __optimize(ops) __attribute__((__optimize__(ops)))+#       else+#           define __optimize(ops)+#       endif+#   else+#       define __optimize(ops)+#   endif+#endif /* __optimize */++#ifndef __hot+#   if defined(__OPTIMIZE__)+#       if defined(__e2k__)+#           define __hot __attribute__((__hot__)) __optimize(3)+#       elif defined(__clang__) && !__has_attribute(__hot_) \+        && __has_attribute(__section__) && (defined(__linux__) || defined(__gnu_linux__))+            /* just put frequently used functions in separate section */+#           define __hot __attribute__((__section__("text.hot"))) __optimize("O3")+#       elif defined(__GNUC__) || __has_attribute(__hot__)+#           define __hot __attribute__((__hot__)) __optimize("O3")+#       else+#           define __hot  __optimize("O3")+#       endif+#   else+#       define __hot+#   endif+#endif /* __hot */++#ifndef __cold+#   if defined(__OPTIMIZE__)+#       if defined(__e2k__)+#           define __cold __attribute__((__cold__)) __optimize(1)+#       elif defined(__clang__) && !__has_attribute(cold) \+        && __has_attribute(__section__) && (defined(__linux__) || defined(__gnu_linux__))+            /* just put infrequently used functions in separate section */+#           define __cold __attribute__((__section__("text.unlikely"))) __optimize("Os")+#       elif defined(__GNUC__) || __has_attribute(cold)+#           define __cold __attribute__((__cold__)) __optimize("Os")+#       else+#           define __cold __optimize("Os")+#       endif+#   else+#       define __cold+#   endif+#endif /* __cold */++#ifndef __flatten+#   if defined(__OPTIMIZE__) && (defined(__GNUC__) || __has_attribute(__flatten__))+#       define __flatten __attribute__((__flatten__))+#   else+#       define __flatten+#   endif+#endif /* __flatten */++#ifndef likely+#   if (defined(__GNUC__) || __has_builtin(__builtin_expect)) && !defined(__COVERITY__)+#       define likely(cond) __builtin_expect(!!(cond), 1)+#   else+#       define likely(x) (!!(x))+#   endif+#endif /* likely */++#ifndef unlikely+#   if (defined(__GNUC__) || __has_builtin(__builtin_expect)) && !defined(__COVERITY__)+#       define unlikely(cond) __builtin_expect(!!(cond), 0)+#   else+#       define unlikely(x) (!!(x))+#   endif+#endif /* unlikely */++#ifndef __anonymous_struct_extension__+#   if defined(__GNUC__)+#       define __anonymous_struct_extension__ __extension__+#   else+#       define __anonymous_struct_extension__+#   endif+#endif /* __anonymous_struct_extension__ */++#ifndef __Wpedantic_format_voidptr+    static __inline __maybe_unused const void* MDBX_PURE_FUNCTION+        __Wpedantic_format_voidptr(const void* ptr) {return ptr;}+#   define __Wpedantic_format_voidptr(ARG) __Wpedantic_format_voidptr(ARG)+#endif /* __Wpedantic_format_voidptr */++/*----------------------------------------------------------------------------*/++#if defined(MDBX_USE_VALGRIND)+#   include <valgrind/memcheck.h>+#   ifndef VALGRIND_DISABLE_ADDR_ERROR_REPORTING_IN_RANGE+        /* LY: available since Valgrind 3.10 */+#       define VALGRIND_DISABLE_ADDR_ERROR_REPORTING_IN_RANGE(a,s)+#       define VALGRIND_ENABLE_ADDR_ERROR_REPORTING_IN_RANGE(a,s)+#   endif+#elif !defined(RUNNING_ON_VALGRIND)+#   define VALGRIND_CREATE_MEMPOOL(h,r,z)+#   define VALGRIND_DESTROY_MEMPOOL(h)+#   define VALGRIND_MEMPOOL_TRIM(h,a,s)+#   define VALGRIND_MEMPOOL_ALLOC(h,a,s)+#   define VALGRIND_MEMPOOL_FREE(h,a)+#   define VALGRIND_MEMPOOL_CHANGE(h,a,b,s)+#   define VALGRIND_MAKE_MEM_NOACCESS(a,s)+#   define VALGRIND_MAKE_MEM_DEFINED(a,s)+#   define VALGRIND_MAKE_MEM_UNDEFINED(a,s)+#   define VALGRIND_DISABLE_ADDR_ERROR_REPORTING_IN_RANGE(a,s)+#   define VALGRIND_ENABLE_ADDR_ERROR_REPORTING_IN_RANGE(a,s)+#   define VALGRIND_CHECK_MEM_IS_ADDRESSABLE(a,s) (0)+#   define VALGRIND_CHECK_MEM_IS_DEFINED(a,s) (0)+#   define RUNNING_ON_VALGRIND (0)+#endif /* MDBX_USE_VALGRIND */++#ifdef __SANITIZE_ADDRESS__+#   include <sanitizer/asan_interface.h>+#elif !defined(ASAN_POISON_MEMORY_REGION)+#   define ASAN_POISON_MEMORY_REGION(addr, size) \+        ((void)(addr), (void)(size))+#   define ASAN_UNPOISON_MEMORY_REGION(addr, size) \+        ((void)(addr), (void)(size))+#endif /* __SANITIZE_ADDRESS__ */++/*----------------------------------------------------------------------------*/++#ifndef ARRAY_LENGTH+#   ifdef __cplusplus+        template <typename T, size_t N>+        char (&__ArraySizeHelper(T (&array)[N]))[N];+#       define ARRAY_LENGTH(array) (sizeof(::__ArraySizeHelper(array)))+#   else+#       define ARRAY_LENGTH(array) (sizeof(array) / sizeof(array[0]))+#   endif+#endif /* ARRAY_LENGTH */++#ifndef ARRAY_END+#   define ARRAY_END(array) (&array[ARRAY_LENGTH(array)])+#endif /* ARRAY_END */++#ifndef STRINGIFY+#   define STRINGIFY_HELPER(x) #x+#   define STRINGIFY(x) STRINGIFY_HELPER(x)+#endif /* STRINGIFY */++#define CONCAT(a,b) a##b+#define XCONCAT(a,b) CONCAT(a,b)++#ifndef offsetof+#   define offsetof(type, member)  __builtin_offsetof(type, member)+#endif /* offsetof */++#ifndef container_of+#   define container_of(ptr, type, member) \+        ((type *)((char *)(ptr) - offsetof(type, member)))+#endif /* container_of */++#define MDBX_TETRAD(a, b, c, d)                                                \+  ((uint32_t)(a) << 24 | (uint32_t)(b) << 16 | (uint32_t)(c) << 8 | (d))++#define MDBX_STRING_TETRAD(str) MDBX_TETRAD(str[0], str[1], str[2], str[3])++#define FIXME "FIXME: " __FILE__ ", " STRINGIFY(__LINE__)++#ifndef STATIC_ASSERT_MSG+#   if defined(static_assert)+#       define STATIC_ASSERT_MSG(expr, msg) static_assert(expr, msg)+#   elif defined(_STATIC_ASSERT)+#       define STATIC_ASSERT_MSG(expr, msg) _STATIC_ASSERT(expr)+#   elif defined(_MSC_VER)+#       include <crtdbg.h>+#       define STATIC_ASSERT_MSG(expr, msg) _STATIC_ASSERT(expr)+#   elif (defined(__STDC_VERSION__) && __STDC_VERSION__ >= 201112L) \+          || __has_feature(c_static_assert)+#       define STATIC_ASSERT_MSG(expr, msg) _Static_assert(expr, msg)+#   else+#       define STATIC_ASSERT_MSG(expr, msg) switch (0) {case 0:case (expr):;}+#   endif+#endif /* STATIC_ASSERT */++#ifndef STATIC_ASSERT+#   define STATIC_ASSERT(expr) STATIC_ASSERT_MSG(expr, #expr)+#endif++/* *INDENT-ON* */+/* clang-format on */++#if defined(__GNUC__) && !__GNUC_PREREQ(4,2)+    /* Actually libmdbx was not tested with compilers older than GCC 4.2.+     * But you could ignore this warning at your own risk.+     * In such case please don't rise up an issues related ONLY to old compilers.+     */+#   warning "libmdbx required GCC >= 4.2"+#endif++#if defined(__clang__) && !__CLANG_PREREQ(3,8)+    /* Actually libmdbx was not tested with CLANG older than 3.8.+     * But you could ignore this warning at your own risk.+     * In such case please don't rise up an issues related ONLY to old compilers.+     */+#   warning "libmdbx required CLANG >= 3.8"+#endif++#if defined(__GLIBC__) && !__GLIBC_PREREQ(2,12)+    /* Actually libmdbx was not tested with something older than glibc 2.12.+     * But you could ignore this warning at your own risk.+     * In such case please don't rise up an issues related ONLY to old systems.+     */+#   warning "libmdbx was only tested with GLIBC >= 2.12."+#endif++#ifdef __SANITIZE_THREAD__+#   warning "libmdbx don't compatible with ThreadSanitizer, you will get a lot of false-positive issues."+#endif /* __SANITIZE_THREAD__ */++#if __has_warning("-Wnested-anon-types")+#   if defined(__clang__)+#       pragma clang diagnostic ignored "-Wnested-anon-types"+#   elif defined(__GNUC__)+#       pragma GCC diagnostic ignored "-Wnested-anon-types"+#   else+#      pragma warning disable "nested-anon-types"+#   endif+#endif /* -Wnested-anon-types */++#if __has_warning("-Wconstant-logical-operand")+#   if defined(__clang__)+#       pragma clang diagnostic ignored "-Wconstant-logical-operand"+#   elif defined(__GNUC__)+#       pragma GCC diagnostic ignored "-Wconstant-logical-operand"+#   else+#      pragma warning disable "constant-logical-operand"+#   endif+#endif /* -Wconstant-logical-operand */++#if defined(__LCC__) && (__LCC__ <= 121)+    /* bug #2798 */+#   pragma diag_suppress alignment_reduction_ignored+#elif defined(__ICC)+#   pragma warning(disable: 3453 1366)+#elif __has_warning("-Walignment-reduction-ignored")+#   if defined(__clang__)+#       pragma clang diagnostic ignored "-Walignment-reduction-ignored"+#   elif defined(__GNUC__)+#       pragma GCC diagnostic ignored "-Walignment-reduction-ignored"+#   else+#       pragma warning disable "alignment-reduction-ignored"+#   endif+#endif /* -Walignment-reduction-ignored */++/* *INDENT-ON* */+/* clang-format on */++#ifdef __cplusplus+extern "C" {+#endif++/* https://en.wikipedia.org/wiki/Operating_system_abstraction_layer */++/*+ * Copyright 2015-2021 Leonid Yuriev <leo@yuriev.ru>+ * and other libmdbx authors: please see AUTHORS file.+ * All rights reserved.+ *+ * Redistribution and use in source and binary forms, with or without+ * modification, are permitted only as authorized by the OpenLDAP+ * Public License.+ *+ * A copy of this license is available in the file LICENSE in the+ * top-level directory of the distribution or, alternatively, at+ * <http://www.OpenLDAP.org/license.html>.+ */+++/*----------------------------------------------------------------------------*/+/* Microsoft compiler generates a lot of warning for self includes... */++#ifdef _MSC_VER+#pragma warning(push, 1)+#pragma warning(disable : 4548) /* expression before comma has no effect;      \+                                   expected expression with side - effect */+#pragma warning(disable : 4530) /* C++ exception handler used, but unwind      \+                                 * semantics are not enabled. Specify /EHsc */+#pragma warning(disable : 4577) /* 'noexcept' used with no exception handling  \+                                 * mode specified; termination on exception is \+                                 * not guaranteed. Specify /EHsc */+#endif                          /* _MSC_VER (warnings) */++#if defined(_WIN32) || defined(_WIN64)+#if !defined(_CRT_SECURE_NO_WARNINGS)+#define _CRT_SECURE_NO_WARNINGS+#endif+#if !defined(_NO_CRT_STDIO_INLINE) && MDBX_BUILD_SHARED_LIBRARY &&             \+    !defined(MDBX_TOOLS) && MDBX_AVOID_CRT+#define _NO_CRT_STDIO_INLINE+#endif+#elif !defined(_POSIX_C_SOURCE)+#define _POSIX_C_SOURCE 200809L+#endif /* Windows */++/*----------------------------------------------------------------------------*/+/* C99 includes */+#include <inttypes.h>+#include <stddef.h>+#include <stdint.h>+#include <stdlib.h>++#include <assert.h>+#include <fcntl.h>+#include <limits.h>+#include <stdio.h>+#include <string.h>+#include <time.h>++/* C11 stdalign.h */+#if __has_include(<stdalign.h>)+#include <stdalign.h>+#elif defined(__STDC_VERSION__) && __STDC_VERSION__ >= 201112L+#define alignas(N) _Alignas(N)+#elif defined(_MSC_VER)+#define alignas(N) __declspec(align(N))+#elif __has_attribute(__aligned__) || defined(__GNUC__)+#define alignas(N) __attribute__((__aligned__(N)))+#else+#error "FIXME: Required _alignas() or equivalent."+#endif++/*----------------------------------------------------------------------------*/+/* Systems includes */++#ifdef __APPLE__+#include <TargetConditionals.h>+#endif /* Apple OSX & iOS */++#if defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__) ||     \+    defined(__BSD__) || defined(__bsdi__) || defined(__DragonFly__) ||         \+    defined(__APPLE__) || defined(__MACH__)+#include <sys/cdefs.h>+#include <sys/mount.h>+#include <sys/sysctl.h>+#include <sys/types.h>+#if defined(__FreeBSD__) || defined(__DragonFly__)+#include <vm/vm_param.h>+#elif defined(__OpenBSD__) || defined(__NetBSD__)+#include <uvm/uvm_param.h>+#else+#define SYSCTL_LEGACY_NONCONST_MIB+#endif+#ifndef __MACH__+#include <sys/vmmeter.h>+#endif+#else+#include <malloc.h>+#if !(defined(__sun) || defined(__SVR4) || defined(__svr4__) ||                \+      defined(_WIN32) || defined(_WIN64))+#include <mntent.h>+#endif /* !Solaris */+#endif /* !xBSD */++#if defined(__FreeBSD__) || __has_include(<malloc_np.h>)+#include <malloc_np.h>+#endif++#if defined(__APPLE__) || defined(__MACH__) || __has_include(<malloc/malloc.h>)+#include <malloc/malloc.h>+#endif /* MacOS */++#if defined(__MACH__)+#include <mach/host_info.h>+#include <mach/mach_host.h>+#include <mach/mach_port.h>+#include <uuid/uuid.h>+#undef P_DIRTY+#endif++#if defined(__linux__) || defined(__gnu_linux__)+#include <linux/sysctl.h>+#include <sched.h>+#include <sys/sendfile.h>+#include <sys/statfs.h>+#endif /* Linux */++#ifndef _XOPEN_SOURCE+#define _XOPEN_SOURCE 0+#endif++#ifndef _XOPEN_SOURCE_EXTENDED+#define _XOPEN_SOURCE_EXTENDED 0+#else+#include <utmpx.h>+#endif /* _XOPEN_SOURCE_EXTENDED */++#if defined(__sun) || defined(__SVR4) || defined(__svr4__)+#include <kstat.h>+#include <sys/mnttab.h>+/* On Solaris, it's easier to add a missing prototype rather than find a+ * combination of #defines that break nothing. */+__extern_C key_t ftok(const char *, int);+#endif /* SunOS/Solaris */++#if defined(_WIN32) || defined(_WIN64)+#ifndef WIN32_LEAN_AND_MEAN+#define WIN32_LEAN_AND_MEAN+#endif+#include <excpt.h>+#include <tlhelp32.h>+#include <windows.h>+#include <winnt.h>+#include <winternl.h>+#define HAVE_SYS_STAT_H+#define HAVE_SYS_TYPES_H+typedef HANDLE mdbx_thread_t;+typedef unsigned mdbx_thread_key_t;+#define MDBX_OSAL_SECTION HANDLE+#define MAP_FAILED NULL+#define HIGH_DWORD(v) ((DWORD)((sizeof(v) > 4) ? ((uint64_t)(v) >> 32) : 0))+#define THREAD_CALL WINAPI+#define THREAD_RESULT DWORD+typedef struct {+  HANDLE mutex;+  HANDLE event[2];+} mdbx_condpair_t;+typedef CRITICAL_SECTION mdbx_fastmutex_t;++#if MDBX_AVOID_CRT+#ifndef mdbx_malloc+static inline void *mdbx_malloc(size_t bytes) {+  return LocalAlloc(LMEM_FIXED, bytes);+}+#endif /* mdbx_malloc */++#ifndef mdbx_calloc+static inline void *mdbx_calloc(size_t nelem, size_t size) {+  return LocalAlloc(LMEM_FIXED | LMEM_ZEROINIT, nelem * size);+}+#endif /* mdbx_calloc */++#ifndef mdbx_realloc+static inline void *mdbx_realloc(void *ptr, size_t bytes) {+  return ptr ? LocalReAlloc(ptr, bytes, LMEM_MOVEABLE)+             : LocalAlloc(LMEM_FIXED, bytes);+}+#endif /* mdbx_realloc */++#ifndef mdbx_free+#define mdbx_free LocalFree+#endif /* mdbx_free */+#else+#define mdbx_malloc malloc+#define mdbx_calloc calloc+#define mdbx_realloc realloc+#define mdbx_free free+#define mdbx_strdup _strdup+#endif /* MDBX_AVOID_CRT */++#ifndef snprintf+#define snprintf _snprintf /* ntdll */+#endif++#ifndef vsnprintf+#define vsnprintf _vsnprintf /* ntdll */+#endif++#else /*----------------------------------------------------------------------*/++#include <pthread.h>+#include <semaphore.h>+#include <signal.h>+#include <sys/file.h>+#include <sys/ipc.h>+#include <sys/mman.h>+#include <sys/param.h>+#include <sys/stat.h>+#include <sys/statvfs.h>+#include <sys/uio.h>+#include <unistd.h>+typedef pthread_t mdbx_thread_t;+typedef pthread_key_t mdbx_thread_key_t;+#define INVALID_HANDLE_VALUE (-1)+#define THREAD_CALL+#define THREAD_RESULT void *+typedef struct {+  pthread_mutex_t mutex;+  pthread_cond_t cond[2];+} mdbx_condpair_t;+typedef pthread_mutex_t mdbx_fastmutex_t;+#define mdbx_malloc malloc+#define mdbx_calloc calloc+#define mdbx_realloc realloc+#define mdbx_free free+#define mdbx_strdup strdup+#endif /* Platform */++#if __GLIBC_PREREQ(2, 12) || defined(__FreeBSD__) || defined(malloc_usable_size)+/* malloc_usable_size() already provided */+#elif defined(__APPLE__)+#define malloc_usable_size(ptr) malloc_size(ptr)+#elif defined(_MSC_VER) && !MDBX_AVOID_CRT+#define malloc_usable_size(ptr) _msize(ptr)+#endif /* malloc_usable_size */++#ifdef __ANDROID_API__+#include <android/log.h>+#if __ANDROID_API__ >= 21+#include <sys/sendfile.h>+#endif+#endif /* Android */++/* *INDENT-OFF* */+/* clang-format off */+#if defined(HAVE_SYS_STAT_H) || __has_include(<sys/stat.h>)+#include <sys/stat.h>+#endif+#if defined(HAVE_SYS_TYPES_H) || __has_include(<sys/types.h>)+#include <sys/types.h>+#endif+#if defined(HAVE_SYS_FILE_H) || __has_include(<sys/file.h>)+#include <sys/file.h>+#endif+/* *INDENT-ON* */+/* clang-format on */++#ifndef SSIZE_MAX+#define SSIZE_MAX INTPTR_MAX+#endif++#if !defined(MADV_DODUMP) && defined(MADV_CORE)+#define MADV_DODUMP MADV_CORE+#endif /* MADV_CORE -> MADV_DODUMP */++#if !defined(MADV_DONTDUMP) && defined(MADV_NOCORE)+#define MADV_DONTDUMP MADV_NOCORE+#endif /* MADV_NOCORE -> MADV_DONTDUMP */++#if defined(i386) || defined(__386) || defined(__i386) || defined(__i386__) || \+    defined(i486) || defined(__i486) || defined(__i486__) ||                   \+    defined(i586) | defined(__i586) || defined(__i586__) || defined(i686) ||   \+    defined(__i686) || defined(__i686__) || defined(_M_IX86) ||                \+    defined(_X86_) || defined(__THW_INTEL__) || defined(__I86__) ||            \+    defined(__INTEL__) || defined(__x86_64) || defined(__x86_64__) ||          \+    defined(__amd64__) || defined(__amd64) || defined(_M_X64) ||               \+    defined(_M_AMD64) || defined(__IA32__) || defined(__INTEL__)+#ifndef __ia32__+/* LY: define neutral __ia32__ for x86 and x86-64 */+#define __ia32__ 1+#endif /* __ia32__ */+#if !defined(__amd64__) && (defined(__x86_64) || defined(__x86_64__) ||        \+                            defined(__amd64) || defined(_M_X64))+/* LY: define trusty __amd64__ for all AMD64/x86-64 arch */+#define __amd64__ 1+#endif /* __amd64__ */+#endif /* all x86 */++#if (-6 & 5) || CHAR_BIT != 8 || UINT_MAX < 0xffffffff || ULONG_MAX % 0xFFFF+#error                                                                         \+    "Sanity checking failed: Two's complement, reasonably sized integer types"+#endif++#if UINTPTR_MAX > 0xffffFFFFul || ULONG_MAX > 0xffffFFFFul+#define MDBX_WORDBITS 64+#else+#define MDBX_WORDBITS 32+#endif /* MDBX_WORDBITS */++/*----------------------------------------------------------------------------*/+/* Compiler's includes for builtins/intrinsics */++#if defined(_MSC_VER) || defined(__INTEL_COMPILER)+#include <intrin.h>+#elif __GNUC_PREREQ(4, 4) || defined(__clang__)+#if defined(__ia32__) || defined(__e2k__)+#include <x86intrin.h>+#endif /* __ia32__ */+#if defined(__ia32__)+#include <cpuid.h>+#endif /* __ia32__ */+#elif defined(__SUNPRO_C) || defined(__sun) || defined(sun)+#include <mbarrier.h>+#elif (defined(_HPUX_SOURCE) || defined(__hpux) || defined(__HP_aCC)) &&       \+    (defined(HP_IA64) || defined(__ia64))+#include <machine/sys/inline.h>+#elif defined(__IBMC__) && defined(__powerpc)+#include <atomic.h>+#elif defined(_AIX)+#include <builtins.h>+#include <sys/atomic_op.h>+#elif (defined(__osf__) && defined(__DECC)) || defined(__alpha)+#include <c_asm.h>+#include <machine/builtins.h>+#elif defined(__MWERKS__)+/* CodeWarrior - troubles ? */+#pragma gcc_extensions+#elif defined(__SNC__)+/* Sony PS3 - troubles ? */+#elif defined(__hppa__) || defined(__hppa)+#include <machine/inline.h>+#else+#error Unsupported C compiler, please use GNU C 4.4 or newer+#endif /* Compiler */++/*----------------------------------------------------------------------------*/+/* Byteorder */++#if !defined(__BYTE_ORDER__) || !defined(__ORDER_LITTLE_ENDIAN__) ||           \+    !defined(__ORDER_BIG_ENDIAN__)++/* *INDENT-OFF* */+/* clang-format off */+#if defined(__GLIBC__) || defined(__GNU_LIBRARY__) || defined(__ANDROID_API__) ||  \+    defined(HAVE_ENDIAN_H) || __has_include(<endian.h>)+#include <endian.h>+#elif defined(__APPLE__) || defined(__MACH__) || defined(__OpenBSD__) ||       \+    defined(HAVE_MACHINE_ENDIAN_H) || __has_include(<machine/endian.h>)+#include <machine/endian.h>+#elif defined(HAVE_SYS_ISA_DEFS_H) || __has_include(<sys/isa_defs.h>)+#include <sys/isa_defs.h>+#elif (defined(HAVE_SYS_TYPES_H) && defined(HAVE_SYS_ENDIAN_H)) ||             \+    (__has_include(<sys/types.h>) && __has_include(<sys/endian.h>))+#include <sys/endian.h>+#include <sys/types.h>+#elif defined(__bsdi__) || defined(__DragonFly__) || defined(__FreeBSD__) ||   \+    defined(__NetBSD__) ||                              \+    defined(HAVE_SYS_PARAM_H) || __has_include(<sys/param.h>)+#include <sys/param.h>+#endif /* OS */+/* *INDENT-ON* */+/* clang-format on */++#if defined(__BYTE_ORDER) && defined(__LITTLE_ENDIAN) && defined(__BIG_ENDIAN)+#define __ORDER_LITTLE_ENDIAN__ __LITTLE_ENDIAN+#define __ORDER_BIG_ENDIAN__ __BIG_ENDIAN+#define __BYTE_ORDER__ __BYTE_ORDER+#elif defined(_BYTE_ORDER) && defined(_LITTLE_ENDIAN) && defined(_BIG_ENDIAN)+#define __ORDER_LITTLE_ENDIAN__ _LITTLE_ENDIAN+#define __ORDER_BIG_ENDIAN__ _BIG_ENDIAN+#define __BYTE_ORDER__ _BYTE_ORDER+#else+#define __ORDER_LITTLE_ENDIAN__ 1234+#define __ORDER_BIG_ENDIAN__ 4321++#if defined(__LITTLE_ENDIAN__) ||                                              \+    (defined(_LITTLE_ENDIAN) && !defined(_BIG_ENDIAN)) ||                      \+    defined(__ARMEL__) || defined(__THUMBEL__) || defined(__AARCH64EL__) ||    \+    defined(__MIPSEL__) || defined(_MIPSEL) || defined(__MIPSEL) ||            \+    defined(_M_ARM) || defined(_M_ARM64) || defined(__e2k__) ||                \+    defined(__elbrus_4c__) || defined(__elbrus_8c__) || defined(__bfin__) ||   \+    defined(__BFIN__) || defined(__ia64__) || defined(_IA64) ||                \+    defined(__IA64__) || defined(__ia64) || defined(_M_IA64) ||                \+    defined(__itanium__) || defined(__ia32__) || defined(__CYGWIN__) ||        \+    defined(_WIN64) || defined(_WIN32) || defined(__TOS_WIN__) ||              \+    defined(__WINDOWS__)+#define __BYTE_ORDER__ __ORDER_LITTLE_ENDIAN__++#elif defined(__BIG_ENDIAN__) ||                                               \+    (defined(_BIG_ENDIAN) && !defined(_LITTLE_ENDIAN)) ||                      \+    defined(__ARMEB__) || defined(__THUMBEB__) || defined(__AARCH64EB__) ||    \+    defined(__MIPSEB__) || defined(_MIPSEB) || defined(__MIPSEB) ||            \+    defined(__m68k__) || defined(M68000) || defined(__hppa__) ||               \+    defined(__hppa) || defined(__HPPA__) || defined(__sparc__) ||              \+    defined(__sparc) || defined(__370__) || defined(__THW_370__) ||            \+    defined(__s390__) || defined(__s390x__) || defined(__SYSC_ZARCH__)+#define __BYTE_ORDER__ __ORDER_BIG_ENDIAN__++#else+#error __BYTE_ORDER__ should be defined.+#endif /* Arch */++#endif+#endif /* __BYTE_ORDER__ || __ORDER_LITTLE_ENDIAN__ || __ORDER_BIG_ENDIAN__ */++/* Get the size of a memory page for the system.+ * This is the basic size that the platform's memory manager uses, and is+ * fundamental to the use of memory-mapped files. */+MDBX_NOTHROW_CONST_FUNCTION static __maybe_unused __inline size_t+mdbx_syspagesize(void) {+#if defined(_WIN32) || defined(_WIN64)+  SYSTEM_INFO si;+  GetSystemInfo(&si);+  return si.dwPageSize;+#else+  return sysconf(_SC_PAGE_SIZE);+#endif+}++typedef struct mdbx_mmap_param {+  union {+    void *address;+    uint8_t *dxb;+    struct MDBX_lockinfo *lck;+  };+  mdbx_filehandle_t fd;+  size_t limit;   /* mapping length, but NOT a size of file nor DB */+  size_t current; /* mapped region size, i.e. the size of file and DB */+#if defined(_WIN32) || defined(_WIN64)+  uint64_t filesize /* in-process cache of a file size. */;+#endif+#ifdef MDBX_OSAL_SECTION+  MDBX_OSAL_SECTION section;+#endif+} mdbx_mmap_t;++typedef union bin128 {+  __anonymous_struct_extension__ struct { uint64_t x, y; };+  __anonymous_struct_extension__ struct { uint32_t a, b, c, d; };+} bin128_t;++#if defined(_WIN32) || defined(_WIN64)+typedef union MDBX_srwlock {+  struct {+    long volatile readerCount;+    long volatile writerCount;+  };+  RTL_SRWLOCK native;+} MDBX_srwlock;+#endif /* Windows */++#ifdef __cplusplus+extern void mdbx_osal_jitter(bool tiny);+#else++/*----------------------------------------------------------------------------*/+/* Atomics */++#if defined(__cplusplus) && !defined(__STDC_NO_ATOMICS__) && (__has_include(<cstdatomic>) || __has_extension(cxx_atomic))+#include <cstdatomic>+#define MDBX_HAVE_C11ATOMICS+#elif !defined(__cplusplus) &&                                                 \+    (__STDC_VERSION__ >= 201112L || __has_extension(c_atomic)) &&              \+    !defined(__STDC_NO_ATOMICS__) &&                                           \+    (__GNUC_PREREQ(4, 9) || __CLANG_PREREQ(3, 8) ||                            \+     !(defined(__GNUC__) || defined(__clang__)))+#include <stdatomic.h>+#define MDBX_HAVE_C11ATOMICS+#elif defined(__GNUC__) || defined(__clang__)+#elif defined(_MSC_VER)+#pragma warning(disable : 4163) /* 'xyz': not available as an intrinsic */+#pragma warning(disable : 4133) /* 'function': incompatible types - from       \+                                   'size_t' to 'LONGLONG' */+#pragma warning(disable : 4244) /* 'return': conversion from 'LONGLONG' to     \+                                   'std::size_t', possible loss of data */+#pragma warning(disable : 4267) /* 'function': conversion from 'size_t' to     \+                                   'long', possible loss of data */+#pragma intrinsic(_InterlockedExchangeAdd, _InterlockedCompareExchange)+#pragma intrinsic(_InterlockedExchangeAdd64, _InterlockedCompareExchange64)+#elif defined(__APPLE__)+#include <libkern/OSAtomic.h>+#else+#error FIXME atomic-ops+#endif++/*----------------------------------------------------------------------------*/+/* Memory/Compiler barriers, cache coherence */++#if __has_include(<sys/cachectl.h>)+#include <sys/cachectl.h>+#elif defined(__mips) || defined(__mips__) || defined(__mips64) ||             \+    defined(__mips64__) || defined(_M_MRX000) || defined(_MIPS_) ||            \+    defined(__MWERKS__) || defined(__sgi)+/* MIPS should have explicit cache control */+#include <sys/cachectl.h>+#endif++static __maybe_unused __inline void mdbx_compiler_barrier(void) {+#if defined(__clang__) || defined(__GNUC__)+  __asm__ __volatile__("" ::: "memory");+#elif defined(_MSC_VER)+  _ReadWriteBarrier();+#elif defined(__INTEL_COMPILER) /* LY: Intel Compiler may mimic GCC and MSC */+  __memory_barrier();+#elif defined(__SUNPRO_C) || defined(__sun) || defined(sun)+  __compiler_barrier();+#elif (defined(_HPUX_SOURCE) || defined(__hpux) || defined(__HP_aCC)) &&       \+    (defined(HP_IA64) || defined(__ia64))+  _Asm_sched_fence(/* LY: no-arg meaning 'all expect ALU', e.g. 0x3D3D */);+#elif defined(_AIX) || defined(__ppc__) || defined(__powerpc__) ||             \+    defined(__ppc64__) || defined(__powerpc64__)+  __fence();+#else+#error "Could not guess the kind of compiler, please report to us."+#endif+}++static __maybe_unused __inline void mdbx_memory_barrier(void) {+#ifdef MDBX_HAVE_C11ATOMICS+  atomic_thread_fence(memory_order_seq_cst);+#elif defined(__ATOMIC_SEQ_CST)+#ifdef __clang__+  __c11_atomic_thread_fence(__ATOMIC_SEQ_CST);+#else+  __atomic_thread_fence(__ATOMIC_SEQ_CST);+#endif+#elif defined(__clang__) || defined(__GNUC__)+  __sync_synchronize();+#elif defined(_WIN32) || defined(_WIN64)+  MemoryBarrier();+#elif defined(__INTEL_COMPILER) /* LY: Intel Compiler may mimic GCC and MSC */+#if defined(__ia32__)+  _mm_mfence();+#else+  __mf();+#endif+#elif defined(__SUNPRO_C) || defined(__sun) || defined(sun)+  __machine_rw_barrier();+#elif (defined(_HPUX_SOURCE) || defined(__hpux) || defined(__HP_aCC)) &&       \+    (defined(HP_IA64) || defined(__ia64))+  _Asm_mf();+#elif defined(_AIX) || defined(__ppc__) || defined(__powerpc__) ||             \+    defined(__ppc64__) || defined(__powerpc64__)+  __lwsync();+#else+#error "Could not guess the kind of compiler, please report to us."+#endif+}++/*----------------------------------------------------------------------------*/+/* libc compatibility stuff */++#if (!defined(__GLIBC__) && __GLIBC_PREREQ(2, 1)) &&                           \+    (defined(_GNU_SOURCE) || defined(_BSD_SOURCE))+#define mdbx_asprintf asprintf+#define mdbx_vasprintf vasprintf+#else+MDBX_INTERNAL_FUNC MDBX_PRINTF_ARGS(2, 3) int __maybe_unused+    mdbx_asprintf(char **strp, const char *fmt, ...);+MDBX_INTERNAL_FUNC int mdbx_vasprintf(char **strp, const char *fmt, va_list ap);+#endif++/*----------------------------------------------------------------------------*/+/* OS abstraction layer stuff */++/* max bytes to write in one call */+#if defined(_WIN32) || defined(_WIN64)+#define MAX_WRITE UINT32_C(0x01000000)+#else+#define MAX_WRITE UINT32_C(0x3fff0000)+#endif++#if defined(__linux__) || defined(__gnu_linux__)+MDBX_INTERNAL_VAR uint32_t mdbx_linux_kernel_version;+MDBX_INTERNAL_VAR bool mdbx_RunningOnWSL1 /* Windows Subsystem 1 for Linux */;+#endif /* Linux */++#ifndef mdbx_strdup+LIBMDBX_API char *mdbx_strdup(const char *str);+#endif++static __maybe_unused __inline int mdbx_get_errno(void) {+#if defined(_WIN32) || defined(_WIN64)+  DWORD rc = GetLastError();+#else+  int rc = errno;+#endif+  return rc;+}++#ifndef mdbx_memalign_alloc+MDBX_INTERNAL_FUNC int mdbx_memalign_alloc(size_t alignment, size_t bytes,+                                           void **result);+#endif+#ifndef mdbx_memalign_free+MDBX_INTERNAL_FUNC void mdbx_memalign_free(void *ptr);+#endif++MDBX_INTERNAL_FUNC int mdbx_condpair_init(mdbx_condpair_t *condpair);+MDBX_INTERNAL_FUNC int mdbx_condpair_lock(mdbx_condpair_t *condpair);+MDBX_INTERNAL_FUNC int mdbx_condpair_unlock(mdbx_condpair_t *condpair);+MDBX_INTERNAL_FUNC int mdbx_condpair_signal(mdbx_condpair_t *condpair,+                                            bool part);+MDBX_INTERNAL_FUNC int mdbx_condpair_wait(mdbx_condpair_t *condpair, bool part);+MDBX_INTERNAL_FUNC int mdbx_condpair_destroy(mdbx_condpair_t *condpair);++MDBX_INTERNAL_FUNC int mdbx_fastmutex_init(mdbx_fastmutex_t *fastmutex);+MDBX_INTERNAL_FUNC int mdbx_fastmutex_acquire(mdbx_fastmutex_t *fastmutex);+MDBX_INTERNAL_FUNC int mdbx_fastmutex_release(mdbx_fastmutex_t *fastmutex);+MDBX_INTERNAL_FUNC int mdbx_fastmutex_destroy(mdbx_fastmutex_t *fastmutex);++MDBX_INTERNAL_FUNC int mdbx_pwritev(mdbx_filehandle_t fd, struct iovec *iov,+                                    int iovcnt, uint64_t offset,+                                    size_t expected_written);+MDBX_INTERNAL_FUNC int mdbx_pread(mdbx_filehandle_t fd, void *buf, size_t count,+                                  uint64_t offset);+MDBX_INTERNAL_FUNC int mdbx_pwrite(mdbx_filehandle_t fd, const void *buf,+                                   size_t count, uint64_t offset);+MDBX_INTERNAL_FUNC int mdbx_write(mdbx_filehandle_t fd, const void *buf,+                                  size_t count);++MDBX_INTERNAL_FUNC int+mdbx_thread_create(mdbx_thread_t *thread,+                   THREAD_RESULT(THREAD_CALL *start_routine)(void *),+                   void *arg);+MDBX_INTERNAL_FUNC int mdbx_thread_join(mdbx_thread_t thread);++enum mdbx_syncmode_bits {+  MDBX_SYNC_NONE = 0,+  MDBX_SYNC_DATA = 1,+  MDBX_SYNC_SIZE = 2,+  MDBX_SYNC_IODQ = 4+};++MDBX_INTERNAL_FUNC int mdbx_fsync(mdbx_filehandle_t fd,+                                  const enum mdbx_syncmode_bits mode_bits);+MDBX_INTERNAL_FUNC int mdbx_ftruncate(mdbx_filehandle_t fd, uint64_t length);+MDBX_INTERNAL_FUNC int mdbx_fseek(mdbx_filehandle_t fd, uint64_t pos);+MDBX_INTERNAL_FUNC int mdbx_filesize(mdbx_filehandle_t fd, uint64_t *length);++enum mdbx_openfile_purpose {+  MDBX_OPEN_DXB_READ = 0,+  MDBX_OPEN_DXB_LAZY = 1,+  MDBX_OPEN_DXB_DSYNC = 2,+  MDBX_OPEN_LCK = 3,+  MDBX_OPEN_COPY = 4,+  MDBX_OPEN_DELETE = 5+};++MDBX_INTERNAL_FUNC int mdbx_openfile(const enum mdbx_openfile_purpose purpose,+                                     const MDBX_env *env, const char *pathname,+                                     mdbx_filehandle_t *fd,+                                     mdbx_mode_t unix_mode_bits);+MDBX_INTERNAL_FUNC int mdbx_closefile(mdbx_filehandle_t fd);+MDBX_INTERNAL_FUNC int mdbx_removefile(const char *pathname);+MDBX_INTERNAL_FUNC int mdbx_removedirectory(const char *pathname);+MDBX_INTERNAL_FUNC int mdbx_is_pipe(mdbx_filehandle_t fd);+MDBX_INTERNAL_FUNC int mdbx_lockfile(mdbx_filehandle_t fd, bool wait);++#define MMAP_OPTION_TRUNCATE 1+#define MMAP_OPTION_SEMAPHORE 2+MDBX_INTERNAL_FUNC int mdbx_mmap(const int flags, mdbx_mmap_t *map,+                                 const size_t must, const size_t limit,+                                 const unsigned options);+MDBX_INTERNAL_FUNC int mdbx_munmap(mdbx_mmap_t *map);+MDBX_INTERNAL_FUNC int mdbx_mresize(int flags, mdbx_mmap_t *map, size_t current,+                                    size_t wanna, const bool may_move);+#if defined(_WIN32) || defined(_WIN64)+typedef struct {+  unsigned limit, count;+  HANDLE handles[31];+} mdbx_handle_array_t;+MDBX_INTERNAL_FUNC int+mdbx_suspend_threads_before_remap(MDBX_env *env, mdbx_handle_array_t **array);+MDBX_INTERNAL_FUNC int+mdbx_resume_threads_after_remap(mdbx_handle_array_t *array);+#endif /* Windows */+MDBX_INTERNAL_FUNC int mdbx_msync(mdbx_mmap_t *map, size_t offset,+                                  size_t length,+                                  enum mdbx_syncmode_bits mode_bits);+MDBX_INTERNAL_FUNC int mdbx_check_fs_rdonly(mdbx_filehandle_t handle,+                                            const char *pathname, int err);++static __maybe_unused __inline uint32_t mdbx_getpid(void) {+  STATIC_ASSERT(sizeof(mdbx_pid_t) <= sizeof(uint32_t));+#if defined(_WIN32) || defined(_WIN64)+  return GetCurrentProcessId();+#else+  return getpid();+#endif+}++static __maybe_unused __inline uintptr_t mdbx_thread_self(void) {+  mdbx_tid_t thunk;+  STATIC_ASSERT(sizeof(uintptr_t) >= sizeof(thunk));+#if defined(_WIN32) || defined(_WIN64)+  thunk = GetCurrentThreadId();+#else+  thunk = pthread_self();+#endif+  return (uintptr_t)thunk;+}++MDBX_INTERNAL_FUNC void __maybe_unused mdbx_osal_jitter(bool tiny);+MDBX_INTERNAL_FUNC uint64_t mdbx_osal_monotime(void);+MDBX_INTERNAL_FUNC uint64_t+mdbx_osal_16dot16_to_monotime(uint32_t seconds_16dot16);+MDBX_INTERNAL_FUNC uint32_t mdbx_osal_monotime_to_16dot16(uint64_t monotime);++MDBX_INTERNAL_FUNC bin128_t mdbx_osal_bootid(void);+/*----------------------------------------------------------------------------*/+/* lck stuff */++/// \brief Initialization of synchronization primitives linked with MDBX_env+///   instance both in LCK-file and within the current process.+/// \param+///   global_uniqueness_flag = true - denotes that there are no other processes+///     working with DB and LCK-file. Thus the function MUST initialize+///     shared synchronization objects in memory-mapped LCK-file.+///   global_uniqueness_flag = false - denotes that at least one process is+///     already working with DB and LCK-file, including the case when DB+///     has already been opened in the current process. Thus the function+///     MUST NOT initialize shared synchronization objects in memory-mapped+///     LCK-file that are already in use.+/// \return Error code or zero on success.+MDBX_INTERNAL_FUNC int mdbx_lck_init(MDBX_env *env,+                                     MDBX_env *inprocess_neighbor,+                                     int global_uniqueness_flag);++/// \brief Disconnects from shared interprocess objects and destructs+///   synchronization objects linked with MDBX_env instance+///   within the current process.+/// \param+///   inprocess_neighbor = NULL - if the current process does not have other+///     instances of MDBX_env linked with the DB being closed.+///     Thus the function MUST check for other processes working with DB or+///     LCK-file, and keep or destroy shared synchronization objects in+///     memory-mapped LCK-file depending on the result.+///   inprocess_neighbor = not-NULL - pointer to another instance of MDBX_env+///     (anyone of there is several) working with DB or LCK-file within the+///     current process. Thus the function MUST NOT try to acquire exclusive+///     lock and/or try to destruct shared synchronization objects linked with+///     DB or LCK-file. Moreover, the implementation MUST ensure correct work+///     of other instances of MDBX_env within the current process, e.g.+///     restore POSIX-fcntl locks after the closing of file descriptors.+/// \return Error code (MDBX_PANIC) or zero on success.+MDBX_INTERNAL_FUNC int mdbx_lck_destroy(MDBX_env *env,+                                        MDBX_env *inprocess_neighbor);++/// \brief Connects to shared interprocess locking objects and tries to acquire+///   the maximum lock level (shared if exclusive is not available)+///   Depending on implementation or/and platform (Windows) this function may+///   acquire the non-OS super-level lock (e.g. for shared synchronization+///   objects initialization), which will be downgraded to OS-exclusive or+///   shared via explicit calling of mdbx_lck_downgrade().+/// \return+///   MDBX_RESULT_TRUE (-1) - if an exclusive lock was acquired and thus+///     the current process is the first and only after the last use of DB.+///   MDBX_RESULT_FALSE (0) - if a shared lock was acquired and thus+///     DB has already been opened and now is used by other processes.+///   Otherwise (not 0 and not -1) - error code.+MDBX_INTERNAL_FUNC int mdbx_lck_seize(MDBX_env *env);++/// \brief Downgrades the level of initially acquired lock to+///   operational level specified by argument. The reson for such downgrade:+///    - unblocking of other processes that are waiting for access, i.e.+///      if (env->me_flags & MDBX_EXCLUSIVE) != 0, then other processes+///      should be made aware that access is unavailable rather than+///      wait for it.+///    - freeing locks that interfere file operation (especially for Windows)+///   (env->me_flags & MDBX_EXCLUSIVE) == 0 - downgrade to shared lock.+///   (env->me_flags & MDBX_EXCLUSIVE) != 0 - downgrade to exclusive+///   operational lock.+/// \return Error code or zero on success+MDBX_INTERNAL_FUNC int mdbx_lck_downgrade(MDBX_env *env);++/// \brief Locks LCK-file or/and table of readers for (de)registering.+/// \return Error code or zero on success+MDBX_INTERNAL_FUNC int mdbx_rdt_lock(MDBX_env *env);++/// \brief Unlocks LCK-file or/and table of readers after (de)registering.+MDBX_INTERNAL_FUNC void mdbx_rdt_unlock(MDBX_env *env);++/// \brief Acquires lock for DB change (on writing transaction start)+///   Reading transactions will not be blocked.+///   Declared as LIBMDBX_API because it is used in mdbx_chk.+/// \return Error code or zero on success+LIBMDBX_API int mdbx_txn_lock(MDBX_env *env, bool dont_wait);++/// \brief Releases lock once DB changes is made (after writing transaction+///   has finished).+///   Declared as LIBMDBX_API because it is used in mdbx_chk.+LIBMDBX_API void mdbx_txn_unlock(MDBX_env *env);++/// \brief Sets alive-flag of reader presence (indicative lock) for PID of+///   the current process. The function does no more than needed for+///   the correct working of mdbx_rpid_check() in other processes.+/// \return Error code or zero on success+MDBX_INTERNAL_FUNC int mdbx_rpid_set(MDBX_env *env);++/// \brief Resets alive-flag of reader presence (indicative lock)+///   for PID of the current process. The function does no more than needed+///   for the correct working of mdbx_rpid_check() in other processes.+/// \return Error code or zero on success+MDBX_INTERNAL_FUNC int mdbx_rpid_clear(MDBX_env *env);++/// \brief Checks for reading process status with the given pid with help of+///   alive-flag of presence (indicative lock) or using another way.+/// \return+///   MDBX_RESULT_TRUE (-1) - if the reader process with the given PID is alive+///     and working with DB (indicative lock is present).+///   MDBX_RESULT_FALSE (0) - if the reader process with the given PID is absent+///     or not working with DB (indicative lock is not present).+///   Otherwise (not 0 and not -1) - error code.+MDBX_INTERNAL_FUNC int mdbx_rpid_check(MDBX_env *env, uint32_t pid);++#if defined(_WIN32) || defined(_WIN64)++typedef void(WINAPI *MDBX_srwlock_function)(MDBX_srwlock *);+MDBX_INTERNAL_VAR MDBX_srwlock_function mdbx_srwlock_Init,+    mdbx_srwlock_AcquireShared, mdbx_srwlock_ReleaseShared,+    mdbx_srwlock_AcquireExclusive, mdbx_srwlock_ReleaseExclusive;++typedef BOOL(WINAPI *MDBX_GetFileInformationByHandleEx)(+    _In_ HANDLE hFile, _In_ FILE_INFO_BY_HANDLE_CLASS FileInformationClass,+    _Out_ LPVOID lpFileInformation, _In_ DWORD dwBufferSize);+MDBX_INTERNAL_VAR MDBX_GetFileInformationByHandleEx+    mdbx_GetFileInformationByHandleEx;++typedef BOOL(WINAPI *MDBX_GetVolumeInformationByHandleW)(+    _In_ HANDLE hFile, _Out_opt_ LPWSTR lpVolumeNameBuffer,+    _In_ DWORD nVolumeNameSize, _Out_opt_ LPDWORD lpVolumeSerialNumber,+    _Out_opt_ LPDWORD lpMaximumComponentLength,+    _Out_opt_ LPDWORD lpFileSystemFlags,+    _Out_opt_ LPWSTR lpFileSystemNameBuffer, _In_ DWORD nFileSystemNameSize);+MDBX_INTERNAL_VAR MDBX_GetVolumeInformationByHandleW+    mdbx_GetVolumeInformationByHandleW;++typedef DWORD(WINAPI *MDBX_GetFinalPathNameByHandleW)(_In_ HANDLE hFile,+                                                      _Out_ LPWSTR lpszFilePath,+                                                      _In_ DWORD cchFilePath,+                                                      _In_ DWORD dwFlags);+MDBX_INTERNAL_VAR MDBX_GetFinalPathNameByHandleW mdbx_GetFinalPathNameByHandleW;++typedef BOOL(WINAPI *MDBX_SetFileInformationByHandle)(+    _In_ HANDLE hFile, _In_ FILE_INFO_BY_HANDLE_CLASS FileInformationClass,+    _Out_ LPVOID lpFileInformation, _In_ DWORD dwBufferSize);+MDBX_INTERNAL_VAR MDBX_SetFileInformationByHandle+    mdbx_SetFileInformationByHandle;++typedef NTSTATUS(NTAPI *MDBX_NtFsControlFile)(+    IN HANDLE FileHandle, IN OUT HANDLE Event,+    IN OUT PVOID /* PIO_APC_ROUTINE */ ApcRoutine, IN OUT PVOID ApcContext,+    OUT PIO_STATUS_BLOCK IoStatusBlock, IN ULONG FsControlCode,+    IN OUT PVOID InputBuffer, IN ULONG InputBufferLength,+    OUT OPTIONAL PVOID OutputBuffer, IN ULONG OutputBufferLength);+MDBX_INTERNAL_VAR MDBX_NtFsControlFile mdbx_NtFsControlFile;++typedef uint64_t(WINAPI *MDBX_GetTickCount64)(void);+MDBX_INTERNAL_VAR MDBX_GetTickCount64 mdbx_GetTickCount64;++#if !defined(_WIN32_WINNT_WIN8) || _WIN32_WINNT < _WIN32_WINNT_WIN8+typedef struct _WIN32_MEMORY_RANGE_ENTRY {+  PVOID VirtualAddress;+  SIZE_T NumberOfBytes;+} WIN32_MEMORY_RANGE_ENTRY, *PWIN32_MEMORY_RANGE_ENTRY;+#endif /* Windows 8.x */++typedef BOOL(WINAPI *MDBX_PrefetchVirtualMemory)(+    HANDLE hProcess, ULONG_PTR NumberOfEntries,+    PWIN32_MEMORY_RANGE_ENTRY VirtualAddresses, ULONG Flags);+MDBX_INTERNAL_VAR MDBX_PrefetchVirtualMemory mdbx_PrefetchVirtualMemory;++#if 0 /* LY: unused for now */+#if !defined(_WIN32_WINNT_WIN81) || _WIN32_WINNT < _WIN32_WINNT_WIN81+typedef enum OFFER_PRIORITY {+  VmOfferPriorityVeryLow = 1,+  VmOfferPriorityLow,+  VmOfferPriorityBelowNormal,+  VmOfferPriorityNormal+} OFFER_PRIORITY;+#endif /* Windows 8.1 */++typedef DWORD(WINAPI *MDBX_DiscardVirtualMemory)(PVOID VirtualAddress,+                                                 SIZE_T Size);+MDBX_INTERNAL_VAR MDBX_DiscardVirtualMemory mdbx_DiscardVirtualMemory;++typedef DWORD(WINAPI *MDBX_ReclaimVirtualMemory)(PVOID VirtualAddress,+                                                 SIZE_T Size);+MDBX_INTERNAL_VAR MDBX_ReclaimVirtualMemory mdbx_ReclaimVirtualMemory;++typedef DWORD(WINAPI *MDBX_OfferVirtualMemory(+  PVOID          VirtualAddress,+  SIZE_T         Size,+  OFFER_PRIORITY Priority+);+MDBX_INTERNAL_VAR MDBX_OfferVirtualMemory mdbx_OfferVirtualMemory;+#endif /* unused for now */++typedef enum _SECTION_INHERIT { ViewShare = 1, ViewUnmap = 2 } SECTION_INHERIT;++typedef NTSTATUS(NTAPI *MDBX_NtExtendSection)(IN HANDLE SectionHandle,+                                              IN PLARGE_INTEGER NewSectionSize);+MDBX_INTERNAL_VAR MDBX_NtExtendSection mdbx_NtExtendSection;++static __inline bool mdbx_RunningUnderWine(void) {+  return !mdbx_NtExtendSection;+}++typedef LSTATUS(WINAPI *MDBX_RegGetValueA)(HKEY hkey, LPCSTR lpSubKey,+                                           LPCSTR lpValue, DWORD dwFlags,+                                           LPDWORD pdwType, PVOID pvData,+                                           LPDWORD pcbData);+MDBX_INTERNAL_VAR MDBX_RegGetValueA mdbx_RegGetValueA;++#endif /* Windows */++#endif /* !__cplusplus */++/*----------------------------------------------------------------------------*/++#if defined(_MSC_VER) && _MSC_VER >= 1900+/* LY: MSVC 2015/2017/2019 has buggy/inconsistent PRIuPTR/PRIxPTR macros+ * for internal format-args checker. */+#undef PRIuPTR+#undef PRIiPTR+#undef PRIdPTR+#undef PRIxPTR+#define PRIuPTR "Iu"+#define PRIiPTR "Ii"+#define PRIdPTR "Id"+#define PRIxPTR "Ix"+#define PRIuSIZE "zu"+#define PRIiSIZE "zi"+#define PRIdSIZE "zd"+#define PRIxSIZE "zx"+#endif /* fix PRI*PTR for _MSC_VER */++#ifndef PRIuSIZE+#define PRIuSIZE PRIuPTR+#define PRIiSIZE PRIiPTR+#define PRIdSIZE PRIdPTR+#define PRIxSIZE PRIxPTR+#endif /* PRI*SIZE macros for MSVC */++#ifdef _MSC_VER+#pragma warning(pop)+#endif++#define mdbx_sourcery_anchor XCONCAT(mdbx_sourcery_, MDBX_BUILD_SOURCERY)+#if defined(MDBX_TOOLS)+extern LIBMDBX_API const char *const mdbx_sourcery_anchor;+#endif++/*******************************************************************************+ *******************************************************************************+ *******************************************************************************+ *+ *+ *         ####   #####    #####     #     ####   #    #   ####+ *        #    #  #    #     #       #    #    #  ##   #  #+ *        #    #  #    #     #       #    #    #  # #  #   ####+ *        #    #  #####      #       #    #    #  #  # #       #+ *        #    #  #          #       #    #    #  #   ##  #    #+ *         ####   #          #       #     ####   #    #   ####+ *+ *+ */++/** \defgroup build_option Build options+ * The libmdbx build options.+ @{ */++#ifdef DOXYGEN+/* !!! Actually this is a fake definitions     !!!+ * !!! for documentation generation by Doxygen !!! */++/** Controls enabling of debugging features.+ *+ *  - `MDBX_DEBUG = 0` (by default) Disables any debugging features at all,+ *                     including logging and assertion controls.+ *                     Logging level and corresponding debug flags changing+ *                     by \ref mdbx_setup_debug() will not have effect.+ *  - `MDBX_DEBUG > 0` Enables code for the debugging features (logging,+ *                     assertions checking and internal audit).+ *                     Simultaneously sets the default logging level+ *                     to the `MDBX_DEBUG` value.+ *                     Also enables \ref MDBX_DBG_AUDIT if `MDBX_DEBUG >= 2`.+ *+ * \ingroup build_option */+#define MDBX_DEBUG 0...7++/** Disables using of GNU libc extensions. */+#define MDBX_DISABLE_GNU_SOURCE 0 or 1++#endif /* DOXYGEN */++/** Using fcntl(F_FULLFSYNC) with 5-10 times slowdown */+#define MDBX_OSX_WANNA_DURABILITY 0+/** Using fsync() with chance of data lost on power failure */+#define MDBX_OSX_WANNA_SPEED 1++#ifndef MDBX_OSX_SPEED_INSTEADOF_DURABILITY+/** Choices \ref MDBX_OSX_WANNA_DURABILITY or \ref MDBX_OSX_WANNA_SPEED+ * for OSX & iOS */+#define MDBX_OSX_SPEED_INSTEADOF_DURABILITY MDBX_OSX_WANNA_DURABILITY+#endif /* MDBX_OSX_SPEED_INSTEADOF_DURABILITY */++/** Controls checking PID against reuse DB environment after the fork() */+#ifndef MDBX_ENV_CHECKPID+#if defined(MADV_DONTFORK) || defined(_WIN32) || defined(_WIN64)+/* PID check could be omitted:+ *  - on Linux when madvise(MADV_DONTFORK) is available, i.e. after the fork()+ *    mapped pages will not be available for child process.+ *  - in Windows where fork() not available. */+#define MDBX_ENV_CHECKPID 0+#else+#define MDBX_ENV_CHECKPID 1+#endif+#define MDBX_ENV_CHECKPID_CONFIG "AUTO=" STRINGIFY(MDBX_ENV_CHECKPID)+#else+#define MDBX_ENV_CHECKPID_CONFIG STRINGIFY(MDBX_ENV_CHECKPID)+#endif /* MDBX_ENV_CHECKPID */++/** Controls checking transaction owner thread against misuse transactions from+ * other threads. */+#ifndef MDBX_TXN_CHECKOWNER+#define MDBX_TXN_CHECKOWNER 1+#define MDBX_TXN_CHECKOWNER_CONFIG "AUTO=" STRINGIFY(MDBX_TXN_CHECKOWNER)+#else+#define MDBX_TXN_CHECKOWNER_CONFIG STRINGIFY(MDBX_TXN_CHECKOWNER)+#endif /* MDBX_TXN_CHECKOWNER */++/** Does a system have battery-backed Real-Time Clock or just a fake. */+#ifndef MDBX_TRUST_RTC+#if defined(__linux__) || defined(__gnu_linux__) || defined(__NetBSD__) ||     \+    defined(__OpenBSD__)+#define MDBX_TRUST_RTC 0 /* a lot of embedded systems have a fake RTC */+#else+#define MDBX_TRUST_RTC 1+#endif+#define MDBX_TRUST_RTC_CONFIG "AUTO=" STRINGIFY(MDBX_TRUST_RTC)+#else+#define MDBX_TRUST_RTC_CONFIG STRINGIFY(MDBX_TRUST_RTC)+#endif /* MDBX_TRUST_RTC */++/** Controls online database auto-compactification during write-transactions. */+#ifndef MDBX_ENABLE_REFUND+#define MDBX_ENABLE_REFUND 1+#endif+#if !(MDBX_ENABLE_REFUND == 0 || MDBX_ENABLE_REFUND == 1)+#error MDBX_ENABLE_REFUND must be defined as 0 or 1+#endif /* MDBX_ENABLE_REFUND */++/** Disable some checks to reduce an overhead and detection probability of+ * database corruption to a values closer to the LMDB. */+#ifndef MDBX_DISABLE_PAGECHECKS+#define MDBX_DISABLE_PAGECHECKS 0+#endif+#if !(MDBX_DISABLE_PAGECHECKS == 0 || MDBX_DISABLE_PAGECHECKS == 1)+#error MDBX_DISABLE_PAGECHECKS must be defined as 0 or 1+#endif /* MDBX_DISABLE_PAGECHECKS */++/** Controls sort order of internal page number lists.+ * The database format depend on this option and libmdbx builded with different+ * option value are incompatible. */+#ifndef MDBX_PNL_ASCENDING+#define MDBX_PNL_ASCENDING 0+#endif+#if !(MDBX_PNL_ASCENDING == 0 || MDBX_PNL_ASCENDING == 1)+#error MDBX_PNL_ASCENDING must be defined as 0 or 1+#endif /* MDBX_PNL_ASCENDING */++//------------------------------------------------------------------------------++/** Win32 File Locking API for \ref MDBX_LOCKING */+#define MDBX_LOCKING_WIN32FILES -1++/** SystemV IPC semaphores for \ref MDBX_LOCKING */+#define MDBX_LOCKING_SYSV 5++/** POSIX-1 Shared anonymous semaphores for \ref MDBX_LOCKING */+#define MDBX_LOCKING_POSIX1988 1988++/** POSIX-2001 Shared Mutexes for \ref MDBX_LOCKING */+#define MDBX_LOCKING_POSIX2001 2001++/** POSIX-2008 Robust Mutexes for \ref MDBX_LOCKING */+#define MDBX_LOCKING_POSIX2008 2008++/** BeOS Benaphores, aka Futexes for \ref MDBX_LOCKING */+#define MDBX_LOCKING_BENAPHORE 1995++/** Advanced: Choices the locking implementation (autodetection by default). */+#if defined(_WIN32) || defined(_WIN64)+#define MDBX_LOCKING MDBX_LOCKING_WIN32FILES+#else+#ifndef MDBX_LOCKING+#if defined(_POSIX_THREAD_PROCESS_SHARED) &&                                   \+    _POSIX_THREAD_PROCESS_SHARED >= 200112L && !defined(__FreeBSD__)++/* Some platforms define the EOWNERDEAD error code even though they+ * don't support Robust Mutexes. If doubt compile with -MDBX_LOCKING=2001. */+#if defined(EOWNERDEAD) && _POSIX_THREAD_PROCESS_SHARED >= 200809L &&          \+    ((defined(_POSIX_THREAD_ROBUST_PRIO_INHERIT) &&                            \+      _POSIX_THREAD_ROBUST_PRIO_INHERIT > 0) ||                                \+     (defined(_POSIX_THREAD_ROBUST_PRIO_PROTECT) &&                            \+      _POSIX_THREAD_ROBUST_PRIO_PROTECT > 0) ||                                \+     defined(PTHREAD_MUTEX_ROBUST) || defined(PTHREAD_MUTEX_ROBUST_NP)) &&     \+    (!defined(__GLIBC__) ||                                                    \+     __GLIBC_PREREQ(2, 10) /* troubles with Robust mutexes before 2.10 */)+#define MDBX_LOCKING MDBX_LOCKING_POSIX2008+#else+#define MDBX_LOCKING MDBX_LOCKING_POSIX2001+#endif+#elif defined(__sun) || defined(__SVR4) || defined(__svr4__)+#define MDBX_LOCKING MDBX_LOCKING_POSIX1988+#else+#define MDBX_LOCKING MDBX_LOCKING_SYSV+#endif+#define MDBX_LOCKING_CONFIG "AUTO=" STRINGIFY(MDBX_LOCKING)+#else+#define MDBX_LOCKING_CONFIG STRINGIFY(MDBX_LOCKING)+#endif /* MDBX_LOCKING */+#endif /* !Windows */++/** Advanced: Using POSIX OFD-locks (autodetection by default). */+#ifndef MDBX_USE_OFDLOCKS+#if defined(F_OFD_SETLK) && defined(F_OFD_SETLKW) && defined(F_OFD_GETLK) &&   \+    !defined(MDBX_SAFE4QEMU) &&                                                \+    !defined(__sun) /* OFD-lock are broken on Solaris */+#define MDBX_USE_OFDLOCKS 1+#else+#define MDBX_USE_OFDLOCKS 0+#endif+#define MDBX_USE_OFDLOCKS_CONFIG "AUTO=" STRINGIFY(MDBX_USE_OFDLOCKS)+#else+#define MDBX_USE_OFDLOCKS_CONFIG STRINGIFY(MDBX_USE_OFDLOCKS)+#endif /* MDBX_USE_OFDLOCKS */++/** Advanced: Using sendfile() syscall (autodetection by default). */+#ifndef MDBX_USE_SENDFILE+#if ((defined(__linux__) || defined(__gnu_linux__)) &&                         \+     !defined(__ANDROID_API__)) ||                                             \+    (defined(__ANDROID_API__) && __ANDROID_API__ >= 21)+#define MDBX_USE_SENDFILE 1+#else+#define MDBX_USE_SENDFILE 0+#endif+#endif /* MDBX_USE_SENDFILE */++/** Advanced: Using copy_file_range() syscall (autodetection by default). */+#ifndef MDBX_USE_COPYFILERANGE+#if __GLIBC_PREREQ(2, 27) && defined(_GNU_SOURCE)+#define MDBX_USE_COPYFILERANGE 1+#else+#define MDBX_USE_COPYFILERANGE 0+#endif+#endif /* MDBX_USE_COPYFILERANGE */++/** Advanced: Using sync_file_range() syscall (autodetection by default). */+#ifndef MDBX_USE_SYNCFILERANGE+#if ((defined(__linux__) || defined(__gnu_linux__)) &&                         \+     defined(SYNC_FILE_RANGE_WRITE) && !defined(__ANDROID_API__)) ||           \+    (defined(__ANDROID_API__) && __ANDROID_API__ >= 26)+#define MDBX_USE_SYNCFILERANGE 1+#else+#define MDBX_USE_SYNCFILERANGE 0+#endif+#endif /* MDBX_USE_SYNCFILERANGE */++//------------------------------------------------------------------------------++#ifndef MDBX_CPU_WRITEBACK_INCOHERENT+#if defined(__ia32__) || defined(__e2k__) || defined(__hppa) ||                \+    defined(__hppa__) || defined(DOXYGEN)+#define MDBX_CPU_WRITEBACK_INCOHERENT 0+#else+#define MDBX_CPU_WRITEBACK_INCOHERENT 1+#endif+#endif /* MDBX_CPU_WRITEBACK_INCOHERENT */++#ifndef MDBX_MMAP_INCOHERENT_FILE_WRITE+#ifdef __OpenBSD__+#define MDBX_MMAP_INCOHERENT_FILE_WRITE 1+#else+#define MDBX_MMAP_INCOHERENT_FILE_WRITE 0+#endif+#endif /* MDBX_MMAP_INCOHERENT_FILE_WRITE */++#ifndef MDBX_MMAP_INCOHERENT_CPU_CACHE+#if defined(__mips) || defined(__mips__) || defined(__mips64) ||               \+    defined(__mips64__) || defined(_M_MRX000) || defined(_MIPS_) ||            \+    defined(__MWERKS__) || defined(__sgi)+/* MIPS has cache coherency issues. */+#define MDBX_MMAP_INCOHERENT_CPU_CACHE 1+#else+/* LY: assume no relevant mmap/dcache issues. */+#define MDBX_MMAP_INCOHERENT_CPU_CACHE 0+#endif+#endif /* MDBX_MMAP_INCOHERENT_CPU_CACHE */++#ifndef MDBX_64BIT_ATOMIC+#if MDBX_WORDBITS >= 64 || defined(DOXYGEN)+#define MDBX_64BIT_ATOMIC 1+#else+#define MDBX_64BIT_ATOMIC 0+#endif+#define MDBX_64BIT_ATOMIC_CONFIG "AUTO=" STRINGIFY(MDBX_64BIT_ATOMIC)+#else+#define MDBX_64BIT_ATOMIC_CONFIG STRINGIFY(MDBX_64BIT_ATOMIC)+#endif /* MDBX_64BIT_ATOMIC */++#ifndef MDBX_64BIT_CAS+#if defined(ATOMIC_LLONG_LOCK_FREE)+#if ATOMIC_LLONG_LOCK_FREE > 1+#define MDBX_64BIT_CAS 1+#else+#define MDBX_64BIT_CAS 0+#endif+#elif defined(__GCC_ATOMIC_LLONG_LOCK_FREE)+#if __GCC_ATOMIC_LLONG_LOCK_FREE > 1+#define MDBX_64BIT_CAS 1+#else+#define MDBX_64BIT_CAS 0+#endif+#elif defined(__CLANG_ATOMIC_LLONG_LOCK_FREE)+#if __CLANG_ATOMIC_LLONG_LOCK_FREE > 1+#define MDBX_64BIT_CAS 1+#else+#define MDBX_64BIT_CAS 0+#endif+#elif defined(_MSC_VER) || defined(__APPLE__) || defined(DOXYGEN)+#define MDBX_64BIT_CAS 1+#else+#define MDBX_64BIT_CAS MDBX_64BIT_ATOMIC+#endif+#define MDBX_64BIT_CAS_CONFIG "AUTO=" STRINGIFY(MDBX_64BIT_CAS)+#else+#define MDBX_64BIT_CAS_CONFIG STRINGIFY(MDBX_64BIT_CAS)+#endif /* MDBX_64BIT_CAS */++#if !defined(MDBX_UNALIGNED_OK)+#if defined(_MSC_VER)+#define MDBX_UNALIGNED_OK 1 /* avoid MSVC misoptimization */+#elif __CLANG_PREREQ(5, 0) || __GNUC_PREREQ(5, 0)+#define MDBX_UNALIGNED_OK 0 /* expecting optimization is well done */+#elif (defined(__ia32__) || defined(__ARM_FEATURE_UNALIGNED)) &&               \+    !defined(__ALIGNED__)+#define MDBX_UNALIGNED_OK 1+#else+#define MDBX_UNALIGNED_OK 0+#endif+#endif /* MDBX_UNALIGNED_OK */++#ifndef MDBX_CACHELINE_SIZE+#if defined(SYSTEM_CACHE_ALIGNMENT_SIZE)+#define MDBX_CACHELINE_SIZE SYSTEM_CACHE_ALIGNMENT_SIZE+#elif defined(__ia64__) || defined(__ia64) || defined(_M_IA64)+#define MDBX_CACHELINE_SIZE 128+#else+#define MDBX_CACHELINE_SIZE 64+#endif+#endif /* MDBX_CACHELINE_SIZE */++/** @} end of build options */+/*******************************************************************************+ *******************************************************************************+ ******************************************************************************/++/*----------------------------------------------------------------------------*/+/* Basic constants and types */++typedef union {+  volatile uint32_t weak;+#ifdef MDBX_HAVE_C11ATOMICS+  volatile _Atomic uint32_t c11a;+#endif /* MDBX_HAVE_C11ATOMICS */+} MDBX_atomic_uint32_t;++typedef union {+  volatile uint64_t weak;+#if defined(MDBX_HAVE_C11ATOMICS) && (MDBX_64BIT_CAS || MDBX_64BIT_ATOMIC)+  volatile _Atomic uint64_t c11a;+#endif+#if !defined(MDBX_HAVE_C11ATOMICS) || !MDBX_64BIT_CAS || !MDBX_64BIT_ATOMIC+  __anonymous_struct_extension__ struct {+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__+    MDBX_atomic_uint32_t low, high;+#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__+    MDBX_atomic_uint32_t high, low;+#else+#error "FIXME: Unsupported byte order"+#endif /* __BYTE_ORDER__ */+  };+#endif+} MDBX_atomic_uint64_t;++/* The minimum number of keys required in a database page.+ * Setting this to a larger value will place a smaller bound on the+ * maximum size of a data item. Data items larger than this size will+ * be pushed into overflow pages instead of being stored directly in+ * the B-tree node. This value used to default to 4. With a page size+ * of 4096 bytes that meant that any item larger than 1024 bytes would+ * go into an overflow page. That also meant that on average 2-3KB of+ * each overflow page was wasted space. The value cannot be lower than+ * 2 because then there would no longer be a tree structure. With this+ * value, items larger than 2KB will go into overflow pages, and on+ * average only 1KB will be wasted. */+#define MDBX_MINKEYS 2++/* A stamp that identifies a file as an MDBX file.+ * There's nothing special about this value other than that it is easily+ * recognizable, and it will reflect any byte order mismatches. */+#define MDBX_MAGIC UINT64_C(/* 56-bit prime */ 0x59659DBDEF4C11)++/* The version number for a database's datafile format. */+#define MDBX_DATA_VERSION 2+/* The version number for a database's lockfile format. */+#define MDBX_LOCK_VERSION 3++/* handle for the DB used to track free pages. */+#define FREE_DBI 0+/* handle for the default DB. */+#define MAIN_DBI 1+/* Number of DBs in metapage (free and main) - also hardcoded elsewhere */+#define CORE_DBS 2++/* Number of meta pages - also hardcoded elsewhere */+#define NUM_METAS 3++/* A page number in the database.+ *+ * MDBX uses 32 bit for page numbers. This limits database+ * size up to 2^44 bytes, in case of 4K pages. */+typedef uint32_t pgno_t;+typedef MDBX_atomic_uint32_t atomic_pgno_t;+#define PRIaPGNO PRIu32+#define MAX_PAGENO UINT32_C(0x7FFFffff)+#define MIN_PAGENO NUM_METAS++#define SAFE64_INVALID_THRESHOLD UINT64_C(0xffffFFFF00000000)++/* A transaction ID. */+typedef uint64_t txnid_t;+typedef MDBX_atomic_uint64_t atomic_txnid_t;+#define PRIaTXN PRIi64+#define MIN_TXNID UINT64_C(1)+#define MAX_TXNID (SAFE64_INVALID_THRESHOLD - 1)+#define INITIAL_TXNID (MIN_TXNID + NUM_METAS - 1)+#define INVALID_TXNID UINT64_MAX+/* LY: for testing non-atomic 64-bit txnid on 32-bit arches.+ * #define MDBX_TXNID_STEP (UINT32_MAX / 3) */+#ifndef MDBX_TXNID_STEP+#if MDBX_64BIT_CAS+#define MDBX_TXNID_STEP 1u+#else+#define MDBX_TXNID_STEP 2u+#endif+#endif /* MDBX_TXNID_STEP */++/* Used for offsets within a single page.+ * Since memory pages are typically 4 or 8KB in size, 12-13 bits,+ * this is plenty. */+typedef uint16_t indx_t;++#define MEGABYTE ((size_t)1 << 20)++/*----------------------------------------------------------------------------*/+/* Core structures for database and shared memory (i.e. format definition) */+#pragma pack(push, 1)++/* Information about a single database in the environment. */+typedef struct MDBX_db {+  uint16_t md_flags;        /* see mdbx_dbi_open */+  uint16_t md_depth;        /* depth of this tree */+  uint32_t md_xsize;        /* key-size for MDBX_DUPFIXED (LEAF2 pages) */+  pgno_t md_root;           /* the root page of this tree */+  pgno_t md_branch_pages;   /* number of internal pages */+  pgno_t md_leaf_pages;     /* number of leaf pages */+  pgno_t md_overflow_pages; /* number of overflow pages */+  uint64_t md_seq;          /* table sequence counter */+  uint64_t md_entries;      /* number of data items */+  uint64_t md_mod_txnid;    /* txnid of last committed modification */+} MDBX_db;++/* database size-related parameters */+typedef struct MDBX_geo {+  uint16_t grow_pv;   /* datafile growth step as a 16-bit packed (exponential+                           quantized) value */+  uint16_t shrink_pv; /* datafile shrink threshold as a 16-bit packed+                           (exponential quantized) value */+  pgno_t lower;       /* minimal size of datafile in pages */+  pgno_t upper;       /* maximal size of datafile in pages */+  pgno_t now;         /* current size of datafile in pages */+  pgno_t next;        /* first unused page in the datafile,+                         but actually the file may be shorter. */+} MDBX_geo;++/* Meta page content.+ * A meta page is the start point for accessing a database snapshot.+ * Pages 0-1 are meta pages. Transaction N writes meta page (N % 2). */+typedef struct MDBX_meta {+  /* Stamp identifying this as an MDBX file.+   * It must be set to MDBX_MAGIC with MDBX_DATA_VERSION. */+  uint32_t mm_magic_and_version[2];++  /* txnid that committed this page, the first of a two-phase-update pair */+  uint32_t mm_txnid_a[2];++  uint16_t mm_extra_flags;  /* extra DB flags, zero (nothing) for now */+  uint8_t mm_validator_id;  /* ID of checksum and page validation method,+                             * zero (nothing) for now */+  uint8_t mm_extra_pagehdr; /* extra bytes in the page header,+                             * zero (nothing) for now */++  MDBX_geo mm_geo; /* database size-related parameters */++  MDBX_db mm_dbs[CORE_DBS]; /* first is free space, 2nd is main db */+                            /* The size of pages used in this DB */+#define mm_psize mm_dbs[FREE_DBI].md_xsize+/* Any persistent environment flags, see mdbx_env */+#define mm_flags mm_dbs[FREE_DBI].md_flags+  MDBX_canary mm_canary;++#define MDBX_DATASIGN_NONE 0u+#define MDBX_DATASIGN_WEAK 1u+#define SIGN_IS_STEADY(sign) ((sign) > MDBX_DATASIGN_WEAK)+#define META_IS_STEADY(meta)                                                   \+  SIGN_IS_STEADY(unaligned_peek_u64(4, (meta)->mm_datasync_sign))+  uint32_t mm_datasync_sign[2];++  /* txnid that committed this page, the second of a two-phase-update pair */+  uint32_t mm_txnid_b[2];++  /* Number of non-meta pages which were put in GC after COW. May be 0 in case+   * DB was previously handled by libmdbx without corresponding feature.+   * This value in couple with mr_snapshot_pages_retired allows fast estimation+   * of "how much reader is restraining GC recycling". */+  uint32_t mm_pages_retired[2];++  /* The analogue /proc/sys/kernel/random/boot_id or similar to determine+   * whether the system was rebooted after the last use of the database files.+   * If there was no reboot, but there is no need to rollback to the last+   * steady sync point. Zeros mean that no relevant information is available+   * from the system. */+  bin128_t mm_bootid;++} MDBX_meta;++/* Common header for all page types. The page type depends on mp_flags.+ *+ * P_BRANCH and P_LEAF pages have unsorted 'MDBX_node's at the end, with+ * sorted mp_ptrs[] entries referring to them. Exception: P_LEAF2 pages+ * omit mp_ptrs and pack sorted MDBX_DUPFIXED values after the page header.+ *+ * P_OVERFLOW records occupy one or more contiguous pages where only the+ * first has a page header. They hold the real data of F_BIGDATA nodes.+ *+ * P_SUBP sub-pages are small leaf "pages" with duplicate data.+ * A node with flag F_DUPDATA but not F_SUBDATA contains a sub-page.+ * (Duplicate data can also go in sub-databases, which use normal pages.)+ *+ * P_META pages contain MDBX_meta, the start point of an MDBX snapshot.+ *+ * Each non-metapage up to MDBX_meta.mm_last_pg is reachable exactly once+ * in the snapshot: Either used by a database or listed in a GC record. */+typedef struct MDBX_page {+  union {+    uint64_t mp_txnid;         /* txnid that committed this page */+    struct MDBX_page *mp_next; /* for in-memory list of freed pages */+  };+  uint16_t mp_leaf2_ksize; /* key size if this is a LEAF2 page */+#define P_BRANCH 0x01      /* branch page */+#define P_LEAF 0x02        /* leaf page */+#define P_OVERFLOW 0x04    /* overflow page */+#define P_META 0x08        /* meta page */+#define P_DIRTY 0x10       /* dirty page, also set for P_SUBP pages */+#define P_LEAF2 0x20       /* for MDBX_DUPFIXED records */+#define P_SUBP 0x40        /* for MDBX_DUPSORT sub-pages */+#define P_BAD 0x80         /* explicit flag for invalid/bad page */+#define P_LOOSE 0x4000     /* page was dirtied then freed, can be reused */+#define P_KEEP 0x8000      /* leave this page alone during spill */+  uint16_t mp_flags;+  union {+    uint32_t mp_pages; /* number of overflow pages */+    __anonymous_struct_extension__ struct {+      indx_t mp_lower; /* lower bound of free space */+      indx_t mp_upper; /* upper bound of free space */+    };+  };+  pgno_t mp_pgno; /* page number */++#if (defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L) ||              \+    (!defined(__cplusplus) && defined(_MSC_VER))+  indx_t mp_ptrs[] /* dynamic size */;+#endif /* C99 */+} MDBX_page;++/* Size of the page header, excluding dynamic data at the end */+#define PAGEHDRSZ ((unsigned)offsetof(MDBX_page, mp_ptrs))++#pragma pack(pop)++#if MDBX_LOCKING == MDBX_LOCKING_WIN32FILES+#define MDBX_CLOCK_SIGN UINT32_C(0xF10C)+typedef void mdbx_ipclock_t;+#elif MDBX_LOCKING == MDBX_LOCKING_SYSV++#define MDBX_CLOCK_SIGN UINT32_C(0xF18D)+typedef mdbx_pid_t mdbx_ipclock_t;+#ifndef EOWNERDEAD+#define EOWNERDEAD MDBX_RESULT_TRUE+#endif++#elif MDBX_LOCKING == MDBX_LOCKING_POSIX2001 ||                                \+    MDBX_LOCKING == MDBX_LOCKING_POSIX2008+#define MDBX_CLOCK_SIGN UINT32_C(0x8017)+typedef pthread_mutex_t mdbx_ipclock_t;+#elif MDBX_LOCKING == MDBX_LOCKING_POSIX1988+#define MDBX_CLOCK_SIGN UINT32_C(0xFC29)+typedef sem_t mdbx_ipclock_t;+#else+#error "FIXME"+#endif /* MDBX_LOCKING */++#if MDBX_LOCKING > MDBX_LOCKING_SYSV && !defined(__cplusplus)+MDBX_INTERNAL_FUNC int mdbx_ipclock_stub(mdbx_ipclock_t *ipc);+MDBX_INTERNAL_FUNC int mdbx_ipclock_destroy(mdbx_ipclock_t *ipc);+#endif /* MDBX_LOCKING */++/* Reader Lock Table+ *+ * Readers don't acquire any locks for their data access. Instead, they+ * simply record their transaction ID in the reader table. The reader+ * mutex is needed just to find an empty slot in the reader table. The+ * slot's address is saved in thread-specific data so that subsequent+ * read transactions started by the same thread need no further locking to+ * proceed.+ *+ * If MDBX_NOTLS is set, the slot address is not saved in thread-specific data.+ * No reader table is used if the database is on a read-only filesystem.+ *+ * Since the database uses multi-version concurrency control, readers don't+ * actually need any locking. This table is used to keep track of which+ * readers are using data from which old transactions, so that we'll know+ * when a particular old transaction is no longer in use. Old transactions+ * that have discarded any data pages can then have those pages reclaimed+ * for use by a later write transaction.+ *+ * The lock table is constructed such that reader slots are aligned with the+ * processor's cache line size. Any slot is only ever used by one thread.+ * This alignment guarantees that there will be no contention or cache+ * thrashing as threads update their own slot info, and also eliminates+ * any need for locking when accessing a slot.+ *+ * A writer thread will scan every slot in the table to determine the oldest+ * outstanding reader transaction. Any freed pages older than this will be+ * reclaimed by the writer. The writer doesn't use any locks when scanning+ * this table. This means that there's no guarantee that the writer will+ * see the most up-to-date reader info, but that's not required for correct+ * operation - all we need is to know the upper bound on the oldest reader,+ * we don't care at all about the newest reader. So the only consequence of+ * reading stale information here is that old pages might hang around a+ * while longer before being reclaimed. That's actually good anyway, because+ * the longer we delay reclaiming old pages, the more likely it is that a+ * string of contiguous pages can be found after coalescing old pages from+ * many old transactions together. */++/* The actual reader record, with cacheline padding. */+typedef struct MDBX_reader {+  /* Current Transaction ID when this transaction began, or (txnid_t)-1.+   * Multiple readers that start at the same time will probably have the+   * same ID here. Again, it's not important to exclude them from+   * anything; all we need to know is which version of the DB they+   * started from so we can avoid overwriting any data used in that+   * particular version. */+  MDBX_atomic_uint64_t /* txnid_t */ mr_txnid;++  /* The information we store in a single slot of the reader table.+   * In addition to a transaction ID, we also record the process and+   * thread ID that owns a slot, so that we can detect stale information,+   * e.g. threads or processes that went away without cleaning up.+   *+   * NOTE: We currently don't check for stale records.+   * We simply re-init the table when we know that we're the only process+   * opening the lock file. */++  /* The thread ID of the thread owning this txn. */+  MDBX_atomic_uint64_t mr_tid;++  /* The process ID of the process owning this reader txn. */+  MDBX_atomic_uint32_t mr_pid;++  /* The number of pages used in the reader's MVCC snapshot,+   * i.e. the value of meta->mm_geo.next and txn->mt_next_pgno */+  atomic_pgno_t mr_snapshot_pages_used;+  /* Number of retired pages at the time this reader starts transaction. So,+   * at any time the difference mm_pages_retired - mr_snapshot_pages_retired+   * will give the number of pages which this reader restraining from reuse. */+  MDBX_atomic_uint64_t mr_snapshot_pages_retired;+} MDBX_reader;++/* The header for the reader table (a memory-mapped lock file). */+typedef struct MDBX_lockinfo {+  /* Stamp identifying this as an MDBX file.+   * It must be set to MDBX_MAGIC with with MDBX_LOCK_VERSION. */+  uint64_t mti_magic_and_version;++  /* Format of this lock file. Must be set to MDBX_LOCK_FORMAT. */+  uint32_t mti_os_and_format;++  /* Flags which environment was opened. */+  MDBX_atomic_uint32_t mti_envmode;++  /* Threshold of un-synced-with-disk pages for auto-sync feature,+   * zero means no-threshold, i.e. auto-sync is disabled. */+  atomic_pgno_t mti_autosync_threshold;++  /* Low 32-bit of txnid with which meta-pages was synced,+   * i.e. for sync-polling in the MDBX_NOMETASYNC mode. */+  MDBX_atomic_uint32_t mti_meta_sync_txnid;++  /* Period for timed auto-sync feature, i.e. at the every steady checkpoint+   * the mti_unsynced_timeout sets to the current_time + mti_autosync_period.+   * The time value is represented in a suitable system-dependent form, for+   * example clock_gettime(CLOCK_BOOTTIME) or clock_gettime(CLOCK_MONOTONIC).+   * Zero means timed auto-sync is disabled. */+  MDBX_atomic_uint64_t mti_autosync_period;++  /* Marker to distinguish uniqueness of DB/CLK.*/+  MDBX_atomic_uint64_t mti_bait_uniqueness;++  alignas(MDBX_CACHELINE_SIZE) /* cacheline ---------------------------------*/++  /* Write transaction lock. */+#if MDBX_LOCKING > 0+      mdbx_ipclock_t mti_wlock;+#endif /* MDBX_LOCKING > 0 */++  atomic_txnid_t mti_oldest_reader;++  /* Timestamp of the last steady sync. Value is represented in a suitable+   * system-dependent form, for example clock_gettime(CLOCK_BOOTTIME) or+   * clock_gettime(CLOCK_MONOTONIC). */+  MDBX_atomic_uint64_t mti_sync_timestamp;++  /* Number un-synced-with-disk pages for auto-sync feature. */+  atomic_pgno_t mti_unsynced_pages;++  /* Number of page which was discarded last time by madvise(MADV_FREE). */+  atomic_pgno_t mti_discarded_tail;++  /* Timestamp of the last readers check. */+  MDBX_atomic_uint64_t mti_reader_check_timestamp;++  alignas(MDBX_CACHELINE_SIZE) /* cacheline ---------------------------------*/++  /* Readeaders registration lock. */+#if MDBX_LOCKING > 0+      mdbx_ipclock_t mti_rlock;+#endif /* MDBX_LOCKING > 0 */++  /* The number of slots that have been used in the reader table.+   * This always records the maximum count, it is not decremented+   * when readers release their slots. */+  MDBX_atomic_uint32_t mti_numreaders;+  MDBX_atomic_uint32_t mti_readers_refresh_flag;++#if (defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L) ||              \+    (!defined(__cplusplus) && defined(_MSC_VER))+  alignas(MDBX_CACHELINE_SIZE) /* cacheline ---------------------------------*/+      MDBX_reader mti_readers[] /* dynamic size */;+#endif /* C99 */+} MDBX_lockinfo;++/* Lockfile format signature: version, features and field layout */+#define MDBX_LOCK_FORMAT                                                       \+  (MDBX_CLOCK_SIGN * 27733 + (unsigned)sizeof(MDBX_reader) * 13 +              \+   (unsigned)offsetof(MDBX_reader, mr_snapshot_pages_used) * 251 +             \+   (unsigned)offsetof(MDBX_lockinfo, mti_oldest_reader) * 83 +                 \+   (unsigned)offsetof(MDBX_lockinfo, mti_numreaders) * 37 +                    \+   (unsigned)offsetof(MDBX_lockinfo, mti_readers) * 29)++#define MDBX_DATA_MAGIC                                                        \+  ((MDBX_MAGIC << 8) + MDBX_PNL_ASCENDING * 64 + MDBX_DATA_VERSION)+#define MDBX_DATA_MAGIC_DEVEL ((MDBX_MAGIC << 8) + 255)++#define MDBX_LOCK_MAGIC ((MDBX_MAGIC << 8) + MDBX_LOCK_VERSION)++#ifndef MDBX_ASSUME_MALLOC_OVERHEAD+#define MDBX_ASSUME_MALLOC_OVERHEAD (sizeof(void *) * 2u)+#endif /* MDBX_ASSUME_MALLOC_OVERHEAD */++/* The maximum size of a database page.+ *+ * It is 64K, but value-PAGEHDRSZ must fit in MDBX_page.mp_upper.+ *+ * MDBX will use database pages < OS pages if needed.+ * That causes more I/O in write transactions: The OS must+ * know (read) the whole page before writing a partial page.+ *+ * Note that we don't currently support Huge pages. On Linux,+ * regular data files cannot use Huge pages, and in general+ * Huge pages aren't actually pageable. We rely on the OS+ * demand-pager to read our data and page it out when memory+ * pressure from other processes is high. So until OSs have+ * actual paging support for Huge pages, they're not viable. */+#define MAX_PAGESIZE MDBX_MAX_PAGESIZE+#define MIN_PAGESIZE MDBX_MIN_PAGESIZE++#define MIN_MAPSIZE (MIN_PAGESIZE * MIN_PAGENO)+#if defined(_WIN32) || defined(_WIN64)+#define MAX_MAPSIZE32 UINT32_C(0x38000000)+#else+#define MAX_MAPSIZE32 UINT32_C(0x7f000000)+#endif+#define MAX_MAPSIZE64 (MAX_PAGENO * (uint64_t)MAX_PAGESIZE)++#if MDBX_WORDBITS >= 64+#define MAX_MAPSIZE MAX_MAPSIZE64+#define MDBX_READERS_LIMIT                                                     \+  ((MAX_PAGESIZE - sizeof(MDBX_lockinfo)) / sizeof(MDBX_reader))+#define MDBX_PGL_LIMIT MAX_PAGENO+#else+#define MDBX_READERS_LIMIT 1024+#define MAX_MAPSIZE MAX_MAPSIZE32+#define MDBX_PGL_LIMIT (MAX_MAPSIZE32 / MIN_PAGESIZE)+#endif /* MDBX_WORDBITS */++/*----------------------------------------------------------------------------*/++/* An PNL is an Page Number List, a sorted array of IDs.+ * The first element of the array is a counter for how many actual page-numbers+ * are in the list. By default PNLs are sorted in descending order, this allow+ * cut off a page with lowest pgno (at the tail) just truncating the list. The+ * sort order of PNLs is controlled by the MDBX_PNL_ASCENDING build option. */+typedef pgno_t *MDBX_PNL;++#if MDBX_PNL_ASCENDING+#define MDBX_PNL_ORDERED(first, last) ((first) < (last))+#define MDBX_PNL_DISORDERED(first, last) ((first) >= (last))+#else+#define MDBX_PNL_ORDERED(first, last) ((first) > (last))+#define MDBX_PNL_DISORDERED(first, last) ((first) <= (last))+#endif++/* List of txnid, only for MDBX_txn.tw.lifo_reclaimed */+typedef txnid_t *MDBX_TXL;++/* An Dirty-Page list item is an pgno/pointer pair. */+typedef struct MDBX_dp {+  pgno_t pgno;+  MDBX_page *ptr;+} MDBX_dp;++/* An DPL (dirty-page list) is a sorted array of MDBX_DPs. */+typedef struct MDBX_dpl {+  unsigned sorted;+  unsigned length;+  unsigned detent; /* allocated size excluding the MDBX_DPL_RESERVE_GAP */+#if (defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L) ||              \+    (!defined(__cplusplus) && defined(_MSC_VER))+  MDBX_dp items[] /* dynamic size with holes at zero and after the last */;+#endif+} MDBX_dpl;++/* PNL sizes */+#define MDBX_PNL_GRANULATE 1024+#define MDBX_PNL_RADIXSORT_THRESHOLD 1024+#define MDBX_PNL_INITIAL                                                       \+  (MDBX_PNL_GRANULATE - 2 - MDBX_ASSUME_MALLOC_OVERHEAD / sizeof(pgno_t))++#define MDBX_TXL_GRANULATE 32+#define MDBX_TXL_INITIAL                                                       \+  (MDBX_TXL_GRANULATE - 2 - MDBX_ASSUME_MALLOC_OVERHEAD / sizeof(txnid_t))+#define MDBX_TXL_MAX                                                           \+  ((1u << 17) - 2 - MDBX_ASSUME_MALLOC_OVERHEAD / sizeof(txnid_t))++#define MDBX_PNL_ALLOCLEN(pl) ((pl)[-1])+#define MDBX_PNL_SIZE(pl) ((pl)[0])+#define MDBX_PNL_FIRST(pl) ((pl)[1])+#define MDBX_PNL_LAST(pl) ((pl)[MDBX_PNL_SIZE(pl)])+#define MDBX_PNL_BEGIN(pl) (&(pl)[1])+#define MDBX_PNL_END(pl) (&(pl)[MDBX_PNL_SIZE(pl) + 1])++#if MDBX_PNL_ASCENDING+#define MDBX_PNL_LEAST(pl) MDBX_PNL_FIRST(pl)+#define MDBX_PNL_MOST(pl) MDBX_PNL_LAST(pl)+#else+#define MDBX_PNL_LEAST(pl) MDBX_PNL_LAST(pl)+#define MDBX_PNL_MOST(pl) MDBX_PNL_FIRST(pl)+#endif++#define MDBX_PNL_SIZEOF(pl) ((MDBX_PNL_SIZE(pl) + 1) * sizeof(pgno_t))+#define MDBX_PNL_IS_EMPTY(pl) (MDBX_PNL_SIZE(pl) == 0)++/*----------------------------------------------------------------------------*/+/* Internal structures */++/* Auxiliary DB info.+ * The information here is mostly static/read-only. There is+ * only a single copy of this record in the environment. */+typedef struct MDBX_dbx {+  MDBX_val md_name;                /* name of the database */+  MDBX_cmp_func *md_cmp;           /* function for comparing keys */+  MDBX_cmp_func *md_dcmp;          /* function for comparing data items */+  size_t md_klen_min, md_klen_max; /* min/max key length for the database */+  size_t md_vlen_min,+      md_vlen_max; /* min/max value/data length for the database */+} MDBX_dbx;++/* A database transaction.+ * Every operation requires a transaction handle. */+struct MDBX_txn {+#define MDBX_MT_SIGNATURE UINT32_C(0x93D53A31)+  size_t mt_signature;+  MDBX_txn *mt_parent; /* parent of a nested txn */+  /* Nested txn under this txn, set together with flag MDBX_TXN_HAS_CHILD */+  MDBX_txn *mt_child;+  MDBX_geo mt_geo;+  /* next unallocated page */+#define mt_next_pgno mt_geo.next+  /* corresponding to the current size of datafile */+#define mt_end_pgno mt_geo.now++  /* Transaction Flags */+  /* mdbx_txn_begin() flags */+#define MDBX_TXN_RO_BEGIN_FLAGS (MDBX_TXN_RDONLY | MDBX_TXN_RDONLY_PREPARE)+#define MDBX_TXN_RW_BEGIN_FLAGS                                                \+  (MDBX_TXN_NOMETASYNC | MDBX_TXN_NOSYNC | MDBX_TXN_TRY)+  /* Additional flag for mdbx_sync_locked() */+#define MDBX_SHRINK_ALLOWED UINT32_C(0x40000000)++  /* internal txn flags */+#define MDBX_TXN_FINISHED 0x01  /* txn is finished or never began */+#define MDBX_TXN_ERROR 0x02     /* txn is unusable after an error */+#define MDBX_TXN_DIRTY 0x04     /* must write, even if dirty list is empty */+#define MDBX_TXN_SPILLS 0x08    /* txn or a parent has spilled pages */+#define MDBX_TXN_HAS_CHILD 0x10 /* txn has an MDBX_txn.mt_child */+  /* most operations on the txn are currently illegal */+#define MDBX_TXN_BLOCKED                                                       \+  (MDBX_TXN_FINISHED | MDBX_TXN_ERROR | MDBX_TXN_HAS_CHILD)++#define TXN_FLAGS                                                              \+  (MDBX_TXN_FINISHED | MDBX_TXN_ERROR | MDBX_TXN_DIRTY | MDBX_TXN_SPILLS |     \+   MDBX_TXN_HAS_CHILD)++#if (TXN_FLAGS & (MDBX_TXN_RW_BEGIN_FLAGS | MDBX_TXN_RO_BEGIN_FLAGS)) ||       \+    ((MDBX_TXN_RW_BEGIN_FLAGS | MDBX_TXN_RO_BEGIN_FLAGS | TXN_FLAGS) &         \+     MDBX_SHRINK_ALLOWED)+#error "Oops, some flags overlapped or wrong"+#endif++  unsigned mt_flags;+  /* The ID of this transaction. IDs are integers incrementing from 1.+   * Only committed write transactions increment the ID. If a transaction+   * aborts, the ID may be re-used by the next writer. */+  txnid_t mt_txnid;+  MDBX_env *mt_env; /* the DB environment */+  /* Array of records for each DB known in the environment. */+  MDBX_dbx *mt_dbxs;+  /* Array of MDBX_db records for each known DB */+  MDBX_db *mt_dbs;+  /* Array of sequence numbers for each DB handle */+  unsigned *mt_dbiseqs;++  /* Transaction DBI Flags */+#define DBI_DIRTY MDBX_DBI_DIRTY /* DB was written in this txn */+#define DBI_STALE MDBX_DBI_STALE /* Named-DB record is older than txnID */+#define DBI_FRESH MDBX_DBI_FRESH /* Named-DB handle opened in this txn */+#define DBI_CREAT MDBX_DBI_CREAT /* Named-DB handle created in this txn */+#define DBI_VALID 0x10           /* DB handle is valid, see also DB_VALID */+#define DBI_USRVALID 0x20        /* As DB_VALID, but not set for FREE_DBI */+#define DBI_DUPDATA 0x40         /* DB is MDBX_DUPSORT data */+#define DBI_AUDITED 0x80         /* Internal flag for accounting during audit */+  /* Array of flags for each DB */+  uint8_t *mt_dbistate;+  /* Number of DB records in use, or 0 when the txn is finished.+   * This number only ever increments until the txn finishes; we+   * don't decrement it when individual DB handles are closed. */+  MDBX_dbi mt_numdbs;+  size_t mt_owner; /* thread ID that owns this transaction */+  MDBX_canary mt_canary;+  void *mt_userctx; /* User-settable context */++  union {+    struct {+      /* For read txns: This thread/txn's reader table slot, or NULL. */+      MDBX_reader *reader;+    } to;+    struct {+      /* In write txns, array of cursors for each DB */+      MDBX_cursor **cursors;+      pgno_t *reclaimed_pglist; /* Reclaimed GC pages */+      txnid_t last_reclaimed;   /* ID of last used record */+#if MDBX_ENABLE_REFUND+      pgno_t loose_refund_wl /* FIXME: describe */;+#endif /* MDBX_ENABLE_REFUND */+      /* dirtylist room: Dirty array size - dirty pages visible to this txn.+       * Includes ancestor txns' dirty pages not hidden by other txns'+       * dirty/spilled pages. Thus commit(nested txn) has room to merge+       * dirtylist into mt_parent after freeing hidden mt_parent pages. */+      unsigned dirtyroom;+      /* For write txns: Modified pages. Sorted when not MDBX_WRITEMAP. */+      MDBX_dpl *dirtylist;+      /* The list of reclaimed txns from GC */+      MDBX_TXL lifo_reclaimed;+      /* The list of pages that became unused during this transaction. */+      MDBX_PNL retired_pages;+      /* The list of loose pages that became unused and may be reused+       * in this transaction, linked through `mp_next`. */+      MDBX_page *loose_pages;+      /* Number of loose pages (tw.loose_pages) */+      unsigned loose_count;+      /* The sorted list of dirty pages we temporarily wrote to disk+       * because the dirty list was full. page numbers in here are+       * shifted left by 1, deleted slots have the LSB set. */+      MDBX_PNL spill_pages;+      unsigned spill_least_removed;+    } tw;+  };+};++#if MDBX_WORDBITS >= 64+#define CURSOR_STACK 32+#else+#define CURSOR_STACK 24+#endif++struct MDBX_xcursor;++/* Cursors are used for all DB operations.+ * A cursor holds a path of (page pointer, key index) from the DB+ * root to a position in the DB, plus other state. MDBX_DUPSORT+ * cursors include an xcursor to the current data item. Write txns+ * track their cursors and keep them up to date when data moves.+ * Exception: An xcursor's pointer to a P_SUBP page can be stale.+ * (A node with F_DUPDATA but no F_SUBDATA contains a subpage). */+struct MDBX_cursor {+#define MDBX_MC_LIVE UINT32_C(0xFE05D5B1)+#define MDBX_MC_READY4CLOSE UINT32_C(0x2817A047)+#define MDBX_MC_WAIT4EOT UINT32_C(0x90E297A7)+  uint32_t mc_signature;+  /* The database handle this cursor operates on */+  MDBX_dbi mc_dbi;+  /* Next cursor on this DB in this txn */+  MDBX_cursor *mc_next;+  /* Backup of the original cursor if this cursor is a shadow */+  MDBX_cursor *mc_backup;+  /* Context used for databases with MDBX_DUPSORT, otherwise NULL */+  struct MDBX_xcursor *mc_xcursor;+  /* The transaction that owns this cursor */+  MDBX_txn *mc_txn;+  /* The database record for this cursor */+  MDBX_db *mc_db;+  /* The database auxiliary record for this cursor */+  MDBX_dbx *mc_dbx;+  /* The mt_dbistate for this database */+  uint8_t *mc_dbistate;+  unsigned mc_snum; /* number of pushed pages */+  unsigned mc_top;  /* index of top page, normally mc_snum-1 */++  /* Cursor state flags. */+#define C_INITIALIZED 0x01 /* cursor has been initialized and is valid */+#define C_EOF 0x02         /* No more data */+#define C_SUB 0x04         /* Cursor is a sub-cursor */+#define C_DEL 0x08         /* last op was a cursor_del */+#define C_UNTRACK 0x10     /* Un-track cursor when closing */+#define C_RECLAIMING 0x20  /* GC lookup is prohibited */+#define C_GCFREEZE 0x40    /* reclaimed_pglist must not be updated */++  /* Cursor checking flags. */+#define C_COPYING 0x100  /* skip key-value length check (copying simplify) */+#define C_UPDATING 0x200 /* update/rebalance pending */+#define C_RETIRING 0x400 /* refs to child pages may be invalid */+#define C_SKIPORD 0x800  /* don't check keys ordering */++  unsigned mc_flags;              /* see mdbx_cursor */+  MDBX_page *mc_pg[CURSOR_STACK]; /* stack of pushed pages */+  indx_t mc_ki[CURSOR_STACK];     /* stack of page indices */+};++/* Context for sorted-dup records.+ * We could have gone to a fully recursive design, with arbitrarily+ * deep nesting of sub-databases. But for now we only handle these+ * levels - main DB, optional sub-DB, sorted-duplicate DB. */+typedef struct MDBX_xcursor {+  /* A sub-cursor for traversing the Dup DB */+  MDBX_cursor mx_cursor;+  /* The database record for this Dup DB */+  MDBX_db mx_db;+  /* The auxiliary DB record for this Dup DB */+  MDBX_dbx mx_dbx;+  /* The mt_dbistate for this Dup DB */+  uint8_t mx_dbistate;+} MDBX_xcursor;++typedef struct MDBX_cursor_couple {+  MDBX_cursor outer;+  void *mc_userctx; /* User-settable context */+  MDBX_xcursor inner;+} MDBX_cursor_couple;++/* The database environment. */+struct MDBX_env {+#define MDBX_ME_SIGNATURE UINT32_C(0x9A899641)+  MDBX_atomic_uint32_t me_signature;+  /* Failed to update the meta page. Probably an I/O error. */+#define MDBX_FATAL_ERROR UINT32_C(0x80000000)+  /* Some fields are initialized. */+#define MDBX_ENV_ACTIVE UINT32_C(0x20000000)+  /* me_txkey is set */+#define MDBX_ENV_TXKEY UINT32_C(0x10000000)+  /* Legacy MDBX_MAPASYNC (prior v0.9) */+#define MDBX_DEPRECATED_MAPASYNC UINT32_C(0x100000)+#define ENV_INTERNAL_FLAGS (MDBX_FATAL_ERROR | MDBX_ENV_ACTIVE | MDBX_ENV_TXKEY)+  uint32_t me_flags;+  mdbx_mmap_t me_dxb_mmap; /* The main data file */+#define me_map me_dxb_mmap.dxb+#define me_lazy_fd me_dxb_mmap.fd+  mdbx_filehandle_t me_dsync_fd;+  mdbx_mmap_t me_lck_mmap; /* The lock file */+#define me_lfd me_lck_mmap.fd+#define me_lck me_lck_mmap.lck++  unsigned me_psize;    /* DB page size, initialized from me_os_psize */+  uint8_t me_psize2log; /* log2 of DB page size */+  int8_t me_stuck_meta; /* recovery-only: target meta page or less that zero */+  unsigned me_os_psize; /* OS page size, from mdbx_syspagesize() */+  unsigned me_maxreaders; /* size of the reader table */+  mdbx_fastmutex_t me_dbi_lock;+  MDBX_dbi me_numdbs;         /* number of DBs opened */+  MDBX_dbi me_maxdbs;         /* size of the DB table */+  uint32_t me_pid;            /* process ID of this env */+  mdbx_thread_key_t me_txkey; /* thread-key for readers */+  char *me_pathname;          /* path to the DB files */+  void *me_pbuf;              /* scratch area for DUPSORT put() */+  MDBX_txn *me_txn;           /* current write transaction */+  MDBX_txn *me_txn0;          /* prealloc'd write transaction */++  /* write-txn lock */+#if MDBX_LOCKING == MDBX_LOCKING_SYSV+  union {+    key_t key;+    int semid;+  } me_sysv_ipc;+#endif /* MDBX_LOCKING == MDBX_LOCKING_SYSV */++#if MDBX_LOCKING > 0+  mdbx_ipclock_t *me_wlock;+#endif /* MDBX_LOCKING > 0 */++  MDBX_dbx *me_dbxs;         /* array of static DB info */+  uint16_t *me_dbflags;      /* array of flags from MDBX_db.md_flags */+  unsigned *me_dbiseqs;      /* array of dbi sequence numbers */+  atomic_txnid_t *me_oldest; /* ID of oldest reader last time we looked */+  MDBX_page *me_dp_reserve;  /* list of malloc'd blocks for re-use */+  /* PNL of pages that became unused in a write txn */+  MDBX_PNL me_retired_pages;+  /* Number of freelist items that can fit in a single overflow page */+  unsigned me_maxgc_ov1page;+  unsigned me_branch_nodemax; /* max size of a branch-node */+  uint32_t me_live_reader;    /* have liveness lock in reader table */+  void *me_userctx;           /* User-settable context */+  MDBX_atomic_uint64_t *me_sync_timestamp;+  MDBX_atomic_uint64_t *me_autosync_period;+  atomic_pgno_t *me_unsynced_pages;+  atomic_pgno_t *me_autosync_threshold;+  atomic_pgno_t *me_discarded_tail;+  MDBX_atomic_uint32_t *me_meta_sync_txnid;+  MDBX_hsr_func *me_hsr_callback; /* Callback for kicking laggard readers */+  unsigned me_dp_reserve_len;+  struct {+    unsigned dp_reserve_limit;+    unsigned rp_augment_limit;+    unsigned dp_limit;+    unsigned dp_initial;+    uint8_t dp_loose_limit;+    uint8_t spill_max_denominator;+    uint8_t spill_min_denominator;+    uint8_t spill_parent4child_denominator;+  } me_options;+  struct {+#if MDBX_LOCKING > 0+    mdbx_ipclock_t wlock;+#endif /* MDBX_LOCKING > 0 */+    atomic_txnid_t oldest;+    MDBX_atomic_uint64_t sync_timestamp;+    MDBX_atomic_uint64_t autosync_period;+    atomic_pgno_t autosync_pending;+    atomic_pgno_t autosync_threshold;+    atomic_pgno_t discarded_tail;+    MDBX_atomic_uint32_t meta_sync_txnid;+  } me_lckless_stub;+#if MDBX_DEBUG+  MDBX_assert_func *me_assert_func; /*  Callback for assertion failures */+#endif+#ifdef MDBX_USE_VALGRIND+  int me_valgrind_handle;+#endif+#if defined(MDBX_USE_VALGRIND) || defined(__SANITIZE_ADDRESS__)+  pgno_t me_poison_edge;+#endif /* MDBX_USE_VALGRIND || __SANITIZE_ADDRESS__ */+  MDBX_env *me_lcklist_next;++  /* struct me_dbgeo used for accepting db-geo params from user for the new+   * database creation, i.e. when mdbx_env_set_geometry() was called before+   * mdbx_env_open(). */+  struct {+    size_t lower;  /* minimal size of datafile */+    size_t upper;  /* maximal size of datafile */+    size_t now;    /* current size of datafile */+    size_t grow;   /* step to grow datafile */+    size_t shrink; /* threshold to shrink datafile */+  } me_dbgeo;++#if defined(_WIN32) || defined(_WIN64)+  MDBX_srwlock me_remap_guard;+  /* Workaround for LockFileEx and WriteFile multithread bug */+  CRITICAL_SECTION me_windowsbug_lock;+#else+  mdbx_fastmutex_t me_remap_guard;+#endif+};++#ifndef __cplusplus+/*----------------------------------------------------------------------------*/+/* Debug and Logging stuff */++#define MDBX_RUNTIME_FLAGS_INIT                                                \+  ((MDBX_DEBUG) > 0) * MDBX_DBG_ASSERT + ((MDBX_DEBUG) > 1) * MDBX_DBG_AUDIT++extern uint8_t mdbx_runtime_flags;+extern uint8_t mdbx_loglevel;+extern MDBX_debug_func *mdbx_debug_logger;++MDBX_INTERNAL_FUNC void MDBX_PRINTF_ARGS(4, 5)+    mdbx_debug_log(int level, const char *function, int line, const char *fmt,+                   ...) MDBX_PRINTF_ARGS(4, 5);+MDBX_INTERNAL_FUNC void mdbx_debug_log_va(int level, const char *function,+                                          int line, const char *fmt,+                                          va_list args);++#define mdbx_log_enabled(msg) unlikely(msg <= mdbx_loglevel)++#if MDBX_DEBUG++#define mdbx_assert_enabled() unlikely(mdbx_runtime_flags &MDBX_DBG_ASSERT)++#define mdbx_audit_enabled() unlikely(mdbx_runtime_flags &MDBX_DBG_AUDIT)++#else /* MDBX_DEBUG */++#define mdbx_audit_enabled() (0)++#if !defined(NDEBUG) || defined(MDBX_FORCE_ASSERTIONS)+#define mdbx_assert_enabled() (1)+#else+#define mdbx_assert_enabled() (0)+#endif /* NDEBUG */++#endif /* MDBX_DEBUG */++#if !MDBX_DEBUG && defined(__ANDROID_API__)+#define mdbx_assert_fail(env, msg, func, line)                                 \+  __android_log_assert(msg, "mdbx", "%s:%u", func, line)+#else+void mdbx_assert_fail(const MDBX_env *env, const char *msg, const char *func,+                      int line);+#endif++#define mdbx_debug_extra(fmt, ...)                                             \+  do {                                                                         \+    if (MDBX_DEBUG && mdbx_log_enabled(MDBX_LOG_EXTRA))                        \+      mdbx_debug_log(MDBX_LOG_EXTRA, __func__, __LINE__, fmt, __VA_ARGS__);    \+  } while (0)++#define mdbx_debug_extra_print(fmt, ...)                                       \+  do {                                                                         \+    if (MDBX_DEBUG && mdbx_log_enabled(MDBX_LOG_EXTRA))                        \+      mdbx_debug_log(MDBX_LOG_EXTRA, NULL, 0, fmt, __VA_ARGS__);               \+  } while (0)++#define mdbx_trace(fmt, ...)                                                   \+  do {                                                                         \+    if (MDBX_DEBUG && mdbx_log_enabled(MDBX_LOG_TRACE))                        \+      mdbx_debug_log(MDBX_LOG_TRACE, __func__, __LINE__, fmt "\n",             \+                     __VA_ARGS__);                                             \+  } while (0)++#define mdbx_debug(fmt, ...)                                                   \+  do {                                                                         \+    if (MDBX_DEBUG && mdbx_log_enabled(MDBX_LOG_DEBUG))                        \+      mdbx_debug_log(MDBX_LOG_DEBUG, __func__, __LINE__, fmt "\n",             \+                     __VA_ARGS__);                                             \+  } while (0)++#define mdbx_verbose(fmt, ...)                                                 \+  do {                                                                         \+    if (MDBX_DEBUG && mdbx_log_enabled(MDBX_LOG_VERBOSE))                      \+      mdbx_debug_log(MDBX_LOG_VERBOSE, __func__, __LINE__, fmt "\n",           \+                     __VA_ARGS__);                                             \+  } while (0)++#define mdbx_notice(fmt, ...)                                                  \+  do {                                                                         \+    if (mdbx_log_enabled(MDBX_LOG_NOTICE))                                     \+      mdbx_debug_log(MDBX_LOG_NOTICE, __func__, __LINE__, fmt "\n",            \+                     __VA_ARGS__);                                             \+  } while (0)++#define mdbx_warning(fmt, ...)                                                 \+  do {                                                                         \+    if (mdbx_log_enabled(MDBX_LOG_WARN))                                       \+      mdbx_debug_log(MDBX_LOG_WARN, __func__, __LINE__, fmt "\n",              \+                     __VA_ARGS__);                                             \+  } while (0)++#define mdbx_error(fmt, ...)                                                   \+  do {                                                                         \+    if (mdbx_log_enabled(MDBX_LOG_ERROR))                                      \+      mdbx_debug_log(MDBX_LOG_ERROR, __func__, __LINE__, fmt "\n",             \+                     __VA_ARGS__);                                             \+  } while (0)++#define mdbx_fatal(fmt, ...)                                                   \+  mdbx_debug_log(MDBX_LOG_FATAL, __func__, __LINE__, fmt "\n", __VA_ARGS__);++#define mdbx_ensure_msg(env, expr, msg)                                        \+  do {                                                                         \+    if (unlikely(!(expr)))                                                     \+      mdbx_assert_fail(env, msg, __func__, __LINE__);                          \+  } while (0)++#define mdbx_ensure(env, expr) mdbx_ensure_msg(env, expr, #expr)++/* assert(3) variant in environment context */+#define mdbx_assert(env, expr)                                                 \+  do {                                                                         \+    if (mdbx_assert_enabled())                                                 \+      mdbx_ensure(env, expr);                                                  \+  } while (0)++/* assert(3) variant in cursor context */+#define mdbx_cassert(mc, expr) mdbx_assert((mc)->mc_txn->mt_env, expr)++/* assert(3) variant in transaction context */+#define mdbx_tassert(txn, expr) mdbx_assert((txn)->mt_env, expr)++#ifndef MDBX_TOOLS /* Avoid using internal mdbx_assert() */+#undef assert+#define assert(expr) mdbx_assert(NULL, expr)+#endif++/*----------------------------------------------------------------------------*/+/* Cache coherence and mmap invalidation */++#if MDBX_CPU_WRITEBACK_INCOHERENT+#define mdbx_flush_incoherent_cpu_writeback() mdbx_memory_barrier()+#else+#define mdbx_flush_incoherent_cpu_writeback() mdbx_compiler_barrier()+#endif /* MDBX_CPU_WRITEBACK_INCOHERENT */++static __maybe_unused __inline void+mdbx_flush_incoherent_mmap(void *addr, size_t nbytes, const intptr_t pagesize) {+#if MDBX_MMAP_INCOHERENT_FILE_WRITE+  char *const begin = (char *)(-pagesize & (intptr_t)addr);+  char *const end =+      (char *)(-pagesize & (intptr_t)((char *)addr + nbytes + pagesize - 1));+  int err = msync(begin, end - begin, MS_SYNC | MS_INVALIDATE) ? errno : 0;+  mdbx_assert(nullptr, err == 0);+  (void)err;+#else+  (void)pagesize;+#endif /* MDBX_MMAP_INCOHERENT_FILE_WRITE */++#if MDBX_MMAP_INCOHERENT_CPU_CACHE+#ifdef DCACHE+  /* MIPS has cache coherency issues.+   * Note: for any nbytes >= on-chip cache size, entire is flushed. */+  cacheflush(addr, nbytes, DCACHE);+#else+#error "Oops, cacheflush() not available"+#endif /* DCACHE */+#endif /* MDBX_MMAP_INCOHERENT_CPU_CACHE */++#if !MDBX_MMAP_INCOHERENT_FILE_WRITE && !MDBX_MMAP_INCOHERENT_CPU_CACHE+  (void)addr;+  (void)nbytes;+#endif+}++/*----------------------------------------------------------------------------*/+/* Internal prototypes */++MDBX_INTERNAL_FUNC int mdbx_cleanup_dead_readers(MDBX_env *env, int rlocked,+                                                 int *dead);+MDBX_INTERNAL_FUNC int mdbx_rthc_alloc(mdbx_thread_key_t *key,+                                       MDBX_reader *begin, MDBX_reader *end);+MDBX_INTERNAL_FUNC void mdbx_rthc_remove(const mdbx_thread_key_t key);++MDBX_INTERNAL_FUNC void mdbx_rthc_global_init(void);+MDBX_INTERNAL_FUNC void mdbx_rthc_global_dtor(void);+MDBX_INTERNAL_FUNC void mdbx_rthc_thread_dtor(void *ptr);++static __maybe_unused __inline void mdbx_jitter4testing(bool tiny) {+#if MDBX_DEBUG+  if (MDBX_DBG_JITTER & mdbx_runtime_flags)+    mdbx_osal_jitter(tiny);+#else+  (void)tiny;+#endif+}++#endif /* !__cplusplus */++#define MDBX_IS_ERROR(rc)                                                      \+  ((rc) != MDBX_RESULT_TRUE && (rc) != MDBX_RESULT_FALSE)++/* Internal error codes, not exposed outside libmdbx */+#define MDBX_NO_ROOT (MDBX_LAST_ADDED_ERRCODE + 10)++/* Debugging output value of a cursor DBI: Negative in a sub-cursor. */+#define DDBI(mc)                                                               \+  (((mc)->mc_flags & C_SUB) ? -(int)(mc)->mc_dbi : (int)(mc)->mc_dbi)++/* Key size which fits in a DKBUF. */+#define DKBUF_MAXKEYSIZE 511 /* FIXME */++#if MDBX_DEBUG+#define DKBUF char _kbuf[DKBUF_MAXKEYSIZE * 4 + 2]+#define DKEY(x) mdbx_dump_val(x, _kbuf, DKBUF_MAXKEYSIZE * 2 + 1)+#define DVAL(x)                                                                \+  mdbx_dump_val(x, _kbuf + DKBUF_MAXKEYSIZE * 2 + 1, DKBUF_MAXKEYSIZE * 2 + 1)+#else+#define DKBUF ((void)(0))+#define DKEY(x) ("-")+#define DVAL(x) ("-")+#endif++/* An invalid page number.+ * Mainly used to denote an empty tree. */+#define P_INVALID (~(pgno_t)0)++/* Test if the flags f are set in a flag word w. */+#define F_ISSET(w, f) (((w) & (f)) == (f))++/* Round n up to an even number. */+#define EVEN(n) (((n) + 1U) & -2) /* sign-extending -2 to match n+1U */++/* Default size of memory map.+ * This is certainly too small for any actual applications. Apps should+ * always set the size explicitly using mdbx_env_set_geometry(). */+#define DEFAULT_MAPSIZE MEGABYTE++/* Number of slots in the reader table.+ * This value was chosen somewhat arbitrarily. The 61 is a prime number,+ * and such readers plus a couple mutexes fit into single 4KB page.+ * Applications should set the table size using mdbx_env_set_maxreaders(). */+#define DEFAULT_READERS 61++/* Test if a page is a leaf page */+#define IS_LEAF(p) (((p)->mp_flags & P_LEAF) != 0)+/* Test if a page is a LEAF2 page */+#define IS_LEAF2(p) unlikely(((p)->mp_flags & P_LEAF2) != 0)+/* Test if a page is a branch page */+#define IS_BRANCH(p) (((p)->mp_flags & P_BRANCH) != 0)+/* Test if a page is an overflow page */+#define IS_OVERFLOW(p) unlikely(((p)->mp_flags & P_OVERFLOW) != 0)+/* Test if a page is a sub page */+#define IS_SUBP(p) (((p)->mp_flags & P_SUBP) != 0)+/* Test if a page is dirty */+#define IS_DIRTY(p) (((p)->mp_flags & P_DIRTY) != 0)++#define PAGETYPE(p) ((p)->mp_flags & (P_BRANCH | P_LEAF | P_LEAF2 | P_OVERFLOW))++/* Header for a single key/data pair within a page.+ * Used in pages of type P_BRANCH and P_LEAF without P_LEAF2.+ * We guarantee 2-byte alignment for 'MDBX_node's.+ *+ * Leaf node flags describe node contents.  F_BIGDATA says the node's+ * data part is the page number of an overflow page with actual data.+ * F_DUPDATA and F_SUBDATA can be combined giving duplicate data in+ * a sub-page/sub-database, and named databases (just F_SUBDATA). */+typedef struct MDBX_node {+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__+  union {+    uint32_t mn_dsize;+    uint32_t mn_pgno32;+  };+  uint8_t mn_flags; /* see mdbx_node flags */+  uint8_t mn_extra;+  uint16_t mn_ksize; /* key size */+#else+  uint16_t mn_ksize; /* key size */+  uint8_t mn_extra;+  uint8_t mn_flags; /* see mdbx_node flags */+  union {+    uint32_t mn_pgno32;+    uint32_t mn_dsize;+  };+#endif /* __BYTE_ORDER__ */++  /* mdbx_node Flags */+#define F_BIGDATA 0x01 /* data put on overflow page */+#define F_SUBDATA 0x02 /* data is a sub-database */+#define F_DUPDATA 0x04 /* data has duplicates */++  /* valid flags for mdbx_node_add() */+#define NODE_ADD_FLAGS (F_DUPDATA | F_SUBDATA | MDBX_RESERVE | MDBX_APPEND)++#if (defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L) ||              \+    (!defined(__cplusplus) && defined(_MSC_VER))+  uint8_t mn_data[] /* key and data are appended here */;+#endif /* C99 */+} MDBX_node;++#define DB_PERSISTENT_FLAGS                                                    \+  (MDBX_REVERSEKEY | MDBX_DUPSORT | MDBX_INTEGERKEY | MDBX_DUPFIXED |          \+   MDBX_INTEGERDUP | MDBX_REVERSEDUP)++/* mdbx_dbi_open() flags */+#define DB_USABLE_FLAGS (DB_PERSISTENT_FLAGS | MDBX_CREATE | MDBX_DB_ACCEDE)++#define DB_VALID 0x8000 /* DB handle is valid, for me_dbflags */+#define DB_INTERNAL_FLAGS DB_VALID++#if DB_INTERNAL_FLAGS & DB_USABLE_FLAGS+#error "Oops, some flags overlapped or wrong"+#endif+#if DB_PERSISTENT_FLAGS & ~DB_USABLE_FLAGS+#error "Oops, some flags overlapped or wrong"+#endif++/* max number of pages to commit in one writev() call */+#define MDBX_COMMIT_PAGES 64+#if defined(IOV_MAX) && IOV_MAX < MDBX_COMMIT_PAGES /* sysconf(_SC_IOV_MAX) */+#undef MDBX_COMMIT_PAGES+#define MDBX_COMMIT_PAGES IOV_MAX+#endif++/*+ *                /+ *                | -1, a < b+ * CMP2INT(a,b) = <  0, a == b+ *                |  1, a > b+ *                \+ */+#if 1+/* LY: fast enough on most systems */+#define CMP2INT(a, b) (((b) > (a)) ? -1 : (a) > (b))+#else+#define CMP2INT(a, b) (((a) > (b)) - ((b) > (a)))+#endif++/* Do not spill pages to disk if txn is getting full, may fail instead */+#define MDBX_NOSPILL 0x8000++MDBX_NOTHROW_CONST_FUNCTION static __maybe_unused __inline pgno_t+pgno_add(pgno_t base, pgno_t augend) {+  assert(base <= MAX_PAGENO);+  return (augend < MAX_PAGENO - base) ? base + augend : MAX_PAGENO;+}++MDBX_NOTHROW_CONST_FUNCTION static __maybe_unused __inline pgno_t+pgno_sub(pgno_t base, pgno_t subtrahend) {+  assert(base >= MIN_PAGENO);+  return (subtrahend < base - MIN_PAGENO) ? base - subtrahend : MIN_PAGENO;+}++MDBX_NOTHROW_CONST_FUNCTION static __always_inline __maybe_unused bool+is_powerof2(size_t x) {+  return (x & (x - 1)) == 0;+}++MDBX_NOTHROW_CONST_FUNCTION static __always_inline __maybe_unused size_t+floor_powerof2(size_t value, size_t granularity) {+  assert(is_powerof2(granularity));+  return value & ~(granularity - 1);+}++MDBX_NOTHROW_CONST_FUNCTION static __always_inline __maybe_unused size_t+ceil_powerof2(size_t value, size_t granularity) {+  return floor_powerof2(value + granularity - 1, granularity);+}++/* Only a subset of the mdbx_env flags can be changed+ * at runtime. Changing other flags requires closing the+ * environment and re-opening it with the new flags. */+#define ENV_CHANGEABLE_FLAGS                                                   \+  (MDBX_SAFE_NOSYNC | MDBX_NOMETASYNC | MDBX_DEPRECATED_MAPASYNC |             \+   MDBX_NOMEMINIT | MDBX_COALESCE | MDBX_PAGEPERTURB | MDBX_ACCEDE)+#define ENV_CHANGELESS_FLAGS                                                   \+  (MDBX_NOSUBDIR | MDBX_RDONLY | MDBX_WRITEMAP | MDBX_NOTLS | MDBX_NORDAHEAD | \+   MDBX_LIFORECLAIM | MDBX_EXCLUSIVE)+#define ENV_USABLE_FLAGS (ENV_CHANGEABLE_FLAGS | ENV_CHANGELESS_FLAGS)++#if !defined(__cplusplus) || defined(__cpp_constexpr)+static __maybe_unused void static_checks(void) {+  STATIC_ASSERT_MSG(INT16_MAX - CORE_DBS == MDBX_MAX_DBI,+                    "Oops, MDBX_MAX_DBI or CORE_DBS?");+  STATIC_ASSERT_MSG((unsigned)(MDBX_DB_ACCEDE | MDBX_CREATE) ==+                        ((DB_USABLE_FLAGS | DB_INTERNAL_FLAGS) &+                         (ENV_USABLE_FLAGS | ENV_INTERNAL_FLAGS)),+                    "Oops, some flags overlapped or wrong");+  STATIC_ASSERT_MSG((ENV_INTERNAL_FLAGS & ENV_USABLE_FLAGS) == 0,+                    "Oops, some flags overlapped or wrong");+}+#endif /* Disabled for MSVC 19.0 (VisualStudio 2015) */++#ifdef __cplusplus+}+#endif+/*+ * Copyright 2015-2021 Leonid Yuriev <leo@yuriev.ru>.+ * and other libmdbx authors: please see AUTHORS file.+ * All rights reserved.+ *+ * This code is derived from "LMDB engine" written by+ * Howard Chu (Symas Corporation), which itself derived from btree.c+ * written by Martin Hedenfalk.+ *+ * ---+ *+ * Portions Copyright 2011-2015 Howard Chu, Symas Corp. All rights reserved.+ *+ * Redistribution and use in source and binary forms, with or without+ * modification, are permitted only as authorized by the OpenLDAP+ * Public License.+ *+ * A copy of this license is available in the file LICENSE in the+ * top-level directory of the distribution or, alternatively, at+ * <http://www.OpenLDAP.org/license.html>.+ *+ * ---+ *+ * Portions Copyright (c) 2009, 2010 Martin Hedenfalk <martin@bzero.se>+ *+ * Permission to use, copy, modify, and distribute this software for any+ * purpose with or without fee is hereby granted, provided that the above+ * copyright notice and this permission notice appear in all copies.+ *+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */+++/*------------------------------------------------------------------------------+ * Internal inline functions */++MDBX_NOTHROW_CONST_FUNCTION static unsigned log2n(size_t value) {+  assert(value > 0 && value < INT32_MAX && is_powerof2(value));+  assert((value & -(int32_t)value) == value);+#if __GNUC_PREREQ(4, 1) || __has_builtin(__builtin_ctzl)+  return __builtin_ctzl(value);+#elif defined(_MSC_VER)+  unsigned long index;+  _BitScanForward(&index, (unsigned long)value);+  return index;+#else+  static const uint8_t debruijn_ctz32[32] = {+      0,  1,  28, 2,  29, 14, 24, 3, 30, 22, 20, 15, 25, 17, 4,  8,+      31, 27, 13, 23, 21, 19, 16, 7, 26, 12, 18, 6,  11, 5,  10, 9};+  return debruijn_ctz32[(uint32_t)(value * 0x077CB531u) >> 27];+#endif+}++/* Pack/Unpack 16-bit values for Grow step & Shrink threshold */+MDBX_NOTHROW_CONST_FUNCTION static __inline pgno_t me2v(unsigned m,+                                                        unsigned e) {+  assert(m < 2048 && e < 8);+  return (pgno_t)(32768 + ((m + 1) << (e + 8)));+}++MDBX_NOTHROW_CONST_FUNCTION static __inline uint16_t v2me(size_t v,+                                                          unsigned e) {+  assert(v > (e ? me2v(2047, e - 1) : 32768));+  assert(v <= me2v(2047, e));+  size_t m = (v - 32768 + ((size_t)1 << (e + 8)) - 1) >> (e + 8);+  m -= m > 0;+  assert(m < 2048 && e < 8);+  // f e d c b a 9 8 7 6 5 4 3 2 1 0+  // 1 e e e m m m m m m m m m m m 1+  const uint16_t pv = (uint16_t)(0x8001 + (e << 12) + (m << 1));+  assert(pv != 65535);+  return pv;+}++/* Convert 16-bit packed (exponential quantized) value to number of pages */+MDBX_NOTHROW_CONST_FUNCTION static pgno_t pv2pages(uint16_t pv) {+  if ((pv & 0x8001) != 0x8001)+    return pv;+  if (pv == 65535)+    return 65536;+  // f e d c b a 9 8 7 6 5 4 3 2 1 0+  // 1 e e e m m m m m m m m m m m 1+  return me2v((pv >> 1) & 2047, (pv >> 12) & 7);+}++/* Convert number of pages to 16-bit packed (exponential quantized) value */+MDBX_NOTHROW_CONST_FUNCTION static uint16_t pages2pv(size_t pages) {+  if (pages < 32769 || (pages < 65536 && (pages & 1) == 0))+    return (uint16_t)pages;+  if (pages <= me2v(2047, 0))+    return v2me(pages, 0);+  if (pages <= me2v(2047, 1))+    return v2me(pages, 1);+  if (pages <= me2v(2047, 2))+    return v2me(pages, 2);+  if (pages <= me2v(2047, 3))+    return v2me(pages, 3);+  if (pages <= me2v(2047, 4))+    return v2me(pages, 4);+  if (pages <= me2v(2047, 5))+    return v2me(pages, 5);+  if (pages <= me2v(2047, 6))+    return v2me(pages, 6);+  return (pages < me2v(2046, 7)) ? v2me(pages, 7) : 65533;+}++/*------------------------------------------------------------------------------+ * Unaligned access */++MDBX_NOTHROW_CONST_FUNCTION static __maybe_unused __always_inline unsigned+field_alignment(unsigned alignment_baseline, size_t field_offset) {+  unsigned merge = alignment_baseline | (unsigned)field_offset;+  return merge & -(int)merge;+}++/* read-thunk for UB-sanitizer */+MDBX_NOTHROW_PURE_FUNCTION static __always_inline uint8_t+peek_u8(const uint8_t *const __restrict ptr) {+  return *ptr;+}++/* write-thunk for UB-sanitizer */+static __always_inline void poke_u8(uint8_t *const __restrict ptr,+                                    const uint8_t v) {+  *ptr = v;+}++MDBX_NOTHROW_PURE_FUNCTION static __always_inline uint16_t+unaligned_peek_u16(const unsigned expected_alignment, const void *const ptr) {+  assert((uintptr_t)ptr % expected_alignment == 0);+  if (MDBX_UNALIGNED_OK || (expected_alignment % sizeof(uint16_t)) == 0)+    return *(const uint16_t *)ptr;+  else {+    uint16_t v;+    memcpy(&v, ptr, sizeof(v));+    return v;+  }+}++static __always_inline void+unaligned_poke_u16(const unsigned expected_alignment,+                   void *const __restrict ptr, const uint16_t v) {+  assert((uintptr_t)ptr % expected_alignment == 0);+  if (MDBX_UNALIGNED_OK || (expected_alignment % sizeof(v)) == 0)+    *(uint16_t *)ptr = v;+  else+    memcpy(ptr, &v, sizeof(v));+}++MDBX_NOTHROW_PURE_FUNCTION static __always_inline uint32_t unaligned_peek_u32(+    const unsigned expected_alignment, const void *const __restrict ptr) {+  assert((uintptr_t)ptr % expected_alignment == 0);+  if (MDBX_UNALIGNED_OK || (expected_alignment % sizeof(uint32_t)) == 0)+    return *(const uint32_t *)ptr;+  else if ((expected_alignment % sizeof(uint16_t)) == 0) {+    const uint16_t lo =+        ((const uint16_t *)ptr)[__BYTE_ORDER__ != __ORDER_LITTLE_ENDIAN__];+    const uint16_t hi =+        ((const uint16_t *)ptr)[__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__];+    return lo | (uint32_t)hi << 16;+  } else {+    uint32_t v;+    memcpy(&v, ptr, sizeof(v));+    return v;+  }+}++static __always_inline void+unaligned_poke_u32(const unsigned expected_alignment,+                   void *const __restrict ptr, const uint32_t v) {+  assert((uintptr_t)ptr % expected_alignment == 0);+  if (MDBX_UNALIGNED_OK || (expected_alignment % sizeof(v)) == 0)+    *(uint32_t *)ptr = v;+  else if ((expected_alignment % sizeof(uint16_t)) == 0) {+    ((uint16_t *)ptr)[__BYTE_ORDER__ != __ORDER_LITTLE_ENDIAN__] = (uint16_t)v;+    ((uint16_t *)ptr)[__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__] =+        (uint16_t)(v >> 16);+  } else+    memcpy(ptr, &v, sizeof(v));+}++MDBX_NOTHROW_PURE_FUNCTION static __always_inline uint64_t unaligned_peek_u64(+    const unsigned expected_alignment, const void *const __restrict ptr) {+  assert((uintptr_t)ptr % expected_alignment == 0);+  if (MDBX_UNALIGNED_OK || (expected_alignment % sizeof(uint64_t)) == 0)+    return *(const uint64_t *)ptr;+  else if ((expected_alignment % sizeof(uint32_t)) == 0) {+    const uint32_t lo =+        ((const uint32_t *)ptr)[__BYTE_ORDER__ != __ORDER_LITTLE_ENDIAN__];+    const uint32_t hi =+        ((const uint32_t *)ptr)[__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__];+    return lo | (uint64_t)hi << 32;+  } else {+    uint64_t v;+    memcpy(&v, ptr, sizeof(v));+    return v;+  }+}++static __always_inline void+unaligned_poke_u64(const unsigned expected_alignment,+                   void *const __restrict ptr, const uint64_t v) {+  assert((uintptr_t)ptr % expected_alignment == 0);+  if (MDBX_UNALIGNED_OK || (expected_alignment % sizeof(v)) == 0)+    *(uint64_t *)ptr = v;+  else if ((expected_alignment % sizeof(uint32_t)) == 0) {+    ((uint32_t *)ptr)[__BYTE_ORDER__ != __ORDER_LITTLE_ENDIAN__] = (uint32_t)v;+    ((uint32_t *)ptr)[__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__] =+        (uint32_t)(v >> 32);+  } else+    memcpy(ptr, &v, sizeof(v));+}++#define UNALIGNED_PEEK_8(ptr, struct, field)                                   \+  peek_u8((const uint8_t *)(ptr) + offsetof(struct, field))+#define UNALIGNED_POKE_8(ptr, struct, field, value)                            \+  poke_u8((uint8_t *)(ptr) + offsetof(struct, field), value)++#define UNALIGNED_PEEK_16(ptr, struct, field)                                  \+  unaligned_peek_u16(1, (const char *)(ptr) + offsetof(struct, field))+#define UNALIGNED_POKE_16(ptr, struct, field, value)                           \+  unaligned_poke_u16(1, (char *)(ptr) + offsetof(struct, field), value)++#define UNALIGNED_PEEK_32(ptr, struct, field)                                  \+  unaligned_peek_u32(1, (const char *)(ptr) + offsetof(struct, field))+#define UNALIGNED_POKE_32(ptr, struct, field, value)                           \+  unaligned_poke_u32(1, (char *)(ptr) + offsetof(struct, field), value)++#define UNALIGNED_PEEK_64(ptr, struct, field)                                  \+  unaligned_peek_u64(1, (const char *)(ptr) + offsetof(struct, field))+#define UNALIGNED_POKE_64(ptr, struct, field, value)                           \+  unaligned_poke_u64(1, (char *)(ptr) + offsetof(struct, field), value)++/* Get the page number pointed to by a branch node */+MDBX_NOTHROW_PURE_FUNCTION static __always_inline pgno_t+node_pgno(const MDBX_node *const __restrict node) {+  pgno_t pgno = UNALIGNED_PEEK_32(node, MDBX_node, mn_pgno32);+  if (sizeof(pgno) > 4)+    pgno |= ((uint64_t)UNALIGNED_PEEK_8(node, MDBX_node, mn_extra)) << 32;+  return pgno;+}++/* Set the page number in a branch node */+static __always_inline void node_set_pgno(MDBX_node *const __restrict node,+                                          pgno_t pgno) {+  assert(pgno >= MIN_PAGENO && pgno <= MAX_PAGENO);++  UNALIGNED_POKE_32(node, MDBX_node, mn_pgno32, (uint32_t)pgno);+  if (sizeof(pgno) > 4)+    UNALIGNED_POKE_8(node, MDBX_node, mn_extra,+                     (uint8_t)((uint64_t)pgno >> 32));+}++/* Get the size of the data in a leaf node */+MDBX_NOTHROW_PURE_FUNCTION static __always_inline size_t+node_ds(const MDBX_node *const __restrict node) {+  return UNALIGNED_PEEK_32(node, MDBX_node, mn_dsize);+}++/* Set the size of the data for a leaf node */+static __always_inline void node_set_ds(MDBX_node *const __restrict node,+                                        size_t size) {+  assert(size < INT_MAX);+  UNALIGNED_POKE_32(node, MDBX_node, mn_dsize, (uint32_t)size);+}++/* The size of a key in a node */+MDBX_NOTHROW_PURE_FUNCTION static __always_inline size_t+node_ks(const MDBX_node *const __restrict node) {+  return UNALIGNED_PEEK_16(node, MDBX_node, mn_ksize);+}++/* Set the size of the key for a leaf node */+static __always_inline void node_set_ks(MDBX_node *const __restrict node,+                                        size_t size) {+  assert(size < INT16_MAX);+  UNALIGNED_POKE_16(node, MDBX_node, mn_ksize, (uint16_t)size);+}++MDBX_NOTHROW_PURE_FUNCTION static __always_inline uint8_t+node_flags(const MDBX_node *const __restrict node) {+  return UNALIGNED_PEEK_8(node, MDBX_node, mn_flags);+}++static __always_inline void node_set_flags(MDBX_node *const __restrict node,+                                           uint8_t flags) {+  UNALIGNED_POKE_8(node, MDBX_node, mn_flags, flags);+}++/* Size of the node header, excluding dynamic data at the end */+#define NODESIZE offsetof(MDBX_node, mn_data)++/* Address of the key for the node */+MDBX_NOTHROW_PURE_FUNCTION static __always_inline void *+node_key(const MDBX_node *const __restrict node) {+  return (char *)node + NODESIZE;+}++/* Address of the data for a node */+MDBX_NOTHROW_PURE_FUNCTION static __always_inline void *+node_data(const MDBX_node *const __restrict node) {+  return (char *)node_key(node) + node_ks(node);+}++/* Size of a node in a leaf page with a given key and data.+ * This is node header plus key plus data size. */+MDBX_NOTHROW_CONST_FUNCTION static __always_inline size_t+node_size_len(const size_t key_len, const size_t value_len) {+  return NODESIZE + EVEN(key_len + value_len);+}+MDBX_NOTHROW_PURE_FUNCTION static __always_inline size_t+node_size(const MDBX_val *key, const MDBX_val *value) {+  return node_size_len(key ? key->iov_len : 0, value ? value->iov_len : 0);+}++MDBX_NOTHROW_PURE_FUNCTION static __always_inline pgno_t+peek_pgno(const void *const __restrict ptr) {+  if (sizeof(pgno_t) == sizeof(uint32_t))+    return (pgno_t)unaligned_peek_u32(1, ptr);+  else if (sizeof(pgno_t) == sizeof(uint64_t))+    return (pgno_t)unaligned_peek_u64(1, ptr);+  else {+    pgno_t pgno;+    memcpy(&pgno, ptr, sizeof(pgno));+    return pgno;+  }+}++static __always_inline void poke_pgno(void *const __restrict ptr,+                                      const pgno_t pgno) {+  if (sizeof(pgno) == sizeof(uint32_t))+    unaligned_poke_u32(1, ptr, pgno);+  else if (sizeof(pgno) == sizeof(uint64_t))+    unaligned_poke_u64(1, ptr, pgno);+  else+    memcpy(ptr, &pgno, sizeof(pgno));+}++MDBX_NOTHROW_PURE_FUNCTION static __always_inline pgno_t+node_largedata_pgno(const MDBX_node *const __restrict node) {+  assert(node_flags(node) & F_BIGDATA);+  return peek_pgno(node_data(node));+}++/*------------------------------------------------------------------------------+ * Key length limitation factors:+ *+ *  - Branch-page must contain at least two (MDBX_MINKEYS) nodes,+ *    within each a key and a child page number. But we can't split a page if+ *    it contains less that 4 keys. Therefore, at least 3 branch-node should+ *    fit in the single branch-page:+ *      pageroom = pagesize - page_hdr_len;+ *      branch.maxnode = even_floor(pageroom / 3 - sizeof(indx_t));+ *      branch.maxkey = branch.maxnode - node_hdr_len;+ *+ *  - Leaf-node of non-dupsort database must fit into one leaf-page,+ *    where a value could be placed on a large/overflow page:+ *      leaf.maxnode = even_floor(pageroom - sizeof(indx_t));+ *      leaf.maxkey = leaf.maxnode - node_hdr_len - sizeof(pgno_t);+ *+ *  - SubDatabase-node must fit into one leaf-page:+ *      subdb.maxname = leaf.maxnode - node_hdr_len - sizeof(MDBX_db);+ *+ *  - Dupsort values itself are a keys in a dupsort-subdb and couldn't be+ *    longer than the branch.maxkey. But dupsort node must fit into one+ *    leaf-page, since dupsort value couldn't be placed on a large/overflow+ *    page.+ *+ * - So, the simplest solution is to use half of branch.maxkey as+ *   a common maxkey value. Nevertheless, the actual values of maxkey are:+ *     nondupsort.maxkey = even_floor(pageroom / 3)+ *                           - sizeof(indx_t) - node_hdr_len;+ *     dupsort.maxkey(value) = min(nondupsort.maxkey,+ *                                 leaf.maxnode - even_ceil(length(value)));+ */++#define PAGEROOM(pagesize) ((pagesize)-PAGEHDRSZ)+#define EVEN_FLOOR(n) ((n) & ~(size_t)1)+#define BRANCH_NODEMAX(pagesize)                                               \+  (EVEN_FLOOR(PAGEROOM(pagesize) / (MDBX_MINKEYS * 2 - 1)) - sizeof(indx_t))+#define LEAF_NODEMAX(pagesize) (PAGEROOM(pagesize) - sizeof(indx_t))+#define MAX_GC1OVPAGE(pagesize) (PAGEROOM(pagesize) / sizeof(pgno_t) - 1)++__cold int mdbx_env_get_maxkeysize(const MDBX_env *env) {+  return mdbx_env_get_maxkeysize_ex(env, MDBX_DUPSORT);+}++__cold int mdbx_env_get_maxkeysize_ex(const MDBX_env *env,+                                      MDBX_db_flags_t flags) {+  if (unlikely(!env || env->me_signature.weak != MDBX_ME_SIGNATURE))+    return -1;++  return (int)mdbx_limits_keysize_max((intptr_t)env->me_psize, flags);+}++size_t mdbx_default_pagesize(void) {+  size_t pagesize = mdbx_syspagesize();+  mdbx_ensure(nullptr, is_powerof2(pagesize));+  pagesize = (pagesize >= MIN_PAGESIZE) ? pagesize : MIN_PAGESIZE;+  pagesize = (pagesize <= MAX_PAGESIZE) ? pagesize : MAX_PAGESIZE;+  return pagesize;+}++__cold intptr_t mdbx_limits_keysize_max(intptr_t pagesize,+                                        MDBX_db_flags_t flags) {+  if (pagesize < 1)+    pagesize = (intptr_t)mdbx_default_pagesize();+  if (unlikely(pagesize < (intptr_t)MIN_PAGESIZE ||+               pagesize > (intptr_t)MAX_PAGESIZE ||+               !is_powerof2((size_t)pagesize)))+    return -1;++  STATIC_ASSERT(BRANCH_NODEMAX(MIN_PAGESIZE) - NODESIZE - sizeof(pgno_t) >= 8);+  STATIC_ASSERT(LEAF_NODEMAX(MIN_PAGESIZE) - NODESIZE - sizeof(pgno_t) >= 8);+  STATIC_ASSERT(LEAF_NODEMAX(MIN_PAGESIZE) - NODESIZE >= sizeof(MDBX_db));+  if (flags & MDBX_INTEGERKEY)+    return 8 /* sizeof(uint64_t) */;++  STATIC_ASSERT(BRANCH_NODEMAX(MAX_PAGESIZE) - NODESIZE - sizeof(pgno_t) <+                LEAF_NODEMAX(MAX_PAGESIZE) - NODESIZE - sizeof(MDBX_db));+  STATIC_ASSERT(BRANCH_NODEMAX(MIN_PAGESIZE) - NODESIZE - sizeof(pgno_t) <+                LEAF_NODEMAX(MIN_PAGESIZE) - NODESIZE - sizeof(MDBX_db));+  if (flags &+      (MDBX_DUPSORT | MDBX_DUPFIXED | MDBX_INTEGERDUP | MDBX_REVERSEDUP))+    return BRANCH_NODEMAX(pagesize) - NODESIZE - sizeof(MDBX_db);++  return BRANCH_NODEMAX(pagesize) - NODESIZE - sizeof(pgno_t);+}++__cold int mdbx_env_get_maxvalsize_ex(const MDBX_env *env,+                                      MDBX_db_flags_t flags) {+  if (unlikely(!env || env->me_signature.weak != MDBX_ME_SIGNATURE))+    return -1;++  return (int)mdbx_limits_valsize_max((intptr_t)env->me_psize, flags);+}++__cold intptr_t mdbx_limits_valsize_max(intptr_t pagesize,+                                        MDBX_db_flags_t flags) {+  if (pagesize < 1)+    pagesize = (intptr_t)mdbx_default_pagesize();+  if (unlikely(pagesize < (intptr_t)MIN_PAGESIZE ||+               pagesize > (intptr_t)MAX_PAGESIZE ||+               !is_powerof2((size_t)pagesize)))+    return -1;++  if (flags & MDBX_INTEGERDUP)+    return 8 /* sizeof(uint64_t) */;++  if (flags & (MDBX_DUPSORT | MDBX_DUPFIXED | MDBX_REVERSEDUP))+    return BRANCH_NODEMAX(pagesize) - NODESIZE;++  const unsigned page_ln2 = log2n(pagesize);+  const size_t hard = 0x7FF00000ul;+  const size_t hard_pages = hard >> page_ln2;+  STATIC_ASSERT(MDBX_PGL_LIMIT <= MAX_PAGENO);+  const size_t pages_limit = MDBX_PGL_LIMIT / 4;+  const size_t limit =+      (hard_pages < pages_limit) ? hard : (pages_limit << page_ln2);+  return (limit < MAX_MAPSIZE / 2) ? limit : MAX_MAPSIZE / 2;+}++/* Calculate the size of a leaf node.+ *+ * The size depends on the environment's page size; if a data item+ * is too large it will be put onto an overflow page and the node+ * size will only include the key and not the data. Sizes are always+ * rounded up to an even number of bytes, to guarantee 2-byte alignment+ * of the MDBX_node headers. */+MDBX_NOTHROW_PURE_FUNCTION static __always_inline size_t+leaf_size(const MDBX_env *env, const MDBX_val *key, const MDBX_val *data) {+  size_t node_bytes = node_size(key, data);+  /* NOTE: The actual limit is LEAF_NODEMAX(env->me_psize), but it reasonable to+   * use env->me_branch_nodemax (which is 3 times less) as the threshold+   * because:+   *  - Large threshold implies that any insertion/update could result split+   *    a single leaf page to THREE, which requires TWO insertion into parent+   *    branch page, then could leads to split parent page and so on up to+   *    the root. Such double-splitting is complex, ie costly (in case simple+   *    clear implementation) either dangerous (in case high-optimized+   *    implementation).+   *  - This does not affect capabilities, i.e. it does not limit the maximum+   *    key size.+   *  - At a lower threshold, on average, the density of keys on leaf pages+   *    increases and the height of the tree decreases. Thus, this lead the+   *    less number of pages participating in the search, and the search+   *    speed increases.+   *  - On the other hand, there is no universal gold ratio here and with a+   *    smaller threshold, we will create more overflows/large pages,+   *    i.e. the database size will be larger as will the IOPS volume.+   *+   * So, the lower threshold is not a silver bullet, but it allow implementation+   * to be much simple and robust, without adding a flaws. */+  if (node_bytes > env->me_branch_nodemax) {+    /* put on overflow page */+    node_bytes = node_size(key, nullptr) + sizeof(pgno_t);+  }++  return node_bytes + sizeof(indx_t);+}++/* Calculate the size of a branch node.+ *+ * The size should depend on the environment's page size but since+ * we currently don't support spilling large keys onto overflow+ * pages, it's simply the size of the MDBX_node header plus the+ * size of the key. Sizes are always rounded up to an even number+ * of bytes, to guarantee 2-byte alignment of the MDBX_node headers.+ *+ * [in] env The environment handle.+ * [in] key The key for the node.+ *+ * Returns The number of bytes needed to store the node. */+MDBX_NOTHROW_PURE_FUNCTION static __always_inline size_t+branch_size(const MDBX_env *env, const MDBX_val *key) {+  /* Size of a node in a branch page with a given key.+   * This is just the node header plus the key, there is no data. */+  size_t node_bytes = node_size(key, nullptr);+  if (unlikely(node_bytes > env->me_branch_nodemax)) {+    /* put on overflow page */+    /* not implemented */+    mdbx_assert_fail(env, "INDXSIZE(key) <= env->me_nodemax", __func__,+                     __LINE__);+    node_bytes = node_size(key, nullptr) + sizeof(pgno_t);+  }++  return node_bytes + sizeof(indx_t);+}++MDBX_NOTHROW_CONST_FUNCTION static __always_inline uint16_t+flags_db2sub(uint16_t db_flags) {+  uint16_t sub_flags = db_flags & MDBX_DUPFIXED;++  /* MDBX_INTEGERDUP => MDBX_INTEGERKEY */+#define SHIFT_INTEGERDUP_TO_INTEGERKEY 2+  STATIC_ASSERT((MDBX_INTEGERDUP >> SHIFT_INTEGERDUP_TO_INTEGERKEY) ==+                MDBX_INTEGERKEY);+  sub_flags |= (db_flags & MDBX_INTEGERDUP) >> SHIFT_INTEGERDUP_TO_INTEGERKEY;++  /* MDBX_REVERSEDUP => MDBX_REVERSEKEY */+#define SHIFT_REVERSEDUP_TO_REVERSEKEY 5+  STATIC_ASSERT((MDBX_REVERSEDUP >> SHIFT_REVERSEDUP_TO_REVERSEKEY) ==+                MDBX_REVERSEKEY);+  sub_flags |= (db_flags & MDBX_REVERSEDUP) >> SHIFT_REVERSEDUP_TO_REVERSEKEY;++  return sub_flags;+}++/*----------------------------------------------------------------------------*/++MDBX_NOTHROW_PURE_FUNCTION static __always_inline size_t+pgno2bytes(const MDBX_env *env, pgno_t pgno) {+  mdbx_assert(env, (1u << env->me_psize2log) == env->me_psize);+  return ((size_t)pgno) << env->me_psize2log;+}++MDBX_NOTHROW_PURE_FUNCTION static __always_inline MDBX_page *+pgno2page(const MDBX_env *env, pgno_t pgno) {+  return (MDBX_page *)(env->me_map + pgno2bytes(env, pgno));+}++MDBX_NOTHROW_PURE_FUNCTION static __always_inline pgno_t+bytes2pgno(const MDBX_env *env, size_t bytes) {+  mdbx_assert(env, (env->me_psize >> env->me_psize2log) == 1);+  return (pgno_t)(bytes >> env->me_psize2log);+}++MDBX_NOTHROW_PURE_FUNCTION static size_t+pgno_align2os_bytes(const MDBX_env *env, pgno_t pgno) {+  return ceil_powerof2(pgno2bytes(env, pgno), env->me_os_psize);+}++MDBX_NOTHROW_PURE_FUNCTION static pgno_t pgno_align2os_pgno(const MDBX_env *env,+                                                            pgno_t pgno) {+  return bytes2pgno(env, pgno_align2os_bytes(env, pgno));+}++MDBX_NOTHROW_PURE_FUNCTION static size_t+bytes_align2os_bytes(const MDBX_env *env, size_t bytes) {+  return ceil_powerof2(ceil_powerof2(bytes, env->me_psize), env->me_os_psize);+}++/* Address of first usable data byte in a page, after the header */+MDBX_NOTHROW_PURE_FUNCTION static __always_inline void *+page_data(const MDBX_page *mp) {+  return (char *)mp + PAGEHDRSZ;+}++MDBX_NOTHROW_PURE_FUNCTION static __always_inline const MDBX_page *+data_page(const void *data) {+  return container_of(data, MDBX_page, mp_ptrs);+}++MDBX_NOTHROW_PURE_FUNCTION static __always_inline MDBX_meta *+page_meta(MDBX_page *mp) {+  return (MDBX_meta *)page_data(mp);+}++/* Number of nodes on a page */+MDBX_NOTHROW_PURE_FUNCTION static __always_inline unsigned+page_numkeys(const MDBX_page *mp) {+  return mp->mp_lower >> 1;+}++/* The amount of space remaining in the page */+MDBX_NOTHROW_PURE_FUNCTION static __always_inline unsigned+page_room(const MDBX_page *mp) {+  return mp->mp_upper - mp->mp_lower;+}++MDBX_NOTHROW_PURE_FUNCTION static __always_inline unsigned+page_space(const MDBX_env *env) {+  STATIC_ASSERT(PAGEHDRSZ % 2 == 0);+  return env->me_psize - PAGEHDRSZ;+}++MDBX_NOTHROW_PURE_FUNCTION static __always_inline unsigned+page_used(const MDBX_env *env, const MDBX_page *mp) {+  return page_space(env) - page_room(mp);+}++/* The percentage of space used in the page, in a percents. */+MDBX_NOTHROW_PURE_FUNCTION static __maybe_unused __inline double+page_fill(const MDBX_env *env, const MDBX_page *mp) {+  return page_used(env, mp) * 100.0 / page_space(env);+}++/* The number of overflow pages needed to store the given size. */+MDBX_NOTHROW_PURE_FUNCTION static __always_inline pgno_t+number_of_ovpages(const MDBX_env *env, size_t bytes) {+  return bytes2pgno(env, PAGEHDRSZ - 1 + bytes) + 1;+}++__cold static int MDBX_PRINTF_ARGS(2, 3)+    bad_page(const MDBX_page *mp, const char *fmt, ...) {+  if (mdbx_log_enabled(MDBX_LOG_ERROR)) {+    static const MDBX_page *prev;+    if (prev != mp) {+      prev = mp;+      mdbx_debug_log(MDBX_LOG_ERROR, "badpage", 0,+                     "corrupted page #%u, mod-txnid %" PRIaTXN "\n",+                     mp->mp_pgno, mp->mp_txnid);+    }++    va_list args;+    va_start(args, fmt);+    mdbx_debug_log_va(MDBX_LOG_ERROR, "badpage", 0, fmt, args);+    va_end(args);+  }+  return MDBX_CORRUPTED;+}++/* Address of node i in page p */+MDBX_NOTHROW_PURE_FUNCTION static __always_inline MDBX_node *+page_node(const MDBX_page *mp, unsigned i) {+  assert((mp->mp_flags & (P_LEAF2 | P_OVERFLOW | P_META)) == 0);+  assert(page_numkeys(mp) > (unsigned)(i));+  assert(mp->mp_ptrs[i] % 2 == 0);+  return (MDBX_node *)((char *)mp + mp->mp_ptrs[i] + PAGEHDRSZ);+}++/* The address of a key in a LEAF2 page.+ * LEAF2 pages are used for MDBX_DUPFIXED sorted-duplicate sub-DBs.+ * There are no node headers, keys are stored contiguously. */+MDBX_NOTHROW_PURE_FUNCTION static __always_inline void *+page_leaf2key(const MDBX_page *mp, unsigned i, size_t keysize) {+  assert((mp->mp_flags & (P_BRANCH | P_LEAF | P_LEAF2 | P_OVERFLOW | P_META)) ==+         (P_LEAF | P_LEAF2));+  assert(mp->mp_leaf2_ksize == keysize);+  (void)keysize;+  return (char *)mp + PAGEHDRSZ + (i * mp->mp_leaf2_ksize);+}++/* Set the node's key into keyptr. */+static __always_inline void get_key(const MDBX_node *node, MDBX_val *keyptr) {+  keyptr->iov_len = node_ks(node);+  keyptr->iov_base = node_key(node);+}++/* Set the node's key into keyptr, if requested. */+static __always_inline void+get_key_optional(const MDBX_node *node, MDBX_val *keyptr /* __may_null */) {+  if (keyptr)+    get_key(node, keyptr);+}++/*------------------------------------------------------------------------------+ * Workaround for mmaped-lookahead-cross-page-boundary bug+ * in an obsolete versions of Elbrus's libc and kernels. */+#if defined(__e2k__) && defined(MDBX_E2K_MLHCPB_WORKAROUND) &&                 \+    MDBX_E2K_MLHCPB_WORKAROUND+int __hot mdbx_e2k_memcmp_bug_workaround(const void *s1, const void *s2,+                                         size_t n) {+  if (unlikely(n > 42+               /* LY: align followed access if reasonable possible */+               && (((uintptr_t)s1) & 7) != 0 &&+               (((uintptr_t)s1) & 7) == (((uintptr_t)s2) & 7))) {+    if (((uintptr_t)s1) & 1) {+      const int diff = *(uint8_t *)s1 - *(uint8_t *)s2;+      if (diff)+        return diff;+      s1 = (char *)s1 + 1;+      s2 = (char *)s2 + 1;+      n -= 1;+    }++    if (((uintptr_t)s1) & 2) {+      const uint16_t a = *(uint16_t *)s1;+      const uint16_t b = *(uint16_t *)s2;+      if (likely(a != b))+        return (__builtin_bswap16(a) > __builtin_bswap16(b)) ? 1 : -1;+      s1 = (char *)s1 + 2;+      s2 = (char *)s2 + 2;+      n -= 2;+    }++    if (((uintptr_t)s1) & 4) {+      const uint32_t a = *(uint32_t *)s1;+      const uint32_t b = *(uint32_t *)s2;+      if (likely(a != b))+        return (__builtin_bswap32(a) > __builtin_bswap32(b)) ? 1 : -1;+      s1 = (char *)s1 + 4;+      s2 = (char *)s2 + 4;+      n -= 4;+    }+  }++  while (n >= 8) {+    const uint64_t a = *(uint64_t *)s1;+    const uint64_t b = *(uint64_t *)s2;+    if (likely(a != b))+      return (__builtin_bswap64(a) > __builtin_bswap64(b)) ? 1 : -1;+    s1 = (char *)s1 + 8;+    s2 = (char *)s2 + 8;+    n -= 8;+  }++  if (n & 4) {+    const uint32_t a = *(uint32_t *)s1;+    const uint32_t b = *(uint32_t *)s2;+    if (likely(a != b))+      return (__builtin_bswap32(a) > __builtin_bswap32(b)) ? 1 : -1;+    s1 = (char *)s1 + 4;+    s2 = (char *)s2 + 4;+  }++  if (n & 2) {+    const uint16_t a = *(uint16_t *)s1;+    const uint16_t b = *(uint16_t *)s2;+    if (likely(a != b))+      return (__builtin_bswap16(a) > __builtin_bswap16(b)) ? 1 : -1;+    s1 = (char *)s1 + 2;+    s2 = (char *)s2 + 2;+  }++  return (n & 1) ? *(uint8_t *)s1 - *(uint8_t *)s2 : 0;+}++int __hot mdbx_e2k_strcmp_bug_workaround(const char *s1, const char *s2) {+  while (true) {+    int diff = *(uint8_t *)s1 - *(uint8_t *)s2;+    if (likely(diff != 0) || *s1 == '\0')+      return diff;+    s1 += 1;+    s2 += 1;+  }+}++int __hot mdbx_e2k_strncmp_bug_workaround(const char *s1, const char *s2,+                                          size_t n) {+  while (n > 0) {+    int diff = *(uint8_t *)s1 - *(uint8_t *)s2;+    if (likely(diff != 0) || *s1 == '\0')+      return diff;+    s1 += 1;+    s2 += 1;+    n -= 1;+  }+  return 0;+}++size_t __hot mdbx_e2k_strlen_bug_workaround(const char *s) {+  size_t n = 0;+  while (*s) {+    s += 1;+    n += 1;+  }+  return n;+}++size_t __hot mdbx_e2k_strnlen_bug_workaround(const char *s, size_t maxlen) {+  size_t n = 0;+  while (maxlen > n && *s) {+    s += 1;+    n += 1;+  }+  return n;+}+#endif /* MDBX_E2K_MLHCPB_WORKAROUND */++/*------------------------------------------------------------------------------+ * safe read/write volatile 64-bit fields on 32-bit architectures. */++enum MDBX_memory_order {+  mo_Relaxed,+  mo_AcquireRelease,+  mo_SequentialConsistency+};++#ifdef MDBX_HAVE_C11ATOMICS++/* Crutches for C11 atomic compiler's bugs */+#if defined(__e2k__) && defined(__LCC__) && __LCC__ < /* FIXME */ 127+#define MDBX_c11a_ro(type, ptr) (&(ptr)->weak)+#define MDBX_c11a_rw(type, ptr) (&(ptr)->weak)+#elif defined(__clang__) && __clang__ < 8+#define MDBX_c11a_ro(type, ptr) ((volatile _Atomic(type) *)&(ptr)->c11a)+#define MDBX_c11a_rw(type, ptr) (&(ptr)->c11a)+#else+#define MDBX_c11a_ro(type, ptr) (&(ptr)->c11a)+#define MDBX_c11a_rw(type, ptr) (&(ptr)->c11a)+#endif /* Crutches for C11 atomic compiler's bugs */++static __always_inline memory_order mo_c11_store(enum MDBX_memory_order fence) {+  switch (fence) {+  default:+    assert(false);+    __unreachable();+  case mo_Relaxed:+    return memory_order_relaxed;+  case mo_AcquireRelease:+    return memory_order_release;+  case mo_SequentialConsistency:+    return memory_order_seq_cst;+  }+}++static __always_inline memory_order mo_c11_load(enum MDBX_memory_order fence) {+  switch (fence) {+  default:+    assert(false);+    __unreachable();+  case mo_Relaxed:+    return memory_order_relaxed;+  case mo_AcquireRelease:+    return memory_order_acquire;+  case mo_SequentialConsistency:+    return memory_order_seq_cst;+  }+}+#endif /* MDBX_HAVE_C11ATOMICS */++static __maybe_unused __always_inline void+mdbx_memory_fence(enum MDBX_memory_order order, bool write) {+#ifdef MDBX_HAVE_C11ATOMICS+  atomic_thread_fence(write ? mo_c11_store(order) : mo_c11_load(order));+#else  /* MDBX_HAVE_C11ATOMICS */+  mdbx_compiler_barrier();+  if (write &&+      order > (MDBX_CPU_WRITEBACK_INCOHERENT ? mo_Relaxed : mo_AcquireRelease))+    mdbx_memory_barrier();+#endif /* MDBX_HAVE_C11ATOMICS */+}++static __maybe_unused __always_inline uint32_t+atomic_store32(MDBX_atomic_uint32_t *p, const uint32_t value,+               enum MDBX_memory_order order) {+  STATIC_ASSERT(sizeof(MDBX_atomic_uint32_t) == 4);+#ifdef MDBX_HAVE_C11ATOMICS+  assert(atomic_is_lock_free(MDBX_c11a_rw(uint32_t, p)));+  atomic_store_explicit(MDBX_c11a_rw(uint32_t, p), value, mo_c11_store(order));+#else  /* MDBX_HAVE_C11ATOMICS */+  if (order != mo_Relaxed)+    mdbx_compiler_barrier();+  p->weak = value;+  mdbx_memory_fence(order, true);+#endif /* MDBX_HAVE_C11ATOMICS */+  return value;+}++static __maybe_unused __always_inline uint32_t+atomic_load32(const MDBX_atomic_uint32_t *p, enum MDBX_memory_order order) {+  STATIC_ASSERT(sizeof(MDBX_atomic_uint32_t) == 4);+#ifdef MDBX_HAVE_C11ATOMICS+  assert(atomic_is_lock_free(MDBX_c11a_ro(uint32_t, p)));+  return atomic_load_explicit(MDBX_c11a_ro(uint32_t, p), mo_c11_load(order));+#else  /* MDBX_HAVE_C11ATOMICS */+  mdbx_memory_fence(order, false);+  const uint32_t value = p->weak;+  if (order != mo_Relaxed)+    mdbx_compiler_barrier();+  return value;+#endif /* MDBX_HAVE_C11ATOMICS */+}++static __always_inline uint64_t atomic_store64(MDBX_atomic_uint64_t *p,+                                               const uint64_t value,+                                               enum MDBX_memory_order order) {+  STATIC_ASSERT(sizeof(MDBX_atomic_uint64_t) == 8);+#if MDBX_64BIT_ATOMIC+#ifdef MDBX_HAVE_C11ATOMICS+  assert(atomic_is_lock_free(MDBX_c11a_rw(uint64_t, p)));+  atomic_store_explicit(MDBX_c11a_rw(uint64_t, p), value, mo_c11_store(order));+#else  /* MDBX_HAVE_C11ATOMICS */+  if (order != mo_Relaxed)+    mdbx_compiler_barrier();+  p->weak = value;+  mdbx_memory_fence(order, true);+#endif /* MDBX_HAVE_C11ATOMICS */+#else  /* !MDBX_64BIT_ATOMIC */+  mdbx_compiler_barrier();+  atomic_store32(&p->low, (uint32_t)value, mo_Relaxed);+  mdbx_jitter4testing(true);+  atomic_store32(&p->high, (uint32_t)(value >> 32), order);+  mdbx_jitter4testing(true);+#endif /* !MDBX_64BIT_ATOMIC */+  return value;+}++static __always_inline uint64_t atomic_load64(const MDBX_atomic_uint64_t *p,+                                              enum MDBX_memory_order order) {+  STATIC_ASSERT(sizeof(MDBX_atomic_uint64_t) == 8);+#if MDBX_64BIT_ATOMIC+#ifdef MDBX_HAVE_C11ATOMICS+  assert(atomic_is_lock_free(MDBX_c11a_ro(uint64_t, p)));+  return atomic_load_explicit(MDBX_c11a_ro(uint64_t, p), mo_c11_load(order));+#else  /* MDBX_HAVE_C11ATOMICS */+  mdbx_memory_fence(order, false);+  const uint64_t value = p->weak;+  if (order != mo_Relaxed)+    mdbx_compiler_barrier();+  return value;+#endif /* MDBX_HAVE_C11ATOMICS */+#else  /* !MDBX_64BIT_ATOMIC */+  mdbx_compiler_barrier();+  uint64_t value = (uint64_t)atomic_load32(&p->high, order) << 32;+  mdbx_jitter4testing(true);+  value |= atomic_load32(&p->low, (order == mo_Relaxed) ? mo_Relaxed+                                                        : mo_AcquireRelease);+  mdbx_jitter4testing(true);+  for (;;) {+    mdbx_compiler_barrier();+    uint64_t again = (uint64_t)atomic_load32(&p->high, order) << 32;+    mdbx_jitter4testing(true);+    again |= atomic_load32(&p->low, (order == mo_Relaxed) ? mo_Relaxed+                                                          : mo_AcquireRelease);+    mdbx_jitter4testing(true);+    if (likely(value == again))+      return value;+    value = again;+  }+#endif /* !MDBX_64BIT_ATOMIC */+}++static __always_inline void atomic_yield(void) {+#if defined(_WIN32) || defined(_WIN64)+  YieldProcessor();+#elif defined(__ia32__) || defined(__e2k__)+  __builtin_ia32_pause();+#elif defined(__ia64__)+#if defined(__HP_cc__) || defined(__HP_aCC__)+  _Asm_hint(_HINT_PAUSE);+#else+  __asm__ __volatile__("hint @pause");+#endif+#elif defined(__aarch64__) || (defined(__ARM_ARCH) && __ARM_ARCH > 6) ||       \+    defined(__ARM_ARCH_6K__)+#ifdef __CC_ARM+  __yield();+#else+  __asm__ __volatile__("yield");+#endif+#elif (defined(__mips64) || defined(__mips64__)) && defined(__mips_isa_rev) && \+    __mips_isa_rev >= 2+  __asm__ __volatile__("pause");+#elif defined(__mips) || defined(__mips__) || defined(__mips64) ||             \+    defined(__mips64__) || defined(_M_MRX000) || defined(_MIPS_) ||            \+    defined(__MWERKS__) || defined(__sgi)+  __asm__ __volatile__(".word 0x00000140");+#elif defined(__linux__) || defined(__gnu_linux__) || defined(_UNIX03_SOURCE)+  sched_yield();+#elif (defined(_GNU_SOURCE) && __GLIBC_PREREQ(2, 1)) || defined(_OPEN_THREADS)+  pthread_yield();+#endif+}++#if MDBX_64BIT_CAS+static __always_inline bool atomic_cas64(MDBX_atomic_uint64_t *p, uint64_t c,+                                         uint64_t v) {+#ifdef MDBX_HAVE_C11ATOMICS+  STATIC_ASSERT(sizeof(long long) >= sizeof(uint64_t));+#ifdef ATOMIC_LLONG_LOCK_FREE+  STATIC_ASSERT(ATOMIC_LLONG_LOCK_FREE > 0);+#if ATOMIC_LLONG_LOCK_FREE < 2+  assert(atomic_is_lock_free(MDBX_c11a_rw(uint64_t, p)));+#endif /* ATOMIC_LLONG_LOCK_FREE < 2 */+#else  /* defined(ATOMIC_LLONG_LOCK_FREE) */+  assert(atomic_is_lock_free(MDBX_c11a_rw(uint64_t, p)));+#endif+  return atomic_compare_exchange_strong(MDBX_c11a_rw(uint64_t, p), &c, v);+#elif defined(__GNUC__) || defined(__clang__)+  return __sync_bool_compare_and_swap(&p->weak, c, v);+#elif defined(_MSC_VER)+  return c == (uint64_t)_InterlockedCompareExchange64(+                  (volatile __int64 *)&p->weak, v, c);+#elif defined(__APPLE__)+  return OSAtomicCompareAndSwap64Barrier(c, v, &p->weak);+#else+#error FIXME: Unsupported compiler+#endif+}+#endif /* MDBX_64BIT_CAS */++static __always_inline bool atomic_cas32(MDBX_atomic_uint32_t *p, uint32_t c,+                                         uint32_t v) {+#ifdef MDBX_HAVE_C11ATOMICS+  STATIC_ASSERT(sizeof(int) >= sizeof(uint32_t));+#ifdef ATOMIC_INT_LOCK_FREE+  STATIC_ASSERT(ATOMIC_INT_LOCK_FREE > 0);+#if ATOMIC_INT_LOCK_FREE < 2+  assert(atomic_is_lock_free(MDBX_c11a_rw(uint32_t, p)));+#endif+#else+  assert(atomic_is_lock_free(MDBX_c11a_rw(uint32_t, p)));+#endif+  return atomic_compare_exchange_strong(MDBX_c11a_rw(uint32_t, p), &c, v);+#elif defined(__GNUC__) || defined(__clang__)+  return __sync_bool_compare_and_swap(&p->weak, c, v);+#elif defined(_MSC_VER)+  STATIC_ASSERT(sizeof(volatile long) == sizeof(volatile uint32_t));+  return c ==+         (uint32_t)_InterlockedCompareExchange((volatile long *)&p->weak, v, c);+#elif defined(__APPLE__)+  return OSAtomicCompareAndSwap32Barrier(c, v, &p->weak);+#else+#error FIXME: Unsupported compiler+#endif+}++static __always_inline uint32_t atomic_add32(MDBX_atomic_uint32_t *p,+                                             uint32_t v) {+#ifdef MDBX_HAVE_C11ATOMICS+  STATIC_ASSERT(sizeof(int) >= sizeof(uint32_t));+#ifdef ATOMIC_INT_LOCK_FREE+  STATIC_ASSERT(ATOMIC_INT_LOCK_FREE > 0);+#if ATOMIC_INT_LOCK_FREE < 2+  assert(atomic_is_lock_free(MDBX_c11a_rw(uint32_t, p)));+#endif+#else+  assert(atomic_is_lock_free(MDBX_c11a_rw(uint32_t, p)));+#endif+  return atomic_fetch_add(MDBX_c11a_rw(uint32_t, p), v);+#elif defined(__GNUC__) || defined(__clang__)+  return __sync_fetch_and_add(&p->weak, v);+#elif defined(_MSC_VER)+  STATIC_ASSERT(sizeof(volatile long) == sizeof(volatile uint32_t));+  return (uint32_t)_InterlockedExchangeAdd((volatile long *)&p->weak, v);+#elif defined(__APPLE__)+  return OSAtomicAdd32Barrier(v, &p->weak);+#else+#error FIXME: Unsupported compiler+#endif+}++#define atomic_sub32(p, v) atomic_add32(p, 0 - (v))++static __always_inline uint64_t safe64_txnid_next(uint64_t txnid) {+  txnid += MDBX_TXNID_STEP;+#if !MDBX_64BIT_CAS+  /* avoid overflow of low-part in safe64_reset() */+  txnid += (UINT32_MAX == (uint32_t)txnid);+#endif+  return txnid;+}++static __always_inline void safe64_reset(MDBX_atomic_uint64_t *p,+                                         bool single_writer) {+#if !MDBX_64BIT_CAS+  if (!single_writer) {+    STATIC_ASSERT(MDBX_TXNID_STEP > 1);+    /* it is safe to increment low-part to avoid ABA, since MDBX_TXNID_STEP > 1+     * and overflow was preserved in safe64_txnid_next() */+    atomic_add32(&p->low, 1) /* avoid ABA in safe64_reset_compare() */;+    atomic_store32(+        &p->high, UINT32_MAX,+        mo_Relaxed) /* atomically make >= SAFE64_INVALID_THRESHOLD */;+    atomic_add32(&p->low, 1) /* avoid ABA in safe64_reset_compare() */;+  } else+#elif MDBX_64BIT_ATOMIC+  /* atomically make value >= SAFE64_INVALID_THRESHOLD by 64-bit operation */+  atomic_store64(p, UINT64_MAX,+                 single_writer ? mo_AcquireRelease : mo_SequentialConsistency);+#else+  /* atomically make value >= SAFE64_INVALID_THRESHOLD by 32-bit operation */+  atomic_store32(&p->high, UINT32_MAX,+                 single_writer ? mo_AcquireRelease : mo_SequentialConsistency);+#endif /* MDBX_64BIT_ATOMIC */+    assert(p->weak >= SAFE64_INVALID_THRESHOLD);+  mdbx_jitter4testing(true);+}++static __always_inline bool safe64_reset_compare(MDBX_atomic_uint64_t *p,+                                                 txnid_t compare) {+  /* LY: This function is used to reset `mr_txnid` from hsr-handler in case+   *     the asynchronously cancellation of read transaction. Therefore,+   *     there may be a collision between the cleanup performed here and+   *     asynchronous termination and restarting of the read transaction+   *     in another proces/thread. In general we MUST NOT reset the `mr_txnid`+   *     if a new transaction was started (i.e. if `mr_txnid` was changed). */+#if MDBX_64BIT_CAS+  bool rc = atomic_cas64(p, compare, UINT64_MAX);+#else+  /* LY: There is no gold ratio here since shared mutex is too costly,+   *     in such way we must acquire/release it for every update of mr_txnid,+   *     i.e. twice for each read transaction). */+  bool rc = false;+  if (likely(atomic_load32(&p->low, mo_AcquireRelease) == (uint32_t)compare &&+             atomic_cas32(&p->high, (uint32_t)(compare >> 32), UINT32_MAX))) {+    if (unlikely(atomic_load32(&p->low, mo_AcquireRelease) !=+                 (uint32_t)compare))+      atomic_cas32(&p->high, UINT32_MAX, (uint32_t)(compare >> 32));+    else+      rc = true;+  }+#endif /* MDBX_64BIT_CAS */+  mdbx_jitter4testing(true);+  return rc;+}++static __always_inline void safe64_write(MDBX_atomic_uint64_t *p,+                                         const uint64_t v) {+  assert(p->weak >= SAFE64_INVALID_THRESHOLD);+#if MDBX_64BIT_ATOMIC+  atomic_store64(p, v, mo_AcquireRelease);+#else  /* MDBX_64BIT_ATOMIC */+  mdbx_compiler_barrier();+  /* update low-part but still value >= SAFE64_INVALID_THRESHOLD */+  atomic_store32(&p->low, (uint32_t)v, mo_Relaxed);+  assert(p->weak >= SAFE64_INVALID_THRESHOLD);+  mdbx_jitter4testing(true);+  /* update high-part from SAFE64_INVALID_THRESHOLD to actual value */+  atomic_store32(&p->high, (uint32_t)(v >> 32), mo_AcquireRelease);+#endif /* MDBX_64BIT_ATOMIC */+  assert(p->weak == v);+  mdbx_jitter4testing(true);+}++static __always_inline uint64_t safe64_read(const MDBX_atomic_uint64_t *p) {+  mdbx_jitter4testing(true);+  uint64_t v = atomic_load64(p, mo_AcquireRelease);+  mdbx_jitter4testing(true);+  return v;+}++#if 0 /* unused for now */+ static __maybe_unused __always_inline bool safe64_is_valid(uint64_t v) {+#if MDBX_WORDBITS >= 64+  return v < SAFE64_INVALID_THRESHOLD;+#else+  return (v >> 32) != UINT32_MAX;+#endif /* MDBX_WORDBITS */+}++ static __maybe_unused __always_inline bool+ safe64_is_valid_ptr(const MDBX_atomic_uint64_t *p) {+#if MDBX_64BIT_ATOMIC+  return atomic_load64(p, mo_AcquireRelease) < SAFE64_INVALID_THRESHOLD;+#else+  return atomic_load32(&p->high, mo_AcquireRelease) != UINT32_MAX;+#endif /* MDBX_64BIT_ATOMIC */+}++static __always_inline void safe64_update(MDBX_atomic_uint64_t *p,+                                          const uint64_t v) {+#if MDBX_64BIT_ATOMIC+  safe64_reset(p, true);+#endif /* MDBX_64BIT_ATOMIC */+  safe64_write(p, v);+}+#endif /* unused for now */++/*----------------------------------------------------------------------------*/+/* rthc (tls keys and destructors) */++typedef struct rthc_entry_t {+  MDBX_reader *begin;+  MDBX_reader *end;+  mdbx_thread_key_t thr_tls_key;+  bool key_valid;+} rthc_entry_t;++#if MDBX_DEBUG+#define RTHC_INITIAL_LIMIT 1+#else+#define RTHC_INITIAL_LIMIT 16+#endif++static bin128_t bootid;++#if defined(_WIN32) || defined(_WIN64)+static CRITICAL_SECTION rthc_critical_section;+static CRITICAL_SECTION lcklist_critical_section;+#else+int __cxa_thread_atexit_impl(void (*dtor)(void *), void *obj, void *dso_symbol)+    __attribute__((__weak__));+#ifdef __APPLE__ /* FIXME: Thread-Local Storage destructors & DSO-unloading */+int __cxa_thread_atexit_impl(void (*dtor)(void *), void *obj,+                             void *dso_symbol) {+  (void)dtor;+  (void)obj;+  (void)dso_symbol;+  return -1;+}+#endif           /* __APPLE__ */++static pthread_mutex_t lcklist_mutex = PTHREAD_MUTEX_INITIALIZER;+static pthread_mutex_t rthc_mutex = PTHREAD_MUTEX_INITIALIZER;+static pthread_cond_t rthc_cond = PTHREAD_COND_INITIALIZER;+static mdbx_thread_key_t rthc_key;+static MDBX_atomic_uint32_t rthc_pending;++static void __cold workaround_glibc_bug21031(void) {+  /* Workaround for https://sourceware.org/bugzilla/show_bug.cgi?id=21031+   *+   * Due race between pthread_key_delete() and __nptl_deallocate_tsd()+   * The destructor(s) of thread-local-storage object(s) may be running+   * in another thread(s) and be blocked or not finished yet.+   * In such case we get a SEGFAULT after unload this library DSO.+   *+   * So just by yielding a few timeslices we give a chance+   * to such destructor(s) for completion and avoids segfault. */+  sched_yield();+  sched_yield();+  sched_yield();+}+#endif++static unsigned rthc_count, rthc_limit;+static rthc_entry_t *rthc_table;+static rthc_entry_t rthc_table_static[RTHC_INITIAL_LIMIT];++static __inline void rthc_lock(void) {+#if defined(_WIN32) || defined(_WIN64)+  EnterCriticalSection(&rthc_critical_section);+#else+  mdbx_ensure(nullptr, pthread_mutex_lock(&rthc_mutex) == 0);+#endif+}++static __inline void rthc_unlock(void) {+#if defined(_WIN32) || defined(_WIN64)+  LeaveCriticalSection(&rthc_critical_section);+#else+  mdbx_ensure(nullptr, pthread_mutex_unlock(&rthc_mutex) == 0);+#endif+}++static __inline int thread_key_create(mdbx_thread_key_t *key) {+  int rc;+#if defined(_WIN32) || defined(_WIN64)+  *key = TlsAlloc();+  rc = (*key != TLS_OUT_OF_INDEXES) ? MDBX_SUCCESS : GetLastError();+#else+  rc = pthread_key_create(key, nullptr);+#endif+  mdbx_trace("&key = %p, value %" PRIuPTR ", rc %d",+             __Wpedantic_format_voidptr(key), (uintptr_t)*key, rc);+  return rc;+}++static __inline void thread_key_delete(mdbx_thread_key_t key) {+  mdbx_trace("key = %" PRIuPTR, (uintptr_t)key);+#if defined(_WIN32) || defined(_WIN64)+  mdbx_ensure(nullptr, TlsFree(key));+#else+  mdbx_ensure(nullptr, pthread_key_delete(key) == 0);+  workaround_glibc_bug21031();+#endif+}++static __inline void *thread_rthc_get(mdbx_thread_key_t key) {+#if defined(_WIN32) || defined(_WIN64)+  return TlsGetValue(key);+#else+  return pthread_getspecific(key);+#endif+}++static void thread_rthc_set(mdbx_thread_key_t key, const void *value) {+#if defined(_WIN32) || defined(_WIN64)+  mdbx_ensure(nullptr, TlsSetValue(key, (void *)value));+#else+#define MDBX_THREAD_RTHC_ZERO 0+#define MDBX_THREAD_RTHC_REGISTERED 1+#define MDBX_THREAD_RTHC_COUNTED 2+  static __thread uint32_t thread_registration_state;+  if (value && unlikely(thread_registration_state == MDBX_THREAD_RTHC_ZERO)) {+    thread_registration_state = MDBX_THREAD_RTHC_REGISTERED;+    mdbx_trace("thread registered 0x%" PRIxPTR, mdbx_thread_self());+    if (&__cxa_thread_atexit_impl == nullptr ||+        __cxa_thread_atexit_impl(mdbx_rthc_thread_dtor,+                                 &thread_registration_state,+                                 (void *)&mdbx_version /* dso_anchor */)) {+      mdbx_ensure(nullptr, pthread_setspecific(+                               rthc_key, &thread_registration_state) == 0);+      thread_registration_state = MDBX_THREAD_RTHC_COUNTED;+      const unsigned count_before = atomic_add32(&rthc_pending, 1);+      mdbx_ensure(nullptr, count_before < INT_MAX);+      mdbx_trace("fallback to pthreads' tsd, key %" PRIuPTR ", count %u",+                 (uintptr_t)rthc_key, count_before);+      (void)count_before;+    }+  }+  mdbx_ensure(nullptr, pthread_setspecific(key, value) == 0);+#endif+}++__cold void mdbx_rthc_global_init(void) {+  rthc_limit = RTHC_INITIAL_LIMIT;+  rthc_table = rthc_table_static;+#if defined(_WIN32) || defined(_WIN64)+  InitializeCriticalSection(&rthc_critical_section);+  InitializeCriticalSection(&lcklist_critical_section);+#else+  mdbx_ensure(nullptr,+              pthread_key_create(&rthc_key, mdbx_rthc_thread_dtor) == 0);+  mdbx_trace("pid %d, &mdbx_rthc_key = %p, value 0x%x", mdbx_getpid(),+             __Wpedantic_format_voidptr(&rthc_key), (unsigned)rthc_key);+#endif+  /* checking time conversion, this also avoids racing on 32-bit architectures+   * during writing calculated 64-bit ratio(s) into memory. */+  uint32_t proba = UINT32_MAX;+  while (true) {+    unsigned time_conversion_checkup =+        mdbx_osal_monotime_to_16dot16(mdbx_osal_16dot16_to_monotime(proba));+    unsigned one_more = (proba < UINT32_MAX) ? proba + 1 : proba;+    unsigned one_less = (proba > 0) ? proba - 1 : proba;+    mdbx_ensure(nullptr, time_conversion_checkup >= one_less &&+                             time_conversion_checkup <= one_more);+    if (proba == 0)+      break;+    proba >>= 1;+  }++  bootid = mdbx_osal_bootid();+#if 0 /* debug */+  for (unsigned i = 0; i < 65536; ++i) {+    size_t pages = pv2pages(i);+    unsigned x = pages2pv(pages);+    size_t xp = pv2pages(x);+    if (!(x == i || (x % 2 == 0 && x < 65536)) || pages != xp)+      printf("%u => %zu => %u => %zu\n", i, pages, x, xp);+    assert(pages == xp);+  }+  fflush(stdout);+#endif+}++/* dtor called for thread, i.e. for all mdbx's environment objects */+__cold void mdbx_rthc_thread_dtor(void *ptr) {+  rthc_lock();+  mdbx_trace(">> pid %d, thread 0x%" PRIxPTR ", rthc %p", mdbx_getpid(),+             mdbx_thread_self(), ptr);++  const uint32_t self_pid = mdbx_getpid();+  for (unsigned i = 0; i < rthc_count; ++i) {+    if (!rthc_table[i].key_valid)+      continue;+    const mdbx_thread_key_t key = rthc_table[i].thr_tls_key;+    MDBX_reader *const rthc = thread_rthc_get(key);+    if (rthc < rthc_table[i].begin || rthc >= rthc_table[i].end)+      continue;+#if !defined(_WIN32) && !defined(_WIN64)+    if (pthread_setspecific(key, nullptr) != 0) {+      mdbx_trace("== thread 0x%" PRIxPTR+                 ", rthc %p: ignore race with tsd-key deletion",+                 mdbx_thread_self(), ptr);+      continue /* ignore race with tsd-key deletion by mdbx_env_close() */;+    }+#endif++    mdbx_trace("== thread 0x%" PRIxPTR+               ", rthc %p, [%i], %p ... %p (%+i), rtch-pid %i, "+               "current-pid %i",+               mdbx_thread_self(), __Wpedantic_format_voidptr(rthc), i,+               __Wpedantic_format_voidptr(rthc_table[i].begin),+               __Wpedantic_format_voidptr(rthc_table[i].end),+               (int)(rthc - rthc_table[i].begin), rthc->mr_pid.weak, self_pid);+    if (atomic_load32(&rthc->mr_pid, mo_Relaxed) == self_pid) {+      mdbx_trace("==== thread 0x%" PRIxPTR ", rthc %p, cleanup",+                 mdbx_thread_self(), __Wpedantic_format_voidptr(rthc));+      atomic_store32(&rthc->mr_pid, 0, mo_AcquireRelease);+    }+  }++#if defined(_WIN32) || defined(_WIN64)+  mdbx_trace("<< thread 0x%" PRIxPTR ", rthc %p", mdbx_thread_self(), ptr);+  rthc_unlock();+#else+  const char self_registration = *(char *)ptr;+  *(char *)ptr = MDBX_THREAD_RTHC_ZERO;+  mdbx_trace("== thread 0x%" PRIxPTR ", rthc %p, pid %d, self-status %d",+             mdbx_thread_self(), ptr, mdbx_getpid(), self_registration);+  if (self_registration == MDBX_THREAD_RTHC_COUNTED)+    mdbx_ensure(nullptr, atomic_sub32(&rthc_pending, 1) > 0);++  if (atomic_load32(&rthc_pending, mo_AcquireRelease) == 0) {+    mdbx_trace("== thread 0x%" PRIxPTR ", rthc %p, pid %d, wake",+               mdbx_thread_self(), ptr, mdbx_getpid());+    mdbx_ensure(nullptr, pthread_cond_broadcast(&rthc_cond) == 0);+  }++  mdbx_trace("<< thread 0x%" PRIxPTR ", rthc %p", mdbx_thread_self(), ptr);+  /* Allow tail call optimization, i.e. gcc should generate the jmp instruction+   * instead of a call for pthread_mutex_unlock() and therefore CPU could not+   * return to current DSO's code section, which may be unloaded immediately+   * after the mutex got released. */+  pthread_mutex_unlock(&rthc_mutex);+#endif+}++__cold void mdbx_rthc_global_dtor(void) {+  mdbx_trace(">> pid %d", mdbx_getpid());++  rthc_lock();+#if !defined(_WIN32) && !defined(_WIN64)+  char *rthc = (char *)pthread_getspecific(rthc_key);+  mdbx_trace("== thread 0x%" PRIxPTR ", rthc %p, pid %d, self-status %d",+             mdbx_thread_self(), __Wpedantic_format_voidptr(rthc),+             mdbx_getpid(), rthc ? *rthc : -1);+  if (rthc) {+    const char self_registration = *(char *)rthc;+    *rthc = MDBX_THREAD_RTHC_ZERO;+    if (self_registration == MDBX_THREAD_RTHC_COUNTED)+      mdbx_ensure(nullptr, atomic_sub32(&rthc_pending, 1) > 0);+  }++  struct timespec abstime;+  mdbx_ensure(nullptr, clock_gettime(CLOCK_REALTIME, &abstime) == 0);+  abstime.tv_nsec += 1000000000l / 10;+  if (abstime.tv_nsec >= 1000000000l) {+    abstime.tv_nsec -= 1000000000l;+    abstime.tv_sec += 1;+  }+#if MDBX_DEBUG > 0+  abstime.tv_sec += 600;+#endif++  for (unsigned left;+       (left = atomic_load32(&rthc_pending, mo_AcquireRelease)) > 0;) {+    mdbx_trace("pid %d, pending %u, wait for...", mdbx_getpid(), left);+    const int rc = pthread_cond_timedwait(&rthc_cond, &rthc_mutex, &abstime);+    if (rc && rc != EINTR)+      break;+  }+  thread_key_delete(rthc_key);+#endif++  const uint32_t self_pid = mdbx_getpid();+  for (unsigned i = 0; i < rthc_count; ++i) {+    if (!rthc_table[i].key_valid)+      continue;+    const mdbx_thread_key_t key = rthc_table[i].thr_tls_key;+    thread_key_delete(key);+    for (MDBX_reader *rthc = rthc_table[i].begin; rthc < rthc_table[i].end;+         ++rthc) {+      mdbx_trace(+          "== [%i] = key %" PRIuPTR ", %p ... %p, rthc %p (%+i), "+          "rthc-pid %i, current-pid %i",+          i, (uintptr_t)key, __Wpedantic_format_voidptr(rthc_table[i].begin),+          __Wpedantic_format_voidptr(rthc_table[i].end),+          __Wpedantic_format_voidptr(rthc), (int)(rthc - rthc_table[i].begin),+          rthc->mr_pid.weak, self_pid);+      if (atomic_load32(&rthc->mr_pid, mo_Relaxed) == self_pid) {+        atomic_store32(&rthc->mr_pid, 0, mo_AcquireRelease);+        mdbx_trace("== cleanup %p", __Wpedantic_format_voidptr(rthc));+      }+    }+  }++  rthc_limit = rthc_count = 0;+  if (rthc_table != rthc_table_static)+    mdbx_free(rthc_table);+  rthc_table = nullptr;+  rthc_unlock();++#if defined(_WIN32) || defined(_WIN64)+  DeleteCriticalSection(&lcklist_critical_section);+  DeleteCriticalSection(&rthc_critical_section);+#else+  /* LY: yielding a few timeslices to give a more chance+   * to racing destructor(s) for completion. */+  workaround_glibc_bug21031();+#endif++  mdbx_trace("<< pid %d\n", mdbx_getpid());+}++__cold int mdbx_rthc_alloc(mdbx_thread_key_t *key, MDBX_reader *begin,+                           MDBX_reader *end) {+  int rc;+  if (key) {+#ifndef NDEBUG+    *key = (mdbx_thread_key_t)0xBADBADBAD;+#endif /* NDEBUG */+    rc = thread_key_create(key);+    if (rc != MDBX_SUCCESS)+      return rc;+  }++  rthc_lock();+  const mdbx_thread_key_t new_key = key ? *key : 0;+  mdbx_trace(">> key %" PRIuPTR ", rthc_count %u, rthc_limit %u",+             (uintptr_t)new_key, rthc_count, rthc_limit);+  if (rthc_count == rthc_limit) {+    rthc_entry_t *new_table =+        mdbx_realloc((rthc_table == rthc_table_static) ? nullptr : rthc_table,+                     sizeof(rthc_entry_t) * rthc_limit * 2);+    if (new_table == nullptr) {+      rc = MDBX_ENOMEM;+      goto bailout;+    }+    if (rthc_table == rthc_table_static)+      memcpy(new_table, rthc_table_static, sizeof(rthc_table_static));+    rthc_table = new_table;+    rthc_limit *= 2;+  }+  mdbx_trace("== [%i] = key %" PRIuPTR ", %p ... %p", rthc_count,+             (uintptr_t)new_key, __Wpedantic_format_voidptr(begin),+             __Wpedantic_format_voidptr(end));+  rthc_table[rthc_count].key_valid = key ? true : false;+  rthc_table[rthc_count].thr_tls_key = key ? new_key : 0;+  rthc_table[rthc_count].begin = begin;+  rthc_table[rthc_count].end = end;+  ++rthc_count;+  mdbx_trace("<< key %" PRIuPTR ", rthc_count %u, rthc_limit %u",+             (uintptr_t)new_key, rthc_count, rthc_limit);+  rthc_unlock();+  return MDBX_SUCCESS;++bailout:+  if (key)+    thread_key_delete(*key);+  rthc_unlock();+  return rc;+}++__cold void mdbx_rthc_remove(const mdbx_thread_key_t key) {+  thread_key_delete(key);+  rthc_lock();+  mdbx_trace(">> key %zu, rthc_count %u, rthc_limit %u", (size_t)key,+             rthc_count, rthc_limit);++  for (unsigned i = 0; i < rthc_count; ++i) {+    if (rthc_table[i].key_valid && key == rthc_table[i].thr_tls_key) {+      const uint32_t self_pid = mdbx_getpid();+      mdbx_trace("== [%i], %p ...%p, current-pid %d", i,+                 __Wpedantic_format_voidptr(rthc_table[i].begin),+                 __Wpedantic_format_voidptr(rthc_table[i].end), self_pid);++      for (MDBX_reader *rthc = rthc_table[i].begin; rthc < rthc_table[i].end;+           ++rthc) {+        if (atomic_load32(&rthc->mr_pid, mo_Relaxed) == self_pid) {+          atomic_store32(&rthc->mr_pid, 0, mo_AcquireRelease);+          mdbx_trace("== cleanup %p", __Wpedantic_format_voidptr(rthc));+        }+      }+      if (--rthc_count > 0)+        rthc_table[i] = rthc_table[rthc_count];+      else if (rthc_table != rthc_table_static) {+        mdbx_free(rthc_table);+        rthc_table = rthc_table_static;+        rthc_limit = RTHC_INITIAL_LIMIT;+      }+      break;+    }+  }++  mdbx_trace("<< key %zu, rthc_count %u, rthc_limit %u", (size_t)key,+             rthc_count, rthc_limit);+  rthc_unlock();+}++//------------------------------------------------------------------------------++#define RTHC_ENVLIST_END ((MDBX_env *)((uintptr_t)50459))+static MDBX_env *inprocess_lcklist_head = RTHC_ENVLIST_END;++static __inline void lcklist_lock(void) {+#if defined(_WIN32) || defined(_WIN64)+  EnterCriticalSection(&lcklist_critical_section);+#else+  mdbx_ensure(nullptr, pthread_mutex_lock(&lcklist_mutex) == 0);+#endif+}++static __inline void lcklist_unlock(void) {+#if defined(_WIN32) || defined(_WIN64)+  LeaveCriticalSection(&lcklist_critical_section);+#else+  mdbx_ensure(nullptr, pthread_mutex_unlock(&lcklist_mutex) == 0);+#endif+}++MDBX_NOTHROW_CONST_FUNCTION static uint64_t rrxmrrxmsx_0(uint64_t v) {+  /* Pelle Evensen's mixer, https://bit.ly/2HOfynt */+  v ^= (v << 39 | v >> 25) ^ (v << 14 | v >> 50);+  v *= UINT64_C(0xA24BAED4963EE407);+  v ^= (v << 40 | v >> 24) ^ (v << 15 | v >> 49);+  v *= UINT64_C(0x9FB21C651E98DF25);+  return v ^ v >> 28;+}++static int uniq_peek(const mdbx_mmap_t *pending, mdbx_mmap_t *scan) {+  int rc;+  uint64_t bait;+  if (pending->address) {+    bait = atomic_load64(&pending->lck->mti_bait_uniqueness, mo_AcquireRelease);+    rc = MDBX_SUCCESS;+  } else {+    bait = 0 /* hush MSVC warning */;+    rc = mdbx_msync(scan, 0, sizeof(MDBX_lockinfo), true);+    if (rc == MDBX_SUCCESS)+      rc =+          mdbx_pread(pending->fd, &bait, sizeof(scan->lck->mti_bait_uniqueness),+                     offsetof(MDBX_lockinfo, mti_bait_uniqueness));+  }+  if (likely(rc == MDBX_SUCCESS) &&+      bait == atomic_load64(&scan->lck->mti_bait_uniqueness, mo_AcquireRelease))+    rc = MDBX_RESULT_TRUE;++  mdbx_trace("uniq-peek: %s, bait 0x%016" PRIx64 ",%s rc %d",+             pending->lck ? "mem" : "file", bait,+             (rc == MDBX_RESULT_TRUE) ? " found," : (rc ? " FAILED," : ""), rc);+  return rc;+}++static int uniq_poke(const mdbx_mmap_t *pending, mdbx_mmap_t *scan,+                     uint64_t *abra) {+  if (*abra == 0) {+    const uintptr_t tid = mdbx_thread_self();+    uintptr_t uit = 0;+    memcpy(&uit, &tid, (sizeof(tid) < sizeof(uit)) ? sizeof(tid) : sizeof(uit));+    *abra =+        rrxmrrxmsx_0(mdbx_osal_monotime() + UINT64_C(5873865991930747) * uit);+  }+  const uint64_t cadabra =+      rrxmrrxmsx_0(*abra + UINT64_C(7680760450171793) * (unsigned)mdbx_getpid())+          << 24 |+      *abra >> 40;+  atomic_store64(&scan->lck->mti_bait_uniqueness, cadabra,+                 mo_SequentialConsistency);+  *abra = *abra * UINT64_C(6364136223846793005) + 1;+  return uniq_peek(pending, scan);+}++__cold static int uniq_check(const mdbx_mmap_t *pending, MDBX_env **found) {+  *found = nullptr;+  uint64_t salt = 0;+  for (MDBX_env *scan = inprocess_lcklist_head; scan != RTHC_ENVLIST_END;+       scan = scan->me_lcklist_next) {+    int err = atomic_load64(&scan->me_lck_mmap.lck->mti_bait_uniqueness,+                            mo_AcquireRelease)+                  ? uniq_peek(pending, &scan->me_lck_mmap)+                  : uniq_poke(pending, &scan->me_lck_mmap, &salt);+    if (err == MDBX_ENODATA) {+      uint64_t length;+      if (likely(mdbx_filesize(pending->fd, &length) == MDBX_SUCCESS &&+                 length == 0)) {+        /* LY: skip checking since LCK-file is empty, i.e. just created. */+        mdbx_debug("uniq-probe: %s", "unique (new/empty lck)");+        return MDBX_RESULT_TRUE;+      }+    }+    if (err == MDBX_RESULT_TRUE)+      err = uniq_poke(pending, &scan->me_lck_mmap, &salt);+    if (err == MDBX_RESULT_TRUE) {+      (void)mdbx_msync(&scan->me_lck_mmap, 0, sizeof(MDBX_lockinfo), false);+      err = uniq_poke(pending, &scan->me_lck_mmap, &salt);+    }+    if (err == MDBX_RESULT_TRUE) {+      err = uniq_poke(pending, &scan->me_lck_mmap, &salt);+      *found = scan;+      mdbx_debug("uniq-probe: found %p", __Wpedantic_format_voidptr(*found));+      return MDBX_RESULT_FALSE;+    }+    if (unlikely(err != MDBX_SUCCESS)) {+      mdbx_debug("uniq-probe: failed rc %d", err);+      return err;+    }+  }++  mdbx_debug("uniq-probe: %s", "unique");+  return MDBX_RESULT_TRUE;+}++static int lcklist_detach_locked(MDBX_env *env) {+  MDBX_env *inprocess_neighbor = nullptr;+  int rc = MDBX_SUCCESS;+  if (env->me_lcklist_next != nullptr) {+    mdbx_ensure(env, env->me_lcklist_next != nullptr);+    mdbx_ensure(env, inprocess_lcklist_head != RTHC_ENVLIST_END);+    for (MDBX_env **ptr = &inprocess_lcklist_head; *ptr != RTHC_ENVLIST_END;+         ptr = &(*ptr)->me_lcklist_next) {+      if (*ptr == env) {+        *ptr = env->me_lcklist_next;+        env->me_lcklist_next = nullptr;+        break;+      }+    }+    mdbx_ensure(env, env->me_lcklist_next == nullptr);+  }++  rc = likely(mdbx_getpid() == env->me_pid)+           ? uniq_check(&env->me_lck_mmap, &inprocess_neighbor)+           : MDBX_PANIC;+  if (!inprocess_neighbor && env->me_live_reader)+    (void)mdbx_rpid_clear(env);+  if (!MDBX_IS_ERROR(rc))+    rc = mdbx_lck_destroy(env, inprocess_neighbor);+  return rc;+}++/*------------------------------------------------------------------------------+ * LY: State of the art quicksort-based sorting, with internal stack+ * and network-sort for small chunks.+ * Thanks to John M. Gamble for the http://pages.ripco.net/~jgamble/nw.html */++#define SORT_CMP_SWAP(TYPE, CMP, a, b)                                         \+  do {                                                                         \+    const TYPE swap_tmp = (a);                                                 \+    const bool swap_cmp = CMP(swap_tmp, b);                                    \+    (a) = swap_cmp ? swap_tmp : b;                                             \+    (b) = swap_cmp ? b : swap_tmp;                                             \+  } while (0)++//  3 comparators, 3 parallel operations+//  o-----^--^--o+//        |  |+//  o--^--|--v--o+//     |  |+//  o--v--v-----o+//+//  [[1,2]]+//  [[0,2]]+//  [[0,1]]+#define SORT_NETWORK_3(TYPE, CMP, begin)                                       \+  do {                                                                         \+    SORT_CMP_SWAP(TYPE, CMP, begin[1], begin[2]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[0], begin[2]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[0], begin[1]);                              \+  } while (0)++//  5 comparators, 3 parallel operations+//  o--^--^--------o+//     |  |+//  o--v--|--^--^--o+//        |  |  |+//  o--^--v--|--v--o+//     |     |+//  o--v-----v-----o+//+//  [[0,1],[2,3]]+//  [[0,2],[1,3]]+//  [[1,2]]+#define SORT_NETWORK_4(TYPE, CMP, begin)                                       \+  do {                                                                         \+    SORT_CMP_SWAP(TYPE, CMP, begin[0], begin[1]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[2], begin[3]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[0], begin[2]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[1], begin[3]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[1], begin[2]);                              \+  } while (0)++//  9 comparators, 5 parallel operations+//  o--^--^-----^-----------o+//     |  |     |+//  o--|--|--^--v-----^--^--o+//     |  |  |        |  |+//  o--|--v--|--^--^--|--v--o+//     |     |  |  |  |+//  o--|-----v--|--v--|--^--o+//     |        |     |  |+//  o--v--------v-----v--v--o+//+//  [[0,4],[1,3]]+//  [[0,2]]+//  [[2,4],[0,1]]+//  [[2,3],[1,4]]+//  [[1,2],[3,4]]+#define SORT_NETWORK_5(TYPE, CMP, begin)                                       \+  do {                                                                         \+    SORT_CMP_SWAP(TYPE, CMP, begin[0], begin[4]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[1], begin[3]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[0], begin[2]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[2], begin[4]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[0], begin[1]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[2], begin[3]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[1], begin[4]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[1], begin[2]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[3], begin[4]);                              \+  } while (0)++//  12 comparators, 6 parallel operations+//  o-----^--^--^-----------------o+//        |  |  |+//  o--^--|--v--|--^--------^-----o+//     |  |     |  |        |+//  o--v--v-----|--|--^--^--|--^--o+//              |  |  |  |  |  |+//  o-----^--^--v--|--|--|--v--v--o+//        |  |     |  |  |+//  o--^--|--v-----v--|--v--------o+//     |  |           |+//  o--v--v-----------v-----------o+//+//  [[1,2],[4,5]]+//  [[0,2],[3,5]]+//  [[0,1],[3,4],[2,5]]+//  [[0,3],[1,4]]+//  [[2,4],[1,3]]+//  [[2,3]]+#define SORT_NETWORK_6(TYPE, CMP, begin)                                       \+  do {                                                                         \+    SORT_CMP_SWAP(TYPE, CMP, begin[1], begin[2]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[4], begin[5]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[0], begin[2]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[3], begin[5]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[0], begin[1]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[3], begin[4]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[2], begin[5]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[0], begin[3]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[1], begin[4]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[2], begin[4]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[1], begin[3]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[2], begin[3]);                              \+  } while (0)++//  16 comparators, 6 parallel operations+//  o--^--------^-----^-----------------o+//     |        |     |+//  o--|--^-----|--^--v--------^--^-----o+//     |  |     |  |           |  |+//  o--|--|--^--v--|--^-----^--|--v-----o+//     |  |  |     |  |     |  |+//  o--|--|--|-----v--|--^--v--|--^--^--o+//     |  |  |        |  |     |  |  |+//  o--v--|--|--^-----v--|--^--v--|--v--o+//        |  |  |        |  |     |+//  o-----v--|--|--------v--v-----|--^--o+//           |  |                 |  |+//  o--------v--v-----------------v--v--o+//+//  [[0,4],[1,5],[2,6]]+//  [[0,2],[1,3],[4,6]]+//  [[2,4],[3,5],[0,1]]+//  [[2,3],[4,5]]+//  [[1,4],[3,6]]+//  [[1,2],[3,4],[5,6]]+#define SORT_NETWORK_7(TYPE, CMP, begin)                                       \+  do {                                                                         \+    SORT_CMP_SWAP(TYPE, CMP, begin[0], begin[4]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[1], begin[5]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[2], begin[6]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[0], begin[2]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[1], begin[3]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[4], begin[6]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[2], begin[4]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[3], begin[5]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[0], begin[1]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[2], begin[3]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[4], begin[5]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[1], begin[4]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[3], begin[6]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[1], begin[2]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[3], begin[4]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[5], begin[6]);                              \+  } while (0)++//  19 comparators, 6 parallel operations+//  o--^--------^-----^-----------------o+//     |        |     |+//  o--|--^-----|--^--v--------^--^-----o+//     |  |     |  |           |  |+//  o--|--|--^--v--|--^-----^--|--v-----o+//     |  |  |     |  |     |  |+//  o--|--|--|--^--v--|--^--v--|--^--^--o+//     |  |  |  |     |  |     |  |  |+//  o--v--|--|--|--^--v--|--^--v--|--v--o+//        |  |  |  |     |  |     |+//  o-----v--|--|--|--^--v--v-----|--^--o+//           |  |  |  |           |  |+//  o--------v--|--v--|--^--------v--v--o+//              |     |  |+//  o-----------v-----v--v--------------o+//+//  [[0,4],[1,5],[2,6],[3,7]]+//  [[0,2],[1,3],[4,6],[5,7]]+//  [[2,4],[3,5],[0,1],[6,7]]+//  [[2,3],[4,5]]+//  [[1,4],[3,6]]+//  [[1,2],[3,4],[5,6]]+#define SORT_NETWORK_8(TYPE, CMP, begin)                                       \+  do {                                                                         \+    SORT_CMP_SWAP(TYPE, CMP, begin[0], begin[4]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[1], begin[5]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[2], begin[6]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[3], begin[7]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[0], begin[2]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[1], begin[3]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[4], begin[6]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[5], begin[7]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[2], begin[4]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[3], begin[5]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[0], begin[1]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[6], begin[7]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[2], begin[3]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[4], begin[5]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[1], begin[4]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[3], begin[6]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[1], begin[2]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[3], begin[4]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[5], begin[6]);                              \+  } while (0)++//  25 comparators, 9 parallel operations+//  o--^-----^--^-----^-----------------------------------o+//     |     |  |     |+//  o--v--^--v--|-----|--^-----^-----------^--------------o+//        |     |     |  |     |           |+//  o-----v-----|-----|--|-----|--^-----^--|--^-----^--^--o+//              |     |  |     |  |     |  |  |     |  |+//  o--^-----^--v--^--v--|-----|--|-----|--v--|-----|--v--o+//     |     |     |     |     |  |     |     |     |+//  o--v--^--v-----|-----v--^--v--|-----|-----|--^--v-----o+//        |        |        |     |     |     |  |+//  o-----v--------|--------|-----v--^--v--^--|--|--^-----o+//                 |        |        |     |  |  |  |+//  o--^-----^-----v--------|--------|-----|--v--v--v-----o+//     |     |              |        |     |+//  o--v--^--v--------------v--------|-----v--------------o+//        |                          |+//  o-----v--------------------------v--------------------o+//+//  [[0,1],[3,4],[6,7]]+//  [[1,2],[4,5],[7,8]]+//  [[0,1],[3,4],[6,7],[2,5]]+//  [[0,3],[1,4],[5,8]]+//  [[3,6],[4,7],[2,5]]+//  [[0,3],[1,4],[5,7],[2,6]]+//  [[1,3],[4,6]]+//  [[2,4],[5,6]]+//  [[2,3]]+#define SORT_NETWORK_9(TYPE, CMP, begin)                                       \+  do {                                                                         \+    SORT_CMP_SWAP(TYPE, CMP, begin[0], begin[1]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[3], begin[4]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[6], begin[7]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[1], begin[2]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[4], begin[5]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[7], begin[8]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[0], begin[1]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[3], begin[4]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[6], begin[7]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[2], begin[5]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[0], begin[3]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[1], begin[4]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[5], begin[8]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[3], begin[6]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[4], begin[7]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[2], begin[5]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[0], begin[3]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[1], begin[4]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[5], begin[7]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[2], begin[6]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[1], begin[3]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[4], begin[6]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[2], begin[4]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[5], begin[6]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[2], begin[3]);                              \+  } while (0)++//  29 comparators, 9 parallel operations+//  o--------------^-----^--^--^-----------------------o+//                 |     |  |  |+//  o-----------^--|--^--|--|--v--^--------^-----------o+//              |  |  |  |  |     |        |+//  o--------^--|--|--|--|--v--^--v-----^--|--^--------o+//           |  |  |  |  |     |        |  |  |+//  o-----^--|--|--|--|--v--^--|-----^--|--v--v--^-----o+//        |  |  |  |  |     |  |     |  |        |+//  o--^--|--|--|--|--v-----|--v--^--|--|--^-----v--^--o+//     |  |  |  |  |        |     |  |  |  |        |+//  o--|--|--|--|--v--^-----|--^--|--v--v--|-----^--v--o+//     |  |  |  |     |     |  |  |        |     |+//  o--|--|--|--v--^--|-----v--|--v--^-----|--^--v-----o+//     |  |  |     |  |        |     |     |  |+//  o--|--|--v-----|--|--^-----v--^--|-----v--v--------o+//     |  |        |  |  |        |  |+//  o--|--v--------|--v--|--^-----v--v-----------------o+//     |           |     |  |+//  o--v-----------v-----v--v--------------------------o+//+//  [[4,9],[3,8],[2,7],[1,6],[0,5]]+//  [[1,4],[6,9],[0,3],[5,8]]+//  [[0,2],[3,6],[7,9]]+//  [[0,1],[2,4],[5,7],[8,9]]+//  [[1,2],[4,6],[7,8],[3,5]]+//  [[2,5],[6,8],[1,3],[4,7]]+//  [[2,3],[6,7]]+//  [[3,4],[5,6]]+//  [[4,5]]+#define SORT_NETWORK_10(TYPE, CMP, begin)                                      \+  do {                                                                         \+    SORT_CMP_SWAP(TYPE, CMP, begin[4], begin[9]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[3], begin[8]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[2], begin[7]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[1], begin[6]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[0], begin[5]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[1], begin[4]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[6], begin[9]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[0], begin[3]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[5], begin[8]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[0], begin[2]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[3], begin[6]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[7], begin[9]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[0], begin[1]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[2], begin[4]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[5], begin[7]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[8], begin[9]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[1], begin[2]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[4], begin[6]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[7], begin[8]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[3], begin[5]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[2], begin[5]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[6], begin[8]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[1], begin[3]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[4], begin[7]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[2], begin[3]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[6], begin[7]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[3], begin[4]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[5], begin[6]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[4], begin[5]);                              \+  } while (0)++//  35 comparators, 9 parallel operations+//  o--^-----^-----------------^--------^--------------------o+//     |     |                 |        |+//  o--v--^--|--^--^--------^--|--------|--^-----------------o+//        |  |  |  |        |  |        |  |+//  o--^--|--v--v--|-----^--|--|--------|--|-----^--^--------o+//     |  |        |     |  |  |        |  |     |  |+//  o--v--v--------|-----|--|--|--^-----|--|--^--v--|--^--^--o+//                 |     |  |  |  |     |  |  |     |  |  |+//  o--^-----^-----|-----|--|--v--|--^--v--v--|-----v--|--v--o+//     |     |     |     |  |     |  |        |        |+//  o--v--^--|--^--v--^--|--v-----|--|--------|--------v--^--o+//        |  |  |     |  |        |  |        |           |+//  o--^--|--v--v--^--|--v--^-----|--|--------|--------^--v--o+//     |  |        |  |     |     |  |        |        |+//  o--v--v--------|--|-----|-----v--|--^-----|-----^--|--^--o+//                 |  |     |        |  |     |     |  |  |+//  o--^--^--------|--|-----|--------v--|-----v--^--|--v--v--o+//     |  |        |  |     |           |        |  |+//  o--v--|--^-----|--v-----|-----------|--------v--v--------o+//        |  |     |        |           |+//  o-----v--v-----v--------v-----------v--------------------o+//+//  [[0,1],[2,3],[4,5],[6,7],[8,9]]+//  [[1,3],[5,7],[0,2],[4,6],[8,10]]+//  [[1,2],[5,6],[9,10],[0,4],[3,7]]+//  [[1,5],[6,10],[4,8]]+//  [[5,9],[2,6],[0,4],[3,8]]+//  [[1,5],[6,10],[2,3],[8,9]]+//  [[1,4],[7,10],[3,5],[6,8]]+//  [[2,4],[7,9],[5,6]]+//  [[3,4],[7,8]]+#define SORT_NETWORK_11(TYPE, CMP, begin)                                      \+  do {                                                                         \+    SORT_CMP_SWAP(TYPE, CMP, begin[0], begin[1]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[2], begin[3]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[4], begin[5]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[6], begin[7]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[8], begin[9]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[1], begin[3]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[5], begin[7]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[0], begin[2]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[4], begin[6]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[8], begin[10]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[1], begin[2]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[5], begin[6]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[9], begin[10]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[0], begin[4]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[3], begin[7]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[1], begin[5]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[6], begin[10]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[4], begin[8]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[5], begin[9]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[2], begin[6]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[0], begin[4]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[3], begin[8]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[1], begin[5]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[6], begin[10]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[2], begin[3]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[8], begin[9]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[1], begin[4]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[7], begin[10]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[3], begin[5]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[6], begin[8]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[2], begin[4]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[7], begin[9]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[5], begin[6]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[3], begin[4]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[7], begin[8]);                              \+  } while (0)++//  39 comparators, parallel operations+//  o--^-----^-----------------^--------^--------------------o+//     |     |                 |        |+//  o--v--^--|--^--^--------^--|--------|--^-----------------o+//        |  |  |  |        |  |        |  |+//  o--^--|--v--v--|-----^--|--|--------|--|-----^--^--------o+//     |  |        |     |  |  |        |  |     |  |+//  o--v--v--------|-----|--|--|--^-----|--|--^--v--|--^--^--o+//                 |     |  |  |  |     |  |  |     |  |  |+//  o--^-----^-----|-----|--|--v--|--^--v--v--|-----v--|--v--o+//     |     |     |     |  |     |  |        |        |+//  o--v--^--|--^--v--^--|--v-----|--|--------|--------v--^--o+//        |  |  |     |  |        |  |        |           |+//  o--^--|--v--v--^--|--v--^-----|--|--------|--------^--v--o+//     |  |        |  |     |     |  |        |        |+//  o--v--v--------|--|-----|--^--v--|--^--^--|-----^--|--^--o+//                 |  |     |  |     |  |  |  |     |  |  |+//  o--^-----^-----|--|-----|--|-----v--|--|--v--^--|--v--v--o+//     |     |     |  |     |  |        |  |     |  |+//  o--v--^--|--^--|--v-----|--|--------|--|-----v--v--------o+//        |  |  |  |        |  |        |  |+//  o--^--|--v--v--v--------v--|--------|--v-----------------o+//     |  |                    |        |+//  o--v--v--------------------v--------v--------------------o+//+//  [[0,1],[2,3],[4,5],[6,7],[8,9],[10,11]]+//  [[1,3],[5,7],[9,11],[0,2],[4,6],[8,10]]+//  [[1,2],[5,6],[9,10],[0,4],[7,11]]+//  [[1,5],[6,10],[3,7],[4,8]]+//  [[5,9],[2,6],[0,4],[7,11],[3,8]]+//  [[1,5],[6,10],[2,3],[8,9]]+//  [[1,4],[7,10],[3,5],[6,8]]+//  [[2,4],[7,9],[5,6]]+//  [[3,4],[7,8]]+#define SORT_NETWORK_12(TYPE, CMP, begin)                                      \+  do {                                                                         \+    SORT_CMP_SWAP(TYPE, CMP, begin[0], begin[1]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[2], begin[3]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[4], begin[5]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[6], begin[7]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[8], begin[9]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[10], begin[11]);                            \+    SORT_CMP_SWAP(TYPE, CMP, begin[1], begin[3]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[5], begin[7]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[9], begin[11]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[0], begin[2]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[4], begin[6]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[8], begin[10]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[1], begin[2]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[5], begin[6]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[9], begin[10]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[0], begin[4]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[7], begin[11]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[1], begin[5]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[6], begin[10]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[3], begin[7]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[4], begin[8]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[5], begin[9]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[2], begin[6]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[0], begin[4]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[7], begin[11]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[3], begin[8]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[1], begin[5]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[6], begin[10]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[2], begin[3]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[8], begin[9]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[1], begin[4]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[7], begin[10]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[3], begin[5]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[6], begin[8]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[2], begin[4]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[7], begin[9]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[5], begin[6]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[3], begin[4]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[7], begin[8]);                              \+  } while (0)++//  45 comparators, 10 parallel operations+//  o--------^--^-----^-----------------------------^-----------------o+//           |  |     |                             |+//  o--^-----|--v-----|-----^--------------^-----^--|-----^-----------o+//     |     |        |     |              |     |  |     |+//  o--|-----|--^--^--v-----|--------------|--^--|--|--^--v--^--------o+//     |     |  |  |        |              |  |  |  |  |     |+//  o--|--^--|--|--v-----^--|--------^-----|--|--v--|--|--^--v-----^--o+//     |  |  |  |        |  |        |     |  |     |  |  |        |+//  o--|--v--|--|--^-----|--v-----^--v-----|--|--^--|--|--|--^--^--v--o+//     |     |  |  |     |        |        |  |  |  |  |  |  |  |+//  o--|--^--|--|--|--^--|--------|-----^--|--|--|--v--v--v--|--v--^--o+//     |  |  |  |  |  |  |        |     |  |  |  |           |     |+//  o--|--|--|--v--v--|--|--^-----|--^--v--|--v--|--^--------v--^--v--o+//     |  |  |        |  |  |     |  |     |     |  |           |+//  o--v--|--|-----^--|--v--|--^--|--|-----v-----v--|--^--------v-----o+//        |  |     |  |     |  |  |  |              |  |+//  o-----v--|--^--|--|-----|--v--|--|--^-----^-----v--v--^-----------o+//           |  |  |  |     |     |  |  |     |           |+//  o--^-----|--|--|--v-----|-----v--|--v--^--|--^--------v-----------o+//     |     |  |  |        |        |     |  |  |+//  o--|-----|--|--|--^-----|--------v--^--|--v--v--------------------o+//     |     |  |  |  |     |           |  |+//  o--v-----|--v--|--v-----|--^--------v--v--------------------------o+//           |     |        |  |+//  o--------v-----v--------v--v--------------------------------------o+//+//  [[1,7],[9,11],[3,4],[5,8],[0,12],[2,6]]+//  [[0,1],[2,3],[4,6],[8,11],[7,12],[5,9]]+//  [[0,2],[3,7],[10,11],[1,4],[6,12]]+//  [[7,8],[11,12],[4,9],[6,10]]+//  [[3,4],[5,6],[8,9],[10,11],[1,7]]+//  [[2,6],[9,11],[1,3],[4,7],[8,10],[0,5]]+//  [[2,5],[6,8],[9,10]]+//  [[1,2],[3,5],[7,8],[4,6]]+//  [[2,3],[4,5],[6,7],[8,9]]+//  [[3,4],[5,6]]+#define SORT_NETWORK_13(TYPE, CMP, begin)                                      \+  do {                                                                         \+    SORT_CMP_SWAP(TYPE, CMP, begin[1], begin[7]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[9], begin[11]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[3], begin[4]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[5], begin[8]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[0], begin[12]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[2], begin[6]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[0], begin[1]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[2], begin[3]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[4], begin[6]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[8], begin[11]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[7], begin[12]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[5], begin[9]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[0], begin[2]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[3], begin[7]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[10], begin[11]);                            \+    SORT_CMP_SWAP(TYPE, CMP, begin[1], begin[4]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[6], begin[12]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[7], begin[8]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[11], begin[12]);                            \+    SORT_CMP_SWAP(TYPE, CMP, begin[4], begin[9]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[6], begin[10]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[3], begin[4]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[5], begin[6]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[8], begin[9]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[10], begin[11]);                            \+    SORT_CMP_SWAP(TYPE, CMP, begin[1], begin[7]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[2], begin[6]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[9], begin[11]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[1], begin[3]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[4], begin[7]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[8], begin[10]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[0], begin[5]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[2], begin[5]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[6], begin[8]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[9], begin[10]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[1], begin[2]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[3], begin[5]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[7], begin[8]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[4], begin[6]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[2], begin[3]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[4], begin[5]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[6], begin[7]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[8], begin[9]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[3], begin[4]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[5], begin[6]);                              \+  } while (0)++/* *INDENT-OFF* */+/* clang-format off */++//  51 comparators, 10 parallel operations+//  o--^--^-----^-----------^-----------------------------------------------------------o+//     |  |     |           |+//  o--v--|--^--|--^--------|--^-----^-----------------------^--------------------------o+//        |  |  |  |        |  |     |                       |+//  o--^--v--|--|--|--^-----|--|--^--v-----------------------|--^--^--------------------o+//     |     |  |  |  |     |  |  |                          |  |  |+//  o--v-----v--|--|--|--^--|--|--|--^--------------^--------|--|--|--^--^--^-----------o+//              |  |  |  |  |  |  |  |              |        |  |  |  |  |  |+//  o--^--^-----v--|--|--|--|--|--|--|--^-----------|-----^--v--|--v--|--|--v-----------o+//     |  |        |  |  |  |  |  |  |  |           |     |     |     |  |+//  o--v--|--^-----v--|--|--|--|--|--|--|--^--^-----|-----|-----|--^--|--v-----^--------o+//        |  |        |  |  |  |  |  |  |  |  |     |     |     |  |  |        |+//  o--^--v--|--------v--|--|--|--|--|--|--|--|--^--|-----|-----|--v--|-----^--v-----^--o+//     |     |           |  |  |  |  |  |  |  |  |  |     |     |     |     |        |+//  o--v-----v-----------v--|--|--|--|--|--|--|--|--|--^--|--^--|-----|--^--|--^--^--v--o+//                          |  |  |  |  |  |  |  |  |  |  |  |  |     |  |  |  |  |+//  o--^--^-----^-----------v--|--|--|--|--|--|--|--|--|--v--|--v-----v--|--v--|--v--^--o+//     |  |     |              |  |  |  |  |  |  |  |  |     |           |     |     |+//  o--v--|--^--|--^-----------v--|--|--|--|--|--v--|--|-----|--^--------|-----v--^--v--o+//        |  |  |  |              |  |  |  |  |     |  |     |  |        |        |+//  o--^--v--|--|--|--------------v--|--|--|--v-----|--|-----|--v--------|--^-----v-----o+//     |     |  |  |                 |  |  |        |  |     |           |  |+//  o--v-----v--|--|-----------------v--|--|--------|--v-----|--^--------|--|--^--------o+//              |  |                    |  |        |        |  |        |  |  |+//  o--^--------v--|--------------------v--|--------v--------|--|--------v--v--v--------o+//     |           |                       |                 |  |+//  o--v-----------v-----------------------v-----------------v--v-----------------------o+//+//  [[0,1],[2,3],[4,5],[6,7],[8,9],[10,11],[12,13]]+//  [[0,2],[4,6],[8,10],[1,3],[5,7],[9,11]]+//  [[0,4],[8,12],[1,5],[9,13],[2,6],[3,7]]+//  [[0,8],[1,9],[2,10],[3,11],[4,12],[5,13]]+//  [[5,10],[6,9],[3,12],[7,11],[1,2],[4,8]]+//  [[1,4],[7,13],[2,8],[5,6],[9,10]]+//  [[2,4],[11,13],[3,8],[7,12]]+//  [[6,8],[10,12],[3,5],[7,9]]+//  [[3,4],[5,6],[7,8],[9,10],[11,12]]+//  [[6,7],[8,9]]++/* *INDENT-ON* */+/* clang-format on */++#define SORT_NETWORK_14(TYPE, CMP, begin)                                      \+  do {                                                                         \+    SORT_CMP_SWAP(TYPE, CMP, begin[0], begin[1]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[2], begin[3]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[4], begin[5]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[6], begin[7]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[8], begin[9]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[10], begin[11]);                            \+    SORT_CMP_SWAP(TYPE, CMP, begin[12], begin[13]);                            \+    SORT_CMP_SWAP(TYPE, CMP, begin[0], begin[2]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[4], begin[6]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[8], begin[10]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[1], begin[3]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[5], begin[7]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[9], begin[11]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[0], begin[4]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[8], begin[12]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[1], begin[5]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[9], begin[13]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[2], begin[6]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[3], begin[7]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[0], begin[8]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[1], begin[9]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[2], begin[10]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[3], begin[11]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[4], begin[12]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[5], begin[13]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[5], begin[10]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[6], begin[9]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[3], begin[12]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[7], begin[11]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[1], begin[2]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[4], begin[8]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[1], begin[4]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[7], begin[13]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[2], begin[8]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[5], begin[6]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[9], begin[10]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[2], begin[4]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[11], begin[13]);                            \+    SORT_CMP_SWAP(TYPE, CMP, begin[3], begin[8]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[7], begin[12]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[6], begin[8]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[10], begin[12]);                            \+    SORT_CMP_SWAP(TYPE, CMP, begin[3], begin[5]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[7], begin[9]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[3], begin[4]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[5], begin[6]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[7], begin[8]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[9], begin[10]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[11], begin[12]);                            \+    SORT_CMP_SWAP(TYPE, CMP, begin[6], begin[7]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[8], begin[9]);                              \+  } while (0)++/* *INDENT-OFF* */+/* clang-format off */++//  56 comparators, 10 parallel operations+//  o--^--^-----^-----------^--------------------------------------------------------------o+//     |  |     |           |+//  o--v--|--^--|--^--------|--^-----^--------------------------^--------------------------o+//        |  |  |  |        |  |     |                          |+//  o--^--v--|--|--|--^-----|--|--^--v--------------------------|--^--^--------------------o+//     |     |  |  |  |     |  |  |                             |  |  |+//  o--v-----v--|--|--|--^--|--|--|--^-----------------^--------|--|--|--^--^--^-----------o+//              |  |  |  |  |  |  |  |                 |        |  |  |  |  |  |+//  o--^--^-----v--|--|--|--|--|--|--|--^--------------|-----^--v--|--v--|--|--v-----------o+//     |  |        |  |  |  |  |  |  |  |              |     |     |     |  |+//  o--v--|--^-----v--|--|--|--|--|--|--|--^-----^-----|-----|-----|--^--|--v-----^--------o+//        |  |        |  |  |  |  |  |  |  |     |     |     |     |  |  |        |+//  o--^--v--|--------v--|--|--|--|--|--|--|--^--|--^--|-----|-----|--v--|-----^--v-----^--o+//     |     |           |  |  |  |  |  |  |  |  |  |  |     |     |     |     |        |+//  o--v-----v-----------v--|--|--|--|--|--|--|--|--|--|--^--|--^--|-----|--^--|--^--^--v--o+//                          |  |  |  |  |  |  |  |  |  |  |  |  |  |     |  |  |  |  |+//  o--^--^-----^-----------v--|--|--|--|--|--|--|--|--|--|--v--|--v-----v--|--v--|--v--^--o+//     |  |     |              |  |  |  |  |  |  |  |  |  |     |           |     |     |+//  o--v--|--^--|--^-----------v--|--|--|--|--|--|--v--|--|-----|--^--------|-----v--^--v--o+//        |  |  |  |              |  |  |  |  |  |     |  |     |  |        |        |+//  o--^--v--|--|--|--^-----------v--|--|--|--|--v-----|--|-----|--v--------|--^-----v-----o+//     |     |  |  |  |              |  |  |  |        |  |     |           |  |+//  o--v-----v--|--|--|--------------v--|--|--|--------|--v-----|--^--^-----|--|--^--------o+//              |  |  |                 |  |  |        |        |  |  |     |  |  |+//  o--^--^-----v--|--|-----------------v--|--|--------v--------|--|--|-----v--v--v--------o+//     |  |        |  |                    |  |                 |  |  |+//  o--v--|--------v--|--------------------v--|--^--------------v--|--v--------------------o+//        |           |                       |  |                 |+//  o-----v-----------v-----------------------v--v-----------------v-----------------------o+//+//  [[0,1],[2,3],[4,5],[6,7],[8,9],[10,11],[12,13]]+//  [[0,2],[4,6],[8,10],[12,14],[1,3],[5,7],[9,11]]+//  [[0,4],[8,12],[1,5],[9,13],[2,6],[10,14],[3,7]]+//  [[0,8],[1,9],[2,10],[3,11],[4,12],[5,13],[6,14]]+//  [[5,10],[6,9],[3,12],[13,14],[7,11],[1,2],[4,8]]+//  [[1,4],[7,13],[2,8],[11,14],[5,6],[9,10]]+//  [[2,4],[11,13],[3,8],[7,12]]+//  [[6,8],[10,12],[3,5],[7,9]]+//  [[3,4],[5,6],[7,8],[9,10],[11,12]]+//  [[6,7],[8,9]]++/* *INDENT-ON* */+/* clang-format on */++#define SORT_NETWORK_15(TYPE, CMP, begin)                                      \+  do {                                                                         \+    SORT_CMP_SWAP(TYPE, CMP, begin[0], begin[1]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[2], begin[3]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[4], begin[5]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[6], begin[7]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[8], begin[9]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[10], begin[11]);                            \+    SORT_CMP_SWAP(TYPE, CMP, begin[12], begin[13]);                            \+    SORT_CMP_SWAP(TYPE, CMP, begin[0], begin[2]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[4], begin[6]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[8], begin[10]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[12], begin[14]);                            \+    SORT_CMP_SWAP(TYPE, CMP, begin[1], begin[3]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[5], begin[7]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[9], begin[11]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[0], begin[4]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[8], begin[12]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[1], begin[5]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[9], begin[13]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[2], begin[6]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[10], begin[14]);                            \+    SORT_CMP_SWAP(TYPE, CMP, begin[3], begin[7]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[0], begin[8]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[1], begin[9]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[2], begin[10]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[3], begin[11]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[4], begin[12]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[5], begin[13]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[6], begin[14]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[5], begin[10]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[6], begin[9]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[3], begin[12]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[13], begin[14]);                            \+    SORT_CMP_SWAP(TYPE, CMP, begin[7], begin[11]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[1], begin[2]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[4], begin[8]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[1], begin[4]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[7], begin[13]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[2], begin[8]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[11], begin[14]);                            \+    SORT_CMP_SWAP(TYPE, CMP, begin[5], begin[6]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[9], begin[10]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[2], begin[4]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[11], begin[13]);                            \+    SORT_CMP_SWAP(TYPE, CMP, begin[3], begin[8]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[7], begin[12]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[6], begin[8]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[10], begin[12]);                            \+    SORT_CMP_SWAP(TYPE, CMP, begin[3], begin[5]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[7], begin[9]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[3], begin[4]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[5], begin[6]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[7], begin[8]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[9], begin[10]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[11], begin[12]);                            \+    SORT_CMP_SWAP(TYPE, CMP, begin[6], begin[7]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[8], begin[9]);                              \+  } while (0)++/* *INDENT-OFF* */+/* clang-format off */++//  60 comparators, 10 parallel operations+//  o--^--^-----^-----------^-----------------------------------------------------------------o+//     |  |     |           |+//  o--v--|--^--|--^--------|--^-----^-----------------------------^--------------------------o+//        |  |  |  |        |  |     |                             |+//  o--^--v--|--|--|--^-----|--|--^--v-----------------------------|--^--^--------------------o+//     |     |  |  |  |     |  |  |                                |  |  |+//  o--v-----v--|--|--|--^--|--|--|--^--------------------^--------|--|--|--^--^--^-----------o+//              |  |  |  |  |  |  |  |                    |        |  |  |  |  |  |+//  o--^--^-----v--|--|--|--|--|--|--|--^-----------------|-----^--v--|--v--|--|--v-----------o+//     |  |        |  |  |  |  |  |  |  |                 |     |     |     |  |+//  o--v--|--^-----v--|--|--|--|--|--|--|--^--------^-----|-----|-----|--^--|--v-----^--------o+//        |  |        |  |  |  |  |  |  |  |        |     |     |     |  |  |        |+//  o--^--v--|--------v--|--|--|--|--|--|--|--^-----|--^--|-----|-----|--v--|-----^--v-----^--o+//     |     |           |  |  |  |  |  |  |  |     |  |  |     |     |     |     |        |+//  o--v-----v-----------v--|--|--|--|--|--|--|--^--|--|--|--^--|--^--|-----|--^--|--^--^--v--o+//                          |  |  |  |  |  |  |  |  |  |  |  |  |  |  |     |  |  |  |  |+//  o--^--^-----^-----------v--|--|--|--|--|--|--|--|--|--|--|--v--|--v-----v--|--v--|--v--^--o+//     |  |     |              |  |  |  |  |  |  |  |  |  |  |     |           |     |     |+//  o--v--|--^--|--^-----------v--|--|--|--|--|--|--|--v--|--|-----|--^--------|-----v--^--v--o+//        |  |  |  |              |  |  |  |  |  |  |     |  |     |  |        |        |+//  o--^--v--|--|--|--^-----------v--|--|--|--|--|--v-----|--|-----|--v--------|--^-----v-----o+//     |     |  |  |  |              |  |  |  |  |        |  |     |           |  |+//  o--v-----v--|--|--|--^-----------v--|--|--|--|--------|--v-----|--^--^-----|--|--^--------o+//              |  |  |  |              |  |  |  |        |        |  |  |     |  |  |+//  o--^--^-----v--|--|--|--------------v--|--|--|--------v--------|--|--|-----v--v--v--------o+//     |  |        |  |  |                 |  |  |                 |  |  |+//  o--v--|--^-----v--|--|-----------------v--|--|--^--------------v--|--v--------------------o+//        |  |        |  |                    |  |  |                 |+//  o--^--v--|--------v--|--------------------v--|--v-----------------v-----------------------o+//     |     |           |                       |+//  o--v-----v-----------v-----------------------v--------------------------------------------o+//+//  [[0,1],[2,3],[4,5],[6,7],[8,9],[10,11],[12,13],[14,15]]+//  [[0,2],[4,6],[8,10],[12,14],[1,3],[5,7],[9,11],[13,15]]+//  [[0,4],[8,12],[1,5],[9,13],[2,6],[10,14],[3,7],[11,15]]+//  [[0,8],[1,9],[2,10],[3,11],[4,12],[5,13],[6,14],[7,15]]+//  [[5,10],[6,9],[3,12],[13,14],[7,11],[1,2],[4,8]]+//  [[1,4],[7,13],[2,8],[11,14],[5,6],[9,10]]+//  [[2,4],[11,13],[3,8],[7,12]]+//  [[6,8],[10,12],[3,5],[7,9]]+//  [[3,4],[5,6],[7,8],[9,10],[11,12]]+//  [[6,7],[8,9]]++/* *INDENT-ON* */+/* clang-format on */++#define SORT_NETWORK_16(TYPE, CMP, begin)                                      \+  do {                                                                         \+    SORT_CMP_SWAP(TYPE, CMP, begin[0], begin[1]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[2], begin[3]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[4], begin[5]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[6], begin[7]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[8], begin[9]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[10], begin[11]);                            \+    SORT_CMP_SWAP(TYPE, CMP, begin[12], begin[13]);                            \+    SORT_CMP_SWAP(TYPE, CMP, begin[14], begin[15]);                            \+    SORT_CMP_SWAP(TYPE, CMP, begin[0], begin[2]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[4], begin[6]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[8], begin[10]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[12], begin[14]);                            \+    SORT_CMP_SWAP(TYPE, CMP, begin[1], begin[3]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[5], begin[7]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[9], begin[11]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[13], begin[15]);                            \+    SORT_CMP_SWAP(TYPE, CMP, begin[0], begin[4]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[8], begin[12]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[1], begin[5]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[9], begin[13]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[2], begin[6]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[10], begin[14]);                            \+    SORT_CMP_SWAP(TYPE, CMP, begin[3], begin[7]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[11], begin[15]);                            \+    SORT_CMP_SWAP(TYPE, CMP, begin[0], begin[8]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[1], begin[9]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[2], begin[10]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[3], begin[11]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[4], begin[12]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[5], begin[13]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[6], begin[14]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[7], begin[15]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[5], begin[10]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[6], begin[9]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[3], begin[12]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[13], begin[14]);                            \+    SORT_CMP_SWAP(TYPE, CMP, begin[7], begin[11]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[1], begin[2]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[4], begin[8]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[1], begin[4]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[7], begin[13]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[2], begin[8]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[11], begin[14]);                            \+    SORT_CMP_SWAP(TYPE, CMP, begin[5], begin[6]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[9], begin[10]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[2], begin[4]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[11], begin[13]);                            \+    SORT_CMP_SWAP(TYPE, CMP, begin[3], begin[8]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[7], begin[12]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[6], begin[8]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[10], begin[12]);                            \+    SORT_CMP_SWAP(TYPE, CMP, begin[3], begin[5]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[7], begin[9]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[3], begin[4]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[5], begin[6]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[7], begin[8]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[9], begin[10]);                             \+    SORT_CMP_SWAP(TYPE, CMP, begin[11], begin[12]);                            \+    SORT_CMP_SWAP(TYPE, CMP, begin[6], begin[7]);                              \+    SORT_CMP_SWAP(TYPE, CMP, begin[8], begin[9]);                              \+  } while (0)++#define SORT_INNER(TYPE, CMP, begin, end, len)                                 \+  switch (len) {                                                               \+  default:                                                                     \+    __unreachable();                                                           \+  case 0:                                                                      \+  case 1:                                                                      \+    break;                                                                     \+  case 2:                                                                      \+    SORT_CMP_SWAP(TYPE, CMP, begin[0], begin[1]);                              \+    break;                                                                     \+  case 3:                                                                      \+    SORT_NETWORK_3(TYPE, CMP, begin);                                          \+    break;                                                                     \+  case 4:                                                                      \+    SORT_NETWORK_4(TYPE, CMP, begin);                                          \+    break;                                                                     \+  case 5:                                                                      \+    SORT_NETWORK_5(TYPE, CMP, begin);                                          \+    break;                                                                     \+  case 6:                                                                      \+    SORT_NETWORK_6(TYPE, CMP, begin);                                          \+    break;                                                                     \+  case 7:                                                                      \+    SORT_NETWORK_7(TYPE, CMP, begin);                                          \+    break;                                                                     \+  case 8:                                                                      \+    SORT_NETWORK_8(TYPE, CMP, begin);                                          \+    break;                                                                     \+  case 9:                                                                      \+    SORT_NETWORK_9(TYPE, CMP, begin);                                          \+    break;                                                                     \+  case 10:                                                                     \+    SORT_NETWORK_10(TYPE, CMP, begin);                                         \+    break;                                                                     \+  case 11:                                                                     \+    SORT_NETWORK_11(TYPE, CMP, begin);                                         \+    break;                                                                     \+  case 12:                                                                     \+    SORT_NETWORK_12(TYPE, CMP, begin);                                         \+    break;                                                                     \+  case 13:                                                                     \+    SORT_NETWORK_13(TYPE, CMP, begin);                                         \+    break;                                                                     \+  case 14:                                                                     \+    SORT_NETWORK_14(TYPE, CMP, begin);                                         \+    break;                                                                     \+  case 15:                                                                     \+    SORT_NETWORK_15(TYPE, CMP, begin);                                         \+    break;                                                                     \+  case 16:                                                                     \+    SORT_NETWORK_16(TYPE, CMP, begin);                                         \+    break;                                                                     \+  }++#define SORT_SWAP(TYPE, a, b)                                                  \+  do {                                                                         \+    const TYPE swap_tmp = (a);                                                 \+    (a) = (b);                                                                 \+    (b) = swap_tmp;                                                            \+  } while (0)++#define SORT_PUSH(low, high)                                                   \+  do {                                                                         \+    top->lo = (low);                                                           \+    top->hi = (high);                                                          \+    ++top;                                                                     \+  } while (0)++#define SORT_POP(low, high)                                                    \+  do {                                                                         \+    --top;                                                                     \+    low = top->lo;                                                             \+    high = top->hi;                                                            \+  } while (0)++#define SORT_IMPL(NAME, EXPECT_LOW_CARDINALITY_OR_PRESORTED, TYPE, CMP)        \+                                                                               \+  static __inline bool NAME##_is_sorted(const TYPE *first, const TYPE *last) { \+    while (++first <= last)                                                    \+      if (CMP(first[0], first[-1]))                                            \+        return false;                                                          \+    return true;                                                               \+  }                                                                            \+                                                                               \+  typedef struct {                                                             \+    TYPE *lo, *hi;                                                             \+  } NAME##_stack;                                                              \+                                                                               \+  static __hot void NAME(TYPE *const begin, TYPE *const end) {                 \+    NAME##_stack stack[sizeof(unsigned) * CHAR_BIT], *top = stack;             \+                                                                               \+    TYPE *hi = end - 1;                                                        \+    TYPE *lo = begin;                                                          \+    while (true) {                                                             \+      const ptrdiff_t len = hi - lo;                                           \+      if (len < 16) {                                                          \+        SORT_INNER(TYPE, CMP, lo, hi + 1, len + 1);                            \+        if (unlikely(top == stack))                                            \+          break;                                                               \+        SORT_POP(lo, hi);                                                      \+        continue;                                                              \+      }                                                                        \+                                                                               \+      TYPE *mid = lo + (len >> 1);                                             \+      SORT_CMP_SWAP(TYPE, CMP, *lo, *mid);                                     \+      SORT_CMP_SWAP(TYPE, CMP, *mid, *hi);                                     \+      SORT_CMP_SWAP(TYPE, CMP, *lo, *mid);                                     \+                                                                               \+      TYPE *right = hi - 1;                                                    \+      TYPE *left = lo + 1;                                                     \+      while (1) {                                                              \+        while (CMP(*left, *mid))                                               \+          ++left;                                                              \+        while (CMP(*mid, *right))                                              \+          --right;                                                             \+        if (unlikely(left > right)) {                                          \+          if (EXPECT_LOW_CARDINALITY_OR_PRESORTED) {                           \+            if (NAME##_is_sorted(lo, right))                                   \+              lo = right + 1;                                                  \+            if (NAME##_is_sorted(left, hi))                                    \+              hi = left;                                                       \+          }                                                                    \+          break;                                                               \+        }                                                                      \+        SORT_SWAP(TYPE, *left, *right);                                        \+        mid = (mid == left) ? right : (mid == right) ? left : mid;             \+        ++left;                                                                \+        --right;                                                               \+      }                                                                        \+                                                                               \+      if (right - lo > hi - left) {                                            \+        SORT_PUSH(lo, right);                                                  \+        lo = left;                                                             \+      } else {                                                                 \+        SORT_PUSH(left, hi);                                                   \+        hi = right;                                                            \+      }                                                                        \+    }                                                                          \+                                                                               \+    if (mdbx_audit_enabled()) {                                                \+      for (TYPE *scan = begin + 1; scan < end; ++scan)                         \+        assert(CMP(scan[-1], scan[0]));                                        \+    }                                                                          \+  }++/*------------------------------------------------------------------------------+ * LY: radix sort for large chunks */++#define RADIXSORT_IMPL(NAME, TYPE, EXTRACT_KEY)                                \+                                                                               \+  __hot static bool NAME##_radixsort(TYPE *const begin,                        \+                                     const unsigned length) {                  \+    TYPE *tmp = mdbx_malloc(sizeof(TYPE) * length);                            \+    if (unlikely(!tmp))                                                        \+      return false;                                                            \+                                                                               \+    unsigned key_shift = 0, key_diff_mask;                                     \+    do {                                                                       \+      struct {                                                                 \+        unsigned a[256], b[256];                                               \+      } counters;                                                              \+      memset(&counters, 0, sizeof(counters));                                  \+                                                                               \+      key_diff_mask = 0;                                                       \+      unsigned prev_key = EXTRACT_KEY(begin) >> key_shift;                     \+      TYPE *r = begin, *end = begin + length;                                  \+      do {                                                                     \+        const unsigned key = EXTRACT_KEY(r) >> key_shift;                      \+        counters.a[key & 255]++;                                               \+        counters.b[(key >> 8) & 255]++;                                        \+        key_diff_mask |= prev_key ^ key;                                       \+        prev_key = key;                                                        \+      } while (++r != end);                                                    \+                                                                               \+      unsigned ta = 0, tb = 0;                                                 \+      for (unsigned i = 0; i < 256; ++i) {                                     \+        const unsigned ia = counters.a[i];                                     \+        counters.a[i] = ta;                                                    \+        ta += ia;                                                              \+        const unsigned ib = counters.b[i];                                     \+        counters.b[i] = tb;                                                    \+        tb += ib;                                                              \+      }                                                                        \+                                                                               \+      r = begin;                                                               \+      do {                                                                     \+        const unsigned key = EXTRACT_KEY(r) >> key_shift;                      \+        tmp[counters.a[key & 255]++] = *r;                                     \+      } while (++r != end);                                                    \+                                                                               \+      if (unlikely(key_diff_mask < 256)) {                                     \+        memcpy(begin, tmp, (char *)end - (char *)begin);                       \+        break;                                                                 \+      }                                                                        \+      end = (r = tmp) + length;                                                \+      do {                                                                     \+        const unsigned key = EXTRACT_KEY(r) >> key_shift;                      \+        begin[counters.b[(key >> 8) & 255]++] = *r;                            \+      } while (++r != end);                                                    \+                                                                               \+      key_shift += 16;                                                         \+    } while (key_diff_mask >> 16);                                             \+                                                                               \+    mdbx_free(tmp);                                                            \+    return true;                                                               \+  }++/*------------------------------------------------------------------------------+ * LY: Binary search */++#define SEARCH_IMPL(NAME, TYPE_LIST, TYPE_ARG, CMP)                            \+  static __always_inline const TYPE_LIST *NAME(                                \+      const TYPE_LIST *first, unsigned length, const TYPE_ARG item) {          \+    const TYPE_LIST *const begin = first, *const end = begin + length;         \+                                                                               \+    while (length > 3) {                                                       \+      const unsigned whole = length;                                           \+      length >>= 1;                                                            \+      const TYPE_LIST *const middle = first + length;                          \+      const unsigned left = whole - length - 1;                                \+      const bool cmp = CMP(*middle, item);                                     \+      length = cmp ? left : length;                                            \+      first = cmp ? middle + 1 : first;                                        \+    }                                                                          \+                                                                               \+    switch (length) {                                                          \+    case 3:                                                                    \+      if (!CMP(*first, item))                                                  \+        break;                                                                 \+      ++first;                                                                 \+      __fallthrough /* fall through */;                                        \+    case 2:                                                                    \+      if (!CMP(*first, item))                                                  \+        break;                                                                 \+      ++first;                                                                 \+      __fallthrough /* fall through */;                                        \+    case 1:                                                                    \+      if (!CMP(*first, item))                                                  \+        break;                                                                 \+      ++first;                                                                 \+      __fallthrough /* fall through */;                                        \+    case 0:                                                                    \+      break;                                                                   \+    default:                                                                   \+      __unreachable();                                                         \+    }                                                                          \+                                                                               \+    if (mdbx_audit_enabled()) {                                                \+      for (const TYPE_LIST *scan = begin; scan < first; ++scan)                \+        assert(CMP(*scan, item));                                              \+      for (const TYPE_LIST *scan = first; scan < end; ++scan)                  \+        assert(!CMP(*scan, item));                                             \+      (void)begin, (void)end;                                                  \+    }                                                                          \+                                                                               \+    return first;                                                              \+  }++/*----------------------------------------------------------------------------*/++static __always_inline size_t pnl2bytes(const size_t size) {+  assert(size > 0 && size <= MDBX_PGL_LIMIT);+  size_t bytes =+      ceil_powerof2(MDBX_ASSUME_MALLOC_OVERHEAD + sizeof(pgno_t) * (size + 2),+                    MDBX_PNL_GRANULATE * sizeof(pgno_t)) -+      MDBX_ASSUME_MALLOC_OVERHEAD;+  return bytes;+}++static __always_inline pgno_t bytes2pnl(const size_t bytes) {+  size_t size = bytes / sizeof(pgno_t);+  assert(size > 2 && size <= MDBX_PGL_LIMIT);+  return (pgno_t)size - 2;+}++static MDBX_PNL mdbx_pnl_alloc(size_t size) {+  size_t bytes = pnl2bytes(size);+  MDBX_PNL pl = mdbx_malloc(bytes);+  if (likely(pl)) {+#if __GLIBC_PREREQ(2, 12) || defined(__FreeBSD__) || defined(malloc_usable_size)+    bytes = malloc_usable_size(pl);+#endif /* malloc_usable_size */+    pl[0] = bytes2pnl(bytes);+    assert(pl[0] >= size);+    pl[1] = 0;+    pl += 1;+  }+  return pl;+}++static void mdbx_pnl_free(MDBX_PNL pl) {+  if (likely(pl))+    mdbx_free(pl - 1);+}++/* Shrink the PNL to the default size if it has grown larger */+static void mdbx_pnl_shrink(MDBX_PNL *ppl) {+  assert(bytes2pnl(pnl2bytes(MDBX_PNL_INITIAL)) == MDBX_PNL_INITIAL);+  assert(MDBX_PNL_SIZE(*ppl) <= MDBX_PGL_LIMIT &&+         MDBX_PNL_ALLOCLEN(*ppl) >= MDBX_PNL_SIZE(*ppl));+  MDBX_PNL_SIZE(*ppl) = 0;+  if (unlikely(MDBX_PNL_ALLOCLEN(*ppl) >+               MDBX_PNL_INITIAL * 2 - MDBX_CACHELINE_SIZE / sizeof(pgno_t))) {+    size_t bytes = pnl2bytes(MDBX_PNL_INITIAL);+    MDBX_PNL pl = mdbx_realloc(*ppl - 1, bytes);+    if (likely(pl)) {+#if __GLIBC_PREREQ(2, 12) || defined(__FreeBSD__) || defined(malloc_usable_size)+      bytes = malloc_usable_size(pl);+#endif /* malloc_usable_size */+      *pl = bytes2pnl(bytes);+      *ppl = pl + 1;+    }+  }+}++/* Grow the PNL to the size growed to at least given size */+static int mdbx_pnl_reserve(MDBX_PNL *ppl, const size_t wanna) {+  const size_t allocated = MDBX_PNL_ALLOCLEN(*ppl);+  assert(MDBX_PNL_SIZE(*ppl) <= MDBX_PGL_LIMIT &&+         MDBX_PNL_ALLOCLEN(*ppl) >= MDBX_PNL_SIZE(*ppl));+  if (likely(allocated >= wanna))+    return MDBX_SUCCESS;++  if (unlikely(wanna > /* paranoia */ MDBX_PGL_LIMIT)) {+    mdbx_error("PNL too long (%zu > %zu)", wanna, (size_t)MDBX_PGL_LIMIT);+    return MDBX_TXN_FULL;+  }++  const size_t size = (wanna + wanna - allocated < MDBX_PGL_LIMIT)+                          ? wanna + wanna - allocated+                          : MDBX_PGL_LIMIT;+  size_t bytes = pnl2bytes(size);+  MDBX_PNL pl = mdbx_realloc(*ppl - 1, bytes);+  if (likely(pl)) {+#if __GLIBC_PREREQ(2, 12) || defined(__FreeBSD__) || defined(malloc_usable_size)+    bytes = malloc_usable_size(pl);+#endif /* malloc_usable_size */+    *pl = bytes2pnl(bytes);+    assert(*pl >= wanna);+    *ppl = pl + 1;+    return MDBX_SUCCESS;+  }+  return MDBX_ENOMEM;+}++/* Make room for num additional elements in an PNL */+static __always_inline int __must_check_result mdbx_pnl_need(MDBX_PNL *ppl,+                                                             size_t num) {+  assert(MDBX_PNL_SIZE(*ppl) <= MDBX_PGL_LIMIT &&+         MDBX_PNL_ALLOCLEN(*ppl) >= MDBX_PNL_SIZE(*ppl));+  assert(num <= MDBX_PGL_LIMIT);+  const size_t wanna = MDBX_PNL_SIZE(*ppl) + num;+  return likely(MDBX_PNL_ALLOCLEN(*ppl) >= wanna)+             ? MDBX_SUCCESS+             : mdbx_pnl_reserve(ppl, wanna);+}++static __always_inline void mdbx_pnl_xappend(MDBX_PNL pl, pgno_t pgno) {+  assert(MDBX_PNL_SIZE(pl) < MDBX_PNL_ALLOCLEN(pl));+  if (mdbx_audit_enabled()) {+    for (unsigned i = MDBX_PNL_SIZE(pl); i > 0; --i)+      assert(pgno != pl[i]);+  }+  MDBX_PNL_SIZE(pl) += 1;+  MDBX_PNL_LAST(pl) = pgno;+}++/* Append an pgno range onto an unsorted PNL */+__always_inline static int __must_check_result+mdbx_pnl_append_range(bool spilled, MDBX_PNL *ppl, pgno_t pgno, unsigned n) {+  assert(n > 0);+  int rc = mdbx_pnl_need(ppl, n);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  const MDBX_PNL pnl = *ppl;+#if MDBX_PNL_ASCENDING+  unsigned w = MDBX_PNL_SIZE(pnl);+  do {+    pnl[++w] = pgno;+    pgno += spilled ? 2 : 1;+  } while (--n);+  MDBX_PNL_SIZE(pnl) = w;+#else+  unsigned w = MDBX_PNL_SIZE(pnl) + n;+  MDBX_PNL_SIZE(pnl) = w;+  do {+    pnl[w--] = pgno;+    pgno += spilled ? 2 : 1;+  } while (--n);+#endif++  return MDBX_SUCCESS;+}++/* Append an pgno range into the sorted PNL */+static __hot int __must_check_result mdbx_pnl_insert_range(MDBX_PNL *ppl,+                                                           pgno_t pgno,+                                                           unsigned n) {+  assert(n > 0);+  int rc = mdbx_pnl_need(ppl, n);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  const MDBX_PNL pnl = *ppl;+  unsigned r = MDBX_PNL_SIZE(pnl), w = r + n;+  MDBX_PNL_SIZE(pnl) = w;+  while (r && MDBX_PNL_DISORDERED(pnl[r], pgno))+    pnl[w--] = pnl[r--];++  for (pgno_t fill = MDBX_PNL_ASCENDING ? pgno + n : pgno; w > r; --w)+    pnl[w] = MDBX_PNL_ASCENDING ? --fill : fill++;++  return MDBX_SUCCESS;+}++static bool mdbx_pnl_check(const MDBX_PNL pl, const pgno_t limit) {+  if (likely(MDBX_PNL_SIZE(pl))) {+    assert(MDBX_PNL_LEAST(pl) >= MIN_PAGENO);+    assert(MDBX_PNL_MOST(pl) < limit);+    assert(MDBX_PNL_SIZE(pl) <= MDBX_PGL_LIMIT);+    if (unlikely(MDBX_PNL_SIZE(pl) > MDBX_PGL_LIMIT))+      return false;+    if (unlikely(MDBX_PNL_LEAST(pl) < MIN_PAGENO))+      return false;+    if (unlikely(MDBX_PNL_MOST(pl) >= limit))+      return false;+    if (mdbx_audit_enabled()) {+      for (const pgno_t *scan = &MDBX_PNL_LAST(pl); --scan > pl;) {+        assert(MDBX_PNL_ORDERED(scan[0], scan[1]));+        if (unlikely(!MDBX_PNL_ORDERED(scan[0], scan[1])))+          return false;+      }+    }+  }+  return true;+}++static __always_inline bool mdbx_pnl_check4assert(const MDBX_PNL pl,+                                                  const pgno_t limit) {+  if (unlikely(pl == nullptr))+    return true;+  assert(MDBX_PNL_ALLOCLEN(pl) >= MDBX_PNL_SIZE(pl));+  if (unlikely(MDBX_PNL_ALLOCLEN(pl) < MDBX_PNL_SIZE(pl)))+    return false;+  return mdbx_pnl_check(pl, limit);+}++/* Merge an PNL onto an PNL. The destination PNL must be big enough */+static void __hot mdbx_pnl_xmerge(MDBX_PNL dst, const MDBX_PNL src) {+  assert(mdbx_pnl_check4assert(dst, MAX_PAGENO + 1));+  assert(mdbx_pnl_check(src, MAX_PAGENO + 1));+  const size_t total = MDBX_PNL_SIZE(dst) + MDBX_PNL_SIZE(src);+  assert(MDBX_PNL_ALLOCLEN(dst) >= total);+  pgno_t *w = dst + total;+  pgno_t *d = dst + MDBX_PNL_SIZE(dst);+  const pgno_t *s = src + MDBX_PNL_SIZE(src);+  dst[0] = /* detent for scan below */ (MDBX_PNL_ASCENDING ? 0 : ~(pgno_t)0);+  while (s > src) {+    while (MDBX_PNL_ORDERED(*s, *d))+      *w-- = *d--;+    *w-- = *s--;+  }+  MDBX_PNL_SIZE(dst) = (pgno_t)total;+  assert(mdbx_pnl_check4assert(dst, MAX_PAGENO + 1));+}++static void mdbx_spill_remove(MDBX_txn *txn, unsigned idx, unsigned npages) {+  mdbx_tassert(txn, idx > 0 && idx <= MDBX_PNL_SIZE(txn->tw.spill_pages) &&+                        txn->tw.spill_least_removed > 0);+  txn->tw.spill_least_removed =+      (idx < txn->tw.spill_least_removed) ? idx : txn->tw.spill_least_removed;+  txn->tw.spill_pages[idx] |= 1;+  MDBX_PNL_SIZE(txn->tw.spill_pages) -=+      (idx == MDBX_PNL_SIZE(txn->tw.spill_pages));++  while (unlikely(npages > 1)) {+    const pgno_t pgno = (txn->tw.spill_pages[idx] >> 1) + 1;+    if (MDBX_PNL_ASCENDING) {+      if (++idx > MDBX_PNL_SIZE(txn->tw.spill_pages) ||+          (txn->tw.spill_pages[idx] >> 1) != pgno)+        return;+    } else {+      if (--idx < 1 || (txn->tw.spill_pages[idx] >> 1) != pgno)+        return;+      txn->tw.spill_least_removed = (idx < txn->tw.spill_least_removed)+                                        ? idx+                                        : txn->tw.spill_least_removed;+    }+    txn->tw.spill_pages[idx] |= 1;+    MDBX_PNL_SIZE(txn->tw.spill_pages) -=+        (idx == MDBX_PNL_SIZE(txn->tw.spill_pages));+    --npages;+  }+}++static MDBX_PNL mdbx_spill_purge(MDBX_txn *txn) {+  mdbx_tassert(txn, txn->tw.spill_least_removed > 0);+  const MDBX_PNL sl = txn->tw.spill_pages;+  if (txn->tw.spill_least_removed != INT_MAX) {+    unsigned len = MDBX_PNL_SIZE(sl), r, w;+    for (w = r = txn->tw.spill_least_removed; r <= len; ++r) {+      sl[w] = sl[r];+      w += 1 - (sl[r] & 1);+    }+    for (size_t i = 1; i < w; ++i)+      mdbx_tassert(txn, (sl[i] & 1) == 0);+    MDBX_PNL_SIZE(sl) = w - 1;+    txn->tw.spill_least_removed = INT_MAX;+  } else {+    for (size_t i = 1; i <= MDBX_PNL_SIZE(sl); ++i)+      mdbx_tassert(txn, (sl[i] & 1) == 0);+  }+  return sl;+}++#if MDBX_PNL_ASCENDING+#define MDBX_PNL_EXTRACT_KEY(ptr) (*(ptr))+#else+#define MDBX_PNL_EXTRACT_KEY(ptr) (P_INVALID - *(ptr))+#endif+RADIXSORT_IMPL(pgno, pgno_t, MDBX_PNL_EXTRACT_KEY)++SORT_IMPL(pgno_sort, false, pgno_t, MDBX_PNL_ORDERED)+static __hot void mdbx_pnl_sort(MDBX_PNL pnl) {+  if (likely(MDBX_PNL_SIZE(pnl) < MDBX_PNL_RADIXSORT_THRESHOLD) ||+      !pgno_radixsort(&MDBX_PNL_FIRST(pnl), MDBX_PNL_SIZE(pnl)))+    pgno_sort(MDBX_PNL_BEGIN(pnl), MDBX_PNL_END(pnl));+  assert(mdbx_pnl_check(pnl, MAX_PAGENO + 1));+}++/* Search for an pgno in an PNL.+ * Returns The index of the first item greater than or equal to pgno. */+SEARCH_IMPL(pgno_bsearch, pgno_t, pgno_t, MDBX_PNL_ORDERED)++static __hot unsigned mdbx_pnl_search(const MDBX_PNL pnl, pgno_t pgno) {+  assert(mdbx_pnl_check4assert(pnl, MAX_PAGENO + 1));+  const pgno_t *begin = MDBX_PNL_BEGIN(pnl);+  const pgno_t *it = pgno_bsearch(begin, MDBX_PNL_SIZE(pnl), pgno);+  const pgno_t *end = begin + MDBX_PNL_SIZE(pnl);+  assert(it >= begin && it <= end);+  if (it != begin)+    assert(MDBX_PNL_ORDERED(it[-1], pgno));+  if (it != end)+    assert(!MDBX_PNL_ORDERED(it[0], pgno));+  return (unsigned)(it - begin + 1);+}++static __inline unsigned mdbx_pnl_exist(const MDBX_PNL pnl, pgno_t pgno) {+  unsigned n = mdbx_pnl_search(pnl, pgno);+  return (n <= MDBX_PNL_SIZE(pnl) && pnl[n] == pgno) ? n : 0;+}++static __inline unsigned mdbx_pnl_intersect(const MDBX_PNL pnl, pgno_t pgno,+                                            unsigned npages) {+  const unsigned len = MDBX_PNL_SIZE(pnl);+  if (mdbx_log_enabled(MDBX_LOG_EXTRA)) {+    mdbx_debug_extra("PNL len %u [", len);+    for (unsigned i = 1; i <= len; ++i)+      mdbx_debug_extra_print(" %" PRIaPGNO, pnl[i]);+    mdbx_debug_extra_print("%s\n", "]");+  }+  const pgno_t range_last = pgno + npages - 1;+#if MDBX_PNL_ASCENDING+  const unsigned n = mdbx_pnl_search(pnl, pgno);+  assert(n && (n == MDBX_PNL_SIZE(pnl) + 1 || pgno <= pnl[n]));+  const bool rc = n <= MDBX_PNL_SIZE(pnl) && pnl[n] <= range_last;+#else+  const unsigned n = mdbx_pnl_search(pnl, range_last);+  assert(n && (n == MDBX_PNL_SIZE(pnl) + 1 || range_last >= pnl[n]));+  const bool rc = n <= MDBX_PNL_SIZE(pnl) && pnl[n] >= pgno;+#endif+  if (mdbx_assert_enabled()) {+    bool check = false;+    for (unsigned i = 0; i < npages; ++i)+      check |= mdbx_pnl_exist(pnl, pgno + i) != 0;+    assert(check == rc);+  }+  return rc;+}++/*----------------------------------------------------------------------------*/++static __always_inline size_t txl2bytes(const size_t size) {+  assert(size > 0 && size <= MDBX_TXL_MAX * 2);+  size_t bytes =+      ceil_powerof2(MDBX_ASSUME_MALLOC_OVERHEAD + sizeof(txnid_t) * (size + 2),+                    MDBX_TXL_GRANULATE * sizeof(txnid_t)) -+      MDBX_ASSUME_MALLOC_OVERHEAD;+  return bytes;+}++static __always_inline size_t bytes2txl(const size_t bytes) {+  size_t size = bytes / sizeof(txnid_t);+  assert(size > 2 && size <= MDBX_TXL_MAX * 2);+  return size - 2;+}++static MDBX_TXL mdbx_txl_alloc(void) {+  size_t bytes = txl2bytes(MDBX_TXL_INITIAL);+  MDBX_TXL tl = mdbx_malloc(bytes);+  if (likely(tl)) {+#if __GLIBC_PREREQ(2, 12) || defined(__FreeBSD__) || defined(malloc_usable_size)+    bytes = malloc_usable_size(tl);+#endif /* malloc_usable_size */+    tl[0] = bytes2txl(bytes);+    assert(tl[0] >= MDBX_TXL_INITIAL);+    tl[1] = 0;+    tl += 1;+  }+  return tl;+}++static void mdbx_txl_free(MDBX_TXL tl) {+  if (likely(tl))+    mdbx_free(tl - 1);+}++static int mdbx_txl_reserve(MDBX_TXL *ptl, const size_t wanna) {+  const size_t allocated = (size_t)MDBX_PNL_ALLOCLEN(*ptl);+  assert(MDBX_PNL_SIZE(*ptl) <= MDBX_TXL_MAX &&+         MDBX_PNL_ALLOCLEN(*ptl) >= MDBX_PNL_SIZE(*ptl));+  if (likely(allocated >= wanna))+    return MDBX_SUCCESS;++  if (unlikely(wanna > /* paranoia */ MDBX_TXL_MAX)) {+    mdbx_error("TXL too long (%zu > %zu)", wanna, (size_t)MDBX_TXL_MAX);+    return MDBX_TXN_FULL;+  }++  const size_t size = (wanna + wanna - allocated < MDBX_TXL_MAX)+                          ? wanna + wanna - allocated+                          : MDBX_TXL_MAX;+  size_t bytes = txl2bytes(size);+  MDBX_TXL tl = mdbx_realloc(*ptl - 1, bytes);+  if (likely(tl)) {+#if __GLIBC_PREREQ(2, 12) || defined(__FreeBSD__) || defined(malloc_usable_size)+    bytes = malloc_usable_size(tl);+#endif /* malloc_usable_size */+    *tl = bytes2txl(bytes);+    assert(*tl >= wanna);+    *ptl = tl + 1;+    return MDBX_SUCCESS;+  }+  return MDBX_ENOMEM;+}++static __always_inline int __must_check_result mdbx_txl_need(MDBX_TXL *ptl,+                                                             size_t num) {+  assert(MDBX_PNL_SIZE(*ptl) <= MDBX_TXL_MAX &&+         MDBX_PNL_ALLOCLEN(*ptl) >= MDBX_PNL_SIZE(*ptl));+  assert(num <= MDBX_PGL_LIMIT);+  const size_t wanna = (size_t)MDBX_PNL_SIZE(*ptl) + num;+  return likely(MDBX_PNL_ALLOCLEN(*ptl) >= wanna)+             ? MDBX_SUCCESS+             : mdbx_txl_reserve(ptl, wanna);+}++static __always_inline void mdbx_txl_xappend(MDBX_TXL tl, txnid_t id) {+  assert(MDBX_PNL_SIZE(tl) < MDBX_PNL_ALLOCLEN(tl));+  MDBX_PNL_SIZE(tl) += 1;+  MDBX_PNL_LAST(tl) = id;+}++#define TXNID_SORT_CMP(first, last) ((first) > (last))+SORT_IMPL(txnid_sort, false, txnid_t, TXNID_SORT_CMP)+static void mdbx_txl_sort(MDBX_TXL tl) {+  txnid_sort(MDBX_PNL_BEGIN(tl), MDBX_PNL_END(tl));+}++static int __must_check_result mdbx_txl_append(MDBX_TXL *ptl, txnid_t id) {+  if (unlikely(MDBX_PNL_SIZE(*ptl) == MDBX_PNL_ALLOCLEN(*ptl))) {+    int rc = mdbx_txl_need(ptl, MDBX_TXL_GRANULATE);+    if (unlikely(rc != MDBX_SUCCESS))+      return rc;+  }+  mdbx_txl_xappend(*ptl, id);+  return MDBX_SUCCESS;+}++/*----------------------------------------------------------------------------*/++#define MDBX_DPL_UNSORTED_BACKLOG 16+#define MDBX_DPL_GAP_FOR_MERGESORT MDBX_DPL_UNSORTED_BACKLOG+#define MDBX_DPL_GAP_FOR_EDGING 2+#define MDBX_DPL_RESERVE_GAP                                                   \+  (MDBX_DPL_GAP_FOR_MERGESORT + MDBX_DPL_GAP_FOR_EDGING)++static __always_inline size_t dpl2bytes(const ptrdiff_t size) {+  assert(size > CURSOR_STACK && (size_t)size <= MDBX_PGL_LIMIT);+  size_t bytes =+      ceil_powerof2(MDBX_ASSUME_MALLOC_OVERHEAD + sizeof(MDBX_dpl) ++                        (size + MDBX_DPL_RESERVE_GAP) * sizeof(MDBX_dp),+                    MDBX_PNL_GRANULATE * sizeof(void *) * 2) -+      MDBX_ASSUME_MALLOC_OVERHEAD;+  return bytes;+}++static __always_inline unsigned bytes2dpl(const ptrdiff_t bytes) {+  size_t size = (bytes - sizeof(MDBX_dpl)) / sizeof(MDBX_dp);+  assert(size > CURSOR_STACK + MDBX_DPL_RESERVE_GAP &&+         size <= MDBX_PGL_LIMIT + MDBX_PNL_GRANULATE);+  return (unsigned)size - MDBX_DPL_RESERVE_GAP;+}++static __always_inline unsigned mdbx_dpl_setlen(MDBX_dpl *dl, unsigned len) {+  static const MDBX_page dpl_stub_pageE = {+      {0}, 0, P_BAD, {0}, /* pgno */ ~(pgno_t)0};+  assert(dpl_stub_pageE.mp_flags == P_BAD &&+         dpl_stub_pageE.mp_pgno == P_INVALID);+  dl->length = len;+  dl->items[len + 1].pgno = P_INVALID;+  dl->items[len + 1].ptr = (MDBX_page *)&dpl_stub_pageE;+  return len;+}++static __always_inline void mdbx_dpl_clear(MDBX_dpl *dl) {+  static const MDBX_page dpl_stub_pageB = {{0}, 0, P_BAD, {0}, /* pgno */ 0};+  assert(dpl_stub_pageB.mp_flags == P_BAD && dpl_stub_pageB.mp_pgno == 0);+  dl->sorted = mdbx_dpl_setlen(dl, 0);+  dl->items[0].pgno = 0;+  dl->items[0].ptr = (MDBX_page *)&dpl_stub_pageB;+  assert(dl->items[0].pgno == 0 && dl->items[dl->length + 1].pgno == P_INVALID);+}++static void mdbx_dpl_free(MDBX_txn *txn) {+  if (likely(txn->tw.dirtylist)) {+    mdbx_free(txn->tw.dirtylist);+    txn->tw.dirtylist = NULL;+  }+}++static MDBX_dpl *mdbx_dpl_reserve(MDBX_txn *txn, size_t size) {+  size_t bytes = dpl2bytes((size < MDBX_PGL_LIMIT) ? size : MDBX_PGL_LIMIT);+  MDBX_dpl *const dl = mdbx_realloc(txn->tw.dirtylist, bytes);+  if (likely(dl)) {+#if __GLIBC_PREREQ(2, 12) || defined(__FreeBSD__) || defined(malloc_usable_size)+    bytes = malloc_usable_size(dl);+#endif /* malloc_usable_size */+    dl->detent = bytes2dpl(bytes);+    mdbx_tassert(txn, txn->tw.dirtylist == NULL || dl->length <= dl->detent);+    txn->tw.dirtylist = dl;+  }+  return dl;+}++static int mdbx_dpl_alloc(MDBX_txn *txn) {+  mdbx_tassert(txn, (txn->mt_flags & MDBX_TXN_RDONLY) == 0);+  const int wanna = (txn->mt_env->me_options.dp_initial < txn->mt_geo.upper)+                        ? txn->mt_env->me_options.dp_initial+                        : txn->mt_geo.upper;+  if (txn->tw.dirtylist) {+    mdbx_dpl_clear(txn->tw.dirtylist);+    const int realloc_threshold = 64;+    if (likely(+            !((int)(txn->tw.dirtylist->detent - wanna) > realloc_threshold ||+              (int)(txn->tw.dirtylist->detent - wanna) < -realloc_threshold)))+      return MDBX_SUCCESS;+  }+  if (unlikely(!mdbx_dpl_reserve(txn, wanna)))+    return MDBX_ENOMEM;+  mdbx_dpl_clear(txn->tw.dirtylist);+  return MDBX_SUCCESS;+}++#define MDBX_DPL_EXTRACT_KEY(ptr) ((ptr)->pgno)+RADIXSORT_IMPL(dpl, MDBX_dp, MDBX_DPL_EXTRACT_KEY)++#define DP_SORT_CMP(first, last) ((first).pgno < (last).pgno)+SORT_IMPL(dp_sort, false, MDBX_dp, DP_SORT_CMP)++__hot static MDBX_dpl *mdbx_dpl_sort_slowpath(MDBX_dpl *dl) {+  const unsigned unsorted = dl->length - dl->sorted;+  if (likely(unsorted < MDBX_PNL_RADIXSORT_THRESHOLD) ||+      !dpl_radixsort(dl->items + 1, dl->length)) {+    if (dl->sorted > unsorted / 4 + 4 &&+        dl->length + unsorted < dl->detent + MDBX_DPL_GAP_FOR_MERGESORT) {+      MDBX_dp *const sorted_begin = dl->items + 1;+      MDBX_dp *const sorted_end = sorted_begin + dl->sorted;+      MDBX_dp *const end = dl->items + dl->detent + MDBX_DPL_RESERVE_GAP;+      MDBX_dp *const tmp = end - unsorted;+      assert(dl->items + dl->length + 1 < tmp);+      /* copy unsorted to the end of allocated space and sort it */+      memcpy(tmp, sorted_end, unsorted * sizeof(MDBX_dp));+      dp_sort(tmp, tmp + unsorted);+      /* merge two parts from end to begin */+      MDBX_dp *w = dl->items + dl->length;+      MDBX_dp *l = dl->items + dl->sorted;+      MDBX_dp *r = end - 1;+      do {+        const bool cmp = l->pgno > r->pgno;+        *w = cmp ? *l : *r;+        l -= cmp;+        r -= !cmp;+      } while (likely(--w > l));+      assert(r == tmp - 1);+      assert(dl->items[0].pgno == 0 &&+             dl->items[dl->length + 1].pgno == P_INVALID);+      if (mdbx_assert_enabled())+        for (unsigned i = 0; i <= dl->length; ++i)+          assert(dl->items[i].pgno < dl->items[i + 1].pgno);+    } else {+      dp_sort(dl->items + 1, dl->items + dl->length + 1);+      assert(dl->items[0].pgno == 0 &&+             dl->items[dl->length + 1].pgno == P_INVALID);+    }+  }+  dl->sorted = dl->length;+  return dl;+}++static __always_inline MDBX_dpl *mdbx_dpl_sort(MDBX_dpl *dl) {+  assert(dl->length <= MDBX_PGL_LIMIT);+  assert(dl->sorted <= dl->length);+  assert(dl->items[0].pgno == 0 && dl->items[dl->length + 1].pgno == P_INVALID);+  return likely(dl->sorted == dl->length) ? dl : mdbx_dpl_sort_slowpath(dl);+}++/* Returns the index of the first dirty-page whose pgno+ * member is greater than or equal to id. */+#define DP_SEARCH_CMP(dp, id) ((dp).pgno < (id))+SEARCH_IMPL(dp_bsearch, MDBX_dp, pgno_t, DP_SEARCH_CMP)++static unsigned __hot mdbx_dpl_search(MDBX_dpl *dl, pgno_t pgno) {+  assert(dl->items[0].pgno == 0 && dl->items[dl->length + 1].pgno == P_INVALID);+  if (mdbx_audit_enabled()) {+    for (const MDBX_dp *ptr = dl->items + dl->sorted; --ptr > dl->items;) {+      assert(ptr[0].pgno < ptr[1].pgno);+      assert(ptr[0].pgno >= NUM_METAS);+    }+  }++  switch (dl->length - dl->sorted) {+  default:+    /* sort a whole */+    mdbx_dpl_sort_slowpath(dl);+    break;+  case 0:+    /* whole sorted cases */+    break;++#define LINEAR_SEARCH_CASE(N)                                                  \+  case N:                                                                      \+    if (dl->items[dl->length - N + 1].pgno == pgno)                            \+      return dl->length - N + 1;                                               \+    __fallthrough++    /* try linear search until the threshold */+    LINEAR_SEARCH_CASE(16); /* fall through */+    LINEAR_SEARCH_CASE(15); /* fall through */+    LINEAR_SEARCH_CASE(14); /* fall through */+    LINEAR_SEARCH_CASE(13); /* fall through */+    LINEAR_SEARCH_CASE(12); /* fall through */+    LINEAR_SEARCH_CASE(11); /* fall through */+    LINEAR_SEARCH_CASE(10); /* fall through */+    LINEAR_SEARCH_CASE(9);  /* fall through */+    LINEAR_SEARCH_CASE(8);  /* fall through */+    LINEAR_SEARCH_CASE(7);  /* fall through */+    LINEAR_SEARCH_CASE(6);  /* fall through */+    LINEAR_SEARCH_CASE(5);  /* fall through */+    LINEAR_SEARCH_CASE(4);  /* fall through */+    LINEAR_SEARCH_CASE(3);  /* fall through */+    LINEAR_SEARCH_CASE(2);  /* fall through */+  case 1:+    if (dl->items[dl->length].pgno == pgno)+      return dl->length;+    /* continue bsearch on the sorted part */+    break;+  }+  return (unsigned)(dp_bsearch(dl->items + 1, dl->sorted, pgno) - dl->items);+}++static __inline bool mdbx_dpl_intersect(MDBX_dpl *dl, pgno_t pgno,+                                        unsigned npages) {+  assert(dl->sorted == dl->length);+  assert(dl->items[0].pgno == 0 && dl->items[dl->length + 1].pgno == P_INVALID);+  unsigned const n = mdbx_dpl_search(dl, pgno);+  assert(n >= 1 && n <= dl->length + 1);+  assert(pgno <= dl->items[n].pgno);+  assert(pgno > dl->items[n - 1].pgno);+  const MDBX_page *const prev = dl->items[n - 1].ptr;+  const bool rc =+      /* intersection with founded */ pgno + npages > dl->items[n].pgno ||+      (/* intersection with prev */ unlikely(IS_OVERFLOW(prev)) &&+       prev->mp_pgno + prev->mp_pages > pgno);+  if (mdbx_assert_enabled()) {+    bool check = false;+    for (unsigned i = 1; i <= dl->length; ++i) {+      const MDBX_page *const dp = dl->items[i].ptr;+      if (!(dp->mp_pgno /* begin */ >= /* end */ pgno + npages ||+            dp->mp_pgno + (IS_OVERFLOW(dp) ? dp->mp_pages : 1) /* end */ <=+                /* begin */ pgno))+        check |= true;+    }+    assert(check == rc);+  }+  return rc;+}++static __always_inline unsigned mdbx_dpl_exist(MDBX_dpl *dl, pgno_t pgno) {+  unsigned i = mdbx_dpl_search(dl, pgno);+  assert((int)i > 0);+  return (dl->items[i].pgno == pgno) ? i : 0;+}++static __always_inline MDBX_page *mdbx_dpl_find(MDBX_dpl *dl, pgno_t pgno) {+  const unsigned i = mdbx_dpl_search(dl, pgno);+  assert((int)i > 0);+  return (dl->items[i].pgno == pgno) ? dl->items[i].ptr : nullptr;+}++static __maybe_unused const MDBX_page *debug_dpl_find(const MDBX_dpl *dl,+                                                      const pgno_t pgno) {+  assert(dl->items[0].pgno == 0 && dl->items[dl->length + 1].pgno == P_INVALID);+  for (unsigned i = dl->length; i > dl->sorted; --i)+    if (dl->items[i].pgno == pgno)+      return dl->items[i].ptr;++  if (dl->sorted) {+    const unsigned i =+        (unsigned)(dp_bsearch(dl->items + 1, dl->sorted, pgno) - dl->items);+    if (dl->items[i].pgno == pgno)+      return dl->items[i].ptr;+  }+  return nullptr;+}++static void mdbx_dpl_remove(MDBX_dpl *dl, unsigned i) {+  assert((int)i > 0 && i <= dl->length);+  assert(dl->items[0].pgno == 0 && dl->items[dl->length + 1].pgno == P_INVALID);+  dl->sorted -= dl->sorted >= i;+  dl->length -= 1;+  memmove(dl->items + i, dl->items + i + 1,+          (dl->length - i + 2) * sizeof(dl->items[0]));+  assert(dl->items[0].pgno == 0 && dl->items[dl->length + 1].pgno == P_INVALID);+}++static __always_inline int __must_check_result+mdbx_dpl_append(MDBX_txn *txn, pgno_t pgno, MDBX_page *page) {+  MDBX_dpl *dl = txn->tw.dirtylist;+  assert(dl->length <= MDBX_PGL_LIMIT + MDBX_PNL_GRANULATE);+  assert(dl->items[0].pgno == 0 && dl->items[dl->length + 1].pgno == P_INVALID);+  if (mdbx_audit_enabled()) {+    for (unsigned i = dl->length; i > 0; --i) {+      assert(dl->items[i].pgno != pgno);+      if (unlikely(dl->items[i].pgno == pgno))+        return MDBX_PROBLEM;+    }+  }++  const unsigned length = dl->length + 1;+  const unsigned sorted =+      (dl->sorted == dl->length && dl->items[dl->length].pgno < pgno)+          ? length+          : dl->sorted;++  if (unlikely(dl->length == dl->detent)) {+    if (unlikely(dl->detent >= MDBX_PGL_LIMIT)) {+      mdbx_error("DPL is full (MDBX_PGL_LIMIT %u)", MDBX_PGL_LIMIT);+      return MDBX_TXN_FULL;+    }+    const size_t size = (dl->detent < MDBX_PNL_INITIAL * 42)+                            ? dl->detent + dl->detent+                            : dl->detent + dl->detent / 2;+    dl = mdbx_dpl_reserve(txn, size);+    if (unlikely(!dl))+      return MDBX_ENOMEM;+    mdbx_tassert(txn, dl->length < dl->detent);+  }++  /* copy the stub beyond the end */+  dl->items[length + 1] = dl->items[length];+  /* append page */+  dl->items[length].pgno = pgno;+  dl->items[length].ptr = page;+  dl->length = length;+  dl->sorted = sorted;+  assert(dl->items[0].pgno == 0 && dl->items[dl->length + 1].pgno == P_INVALID);+  return MDBX_SUCCESS;+}++/*----------------------------------------------------------------------------*/++uint8_t mdbx_runtime_flags = MDBX_RUNTIME_FLAGS_INIT;+uint8_t mdbx_loglevel = MDBX_LOG_FATAL;+MDBX_debug_func *mdbx_debug_logger;++static __must_check_result int mdbx_page_retire(MDBX_cursor *mc, MDBX_page *mp);+static __must_check_result int mdbx_page_loose(MDBX_txn *txn, MDBX_page *mp);+static int mdbx_page_alloc(MDBX_cursor *mc, const unsigned num,+                           MDBX_page **const mp, int flags);+static txnid_t mdbx_kick_longlived_readers(MDBX_env *env,+                                           const txnid_t laggard);++static int mdbx_page_new(MDBX_cursor *mc, uint32_t flags, unsigned num,+                         MDBX_page **mp);+static int mdbx_page_touch(MDBX_cursor *mc);+static int mdbx_cursor_touch(MDBX_cursor *mc);++#define MDBX_END_NAMES                                                         \+  {                                                                            \+    "committed", "empty-commit", "abort", "reset", "reset-tmp", "fail-begin",  \+        "fail-beginchild"                                                      \+  }+enum {+  /* mdbx_txn_end operation number, for logging */+  MDBX_END_COMMITTED,+  MDBX_END_PURE_COMMIT,+  MDBX_END_ABORT,+  MDBX_END_RESET,+  MDBX_END_RESET_TMP,+  MDBX_END_FAIL_BEGIN,+  MDBX_END_FAIL_BEGINCHILD+};+#define MDBX_END_OPMASK 0x0F  /* mask for mdbx_txn_end() operation number */+#define MDBX_END_UPDATE 0x10  /* update env state (DBIs) */+#define MDBX_END_FREE 0x20    /* free txn unless it is MDBX_env.me_txn0 */+#define MDBX_END_EOTDONE 0x40 /* txn's cursors already closed */+#define MDBX_END_SLOT 0x80    /* release any reader slot if MDBX_NOTLS */+static int mdbx_txn_end(MDBX_txn *txn, const unsigned mode);++#if MDBX_DISABLE_PAGECHECKS+static int __must_check_result __mdbx_page_get(MDBX_cursor *mc, pgno_t pgno,+                                               MDBX_page **mp, int *lvl);+static __always_inline int __must_check_result mdbx_page_get(+    MDBX_cursor *mc, pgno_t pgno, MDBX_page **mp, int *lvl, txnid_t pp_txnid) {+  (void)pp_txnid;+  return __mdbx_page_get(mc, pgno, mp, lvl);+}+#else+static int __must_check_result mdbx_page_get(MDBX_cursor *mc, pgno_t pgno,+                                             MDBX_page **mp, int *lvl,+                                             txnid_t pp_txnid);+#endif /* MDBX_DISABLE_PAGECHECKS */+static int __must_check_result mdbx_page_search_root(MDBX_cursor *mc,+                                                     const MDBX_val *key,+                                                     int flags);++#define MDBX_PS_MODIFY 1+#define MDBX_PS_ROOTONLY 2+#define MDBX_PS_FIRST 4+#define MDBX_PS_LAST 8+static int __must_check_result mdbx_page_search(MDBX_cursor *mc,+                                                const MDBX_val *key, int flags);+static int __must_check_result mdbx_page_merge(MDBX_cursor *csrc,+                                               MDBX_cursor *cdst);+static int __must_check_result mdbx_page_flush(MDBX_txn *txn,+                                               const unsigned keep);++#define MDBX_SPLIT_REPLACE MDBX_APPENDDUP /* newkey is not new */+static int __must_check_result mdbx_page_split(MDBX_cursor *mc,+                                               const MDBX_val *newkey,+                                               MDBX_val *newdata,+                                               pgno_t newpgno, unsigned nflags);++static int __must_check_result mdbx_read_header(MDBX_env *env, MDBX_meta *meta,+                                                uint64_t *filesize,+                                                const int lck_exclusive);+static int __must_check_result mdbx_sync_locked(MDBX_env *env, unsigned flags,+                                                MDBX_meta *const pending);+static int mdbx_env_close0(MDBX_env *env);++static MDBX_node *mdbx_node_search(MDBX_cursor *mc, const MDBX_val *key,+                                   int *exactp);++static int __must_check_result mdbx_node_add_branch(MDBX_cursor *mc,+                                                    unsigned indx,+                                                    const MDBX_val *key,+                                                    pgno_t pgno);+static int __must_check_result mdbx_node_add_leaf(MDBX_cursor *mc,+                                                  unsigned indx,+                                                  const MDBX_val *key,+                                                  MDBX_val *data,+                                                  unsigned flags);+static int __must_check_result mdbx_node_add_leaf2(MDBX_cursor *mc,+                                                   unsigned indx,+                                                   const MDBX_val *key);++static void mdbx_node_del(MDBX_cursor *mc, size_t ksize);+static void mdbx_node_shrink(MDBX_page *mp, unsigned indx);+static int __must_check_result mdbx_node_move(MDBX_cursor *csrc,+                                              MDBX_cursor *cdst, int fromleft);+static int __must_check_result mdbx_node_read(MDBX_cursor *mc, MDBX_node *leaf,+                                              MDBX_val *data,+                                              const txnid_t pp_txnid);+static int __must_check_result mdbx_rebalance(MDBX_cursor *mc);+static int __must_check_result mdbx_update_key(MDBX_cursor *mc,+                                               const MDBX_val *key);++static void mdbx_cursor_pop(MDBX_cursor *mc);+static int __must_check_result mdbx_cursor_push(MDBX_cursor *mc, MDBX_page *mp);++static int __must_check_result mdbx_audit_ex(MDBX_txn *txn,+                                             unsigned retired_stored,+                                             bool dont_filter_gc);++static int __must_check_result mdbx_page_check(MDBX_cursor *const mc,+                                               const MDBX_page *const mp,+                                               unsigned options);+static int __must_check_result mdbx_cursor_check(MDBX_cursor *mc,+                                                 unsigned options);+static int __must_check_result mdbx_cursor_del0(MDBX_cursor *mc);+static int __must_check_result mdbx_del0(MDBX_txn *txn, MDBX_dbi dbi,+                                         const MDBX_val *key,+                                         const MDBX_val *data, unsigned flags);+#define SIBLING_LEFT 0+#define SIBLING_RIGHT 2+static int __must_check_result mdbx_cursor_sibling(MDBX_cursor *mc, int dir);+static int __must_check_result mdbx_cursor_next(MDBX_cursor *mc, MDBX_val *key,+                                                MDBX_val *data,+                                                MDBX_cursor_op op);+static int __must_check_result mdbx_cursor_prev(MDBX_cursor *mc, MDBX_val *key,+                                                MDBX_val *data,+                                                MDBX_cursor_op op);+static int __must_check_result mdbx_cursor_set(MDBX_cursor *mc, MDBX_val *key,+                                               MDBX_val *data,+                                               MDBX_cursor_op op, int *exactp);+static int __must_check_result mdbx_cursor_first(MDBX_cursor *mc, MDBX_val *key,+                                                 MDBX_val *data);+static int __must_check_result mdbx_cursor_last(MDBX_cursor *mc, MDBX_val *key,+                                                MDBX_val *data);++static int __must_check_result mdbx_cursor_init(MDBX_cursor *mc, MDBX_txn *txn,+                                                MDBX_dbi dbi);+static int __must_check_result mdbx_xcursor_init0(MDBX_cursor *mc);+static int __must_check_result mdbx_xcursor_init1(MDBX_cursor *mc,+                                                  MDBX_node *node,+                                                  const MDBX_page *mp);+static int __must_check_result mdbx_xcursor_init2(MDBX_cursor *mc,+                                                  MDBX_xcursor *src_mx,+                                                  bool new_dupdata);+static void cursor_copy_internal(const MDBX_cursor *csrc, MDBX_cursor *cdst);++static int __must_check_result mdbx_drop0(MDBX_cursor *mc, bool subs);+static int __must_check_result mdbx_fetch_sdb(MDBX_txn *txn, MDBX_dbi dbi);+static int __must_check_result mdbx_setup_dbx(MDBX_dbx *const dbx,+                                              const MDBX_db *const db,+                                              const unsigned pagesize);++static MDBX_cmp_func cmp_lexical, cmp_reverse, cmp_int_align4, cmp_int_align2,+    cmp_int_unaligned, cmp_lenfast;++static __inline MDBX_cmp_func *get_default_keycmp(unsigned flags);+static __inline MDBX_cmp_func *get_default_datacmp(unsigned flags);++__cold const char *mdbx_liberr2str(int errnum) {+  /* Table of descriptions for MDBX errors */+  static const char *const tbl[] = {+      "MDBX_KEYEXIST: Key/data pair already exists",+      "MDBX_NOTFOUND: No matching key/data pair found",+      "MDBX_PAGE_NOTFOUND: Requested page not found",+      "MDBX_CORRUPTED: Database is corrupted",+      "MDBX_PANIC: Environment had fatal error",+      "MDBX_VERSION_MISMATCH: DB version mismatch libmdbx",+      "MDBX_INVALID: File is not an MDBX file",+      "MDBX_MAP_FULL: Environment mapsize limit reached",+      "MDBX_DBS_FULL: Too many DBI-handles (maxdbs reached)",+      "MDBX_READERS_FULL: Too many readers (maxreaders reached)",+      NULL /* MDBX_TLS_FULL (-30789): unused in MDBX */,+      "MDBX_TXN_FULL: Transaction has too many dirty pages,"+      " i.e transaction is too big",+      "MDBX_CURSOR_FULL: Cursor stack limit reachedn - this usually indicates"+      " corruption, i.e branch-pages loop",+      "MDBX_PAGE_FULL: Internal error - Page has no more space",+      "MDBX_UNABLE_EXTEND_MAPSIZE: Database engine was unable to extend"+      " mapping, e.g. since address space is unavailable or busy,"+      " or Operation system not supported such operations",+      "MDBX_INCOMPATIBLE: Environment or database is not compatible"+      " with the requested operation or the specified flags",+      "MDBX_BAD_RSLOT: Invalid reuse of reader locktable slot,"+      " e.g. read-transaction already run for current thread",+      "MDBX_BAD_TXN: Transaction is not valid for requested operation,"+      " e.g. had errored and be must aborted, has a child, or is invalid",+      "MDBX_BAD_VALSIZE: Invalid size or alignment of key or data"+      " for target database, either invalid subDB name",+      "MDBX_BAD_DBI: The specified DBI-handle is invalid"+      " or changed by another thread/transaction",+      "MDBX_PROBLEM: Unexpected internal error, transaction should be aborted",+      "MDBX_BUSY: Another write transaction is running,"+      " or environment is already used while opening with MDBX_EXCLUSIVE flag",+  };++  if (errnum >= MDBX_KEYEXIST && errnum <= MDBX_BUSY) {+    int i = errnum - MDBX_KEYEXIST;+    return tbl[i];+  }++  switch (errnum) {+  case MDBX_SUCCESS:+    return "MDBX_SUCCESS: Successful";+  case MDBX_EMULTIVAL:+    return "MDBX_EMULTIVAL: The specified key has"+           " more than one associated value";+  case MDBX_EBADSIGN:+    return "MDBX_EBADSIGN: Wrong signature of a runtime object(s),"+           " e.g. memory corruption or double-free";+  case MDBX_WANNA_RECOVERY:+    return "MDBX_WANNA_RECOVERY: Database should be recovered,"+           " but this could NOT be done automatically for now"+           " since it opened in read-only mode";+  case MDBX_EKEYMISMATCH:+    return "MDBX_EKEYMISMATCH: The given key value is mismatched to the"+           " current cursor position";+  case MDBX_TOO_LARGE:+    return "MDBX_TOO_LARGE: Database is too large for current system,"+           " e.g. could NOT be mapped into RAM";+  case MDBX_THREAD_MISMATCH:+    return "MDBX_THREAD_MISMATCH: A thread has attempted to use a not"+           " owned object, e.g. a transaction that started by another thread";+  case MDBX_TXN_OVERLAPPING:+    return "MDBX_TXN_OVERLAPPING: Overlapping read and write transactions for"+           " the current thread";+  default:+    return NULL;+  }+}++const char *__cold mdbx_strerror_r(int errnum, char *buf, size_t buflen) {+  const char *msg = mdbx_liberr2str(errnum);+  if (!msg && buflen > 0 && buflen < INT_MAX) {+#if defined(_WIN32) || defined(_WIN64)+    const DWORD size = FormatMessageA(+        FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS, NULL,+        errnum, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), buf, (DWORD)buflen,+        NULL);+    return size ? buf : "FormatMessageA(FORMAT_MESSAGE_FROM_SYSTEM) failed";+#elif defined(_GNU_SOURCE) && defined(__GLIBC__)+    /* GNU-specific */+    if (errnum > 0)+      msg = strerror_r(errnum, buf, buflen);+#elif (_POSIX_C_SOURCE >= 200112L || _XOPEN_SOURCE >= 600)+    /* XSI-compliant */+    if (errnum > 0 && strerror_r(errnum, buf, buflen) == 0)+      msg = buf;+#else+    if (errnum > 0) {+      msg = strerror(errnum);+      if (msg) {+        strncpy(buf, msg, buflen);+        msg = buf;+      }+    }+#endif+    if (!msg) {+      (void)snprintf(buf, buflen, "error %d", errnum);+      msg = buf;+    }+    buf[buflen - 1] = '\0';+  }+  return msg;+}++const char *__cold mdbx_strerror(int errnum) {+#if defined(_WIN32) || defined(_WIN64)+  static char buf[1024];+  return mdbx_strerror_r(errnum, buf, sizeof(buf));+#else+  const char *msg = mdbx_liberr2str(errnum);+  if (!msg) {+    if (errnum > 0)+      msg = strerror(errnum);+    if (!msg) {+      static char buf[32];+      (void)snprintf(buf, sizeof(buf) - 1, "error %d", errnum);+      msg = buf;+    }+  }+  return msg;+#endif+}++#if defined(_WIN32) || defined(_WIN64) /* Bit of madness for Windows */+const char *mdbx_strerror_r_ANSI2OEM(int errnum, char *buf, size_t buflen) {+  const char *msg = mdbx_liberr2str(errnum);+  if (!msg && buflen > 0 && buflen < INT_MAX) {+    const DWORD size = FormatMessageA(+        FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS, NULL,+        errnum, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), buf, (DWORD)buflen,+        NULL);+    if (!size)+      msg = "FormatMessageA(FORMAT_MESSAGE_FROM_SYSTEM) failed";+    else if (!CharToOemBuffA(buf, buf, size))+      msg = "CharToOemBuffA() failed";+    else+      msg = buf;+  }+  return msg;+}++const char *mdbx_strerror_ANSI2OEM(int errnum) {+  static char buf[1024];+  return mdbx_strerror_r_ANSI2OEM(errnum, buf, sizeof(buf));+}+#endif /* Bit of madness for Windows */++void __cold mdbx_debug_log_va(int level, const char *function, int line,+                              const char *fmt, va_list args) {+  if (mdbx_debug_logger)+    mdbx_debug_logger(level, function, line, fmt, args);+  else {+#if defined(_WIN32) || defined(_WIN64)+    if (IsDebuggerPresent()) {+      int prefix_len = 0;+      char *prefix = nullptr;+      if (function && line > 0)+        prefix_len = mdbx_asprintf(&prefix, "%s:%d ", function, line);+      else if (function)+        prefix_len = mdbx_asprintf(&prefix, "%s: ", function);+      else if (line > 0)+        prefix_len = mdbx_asprintf(&prefix, "%d: ", line);+      if (prefix_len > 0 && prefix) {+        OutputDebugStringA(prefix);+        mdbx_free(prefix);+      }+      char *msg = nullptr;+      int msg_len = mdbx_vasprintf(&msg, fmt, args);+      if (msg_len > 0 && msg) {+        OutputDebugStringA(msg);+        mdbx_free(msg);+      }+    }+#else+    if (function && line > 0)+      fprintf(stderr, "%s:%d ", function, line);+    else if (function)+      fprintf(stderr, "%s: ", function);+    else if (line > 0)+      fprintf(stderr, "%d: ", line);+    vfprintf(stderr, fmt, args);+    fflush(stderr);+#endif+  }+}++void __cold mdbx_debug_log(int level, const char *function, int line,+                           const char *fmt, ...) {+  va_list args;+  va_start(args, fmt);+  mdbx_debug_log_va(level, function, line, fmt, args);+  va_end(args);+}++/* Dump a key in ascii or hexadecimal. */+const char *mdbx_dump_val(const MDBX_val *key, char *const buf,+                          const size_t bufsize) {+  if (!key)+    return "<null>";+  if (!key->iov_len)+    return "<empty>";+  if (!buf || bufsize < 4)+    return nullptr;++  bool is_ascii = true;+  const uint8_t *const data = key->iov_base;+  for (unsigned i = 0; i < key->iov_len; i++)+    if (data[i] < ' ' || data[i] > '~') {+      is_ascii = false;+      break;+    }++  if (is_ascii) {+    int len =+        snprintf(buf, bufsize, "%.*s",+                 (key->iov_len > INT_MAX) ? INT_MAX : (int)key->iov_len, data);+    assert(len > 0 && (unsigned)len < bufsize);+    (void)len;+  } else {+    char *const detent = buf + bufsize - 2;+    char *ptr = buf;+    *ptr++ = '<';+    for (unsigned i = 0; i < key->iov_len; i++) {+      const ptrdiff_t left = detent - ptr;+      assert(left > 0);+      int len = snprintf(ptr, left, "%02x", data[i]);+      if (len < 0 || len >= left)+        break;+      ptr += len;+    }+    if (ptr < detent) {+      ptr[0] = '>';+      ptr[1] = '\0';+    }+  }+  return buf;+}++/*------------------------------------------------------------------------------+ LY: debug stuff */++static const char *mdbx_leafnode_type(MDBX_node *n) {+  static const char *const tp[2][2] = {{"", ": DB"},+                                       {": sub-page", ": sub-DB"}};+  return F_ISSET(node_flags(n), F_BIGDATA)+             ? ": overflow page"+             : tp[F_ISSET(node_flags(n), F_DUPDATA)]+                 [F_ISSET(node_flags(n), F_SUBDATA)];+}++/* Display all the keys in the page. */+static __maybe_unused void mdbx_page_list(MDBX_page *mp) {+  pgno_t pgno = mp->mp_pgno;+  const char *type, *state = IS_DIRTY(mp) ? ", dirty" : "";+  MDBX_node *node;+  unsigned i, nkeys, nsize, total = 0;+  MDBX_val key;+  DKBUF;++  switch (mp->mp_flags &+          (P_BRANCH | P_LEAF | P_LEAF2 | P_META | P_OVERFLOW | P_SUBP)) {+  case P_BRANCH:+    type = "Branch page";+    break;+  case P_LEAF:+    type = "Leaf page";+    break;+  case P_LEAF | P_SUBP:+    type = "Leaf sub-page";+    break;+  case P_LEAF | P_LEAF2:+    type = "Leaf2 page";+    break;+  case P_LEAF | P_LEAF2 | P_SUBP:+    type = "Leaf2 sub-page";+    break;+  case P_OVERFLOW:+    mdbx_verbose("Overflow page %" PRIaPGNO " pages %u%s\n", pgno, mp->mp_pages,+                 state);+    return;+  case P_META:+    mdbx_verbose("Meta-page %" PRIaPGNO " txnid %" PRIu64 "\n", pgno,+                 unaligned_peek_u64(4, page_meta(mp)->mm_txnid_a));+    return;+  default:+    mdbx_verbose("Bad page %" PRIaPGNO " flags 0x%X\n", pgno, mp->mp_flags);+    return;+  }++  nkeys = page_numkeys(mp);+  mdbx_verbose("%s %" PRIaPGNO " numkeys %u%s\n", type, pgno, nkeys, state);++  for (i = 0; i < nkeys; i++) {+    if (IS_LEAF2(mp)) { /* LEAF2 pages have no mp_ptrs[] or node headers */+      key.iov_len = nsize = mp->mp_leaf2_ksize;+      key.iov_base = page_leaf2key(mp, i, nsize);+      total += nsize;+      mdbx_verbose("key %u: nsize %u, %s\n", i, nsize, DKEY(&key));+      continue;+    }+    node = page_node(mp, i);+    key.iov_len = node_ks(node);+    key.iov_base = node->mn_data;+    nsize = (unsigned)(NODESIZE + key.iov_len);+    if (IS_BRANCH(mp)) {+      mdbx_verbose("key %u: page %" PRIaPGNO ", %s\n", i, node_pgno(node),+                   DKEY(&key));+      total += nsize;+    } else {+      if (F_ISSET(node_flags(node), F_BIGDATA))+        nsize += sizeof(pgno_t);+      else+        nsize += (unsigned)node_ds(node);+      total += nsize;+      nsize += sizeof(indx_t);+      mdbx_verbose("key %u: nsize %u, %s%s\n", i, nsize, DKEY(&key),+                   mdbx_leafnode_type(node));+    }+    total = EVEN(total);+  }+  mdbx_verbose("Total: header %u + contents %u + unused %u\n",+               IS_LEAF2(mp) ? PAGEHDRSZ : PAGEHDRSZ + mp->mp_lower, total,+               page_room(mp));+}++/*----------------------------------------------------------------------------*/++/* Check if there is an initialized xcursor, so XCURSOR_REFRESH() is proper */+#define XCURSOR_INITED(mc)                                                     \+  ((mc)->mc_xcursor && ((mc)->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED))++/* Update sub-page pointer, if any, in mc->mc_xcursor.+ * Needed when the node which contains the sub-page may have moved.+ * Called with mp = mc->mc_pg[mc->mc_top], ki = mc->mc_ki[mc->mc_top]. */+#define XCURSOR_REFRESH(mc, mp, ki)                                            \+  do {                                                                         \+    MDBX_page *xr_pg = (mp);                                                   \+    MDBX_node *xr_node = page_node(xr_pg, ki);                                 \+    if ((node_flags(xr_node) & (F_DUPDATA | F_SUBDATA)) == F_DUPDATA)          \+      (mc)->mc_xcursor->mx_cursor.mc_pg[0] = node_data(xr_node);               \+  } while (0)++static __maybe_unused bool cursor_is_tracked(const MDBX_cursor *mc) {+  for (MDBX_cursor *scan = mc->mc_txn->tw.cursors[mc->mc_dbi]; scan;+       scan = scan->mc_next)+    if (mc == ((mc->mc_flags & C_SUB) ? &scan->mc_xcursor->mx_cursor : scan))+      return true;+  return false;+}++/* Perform act while tracking temporary cursor mn */+#define WITH_CURSOR_TRACKING(mn, act)                                          \+  do {                                                                         \+    mdbx_cassert(&(mn),                                                        \+                 mn.mc_txn->tw.cursors != NULL /* must be not rdonly txt */);  \+    mdbx_cassert(&(mn), !cursor_is_tracked(&(mn)));                            \+    MDBX_cursor mc_dummy;                                                      \+    MDBX_cursor **tracking_head = &(mn).mc_txn->tw.cursors[mn.mc_dbi];         \+    MDBX_cursor *tracked = &(mn);                                              \+    if ((mn).mc_flags & C_SUB) {                                               \+      mc_dummy.mc_flags = C_INITIALIZED;                                       \+      mc_dummy.mc_top = 0;                                                     \+      mc_dummy.mc_xcursor = (MDBX_xcursor *)&(mn);                             \+      tracked = &mc_dummy;                                                     \+    }                                                                          \+    tracked->mc_next = *tracking_head;                                         \+    *tracking_head = tracked;                                                  \+    { act; }                                                                   \+    *tracking_head = tracked->mc_next;                                         \+  } while (0)++int mdbx_cmp(const MDBX_txn *txn, MDBX_dbi dbi, const MDBX_val *a,+             const MDBX_val *b) {+  mdbx_assert(NULL, txn->mt_signature == MDBX_MT_SIGNATURE);+  return txn->mt_dbxs[dbi].md_cmp(a, b);+}++int mdbx_dcmp(const MDBX_txn *txn, MDBX_dbi dbi, const MDBX_val *a,+              const MDBX_val *b) {+  mdbx_assert(NULL, txn->mt_signature == MDBX_MT_SIGNATURE);+  return txn->mt_dbxs[dbi].md_dcmp(a, b);+}++/* Allocate memory for a page.+ * Re-use old malloc'd pages first for singletons, otherwise just malloc.+ * Set MDBX_TXN_ERROR on failure. */+static MDBX_page *mdbx_page_malloc(MDBX_txn *txn, unsigned num) {+  MDBX_env *env = txn->mt_env;+  MDBX_page *np = env->me_dp_reserve;+  size_t size = env->me_psize;+  if (likely(num == 1 && np)) {+    mdbx_assert(env, env->me_dp_reserve_len > 0);+    ASAN_UNPOISON_MEMORY_REGION(np, size);+    VALGRIND_MEMPOOL_ALLOC(env, np, size);+    VALGRIND_MAKE_MEM_DEFINED(&np->mp_next, sizeof(np->mp_next));+    env->me_dp_reserve = np->mp_next;+    env->me_dp_reserve_len -= 1;+  } else {+    size = pgno2bytes(env, num);+    np = mdbx_malloc(size);+    if (unlikely(!np)) {+      txn->mt_flags |= MDBX_TXN_ERROR;+      return np;+    }+    VALGRIND_MEMPOOL_ALLOC(env, np, size);+  }++  if ((env->me_flags & MDBX_NOMEMINIT) == 0) {+    /* For a single page alloc, we init everything after the page header.+     * For multi-page, we init the final page; if the caller needed that+     * many pages they will be filling in at least up to the last page. */+    size_t skip = PAGEHDRSZ;+    if (num > 1)+      skip += pgno2bytes(env, num - 1);+    memset((char *)np + skip, 0, size - skip);+  }+#if MDBX_DEBUG+  np->mp_pgno = 0;+#endif+  VALGRIND_MAKE_MEM_UNDEFINED(np, size);+  np->mp_flags = 0;+  np->mp_pages = num;+  return np;+}++/* Free a shadow dirty page */+static void mdbx_dpage_free(MDBX_env *env, MDBX_page *dp, unsigned npages) {+  VALGRIND_MAKE_MEM_UNDEFINED(dp, pgno2bytes(env, npages));+  ASAN_UNPOISON_MEMORY_REGION(dp, pgno2bytes(env, npages));+  if (MDBX_DEBUG || unlikely(env->me_flags & MDBX_PAGEPERTURB))+    memset(dp, -1, pgno2bytes(env, npages));+  if (npages == 1 &&+      env->me_dp_reserve_len < env->me_options.dp_reserve_limit) {+    ASAN_POISON_MEMORY_REGION((char *)dp + sizeof(dp->mp_next),+                              pgno2bytes(env, npages) - sizeof(dp->mp_next));+    dp->mp_next = env->me_dp_reserve;+    VALGRIND_MEMPOOL_FREE(env, dp);+    env->me_dp_reserve = dp;+    env->me_dp_reserve_len += 1;+  } else {+    /* large pages just get freed directly */+    VALGRIND_MEMPOOL_FREE(env, dp);+    mdbx_free(dp);+  }+}++/* Return all dirty pages to dpage list */+static void mdbx_dlist_free(MDBX_txn *txn) {+  MDBX_env *env = txn->mt_env;+  MDBX_dpl *const dl = txn->tw.dirtylist;+  const size_t len = dl->length;++  for (size_t i = 1; i <= len; i++) {+    MDBX_page *dp = dl->items[i].ptr;+    mdbx_dpage_free(env, dp, IS_OVERFLOW(dp) ? dp->mp_pages : 1);+  }++  mdbx_dpl_clear(dl);+}++static __always_inline MDBX_db *mdbx_outer_db(MDBX_cursor *mc) {+  mdbx_cassert(mc, (mc->mc_flags & C_SUB) != 0);+  MDBX_xcursor *mx = container_of(mc->mc_db, MDBX_xcursor, mx_db);+  MDBX_cursor_couple *couple = container_of(mx, MDBX_cursor_couple, inner);+  mdbx_cassert(mc, mc->mc_db == &couple->outer.mc_xcursor->mx_db);+  mdbx_cassert(mc, mc->mc_dbx == &couple->outer.mc_xcursor->mx_dbx);+  return couple->outer.mc_db;+}++static __cold __maybe_unused bool mdbx_dirtylist_check(MDBX_txn *txn) {+  const MDBX_dpl *const dl = txn->tw.dirtylist;+  assert(dl->items[0].pgno == 0 && dl->items[dl->length + 1].pgno == P_INVALID);+  if (!mdbx_audit_enabled())+    return true;++  unsigned loose = 0;+  for (unsigned i = dl->length; i > 0; --i) {+    const MDBX_page *const dp = dl->items[i].ptr;+    if (!dp)+      continue;++    mdbx_tassert(txn, dp->mp_pgno == dl->items[i].pgno);+    if (unlikely(dp->mp_pgno != dl->items[i].pgno))+      return false;++    mdbx_tassert(txn, dp->mp_flags & P_DIRTY);+    if (unlikely((dp->mp_flags & P_DIRTY) == 0))+      return false;+    if (dp->mp_flags & P_LOOSE) {+      mdbx_tassert(txn, dp->mp_flags == (P_LOOSE | P_DIRTY));+      if (unlikely(dp->mp_flags != (P_LOOSE | P_DIRTY)))+        return false;+      loose += 1;+    }++    const unsigned num = IS_OVERFLOW(dp) ? dp->mp_pages : 1;+    mdbx_tassert(txn, txn->mt_next_pgno >= dp->mp_pgno + num);+    if (unlikely(txn->mt_next_pgno < dp->mp_pgno + num))+      return false;++    if (i < dl->sorted) {+      mdbx_tassert(txn, dl->items[i + 1].pgno >= dp->mp_pgno + num);+      if (unlikely(dl->items[i + 1].pgno < dp->mp_pgno + num))+        return false;+    }++    const unsigned rpa = mdbx_pnl_search(txn->tw.reclaimed_pglist, dp->mp_pgno);+    mdbx_tassert(txn, rpa > MDBX_PNL_SIZE(txn->tw.reclaimed_pglist) ||+                          txn->tw.reclaimed_pglist[rpa] != dp->mp_pgno);+    if (rpa <= MDBX_PNL_SIZE(txn->tw.reclaimed_pglist) &&+        unlikely(txn->tw.reclaimed_pglist[rpa] == dp->mp_pgno))+      return false;+    if (num > 1) {+      const unsigned rpb =+          mdbx_pnl_search(txn->tw.reclaimed_pglist, dp->mp_pgno + num - 1);+      mdbx_tassert(txn, rpa == rpb);+      if (unlikely(rpa != rpb))+        return false;+    }+  }++  mdbx_tassert(txn, loose == txn->tw.loose_count);+  if (unlikely(loose != txn->tw.loose_count))+    return false;++  for (unsigned i = 1; i <= MDBX_PNL_SIZE(txn->tw.retired_pages); ++i) {+    const MDBX_page *const dp = debug_dpl_find(dl, txn->tw.retired_pages[i]);+    mdbx_tassert(txn, !dp);+    if (unlikely(dp))+      return false;+  }++  return true;+}++#if MDBX_ENABLE_REFUND+static void mdbx_refund_reclaimed(MDBX_txn *txn) {+  /* Scanning in descend order */+  pgno_t next_pgno = txn->mt_next_pgno;+  const MDBX_PNL pnl = txn->tw.reclaimed_pglist;+  mdbx_tassert(txn, MDBX_PNL_SIZE(pnl) && MDBX_PNL_MOST(pnl) == next_pgno - 1);+#if MDBX_PNL_ASCENDING+  unsigned i = MDBX_PNL_SIZE(pnl);+  mdbx_tassert(txn, pnl[i] == next_pgno - 1);+  while (--next_pgno, --i > 0 && pnl[i] == next_pgno - 1)+    ;+  MDBX_PNL_SIZE(pnl) = i;+#else+  unsigned i = 1;+  mdbx_tassert(txn, pnl[i] == next_pgno - 1);+  unsigned len = MDBX_PNL_SIZE(pnl);+  while (--next_pgno, ++i <= len && pnl[i] == next_pgno - 1)+    ;+  MDBX_PNL_SIZE(pnl) = len -= i - 1;+  for (unsigned move = 0; move < len; ++move)+    pnl[1 + move] = pnl[i + move];+#endif+  mdbx_verbose("refunded %" PRIaPGNO " pages: %" PRIaPGNO " -> %" PRIaPGNO,+               txn->mt_next_pgno - next_pgno, txn->mt_next_pgno, next_pgno);+  txn->mt_next_pgno = next_pgno;+  mdbx_tassert(txn, mdbx_pnl_check4assert(txn->tw.reclaimed_pglist,+                                          txn->mt_next_pgno - 1));+}++static void mdbx_refund_loose(MDBX_txn *txn) {+  mdbx_tassert(txn, txn->tw.loose_pages != nullptr);+  mdbx_tassert(txn, txn->tw.loose_count > 0);++  MDBX_dpl *const dl = txn->tw.dirtylist;+  mdbx_tassert(txn, dl->length >= txn->tw.loose_count);++  pgno_t onstack[MDBX_CACHELINE_SIZE * 8 / sizeof(pgno_t)];+  MDBX_PNL suitable = onstack;++  if (dl->length - dl->sorted > txn->tw.loose_count) {+    /* Dirty list is useless since unsorted. */+    if (bytes2pnl(sizeof(onstack)) < txn->tw.loose_count) {+      suitable = mdbx_pnl_alloc(txn->tw.loose_count);+      if (unlikely(!suitable))+        return /* this is not a reason for transaction fail */;+    }++    /* Collect loose-pages which may be refunded. */+    mdbx_tassert(txn, txn->mt_next_pgno >= MIN_PAGENO + txn->tw.loose_count);+    pgno_t most = MIN_PAGENO;+    unsigned w = 0;+    for (const MDBX_page *lp = txn->tw.loose_pages; lp; lp = lp->mp_next) {+      mdbx_tassert(txn, lp->mp_flags == (P_LOOSE | P_DIRTY));+      mdbx_tassert(txn, txn->mt_next_pgno > lp->mp_pgno);+      if (likely(txn->mt_next_pgno - txn->tw.loose_count <= lp->mp_pgno)) {+        mdbx_tassert(txn,+                     w < ((suitable == onstack) ? bytes2pnl(sizeof(onstack))+                                                : MDBX_PNL_ALLOCLEN(suitable)));+        suitable[++w] = lp->mp_pgno;+        most = (lp->mp_pgno > most) ? lp->mp_pgno : most;+      }+    }++    if (most + 1 == txn->mt_next_pgno) {+      /* Sort suitable list and refund pages at the tail. */+      MDBX_PNL_SIZE(suitable) = w;+      mdbx_pnl_sort(suitable);++      /* Scanning in descend order */+      const int step = MDBX_PNL_ASCENDING ? -1 : 1;+      const int begin = MDBX_PNL_ASCENDING ? MDBX_PNL_SIZE(suitable) : 1;+      const int end = MDBX_PNL_ASCENDING ? 0 : MDBX_PNL_SIZE(suitable) + 1;+      mdbx_tassert(txn, suitable[begin] >= suitable[end - step]);+      mdbx_tassert(txn, most == suitable[begin]);++      for (int i = begin + step; i != end; i += step) {+        if (suitable[i] != most - 1)+          break;+        most -= 1;+      }+      const unsigned refunded = txn->mt_next_pgno - most;+      mdbx_debug("refund-suitable %u pages %" PRIaPGNO " -> %" PRIaPGNO,+                 refunded, most, txn->mt_next_pgno);+      txn->tw.loose_count -= refunded;+      txn->tw.dirtyroom += refunded;+      assert(txn->tw.dirtyroom <= txn->mt_env->me_options.dp_limit);+      txn->mt_next_pgno = most;++      /* Filter-out dirty list */+      unsigned r = 0;+      w = 0;+      if (dl->sorted) {+        do {+          if (dl->items[++r].pgno < most) {+            if (++w != r)+              dl->items[w] = dl->items[r];+          }+        } while (r < dl->sorted);+        dl->sorted = w;+      }+      while (r < dl->length) {+        if (dl->items[++r].pgno < most) {+          if (++w != r)+            dl->items[w] = dl->items[r];+        }+      }+      mdbx_dpl_setlen(dl, w);+      mdbx_tassert(txn, txn->mt_parent || txn->tw.dirtyroom + dl->length ==+                                              txn->mt_env->me_options.dp_limit);+      goto unlink_loose;+    }+  } else {+    /* Dirtylist is mostly sorted, just refund loose pages at the end. */+    mdbx_dpl_sort(dl);+    mdbx_tassert(txn, dl->length < 2 ||+                          dl->items[1].pgno < dl->items[dl->length].pgno);+    mdbx_tassert(txn, dl->sorted == dl->length);++    /* Scan dirtylist tail-forward and cutoff suitable pages. */+    unsigned n;+    for (n = dl->length; dl->items[n].pgno == txn->mt_next_pgno - 1 &&+                         dl->items[n].ptr->mp_flags == (P_LOOSE | P_DIRTY);+         --n) {+      mdbx_tassert(txn, n > 0);+      MDBX_page *dp = dl->items[n].ptr;+      mdbx_debug("refund-sorted page %" PRIaPGNO, dp->mp_pgno);+      mdbx_tassert(txn, dp->mp_pgno == dl->items[n].pgno);+      txn->mt_next_pgno -= 1;+    }+    mdbx_dpl_setlen(dl, n);++    if (dl->sorted != dl->length) {+      const unsigned refunded = dl->sorted - dl->length;+      dl->sorted = dl->length;+      txn->tw.loose_count -= refunded;+      txn->tw.dirtyroom += refunded;+      mdbx_tassert(txn, txn->mt_parent || txn->tw.dirtyroom + dl->length ==+                                              txn->mt_env->me_options.dp_limit);+      assert(txn->tw.dirtyroom <= txn->mt_env->me_options.dp_limit);++      /* Filter-out loose chain & dispose refunded pages. */+    unlink_loose:+      for (MDBX_page **link = &txn->tw.loose_pages; *link;) {+        MDBX_page *dp = *link;+        mdbx_tassert(txn, dp->mp_flags == (P_LOOSE | P_DIRTY));+        if (txn->mt_next_pgno > dp->mp_pgno) {+          link = &dp->mp_next;+        } else {+          *link = dp->mp_next;+          if ((txn->mt_flags & MDBX_WRITEMAP) == 0)+            mdbx_dpage_free(txn->mt_env, dp, 1);+        }+      }+    }+  }++  mdbx_tassert(txn, mdbx_dirtylist_check(txn));+  mdbx_tassert(txn, txn->mt_parent || txn->tw.dirtyroom + dl->length ==+                                          txn->mt_env->me_options.dp_limit);+  if (suitable != onstack)+    mdbx_pnl_free(suitable);+  txn->tw.loose_refund_wl = txn->mt_next_pgno;+}++static bool mdbx_refund(MDBX_txn *txn) {+  const pgno_t before = txn->mt_next_pgno;++  if (txn->tw.loose_pages && txn->tw.loose_refund_wl > txn->mt_next_pgno)+    mdbx_refund_loose(txn);++  while (true) {+    if (MDBX_PNL_SIZE(txn->tw.reclaimed_pglist) == 0 ||+        MDBX_PNL_MOST(txn->tw.reclaimed_pglist) != txn->mt_next_pgno - 1)+      break;++    mdbx_refund_reclaimed(txn);+    if (!txn->tw.loose_pages || txn->tw.loose_refund_wl <= txn->mt_next_pgno)+      break;++    const pgno_t memo = txn->mt_next_pgno;+    mdbx_refund_loose(txn);+    if (memo == txn->mt_next_pgno)+      break;+  }++  if (before == txn->mt_next_pgno)+    return false;++  if (txn->tw.spill_pages)+    /* Squash deleted pagenums if we refunded any */+    mdbx_spill_purge(txn);++  return true;+}+#else  /* MDBX_ENABLE_REFUND */+static __inline bool mdbx_refund(MDBX_txn *txn) {+  (void)txn;+  /* No online auto-compactification. */+  return false;+}+#endif /* MDBX_ENABLE_REFUND */++static __cold void mdbx_kill_page(MDBX_env *env, MDBX_page *mp, pgno_t pgno,+                                  unsigned npages) {+  mdbx_debug("kill%s %u page %" PRIaPGNO, IS_DIRTY(mp) ? " dirty" : "", npages,+             pgno);+  mdbx_assert(env, pgno >= NUM_METAS && npages);+  if (IS_DIRTY(mp) || (env->me_flags & MDBX_WRITEMAP)) {+    const size_t bytes = pgno2bytes(env, npages);+    memset(mp, -1, bytes);+    mp->mp_pgno = pgno;+    if ((env->me_flags & MDBX_WRITEMAP) == 0)+      mdbx_pwrite(env->me_lazy_fd, mp, bytes, pgno2bytes(env, pgno));+  } else {+    struct iovec iov[MDBX_COMMIT_PAGES];+    iov[0].iov_len = env->me_psize;+    iov[0].iov_base = (char *)env->me_pbuf + env->me_psize;+    size_t iov_off = pgno2bytes(env, pgno);+    unsigned n = 1;+    while (--npages) {+      iov[n] = iov[0];+      if (++n == MDBX_COMMIT_PAGES) {+        mdbx_pwritev(env->me_lazy_fd, iov, MDBX_COMMIT_PAGES, iov_off,+                     pgno2bytes(env, MDBX_COMMIT_PAGES));+        iov_off += pgno2bytes(env, MDBX_COMMIT_PAGES);+        n = 0;+      }+    }+    mdbx_pwritev(env->me_lazy_fd, iov, n, iov_off, pgno2bytes(env, n));+  }+}++/* Remove page from dirty list */+static __inline void mdbx_page_wash(MDBX_txn *txn, const unsigned di,+                                    MDBX_page *const mp,+                                    const unsigned npages) {+  mdbx_tassert(txn, di && di <= txn->tw.dirtylist->length &&+                        txn->tw.dirtylist->items[di].ptr == mp);+  mdbx_dpl_remove(txn->tw.dirtylist, di);+  txn->tw.dirtyroom++;+  assert(txn->tw.dirtyroom <= txn->mt_env->me_options.dp_limit);+  mdbx_tassert(txn, txn->mt_parent ||+                        txn->tw.dirtyroom + txn->tw.dirtylist->length ==+                            txn->mt_env->me_options.dp_limit);+  mp->mp_txnid = INVALID_TXNID;+  mp->mp_flags = 0xFFFF;+  VALGRIND_MAKE_MEM_UNDEFINED(mp, PAGEHDRSZ);+  if (txn->mt_flags & MDBX_WRITEMAP) {+    VALGRIND_MAKE_MEM_NOACCESS(page_data(mp),+                               pgno2bytes(txn->mt_env, npages) - PAGEHDRSZ);+    ASAN_POISON_MEMORY_REGION(page_data(mp),+                              pgno2bytes(txn->mt_env, npages) - PAGEHDRSZ);+  } else+    mdbx_dpage_free(txn->mt_env, mp, npages);+}++/* Retire, loosen or free a single page.+ *+ * Saves single pages to a list for future reuse+ * in this same txn. It has been pulled from the GC+ * and already resides on the dirty list, but has been+ * deleted. Use these pages first before pulling again+ * from the GC.+ *+ * If the page wasn't dirtied in this txn, just add it+ * to this txn's free list. */+static int mdbx_page_loose(MDBX_txn *txn, MDBX_page *mp) {+  const unsigned npages = IS_OVERFLOW(mp) ? mp->mp_pages : 1;+  const pgno_t pgno = mp->mp_pgno;+  const bool is_dirty = IS_DIRTY(mp);++  if (is_dirty) {+    mdbx_tassert(txn, !txn->tw.spill_pages ||+                          !mdbx_pnl_exist(txn->tw.spill_pages, pgno << 1));+    mdbx_tassert(txn, debug_dpl_find(txn->tw.dirtylist, pgno) == mp ||+                          txn->mt_parent);+  } else {+    mdbx_tassert(txn, !debug_dpl_find(txn->tw.dirtylist, pgno));+  }++  const unsigned di = is_dirty ? mdbx_dpl_exist(txn->tw.dirtylist, pgno) : 0;+  const unsigned si = (!is_dirty && txn->tw.spill_pages)+                          ? mdbx_pnl_exist(txn->tw.spill_pages, pgno << 1)+                          : 0;++  if (MDBX_ENABLE_REFUND && unlikely(pgno + npages == txn->mt_next_pgno)) {+    const char *kind;+    if (di) {+      mdbx_tassert(txn, txn->tw.dirtylist->items[di].ptr == mp);+      if (unlikely(txn->tw.dirtylist->items[di].ptr != mp)) {+      wrong_dirty:+        mdbx_error("wrong dirty page 0x%p #%" PRIaPGNO,+                   __Wpedantic_format_voidptr(mp), pgno);+        txn->mt_flags |= MDBX_TXN_ERROR;+        return MDBX_PROBLEM;+      }+      /* Страница испачкана в этой транзакции, но до этого могла быть+       * аллоцирована, испачкана и пролита в одной из родительских транзакций.+       * Её МОЖНО вытолкнуть в нераспределенный хвост. */+      kind = "dirty";+      /* Remove from dirty list */+      mdbx_page_wash(txn, di, mp, npages);+    } else if (is_dirty) {+      /* The page MUST BE from parent transaction. */+      if (mdbx_audit_enabled()) {+        const MDBX_page *parent_dp = nullptr;+        for (MDBX_txn *parent = txn->mt_parent; parent && !parent_dp;+             parent = parent->mt_parent) {+          mdbx_tassert(txn,+                       !parent->tw.spill_pages ||+                           !mdbx_pnl_exist(parent->tw.spill_pages, pgno << 1));+          parent_dp = debug_dpl_find(parent->tw.dirtylist, pgno);+        }+        mdbx_tassert(txn, parent_dp == mp);+      }+      kind = "parent-dirty";+    } else if (si) {+      /* Страница пролита в этой транзакции, следовательно она аллоцирована+       * и запачкана в этой или одной из родительских транзакций.+       * Её МОЖНО вытолкнуть в нераспределенный хвост. */+      kind = "spilled";+      mdbx_spill_remove(txn, si, npages);+    } else {+      for (MDBX_txn *parent = txn->mt_parent;+           parent && (parent->mt_flags & MDBX_TXN_SPILLS);+           parent = parent->mt_parent)+        if (parent->tw.spill_pages &&+            mdbx_pnl_exist(parent->tw.spill_pages, pgno << 1)) {+          /* Страница аллоцирована, запачкана и пролита в одной из родительских+           * транзакций. Её МОЖНО вытолкнуть в нераспределенный хвост. */+          kind = "parent-spilled";+          goto refund;+        }+      /* Страница используется (входит в MVCC-снимки доступные читателям).+       * Её НЕЛЬЗЯ вытолкнуть в нераспределенных хвост. */+      goto retire;+    }+  refund:+    mdbx_debug("refunded %u %s page %" PRIaPGNO, npages, kind, pgno);+    txn->mt_next_pgno = pgno;+    mdbx_refund(txn);+    return MDBX_SUCCESS;+  }++  if (is_dirty) {+    if (di) {+      /* Dirty page from this transaction */+      mdbx_tassert(txn, txn->tw.dirtylist->items[di].ptr == mp);+      if (unlikely(txn->tw.dirtylist->items[di].ptr != mp))+        goto wrong_dirty;++      /* If suitable we can reuse it through loose list */+      if (likely(+              npages == 1 &&+              txn->tw.loose_count < txn->mt_env->me_options.dp_loose_limit &&+              (!MDBX_ENABLE_REFUND ||+               /* skip pages near to the end in favor of compactification */+               txn->mt_next_pgno >+                   pgno + txn->mt_env->me_options.dp_loose_limit ||+               txn->mt_next_pgno <= txn->mt_env->me_options.dp_loose_limit))) {+        mdbx_debug("loosen dirty page %" PRIaPGNO, pgno);+        mp->mp_flags = P_LOOSE | P_DIRTY;+        mp->mp_next = txn->tw.loose_pages;+        txn->tw.loose_pages = mp;+        txn->tw.loose_count++;+#if MDBX_ENABLE_REFUND+        txn->tw.loose_refund_wl = (pgno + 2 > txn->tw.loose_refund_wl)+                                      ? pgno + 2+                                      : txn->tw.loose_refund_wl;+#endif /* MDBX_ENABLE_REFUND */+        if (MDBX_DEBUG || unlikely(txn->mt_env->me_flags & MDBX_PAGEPERTURB))+          memset(page_data(mp), -1, txn->mt_env->me_psize - PAGEHDRSZ);+        VALGRIND_MAKE_MEM_NOACCESS(page_data(mp),+                                   txn->mt_env->me_psize - PAGEHDRSZ);+        ASAN_POISON_MEMORY_REGION(page_data(mp),+                                  txn->mt_env->me_psize - PAGEHDRSZ);+        return MDBX_SUCCESS;+      }++#if !MDBX_DEBUG && !defined(MDBX_USE_VALGRIND) && !defined(__SANITIZE_ADDRESS__)+      if (unlikely(txn->mt_env->me_flags & MDBX_PAGEPERTURB))+#endif+      {+        /* Страница могла быть изменена в одной из родительских транзакций,+         * в том числе, позже выгружена и затем снова загружена и изменена.+         * В обоих случаях её нельзя затирать на диске и помечать недоступной+         * в asan и/или valgrind */+        for (MDBX_txn *parent = txn->mt_parent;+             parent && (parent->mt_flags & MDBX_TXN_SPILLS);+             parent = parent->mt_parent) {+          if (parent->tw.spill_pages &&+              mdbx_pnl_intersect(parent->tw.spill_pages, pgno << 1,+                                 npages << 1))+            goto skip_invalidate;+          if (mdbx_dpl_intersect(parent->tw.dirtylist, pgno, npages))+            goto skip_invalidate;+        }++#if defined(MDBX_USE_VALGRIND) || defined(__SANITIZE_ADDRESS__)+        if (MDBX_DEBUG || unlikely(txn->mt_env->me_flags & MDBX_PAGEPERTURB))+#endif+          mdbx_kill_page(txn->mt_env, mp, pgno, npages);+        if (!(txn->mt_flags & MDBX_WRITEMAP)) {+          VALGRIND_MAKE_MEM_NOACCESS(page_data(pgno2page(txn->mt_env, pgno)),+                                     pgno2bytes(txn->mt_env, npages) -+                                         PAGEHDRSZ);+          ASAN_POISON_MEMORY_REGION(page_data(pgno2page(txn->mt_env, pgno)),+                                    pgno2bytes(txn->mt_env, npages) -+                                        PAGEHDRSZ);+        }+      }+    skip_invalidate:+      /* Remove from dirty list */+      mdbx_page_wash(txn, di, mp, npages);+    } else {+      /* Dirty page MUST BE a clone from (one of) parent transaction(s). */+      if (mdbx_audit_enabled()) {+        const MDBX_page *parent_dp = nullptr;+        /* Check parent(s)'s dirty lists. */+        for (MDBX_txn *parent = txn->mt_parent; parent && !parent_dp;+             parent = parent->mt_parent) {+          mdbx_tassert(txn,+                       !parent->tw.spill_pages ||+                           !mdbx_pnl_exist(parent->tw.spill_pages, pgno << 1));+          parent_dp = debug_dpl_find(parent->tw.dirtylist, pgno);+        }+        mdbx_tassert(txn, parent_dp == mp);+      }+    }++  reclaim:+    mdbx_debug("reclaim %u %s page %" PRIaPGNO, npages, "dirty", pgno);+    int rc = mdbx_pnl_insert_range(&txn->tw.reclaimed_pglist, pgno, npages);+    mdbx_tassert(txn,+                 mdbx_pnl_check4assert(txn->tw.reclaimed_pglist,+                                       txn->mt_next_pgno - MDBX_ENABLE_REFUND));+    mdbx_tassert(txn, mdbx_dirtylist_check(txn));+    return rc;+  }++  if (si) {+    /* Page ws spilled in this txn */+    mdbx_spill_remove(txn, si, npages);+    /* Страница могла быть выделена и затем пролита в этой транзакции,+     * тогда её необходимо поместить в reclaimed-список.+     * Либо она могла быть выделена в одной из родительских транзакций и затем+     * пролита в этой транзакции, тогда её необходимо поместить в retired-список+     * для последующей фильтрации при коммите. */+    for (MDBX_txn *parent = txn->mt_parent; parent;+         parent = parent->mt_parent) {+      if (mdbx_dpl_exist(parent->tw.dirtylist, pgno))+        goto retire;+    }+    /* Страница точно была выделена в этой транзакции+     * и теперь может быть использована повторно. */+    goto reclaim;+  } else {+    /* Страница может входить в доступный читателям MVCC-снимок, либо же она+     * могла быть выделена, а затем пролита в одной из родительских транзакций.+     * Поэтому пока помещаем её в retired-список, который будет фильтроваться+     * относительно dirty- и spilled-списков родительских транзакций при коммите+     * дочерних транзакций, либо же будет записан в GC в неизменном виде. */+  }++retire:+  mdbx_debug("retire %u page %" PRIaPGNO, npages, pgno);+  int rc = mdbx_pnl_append_range(false, &txn->tw.retired_pages, pgno, npages);+  mdbx_tassert(txn, mdbx_dirtylist_check(txn));+  return rc;+}++static int mdbx_page_retire(MDBX_cursor *mc, MDBX_page *mp) {+  if (unlikely(mc->mc_flags & C_SUB)) {+    MDBX_db *outer = mdbx_outer_db(mc);+    mdbx_cassert(mc, !IS_BRANCH(mp) || outer->md_branch_pages > 0);+    outer->md_branch_pages -= IS_BRANCH(mp);+    mdbx_cassert(mc, !IS_LEAF(mp) || outer->md_leaf_pages > 0);+    outer->md_leaf_pages -= IS_LEAF(mp);+    mdbx_cassert(mc, !IS_OVERFLOW(mp));+  }+  mdbx_cassert(mc, !IS_BRANCH(mp) || mc->mc_db->md_branch_pages > 0);+  mc->mc_db->md_branch_pages -= IS_BRANCH(mp);+  mdbx_cassert(mc, !IS_LEAF(mp) || mc->mc_db->md_leaf_pages > 0);+  mc->mc_db->md_leaf_pages -= IS_LEAF(mp);+  mdbx_cassert(mc, !IS_OVERFLOW(mp) ||+                       mc->mc_db->md_overflow_pages >= mp->mp_pages);+  mc->mc_db->md_overflow_pages -= IS_OVERFLOW(mp) ? mp->mp_pages : 0;+  return mdbx_page_loose(mc->mc_txn, mp);+}++static __must_check_result __always_inline int+mdbx_retire_pgno(MDBX_cursor *mc, const pgno_t pgno) {+  MDBX_page *mp;+  int rc;+  if (mdbx_audit_enabled()) {+    const unsigned save_flags = mc->mc_flags;+    mc->mc_flags |= C_RETIRING;+    rc = mdbx_page_get(mc, pgno, &mp, NULL, mc->mc_txn->mt_txnid);+    if (likely(rc == MDBX_SUCCESS))+      rc = mdbx_page_retire(mc, mp);+    mc->mc_flags = (mc->mc_flags & ~C_RETIRING) | (save_flags & C_RETIRING);+  } else {+    rc = mdbx_page_get(mc, pgno, &mp, NULL, mc->mc_txn->mt_txnid);+    if (likely(rc == MDBX_SUCCESS))+      rc = mdbx_page_retire(mc, mp);+  }+  return rc;+}++/* Toggle P_KEEP in dirty, non-overflow, non-sub pages watched by txn.+ *+ * [in] mc      A cursor handle for the current operation.+ * [in] pflags  Flags of the pages to update:+ *                - P_DIRTY to set P_KEEP,+ *                - P_DIRTY|P_KEEP to clear it. */+static void mdbx_cursor_xkeep(MDBX_cursor *mc, unsigned pflags) {+  const unsigned mask = P_SUBP | P_DIRTY | P_LOOSE | P_KEEP;+  if (mc->mc_flags & C_INITIALIZED) {+    MDBX_cursor *m3 = mc;+    for (;;) {+      MDBX_page *mp = NULL;+      for (unsigned j = 0; j < m3->mc_snum; j++) {+        mp = m3->mc_pg[j];+        if ((mp->mp_flags & mask) == pflags)+          mp->mp_flags ^= P_KEEP;+      }+      if (!(mp && IS_LEAF(mp)))+        break;+      /* Proceed to mx if it is at a sub-database */+      MDBX_xcursor *mx = m3->mc_xcursor;+      if (!(mx && (mx->mx_cursor.mc_flags & C_INITIALIZED)))+        break;+      const unsigned nkeys = page_numkeys(mp);+      unsigned ki = m3->mc_ki[m3->mc_top];+      mdbx_cassert(mc, nkeys > 0 &&+                           (ki < nkeys ||+                            (ki == nkeys && (mx->mx_cursor.mc_flags & C_EOF))));+      ki -= ki >= nkeys;+      if (!(node_flags(page_node(mp, ki)) & F_SUBDATA))+        break;+      m3 = &mx->mx_cursor;+    }+  }+}++/* Mark pages seen by cursors: First m0, then tracked cursors+ * [in] all     No shortcuts. Needed except after a full mdbx_page_flush(). */+static void mdbx_txn_xkeep(MDBX_txn *txn, MDBX_cursor *m0,+                           const unsigned pflags, const bool all) {+  if (m0)+    mdbx_cursor_xkeep(m0, pflags);++  for (unsigned i = FREE_DBI; i < txn->mt_numdbs; ++i)+    if (txn->mt_dbistate[i] & DBI_DIRTY)+      for (MDBX_cursor *mc = txn->tw.cursors[i]; mc; mc = mc->mc_next)+        if (mc != m0)+          mdbx_cursor_xkeep(mc, pflags);++  if (all) {+    /* Mark dirty root pages */+    const unsigned mask = P_SUBP | P_DIRTY | P_LOOSE | P_KEEP;+    for (unsigned i = 0; i < txn->mt_numdbs; i++) {+      if (txn->mt_dbistate[i] & DBI_DIRTY) {+        pgno_t pgno = txn->mt_dbs[i].md_root;+        if (pgno == P_INVALID)+          continue;+        MDBX_page *dp = mdbx_dpl_find(txn->tw.dirtylist, pgno);+        if (dp && (dp->mp_flags & mask) == pflags)+          dp->mp_flags ^= P_KEEP;+      }+    }+  }+}++/* Spill pages from the dirty list back to disk.+ * This is intended to prevent running into MDBX_TXN_FULL situations,+ * but note that they may still occur in a few cases:+ *+ * 1) our estimate of the txn size could be too small. Currently this+ *  seems unlikely, except with a large number of MDBX_MULTIPLE items.+ *+ * 2) child txns may run out of space if their parents dirtied a+ *  lot of pages and never spilled them. TODO: we probably should do+ *  a preemptive spill during mdbx_txn_begin() of a child txn, if+ *  the parent's dirtyroom is below a given threshold.+ *+ * Otherwise, if not using nested txns, it is expected that apps will+ * not run into MDBX_TXN_FULL any more. The pages are flushed to disk+ * the same way as for a txn commit, e.g. their P_DIRTY flag is cleared.+ * If the txn never references them again, they can be left alone.+ * If the txn only reads them, they can be used without any fuss.+ * If the txn writes them again, they can be dirtied immediately without+ * going thru all of the work of mdbx_page_touch(). Such references are+ * handled by mdbx_page_unspill().+ *+ * Also note, we never spill DB root pages, nor pages of active cursors,+ * because we'll need these back again soon anyway. And in nested txns,+ * we can't spill a page in a child txn if it was already spilled in a+ * parent txn. That would alter the parent txns' data even though+ * the child hasn't committed yet, and we'd have no way to undo it if+ * the child aborted. */+static int mdbx_txn_spill(MDBX_txn *txn, MDBX_cursor *m0, unsigned need) {+#ifndef MDBX_DEBUG_SPILLING+  if (likely(txn->tw.dirtyroom >= need))+    return MDBX_SUCCESS;+  unsigned spill = need - txn->tw.dirtyroom;+#else+  /* spill at least one page if defined MDBX_DEBUG_SPILLING */+  unsigned spill = (need > txn->tw.dirtyroom) ? need - txn->tw.dirtyroom : 1;+#endif /* MDBX_DEBUG_SPILLING */++  const unsigned dirty = txn->tw.dirtylist->length;+  const unsigned spill_min =+      txn->mt_env->me_options.spill_min_denominator+          ? dirty / txn->mt_env->me_options.spill_min_denominator+          : 0;+  const unsigned spill_max =+      dirty - (txn->mt_env->me_options.spill_max_denominator+                   ? dirty / txn->mt_env->me_options.spill_max_denominator+                   : 0);+  spill = (spill > spill_min) ? spill : spill_min;+  spill = (spill < spill_max) ? spill : spill_max;+  if (!spill)+    return MDBX_SUCCESS;++  mdbx_notice("spilling %u dirty-entries (have %u dirty-room, need %u)", spill,+              txn->tw.dirtyroom, need);+  mdbx_tassert(txn, txn->tw.dirtylist->length >= spill);++  int rc;+  if (!txn->tw.spill_pages) {+    txn->tw.spill_least_removed = INT_MAX;+    txn->tw.spill_pages = mdbx_pnl_alloc(spill);+    if (unlikely(!txn->tw.spill_pages)) {+      rc = MDBX_ENOMEM;+      goto bailout;+    }+  } else {+    /* purge deleted slots */+    mdbx_spill_purge(txn);+    rc = mdbx_pnl_reserve(&txn->tw.spill_pages, spill);+    (void)rc /* ignore since the resulting list may be shorter+     and mdbx_pnl_append() will increase pnl on demand */+        ;+  }++  /* Preserve pages which may soon be dirtied again */+  mdbx_txn_xkeep(txn, m0, P_DIRTY, true);++  MDBX_dpl *const dl = mdbx_dpl_sort(txn->tw.dirtylist);+  /* Save the page IDs of all the pages we're flushing */+  /* flush from the tail forward, this saves a lot of shifting later on. */+  const unsigned dl_len_before = dl->length;+  unsigned spilled = 0;+  unsigned keep = dl_len_before;+  for (; keep && spill; keep--) {+    const pgno_t pgno = dl->items[keep].pgno;+    MDBX_page *dp = dl->items[keep].ptr;+    const unsigned npages = IS_OVERFLOW(dp) ? dp->mp_pages : 1;+    if (dp->mp_flags & (P_LOOSE | P_KEEP)) {+      mdbx_debug("skip %s %u page %" PRIaPGNO,+                 (dp->mp_flags & P_LOOSE) ? "loose" : "keep", npages,+                 dp->mp_pgno);+    skip:+      continue;+    }+    /* Can't spill twice,+     * make sure it's not already in a parent's spill list(s). */+    MDBX_txn *parent = txn->mt_parent;+    if (parent && (parent->mt_flags & MDBX_TXN_SPILLS)) {+      do+        if (parent->tw.spill_pages &&+            mdbx_pnl_intersect(parent->tw.spill_pages, pgno << 1,+                               npages << 1)) {+          mdbx_debug("skip parent-spilled %u page %" PRIaPGNO, npages, pgno);+          dp->mp_flags |= P_KEEP;+          goto skip;+        }+      while ((parent = parent->mt_parent) != nullptr);+    }+    mdbx_debug("spill %u page %" PRIaPGNO, npages, dp->mp_pgno);+    rc = mdbx_pnl_append_range(true, &txn->tw.spill_pages, pgno << 1, npages);+    if (unlikely(rc != MDBX_SUCCESS))+      goto bailout;+    spill--;+    spilled += 1;+  }+  mdbx_pnl_sort(txn->tw.spill_pages);++  /* Flush the spilled part of dirty list */+  rc = mdbx_page_flush(txn, keep);+  if (unlikely(rc != MDBX_SUCCESS))+    goto bailout;++  /* Reset any dirty pages we kept that page_flush didn't see */+  mdbx_tassert(txn, dl_len_before - spilled == dl->length);+  mdbx_txn_xkeep(txn, m0, P_DIRTY | P_KEEP, keep > 0);+  mdbx_tassert(txn, mdbx_dirtylist_check(txn));++bailout:+  txn->mt_flags |= rc ? MDBX_TXN_ERROR : MDBX_TXN_SPILLS;+  return rc;+}++static int mdbx_cursor_spill(MDBX_cursor *mc, const MDBX_val *key,+                             const MDBX_val *data) {+  if (mc->mc_flags & C_SUB)+    return MDBX_SUCCESS;+  MDBX_txn *txn = mc->mc_txn;+  if (txn->mt_flags & MDBX_WRITEMAP)+    return MDBX_SUCCESS;++  /* Estimate how much space this operation will take: */+  /* 1) Max b-tree height, reasonable enough with including dups' sub-tree */+  unsigned need = CURSOR_STACK + 3;+  /* 2) GC/FreeDB for any payload */+  if (mc->mc_dbi > FREE_DBI) {+    need += txn->mt_dbs[FREE_DBI].md_depth + 3;+    /* 3) Named DBs also dirty the main DB */+    if (mc->mc_dbi > MAIN_DBI)+      need += txn->mt_dbs[MAIN_DBI].md_depth + 3;+  }+  /* 4) Factor the key+data which to be put in */+  need += bytes2pgno(txn->mt_env, node_size(key, data)) + 1;+  return mdbx_txn_spill(txn, mc, need);+}++/*----------------------------------------------------------------------------*/++static __always_inline bool meta_bootid_match(const MDBX_meta *meta) {+  return memcmp(&meta->mm_bootid, &bootid, 16) == 0 &&+         (bootid.x | bootid.y) != 0;+}++static bool meta_weak_acceptable(const MDBX_env *env, const MDBX_meta *meta,+                                 const int lck_exclusive) {+  return lck_exclusive ? /* exclusive lock */ meta_bootid_match(meta)+                       : /* db already opened */ env->me_lck &&+                             (env->me_lck->mti_envmode.weak & MDBX_RDONLY) == 0;+}++#define METAPAGE(env, n) page_meta(pgno2page(env, n))+#define METAPAGE_END(env) METAPAGE(env, NUM_METAS)++static __inline txnid_t meta_txnid(const MDBX_env *env, const MDBX_meta *meta,+                                   const bool allow_volatile) {+  mdbx_memory_fence(mo_AcquireRelease, false);+  txnid_t a = unaligned_peek_u64(4, &meta->mm_txnid_a);+  txnid_t b = unaligned_peek_u64(4, &meta->mm_txnid_b);+  if (allow_volatile)+    return (a == b) ? a : 0;+  mdbx_assert(env, a == b);+  return a;+}++static __inline txnid_t mdbx_meta_txnid_stable(const MDBX_env *env,+                                               const MDBX_meta *meta) {+  return meta_txnid(env, meta, false);+}++static __inline txnid_t mdbx_meta_txnid_fluid(const MDBX_env *env,+                                              const MDBX_meta *meta) {+  return meta_txnid(env, meta, true);+}++static __inline void mdbx_meta_update_begin(const MDBX_env *env,+                                            MDBX_meta *meta, txnid_t txnid) {+  mdbx_assert(env, meta >= METAPAGE(env, 0) && meta < METAPAGE_END(env));+  mdbx_assert(env, unaligned_peek_u64(4, meta->mm_txnid_a) < txnid &&+                       unaligned_peek_u64(4, meta->mm_txnid_b) < txnid);+  (void)env;+  unaligned_poke_u64(4, meta->mm_txnid_b, 0);+  mdbx_memory_fence(mo_AcquireRelease, true);+  unaligned_poke_u64(4, meta->mm_txnid_a, txnid);+}++static __inline void mdbx_meta_update_end(const MDBX_env *env, MDBX_meta *meta,+                                          txnid_t txnid) {+  mdbx_assert(env, meta >= METAPAGE(env, 0) && meta < METAPAGE_END(env));+  mdbx_assert(env, unaligned_peek_u64(4, meta->mm_txnid_a) == txnid);+  mdbx_assert(env, unaligned_peek_u64(4, meta->mm_txnid_b) < txnid);+  (void)env;+  mdbx_jitter4testing(true);+  memcpy(&meta->mm_bootid, &bootid, 16);+  unaligned_poke_u64(4, meta->mm_txnid_b, txnid);+  mdbx_memory_fence(mo_AcquireRelease, true);+}++static __inline void mdbx_meta_set_txnid(const MDBX_env *env, MDBX_meta *meta,+                                         txnid_t txnid) {+  mdbx_assert(env, !env->me_map || meta < METAPAGE(env, 0) ||+                       meta >= METAPAGE_END(env));+  (void)env;+  /* update inconsistent since this function used ONLY for filling meta-image+   * for writing, but not the actual meta-page */+  memcpy(&meta->mm_bootid, &bootid, 16);+  unaligned_poke_u64(4, meta->mm_txnid_a, txnid);+  unaligned_poke_u64(4, meta->mm_txnid_b, txnid);+}++static __inline uint64_t mdbx_meta_sign(const MDBX_meta *meta) {+  uint64_t sign = MDBX_DATASIGN_NONE;+#if 0 /* TODO */+  sign = hippeus_hash64(...);+#else+  (void)meta;+#endif+  /* LY: newer returns MDBX_DATASIGN_NONE or MDBX_DATASIGN_WEAK */+  return (sign > MDBX_DATASIGN_WEAK) ? sign : ~sign;+}++enum meta_choise_mode { prefer_last, prefer_steady };++static __inline bool mdbx_meta_ot(const enum meta_choise_mode mode,+                                  const MDBX_env *env, const MDBX_meta *a,+                                  const MDBX_meta *b) {+  mdbx_jitter4testing(true);+  txnid_t txnid_a = mdbx_meta_txnid_fluid(env, a);+  txnid_t txnid_b = mdbx_meta_txnid_fluid(env, b);++  mdbx_jitter4testing(true);+  switch (mode) {+  default:+    assert(false);+    __unreachable();+    /* fall through */+    __fallthrough;+  case prefer_steady:+    if (META_IS_STEADY(a) != META_IS_STEADY(b))+      return META_IS_STEADY(b);+    /* fall through */+    __fallthrough;+  case prefer_last:+    mdbx_jitter4testing(true);+    if (txnid_a == txnid_b)+      return META_IS_STEADY(b);+    return txnid_a < txnid_b;+  }+}++static __inline bool mdbx_meta_eq(const MDBX_env *env, const MDBX_meta *a,+                                  const MDBX_meta *b) {+  mdbx_jitter4testing(true);+  const txnid_t txnid = mdbx_meta_txnid_fluid(env, a);+  if (!txnid || txnid != mdbx_meta_txnid_fluid(env, b))+    return false;++  mdbx_jitter4testing(true);+  if (META_IS_STEADY(a) != META_IS_STEADY(b))+    return false;++  mdbx_jitter4testing(true);+  return true;+}++static int mdbx_meta_eq_mask(const MDBX_env *env) {+  MDBX_meta *m0 = METAPAGE(env, 0);+  MDBX_meta *m1 = METAPAGE(env, 1);+  MDBX_meta *m2 = METAPAGE(env, 2);++  int rc = mdbx_meta_eq(env, m0, m1) ? 1 : 0;+  if (mdbx_meta_eq(env, m1, m2))+    rc += 2;+  if (mdbx_meta_eq(env, m2, m0))+    rc += 4;+  return rc;+}++static __inline MDBX_meta *mdbx_meta_recent(const enum meta_choise_mode mode,+                                            const MDBX_env *env, MDBX_meta *a,+                                            MDBX_meta *b) {+  const bool a_older_that_b = mdbx_meta_ot(mode, env, a, b);+  mdbx_assert(env, !mdbx_meta_eq(env, a, b));+  return a_older_that_b ? b : a;+}++static __inline MDBX_meta *mdbx_meta_ancient(const enum meta_choise_mode mode,+                                             const MDBX_env *env, MDBX_meta *a,+                                             MDBX_meta *b) {+  const bool a_older_that_b = mdbx_meta_ot(mode, env, a, b);+  mdbx_assert(env, !mdbx_meta_eq(env, a, b));+  return a_older_that_b ? a : b;+}++static __inline MDBX_meta *+mdbx_meta_mostrecent(const enum meta_choise_mode mode, const MDBX_env *env) {+  MDBX_meta *m0 = METAPAGE(env, 0);+  MDBX_meta *m1 = METAPAGE(env, 1);+  MDBX_meta *m2 = METAPAGE(env, 2);++  MDBX_meta *head = mdbx_meta_recent(mode, env, m0, m1);+  head = mdbx_meta_recent(mode, env, head, m2);+  return head;+}++static MDBX_meta *mdbx_meta_steady(const MDBX_env *env) {+  return mdbx_meta_mostrecent(prefer_steady, env);+}++static MDBX_meta *mdbx_meta_head(const MDBX_env *env) {+  return mdbx_meta_mostrecent(prefer_last, env);+}++static txnid_t mdbx_recent_committed_txnid(const MDBX_env *env) {+  while (true) {+    const MDBX_meta *head = mdbx_meta_head(env);+    const txnid_t recent = mdbx_meta_txnid_fluid(env, head);+    mdbx_compiler_barrier();+    if (likely(head == mdbx_meta_head(env) &&+               recent == mdbx_meta_txnid_fluid(env, head)))+      return recent;+  }+}++static txnid_t mdbx_recent_steady_txnid(const MDBX_env *env) {+  while (true) {+    const MDBX_meta *head = mdbx_meta_steady(env);+    const txnid_t recent = mdbx_meta_txnid_fluid(env, head);+    mdbx_compiler_barrier();+    if (likely(head == mdbx_meta_steady(env) &&+               recent == mdbx_meta_txnid_fluid(env, head)))+      return recent;+  }+}++static const char *mdbx_durable_str(const MDBX_meta *const meta) {+  if (META_IS_STEADY(meta))+    return (unaligned_peek_u64(4, meta->mm_datasync_sign) ==+            mdbx_meta_sign(meta))+               ? "Steady"+               : "Tainted";+  return "Weak";+}++/*----------------------------------------------------------------------------*/++/* Find oldest txnid still referenced. */+static txnid_t mdbx_find_oldest(const MDBX_txn *txn) {+  mdbx_tassert(txn, (txn->mt_flags & MDBX_TXN_RDONLY) == 0);+  MDBX_env *env = txn->mt_env;+  const txnid_t edge = mdbx_recent_steady_txnid(env);+  mdbx_tassert(txn, edge <= txn->mt_txnid);++  MDBX_lockinfo *const lck = env->me_lck;+  if (unlikely(lck == NULL /* exclusive mode */))+    return atomic_store64(&env->me_lckless_stub.oldest, edge, mo_Relaxed);++  const txnid_t last_oldest =+      atomic_load64(&lck->mti_oldest_reader, mo_AcquireRelease);+  mdbx_tassert(txn, edge >= last_oldest);+  if (likely(last_oldest == edge))+    return edge;++  const uint32_t nothing_changed = MDBX_STRING_TETRAD("None");+  const uint32_t snap_readers_refresh_flag =+      atomic_load32(&lck->mti_readers_refresh_flag, mo_AcquireRelease);+  mdbx_jitter4testing(false);+  if (snap_readers_refresh_flag == nothing_changed)+    return last_oldest;++  txnid_t oldest = edge;+  atomic_store32(&lck->mti_readers_refresh_flag, nothing_changed, mo_Relaxed);+  const unsigned snap_nreaders =+      atomic_load32(&lck->mti_numreaders, mo_AcquireRelease);+  for (unsigned i = 0; i < snap_nreaders; ++i) {+    if (atomic_load32(&lck->mti_readers[i].mr_pid, mo_AcquireRelease)) {+      /* mdbx_jitter4testing(true); */+      const txnid_t snap = safe64_read(&lck->mti_readers[i].mr_txnid);+      if (oldest > snap && last_oldest <= /* ignore pending updates */ snap) {+        oldest = snap;+        if (oldest == last_oldest)+          return oldest;+      }+    }+  }++  if (oldest != last_oldest) {+    mdbx_notice("update oldest %" PRIaTXN " -> %" PRIaTXN, last_oldest, oldest);+    mdbx_tassert(txn, oldest >= lck->mti_oldest_reader.weak);+    atomic_store64(&lck->mti_oldest_reader, oldest, mo_Relaxed);+  }+  return oldest;+}++/* Find largest mvcc-snapshot still referenced. */+static __cold pgno_t mdbx_find_largest(MDBX_env *env, pgno_t largest) {+  MDBX_lockinfo *const lck = env->me_lck;+  if (likely(lck != NULL /* exclusive mode */)) {+    const unsigned snap_nreaders =+        atomic_load32(&lck->mti_numreaders, mo_AcquireRelease);+    for (unsigned i = 0; i < snap_nreaders; ++i) {+    retry:+      if (atomic_load32(&lck->mti_readers[i].mr_pid, mo_AcquireRelease)) {+        /* mdbx_jitter4testing(true); */+        const pgno_t snap_pages = atomic_load32(+            &lck->mti_readers[i].mr_snapshot_pages_used, mo_Relaxed);+        const txnid_t snap_txnid = safe64_read(&lck->mti_readers[i].mr_txnid);+        if (unlikely(+                snap_pages !=+                    atomic_load32(&lck->mti_readers[i].mr_snapshot_pages_used,+                                  mo_AcquireRelease) ||+                snap_txnid != safe64_read(&lck->mti_readers[i].mr_txnid)))+          goto retry;+        if (largest < snap_pages &&+            atomic_load64(&lck->mti_oldest_reader, mo_AcquireRelease) <=+                /* ignore pending updates */ snap_txnid &&+            snap_txnid <= env->me_txn0->mt_txnid)+          largest = snap_pages;+      }+    }+  }++  return largest;+}++/* Add a page to the txn's dirty list */+static int __must_check_result mdbx_page_dirty(MDBX_txn *txn, MDBX_page *mp) {+  mp->mp_txnid = INVALID_TXNID;+  mp->mp_flags |= P_DIRTY;+  if (unlikely(txn->tw.dirtyroom == 0)) {+    mdbx_error("Dirtyroom is depleted, DPL length %u",+               txn->tw.dirtylist->length);+    return MDBX_TXN_FULL;+  }+  const int rc = mdbx_dpl_append(txn, mp->mp_pgno, mp);+  if (unlikely(rc != MDBX_SUCCESS)) {+    txn->mt_flags |= MDBX_TXN_ERROR;+    return rc;+  }+  txn->tw.dirtyroom--;+  assert(txn->tw.dirtyroom <= txn->mt_env->me_options.dp_limit);+  mdbx_tassert(txn, txn->mt_parent ||+                        txn->tw.dirtyroom + txn->tw.dirtylist->length ==+                            txn->mt_env->me_options.dp_limit);+  mdbx_tassert(txn, mdbx_dirtylist_check(txn));+  return MDBX_SUCCESS;+}++#if !(defined(_WIN32) || defined(_WIN64))+static __always_inline __maybe_unused int ignore_enosys(int err) {+#ifdef ENOSYS+  if (err == ENOSYS)+    return MDBX_RESULT_TRUE;+#endif /* ENOSYS */+#ifdef ENOIMPL+  if (err == ENOIMPL)+    return MDBX_RESULT_TRUE;+#endif /* ENOIMPL */+#ifdef ENOTSUP+  if (err == ENOTSUP)+    return MDBX_RESULT_TRUE;+#endif /* ENOTSUP */+#ifdef ENOSUPP+  if (err == ENOSUPP)+    return MDBX_RESULT_TRUE;+#endif /* ENOSUPP */+#ifdef EOPNOTSUPP+  if (err == EOPNOTSUPP)+    return MDBX_RESULT_TRUE;+#endif /* EOPNOTSUPP */+  if (err == EAGAIN)+    return MDBX_RESULT_TRUE;+  return err;+}+#endif /* defined(_WIN32) || defined(_WIN64) */++/* Turn on/off readahead. It's harmful when the DB is larger than RAM. */+static __cold int mdbx_set_readahead(MDBX_env *env, const size_t offset,+                                     const size_t length, const bool enable) {+  assert(length > 0);+  mdbx_notice("readahead %s %u..%u", enable ? "ON" : "OFF",+              bytes2pgno(env, offset), bytes2pgno(env, offset + length));++#if defined(F_RDAHEAD)+  if (unlikely(fcntl(env->me_lazy_fd, F_RDAHEAD, enable) == -1))+    return errno;+#endif /* F_RDAHEAD */++  if (enable) {+#if defined(F_RDADVISE)+    struct radvisory hint;+    hint.ra_offset = offset;+    hint.ra_count = length;+    (void)/* Ignore ENOTTY for DB on the ram-disk and so on */ fcntl(+        env->me_lazy_fd, F_RDADVISE, &hint);+#endif /* F_RDADVISE */+#if defined(MADV_WILLNEED)+    int err = madvise(env->me_map + offset, length, MADV_WILLNEED)+                  ? ignore_enosys(errno)+                  : MDBX_SUCCESS;+    if (unlikely(MDBX_IS_ERROR(err)))+      return err;+#elif defined(POSIX_MADV_WILLNEED)+    int err = ignore_enosys(+        posix_madvise(env->me_map + offset, length, POSIX_MADV_WILLNEED));+    if (unlikely(MDBX_IS_ERROR(err)))+      return err;+#elif defined(_WIN32) || defined(_WIN64)+    if (mdbx_PrefetchVirtualMemory) {+      WIN32_MEMORY_RANGE_ENTRY hint;+      hint.VirtualAddress = env->me_map + offset;+      hint.NumberOfBytes = length;+      (void)mdbx_PrefetchVirtualMemory(GetCurrentProcess(), 1, &hint, 0);+    }+#elif defined(POSIX_FADV_WILLNEED)+    int err = ignore_enosys(+        posix_fadvise(env->me_lazy_fd, offset, length, POSIX_FADV_WILLNEED));+    if (unlikely(MDBX_IS_ERROR(err)))+      return err;+#endif /* MADV_WILLNEED */+  } else {+#if defined(MADV_RANDOM)+    int err = madvise(env->me_map + offset, length, MADV_RANDOM)+                  ? ignore_enosys(errno)+                  : MDBX_SUCCESS;+    if (unlikely(MDBX_IS_ERROR(err)))+      return err;+#elif defined(POSIX_MADV_RANDOM)+    int err = ignore_enosys(+        posix_madvise(env->me_map + offset, length, POSIX_MADV_RANDOM));+    if (unlikely(MDBX_IS_ERROR(err)))+      return err;+#elif defined(POSIX_FADV_RANDOM)+    int err = ignore_enosys(+        posix_fadvise(env->me_lazy_fd, offset, length, POSIX_FADV_RANDOM));+    if (unlikely(MDBX_IS_ERROR(err)))+      return err;+#endif /* MADV_RANDOM */+  }+  return MDBX_SUCCESS;+}++static __cold int mdbx_mapresize(MDBX_env *env, const pgno_t used_pgno,+                                 const pgno_t size_pgno,+                                 const pgno_t limit_pgno, const bool implicit) {+  if ((env->me_flags & MDBX_WRITEMAP) && env->me_unsynced_pages->weak) {+    int err = mdbx_msync(&env->me_dxb_mmap, 0,+                         pgno_align2os_bytes(env, used_pgno), true);+    if (unlikely(err != MDBX_SUCCESS))+      return err;+  }++  const size_t limit_bytes = pgno_align2os_bytes(env, limit_pgno);+  const size_t size_bytes = pgno_align2os_bytes(env, size_pgno);+  const size_t prev_size = env->me_dxb_mmap.current;+  const size_t prev_limit = env->me_dxb_mmap.limit;+  const void *const prev_addr = env->me_map;++  mdbx_verbose("resize datafile/mapping: "+               "present %" PRIuPTR " -> %" PRIuPTR ", "+               "limit %" PRIuPTR " -> %" PRIuPTR,+               prev_size, size_bytes, prev_limit, limit_bytes);++  mdbx_assert(env, limit_bytes >= size_bytes);+  mdbx_assert(env, bytes2pgno(env, size_bytes) >= size_pgno);+  mdbx_assert(env, bytes2pgno(env, limit_bytes) >= limit_pgno);++#if defined(_WIN32) || defined(_WIN64)+  /* Acquire guard in exclusive mode for:+   *   - to avoid collision between read and write txns around env->me_dbgeo;+   *   - to avoid attachment of new reading threads (see mdbx_rdt_lock); */+  mdbx_srwlock_AcquireExclusive(&env->me_remap_guard);+  mdbx_handle_array_t *suspended = NULL;+  mdbx_handle_array_t array_onstack;+  int rc = MDBX_SUCCESS;+  if (limit_bytes == env->me_dxb_mmap.limit &&+      size_bytes == env->me_dxb_mmap.current &&+      size_bytes == env->me_dxb_mmap.filesize)+    goto bailout;++  /* 1) Windows allows only extending a read-write section, but not a+   *    corresponding mapped view. Therefore in other cases we must suspend+   *    the local threads for safe remap.+   * 2) At least on Windows 10 1803 the entire mapped section is unavailable+   *    for short time during NtExtendSection() or VirtualAlloc() execution.+   * 3) Under Wine runtime environment on Linux a section extending is not+   *    supported. Therefore thread suspending is always required.+   *+   * THEREFORE LOCAL THREADS SUSPENDING IS ALWAYS REQUIRED! */+  array_onstack.limit = ARRAY_LENGTH(array_onstack.handles);+  array_onstack.count = 0;+  suspended = &array_onstack;+  rc = mdbx_suspend_threads_before_remap(env, &suspended);+  if (rc != MDBX_SUCCESS) {+    mdbx_error("failed suspend-for-remap: errcode %d", rc);+    goto bailout;+  }+  const bool mapping_can_be_moved = !implicit;+#else /* Windows */+  /* Acquire guard to avoid collision between read and write txns+   * around env->me_dbgeo */+  bool mapping_can_be_moved = false;+  int rc = mdbx_fastmutex_acquire(&env->me_remap_guard);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;+  if (limit_bytes == env->me_dxb_mmap.limit &&+      size_bytes == env->me_dxb_mmap.current)+    goto bailout;++  if (limit_bytes != env->me_dxb_mmap.limit && env->me_lck && !implicit) {+    int err = mdbx_rdt_lock(env) /* lock readers table until remap done */;+    if (unlikely(MDBX_IS_ERROR(err))) {+      rc = err;+      goto bailout;+    }++    /* looking for readers from this process */+    MDBX_lockinfo *const lck = env->me_lck;+    const unsigned snap_nreaders =+        atomic_load32(&lck->mti_numreaders, mo_AcquireRelease);+    mapping_can_be_moved = true;+    for (unsigned i = 0; i < snap_nreaders; ++i) {+      if (lck->mti_readers[i].mr_pid.weak == env->me_pid &&+          lck->mti_readers[i].mr_tid.weak != mdbx_thread_self()) {+        /* the base address of the mapping can't be changed since+         * the other reader thread from this process exists. */+        mdbx_rdt_unlock(env);+        mapping_can_be_moved = false;+        break;+      }+    }+  }++#endif /* ! Windows */++  if (size_bytes < prev_size) {+    mdbx_notice("resize-MADV_%s %u..%u",+                (env->me_flags & MDBX_WRITEMAP) ? "REMOVE" : "DONTNEED",+                size_pgno, bytes2pgno(env, prev_size));+    rc = MDBX_RESULT_TRUE;+#if defined(MADV_REMOVE)+    if (env->me_flags & MDBX_WRITEMAP)+      rc =+          madvise(env->me_map + size_bytes, prev_size - size_bytes, MADV_REMOVE)+              ? ignore_enosys(errno)+              : MDBX_SUCCESS;+#endif /* MADV_REMOVE */+#if defined(MADV_DONTNEED)+    if (rc == MDBX_RESULT_TRUE)+      rc = madvise(env->me_map + size_bytes, prev_size - size_bytes,+                   MADV_DONTNEED)+               ? ignore_enosys(errno)+               : MDBX_SUCCESS;+#elif defined(POSIX_MADV_DONTNEED)+    if (rc == MDBX_RESULT_TRUE)+      rc = ignore_enosys(posix_madvise(env->me_map + size_bytes,+                                       prev_size - size_bytes,+                                       POSIX_MADV_DONTNEED));+#elif defined(POSIX_FADV_DONTNEED)+    if (rc == MDBX_RESULT_TRUE)+      rc = ignore_enosys(posix_fadvise(env->me_lazy_fd, size_bytes,+                                       prev_size - size_bytes,+                                       POSIX_FADV_DONTNEED));+#endif /* MADV_DONTNEED */+    if (unlikely(MDBX_IS_ERROR(rc)))+      goto bailout;+    if (env->me_discarded_tail->weak > size_pgno)+      env->me_discarded_tail->weak = size_pgno;+  }++  rc = mdbx_mresize(env->me_flags, &env->me_dxb_mmap, size_bytes, limit_bytes,+                    mapping_can_be_moved);+  if (rc == MDBX_SUCCESS && (env->me_flags & MDBX_NORDAHEAD) == 0) {+    const int readahead =+        mdbx_is_readahead_reasonable(size_bytes, -(intptr_t)prev_size);+    if (readahead == MDBX_RESULT_FALSE)+      rc = mdbx_set_readahead(+          env, 0, (size_bytes > prev_size) ? size_bytes : prev_size, false);+    else if (readahead == MDBX_RESULT_TRUE) {+      const size_t readahead_pivot =+          (limit_bytes != prev_limit || env->me_dxb_mmap.address != prev_addr+#if defined(_WIN32) || defined(_WIN64)+           || prev_size > size_bytes+#endif /* Windows */+           )+              ? 0 /* reassign readahead to the entire map+                     because it was remapped */+              : prev_size;+      if (size_bytes > readahead_pivot) {+        env->me_discarded_tail->weak = size_pgno;+        rc = mdbx_set_readahead(env, readahead_pivot,+                                size_bytes - readahead_pivot, true);+      }+    }+  }++bailout:+  if (rc == MDBX_SUCCESS) {+#if defined(_WIN32) || defined(_WIN64)+    mdbx_assert(env, size_bytes == env->me_dxb_mmap.current);+    mdbx_assert(env, size_bytes <= env->me_dxb_mmap.filesize);+    mdbx_assert(env, limit_bytes == env->me_dxb_mmap.limit);+#endif /* Windows */+#ifdef MDBX_USE_VALGRIND+    if (prev_limit != env->me_dxb_mmap.limit || prev_addr != env->me_map) {+      VALGRIND_DISCARD(env->me_valgrind_handle);+      env->me_valgrind_handle = 0;+      if (env->me_dxb_mmap.limit)+        env->me_valgrind_handle =+            VALGRIND_CREATE_BLOCK(env->me_map, env->me_dxb_mmap.limit, "mdbx");+    }+#endif /* MDBX_USE_VALGRIND */+  } else {+    if (rc != MDBX_UNABLE_EXTEND_MAPSIZE) {+      mdbx_error("failed resize datafile/mapping: "+                 "present %" PRIuPTR " -> %" PRIuPTR ", "+                 "limit %" PRIuPTR " -> %" PRIuPTR ", errcode %d",+                 prev_size, size_bytes, prev_limit, limit_bytes, rc);+    } else {+      mdbx_warning("unable resize datafile/mapping: "+                   "present %" PRIuPTR " -> %" PRIuPTR ", "+                   "limit %" PRIuPTR " -> %" PRIuPTR ", errcode %d",+                   prev_size, size_bytes, prev_limit, limit_bytes, rc);+    }+    if (!env->me_dxb_mmap.address) {+      env->me_flags |= MDBX_FATAL_ERROR;+      if (env->me_txn)+        env->me_txn->mt_flags |= MDBX_TXN_ERROR;+      rc = MDBX_PANIC;+    }+  }++#if defined(_WIN32) || defined(_WIN64)+  int err = MDBX_SUCCESS;+  mdbx_srwlock_ReleaseExclusive(&env->me_remap_guard);+  if (suspended) {+    err = mdbx_resume_threads_after_remap(suspended);+    if (suspended != &array_onstack)+      mdbx_free(suspended);+  }+#else+  if (env->me_lck && mapping_can_be_moved)+    mdbx_rdt_unlock(env);+  int err = mdbx_fastmutex_release(&env->me_remap_guard);+#endif /* Windows */+  if (err != MDBX_SUCCESS) {+    mdbx_fatal("failed resume-after-remap: errcode %d", err);+    return MDBX_PANIC;+  }+  return rc;+}++static __cold int mdbx_mapresize_implicit(MDBX_env *env, const pgno_t used_pgno,+                                          const pgno_t size_pgno,+                                          const pgno_t limit_pgno) {+  const pgno_t mapped_pgno = bytes2pgno(env, env->me_dxb_mmap.limit);+  mdbx_assert(env, mapped_pgno >= used_pgno);+  return mdbx_mapresize(+      env, used_pgno, size_pgno,+      (size_pgno > mapped_pgno)+          ? limit_pgno+          : /* The actual mapsize may be less since the geo.upper may be changed+               by other process. So, avoids remapping until it necessary. */+          mapped_pgno,+      true);+}++static int mdbx_meta_unsteady(MDBX_env *env, const txnid_t last_steady,+                              MDBX_meta *const meta) {+  const uint64_t wipe = MDBX_DATASIGN_NONE;+  if (unlikely(META_IS_STEADY(meta)) &&+      mdbx_meta_txnid_stable(env, meta) <= last_steady) {+    mdbx_warning("wipe txn #%" PRIaTXN ", meta %" PRIaPGNO, last_steady,+                 data_page(meta)->mp_pgno);+    if (env->me_flags & MDBX_WRITEMAP)+      unaligned_poke_u64(4, meta->mm_datasync_sign, wipe);+    else+      return mdbx_pwrite(env->me_lazy_fd, &wipe, sizeof(meta->mm_datasync_sign),+                         (uint8_t *)&meta->mm_datasync_sign - env->me_map);+  }+  return MDBX_SUCCESS;+}++__cold static int mdbx_wipe_steady(MDBX_env *env, const txnid_t last_steady) {+  int err = mdbx_meta_unsteady(env, last_steady, METAPAGE(env, 0));+  if (unlikely(err != MDBX_SUCCESS))+    return err;+  err = mdbx_meta_unsteady(env, last_steady, METAPAGE(env, 1));+  if (unlikely(err != MDBX_SUCCESS))+    return err;+  err = mdbx_meta_unsteady(env, last_steady, METAPAGE(env, 2));+  if (unlikely(err != MDBX_SUCCESS))+    return err;++  if (env->me_flags & MDBX_WRITEMAP) {+    mdbx_flush_incoherent_cpu_writeback();+    err = mdbx_msync(&env->me_dxb_mmap, 0, pgno_align2os_bytes(env, NUM_METAS),+                     false);+    if (unlikely(err != MDBX_SUCCESS))+      return err;+  } else {+#if MDBX_USE_SYNCFILERANGE+    static bool syncfilerange_unavailable;+    if (likely(!syncfilerange_unavailable)) {+      if (likely(!sync_file_range(+              env->me_lazy_fd, 0, pgno2bytes(env, NUM_METAS),+              SYNC_FILE_RANGE_WRITE | SYNC_FILE_RANGE_WAIT_AFTER)))+        goto done_filesync;+      err = errno;+      if (ignore_enosys(err) != MDBX_RESULT_TRUE)+        return err;+      syncfilerange_unavailable = true;+    }+#endif /* MDBX_USE_SYNCFILERANGE */+    err = mdbx_fsync(env->me_lazy_fd, MDBX_SYNC_DATA);+    if (unlikely(err != MDBX_SUCCESS))+      return err;+#if MDBX_USE_SYNCFILERANGE+  done_filesync:+#endif /* MDBX_USE_SYNCFILERANGE */+    mdbx_flush_incoherent_mmap(env->me_map, pgno2bytes(env, NUM_METAS),+                               env->me_os_psize);+  }++  if (likely(env->me_lck))+    /* force oldest refresh */+    atomic_store32(&env->me_lck->mti_readers_refresh_flag, true, mo_Relaxed);+  return MDBX_SUCCESS;+}++static __inline txnid_t pp_txnid4chk(const MDBX_page *mp, const MDBX_txn *txn) {+#if MDBX_DISABLE_PAGECHECKS+  (void)mp;+  (void)txn;+  return 0;+#else+  return IS_DIRTY(mp)+             ? txn->mt_txnid - 1+             : (/* maybe zero in legacy DB */ mp->mp_txnid ? mp->mp_txnid+                                                           : MIN_TXNID);+#endif /* !MDBX_DISABLE_PAGECHECKS */+}++static __inline txnid_t pp_txnid2chk(const MDBX_txn *txn) {+#ifdef MDBX_DEBUG_LEGACY+  if (txn->mt_txnid < 2222)+    return 0;+#endif+  return txn->mt_txnid;+}++/* Allocate page numbers and memory for writing.  Maintain mt_last_reclaimed,+ * mt_reclaimed_pglist and mt_next_pgno.  Set MDBX_TXN_ERROR on failure.+ *+ * If there are free pages available from older transactions, they+ * are re-used first. Otherwise allocate a new page at mt_next_pgno.+ * Do not modify the GC, just merge GC records into mt_reclaimed_pglist+ * and move mt_last_reclaimed to say which records were consumed.  Only this+ * function can create mt_reclaimed_pglist and move+ * mt_last_reclaimed/mt_next_pgno.+ *+ * [in] mc    cursor A cursor handle identifying the transaction and+ *            database for which we are allocating.+ * [in] num   the number of pages to allocate.+ * [out] mp   Address of the allocated page(s). Requests for multiple pages+ *            will always be satisfied by a single contiguous chunk of memory.+ *+ * Returns 0 on success, non-zero on failure.*/++#define MDBX_ALLOC_CACHE 1+#define MDBX_ALLOC_GC 2+#define MDBX_ALLOC_NEW 4+#define MDBX_ALLOC_ALL (MDBX_ALLOC_CACHE | MDBX_ALLOC_GC | MDBX_ALLOC_NEW)++__hot static int mdbx_page_alloc(MDBX_cursor *mc, const unsigned num,+                                 MDBX_page **const mp, int flags) {+  int rc;+  MDBX_txn *const txn = mc->mc_txn;+  MDBX_env *const env = txn->mt_env;+  MDBX_page *np;++  const unsigned coalesce_threshold =+      env->me_maxgc_ov1page - env->me_maxgc_ov1page / 4;+  if (likely(flags & MDBX_ALLOC_GC)) {+    flags |= env->me_flags & (MDBX_COALESCE | MDBX_LIFORECLAIM);+    if (MDBX_PNL_SIZE(txn->tw.reclaimed_pglist) > coalesce_threshold)+      flags &= ~MDBX_COALESCE;+    if (unlikely(+            /* If mc is updating the GC, then the retired-list cannot play+               catch-up with itself by growing while trying to save it. */+            (mc->mc_flags & C_RECLAIMING) ||+            /* avoid (recursive) search inside empty tree and while tree is+               updating, https://github.com/erthink/libmdbx/issues/31 */+            txn->mt_dbs[FREE_DBI].md_entries == 0 ||+            /* If our dirty list is already full, we can't touch GC */+            (txn->tw.dirtyroom < txn->mt_dbs[FREE_DBI].md_depth &&+             !(txn->mt_dbistate[FREE_DBI] & DBI_DIRTY))))+      flags &= ~(MDBX_ALLOC_GC | MDBX_COALESCE);+  }++  if (likely(num == 1 && (flags & MDBX_ALLOC_CACHE) != 0)) {+    /* If there are any loose pages, just use them */+    mdbx_assert(env, mp && num);+    if (likely(txn->tw.loose_pages)) {+#if MDBX_ENABLE_REFUND+      if (txn->tw.loose_refund_wl > txn->mt_next_pgno) {+        mdbx_refund(txn);+        if (unlikely(!txn->tw.loose_pages))+          goto no_loose;+      }+#endif /* MDBX_ENABLE_REFUND */++      np = txn->tw.loose_pages;+      txn->tw.loose_pages = np->mp_next;+      txn->tw.loose_count--;+      mdbx_debug("db %d use loose page %" PRIaPGNO, DDBI(mc), np->mp_pgno);+      mdbx_tassert(txn, np->mp_pgno < txn->mt_next_pgno);+      mdbx_ensure(env, np->mp_pgno >= NUM_METAS);+      VALGRIND_MAKE_MEM_UNDEFINED(page_data(np), page_space(txn->mt_env));+      ASAN_UNPOISON_MEMORY_REGION(page_data(np), page_space(txn->mt_env));+      np->mp_flags = P_DIRTY;+      np->mp_txnid = INVALID_TXNID;+      *mp = np;+      return MDBX_SUCCESS;+    }+  }+#if MDBX_ENABLE_REFUND+no_loose:+#endif /* MDBX_ENABLE_REFUND */++  mdbx_tassert(txn,+               mdbx_pnl_check4assert(txn->tw.reclaimed_pglist,+                                     txn->mt_next_pgno - MDBX_ENABLE_REFUND));+  pgno_t pgno, *re_list = txn->tw.reclaimed_pglist;+  unsigned range_begin = 0, re_len = MDBX_PNL_SIZE(re_list);+  txnid_t oldest = 0, last = 0;+  const unsigned wanna_range = num - 1;++  while (true) { /* hsr-kick retry loop */+    MDBX_cursor_couple recur;+    for (MDBX_cursor_op op = MDBX_FIRST;;+         op = (flags & MDBX_LIFORECLAIM) ? MDBX_PREV : MDBX_NEXT) {+      MDBX_val key, data;++      /* Seek a big enough contiguous page range.+       * Prefer pages with lower pgno. */+      mdbx_tassert(txn, mdbx_pnl_check4assert(txn->tw.reclaimed_pglist,+                                              txn->mt_next_pgno));+      if ((flags & (MDBX_COALESCE | MDBX_ALLOC_CACHE)) == MDBX_ALLOC_CACHE &&+          re_len > wanna_range) {+        mdbx_tassert(txn, MDBX_PNL_LAST(re_list) < txn->mt_next_pgno &&+                              MDBX_PNL_FIRST(re_list) < txn->mt_next_pgno);+        range_begin = MDBX_PNL_ASCENDING ? 1 : re_len;+        pgno = MDBX_PNL_LEAST(re_list);+        if (likely(wanna_range == 0))+          goto done;+#if MDBX_PNL_ASCENDING+        mdbx_tassert(txn, pgno == re_list[1] && range_begin == 1);+        while (true) {+          unsigned range_end = range_begin + wanna_range;+          if (re_list[range_end] - pgno == wanna_range)+            goto done;+          if (range_end == re_len)+            break;+          pgno = re_list[++range_begin];+        }+#else+        mdbx_tassert(txn, pgno == re_list[re_len] && range_begin == re_len);+        while (true) {+          if (re_list[range_begin - wanna_range] - pgno == wanna_range)+            goto done;+          if (range_begin == wanna_range)+            break;+          pgno = re_list[--range_begin];+        }+#endif /* MDBX_PNL sort-order */+      }++      if (op == MDBX_FIRST) { /* 1st iteration, setup cursor, etc */+        if (unlikely(!(flags & MDBX_ALLOC_GC)))+          break /* reclaiming is prohibited for now */;++        /* Prepare to fetch more and coalesce */+        oldest = (flags & MDBX_LIFORECLAIM)+                     ? mdbx_find_oldest(txn)+                     : atomic_load64(env->me_oldest, mo_AcquireRelease);+        rc = mdbx_cursor_init(&recur.outer, txn, FREE_DBI);+        if (unlikely(rc != MDBX_SUCCESS))+          goto fail;+        if (flags & MDBX_LIFORECLAIM) {+          /* Begin from oldest reader if any */+          if (oldest > MIN_TXNID) {+            last = oldest - 1;+            op = MDBX_SET_RANGE;+          }+        } else if (txn->tw.last_reclaimed) {+          /* Continue lookup from txn->tw.last_reclaimed to oldest reader */+          last = txn->tw.last_reclaimed;+          op = MDBX_SET_RANGE;+        }++        key.iov_base = &last;+        key.iov_len = sizeof(last);+      }++      if (!(flags & MDBX_LIFORECLAIM)) {+        /* Do not try fetch more if the record will be too recent */+        if (op != MDBX_FIRST && ++last >= oldest) {+          oldest = mdbx_find_oldest(txn);+          if (oldest <= last)+            break;+        }+      }++      rc = mdbx_cursor_get(&recur.outer, &key, NULL, op);+      if (rc == MDBX_NOTFOUND && (flags & MDBX_LIFORECLAIM)) {+        if (op == MDBX_SET_RANGE)+          continue;+        txnid_t snap = mdbx_find_oldest(txn);+        if (oldest < snap) {+          oldest = snap;+          last = oldest - 1;+          key.iov_base = &last;+          key.iov_len = sizeof(last);+          op = MDBX_SET_RANGE;+          rc = mdbx_cursor_get(&recur.outer, &key, NULL, op);+        }+      }+      if (unlikely(rc)) {+        if (rc == MDBX_NOTFOUND)+          break;+        goto fail;+      }++      if (!MDBX_DISABLE_PAGECHECKS &&+          unlikely(key.iov_len != sizeof(txnid_t))) {+        rc = MDBX_CORRUPTED;+        goto fail;+      }+      last = unaligned_peek_u64(4, key.iov_base);+      if (!MDBX_DISABLE_PAGECHECKS &&+          unlikely(last < MIN_TXNID || last > MAX_TXNID)) {+        rc = MDBX_CORRUPTED;+        goto fail;+      }+      if (oldest <= last) {+        oldest = mdbx_find_oldest(txn);+        if (oldest <= last) {+          if (flags & MDBX_LIFORECLAIM)+            continue;+          break;+        }+      }++      if (flags & MDBX_LIFORECLAIM) {+        /* skip IDs of records that already reclaimed */+        if (txn->tw.lifo_reclaimed) {+          size_t i;+          for (i = (size_t)MDBX_PNL_SIZE(txn->tw.lifo_reclaimed); i > 0; --i)+            if (txn->tw.lifo_reclaimed[i] == last)+              break;+          if (i)+            continue;+        }+      }++      /* Reading next GC record */+      np = recur.outer.mc_pg[recur.outer.mc_top];+      if (unlikely((rc = mdbx_node_read(+                        &recur.outer,+                        page_node(np, recur.outer.mc_ki[recur.outer.mc_top]),+                        &data, pp_txnid4chk(np, txn))) != MDBX_SUCCESS))+        goto fail;++      if ((flags & MDBX_LIFORECLAIM) && !txn->tw.lifo_reclaimed) {+        txn->tw.lifo_reclaimed = mdbx_txl_alloc();+        if (unlikely(!txn->tw.lifo_reclaimed)) {+          rc = MDBX_ENOMEM;+          goto fail;+        }+      }++      /* Append PNL from GC record to tw.reclaimed_pglist */+      mdbx_cassert(mc, (mc->mc_flags & C_GCFREEZE) == 0);+      pgno_t *gc_pnl = (pgno_t *)data.iov_base;+      mdbx_tassert(txn, data.iov_len >= MDBX_PNL_SIZEOF(gc_pnl));+      if (unlikely(data.iov_len < MDBX_PNL_SIZEOF(gc_pnl) ||+                   !mdbx_pnl_check(gc_pnl, txn->mt_next_pgno))) {+        rc = MDBX_CORRUPTED;+        goto fail;+      }+      const unsigned gc_len = MDBX_PNL_SIZE(gc_pnl);+      if (unlikely(/* resulting list is tool long */ gc_len ++                       MDBX_PNL_SIZE(txn->tw.reclaimed_pglist) >+                   env->me_options.rp_augment_limit) &&+          (((/* not a slot-request from gc-update */+             mp || (flags & MDBX_LIFORECLAIM) == 0 ||+             (txn->tw.lifo_reclaimed &&+              MDBX_PNL_SIZE(txn->tw.lifo_reclaimed))) &&+            /* have enough unallocated space */ pgno_add(+                txn->mt_next_pgno, num) <= txn->mt_geo.upper) ||+           gc_len + MDBX_PNL_SIZE(txn->tw.reclaimed_pglist) >=+               MDBX_PGL_LIMIT / 16 * 15)) {+        /* Stop reclaiming to avoid overflow the page list.+         * This is a rare case while search for a continuously multi-page region+         * in a large database. https://github.com/erthink/libmdbx/issues/123 */+        mdbx_debug("stop reclaiming to avoid PNL overflow: %u (current) + %u "+                   "(chunk) -> %u",+                   MDBX_PNL_SIZE(txn->tw.reclaimed_pglist), gc_len,+                   gc_len + MDBX_PNL_SIZE(txn->tw.reclaimed_pglist));+        flags &= ~(MDBX_ALLOC_GC | MDBX_COALESCE);+        break;+      }+      rc = mdbx_pnl_need(&txn->tw.reclaimed_pglist, gc_len);+      if (unlikely(rc != MDBX_SUCCESS))+        goto fail;+      re_list = txn->tw.reclaimed_pglist;++      /* Remember ID of GC record */+      if (flags & MDBX_LIFORECLAIM) {+        rc = mdbx_txl_append(&txn->tw.lifo_reclaimed, last);+        if (unlikely(rc != MDBX_SUCCESS))+          goto fail;+      }+      txn->tw.last_reclaimed = last;++      if (mdbx_log_enabled(MDBX_LOG_EXTRA)) {+        mdbx_debug_extra("PNL read txn %" PRIaTXN " root %" PRIaPGNO+                         " num %u, PNL",+                         last, txn->mt_dbs[FREE_DBI].md_root, gc_len);+        for (unsigned i = gc_len; i; i--)+          mdbx_debug_extra_print(" %" PRIaPGNO, gc_pnl[i]);+        mdbx_debug_extra_print("%s\n", ".");+      }++      /* Merge in descending sorted order */+      const unsigned prev_re_len = MDBX_PNL_SIZE(re_list);+      mdbx_pnl_xmerge(re_list, gc_pnl);+      /* re-check to avoid duplicates */+      if (!MDBX_DISABLE_PAGECHECKS &&+          unlikely(!mdbx_pnl_check(re_list, txn->mt_next_pgno))) {+        rc = MDBX_CORRUPTED;+        goto fail;+      }+      mdbx_tassert(txn, mdbx_dirtylist_check(txn));++      re_len = MDBX_PNL_SIZE(re_list);+      mdbx_tassert(txn, re_len == 0 || re_list[re_len] < txn->mt_next_pgno);+      if (MDBX_ENABLE_REFUND && re_len &&+          unlikely(MDBX_PNL_MOST(re_list) == txn->mt_next_pgno - 1)) {+        /* Refund suitable pages into "unallocated" space */+        mdbx_refund(txn);+        re_list = txn->tw.reclaimed_pglist;+        re_len = MDBX_PNL_SIZE(re_list);+      }++      /* Done for a kick-reclaim mode, actually no page needed */+      if (unlikely((flags & MDBX_ALLOC_CACHE) == 0))+        return MDBX_SUCCESS;++      /* Don't try to coalesce too much. */+      if (re_len /* current size */ > coalesce_threshold ||+          (re_len > prev_re_len && re_len - prev_re_len /* delta from prev */ >=+                                       coalesce_threshold / 2))+        flags &= ~MDBX_COALESCE;+    }++    if (F_ISSET(flags, MDBX_COALESCE | MDBX_ALLOC_CACHE)) {+      flags -= MDBX_COALESCE;+      continue;+    }++    /* There is no suitable pages in the GC and to be able to allocate+     * we should CHOICE one of:+     *  - make a new steady checkpoint if reclaiming was stopped by+     *    the last steady-sync, or wipe it in the MDBX_UTTERLY_NOSYNC mode;+     *  - kick lagging reader(s) if reclaiming was stopped by ones of it.+     *  - extend the database file. */++    /* Will use new pages from the map if nothing is suitable in the GC. */+    range_begin = 0;+    pgno = txn->mt_next_pgno;+    const pgno_t next = pgno_add(pgno, num);++    if (flags & MDBX_ALLOC_GC) {+      const MDBX_meta *const head = mdbx_meta_head(env);+      MDBX_meta *const steady = mdbx_meta_steady(env);+      /* does reclaiming stopped at the last steady point? */+      if (head != steady && META_IS_STEADY(steady) &&+          oldest == mdbx_meta_txnid_stable(env, steady)) {+        mdbx_debug("gc-kick-steady: head %" PRIaTXN "-%s, tail %" PRIaTXN+                   "-%s, oldest %" PRIaTXN,+                   mdbx_meta_txnid_stable(env, head), mdbx_durable_str(head),+                   mdbx_meta_txnid_stable(env, steady),+                   mdbx_durable_str(steady), oldest);+        rc = MDBX_RESULT_TRUE;+        const pgno_t autosync_threshold =+            atomic_load32(env->me_autosync_threshold, mo_Relaxed);+        const uint64_t autosync_period =+            atomic_load64(env->me_autosync_period, mo_Relaxed);+        /* wipe the last steady-point if one of:+         *  - UTTERLY_NOSYNC mode AND auto-sync threshold is NOT specified+         *  - UTTERLY_NOSYNC mode AND free space at steady-point is exhausted+         * otherwise, make a new steady-point if one of:+         *  - auto-sync threshold is specified and reached;+         *  - upper limit of database size is reached;+         *  - database is full (with the current file size)+         *       AND auto-sync threshold it NOT specified */+        if (F_ISSET(env->me_flags, MDBX_UTTERLY_NOSYNC) &&+            ((autosync_threshold | autosync_period) == 0 ||+             next >= steady->mm_geo.now)) {+          /* wipe steady checkpoint in MDBX_UTTERLY_NOSYNC mode+           * without any auto-sync threshold(s). */+          rc = mdbx_wipe_steady(env, oldest);+          mdbx_debug("gc-wipe-steady, rc %d", rc);+          mdbx_assert(env, steady != mdbx_meta_steady(env));+        } else if ((flags & MDBX_ALLOC_NEW) == 0 ||+                   (autosync_threshold &&+                    atomic_load32(env->me_unsynced_pages, mo_Relaxed) >=+                        autosync_threshold) ||+                   (autosync_period &&+                    mdbx_osal_monotime() -+                            atomic_load64(env->me_sync_timestamp, mo_Relaxed) >=+                        autosync_period) ||+                   next >= txn->mt_geo.upper ||+                   (next >= txn->mt_end_pgno &&+                    (autosync_threshold | autosync_period) == 0)) {+          /* make steady checkpoint. */+          MDBX_meta meta = *head;+          rc = mdbx_sync_locked(env, env->me_flags & MDBX_WRITEMAP, &meta);+          mdbx_debug("gc-make-steady, rc %d", rc);+          mdbx_assert(env, steady != mdbx_meta_steady(env));+        }+        if (rc == MDBX_SUCCESS) {+          if (mdbx_find_oldest(txn) > oldest)+            continue;+          /* it is reasonable check/kick lagging reader(s) here,+           * since we made a new steady point or wipe the last. */+          if (oldest < txn->mt_txnid - MDBX_TXNID_STEP &&+              mdbx_kick_longlived_readers(env, oldest) > oldest)+            continue;+        } else if (unlikely(rc != MDBX_RESULT_TRUE))+          goto fail;+      }+    }++    /* don't kick lagging reader(s) if is enough unallocated space+     * at the end of database file. */+    if ((flags & MDBX_ALLOC_NEW) && next <= txn->mt_end_pgno)+      goto done;+    if ((flags & MDBX_ALLOC_GC) && oldest < txn->mt_txnid - MDBX_TXNID_STEP &&+        mdbx_kick_longlived_readers(env, oldest) > oldest)+      continue;++    rc = MDBX_NOTFOUND;+    if (flags & MDBX_ALLOC_NEW) {+      rc = MDBX_MAP_FULL;+      if (next <= txn->mt_geo.upper && txn->mt_geo.grow_pv) {+        mdbx_assert(env, next > txn->mt_end_pgno);+        const pgno_t grow_step = pv2pages(txn->mt_geo.grow_pv);+        pgno_t aligned = pgno_align2os_pgno(+            env, pgno_add(next, grow_step - next % grow_step));++        if (aligned > txn->mt_geo.upper)+          aligned = txn->mt_geo.upper;+        mdbx_assert(env, aligned > txn->mt_end_pgno);++        mdbx_verbose("try growth datafile to %" PRIaPGNO " pages (+%" PRIaPGNO+                     ")",+                     aligned, aligned - txn->mt_end_pgno);+        rc = mdbx_mapresize_implicit(env, txn->mt_next_pgno, aligned,+                                     txn->mt_geo.upper);+        if (rc == MDBX_SUCCESS) {+          env->me_txn->mt_end_pgno = aligned;+          goto done;+        }++        mdbx_error("unable growth datafile to %" PRIaPGNO " pages (+%" PRIaPGNO+                   "), errcode %d",+                   aligned, aligned - txn->mt_end_pgno, rc);+      } else {+        mdbx_debug("gc-alloc: next %u > upper %u", next, txn->mt_geo.upper);+      }+    }++  fail:+    mdbx_tassert(txn,+                 mdbx_pnl_check4assert(txn->tw.reclaimed_pglist,+                                       txn->mt_next_pgno - MDBX_ENABLE_REFUND));+    if (likely(mp)) {+      *mp = nullptr;+      txn->mt_flags |= MDBX_TXN_ERROR;+    }+    mdbx_assert(env, rc != MDBX_SUCCESS);+    return rc;+  }++done:+  if (unlikely(mp == nullptr))+    return MDBX_SUCCESS;+  if (unlikely(txn->tw.dirtyroom < 1))+    return MDBX_TXN_FULL;+  mdbx_ensure(env, pgno >= NUM_METAS);+  if (env->me_flags & MDBX_WRITEMAP) {+    np = pgno2page(env, pgno);+    /* LY: reset no-access flag from mdbx_page_loose() */+    VALGRIND_MAKE_MEM_UNDEFINED(np, pgno2bytes(env, num));+    ASAN_UNPOISON_MEMORY_REGION(np, pgno2bytes(env, num));+  } else {+    if (unlikely(!(np = mdbx_page_malloc(txn, num)))) {+      rc = MDBX_ENOMEM;+      goto fail;+    }+  }++  if (range_begin) {+    mdbx_cassert(mc, (mc->mc_flags & C_GCFREEZE) == 0);+    mdbx_tassert(txn, pgno < txn->mt_next_pgno);+    mdbx_tassert(txn, pgno == re_list[range_begin]);+    /* Cutoff allocated pages from tw.reclaimed_pglist */+#if MDBX_PNL_ASCENDING+    for (unsigned i = range_begin + num; i <= re_len;)+      re_list[range_begin++] = re_list[i++];+    MDBX_PNL_SIZE(re_list) = re_len = range_begin - 1;+#else+    MDBX_PNL_SIZE(re_list) = re_len -= num;+    for (unsigned i = range_begin - num; i < re_len;)+      re_list[++i] = re_list[++range_begin];+#endif+    mdbx_tassert(txn,+                 mdbx_pnl_check4assert(txn->tw.reclaimed_pglist,+                                       txn->mt_next_pgno - MDBX_ENABLE_REFUND));+  } else {+    txn->mt_next_pgno = pgno + num;+    mdbx_assert(env, txn->mt_next_pgno <= txn->mt_end_pgno);+  }++  if (unlikely(env->me_flags & MDBX_PAGEPERTURB))+    memset(np, -1, pgno2bytes(env, num));+  VALGRIND_MAKE_MEM_UNDEFINED(np, pgno2bytes(env, num));++  np->mp_pgno = pgno;+  np->mp_leaf2_ksize = 0;+  np->mp_flags = 0;+  if ((mdbx_assert_enabled() || mdbx_audit_enabled()) && num > 1) {+    np->mp_pages = num;+    np->mp_flags = P_OVERFLOW;+  }+  rc = mdbx_page_dirty(txn, np);+  if (unlikely(rc != MDBX_SUCCESS))+    goto fail;+  *mp = np;++  mdbx_tassert(txn,+               mdbx_pnl_check4assert(txn->tw.reclaimed_pglist,+                                     txn->mt_next_pgno - MDBX_ENABLE_REFUND));+  return MDBX_SUCCESS;+}++/* Copy the used portions of a non-overflow page. */+__hot static void mdbx_page_copy(MDBX_page *dst, MDBX_page *src, size_t psize) {+  STATIC_ASSERT(UINT16_MAX > MAX_PAGESIZE - PAGEHDRSZ);+  STATIC_ASSERT(MIN_PAGESIZE > PAGEHDRSZ + NODESIZE * 4);+  if (!IS_LEAF2(src)) {+    size_t upper = src->mp_upper, lower = src->mp_lower, unused = upper - lower;++    /* If page isn't full, just copy the used portion. Adjust+     * alignment so memcpy may copy words instead of bytes. */+    if (unused >= MDBX_CACHELINE_SIZE * 2) {+      lower = ceil_powerof2(lower + PAGEHDRSZ, sizeof(void *));+      upper = floor_powerof2(upper + PAGEHDRSZ, sizeof(void *));+      memcpy(dst, src, lower);+      dst = (void *)((char *)dst + upper);+      src = (void *)((char *)src + upper);+      psize -= upper;+    }+  }+  memcpy(dst, src, psize);+}++/* Pull a page off the txn's spill list, if present.+ *+ * If a page being referenced was spilled to disk in this txn, bring+ * it back and make it dirty/writable again.+ *+ * [in] txn   the transaction handle.+ * [in] mp    the page being referenced. It must not be dirty.+ * [out] ret  the writable page, if any.+ *            ret is unchanged if mp wasn't spilled. */+static int __must_check_result mdbx_page_unspill(MDBX_txn *txn, MDBX_page *mp,+                                                 MDBX_page **ret) {+  mdbx_tassert(txn, !IS_DIRTY(mp));+  const pgno_t spilled_pgno = mp->mp_pgno << 1;+  const MDBX_txn *scan = txn;+  do {+    if ((scan->mt_flags & MDBX_TXN_SPILLS) == 0)+      break;+    if (!scan->tw.spill_pages)+      continue;+    const unsigned si = mdbx_pnl_exist(scan->tw.spill_pages, spilled_pgno);+    if (!si)+      continue;+    const unsigned npages = IS_OVERFLOW(mp) ? mp->mp_pages : 1;+    MDBX_page *np = mp;+    if ((txn->mt_flags & MDBX_WRITEMAP) == 0) {+      np = mdbx_page_malloc(txn, npages);+      if (unlikely(!np))+        return MDBX_ENOMEM;+      if (likely(npages == 1))+        mdbx_page_copy(np, mp, txn->mt_env->me_psize);+      else+        memcpy(np, mp, pgno2bytes(txn->mt_env, npages));+    }+    mdbx_debug("unspill page %" PRIaPGNO, mp->mp_pgno);+    if (scan == txn) {+      /* If in current txn, this page is no longer spilled.+       * If it happens to be the last page, truncate the spill list.+       * Otherwise mark it as deleted by setting the LSB. */+      mdbx_spill_remove(txn, si, npages);+    } /* otherwise, if belonging to a parent txn, the+       * page remains spilled until child commits */++    int rc = mdbx_page_dirty(txn, np);+    if (unlikely(rc != MDBX_SUCCESS)) {+      if ((txn->mt_flags & MDBX_WRITEMAP) == 0)+        mdbx_dpage_free(txn->mt_env, np, npages);+      return rc;+    }+    *ret = np;+    break;+  } while ((scan = scan->mt_parent) != nullptr);+  return MDBX_SUCCESS;+}++/* Touch a page: make it dirty and re-insert into tree with updated pgno.+ * Set MDBX_TXN_ERROR on failure.+ *+ * [in] mc  cursor pointing to the page to be touched+ *+ * Returns 0 on success, non-zero on failure. */+__hot static int mdbx_page_touch(MDBX_cursor *mc) {+  MDBX_page *const mp = mc->mc_pg[mc->mc_top], *np;+  MDBX_txn *txn = mc->mc_txn;+  MDBX_cursor *m2, *m3;+  pgno_t pgno;+  int rc;++  if (mdbx_assert_enabled()) {+    if (mc->mc_dbi >= CORE_DBS) {+      if (mc->mc_flags & C_SUB) {+        MDBX_xcursor *mx = container_of(mc->mc_db, MDBX_xcursor, mx_db);+        MDBX_cursor_couple *couple =+            container_of(mx, MDBX_cursor_couple, inner);+        mdbx_cassert(mc, mc->mc_db == &couple->outer.mc_xcursor->mx_db);+        mdbx_cassert(mc, mc->mc_dbx == &couple->outer.mc_xcursor->mx_dbx);+        mdbx_cassert(mc, *couple->outer.mc_dbistate & DBI_DIRTY);+      } else {+        mdbx_cassert(mc, *mc->mc_dbistate & DBI_DIRTY);+      }+      mdbx_cassert(mc, mc->mc_txn->mt_flags & MDBX_TXN_DIRTY);+    }+    mdbx_cassert(mc, !IS_OVERFLOW(mp));+    mdbx_tassert(txn, mdbx_dirtylist_check(txn));+  }++  if (!IS_DIRTY(mp)) {+    if (txn->mt_flags & MDBX_TXN_SPILLS) {+      np = NULL;+      rc = mdbx_page_unspill(txn, mp, &np);+      if (unlikely(rc))+        goto fail;+      if (likely(np))+        goto done;+    }++    if (unlikely((rc = mdbx_pnl_need(&txn->tw.retired_pages, 1)) ||+                 (rc = mdbx_page_alloc(mc, 1, &np, MDBX_ALLOC_ALL))))+      goto fail;++    pgno = np->mp_pgno;+    mdbx_debug("touched db %d page %" PRIaPGNO " -> %" PRIaPGNO, DDBI(mc),+               mp->mp_pgno, pgno);+    mdbx_cassert(mc, mp->mp_pgno != pgno);+    mdbx_pnl_xappend(txn->tw.retired_pages, mp->mp_pgno);+    /* Update the parent page, if any, to point to the new page */+    if (mc->mc_top) {+      MDBX_page *parent = mc->mc_pg[mc->mc_top - 1];+      MDBX_node *node = page_node(parent, mc->mc_ki[mc->mc_top - 1]);+      node_set_pgno(node, pgno);+    } else {+      mc->mc_db->md_root = pgno;+    }+  } else if (txn->mt_parent && !IS_SUBP(mp)) {+    mdbx_tassert(txn, (txn->mt_env->me_flags & MDBX_WRITEMAP) == 0);+    pgno = mp->mp_pgno;+    /* If txn has a parent, make sure the page is in our dirty list. */+    const MDBX_page *const dp = mdbx_dpl_find(txn->tw.dirtylist, pgno);+    if (dp) {+      if (unlikely(mp != dp)) { /* bad cursor? */+        mdbx_error("wrong page 0x%p #%" PRIaPGNO+                   " in the dirtylist, expecting %p",+                   __Wpedantic_format_voidptr(dp), pgno,+                   __Wpedantic_format_voidptr(mp));+        mc->mc_flags &= ~(C_INITIALIZED | C_EOF);+        rc = MDBX_PROBLEM;+        goto fail;+      }+      return MDBX_SUCCESS;+    }++    mdbx_debug("clone db %d page %" PRIaPGNO, DDBI(mc), mp->mp_pgno);+    mdbx_cassert(mc, txn->tw.dirtylist->length <=+                         MDBX_PGL_LIMIT + MDBX_PNL_GRANULATE);+    /* No - copy it */+    np = mdbx_page_malloc(txn, 1);+    if (unlikely(!np)) {+      rc = MDBX_ENOMEM;+      goto fail;+    }+    /* insert a clone of parent's dirty page, so don't touch dirtyroom */+    rc = mdbx_dpl_append(txn, pgno, np);+    if (unlikely(rc)) {+      mdbx_dpage_free(txn->mt_env, np, 1);+      goto fail;+    }++    np->mp_pgno = pgno;+    np->mp_txnid = INVALID_TXNID;+    np->mp_flags |= P_DIRTY;+    mdbx_tassert(txn, mdbx_dirtylist_check(txn));+  } else {+    return MDBX_SUCCESS;+  }++  mdbx_page_copy(np, mp, txn->mt_env->me_psize);+  np->mp_pgno = pgno;+  np->mp_txnid = INVALID_TXNID;+  np->mp_flags |= P_DIRTY;++done:+  /* Adjust cursors pointing to mp */+  mc->mc_pg[mc->mc_top] = np;+  m2 = txn->tw.cursors[mc->mc_dbi];+  if (mc->mc_flags & C_SUB) {+    for (; m2; m2 = m2->mc_next) {+      m3 = &m2->mc_xcursor->mx_cursor;+      if (m3->mc_snum < mc->mc_snum)+        continue;+      if (m3->mc_pg[mc->mc_top] == mp)+        m3->mc_pg[mc->mc_top] = np;+    }+  } else {+    for (; m2; m2 = m2->mc_next) {+      if (m2->mc_snum < mc->mc_snum)+        continue;+      if (m2 == mc)+        continue;+      if (m2->mc_pg[mc->mc_top] == mp) {+        m2->mc_pg[mc->mc_top] = np;+        if (XCURSOR_INITED(m2) && IS_LEAF(np))+          XCURSOR_REFRESH(m2, np, m2->mc_ki[mc->mc_top]);+      }+    }+  }+  return MDBX_SUCCESS;++fail:+  txn->mt_flags |= MDBX_TXN_ERROR;+  return rc;+}++__cold static int mdbx_env_sync_internal(MDBX_env *env, bool force,+                                         bool nonblock) {+  unsigned flags = env->me_flags & ~MDBX_NOMETASYNC;+  if (unlikely(flags & (MDBX_RDONLY | MDBX_FATAL_ERROR)))+    return MDBX_EACCESS;++  int rc = MDBX_RESULT_TRUE /* means "nothing to sync" */;+  bool need_unlock = false;+  if (nonblock && atomic_load32(env->me_unsynced_pages, mo_AcquireRelease) == 0)+    goto fastpath;++  const bool outside_txn = (env->me_txn0->mt_owner != mdbx_thread_self());+  if (outside_txn) {+    int err = mdbx_txn_lock(env, nonblock);+    if (unlikely(err != MDBX_SUCCESS))+      return err;+    need_unlock = true;+  }++  const MDBX_meta *head = mdbx_meta_head(env);+  pgno_t unsynced_pages = atomic_load32(env->me_unsynced_pages, mo_Relaxed);+  if (!META_IS_STEADY(head) || unsynced_pages) {+    const pgno_t autosync_threshold =+        atomic_load32(env->me_autosync_threshold, mo_Relaxed);+    const uint64_t autosync_period =+        atomic_load64(env->me_autosync_period, mo_Relaxed);+    if (force || (autosync_threshold && unsynced_pages >= autosync_threshold) ||+        (autosync_period &&+         mdbx_osal_monotime() -+                 atomic_load64(env->me_sync_timestamp, mo_Relaxed) >=+             autosync_period))+      flags &= MDBX_WRITEMAP /* clear flags for full steady sync */;++    if (outside_txn) {+      if (unsynced_pages > /* FIXME: define threshold */ 16 &&+          (flags & MDBX_SAFE_NOSYNC) == 0) {+        mdbx_assert(env, ((flags ^ env->me_flags) & MDBX_WRITEMAP) == 0);+        const size_t usedbytes = pgno_align2os_bytes(env, head->mm_geo.next);++        mdbx_txn_unlock(env);++        /* LY: pre-sync without holding lock to reduce latency for writer(s) */+        int err = (flags & MDBX_WRITEMAP)+                      ? mdbx_msync(&env->me_dxb_mmap, 0, usedbytes, false)+                      : mdbx_fsync(env->me_lazy_fd, MDBX_SYNC_DATA);+        if (unlikely(err != MDBX_SUCCESS))+          return err;++        err = mdbx_txn_lock(env, nonblock);+        if (unlikely(err != MDBX_SUCCESS))+          return err;++        /* LY: head and unsynced_pages may be changed. */+        head = mdbx_meta_head(env);+        unsynced_pages = atomic_load32(env->me_unsynced_pages, mo_Relaxed);+      }+      env->me_txn0->mt_txnid = meta_txnid(env, head, false);+      mdbx_find_oldest(env->me_txn0);+      rc = MDBX_RESULT_FALSE /* means "some data was synced" */;+    }++    if (!META_IS_STEADY(head) ||+        ((flags & MDBX_SAFE_NOSYNC) == 0 && unsynced_pages)) {+      mdbx_debug("meta-head %" PRIaPGNO ", %s, sync_pending %" PRIaPGNO,+                 data_page(head)->mp_pgno, mdbx_durable_str(head),+                 unsynced_pages);+      MDBX_meta meta = *head;+      int err = mdbx_sync_locked(env, flags | MDBX_SHRINK_ALLOWED, &meta);+      if (unlikely(err != MDBX_SUCCESS)) {+        if (need_unlock)+          mdbx_txn_unlock(env);+        return err;+      }+      rc = MDBX_RESULT_FALSE /* means "some data was synced" */;+    }+  }++fastpath:+  /* LY: sync meta-pages if MDBX_NOMETASYNC enabled+   *     and someone was not synced above. */+  if (rc == MDBX_RESULT_TRUE && (env->me_flags & MDBX_NOMETASYNC) != 0) {+    const txnid_t head_txnid = mdbx_recent_committed_txnid(env);+    if (atomic_load32(env->me_meta_sync_txnid, mo_Relaxed) !=+        (uint32_t)head_txnid) {+      rc = (flags & MDBX_WRITEMAP)+               ? mdbx_msync(&env->me_dxb_mmap, 0,+                            pgno_align2os_bytes(env, NUM_METAS), false)+               : mdbx_fsync(env->me_lazy_fd, MDBX_SYNC_DATA | MDBX_SYNC_IODQ);+      if (likely(rc == MDBX_SUCCESS))+        atomic_store32(env->me_meta_sync_txnid, (uint32_t)head_txnid,+                       mo_Relaxed);+    }+  }+  if (need_unlock)+    mdbx_txn_unlock(env);+  return rc;+}++static __inline int check_env(const MDBX_env *env, const bool wanna_active) {+  if (unlikely(!env))+    return MDBX_EINVAL;++  if (unlikely(env->me_signature.weak != MDBX_ME_SIGNATURE))+    return MDBX_EBADSIGN;++#if MDBX_ENV_CHECKPID+  if (unlikely(env->me_pid != mdbx_getpid())) {+    ((MDBX_env *)env)->me_flags |= MDBX_FATAL_ERROR;+    return MDBX_PANIC;+  }+#endif /* MDBX_ENV_CHECKPID */++  if (unlikely(env->me_flags & MDBX_FATAL_ERROR))+    return MDBX_PANIC;++  if (wanna_active) {+    if (unlikely((env->me_flags & MDBX_ENV_ACTIVE) == 0))+      return MDBX_EPERM;+    mdbx_assert(env, env->me_map != nullptr);+  }++  return MDBX_SUCCESS;+}++__cold int mdbx_env_sync_ex(MDBX_env *env, bool force, bool nonblock) {+  int rc = check_env(env, true);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  return mdbx_env_sync_internal(env, force, nonblock);+}++#ifndef LIBMDBX_NO_EXPORTS_LEGACY_API+__cold int mdbx_env_sync(MDBX_env *env) { return __inline_mdbx_env_sync(env); }++__cold int mdbx_env_sync_poll(MDBX_env *env) {+  return __inline_mdbx_env_sync_poll(env);+}+#endif /* LIBMDBX_NO_EXPORTS_LEGACY_API */++/* Back up parent txn's cursors, then grab the originals for tracking */+static int mdbx_cursor_shadow(MDBX_txn *parent, MDBX_txn *nested) {+  for (int i = parent->mt_numdbs; --i >= 0;) {+    nested->tw.cursors[i] = NULL;+    MDBX_cursor *mc = parent->tw.cursors[i];+    if (mc != NULL) {+      size_t size = mc->mc_xcursor ? sizeof(MDBX_cursor) + sizeof(MDBX_xcursor)+                                   : sizeof(MDBX_cursor);+      for (MDBX_cursor *bk; mc; mc = bk->mc_next) {+        bk = mc;+        if (mc->mc_signature != MDBX_MC_LIVE)+          continue;+        bk = mdbx_malloc(size);+        if (unlikely(!bk))+          return MDBX_ENOMEM;+        *bk = *mc;+        mc->mc_backup = bk;+        /* Kill pointers into src to reduce abuse: The+         * user may not use mc until dst ends. But we need a valid+         * txn pointer here for cursor fixups to keep working. */+        mc->mc_txn = nested;+        mc->mc_db = &nested->mt_dbs[i];+        mc->mc_dbistate = &nested->mt_dbistate[i];+        MDBX_xcursor *mx = mc->mc_xcursor;+        if (mx != NULL) {+          *(MDBX_xcursor *)(bk + 1) = *mx;+          mx->mx_cursor.mc_txn = nested;+        }+        mc->mc_next = nested->tw.cursors[i];+        nested->tw.cursors[i] = mc;+      }+    }+  }+  return MDBX_SUCCESS;+}++/* Close this write txn's cursors, give parent txn's cursors back to parent.+ *+ * [in] txn     the transaction handle.+ * [in] merge   true to keep changes to parent cursors, false to revert.+ *+ * Returns 0 on success, non-zero on failure. */+static void mdbx_cursors_eot(MDBX_txn *txn, const bool merge) {+  mdbx_tassert(txn, (txn->mt_flags & MDBX_TXN_RDONLY) == 0);+  for (int i = txn->mt_numdbs; --i >= 0;) {+    MDBX_cursor *next, *mc = txn->tw.cursors[i];+    if (!mc)+      continue;+    txn->tw.cursors[i] = NULL;+    do {+      const unsigned stage = mc->mc_signature;+      MDBX_cursor *bk = mc->mc_backup;+      next = mc->mc_next;+      mdbx_ensure(txn->mt_env,+                  stage == MDBX_MC_LIVE || (stage == MDBX_MC_WAIT4EOT && bk));+      mdbx_cassert(mc, mc->mc_dbi == (unsigned)i);+      if (bk) {+        MDBX_xcursor *mx = mc->mc_xcursor;+        mdbx_cassert(mc, mx == bk->mc_xcursor);+        mdbx_tassert(txn, txn->mt_parent != NULL);+        mdbx_ensure(txn->mt_env, bk->mc_signature == MDBX_MC_LIVE);+        if (stage == MDBX_MC_WAIT4EOT /* Cursor was closed by user */)+          mc->mc_signature = stage /* Promote closed state to parent txn */;+        else if (merge) {+          /* Restore pointers to parent txn */+          mc->mc_next = bk->mc_next;+          mc->mc_backup = bk->mc_backup;+          mc->mc_txn = bk->mc_txn;+          mc->mc_db = bk->mc_db;+          mc->mc_dbistate = bk->mc_dbistate;+          if (mx) {+            if (mx != bk->mc_xcursor) {+              *bk->mc_xcursor = *mx;+              mx = bk->mc_xcursor;+            }+            mx->mx_cursor.mc_txn = bk->mc_txn;+          }+        } else {+          /* Restore from backup, i.e. rollback/abort nested txn */+          *mc = *bk;+          if (mx)+            *mx = *(MDBX_xcursor *)(bk + 1);+        }+        bk->mc_signature = 0;+        mdbx_free(bk);+      } else {+        mdbx_ensure(txn->mt_env, stage == MDBX_MC_LIVE);+        mc->mc_signature = MDBX_MC_READY4CLOSE /* Cursor may be reused */;+        mc->mc_flags = 0 /* reset C_UNTRACK */;+      }+    } while ((mc = next) != NULL);+  }+}++#if defined(MDBX_USE_VALGRIND) || defined(__SANITIZE_ADDRESS__)+/* Find largest mvcc-snapshot still referenced by this process. */+static pgno_t mdbx_find_largest_this(MDBX_env *env, pgno_t largest) {+  MDBX_lockinfo *const lck = env->me_lck;+  if (likely(lck != NULL /* exclusive mode */)) {+    const unsigned snap_nreaders =+        atomic_load32(&lck->mti_numreaders, mo_AcquireRelease);+    for (unsigned i = 0; i < snap_nreaders; ++i) {+    retry:+      if (atomic_load32(&lck->mti_readers[i].mr_pid, mo_AcquireRelease) ==+          env->me_pid) {+        /* mdbx_jitter4testing(true); */+        const pgno_t snap_pages = atomic_load32(+            &lck->mti_readers[i].mr_snapshot_pages_used, mo_Relaxed);+        const txnid_t snap_txnid = safe64_read(&lck->mti_readers[i].mr_txnid);+        if (unlikely(+                snap_pages !=+                    atomic_load32(&lck->mti_readers[i].mr_snapshot_pages_used,+                                  mo_AcquireRelease) ||+                snap_txnid != safe64_read(&lck->mti_readers[i].mr_txnid)))+          goto retry;+        if (largest < snap_pages &&+            atomic_load64(&lck->mti_oldest_reader, mo_AcquireRelease) <=+                /* ignore pending updates */ snap_txnid &&+            snap_txnid <= MAX_TXNID)+          largest = snap_pages;+      }+    }+  }+  return largest;+}++static void mdbx_txn_valgrind(MDBX_env *env, MDBX_txn *txn) {+#if !defined(__SANITIZE_ADDRESS__)+  if (!RUNNING_ON_VALGRIND)+    return;+#endif++  if (txn) { /* transaction start */+    if (env->me_poison_edge < txn->mt_next_pgno)+      env->me_poison_edge = txn->mt_next_pgno;+    VALGRIND_MAKE_MEM_DEFINED(env->me_map, pgno2bytes(env, txn->mt_next_pgno));+    ASAN_UNPOISON_MEMORY_REGION(env->me_map,+                                pgno2bytes(env, txn->mt_next_pgno));+    /* don't touch more, it should be already poisoned */+  } else { /* transaction end */+    bool should_unlock = false;+    pgno_t last = MAX_PAGENO;+    if (env->me_txn0 && env->me_txn0->mt_owner == mdbx_thread_self()) {+      /* inside write-txn */+      MDBX_meta *head = mdbx_meta_head(env);+      last = head->mm_geo.next;+    } else if (env->me_flags & MDBX_RDONLY) {+      /* read-only mode, no write-txn, no wlock mutex */+      last = NUM_METAS;+    } else if (mdbx_txn_lock(env, true) == MDBX_SUCCESS) {+      /* no write-txn */+      last = NUM_METAS;+      should_unlock = true;+    } else {+      /* write txn is running, therefore shouldn't poison any memory range */+      return;+    }++    last = mdbx_find_largest_this(env, last);+    const pgno_t edge = env->me_poison_edge;+    if (edge > last) {+      mdbx_assert(env, last >= NUM_METAS);+      env->me_poison_edge = last;+      VALGRIND_MAKE_MEM_NOACCESS(env->me_map + pgno2bytes(env, last),+                                 pgno2bytes(env, edge - last));+      ASAN_POISON_MEMORY_REGION(env->me_map + pgno2bytes(env, last),+                                pgno2bytes(env, edge - last));+    }+    if (should_unlock)+      mdbx_txn_unlock(env);+  }+}+#endif /* MDBX_USE_VALGRIND || __SANITIZE_ADDRESS__ */++typedef struct {+  int err;+  MDBX_reader *rslot;+} bind_rslot_result;++static bind_rslot_result bind_rslot(MDBX_env *env, const uintptr_t tid) {+  mdbx_assert(env, env->me_lck);+  mdbx_assert(env, env->me_lck->mti_magic_and_version == MDBX_LOCK_MAGIC);+  mdbx_assert(env, env->me_lck->mti_os_and_format == MDBX_LOCK_FORMAT);++  bind_rslot_result result = {mdbx_rdt_lock(env), nullptr};+  if (unlikely(MDBX_IS_ERROR(result.err)))+    return result;+  if (unlikely(env->me_flags & MDBX_FATAL_ERROR)) {+    mdbx_rdt_unlock(env);+    result.err = MDBX_PANIC;+    return result;+  }+  if (unlikely(!env->me_map)) {+    mdbx_rdt_unlock(env);+    result.err = MDBX_EPERM;+    return result;+  }++  if (unlikely(env->me_live_reader != env->me_pid)) {+    result.err = mdbx_rpid_set(env);+    if (unlikely(result.err != MDBX_SUCCESS)) {+      mdbx_rdt_unlock(env);+      return result;+    }+    env->me_live_reader = env->me_pid;+  }++  result.err = MDBX_SUCCESS;+  unsigned slot, nreaders;+  while (1) {+    nreaders = atomic_load32(&env->me_lck->mti_numreaders, mo_Relaxed);+    for (slot = 0; slot < nreaders; slot++)+      if (atomic_load32(&env->me_lck->mti_readers[slot].mr_pid, mo_Relaxed) ==+          0)+        break;++    if (likely(slot < env->me_maxreaders))+      break;++    result.err = mdbx_cleanup_dead_readers(env, true, NULL);+    if (result.err != MDBX_RESULT_TRUE) {+      mdbx_rdt_unlock(env);+      result.err =+          (result.err == MDBX_SUCCESS) ? MDBX_READERS_FULL : result.err;+      return result;+    }+  }++  result.rslot = &env->me_lck->mti_readers[slot];+  /* Claim the reader slot, carefully since other code+   * uses the reader table un-mutexed: First reset the+   * slot, next publish it in lck->mti_numreaders.  After+   * that, it is safe for mdbx_env_close() to touch it.+   * When it will be closed, we can finally claim it. */+  atomic_store32(&result.rslot->mr_pid, 0, mo_Relaxed);+  safe64_reset(&result.rslot->mr_txnid, true);+  if (slot == nreaders)+    atomic_store32(&env->me_lck->mti_numreaders, ++nreaders, mo_Relaxed);+  atomic_store64(&result.rslot->mr_tid, (env->me_flags & MDBX_NOTLS) ? 0 : tid,+                 mo_Relaxed);+  atomic_store32(&result.rslot->mr_pid, env->me_pid, mo_Relaxed);+  mdbx_rdt_unlock(env);++  if (likely(env->me_flags & MDBX_ENV_TXKEY)) {+    mdbx_assert(env, env->me_live_reader == env->me_pid);+    thread_rthc_set(env->me_txkey, result.rslot);+  }+  return result;+}++__cold int mdbx_thread_register(const MDBX_env *env) {+  int rc = check_env(env, true);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  if (unlikely(!env->me_lck))+    return (env->me_flags & MDBX_EXCLUSIVE) ? MDBX_EINVAL : MDBX_EPERM;++  if (unlikely((env->me_flags & MDBX_ENV_TXKEY) == 0)) {+    mdbx_assert(env, !env->me_lck || (env->me_flags & MDBX_NOTLS));+    return MDBX_EINVAL /* MDBX_NOTLS mode */;+  }++  mdbx_assert(env, (env->me_flags & (MDBX_NOTLS | MDBX_ENV_TXKEY |+                                     MDBX_EXCLUSIVE)) == MDBX_ENV_TXKEY);+  MDBX_reader *r = thread_rthc_get(env->me_txkey);+  if (unlikely(r != NULL)) {+    mdbx_assert(env, r->mr_pid.weak == env->me_pid);+    mdbx_assert(env, r->mr_tid.weak == mdbx_thread_self());+    if (unlikely(r->mr_pid.weak != env->me_pid))+      return MDBX_BAD_RSLOT;+    return MDBX_RESULT_TRUE /* already registered */;+  }++  const uintptr_t tid = mdbx_thread_self();+  if (env->me_txn0 && unlikely(env->me_txn0->mt_owner == tid))+    return MDBX_TXN_OVERLAPPING;+  return bind_rslot((MDBX_env *)env, tid).err;+}++__cold int mdbx_thread_unregister(const MDBX_env *env) {+  int rc = check_env(env, true);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  if (unlikely(!env->me_lck))+    return MDBX_RESULT_TRUE;++  if (unlikely((env->me_flags & MDBX_ENV_TXKEY) == 0)) {+    mdbx_assert(env, !env->me_lck || (env->me_flags & MDBX_NOTLS));+    return MDBX_RESULT_TRUE /* MDBX_NOTLS mode */;+  }++  mdbx_assert(env, (env->me_flags & (MDBX_NOTLS | MDBX_ENV_TXKEY |+                                     MDBX_EXCLUSIVE)) == MDBX_ENV_TXKEY);+  MDBX_reader *r = thread_rthc_get(env->me_txkey);+  if (unlikely(r == NULL))+    return MDBX_RESULT_TRUE /* not registered */;++  mdbx_assert(env, r->mr_pid.weak == env->me_pid);+  mdbx_assert(env, r->mr_tid.weak == mdbx_thread_self());+  if (unlikely(r->mr_pid.weak != env->me_pid ||+               r->mr_tid.weak != mdbx_thread_self()))+    return MDBX_BAD_RSLOT;++  if (unlikely(r->mr_txnid.weak < SAFE64_INVALID_THRESHOLD))+    return MDBX_BUSY /* transaction is still active */;++  atomic_store32(&r->mr_pid, 0, mo_Relaxed);+  atomic_store32(&env->me_lck->mti_readers_refresh_flag, true,+                 mo_AcquireRelease);+  thread_rthc_set(env->me_txkey, nullptr);+  return MDBX_SUCCESS;+}++/* Common code for mdbx_txn_begin() and mdbx_txn_renew(). */+static int mdbx_txn_renew0(MDBX_txn *txn, const unsigned flags) {+  MDBX_env *env = txn->mt_env;+  int rc;++#if MDBX_ENV_CHECKPID+  if (unlikely(env->me_pid != mdbx_getpid())) {+    env->me_flags |= MDBX_FATAL_ERROR;+    return MDBX_PANIC;+  }+#endif /* MDBX_ENV_CHECKPID */++  STATIC_ASSERT(sizeof(MDBX_reader) == 32);+#if MDBX_LOCKING > 0+  STATIC_ASSERT(offsetof(MDBX_lockinfo, mti_wlock) % MDBX_CACHELINE_SIZE == 0);+  STATIC_ASSERT(offsetof(MDBX_lockinfo, mti_rlock) % MDBX_CACHELINE_SIZE == 0);+#else+  STATIC_ASSERT(+      offsetof(MDBX_lockinfo, mti_oldest_reader) % MDBX_CACHELINE_SIZE == 0);+  STATIC_ASSERT(offsetof(MDBX_lockinfo, mti_numreaders) % MDBX_CACHELINE_SIZE ==+                0);+#endif /* MDBX_LOCKING */+  STATIC_ASSERT(offsetof(MDBX_lockinfo, mti_readers) % MDBX_CACHELINE_SIZE ==+                0);++  const uintptr_t tid = mdbx_thread_self();+  if (flags & MDBX_TXN_RDONLY) {+    mdbx_assert(env, (flags & ~(MDBX_TXN_RO_BEGIN_FLAGS | MDBX_WRITEMAP)) == 0);+    txn->mt_flags =+        MDBX_TXN_RDONLY | (env->me_flags & (MDBX_NOTLS | MDBX_WRITEMAP));+    MDBX_reader *r = txn->to.reader;+    STATIC_ASSERT(sizeof(uintptr_t) <= sizeof(r->mr_tid));+    if (likely(env->me_flags & MDBX_ENV_TXKEY)) {+      mdbx_assert(env, !(env->me_flags & MDBX_NOTLS));+      r = thread_rthc_get(env->me_txkey);+      if (likely(r)) {+        if (unlikely(!r->mr_pid.weak) &&+            (mdbx_runtime_flags & MDBX_DBG_LEGACY_MULTIOPEN)) {+          thread_rthc_set(env->me_txkey, nullptr);+          r = nullptr;+        } else {+          mdbx_assert(env, r->mr_pid.weak == env->me_pid);+          mdbx_assert(env, r->mr_tid.weak == mdbx_thread_self());+        }+      }+    } else {+      mdbx_assert(env, !env->me_lck || (env->me_flags & MDBX_NOTLS));+    }++    if (likely(r)) {+      if (unlikely(r->mr_pid.weak != env->me_pid ||+                   r->mr_txnid.weak < SAFE64_INVALID_THRESHOLD))+        return MDBX_BAD_RSLOT;+    } else if (env->me_lck) {+      bind_rslot_result brs = bind_rslot(env, tid);+      if (unlikely(brs.err != MDBX_SUCCESS))+        return brs.err;+      r = brs.rslot;+    }+    txn->to.reader = r;+    if (flags & (MDBX_TXN_RDONLY_PREPARE - MDBX_TXN_RDONLY)) {+      mdbx_assert(env, txn->mt_txnid == 0);+      mdbx_assert(env, txn->mt_owner == 0);+      mdbx_assert(env, txn->mt_numdbs == 0);+      if (likely(r)) {+        mdbx_assert(env, r->mr_snapshot_pages_used.weak == 0);+        mdbx_assert(env, r->mr_txnid.weak >= SAFE64_INVALID_THRESHOLD);+        atomic_store32(&r->mr_snapshot_pages_used, 0, mo_Relaxed);+      }+      txn->mt_flags = MDBX_TXN_RDONLY | MDBX_TXN_FINISHED;+      return MDBX_SUCCESS;+    }++    /* Seek & fetch the last meta */+    if (likely(/* not recovery mode */ env->me_stuck_meta < 0)) {+      while (1) {+        MDBX_meta *const meta = mdbx_meta_head(env);+        mdbx_jitter4testing(false);+        const txnid_t snap = mdbx_meta_txnid_fluid(env, meta);+        mdbx_jitter4testing(false);+        if (likely(r)) {+          safe64_reset(&r->mr_txnid, false);+          atomic_store32(&r->mr_snapshot_pages_used, meta->mm_geo.next,+                         mo_Relaxed);+          atomic_store64(&r->mr_snapshot_pages_retired,+                         unaligned_peek_u64(4, meta->mm_pages_retired),+                         mo_Relaxed);+          safe64_write(&r->mr_txnid, snap);+          mdbx_jitter4testing(false);+          mdbx_assert(env, r->mr_pid.weak == mdbx_getpid());+          mdbx_assert(+              env, r->mr_tid.weak ==+                       ((env->me_flags & MDBX_NOTLS) ? 0 : mdbx_thread_self()));+          mdbx_assert(env, r->mr_txnid.weak == snap);+          atomic_store32(&env->me_lck->mti_readers_refresh_flag, true,+                         mo_AcquireRelease);+        }+        mdbx_jitter4testing(true);++        /* Snap the state from current meta-head */+        txn->mt_txnid = snap;+        txn->mt_geo = meta->mm_geo;+        memcpy(txn->mt_dbs, meta->mm_dbs, CORE_DBS * sizeof(MDBX_db));+        txn->mt_canary = meta->mm_canary;++        /* LY: Retry on a race, ITS#7970. */+        if (likely(meta == mdbx_meta_head(env) &&+                   snap == mdbx_meta_txnid_fluid(env, meta) &&+                   snap >= atomic_load64(env->me_oldest, mo_AcquireRelease))) {+          mdbx_jitter4testing(false);+          break;+        }+      }+    } else {+      /* recovery mode */+      MDBX_meta *const meta = METAPAGE(env, env->me_stuck_meta);+      txn->mt_txnid = mdbx_meta_txnid_stable(env, meta);+      txn->mt_geo = meta->mm_geo;+      memcpy(txn->mt_dbs, meta->mm_dbs, CORE_DBS * sizeof(MDBX_db));+      txn->mt_canary = meta->mm_canary;+      if (likely(r)) {+        atomic_store32(&r->mr_snapshot_pages_used, meta->mm_geo.next,+                       mo_Relaxed);+        atomic_store64(&r->mr_snapshot_pages_retired,+                       unaligned_peek_u64(4, meta->mm_pages_retired),+                       mo_Relaxed);+        atomic_store64(&r->mr_txnid, txn->mt_txnid, mo_Relaxed);+        mdbx_jitter4testing(false);+        mdbx_assert(env, r->mr_pid.weak == mdbx_getpid());+        mdbx_assert(+            env, r->mr_tid.weak ==+                     ((env->me_flags & MDBX_NOTLS) ? 0 : mdbx_thread_self()));+        mdbx_assert(env, r->mr_txnid.weak == txn->mt_txnid);+        atomic_store32(&env->me_lck->mti_readers_refresh_flag, true,+                       mo_Relaxed);+      }+    }++    if (unlikely(txn->mt_txnid < MIN_TXNID || txn->mt_txnid > MAX_TXNID)) {+      mdbx_error("%s", "environment corrupted by died writer, must shutdown!");+      rc = MDBX_CORRUPTED;+      goto bailout;+    }+    mdbx_assert(env, txn->mt_txnid >= env->me_oldest->weak);+    txn->mt_dbxs = env->me_dbxs; /* mostly static anyway */+    mdbx_ensure(env,+                txn->mt_txnid >=+                    /* paranoia is appropriate here */ env->me_oldest->weak);+    txn->mt_numdbs = env->me_numdbs;+  } else {+    mdbx_assert(env, (flags & ~(MDBX_TXN_RW_BEGIN_FLAGS | MDBX_TXN_SPILLS |+                                MDBX_WRITEMAP)) == 0);+    if (unlikely(txn->mt_owner == tid ||+                 /* not recovery mode */ env->me_stuck_meta >= 0))+      return MDBX_BUSY;+    MDBX_lockinfo *const lck = env->me_lck;+    if (lck && (env->me_flags & MDBX_NOTLS) == 0 &&+        (mdbx_runtime_flags & MDBX_DBG_LEGACY_OVERLAP) == 0) {+      const unsigned snap_nreaders =+          atomic_load32(&lck->mti_numreaders, mo_AcquireRelease);+      for (unsigned i = 0; i < snap_nreaders; ++i) {+        if (atomic_load32(&lck->mti_readers[i].mr_pid, mo_Relaxed) ==+                env->me_pid &&+            unlikely(atomic_load64(&lck->mti_readers[i].mr_tid, mo_Relaxed) ==+                     tid)) {+          const txnid_t txnid = safe64_read(&lck->mti_readers[i].mr_txnid);+          if (txnid >= MIN_TXNID && txnid <= MAX_TXNID)+            return MDBX_TXN_OVERLAPPING;+        }+      }+    }++    /* Not yet touching txn == env->me_txn0, it may be active */+    mdbx_jitter4testing(false);+    rc = mdbx_txn_lock(env, F_ISSET(flags, MDBX_TXN_TRY));+    if (unlikely(rc))+      return rc;+    if (unlikely(env->me_flags & MDBX_FATAL_ERROR)) {+      mdbx_txn_unlock(env);+      return MDBX_PANIC;+    }+#if defined(_WIN32) || defined(_WIN64)+    if (unlikely(!env->me_map)) {+      mdbx_txn_unlock(env);+      return MDBX_EPERM;+    }+#endif /* Windows */++    mdbx_jitter4testing(false);+    MDBX_meta *meta = mdbx_meta_head(env);+    mdbx_jitter4testing(false);+    txn->mt_canary = meta->mm_canary;+    const txnid_t snap = mdbx_meta_txnid_stable(env, meta);+    txn->mt_txnid = safe64_txnid_next(snap);+    if (unlikely(txn->mt_txnid > MAX_TXNID)) {+      rc = MDBX_TXN_FULL;+      mdbx_error("txnid overflow, raise %d", rc);+      goto bailout;+    }++    txn->mt_flags = flags;+    txn->mt_child = NULL;+    txn->tw.loose_pages = NULL;+    txn->tw.loose_count = 0;+#if MDBX_ENABLE_REFUND+    txn->tw.loose_refund_wl = 0;+#endif /* MDBX_ENABLE_REFUND */+    MDBX_PNL_SIZE(txn->tw.retired_pages) = 0;+    txn->tw.spill_pages = NULL;+    txn->tw.spill_least_removed = 0;+    txn->tw.last_reclaimed = 0;+    if (txn->tw.lifo_reclaimed)+      MDBX_PNL_SIZE(txn->tw.lifo_reclaimed) = 0;+    env->me_txn = txn;+    txn->mt_numdbs = env->me_numdbs;+    memcpy(txn->mt_dbiseqs, env->me_dbiseqs, txn->mt_numdbs * sizeof(unsigned));+    /* Copy the DB info and flags */+    memcpy(txn->mt_dbs, meta->mm_dbs, CORE_DBS * sizeof(MDBX_db));+    /* Moved to here to avoid a data race in read TXNs */+    txn->mt_geo = meta->mm_geo;++    rc = mdbx_dpl_alloc(txn);+    if (unlikely(rc != MDBX_SUCCESS))+      goto bailout;+    txn->tw.dirtyroom = txn->mt_env->me_options.dp_limit;+  }++  /* Setup db info */+  mdbx_compiler_barrier();+  for (unsigned i = CORE_DBS; i < txn->mt_numdbs; i++) {+    const unsigned db_flags = env->me_dbflags[i];+    txn->mt_dbs[i].md_flags = db_flags & DB_PERSISTENT_FLAGS;+    txn->mt_dbistate[i] =+        (db_flags & DB_VALID) ? DBI_VALID | DBI_USRVALID | DBI_STALE : 0;+  }+  txn->mt_dbistate[MAIN_DBI] = DBI_VALID | DBI_USRVALID;+  txn->mt_dbistate[FREE_DBI] = DBI_VALID;++  if (unlikely(env->me_flags & MDBX_FATAL_ERROR)) {+    mdbx_warning("%s", "environment had fatal error, must shutdown!");+    rc = MDBX_PANIC;+  } else {+    const size_t size =+        pgno2bytes(env, (txn->mt_flags & MDBX_TXN_RDONLY) ? txn->mt_next_pgno+                                                          : txn->mt_end_pgno);+    if (unlikely(size > env->me_dxb_mmap.limit)) {+      if (txn->mt_geo.upper > MAX_PAGENO ||+          bytes2pgno(env, pgno2bytes(env, txn->mt_geo.upper)) !=+              txn->mt_geo.upper) {+        rc = MDBX_UNABLE_EXTEND_MAPSIZE;+        goto bailout;+      }+      rc = mdbx_mapresize(env, txn->mt_next_pgno, txn->mt_end_pgno,+                          txn->mt_geo.upper,+                          (txn->mt_flags & MDBX_TXN_RDONLY) ? true : false);+      if (rc != MDBX_SUCCESS)+        goto bailout;+    }+    if (txn->mt_flags & MDBX_TXN_RDONLY) {+#if defined(_WIN32) || defined(_WIN64)+      if ((size > env->me_dbgeo.lower && env->me_dbgeo.shrink) ||+          (mdbx_RunningUnderWine() &&+           /* under Wine acquisition of remap_guard is always required,+            * since Wine don't support section extending,+            * i.e. in both cases unmap+map are required. */+           size < env->me_dbgeo.upper && env->me_dbgeo.grow)) {+        txn->mt_flags |= MDBX_SHRINK_ALLOWED;+        mdbx_srwlock_AcquireShared(&env->me_remap_guard);+      }+#endif /* Windows */+    } else {+      env->me_dxb_mmap.current = size;+#if defined(_WIN32) || defined(_WIN64)+      env->me_dxb_mmap.filesize =+          (env->me_dxb_mmap.filesize < size) ? size : env->me_dxb_mmap.filesize;+#endif /* Windows */+    }+#if defined(MDBX_USE_VALGRIND) || defined(__SANITIZE_ADDRESS__)+    mdbx_txn_valgrind(env, txn);+#endif+    txn->mt_owner = tid;+    return MDBX_SUCCESS;+  }+bailout:+  mdbx_tassert(txn, rc != MDBX_SUCCESS);+  mdbx_txn_end(txn, MDBX_END_SLOT | MDBX_END_FAIL_BEGIN);+  return rc;+}++static __always_inline int check_txn(const MDBX_txn *txn, int bad_bits) {+  if (unlikely(!txn))+    return MDBX_EINVAL;++  if (unlikely(txn->mt_signature != MDBX_MT_SIGNATURE))+    return MDBX_EBADSIGN;++  if (unlikely(txn->mt_flags & bad_bits))+    return MDBX_BAD_TXN;++#if MDBX_TXN_CHECKOWNER+  if ((txn->mt_flags & MDBX_NOTLS) == 0 &&+      unlikely(txn->mt_owner != mdbx_thread_self()))+    return txn->mt_owner ? MDBX_THREAD_MISMATCH : MDBX_BAD_TXN;+#endif /* MDBX_TXN_CHECKOWNER */++  if (unlikely(!txn->mt_env->me_map))+    return MDBX_EPERM;++  return MDBX_SUCCESS;+}++static __always_inline int check_txn_rw(const MDBX_txn *txn, int bad_bits) {+  int err = check_txn(txn, bad_bits);+  if (unlikely(err))+    return err;++  if (unlikely(F_ISSET(txn->mt_flags, MDBX_TXN_RDONLY)))+    return MDBX_EACCESS;++  return MDBX_SUCCESS;+}++int mdbx_txn_renew(MDBX_txn *txn) {+  if (unlikely(!txn))+    return MDBX_EINVAL;++  if (unlikely(txn->mt_signature != MDBX_MT_SIGNATURE))+    return MDBX_EBADSIGN;++  if (unlikely((txn->mt_flags & MDBX_TXN_RDONLY) == 0))+    return MDBX_EINVAL;++  int rc;+  if (unlikely(txn->mt_owner != 0 || !(txn->mt_flags & MDBX_TXN_FINISHED))) {+    rc = mdbx_txn_reset(txn);+    if (unlikely(rc != MDBX_SUCCESS))+      return rc;+  }++  rc = mdbx_txn_renew0(txn, MDBX_TXN_RDONLY);+  if (rc == MDBX_SUCCESS) {+    txn->mt_owner = mdbx_thread_self();+    mdbx_debug("renew txn %" PRIaTXN "%c %p on env %p, root page %" PRIaPGNO+               "/%" PRIaPGNO,+               txn->mt_txnid, (txn->mt_flags & MDBX_TXN_RDONLY) ? 'r' : 'w',+               (void *)txn, (void *)txn->mt_env, txn->mt_dbs[MAIN_DBI].md_root,+               txn->mt_dbs[FREE_DBI].md_root);+  }+  return rc;+}++#ifndef LIBMDBX_NO_EXPORTS_LEGACY_API+int mdbx_txn_begin(MDBX_env *env, MDBX_txn *parent, MDBX_txn_flags_t flags,+                   MDBX_txn **ret) {+  return __inline_mdbx_txn_begin(env, parent, flags, ret);+}+#endif /* LIBMDBX_NO_EXPORTS_LEGACY_API */++int mdbx_txn_set_userctx(MDBX_txn *txn, void *ctx) {+  int rc = check_txn(txn, MDBX_TXN_BLOCKED - MDBX_TXN_HAS_CHILD);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  txn->mt_userctx = ctx;+  return MDBX_SUCCESS;+}++void *mdbx_txn_get_userctx(const MDBX_txn *txn) {+  return check_txn(txn, MDBX_TXN_BLOCKED - MDBX_TXN_HAS_CHILD)+             ? nullptr+             : txn->mt_userctx;+}++int mdbx_txn_begin_ex(MDBX_env *env, MDBX_txn *parent, MDBX_txn_flags_t flags,+                      MDBX_txn **ret, void *context) {+  MDBX_txn *txn;+  unsigned size, tsize;++  if (unlikely(!ret))+    return MDBX_EINVAL;+  *ret = NULL;++  if (unlikely((flags & ~MDBX_TXN_RW_BEGIN_FLAGS) &&+               (flags & ~MDBX_TXN_RO_BEGIN_FLAGS)))+    return MDBX_EINVAL;++  int rc = check_env(env, true);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  if (unlikely(env->me_flags & MDBX_RDONLY &+               ~flags)) /* write txn in RDONLY env */+    return MDBX_EACCESS;++  flags |= env->me_flags & MDBX_WRITEMAP;++  if (parent) {+    /* Nested transactions: Max 1 child, write txns only, no writemap */+    rc = check_txn_rw(parent,+                      MDBX_TXN_RDONLY | MDBX_WRITEMAP | MDBX_TXN_BLOCKED);+    if (unlikely(rc != MDBX_SUCCESS))+      return rc;++    if (env->me_options.spill_parent4child_denominator) {+      /* Spill dirty-pages of parent to provide dirtyroom for child txn */+      rc = mdbx_txn_spill(parent, nullptr,+                          parent->tw.dirtylist->length /+                              env->me_options.spill_parent4child_denominator);+      if (unlikely(rc != MDBX_SUCCESS))+        return rc;+    }+    mdbx_tassert(parent, mdbx_audit_ex(parent, 0, false) == 0);++    flags |= parent->mt_flags & (MDBX_TXN_RW_BEGIN_FLAGS | MDBX_TXN_SPILLS);+    /* Child txns save MDBX_pgstate and use own copy of cursors */+    size = env->me_maxdbs * (sizeof(MDBX_db) + sizeof(MDBX_cursor *) + 1);+    size += tsize = sizeof(MDBX_txn);+  } else if (flags & MDBX_TXN_RDONLY) {+    if (env->me_txn0 &&+        unlikely(env->me_txn0->mt_owner == mdbx_thread_self()) &&+        (mdbx_runtime_flags & MDBX_DBG_LEGACY_OVERLAP) == 0)+      return MDBX_TXN_OVERLAPPING;+    size = env->me_maxdbs * (sizeof(MDBX_db) + 1);+    size += tsize = sizeof(MDBX_txn);+  } else {+    /* Reuse preallocated write txn. However, do not touch it until+     * mdbx_txn_renew0() succeeds, since it currently may be active. */+    txn = env->me_txn0;+    goto renew;+  }+  if (unlikely((txn = mdbx_malloc(size)) == NULL)) {+    mdbx_debug("calloc: %s", "failed");+    return MDBX_ENOMEM;+  }+  memset(txn, 0, tsize);+  txn->mt_dbxs = env->me_dbxs; /* static */+  txn->mt_dbs = (MDBX_db *)((char *)txn + tsize);+  txn->mt_dbistate = (uint8_t *)txn + size - env->me_maxdbs;+  txn->mt_flags = flags;+  txn->mt_env = env;++  if (parent) {+    mdbx_tassert(parent, mdbx_dirtylist_check(parent));+    txn->tw.cursors = (MDBX_cursor **)(txn->mt_dbs + env->me_maxdbs);+    txn->mt_dbiseqs = parent->mt_dbiseqs;+    txn->mt_geo = parent->mt_geo;+    rc = mdbx_dpl_alloc(txn);+    if (likely(rc == MDBX_SUCCESS)) {+      const unsigned len =+          MDBX_PNL_SIZE(parent->tw.reclaimed_pglist) + parent->tw.loose_count;+      txn->tw.reclaimed_pglist =+          mdbx_pnl_alloc((len > MDBX_PNL_INITIAL) ? len : MDBX_PNL_INITIAL);+      if (unlikely(!txn->tw.reclaimed_pglist))+        rc = MDBX_ENOMEM;+    }+    if (unlikely(rc != MDBX_SUCCESS)) {+    nested_failed:+      mdbx_pnl_free(txn->tw.reclaimed_pglist);+      mdbx_dpl_free(txn);+      mdbx_free(txn);+      return rc;+    }++    /* Move loose pages to reclaimed list */+    if (parent->tw.loose_count) {+      do {+        MDBX_page *lp = parent->tw.loose_pages;+        const unsigned di = mdbx_dpl_exist(parent->tw.dirtylist, lp->mp_pgno);+        mdbx_tassert(parent, di && parent->tw.dirtylist->items[di].ptr == lp);+        mdbx_tassert(parent, lp->mp_flags == (P_LOOSE | P_DIRTY));+        rc =+            mdbx_pnl_insert_range(&parent->tw.reclaimed_pglist, lp->mp_pgno, 1);+        if (unlikely(rc != MDBX_SUCCESS))+          goto nested_failed;+        parent->tw.loose_pages = lp->mp_next;+        /* Remove from dirty list */+        mdbx_page_wash(parent, di, lp, 1);+      } while (parent->tw.loose_pages);+      parent->tw.loose_count = 0;+#if MDBX_ENABLE_REFUND+      parent->tw.loose_refund_wl = 0;+#endif /* MDBX_ENABLE_REFUND */+      mdbx_tassert(parent, mdbx_dirtylist_check(parent));+    }+    txn->tw.dirtyroom = parent->tw.dirtyroom;++    mdbx_dpl_sort(parent->tw.dirtylist);+    if (parent->tw.spill_pages)+      mdbx_spill_purge(parent);++    mdbx_tassert(txn, MDBX_PNL_ALLOCLEN(txn->tw.reclaimed_pglist) >=+                          MDBX_PNL_SIZE(parent->tw.reclaimed_pglist));+    memcpy(txn->tw.reclaimed_pglist, parent->tw.reclaimed_pglist,+           MDBX_PNL_SIZEOF(parent->tw.reclaimed_pglist));+    mdbx_assert(env, mdbx_pnl_check4assert(+                         txn->tw.reclaimed_pglist,+                         (txn->mt_next_pgno /* LY: intentional assignment here,+                                                   only for assertion */+                          = parent->mt_next_pgno) -+                             MDBX_ENABLE_REFUND));++    txn->tw.last_reclaimed = parent->tw.last_reclaimed;+    if (parent->tw.lifo_reclaimed) {+      txn->tw.lifo_reclaimed = parent->tw.lifo_reclaimed;+      parent->tw.lifo_reclaimed =+          (void *)(intptr_t)MDBX_PNL_SIZE(parent->tw.lifo_reclaimed);+    }++    txn->tw.retired_pages = parent->tw.retired_pages;+    parent->tw.retired_pages =+        (void *)(intptr_t)MDBX_PNL_SIZE(parent->tw.retired_pages);++    txn->mt_txnid = parent->mt_txnid;+#if MDBX_ENABLE_REFUND+    txn->tw.loose_refund_wl = 0;+#endif /* MDBX_ENABLE_REFUND */+    txn->mt_canary = parent->mt_canary;+    parent->mt_flags |= MDBX_TXN_HAS_CHILD;+    parent->mt_child = txn;+    txn->mt_parent = parent;+    txn->mt_numdbs = parent->mt_numdbs;+    txn->mt_owner = parent->mt_owner;+    memcpy(txn->mt_dbs, parent->mt_dbs, txn->mt_numdbs * sizeof(MDBX_db));+    /* Copy parent's mt_dbistate, but clear DB_NEW */+    for (unsigned i = 0; i < txn->mt_numdbs; i++)+      txn->mt_dbistate[i] =+          parent->mt_dbistate[i] & ~(DBI_FRESH | DBI_CREAT | DBI_DIRTY);+    mdbx_tassert(parent,+                 parent->mt_parent ||+                     parent->tw.dirtyroom + parent->tw.dirtylist->length ==+                         env->me_options.dp_limit);+    assert(txn->tw.dirtyroom <= txn->mt_env->me_options.dp_limit);+    env->me_txn = txn;+    rc = mdbx_cursor_shadow(parent, txn);+    if (mdbx_audit_enabled() && mdbx_assert_enabled()) {+      txn->mt_signature = MDBX_MT_SIGNATURE;+      mdbx_tassert(txn, mdbx_audit_ex(txn, 0, false) == 0);+    }+    if (unlikely(rc != MDBX_SUCCESS))+      mdbx_txn_end(txn, MDBX_END_FAIL_BEGINCHILD);+  } else { /* MDBX_TXN_RDONLY */+    txn->mt_dbiseqs = env->me_dbiseqs;+  renew:+    rc = mdbx_txn_renew0(txn, flags);+  }++  if (unlikely(rc != MDBX_SUCCESS)) {+    if (txn != env->me_txn0)+      mdbx_free(txn);+  } else {+    if (flags & (MDBX_TXN_RDONLY_PREPARE - MDBX_TXN_RDONLY))+      mdbx_assert(env, txn->mt_flags == (MDBX_TXN_RDONLY | MDBX_TXN_FINISHED));+    else if (flags & MDBX_TXN_RDONLY)+      mdbx_assert(env, (txn->mt_flags &+                        ~(MDBX_NOTLS | MDBX_TXN_RDONLY | MDBX_WRITEMAP |+                          /* Win32: SRWL flag */ MDBX_SHRINK_ALLOWED)) == 0);+    else {+      mdbx_assert(env, (txn->mt_flags & ~(MDBX_WRITEMAP | MDBX_SHRINK_ALLOWED |+                                          MDBX_NOMETASYNC | MDBX_SAFE_NOSYNC |+                                          MDBX_TXN_SPILLS)) == 0);+      assert(!txn->tw.spill_pages && !txn->tw.spill_least_removed);+    }+    txn->mt_signature = MDBX_MT_SIGNATURE;+    txn->mt_userctx = context;+    *ret = txn;+    mdbx_debug("begin txn %" PRIaTXN "%c %p on env %p, root page %" PRIaPGNO+               "/%" PRIaPGNO,+               txn->mt_txnid, (flags & MDBX_TXN_RDONLY) ? 'r' : 'w',+               (void *)txn, (void *)env, txn->mt_dbs[MAIN_DBI].md_root,+               txn->mt_dbs[FREE_DBI].md_root);+  }++  return rc;+}++int mdbx_txn_info(const MDBX_txn *txn, MDBX_txn_info *info, bool scan_rlt) {+  int rc = check_txn(txn, MDBX_TXN_BLOCKED - MDBX_TXN_HAS_CHILD);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  if (unlikely(!info))+    return MDBX_EINVAL;++  MDBX_env *const env = txn->mt_env;+#if MDBX_ENV_CHECKPID+  if (unlikely(env->me_pid != mdbx_getpid())) {+    env->me_flags |= MDBX_FATAL_ERROR;+    return MDBX_PANIC;+  }+#endif /* MDBX_ENV_CHECKPID */++  info->txn_id = txn->mt_txnid;+  info->txn_space_used = pgno2bytes(env, txn->mt_geo.next);++  if (txn->mt_flags & MDBX_TXN_RDONLY) {+    const MDBX_meta *head_meta;+    txnid_t head_txnid;+    uint64_t head_retired;+    do {+      /* fetch info from volatile head */+      head_meta = mdbx_meta_head(env);+      head_txnid = mdbx_meta_txnid_fluid(env, head_meta);+      head_retired = unaligned_peek_u64(4, head_meta->mm_pages_retired);+      info->txn_space_limit_soft = pgno2bytes(env, head_meta->mm_geo.now);+      info->txn_space_limit_hard = pgno2bytes(env, head_meta->mm_geo.upper);+      info->txn_space_leftover =+          pgno2bytes(env, head_meta->mm_geo.now - head_meta->mm_geo.next);+      mdbx_compiler_barrier();+    } while (unlikely(head_meta != mdbx_meta_head(env) ||+                      head_txnid != mdbx_meta_txnid_fluid(env, head_meta)));++    info->txn_reader_lag = head_txnid - info->txn_id;+    info->txn_space_dirty = info->txn_space_retired = 0;+    uint64_t reader_snapshot_pages_retired;+    if (txn->to.reader &&+        head_retired >+            (reader_snapshot_pages_retired = atomic_load64(+                 &txn->to.reader->mr_snapshot_pages_retired, mo_Relaxed))) {+      info->txn_space_dirty = info->txn_space_retired = pgno2bytes(+          env, (pgno_t)(head_retired - reader_snapshot_pages_retired));++      size_t retired_next_reader = 0;+      MDBX_lockinfo *const lck = env->me_lck;+      if (scan_rlt && info->txn_reader_lag > 1 && lck) {+        /* find next more recent reader */+        txnid_t next_reader = head_txnid;+        const unsigned snap_nreaders =+            atomic_load32(&lck->mti_numreaders, mo_AcquireRelease);+        for (unsigned i = 0; i < snap_nreaders; ++i) {+        retry:+          if (atomic_load32(&lck->mti_readers[i].mr_pid, mo_AcquireRelease)) {+            mdbx_jitter4testing(true);+            const txnid_t snap_txnid =+                safe64_read(&lck->mti_readers[i].mr_txnid);+            const uint64_t snap_retired =+                atomic_load64(&lck->mti_readers[i].mr_snapshot_pages_retired,+                              mo_AcquireRelease);+            if (unlikely(snap_retired !=+                         atomic_load64(+                             &lck->mti_readers[i].mr_snapshot_pages_retired,+                             mo_Relaxed)) ||+                snap_txnid != safe64_read(&lck->mti_readers[i].mr_txnid))+              goto retry;+            if (snap_txnid <= txn->mt_txnid) {+              retired_next_reader = 0;+              break;+            }+            if (snap_txnid < next_reader) {+              next_reader = snap_txnid;+              retired_next_reader = pgno2bytes(+                  env, (pgno_t)(snap_retired -+                                atomic_load64(+                                    &txn->to.reader->mr_snapshot_pages_retired,+                                    mo_Relaxed)));+            }+          }+        }+      }+      info->txn_space_dirty = retired_next_reader;+    }+  } else {+    info->txn_space_limit_soft = pgno2bytes(env, txn->mt_geo.now);+    info->txn_space_limit_hard = pgno2bytes(env, txn->mt_geo.upper);+    info->txn_space_retired = pgno2bytes(+        env, txn->mt_child ? (unsigned)(uintptr_t)txn->tw.retired_pages+                           : MDBX_PNL_SIZE(txn->tw.retired_pages));+    info->txn_space_leftover = pgno2bytes(env, txn->tw.dirtyroom);+    info->txn_space_dirty =+        pgno2bytes(env, txn->mt_env->me_options.dp_limit - txn->tw.dirtyroom);+    info->txn_reader_lag = INT64_MAX;+    MDBX_lockinfo *const lck = env->me_lck;+    if (scan_rlt && lck) {+      txnid_t oldest_snapshot = txn->mt_txnid;+      const unsigned snap_nreaders =+          atomic_load32(&lck->mti_numreaders, mo_AcquireRelease);+      if (snap_nreaders) {+        oldest_snapshot = mdbx_find_oldest(txn);+        if (oldest_snapshot == txn->mt_txnid - 1) {+          /* check if there is at least one reader */+          bool exists = false;+          for (unsigned i = 0; i < snap_nreaders; ++i) {+            if (atomic_load32(&lck->mti_readers[i].mr_pid, mo_Relaxed) &&+                txn->mt_txnid > safe64_read(&lck->mti_readers[i].mr_txnid)) {+              exists = true;+              break;+            }+          }+          oldest_snapshot += !exists;+        }+      }+      info->txn_reader_lag = txn->mt_txnid - oldest_snapshot;+    }+  }++  return MDBX_SUCCESS;+}++MDBX_env *mdbx_txn_env(const MDBX_txn *txn) {+  if (unlikely(!txn || txn->mt_signature != MDBX_MT_SIGNATURE ||+               txn->mt_env->me_signature.weak != MDBX_ME_SIGNATURE))+    return NULL;+  return txn->mt_env;+}++uint64_t mdbx_txn_id(const MDBX_txn *txn) {+  if (unlikely(!txn || txn->mt_signature != MDBX_MT_SIGNATURE))+    return 0;+  return txn->mt_txnid;+}++int mdbx_txn_flags(const MDBX_txn *txn) {+  if (unlikely(!txn || txn->mt_signature != MDBX_MT_SIGNATURE))+    return -1;+  return txn->mt_flags;+}++/* Check for misused dbi handles */+#define TXN_DBI_CHANGED(txn, dbi)                                              \+  ((txn)->mt_dbiseqs[dbi] != (txn)->mt_env->me_dbiseqs[dbi])++static void dbi_import_locked(MDBX_txn *txn) {+  MDBX_env *const env = txn->mt_env;+  const unsigned n = env->me_numdbs;+  for (unsigned i = CORE_DBS; i < n; ++i) {+    if (i >= txn->mt_numdbs) {+      txn->mt_dbistate[i] = 0;+      if (!(txn->mt_flags & MDBX_TXN_RDONLY))+        txn->tw.cursors[i] = NULL;+    }+    if ((env->me_dbflags[i] & DB_VALID) &&+        !(txn->mt_dbistate[i] & DBI_USRVALID)) {+      txn->mt_dbiseqs[i] = env->me_dbiseqs[i];+      txn->mt_dbs[i].md_flags = env->me_dbflags[i] & DB_PERSISTENT_FLAGS;+      txn->mt_dbistate[i] = DBI_VALID | DBI_USRVALID | DBI_STALE;+      mdbx_tassert(txn, txn->mt_dbxs[i].md_cmp != NULL);+    }+  }+  txn->mt_numdbs = n;+}++/* Import DBI which opened after txn started into context */+static __cold bool dbi_import(MDBX_txn *txn, MDBX_dbi dbi) {+  if (dbi < CORE_DBS || dbi >= txn->mt_env->me_numdbs)+    return false;++  mdbx_ensure(txn->mt_env, mdbx_fastmutex_acquire(&txn->mt_env->me_dbi_lock) ==+                               MDBX_SUCCESS);+  dbi_import_locked(txn);+  mdbx_ensure(txn->mt_env, mdbx_fastmutex_release(&txn->mt_env->me_dbi_lock) ==+                               MDBX_SUCCESS);+  return txn->mt_dbistate[dbi] & DBI_USRVALID;+}++/* Export or close DBI handles opened in this txn. */+static void dbi_update(MDBX_txn *txn, int keep) {+  mdbx_tassert(txn, !txn->mt_parent && txn == txn->mt_env->me_txn0);+  MDBX_dbi n = txn->mt_numdbs;+  if (n) {+    bool locked = false;+    MDBX_env *const env = txn->mt_env;++    for (unsigned i = n; --i >= CORE_DBS;) {+      if (likely((txn->mt_dbistate[i] & DBI_CREAT) == 0))+        continue;+      if (!locked) {+        mdbx_ensure(env,+                    mdbx_fastmutex_acquire(&env->me_dbi_lock) == MDBX_SUCCESS);+        locked = true;+      }+      if (env->me_numdbs <= i || txn->mt_dbiseqs[i] != env->me_dbiseqs[i])+        continue /* dbi explicitly closed and/or then re-opened by other txn */;+      if (keep) {+        env->me_dbflags[i] = txn->mt_dbs[i].md_flags | DB_VALID;+      } else {+        char *ptr = env->me_dbxs[i].md_name.iov_base;+        if (ptr) {+          env->me_dbxs[i].md_name.iov_len = 0;+          mdbx_memory_fence(mo_AcquireRelease, true);+          mdbx_assert(env, env->me_dbflags[i] == 0);+          env->me_dbiseqs[i]++;+          env->me_dbxs[i].md_name.iov_base = NULL;+          mdbx_free(ptr);+        }+      }+    }++    n = env->me_numdbs;+    if (n > CORE_DBS && unlikely(!(env->me_dbflags[n - 1] & DB_VALID))) {+      if (!locked) {+        mdbx_ensure(env,+                    mdbx_fastmutex_acquire(&env->me_dbi_lock) == MDBX_SUCCESS);+        locked = true;+      }++      n = env->me_numdbs;+      while (n > CORE_DBS && !(env->me_dbflags[n - 1] & DB_VALID))+        --n;+      env->me_numdbs = n;+    }++    if (unlikely(locked))+      mdbx_ensure(env,+                  mdbx_fastmutex_release(&env->me_dbi_lock) == MDBX_SUCCESS);+  }+}++/* Filter-out pgno list from transaction's dirty-page list */+static void mdbx_dpl_sift(MDBX_txn *const txn, MDBX_PNL pl,+                          const bool spilled) {+  if (MDBX_PNL_SIZE(pl) && txn->tw.dirtylist->length) {+    mdbx_tassert(txn, mdbx_pnl_check4assert(pl, txn->mt_next_pgno << spilled));+    MDBX_dpl *dl = mdbx_dpl_sort(txn->tw.dirtylist);++    /* Scanning in ascend order */+    const int step = MDBX_PNL_ASCENDING ? 1 : -1;+    const int begin = MDBX_PNL_ASCENDING ? 1 : MDBX_PNL_SIZE(pl);+    const int end = MDBX_PNL_ASCENDING ? MDBX_PNL_SIZE(pl) + 1 : 0;+    mdbx_tassert(txn, pl[begin] <= pl[end - step]);++    unsigned r = mdbx_dpl_search(dl, pl[begin] >> spilled);+    mdbx_tassert(txn, dl->sorted == dl->length);+    for (int i = begin; r <= dl->length;) { /* scan loop */+      assert(i != end);+      mdbx_tassert(txn, !spilled || (pl[i] & 1) == 0);+      pgno_t pl_pgno = pl[i] >> spilled;+      pgno_t dp_pgno = dl->items[r].pgno;+      if (likely(dp_pgno != pl_pgno)) {+        const bool cmp = dp_pgno < pl_pgno;+        r += cmp;+        i += cmp ? 0 : step;+        if (likely(i != end))+          continue;+        return;+      }++      /* update loop */+      unsigned w = r;+    remove_dl:+      if ((txn->mt_env->me_flags & MDBX_WRITEMAP) == 0) {+        MDBX_page *dp = dl->items[r].ptr;+        mdbx_dpage_free(txn->mt_env, dp, IS_OVERFLOW(dp) ? dp->mp_pages : 1);+      }+      ++r;+    next_i:+      i += step;+      if (unlikely(i == end)) {+        while (r <= dl->length)+          dl->items[w++] = dl->items[r++];+      } else {+        while (r <= dl->length) {+          assert(i != end);+          mdbx_tassert(txn, !spilled || (pl[i] & 1) == 0);+          pl_pgno = pl[i] >> spilled;+          dp_pgno = dl->items[r].pgno;+          if (dp_pgno < pl_pgno)+            dl->items[w++] = dl->items[r++];+          else if (dp_pgno > pl_pgno)+            goto next_i;+          else+            goto remove_dl;+        }+      }+      dl->sorted = mdbx_dpl_setlen(dl, w - 1);+      txn->tw.dirtyroom += r - w;+      assert(txn->tw.dirtyroom <= txn->mt_env->me_options.dp_limit);+      return;+    }+  }+}++/* End a transaction, except successful commit of a nested transaction.+ * May be called twice for readonly txns: First reset it, then abort.+ * [in] txn   the transaction handle to end+ * [in] mode  why and how to end the transaction */+static int mdbx_txn_end(MDBX_txn *txn, const unsigned mode) {+  MDBX_env *env = txn->mt_env;+  static const char *const names[] = MDBX_END_NAMES;++#if MDBX_ENV_CHECKPID+  if (unlikely(txn->mt_env->me_pid != mdbx_getpid())) {+    env->me_flags |= MDBX_FATAL_ERROR;+    return MDBX_PANIC;+  }+#endif /* MDBX_ENV_CHECKPID */++  mdbx_debug("%s txn %" PRIaTXN "%c %p on mdbenv %p, root page %" PRIaPGNO+             "/%" PRIaPGNO,+             names[mode & MDBX_END_OPMASK], txn->mt_txnid,+             (txn->mt_flags & MDBX_TXN_RDONLY) ? 'r' : 'w', (void *)txn,+             (void *)env, txn->mt_dbs[MAIN_DBI].md_root,+             txn->mt_dbs[FREE_DBI].md_root);++  mdbx_ensure(env, txn->mt_txnid >=+                       /* paranoia is appropriate here */ env->me_oldest->weak);++  int rc = MDBX_SUCCESS;+  if (F_ISSET(txn->mt_flags, MDBX_TXN_RDONLY)) {+    if (txn->to.reader) {+      MDBX_reader *slot = txn->to.reader;+      mdbx_assert(env, slot->mr_pid.weak == env->me_pid);+      if (likely(!F_ISSET(txn->mt_flags, MDBX_TXN_FINISHED))) {+        mdbx_assert(env, txn->mt_txnid == slot->mr_txnid.weak &&+                             slot->mr_txnid.weak >=+                                 env->me_lck->mti_oldest_reader.weak);+#if defined(MDBX_USE_VALGRIND) || defined(__SANITIZE_ADDRESS__)+        mdbx_txn_valgrind(env, nullptr);+#endif+        atomic_store32(&slot->mr_snapshot_pages_used, 0, mo_Relaxed);+        safe64_reset(&slot->mr_txnid, false);+        atomic_store32(&env->me_lck->mti_readers_refresh_flag, true,+                       mo_Relaxed);+      } else {+        mdbx_assert(env, slot->mr_pid.weak == env->me_pid);+        mdbx_assert(env, slot->mr_txnid.weak >= SAFE64_INVALID_THRESHOLD);+      }+      if (mode & MDBX_END_SLOT) {+        if ((env->me_flags & MDBX_ENV_TXKEY) == 0)+          atomic_store32(&slot->mr_pid, 0, mo_Relaxed);+        txn->to.reader = NULL;+      }+    }+#if defined(_WIN32) || defined(_WIN64)+    if (txn->mt_flags & MDBX_SHRINK_ALLOWED)+      mdbx_srwlock_ReleaseShared(&env->me_remap_guard);+#endif+    txn->mt_numdbs = 0; /* prevent further DBI activity */+    txn->mt_flags = MDBX_TXN_RDONLY | MDBX_TXN_FINISHED;+    txn->mt_owner = 0;+  } else if (!F_ISSET(txn->mt_flags, MDBX_TXN_FINISHED)) {+#if defined(MDBX_USE_VALGRIND) || defined(__SANITIZE_ADDRESS__)+    if (txn == env->me_txn0)+      mdbx_txn_valgrind(env, nullptr);+#endif+    if (!(mode & MDBX_END_EOTDONE)) /* !(already closed cursors) */+      mdbx_cursors_eot(txn, false);++    txn->mt_flags = MDBX_TXN_FINISHED;+    txn->mt_owner = 0;+    env->me_txn = txn->mt_parent;+    mdbx_pnl_free(txn->tw.spill_pages);+    txn->tw.spill_pages = nullptr;+    if (txn == env->me_txn0) {+      mdbx_assert(env, txn->mt_parent == NULL);+      /* Export or close DBI handles created in this txn */+      dbi_update(txn, mode & MDBX_END_UPDATE);+      mdbx_pnl_shrink(&txn->tw.retired_pages);+      mdbx_pnl_shrink(&txn->tw.reclaimed_pglist);+      if (!(env->me_flags & MDBX_WRITEMAP))+        mdbx_dlist_free(txn);+      /* The writer mutex was locked in mdbx_txn_begin. */+      mdbx_txn_unlock(env);+    } else {+      mdbx_assert(env, txn->mt_parent != NULL);+      MDBX_txn *const parent = txn->mt_parent;+      mdbx_assert(env, parent->mt_signature == MDBX_MT_SIGNATURE);+      mdbx_assert(env, parent->mt_child == txn &&+                           (parent->mt_flags & MDBX_TXN_HAS_CHILD) != 0);+      mdbx_assert(+          env, mdbx_pnl_check4assert(txn->tw.reclaimed_pglist,+                                     txn->mt_next_pgno - MDBX_ENABLE_REFUND));++      if (txn->tw.lifo_reclaimed) {+        mdbx_assert(env, MDBX_PNL_SIZE(txn->tw.lifo_reclaimed) >=+                             (unsigned)(uintptr_t)parent->tw.lifo_reclaimed);+        MDBX_PNL_SIZE(txn->tw.lifo_reclaimed) =+            (unsigned)(uintptr_t)parent->tw.lifo_reclaimed;+        parent->tw.lifo_reclaimed = txn->tw.lifo_reclaimed;+      }++      if (txn->tw.retired_pages) {+        mdbx_assert(env, MDBX_PNL_SIZE(txn->tw.retired_pages) >=+                             (unsigned)(uintptr_t)parent->tw.retired_pages);+        MDBX_PNL_SIZE(txn->tw.retired_pages) =+            (unsigned)(uintptr_t)parent->tw.retired_pages;+        parent->tw.retired_pages = txn->tw.retired_pages;+      }++      parent->mt_child = nullptr;+      parent->mt_flags &= ~MDBX_TXN_HAS_CHILD;+      mdbx_tassert(parent, mdbx_dirtylist_check(parent));+      mdbx_tassert(parent, mdbx_audit_ex(parent, 0, false) == 0);+      if (!(env->me_flags & MDBX_WRITEMAP))+        mdbx_dlist_free(txn);+      mdbx_dpl_free(txn);+      mdbx_pnl_free(txn->tw.reclaimed_pglist);++      if (parent->mt_geo.upper != txn->mt_geo.upper ||+          parent->mt_geo.now != txn->mt_geo.now) {+        /* undo resize performed by child txn */+        rc = mdbx_mapresize_implicit(env, parent->mt_next_pgno,+                                     parent->mt_geo.now, parent->mt_geo.upper);+        if (rc == MDBX_RESULT_TRUE) {+          /* unable undo resize (it is regular for Windows),+           * therefore promote size changes from child to the parent txn */+          mdbx_warning("unable undo resize performed by child txn, promote to "+                       "the parent (%u->%u, %u->%u)",+                       txn->mt_geo.now, parent->mt_geo.now, txn->mt_geo.upper,+                       parent->mt_geo.upper);+          parent->mt_geo.now = txn->mt_geo.now;+          parent->mt_geo.upper = txn->mt_geo.upper;+          rc = MDBX_SUCCESS;+        } else if (unlikely(rc != MDBX_SUCCESS)) {+          mdbx_error("error %d while undo resize performed by child txn, fail "+                     "the parent",+                     rc);+          parent->mt_flags |= MDBX_TXN_ERROR;+          if (!env->me_dxb_mmap.address)+            env->me_flags |= MDBX_FATAL_ERROR;+        }+      }+    }+  }++  mdbx_assert(env, txn == env->me_txn0 || txn->mt_owner == 0);+  if ((mode & MDBX_END_FREE) != 0 && txn != env->me_txn0) {+    txn->mt_signature = 0;+    mdbx_free(txn);+  }++  return rc;+}++int mdbx_txn_reset(MDBX_txn *txn) {+  int rc = check_txn(txn, 0);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  /* This call is only valid for read-only txns */+  if (unlikely((txn->mt_flags & MDBX_TXN_RDONLY) == 0))+    return MDBX_EINVAL;++  /* LY: don't close DBI-handles */+  rc = mdbx_txn_end(txn, MDBX_END_RESET | MDBX_END_UPDATE);+  if (rc == MDBX_SUCCESS) {+    mdbx_tassert(txn, txn->mt_signature == MDBX_MT_SIGNATURE);+    mdbx_tassert(txn, txn->mt_owner == 0);+  }+  return rc;+}++int mdbx_txn_break(MDBX_txn *txn) {+  do {+    int rc = check_txn(txn, 0);+    if (unlikely(rc != MDBX_SUCCESS))+      return rc;+    txn->mt_flags |= MDBX_TXN_ERROR;+    if (txn->mt_flags & MDBX_TXN_RDONLY)+      break;+    txn = txn->mt_child;+  } while (txn);+  return MDBX_SUCCESS;+}++int mdbx_txn_abort(MDBX_txn *txn) {+  int rc = check_txn(txn, 0);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  if (F_ISSET(txn->mt_flags, MDBX_TXN_RDONLY))+    /* LY: don't close DBI-handles */+    return mdbx_txn_end(txn, MDBX_END_ABORT | MDBX_END_UPDATE | MDBX_END_SLOT |+                                 MDBX_END_FREE);++  if (txn->mt_child)+    mdbx_txn_abort(txn->mt_child);++  mdbx_tassert(txn, mdbx_dirtylist_check(txn));+  return mdbx_txn_end(txn, MDBX_END_ABORT | MDBX_END_SLOT | MDBX_END_FREE);+}++/* Count all the pages in each DB and in the freelist and make sure+ * it matches the actual number of pages being used.+ * All named DBs must be open for a correct count. */+static __cold int mdbx_audit_ex(MDBX_txn *txn, unsigned retired_stored,+                                bool dont_filter_gc) {+  pgno_t pending = 0;+  if ((txn->mt_flags & MDBX_TXN_RDONLY) == 0) {+    pending = txn->tw.loose_count + MDBX_PNL_SIZE(txn->tw.reclaimed_pglist) ++              (MDBX_PNL_SIZE(txn->tw.retired_pages) - retired_stored);+  }++  MDBX_cursor_couple cx;+  int rc = mdbx_cursor_init(&cx.outer, txn, FREE_DBI);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  pgno_t freecount = 0;+  MDBX_val key, data;+  while ((rc = mdbx_cursor_get(&cx.outer, &key, &data, MDBX_NEXT)) == 0) {+    if (!dont_filter_gc) {+      if (unlikely(key.iov_len != sizeof(txnid_t)))+        return MDBX_CORRUPTED;+      txnid_t id = unaligned_peek_u64(4, key.iov_base);+      if (txn->tw.lifo_reclaimed) {+        for (unsigned i = 1; i <= MDBX_PNL_SIZE(txn->tw.lifo_reclaimed); ++i)+          if (id == txn->tw.lifo_reclaimed[i])+            goto skip;+      } else if (id <= txn->tw.last_reclaimed)+        goto skip;+    }++    freecount += *(pgno_t *)data.iov_base;+  skip:;+  }+  mdbx_tassert(txn, rc == MDBX_NOTFOUND);++  for (MDBX_dbi i = FREE_DBI; i < txn->mt_numdbs; i++)+    txn->mt_dbistate[i] &= ~DBI_AUDITED;++  pgno_t count = 0;+  for (MDBX_dbi i = FREE_DBI; i <= MAIN_DBI; i++) {+    if (!(txn->mt_dbistate[i] & DBI_VALID))+      continue;+    rc = mdbx_cursor_init(&cx.outer, txn, i);+    if (unlikely(rc != MDBX_SUCCESS))+      return rc;+    txn->mt_dbistate[i] |= DBI_AUDITED;+    if (txn->mt_dbs[i].md_root == P_INVALID)+      continue;+    count += txn->mt_dbs[i].md_branch_pages + txn->mt_dbs[i].md_leaf_pages ++             txn->mt_dbs[i].md_overflow_pages;++    if (i != MAIN_DBI)+      continue;+    rc = mdbx_page_search(&cx.outer, NULL, MDBX_PS_FIRST);+    while (rc == MDBX_SUCCESS) {+      MDBX_page *mp = cx.outer.mc_pg[cx.outer.mc_top];+      for (unsigned j = 0; j < page_numkeys(mp); j++) {+        MDBX_node *node = page_node(mp, j);+        if (node_flags(node) == F_SUBDATA) {+          if (unlikely(node_ds(node) != sizeof(MDBX_db)))+            return MDBX_CORRUPTED;+          MDBX_db db_copy, *db;+          memcpy(db = &db_copy, node_data(node), sizeof(db_copy));+          if ((txn->mt_flags & MDBX_TXN_RDONLY) == 0) {+            for (MDBX_dbi k = txn->mt_numdbs; --k > MAIN_DBI;) {+              if ((txn->mt_dbistate[k] & DBI_VALID) &&+                  /* txn->mt_dbxs[k].md_name.iov_len > 0 && */+                  node_ks(node) == txn->mt_dbxs[k].md_name.iov_len &&+                  memcmp(node_key(node), txn->mt_dbxs[k].md_name.iov_base,+                         node_ks(node)) == 0) {+                txn->mt_dbistate[k] |= DBI_AUDITED;+                if (!(txn->mt_dbistate[k] & MDBX_DBI_STALE))+                  db = txn->mt_dbs + k;+                break;+              }+            }+          }+          count +=+              db->md_branch_pages + db->md_leaf_pages + db->md_overflow_pages;+        }+      }+      rc = mdbx_cursor_sibling(&cx.outer, SIBLING_RIGHT);+    }+    mdbx_tassert(txn, rc == MDBX_NOTFOUND);+  }++  for (MDBX_dbi i = FREE_DBI; i < txn->mt_numdbs; i++) {+    if ((txn->mt_dbistate[i] & (DBI_VALID | DBI_AUDITED | DBI_STALE)) !=+        DBI_VALID)+      continue;+    for (MDBX_txn *t = txn; t; t = t->mt_parent)+      if (F_ISSET(t->mt_dbistate[i], DBI_DIRTY | DBI_CREAT)) {+        count += t->mt_dbs[i].md_branch_pages + t->mt_dbs[i].md_leaf_pages ++                 t->mt_dbs[i].md_overflow_pages;+        txn->mt_dbistate[i] |= DBI_AUDITED;+        break;+      }+    if (!(txn->mt_dbistate[i] & DBI_AUDITED)) {+      mdbx_warning("audit %s@%" PRIaTXN+                   ": unable account dbi %d / \"%*s\", state 0x%02x",+                   txn->mt_parent ? "nested-" : "", txn->mt_txnid, i,+                   (int)txn->mt_dbxs[i].md_name.iov_len,+                   (const char *)txn->mt_dbxs[i].md_name.iov_base,+                   txn->mt_dbistate[i]);+    }+  }++  if (pending + freecount + count + NUM_METAS == txn->mt_next_pgno)+    return MDBX_SUCCESS;++  if ((txn->mt_flags & MDBX_TXN_RDONLY) == 0)+    mdbx_error("audit @%" PRIaTXN ": %u(pending) = %u(loose-count) + "+               "%u(reclaimed-list) + %u(retired-pending) - %u(retired-stored)",+               txn->mt_txnid, pending, txn->tw.loose_count,+               MDBX_PNL_SIZE(txn->tw.reclaimed_pglist),+               txn->tw.retired_pages ? MDBX_PNL_SIZE(txn->tw.retired_pages) : 0,+               retired_stored);+  mdbx_error("audit @%" PRIaTXN ": %" PRIaPGNO "(pending) + %" PRIaPGNO+             "(free) + %" PRIaPGNO "(count) = %" PRIaPGNO+             "(total) <> %" PRIaPGNO "(next-pgno)",+             txn->mt_txnid, pending, freecount, count + NUM_METAS,+             pending + freecount + count + NUM_METAS, txn->mt_next_pgno);+  return MDBX_PROBLEM;+}++static __always_inline unsigned backlog_size(MDBX_txn *txn) {+  return MDBX_PNL_SIZE(txn->tw.reclaimed_pglist) + txn->tw.loose_count;+}++/* LY: Prepare a backlog of pages to modify GC itself,+ * while reclaiming is prohibited. It should be enough to prevent search+ * in mdbx_page_alloc() during a deleting, when GC tree is unbalanced. */+static int mdbx_prep_backlog(MDBX_txn *txn, MDBX_cursor *gc_cursor,+                             const size_t pnl_bytes) {+  const unsigned linear4list = number_of_ovpages(txn->mt_env, pnl_bytes);+  const unsigned backlog4cow = txn->mt_dbs[FREE_DBI].md_depth;+  const unsigned backlog4rebalance = backlog4cow + 1;++  if (likely(linear4list == 1 &&+             backlog_size(txn) > (pnl_bytes+                                      ? backlog4rebalance+                                      : (backlog4cow + backlog4rebalance))))+    return MDBX_SUCCESS;++  mdbx_trace(">> pnl_bytes %zu, backlog %u, 4list %u, 4cow %u, 4rebalance %u",+             pnl_bytes, backlog_size(txn), linear4list, backlog4cow,+             backlog4rebalance);++  gc_cursor->mc_flags &= ~C_RECLAIMING;+  int err = mdbx_cursor_touch(gc_cursor);+  mdbx_trace("== after-touch, backlog %u, err %d", backlog_size(txn), err);++  if (linear4list > 1 && err == MDBX_SUCCESS) {+    err = mdbx_page_alloc(gc_cursor, linear4list, nullptr,+                          MDBX_ALLOC_GC | MDBX_ALLOC_CACHE);+    mdbx_trace("== after-4linear, backlog %u, err %d", backlog_size(txn), err);+  }++  while (backlog_size(txn) < backlog4cow + linear4list && err == MDBX_SUCCESS)+    err = mdbx_page_alloc(gc_cursor, 1, NULL, MDBX_ALLOC_GC);++  gc_cursor->mc_flags |= C_RECLAIMING;+  mdbx_trace("<< backlog %u, err %d", backlog_size(txn), err);+  return (err != MDBX_NOTFOUND) ? err : MDBX_SUCCESS;+}++static __inline void clean_reserved_gc_pnl(MDBX_env *env, MDBX_val pnl) {+  /* PNL is initially empty, zero out at least the length */+  memset(pnl.iov_base, 0, sizeof(pgno_t));+  if ((env->me_flags & (MDBX_WRITEMAP | MDBX_NOMEMINIT)) == 0)+    /* zero out to avoid leaking values from uninitialized malloc'ed memory+     * to the file in non-writemap mode if length of the saving page-list+     * was changed during space reservation. */+    memset(pnl.iov_base, 0, pnl.iov_len);+}++/* Cleanup reclaimed GC records, than save the retired-list as of this+ * transaction to GC (aka freeDB). This recursive changes the reclaimed-list+ * loose-list and retired-list. Keep trying until it stabilizes. */+static int mdbx_update_gc(MDBX_txn *txn) {+  /* txn->tw.reclaimed_pglist[] can grow and shrink during this call.+   * txn->tw.last_reclaimed and txn->tw.retired_pages[] can only grow.+   * Page numbers cannot disappear from txn->tw.retired_pages[]. */+  MDBX_env *const env = txn->mt_env;+  const bool lifo = (env->me_flags & MDBX_LIFORECLAIM) != 0;+  const char *dbg_prefix_mode = lifo ? "    lifo" : "    fifo";+  (void)dbg_prefix_mode;+  mdbx_trace("\n>>> @%" PRIaTXN, txn->mt_txnid);++  unsigned retired_stored = 0, loop = 0;+  MDBX_cursor_couple couple;+  int rc = mdbx_cursor_init(&couple.outer, txn, FREE_DBI);+  if (unlikely(rc != MDBX_SUCCESS))+    goto bailout_notracking;++  couple.outer.mc_flags |= C_RECLAIMING;+  couple.outer.mc_next = txn->tw.cursors[FREE_DBI];+  txn->tw.cursors[FREE_DBI] = &couple.outer;++retry:+  ++loop;+retry_noaccount:+  mdbx_trace("%s", " >> restart");+  mdbx_tassert(txn,+               mdbx_pnl_check4assert(txn->tw.reclaimed_pglist,+                                     txn->mt_next_pgno - MDBX_ENABLE_REFUND));+  mdbx_tassert(txn, mdbx_dirtylist_check(txn));+  mdbx_tassert(txn, txn->tw.dirtyroom + txn->tw.dirtylist->length ==+                        txn->mt_env->me_options.dp_limit);+  if (unlikely(/* paranoia */ loop > ((MDBX_DEBUG > 0) ? 9 : 99))) {+    mdbx_error("too more loops %u, bailout", loop);+    rc = MDBX_PROBLEM;+    goto bailout;+  }++  rc = mdbx_prep_backlog(txn, &couple.outer,+                         MDBX_PNL_SIZEOF(txn->tw.retired_pages));+  if (unlikely(rc != MDBX_SUCCESS))+    goto bailout;++  unsigned settled = 0, cleaned_gc_slot = 0, reused_gc_slot = 0,+           filled_gc_slot = ~0u;+  txnid_t cleaned_gc_id = 0, gc_rid = txn->tw.last_reclaimed;+  while (true) {+    /* Come back here after each Put() in case retired-list changed */+    MDBX_val key, data;+    mdbx_trace("%s", " >> continue");++    mdbx_tassert(txn,+                 mdbx_pnl_check4assert(txn->tw.reclaimed_pglist,+                                       txn->mt_next_pgno - MDBX_ENABLE_REFUND));+    if (lifo) {+      if (cleaned_gc_slot < (txn->tw.lifo_reclaimed+                                 ? MDBX_PNL_SIZE(txn->tw.lifo_reclaimed)+                                 : 0)) {+        settled = 0;+        cleaned_gc_slot = 0;+        reused_gc_slot = 0;+        filled_gc_slot = ~0u;+        /* LY: cleanup reclaimed records. */+        do {+          cleaned_gc_id = txn->tw.lifo_reclaimed[++cleaned_gc_slot];+          mdbx_tassert(txn, cleaned_gc_slot > 0 &&+                                cleaned_gc_id < env->me_oldest->weak);+          key.iov_base = &cleaned_gc_id;+          key.iov_len = sizeof(cleaned_gc_id);+          rc = mdbx_cursor_get(&couple.outer, &key, NULL, MDBX_SET);+          if (rc == MDBX_NOTFOUND)+            continue;+          if (unlikely(rc != MDBX_SUCCESS))+            goto bailout;+          rc = mdbx_prep_backlog(txn, &couple.outer, 0);+          if (unlikely(rc != MDBX_SUCCESS))+            goto bailout;+          mdbx_tassert(txn, cleaned_gc_id < env->me_oldest->weak);+          mdbx_trace("%s.cleanup-reclaimed-id [%u]%" PRIaTXN, dbg_prefix_mode,+                     cleaned_gc_slot, cleaned_gc_id);+          rc = mdbx_cursor_del(&couple.outer, 0);+          if (unlikely(rc != MDBX_SUCCESS))+            goto bailout;+        } while (cleaned_gc_slot < MDBX_PNL_SIZE(txn->tw.lifo_reclaimed));+        mdbx_txl_sort(txn->tw.lifo_reclaimed);+      }+    } else {+      /* If using records from GC which we have not yet deleted,+       * now delete them and any we reserved for tw.reclaimed_pglist. */+      while (cleaned_gc_id <= txn->tw.last_reclaimed) {+        gc_rid = cleaned_gc_id;+        settled = 0;+        rc = mdbx_cursor_first(&couple.outer, &key, NULL);+        if (unlikely(rc != MDBX_SUCCESS)) {+          if (rc == MDBX_NOTFOUND)+            break;+          goto bailout;+        }+        if (!MDBX_DISABLE_PAGECHECKS &&+            unlikely(key.iov_len != sizeof(txnid_t))) {+          rc = MDBX_CORRUPTED;+          goto bailout;+        }+        cleaned_gc_id = unaligned_peek_u64(4, key.iov_base);+        if (!MDBX_DISABLE_PAGECHECKS &&+            unlikely(cleaned_gc_id < MIN_TXNID || cleaned_gc_id > MAX_TXNID)) {+          rc = MDBX_CORRUPTED;+          goto bailout;+        }+        if (cleaned_gc_id > txn->tw.last_reclaimed)+          break;+        if (cleaned_gc_id < txn->tw.last_reclaimed) {+          rc = mdbx_prep_backlog(txn, &couple.outer, 0);+          if (unlikely(rc != MDBX_SUCCESS))+            goto bailout;+        }+        mdbx_tassert(txn, cleaned_gc_id <= txn->tw.last_reclaimed);+        mdbx_tassert(txn, cleaned_gc_id < env->me_oldest->weak);+        mdbx_trace("%s.cleanup-reclaimed-id %" PRIaTXN, dbg_prefix_mode,+                   cleaned_gc_id);+        rc = mdbx_cursor_del(&couple.outer, 0);+        if (unlikely(rc != MDBX_SUCCESS))+          goto bailout;+      }+    }++    mdbx_tassert(txn,+                 mdbx_pnl_check4assert(txn->tw.reclaimed_pglist,+                                       txn->mt_next_pgno - MDBX_ENABLE_REFUND));+    mdbx_tassert(txn, mdbx_dirtylist_check(txn));+    mdbx_tassert(txn, txn->tw.dirtyroom + txn->tw.dirtylist->length ==+                          txn->mt_env->me_options.dp_limit);+    if (mdbx_audit_enabled()) {+      rc = mdbx_audit_ex(txn, retired_stored, false);+      if (unlikely(rc != MDBX_SUCCESS))+        goto bailout;+    }++    /* return suitable into unallocated space */+    if (mdbx_refund(txn)) {+      mdbx_tassert(+          txn, mdbx_pnl_check4assert(txn->tw.reclaimed_pglist,+                                     txn->mt_next_pgno - MDBX_ENABLE_REFUND));+      if (mdbx_audit_enabled()) {+        rc = mdbx_audit_ex(txn, retired_stored, false);+        if (unlikely(rc != MDBX_SUCCESS))+          goto bailout;+      }+    }++    /* handle loose pages - put ones into the reclaimed- or retired-list */+    if (txn->tw.loose_pages) {+      /* Return loose page numbers to tw.reclaimed_pglist,+       * though usually none are left at this point.+       * The pages themselves remain in dirtylist. */+      if (unlikely(!txn->tw.lifo_reclaimed && txn->tw.last_reclaimed < 1)) {+        if (txn->tw.loose_count > 0) {+          /* Put loose page numbers in tw.retired_pages,+           * since unable to return them to tw.reclaimed_pglist. */+          if (unlikely((rc = mdbx_pnl_need(&txn->tw.retired_pages,+                                           txn->tw.loose_count)) != 0))+            goto bailout;+          for (MDBX_page *mp = txn->tw.loose_pages; mp; mp = mp->mp_next)+            mdbx_pnl_xappend(txn->tw.retired_pages, mp->mp_pgno);+          mdbx_trace("%s: append %u loose-pages to retired-pages",+                     dbg_prefix_mode, txn->tw.loose_count);+        }+      } else {+        /* Room for loose pages + temp PNL with same */+        rc = mdbx_pnl_need(&txn->tw.reclaimed_pglist,+                           2 * txn->tw.loose_count + 2);+        if (unlikely(rc != MDBX_SUCCESS))+          goto bailout;+        MDBX_PNL loose = txn->tw.reclaimed_pglist ++                         MDBX_PNL_ALLOCLEN(txn->tw.reclaimed_pglist) -+                         txn->tw.loose_count - 1;+        unsigned count = 0;+        for (MDBX_page *mp = txn->tw.loose_pages; mp; mp = mp->mp_next) {+          mdbx_tassert(txn, mp->mp_flags == (P_LOOSE | P_DIRTY));+          loose[++count] = mp->mp_pgno;+        }+        mdbx_tassert(txn, count == txn->tw.loose_count);+        MDBX_PNL_SIZE(loose) = count;+        mdbx_pnl_sort(loose);+        mdbx_pnl_xmerge(txn->tw.reclaimed_pglist, loose);+        mdbx_trace("%s: append %u loose-pages to reclaimed-pages",+                   dbg_prefix_mode, txn->tw.loose_count);+      }++      /* filter-out list of dirty-pages from loose-pages */+      MDBX_dpl *const dl = txn->tw.dirtylist;+      unsigned w = 0;+      for (unsigned r = w; ++r <= dl->length;) {+        MDBX_page *dp = dl->items[r].ptr;+        mdbx_tassert(txn, (dp->mp_flags & P_DIRTY));+        mdbx_tassert(txn,+                     dl->items[r].pgno + (IS_OVERFLOW(dp) ? dp->mp_pages : 1) <=+                         txn->mt_next_pgno);+        if ((dp->mp_flags & P_LOOSE) == 0) {+          if (++w != r)+            dl->items[w] = dl->items[r];+        } else {+          mdbx_tassert(txn, dp->mp_flags == (P_LOOSE | P_DIRTY));+          if ((env->me_flags & MDBX_WRITEMAP) == 0)+            mdbx_dpage_free(env, dp, 1);+        }+      }+      mdbx_trace("%s: filtered-out loose-pages from %u -> %u dirty-pages",+                 dbg_prefix_mode, dl->length, w);+      mdbx_tassert(txn, txn->tw.loose_count == dl->length - w);+      mdbx_dpl_setlen(dl, w);+      dl->sorted = 0;+      txn->tw.dirtyroom += txn->tw.loose_count;+      assert(txn->tw.dirtyroom <= txn->mt_env->me_options.dp_limit);+      txn->tw.loose_pages = NULL;+      txn->tw.loose_count = 0;+#if MDBX_ENABLE_REFUND+      txn->tw.loose_refund_wl = 0;+#endif /* MDBX_ENABLE_REFUND */+    }++    const unsigned amount = (unsigned)MDBX_PNL_SIZE(txn->tw.reclaimed_pglist);+    /* handle retired-list - store ones into single gc-record */+    if (retired_stored < MDBX_PNL_SIZE(txn->tw.retired_pages)) {+      if (unlikely(!retired_stored)) {+        /* Make sure last page of GC is touched and on retired-list */+        couple.outer.mc_flags &= ~C_RECLAIMING;+        rc = mdbx_page_search(&couple.outer, NULL,+                              MDBX_PS_LAST | MDBX_PS_MODIFY);+        couple.outer.mc_flags |= C_RECLAIMING;+        if (unlikely(rc != MDBX_SUCCESS) && rc != MDBX_NOTFOUND)+          goto bailout;+      }+      /* Write to last page of GC */+      key.iov_len = sizeof(txn->mt_txnid);+      key.iov_base = &txn->mt_txnid;+      do {+        data.iov_len = MDBX_PNL_SIZEOF(txn->tw.retired_pages);+        mdbx_prep_backlog(txn, &couple.outer, data.iov_len);+        rc = mdbx_cursor_put(&couple.outer, &key, &data, MDBX_RESERVE);+        if (unlikely(rc != MDBX_SUCCESS))+          goto bailout;+        /* Retry if tw.retired_pages[] grew during the Put() */+      } while (data.iov_len < MDBX_PNL_SIZEOF(txn->tw.retired_pages));++      retired_stored = (unsigned)MDBX_PNL_SIZE(txn->tw.retired_pages);+      mdbx_pnl_sort(txn->tw.retired_pages);+      mdbx_assert(env, data.iov_len == MDBX_PNL_SIZEOF(txn->tw.retired_pages));+      memcpy(data.iov_base, txn->tw.retired_pages, data.iov_len);++      mdbx_trace("%s.put-retired #%u @ %" PRIaTXN, dbg_prefix_mode,+                 retired_stored, txn->mt_txnid);++      if (mdbx_log_enabled(MDBX_LOG_EXTRA)) {+        unsigned i = retired_stored;+        mdbx_debug_extra("PNL write txn %" PRIaTXN " root %" PRIaPGNO+                         " num %u, PNL",+                         txn->mt_txnid, txn->mt_dbs[FREE_DBI].md_root, i);+        for (; i; i--)+          mdbx_debug_extra_print(" %" PRIaPGNO, txn->tw.retired_pages[i]);+        mdbx_debug_extra_print("%s\n", ".");+      }+      if (unlikely(amount != MDBX_PNL_SIZE(txn->tw.reclaimed_pglist))) {+        mdbx_trace("%s.reclaimed-list changed %u -> %u, retry", dbg_prefix_mode,+                   amount, (unsigned)MDBX_PNL_SIZE(txn->tw.reclaimed_pglist));+        goto retry_noaccount /* rare case, but avoids GC fragmentation and one+                                cycle. */+            ;+      }+      continue;+    }++    /* handle reclaimed and lost pages - merge and store both into gc */+    mdbx_tassert(txn,+                 mdbx_pnl_check4assert(txn->tw.reclaimed_pglist,+                                       txn->mt_next_pgno - MDBX_ENABLE_REFUND));+    mdbx_tassert(txn, txn->tw.loose_count == 0);++    mdbx_trace("%s", " >> reserving");+    if (mdbx_audit_enabled()) {+      rc = mdbx_audit_ex(txn, retired_stored, false);+      if (unlikely(rc != MDBX_SUCCESS))+        goto bailout;+    }+    const unsigned left = amount - settled;+    mdbx_trace("%s: amount %u, settled %d, left %d, lifo-reclaimed-slots %u, "+               "reused-gc-slots %u",+               dbg_prefix_mode, amount, settled, (int)left,+               txn->tw.lifo_reclaimed+                   ? (unsigned)MDBX_PNL_SIZE(txn->tw.lifo_reclaimed)+                   : 0,+               reused_gc_slot);+    if (0 >= (int)left)+      break;++    const unsigned prefer_max_scatter = 257;+    txnid_t reservation_gc_id;+    if (lifo) {+      if (txn->tw.lifo_reclaimed == nullptr) {+        txn->tw.lifo_reclaimed = mdbx_txl_alloc();+        if (unlikely(!txn->tw.lifo_reclaimed)) {+          rc = MDBX_ENOMEM;+          goto bailout;+        }+      }+      if ((unsigned)MDBX_PNL_SIZE(txn->tw.lifo_reclaimed) <+              prefer_max_scatter &&+          left > ((unsigned)MDBX_PNL_SIZE(txn->tw.lifo_reclaimed) -+                  reused_gc_slot) *+                     env->me_maxgc_ov1page) {++        /* LY: need just a txn-id for save page list. */+        bool need_cleanup = false;+        txnid_t snap_oldest;+      retry_rid:+        couple.outer.mc_flags &= ~C_RECLAIMING;+        do {+          snap_oldest = mdbx_find_oldest(txn);+          rc = mdbx_page_alloc(&couple.outer, 0, NULL, MDBX_ALLOC_GC);+          if (likely(rc == MDBX_SUCCESS)) {+            mdbx_trace("%s: took @%" PRIaTXN " from GC", dbg_prefix_mode,+                       MDBX_PNL_LAST(txn->tw.lifo_reclaimed));+            need_cleanup = true;+          }+        } while (rc == MDBX_SUCCESS &&+                 (unsigned)MDBX_PNL_SIZE(txn->tw.lifo_reclaimed) <+                     prefer_max_scatter &&+                 left > ((unsigned)MDBX_PNL_SIZE(txn->tw.lifo_reclaimed) -+                         reused_gc_slot) *+                            env->me_maxgc_ov1page);+        couple.outer.mc_flags |= C_RECLAIMING;++        if (likely(rc == MDBX_SUCCESS)) {+          mdbx_trace("%s: got enough from GC.", dbg_prefix_mode);+          continue;+        } else if (unlikely(rc != MDBX_NOTFOUND))+          /* LY: some troubles... */+          goto bailout;++        if (MDBX_PNL_SIZE(txn->tw.lifo_reclaimed)) {+          if (need_cleanup) {+            mdbx_txl_sort(txn->tw.lifo_reclaimed);+            cleaned_gc_slot = 0;+          }+          gc_rid = MDBX_PNL_LAST(txn->tw.lifo_reclaimed);+        } else {+          mdbx_tassert(txn, txn->tw.last_reclaimed == 0);+          if (unlikely(mdbx_find_oldest(txn) != snap_oldest))+            /* should retry mdbx_page_alloc(MDBX_ALLOC_GC)+             * if the oldest reader changes since the last attempt */+            goto retry_rid;+          /* no reclaimable GC entries,+           * therefore no entries with ID < mdbx_find_oldest(txn) */+          txn->tw.last_reclaimed = gc_rid = snap_oldest - 1;+          mdbx_trace("%s: none recycled yet, set rid to @%" PRIaTXN,+                     dbg_prefix_mode, gc_rid);+        }++        /* LY: GC is empty, will look any free txn-id in high2low order. */+        while (MDBX_PNL_SIZE(txn->tw.lifo_reclaimed) < prefer_max_scatter &&+               left > ((unsigned)MDBX_PNL_SIZE(txn->tw.lifo_reclaimed) -+                       reused_gc_slot) *+                          env->me_maxgc_ov1page) {+          if (unlikely(gc_rid < 2)) {+            if (unlikely(MDBX_PNL_SIZE(txn->tw.lifo_reclaimed) <=+                         reused_gc_slot)) {+              mdbx_notice("** restart: reserve depleted (reused_gc_slot %u >= "+                          "lifo_reclaimed %u" PRIaTXN,+                          reused_gc_slot,+                          (unsigned)MDBX_PNL_SIZE(txn->tw.lifo_reclaimed));+              goto retry;+            }+            break;+          }++          mdbx_tassert(txn, gc_rid >= MIN_TXNID && gc_rid <= MAX_TXNID);+          --gc_rid;+          key.iov_base = &gc_rid;+          key.iov_len = sizeof(gc_rid);+          rc = mdbx_cursor_get(&couple.outer, &key, &data, MDBX_SET_KEY);+          if (unlikely(rc == MDBX_SUCCESS)) {+            mdbx_debug("%s: GC's id %" PRIaTXN+                       " is used, continue bottom-up search",+                       dbg_prefix_mode, gc_rid);+            ++gc_rid;+            rc = mdbx_cursor_get(&couple.outer, &key, &data, MDBX_FIRST);+            if (rc == MDBX_NOTFOUND) {+              mdbx_debug("%s: GC is empty", dbg_prefix_mode);+              break;+            }+            if (unlikely(rc != MDBX_SUCCESS ||+                         key.iov_len != sizeof(mdbx_tid_t))) {+              rc = MDBX_CORRUPTED;+              goto bailout;+            }+            txnid_t gc_first = unaligned_peek_u64(4, key.iov_base);+            if (!MDBX_DISABLE_PAGECHECKS &&+                unlikely(gc_first < MIN_TXNID || gc_first > MAX_TXNID)) {+              rc = MDBX_CORRUPTED;+              goto bailout;+            }+            if (gc_first < 2) {+              mdbx_debug("%s: no free GC's id(s) less than %" PRIaTXN,+                         dbg_prefix_mode, gc_rid);+              break;+            }+            gc_rid = gc_first - 1;+          }++          rc = mdbx_txl_append(&txn->tw.lifo_reclaimed, gc_rid);+          if (unlikely(rc != MDBX_SUCCESS))+            goto bailout;++          if (reused_gc_slot)+            /* rare case, but it is better to clear and re-create GC entries+             * with less fragmentation. */+            need_cleanup = true;+          else+            cleaned_gc_slot +=+                1 /* mark cleanup is not needed for added slot. */;++          mdbx_trace("%s: append @%" PRIaTXN+                     " to lifo-reclaimed, cleaned-gc-slot = %u",+                     dbg_prefix_mode, gc_rid, cleaned_gc_slot);+        }++        if (need_cleanup) {+          cleaned_gc_slot = 0;+          mdbx_trace("%s: restart inner-loop to clear and re-create GC entries",+                     dbg_prefix_mode);+          continue;+        }+      }++      const unsigned i =+          (unsigned)MDBX_PNL_SIZE(txn->tw.lifo_reclaimed) - reused_gc_slot;+      mdbx_tassert(txn, i > 0 && i <= MDBX_PNL_SIZE(txn->tw.lifo_reclaimed));+      reservation_gc_id = txn->tw.lifo_reclaimed[i];+      mdbx_trace("%s: take @%" PRIaTXN " from lifo-reclaimed[%u]",+                 dbg_prefix_mode, reservation_gc_id, i);+    } else {+      mdbx_tassert(txn, txn->tw.lifo_reclaimed == NULL);+      if (unlikely(gc_rid == 0)) {+        gc_rid = mdbx_find_oldest(txn) - 1;+        rc = mdbx_cursor_get(&couple.outer, &key, NULL, MDBX_FIRST);+        if (rc == MDBX_SUCCESS) {+          if (!MDBX_DISABLE_PAGECHECKS &&+              unlikely(key.iov_len != sizeof(txnid_t))) {+            rc = MDBX_CORRUPTED;+            goto bailout;+          }+          txnid_t gc_first = unaligned_peek_u64(4, key.iov_base);+          if (!MDBX_DISABLE_PAGECHECKS &&+              unlikely(gc_first < MIN_TXNID || gc_first > MAX_TXNID)) {+            rc = MDBX_CORRUPTED;+            goto bailout;+          }+          if (gc_rid >= gc_first)+            gc_rid = gc_first - 1;+          if (unlikely(gc_rid == 0)) {+            mdbx_error("%s", "** no GC tail-space to store");+            goto retry;+          }+        } else if (rc != MDBX_NOTFOUND)+          goto bailout;+        txn->tw.last_reclaimed = gc_rid;+      }+      reservation_gc_id = gc_rid--;+      mdbx_trace("%s: take @%" PRIaTXN " from head-gc-id", dbg_prefix_mode,+                 reservation_gc_id);+    }+    ++reused_gc_slot;++    unsigned chunk = left;+    if (unlikely(chunk > env->me_maxgc_ov1page)) {+      const unsigned avail_gc_slots =+          txn->tw.lifo_reclaimed+              ? (unsigned)MDBX_PNL_SIZE(txn->tw.lifo_reclaimed) -+                    reused_gc_slot + 1+              : (gc_rid < INT16_MAX) ? (unsigned)gc_rid : INT16_MAX;+      if (avail_gc_slots > 1) {+        if (chunk < env->me_maxgc_ov1page * 2)+          chunk /= 2;+        else {+          const unsigned threshold =+              env->me_maxgc_ov1page * ((avail_gc_slots < prefer_max_scatter)+                                           ? avail_gc_slots+                                           : prefer_max_scatter);+          if (left < threshold)+            chunk = env->me_maxgc_ov1page;+          else {+            const unsigned tail = left - threshold + env->me_maxgc_ov1page + 1;+            unsigned span = 1;+            unsigned avail = (unsigned)((pgno2bytes(env, span) - PAGEHDRSZ) /+                                        sizeof(pgno_t)) /*- 1 + span */;+            if (tail > avail) {+              for (unsigned i = amount - span; i > 0; --i) {+                if (MDBX_PNL_ASCENDING+                        ? (txn->tw.reclaimed_pglist[i] + span)+                        : (txn->tw.reclaimed_pglist[i] - span) ==+                              txn->tw.reclaimed_pglist[i + span]) {+                  span += 1;+                  avail = (unsigned)((pgno2bytes(env, span) - PAGEHDRSZ) /+                                     sizeof(pgno_t)) -+                          1 + span;+                  if (avail >= tail)+                    break;+                }+              }+            }++            chunk = (avail >= tail) ? tail - span+                                    : (avail_gc_slots > 3 &&+                                       reused_gc_slot < prefer_max_scatter - 3)+                                          ? avail - span+                                          : tail;+          }+        }+      }+    }+    mdbx_tassert(txn, chunk > 0);++    mdbx_trace("%s: gc_rid %" PRIaTXN ", reused_gc_slot %u, reservation-id "+               "%" PRIaTXN,+               dbg_prefix_mode, gc_rid, reused_gc_slot, reservation_gc_id);++    mdbx_trace("%s: chunk %u, gc-per-ovpage %u", dbg_prefix_mode, chunk,+               env->me_maxgc_ov1page);++    mdbx_tassert(txn, reservation_gc_id < env->me_oldest->weak);+    if (unlikely(reservation_gc_id < 1 ||+                 reservation_gc_id >=+                     atomic_load64(env->me_oldest, mo_Relaxed))) {+      mdbx_error("%s", "** internal error (reservation_gc_id)");+      rc = MDBX_PROBLEM;+      goto bailout;+    }++    key.iov_len = sizeof(reservation_gc_id);+    key.iov_base = &reservation_gc_id;+    data.iov_len = (chunk + 1) * sizeof(pgno_t);+    mdbx_trace("%s.reserve: %u [%u...%u] @%" PRIaTXN, dbg_prefix_mode, chunk,+               settled + 1, settled + chunk + 1, reservation_gc_id);+    mdbx_prep_backlog(txn, &couple.outer, data.iov_len);+    rc = mdbx_cursor_put(&couple.outer, &key, &data,+                         MDBX_RESERVE | MDBX_NOOVERWRITE);+    mdbx_tassert(txn,+                 mdbx_pnl_check4assert(txn->tw.reclaimed_pglist,+                                       txn->mt_next_pgno - MDBX_ENABLE_REFUND));+    if (unlikely(rc != MDBX_SUCCESS))+      goto bailout;++    clean_reserved_gc_pnl(env, data);+    settled += chunk;+    mdbx_trace("%s.settled %u (+%u), continue", dbg_prefix_mode, settled,+               chunk);++    if (txn->tw.lifo_reclaimed &&+        unlikely(amount < MDBX_PNL_SIZE(txn->tw.reclaimed_pglist))) {+      mdbx_notice("** restart: reclaimed-list growth %u -> %u", amount,+                  (unsigned)MDBX_PNL_SIZE(txn->tw.reclaimed_pglist));+      goto retry_noaccount;+    }++    continue;+  }++  mdbx_tassert(+      txn,+      cleaned_gc_slot ==+          (txn->tw.lifo_reclaimed ? MDBX_PNL_SIZE(txn->tw.lifo_reclaimed) : 0));++  mdbx_trace("%s", " >> filling");+  /* Fill in the reserved records */+  filled_gc_slot =+      txn->tw.lifo_reclaimed+          ? (unsigned)MDBX_PNL_SIZE(txn->tw.lifo_reclaimed) - reused_gc_slot+          : reused_gc_slot;+  rc = MDBX_SUCCESS;+  mdbx_tassert(txn,+               mdbx_pnl_check4assert(txn->tw.reclaimed_pglist,+                                     txn->mt_next_pgno - MDBX_ENABLE_REFUND));+  mdbx_tassert(txn, mdbx_dirtylist_check(txn));+  if (MDBX_PNL_SIZE(txn->tw.reclaimed_pglist)) {+    MDBX_val key, data;+    key.iov_len = data.iov_len = 0; /* avoid MSVC warning */+    key.iov_base = data.iov_base = NULL;++    const unsigned amount = MDBX_PNL_SIZE(txn->tw.reclaimed_pglist);+    unsigned left = amount;+    if (txn->tw.lifo_reclaimed == nullptr) {+      mdbx_tassert(txn, lifo == 0);+      rc = mdbx_cursor_first(&couple.outer, &key, &data);+      if (unlikely(rc != MDBX_SUCCESS))+        goto bailout;+    } else {+      mdbx_tassert(txn, lifo != 0);+    }++    while (true) {+      txnid_t fill_gc_id;+      mdbx_trace("%s: left %u of %u", dbg_prefix_mode, left,+                 (unsigned)MDBX_PNL_SIZE(txn->tw.reclaimed_pglist));+      if (txn->tw.lifo_reclaimed == nullptr) {+        mdbx_tassert(txn, lifo == 0);+        fill_gc_id = unaligned_peek_u64(4, key.iov_base);+        if (filled_gc_slot-- == 0 || fill_gc_id > txn->tw.last_reclaimed) {+          mdbx_notice(+              "** restart: reserve depleted (filled_slot %u, fill_id %" PRIaTXN+              " > last_reclaimed %" PRIaTXN,+              filled_gc_slot, fill_gc_id, txn->tw.last_reclaimed);+          goto retry;+        }+      } else {+        mdbx_tassert(txn, lifo != 0);+        if (++filled_gc_slot >+            (unsigned)MDBX_PNL_SIZE(txn->tw.lifo_reclaimed)) {+          mdbx_notice("** restart: reserve depleted (filled_gc_slot %u > "+                      "lifo_reclaimed %u" PRIaTXN,+                      filled_gc_slot,+                      (unsigned)MDBX_PNL_SIZE(txn->tw.lifo_reclaimed));+          goto retry;+        }+        fill_gc_id = txn->tw.lifo_reclaimed[filled_gc_slot];+        mdbx_trace("%s.seek-reservation @%" PRIaTXN " at lifo_reclaimed[%u]",+                   dbg_prefix_mode, fill_gc_id, filled_gc_slot);+        key.iov_base = &fill_gc_id;+        key.iov_len = sizeof(fill_gc_id);+        rc = mdbx_cursor_get(&couple.outer, &key, &data, MDBX_SET_KEY);+        if (unlikely(rc != MDBX_SUCCESS))+          goto bailout;+      }+      mdbx_tassert(txn, cleaned_gc_slot ==+                            (txn->tw.lifo_reclaimed+                                 ? MDBX_PNL_SIZE(txn->tw.lifo_reclaimed)+                                 : 0));+      mdbx_tassert(txn, fill_gc_id > 0 && fill_gc_id < env->me_oldest->weak);+      key.iov_base = &fill_gc_id;+      key.iov_len = sizeof(fill_gc_id);++      mdbx_tassert(txn, data.iov_len >= sizeof(pgno_t) * 2);+      couple.outer.mc_flags |= C_GCFREEZE;+      unsigned chunk = (unsigned)(data.iov_len / sizeof(pgno_t)) - 1;+      if (unlikely(chunk > left)) {+        mdbx_trace("%s: chunk %u > left %u, @%" PRIaTXN, dbg_prefix_mode, chunk,+                   left, fill_gc_id);+        if ((loop < 5 && chunk - left > loop / 2) ||+            chunk - left > env->me_maxgc_ov1page) {+          data.iov_len = (left + 1) * sizeof(pgno_t);+          if (loop < 7)+            couple.outer.mc_flags &= ~C_GCFREEZE;+        }+        chunk = left;+      }+      rc = mdbx_cursor_put(&couple.outer, &key, &data,+                           MDBX_CURRENT | MDBX_RESERVE);+      couple.outer.mc_flags &= ~C_GCFREEZE;+      if (unlikely(rc != MDBX_SUCCESS))+        goto bailout;+      clean_reserved_gc_pnl(env, data);++      if (unlikely(txn->tw.loose_count ||+                   amount != MDBX_PNL_SIZE(txn->tw.reclaimed_pglist))) {+        mdbx_notice("** restart: reclaimed-list growth (%u -> %u, loose +%u)",+                    amount, MDBX_PNL_SIZE(txn->tw.reclaimed_pglist),+                    txn->tw.loose_count);+        goto retry;+      }+      if (unlikely(txn->tw.lifo_reclaimed+                       ? cleaned_gc_slot < MDBX_PNL_SIZE(txn->tw.lifo_reclaimed)+                       : cleaned_gc_id < txn->tw.last_reclaimed)) {+        mdbx_notice("%s", "** restart: reclaimed-slots changed");+        goto retry;+      }+      if (unlikely(retired_stored != MDBX_PNL_SIZE(txn->tw.retired_pages))) {+        mdbx_tassert(txn,+                     retired_stored < MDBX_PNL_SIZE(txn->tw.retired_pages));+        mdbx_notice("** restart: retired-list growth (%u -> %u)",+                    retired_stored, MDBX_PNL_SIZE(txn->tw.retired_pages));+        goto retry;+      }++      pgno_t *dst = data.iov_base;+      *dst++ = chunk;+      pgno_t *src = MDBX_PNL_BEGIN(txn->tw.reclaimed_pglist) + left - chunk;+      memcpy(dst, src, chunk * sizeof(pgno_t));+      pgno_t *from = src, *to = src + chunk;+      mdbx_trace("%s.fill: %u [ %u:%" PRIaPGNO "...%u:%" PRIaPGNO+                 "] @%" PRIaTXN,+                 dbg_prefix_mode, chunk,+                 (unsigned)(from - txn->tw.reclaimed_pglist), from[0],+                 (unsigned)(to - txn->tw.reclaimed_pglist), to[-1], fill_gc_id);++      left -= chunk;+      if (mdbx_audit_enabled()) {+        rc = mdbx_audit_ex(txn, retired_stored + amount - left, true);+        if (unlikely(rc != MDBX_SUCCESS))+          goto bailout;+      }+      if (left == 0) {+        rc = MDBX_SUCCESS;+        break;+      }++      if (txn->tw.lifo_reclaimed == nullptr) {+        mdbx_tassert(txn, lifo == 0);+        rc = mdbx_cursor_next(&couple.outer, &key, &data, MDBX_NEXT);+        if (unlikely(rc != MDBX_SUCCESS))+          goto bailout;+      } else {+        mdbx_tassert(txn, lifo != 0);+      }+    }+  }++  mdbx_tassert(txn, rc == MDBX_SUCCESS);+  if (unlikely(txn->tw.loose_count != 0 ||+               filled_gc_slot !=+                   (txn->tw.lifo_reclaimed+                        ? (unsigned)MDBX_PNL_SIZE(txn->tw.lifo_reclaimed)+                        : 0))) {+    mdbx_notice("** restart: reserve excess (filled-slot %u, loose-count %u)",+                filled_gc_slot, txn->tw.loose_count);+    goto retry;+  }++  mdbx_tassert(txn,+               txn->tw.lifo_reclaimed == NULL ||+                   cleaned_gc_slot == MDBX_PNL_SIZE(txn->tw.lifo_reclaimed));++bailout:+  txn->tw.cursors[FREE_DBI] = couple.outer.mc_next;++bailout_notracking:+  MDBX_PNL_SIZE(txn->tw.reclaimed_pglist) = 0;+  mdbx_trace("<<< %u loops, rc = %d", loop, rc);+  return rc;+}++static int mdbx_flush_iov(MDBX_txn *const txn, struct iovec *iov,+                          unsigned iov_items, size_t iov_off,+                          size_t iov_bytes) {+  MDBX_env *const env = txn->mt_env;+  mdbx_assert(env, iov_items > 0);+  int rc;+  if (likely(iov_items == 1)) {+    mdbx_assert(env, iov->iov_len == iov_bytes);+    rc = mdbx_pwrite(env->me_lazy_fd, iov->iov_base, iov_bytes, iov_off);+  } else {+    rc = mdbx_pwritev(env->me_lazy_fd, iov, iov_items, iov_off, iov_bytes);+  }++  if (unlikely(rc != MDBX_SUCCESS))+    mdbx_error("Write error: %s", mdbx_strerror(rc));+  else {+    VALGRIND_MAKE_MEM_DEFINED(txn->mt_env->me_map + iov_off, iov_bytes);+    ASAN_UNPOISON_MEMORY_REGION(txn->mt_env->me_map + iov_off, iov_bytes);+  }++  for (unsigned i = 0; i < iov_items; i++)+    mdbx_dpage_free(env, (MDBX_page *)iov[i].iov_base,+                    bytes2pgno(env, iov[i].iov_len));+  return rc;+}++/* Flush (some) dirty pages to the map, after clearing their dirty flag.+ * [in] txn   the transaction that's being committed+ * [in] keep  number of initial pages in dirtylist to keep dirty.+ * Returns 0 on success, non-zero on failure. */+__hot static int mdbx_page_flush(MDBX_txn *txn, const unsigned keep) {+  struct iovec iov[MDBX_COMMIT_PAGES];+  MDBX_dpl *const dl = mdbx_dpl_sort(txn->tw.dirtylist);+  MDBX_env *const env = txn->mt_env;+  pgno_t flush_begin = MAX_PAGENO;+  pgno_t flush_end = MIN_PAGENO;+  int rc = MDBX_SUCCESS;+  unsigned iov_items = 0;+  size_t iov_bytes = 0;+  size_t iov_off = 0;++  unsigned r, w;+  for (r = w = keep; ++r <= dl->length;) {+    MDBX_page *dp = dl->items[r].ptr;+    mdbx_tassert(txn,+                 dp->mp_pgno >= MIN_PAGENO && dp->mp_pgno < txn->mt_next_pgno);+    mdbx_tassert(txn, dp->mp_flags & P_DIRTY);++    /* Don't flush this page yet */+    if (dp->mp_flags & P_KEEP) {+      dp->mp_flags -= P_KEEP;+      dl->items[++w] = dl->items[r];+      continue;+    }+    if (dp->mp_flags & P_LOOSE) {+      dl->items[++w] = dl->items[r];+      continue;+    }++    const unsigned npages = IS_OVERFLOW(dp) ? dp->mp_pages : 1;+    flush_begin = (flush_begin < dp->mp_pgno) ? flush_begin : dp->mp_pgno;+    flush_end =+        (flush_end > dp->mp_pgno + npages) ? flush_end : dp->mp_pgno + npages;+    env->me_unsynced_pages->weak += npages;+    dp->mp_flags -= P_DIRTY;+    dp->mp_txnid = pp_txnid2chk(txn);++    if ((env->me_flags & MDBX_WRITEMAP) == 0) {+      const size_t size = pgno2bytes(env, npages);+      if (iov_off + iov_bytes != pgno2bytes(env, dp->mp_pgno) ||+          iov_items == ARRAY_LENGTH(iov) || iov_bytes + size > MAX_WRITE) {+        if (iov_items) {+          rc = mdbx_flush_iov(txn, iov, iov_items, iov_off, iov_bytes);+#if defined(__linux__) || defined(__gnu_linux__)+          if (mdbx_linux_kernel_version >= 0x02060b00)+          /* Linux kernels older than version 2.6.11 ignore the addr and nbytes+           * arguments, making this function fairly expensive. Therefore, the+           * whole cache is always flushed. */+#endif /* Linux */+            mdbx_flush_incoherent_mmap(env->me_map + iov_off, iov_bytes,+                                       env->me_os_psize);+          iov_items = 0;+          iov_bytes = 0;+          if (unlikely(rc != MDBX_SUCCESS)) {+            do+              dl->items[++w] = dl->items[r];+            while (++r <= dl->length);+            break;+          }+        }+        iov_off = pgno2bytes(env, dp->mp_pgno);+      }+      iov[iov_items].iov_base = (void *)dp;+      iov[iov_items].iov_len = size;+      iov_items += 1;+      iov_bytes += size;+    }+  }++  mdbx_tassert(txn, dl->sorted == dl->length && r == dl->length + 1);+  txn->tw.dirtyroom += dl->length - w;+  assert(txn->tw.dirtyroom <= txn->mt_env->me_options.dp_limit);+  dl->sorted = mdbx_dpl_setlen(dl, w);+  mdbx_tassert(txn, txn->mt_parent ||+                        txn->tw.dirtyroom + txn->tw.dirtylist->length ==+                            txn->mt_env->me_options.dp_limit);++  if (iov_items)+    rc = mdbx_flush_iov(txn, iov, iov_items, iov_off, iov_bytes);++  if (unlikely(rc != MDBX_SUCCESS)) {+    txn->mt_flags |= MDBX_TXN_ERROR;+    return rc;+  }++#if defined(__linux__) || defined(__gnu_linux__)+  if ((env->me_flags & MDBX_WRITEMAP) == 0 &&+      mdbx_linux_kernel_version < 0x02060b00)+    /* Linux kernels older than version 2.6.11 ignore the addr and nbytes+     * arguments, making this function fairly expensive. Therefore, the+     * whole cache is always flushed. */+    mdbx_flush_incoherent_mmap(env->me_map + pgno2bytes(env, flush_begin),+                               pgno2bytes(env, flush_end - flush_begin),+                               env->me_os_psize);+#endif /* Linux */++  /* TODO: use flush_begin & flush_end for msync() & sync_file_range(). */+  (void)flush_begin;+  (void)flush_end;+  return MDBX_SUCCESS;+}++/* Check txn and dbi arguments to a function */+static __always_inline bool mdbx_txn_dbi_exists(MDBX_txn *txn, MDBX_dbi dbi,+                                                unsigned validity) {+  if (likely(dbi < txn->mt_numdbs && (txn->mt_dbistate[dbi] & validity)))+    return true;++  return dbi_import(txn, dbi);+}++#ifndef LIBMDBX_NO_EXPORTS_LEGACY_API+int mdbx_txn_commit(MDBX_txn *txn) { return __inline_mdbx_txn_commit(txn); }+#endif /* LIBMDBX_NO_EXPORTS_LEGACY_API */++/* Merge child txn into parent */+static __inline void mdbx_txn_merge(MDBX_txn *const parent, MDBX_txn *const txn,+                                    const unsigned parent_retired_len) {+  MDBX_dpl *const src = mdbx_dpl_sort(txn->tw.dirtylist);++  /* Remove refunded pages from parent's dirty list */+  MDBX_dpl *const dst = mdbx_dpl_sort(parent->tw.dirtylist);+  if (MDBX_ENABLE_REFUND) {+    unsigned n = dst->length;+    while (n && dst->items[n].pgno >= parent->mt_next_pgno) {+      if (!(txn->mt_env->me_flags & MDBX_WRITEMAP)) {+        MDBX_page *dp = dst->items[n].ptr;+        mdbx_dpage_free(txn->mt_env, dp, IS_OVERFLOW(dp) ? dp->mp_pages : 1);+      }+      --n;+    }+    parent->tw.dirtyroom += dst->sorted - n;+    assert(parent->tw.dirtyroom <= parent->mt_env->me_options.dp_limit);+    dst->sorted = mdbx_dpl_setlen(dst, n);+    mdbx_tassert(parent,+                 parent->mt_parent ||+                     parent->tw.dirtyroom + parent->tw.dirtylist->length ==+                         parent->mt_env->me_options.dp_limit);+  }++  /* Remove reclaimed pages from parent's dirty list */+  const MDBX_PNL reclaimed_list = parent->tw.reclaimed_pglist;+  mdbx_dpl_sift(parent, reclaimed_list, false);++  /* Move retired pages from parent's dirty & spilled list to reclaimed */+  unsigned r, w, d, s, l;+  for (r = w = parent_retired_len;+       ++r <= MDBX_PNL_SIZE(parent->tw.retired_pages);) {+    const pgno_t pgno = parent->tw.retired_pages[r];+    const unsigned di = mdbx_dpl_exist(parent->tw.dirtylist, pgno);+    const unsigned si = (!di && unlikely(parent->tw.spill_pages))+                            ? mdbx_pnl_exist(parent->tw.spill_pages, pgno << 1)+                            : 0;+    unsigned npages;+    const char *kind;+    if (di) {+      MDBX_page *dp = parent->tw.dirtylist->items[di].ptr;+      mdbx_tassert(parent, (dp->mp_flags & ~(P_LEAF | P_LEAF2 | P_BRANCH |+                                             P_OVERFLOW | P_DIRTY)) == 0);+      npages = IS_OVERFLOW(dp) ? dp->mp_pages : 1;+      mdbx_page_wash(parent, di, dp, npages);+      kind = "dirty";+      l = 1;+      if (unlikely(npages > l)) {+        /* OVERFLOW-страница могла быть переиспользована по частям. Тогда+         * в retired-списке может быть только начало последовательности,+         * а остаток растащен по dirty, spilled и reclaimed спискам. Поэтому+         * переносим в reclaimed с проверкой на обрыв последовательности.+         * В любом случае, все осколки будут учтены и отфильтрованы, т.е. если+         * страница была разбита на части, то важно удалить dirty-элемент,+         * а все осколки будут учтены отдельно. */++        /* Список retired страниц не сортирован, но для ускорения сортировки+         * дополняется в соответствии с MDBX_PNL_ASCENDING */+#if MDBX_PNL_ASCENDING+        const unsigned len = MDBX_PNL_SIZE(parent->tw.retired_pages);+        while (r < len && parent->tw.retired_pages[r + 1] == pgno + l) {+          ++r;+          if (++l == npages)+            break;+        }+#else+        while (w > parent_retired_len &&+               parent->tw.retired_pages[w - 1] == pgno + l) {+          --w;+          if (++l == npages)+            break;+        }+#endif+      }+    } else if (unlikely(si)) {+      l = npages = 1;+      mdbx_spill_remove(parent, si, 1);+      kind = "spilled";+    } else {+      parent->tw.retired_pages[++w] = pgno;+      continue;+    }++    mdbx_debug("reclaim retired parent's %u->%u %s page %" PRIaPGNO, npages, l,+               kind, pgno);+    int err = mdbx_pnl_insert_range(&parent->tw.reclaimed_pglist, pgno, l);+    mdbx_ensure(txn->mt_env, err == MDBX_SUCCESS);+  }+  MDBX_PNL_SIZE(parent->tw.retired_pages) = w;++  /* Filter-out parent spill list */+  if (parent->tw.spill_pages && MDBX_PNL_SIZE(parent->tw.spill_pages) > 0) {+    const MDBX_PNL sl = mdbx_spill_purge(parent);+    unsigned len = MDBX_PNL_SIZE(sl);+    if (len) {+      /* Remove refunded pages from parent's spill list */+      if (MDBX_ENABLE_REFUND &&+          MDBX_PNL_MOST(sl) >= (parent->mt_next_pgno << 1)) {+#if MDBX_PNL_ASCENDING+        unsigned i = MDBX_PNL_SIZE(sl);+        assert(MDBX_PNL_MOST(sl) == MDBX_PNL_LAST(sl));+        do {+          if ((sl[i] & 1) == 0)+            mdbx_debug("refund parent's spilled page %" PRIaPGNO, sl[i] >> 1);+          i -= 1;+        } while (i && sl[i] >= (parent->mt_next_pgno << 1));+        MDBX_PNL_SIZE(sl) = i;+#else+        assert(MDBX_PNL_MOST(sl) == MDBX_PNL_FIRST(sl));+        unsigned i = 0;+        do {+          ++i;+          if ((sl[i] & 1) == 0)+            mdbx_debug("refund parent's spilled page %" PRIaPGNO, sl[i] >> 1);+        } while (i < len && sl[i + 1] >= (parent->mt_next_pgno << 1));+        MDBX_PNL_SIZE(sl) = len -= i;+        memmove(sl + 1, sl + 1 + i, len * sizeof(sl[0]));+#endif+      }+      mdbx_tassert(txn, mdbx_pnl_check4assert(sl, parent->mt_next_pgno << 1));++      /* Remove reclaimed pages from parent's spill list */+      s = MDBX_PNL_SIZE(sl), r = MDBX_PNL_SIZE(reclaimed_list);+      /* Scanning from end to begin */+      while (s && r) {+        if (sl[s] & 1) {+          --s;+          continue;+        }+        const pgno_t spilled_pgno = sl[s] >> 1;+        const pgno_t reclaimed_pgno = reclaimed_list[r];+        if (reclaimed_pgno != spilled_pgno) {+          const bool cmp = MDBX_PNL_ORDERED(spilled_pgno, reclaimed_pgno);+          s -= !cmp;+          r -= cmp;+        } else {+          mdbx_debug("remove reclaimed parent's spilled page %" PRIaPGNO,+                     reclaimed_pgno);+          mdbx_spill_remove(parent, s, 1);+          --s;+          --r;+        }+      }++      /* Remove anything in our dirty list from parent's spill list */+      /* Scanning spill list in descend order */+      const int step = MDBX_PNL_ASCENDING ? -1 : 1;+      s = MDBX_PNL_ASCENDING ? MDBX_PNL_SIZE(sl) : 1;+      d = src->length;+      while (d && (MDBX_PNL_ASCENDING ? s > 0 : s <= MDBX_PNL_SIZE(sl))) {+        if (sl[s] & 1) {+          s += step;+          continue;+        }+        const pgno_t spilled_pgno = sl[s] >> 1;+        const pgno_t dirty_pgno_form = src->items[d].pgno;+        MDBX_page *dp = src->items[d].ptr;+        const unsigned npages = IS_OVERFLOW(dp) ? dp->mp_pages : 1;+        const pgno_t dirty_pgno_to = dirty_pgno_form + npages;+        if (dirty_pgno_form > spilled_pgno) {+          --d;+          continue;+        }+        if (dirty_pgno_to <= spilled_pgno) {+          s += step;+          continue;+        }++        mdbx_debug("remove dirtied parent's spilled %u page %" PRIaPGNO, npages,+                   dirty_pgno_form);+        mdbx_spill_remove(parent, s, 1);+        s += step;+      }++      /* Squash deleted pagenums if we deleted any */+      mdbx_spill_purge(parent);+    }+  }++  /* Remove anything in our spill list from parent's dirty list */+  if (txn->tw.spill_pages) {+    mdbx_tassert(txn, mdbx_pnl_check4assert(txn->tw.spill_pages,+                                            parent->mt_next_pgno << 1));+    mdbx_dpl_sift(parent, txn->tw.spill_pages, true);+    mdbx_tassert(parent,+                 parent->mt_parent ||+                     parent->tw.dirtyroom + parent->tw.dirtylist->length ==+                         parent->mt_env->me_options.dp_limit);+  }++  /* Find length of merging our dirty list with parent's and release+   * filter-out pages */+  for (l = 0, d = dst->length, s = src->length; d > 0 && s > 0;) {+    const MDBX_page *sp = src->items[s].ptr;+    mdbx_tassert(parent,+                 (sp->mp_flags & ~(P_LEAF | P_LEAF2 | P_BRANCH | P_OVERFLOW |+                                   P_DIRTY | P_LOOSE)) == 0);+    const unsigned s_npages = IS_OVERFLOW(sp) ? sp->mp_pages : 1;+    const pgno_t s_pgno = src->items[s].pgno;++    MDBX_page *dp = dst->items[d].ptr;+    mdbx_tassert(parent, (dp->mp_flags & ~(P_LEAF | P_LEAF2 | P_BRANCH |+                                           P_OVERFLOW | P_DIRTY)) == 0);+    const unsigned d_npages = IS_OVERFLOW(dp) ? dp->mp_pages : 1;+    const pgno_t d_pgno = dst->items[d].pgno;++    if (d_pgno >= s_pgno + s_npages) {+      --d;+      ++l;+    } else if (d_pgno + d_npages <= s_pgno) {+      --s;+      ++l;+    } else {+      dst->items[d--].ptr = nullptr;+      if ((txn->mt_flags & MDBX_WRITEMAP) == 0)+        mdbx_dpage_free(txn->mt_env, dp, d_npages);+    }+  }+  assert(dst->sorted == dst->length);+  mdbx_tassert(parent, dst->detent >= l + d + s);+  dst->sorted = l + d + s; /* the merged length */++  /* Merge our dirty list into parent's, i.e. merge(dst, src) -> dst */+  if (dst->sorted >= dst->length) {+    /* from end to begin with dst extending */+    for (l = dst->sorted, s = src->length, d = dst->length; s > 0 && d > 0;) {+      if (unlikely(l <= d)) {+        /* squash to get a gap of free space for merge */+        for (r = w = 1; r <= d; ++r)+          if (dst->items[r].ptr) {+            if (w != r) {+              dst->items[w] = dst->items[r];+              dst->items[r].ptr = nullptr;+            }+            ++w;+          }+        mdbx_notice("squash to begin for extending-merge %u -> %u", d, w - 1);+        d = w - 1;+        continue;+      }+      assert(l > d);+      if (dst->items[d].ptr) {+        dst->items[l--] = (dst->items[d].pgno > src->items[s].pgno)+                              ? dst->items[d--]+                              : src->items[s--];+      } else+        --d;+    }+    if (s > 0) {+      assert(l == s);+      while (d > 0) {+        assert(dst->items[d].ptr == nullptr);+        --d;+      }+      do {+        assert(l > 0);+        dst->items[l--] = src->items[s--];+      } while (s > 0);+    } else {+      assert(l == d);+      while (l > 0) {+        assert(dst->items[l].ptr != nullptr);+        --l;+      }+    }+  } else {+    /* from begin to end with dst shrinking (a lot of new overflow pages) */+    for (l = s = d = 1; s <= src->length && d <= dst->length;) {+      if (unlikely(l >= d)) {+        /* squash to get a gap of free space for merge */+        for (r = w = dst->length; r >= d; --r)+          if (dst->items[r].ptr) {+            if (w != r) {+              dst->items[w] = dst->items[r];+              dst->items[r].ptr = nullptr;+            }+            --w;+          }+        mdbx_notice("squash to end for shrinking-merge %u -> %u", d, w + 1);+        d = w + 1;+        continue;+      }+      assert(l < d);+      if (dst->items[d].ptr) {+        dst->items[l++] = (dst->items[d].pgno < src->items[s].pgno)+                              ? dst->items[d++]+                              : src->items[s++];+      } else+        ++d;+    }+    if (s <= src->length) {+      assert(dst->sorted - l == src->length - s);+      while (d <= dst->length) {+        assert(dst->items[d].ptr == nullptr);+        --d;+      }+      do {+        assert(l <= dst->sorted);+        dst->items[l++] = src->items[s++];+      } while (s <= src->length);+    } else {+      assert(dst->sorted - l == dst->length - d);+      while (l <= dst->sorted) {+        assert(l <= d && d <= dst->length && dst->items[d].ptr);+        dst->items[l++] = dst->items[d++];+      }+    }+  }+  parent->tw.dirtyroom -= dst->sorted - dst->length;+  assert(parent->tw.dirtyroom <= parent->mt_env->me_options.dp_limit);+  mdbx_dpl_setlen(dst, dst->sorted);+  mdbx_tassert(parent,+               parent->mt_parent ||+                   parent->tw.dirtyroom + parent->tw.dirtylist->length ==+                       parent->mt_env->me_options.dp_limit);+  mdbx_tassert(parent, mdbx_dirtylist_check(parent));+  mdbx_dpl_free(txn);++  if (txn->tw.spill_pages) {+    if (parent->tw.spill_pages) {+      /* Must not fail since space was preserved above. */+      mdbx_pnl_xmerge(parent->tw.spill_pages, txn->tw.spill_pages);+      mdbx_pnl_free(txn->tw.spill_pages);+    } else {+      parent->tw.spill_pages = txn->tw.spill_pages;+      parent->tw.spill_least_removed = txn->tw.spill_least_removed;+    }+    mdbx_tassert(parent, mdbx_dirtylist_check(parent));+  }++  parent->mt_flags &= ~MDBX_TXN_HAS_CHILD;+  if (parent->tw.spill_pages) {+    assert(mdbx_pnl_check4assert(parent->tw.spill_pages,+                                 parent->mt_next_pgno << 1));+    if (MDBX_PNL_SIZE(parent->tw.spill_pages))+      parent->mt_flags |= MDBX_TXN_SPILLS;+  }+}++int mdbx_txn_commit_ex(MDBX_txn *txn, MDBX_commit_latency *latency) {+  STATIC_ASSERT(MDBX_TXN_FINISHED ==+                MDBX_TXN_BLOCKED - MDBX_TXN_HAS_CHILD - MDBX_TXN_ERROR);+  const uint64_t ts_0 = latency ? mdbx_osal_monotime() : 0;+  uint64_t ts_1 = 0, ts_2 = 0, ts_3 = 0, ts_4 = 0;+  uint32_t audit_duration = 0;++  int rc = check_txn(txn, MDBX_TXN_FINISHED);+  if (unlikely(rc != MDBX_SUCCESS))+    goto provide_latency;++  if (unlikely(txn->mt_flags & MDBX_TXN_ERROR)) {+    rc = MDBX_RESULT_TRUE;+    goto fail;+  }++  MDBX_env *env = txn->mt_env;+#if MDBX_ENV_CHECKPID+  if (unlikely(env->me_pid != mdbx_getpid())) {+    env->me_flags |= MDBX_FATAL_ERROR;+    rc = MDBX_PANIC;+    goto provide_latency;+  }+#endif /* MDBX_ENV_CHECKPID */++  /* mdbx_txn_end() mode for a commit which writes nothing */+  unsigned end_mode =+      MDBX_END_PURE_COMMIT | MDBX_END_UPDATE | MDBX_END_SLOT | MDBX_END_FREE;+  if (unlikely(F_ISSET(txn->mt_flags, MDBX_TXN_RDONLY)))+    goto done;++  if (txn->mt_child) {+    rc = mdbx_txn_commit_ex(txn->mt_child, NULL);+    mdbx_tassert(txn, txn->mt_child == NULL);+    if (unlikely(rc != MDBX_SUCCESS))+      goto fail;+  }++  if (unlikely(txn != env->me_txn)) {+    mdbx_debug("%s", "attempt to commit unknown transaction");+    rc = MDBX_EINVAL;+    goto fail;+  }++  if (txn->mt_parent) {+    mdbx_tassert(txn, mdbx_audit_ex(txn, 0, false) == 0);+    mdbx_assert(env, txn != env->me_txn0);+    MDBX_txn *const parent = txn->mt_parent;+    mdbx_assert(env, parent->mt_signature == MDBX_MT_SIGNATURE);+    mdbx_assert(env, parent->mt_child == txn &&+                         (parent->mt_flags & MDBX_TXN_HAS_CHILD) != 0);+    mdbx_assert(env, mdbx_dirtylist_check(txn));++    if (txn->tw.dirtylist->length == 0 && !(txn->mt_flags & MDBX_TXN_DIRTY) &&+        parent->mt_numdbs == txn->mt_numdbs) {+      for (int i = txn->mt_numdbs; --i >= 0;) {+        mdbx_tassert(txn, (txn->mt_dbistate[i] & DBI_DIRTY) == 0);+        if ((txn->mt_dbistate[i] & DBI_STALE) &&+            !(parent->mt_dbistate[i] & DBI_STALE))+          mdbx_tassert(txn, memcmp(&parent->mt_dbs[i], &txn->mt_dbs[i],+                                   sizeof(MDBX_db)) == 0);+      }++      mdbx_tassert(txn, memcmp(&parent->mt_geo, &txn->mt_geo,+                               sizeof(parent->mt_geo)) == 0);+      mdbx_tassert(txn, memcmp(&parent->mt_canary, &txn->mt_canary,+                               sizeof(parent->mt_canary)) == 0);+      mdbx_tassert(txn, !txn->tw.spill_pages ||+                            MDBX_PNL_SIZE(txn->tw.spill_pages) == 0);+      mdbx_tassert(txn, txn->tw.loose_count == 0);++      /* fast completion of pure nested transaction */+      end_mode = MDBX_END_PURE_COMMIT | MDBX_END_SLOT | MDBX_END_FREE;+      goto done;+    }++    /* Preserve space for spill list to avoid parent's state corruption+     * if allocation fails. */+    const unsigned parent_retired_len =+        (unsigned)(uintptr_t)parent->tw.retired_pages;+    mdbx_tassert(txn,+                 parent_retired_len <= MDBX_PNL_SIZE(txn->tw.retired_pages));+    const unsigned retired_delta =+        MDBX_PNL_SIZE(txn->tw.retired_pages) - parent_retired_len;+    if (retired_delta) {+      rc = mdbx_pnl_need(&txn->tw.reclaimed_pglist, retired_delta);+      if (unlikely(rc != MDBX_SUCCESS))+        goto fail;+    }++    if (txn->tw.spill_pages) {+      if (parent->tw.spill_pages) {+        rc = mdbx_pnl_need(&parent->tw.spill_pages,+                           MDBX_PNL_SIZE(txn->tw.spill_pages));+        if (unlikely(rc != MDBX_SUCCESS))+          goto fail;+      }+      mdbx_spill_purge(txn);+    }++    if (unlikely(txn->tw.dirtylist->length + parent->tw.dirtylist->length >+                     parent->tw.dirtylist->detent &&+                 !mdbx_dpl_reserve(parent, txn->tw.dirtylist->length ++                                               parent->tw.dirtylist->length))) {+      rc = MDBX_ENOMEM;+      goto fail;+    }++    //-------------------------------------------------------------------------++    parent->tw.lifo_reclaimed = txn->tw.lifo_reclaimed;+    txn->tw.lifo_reclaimed = NULL;++    parent->tw.retired_pages = txn->tw.retired_pages;+    txn->tw.retired_pages = NULL;++    mdbx_pnl_free(parent->tw.reclaimed_pglist);+    parent->tw.reclaimed_pglist = txn->tw.reclaimed_pglist;+    txn->tw.reclaimed_pglist = NULL;+    parent->tw.last_reclaimed = txn->tw.last_reclaimed;++    parent->mt_geo = txn->mt_geo;+    parent->mt_canary = txn->mt_canary;+    parent->mt_flags |= txn->mt_flags & MDBX_TXN_DIRTY;++    /* Move loose pages to parent */+#if MDBX_ENABLE_REFUND+    parent->tw.loose_refund_wl = txn->tw.loose_refund_wl;+#endif /* MDBX_ENABLE_REFUND */+    parent->tw.loose_count = txn->tw.loose_count;+    parent->tw.loose_pages = txn->tw.loose_pages;++    /* Merge our cursors into parent's and close them */+    mdbx_cursors_eot(txn, true);+    end_mode |= MDBX_END_EOTDONE;++    /* Update parent's DBs array */+    memcpy(parent->mt_dbs, txn->mt_dbs, txn->mt_numdbs * sizeof(MDBX_db));+    parent->mt_numdbs = txn->mt_numdbs;+    parent->mt_dbistate[FREE_DBI] = txn->mt_dbistate[FREE_DBI];+    parent->mt_dbistate[MAIN_DBI] = txn->mt_dbistate[MAIN_DBI];+    for (unsigned i = CORE_DBS; i < txn->mt_numdbs; i++) {+      /* preserve parent's status */+      const uint8_t state =+          txn->mt_dbistate[i] |+          (parent->mt_dbistate[i] & (DBI_CREAT | DBI_FRESH | DBI_DIRTY));+      mdbx_debug("db %u dbi-state %s 0x%02x -> 0x%02x", i,+                 (parent->mt_dbistate[i] != state) ? "update" : "still",+                 parent->mt_dbistate[i], state);+      parent->mt_dbistate[i] = state;+    }++    ts_1 = latency ? mdbx_osal_monotime() : 0;+    mdbx_txn_merge(parent, txn, parent_retired_len);+    ts_2 = latency ? mdbx_osal_monotime() : 0;+    env->me_txn = parent;+    parent->mt_child = NULL;+    mdbx_tassert(parent, mdbx_dirtylist_check(parent));++#if MDBX_ENABLE_REFUND+    mdbx_refund(parent);+    if (mdbx_assert_enabled()) {+      /* Check parent's loose pages not suitable for refund */+      for (MDBX_page *lp = parent->tw.loose_pages; lp; lp = lp->mp_next)+        mdbx_tassert(parent, lp->mp_pgno < parent->tw.loose_refund_wl &&+                                 lp->mp_pgno + 1 < parent->mt_next_pgno);+      /* Check parent's reclaimed pages not suitable for refund */+      if (MDBX_PNL_SIZE(parent->tw.reclaimed_pglist))+        mdbx_tassert(parent, MDBX_PNL_MOST(parent->tw.reclaimed_pglist) + 1 <+                                 parent->mt_next_pgno);+    }+#endif /* MDBX_ENABLE_REFUND */++    ts_4 = ts_3 = latency ? mdbx_osal_monotime() : 0;+    txn->mt_signature = 0;+    mdbx_free(txn);+    mdbx_tassert(parent, mdbx_audit_ex(parent, 0, false) == 0);+    rc = MDBX_SUCCESS;+    goto provide_latency;+  }++  mdbx_tassert(txn, txn->tw.dirtyroom + txn->tw.dirtylist->length ==+                        txn->mt_env->me_options.dp_limit);+  mdbx_cursors_eot(txn, false);+  end_mode |= MDBX_END_EOTDONE;++  if (txn->tw.dirtylist->length == 0 &&+      (txn->mt_flags & (MDBX_TXN_DIRTY | MDBX_TXN_SPILLS)) == 0) {+    for (int i = txn->mt_numdbs; --i >= 0;)+      mdbx_tassert(txn, (txn->mt_dbistate[i] & DBI_DIRTY) == 0);+    rc = MDBX_SUCCESS;+    goto done;+  }++  mdbx_debug("committing txn %" PRIaTXN " %p on mdbenv %p, root page %" PRIaPGNO+             "/%" PRIaPGNO,+             txn->mt_txnid, (void *)txn, (void *)env,+             txn->mt_dbs[MAIN_DBI].md_root, txn->mt_dbs[FREE_DBI].md_root);++  /* Update DB root pointers */+  if (txn->mt_numdbs > CORE_DBS) {+    MDBX_cursor_couple couple;+    MDBX_val data;+    data.iov_len = sizeof(MDBX_db);++    rc = mdbx_cursor_init(&couple.outer, txn, MAIN_DBI);+    if (unlikely(rc != MDBX_SUCCESS))+      goto fail;+    for (MDBX_dbi i = CORE_DBS; i < txn->mt_numdbs; i++) {+      if (txn->mt_dbistate[i] & DBI_DIRTY) {+        if (unlikely(TXN_DBI_CHANGED(txn, i))) {+          rc = MDBX_BAD_DBI;+          goto fail;+        }+        MDBX_db *db = &txn->mt_dbs[i];+        mdbx_debug("update main's entry for sub-db %u, mod_txnid %" PRIaTXN+                   " -> %" PRIaTXN,+                   i, pp_txnid2chk(txn), db->md_mod_txnid);+        db->md_mod_txnid = pp_txnid2chk(txn);+        data.iov_base = db;+        WITH_CURSOR_TRACKING(couple.outer,+                             rc = mdbx_cursor_put(&couple.outer,+                                                  &txn->mt_dbxs[i].md_name,+                                                  &data, F_SUBDATA));+        if (unlikely(rc != MDBX_SUCCESS))+          goto fail;+      }+    }+  }++  ts_1 = latency ? mdbx_osal_monotime() : 0;+  rc = mdbx_update_gc(txn);+  if (unlikely(rc != MDBX_SUCCESS))+    goto fail;++  ts_2 = latency ? mdbx_osal_monotime() : 0;+  if (mdbx_audit_enabled()) {+    rc = mdbx_audit_ex(txn, MDBX_PNL_SIZE(txn->tw.retired_pages), true);+    const uint64_t audit_end = mdbx_osal_monotime();+    audit_duration = mdbx_osal_monotime_to_16dot16(audit_end - ts_2);+    ts_2 = audit_end;+    if (unlikely(rc != MDBX_SUCCESS))+      goto fail;+  }++  rc = mdbx_page_flush(txn, 0);+  ts_3 = latency ? mdbx_osal_monotime() : 0;+  if (likely(rc == MDBX_SUCCESS)) {+    if (txn->mt_dbs[MAIN_DBI].md_flags & DBI_DIRTY)+      txn->mt_dbs[MAIN_DBI].md_mod_txnid = pp_txnid2chk(txn);++    MDBX_meta meta, *head = mdbx_meta_head(env);+    memcpy(meta.mm_magic_and_version, head->mm_magic_and_version, 8);+    meta.mm_extra_flags = head->mm_extra_flags;+    meta.mm_validator_id = head->mm_validator_id;+    meta.mm_extra_pagehdr = head->mm_extra_pagehdr;+    unaligned_poke_u64(4, meta.mm_pages_retired,+                       unaligned_peek_u64(4, head->mm_pages_retired) ++                           MDBX_PNL_SIZE(txn->tw.retired_pages));++    meta.mm_geo = txn->mt_geo;+    meta.mm_dbs[FREE_DBI] = txn->mt_dbs[FREE_DBI];+    meta.mm_dbs[MAIN_DBI] = txn->mt_dbs[MAIN_DBI];+    meta.mm_canary = txn->mt_canary;+    mdbx_meta_set_txnid(env, &meta, txn->mt_txnid);++    rc = mdbx_sync_locked(+        env, env->me_flags | txn->mt_flags | MDBX_SHRINK_ALLOWED, &meta);+  }+  ts_4 = latency ? mdbx_osal_monotime() : 0;+  if (unlikely(rc != MDBX_SUCCESS)) {+    env->me_flags |= MDBX_FATAL_ERROR;+    goto fail;+  }++  end_mode = MDBX_END_COMMITTED | MDBX_END_UPDATE | MDBX_END_EOTDONE;++done:+  rc = mdbx_txn_end(txn, end_mode);++provide_latency:+  if (latency) {+    latency->audit = audit_duration;+    latency->preparation =+        ts_1 ? mdbx_osal_monotime_to_16dot16(ts_1 - ts_0) : 0;+    latency->gc =+        (ts_1 && ts_2) ? mdbx_osal_monotime_to_16dot16(ts_2 - ts_1) : 0;+    latency->write =+        (ts_2 && ts_3) ? mdbx_osal_monotime_to_16dot16(ts_3 - ts_2) : 0;+    latency->sync =+        (ts_3 && ts_4) ? mdbx_osal_monotime_to_16dot16(ts_4 - ts_3) : 0;+    const uint64_t ts_5 = mdbx_osal_monotime();+    latency->ending = ts_4 ? mdbx_osal_monotime_to_16dot16(ts_5 - ts_4) : 0;+    latency->whole = mdbx_osal_monotime_to_16dot16(ts_5 - ts_0);+  }+  return rc;++fail:+  mdbx_txn_abort(txn);+  goto provide_latency;+}++static __cold int+mdbx_validate_meta(MDBX_env *env, MDBX_meta *const meta, uint64_t *filesize,+                   const MDBX_page *const page, const unsigned meta_number,+                   MDBX_meta *dest, const unsigned guess_pagesize) {+  const uint64_t magic_and_version =+      unaligned_peek_u64(4, &meta->mm_magic_and_version);+  if (magic_and_version != MDBX_DATA_MAGIC &&+      magic_and_version != MDBX_DATA_MAGIC_DEVEL) {+    mdbx_error("meta[%u] has invalid magic/version %" PRIx64, meta_number,+               magic_and_version);+    return ((magic_and_version >> 8) != MDBX_MAGIC) ? MDBX_INVALID+                                                    : MDBX_VERSION_MISMATCH;+  }++  if (page->mp_pgno != meta_number) {+    mdbx_error("meta[%u] has invalid pageno %" PRIaPGNO, meta_number,+               page->mp_pgno);+    return MDBX_INVALID;+  }++  if (page->mp_flags != P_META) {+    mdbx_error("page #%u not a meta-page", meta_number);+    return MDBX_INVALID;+  }++  /* LY: check pagesize */+  if (!is_powerof2(meta->mm_psize) || meta->mm_psize < MIN_PAGESIZE ||+      meta->mm_psize > MAX_PAGESIZE) {+    mdbx_warning("meta[%u] has invalid pagesize (%u), skip it", meta_number,+                 meta->mm_psize);+    return is_powerof2(meta->mm_psize) ? MDBX_VERSION_MISMATCH : MDBX_INVALID;+  }++  if (dest && meta_number == 0 && guess_pagesize != meta->mm_psize) {+    dest->mm_psize = meta->mm_psize;+    mdbx_verbose("meta[%u] took pagesize %u", meta_number, meta->mm_psize);+  }++  if (unaligned_peek_u64(4, &meta->mm_txnid_a) !=+      unaligned_peek_u64(4, &meta->mm_txnid_b)) {+    mdbx_warning("meta[%u] not completely updated, skip it", meta_number);+    return MDBX_RESULT_TRUE;+  }++  /* LY: check signature as a checksum */+  if (META_IS_STEADY(meta) &&+      unaligned_peek_u64(4, &meta->mm_datasync_sign) != mdbx_meta_sign(meta)) {+    mdbx_warning("meta[%u] has invalid steady-checksum (0x%" PRIx64+                 " != 0x%" PRIx64 "), skip it",+                 meta_number, unaligned_peek_u64(4, &meta->mm_datasync_sign),+                 mdbx_meta_sign(meta));+    return MDBX_RESULT_TRUE;+  }++  mdbx_debug("read meta%" PRIaPGNO " = root %" PRIaPGNO "/%" PRIaPGNO+             ", geo %" PRIaPGNO "/%" PRIaPGNO "-%" PRIaPGNO "/%" PRIaPGNO+             " +%u -%u, txn_id %" PRIaTXN ", %s",+             page->mp_pgno, meta->mm_dbs[MAIN_DBI].md_root,+             meta->mm_dbs[FREE_DBI].md_root, meta->mm_geo.lower,+             meta->mm_geo.next, meta->mm_geo.now, meta->mm_geo.upper,+             pv2pages(meta->mm_geo.grow_pv), pv2pages(meta->mm_geo.shrink_pv),+             unaligned_peek_u64(4, meta->mm_txnid_a), mdbx_durable_str(meta));++  /* LY: check min-pages value */+  if (meta->mm_geo.lower < MIN_PAGENO || meta->mm_geo.lower > MAX_PAGENO) {+    mdbx_warning("meta[%u] has invalid min-pages (%" PRIaPGNO "), skip it",+                 meta_number, meta->mm_geo.lower);+    return MDBX_INVALID;+  }++  /* LY: check max-pages value */+  if (meta->mm_geo.upper < MIN_PAGENO || meta->mm_geo.upper > MAX_PAGENO ||+      meta->mm_geo.upper < meta->mm_geo.lower) {+    mdbx_warning("meta[%u] has invalid max-pages (%" PRIaPGNO "), skip it",+                 meta_number, meta->mm_geo.upper);+    return MDBX_INVALID;+  }++  /* LY: check last_pgno */+  if (meta->mm_geo.next < MIN_PAGENO || meta->mm_geo.next - 1 > MAX_PAGENO) {+    mdbx_warning("meta[%u] has invalid next-pageno (%" PRIaPGNO "), skip it",+                 meta_number, meta->mm_geo.next);+    return MDBX_CORRUPTED;+  }++  /* LY: check filesize & used_bytes */+  const uint64_t used_bytes = meta->mm_geo.next * (uint64_t)meta->mm_psize;+  if (used_bytes > *filesize) {+    /* Here could be a race with DB-shrinking performed by other process */+    int err = mdbx_filesize(env->me_lazy_fd, filesize);+    if (unlikely(err != MDBX_SUCCESS))+      return err;+    if (used_bytes > *filesize) {+      mdbx_warning("meta[%u] used-bytes (%" PRIu64 ") beyond filesize (%" PRIu64+                   "), skip it",+                   meta_number, used_bytes, *filesize);+      return MDBX_CORRUPTED;+    }+  }+  if (meta->mm_geo.next - 1 > MAX_PAGENO || used_bytes > MAX_MAPSIZE) {+    mdbx_warning("meta[%u] has too large used-space (%" PRIu64 "), skip it",+                 meta_number, used_bytes);+    return MDBX_TOO_LARGE;+  }++  /* LY: check mapsize limits */+  const uint64_t mapsize_min = meta->mm_geo.lower * (uint64_t)meta->mm_psize;+  STATIC_ASSERT(MAX_MAPSIZE < PTRDIFF_MAX - MAX_PAGESIZE);+  STATIC_ASSERT(MIN_MAPSIZE < MAX_MAPSIZE);+  if (mapsize_min < MIN_MAPSIZE || mapsize_min > MAX_MAPSIZE) {+    if (MAX_MAPSIZE != MAX_MAPSIZE64 && mapsize_min > MAX_MAPSIZE &&+        mapsize_min <= MAX_MAPSIZE64) {+      mdbx_assert(env, meta->mm_geo.next - 1 <= MAX_PAGENO &&+                           used_bytes <= MAX_MAPSIZE);+      mdbx_warning("meta[%u] has too large min-mapsize (%" PRIu64 "), "+                   "but size of used space still acceptable (%" PRIu64 ")",+                   meta_number, mapsize_min, used_bytes);+      meta->mm_geo.lower = (pgno_t)(MAX_MAPSIZE / meta->mm_psize);+    } else {+      mdbx_warning("meta[%u] has invalid min-mapsize (%" PRIu64 "), skip it",+                   meta_number, mapsize_min);+      return MDBX_VERSION_MISMATCH;+    }+  }++  const uint64_t mapsize_max = meta->mm_geo.upper * (uint64_t)meta->mm_psize;+  STATIC_ASSERT(MIN_MAPSIZE < MAX_MAPSIZE);+  if (mapsize_max > MAX_MAPSIZE ||+      MAX_PAGENO < ceil_powerof2((size_t)mapsize_max, env->me_os_psize) /+                       (size_t)meta->mm_psize) {+    /* allow to open large DB from a 32-bit environment */+    mdbx_assert(env, meta->mm_geo.next - 1 <= MAX_PAGENO &&+                         used_bytes <= MAX_MAPSIZE);+    mdbx_warning("meta[%u] has too large max-mapsize (%" PRIu64 "), "+                 "but size of used space still acceptable (%" PRIu64 ")",+                 meta_number, mapsize_max, used_bytes);+    meta->mm_geo.upper = (pgno_t)(MAX_MAPSIZE / meta->mm_psize);+  }++  /* LY: check and silently put mm_geo.now into [geo.lower...geo.upper].+   *+   * Copy-with-compaction by previous version of libmdbx could produce DB-file+   * less than meta.geo.lower bound, in case actual filling is low or no data+   * at all. This is not a problem as there is no damage or loss of data.+   * Therefore it is better not to consider such situation as an error, but+   * silently correct it. */+  if (meta->mm_geo.now < meta->mm_geo.lower)+    meta->mm_geo.now = meta->mm_geo.lower;+  if (meta->mm_geo.now > meta->mm_geo.upper &&+      meta->mm_geo.next <= meta->mm_geo.upper)+    meta->mm_geo.now = meta->mm_geo.upper;++  if (meta->mm_geo.next > meta->mm_geo.now) {+    mdbx_warning("meta[%u] next-pageno (%" PRIaPGNO+                 ") is beyond end-pgno (%" PRIaPGNO "), skip it",+                 meta_number, meta->mm_geo.next, meta->mm_geo.now);+    return MDBX_CORRUPTED;+  }++  /* LY: GC root */+  if (meta->mm_dbs[FREE_DBI].md_root == P_INVALID) {+    if (meta->mm_dbs[FREE_DBI].md_branch_pages ||+        meta->mm_dbs[FREE_DBI].md_depth || meta->mm_dbs[FREE_DBI].md_entries ||+        meta->mm_dbs[FREE_DBI].md_leaf_pages ||+        meta->mm_dbs[FREE_DBI].md_overflow_pages) {+      mdbx_warning("meta[%u] has false-empty GC, skip it", meta_number);+      return MDBX_CORRUPTED;+    }+  } else if (meta->mm_dbs[FREE_DBI].md_root >= meta->mm_geo.next) {+    mdbx_warning("meta[%u] has invalid GC-root %" PRIaPGNO ", skip it",+                 meta_number, meta->mm_dbs[FREE_DBI].md_root);+    return MDBX_CORRUPTED;+  }++  /* LY: MainDB root */+  if (meta->mm_dbs[MAIN_DBI].md_root == P_INVALID) {+    if (meta->mm_dbs[MAIN_DBI].md_branch_pages ||+        meta->mm_dbs[MAIN_DBI].md_depth || meta->mm_dbs[MAIN_DBI].md_entries ||+        meta->mm_dbs[MAIN_DBI].md_leaf_pages ||+        meta->mm_dbs[MAIN_DBI].md_overflow_pages) {+      mdbx_warning("meta[%u] has false-empty maindb", meta_number);+      return MDBX_CORRUPTED;+    }+  } else if (meta->mm_dbs[MAIN_DBI].md_root >= meta->mm_geo.next) {+    mdbx_warning("meta[%u] has invalid maindb-root %" PRIaPGNO ", skip it",+                 meta_number, meta->mm_dbs[MAIN_DBI].md_root);+    return MDBX_CORRUPTED;+  }++  if (unaligned_peek_u64(4, &meta->mm_txnid_a) == 0) {+    mdbx_warning("meta[%u] has zero txnid, skip it", meta_number);+    return MDBX_RESULT_TRUE;+  }++  return MDBX_SUCCESS;+}++/* Read the environment parameters of a DB environment+ * before mapping it into memory. */+static __cold int mdbx_read_header(MDBX_env *env, MDBX_meta *dest,+                                   uint64_t *filesize,+                                   const int lck_exclusive) {+  int rc = mdbx_filesize(env->me_lazy_fd, filesize);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  memset(dest, 0, sizeof(MDBX_meta));+  unaligned_poke_u64(4, dest->mm_datasync_sign, MDBX_DATASIGN_WEAK);+  rc = MDBX_CORRUPTED;++  /* Read twice all meta pages so we can find the latest one. */+  unsigned loop_limit = NUM_METAS * 2;+  for (unsigned loop_count = 0; loop_count < loop_limit; ++loop_count) {+    /* We don't know the page size on first time.+     * So, just guess it. */+    unsigned guess_pagesize = dest->mm_psize;+    if (guess_pagesize == 0)+      guess_pagesize =+          (loop_count > NUM_METAS) ? env->me_psize : env->me_os_psize;++    const unsigned meta_number = loop_count % NUM_METAS;+    const unsigned offset = guess_pagesize * meta_number;++    char buffer[MIN_PAGESIZE];+    unsigned retryleft = 42;+    while (1) {+      mdbx_trace("reading meta[%d]: offset %u, bytes %u, retry-left %u",+                 meta_number, offset, MIN_PAGESIZE, retryleft);+      int err = mdbx_pread(env->me_lazy_fd, buffer, MIN_PAGESIZE, offset);+      if (err != MDBX_SUCCESS) {+        if (err == MDBX_ENODATA && offset == 0 && loop_count == 0 &&+            *filesize == 0 && (env->me_flags & MDBX_RDONLY) == 0)+          mdbx_warning("read meta: empty file (%d, %s)", err,+                       mdbx_strerror(err));+        else+          mdbx_error("read meta[%u,%u]: %i, %s", offset, MIN_PAGESIZE, err,+                     mdbx_strerror(err));+        return err;+      }++      char again[MIN_PAGESIZE];+      err = mdbx_pread(env->me_lazy_fd, again, MIN_PAGESIZE, offset);+      if (err != MDBX_SUCCESS) {+        mdbx_error("read meta[%u,%u]: %i, %s", offset, MIN_PAGESIZE, err,+                   mdbx_strerror(err));+        return err;+      }++      if (memcmp(buffer, again, MIN_PAGESIZE) == 0 || --retryleft == 0)+        break;++      mdbx_verbose("meta[%u] was updated, re-read it", meta_number);+    }++    if (!retryleft) {+      mdbx_error("meta[%u] is too volatile, skip it", meta_number);+      continue;+    }++    MDBX_page *const page = (MDBX_page *)buffer;+    MDBX_meta *const meta = page_meta(page);+    rc = mdbx_validate_meta(env, meta, filesize, page, meta_number, dest,+                            guess_pagesize);+    if (rc != MDBX_SUCCESS)+      continue;++    if ((env->me_stuck_meta < 0)+            ? mdbx_meta_ot(meta_bootid_match(meta) ? prefer_last+                                                   : prefer_steady,+                           env, dest, meta)+            : (meta_number == (unsigned)env->me_stuck_meta)) {+      *dest = *meta;+      if (!lck_exclusive && !META_IS_STEADY(dest))+        loop_limit += 1; /* LY: should re-read to hush race with update */+      mdbx_verbose("latch meta[%u]", meta_number);+    }+  }++  if (dest->mm_psize == 0 ||+      ((env->me_stuck_meta < 0)+           ? (!META_IS_STEADY(dest) &&+              !meta_weak_acceptable(env, dest, lck_exclusive))+           : false)) {+    mdbx_error("%s", "no usable meta-pages, database is corrupted");+    if (rc == MDBX_SUCCESS) {+      /* TODO: try to restore the database by fully checking b-tree structure+       * for the each meta page, if the corresponding option was given */+      return MDBX_CORRUPTED;+    }+    return rc;+  }++  return MDBX_SUCCESS;+}++static MDBX_page *__cold mdbx_meta_model(const MDBX_env *env, MDBX_page *model,+                                         unsigned num) {++  mdbx_ensure(env, is_powerof2(env->me_psize));+  mdbx_ensure(env, env->me_psize >= MIN_PAGESIZE);+  mdbx_ensure(env, env->me_psize <= MAX_PAGESIZE);+  mdbx_ensure(env, env->me_dbgeo.lower >= MIN_MAPSIZE);+  mdbx_ensure(env, env->me_dbgeo.upper <= MAX_MAPSIZE);+  mdbx_ensure(env, env->me_dbgeo.now >= env->me_dbgeo.lower);+  mdbx_ensure(env, env->me_dbgeo.now <= env->me_dbgeo.upper);++  memset(model, 0, sizeof(*model));+  model->mp_pgno = num;+  model->mp_flags = P_META;+  MDBX_meta *const model_meta = page_meta(model);+  unaligned_poke_u64(4, model_meta->mm_magic_and_version, MDBX_DATA_MAGIC);++  model_meta->mm_geo.lower = bytes2pgno(env, env->me_dbgeo.lower);+  model_meta->mm_geo.upper = bytes2pgno(env, env->me_dbgeo.upper);+  model_meta->mm_geo.grow_pv = pages2pv(bytes2pgno(env, env->me_dbgeo.grow));+  model_meta->mm_geo.shrink_pv =+      pages2pv(bytes2pgno(env, env->me_dbgeo.shrink));+  model_meta->mm_geo.now = bytes2pgno(env, env->me_dbgeo.now);+  model_meta->mm_geo.next = NUM_METAS;++  mdbx_ensure(env, model_meta->mm_geo.lower >= MIN_PAGENO);+  mdbx_ensure(env, model_meta->mm_geo.upper <= MAX_PAGENO);+  mdbx_ensure(env, model_meta->mm_geo.now >= model_meta->mm_geo.lower);+  mdbx_ensure(env, model_meta->mm_geo.now <= model_meta->mm_geo.upper);+  mdbx_ensure(env, model_meta->mm_geo.next >= MIN_PAGENO);+  mdbx_ensure(env, model_meta->mm_geo.next <= model_meta->mm_geo.now);+  mdbx_ensure(env, model_meta->mm_geo.grow_pv ==+                       pages2pv(pv2pages(model_meta->mm_geo.grow_pv)));+  mdbx_ensure(env, model_meta->mm_geo.shrink_pv ==+                       pages2pv(pv2pages(model_meta->mm_geo.shrink_pv)));++  model_meta->mm_psize = env->me_psize;+  model_meta->mm_flags = (uint16_t)env->me_flags;+  model_meta->mm_flags |=+      MDBX_INTEGERKEY; /* this is mm_dbs[FREE_DBI].md_flags */+  model_meta->mm_dbs[FREE_DBI].md_root = P_INVALID;+  model_meta->mm_dbs[MAIN_DBI].md_root = P_INVALID;+  mdbx_meta_set_txnid(env, model_meta, MIN_TXNID + num);+  unaligned_poke_u64(4, model_meta->mm_datasync_sign,+                     mdbx_meta_sign(model_meta));+  return (MDBX_page *)((uint8_t *)model + env->me_psize);+}++/* Fill in most of the zeroed meta-pages for an empty database environment.+ * Return pointer to recently (head) meta-page. */+static MDBX_meta *__cold mdbx_init_metas(const MDBX_env *env, void *buffer) {+  MDBX_page *page0 = (MDBX_page *)buffer;+  MDBX_page *page1 = mdbx_meta_model(env, page0, 0);+  MDBX_page *page2 = mdbx_meta_model(env, page1, 1);+  mdbx_meta_model(env, page2, 2);+  mdbx_assert(env, !mdbx_meta_eq(env, page_meta(page0), page_meta(page1)));+  mdbx_assert(env, !mdbx_meta_eq(env, page_meta(page1), page_meta(page2)));+  mdbx_assert(env, !mdbx_meta_eq(env, page_meta(page2), page_meta(page0)));+  return page_meta(page2);+}++static size_t mdbx_madvise_threshold(const MDBX_env *env,+                                     const size_t largest_bytes) {+  /* TODO: use options */+  const unsigned factor = 9;+  const size_t threshold = (largest_bytes < (65536ul << factor))+                               ? 65536 /* minimal threshold */+                               : (largest_bytes > (MEGABYTE * 4 << factor))+                                     ? MEGABYTE * 4 /* maximal threshold */+                                     : largest_bytes >> factor;+  return bytes_align2os_bytes(env, threshold);+}++static int mdbx_sync_locked(MDBX_env *env, unsigned flags,+                            MDBX_meta *const pending) {+  mdbx_assert(env, ((env->me_flags ^ flags) & MDBX_WRITEMAP) == 0);+  MDBX_meta *const meta0 = METAPAGE(env, 0);+  MDBX_meta *const meta1 = METAPAGE(env, 1);+  MDBX_meta *const meta2 = METAPAGE(env, 2);+  MDBX_meta *const head = mdbx_meta_head(env);+  int rc;++  mdbx_assert(env, mdbx_meta_eq_mask(env) == 0);+  mdbx_assert(env,+              pending < METAPAGE(env, 0) || pending > METAPAGE(env, NUM_METAS));+  mdbx_assert(env, (env->me_flags & (MDBX_RDONLY | MDBX_FATAL_ERROR)) == 0);+  mdbx_assert(env, pending->mm_geo.next <= pending->mm_geo.now);++  if (flags & MDBX_SAFE_NOSYNC) {+    /* Check auto-sync conditions */+    const pgno_t autosync_threshold =+        atomic_load32(env->me_autosync_threshold, mo_Relaxed);+    const uint64_t autosync_period =+        atomic_load64(env->me_autosync_period, mo_Relaxed);+    if ((autosync_threshold &&+         atomic_load32(env->me_unsynced_pages, mo_Relaxed) >=+             autosync_threshold) ||+        (autosync_period &&+         mdbx_osal_monotime() -+                 atomic_load64(env->me_sync_timestamp, mo_Relaxed) >=+             autosync_period))+      flags &= MDBX_WRITEMAP | MDBX_SHRINK_ALLOWED; /* force steady */+  }++  pgno_t shrink = 0;+  if (flags & MDBX_SHRINK_ALLOWED) {+    /* LY: check conditions to discard unused pages */+    const pgno_t largest_pgno = mdbx_find_largest(+        env, (head->mm_geo.next > pending->mm_geo.next) ? head->mm_geo.next+                                                        : pending->mm_geo.next);+    mdbx_assert(env, largest_pgno >= NUM_METAS);+#if defined(MDBX_USE_VALGRIND) || defined(__SANITIZE_ADDRESS__)+    const pgno_t edge = env->me_poison_edge;+    if (edge > largest_pgno) {+      env->me_poison_edge = largest_pgno;+      VALGRIND_MAKE_MEM_NOACCESS(env->me_map + pgno2bytes(env, largest_pgno),+                                 pgno2bytes(env, edge - largest_pgno));+      ASAN_POISON_MEMORY_REGION(env->me_map + pgno2bytes(env, largest_pgno),+                                pgno2bytes(env, edge - largest_pgno));+    }+#endif /* MDBX_USE_VALGRIND || __SANITIZE_ADDRESS__ */+#if defined(MADV_DONTNEED)+    const size_t largest_bytes = pgno2bytes(env, largest_pgno);+    /* threshold to avoid unreasonable frequent madvise() calls */+    const size_t madvise_threshold = mdbx_madvise_threshold(env, largest_bytes);+    const size_t discard_edge_bytes = bytes_align2os_bytes(+        env, ((MDBX_RDONLY &+               (env->me_lck ? env->me_lck->mti_envmode.weak : env->me_flags))+                  ? largest_bytes+                  : largest_bytes + madvise_threshold));+    const pgno_t discard_edge_pgno = bytes2pgno(env, discard_edge_bytes);+    const pgno_t prev_discarded_pgno =+        atomic_load32(env->me_discarded_tail, mo_Relaxed);+    if (prev_discarded_pgno >=+        discard_edge_pgno + bytes2pgno(env, madvise_threshold)) {+      mdbx_notice("open-MADV_%s %u..%u", "DONTNEED", prev_discarded_pgno,+                  largest_pgno);+      atomic_store32(env->me_discarded_tail, discard_edge_pgno, mo_Relaxed);+      const size_t prev_discarded_bytes =+          ceil_powerof2(pgno2bytes(env, prev_discarded_pgno), env->me_os_psize);+      mdbx_ensure(env, prev_discarded_bytes > discard_edge_bytes);+      int advise = MADV_DONTNEED;+#if defined(MADV_FREE) &&                                                      \+    0 /* MADV_FREE works for only anonymous vma at the moment */+      if ((env->me_flags & MDBX_WRITEMAP) &&+          mdbx_linux_kernel_version > 0x04050000)+        advise = MADV_FREE;+#endif /* MADV_FREE */+      int err = madvise(env->me_map + discard_edge_bytes,+                        prev_discarded_bytes - discard_edge_bytes, advise)+                    ? ignore_enosys(errno)+                    : MDBX_SUCCESS;+      if (unlikely(MDBX_IS_ERROR(err)))+        return err;+    }+#endif /* MADV_FREE || MADV_DONTNEED */++    /* LY: check conditions to shrink datafile */+    const pgno_t backlog_gap = 3 + pending->mm_dbs[FREE_DBI].md_depth * 3;+    pgno_t shrink_step = 0;+    if (pending->mm_geo.shrink_pv &&+        pending->mm_geo.now - pending->mm_geo.next >+            (shrink_step = pv2pages(pending->mm_geo.shrink_pv)) + backlog_gap) {+      if (pending->mm_geo.now > largest_pgno &&+          pending->mm_geo.now - largest_pgno > shrink_step + backlog_gap) {+        pgno_t grow_step = 0;+        const pgno_t aligner =+            pending->mm_geo.grow_pv+                ? (grow_step = pv2pages(pending->mm_geo.grow_pv))+                : shrink_step;+        const pgno_t with_backlog_gap = largest_pgno + backlog_gap;+        const pgno_t aligned = pgno_align2os_pgno(+            env, with_backlog_gap + aligner - with_backlog_gap % aligner);+        const pgno_t bottom =+            (aligned > pending->mm_geo.lower) ? aligned : pending->mm_geo.lower;+        if (pending->mm_geo.now > bottom) {+          if (META_IS_STEADY(mdbx_meta_steady(env)))+            /* force steady, but only if steady-checkpoint is present */+            flags &= MDBX_WRITEMAP | MDBX_SHRINK_ALLOWED;+          shrink = pending->mm_geo.now - bottom;+          pending->mm_geo.now = bottom;+          if (unlikely(mdbx_meta_txnid_stable(env, head) ==+                       unaligned_peek_u64(4, pending->mm_txnid_a))) {+            const txnid_t txnid =+                safe64_txnid_next(unaligned_peek_u64(4, pending->mm_txnid_a));+            if (unlikely(txnid > MAX_TXNID)) {+              rc = MDBX_TXN_FULL;+              mdbx_error("txnid overflow, raise %d", rc);+              goto fail;+            }+            mdbx_meta_set_txnid(env, pending, txnid);+          }+        }+      }+    }+  }++  /* LY: step#1 - sync previously written/updated data-pages */+  rc = MDBX_RESULT_FALSE /* carry steady */;+  if (atomic_load32(env->me_unsynced_pages, mo_Relaxed)) {+    mdbx_assert(env, ((flags ^ env->me_flags) & MDBX_WRITEMAP) == 0);+    enum mdbx_syncmode_bits mode_bits = MDBX_SYNC_NONE;+    if ((flags & MDBX_SAFE_NOSYNC) == 0) {+      mode_bits = MDBX_SYNC_DATA;+      if (pending->mm_geo.next > mdbx_meta_steady(env)->mm_geo.now)+        mode_bits |= MDBX_SYNC_SIZE;+      if (flags & MDBX_NOMETASYNC)+        mode_bits |= MDBX_SYNC_IODQ;+    }+    if (flags & MDBX_WRITEMAP)+      rc =+          mdbx_msync(&env->me_dxb_mmap, 0,+                     pgno_align2os_bytes(env, pending->mm_geo.next), mode_bits);+    else+      rc = mdbx_fsync(env->me_lazy_fd, mode_bits);+    if (unlikely(rc != MDBX_SUCCESS))+      goto fail;+    rc = (flags & MDBX_SAFE_NOSYNC) ? MDBX_RESULT_TRUE /* carry non-steady */+                                    : MDBX_RESULT_FALSE /* carry steady */;+  }++  /* Steady or Weak */+  if (rc == MDBX_RESULT_FALSE /* carry steady */) {+    atomic_store64(env->me_sync_timestamp, mdbx_osal_monotime(), mo_Relaxed);+    unaligned_poke_u64(4, pending->mm_datasync_sign, mdbx_meta_sign(pending));+    atomic_store32(env->me_unsynced_pages, 0, mo_Relaxed);+  } else {+    assert(rc == MDBX_RESULT_TRUE /* carry non-steady */);+    unaligned_poke_u64(4, pending->mm_datasync_sign, MDBX_DATASIGN_WEAK);+  }++  MDBX_meta *target = nullptr;+  if (mdbx_meta_txnid_stable(env, head) ==+      unaligned_peek_u64(4, pending->mm_txnid_a)) {+    mdbx_assert(env, memcmp(&head->mm_dbs, &pending->mm_dbs,+                            sizeof(head->mm_dbs)) == 0);+    mdbx_assert(env, memcmp(&head->mm_canary, &pending->mm_canary,+                            sizeof(head->mm_canary)) == 0);+    mdbx_assert(env, memcmp(&head->mm_geo, &pending->mm_geo,+                            sizeof(pending->mm_geo)) == 0);+    if (!META_IS_STEADY(head) && META_IS_STEADY(pending))+      target = head;+    else {+      mdbx_ensure(env, mdbx_meta_eq(env, head, pending));+      mdbx_debug("%s", "skip update meta");+      return MDBX_SUCCESS;+    }+  } else if (head == meta0)+    target = mdbx_meta_ancient(prefer_steady, env, meta1, meta2);+  else if (head == meta1)+    target = mdbx_meta_ancient(prefer_steady, env, meta0, meta2);+  else {+    mdbx_assert(env, head == meta2);+    target = mdbx_meta_ancient(prefer_steady, env, meta0, meta1);+  }++  /* LY: step#2 - update meta-page. */+  mdbx_debug(+      "writing meta%" PRIaPGNO " = root %" PRIaPGNO "/%" PRIaPGNO+      ", geo %" PRIaPGNO "/%" PRIaPGNO "-%" PRIaPGNO "/%" PRIaPGNO+      " +%u -%u, txn_id %" PRIaTXN ", %s",+      data_page(target)->mp_pgno, pending->mm_dbs[MAIN_DBI].md_root,+      pending->mm_dbs[FREE_DBI].md_root, pending->mm_geo.lower,+      pending->mm_geo.next, pending->mm_geo.now, pending->mm_geo.upper,+      pv2pages(pending->mm_geo.grow_pv), pv2pages(pending->mm_geo.shrink_pv),+      unaligned_peek_u64(4, pending->mm_txnid_a), mdbx_durable_str(pending));++  mdbx_debug("meta0: %s, %s, txn_id %" PRIaTXN ", root %" PRIaPGNO+             "/%" PRIaPGNO,+             (meta0 == head) ? "head" : (meta0 == target) ? "tail" : "stay",+             mdbx_durable_str(meta0), mdbx_meta_txnid_fluid(env, meta0),+             meta0->mm_dbs[MAIN_DBI].md_root, meta0->mm_dbs[FREE_DBI].md_root);+  mdbx_debug("meta1: %s, %s, txn_id %" PRIaTXN ", root %" PRIaPGNO+             "/%" PRIaPGNO,+             (meta1 == head) ? "head" : (meta1 == target) ? "tail" : "stay",+             mdbx_durable_str(meta1), mdbx_meta_txnid_fluid(env, meta1),+             meta1->mm_dbs[MAIN_DBI].md_root, meta1->mm_dbs[FREE_DBI].md_root);+  mdbx_debug("meta2: %s, %s, txn_id %" PRIaTXN ", root %" PRIaPGNO+             "/%" PRIaPGNO,+             (meta2 == head) ? "head" : (meta2 == target) ? "tail" : "stay",+             mdbx_durable_str(meta2), mdbx_meta_txnid_fluid(env, meta2),+             meta2->mm_dbs[MAIN_DBI].md_root, meta2->mm_dbs[FREE_DBI].md_root);++  mdbx_assert(env, !mdbx_meta_eq(env, pending, meta0));+  mdbx_assert(env, !mdbx_meta_eq(env, pending, meta1));+  mdbx_assert(env, !mdbx_meta_eq(env, pending, meta2));++  mdbx_assert(env, ((env->me_flags ^ flags) & MDBX_WRITEMAP) == 0);+  mdbx_ensure(env,+              target == head || mdbx_meta_txnid_stable(env, target) <+                                    unaligned_peek_u64(4, pending->mm_txnid_a));+  if (flags & MDBX_WRITEMAP) {+    mdbx_jitter4testing(true);+    if (likely(target != head)) {+      /* LY: 'invalidate' the meta. */+      mdbx_meta_update_begin(env, target,+                             unaligned_peek_u64(4, pending->mm_txnid_a));+      unaligned_poke_u64(4, target->mm_datasync_sign, MDBX_DATASIGN_WEAK);+#ifndef NDEBUG+      /* debug: provoke failure to catch a violators, but don't touch mm_psize+       * and mm_flags to allow readers catch actual pagesize. */+      uint8_t *provoke_begin = (uint8_t *)&target->mm_dbs[FREE_DBI].md_root;+      uint8_t *provoke_end = (uint8_t *)&target->mm_datasync_sign;+      memset(provoke_begin, 0xCC, provoke_end - provoke_begin);+      mdbx_jitter4testing(false);+#endif++      /* LY: update info */+      target->mm_geo = pending->mm_geo;+      target->mm_dbs[FREE_DBI] = pending->mm_dbs[FREE_DBI];+      target->mm_dbs[MAIN_DBI] = pending->mm_dbs[MAIN_DBI];+      target->mm_canary = pending->mm_canary;+      memcpy(target->mm_pages_retired, pending->mm_pages_retired, 8);+      mdbx_jitter4testing(true);++      /* LY: 'commit' the meta */+      mdbx_meta_update_end(env, target,+                           unaligned_peek_u64(4, pending->mm_txnid_b));+      mdbx_jitter4testing(true);+    } else {+      /* dangerous case (target == head), only mm_datasync_sign could+       * me updated, check assertions once again */+      mdbx_ensure(env, mdbx_meta_txnid_stable(env, head) ==+                               unaligned_peek_u64(4, pending->mm_txnid_a) &&+                           !META_IS_STEADY(head) && META_IS_STEADY(pending));+      mdbx_ensure(env, memcmp(&head->mm_geo, &pending->mm_geo,+                              sizeof(head->mm_geo)) == 0);+      mdbx_ensure(env, memcmp(&head->mm_dbs, &pending->mm_dbs,+                              sizeof(head->mm_dbs)) == 0);+      mdbx_ensure(env, memcmp(&head->mm_canary, &pending->mm_canary,+                              sizeof(head->mm_canary)) == 0);+    }+    memcpy(target->mm_datasync_sign, pending->mm_datasync_sign, 8);+    mdbx_flush_incoherent_cpu_writeback();+    mdbx_jitter4testing(true);+    /* sync meta-pages */+    rc =+        mdbx_msync(&env->me_dxb_mmap, 0, pgno_align2os_bytes(env, NUM_METAS),+                   (flags & MDBX_NOMETASYNC) ? MDBX_SYNC_NONE+                                             : MDBX_SYNC_DATA | MDBX_SYNC_IODQ);+    if (unlikely(rc != MDBX_SUCCESS))+      goto fail;+  } else {+    const MDBX_meta undo_meta = *target;+    const mdbx_filehandle_t fd = (env->me_dsync_fd != INVALID_HANDLE_VALUE)+                                     ? env->me_dsync_fd+                                     : env->me_lazy_fd;+    rc = mdbx_pwrite(fd, pending, sizeof(MDBX_meta),+                     (uint8_t *)target - env->me_map);+    if (unlikely(rc != MDBX_SUCCESS)) {+    undo:+      mdbx_debug("%s", "write failed, disk error?");+      /* On a failure, the pagecache still contains the new data.+       * Try write some old data back, to prevent it from being used. */+      mdbx_pwrite(fd, &undo_meta, sizeof(MDBX_meta),+                  (uint8_t *)target - env->me_map);+      goto fail;+    }+    mdbx_flush_incoherent_mmap(target, sizeof(MDBX_meta), env->me_os_psize);+    /* sync meta-pages */+    if ((flags & MDBX_NOMETASYNC) == 0 && fd == env->me_lazy_fd) {+      rc = mdbx_fsync(env->me_lazy_fd, MDBX_SYNC_DATA | MDBX_SYNC_IODQ);+      if (rc != MDBX_SUCCESS)+        goto undo;+    }+  }+  if (flags & MDBX_NOMETASYNC)+    env->me_unsynced_pages->weak += 1;+  else+    env->me_meta_sync_txnid->weak =+        (uint32_t)unaligned_peek_u64(4, pending->mm_txnid_a);++  /* LY: shrink datafile if needed */+  if (unlikely(shrink)) {+    mdbx_verbose("shrink to %" PRIaPGNO " pages (-%" PRIaPGNO ")",+                 pending->mm_geo.now, shrink);+    rc = mdbx_mapresize_implicit(env, pending->mm_geo.next, pending->mm_geo.now,+                                 pending->mm_geo.upper);+    if (MDBX_IS_ERROR(rc))+      goto fail;+  }++  if (likely(env->me_lck))+    /* toggle oldest refresh */+    atomic_store32(&env->me_lck->mti_readers_refresh_flag, false, mo_Relaxed);++  return MDBX_SUCCESS;++fail:+  env->me_flags |= MDBX_FATAL_ERROR;+  return rc;+}++static void __cold mdbx_setup_pagesize(MDBX_env *env, const size_t pagesize) {+  STATIC_ASSERT(PTRDIFF_MAX > MAX_MAPSIZE);+  STATIC_ASSERT(MIN_PAGESIZE > sizeof(MDBX_page) + sizeof(MDBX_meta));+  mdbx_ensure(env, is_powerof2(pagesize));+  mdbx_ensure(env, pagesize >= MIN_PAGESIZE);+  mdbx_ensure(env, pagesize <= MAX_PAGESIZE);+  env->me_psize = (unsigned)pagesize;++  STATIC_ASSERT(MAX_GC1OVPAGE(MIN_PAGESIZE) > 4);+  STATIC_ASSERT(MAX_GC1OVPAGE(MAX_PAGESIZE) < MDBX_PGL_LIMIT / 4);+  const intptr_t maxgc_ov1page = (pagesize - PAGEHDRSZ) / sizeof(pgno_t) - 1;+  mdbx_ensure(env, maxgc_ov1page > 42 &&+                       maxgc_ov1page < (intptr_t)MDBX_PGL_LIMIT / 4);+  env->me_maxgc_ov1page = (unsigned)maxgc_ov1page;++  STATIC_ASSERT(LEAF_NODEMAX(MIN_PAGESIZE) > sizeof(MDBX_db) + NODESIZE + 42);+  STATIC_ASSERT(LEAF_NODEMAX(MAX_PAGESIZE) < UINT16_MAX);+  STATIC_ASSERT(LEAF_NODEMAX(MIN_PAGESIZE) > BRANCH_NODEMAX(MIN_PAGESIZE));+  STATIC_ASSERT(BRANCH_NODEMAX(MAX_PAGESIZE) > NODESIZE + 42);+  STATIC_ASSERT(BRANCH_NODEMAX(MAX_PAGESIZE) < UINT16_MAX);+  const intptr_t branch_nodemax = BRANCH_NODEMAX(pagesize);+  mdbx_ensure(env, branch_nodemax > 42 && branch_nodemax < (int)UINT16_MAX &&+                       branch_nodemax % 2 == 0);+  env->me_branch_nodemax = (unsigned)branch_nodemax;+  env->me_psize2log = (uint8_t)log2n(pagesize);+  mdbx_assert(env, pgno2bytes(env, 1) == pagesize);+  mdbx_assert(env, bytes2pgno(env, pagesize + pagesize) == 2);++  const pgno_t max_pgno = bytes2pgno(env, MAX_MAPSIZE);+  if (env->me_options.dp_limit > max_pgno - NUM_METAS)+    env->me_options.dp_limit = max_pgno - NUM_METAS;+  if (env->me_options.dp_initial > env->me_options.dp_limit)+    env->me_options.dp_initial = env->me_options.dp_limit;+}++__cold int mdbx_env_create(MDBX_env **penv) {+  MDBX_env *env = mdbx_calloc(1, sizeof(MDBX_env));+  if (unlikely(!env))+    return MDBX_ENOMEM;++  env->me_maxreaders = DEFAULT_READERS;+  env->me_maxdbs = env->me_numdbs = CORE_DBS;+  env->me_lazy_fd = INVALID_HANDLE_VALUE;+  env->me_dsync_fd = INVALID_HANDLE_VALUE;+  env->me_lfd = INVALID_HANDLE_VALUE;+  env->me_pid = mdbx_getpid();+  env->me_stuck_meta = -1;++  env->me_options.dp_reserve_limit = 1024;+  env->me_options.rp_augment_limit = 256 * 1024;+  env->me_options.dp_limit = 64 * 1024;+  if (env->me_options.dp_limit > MAX_PAGENO - NUM_METAS)+    env->me_options.dp_limit = MAX_PAGENO - NUM_METAS;+  env->me_options.dp_initial = MDBX_PNL_INITIAL;+  if (env->me_options.dp_initial > env->me_options.dp_limit)+    env->me_options.dp_initial = env->me_options.dp_limit;+  env->me_options.spill_max_denominator = 8;+  env->me_options.spill_min_denominator = 8;+  env->me_options.spill_parent4child_denominator = 0;+  env->me_options.dp_loose_limit = 64;++  int rc;+  const size_t os_psize = mdbx_syspagesize();+  if (unlikely(!is_powerof2(os_psize) || os_psize < MIN_PAGESIZE)) {+    mdbx_error("unsuitable system pagesize %" PRIuPTR, os_psize);+    rc = MDBX_INCOMPATIBLE;+    goto bailout;+  }+  env->me_os_psize = (unsigned)os_psize;+  mdbx_setup_pagesize(env, (env->me_os_psize < MAX_PAGESIZE) ? env->me_os_psize+                                                             : MAX_PAGESIZE);++  rc = mdbx_fastmutex_init(&env->me_dbi_lock);+  if (unlikely(rc != MDBX_SUCCESS))+    goto bailout;++#if defined(_WIN32) || defined(_WIN64)+  mdbx_srwlock_Init(&env->me_remap_guard);+  InitializeCriticalSection(&env->me_windowsbug_lock);+#else+  rc = mdbx_fastmutex_init(&env->me_remap_guard);+  if (unlikely(rc != MDBX_SUCCESS)) {+    mdbx_fastmutex_destroy(&env->me_dbi_lock);+    goto bailout;+  }++#if MDBX_LOCKING > MDBX_LOCKING_SYSV+  rc = mdbx_ipclock_stub(&env->me_lckless_stub.wlock);+#endif /* MDBX_LOCKING */+  if (unlikely(rc != MDBX_SUCCESS)) {+    mdbx_fastmutex_destroy(&env->me_remap_guard);+    mdbx_fastmutex_destroy(&env->me_dbi_lock);+    goto bailout;+  }+#endif /* Windows */++  VALGRIND_CREATE_MEMPOOL(env, 0, 0);+  env->me_signature.weak = MDBX_ME_SIGNATURE;+  *penv = env;+  return MDBX_SUCCESS;++bailout:+  mdbx_free(env);+  *penv = nullptr;+  return rc;+}++__cold LIBMDBX_API int+mdbx_env_set_geometry(MDBX_env *env, intptr_t size_lower, intptr_t size_now,+                      intptr_t size_upper, intptr_t growth_step,+                      intptr_t shrink_threshold, intptr_t pagesize) {+  int rc = check_env(env, false);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  const bool inside_txn =+      (env->me_txn0 && env->me_txn0->mt_owner == mdbx_thread_self());++#if MDBX_DEBUG+  if (growth_step < 0)+    growth_step = 1;+  if (shrink_threshold < 0)+    shrink_threshold = 1;+#endif++  bool need_unlock = false;+  if (env->me_map) {+    /* env already mapped */+    if (unlikely(env->me_flags & MDBX_RDONLY))+      return MDBX_EACCESS;++    if (!inside_txn) {+      int err = mdbx_txn_lock(env, false);+      if (unlikely(err != MDBX_SUCCESS))+        return err;+      need_unlock = true;+    }+    MDBX_meta *head = mdbx_meta_head(env);+    if (!inside_txn) {+      env->me_txn0->mt_txnid = meta_txnid(env, head, false);+      mdbx_find_oldest(env->me_txn0);+    }++    /* get untouched params from DB */+    if (pagesize <= 0 || pagesize >= INT_MAX)+      pagesize = env->me_psize;+    if (size_lower < 0)+      size_lower = pgno2bytes(env, head->mm_geo.lower);+    if (size_now < 0)+      size_now = pgno2bytes(env, head->mm_geo.now);+    if (size_upper < 0)+      size_upper = pgno2bytes(env, head->mm_geo.upper);+    if (growth_step < 0)+      growth_step = pgno2bytes(env, pv2pages(head->mm_geo.grow_pv));+    if (shrink_threshold < 0)+      shrink_threshold = pgno2bytes(env, pv2pages(head->mm_geo.shrink_pv));++    if (pagesize != (intptr_t)env->me_psize) {+      rc = MDBX_EINVAL;+      goto bailout;+    }+    const size_t usedbytes =+        pgno2bytes(env, mdbx_find_largest(env, head->mm_geo.next));+    if ((size_t)size_upper < usedbytes) {+      rc = MDBX_MAP_FULL;+      goto bailout;+    }+    if ((size_t)size_now < usedbytes)+      size_now = usedbytes;+  } else {+    /* env NOT yet mapped */+    if (unlikely(inside_txn))+      return MDBX_PANIC;++    /* is requested some auto-value for pagesize ? */+    if (pagesize >= INT_MAX /* maximal */)+      pagesize = MAX_PAGESIZE;+    else if (pagesize <= 0) {+      if (pagesize < 0 /* default */) {+        pagesize = env->me_os_psize;+        if ((uintptr_t)pagesize > MAX_PAGESIZE)+          pagesize = MAX_PAGESIZE;+        mdbx_assert(env, (uintptr_t)pagesize >= MIN_PAGESIZE);+      } else if (pagesize == 0 /* minimal */)+        pagesize = MIN_PAGESIZE;++      /* choose pagesize */+      intptr_t max_size = (size_now > size_lower) ? size_now : size_lower;+      max_size = (size_upper > max_size) ? size_upper : max_size;+      if (max_size < 0 /* default */)+        max_size = DEFAULT_MAPSIZE;+      else if (max_size == 0 /* minimal */)+        max_size = MIN_MAPSIZE;+      else if (max_size >= (intptr_t)MAX_MAPSIZE /* maximal */)+        max_size = MAX_MAPSIZE;++      while (max_size > pagesize * (int64_t)MAX_PAGENO &&+             pagesize < MAX_PAGESIZE)+        pagesize <<= 1;+    }+  }++  if (pagesize < (intptr_t)MIN_PAGESIZE || pagesize > (intptr_t)MAX_PAGESIZE ||+      !is_powerof2(pagesize)) {+    rc = MDBX_EINVAL;+    goto bailout;+  }++  if (size_lower <= 0) {+    size_lower = MIN_MAPSIZE;+    if (MIN_MAPSIZE / pagesize < MIN_PAGENO)+      size_lower = MIN_PAGENO * pagesize;+  }+  if (size_lower >= INTPTR_MAX) {+    size_lower = MAX_MAPSIZE;+    if ((size_t)size_lower / pagesize > MAX_PAGENO)+      size_lower = pagesize * MAX_PAGENO;+  }++  if (size_now <= 0) {+    size_now = size_lower;+    if (size_upper >= size_lower && size_now > size_upper)+      size_now = size_upper;+  }+  if (size_now >= INTPTR_MAX) {+    size_now = MAX_MAPSIZE;+    if ((size_t)size_now / pagesize > MAX_PAGENO)+      size_now = pagesize * MAX_PAGENO;+  }++  if (size_upper <= 0) {+    if ((size_t)size_now >= MAX_MAPSIZE / 2)+      size_upper = MAX_MAPSIZE;+    else if (MAX_MAPSIZE != MAX_MAPSIZE32 &&+             (size_t)size_now >= MAX_MAPSIZE32 / 2 &&+             (size_t)size_now <= MAX_MAPSIZE32 / 4 * 3)+      size_upper = MAX_MAPSIZE32;+    else {+      size_upper = size_now + size_now;+      if ((size_t)size_upper < DEFAULT_MAPSIZE * 2)+        size_upper = DEFAULT_MAPSIZE * 2;+    }+    if ((size_t)size_upper / pagesize > MAX_PAGENO)+      size_upper = pagesize * MAX_PAGENO;+  } else if (size_upper >= INTPTR_MAX) {+    size_upper = MAX_MAPSIZE;+    if ((size_t)size_upper / pagesize > MAX_PAGENO)+      size_upper = pagesize * MAX_PAGENO;+  }++  if (unlikely(size_lower < (intptr_t)MIN_MAPSIZE || size_lower > size_upper)) {+    rc = MDBX_EINVAL;+    goto bailout;+  }++  if ((uint64_t)size_lower / pagesize < MIN_PAGENO) {+    rc = MDBX_EINVAL;+    goto bailout;+  }++  if (unlikely((size_t)size_upper > MAX_MAPSIZE ||+               (uint64_t)size_upper / pagesize > MAX_PAGENO)) {+    rc = MDBX_TOO_LARGE;+    goto bailout;+  }++  const size_t unit = (env->me_os_psize > (size_t)pagesize) ? env->me_os_psize+                                                            : (size_t)pagesize;+  size_lower = ceil_powerof2(size_lower, unit);+  size_upper = ceil_powerof2(size_upper, unit);+  size_now = ceil_powerof2(size_now, unit);++  /* LY: подбираем значение size_upper:+   *  - кратное размеру страницы+   *  - без нарушения MAX_MAPSIZE и MAX_PAGENO */+  while (unlikely((size_t)size_upper > MAX_MAPSIZE ||+                  (uint64_t)size_upper / pagesize > MAX_PAGENO)) {+    if ((size_t)size_upper < unit + MIN_MAPSIZE ||+        (size_t)size_upper < (size_t)pagesize * (MIN_PAGENO + 1)) {+      /* паранойа на случай переполнения при невероятных значениях */+      rc = MDBX_EINVAL;+      goto bailout;+    }+    size_upper -= unit;+    if ((size_t)size_upper < (size_t)size_lower)+      size_lower = size_upper;+  }+  mdbx_assert(env, (size_upper - size_lower) % env->me_os_psize == 0);++  if (size_now < size_lower)+    size_now = size_lower;+  if (size_now > size_upper)+    size_now = size_upper;++  if (growth_step < 0) {+    growth_step = ((size_t)(size_upper - size_lower)) / 42;+    if (growth_step > size_lower && size_lower < (intptr_t)MEGABYTE)+      growth_step = size_lower;+    if (growth_step < 65536)+      growth_step = 65536;+    if ((size_t)growth_step > MAX_MAPSIZE / 64)+      growth_step = MAX_MAPSIZE / 64;+  }+  if (growth_step == 0 && shrink_threshold > 0)+    growth_step = 1;+  growth_step = ceil_powerof2(growth_step, unit);++  if (shrink_threshold < 0)+    shrink_threshold = growth_step + growth_step;+  shrink_threshold = ceil_powerof2(shrink_threshold, unit);++  //----------------------------------------------------------------------------++  if (!env->me_map) {+    /* save user's geo-params for future open/create */+    if (pagesize != (intptr_t)env->me_psize)+      mdbx_setup_pagesize(env, pagesize);+    env->me_dbgeo.lower = size_lower;+    env->me_dbgeo.now = size_now;+    env->me_dbgeo.upper = size_upper;+    env->me_dbgeo.grow =+        pgno2bytes(env, pv2pages(pages2pv(bytes2pgno(env, growth_step))));+    env->me_dbgeo.shrink =+        pgno2bytes(env, pv2pages(pages2pv(bytes2pgno(env, shrink_threshold))));++    mdbx_ensure(env, env->me_dbgeo.lower >= MIN_MAPSIZE);+    mdbx_ensure(env, env->me_dbgeo.lower / (unsigned)pagesize >= MIN_PAGENO);+    mdbx_ensure(env, env->me_dbgeo.lower % (unsigned)pagesize == 0);+    mdbx_ensure(env, env->me_dbgeo.lower % env->me_os_psize == 0);++    mdbx_ensure(env, env->me_dbgeo.upper <= MAX_MAPSIZE);+    mdbx_ensure(env, env->me_dbgeo.upper / (unsigned)pagesize <= MAX_PAGENO);+    mdbx_ensure(env, env->me_dbgeo.upper % (unsigned)pagesize == 0);+    mdbx_ensure(env, env->me_dbgeo.upper % env->me_os_psize == 0);++    mdbx_ensure(env, env->me_dbgeo.now >= env->me_dbgeo.lower);+    mdbx_ensure(env, env->me_dbgeo.now <= env->me_dbgeo.upper);+    mdbx_ensure(env, env->me_dbgeo.now % (unsigned)pagesize == 0);+    mdbx_ensure(env, env->me_dbgeo.now % env->me_os_psize == 0);++    mdbx_ensure(env, env->me_dbgeo.grow % (unsigned)pagesize == 0);+    mdbx_ensure(env, env->me_dbgeo.grow % env->me_os_psize == 0);+    mdbx_ensure(env, env->me_dbgeo.shrink % (unsigned)pagesize == 0);+    mdbx_ensure(env, env->me_dbgeo.shrink % env->me_os_psize == 0);++    rc = MDBX_SUCCESS;+  } else {+    /* apply new params to opened environment */+    mdbx_ensure(env, pagesize == (intptr_t)env->me_psize);+    MDBX_meta meta;+    MDBX_meta *head = nullptr;+    const MDBX_geo *current_geo;+    if (inside_txn) {+      current_geo = &env->me_txn->mt_geo;+    } else {+      head = mdbx_meta_head(env);+      meta = *head;+      current_geo = &meta.mm_geo;+    }++    MDBX_geo new_geo;+    new_geo.lower = bytes2pgno(env, size_lower);+    new_geo.now = bytes2pgno(env, size_now);+    new_geo.upper = bytes2pgno(env, size_upper);+    new_geo.grow_pv = pages2pv(bytes2pgno(env, growth_step));+    new_geo.shrink_pv = pages2pv(bytes2pgno(env, shrink_threshold));+    new_geo.next = current_geo->next;++    mdbx_ensure(env,+                pgno_align2os_bytes(env, new_geo.lower) == (size_t)size_lower);+    mdbx_ensure(env,+                pgno_align2os_bytes(env, new_geo.upper) == (size_t)size_upper);+    mdbx_ensure(env, pgno_align2os_bytes(env, new_geo.now) == (size_t)size_now);+    mdbx_ensure(env, new_geo.grow_pv == pages2pv(pv2pages(new_geo.grow_pv)));+    mdbx_ensure(env,+                new_geo.shrink_pv == pages2pv(pv2pages(new_geo.shrink_pv)));++    mdbx_ensure(env, (size_t)size_lower >= MIN_MAPSIZE);+    mdbx_ensure(env, new_geo.lower >= MIN_PAGENO);+    mdbx_ensure(env, (size_t)size_upper <= MAX_MAPSIZE);+    mdbx_ensure(env, new_geo.upper <= MAX_PAGENO);+    mdbx_ensure(env, new_geo.now >= new_geo.next);+    mdbx_ensure(env, new_geo.upper >= new_geo.now);+    mdbx_ensure(env, new_geo.now >= new_geo.lower);++    if (memcmp(current_geo, &new_geo, sizeof(MDBX_geo)) != 0) {+#if defined(_WIN32) || defined(_WIN64)+      /* Was DB shrinking disabled before and now it will be enabled? */+      if (new_geo.lower < new_geo.upper && new_geo.shrink_pv &&+          !(current_geo->lower < current_geo->upper &&+            current_geo->shrink_pv)) {+        if (!env->me_lck) {+          rc = MDBX_EPERM;+          goto bailout;+        }+        int err = mdbx_rdt_lock(env);+        if (unlikely(MDBX_IS_ERROR(err))) {+          rc = err;+          goto bailout;+        }++        /* Check if there are any reading threads that do not use the SRWL */+        const size_t CurrentTid = GetCurrentThreadId();+        const MDBX_reader *const begin = env->me_lck->mti_readers;+        const MDBX_reader *const end =+            begin ++            atomic_load32(&env->me_lck->mti_numreaders, mo_AcquireRelease);+        for (const MDBX_reader *reader = begin; reader < end; ++reader) {+          if (reader->mr_pid.weak == env->me_pid && reader->mr_tid.weak &&+              reader->mr_tid.weak != CurrentTid) {+            /* At least one thread may don't use SRWL */+            rc = MDBX_EPERM;+            break;+          }+        }++        mdbx_rdt_unlock(env);+        if (unlikely(rc != MDBX_SUCCESS))+          goto bailout;+      }+#endif++      if (new_geo.now != current_geo->now ||+          new_geo.upper != current_geo->upper) {+        rc = mdbx_mapresize(env, current_geo->next, new_geo.now, new_geo.upper,+                            false);+        if (unlikely(rc != MDBX_SUCCESS))+          goto bailout;+        mdbx_assert(env, (head == nullptr) == inside_txn);+        if (head)+          head = /* base address could be changed */ mdbx_meta_head(env);+      }+      if (inside_txn) {+        env->me_txn->mt_geo = new_geo;+        env->me_txn->mt_flags |= MDBX_TXN_DIRTY;+      } else {+        meta.mm_geo = new_geo;+        const txnid_t txnid =+            safe64_txnid_next(mdbx_meta_txnid_stable(env, head));+        if (unlikely(txnid > MAX_TXNID)) {+          rc = MDBX_TXN_FULL;+          mdbx_error("txnid overflow, raise %d", rc);+        } else {+          mdbx_meta_set_txnid(env, &meta, txnid);+          rc = mdbx_sync_locked(env, env->me_flags, &meta);+        }+      }++      if (likely(rc == MDBX_SUCCESS)) {+        /* store new geo to env to avoid influences */+        env->me_dbgeo.now = pgno2bytes(env, new_geo.now);+        env->me_dbgeo.lower = pgno2bytes(env, new_geo.lower);+        env->me_dbgeo.upper = pgno2bytes(env, new_geo.upper);+        env->me_dbgeo.grow = pgno2bytes(env, pv2pages(new_geo.grow_pv));+        env->me_dbgeo.shrink = pgno2bytes(env, pv2pages(new_geo.shrink_pv));+      }+    }+  }++bailout:+  if (need_unlock)+    mdbx_txn_unlock(env);+  return rc;+}++#ifndef LIBMDBX_NO_EXPORTS_LEGACY_API+__cold int mdbx_env_set_mapsize(MDBX_env *env, size_t size) {+  return __inline_mdbx_env_set_mapsize(env, size);+}++__cold int mdbx_env_set_maxdbs(MDBX_env *env, MDBX_dbi dbs) {+  return __inline_mdbx_env_set_maxdbs(env, dbs);+}++__cold int mdbx_env_get_maxdbs(const MDBX_env *env, MDBX_dbi *dbs) {+  return __inline_mdbx_env_get_maxdbs(env, dbs);+}++__cold int mdbx_env_set_maxreaders(MDBX_env *env, unsigned readers) {+  return __inline_mdbx_env_set_maxreaders(env, readers);+}++__cold int mdbx_env_get_maxreaders(const MDBX_env *env, unsigned *readers) {+  return __inline_mdbx_env_get_maxreaders(env, readers);+}+#endif /* LIBMDBX_NO_EXPORTS_LEGACY_API */++/* Further setup required for opening an MDBX environment */+static __cold int mdbx_setup_dxb(MDBX_env *env, const int lck_rc) {+  uint64_t filesize_before;+  MDBX_meta meta;+  int rc = MDBX_RESULT_FALSE;+  int err = mdbx_read_header(env, &meta, &filesize_before, lck_rc);+  if (unlikely(err != MDBX_SUCCESS)) {+    if (lck_rc != /* lck exclusive */ MDBX_RESULT_TRUE || err != MDBX_ENODATA ||+        (env->me_flags & MDBX_RDONLY) != 0 ||+        /* recovery mode */ env->me_stuck_meta >= 0)+      return err;++    mdbx_debug("%s", "create new database");+    rc = /* new database */ MDBX_RESULT_TRUE;++    if (!env->me_dbgeo.now) {+      /* set defaults if not configured */+      err = mdbx_env_set_geometry(env, 0, -1, DEFAULT_MAPSIZE, -1, -1, -1);+      if (unlikely(err != MDBX_SUCCESS))+        return err;+    }++    void *buffer = mdbx_calloc(NUM_METAS, env->me_psize);+    if (!buffer)+      return MDBX_ENOMEM;++    meta = *mdbx_init_metas(env, buffer);+    err = mdbx_pwrite(env->me_lazy_fd, buffer, env->me_psize * NUM_METAS, 0);+    mdbx_free(buffer);+    if (unlikely(err != MDBX_SUCCESS))+      return err;++    err = mdbx_ftruncate(env->me_lazy_fd, filesize_before = env->me_dbgeo.now);+    if (unlikely(err != MDBX_SUCCESS))+      return err;++#ifndef NDEBUG /* just for checking */+    err = mdbx_read_header(env, &meta, &filesize_before, lck_rc);+    if (unlikely(err != MDBX_SUCCESS))+      return err;+#endif+  }++  mdbx_verbose(+      "header: root %" PRIaPGNO "/%" PRIaPGNO ", geo %" PRIaPGNO "/%" PRIaPGNO+      "-%" PRIaPGNO "/%" PRIaPGNO " +%u -%u, txn_id %" PRIaTXN ", %s",+      meta.mm_dbs[MAIN_DBI].md_root, meta.mm_dbs[FREE_DBI].md_root,+      meta.mm_geo.lower, meta.mm_geo.next, meta.mm_geo.now, meta.mm_geo.upper,+      pv2pages(meta.mm_geo.grow_pv), pv2pages(meta.mm_geo.shrink_pv),+      unaligned_peek_u64(4, meta.mm_txnid_a), mdbx_durable_str(&meta));++  mdbx_setup_pagesize(env, meta.mm_psize);+  const size_t used_bytes = pgno2bytes(env, meta.mm_geo.next);+  const size_t used_aligned2os_bytes =+      ceil_powerof2(used_bytes, env->me_os_psize);+  if ((env->me_flags & MDBX_RDONLY) /* readonly */+      || lck_rc != MDBX_RESULT_TRUE /* not exclusive */+      || /* recovery mode */ env->me_stuck_meta >= 0) {+    /* use present params from db */+    const size_t pagesize = meta.mm_psize;+    err = mdbx_env_set_geometry(+        env, meta.mm_geo.lower * pagesize, meta.mm_geo.now * pagesize,+        meta.mm_geo.upper * pagesize, pv2pages(meta.mm_geo.grow_pv) * pagesize,+        pv2pages(meta.mm_geo.shrink_pv) * pagesize, meta.mm_psize);+    if (unlikely(err != MDBX_SUCCESS)) {+      mdbx_error("%s: err %d", "could not apply preconfigured geometry from db",+                 err);+      return (err == MDBX_EINVAL) ? MDBX_INCOMPATIBLE : err;+    }+  } else if (env->me_dbgeo.now) {+    /* silently growth to last used page */+    if (env->me_dbgeo.now < used_aligned2os_bytes)+      env->me_dbgeo.now = used_aligned2os_bytes;+    if (env->me_dbgeo.upper < used_aligned2os_bytes)+      env->me_dbgeo.upper = used_aligned2os_bytes;++    /* apply preconfigured params, but only if substantial changes:+     *  - upper or lower limit changes+     *  - shrink threshold or growth step+     * But ignore change just a 'now/current' size. */+    if (bytes_align2os_bytes(env, env->me_dbgeo.upper) !=+            pgno2bytes(env, meta.mm_geo.upper) ||+        bytes_align2os_bytes(env, env->me_dbgeo.lower) !=+            pgno2bytes(env, meta.mm_geo.lower) ||+        bytes_align2os_bytes(env, env->me_dbgeo.shrink) !=+            pgno2bytes(env, pv2pages(meta.mm_geo.shrink_pv)) ||+        bytes_align2os_bytes(env, env->me_dbgeo.grow) !=+            pgno2bytes(env, pv2pages(meta.mm_geo.grow_pv))) {++      if (env->me_dbgeo.shrink && env->me_dbgeo.now > used_bytes)+        /* pre-shrink if enabled */+        env->me_dbgeo.now = used_bytes + env->me_dbgeo.shrink -+                            used_bytes % env->me_dbgeo.shrink;++      err = mdbx_env_set_geometry(env, env->me_dbgeo.lower, env->me_dbgeo.now,+                                  env->me_dbgeo.upper, env->me_dbgeo.grow,+                                  env->me_dbgeo.shrink, meta.mm_psize);+      if (unlikely(err != MDBX_SUCCESS)) {+        mdbx_error("%s: err %d", "could not apply preconfigured db-geometry",+                   err);+        return (err == MDBX_EINVAL) ? MDBX_INCOMPATIBLE : err;+      }++      /* update meta fields */+      meta.mm_geo.now = bytes2pgno(env, env->me_dbgeo.now);+      meta.mm_geo.lower = bytes2pgno(env, env->me_dbgeo.lower);+      meta.mm_geo.upper = bytes2pgno(env, env->me_dbgeo.upper);+      meta.mm_geo.grow_pv = pages2pv(bytes2pgno(env, env->me_dbgeo.grow));+      meta.mm_geo.shrink_pv = pages2pv(bytes2pgno(env, env->me_dbgeo.shrink));++      mdbx_verbose("amended: root %" PRIaPGNO "/%" PRIaPGNO ", geo %" PRIaPGNO+                   "/%" PRIaPGNO "-%" PRIaPGNO "/%" PRIaPGNO+                   " +%u -%u, txn_id %" PRIaTXN ", %s",+                   meta.mm_dbs[MAIN_DBI].md_root, meta.mm_dbs[FREE_DBI].md_root,+                   meta.mm_geo.lower, meta.mm_geo.next, meta.mm_geo.now,+                   meta.mm_geo.upper, pv2pages(meta.mm_geo.grow_pv),+                   pv2pages(meta.mm_geo.shrink_pv),+                   unaligned_peek_u64(4, meta.mm_txnid_a),+                   mdbx_durable_str(&meta));+    } else {+      /* fetch back 'now/current' size, since it was ignored during comparison+       * and may differ. */+      env->me_dbgeo.now = pgno_align2os_bytes(env, meta.mm_geo.now);+    }+    mdbx_ensure(env, meta.mm_geo.now >= meta.mm_geo.next);+  } else {+    /* geo-params are not pre-configured by user,+     * get current values from the meta. */+    env->me_dbgeo.now = pgno2bytes(env, meta.mm_geo.now);+    env->me_dbgeo.lower = pgno2bytes(env, meta.mm_geo.lower);+    env->me_dbgeo.upper = pgno2bytes(env, meta.mm_geo.upper);+    env->me_dbgeo.grow = pgno2bytes(env, pv2pages(meta.mm_geo.grow_pv));+    env->me_dbgeo.shrink = pgno2bytes(env, pv2pages(meta.mm_geo.shrink_pv));+  }++  mdbx_ensure(env,+              pgno_align2os_bytes(env, meta.mm_geo.now) == env->me_dbgeo.now);+  mdbx_ensure(env, env->me_dbgeo.now >= used_bytes);+  if (unlikely(filesize_before != env->me_dbgeo.now)) {+    if (lck_rc != /* lck exclusive */ MDBX_RESULT_TRUE) {+      mdbx_verbose("filesize mismatch (expect %" PRIuPTR "b/%" PRIaPGNO+                   "p, have %" PRIu64 "b/%" PRIaPGNO "p), "+                   "assume other process working",+                   env->me_dbgeo.now, bytes2pgno(env, env->me_dbgeo.now),+                   filesize_before, bytes2pgno(env, (size_t)filesize_before));+    } else {+      mdbx_warning("filesize mismatch (expect %" PRIuSIZE "b/%" PRIaPGNO+                   "p, have %" PRIu64 "b/%" PRIaPGNO "p)",+                   env->me_dbgeo.now, bytes2pgno(env, env->me_dbgeo.now),+                   filesize_before, bytes2pgno(env, (size_t)filesize_before));+      if (filesize_before < used_bytes) {+        mdbx_error("last-page beyond end-of-file (last %" PRIaPGNO+                   ", have %" PRIaPGNO ")",+                   meta.mm_geo.next, bytes2pgno(env, (size_t)filesize_before));+        return MDBX_CORRUPTED;+      }++      if (env->me_flags & MDBX_RDONLY) {+        if (filesize_before & (env->me_os_psize - 1)) {+          mdbx_error("%s", "filesize should be rounded-up to system page");+          return MDBX_WANNA_RECOVERY;+        }+        mdbx_warning("%s", "ignore filesize mismatch in readonly-mode");+      } else {+        mdbx_verbose("will resize datafile to %" PRIuSIZE " bytes, %" PRIaPGNO+                     " pages",+                     env->me_dbgeo.now, bytes2pgno(env, env->me_dbgeo.now));+      }+    }+  }++  mdbx_verbose("current boot-id %" PRIx64 "-%" PRIx64 " (%savailable)",+               bootid.x, bootid.y, (bootid.x | bootid.y) ? "" : "not-");++  /* calculate readahead hint before mmap with zero redundant pages */+  const bool readahead =+      (env->me_flags & MDBX_NORDAHEAD) == 0 &&+      mdbx_is_readahead_reasonable(used_bytes, 0) == MDBX_RESULT_TRUE;+  err = mdbx_mmap(env->me_flags, &env->me_dxb_mmap, env->me_dbgeo.now,+                  env->me_dbgeo.upper, lck_rc ? MMAP_OPTION_TRUNCATE : 0);+  if (unlikely(err != MDBX_SUCCESS))+    return err;++#if defined(MADV_DONTDUMP)+  err = madvise(env->me_map, env->me_dxb_mmap.limit, MADV_DONTDUMP)+            ? ignore_enosys(errno)+            : MDBX_SUCCESS;+  if (unlikely(MDBX_IS_ERROR(err)))+    return err;+#endif /* MADV_DONTDUMP */+#if defined(MADV_DODUMP)+  if (mdbx_runtime_flags & MDBX_DBG_DUMP) {+    const size_t meta_length_aligned2os = pgno_align2os_bytes(env, NUM_METAS);+    err = madvise(env->me_map, meta_length_aligned2os, MADV_DODUMP)+              ? ignore_enosys(errno)+              : MDBX_SUCCESS;+    if (unlikely(MDBX_IS_ERROR(err)))+      return err;+  }+#endif /* MADV_DODUMP */++#ifdef MDBX_USE_VALGRIND+  env->me_valgrind_handle =+      VALGRIND_CREATE_BLOCK(env->me_map, env->me_dxb_mmap.limit, "mdbx");+#endif /* MDBX_USE_VALGRIND */++  mdbx_assert(env, used_bytes >= pgno2bytes(env, NUM_METAS) &&+                       used_bytes <= env->me_dxb_mmap.limit);+#if defined(MDBX_USE_VALGRIND) || defined(__SANITIZE_ADDRESS__)+  VALGRIND_MAKE_MEM_NOACCESS(env->me_map + used_bytes,+                             env->me_dxb_mmap.limit - used_bytes);+  ASAN_POISON_MEMORY_REGION(env->me_map + used_bytes,+                            env->me_dxb_mmap.limit - used_bytes);+  env->me_poison_edge = bytes2pgno(env, env->me_dxb_mmap.limit);+#endif /* MDBX_USE_VALGRIND || __SANITIZE_ADDRESS__ */++  const unsigned meta_clash_mask = mdbx_meta_eq_mask(env);+  if (unlikely(meta_clash_mask)) {+    if (/* not recovery mode */ env->me_stuck_meta < 0) {+      mdbx_error("meta-pages are clashed: mask 0x%d", meta_clash_mask);+      return MDBX_CORRUPTED;+    } else {+      mdbx_warning("ignore meta-pages clashing (mask 0x%d) in recovery mode",+                   meta_clash_mask);+    }+  }++  while (likely(/* not recovery mode */ env->me_stuck_meta < 0)) {+    MDBX_meta *const head = mdbx_meta_head(env);+    const txnid_t head_txnid = mdbx_meta_txnid_fluid(env, head);+    MDBX_meta *const steady = mdbx_meta_steady(env);+    const txnid_t steady_txnid = mdbx_meta_txnid_fluid(env, steady);+    if (head_txnid == steady_txnid)+      break;++    if (lck_rc == /* lck exclusive */ MDBX_RESULT_TRUE) {+      mdbx_assert(env, META_IS_STEADY(steady) && !META_IS_STEADY(head));+      if (meta_bootid_match(head)) {+        MDBX_meta clone = *head;+        uint64_t filesize = env->me_dbgeo.now;+        err = mdbx_validate_meta(+            env, &clone, &filesize, data_page(head),+            bytes2pgno(env, (uint8_t *)data_page(head) - env->me_map), nullptr,+            env->me_psize);+        if (err == MDBX_SUCCESS) {+          mdbx_warning(+              "opening after an unclean shutdown, but boot-id(%016" PRIx64+              "-%016" PRIx64+              ") is MATCH: rollback NOT needed, steady-sync NEEDED%s",+              bootid.x, bootid.y,+              (env->me_flags & MDBX_RDONLY) ? ", but unable in read-only mode"+                                            : "");+          if (env->me_flags & MDBX_RDONLY)+            return MDBX_WANNA_RECOVERY /* LY: could not recovery/sync */;+          meta = clone;+          atomic_store32(env->me_unsynced_pages, meta.mm_geo.next, mo_Relaxed);+          break;+        }+        mdbx_warning("opening after an unclean shutdown, "+                     "but boot-id(%016" PRIx64 "-%016" PRIx64 ") is MATCH, "+                     "but last meta not valid, rollback needed",+                     bootid.x, bootid.y);+      }+      if (env->me_flags & MDBX_RDONLY) {+        mdbx_error("rollback needed: (from head %" PRIaTXN+                   " to steady %" PRIaTXN "), but unable in read-only mode",+                   head_txnid, steady_txnid);+        return MDBX_WANNA_RECOVERY /* LY: could not recovery/rollback */;+      }++      const MDBX_meta *const meta0 = METAPAGE(env, 0);+      const MDBX_meta *const meta1 = METAPAGE(env, 1);+      const MDBX_meta *const meta2 = METAPAGE(env, 2);+      txnid_t undo_txnid = 0 /* zero means undo is unneeded */;+      while (+          (head != meta0 && mdbx_meta_txnid_fluid(env, meta0) == undo_txnid) ||+          (head != meta1 && mdbx_meta_txnid_fluid(env, meta1) == undo_txnid) ||+          (head != meta2 && mdbx_meta_txnid_fluid(env, meta2) == undo_txnid))+        undo_txnid = safe64_txnid_next(undo_txnid);+      if (unlikely(undo_txnid >= steady_txnid)) {+        mdbx_fatal("rollback failed: no suitable txnid (0,1,2) < %" PRIaTXN,+                   steady_txnid);+        return MDBX_PANIC /* LY: could not recovery/rollback */;+      }++      /* LY: rollback weak checkpoint */+      mdbx_notice("rollback: from %" PRIaTXN ", to %" PRIaTXN " as %" PRIaTXN,+                  head_txnid, steady_txnid, undo_txnid);+      mdbx_ensure(env, head_txnid == mdbx_meta_txnid_stable(env, head));++      if (env->me_flags & MDBX_WRITEMAP) {+        /* It is possible to update txnid without safe64_write(),+         * since DB opened exclusive for now */+        unaligned_poke_u64(4, head->mm_txnid_a, undo_txnid);+        unaligned_poke_u64(4, head->mm_datasync_sign, MDBX_DATASIGN_WEAK);+        unaligned_poke_u64(4, head->mm_txnid_b, undo_txnid);+        const size_t offset = (uint8_t *)data_page(head) - env->me_dxb_mmap.dxb;+        const size_t paged_offset = floor_powerof2(offset, env->me_os_psize);+        const size_t paged_length = ceil_powerof2(+            env->me_psize + offset - paged_offset, env->me_os_psize);+        err = mdbx_msync(&env->me_dxb_mmap, paged_offset, paged_length, false);+      } else {+        MDBX_meta rollback = *head;+        mdbx_meta_set_txnid(env, &rollback, undo_txnid);+        unaligned_poke_u64(4, rollback.mm_datasync_sign, MDBX_DATASIGN_WEAK);+        err = mdbx_pwrite(env->me_lazy_fd, &rollback, sizeof(MDBX_meta),+                          (uint8_t *)head - (uint8_t *)env->me_map);+      }+      if (err) {+        mdbx_error("error %d rollback from %" PRIaTXN ", to %" PRIaTXN+                   " as %" PRIaTXN,+                   err, head_txnid, steady_txnid, undo_txnid);+        return err;+      }++      mdbx_flush_incoherent_mmap(env->me_map, pgno2bytes(env, NUM_METAS),+                                 env->me_os_psize);+      mdbx_ensure(env, undo_txnid == mdbx_meta_txnid_fluid(env, head));+      mdbx_ensure(env, 0 == mdbx_meta_eq_mask(env));+      continue;+    }++    if (!env->me_lck) {+      /* LY: without-lck (read-only) mode, so it is impossible that other+       * process made weak checkpoint. */+      mdbx_error("%s", "without-lck, unable recovery/rollback");+      return MDBX_WANNA_RECOVERY;+    }++    /* LY: assume just have a collision with other running process,+     *     or someone make a weak checkpoint */+    mdbx_verbose("%s", "assume collision or online weak checkpoint");+    break;+  }++  const MDBX_meta *head = mdbx_meta_head(env);+  if (lck_rc == /* lck exclusive */ MDBX_RESULT_TRUE) {+    /* re-check size after mmap */+    if ((env->me_dxb_mmap.current & (env->me_os_psize - 1)) != 0 ||+        env->me_dxb_mmap.current < used_bytes) {+      mdbx_error("unacceptable/unexpected datafile size %" PRIuPTR,+                 env->me_dxb_mmap.current);+      return MDBX_PROBLEM;+    }+    if (env->me_dxb_mmap.current != env->me_dbgeo.now) {+      meta.mm_geo.now = bytes2pgno(env, env->me_dxb_mmap.current);+      mdbx_notice("need update meta-geo to filesize %" PRIuPTR+                  " bytes, %" PRIaPGNO " pages",+                  env->me_dxb_mmap.current, meta.mm_geo.now);+    }++    if (memcmp(&meta.mm_geo, &head->mm_geo, sizeof(meta.mm_geo))) {+      if ((env->me_flags & MDBX_RDONLY) != 0 ||+          /* recovery mode */ env->me_stuck_meta >= 0) {+        mdbx_warning(+            "skipped update meta.geo in %s mode: from l%" PRIaPGNO+            "-n%" PRIaPGNO "-u%" PRIaPGNO "/s%u-g%u, to l%" PRIaPGNO+            "-n%" PRIaPGNO "-u%" PRIaPGNO "/s%u-g%u",+            (env->me_stuck_meta < 0) ? "read-only" : "recovery",+            head->mm_geo.lower, head->mm_geo.now, head->mm_geo.upper,+            pv2pages(head->mm_geo.shrink_pv), pv2pages(head->mm_geo.grow_pv),+            meta.mm_geo.lower, meta.mm_geo.now, meta.mm_geo.upper,+            pv2pages(meta.mm_geo.shrink_pv), pv2pages(meta.mm_geo.grow_pv));+      } else {+        const txnid_t txnid = mdbx_meta_txnid_stable(env, head);+        const txnid_t next_txnid = safe64_txnid_next(txnid);+        if (unlikely(txnid > MAX_TXNID)) {+          mdbx_error("txnid overflow, raise %d", MDBX_TXN_FULL);+          return MDBX_TXN_FULL;+        }+        mdbx_notice("updating meta.geo: "+                    "from l%" PRIaPGNO "-n%" PRIaPGNO "-u%" PRIaPGNO+                    "/s%u-g%u (txn#%" PRIaTXN "), "+                    "to l%" PRIaPGNO "-n%" PRIaPGNO "-u%" PRIaPGNO+                    "/s%u-g%u (txn#%" PRIaTXN ")",+                    head->mm_geo.lower, head->mm_geo.now, head->mm_geo.upper,+                    pv2pages(head->mm_geo.shrink_pv),+                    pv2pages(head->mm_geo.grow_pv), txnid, meta.mm_geo.lower,+                    meta.mm_geo.now, meta.mm_geo.upper,+                    pv2pages(meta.mm_geo.shrink_pv),+                    pv2pages(meta.mm_geo.grow_pv), next_txnid);++        mdbx_ensure(env, mdbx_meta_eq(env, &meta, head));+        mdbx_meta_set_txnid(env, &meta, next_txnid);+        err = mdbx_sync_locked(env, env->me_flags | MDBX_SHRINK_ALLOWED, &meta);+        if (err) {+          mdbx_error("error %d, while updating meta.geo: "+                     "from l%" PRIaPGNO "-n%" PRIaPGNO "-u%" PRIaPGNO+                     "/s%u-g%u (txn#%" PRIaTXN "), "+                     "to l%" PRIaPGNO "-n%" PRIaPGNO "-u%" PRIaPGNO+                     "/s%u-g%u (txn#%" PRIaTXN ")",+                     err, head->mm_geo.lower, head->mm_geo.now,+                     head->mm_geo.upper, pv2pages(head->mm_geo.shrink_pv),+                     pv2pages(head->mm_geo.grow_pv), txnid, meta.mm_geo.lower,+                     meta.mm_geo.now, meta.mm_geo.upper,+                     pv2pages(meta.mm_geo.shrink_pv),+                     pv2pages(meta.mm_geo.grow_pv), next_txnid);+          return err;+        }+      }+    }+  }++  atomic_store32(env->me_discarded_tail, bytes2pgno(env, used_aligned2os_bytes),+                 mo_Relaxed);+  if (used_aligned2os_bytes < env->me_dxb_mmap.current) {+#if defined(MADV_REMOVE)+    if (lck_rc && (env->me_flags & MDBX_WRITEMAP) != 0 &&+        /* not recovery mode */ env->me_stuck_meta < 0) {+      mdbx_notice("open-MADV_%s %u..%u", "REMOVE (deallocate file space)",+                  env->me_discarded_tail->weak,+                  bytes2pgno(env, env->me_dxb_mmap.current));+      err =+          madvise(env->me_map + used_aligned2os_bytes,+                  env->me_dxb_mmap.current - used_aligned2os_bytes, MADV_REMOVE)+              ? ignore_enosys(errno)+              : MDBX_SUCCESS;+      if (unlikely(MDBX_IS_ERROR(err)))+        return err;+    }+#endif /* MADV_REMOVE */+#if defined(MADV_DONTNEED)+    mdbx_notice("open-MADV_%s %u..%u", "DONTNEED", env->me_discarded_tail->weak,+                bytes2pgno(env, env->me_dxb_mmap.current));+    err =+        madvise(env->me_map + used_aligned2os_bytes,+                env->me_dxb_mmap.current - used_aligned2os_bytes, MADV_DONTNEED)+            ? ignore_enosys(errno)+            : MDBX_SUCCESS;+    if (unlikely(MDBX_IS_ERROR(err)))+      return err;+#elif defined(POSIX_MADV_DONTNEED)+    err = ignore_enosys(posix_madvise(+        env->me_map + used_aligned2os_bytes,+        env->me_dxb_mmap.current - used_aligned2os_bytes, POSIX_MADV_DONTNEED));+    if (unlikely(MDBX_IS_ERROR(err)))+      return err;+#elif defined(POSIX_FADV_DONTNEED)+    err = ignore_enosys(posix_fadvise(+        env->me_lazy_fd, used_aligned2os_bytes,+        env->me_dxb_mmap.current - used_aligned2os_bytes, POSIX_FADV_DONTNEED));+    if (unlikely(MDBX_IS_ERROR(err)))+      return err;+#endif /* MADV_DONTNEED */+  }++  err = mdbx_set_readahead(env, 0, used_bytes, readahead);+  if (err != MDBX_SUCCESS && lck_rc == /* lck exclusive */ MDBX_RESULT_TRUE)+    return err;++  return rc;+}++/******************************************************************************/++/* Open and/or initialize the lock region for the environment. */+static __cold int mdbx_setup_lck(MDBX_env *env, char *lck_pathname,+                                 mdbx_mode_t mode) {+  mdbx_assert(env, env->me_lazy_fd != INVALID_HANDLE_VALUE);+  mdbx_assert(env, env->me_lfd == INVALID_HANDLE_VALUE);++  int err = mdbx_openfile(MDBX_OPEN_LCK, env, lck_pathname, &env->me_lfd, mode);+  if (err != MDBX_SUCCESS) {+    if (!(err == MDBX_ENOFILE && (env->me_flags & MDBX_EXCLUSIVE)) &&+        !((err == MDBX_EROFS || err == MDBX_EACCESS || err == MDBX_EPERM) &&+          (env->me_flags & MDBX_RDONLY)))+      return err;++    /* ensure the file system is read-only */+    err = mdbx_check_fs_rdonly(env->me_lazy_fd, lck_pathname, err);+    if (err != MDBX_SUCCESS &&+        /* ignore ERROR_NOT_SUPPORTED for exclusive mode */+        !(err == MDBX_ENOSYS && (env->me_flags & MDBX_EXCLUSIVE)))+      return err;++    /* LY: without-lck mode (e.g. exclusive or on read-only filesystem) */+    /* beginning of a locked section ---------------------------------------- */+    lcklist_lock();+    mdbx_assert(env, env->me_lcklist_next == nullptr);+    env->me_lfd = INVALID_HANDLE_VALUE;+    const int rc = mdbx_lck_seize(env);+    if (MDBX_IS_ERROR(rc)) {+      /* Calling lcklist_detach_locked() is required to restore POSIX-filelock+       * and this job will be done by mdbx_env_close0(). */+      lcklist_unlock();+      return rc;+    }+    /* insert into inprocess lck-list */+    env->me_lcklist_next = inprocess_lcklist_head;+    inprocess_lcklist_head = env;+    lcklist_unlock();+    /* end of a locked section ---------------------------------------------- */++    env->me_oldest = &env->me_lckless_stub.oldest;+    env->me_sync_timestamp = &env->me_lckless_stub.sync_timestamp;+    env->me_autosync_period = &env->me_lckless_stub.autosync_period;+    env->me_unsynced_pages = &env->me_lckless_stub.autosync_pending;+    env->me_autosync_threshold = &env->me_lckless_stub.autosync_threshold;+    env->me_discarded_tail = &env->me_lckless_stub.discarded_tail;+    env->me_meta_sync_txnid = &env->me_lckless_stub.meta_sync_txnid;+    env->me_maxreaders = UINT_MAX;+#if MDBX_LOCKING > 0+    env->me_wlock = &env->me_lckless_stub.wlock;+#endif /* MDBX_LOCKING > 0 */+    mdbx_debug("lck-setup:%s%s%s", " lck-less",+               (env->me_flags & MDBX_RDONLY) ? " readonly" : "",+               (rc == MDBX_RESULT_TRUE) ? " exclusive" : " cooperative");+    return rc;+  }++  /* beginning of a locked section ------------------------------------------ */+  lcklist_lock();+  mdbx_assert(env, env->me_lcklist_next == nullptr);++  /* Try to get exclusive lock. If we succeed, then+   * nobody is using the lock region and we should initialize it. */+  err = mdbx_lck_seize(env);+  if (MDBX_IS_ERROR(err)) {+  bailout:+    /* Calling lcklist_detach_locked() is required to restore POSIX-filelock+     * and this job will be done by mdbx_env_close0(). */+    lcklist_unlock();+    return err;+  }++  MDBX_env *inprocess_neighbor = nullptr;+  if (err == MDBX_RESULT_TRUE) {+    err = uniq_check(&env->me_lck_mmap, &inprocess_neighbor);+    if (MDBX_IS_ERROR(err))+      goto bailout;+    if (inprocess_neighbor &&+        ((mdbx_runtime_flags & MDBX_DBG_LEGACY_MULTIOPEN) == 0 ||+         (inprocess_neighbor->me_flags & MDBX_EXCLUSIVE) != 0)) {+      err = MDBX_BUSY;+      goto bailout;+    }+  }+  const int lck_seize_rc = err;++  mdbx_debug("lck-setup:%s%s%s", " with-lck",+             (env->me_flags & MDBX_RDONLY) ? " readonly" : "",+             (lck_seize_rc == MDBX_RESULT_TRUE) ? " exclusive"+                                                : " cooperative");++  uint64_t size = 0;+  err = mdbx_filesize(env->me_lfd, &size);+  if (unlikely(err != MDBX_SUCCESS))+    goto bailout;++  if (lck_seize_rc == MDBX_RESULT_TRUE) {+    size = ceil_powerof2(env->me_maxreaders * sizeof(MDBX_reader) ++                             sizeof(MDBX_lockinfo),+                         env->me_os_psize);+    mdbx_jitter4testing(false);+  } else {+    if (env->me_flags & MDBX_EXCLUSIVE) {+      err = MDBX_BUSY;+      goto bailout;+    }+    if (size > INT_MAX || (size & (env->me_os_psize - 1)) != 0 ||+        size < env->me_os_psize) {+      mdbx_error("lck-file has invalid size %" PRIu64 " bytes", size);+      err = MDBX_PROBLEM;+      goto bailout;+    }+  }++  const size_t maxreaders =+      ((size_t)size - sizeof(MDBX_lockinfo)) / sizeof(MDBX_reader);+  if (maxreaders < 4) {+    mdbx_error("lck-size too small (up to %" PRIuPTR " readers)", maxreaders);+    err = MDBX_PROBLEM;+    goto bailout;+  }+  env->me_maxreaders = (maxreaders <= MDBX_READERS_LIMIT)+                           ? (unsigned)maxreaders+                           : (unsigned)MDBX_READERS_LIMIT;++  err = mdbx_mmap((env->me_flags & MDBX_EXCLUSIVE) | MDBX_WRITEMAP,+                  &env->me_lck_mmap, (size_t)size, (size_t)size,+                  lck_seize_rc ? MMAP_OPTION_TRUNCATE | MMAP_OPTION_SEMAPHORE+                               : MMAP_OPTION_SEMAPHORE);+  if (unlikely(err != MDBX_SUCCESS))+    goto bailout;++#ifdef MADV_DODUMP+  err = madvise(env->me_lck, size, MADV_DODUMP) ? ignore_enosys(errno)+                                                : MDBX_SUCCESS;+  if (unlikely(MDBX_IS_ERROR(err)))+    goto bailout;+#endif /* MADV_DODUMP */++#ifdef MADV_WILLNEED+  err = madvise(env->me_lck, size, MADV_WILLNEED) ? ignore_enosys(errno)+                                                  : MDBX_SUCCESS;+  if (unlikely(MDBX_IS_ERROR(err)))+    goto bailout;+#endif /* MADV_WILLNEED */++  struct MDBX_lockinfo *const lck = env->me_lck;+  if (lck_seize_rc == MDBX_RESULT_TRUE) {+    /* LY: exclusive mode, check and reset lck content */+    memset(lck, 0, (size_t)size);+    mdbx_jitter4testing(false);+    lck->mti_magic_and_version = MDBX_LOCK_MAGIC;+    lck->mti_os_and_format = MDBX_LOCK_FORMAT;+    err = mdbx_msync(&env->me_lck_mmap, 0, (size_t)size, false);+    if (unlikely(err != MDBX_SUCCESS)) {+      mdbx_error("initial-%s for lck-file failed", "msync");+      goto bailout;+    }+    err = mdbx_fsync(env->me_lck_mmap.fd, MDBX_SYNC_SIZE);+    if (unlikely(err != MDBX_SUCCESS)) {+      mdbx_error("initial-%s for lck-file failed", "fsync");+      goto bailout;+    }+  } else {+    if (lck->mti_magic_and_version != MDBX_LOCK_MAGIC) {+      mdbx_error("%s", "lock region has invalid magic/version");+      err = ((lck->mti_magic_and_version >> 8) != MDBX_MAGIC)+                ? MDBX_INVALID+                : MDBX_VERSION_MISMATCH;+      goto bailout;+    }+    if (lck->mti_os_and_format != MDBX_LOCK_FORMAT) {+      mdbx_error("lock region has os/format 0x%" PRIx32 ", expected 0x%" PRIx32,+                 lck->mti_os_and_format, MDBX_LOCK_FORMAT);+      err = MDBX_VERSION_MISMATCH;+      goto bailout;+    }+  }++  err = mdbx_lck_init(env, inprocess_neighbor, lck_seize_rc);+  if (MDBX_IS_ERROR(err))+    goto bailout;++  mdbx_ensure(env, env->me_lcklist_next == nullptr);+  /* insert into inprocess lck-list */+  env->me_lcklist_next = inprocess_lcklist_head;+  inprocess_lcklist_head = env;+  lcklist_unlock();+  /* end of a locked section ------------------------------------------------ */++  mdbx_assert(env, !MDBX_IS_ERROR(lck_seize_rc));+  env->me_oldest = &lck->mti_oldest_reader;+  env->me_sync_timestamp = &lck->mti_sync_timestamp;+  env->me_autosync_period = &lck->mti_autosync_period;+  env->me_unsynced_pages = &lck->mti_unsynced_pages;+  env->me_autosync_threshold = &lck->mti_autosync_threshold;+  env->me_discarded_tail = &lck->mti_discarded_tail;+  env->me_meta_sync_txnid = &lck->mti_meta_sync_txnid;+#if MDBX_LOCKING > 0+  env->me_wlock = &lck->mti_wlock;+#endif /* MDBX_LOCKING > 0 */+  return lck_seize_rc;+}++__cold int mdbx_is_readahead_reasonable(size_t volume, intptr_t redundancy) {+  if (volume <= 1024 * 1024 * 4ul)+    return MDBX_RESULT_TRUE;++  const intptr_t pagesize = mdbx_syspagesize();+  if (unlikely(pagesize < MIN_PAGESIZE || !is_powerof2(pagesize)))+    return MDBX_INCOMPATIBLE;++#if defined(_WIN32) || defined(_WIN64)+  MEMORYSTATUSEX info;+  memset(&info, 0, sizeof(info));+  info.dwLength = sizeof(info);+  if (!GlobalMemoryStatusEx(&info))+    return GetLastError();+#endif+  const int log2page = log2n(pagesize);++#if defined(_WIN32) || defined(_WIN64)+  const intptr_t total_ram_pages = (intptr_t)(info.ullTotalPhys >> log2page);+#elif defined(_SC_PHYS_PAGES)+  const intptr_t total_ram_pages = sysconf(_SC_PHYS_PAGES);+  if (total_ram_pages == -1)+    return errno;+#elif defined(_SC_AIX_REALMEM)+  const intptr_t total_ram_Kb = sysconf(_SC_AIX_REALMEM);+  if (total_ram_Kb == -1)+    return errno;+  const intptr_t total_ram_pages = (total_ram_Kb << 10) >> log2page;+#elif defined(HW_USERMEM) || defined(HW_PHYSMEM64) || defined(HW_MEMSIZE) ||   \+    defined(HW_PHYSMEM)+  size_t ram, len = sizeof(ram);+  static const int mib[] = {+    CTL_HW,+#if defined(HW_USERMEM)+    HW_USERMEM+#elif defined(HW_PHYSMEM64)+    HW_PHYSMEM64+#elif defined(HW_MEMSIZE)+    HW_MEMSIZE+#else+    HW_PHYSMEM+#endif+  };+  if (sysctl(+#ifdef SYSCTL_LEGACY_NONCONST_MIB+          (int *)+#endif+              mib,+          ARRAY_LENGTH(mib), &ram, &len, NULL, 0) != 0)+    return errno;+  if (len != sizeof(ram))+    return MDBX_ENOSYS;+  const intptr_t total_ram_pages = (intptr_t)(ram >> log2page);+#else+#error "FIXME: Get User-accessible or physical RAM"+#endif+  if (total_ram_pages < 1)+    return MDBX_ENOSYS;++  const intptr_t volume_pages = (volume + pagesize - 1) >> log2page;+  const intptr_t redundancy_pages =+      (redundancy < 0) ? -(intptr_t)((-redundancy + pagesize - 1) >> log2page)+                       : (intptr_t)(redundancy + pagesize - 1) >> log2page;+  if (volume_pages >= total_ram_pages ||+      volume_pages + redundancy_pages >= total_ram_pages)+    return MDBX_RESULT_FALSE;++#if defined(_WIN32) || defined(_WIN64)+  const intptr_t avail_ram_pages = (intptr_t)(info.ullAvailPhys >> log2page);+#elif defined(_SC_AVPHYS_PAGES)+  const intptr_t avail_ram_pages = sysconf(_SC_AVPHYS_PAGES);+  if (avail_ram_pages == -1)+    return errno;+#elif defined(__MACH__)+  mach_msg_type_number_t count = HOST_VM_INFO_COUNT;+  vm_statistics_data_t vmstat;+  mach_port_t mport = mach_host_self();+  kern_return_t kerr = host_statistics(mach_host_self(), HOST_VM_INFO,+                                       (host_info_t)&vmstat, &count);+  mach_port_deallocate(mach_task_self(), mport);+  if (unlikely(kerr != KERN_SUCCESS))+    return MDBX_ENOSYS;+  const intptr_t avail_ram_pages = vmstat.free_count;+#elif defined(VM_TOTAL) || defined(VM_METER)+  struct vmtotal info;+  size_t len = sizeof(info);+  static const int mib[] = {+    CTL_VM,+#if defined(VM_TOTAL)+    VM_TOTAL+#elif defined(VM_METER)+    VM_METER+#endif+  };+  if (sysctl(+#ifdef SYSCTL_LEGACY_NONCONST_MIB+          (int *)+#endif+              mib,+          ARRAY_LENGTH(mib), &info, &len, NULL, 0) != 0)+    return errno;+  if (len != sizeof(info))+    return MDBX_ENOSYS;+  const intptr_t avail_ram_pages = info.t_free;+#else+#error "FIXME: Get Available RAM"+#endif+  if (avail_ram_pages < 1)+    return MDBX_ENOSYS;++  return (volume_pages + redundancy_pages >= avail_ram_pages)+             ? MDBX_RESULT_FALSE+             : MDBX_RESULT_TRUE;+}++/* Merge sync flags */+static uint32_t merge_sync_flags(const uint32_t a, const uint32_t b) {+  uint32_t r = a | b;++  /* avoid false MDBX_UTTERLY_NOSYNC */+  if (F_ISSET(r, MDBX_UTTERLY_NOSYNC) && !F_ISSET(a, MDBX_UTTERLY_NOSYNC) &&+      !F_ISSET(b, MDBX_UTTERLY_NOSYNC))+    r = (r - MDBX_UTTERLY_NOSYNC) | MDBX_SAFE_NOSYNC;++  /* convert MDBX_DEPRECATED_MAPASYNC to MDBX_SAFE_NOSYNC */+  if ((r & (MDBX_WRITEMAP | MDBX_DEPRECATED_MAPASYNC)) ==+          (MDBX_WRITEMAP | MDBX_DEPRECATED_MAPASYNC) &&+      !F_ISSET(r, MDBX_UTTERLY_NOSYNC))+    r = (r - MDBX_DEPRECATED_MAPASYNC) | MDBX_SAFE_NOSYNC;++  /* force MDBX_NOMETASYNC if MDBX_SAFE_NOSYNC enabled */+  if (r & MDBX_SAFE_NOSYNC)+    r |= MDBX_NOMETASYNC;++  assert(!(F_ISSET(r, MDBX_UTTERLY_NOSYNC) &&+           !F_ISSET(a, MDBX_UTTERLY_NOSYNC) &&+           !F_ISSET(b, MDBX_UTTERLY_NOSYNC)));+  return r;+}++__cold int mdbx_env_turn_for_recovery(MDBX_env *env, unsigned target_meta) {+  if (unlikely(target_meta >= NUM_METAS))+    return MDBX_EINVAL;+  int rc = check_env(env, true);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  if (unlikely((env->me_flags & (MDBX_EXCLUSIVE | MDBX_RDONLY)) !=+               MDBX_EXCLUSIVE))+    return MDBX_EPERM;++  MDBX_page *page =+      (env->me_flags & MDBX_WRITEMAP)+          ? pgno2page(env, target_meta)+          : memcpy(env->me_pbuf, pgno2page(env, target_meta), env->me_psize);+  page->mp_pgno = target_meta;+  page->mp_flags = P_META;++  MDBX_meta *meta = page_meta(page);+  unaligned_poke_u64(4, meta->mm_magic_and_version, MDBX_DATA_MAGIC);+  meta->mm_psize = env->me_psize;+  txnid_t txnid = mdbx_meta_txnid_stable(env, meta);+  const txnid_t txnid0 = mdbx_meta_txnid_stable(env, METAPAGE(env, 0));+  if (target_meta != 0 && txnid <= txnid0)+    txnid = safe64_txnid_next(txnid0);+  const txnid_t txnid1 = mdbx_meta_txnid_stable(env, METAPAGE(env, 1));+  if (target_meta != 1 && txnid <= txnid1)+    txnid = safe64_txnid_next(txnid1);+  const txnid_t txnid2 = mdbx_meta_txnid_stable(env, METAPAGE(env, 2));+  if (target_meta != 2 && txnid <= txnid2)+    txnid = safe64_txnid_next(txnid2);++  if (!META_IS_STEADY(meta) || mdbx_recent_committed_txnid(env) != txnid) {+    if (unlikely(txnid > MAX_TXNID)) {+      mdbx_error("txnid overflow, raise %d", MDBX_TXN_FULL);+      return MDBX_TXN_FULL;+    }+    mdbx_meta_set_txnid(env, meta, txnid);+    unaligned_poke_u64(4, meta->mm_datasync_sign, mdbx_meta_sign(meta));+  }++  if (env->me_flags & MDBX_WRITEMAP) {+    mdbx_flush_incoherent_cpu_writeback();+    rc = mdbx_msync(&env->me_dxb_mmap, 0, pgno_align2os_bytes(env, target_meta),+                    MDBX_SYNC_DATA | MDBX_SYNC_IODQ);+  } else {+    const mdbx_filehandle_t fd = (env->me_dsync_fd != INVALID_HANDLE_VALUE)+                                     ? env->me_dsync_fd+                                     : env->me_lazy_fd;+    rc = mdbx_pwrite(fd, page, env->me_psize, pgno2bytes(env, target_meta));+    if (rc == MDBX_SUCCESS && fd == env->me_lazy_fd)+      rc = mdbx_fsync(env->me_lazy_fd, MDBX_SYNC_DATA | MDBX_SYNC_IODQ);+  }++  return rc;+}++__cold int mdbx_env_open_for_recovery(MDBX_env *env, const char *pathname,+                                      unsigned target_meta, bool writeable) {+  if (unlikely(target_meta >= NUM_METAS))+    return MDBX_EINVAL;+  int rc = check_env(env, false);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;+  if (unlikely(env->me_map))+    return MDBX_EPERM;++  env->me_stuck_meta = (int8_t)target_meta;+  return mdbx_env_open(+      env, pathname, writeable ? MDBX_EXCLUSIVE : MDBX_EXCLUSIVE | MDBX_RDONLY,+      0);+}++typedef struct {+  void *buffer_for_free;+  char *lck, *dxb;+  size_t ent_len;+} MDBX_handle_env_pathname;++__cold static int mdbx_handle_env_pathname(MDBX_handle_env_pathname *ctx,+                                           const char *pathname,+                                           MDBX_env_flags_t *flags,+                                           const mdbx_mode_t mode) {+  int rc;+  memset(ctx, 0, sizeof(*ctx));+  if (unlikely(!pathname))+    return MDBX_EINVAL;++#if defined(_WIN32) || defined(_WIN64)+  const size_t wlen = mbstowcs(nullptr, pathname, INT_MAX);+  if (wlen < 1 || wlen > /* MAX_PATH */ INT16_MAX)+    return ERROR_INVALID_NAME;+  wchar_t *const pathnameW = _alloca((wlen + 1) * sizeof(wchar_t));+  if (wlen != mbstowcs(pathnameW, pathname, wlen + 1))+    return ERROR_INVALID_NAME;++  const DWORD dwAttrib = GetFileAttributesW(pathnameW);+  if (dwAttrib == INVALID_FILE_ATTRIBUTES) {+    rc = GetLastError();+    if (rc != MDBX_ENOFILE)+      return rc;+    if (mode == 0 || (*flags & MDBX_RDONLY) != 0)+      /* can't open existing */+      return rc;++    /* auto-create directory if requested */+    if ((*flags & MDBX_NOSUBDIR) == 0 &&+        !CreateDirectoryW(pathnameW, nullptr)) {+      rc = GetLastError();+      if (rc != ERROR_ALREADY_EXISTS)+        return rc;+    }+  } else {+    /* ignore passed MDBX_NOSUBDIR flag and set it automatically */+    *flags |= MDBX_NOSUBDIR;+    if (dwAttrib & FILE_ATTRIBUTE_DIRECTORY)+      *flags -= MDBX_NOSUBDIR;+  }+#else+  struct stat st;+  if (stat(pathname, &st)) {+    rc = errno;+    if (rc != MDBX_ENOFILE)+      return rc;+    if (mode == 0 || (*flags & MDBX_RDONLY) != 0)+      /* can't open existing */+      return rc;++    /* auto-create directory if requested */+    const mdbx_mode_t dir_mode =+        (/* inherit read/write permissions for group and others */ mode &+         (S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH)) |+        /* always add read/write/search for owner */ S_IRWXU |+        ((mode & S_IRGRP) ? /* +search if readable by group */ S_IXGRP : 0) |+        ((mode & S_IROTH) ? /* +search if readable by others */ S_IXOTH : 0);+    if ((*flags & MDBX_NOSUBDIR) == 0 && mkdir(pathname, dir_mode)) {+      rc = errno;+      if (rc != EEXIST)+        return rc;+    }+  } else {+    /* ignore passed MDBX_NOSUBDIR flag and set it automatically */+    *flags |= MDBX_NOSUBDIR;+    if (S_ISDIR(st.st_mode))+      *flags -= MDBX_NOSUBDIR;+  }+#endif++  static const char dxb_name[] = MDBX_DATANAME;+  static const size_t dxb_name_len = sizeof(dxb_name) - 1;+  static const char lck_name[] = MDBX_LOCKNAME;+  static const char lock_suffix[] = MDBX_LOCK_SUFFIX;++  ctx->ent_len = strlen(pathname);+  if ((*flags & MDBX_NOSUBDIR) && ctx->ent_len >= dxb_name_len &&+      !memcmp(dxb_name, pathname + ctx->ent_len - dxb_name_len, dxb_name_len)) {+    *flags -= MDBX_NOSUBDIR;+    ctx->ent_len -= dxb_name_len;+  }++  const size_t bytes_needed =+      ctx->ent_len * 2 + ((*flags & MDBX_NOSUBDIR)+                              ? sizeof(lock_suffix) + 1+                              : sizeof(lck_name) + sizeof(dxb_name));+  ctx->buffer_for_free = mdbx_malloc(bytes_needed);+  if (!ctx->buffer_for_free)+    return MDBX_ENOMEM;++  ctx->lck = ctx->buffer_for_free;+  if (*flags & MDBX_NOSUBDIR) {+    ctx->dxb = ctx->lck + ctx->ent_len + sizeof(lock_suffix);+    sprintf(ctx->lck, "%s%s", pathname, lock_suffix);+    strcpy(ctx->dxb, pathname);+  } else {+    ctx->dxb = ctx->lck + ctx->ent_len + sizeof(lck_name);+    sprintf(ctx->lck, "%.*s%s", (int)ctx->ent_len, pathname, lck_name);+    sprintf(ctx->dxb, "%.*s%s", (int)ctx->ent_len, pathname, dxb_name);+  }++  return MDBX_SUCCESS;+}++__cold int mdbx_env_delete(const char *pathname, MDBX_env_delete_mode_t mode) {+  switch (mode) {+  default:+    return MDBX_EINVAL;+  case MDBX_ENV_JUST_DELETE:+  case MDBX_ENV_ENSURE_UNUSED:+  case MDBX_ENV_WAIT_FOR_UNUSED:+    break;+  }++  MDBX_env dummy_env;+  memset(&dummy_env, 0, sizeof(dummy_env));+  dummy_env.me_flags =+      (mode == MDBX_ENV_ENSURE_UNUSED) ? MDBX_EXCLUSIVE : MDBX_ENV_DEFAULTS;+  dummy_env.me_os_psize = (unsigned)mdbx_syspagesize();+  dummy_env.me_psize = (unsigned)mdbx_default_pagesize();+  dummy_env.me_pathname = (char *)pathname;++  MDBX_handle_env_pathname env_pathname;+  STATIC_ASSERT(sizeof(dummy_env.me_flags) == sizeof(MDBX_env_flags_t));+  int rc = MDBX_RESULT_TRUE,+      err = mdbx_handle_env_pathname(+          &env_pathname, pathname, (MDBX_env_flags_t *)&dummy_env.me_flags, 0);+  if (likely(err == MDBX_SUCCESS)) {+    mdbx_filehandle_t clk_handle = INVALID_HANDLE_VALUE,+                      dxb_handle = INVALID_HANDLE_VALUE;+    if (mode > MDBX_ENV_JUST_DELETE) {+      err = mdbx_openfile(MDBX_OPEN_DELETE, &dummy_env, env_pathname.dxb,+                          &dxb_handle, 0);+      err = (err == MDBX_ENOFILE) ? MDBX_SUCCESS : err;+      if (err == MDBX_SUCCESS) {+        err = mdbx_openfile(MDBX_OPEN_DELETE, &dummy_env, env_pathname.lck,+                            &clk_handle, 0);+        err = (err == MDBX_ENOFILE) ? MDBX_SUCCESS : err;+      }+      if (err == MDBX_SUCCESS && clk_handle != INVALID_HANDLE_VALUE)+        err = mdbx_lockfile(clk_handle, mode == MDBX_ENV_WAIT_FOR_UNUSED);+      if (err == MDBX_SUCCESS && dxb_handle != INVALID_HANDLE_VALUE)+        err = mdbx_lockfile(dxb_handle, mode == MDBX_ENV_WAIT_FOR_UNUSED);+    }++    if (err == MDBX_SUCCESS) {+      err = mdbx_removefile(env_pathname.dxb);+      if (err == MDBX_SUCCESS)+        rc = MDBX_SUCCESS;+      else if (err == MDBX_ENOFILE)+        err = MDBX_SUCCESS;+    }++    if (err == MDBX_SUCCESS) {+      err = mdbx_removefile(env_pathname.lck);+      if (err == MDBX_SUCCESS)+        rc = MDBX_SUCCESS;+      else if (err == MDBX_ENOFILE)+        err = MDBX_SUCCESS;+    }++    if (err == MDBX_SUCCESS && !(dummy_env.me_flags & MDBX_NOSUBDIR)) {+      err = mdbx_removedirectory(pathname);+      if (err == MDBX_SUCCESS)+        rc = MDBX_SUCCESS;+      else if (err == MDBX_ENOFILE)+        err = MDBX_SUCCESS;+    }++    if (dxb_handle != INVALID_HANDLE_VALUE)+      mdbx_closefile(dxb_handle);+    if (clk_handle != INVALID_HANDLE_VALUE)+      mdbx_closefile(clk_handle);+  } else if (err == MDBX_ENOFILE)+    err = MDBX_SUCCESS;++  mdbx_free(env_pathname.buffer_for_free);+  return (err == MDBX_SUCCESS) ? rc : err;+}++__cold int mdbx_env_open(MDBX_env *env, const char *pathname,+                         MDBX_env_flags_t flags, mdbx_mode_t mode) {+  int rc = check_env(env, false);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  if (flags & ~ENV_USABLE_FLAGS)+    return MDBX_EINVAL;++  if (env->me_lazy_fd != INVALID_HANDLE_VALUE ||+      (env->me_flags & MDBX_ENV_ACTIVE) != 0 || env->me_map)+    return MDBX_EPERM;++  /* pickup previously mdbx_env_set_flags(),+   * but avoid MDBX_UTTERLY_NOSYNC by disjunction */+  const uint32_t saved_me_flags = env->me_flags;+  flags = merge_sync_flags(flags, env->me_flags);++  MDBX_handle_env_pathname env_pathname;+  rc = mdbx_handle_env_pathname(&env_pathname, pathname, &flags, mode);+  if (unlikely(rc != MDBX_SUCCESS))+    goto bailout;++  if (flags & MDBX_RDONLY) {+    /* LY: silently ignore irrelevant flags when+     * we're only getting read access */+    flags &= ~(MDBX_WRITEMAP | MDBX_DEPRECATED_MAPASYNC | MDBX_SAFE_NOSYNC |+               MDBX_NOMETASYNC | MDBX_COALESCE | MDBX_LIFORECLAIM |+               MDBX_NOMEMINIT | MDBX_ACCEDE);+  } else {+#if MDBX_MMAP_INCOHERENT_FILE_WRITE+    /* Temporary `workaround` for OpenBSD kernel's flaw.+     * See https://github.com/erthink/libmdbx/issues/67 */+    if ((flags & MDBX_WRITEMAP) == 0) {+      if (flags & MDBX_ACCEDE)+        flags |= MDBX_WRITEMAP;+      else {+        mdbx_debug_log(MDBX_LOG_ERROR, __func__, __LINE__,+                       "System (i.e. OpenBSD) requires MDBX_WRITEMAP because "+                       "of an internal flaw(s) in a file/buffer/page cache.\n");+        rc = 42 /* ENOPROTOOPT */;+        goto bailout;+      }+    }+#endif /* MDBX_MMAP_INCOHERENT_FILE_WRITE */+  }++  env->me_flags = (flags & ~MDBX_FATAL_ERROR) | MDBX_ENV_ACTIVE;+  env->me_pathname = mdbx_calloc(env_pathname.ent_len + 1, 1);+  env->me_dbxs = mdbx_calloc(env->me_maxdbs, sizeof(MDBX_dbx));+  env->me_dbflags = mdbx_calloc(env->me_maxdbs, sizeof(env->me_dbflags[0]));+  env->me_dbiseqs = mdbx_calloc(env->me_maxdbs, sizeof(env->me_dbiseqs[0]));+  if (!(env->me_dbxs && env->me_pathname && env->me_dbflags &&+        env->me_dbiseqs)) {+    rc = MDBX_ENOMEM;+    goto bailout;+  }+  memcpy(env->me_pathname, env_pathname.dxb, env_pathname.ent_len);+  env->me_dbxs[FREE_DBI].md_cmp = cmp_int_align4; /* aligned MDBX_INTEGERKEY */+  env->me_dbxs[FREE_DBI].md_dcmp = cmp_lenfast;++  rc = mdbx_openfile(F_ISSET(flags, MDBX_RDONLY) ? MDBX_OPEN_DXB_READ+                                                 : MDBX_OPEN_DXB_LAZY,+                     env, env_pathname.dxb, &env->me_lazy_fd, mode);+  if (rc != MDBX_SUCCESS)+    goto bailout;++  mdbx_assert(env, env->me_dsync_fd == INVALID_HANDLE_VALUE);+  if ((flags & (MDBX_RDONLY | MDBX_SAFE_NOSYNC | MDBX_NOMETASYNC)) == 0) {+    rc = mdbx_openfile(MDBX_OPEN_DXB_DSYNC, env, env_pathname.dxb,+                       &env->me_dsync_fd, 0);+    mdbx_ensure(env, (rc != MDBX_SUCCESS) ==+                         (env->me_dsync_fd == INVALID_HANDLE_VALUE));+  }++#if MDBX_LOCKING == MDBX_LOCKING_SYSV+  env->me_sysv_ipc.key = ftok(env_pathname.dxb, 42);+  if (env->me_sysv_ipc.key == -1) {+    rc = errno;+    goto bailout;+  }+#endif /* MDBX_LOCKING */++#if !(defined(_WIN32) || defined(_WIN64))+  if (mode == 0) {+    /* pickup mode for lck-file */+    struct stat st;+    if (fstat(env->me_lazy_fd, &st)) {+      rc = errno;+      goto bailout;+    }+    mode = st.st_mode;+  }+  mode = (/* inherit read permissions for group and others */ mode &+          (S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH)) |+         /* always add read/write/search for owner */ S_IRUSR | S_IWUSR |+         ((mode & S_IRGRP) ? /* +write if readable by group */ S_IWGRP : 0) |+         ((mode & S_IROTH) ? /* +write if readable by others */ S_IWOTH : 0);+#endif /* !Windows */+  const int lck_rc = mdbx_setup_lck(env, env_pathname.lck, mode);+  if (MDBX_IS_ERROR(lck_rc)) {+    rc = lck_rc;+    goto bailout;+  }++  /* Set the position in files outside of the data to avoid corruption+   * due to erroneous use of file descriptors in the application code. */+  mdbx_fseek(env->me_lfd, UINT64_C(1) << 63);+  mdbx_fseek(env->me_lazy_fd, UINT64_C(1) << 63);+  if (env->me_dsync_fd != INVALID_HANDLE_VALUE)+    mdbx_fseek(env->me_dsync_fd, UINT64_C(1) << 63);++  const MDBX_env_flags_t rigorous_flags =+      MDBX_SAFE_NOSYNC | MDBX_DEPRECATED_MAPASYNC;+  const MDBX_env_flags_t mode_flags = rigorous_flags | MDBX_NOMETASYNC |+                                      MDBX_LIFORECLAIM | MDBX_COALESCE |+                                      MDBX_NORDAHEAD;++  if (env->me_lck && lck_rc != MDBX_RESULT_TRUE &&+      (env->me_flags & MDBX_RDONLY) == 0) {+    while (atomic_load32(&env->me_lck->mti_envmode, mo_AcquireRelease) ==+           MDBX_RDONLY) {+      if (atomic_cas32(&env->me_lck->mti_envmode, MDBX_RDONLY,+                       env->me_flags & mode_flags))+        break;+      atomic_yield();+    }++    if (env->me_flags & MDBX_ACCEDE) {+      /* pickup current mode-flags, including MDBX_LIFORECLAIM |+       * MDBX_COALESCE | MDBX_NORDAHEAD */+      const unsigned diff =+          (env->me_lck->mti_envmode.weak ^ env->me_flags) & mode_flags;+      mdbx_notice("accede mode-flags: 0x%X, 0x%X -> 0x%X", diff, env->me_flags,+                  env->me_flags ^ diff);+      env->me_flags ^= diff;+    }++    if ((env->me_lck->mti_envmode.weak ^ env->me_flags) & rigorous_flags) {+      mdbx_error("%s", "current mode/flags incompatible with requested");+      rc = MDBX_INCOMPATIBLE;+      goto bailout;+    }+  }++  const int dxb_rc = mdbx_setup_dxb(env, lck_rc);+  if (MDBX_IS_ERROR(dxb_rc)) {+    rc = dxb_rc;+    goto bailout;+  }++  if (unlikely(/* recovery mode */ env->me_stuck_meta >= 0) &&+      (lck_rc != /* exclusive */ MDBX_RESULT_TRUE ||+       (flags & MDBX_EXCLUSIVE) == 0)) {+    mdbx_error("%s", "recovery requires exclusive mode");+    rc = MDBX_BUSY;+    goto bailout;+  }++  mdbx_debug("opened dbenv %p", (void *)env);+  if (env->me_lck) {+    if (lck_rc == MDBX_RESULT_TRUE) {+      env->me_lck->mti_envmode.weak =+          env->me_flags & (mode_flags | MDBX_RDONLY);+      rc = mdbx_lck_downgrade(env);+      mdbx_debug("lck-downgrade-%s: rc %i",+                 (env->me_flags & MDBX_EXCLUSIVE) ? "partial" : "full", rc);+      if (rc != MDBX_SUCCESS)+        goto bailout;+    } else {+      rc = mdbx_cleanup_dead_readers(env, false, NULL);+      if (MDBX_IS_ERROR(rc))+        goto bailout;+    }++    if ((env->me_flags & MDBX_NOTLS) == 0) {+      rc = mdbx_rthc_alloc(&env->me_txkey, &env->me_lck->mti_readers[0],+                           &env->me_lck->mti_readers[env->me_maxreaders]);+      if (unlikely(rc != MDBX_SUCCESS))+        goto bailout;+      env->me_flags |= MDBX_ENV_TXKEY;+    }+  }++  if ((flags & MDBX_RDONLY) == 0) {+    const size_t tsize = sizeof(MDBX_txn),+                 size = tsize + env->me_maxdbs *+                                    (sizeof(MDBX_db) + sizeof(MDBX_cursor *) ++                                     sizeof(unsigned) + 1);+    rc = mdbx_memalign_alloc(+        env->me_os_psize,+        env->me_psize * (1 /* page buffer */ + 1 /* page killer buffer */),+        &env->me_pbuf);+    if (rc == MDBX_SUCCESS) {+      memset(env->me_pbuf, -1, env->me_psize * 2);+      MDBX_txn *txn = mdbx_calloc(1, size);+      if (txn) {+        txn->mt_dbs = (MDBX_db *)((char *)txn + tsize);+        txn->tw.cursors = (MDBX_cursor **)(txn->mt_dbs + env->me_maxdbs);+        txn->mt_dbiseqs = (unsigned *)(txn->tw.cursors + env->me_maxdbs);+        txn->mt_dbistate = (uint8_t *)(txn->mt_dbiseqs + env->me_maxdbs);+        txn->mt_env = env;+        txn->mt_dbxs = env->me_dbxs;+        txn->mt_flags = MDBX_TXN_FINISHED;+        env->me_txn0 = txn;+        txn->tw.retired_pages = mdbx_pnl_alloc(MDBX_PNL_INITIAL);+        txn->tw.reclaimed_pglist = mdbx_pnl_alloc(MDBX_PNL_INITIAL);+        if (unlikely(!txn->tw.retired_pages || !txn->tw.reclaimed_pglist))+          rc = MDBX_ENOMEM;+      } else+        rc = MDBX_ENOMEM;+    }+  }++#if MDBX_DEBUG+  if (rc == MDBX_SUCCESS) {+    MDBX_meta *meta = mdbx_meta_head(env);+    MDBX_db *db = &meta->mm_dbs[MAIN_DBI];++    mdbx_debug("opened database version %u, pagesize %u",+               (uint8_t)unaligned_peek_u64(4, meta->mm_magic_and_version),+               env->me_psize);+    mdbx_debug("using meta page %" PRIaPGNO ", txn %" PRIaTXN,+               data_page(meta)->mp_pgno, mdbx_meta_txnid_fluid(env, meta));+    mdbx_debug("depth: %u", db->md_depth);+    mdbx_debug("entries: %" PRIu64, db->md_entries);+    mdbx_debug("branch pages: %" PRIaPGNO, db->md_branch_pages);+    mdbx_debug("leaf pages: %" PRIaPGNO, db->md_leaf_pages);+    mdbx_debug("overflow pages: %" PRIaPGNO, db->md_overflow_pages);+    mdbx_debug("root: %" PRIaPGNO, db->md_root);+    mdbx_debug("schema_altered: %" PRIaTXN, db->md_mod_txnid);+  }+#endif++bailout:+  if (rc != MDBX_SUCCESS) {+    rc = mdbx_env_close0(env) ? MDBX_PANIC : rc;+    env->me_flags =+        saved_me_flags | ((rc != MDBX_PANIC) ? 0 : MDBX_FATAL_ERROR);+  } else {+#if defined(MDBX_USE_VALGRIND) || defined(__SANITIZE_ADDRESS__)+    mdbx_txn_valgrind(env, nullptr);+#endif+  }+  mdbx_free(env_pathname.buffer_for_free);+  return rc;+}++/* Destroy resources from mdbx_env_open(), clear our readers & DBIs */+static __cold int mdbx_env_close0(MDBX_env *env) {+  env->me_stuck_meta = -1;+  if (!(env->me_flags & MDBX_ENV_ACTIVE)) {+    mdbx_ensure(env, env->me_lcklist_next == nullptr);+    return MDBX_SUCCESS;+  }++  env->me_flags &= ~MDBX_ENV_ACTIVE;+  env->me_oldest = nullptr;+  env->me_sync_timestamp = nullptr;+  env->me_autosync_period = nullptr;+  env->me_unsynced_pages = nullptr;+  env->me_autosync_threshold = nullptr;+  env->me_discarded_tail = nullptr;+  env->me_meta_sync_txnid = nullptr;+  if (env->me_flags & MDBX_ENV_TXKEY)+    mdbx_rthc_remove(env->me_txkey);++  lcklist_lock();+  const int rc = lcklist_detach_locked(env);+  lcklist_unlock();++  if (env->me_map) {+    mdbx_munmap(&env->me_dxb_mmap);+#ifdef MDBX_USE_VALGRIND+    VALGRIND_DISCARD(env->me_valgrind_handle);+    env->me_valgrind_handle = -1;+#endif+  }++  if (env->me_dsync_fd != INVALID_HANDLE_VALUE) {+    (void)mdbx_closefile(env->me_dsync_fd);+    env->me_dsync_fd = INVALID_HANDLE_VALUE;+  }++  if (env->me_lazy_fd != INVALID_HANDLE_VALUE) {+    (void)mdbx_closefile(env->me_lazy_fd);+    env->me_lazy_fd = INVALID_HANDLE_VALUE;+  }++  if (env->me_lck)+    mdbx_munmap(&env->me_lck_mmap);++  if (env->me_lfd != INVALID_HANDLE_VALUE) {+    (void)mdbx_closefile(env->me_lfd);+    env->me_lfd = INVALID_HANDLE_VALUE;+  }++  if (env->me_dbxs) {+    for (unsigned i = env->me_numdbs; --i >= CORE_DBS;)+      mdbx_free(env->me_dbxs[i].md_name.iov_base);+    mdbx_free(env->me_dbxs);+  }+  mdbx_memalign_free(env->me_pbuf);+  mdbx_free(env->me_dbiseqs);+  mdbx_free(env->me_dbflags);+  mdbx_free(env->me_pathname);+  if (env->me_txn0) {+    mdbx_dpl_free(env->me_txn0);+    mdbx_txl_free(env->me_txn0->tw.lifo_reclaimed);+    mdbx_pnl_free(env->me_txn0->tw.retired_pages);+    mdbx_pnl_free(env->me_txn0->tw.spill_pages);+    mdbx_pnl_free(env->me_txn0->tw.reclaimed_pglist);+    mdbx_free(env->me_txn0);+  }+  env->me_flags = 0;+  return rc;+}++__cold int mdbx_env_close_ex(MDBX_env *env, bool dont_sync) {+  MDBX_page *dp;+  int rc = MDBX_SUCCESS;++  if (unlikely(!env))+    return MDBX_EINVAL;++  if (unlikely(env->me_signature.weak != MDBX_ME_SIGNATURE))+    return MDBX_EBADSIGN;++#if MDBX_ENV_CHECKPID || !(defined(_WIN32) || defined(_WIN64))+  /* Check the PID even if MDBX_ENV_CHECKPID=0 on non-Windows+   * platforms (i.e. where fork() is available).+   * This is required to legitimize a call after fork()+   * from a child process, that should be allowed to free resources. */+  if (unlikely(env->me_pid != mdbx_getpid()))+    env->me_flags |= MDBX_FATAL_ERROR;+#endif /* MDBX_ENV_CHECKPID */++  if (env->me_map && (env->me_flags & (MDBX_RDONLY | MDBX_FATAL_ERROR)) == 0 &&+      env->me_txn0) {+    if (env->me_txn0->mt_owner && env->me_txn0->mt_owner != mdbx_thread_self())+      return MDBX_BUSY;+  } else+    dont_sync = true;++  if (!atomic_cas32(&env->me_signature, MDBX_ME_SIGNATURE, 0))+    return MDBX_EBADSIGN;++  if (!dont_sync) {+#if defined(_WIN32) || defined(_WIN64)+    /* On windows, without blocking is impossible to determine whether another+     * process is running a writing transaction or not.+     * Because in the "owner died" condition kernel don't release+     * file lock immediately. */+    rc = mdbx_env_sync_internal(env, true, false);+    rc = (rc == MDBX_RESULT_TRUE) ? MDBX_SUCCESS : rc;+#else+    struct stat st;+    if (unlikely(fstat(env->me_lazy_fd, &st)))+      rc = errno;+    else if (st.st_nlink > 0 /* don't sync deleted files */) {+      rc = mdbx_env_sync_internal(env, true, true);+      rc = (rc == MDBX_BUSY || rc == EAGAIN || rc == EACCES || rc == EBUSY ||+            rc == EWOULDBLOCK || rc == MDBX_RESULT_TRUE)+               ? MDBX_SUCCESS+               : rc;+    }+#endif+  }++  mdbx_assert(env, env->me_signature.weak == 0);+  rc = mdbx_env_close0(env) ? MDBX_PANIC : rc;+  mdbx_ensure(env, mdbx_fastmutex_destroy(&env->me_dbi_lock) == MDBX_SUCCESS);+#if defined(_WIN32) || defined(_WIN64)+  /* me_remap_guard don't have destructor (Slim Reader/Writer Lock) */+  DeleteCriticalSection(&env->me_windowsbug_lock);+#else+  mdbx_ensure(env,+              mdbx_fastmutex_destroy(&env->me_remap_guard) == MDBX_SUCCESS);+#endif /* Windows */++#if MDBX_LOCKING > MDBX_LOCKING_SYSV+  mdbx_ensure(env, mdbx_ipclock_destroy(&env->me_lckless_stub.wlock) == 0);+#endif /* MDBX_LOCKING */++  while ((dp = env->me_dp_reserve) != NULL) {+    ASAN_UNPOISON_MEMORY_REGION(dp, env->me_psize);+    VALGRIND_MAKE_MEM_DEFINED(&dp->mp_next, sizeof(dp->mp_next));+    env->me_dp_reserve = dp->mp_next;+    mdbx_free(dp);+  }+  VALGRIND_DESTROY_MEMPOOL(env);+  mdbx_ensure(env, env->me_lcklist_next == nullptr);+  env->me_pid = 0;+  mdbx_free(env);++  return rc;+}++#ifndef LIBMDBX_NO_EXPORTS_LEGACY_API+__cold int mdbx_env_close(MDBX_env *env) {+  return __inline_mdbx_env_close(env);+}+#endif /* LIBMDBX_NO_EXPORTS_LEGACY_API */++/* Compare two items pointing at aligned unsigned int's. */+static int __hot cmp_int_align4(const MDBX_val *a, const MDBX_val *b) {+  mdbx_assert(NULL, a->iov_len == b->iov_len);+  switch (a->iov_len) {+  case 4:+    return CMP2INT(unaligned_peek_u32(4, a->iov_base),+                   unaligned_peek_u32(4, b->iov_base));+  case 8:+    return CMP2INT(unaligned_peek_u64(4, a->iov_base),+                   unaligned_peek_u64(4, b->iov_base));+  default:+    mdbx_assert_fail(NULL, "invalid size for INTEGERKEY/INTEGERDUP", __func__,+                     __LINE__);+    return 0;+  }+}++/* Compare two items pointing at 2-byte aligned unsigned int's. */+static int __hot cmp_int_align2(const MDBX_val *a, const MDBX_val *b) {+  mdbx_assert(NULL, a->iov_len == b->iov_len);+  switch (a->iov_len) {+  case 4:+    return CMP2INT(unaligned_peek_u32(2, a->iov_base),+                   unaligned_peek_u32(2, b->iov_base));+  case 8:+    return CMP2INT(unaligned_peek_u64(2, a->iov_base),+                   unaligned_peek_u64(2, b->iov_base));+  default:+    mdbx_assert_fail(NULL, "invalid size for INTEGERKEY/INTEGERDUP", __func__,+                     __LINE__);+    return 0;+  }+}++/* Compare two items pointing at unsigned values with unknown alignment.+ *+ * This is also set as MDBX_INTEGERDUP|MDBX_DUPFIXED's MDBX_dbx.md_dcmp. */+static int __hot cmp_int_unaligned(const MDBX_val *a, const MDBX_val *b) {+  mdbx_assert(NULL, a->iov_len == b->iov_len);+  switch (a->iov_len) {+  case 4:+    return CMP2INT(unaligned_peek_u32(1, a->iov_base),+                   unaligned_peek_u32(1, b->iov_base));+  case 8:+    return CMP2INT(unaligned_peek_u64(1, a->iov_base),+                   unaligned_peek_u64(1, b->iov_base));+  default:+    mdbx_assert_fail(NULL, "invalid size for INTEGERKEY/INTEGERDUP", __func__,+                     __LINE__);+    return 0;+  }+}++/* Compare two items lexically */+static int __hot cmp_lexical(const MDBX_val *a, const MDBX_val *b) {+  if (a->iov_len == b->iov_len)+    return memcmp(a->iov_base, b->iov_base, a->iov_len);++  const int diff_len = (a->iov_len < b->iov_len) ? -1 : 1;+  const size_t shortest = (a->iov_len < b->iov_len) ? a->iov_len : b->iov_len;+  int diff_data = memcmp(a->iov_base, b->iov_base, shortest);+  return likely(diff_data) ? diff_data : diff_len;+}++/* Compare two items in reverse byte order */+static int __hot cmp_reverse(const MDBX_val *a, const MDBX_val *b) {+  const uint8_t *pa = (const uint8_t *)a->iov_base + a->iov_len;+  const uint8_t *pb = (const uint8_t *)b->iov_base + b->iov_len;+  const size_t shortest = (a->iov_len < b->iov_len) ? a->iov_len : b->iov_len;++  const uint8_t *const end = pa - shortest;+  while (pa != end) {+    int diff = *--pa - *--pb;+    if (likely(diff))+      return diff;+  }+  return CMP2INT(a->iov_len, b->iov_len);+}++/* Fast non-lexically comparator */+static int __hot cmp_lenfast(const MDBX_val *a, const MDBX_val *b) {+  int diff = CMP2INT(a->iov_len, b->iov_len);+  return likely(diff) ? diff : memcmp(a->iov_base, b->iov_base, a->iov_len);+}++static bool unsure_equal(MDBX_cmp_func cmp, const MDBX_val *a,+                         const MDBX_val *b) {+  return cmp == cmp_lenfast || cmp == cmp_lexical || cmp == cmp_reverse ||+         cmp == cmp_int_unaligned || cmp_lenfast(a, b) == 0;+}++/* Search for key within a page, using binary search.+ * Returns the smallest entry larger or equal to the key.+ * If exactp is non-null, stores whether the found entry was an exact match+ * in *exactp (1 or 0).+ * Updates the cursor index with the index of the found entry.+ * If no entry larger or equal to the key is found, returns NULL. */+static MDBX_node *__hot mdbx_node_search(MDBX_cursor *mc, const MDBX_val *key,+                                         int *exactp) {+  MDBX_page *mp = mc->mc_pg[mc->mc_top];+  const int nkeys = page_numkeys(mp);+  DKBUF;++  mdbx_debug("searching %u keys in %s %spage %" PRIaPGNO, nkeys,+             IS_LEAF(mp) ? "leaf" : "branch", IS_SUBP(mp) ? "sub-" : "",+             mp->mp_pgno);++  int low = IS_LEAF(mp) ? 0 : 1;+  int high = nkeys - 1;+  *exactp = 0;+  if (unlikely(high < low)) {+    mc->mc_ki[mc->mc_top] = 0;+    return NULL;+  }++  int rc = 0, i = 0;+  MDBX_cmp_func *cmp = mc->mc_dbx->md_cmp;+  MDBX_val nodekey;+  if (unlikely(IS_LEAF2(mp))) {+    mdbx_cassert(mc, mp->mp_leaf2_ksize == mc->mc_db->md_xsize);+    nodekey.iov_len = mp->mp_leaf2_ksize;+    do {+      i = (low + high) >> 1;+      nodekey.iov_base = page_leaf2key(mp, i, nodekey.iov_len);+      mdbx_cassert(mc, (char *)mp + mc->mc_txn->mt_env->me_psize >=+                           (char *)nodekey.iov_base + nodekey.iov_len);+      rc = cmp(key, &nodekey);+      mdbx_debug("found leaf index %u [%s], rc = %i", i, DKEY(&nodekey), rc);+      if (unlikely(rc == 0)) {+        *exactp = 1;+        break;+      }+      low = (rc < 0) ? low : i + 1;+      high = (rc < 0) ? i - 1 : high;+    } while (likely(low <= high));++    /* Found entry is less than the key. */+    /* Skip to get the smallest entry larger than key. */+    i += rc > 0;++    /* store the key index */+    mc->mc_ki[mc->mc_top] = (indx_t)i;+    return (i < nkeys)+               ? /* fake for LEAF2 */ (MDBX_node *)(intptr_t)-1+               : /* There is no entry larger or equal to the key. */ NULL;+  }++  if (IS_BRANCH(mp) && cmp == cmp_int_align2)+    /* Branch pages have no data, so if using integer keys,+     * alignment is guaranteed. Use faster cmp_int_align4(). */+    cmp = cmp_int_align4;++  MDBX_node *node;+  do {+    i = (low + high) >> 1;++    node = page_node(mp, i);+    nodekey.iov_len = node_ks(node);+    nodekey.iov_base = node_key(node);+    mdbx_cassert(mc, (char *)mp + mc->mc_txn->mt_env->me_psize >=+                         (char *)nodekey.iov_base + nodekey.iov_len);++    rc = cmp(key, &nodekey);+    if (IS_LEAF(mp))+      mdbx_debug("found leaf index %u [%s], rc = %i", i, DKEY(&nodekey), rc);+    else+      mdbx_debug("found branch index %u [%s -> %" PRIaPGNO "], rc = %i", i,+                 DKEY(&nodekey), node_pgno(node), rc);+    if (unlikely(rc == 0)) {+      *exactp = 1;+      break;+    }+    low = (rc < 0) ? low : i + 1;+    high = (rc < 0) ? i - 1 : high;+  } while (likely(low <= high));++  /* Found entry is less than the key. */+  /* Skip to get the smallest entry larger than key. */+  i += rc > 0;++  /* store the key index */+  mc->mc_ki[mc->mc_top] = (indx_t)i;+  return (i < nkeys) ? page_node(mp, i)+                     : /* There is no entry larger or equal to the key. */ NULL;+}++#if 0 /* unused for now */+static void mdbx_cursor_adjust(MDBX_cursor *mc, func) {+  MDBX_cursor *m2;++  for (m2 = mc->mc_txn->tw.cursors[mc->mc_dbi]; m2; m2 = m2->mc_next) {+    if (m2->mc_pg[m2->mc_top] == mc->mc_pg[mc->mc_top]) {+      func(mc, m2);+    }+  }+}+#endif++/* Pop a page off the top of the cursor's stack. */+static __inline void mdbx_cursor_pop(MDBX_cursor *mc) {+  if (mc->mc_snum) {+    mdbx_debug("popped page %" PRIaPGNO " off db %d cursor %p",+               mc->mc_pg[mc->mc_top]->mp_pgno, DDBI(mc), (void *)mc);+    if (--mc->mc_snum) {+      mc->mc_top--;+    } else {+      mc->mc_flags &= ~C_INITIALIZED;+    }+  }+}++/* Push a page onto the top of the cursor's stack.+ * Set MDBX_TXN_ERROR on failure. */+static __inline int mdbx_cursor_push(MDBX_cursor *mc, MDBX_page *mp) {+  mdbx_debug("pushing page %" PRIaPGNO " on db %d cursor %p", mp->mp_pgno,+             DDBI(mc), (void *)mc);++  if (unlikely(mc->mc_snum >= CURSOR_STACK)) {+    mc->mc_txn->mt_flags |= MDBX_TXN_ERROR;+    return MDBX_CURSOR_FULL;+  }++  mdbx_cassert(mc, mc->mc_snum < UINT16_MAX);+  mc->mc_top = mc->mc_snum++;+  mc->mc_pg[mc->mc_top] = mp;+  mc->mc_ki[mc->mc_top] = 0;++  return MDBX_SUCCESS;+}++/* Find the address of the page corresponding to a given page number.+ * Set MDBX_TXN_ERROR on failure.+ *+ * [in] mc    the cursor accessing the page.+ * [in] pgno  the page number for the page to retrieve.+ * [out] ret  address of a pointer where the page's address will be+ *            stored.+ * [out] lvl  dirtylist inheritance level of found page. 1=current txn,+ *            0=mapped page.+ *+ * Returns 0 on success, non-zero on failure. */+#if MDBX_DISABLE_PAGECHECKS+__hot static int __mdbx_page_get(MDBX_cursor *mc, pgno_t pgno, MDBX_page **ret,+                                 int *lvl)+#else+__hot static int mdbx_page_get(MDBX_cursor *mc, pgno_t pgno, MDBX_page **ret,+                               int *lvl, txnid_t pp_txnid)+#endif /* MDBX_DISABLE_PAGECHECKS */+{+  MDBX_txn *txn = mc->mc_txn;+  if (unlikely(pgno >= txn->mt_next_pgno)) {+    mdbx_error("page #%" PRIaPGNO " beyond next-pgno", pgno);+    *ret = nullptr;+  corrupted:+    mc->mc_txn->mt_flags |= MDBX_TXN_ERROR;+    return MDBX_PAGE_NOTFOUND;+  }++#if !MDBX_DISABLE_PAGECHECKS+  mdbx_tassert(txn, pp_txnid >= MIN_TXNID && pp_txnid <= txn->mt_txnid);+  const uint16_t illegal_bits =+      (txn->mt_flags & MDBX_TXN_RDONLY)+          ? ~(P_BRANCH | P_LEAF | P_LEAF2 | P_OVERFLOW)+          : ~(P_BRANCH | P_LEAF | P_LEAF2 | P_OVERFLOW | P_DIRTY);+#endif /* !MDBX_DISABLE_PAGECHECKS */++  MDBX_env *const env = txn->mt_env;+  mdbx_assert(env, ((txn->mt_flags ^ env->me_flags) & MDBX_WRITEMAP) == 0);+  MDBX_page *p;+  int level;+  if (unlikely((txn->mt_flags & (MDBX_TXN_RDONLY | MDBX_WRITEMAP)) == 0)) {+    level = 1;+    do {+      /* Spilled pages were dirtied in this txn and flushed+       * because the dirty list got full. Bring this page+       * back in from the map (but don't unspill it here,+       * leave that unless page_touch happens again). */+      if (unlikely(txn->mt_flags & MDBX_TXN_SPILLS) && txn->tw.spill_pages &&+          mdbx_pnl_exist(txn->tw.spill_pages, pgno << 1)) {+#if !MDBX_DISABLE_PAGECHECKS+        pp_txnid = txn->mt_txnid;+#endif /* !MDBX_DISABLE_PAGECHECKS */+        goto spilled;+      }+      p = mdbx_dpl_find(txn->tw.dirtylist, pgno);+      if (p)+        goto dirty;+      level++;+    } while ((txn = txn->mt_parent) != NULL);+  }+  level = 0;++spilled:+  p = pgno2page(env, pgno);++dirty:+  *(lvl ? lvl : &level) = level;+  *ret = p;++  if (unlikely(p->mp_pgno != pgno)) {+    bad_page(+        p, "mismatch actual pgno (%" PRIaPGNO ") != expected (%" PRIaPGNO ")\n",+        p->mp_pgno, pgno);+    goto corrupted;+  }++#if !MDBX_DISABLE_PAGECHECKS+  if (unlikely(p->mp_flags & illegal_bits)) {+    bad_page(p, "invalid page's flags (%u)\n", p->mp_flags);+    goto corrupted;+  }++  if (unlikely(p->mp_txnid >+               ((p->mp_flags & P_DIRTY) ? UINT64_MAX : pp_txnid))) {+    bad_page(p, "page mod-txnid (%" PRIaTXN ") > parent (%" PRIaTXN ")\n",+             p->mp_txnid, pp_txnid);+    goto corrupted;+  }++  if (unlikely((p->mp_upper < p->mp_lower ||+                ((p->mp_lower | p->mp_upper) & 1) != 0 ||+                PAGEHDRSZ + p->mp_upper > env->me_psize) &&+               !IS_OVERFLOW(p))) {+    bad_page(p, "invalid page lower(%u)/upper(%u) with limit (%u)\n",+             p->mp_lower, p->mp_upper, page_space(env));+    goto corrupted;+  }+#endif /* !MDBX_DISABLE_PAGECHECKS */++  if (mdbx_audit_enabled())+    return mdbx_page_check(mc, p, C_UPDATING);++  return MDBX_SUCCESS;+}++/* Finish mdbx_page_search() / mdbx_page_search_lowest().+ * The cursor is at the root page, set up the rest of it. */+__hot static int mdbx_page_search_root(MDBX_cursor *mc, const MDBX_val *key,+                                       int flags) {+  MDBX_page *mp = mc->mc_pg[mc->mc_top];+  int rc;+  DKBUF;++  while (IS_BRANCH(mp)) {+    MDBX_node *node;+    int i;++    mdbx_debug("branch page %" PRIaPGNO " has %u keys", mp->mp_pgno,+               page_numkeys(mp));+    /* Don't assert on branch pages in the GC. We can get here+     * while in the process of rebalancing a GC branch page; we must+     * let that proceed. ITS#8336 */+    mdbx_cassert(mc, !mc->mc_dbi || page_numkeys(mp) > 1);+    mdbx_debug("found index 0 to page %" PRIaPGNO, node_pgno(page_node(mp, 0)));++    if (flags & (MDBX_PS_FIRST | MDBX_PS_LAST)) {+      i = 0;+      if (flags & MDBX_PS_LAST) {+        i = page_numkeys(mp) - 1;+        /* if already init'd, see if we're already in right place */+        if (mc->mc_flags & C_INITIALIZED) {+          if (mc->mc_ki[mc->mc_top] == i) {+            mc->mc_top = mc->mc_snum++;+            mp = mc->mc_pg[mc->mc_top];+            goto ready;+          }+        }+      }+    } else {+      int exact;+      node = mdbx_node_search(mc, key, &exact);+      if (node == NULL)+        i = page_numkeys(mp) - 1;+      else {+        i = mc->mc_ki[mc->mc_top];+        if (!exact) {+          mdbx_cassert(mc, i > 0);+          i--;+        }+      }+      mdbx_debug("following index %u for key [%s]", i, DKEY(key));+    }++    mdbx_cassert(mc, i < (int)page_numkeys(mp));+    node = page_node(mp, i);++    if (unlikely((rc = mdbx_page_get(mc, node_pgno(node), &mp, NULL,+                                     pp_txnid4chk(mp, mc->mc_txn))) != 0))+      return rc;++    mc->mc_ki[mc->mc_top] = (indx_t)i;+    if (unlikely(rc = mdbx_cursor_push(mc, mp)))+      return rc;++  ready:+    if (flags & MDBX_PS_MODIFY) {+      if (unlikely((rc = mdbx_page_touch(mc)) != 0))+        return rc;+      mp = mc->mc_pg[mc->mc_top];+    }+  }++  if (unlikely(!IS_LEAF(mp))) {+    mc->mc_txn->mt_flags |= MDBX_TXN_ERROR;+    return bad_page(mp, "index points to a page with 0x%02x flags\n",+                    mp->mp_flags);+  }++  mdbx_debug("found leaf page %" PRIaPGNO " for key [%s]", mp->mp_pgno,+             DKEY(key));+  mc->mc_flags |= C_INITIALIZED;+  mc->mc_flags &= ~C_EOF;++  return MDBX_SUCCESS;+}++static int mdbx_setup_dbx(MDBX_dbx *const dbx, const MDBX_db *const db,+                          const unsigned pagesize) {+  if (unlikely(!dbx->md_cmp)) {+    dbx->md_cmp = get_default_keycmp(db->md_flags);+    dbx->md_dcmp = get_default_datacmp(db->md_flags);+  }++  dbx->md_klen_min =+      (db->md_flags & MDBX_INTEGERKEY) ? 4 /* sizeof(uint32_t) */ : 0;+  dbx->md_klen_max = mdbx_limits_keysize_max(pagesize, db->md_flags);+  assert(dbx->md_klen_max != (unsigned)-1);++  dbx->md_vlen_min = (db->md_flags & MDBX_INTEGERDUP)+                         ? 4 /* sizeof(uint32_t) */+                         : ((db->md_flags & MDBX_DUPFIXED) ? 1 : 0);+  dbx->md_vlen_max = mdbx_limits_valsize_max(pagesize, db->md_flags);+  assert(dbx->md_vlen_max != (unsigned)-1);++  if ((db->md_flags & (MDBX_DUPFIXED | MDBX_INTEGERDUP)) != 0 && db->md_xsize) {+    if (!MDBX_DISABLE_PAGECHECKS && unlikely(db->md_xsize < dbx->md_vlen_min ||+                                             db->md_xsize > dbx->md_vlen_max)) {+      mdbx_error("db.md_xsize (%u) <> min/max value-length (%zu/%zu)",+                 db->md_xsize, dbx->md_vlen_min, dbx->md_vlen_max);+      return MDBX_CORRUPTED;+    }+    dbx->md_vlen_min = dbx->md_vlen_max = db->md_xsize;+  }+  return MDBX_SUCCESS;+}++static int mdbx_fetch_sdb(MDBX_txn *txn, MDBX_dbi dbi) {+  MDBX_cursor_couple couple;+  if (unlikely(TXN_DBI_CHANGED(txn, dbi)))+    return MDBX_BAD_DBI;+  int rc = mdbx_cursor_init(&couple.outer, txn, MAIN_DBI);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  MDBX_dbx *const dbx = &txn->mt_dbxs[dbi];+  rc = mdbx_page_search(&couple.outer, &dbx->md_name, 0);+  if (unlikely(rc != MDBX_SUCCESS))+    return (rc == MDBX_NOTFOUND) ? MDBX_BAD_DBI : rc;++  MDBX_val data;+  int exact = 0;+  MDBX_node *node = mdbx_node_search(&couple.outer, &dbx->md_name, &exact);+  if (unlikely(!exact))+    return MDBX_BAD_DBI;+  if (unlikely((node_flags(node) & (F_DUPDATA | F_SUBDATA)) != F_SUBDATA))+    return MDBX_INCOMPATIBLE; /* not a named DB */++  const txnid_t pp_txnid =+      pp_txnid4chk(couple.outer.mc_pg[couple.outer.mc_top], txn);+  rc = mdbx_node_read(&couple.outer, node, &data, pp_txnid);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  if (unlikely(data.iov_len != sizeof(MDBX_db)))+    return MDBX_INCOMPATIBLE; /* not a named DB */++  uint16_t md_flags = UNALIGNED_PEEK_16(data.iov_base, MDBX_db, md_flags);+  /* The txn may not know this DBI, or another process may+   * have dropped and recreated the DB with other flags. */+  MDBX_db *const db = &txn->mt_dbs[dbi];+  if (unlikely((db->md_flags & DB_PERSISTENT_FLAGS) != md_flags))+    return MDBX_INCOMPATIBLE;++  memcpy(db, data.iov_base, sizeof(MDBX_db));+#if !MDBX_DISABLE_PAGECHECKS+  mdbx_tassert(txn, txn->mt_txnid >= pp_txnid);+  if (unlikely(db->md_mod_txnid > pp_txnid)) {+    mdbx_error("db.md_mod_txnid (%" PRIaTXN ") > page-txnid (%" PRIaTXN ")",+               db->md_mod_txnid, pp_txnid);+    return MDBX_CORRUPTED;+  }+#endif /* !MDBX_DISABLE_PAGECHECKS */+  rc = mdbx_setup_dbx(dbx, db, txn->mt_env->me_psize);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  txn->mt_dbistate[dbi] &= ~DBI_STALE;+  return MDBX_SUCCESS;+}++/* Search for the lowest key under the current branch page.+ * This just bypasses a numkeys check in the current page+ * before calling mdbx_page_search_root(), because the callers+ * are all in situations where the current page is known to+ * be underfilled. */+__hot static int mdbx_page_search_lowest(MDBX_cursor *mc) {+  MDBX_page *mp = mc->mc_pg[mc->mc_top];+  mdbx_cassert(mc, IS_BRANCH(mp));+  MDBX_node *node = page_node(mp, 0);+  int rc;++  if (unlikely((rc = mdbx_page_get(mc, node_pgno(node), &mp, NULL,+                                   pp_txnid4chk(mp, mc->mc_txn))) != 0))+    return rc;++  mc->mc_ki[mc->mc_top] = 0;+  if (unlikely(rc = mdbx_cursor_push(mc, mp)))+    return rc;+  return mdbx_page_search_root(mc, NULL, MDBX_PS_FIRST);+}++/* Search for the page a given key should be in.+ * Push it and its parent pages on the cursor stack.+ *+ * [in,out] mc  the cursor for this operation.+ * [in] key     the key to search for, or NULL for first/last page.+ * [in] flags   If MDBX_PS_MODIFY is set, visited pages in the DB+ *              are touched (updated with new page numbers).+ *              If MDBX_PS_FIRST or MDBX_PS_LAST is set, find first or last+ * leaf.+ *              This is used by mdbx_cursor_first() and mdbx_cursor_last().+ *              If MDBX_PS_ROOTONLY set, just fetch root node, no further+ *              lookups.+ *+ * Returns 0 on success, non-zero on failure. */+__hot static int mdbx_page_search(MDBX_cursor *mc, const MDBX_val *key,+                                  int flags) {+  int rc;+  pgno_t root;++  /* Make sure the txn is still viable, then find the root from+   * the txn's db table and set it as the root of the cursor's stack. */+  if (unlikely(mc->mc_txn->mt_flags & MDBX_TXN_BLOCKED)) {+    mdbx_debug("%s", "transaction has failed, must abort");+    return MDBX_BAD_TXN;+  }++  /* Make sure we're using an up-to-date root */+  if (unlikely(*mc->mc_dbistate & DBI_STALE)) {+    rc = mdbx_fetch_sdb(mc->mc_txn, mc->mc_dbi);+    if (unlikely(rc != MDBX_SUCCESS))+      return rc;+  }+  root = mc->mc_db->md_root;++  if (unlikely(root == P_INVALID)) { /* Tree is empty. */+    mdbx_debug("%s", "tree is empty");+    return MDBX_NOTFOUND;+  }++  mdbx_cassert(mc, root >= NUM_METAS);+  if (!mc->mc_pg[0] || mc->mc_pg[0]->mp_pgno != root) {+    if (unlikely((rc = mdbx_page_get(+                      mc, root, &mc->mc_pg[0], NULL,+                      (/* maybe zero in legacy DB */ mc->mc_db->md_mod_txnid &&+                       !(*mc->mc_dbistate & DBI_DIRTY))+                          ? mc->mc_db->md_mod_txnid+                          : mc->mc_txn->mt_txnid)) != 0))+      return rc;+  }++  mc->mc_snum = 1;+  mc->mc_top = 0;++  mdbx_debug("db %d root page %" PRIaPGNO " has flags 0x%X", DDBI(mc), root,+             mc->mc_pg[0]->mp_flags);++  if (flags & MDBX_PS_MODIFY) {+    if (unlikely(rc = mdbx_page_touch(mc)))+      return rc;+  }++  if (flags & MDBX_PS_ROOTONLY)+    return MDBX_SUCCESS;++  return mdbx_page_search_root(mc, key, flags);+}++/* Return the data associated with a given node.+ *+ * [in] mc      The cursor for this operation.+ * [in] leaf    The node being read.+ * [out] data   Updated to point to the node's data.+ *+ * Returns 0 on success, non-zero on failure. */+static __always_inline int mdbx_node_read(MDBX_cursor *mc, MDBX_node *node,+                                          MDBX_val *data,+                                          const txnid_t pp_txnid) {+  data->iov_len = node_ds(node);+  data->iov_base = node_data(node);+  if (unlikely(F_ISSET(node_flags(node), F_BIGDATA))) {+    /* Read overflow data. */+    MDBX_page *omp; /* overflow page */+    int rc = mdbx_page_get(mc, node_largedata_pgno(node), &omp, NULL, pp_txnid);+    if (unlikely((rc != MDBX_SUCCESS))) {+      mdbx_debug("read overflow page %" PRIaPGNO " failed",+                 node_largedata_pgno(node));+      return rc;+    }+    data->iov_base = page_data(omp);+  }+  return MDBX_SUCCESS;+}++int mdbx_get(MDBX_txn *txn, MDBX_dbi dbi, const MDBX_val *key, MDBX_val *data) {+  DKBUF;+  mdbx_debug("===> get db %u key [%s]", dbi, DKEY(key));++  int rc = check_txn(txn, MDBX_TXN_BLOCKED);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  if (unlikely(!key || !data))+    return MDBX_EINVAL;++  if (unlikely(!mdbx_txn_dbi_exists(txn, dbi, DBI_USRVALID)))+    return MDBX_BAD_DBI;++  MDBX_cursor_couple cx;+  rc = mdbx_cursor_init(&cx.outer, txn, dbi);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  int exact = 0;+  return mdbx_cursor_set(&cx.outer, (MDBX_val *)key, data, MDBX_SET, &exact);+}++int mdbx_get_equal_or_great(MDBX_txn *txn, MDBX_dbi dbi, MDBX_val *key,+                            MDBX_val *data) {+  int rc = check_txn(txn, MDBX_TXN_BLOCKED);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  if (unlikely(!key || !data))+    return MDBX_EINVAL;++  if (unlikely(!mdbx_txn_dbi_exists(txn, dbi, DBI_USRVALID)))+    return MDBX_BAD_DBI;++  if (unlikely(txn->mt_flags & MDBX_TXN_BLOCKED))+    return MDBX_BAD_TXN;++  MDBX_cursor_couple cx;+  rc = mdbx_cursor_init(&cx.outer, txn, dbi);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  return mdbx_cursor_get(&cx.outer, key, data, MDBX_SET_LOWERBOUND);+}++int mdbx_get_ex(MDBX_txn *txn, MDBX_dbi dbi, MDBX_val *key, MDBX_val *data,+                size_t *values_count) {+  DKBUF;+  mdbx_debug("===> get db %u key [%s]", dbi, DKEY(key));++  int rc = check_txn(txn, MDBX_TXN_BLOCKED);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  if (unlikely(!key || !data))+    return MDBX_EINVAL;++  if (unlikely(!mdbx_txn_dbi_exists(txn, dbi, DBI_USRVALID)))+    return MDBX_BAD_DBI;++  MDBX_cursor_couple cx;+  rc = mdbx_cursor_init(&cx.outer, txn, dbi);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  int exact = 0;+  rc = mdbx_cursor_set(&cx.outer, key, data, MDBX_SET_KEY, &exact);+  if (unlikely(rc != MDBX_SUCCESS)) {+    if (rc == MDBX_NOTFOUND && values_count)+      *values_count = 0;+    return rc;+  }++  if (values_count) {+    *values_count = 1;+    if (cx.outer.mc_xcursor != NULL) {+      MDBX_node *node = page_node(cx.outer.mc_pg[cx.outer.mc_top],+                                  cx.outer.mc_ki[cx.outer.mc_top]);+      if (F_ISSET(node_flags(node), F_DUPDATA)) {+        mdbx_tassert(txn, cx.outer.mc_xcursor == &cx.inner &&+                              (cx.inner.mx_cursor.mc_flags & C_INITIALIZED));+        *values_count =+            (sizeof(*values_count) >= sizeof(cx.inner.mx_db.md_entries) ||+             cx.inner.mx_db.md_entries <= PTRDIFF_MAX)+                ? (size_t)cx.inner.mx_db.md_entries+                : PTRDIFF_MAX;+      }+    }+  }+  return MDBX_SUCCESS;+}++/* Find a sibling for a page.+ * Replaces the page at the top of the cursor's stack with the specified+ * sibling, if one exists.+ *+ * [in] mc    The cursor for this operation.+ * [in] dir   SIBLING_LEFT or SIBLING_RIGHT.+ *+ * Returns 0 on success, non-zero on failure. */+static int mdbx_cursor_sibling(MDBX_cursor *mc, int dir) {+  int rc;+  MDBX_node *node;+  MDBX_page *mp;+  assert(dir == SIBLING_LEFT || dir == SIBLING_RIGHT);++  if (unlikely(mc->mc_snum < 2))+    return MDBX_NOTFOUND; /* root has no siblings */++  mdbx_cursor_pop(mc);+  mdbx_debug("parent page is page %" PRIaPGNO ", index %u",+             mc->mc_pg[mc->mc_top]->mp_pgno, mc->mc_ki[mc->mc_top]);++  if ((dir == SIBLING_RIGHT)+          ? (mc->mc_ki[mc->mc_top] + 1u >= page_numkeys(mc->mc_pg[mc->mc_top]))+          : (mc->mc_ki[mc->mc_top] == 0)) {+    mdbx_debug("no more keys aside, moving to next %s sibling",+               dir ? "right" : "left");+    if (unlikely((rc = mdbx_cursor_sibling(mc, dir)) != MDBX_SUCCESS)) {+      /* undo cursor_pop before returning */+      mc->mc_top++;+      mc->mc_snum++;+      return rc;+    }+  } else {+    assert((dir - 1) == -1 || (dir - 1) == 1);+    mc->mc_ki[mc->mc_top] += (indx_t)(dir - 1);+    mdbx_debug("just moving to %s index key %u",+               (dir == SIBLING_RIGHT) ? "right" : "left",+               mc->mc_ki[mc->mc_top]);+  }+  mdbx_cassert(mc, IS_BRANCH(mc->mc_pg[mc->mc_top]));++  node = page_node(mp = mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);+  if (unlikely((rc = mdbx_page_get(mc, node_pgno(node), &mp, NULL,+                                   pp_txnid4chk(mp, mc->mc_txn))) != 0)) {+    /* mc will be inconsistent if caller does mc_snum++ as above */+    mc->mc_flags &= ~(C_INITIALIZED | C_EOF);+    return rc;+  }++  rc = mdbx_cursor_push(mc, mp);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  mc->mc_ki[mc->mc_top] =+      (indx_t)((dir == SIBLING_LEFT) ? page_numkeys(mp) - 1 : 0);+  return MDBX_SUCCESS;+}++/* Move the cursor to the next data item. */+static int mdbx_cursor_next(MDBX_cursor *mc, MDBX_val *key, MDBX_val *data,+                            MDBX_cursor_op op) {+  MDBX_page *mp;+  MDBX_node *node;+  int rc;++  if ((mc->mc_flags & C_DEL) && op == MDBX_NEXT_DUP)+    return MDBX_NOTFOUND;++  if (!(mc->mc_flags & C_INITIALIZED))+    return mdbx_cursor_first(mc, key, data);++  mp = mc->mc_pg[mc->mc_top];+  if (mc->mc_flags & C_EOF) {+    if (mc->mc_ki[mc->mc_top] + 1u >= page_numkeys(mp))+      return MDBX_NOTFOUND;+    mc->mc_flags ^= C_EOF;+  }++  if (mc->mc_db->md_flags & MDBX_DUPSORT) {+    node = page_node(mp, mc->mc_ki[mc->mc_top]);+    if (F_ISSET(node_flags(node), F_DUPDATA)) {+      if (op == MDBX_NEXT || op == MDBX_NEXT_DUP) {+        rc =+            mdbx_cursor_next(&mc->mc_xcursor->mx_cursor, data, NULL, MDBX_NEXT);+        if (op != MDBX_NEXT || rc != MDBX_NOTFOUND) {+          if (likely(rc == MDBX_SUCCESS))+            get_key_optional(node, key);+          return rc;+        }+      }+    } else {+      mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED | C_EOF);+      if (op == MDBX_NEXT_DUP)+        return MDBX_NOTFOUND;+    }+  }++  mdbx_debug("cursor_next: top page is %" PRIaPGNO " in cursor %p", mp->mp_pgno,+             (void *)mc);+  if (mc->mc_flags & C_DEL) {+    mc->mc_flags ^= C_DEL;+    goto skip;+  }++  int ki = mc->mc_ki[mc->mc_top];+  mc->mc_ki[mc->mc_top] = (indx_t)++ki;+  const int numkeys = page_numkeys(mp);+  if (unlikely(ki >= numkeys)) {+    mdbx_debug("%s", "=====> move to next sibling page");+    mc->mc_ki[mc->mc_top] = (indx_t)(numkeys - 1);+    if (unlikely((rc = mdbx_cursor_sibling(mc, SIBLING_RIGHT)) !=+                 MDBX_SUCCESS)) {+      mc->mc_flags |= C_EOF;+      return rc;+    }+    mp = mc->mc_pg[mc->mc_top];+    mdbx_debug("next page is %" PRIaPGNO ", key index %u", mp->mp_pgno,+               mc->mc_ki[mc->mc_top]);+  }++skip:+  mdbx_debug("==> cursor points to page %" PRIaPGNO+             " with %u keys, key index %u",+             mp->mp_pgno, page_numkeys(mp), mc->mc_ki[mc->mc_top]);++  if (!MDBX_DISABLE_PAGECHECKS && unlikely(!IS_LEAF(mp)))+    return MDBX_CORRUPTED;++  if (IS_LEAF2(mp)) {+    if (likely(key)) {+      key->iov_len = mc->mc_db->md_xsize;+      key->iov_base = page_leaf2key(mp, mc->mc_ki[mc->mc_top], key->iov_len);+    }+    return MDBX_SUCCESS;+  }++  node = page_node(mp, mc->mc_ki[mc->mc_top]);+  if (F_ISSET(node_flags(node), F_DUPDATA)) {+    rc = mdbx_xcursor_init1(mc, node, mp);+    if (unlikely(rc != MDBX_SUCCESS))+      return rc;+    rc = mdbx_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL);+    if (unlikely(rc != MDBX_SUCCESS))+      return rc;+  } else if (likely(data)) {+    if (unlikely((rc = mdbx_node_read(mc, node, data,+                                      pp_txnid4chk(mp, mc->mc_txn))) !=+                 MDBX_SUCCESS))+      return rc;+  }++  get_key_optional(node, key);+  return MDBX_SUCCESS;+}++/* Move the cursor to the previous data item. */+static int mdbx_cursor_prev(MDBX_cursor *mc, MDBX_val *key, MDBX_val *data,+                            MDBX_cursor_op op) {+  MDBX_page *mp;+  MDBX_node *node;+  int rc;++  if ((mc->mc_flags & C_DEL) && op == MDBX_PREV_DUP)+    return MDBX_NOTFOUND;++  if (!(mc->mc_flags & C_INITIALIZED)) {+    rc = mdbx_cursor_last(mc, key, data);+    if (unlikely(rc))+      return rc;+    mc->mc_ki[mc->mc_top]++;+  }++  mp = mc->mc_pg[mc->mc_top];+  if ((mc->mc_db->md_flags & MDBX_DUPSORT) &&+      mc->mc_ki[mc->mc_top] < page_numkeys(mp)) {+    node = page_node(mp, mc->mc_ki[mc->mc_top]);+    if (F_ISSET(node_flags(node), F_DUPDATA)) {+      if (op == MDBX_PREV || op == MDBX_PREV_DUP) {+        rc =+            mdbx_cursor_prev(&mc->mc_xcursor->mx_cursor, data, NULL, MDBX_PREV);+        if (op != MDBX_PREV || rc != MDBX_NOTFOUND) {+          if (likely(rc == MDBX_SUCCESS)) {+            get_key_optional(node, key);+            mc->mc_flags &= ~C_EOF;+          }+          return rc;+        }+      }+    } else {+      mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED | C_EOF);+      if (op == MDBX_PREV_DUP)+        return MDBX_NOTFOUND;+    }+  }++  mdbx_debug("cursor_prev: top page is %" PRIaPGNO " in cursor %p", mp->mp_pgno,+             (void *)mc);++  mc->mc_flags &= ~(C_EOF | C_DEL);++  int ki = mc->mc_ki[mc->mc_top];+  mc->mc_ki[mc->mc_top] = (indx_t)--ki;+  if (unlikely(ki < 0)) {+    mc->mc_ki[mc->mc_top] = 0;+    mdbx_debug("%s", "=====> move to prev sibling page");+    if ((rc = mdbx_cursor_sibling(mc, SIBLING_LEFT)) != MDBX_SUCCESS)+      return rc;+    mp = mc->mc_pg[mc->mc_top];+    mdbx_debug("prev page is %" PRIaPGNO ", key index %u", mp->mp_pgno,+               mc->mc_ki[mc->mc_top]);+  }+  mdbx_debug("==> cursor points to page %" PRIaPGNO+             " with %u keys, key index %u",+             mp->mp_pgno, page_numkeys(mp), mc->mc_ki[mc->mc_top]);++  if (!MDBX_DISABLE_PAGECHECKS && unlikely(!IS_LEAF(mp)))+    return MDBX_CORRUPTED;++  if (IS_LEAF2(mp)) {+    if (likely(key)) {+      key->iov_len = mc->mc_db->md_xsize;+      key->iov_base = page_leaf2key(mp, mc->mc_ki[mc->mc_top], key->iov_len);+    }+    return MDBX_SUCCESS;+  }++  node = page_node(mp, mc->mc_ki[mc->mc_top]);++  if (F_ISSET(node_flags(node), F_DUPDATA)) {+    rc = mdbx_xcursor_init1(mc, node, mp);+    if (unlikely(rc != MDBX_SUCCESS))+      return rc;+    rc = mdbx_cursor_last(&mc->mc_xcursor->mx_cursor, data, NULL);+    if (unlikely(rc != MDBX_SUCCESS))+      return rc;+  } else if (likely(data)) {+    if (unlikely((rc = mdbx_node_read(mc, node, data,+                                      pp_txnid4chk(mp, mc->mc_txn))) !=+                 MDBX_SUCCESS))+      return rc;+  }++  get_key_optional(node, key);+  return MDBX_SUCCESS;+}++/* Set the cursor on a specific data item. */+static int mdbx_cursor_set(MDBX_cursor *mc, MDBX_val *key, MDBX_val *data,+                           MDBX_cursor_op op, int *exactp) {+  int rc;+  MDBX_page *mp;+  MDBX_node *node = NULL;+  int stub_exactp;+  DKBUF;++  exactp = exactp ? exactp : &stub_exactp;++  if (unlikely(key->iov_len < mc->mc_dbx->md_klen_min ||+               key->iov_len > mc->mc_dbx->md_klen_max)) {+    mdbx_cassert(mc, !"Invalid key-size");+    return MDBX_BAD_VALSIZE;+  }++  MDBX_val aligned_key = *key;+  uint64_t aligned_keybytes;+  if (mc->mc_db->md_flags & MDBX_INTEGERKEY) {+    switch (aligned_key.iov_len) {+    default:+      mdbx_cassert(mc, !"key-size is invalid for MDBX_INTEGERKEY");+      return MDBX_BAD_VALSIZE;+    case 4:+      if (unlikely(3 & (uintptr_t)aligned_key.iov_base))+        /* copy instead of return error to avoid break compatibility */+        aligned_key.iov_base =+            memcpy(&aligned_keybytes, aligned_key.iov_base, 4);+      break;+    case 8:+      if (unlikely(7 & (uintptr_t)aligned_key.iov_base))+        /* copy instead of return error to avoid break compatibility */+        aligned_key.iov_base =+            memcpy(&aligned_keybytes, aligned_key.iov_base, 8);+      break;+    }+  }++  if (mc->mc_xcursor)+    mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED | C_EOF);++  /* See if we're already on the right page */+  if (mc->mc_flags & C_INITIALIZED) {+    MDBX_val nodekey;++    mdbx_cassert(mc, IS_LEAF(mc->mc_pg[mc->mc_top]));+    mp = mc->mc_pg[mc->mc_top];+    if (unlikely(!page_numkeys(mp))) {+      mc->mc_ki[mc->mc_top] = 0;+      mc->mc_flags |= C_EOF;+      return MDBX_NOTFOUND;+    }+    if (IS_LEAF2(mp)) {+      nodekey.iov_len = mc->mc_db->md_xsize;+      nodekey.iov_base = page_leaf2key(mp, 0, nodekey.iov_len);+    } else {+      node = page_node(mp, 0);+      get_key(node, &nodekey);+    }+    rc = mc->mc_dbx->md_cmp(&aligned_key, &nodekey);+    if (unlikely(rc == 0)) {+      /* Probably happens rarely, but first node on the page+       * was the one we wanted. */+      mc->mc_ki[mc->mc_top] = 0;+      *exactp = 1;+      mdbx_cassert(mc, mc->mc_ki[mc->mc_top] <+                               page_numkeys(mc->mc_pg[mc->mc_top]) ||+                           (mc->mc_flags & C_EOF));+      goto set1;+    }+    if (rc > 0) {+      const unsigned nkeys = page_numkeys(mp);+      unsigned i;+      if (nkeys > 1) {+        if (IS_LEAF2(mp)) {+          nodekey.iov_base = page_leaf2key(mp, nkeys - 1, nodekey.iov_len);+        } else {+          node = page_node(mp, nkeys - 1);+          get_key(node, &nodekey);+        }+        rc = mc->mc_dbx->md_cmp(&aligned_key, &nodekey);+        if (rc == 0) {+          /* last node was the one we wanted */+          mdbx_cassert(mc, nkeys >= 1 && nkeys <= UINT16_MAX + 1);+          mc->mc_ki[mc->mc_top] = (indx_t)(nkeys - 1);+          *exactp = 1;+          mdbx_cassert(mc, mc->mc_ki[mc->mc_top] <+                                   page_numkeys(mc->mc_pg[mc->mc_top]) ||+                               (mc->mc_flags & C_EOF));+          goto set1;+        }+        if (rc < 0) {+          if (mc->mc_ki[mc->mc_top] < page_numkeys(mp)) {+            /* This is definitely the right page, skip search_page */+            if (IS_LEAF2(mp)) {+              nodekey.iov_base =+                  page_leaf2key(mp, mc->mc_ki[mc->mc_top], nodekey.iov_len);+            } else {+              node = page_node(mp, mc->mc_ki[mc->mc_top]);+              get_key(node, &nodekey);+            }+            rc = mc->mc_dbx->md_cmp(&aligned_key, &nodekey);+            if (rc == 0) {+              /* current node was the one we wanted */+              *exactp = 1;+              mdbx_cassert(mc, mc->mc_ki[mc->mc_top] <+                                       page_numkeys(mc->mc_pg[mc->mc_top]) ||+                                   (mc->mc_flags & C_EOF));+              goto set1;+            }+          }+          rc = 0;+          mc->mc_flags &= ~C_EOF;+          goto set2;+        }+      }+      /* If any parents have right-sibs, search.+       * Otherwise, there's nothing further. */+      for (i = 0; i < mc->mc_top; i++)+        if (mc->mc_ki[i] < page_numkeys(mc->mc_pg[i]) - 1)+          break;+      if (i == mc->mc_top) {+        /* There are no other pages */+        mdbx_cassert(mc, nkeys <= UINT16_MAX);+        mc->mc_ki[mc->mc_top] = (uint16_t)nkeys;+        mc->mc_flags |= C_EOF;+        return MDBX_NOTFOUND;+      }+    }+    if (!mc->mc_top) {+      /* There are no other pages */+      mc->mc_ki[mc->mc_top] = 0;+      if (op == MDBX_SET_RANGE) {+        rc = 0;+        goto set1;+      } else {+        mdbx_cassert(mc, mc->mc_ki[mc->mc_top] <+                                 page_numkeys(mc->mc_pg[mc->mc_top]) ||+                             (mc->mc_flags & C_EOF));+        return MDBX_NOTFOUND;+      }+    }+  } else {+    mc->mc_pg[0] = 0;+  }++  rc = mdbx_page_search(mc, &aligned_key, 0);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  mp = mc->mc_pg[mc->mc_top];+  mdbx_cassert(mc, IS_LEAF(mp));++set2:+  node = mdbx_node_search(mc, &aligned_key, exactp);+  if (!*exactp && op != MDBX_SET_RANGE) {+    /* MDBX_SET specified and not an exact match. */+    if (unlikely(mc->mc_ki[mc->mc_top] >= page_numkeys(mc->mc_pg[mc->mc_top])))+      mc->mc_flags |= C_EOF;+    return MDBX_NOTFOUND;+  }++  if (node == NULL) {+    mdbx_debug("%s", "===> inexact leaf not found, goto sibling");+    if (unlikely((rc = mdbx_cursor_sibling(mc, SIBLING_RIGHT)) !=+                 MDBX_SUCCESS)) {+      mc->mc_flags |= C_EOF;+      return rc; /* no entries matched */+    }+    mp = mc->mc_pg[mc->mc_top];+    mdbx_cassert(mc, IS_LEAF(mp));+    if (!IS_LEAF2(mp))+      node = page_node(mp, 0);+  }+  mdbx_cassert(mc,+               mc->mc_ki[mc->mc_top] < page_numkeys(mc->mc_pg[mc->mc_top]) ||+                   (mc->mc_flags & C_EOF));++set1:+  mc->mc_flags |= C_INITIALIZED;+  mc->mc_flags &= ~C_EOF;++  if (IS_LEAF2(mp)) {+    if (op == MDBX_SET_RANGE || op == MDBX_SET_KEY) {+      key->iov_len = mc->mc_db->md_xsize;+      key->iov_base = page_leaf2key(mp, mc->mc_ki[mc->mc_top], key->iov_len);+    }+    return MDBX_SUCCESS;+  }++  if (F_ISSET(node_flags(node), F_DUPDATA)) {+    rc = mdbx_xcursor_init1(mc, node, mp);+    if (unlikely(rc != MDBX_SUCCESS))+      return rc;+    if (op == MDBX_SET || op == MDBX_SET_KEY || op == MDBX_SET_RANGE) {+      rc = mdbx_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL);+    } else {+      rc = mdbx_cursor_set(&mc->mc_xcursor->mx_cursor, data, NULL,+                           MDBX_SET_RANGE, NULL);+    }+    if (unlikely(rc != MDBX_SUCCESS))+      return rc;+  } else if (likely(data)) {+    if (op == MDBX_GET_BOTH || op == MDBX_GET_BOTH_RANGE) {+      if (unlikely(data->iov_len < mc->mc_dbx->md_vlen_min ||+                   data->iov_len > mc->mc_dbx->md_vlen_max)) {+        mdbx_cassert(mc, !"Invalid data-size");+        return MDBX_BAD_VALSIZE;+      }+      MDBX_val aligned_data = *data;+      uint64_t aligned_databytes;+      if (mc->mc_db->md_flags & MDBX_INTEGERDUP) {+        switch (aligned_data.iov_len) {+        default:+          mdbx_cassert(mc, !"data-size is invalid for MDBX_INTEGERDUP");+          return MDBX_BAD_VALSIZE;+        case 4:+          if (unlikely(3 & (uintptr_t)aligned_data.iov_base))+            /* copy instead of return error to avoid break compatibility */+            aligned_data.iov_base =+                memcpy(&aligned_databytes, aligned_data.iov_base, 4);+          break;+        case 8:+          if (unlikely(7 & (uintptr_t)aligned_data.iov_base))+            /* copy instead of return error to avoid break compatibility */+            aligned_data.iov_base =+                memcpy(&aligned_databytes, aligned_data.iov_base, 8);+          break;+        }+      }+      MDBX_val olddata;+      if (unlikely((rc = mdbx_node_read(+                        mc, node, &olddata,+                        pp_txnid4chk(mc->mc_pg[mc->mc_top], mc->mc_txn))) !=+                   MDBX_SUCCESS))+        return rc;+      rc = mc->mc_dbx->md_dcmp(&aligned_data, &olddata);+      if (rc) {+        mdbx_cassert(mc, mc->mc_ki[mc->mc_top] <+                                 page_numkeys(mc->mc_pg[mc->mc_top]) ||+                             (mc->mc_flags & C_EOF));+        if (op != MDBX_GET_BOTH_RANGE || rc > 0)+          return MDBX_NOTFOUND;+        *exactp = 0;+        rc = 0;+      }+      *data = olddata;+    } else if (unlikely((rc = mdbx_node_read(mc, node, data,+                                             pp_txnid4chk(mc->mc_pg[mc->mc_top],+                                                          mc->mc_txn))) !=+                        MDBX_SUCCESS))+      return rc;+  }++  /* The key already matches in all other cases */+  if (op == MDBX_SET_RANGE || op == MDBX_SET_KEY)+    get_key_optional(node, key);++  mdbx_debug("==> cursor placed on key [%s], data [%s]", DKEY(key), DVAL(data));+  return rc;+}++/* Move the cursor to the first item in the database. */+static int mdbx_cursor_first(MDBX_cursor *mc, MDBX_val *key, MDBX_val *data) {+  int rc;++  if (mc->mc_xcursor)+    mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED | C_EOF);++  if (!(mc->mc_flags & C_INITIALIZED) || mc->mc_top) {+    rc = mdbx_page_search(mc, NULL, MDBX_PS_FIRST);+    if (unlikely(rc != MDBX_SUCCESS))+      return rc;+  }++  if (!MDBX_DISABLE_PAGECHECKS && unlikely(!IS_LEAF(mc->mc_pg[mc->mc_top])))+    return MDBX_CORRUPTED;++  mc->mc_flags |= C_INITIALIZED;+  mc->mc_flags &= ~C_EOF;+  mc->mc_ki[mc->mc_top] = 0;++  if (IS_LEAF2(mc->mc_pg[mc->mc_top])) {+    if (likely(key)) {+      key->iov_len = mc->mc_db->md_xsize;+      key->iov_base = page_leaf2key(mc->mc_pg[mc->mc_top], 0, key->iov_len);+    }+    return MDBX_SUCCESS;+  }++  MDBX_node *node = page_node(mc->mc_pg[mc->mc_top], 0);+  if (F_ISSET(node_flags(node), F_DUPDATA)) {+    rc = mdbx_xcursor_init1(mc, node, mc->mc_pg[mc->mc_top]);+    if (unlikely(rc != MDBX_SUCCESS))+      return rc;+    rc = mdbx_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL);+    if (unlikely(rc))+      return rc;+  } else if (likely(data)) {+    if (unlikely((rc = mdbx_node_read(+                      mc, node, data,+                      pp_txnid4chk(mc->mc_pg[mc->mc_top], mc->mc_txn))) !=+                 MDBX_SUCCESS))+      return rc;+  }++  get_key_optional(node, key);+  return MDBX_SUCCESS;+}++/* Move the cursor to the last item in the database. */+static int mdbx_cursor_last(MDBX_cursor *mc, MDBX_val *key, MDBX_val *data) {+  int rc;++  if (mc->mc_xcursor)+    mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED | C_EOF);++  if (!(mc->mc_flags & C_INITIALIZED) || mc->mc_top) {+    rc = mdbx_page_search(mc, NULL, MDBX_PS_LAST);+    if (unlikely(rc != MDBX_SUCCESS))+      return rc;+  }++  if (!MDBX_DISABLE_PAGECHECKS && unlikely(!IS_LEAF(mc->mc_pg[mc->mc_top])))+    return MDBX_CORRUPTED;++  mc->mc_ki[mc->mc_top] = (indx_t)page_numkeys(mc->mc_pg[mc->mc_top]) - 1;+  mc->mc_flags |= C_INITIALIZED | C_EOF;++  if (IS_LEAF2(mc->mc_pg[mc->mc_top])) {+    if (likely(key)) {+      key->iov_len = mc->mc_db->md_xsize;+      key->iov_base = page_leaf2key(mc->mc_pg[mc->mc_top],+                                    mc->mc_ki[mc->mc_top], key->iov_len);+    }+    return MDBX_SUCCESS;+  }++  MDBX_node *node = page_node(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);+  if (F_ISSET(node_flags(node), F_DUPDATA)) {+    rc = mdbx_xcursor_init1(mc, node, mc->mc_pg[mc->mc_top]);+    if (unlikely(rc != MDBX_SUCCESS))+      return rc;+    rc = mdbx_cursor_last(&mc->mc_xcursor->mx_cursor, data, NULL);+    if (unlikely(rc))+      return rc;+  } else if (likely(data)) {+    if (unlikely((rc = mdbx_node_read(+                      mc, node, data,+                      pp_txnid4chk(mc->mc_pg[mc->mc_top], mc->mc_txn))) !=+                 MDBX_SUCCESS))+      return rc;+  }++  get_key_optional(node, key);+  return MDBX_SUCCESS;+}++int mdbx_cursor_get(MDBX_cursor *mc, MDBX_val *key, MDBX_val *data,+                    MDBX_cursor_op op) {+  if (unlikely(mc == NULL))+    return MDBX_EINVAL;++  if (unlikely(mc->mc_signature != MDBX_MC_LIVE))+    return (mc->mc_signature == MDBX_MC_READY4CLOSE) ? MDBX_EINVAL+                                                     : MDBX_EBADSIGN;++  int rc = check_txn(mc->mc_txn, MDBX_TXN_BLOCKED);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  int exact = 0;+  int (*mfunc)(MDBX_cursor * mc, MDBX_val * key, MDBX_val * data);+  switch (op) {+  case MDBX_GET_CURRENT: {+    if (unlikely(!(mc->mc_flags & C_INITIALIZED)))+      return MDBX_ENODATA;+    MDBX_page *mp = mc->mc_pg[mc->mc_top];+    const unsigned nkeys = page_numkeys(mp);+    if (mc->mc_ki[mc->mc_top] >= nkeys) {+      mdbx_cassert(mc, nkeys <= UINT16_MAX);+      mc->mc_ki[mc->mc_top] = (uint16_t)nkeys;+      mc->mc_flags |= C_EOF;+      return MDBX_NOTFOUND;+    }+    mdbx_cassert(mc, nkeys > 0);++    rc = MDBX_SUCCESS;+    if (IS_LEAF2(mp)) {+      key->iov_len = mc->mc_db->md_xsize;+      key->iov_base = page_leaf2key(mp, mc->mc_ki[mc->mc_top], key->iov_len);+    } else {+      MDBX_node *node = page_node(mp, mc->mc_ki[mc->mc_top]);+      get_key_optional(node, key);+      if (data) {+        if (F_ISSET(node_flags(node), F_DUPDATA)) {+          if (unlikely(!(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED))) {+            rc = mdbx_xcursor_init1(mc, node, mp);+            if (unlikely(rc != MDBX_SUCCESS))+              return rc;+            rc = mdbx_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL);+            if (unlikely(rc))+              return rc;+          } else {+            rc = mdbx_cursor_get(&mc->mc_xcursor->mx_cursor, data, NULL,+                                 MDBX_GET_CURRENT);+            if (unlikely(rc))+              return rc;+          }+        } else {+          rc = mdbx_node_read(mc, node, data, pp_txnid4chk(mp, mc->mc_txn));+          if (unlikely(rc))+            return rc;+        }+      }+    }+    break;+  }+  case MDBX_GET_BOTH:+  case MDBX_GET_BOTH_RANGE:+    if (unlikely(data == NULL))+      return MDBX_EINVAL;+    if (unlikely(mc->mc_xcursor == NULL))+      return MDBX_INCOMPATIBLE;+    /* fall through */+    __fallthrough;+  case MDBX_SET:+  case MDBX_SET_KEY:+  case MDBX_SET_RANGE:+    if (unlikely(key == NULL))+      return MDBX_EINVAL;+    rc = mdbx_cursor_set(mc, key, data, op, &exact);+    if (mc->mc_flags & C_INITIALIZED) {+      mdbx_cassert(mc, mc->mc_snum > 0 && mc->mc_top < mc->mc_snum);+      mdbx_cassert(mc, mc->mc_ki[mc->mc_top] <+                               page_numkeys(mc->mc_pg[mc->mc_top]) ||+                           (mc->mc_flags & C_EOF));+    }+    break;+  case MDBX_GET_MULTIPLE:+    if (unlikely(data == NULL || !(mc->mc_flags & C_INITIALIZED)))+      return MDBX_EINVAL;+    if (unlikely(!(mc->mc_db->md_flags & MDBX_DUPFIXED)))+      return MDBX_INCOMPATIBLE;+    rc = MDBX_SUCCESS;+    if ((mc->mc_xcursor->mx_cursor.mc_flags & (C_INITIALIZED | C_EOF)) !=+        C_INITIALIZED)+      break;+    goto fetchm;+  case MDBX_NEXT_MULTIPLE:+    if (unlikely(data == NULL))+      return MDBX_EINVAL;+    if (unlikely(!(mc->mc_db->md_flags & MDBX_DUPFIXED)))+      return MDBX_INCOMPATIBLE;+    rc = mdbx_cursor_next(mc, key, data, MDBX_NEXT_DUP);+    if (rc == MDBX_SUCCESS) {+      if (mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) {+        MDBX_cursor *mx;+      fetchm:+        mx = &mc->mc_xcursor->mx_cursor;+        data->iov_len =+            page_numkeys(mx->mc_pg[mx->mc_top]) * mx->mc_db->md_xsize;+        data->iov_base = page_data(mx->mc_pg[mx->mc_top]);+        mx->mc_ki[mx->mc_top] = (indx_t)page_numkeys(mx->mc_pg[mx->mc_top]) - 1;+      } else {+        rc = MDBX_NOTFOUND;+      }+    }+    break;+  case MDBX_PREV_MULTIPLE:+    if (data == NULL)+      return MDBX_EINVAL;+    if (!(mc->mc_db->md_flags & MDBX_DUPFIXED))+      return MDBX_INCOMPATIBLE;+    rc = MDBX_SUCCESS;+    if (!(mc->mc_flags & C_INITIALIZED))+      rc = mdbx_cursor_last(mc, key, data);+    if (rc == MDBX_SUCCESS) {+      MDBX_cursor *mx = &mc->mc_xcursor->mx_cursor;+      if (mx->mc_flags & C_INITIALIZED) {+        rc = mdbx_cursor_sibling(mx, SIBLING_LEFT);+        if (rc == MDBX_SUCCESS)+          goto fetchm;+      } else {+        rc = MDBX_NOTFOUND;+      }+    }+    break;+  case MDBX_NEXT:+  case MDBX_NEXT_DUP:+  case MDBX_NEXT_NODUP:+    rc = mdbx_cursor_next(mc, key, data, op);+    break;+  case MDBX_PREV:+  case MDBX_PREV_DUP:+  case MDBX_PREV_NODUP:+    rc = mdbx_cursor_prev(mc, key, data, op);+    break;+  case MDBX_FIRST:+    rc = mdbx_cursor_first(mc, key, data);+    break;+  case MDBX_FIRST_DUP:+    mfunc = mdbx_cursor_first;+  mmove:+    if (unlikely(data == NULL || !(mc->mc_flags & C_INITIALIZED)))+      return MDBX_EINVAL;+    if (unlikely(mc->mc_xcursor == NULL))+      return MDBX_INCOMPATIBLE;+    if (mc->mc_ki[mc->mc_top] >= page_numkeys(mc->mc_pg[mc->mc_top])) {+      mc->mc_ki[mc->mc_top] = (indx_t)page_numkeys(mc->mc_pg[mc->mc_top]);+      mc->mc_flags |= C_EOF;+      return MDBX_NOTFOUND;+    }+    {+      MDBX_node *node = page_node(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);+      if (!F_ISSET(node_flags(node), F_DUPDATA)) {+        get_key_optional(node, key);+        rc = mdbx_node_read(mc, node, data,+                            pp_txnid4chk(mc->mc_pg[mc->mc_top], mc->mc_txn));+        break;+      }+    }+    if (unlikely(!(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED)))+      return MDBX_EINVAL;+    rc = mfunc(&mc->mc_xcursor->mx_cursor, data, NULL);+    break;+  case MDBX_LAST:+    rc = mdbx_cursor_last(mc, key, data);+    break;+  case MDBX_LAST_DUP:+    mfunc = mdbx_cursor_last;+    goto mmove;+  case MDBX_SET_LOWERBOUND: {+    if (unlikely(key == NULL || data == NULL))+      return MDBX_EINVAL;+    MDBX_val save_data = *data;+    rc = mdbx_cursor_set(mc, key, data, MDBX_SET_RANGE, &exact);+    if (rc == MDBX_SUCCESS && exact && mc->mc_xcursor) {+      mc->mc_flags &= ~C_DEL;+      if (mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) {+        *data = save_data;+        exact = 0;+        rc = mdbx_cursor_set(&mc->mc_xcursor->mx_cursor, data, NULL,+                             MDBX_SET_RANGE, &exact);+        if (rc == MDBX_NOTFOUND) {+          mdbx_cassert(mc, !exact);+          rc = mdbx_cursor_next(mc, key, data, MDBX_NEXT_NODUP);+        }+      } else {+        int cmp = mc->mc_dbx->md_dcmp(&save_data, data);+        exact = (cmp == 0);+        if (cmp > 0)+          rc = mdbx_cursor_next(mc, key, data, MDBX_NEXT_NODUP);+      }+    }+    if (rc == MDBX_SUCCESS && !exact)+      rc = MDBX_RESULT_TRUE;+    break;+  }+  default:+    mdbx_debug("unhandled/unimplemented cursor operation %u", op);+    return MDBX_EINVAL;+  }++  mc->mc_flags &= ~C_DEL;+  return rc;+}++/* Touch all the pages in the cursor stack. Set mc_top.+ * Makes sure all the pages are writable, before attempting a write operation.+ * [in] mc The cursor to operate on. */+static int mdbx_cursor_touch(MDBX_cursor *mc) {+  int rc = MDBX_SUCCESS;+  if (unlikely((*mc->mc_dbistate & (DBI_DIRTY | DBI_DUPDATA)) == 0)) {+    *mc->mc_dbistate |= DBI_DIRTY;+    mc->mc_txn->mt_flags |= MDBX_TXN_DIRTY;+    if (mc->mc_dbi >= CORE_DBS) {+      mdbx_cassert(mc, (mc->mc_flags & C_RECLAIMING) == 0);+      /* Touch DB record of named DB */+      MDBX_cursor_couple cx;+      if (TXN_DBI_CHANGED(mc->mc_txn, mc->mc_dbi))+        return MDBX_BAD_DBI;+      rc = mdbx_cursor_init(&cx.outer, mc->mc_txn, MAIN_DBI);+      if (unlikely(rc != MDBX_SUCCESS))+        return rc;+      rc = mdbx_page_search(&cx.outer, &mc->mc_dbx->md_name, MDBX_PS_MODIFY);+      if (unlikely(rc))+        return rc;+    }+  }+  mc->mc_top = 0;+  if (mc->mc_snum) {+    do {+      rc = mdbx_page_touch(mc);+    } while (!rc && ++(mc->mc_top) < mc->mc_snum);+    mc->mc_top = mc->mc_snum - 1;+  }+  return rc;+}++int mdbx_cursor_put(MDBX_cursor *mc, const MDBX_val *key, MDBX_val *data,+                    unsigned flags) {+  MDBX_env *env;+  MDBX_page *sub_root = NULL;+  MDBX_val xdata, *rdata, dkey, olddata;+  MDBX_db nested_dupdb;+  int rc2;+  DKBUF;++  if (unlikely(mc == NULL || key == NULL || data == NULL))+    return MDBX_EINVAL;++  if (unlikely(mc->mc_signature != MDBX_MC_LIVE))+    return (mc->mc_signature == MDBX_MC_READY4CLOSE) ? MDBX_EINVAL+                                                     : MDBX_EBADSIGN;++  int rc = check_txn_rw(mc->mc_txn, MDBX_TXN_BLOCKED);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  if (unlikely(TXN_DBI_CHANGED(mc->mc_txn, mc->mc_dbi)))+    return MDBX_BAD_DBI;++  mdbx_cassert(mc, cursor_is_tracked(mc));+  env = mc->mc_txn->mt_env;++  /* Check this first so counter will always be zero on any early failures. */+  size_t mcount = 0, dcount = 0;+  if (unlikely(flags & MDBX_MULTIPLE)) {+    if (unlikely(flags & MDBX_RESERVE))+      return MDBX_EINVAL;+    if (unlikely(!F_ISSET(mc->mc_db->md_flags, MDBX_DUPFIXED)))+      return MDBX_INCOMPATIBLE;+    dcount = data[1].iov_len;+    if (unlikely(dcount < 2 || data->iov_len == 0))+      return MDBX_BAD_VALSIZE;+    if (unlikely(mc->mc_db->md_xsize != data->iov_len) && mc->mc_db->md_xsize)+      return MDBX_BAD_VALSIZE;+    if (unlikely(dcount >+                 MAX_MAPSIZE / 2 / (BRANCH_NODEMAX(MAX_PAGESIZE) - NODESIZE))) {+      /* checking for multiplication overflow */+      if (unlikely(dcount > MAX_MAPSIZE / 2 / data->iov_len))+        return MDBX_TOO_LARGE;+    }+    data[1].iov_len = 0 /* reset done item counter */;+  }++  if (flags & MDBX_RESERVE) {+    if (unlikely(mc->mc_db->md_flags & (MDBX_DUPSORT | MDBX_REVERSEDUP |+                                        MDBX_INTEGERDUP | MDBX_DUPFIXED)))+      return MDBX_INCOMPATIBLE;+    data->iov_base = nullptr;+  }++  const unsigned nospill = flags & MDBX_NOSPILL;+  flags -= nospill;++  if (unlikely(mc->mc_txn->mt_flags & (MDBX_TXN_RDONLY | MDBX_TXN_BLOCKED)))+    return (mc->mc_txn->mt_flags & MDBX_TXN_RDONLY) ? MDBX_EACCESS+                                                    : MDBX_BAD_TXN;++  uint64_t aligned_keybytes, aligned_databytes;+  MDBX_val aligned_key, aligned_data;+  if (likely((mc->mc_flags & C_SUB) == 0)) {+    if (unlikely(key->iov_len < mc->mc_dbx->md_klen_min ||+                 key->iov_len > mc->mc_dbx->md_klen_max)) {+      mdbx_cassert(mc, !"Invalid key-size");+      return MDBX_BAD_VALSIZE;+    }+    if (unlikely(data->iov_len < mc->mc_dbx->md_vlen_min ||+                 data->iov_len > mc->mc_dbx->md_vlen_max)) {+      mdbx_cassert(mc, !"Invalid data-size");+      return MDBX_BAD_VALSIZE;+    }++    if (mc->mc_db->md_flags & MDBX_INTEGERKEY) {+      switch (key->iov_len) {+      default:+        mdbx_cassert(mc, !"key-size is invalid for MDBX_INTEGERKEY");+        return MDBX_BAD_VALSIZE;+      case 4:+        if (unlikely(3 & (uintptr_t)key->iov_base)) {+          /* copy instead of return error to avoid break compatibility */+          aligned_key.iov_base =+              memcpy(&aligned_keybytes, key->iov_base, aligned_key.iov_len = 4);+          key = &aligned_key;+        }+        break;+      case 8:+        if (unlikely(7 & (uintptr_t)key->iov_base)) {+          /* copy instead of return error to avoid break compatibility */+          aligned_key.iov_base =+              memcpy(&aligned_keybytes, key->iov_base, aligned_key.iov_len = 8);+          key = &aligned_key;+        }+        break;+      }+    }+    if (mc->mc_db->md_flags & MDBX_INTEGERDUP) {+      switch (data->iov_len) {+      default:+        mdbx_cassert(mc, !"data-size is invalid for MDBX_INTEGERKEY");+        return MDBX_BAD_VALSIZE;+      case 4:+        if (unlikely(3 & (uintptr_t)data->iov_base)) {+          if (unlikely(flags & MDBX_MULTIPLE))+            return MDBX_BAD_VALSIZE;+          /* copy instead of return error to avoid break compatibility */+          aligned_data.iov_base = memcpy(&aligned_databytes, data->iov_base,+                                         aligned_data.iov_len = 4);+          data = &aligned_data;+        }+        break;+      case 8:+        if (unlikely(7 & (uintptr_t)data->iov_base)) {+          if (unlikely(flags & MDBX_MULTIPLE))+            return MDBX_BAD_VALSIZE;+          /* copy instead of return error to avoid break compatibility */+          aligned_data.iov_base = memcpy(&aligned_databytes, data->iov_base,+                                         aligned_data.iov_len = 8);+          data = &aligned_data;+        }+        break;+      }+    }+  }++  mdbx_debug("==> put db %d key [%s], size %" PRIuPTR+             ", data [%s] size %" PRIuPTR,+             DDBI(mc), DKEY(key), key->iov_len,+             DVAL((flags & MDBX_RESERVE) ? nullptr : data), data->iov_len);++  int dupdata_flag = 0;+  if ((flags & MDBX_CURRENT) != 0 && (mc->mc_flags & C_SUB) == 0) {+    if (unlikely(flags & (MDBX_APPEND | MDBX_NOOVERWRITE)))+      return MDBX_EINVAL;+    /* Опция MDBX_CURRENT означает, что запрошено обновление текущей записи,+     * на которой сейчас стоит курсор. Проверяем что переданный ключ совпадает+     * со значением в текущей позиции курсора.+     * Здесь проще вызвать mdbx_cursor_get(), так как для обслуживания таблиц+     * с MDBX_DUPSORT также требуется текущий размер данных. */+    MDBX_val current_key, current_data;+    rc = mdbx_cursor_get(mc, &current_key, &current_data, MDBX_GET_CURRENT);+    if (unlikely(rc != MDBX_SUCCESS))+      return rc;+    if (mc->mc_dbx->md_cmp(key, &current_key) != 0)+      return MDBX_EKEYMISMATCH;++    if (unlikely((flags & MDBX_MULTIPLE)))+      goto drop_current;++    if (F_ISSET(mc->mc_db->md_flags, MDBX_DUPSORT)) {+      MDBX_node *node = page_node(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);+      if (F_ISSET(node_flags(node), F_DUPDATA)) {+        mdbx_cassert(mc,+                     mc->mc_xcursor != NULL &&+                         (mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED));+        /* Если за ключом более одного значения, либо если размер данных+         * отличается, то вместо обновления требуется удаление и+         * последующая вставка. */+        if (mc->mc_xcursor->mx_db.md_entries > 1 ||+            current_data.iov_len != data->iov_len) {+        drop_current:+          rc = mdbx_cursor_del(mc, flags & MDBX_ALLDUPS);+          if (unlikely(rc != MDBX_SUCCESS))+            return rc;+          flags -= MDBX_CURRENT;+          goto skip_check_samedata;+        }+      } else if (unlikely(node_size(key, data) >+                          /* See note inside leaf_size() */+                          env->me_branch_nodemax)) {+        rc = mdbx_cursor_del(mc, 0);+        if (unlikely(rc != MDBX_SUCCESS))+          return rc;+        flags -= MDBX_CURRENT;+        goto skip_check_samedata;+      }+    }+    if (!(flags & MDBX_RESERVE) &&+        unlikely(cmp_lenfast(&current_data, data) == 0))+      return MDBX_SUCCESS /* the same data, nothing to update */;+  skip_check_samedata:;+  }++  if (mc->mc_db->md_root == P_INVALID) {+    /* new database, cursor has nothing to point to */+    mc->mc_snum = 0;+    mc->mc_top = 0;+    mc->mc_flags &= ~C_INITIALIZED;+    rc = MDBX_NO_ROOT;+  } else if ((flags & MDBX_CURRENT) == 0) {+    int exact = false;+    if ((flags & MDBX_APPEND) && mc->mc_db->md_entries > 0) {+      rc = mdbx_cursor_last(mc, &dkey, &olddata);+      if (likely(rc == MDBX_SUCCESS)) {+        rc = mc->mc_dbx->md_cmp(key, &dkey);+        if (likely(rc > 0)) {+          mc->mc_ki[mc->mc_top]++; /* step forward for appending */+          rc = MDBX_NOTFOUND;+        } else {+          if (unlikely(rc != MDBX_SUCCESS || !(flags & MDBX_APPENDDUP)))+            /* new-key < last-key+             * or new-key == last-key without MDBX_APPENDDUP */+            return MDBX_EKEYMISMATCH;+          exact = true;+        }+      }+    } else {+      rc = mdbx_cursor_set(mc, (MDBX_val *)key, &olddata, MDBX_SET, &exact);+    }+    if (likely(rc == MDBX_SUCCESS)) {+      if (exact) {+        if (unlikely(flags & MDBX_NOOVERWRITE)) {+          mdbx_debug("duplicate key [%s]", DKEY(key));+          *data = olddata;+          return MDBX_KEYEXIST;+        }+        if (unlikely(mc->mc_flags & C_SUB)) {+          /* nested subtree of DUPSORT-database with the same key,+           * nothing to update */+          mdbx_assert(env, data->iov_len == 0 && olddata.iov_len == 0);+          return MDBX_SUCCESS;+        }+        if (unlikely(flags & MDBX_ALLDUPS) && mc->mc_xcursor &&+            (mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED)) {+          rc = mdbx_cursor_del(mc, MDBX_ALLDUPS);+          if (unlikely(rc != MDBX_SUCCESS))+            return rc;+          flags -= MDBX_ALLDUPS;+          rc = MDBX_NOTFOUND;+          exact = false;+        } else /* checking for early exit without dirtying pages */+            if (!(flags & (MDBX_RESERVE | MDBX_MULTIPLE)) &&+                unlikely(mc->mc_dbx->md_dcmp(data, &olddata) == 0)) {+          if (!mc->mc_xcursor)+            /* the same data, nothing to update */+            return MDBX_SUCCESS;+          if (flags & MDBX_NODUPDATA)+            return MDBX_KEYEXIST;+          if (flags & MDBX_APPENDDUP)+            return MDBX_EKEYMISMATCH;+          if (likely(unsure_equal(mc->mc_dbx->md_dcmp, data, &olddata)))+            /* data is match exactly byte-to-byte, nothing to update */+            return MDBX_SUCCESS;+          else {+            /* The data has differences, but the user-provided comparator+             * considers them equal. So continue update since called without.+             * Continue to update since was called without MDBX_NODUPDATA. */+          }+        }+      }+    } else if (unlikely(rc != MDBX_NOTFOUND))+      return rc;+  }++  mc->mc_flags &= ~C_DEL;++  /* Cursor is positioned, check for room in the dirty list */+  if (!nospill) {+    if (unlikely(flags & MDBX_MULTIPLE)) {+      rdata = &xdata;+      xdata.iov_len = data->iov_len * dcount;+    } else {+      rdata = data;+    }+    if (unlikely(rc2 = mdbx_cursor_spill(mc, key, rdata)))+      return rc2;+  }++  if (unlikely(rc == MDBX_NO_ROOT)) {+    MDBX_page *np;+    /* new database, write a root leaf page */+    mdbx_debug("%s", "allocating new root leaf page");+    if (unlikely(rc2 = mdbx_page_new(mc, P_LEAF, 1, &np))) {+      return rc2;+    }+    rc2 = mdbx_cursor_push(mc, np);+    if (unlikely(rc2 != MDBX_SUCCESS))+      return rc2;+    mc->mc_db->md_root = np->mp_pgno;+    mc->mc_db->md_depth++;+    if (mc->mc_db->md_flags & MDBX_INTEGERKEY) {+      assert(key->iov_len >= mc->mc_dbx->md_klen_min &&+             key->iov_len <= mc->mc_dbx->md_klen_max);+      mc->mc_dbx->md_klen_min = mc->mc_dbx->md_klen_max = key->iov_len;+    }+    if (mc->mc_db->md_flags & (MDBX_INTEGERDUP | MDBX_DUPFIXED)) {+      assert(data->iov_len >= mc->mc_dbx->md_vlen_min &&+             data->iov_len <= mc->mc_dbx->md_vlen_max);+      assert(mc->mc_xcursor != NULL);+      mc->mc_db->md_xsize = mc->mc_xcursor->mx_db.md_xsize =+          (unsigned)(mc->mc_dbx->md_vlen_min = mc->mc_dbx->md_vlen_max =+                         mc->mc_xcursor->mx_dbx.md_klen_min =+                             mc->mc_xcursor->mx_dbx.md_klen_max =+                                 data->iov_len);+    }+    if ((mc->mc_db->md_flags & (MDBX_DUPSORT | MDBX_DUPFIXED)) == MDBX_DUPFIXED)+      np->mp_flags |= P_LEAF2;+    mc->mc_flags |= C_INITIALIZED;+  } else {+    /* make sure all cursor pages are writable */+    rc2 = mdbx_cursor_touch(mc);+    if (unlikely(rc2))+      return rc2;+  }++  bool insert_key, insert_data, do_sub = false;+  insert_key = insert_data = (rc != MDBX_SUCCESS);+  uint16_t fp_flags = P_LEAF | P_DIRTY;+  MDBX_page *fp = env->me_pbuf;+  fp->mp_txnid = pp_txnid2chk(mc->mc_txn);+  if (insert_key) {+    /* The key does not exist */+    mdbx_debug("inserting key at index %i", mc->mc_ki[mc->mc_top]);+    if ((mc->mc_db->md_flags & MDBX_DUPSORT) &&+        node_size(key, data) >+            /* See note inside leaf_size() */ env->me_branch_nodemax) {+      /* Too big for a node, insert in sub-DB.  Set up an empty+       * "old sub-page" for prep_subDB to expand to a full page. */+      fp->mp_leaf2_ksize =+          (mc->mc_db->md_flags & MDBX_DUPFIXED) ? (uint16_t)data->iov_len : 0;+      fp->mp_lower = fp->mp_upper = 0;+      olddata.iov_len = PAGEHDRSZ;+      goto prep_subDB;+    }+  } else {+    /* there's only a key anyway, so this is a no-op */+    if (IS_LEAF2(mc->mc_pg[mc->mc_top])) {+      char *ptr;+      unsigned ksize = mc->mc_db->md_xsize;+      if (unlikely(key->iov_len != ksize))+        return MDBX_BAD_VALSIZE;+      ptr = page_leaf2key(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], ksize);+      memcpy(ptr, key->iov_base, ksize);+    fix_parent:+      /* if overwriting slot 0 of leaf, need to+       * update branch key if there is a parent page */+      if (mc->mc_top && !mc->mc_ki[mc->mc_top]) {+        unsigned dtop = 1;+        mc->mc_top--;+        /* slot 0 is always an empty key, find real slot */+        while (mc->mc_top && !mc->mc_ki[mc->mc_top]) {+          mc->mc_top--;+          dtop++;+        }+        if (mc->mc_ki[mc->mc_top])+          rc2 = mdbx_update_key(mc, key);+        else+          rc2 = MDBX_SUCCESS;+        mdbx_cassert(mc, mc->mc_top + dtop < UINT16_MAX);+        mc->mc_top += (uint16_t)dtop;+        if (rc2)+          return rc2;+      }++      if (mdbx_audit_enabled()) {+        int err = mdbx_cursor_check(mc, 0);+        if (unlikely(err != MDBX_SUCCESS))+          return err;+      }+      return MDBX_SUCCESS;+    }++  more:;+    if (mdbx_audit_enabled()) {+      int err = mdbx_cursor_check(mc, 0);+      if (unlikely(err != MDBX_SUCCESS))+        return err;+    }+    MDBX_node *node = page_node(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);++    /* overflow page overwrites need special handling */+    if (unlikely(F_ISSET(node_flags(node), F_BIGDATA))) {+      int level, ovpages,+          dpages = (node_size(key, data) >+                    /* See note inside leaf_size() */ env->me_branch_nodemax)+                       ? number_of_ovpages(env, data->iov_len)+                       : 0;++      const pgno_t pg = node_largedata_pgno(node);+      MDBX_page *omp;+      if (unlikely((rc2 = mdbx_page_get(+                        mc, pg, &omp, &level,+                        pp_txnid4chk(mc->mc_pg[mc->mc_top], mc->mc_txn))) != 0))+        return rc2;+      ovpages = omp->mp_pages;++      /* Is the ov page large enough? */+      if (unlikely(mc->mc_flags & C_GCFREEZE)+              ? ovpages >= dpages+              : ovpages ==+                    /* LY: add configurable threshold to keep reserve space */+                    dpages) {+        if (!IS_DIRTY(omp) && (level || (env->me_flags & MDBX_WRITEMAP))) {+          rc2 = mdbx_page_unspill(mc->mc_txn, omp, &omp);+          if (unlikely(rc2))+            return rc2;+          level = 0; /* dirty in this txn or clean */+        }+        /* Is it dirty? */+        if (IS_DIRTY(omp)) {+          mdbx_cassert(mc, omp->mp_txnid > SAFE64_INVALID_THRESHOLD);+          /* yes, overwrite it. Note in this case we don't+           * bother to try shrinking the page if the new data+           * is smaller than the overflow threshold. */+          if (unlikely(level > 1)) {+            /* It is writable only in a parent txn */+            MDBX_page *np = mdbx_page_malloc(mc->mc_txn, ovpages);+            if (unlikely(!np))+              return MDBX_ENOMEM;+            /* Note - this page is already counted in parent's dirtyroom */+            rc2 = mdbx_dpl_append(mc->mc_txn, pg, np);+            if (unlikely(rc2 != MDBX_SUCCESS)) {+              rc = rc2;+              mdbx_dpage_free(env, np, ovpages);+              goto fail;+            }++            /* Currently we make the page look as with put() in the+             * parent txn, in case the user peeks at MDBX_RESERVEd+             * or unused parts. Some users treat ovpages specially. */+            const size_t whole = pgno2bytes(env, ovpages);+            /* Skip the part where MDBX will put *data.+             * Copy end of page, adjusting alignment so+             * compiler may copy words instead of bytes. */+            const size_t off =+                (PAGEHDRSZ + data->iov_len) & -(intptr_t)sizeof(size_t);+            memcpy((size_t *)((char *)np + off), (size_t *)((char *)omp + off),+                   whole - off);+            memcpy(np, omp, PAGEHDRSZ); /* Copy header of page */+            omp = np;+            mdbx_cassert(mc, mdbx_dirtylist_check(mc->mc_txn));+          }+          node_set_ds(node, data->iov_len);+          if (F_ISSET(flags, MDBX_RESERVE))+            data->iov_base = page_data(omp);+          else+            memcpy(page_data(omp), data->iov_base, data->iov_len);++          if (mdbx_audit_enabled()) {+            int err = mdbx_cursor_check(mc, 0);+            if (unlikely(err != MDBX_SUCCESS))+              return err;+          }+          return MDBX_SUCCESS;+        }+      }+      if ((rc2 = mdbx_page_retire(mc, omp)) != MDBX_SUCCESS)+        return rc2;+    } else {+      olddata.iov_len = node_ds(node);+      olddata.iov_base = node_data(node);+      mdbx_cassert(mc, (char *)olddata.iov_base + olddata.iov_len <=+                           (char *)(mc->mc_pg[mc->mc_top]) + env->me_psize);++      /* DB has dups? */+      if (F_ISSET(mc->mc_db->md_flags, MDBX_DUPSORT)) {+        /* Prepare (sub-)page/sub-DB to accept the new item, if needed.+         * fp: old sub-page or a header faking it.+         * mp: new (sub-)page.  offset: growth in page size.+         * xdata: node data with new page or DB. */+        unsigned i;+        size_t offset = 0;+        MDBX_page *mp = fp = xdata.iov_base = env->me_pbuf;+        mp->mp_pgno = mc->mc_pg[mc->mc_top]->mp_pgno;++        /* Was a single item before, must convert now */+        if (!F_ISSET(node_flags(node), F_DUPDATA)) {++          /* does data match? */+          const int cmp = mc->mc_dbx->md_dcmp(data, &olddata);+          if ((flags & MDBX_APPENDDUP) && unlikely(cmp <= 0))+            return MDBX_EKEYMISMATCH;+          if (cmp == 0) {+            if (flags & MDBX_NODUPDATA)+              return MDBX_KEYEXIST;+            if (likely(unsure_equal(mc->mc_dbx->md_dcmp, data, &olddata))) {+              /* data is match exactly byte-to-byte, nothing to update */+              if (unlikely(flags & MDBX_MULTIPLE)) {+                rc = MDBX_SUCCESS;+                goto continue_multiple;+              }+              return MDBX_SUCCESS;+            } else {+              /* The data has differences, but the user-provided comparator+               * considers them equal. So continue update since called without.+               * Continue to update since was called without MDBX_NODUPDATA. */+            }+            mdbx_cassert(+                mc,+                node_size(key, data) <=+                    /* See note inside leaf_size() */ env->me_branch_nodemax);+            goto current;+          }++          /* Just overwrite the current item */+          if (flags & MDBX_CURRENT) {+            mdbx_cassert(+                mc,+                node_size(key, data) <=+                    /* See note inside leaf_size() */ env->me_branch_nodemax);+            goto current;+          }++          /* Back up original data item */+          memcpy(dkey.iov_base = fp + 1, olddata.iov_base,+                 dkey.iov_len = olddata.iov_len);+          dupdata_flag = 1;++          /* Make sub-page header for the dup items, with dummy body */+          fp->mp_flags = P_LEAF | P_DIRTY | P_SUBP;+          fp->mp_lower = 0;+          xdata.iov_len = PAGEHDRSZ + dkey.iov_len + data->iov_len;+          if (mc->mc_db->md_flags & MDBX_DUPFIXED) {+            fp->mp_flags |= P_LEAF2;+            fp->mp_leaf2_ksize = (uint16_t)data->iov_len;+            xdata.iov_len += 2 * data->iov_len; /* leave space for 2 more */+            mdbx_cassert(mc, xdata.iov_len <= env->me_psize);+          } else {+            xdata.iov_len += 2 * (sizeof(indx_t) + NODESIZE) ++                             (dkey.iov_len & 1) + (data->iov_len & 1);+            mdbx_cassert(mc, xdata.iov_len <= env->me_psize);+          }+          fp->mp_upper = (uint16_t)(xdata.iov_len - PAGEHDRSZ);+          olddata.iov_len = xdata.iov_len; /* pretend olddata is fp */+        } else if (node_flags(node) & F_SUBDATA) {+          /* Data is on sub-DB, just store it */+          flags |= F_DUPDATA | F_SUBDATA;+          goto put_sub;+        } else {+          /* Data is on sub-page */+          fp = olddata.iov_base;+          switch (flags) {+          default:+            if (!(mc->mc_db->md_flags & MDBX_DUPFIXED)) {+              offset = node_size(data, nullptr) + sizeof(indx_t);+              break;+            }+            offset = fp->mp_leaf2_ksize;+            if (page_room(fp) < offset) {+              offset *= 4; /* space for 4 more */+              break;+            }+            /* FALLTHRU: Big enough MDBX_DUPFIXED sub-page */+            __fallthrough;+          case MDBX_CURRENT | MDBX_NODUPDATA:+          case MDBX_CURRENT:+            fp->mp_flags |= P_DIRTY;+            fp->mp_txnid = INVALID_TXNID;+            fp->mp_pgno = mp->mp_pgno;+            mc->mc_xcursor->mx_cursor.mc_pg[0] = fp;+            flags |= F_DUPDATA;+            goto put_sub;+          }+          xdata.iov_len = olddata.iov_len + offset;+        }++        fp_flags = fp->mp_flags;+        if (NODESIZE + node_ks(node) + xdata.iov_len >+            /* See note inside leaf_size() */ env->me_branch_nodemax) {+          /* Too big for a sub-page, convert to sub-DB */+          fp_flags &= ~P_SUBP;+        prep_subDB:+          nested_dupdb.md_xsize = 0;+          nested_dupdb.md_flags = flags_db2sub(mc->mc_db->md_flags);+          if (mc->mc_db->md_flags & MDBX_DUPFIXED) {+            fp_flags |= P_LEAF2;+            nested_dupdb.md_xsize = fp->mp_leaf2_ksize;+          }+          nested_dupdb.md_depth = 1;+          nested_dupdb.md_branch_pages = 0;+          nested_dupdb.md_leaf_pages = 1;+          nested_dupdb.md_overflow_pages = 0;+          nested_dupdb.md_entries = page_numkeys(fp);+          xdata.iov_len = sizeof(nested_dupdb);+          xdata.iov_base = &nested_dupdb;+          if ((rc2 = mdbx_page_alloc(mc, 1, &mp, MDBX_ALLOC_ALL)))+            return rc2;+          mc->mc_db->md_leaf_pages += 1;+          mdbx_cassert(mc, env->me_psize > olddata.iov_len);+          offset = env->me_psize - (unsigned)olddata.iov_len;+          flags |= F_DUPDATA | F_SUBDATA;+          nested_dupdb.md_root = mp->mp_pgno;+          nested_dupdb.md_seq = 0;+          nested_dupdb.md_mod_txnid = pp_txnid2chk(mc->mc_txn);+          sub_root = mp;+        }+        if (mp != fp) {+          mp->mp_flags = fp_flags | P_DIRTY;+          mp->mp_txnid = INVALID_TXNID;+          mp->mp_leaf2_ksize = fp->mp_leaf2_ksize;+          mp->mp_lower = fp->mp_lower;+          mdbx_cassert(mc, fp->mp_upper + offset <= UINT16_MAX);+          mp->mp_upper = (indx_t)(fp->mp_upper + offset);+          if (unlikely(fp_flags & P_LEAF2)) {+            memcpy(page_data(mp), page_data(fp),+                   page_numkeys(fp) * fp->mp_leaf2_ksize);+          } else {+            memcpy((char *)mp + mp->mp_upper + PAGEHDRSZ,+                   (char *)fp + fp->mp_upper + PAGEHDRSZ,+                   olddata.iov_len - fp->mp_upper - PAGEHDRSZ);+            memcpy((char *)(&mp->mp_ptrs), (char *)(&fp->mp_ptrs),+                   page_numkeys(fp) * sizeof(mp->mp_ptrs[0]));+            for (i = 0; i < page_numkeys(fp); i++) {+              mdbx_cassert(mc, mp->mp_ptrs[i] + offset <= UINT16_MAX);+              mp->mp_ptrs[i] += (indx_t)offset;+            }+          }+        }++        rdata = &xdata;+        flags |= F_DUPDATA;+        do_sub = true;+        if (!insert_key)+          mdbx_node_del(mc, 0);+        goto new_sub;+      }++      /* MDBX passes F_SUBDATA in 'flags' to write a DB record */+      if (unlikely((node_flags(node) ^ flags) & F_SUBDATA))+        return MDBX_INCOMPATIBLE;++    current:+      if (data->iov_len == olddata.iov_len) {+        mdbx_cassert(mc, EVEN(key->iov_len) == EVEN(node_ks(node)));+        /* same size, just replace it. Note that we could+         * also reuse this node if the new data is smaller,+         * but instead we opt to shrink the node in that case. */+        if (F_ISSET(flags, MDBX_RESERVE))+          data->iov_base = olddata.iov_base;+        else if (!(mc->mc_flags & C_SUB))+          memcpy(olddata.iov_base, data->iov_base, data->iov_len);+        else {+          mdbx_cassert(mc, page_numkeys(mc->mc_pg[mc->mc_top]) == 1);+          mdbx_cassert(mc, PAGETYPE(mc->mc_pg[mc->mc_top]) == P_LEAF);+          mdbx_cassert(mc, node_ds(node) == 0);+          mdbx_cassert(mc, node_flags(node) == 0);+          mdbx_cassert(mc, key->iov_len < UINT16_MAX);+          node_set_ks(node, key->iov_len);+          memcpy(node_key(node), key->iov_base, key->iov_len);+          mdbx_cassert(mc, (char *)node_key(node) + node_ds(node) <+                               (char *)(mc->mc_pg[mc->mc_top]) + env->me_psize);+          goto fix_parent;+        }++        if (mdbx_audit_enabled()) {+          int err = mdbx_cursor_check(mc, 0);+          if (unlikely(err != MDBX_SUCCESS))+            return err;+        }+        return MDBX_SUCCESS;+      }+    }+    mdbx_node_del(mc, 0);+  }++  rdata = data;++new_sub:;+  unsigned nflags = flags & NODE_ADD_FLAGS;+  size_t nsize = IS_LEAF2(mc->mc_pg[mc->mc_top]) ? key->iov_len+                                                 : leaf_size(env, key, rdata);+  if (page_room(mc->mc_pg[mc->mc_top]) < nsize) {+    if ((flags & (F_DUPDATA | F_SUBDATA)) == F_DUPDATA)+      nflags &= ~MDBX_APPEND; /* sub-page may need room to grow */+    if (!insert_key)+      nflags |= MDBX_SPLIT_REPLACE;+    rc = mdbx_page_split(mc, key, rdata, P_INVALID, nflags);+    if (rc == MDBX_SUCCESS && mdbx_audit_enabled())+      rc = mdbx_cursor_check(mc, 0);+  } else {+    /* There is room already in this leaf page. */+    if (IS_LEAF2(mc->mc_pg[mc->mc_top])) {+      mdbx_cassert(mc, (nflags & (F_BIGDATA | F_SUBDATA | F_DUPDATA)) == 0 &&+                           rdata->iov_len == 0);+      rc = mdbx_node_add_leaf2(mc, mc->mc_ki[mc->mc_top], key);+    } else+      rc = mdbx_node_add_leaf(mc, mc->mc_ki[mc->mc_top], key, rdata, nflags);+    if (likely(rc == 0)) {+      /* Adjust other cursors pointing to mp */+      const MDBX_dbi dbi = mc->mc_dbi;+      const unsigned i = mc->mc_top;+      MDBX_page *const mp = mc->mc_pg[i];+      for (MDBX_cursor *m2 = mc->mc_txn->tw.cursors[dbi]; m2;+           m2 = m2->mc_next) {+        MDBX_cursor *m3 =+            (mc->mc_flags & C_SUB) ? &m2->mc_xcursor->mx_cursor : m2;+        if (m3 == mc || m3->mc_snum < mc->mc_snum || m3->mc_pg[i] != mp)+          continue;+        if (m3->mc_ki[i] >= mc->mc_ki[i])+          m3->mc_ki[i] += insert_key;+        if (XCURSOR_INITED(m3))+          XCURSOR_REFRESH(m3, mp, m3->mc_ki[i]);+      }+    }+  }++  if (likely(rc == MDBX_SUCCESS)) {+    /* Now store the actual data in the child DB. Note that we're+     * storing the user data in the keys field, so there are strict+     * size limits on dupdata. The actual data fields of the child+     * DB are all zero size. */+    if (do_sub) {+      int xflags;+      size_t ecount;+    put_sub:+      xdata.iov_len = 0;+      xdata.iov_base = nullptr;+      MDBX_node *node = page_node(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);+#define SHIFT_MDBX_NODUPDATA_TO_MDBX_NOOVERWRITE 1+      STATIC_ASSERT(+          (MDBX_NODUPDATA >> SHIFT_MDBX_NODUPDATA_TO_MDBX_NOOVERWRITE) ==+          MDBX_NOOVERWRITE);+      xflags = MDBX_CURRENT | MDBX_NOSPILL |+               ((flags & MDBX_NODUPDATA) >>+                SHIFT_MDBX_NODUPDATA_TO_MDBX_NOOVERWRITE);+      if ((flags & MDBX_CURRENT) == 0) {+        xflags -= MDBX_CURRENT;+        rc2 = mdbx_xcursor_init1(mc, node, mc->mc_pg[mc->mc_top]);+        if (unlikely(rc2 != MDBX_SUCCESS))+          return rc2;+      }+      if (sub_root)+        mc->mc_xcursor->mx_cursor.mc_pg[0] = sub_root;+      /* converted, write the original data first */+      if (dupdata_flag) {+        rc = mdbx_cursor_put(&mc->mc_xcursor->mx_cursor, &dkey, &xdata, xflags);+        if (unlikely(rc))+          goto bad_sub;+        /* we've done our job */+        dkey.iov_len = 0;+      }+      if (!(node_flags(node) & F_SUBDATA) || sub_root) {+        /* Adjust other cursors pointing to mp */+        MDBX_cursor *m2;+        MDBX_xcursor *mx = mc->mc_xcursor;+        unsigned i = mc->mc_top;+        MDBX_page *mp = mc->mc_pg[i];+        const int nkeys = page_numkeys(mp);++        for (m2 = mc->mc_txn->tw.cursors[mc->mc_dbi]; m2; m2 = m2->mc_next) {+          if (m2 == mc || m2->mc_snum < mc->mc_snum)+            continue;+          if (!(m2->mc_flags & C_INITIALIZED))+            continue;+          if (m2->mc_pg[i] == mp) {+            if (m2->mc_ki[i] == mc->mc_ki[i]) {+              rc2 = mdbx_xcursor_init2(m2, mx, dupdata_flag);+              if (unlikely(rc2 != MDBX_SUCCESS))+                return rc2;+            } else if (!insert_key && m2->mc_ki[i] < nkeys) {+              XCURSOR_REFRESH(m2, mp, m2->mc_ki[i]);+            }+          }+        }+      }+      mdbx_cassert(mc, mc->mc_xcursor->mx_db.md_entries < PTRDIFF_MAX);+      ecount = (size_t)mc->mc_xcursor->mx_db.md_entries;+#define SHIFT_MDBX_APPENDDUP_TO_MDBX_APPEND 1+      STATIC_ASSERT((MDBX_APPENDDUP >> SHIFT_MDBX_APPENDDUP_TO_MDBX_APPEND) ==+                    MDBX_APPEND);+      xflags |= (flags & MDBX_APPENDDUP) >> SHIFT_MDBX_APPENDDUP_TO_MDBX_APPEND;+      rc = mdbx_cursor_put(&mc->mc_xcursor->mx_cursor, data, &xdata, xflags);+      if (flags & F_SUBDATA) {+        void *db = node_data(node);+        mc->mc_xcursor->mx_db.md_mod_txnid = pp_txnid2chk(mc->mc_txn);+        memcpy(db, &mc->mc_xcursor->mx_db, sizeof(MDBX_db));+      }+      insert_data = (ecount != (size_t)mc->mc_xcursor->mx_db.md_entries);+    }+    /* Increment count unless we just replaced an existing item. */+    if (insert_data)+      mc->mc_db->md_entries++;+    if (insert_key) {+      /* Invalidate txn if we created an empty sub-DB */+      if (unlikely(rc))+        goto bad_sub;+      /* If we succeeded and the key didn't exist before,+       * make sure the cursor is marked valid. */+      mc->mc_flags |= C_INITIALIZED;+    }+    if (flags & MDBX_MULTIPLE) {+      if (!rc) {+      continue_multiple:+        mcount++;+        /* let caller know how many succeeded, if any */+        data[1].iov_len = mcount;+        if (mcount < dcount) {+          data[0].iov_base = (char *)data[0].iov_base + data[0].iov_len;+          insert_key = insert_data = false;+          goto more;+        }+      }+    }+    if (rc == MDBX_SUCCESS && mdbx_audit_enabled())+      rc = mdbx_cursor_check(mc, 0);+    return rc;+  bad_sub:+    if (unlikely(rc == MDBX_KEYEXIST))+      mdbx_error("unexpected %s", "MDBX_KEYEXIST");+    /* should not happen, we deleted that item */+    rc = MDBX_PROBLEM;+  }+fail:+  mc->mc_txn->mt_flags |= MDBX_TXN_ERROR;+  return rc;+}++int mdbx_cursor_del(MDBX_cursor *mc, MDBX_put_flags_t flags) {+  if (unlikely(!mc))+    return MDBX_EINVAL;++  if (unlikely(mc->mc_signature != MDBX_MC_LIVE))+    return (mc->mc_signature == MDBX_MC_READY4CLOSE) ? MDBX_EINVAL+                                                     : MDBX_EBADSIGN;++  int rc = check_txn_rw(mc->mc_txn, MDBX_TXN_BLOCKED);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  if (unlikely(TXN_DBI_CHANGED(mc->mc_txn, mc->mc_dbi)))+    return MDBX_BAD_DBI;++  if (unlikely(!(mc->mc_flags & C_INITIALIZED)))+    return MDBX_ENODATA;++  if (unlikely(mc->mc_ki[mc->mc_top] >= page_numkeys(mc->mc_pg[mc->mc_top])))+    return MDBX_NOTFOUND;++  if (likely((flags & MDBX_NOSPILL) == 0) &&+      unlikely(rc = mdbx_cursor_spill(mc, NULL, NULL)))+    return rc;++  rc = mdbx_cursor_touch(mc);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  MDBX_page *mp = mc->mc_pg[mc->mc_top];+  if (!MDBX_DISABLE_PAGECHECKS && unlikely(!IS_LEAF(mp)))+    return MDBX_CORRUPTED;+  if (IS_LEAF2(mp))+    goto del_key;++  MDBX_node *node = page_node(mp, mc->mc_ki[mc->mc_top]);+  if (F_ISSET(node_flags(node), F_DUPDATA)) {+    if (flags & (MDBX_ALLDUPS | /* for compatibility */ MDBX_NODUPDATA)) {+      /* mdbx_cursor_del0() will subtract the final entry */+      mc->mc_db->md_entries -= mc->mc_xcursor->mx_db.md_entries - 1;+      mc->mc_xcursor->mx_cursor.mc_flags &= ~C_INITIALIZED;+    } else {+      if (!F_ISSET(node_flags(node), F_SUBDATA))+        mc->mc_xcursor->mx_cursor.mc_pg[0] = node_data(node);+      rc = mdbx_cursor_del(&mc->mc_xcursor->mx_cursor, MDBX_NOSPILL);+      if (unlikely(rc))+        return rc;+      /* If sub-DB still has entries, we're done */+      if (mc->mc_xcursor->mx_db.md_entries) {+        if (node_flags(node) & F_SUBDATA) {+          /* update subDB info */+          void *db = node_data(node);+          mc->mc_xcursor->mx_db.md_mod_txnid = pp_txnid2chk(mc->mc_txn);+          memcpy(db, &mc->mc_xcursor->mx_db, sizeof(MDBX_db));+        } else {+          MDBX_cursor *m2;+          /* shrink fake page */+          mdbx_node_shrink(mp, mc->mc_ki[mc->mc_top]);+          node = page_node(mp, mc->mc_ki[mc->mc_top]);+          mc->mc_xcursor->mx_cursor.mc_pg[0] = node_data(node);+          /* fix other sub-DB cursors pointed at fake pages on this page */+          for (m2 = mc->mc_txn->tw.cursors[mc->mc_dbi]; m2; m2 = m2->mc_next) {+            if (m2 == mc || m2->mc_snum < mc->mc_snum)+              continue;+            if (!(m2->mc_flags & C_INITIALIZED))+              continue;+            if (m2->mc_pg[mc->mc_top] == mp) {+              MDBX_node *inner = node;+              if (m2->mc_ki[mc->mc_top] >= page_numkeys(mp))+                continue;+              if (m2->mc_ki[mc->mc_top] != mc->mc_ki[mc->mc_top]) {+                inner = page_node(mp, m2->mc_ki[mc->mc_top]);+                if (node_flags(inner) & F_SUBDATA)+                  continue;+              }+              m2->mc_xcursor->mx_cursor.mc_pg[0] = node_data(inner);+            }+          }+        }+        mc->mc_db->md_entries--;+        mdbx_cassert(mc, mc->mc_db->md_entries > 0 && mc->mc_db->md_depth > 0 &&+                             mc->mc_db->md_root != P_INVALID);+        return rc;+      } else {+        mc->mc_xcursor->mx_cursor.mc_flags &= ~C_INITIALIZED;+      }+      /* otherwise fall thru and delete the sub-DB */+    }++    if (node_flags(node) & F_SUBDATA) {+      /* add all the child DB's pages to the free list */+      rc = mdbx_drop0(&mc->mc_xcursor->mx_cursor, false);+      if (unlikely(rc))+        goto fail;+    }+  }+  /* MDBX passes F_SUBDATA in 'flags' to delete a DB record */+  else if (unlikely((node_flags(node) ^ flags) & F_SUBDATA))+    return MDBX_INCOMPATIBLE;++  /* add overflow pages to free list */+  if (F_ISSET(node_flags(node), F_BIGDATA)) {+    MDBX_page *omp;+    if (unlikely((rc = mdbx_page_get(mc, node_largedata_pgno(node), &omp, NULL,+                                     pp_txnid4chk(mp, mc->mc_txn))) ||+                 (rc = mdbx_page_retire(mc, omp))))+      goto fail;+  }++del_key:+  return mdbx_cursor_del0(mc);++fail:+  mc->mc_txn->mt_flags |= MDBX_TXN_ERROR;+  return rc;+}++/* Allocate and initialize new pages for a database.+ * Set MDBX_TXN_ERROR on failure.+ *+ * [in] mc a  cursor on the database being added to.+ * [in] flags flags defining what type of page is being allocated.+ * [in] num   the number of pages to allocate. This is usually 1,+ *            unless allocating overflow pages for a large record.+ * [out] mp   Address of a page, or NULL on failure.+ *+ * Returns 0 on success, non-zero on failure. */+static int mdbx_page_new(MDBX_cursor *mc, unsigned flags, unsigned num,+                         MDBX_page **mp) {+  MDBX_page *np;+  int rc;++  if (unlikely((rc = mdbx_page_alloc(mc, num, &np, MDBX_ALLOC_ALL))))+    return rc;+  *mp = np;+  mdbx_debug("db %u allocated new page %" PRIaPGNO ", num %u", mc->mc_dbi,+             np->mp_pgno, num);+  np->mp_flags = (uint16_t)(flags | P_DIRTY);+  np->mp_txnid = INVALID_TXNID;+  np->mp_lower = 0;+  np->mp_upper = (indx_t)(mc->mc_txn->mt_env->me_psize - PAGEHDRSZ);++  *mc->mc_dbistate |= DBI_DIRTY;+  mc->mc_txn->mt_flags |= MDBX_TXN_DIRTY;+  mc->mc_db->md_branch_pages += IS_BRANCH(np);+  mc->mc_db->md_leaf_pages += IS_LEAF(np);+  if (unlikely(IS_OVERFLOW(np))) {+    mc->mc_db->md_overflow_pages += num;+    np->mp_pages = num;+    mdbx_cassert(mc, !(mc->mc_flags & C_SUB));+  } else if (unlikely(mc->mc_flags & C_SUB)) {+    MDBX_db *outer = mdbx_outer_db(mc);+    outer->md_branch_pages += IS_BRANCH(np);+    outer->md_leaf_pages += IS_LEAF(np);+  }++  return MDBX_SUCCESS;+}++static int __must_check_result mdbx_node_add_leaf2(MDBX_cursor *mc,+                                                   unsigned indx,+                                                   const MDBX_val *key) {+  MDBX_page *mp = mc->mc_pg[mc->mc_top];+  DKBUF;+  mdbx_debug("add to leaf2-%spage %" PRIaPGNO " index %i, "+             " key size %" PRIuPTR " [%s]",+             IS_SUBP(mp) ? "sub-" : "", mp->mp_pgno, indx,+             key ? key->iov_len : 0, DKEY(key));++  mdbx_cassert(mc, key);+  mdbx_cassert(mc, PAGETYPE(mp) == (P_LEAF | P_LEAF2));+  const unsigned ksize = mc->mc_db->md_xsize;+  mdbx_cassert(mc, ksize == key->iov_len);+  const unsigned nkeys = page_numkeys(mp);++  /* Just using these for counting */+  const intptr_t lower = mp->mp_lower + sizeof(indx_t);+  const intptr_t upper = mp->mp_upper - (ksize - sizeof(indx_t));+  if (unlikely(lower > upper)) {+    mc->mc_txn->mt_flags |= MDBX_TXN_ERROR;+    return MDBX_PAGE_FULL;+  }+  mp->mp_lower = (indx_t)lower;+  mp->mp_upper = (indx_t)upper;++  char *const ptr = page_leaf2key(mp, indx, ksize);+  mdbx_cassert(mc, nkeys >= indx);+  const unsigned diff = nkeys - indx;+  if (likely(diff > 0))+    /* Move higher keys up one slot. */+    memmove(ptr + ksize, ptr, diff * ksize);+  /* insert new key */+  memcpy(ptr, key->iov_base, ksize);+  return MDBX_SUCCESS;+}++static int __must_check_result mdbx_node_add_branch(MDBX_cursor *mc,+                                                    unsigned indx,+                                                    const MDBX_val *key,+                                                    pgno_t pgno) {+  MDBX_page *mp = mc->mc_pg[mc->mc_top];+  DKBUF;+  mdbx_debug("add to branch-%spage %" PRIaPGNO " index %i, node-pgno %" PRIaPGNO+             " key size %" PRIuPTR " [%s]",+             IS_SUBP(mp) ? "sub-" : "", mp->mp_pgno, indx, pgno,+             key ? key->iov_len : 0, DKEY(key));++  mdbx_cassert(mc, PAGETYPE(mp) == P_BRANCH);+  STATIC_ASSERT(NODESIZE % 2 == 0);++  /* Move higher pointers up one slot. */+  const unsigned nkeys = page_numkeys(mp);+  mdbx_cassert(mc, nkeys >= indx);+  for (unsigned i = nkeys; i > indx; --i)+    mp->mp_ptrs[i] = mp->mp_ptrs[i - 1];++  /* Adjust free space offsets. */+  const size_t branch_bytes = branch_size(mc->mc_txn->mt_env, key);+  const intptr_t lower = mp->mp_lower + sizeof(indx_t);+  const intptr_t upper = mp->mp_upper - (branch_bytes - sizeof(indx_t));+  if (unlikely(lower > upper)) {+    mc->mc_txn->mt_flags |= MDBX_TXN_ERROR;+    return MDBX_PAGE_FULL;+  }+  mp->mp_lower = (indx_t)lower;+  mp->mp_ptrs[indx] = mp->mp_upper = (indx_t)upper;++  /* Write the node data. */+  MDBX_node *node = page_node(mp, indx);+  node_set_pgno(node, pgno);+  node_set_flags(node, 0);+  UNALIGNED_POKE_8(node, MDBX_node, mn_extra, 0);+  node_set_ks(node, 0);+  if (likely(key != NULL)) {+    node_set_ks(node, key->iov_len);+    memcpy(node_key(node), key->iov_base, key->iov_len);+  }+  return MDBX_SUCCESS;+}++static int __must_check_result mdbx_node_add_leaf(MDBX_cursor *mc,+                                                  unsigned indx,+                                                  const MDBX_val *key,+                                                  MDBX_val *data,+                                                  unsigned flags) {+  MDBX_page *mp = mc->mc_pg[mc->mc_top];+  DKBUF;+  mdbx_debug("add to leaf-%spage %" PRIaPGNO " index %i, data size %" PRIuPTR+             " key size %" PRIuPTR " [%s]",+             IS_SUBP(mp) ? "sub-" : "", mp->mp_pgno, indx,+             data ? data->iov_len : 0, key ? key->iov_len : 0, DKEY(key));+  mdbx_cassert(mc, key != NULL && data != NULL);+  mdbx_cassert(mc, PAGETYPE(mp) == P_LEAF);+  MDBX_page *largepage = NULL;++  size_t leaf_bytes;+  if (unlikely(flags & F_BIGDATA)) {+    /* Data already on overflow page. */+    STATIC_ASSERT(sizeof(pgno_t) % 2 == 0);+    leaf_bytes = node_size(key, nullptr) + sizeof(pgno_t) + sizeof(indx_t);+  } else if (unlikely(node_size(key, data) >+                      /* See note inside leaf_size() */+                      mc->mc_txn->mt_env->me_branch_nodemax)) {+    /* Put data on overflow page. */+    mdbx_ensure(mc->mc_txn->mt_env,+                !F_ISSET(mc->mc_db->md_flags, MDBX_DUPSORT));+    if (unlikely(flags & (F_DUPDATA | F_SUBDATA)))+      return MDBX_PROBLEM;+    const pgno_t ovpages = number_of_ovpages(mc->mc_txn->mt_env, data->iov_len);+    int rc = mdbx_page_new(mc, P_OVERFLOW, ovpages, &largepage);+    if (unlikely(rc != MDBX_SUCCESS))+      return rc;+    mdbx_debug("allocated %u overflow page(s) %" PRIaPGNO "for %" PRIuPTR+               " data bytes",+               largepage->mp_pages, largepage->mp_pgno, data->iov_len);+    flags |= F_BIGDATA;+    leaf_bytes = node_size(key, nullptr) + sizeof(pgno_t) + sizeof(indx_t);+  } else {+    leaf_bytes = node_size(key, data) + sizeof(indx_t);+  }+  mdbx_cassert(mc, leaf_bytes == leaf_size(mc->mc_txn->mt_env, key, data));++  /* Move higher pointers up one slot. */+  const unsigned nkeys = page_numkeys(mp);+  mdbx_cassert(mc, nkeys >= indx);+  for (unsigned i = nkeys; i > indx; --i)+    mp->mp_ptrs[i] = mp->mp_ptrs[i - 1];++  /* Adjust free space offsets. */+  const intptr_t lower = mp->mp_lower + sizeof(indx_t);+  const intptr_t upper = mp->mp_upper - (leaf_bytes - sizeof(indx_t));+  if (unlikely(lower > upper)) {+    mc->mc_txn->mt_flags |= MDBX_TXN_ERROR;+    return MDBX_PAGE_FULL;+  }+  mp->mp_lower = (indx_t)lower;+  mp->mp_ptrs[indx] = mp->mp_upper = (indx_t)upper;++  /* Write the node data. */+  MDBX_node *node = page_node(mp, indx);+  node_set_ks(node, key->iov_len);+  node_set_flags(node, (uint8_t)flags);+  UNALIGNED_POKE_8(node, MDBX_node, mn_extra, 0);+  node_set_ds(node, data->iov_len);+  memcpy(node_key(node), key->iov_base, key->iov_len);++  void *nodedata = node_data(node);+  if (likely(largepage == NULL)) {+    if (unlikely(flags & F_BIGDATA))+      memcpy(nodedata, data->iov_base, sizeof(pgno_t));+    else if (unlikely(flags & MDBX_RESERVE))+      data->iov_base = nodedata;+    else if (likely(nodedata != data->iov_base &&+                    data->iov_len /* to avoid UBSAN traps*/ != 0))+      memcpy(nodedata, data->iov_base, data->iov_len);+  } else {+    poke_pgno(nodedata, largepage->mp_pgno);+    nodedata = page_data(largepage);+    if (unlikely(flags & MDBX_RESERVE))+      data->iov_base = nodedata;+    else if (likely(nodedata != data->iov_base &&+                    data->iov_len /* to avoid UBSAN traps*/ != 0))+      memcpy(nodedata, data->iov_base, data->iov_len);+  }+  return MDBX_SUCCESS;+}++/* Delete the specified node from a page.+ * [in] mc Cursor pointing to the node to delete.+ * [in] ksize The size of a node. Only used if the page is+ * part of a MDBX_DUPFIXED database. */+static void mdbx_node_del(MDBX_cursor *mc, size_t ksize) {+  MDBX_page *mp = mc->mc_pg[mc->mc_top];+  int indx = mc->mc_ki[mc->mc_top];+  int i, j, nkeys, ptr;+  MDBX_node *node;+  char *base;++  mdbx_debug("delete node %u on %s page %" PRIaPGNO, indx,+             IS_LEAF(mp) ? "leaf" : "branch", mp->mp_pgno);+  nkeys = page_numkeys(mp);+  mdbx_cassert(mc, indx < nkeys);++  if (IS_LEAF2(mp)) {+    mdbx_cassert(mc, ksize >= sizeof(indx_t));+    unsigned diff = nkeys - 1 - indx;+    base = page_leaf2key(mp, indx, ksize);+    if (diff)+      memmove(base, base + ksize, diff * ksize);+    mdbx_cassert(mc, mp->mp_lower >= sizeof(indx_t));+    mp->mp_lower -= sizeof(indx_t);+    mdbx_cassert(mc,+                 (size_t)UINT16_MAX - mp->mp_upper >= ksize - sizeof(indx_t));+    mp->mp_upper += (indx_t)(ksize - sizeof(indx_t));+    return;+  }++  node = page_node(mp, indx);+  size_t sz = NODESIZE + node_ks(node);+  if (IS_LEAF(mp)) {+    if (F_ISSET(node_flags(node), F_BIGDATA))+      sz += sizeof(pgno_t);+    else+      sz += node_ds(node);+  }+  sz = EVEN(sz);++  ptr = mp->mp_ptrs[indx];+  for (i = j = 0; i < nkeys; i++) {+    if (i != indx) {+      mp->mp_ptrs[j] = mp->mp_ptrs[i];+      if (mp->mp_ptrs[i] < ptr) {+        mdbx_cassert(mc, (size_t)UINT16_MAX - mp->mp_ptrs[j] >= sz);+        mp->mp_ptrs[j] += (indx_t)sz;+      }+      j++;+    }+  }++  base = (char *)mp + mp->mp_upper + PAGEHDRSZ;+  memmove(base + sz, base, ptr - mp->mp_upper);++  mdbx_cassert(mc, mp->mp_lower >= sizeof(indx_t));+  mp->mp_lower -= sizeof(indx_t);+  mdbx_cassert(mc, (size_t)UINT16_MAX - mp->mp_upper >= sz);+  mp->mp_upper += (indx_t)sz;++#if MDBX_DEBUG > 0+  if (mdbx_audit_enabled()) {+    int page_check_err = mdbx_page_check(mc, mp, C_UPDATING);+    mdbx_cassert(mc, page_check_err == MDBX_SUCCESS);+  }+#endif+}++/* Compact the main page after deleting a node on a subpage.+ * [in] mp The main page to operate on.+ * [in] indx The index of the subpage on the main page. */+static void mdbx_node_shrink(MDBX_page *mp, unsigned indx) {+  MDBX_node *node;+  MDBX_page *sp, *xp;+  char *base;+  size_t nsize, delta, len, ptr;+  int i;++  node = page_node(mp, indx);+  sp = (MDBX_page *)node_data(node);+  delta = page_room(sp);+  assert(delta > 0);++  /* Prepare to shift upward, set len = length(subpage part to shift) */+  if (IS_LEAF2(sp)) {+    delta &= /* do not make the node uneven-sized */ ~(size_t)1;+    if (unlikely(delta) == 0)+      return;+    nsize = node_ds(node) - delta;+    assert(nsize % 1 == 0);+    len = nsize;+  } else {+    xp = (MDBX_page *)((char *)sp + delta); /* destination subpage */+    for (i = page_numkeys(sp); --i >= 0;) {+      assert(sp->mp_ptrs[i] >= delta);+      xp->mp_ptrs[i] = (indx_t)(sp->mp_ptrs[i] - delta);+    }+    nsize = node_ds(node) - delta;+    len = PAGEHDRSZ;+  }+  sp->mp_upper = sp->mp_lower;+  sp->mp_pgno = mp->mp_pgno;+  node_set_ds(node, nsize);++  /* Shift <lower nodes...initial part of subpage> upward */+  base = (char *)mp + mp->mp_upper + PAGEHDRSZ;+  memmove(base + delta, base, (char *)sp + len - base);++  ptr = mp->mp_ptrs[indx];+  for (i = page_numkeys(mp); --i >= 0;) {+    if (mp->mp_ptrs[i] <= ptr) {+      assert((size_t)UINT16_MAX - mp->mp_ptrs[i] >= delta);+      mp->mp_ptrs[i] += (indx_t)delta;+    }+  }+  assert((size_t)UINT16_MAX - mp->mp_upper >= delta);+  mp->mp_upper += (indx_t)delta;+}++/* Initial setup of a sorted-dups cursor.+ *+ * Sorted duplicates are implemented as a sub-database for the given key.+ * The duplicate data items are actually keys of the sub-database.+ * Operations on the duplicate data items are performed using a sub-cursor+ * initialized when the sub-database is first accessed. This function does+ * the preliminary setup of the sub-cursor, filling in the fields that+ * depend only on the parent DB.+ *+ * [in] mc The main cursor whose sorted-dups cursor is to be initialized. */+static int mdbx_xcursor_init0(MDBX_cursor *mc) {+  MDBX_xcursor *mx = mc->mc_xcursor;+  if (!MDBX_DISABLE_PAGECHECKS && unlikely(mx == nullptr)) {+    mdbx_error("unexpected dupsort-page for non-dupsort db/cursor (dbi %u)",+               mc->mc_dbi);+    return MDBX_CORRUPTED;+  }++  mx->mx_cursor.mc_xcursor = NULL;+  mx->mx_cursor.mc_txn = mc->mc_txn;+  mx->mx_cursor.mc_db = &mx->mx_db;+  mx->mx_cursor.mc_dbx = &mx->mx_dbx;+  mx->mx_cursor.mc_dbi = mc->mc_dbi;+  mx->mx_cursor.mc_dbistate = &mx->mx_dbistate;+  mx->mx_cursor.mc_snum = 0;+  mx->mx_cursor.mc_top = 0;+  mx->mx_cursor.mc_flags = C_SUB | (mc->mc_flags & (C_COPYING | C_SKIPORD));+  mx->mx_dbx.md_name.iov_len = 0;+  mx->mx_dbx.md_name.iov_base = NULL;+  mx->mx_dbx.md_cmp = mc->mc_dbx->md_dcmp;+  mx->mx_dbx.md_dcmp = NULL;+  mx->mx_dbx.md_klen_min = INT_MAX;+  mx->mx_dbx.md_vlen_min = mx->mx_dbx.md_klen_max = mx->mx_dbx.md_vlen_max = 0;+  return MDBX_SUCCESS;+}++/* Final setup of a sorted-dups cursor.+ * Sets up the fields that depend on the data from the main cursor.+ * [in] mc The main cursor whose sorted-dups cursor is to be initialized.+ * [in] node The data containing the MDBX_db record for the sorted-dup database.+ */+static int mdbx_xcursor_init1(MDBX_cursor *mc, MDBX_node *node,+                              const MDBX_page *mp) {+  MDBX_xcursor *mx = mc->mc_xcursor;+  if (!MDBX_DISABLE_PAGECHECKS && unlikely(mx == nullptr)) {+    mdbx_error("unexpected dupsort-page for non-dupsort db/cursor (dbi %u)",+               mc->mc_dbi);+    return MDBX_CORRUPTED;+  }++  const uint8_t flags = node_flags(node);+  switch (flags) {+  default:+    mdbx_error("invalid node flags %u", flags);+    return MDBX_CORRUPTED;+  case F_DUPDATA | F_SUBDATA:+    if (!MDBX_DISABLE_PAGECHECKS &&+        unlikely(node_ds(node) != sizeof(MDBX_db))) {+      mdbx_error("invalid nested-db record size %zu", node_ds(node));+      return MDBX_CORRUPTED;+    }+    memcpy(&mx->mx_db, node_data(node), sizeof(MDBX_db));+    const txnid_t pp_txnid = IS_DIRTY(mp) ? mc->mc_txn->mt_txnid : mp->mp_txnid;+    if (!MDBX_DISABLE_PAGECHECKS &&+        unlikely(mx->mx_db.md_mod_txnid > pp_txnid)) {+      mdbx_error("nested-db.md_mod_txnid (%" PRIaTXN ") > page-txnid (%" PRIaTXN+                 ")",+                 mx->mx_db.md_mod_txnid, pp_txnid);+      return MDBX_CORRUPTED;+    }+    mx->mx_cursor.mc_pg[0] = 0;+    mx->mx_cursor.mc_snum = 0;+    mx->mx_cursor.mc_top = 0;+    mx->mx_cursor.mc_flags = C_SUB | (mc->mc_flags & (C_COPYING | C_SKIPORD));+    break;+  case F_DUPDATA:+    if (!MDBX_DISABLE_PAGECHECKS && unlikely(node_ds(node) <= PAGEHDRSZ)) {+      mdbx_error("invalid nested-page size %zu", node_ds(node));+      return MDBX_CORRUPTED;+    }+    MDBX_page *fp = node_data(node);+    mx->mx_db.md_depth = 1;+    mx->mx_db.md_branch_pages = 0;+    mx->mx_db.md_leaf_pages = 1;+    mx->mx_db.md_overflow_pages = 0;+    mx->mx_db.md_entries = page_numkeys(fp);+    mx->mx_db.md_root = fp->mp_pgno;+    mx->mx_db.md_mod_txnid = mp->mp_txnid;+    mx->mx_cursor.mc_snum = 1;+    mx->mx_cursor.mc_top = 0;+    mx->mx_cursor.mc_flags =+        C_INITIALIZED | C_SUB | (mc->mc_flags & (C_COPYING | C_SKIPORD));+    mx->mx_cursor.mc_pg[0] = fp;+    mx->mx_cursor.mc_ki[0] = 0;+    mx->mx_db.md_flags = flags_db2sub(mc->mc_db->md_flags);+    mx->mx_db.md_xsize =+        (mc->mc_db->md_flags & MDBX_DUPFIXED) ? fp->mp_leaf2_ksize : 0;+    break;+  }++  if (unlikely(mx->mx_db.md_xsize != mc->mc_db->md_xsize)) {+    if (!MDBX_DISABLE_PAGECHECKS && unlikely(mc->mc_db->md_xsize != 0)) {+      mdbx_error("cursor mismatched nested-db md_xsize %u",+                 mc->mc_db->md_xsize);+      return MDBX_CORRUPTED;+    }+    if (!MDBX_DISABLE_PAGECHECKS &&+        unlikely((mc->mc_db->md_flags & MDBX_DUPFIXED) == 0)) {+      mdbx_error("mismatched nested-db md_flags %u", mc->mc_db->md_flags);+      return MDBX_CORRUPTED;+    }+    if (!MDBX_DISABLE_PAGECHECKS &&+        unlikely(mx->mx_db.md_xsize < mc->mc_dbx->md_vlen_min ||+                 mx->mx_db.md_xsize > mc->mc_dbx->md_vlen_max)) {+      mdbx_error("mismatched nested-db.md_xsize (%u) <> min/max value-length "+                 "(%zu/%zu)",+                 mx->mx_db.md_xsize, mc->mc_dbx->md_vlen_min,+                 mc->mc_dbx->md_vlen_max);+      return MDBX_CORRUPTED;+    }+    mc->mc_db->md_xsize = mx->mx_db.md_xsize;+    mc->mc_dbx->md_vlen_min = mc->mc_dbx->md_vlen_max = mx->mx_db.md_xsize;+  }+  mx->mx_dbx.md_klen_min = mc->mc_dbx->md_vlen_min;+  mx->mx_dbx.md_klen_max = mc->mc_dbx->md_vlen_max;++  mdbx_debug("Sub-db -%u root page %" PRIaPGNO, mx->mx_cursor.mc_dbi,+             mx->mx_db.md_root);+  mx->mx_dbistate = DBI_VALID | DBI_USRVALID | DBI_DUPDATA;+  return MDBX_SUCCESS;+}++/* Fixup a sorted-dups cursor due to underlying update.+ * Sets up some fields that depend on the data from the main cursor.+ * Almost the same as init1, but skips initialization steps if the+ * xcursor had already been used.+ * [in] mc The main cursor whose sorted-dups cursor is to be fixed up.+ * [in] src_mx The xcursor of an up-to-date cursor.+ * [in] new_dupdata True if converting from a non-F_DUPDATA item. */+static int mdbx_xcursor_init2(MDBX_cursor *mc, MDBX_xcursor *src_mx,+                              bool new_dupdata) {+  MDBX_xcursor *mx = mc->mc_xcursor;+  if (!MDBX_DISABLE_PAGECHECKS && unlikely(mx == nullptr)) {+    mdbx_error("unexpected dupsort-page for non-dupsort db/cursor (dbi %u)",+               mc->mc_dbi);+    return MDBX_CORRUPTED;+  }++  if (new_dupdata) {+    mx->mx_cursor.mc_snum = 1;+    mx->mx_cursor.mc_top = 0;+    mx->mx_cursor.mc_flags |= C_INITIALIZED;+    mx->mx_cursor.mc_ki[0] = 0;+    mx->mx_dbistate = DBI_VALID | DBI_USRVALID | DBI_DUPDATA;+  }++  mx->mx_dbx.md_klen_min = src_mx->mx_dbx.md_klen_min;+  mx->mx_dbx.md_klen_max = src_mx->mx_dbx.md_klen_max;+  mx->mx_dbx.md_cmp = src_mx->mx_dbx.md_cmp;+  mx->mx_db = src_mx->mx_db;+  mx->mx_cursor.mc_pg[0] = src_mx->mx_cursor.mc_pg[0];+  if (mx->mx_cursor.mc_flags & C_INITIALIZED) {+    mdbx_debug("Sub-db -%u root page %" PRIaPGNO, mx->mx_cursor.mc_dbi,+               mx->mx_db.md_root);+  }+  return MDBX_SUCCESS;+}++static __inline int mdbx_couple_init(MDBX_cursor_couple *couple,+                                     const MDBX_dbi dbi, MDBX_txn *const txn,+                                     MDBX_db *const db, MDBX_dbx *const dbx,+                                     uint8_t *const dbstate) {+  couple->outer.mc_signature = MDBX_MC_LIVE;+  couple->outer.mc_next = NULL;+  couple->outer.mc_backup = NULL;+  couple->outer.mc_dbi = dbi;+  couple->outer.mc_txn = txn;+  couple->outer.mc_db = db;+  couple->outer.mc_dbx = dbx;+  couple->outer.mc_dbistate = dbstate;+  couple->outer.mc_snum = 0;+  couple->outer.mc_top = 0;+  couple->outer.mc_pg[0] = 0;+  couple->outer.mc_flags = 0;+  couple->outer.mc_ki[0] = 0;+  couple->outer.mc_xcursor = NULL;++  int rc = MDBX_SUCCESS;+  if (unlikely(*couple->outer.mc_dbistate & DBI_STALE)) {+    rc = mdbx_page_search(&couple->outer, NULL, MDBX_PS_ROOTONLY);+    rc = (rc != MDBX_NOTFOUND) ? rc : MDBX_SUCCESS;+  } else if (unlikely(couple->outer.mc_dbx->md_klen_max == 0)) {+    rc = mdbx_setup_dbx(couple->outer.mc_dbx, couple->outer.mc_db,+                        txn->mt_env->me_psize);+  }++  if (couple->outer.mc_db->md_flags & MDBX_DUPSORT) {+    couple->inner.mx_cursor.mc_signature = MDBX_MC_LIVE;+    couple->outer.mc_xcursor = &couple->inner;+    rc = mdbx_xcursor_init0(&couple->outer);+    if (unlikely(rc != MDBX_SUCCESS))+      return rc;+    couple->inner.mx_dbx.md_klen_min = couple->outer.mc_dbx->md_vlen_min;+    couple->inner.mx_dbx.md_klen_max = couple->outer.mc_dbx->md_vlen_max;+  }+  return rc;+}++/* Initialize a cursor for a given transaction and database. */+static int mdbx_cursor_init(MDBX_cursor *mc, MDBX_txn *txn, MDBX_dbi dbi) {+  STATIC_ASSERT(offsetof(MDBX_cursor_couple, outer) == 0);+  if (unlikely(TXN_DBI_CHANGED(txn, dbi)))+    return MDBX_BAD_DBI;++  return mdbx_couple_init(container_of(mc, MDBX_cursor_couple, outer), dbi, txn,+                          &txn->mt_dbs[dbi], &txn->mt_dbxs[dbi],+                          &txn->mt_dbistate[dbi]);+}++MDBX_cursor *mdbx_cursor_create(void *context) {+  MDBX_cursor_couple *couple = mdbx_calloc(1, sizeof(MDBX_cursor_couple));+  if (unlikely(!couple))+    return nullptr;++  couple->outer.mc_signature = MDBX_MC_READY4CLOSE;+  couple->outer.mc_dbi = UINT_MAX;+  couple->mc_userctx = context;+  return &couple->outer;+}++int mdbx_cursor_set_userctx(MDBX_cursor *mc, void *ctx) {+  if (unlikely(!mc))+    return MDBX_EINVAL;++  if (unlikely(mc->mc_signature != MDBX_MC_READY4CLOSE &&+               mc->mc_signature != MDBX_MC_LIVE))+    return MDBX_EBADSIGN;++  MDBX_cursor_couple *couple = container_of(mc, MDBX_cursor_couple, outer);+  couple->mc_userctx = ctx;+  return MDBX_SUCCESS;+}++void *mdbx_cursor_get_userctx(const MDBX_cursor *mc) {+  if (unlikely(!mc))+    return nullptr;++  if (unlikely(mc->mc_signature != MDBX_MC_READY4CLOSE &&+               mc->mc_signature != MDBX_MC_LIVE))+    return nullptr;++  MDBX_cursor_couple *couple = container_of(mc, MDBX_cursor_couple, outer);+  return couple->mc_userctx;+}++int mdbx_cursor_bind(MDBX_txn *txn, MDBX_cursor *mc, MDBX_dbi dbi) {+  if (unlikely(!mc))+    return MDBX_EINVAL;++  if (unlikely(mc->mc_signature != MDBX_MC_READY4CLOSE &&+               mc->mc_signature != MDBX_MC_LIVE))+    return MDBX_EBADSIGN;++  int rc = check_txn(txn, MDBX_TXN_BLOCKED);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  if (unlikely(!mdbx_txn_dbi_exists(txn, dbi, DBI_VALID)))+    return MDBX_BAD_DBI;++  if (unlikely(dbi == FREE_DBI && !F_ISSET(txn->mt_flags, MDBX_TXN_RDONLY)))+    return MDBX_EACCESS;++  if (unlikely(mc->mc_backup)) /* Cursor from parent transaction */ {+    mdbx_cassert(mc, mc->mc_signature == MDBX_MC_LIVE);+    if (unlikely(mc->mc_dbi != dbi ||+                 /* paranoia */ mc->mc_signature != MDBX_MC_LIVE ||+                 mc->mc_txn != txn))+      return MDBX_EINVAL;++    assert(mc->mc_db == &txn->mt_dbs[dbi]);+    assert(mc->mc_dbx == &txn->mt_dbxs[dbi]);+    assert(mc->mc_dbi == dbi);+    assert(mc->mc_dbistate == &txn->mt_dbistate[dbi]);+    return likely(mc->mc_dbi == dbi &&+                  /* paranoia */ mc->mc_signature == MDBX_MC_LIVE &&+                  mc->mc_txn == txn)+               ? MDBX_SUCCESS+               : MDBX_EINVAL /* Disallow change DBI in nested transactions */;+  }++  if (mc->mc_signature == MDBX_MC_LIVE) {+    if (unlikely(!mc->mc_txn || mc->mc_txn->mt_signature != MDBX_MT_SIGNATURE))+      return MDBX_PROBLEM;+    if (mc->mc_flags & C_UNTRACK) {+      mdbx_cassert(mc, !(mc->mc_txn->mt_flags & MDBX_TXN_RDONLY));+      MDBX_cursor **prev = &mc->mc_txn->tw.cursors[mc->mc_dbi];+      while (*prev && *prev != mc)+        prev = &(*prev)->mc_next;+      mdbx_cassert(mc, *prev == mc);+      *prev = mc->mc_next;+    }+    mc->mc_signature = MDBX_MC_READY4CLOSE;+    mc->mc_flags = 0;+    mc->mc_dbi = UINT_MAX;+    mc->mc_next = NULL;+    mc->mc_db = NULL;+    mc->mc_dbx = NULL;+    mc->mc_dbistate = NULL;+  }+  mdbx_cassert(mc, !(mc->mc_flags & C_UNTRACK));++  rc = mdbx_cursor_init(mc, txn, dbi);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  if (!(txn->mt_flags & MDBX_TXN_RDONLY)) {+    mc->mc_next = txn->tw.cursors[dbi];+    txn->tw.cursors[dbi] = mc;+    mc->mc_flags |= C_UNTRACK;+  }++  return MDBX_SUCCESS;+}++int mdbx_cursor_open(MDBX_txn *txn, MDBX_dbi dbi, MDBX_cursor **ret) {+  if (unlikely(!ret))+    return MDBX_EINVAL;+  *ret = NULL;++  MDBX_cursor *const mc = mdbx_cursor_create(nullptr);+  if (unlikely(!mc))+    return MDBX_ENOMEM;++  int rc = mdbx_cursor_bind(txn, mc, dbi);+  if (unlikely(rc != MDBX_SUCCESS)) {+    mdbx_cursor_close(mc);+    return rc;+  }++  *ret = mc;+  return MDBX_SUCCESS;+}++int mdbx_cursor_renew(MDBX_txn *txn, MDBX_cursor *mc) {+  return likely(mc) ? mdbx_cursor_bind(txn, mc, mc->mc_dbi) : MDBX_EINVAL;+}++int mdbx_cursor_copy(const MDBX_cursor *src, MDBX_cursor *dest) {+  if (unlikely(!src))+    return MDBX_EINVAL;+  if (unlikely(src->mc_signature != MDBX_MC_LIVE))+    return (src->mc_signature == MDBX_MC_READY4CLOSE) ? MDBX_EINVAL+                                                      : MDBX_EBADSIGN;++  int rc = mdbx_cursor_bind(src->mc_txn, dest, src->mc_dbi);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  assert(dest->mc_db == src->mc_db);+  assert(dest->mc_dbi == src->mc_dbi);+  assert(dest->mc_dbx == src->mc_dbx);+  assert(dest->mc_dbistate == src->mc_dbistate);+again:+  assert(dest->mc_txn == src->mc_txn);+  dest->mc_flags ^= (dest->mc_flags ^ src->mc_flags) & ~C_UNTRACK;+  dest->mc_top = src->mc_top;+  dest->mc_snum = src->mc_snum;+  for (unsigned i = 0; i < src->mc_snum; ++i) {+    dest->mc_ki[i] = src->mc_ki[i];+    dest->mc_pg[i] = src->mc_pg[i];+  }++  if (src->mc_xcursor) {+    dest->mc_xcursor->mx_db = src->mc_xcursor->mx_db;+    dest->mc_xcursor->mx_dbx = src->mc_xcursor->mx_dbx;+    src = &src->mc_xcursor->mx_cursor;+    dest = &dest->mc_xcursor->mx_cursor;+    goto again;+  }++  return MDBX_SUCCESS;+}++void mdbx_cursor_close(MDBX_cursor *mc) {+  if (likely(mc)) {+    mdbx_ensure(NULL, mc->mc_signature == MDBX_MC_LIVE ||+                          mc->mc_signature == MDBX_MC_READY4CLOSE);+    MDBX_txn *const txn = mc->mc_txn;+    if (!mc->mc_backup) {+      mc->mc_txn = NULL;+      /* Remove from txn, if tracked.+       * A read-only txn (!C_UNTRACK) may have been freed already,+       * so do not peek inside it.  Only write txns track cursors. */+      if (mc->mc_flags & C_UNTRACK) {+        mdbx_ensure(txn->mt_env, check_txn_rw(txn, 0) == MDBX_SUCCESS);+        MDBX_cursor **prev = &txn->tw.cursors[mc->mc_dbi];+        while (*prev && *prev != mc)+          prev = &(*prev)->mc_next;+        mdbx_tassert(txn, *prev == mc);+        *prev = mc->mc_next;+      }+      mc->mc_signature = 0;+      mc->mc_next = mc;+      mdbx_free(mc);+    } else {+      /* Cursor closed before nested txn ends */+      mdbx_tassert(txn, mc->mc_signature == MDBX_MC_LIVE);+      mdbx_ensure(txn->mt_env, check_txn_rw(txn, 0) == MDBX_SUCCESS);+      mc->mc_signature = MDBX_MC_WAIT4EOT;+    }+  }+}++MDBX_txn *mdbx_cursor_txn(const MDBX_cursor *mc) {+  if (unlikely(!mc || mc->mc_signature != MDBX_MC_LIVE))+    return NULL;+  MDBX_txn *txn = mc->mc_txn;+  if (unlikely(!txn || txn->mt_signature != MDBX_MT_SIGNATURE))+    return NULL;+  if (unlikely(txn->mt_flags & MDBX_TXN_FINISHED))+    return NULL;+  return txn;+}++MDBX_dbi mdbx_cursor_dbi(const MDBX_cursor *mc) {+  if (unlikely(!mc || mc->mc_signature != MDBX_MC_LIVE))+    return UINT_MAX;+  return mc->mc_dbi;+}++/* Return the count of duplicate data items for the current key */+int mdbx_cursor_count(const MDBX_cursor *mc, size_t *countp) {+  if (unlikely(mc == NULL))+    return MDBX_EINVAL;++  if (unlikely(mc->mc_signature != MDBX_MC_LIVE))+    return (mc->mc_signature == MDBX_MC_READY4CLOSE) ? MDBX_EINVAL+                                                     : MDBX_EBADSIGN;++  int rc = check_txn(mc->mc_txn, MDBX_TXN_BLOCKED);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  if (unlikely(countp == NULL || !(mc->mc_flags & C_INITIALIZED)))+    return MDBX_EINVAL;++  if (!mc->mc_snum) {+    *countp = 0;+    return MDBX_NOTFOUND;+  }++  MDBX_page *mp = mc->mc_pg[mc->mc_top];+  if ((mc->mc_flags & C_EOF) && mc->mc_ki[mc->mc_top] >= page_numkeys(mp)) {+    *countp = 0;+    return MDBX_NOTFOUND;+  }++  *countp = 1;+  if (mc->mc_xcursor != NULL) {+    MDBX_node *node = page_node(mp, mc->mc_ki[mc->mc_top]);+    if (F_ISSET(node_flags(node), F_DUPDATA)) {+      mdbx_cassert(mc, mc->mc_xcursor && (mc->mc_xcursor->mx_cursor.mc_flags &+                                          C_INITIALIZED));+      *countp = unlikely(mc->mc_xcursor->mx_db.md_entries > PTRDIFF_MAX)+                    ? PTRDIFF_MAX+                    : (size_t)mc->mc_xcursor->mx_db.md_entries;+    }+  }+  return MDBX_SUCCESS;+}++/* Replace the key for a branch node with a new key.+ * Set MDBX_TXN_ERROR on failure.+ * [in] mc Cursor pointing to the node to operate on.+ * [in] key The new key to use.+ * Returns 0 on success, non-zero on failure. */+static int mdbx_update_key(MDBX_cursor *mc, const MDBX_val *key) {+  MDBX_page *mp;+  MDBX_node *node;+  char *base;+  size_t len;+  int delta, ksize, oksize;+  int ptr, i, nkeys, indx;+  DKBUF;++  mdbx_cassert(mc, cursor_is_tracked(mc));+  indx = mc->mc_ki[mc->mc_top];+  mp = mc->mc_pg[mc->mc_top];+  node = page_node(mp, indx);+  ptr = mp->mp_ptrs[indx];+  if (MDBX_DEBUG) {+    MDBX_val k2;+    char kbuf2[DKBUF_MAXKEYSIZE * 2 + 1];+    k2.iov_base = node_key(node);+    k2.iov_len = node_ks(node);+    mdbx_debug("update key %u (offset %u) [%s] to [%s] on page %" PRIaPGNO,+               indx, ptr, mdbx_dump_val(&k2, kbuf2, sizeof(kbuf2)), DKEY(key),+               mp->mp_pgno);+  }++  /* Sizes must be 2-byte aligned. */+  ksize = EVEN(key->iov_len);+  oksize = EVEN(node_ks(node));+  delta = ksize - oksize;++  /* Shift node contents if EVEN(key length) changed. */+  if (delta) {+    if (delta > (int)page_room(mp)) {+      /* not enough space left, do a delete and split */+      mdbx_debug("Not enough room, delta = %d, splitting...", delta);+      pgno_t pgno = node_pgno(node);+      mdbx_node_del(mc, 0);+      int rc = mdbx_page_split(mc, key, NULL, pgno, MDBX_SPLIT_REPLACE);+      if (rc == MDBX_SUCCESS && mdbx_audit_enabled())+        rc = mdbx_cursor_check(mc, C_UPDATING);+      return rc;+    }++    nkeys = page_numkeys(mp);+    for (i = 0; i < nkeys; i++) {+      if (mp->mp_ptrs[i] <= ptr) {+        mdbx_cassert(mc, mp->mp_ptrs[i] >= delta);+        mp->mp_ptrs[i] -= (indx_t)delta;+      }+    }++    base = (char *)mp + mp->mp_upper + PAGEHDRSZ;+    len = ptr - mp->mp_upper + NODESIZE;+    memmove(base - delta, base, len);+    mdbx_cassert(mc, mp->mp_upper >= delta);+    mp->mp_upper -= (indx_t)delta;++    node = page_node(mp, indx);+  }++  /* But even if no shift was needed, update ksize */+  node_set_ks(node, key->iov_len);++  if (likely(key->iov_len /* to avoid UBSAN traps*/ != 0))+    memcpy(node_key(node), key->iov_base, key->iov_len);+  return MDBX_SUCCESS;+}++/* Move a node from csrc to cdst. */+static int mdbx_node_move(MDBX_cursor *csrc, MDBX_cursor *cdst, int fromleft) {+  int rc;+  DKBUF;++  MDBX_page *psrc = csrc->mc_pg[csrc->mc_top];+  MDBX_page *pdst = cdst->mc_pg[cdst->mc_top];+  mdbx_cassert(csrc, PAGETYPE(psrc) == PAGETYPE(pdst));+  mdbx_cassert(csrc, csrc->mc_dbi == cdst->mc_dbi);+  mdbx_cassert(csrc, csrc->mc_top == cdst->mc_top);+  if (unlikely(PAGETYPE(psrc) != PAGETYPE(pdst))) {+  bailout:+    csrc->mc_txn->mt_flags |= MDBX_TXN_ERROR;+    return MDBX_PROBLEM;+  }++  MDBX_val key4move;+  switch (PAGETYPE(psrc)) {+  case P_BRANCH: {+    const MDBX_node *srcnode = page_node(psrc, csrc->mc_ki[csrc->mc_top]);+    mdbx_cassert(csrc, node_flags(srcnode) == 0);+    const pgno_t srcpg = node_pgno(srcnode);+    key4move.iov_len = node_ks(srcnode);+    key4move.iov_base = node_key(srcnode);++    if (csrc->mc_ki[csrc->mc_top] == 0) {+      const unsigned snum = csrc->mc_snum;+      mdbx_cassert(csrc, snum > 0);+      /* must find the lowest key below src */+      rc = mdbx_page_search_lowest(csrc);+      MDBX_page *lowest_page = csrc->mc_pg[csrc->mc_top];+      if (unlikely(rc))+        return rc;+      mdbx_cassert(csrc, IS_LEAF(lowest_page));+      if (unlikely(!IS_LEAF(lowest_page)))+        goto bailout;+      if (IS_LEAF2(lowest_page)) {+        key4move.iov_len = csrc->mc_db->md_xsize;+        key4move.iov_base = page_leaf2key(lowest_page, 0, key4move.iov_len);+      } else {+        const MDBX_node *lowest_node = page_node(lowest_page, 0);+        key4move.iov_len = node_ks(lowest_node);+        key4move.iov_base = node_key(lowest_node);+      }++      /* restore cursor after mdbx_page_search_lowest() */+      csrc->mc_snum = snum;+      csrc->mc_top = snum - 1;+      csrc->mc_ki[csrc->mc_top] = 0;++      /* paranoia */+      mdbx_cassert(csrc, psrc == csrc->mc_pg[csrc->mc_top]);+      mdbx_cassert(csrc, IS_BRANCH(psrc));+      if (unlikely(!IS_BRANCH(psrc)))+        goto bailout;+    }++    if (cdst->mc_ki[cdst->mc_top] == 0) {+      const unsigned snum = cdst->mc_snum;+      mdbx_cassert(csrc, snum > 0);+      MDBX_cursor mn;+      cursor_copy_internal(cdst, &mn);+      mn.mc_xcursor = NULL;+      /* must find the lowest key below dst */+      rc = mdbx_page_search_lowest(&mn);+      if (unlikely(rc))+        return rc;+      MDBX_page *const lowest_page = mn.mc_pg[mn.mc_top];+      mdbx_cassert(cdst, IS_LEAF(lowest_page));+      if (unlikely(!IS_LEAF(lowest_page)))+        goto bailout;+      MDBX_val key;+      if (IS_LEAF2(lowest_page)) {+        key.iov_len = mn.mc_db->md_xsize;+        key.iov_base = page_leaf2key(lowest_page, 0, key.iov_len);+      } else {+        MDBX_node *lowest_node = page_node(lowest_page, 0);+        key.iov_len = node_ks(lowest_node);+        key.iov_base = node_key(lowest_node);+      }++      /* restore cursor after mdbx_page_search_lowest() */+      mn.mc_snum = snum;+      mn.mc_top = snum - 1;+      mn.mc_ki[mn.mc_top] = 0;++      const intptr_t delta =+          EVEN(key.iov_len) - EVEN(node_ks(page_node(mn.mc_pg[mn.mc_top], 0)));+      const intptr_t needed =+          branch_size(cdst->mc_txn->mt_env, &key4move) + delta;+      const intptr_t have = page_room(pdst);+      if (unlikely(needed > have))+        return MDBX_RESULT_TRUE;++      if (unlikely((rc = mdbx_page_touch(csrc)) ||+                   (rc = mdbx_page_touch(cdst))))+        return rc;+      psrc = csrc->mc_pg[csrc->mc_top];+      pdst = cdst->mc_pg[cdst->mc_top];++      WITH_CURSOR_TRACKING(mn, rc = mdbx_update_key(&mn, &key));+      if (unlikely(rc))+        return rc;+    } else {+      const size_t needed = branch_size(cdst->mc_txn->mt_env, &key4move);+      const size_t have = page_room(pdst);+      if (unlikely(needed > have))+        return MDBX_RESULT_TRUE;++      if (unlikely((rc = mdbx_page_touch(csrc)) ||+                   (rc = mdbx_page_touch(cdst))))+        return rc;+      psrc = csrc->mc_pg[csrc->mc_top];+      pdst = cdst->mc_pg[cdst->mc_top];+    }++    mdbx_debug("moving %s-node %u [%s] on page %" PRIaPGNO+               " to node %u on page %" PRIaPGNO,+               "branch", csrc->mc_ki[csrc->mc_top], DKEY(&key4move),+               psrc->mp_pgno, cdst->mc_ki[cdst->mc_top], pdst->mp_pgno);+    /* Add the node to the destination page. */+    rc =+        mdbx_node_add_branch(cdst, cdst->mc_ki[cdst->mc_top], &key4move, srcpg);+  } break;++  case P_LEAF: {+    /* Mark src and dst as dirty. */+    if (unlikely((rc = mdbx_page_touch(csrc)) || (rc = mdbx_page_touch(cdst))))+      return rc;+    psrc = csrc->mc_pg[csrc->mc_top];+    pdst = cdst->mc_pg[cdst->mc_top];+    const MDBX_node *srcnode = page_node(psrc, csrc->mc_ki[csrc->mc_top]);+    MDBX_val data;+    data.iov_len = node_ds(srcnode);+    data.iov_base = node_data(srcnode);+    key4move.iov_len = node_ks(srcnode);+    key4move.iov_base = node_key(srcnode);+    mdbx_debug("moving %s-node %u [%s] on page %" PRIaPGNO+               " to node %u on page %" PRIaPGNO,+               "leaf", csrc->mc_ki[csrc->mc_top], DKEY(&key4move),+               psrc->mp_pgno, cdst->mc_ki[cdst->mc_top], pdst->mp_pgno);+    /* Add the node to the destination page. */+    rc = mdbx_node_add_leaf(cdst, cdst->mc_ki[cdst->mc_top], &key4move, &data,+                            node_flags(srcnode));+  } break;++  case P_LEAF | P_LEAF2: {+    /* Mark src and dst as dirty. */+    if (unlikely((rc = mdbx_page_touch(csrc)) || (rc = mdbx_page_touch(cdst))))+      return rc;+    psrc = csrc->mc_pg[csrc->mc_top];+    pdst = cdst->mc_pg[cdst->mc_top];+    key4move.iov_len = csrc->mc_db->md_xsize;+    key4move.iov_base =+        page_leaf2key(psrc, csrc->mc_ki[csrc->mc_top], key4move.iov_len);+    mdbx_debug("moving %s-node %u [%s] on page %" PRIaPGNO+               " to node %u on page %" PRIaPGNO,+               "leaf2", csrc->mc_ki[csrc->mc_top], DKEY(&key4move),+               psrc->mp_pgno, cdst->mc_ki[cdst->mc_top], pdst->mp_pgno);+    /* Add the node to the destination page. */+    rc = mdbx_node_add_leaf2(cdst, cdst->mc_ki[cdst->mc_top], &key4move);+  } break;++  default:+    goto bailout;+  }++  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  /* Delete the node from the source page. */+  mdbx_node_del(csrc, key4move.iov_len);++  mdbx_cassert(csrc, psrc == csrc->mc_pg[csrc->mc_top]);+  mdbx_cassert(cdst, pdst == cdst->mc_pg[cdst->mc_top]);+  mdbx_cassert(csrc, PAGETYPE(psrc) == PAGETYPE(pdst));++  {+    /* Adjust other cursors pointing to mp */+    MDBX_cursor *m2, *m3;+    const MDBX_dbi dbi = csrc->mc_dbi;+    mdbx_cassert(csrc, csrc->mc_top == cdst->mc_top);+    if (fromleft) {+      /* If we're adding on the left, bump others up */+      for (m2 = csrc->mc_txn->tw.cursors[dbi]; m2; m2 = m2->mc_next) {+        m3 = (csrc->mc_flags & C_SUB) ? &m2->mc_xcursor->mx_cursor : m2;+        if (!(m3->mc_flags & C_INITIALIZED) || m3->mc_top < csrc->mc_top)+          continue;+        if (m3 != cdst && m3->mc_pg[csrc->mc_top] == pdst &&+            m3->mc_ki[csrc->mc_top] >= cdst->mc_ki[csrc->mc_top]) {+          m3->mc_ki[csrc->mc_top]++;+        }+        if (m3 != csrc && m3->mc_pg[csrc->mc_top] == psrc &&+            m3->mc_ki[csrc->mc_top] == csrc->mc_ki[csrc->mc_top]) {+          m3->mc_pg[csrc->mc_top] = pdst;+          m3->mc_ki[csrc->mc_top] = cdst->mc_ki[cdst->mc_top];+          mdbx_cassert(csrc, csrc->mc_top > 0);+          m3->mc_ki[csrc->mc_top - 1]++;+        }+        if (XCURSOR_INITED(m3) && IS_LEAF(psrc))+          XCURSOR_REFRESH(m3, m3->mc_pg[csrc->mc_top], m3->mc_ki[csrc->mc_top]);+      }+    } else {+      /* Adding on the right, bump others down */+      for (m2 = csrc->mc_txn->tw.cursors[dbi]; m2; m2 = m2->mc_next) {+        m3 = (csrc->mc_flags & C_SUB) ? &m2->mc_xcursor->mx_cursor : m2;+        if (m3 == csrc)+          continue;+        if (!(m3->mc_flags & C_INITIALIZED) || m3->mc_top < csrc->mc_top)+          continue;+        if (m3->mc_pg[csrc->mc_top] == psrc) {+          if (!m3->mc_ki[csrc->mc_top]) {+            m3->mc_pg[csrc->mc_top] = pdst;+            m3->mc_ki[csrc->mc_top] = cdst->mc_ki[cdst->mc_top];+            mdbx_cassert(csrc, csrc->mc_top > 0);+            m3->mc_ki[csrc->mc_top - 1]--;+          } else {+            m3->mc_ki[csrc->mc_top]--;+          }+          if (XCURSOR_INITED(m3) && IS_LEAF(psrc))+            XCURSOR_REFRESH(m3, m3->mc_pg[csrc->mc_top],+                            m3->mc_ki[csrc->mc_top]);+        }+      }+    }+  }++  /* Update the parent separators. */+  if (csrc->mc_ki[csrc->mc_top] == 0) {+    mdbx_cassert(csrc, csrc->mc_top > 0);+    if (csrc->mc_ki[csrc->mc_top - 1] != 0) {+      MDBX_val key;+      if (IS_LEAF2(psrc)) {+        key.iov_len = psrc->mp_leaf2_ksize;+        key.iov_base = page_leaf2key(psrc, 0, key.iov_len);+      } else {+        MDBX_node *srcnode = page_node(psrc, 0);+        key.iov_len = node_ks(srcnode);+        key.iov_base = node_key(srcnode);+      }+      mdbx_debug("update separator for source page %" PRIaPGNO " to [%s]",+                 psrc->mp_pgno, DKEY(&key));+      MDBX_cursor mn;+      cursor_copy_internal(csrc, &mn);+      mn.mc_xcursor = NULL;+      mdbx_cassert(csrc, mn.mc_snum > 0);+      mn.mc_snum--;+      mn.mc_top--;+      /* We want mdbx_rebalance to find mn when doing fixups */+      WITH_CURSOR_TRACKING(mn, rc = mdbx_update_key(&mn, &key));+      if (unlikely(rc != MDBX_SUCCESS))+        return rc;+    }+    if (IS_BRANCH(psrc)) {+      const MDBX_val nullkey = {0, 0};+      const indx_t ix = csrc->mc_ki[csrc->mc_top];+      csrc->mc_ki[csrc->mc_top] = 0;+      rc = mdbx_update_key(csrc, &nullkey);+      csrc->mc_ki[csrc->mc_top] = ix;+      mdbx_cassert(csrc, rc == MDBX_SUCCESS);+    }+  }++  if (cdst->mc_ki[cdst->mc_top] == 0) {+    mdbx_cassert(cdst, cdst->mc_top > 0);+    if (cdst->mc_ki[cdst->mc_top - 1] != 0) {+      MDBX_val key;+      if (IS_LEAF2(pdst)) {+        key.iov_len = pdst->mp_leaf2_ksize;+        key.iov_base = page_leaf2key(pdst, 0, key.iov_len);+      } else {+        MDBX_node *srcnode = page_node(pdst, 0);+        key.iov_len = node_ks(srcnode);+        key.iov_base = node_key(srcnode);+      }+      mdbx_debug("update separator for destination page %" PRIaPGNO " to [%s]",+                 pdst->mp_pgno, DKEY(&key));+      MDBX_cursor mn;+      cursor_copy_internal(cdst, &mn);+      mn.mc_xcursor = NULL;+      mdbx_cassert(cdst, mn.mc_snum > 0);+      mn.mc_snum--;+      mn.mc_top--;+      /* We want mdbx_rebalance to find mn when doing fixups */+      WITH_CURSOR_TRACKING(mn, rc = mdbx_update_key(&mn, &key));+      if (unlikely(rc != MDBX_SUCCESS))+        return rc;+    }+    if (IS_BRANCH(pdst)) {+      const MDBX_val nullkey = {0, 0};+      const indx_t ix = cdst->mc_ki[cdst->mc_top];+      cdst->mc_ki[cdst->mc_top] = 0;+      rc = mdbx_update_key(cdst, &nullkey);+      cdst->mc_ki[cdst->mc_top] = ix;+      mdbx_cassert(cdst, rc == MDBX_SUCCESS);+    }+  }++  return MDBX_SUCCESS;+}++/* Merge one page into another.+ *+ * The nodes from the page pointed to by csrc will be copied to the page+ * pointed to by cdst and then the csrc page will be freed.+ *+ * [in] csrc Cursor pointing to the source page.+ * [in] cdst Cursor pointing to the destination page.+ *+ * Returns 0 on success, non-zero on failure. */+static int mdbx_page_merge(MDBX_cursor *csrc, MDBX_cursor *cdst) {+  MDBX_val key;+  int rc;++  mdbx_cassert(csrc, csrc != cdst);+  mdbx_cassert(csrc, cursor_is_tracked(csrc));+  mdbx_cassert(cdst, cursor_is_tracked(cdst));+  const MDBX_page *const psrc = csrc->mc_pg[csrc->mc_top];+  MDBX_page *pdst = cdst->mc_pg[cdst->mc_top];+  mdbx_debug("merging page %" PRIaPGNO " into %" PRIaPGNO, psrc->mp_pgno,+             pdst->mp_pgno);++  mdbx_cassert(csrc, PAGETYPE(psrc) == PAGETYPE(pdst));+  mdbx_cassert(csrc,+               csrc->mc_dbi == cdst->mc_dbi && csrc->mc_db == cdst->mc_db);+  mdbx_cassert(csrc, csrc->mc_snum > 1); /* can't merge root page */+  mdbx_cassert(cdst, cdst->mc_snum > 1);+  mdbx_cassert(cdst, cdst->mc_snum < cdst->mc_db->md_depth ||+                         IS_LEAF(cdst->mc_pg[cdst->mc_db->md_depth - 1]));+  mdbx_cassert(csrc, csrc->mc_snum < csrc->mc_db->md_depth ||+                         IS_LEAF(csrc->mc_pg[csrc->mc_db->md_depth - 1]));+  mdbx_cassert(cdst, page_room(pdst) >= page_used(cdst->mc_txn->mt_env, psrc));+  const int pagetype = PAGETYPE(psrc);++  /* Move all nodes from src to dst */+  const unsigned dst_nkeys = page_numkeys(pdst);+  const unsigned src_nkeys = page_numkeys(psrc);+  mdbx_cassert(cdst, dst_nkeys + src_nkeys >=+                         (unsigned)(IS_LEAF(psrc) ? 1 : MDBX_MINKEYS));+  if (likely(src_nkeys)) {+    unsigned j = dst_nkeys;+    if (unlikely(pagetype & P_LEAF2)) {+      /* Mark dst as dirty. */+      if (unlikely(rc = mdbx_page_touch(cdst)))+        return rc;++      key.iov_len = csrc->mc_db->md_xsize;+      key.iov_base = page_data(psrc);+      unsigned i = 0;+      do {+        rc = mdbx_node_add_leaf2(cdst, j++, &key);+        if (unlikely(rc != MDBX_SUCCESS))+          return rc;+        key.iov_base = (char *)key.iov_base + key.iov_len;+      } while (++i != src_nkeys);+    } else {+      MDBX_node *srcnode = page_node(psrc, 0);+      key.iov_len = node_ks(srcnode);+      key.iov_base = node_key(srcnode);+      if (pagetype & P_BRANCH) {+        MDBX_cursor mn;+        cursor_copy_internal(csrc, &mn);+        mn.mc_xcursor = NULL;+        /* must find the lowest key below src */+        rc = mdbx_page_search_lowest(&mn);+        if (unlikely(rc))+          return rc;++        const MDBX_page *mp = mn.mc_pg[mn.mc_top];+        if (likely(!IS_LEAF2(mp))) {+          mdbx_cassert(&mn, IS_LEAF(mp));+          const MDBX_node *lowest = page_node(mp, 0);+          key.iov_len = node_ks(lowest);+          key.iov_base = node_key(lowest);+        } else {+          mdbx_cassert(&mn, mn.mc_top > csrc->mc_top);+          key.iov_len = mp->mp_leaf2_ksize;+          key.iov_base = page_leaf2key(mp, mn.mc_ki[mn.mc_top], key.iov_len);+        }+        mdbx_cassert(&mn, key.iov_len >= csrc->mc_dbx->md_klen_min);+        mdbx_cassert(&mn, key.iov_len <= csrc->mc_dbx->md_klen_max);++        const size_t dst_room = page_room(pdst);+        const size_t src_used = page_used(cdst->mc_txn->mt_env, psrc);+        const size_t space_needed = src_used - node_ks(srcnode) + key.iov_len;+        if (unlikely(space_needed > dst_room))+          return MDBX_RESULT_TRUE;+      }++      /* Mark dst as dirty. */+      if (unlikely(rc = mdbx_page_touch(cdst)))+        return rc;++      unsigned i = 0;+      while (true) {+        if (pagetype & P_LEAF) {+          MDBX_val data;+          data.iov_len = node_ds(srcnode);+          data.iov_base = node_data(srcnode);+          rc = mdbx_node_add_leaf(cdst, j++, &key, &data, node_flags(srcnode));+        } else {+          mdbx_cassert(csrc, node_flags(srcnode) == 0);+          rc = mdbx_node_add_branch(cdst, j++, &key, node_pgno(srcnode));+        }+        if (unlikely(rc != MDBX_SUCCESS))+          return rc;++        if (++i == src_nkeys)+          break;+        srcnode = page_node(psrc, i);+        key.iov_len = node_ks(srcnode);+        key.iov_base = node_key(srcnode);+      }+    }++    pdst = cdst->mc_pg[cdst->mc_top];+    mdbx_debug("dst page %" PRIaPGNO " now has %u keys (%.1f%% filled)",+               pdst->mp_pgno, page_numkeys(pdst),+               page_fill(cdst->mc_txn->mt_env, pdst));++    mdbx_cassert(csrc, psrc == csrc->mc_pg[csrc->mc_top]);+    mdbx_cassert(cdst, pdst == cdst->mc_pg[cdst->mc_top]);+  }++  /* Unlink the src page from parent and add to free list. */+  csrc->mc_top--;+  mdbx_node_del(csrc, 0);+  if (csrc->mc_ki[csrc->mc_top] == 0) {+    const MDBX_val nullkey = {0, 0};+    rc = mdbx_update_key(csrc, &nullkey);+    if (unlikely(rc)) {+      csrc->mc_top++;+      return rc;+    }+  }+  csrc->mc_top++;++  mdbx_cassert(csrc, psrc == csrc->mc_pg[csrc->mc_top]);+  mdbx_cassert(cdst, pdst == cdst->mc_pg[cdst->mc_top]);++  {+    /* Adjust other cursors pointing to mp */+    MDBX_cursor *m2, *m3;+    const MDBX_dbi dbi = csrc->mc_dbi;+    const unsigned top = csrc->mc_top;++    for (m2 = csrc->mc_txn->tw.cursors[dbi]; m2; m2 = m2->mc_next) {+      m3 = (csrc->mc_flags & C_SUB) ? &m2->mc_xcursor->mx_cursor : m2;+      if (m3 == csrc || top >= m3->mc_snum)+        continue;+      if (m3->mc_pg[top] == psrc) {+        m3->mc_pg[top] = pdst;+        mdbx_cassert(m3, dst_nkeys + m3->mc_ki[top] <= UINT16_MAX);+        m3->mc_ki[top] += (indx_t)dst_nkeys;+        m3->mc_ki[top - 1] = cdst->mc_ki[top - 1];+      } else if (m3->mc_pg[top - 1] == csrc->mc_pg[top - 1] &&+                 m3->mc_ki[top - 1] > csrc->mc_ki[top - 1]) {+        m3->mc_ki[top - 1]--;+      }+      if (XCURSOR_INITED(m3) && IS_LEAF(psrc))+        XCURSOR_REFRESH(m3, m3->mc_pg[top], m3->mc_ki[top]);+    }+  }++  /* If not operating on GC, allow this page to be reused+   * in this txn. Otherwise just add to free list. */+  rc = mdbx_page_retire(csrc, (MDBX_page *)psrc);+  if (unlikely(rc))+    return rc;++  mdbx_cassert(cdst, cdst->mc_db->md_entries > 0);+  mdbx_cassert(cdst, cdst->mc_snum <= cdst->mc_db->md_depth);+  mdbx_cassert(cdst, cdst->mc_top > 0);+  mdbx_cassert(cdst, cdst->mc_snum == cdst->mc_top + 1);+  MDBX_page *const top_page = cdst->mc_pg[cdst->mc_top];+  const indx_t top_indx = cdst->mc_ki[cdst->mc_top];+  const unsigned save_snum = cdst->mc_snum;+  const uint16_t save_depth = cdst->mc_db->md_depth;+  mdbx_cursor_pop(cdst);+  rc = mdbx_rebalance(cdst);+  if (unlikely(rc))+    return rc;++  mdbx_cassert(cdst, cdst->mc_db->md_entries > 0);+  mdbx_cassert(cdst, cdst->mc_snum <= cdst->mc_db->md_depth);+  mdbx_cassert(cdst, cdst->mc_snum == cdst->mc_top + 1);++  if (IS_LEAF(cdst->mc_pg[cdst->mc_top])) {+    /* LY: don't touch cursor if top-page is a LEAF */+    mdbx_cassert(cdst, IS_LEAF(cdst->mc_pg[cdst->mc_top]) ||+                           PAGETYPE(cdst->mc_pg[cdst->mc_top]) == pagetype);+    return MDBX_SUCCESS;+  }++  mdbx_cassert(cdst, page_numkeys(top_page) == dst_nkeys + src_nkeys);++  if (pagetype != PAGETYPE(top_page)) {+    /* LY: LEAF-page becomes BRANCH, unable restore cursor's stack */+    goto bailout;+  }++  if (top_page == cdst->mc_pg[cdst->mc_top]) {+    /* LY: don't touch cursor if prev top-page already on the top */+    mdbx_cassert(cdst, cdst->mc_ki[cdst->mc_top] == top_indx);+    mdbx_cassert(cdst, IS_LEAF(cdst->mc_pg[cdst->mc_top]) ||+                           PAGETYPE(cdst->mc_pg[cdst->mc_top]) == pagetype);+    return MDBX_SUCCESS;+  }++  const int new_snum = save_snum - save_depth + cdst->mc_db->md_depth;+  if (unlikely(new_snum < 1 || new_snum > cdst->mc_db->md_depth)) {+    /* LY: out of range, unable restore cursor's stack */+    goto bailout;+  }++  if (top_page == cdst->mc_pg[new_snum - 1]) {+    mdbx_cassert(cdst, cdst->mc_ki[new_snum - 1] == top_indx);+    /* LY: restore cursor stack */+    cdst->mc_snum = (uint16_t)new_snum;+    cdst->mc_top = (uint16_t)new_snum - 1;+    mdbx_cassert(cdst, cdst->mc_snum < cdst->mc_db->md_depth ||+                           IS_LEAF(cdst->mc_pg[cdst->mc_db->md_depth - 1]));+    mdbx_cassert(cdst, IS_LEAF(cdst->mc_pg[cdst->mc_top]) ||+                           PAGETYPE(cdst->mc_pg[cdst->mc_top]) == pagetype);+    return MDBX_SUCCESS;+  }++  MDBX_page *const stub_page = (MDBX_page *)(~(uintptr_t)top_page);+  const indx_t stub_indx = top_indx;+  if (save_depth > cdst->mc_db->md_depth &&+      ((cdst->mc_pg[save_snum - 1] == top_page &&+        cdst->mc_ki[save_snum - 1] == top_indx) ||+       (cdst->mc_pg[save_snum - 1] == stub_page &&+        cdst->mc_ki[save_snum - 1] == stub_indx))) {+    /* LY: restore cursor stack */+    cdst->mc_pg[new_snum - 1] = top_page;+    cdst->mc_ki[new_snum - 1] = top_indx;+    cdst->mc_pg[new_snum] = (MDBX_page *)(~(uintptr_t)cdst->mc_pg[new_snum]);+    cdst->mc_ki[new_snum] = ~cdst->mc_ki[new_snum];+    cdst->mc_snum = (uint16_t)new_snum;+    cdst->mc_top = (uint16_t)new_snum - 1;+    mdbx_cassert(cdst, cdst->mc_snum < cdst->mc_db->md_depth ||+                           IS_LEAF(cdst->mc_pg[cdst->mc_db->md_depth - 1]));+    mdbx_cassert(cdst, IS_LEAF(cdst->mc_pg[cdst->mc_top]) ||+                           PAGETYPE(cdst->mc_pg[cdst->mc_top]) == pagetype);+    return MDBX_SUCCESS;+  }++bailout:+  /* LY: unable restore cursor's stack */+  cdst->mc_flags &= ~C_INITIALIZED;+  return MDBX_CURSOR_FULL;+}++/* Copy the contents of a cursor.+ * [in] csrc The cursor to copy from.+ * [out] cdst The cursor to copy to. */+static void cursor_copy_internal(const MDBX_cursor *csrc, MDBX_cursor *cdst) {+  mdbx_cassert(csrc,+               csrc->mc_txn->mt_txnid >= csrc->mc_txn->mt_env->me_oldest->weak);+  cdst->mc_txn = csrc->mc_txn;+  cdst->mc_dbi = csrc->mc_dbi;+  cdst->mc_db = csrc->mc_db;+  cdst->mc_dbx = csrc->mc_dbx;+  cdst->mc_snum = csrc->mc_snum;+  cdst->mc_top = csrc->mc_top;+  cdst->mc_flags = csrc->mc_flags;+  cdst->mc_dbistate = csrc->mc_dbistate;++  for (unsigned i = 0; i < csrc->mc_snum; i++) {+    cdst->mc_pg[i] = csrc->mc_pg[i];+    cdst->mc_ki[i] = csrc->mc_ki[i];+  }+}++/* Rebalance the tree after a delete operation.+ * [in] mc Cursor pointing to the page where rebalancing should begin.+ * Returns 0 on success, non-zero on failure. */+static int mdbx_rebalance(MDBX_cursor *mc) {+  mdbx_cassert(mc, cursor_is_tracked(mc));+  mdbx_cassert(mc, mc->mc_snum > 0);+  mdbx_cassert(mc, mc->mc_snum < mc->mc_db->md_depth ||+                       IS_LEAF(mc->mc_pg[mc->mc_db->md_depth - 1]));+  const int pagetype = PAGETYPE(mc->mc_pg[mc->mc_top]);++  STATIC_ASSERT(P_BRANCH == 1);+  const unsigned minkeys = (pagetype & P_BRANCH) + 1;++  /* The threshold of minimum page fill factor, in form of a negative binary+   * exponent, i.e. X = 2 means 1/(2**X) == 1/(2**2) == 1/4 == 25%.+   * Pages emptier than this are candidates for merging. */+  const unsigned threshold_fill_exp2 = 2;++  /* The threshold of minimum page fill factor, as a number of free bytes on a+   * page. Pages emptier than this are candidates for merging. */+  unsigned room_threshold =+      page_space(mc->mc_txn->mt_env) -+      (page_space(mc->mc_txn->mt_env) >> threshold_fill_exp2);++  const MDBX_page *const tp = mc->mc_pg[mc->mc_top];+  const unsigned numkeys = page_numkeys(tp);+  const unsigned room = page_room(tp);+  mdbx_debug("rebalancing %s page %" PRIaPGNO+             " (has %u keys, full %.1f%%, used %u, room %u bytes )",+             (pagetype & P_LEAF) ? "leaf" : "branch", tp->mp_pgno, numkeys,+             page_fill(mc->mc_txn->mt_env, tp),+             page_used(mc->mc_txn->mt_env, tp), room);++  if (unlikely(numkeys < minkeys)) {+    mdbx_debug("page %" PRIaPGNO " must be merged due keys < %u threshold",+               tp->mp_pgno, minkeys);+  } else if (unlikely(room > room_threshold)) {+    mdbx_debug("page %" PRIaPGNO " should be merged due room %u > %u threshold",+               tp->mp_pgno, room, room_threshold);+  } else {+    mdbx_debug("no need to rebalance page %" PRIaPGNO+               ", room %u < %u threshold",+               tp->mp_pgno, room, room_threshold);+    mdbx_cassert(mc, mc->mc_db->md_entries > 0);+    return MDBX_SUCCESS;+  }++  int rc;+  if (mc->mc_snum < 2) {+    MDBX_page *const mp = mc->mc_pg[0];+    const unsigned nkeys = page_numkeys(mp);+    mdbx_cassert(mc, (mc->mc_db->md_entries == 0) == (nkeys == 0));+    if (IS_SUBP(mp)) {+      mdbx_debug("%s", "Can't rebalance a subpage, ignoring");+      mdbx_cassert(mc, pagetype & P_LEAF);+      return MDBX_SUCCESS;+    }+    if (nkeys == 0) {+      mdbx_cassert(mc, IS_LEAF(mp));+      mdbx_debug("%s", "tree is completely empty");+      mc->mc_db->md_root = P_INVALID;+      mc->mc_db->md_depth = 0;+      mdbx_cassert(mc, mc->mc_db->md_branch_pages == 0 &&+                           mc->mc_db->md_overflow_pages == 0 &&+                           mc->mc_db->md_leaf_pages == 1);+      /* Adjust cursors pointing to mp */+      for (MDBX_cursor *m2 = mc->mc_txn->tw.cursors[mc->mc_dbi]; m2;+           m2 = m2->mc_next) {+        MDBX_cursor *m3 =+            (mc->mc_flags & C_SUB) ? &m2->mc_xcursor->mx_cursor : m2;+        if (m3 == mc || !(m3->mc_flags & C_INITIALIZED))+          continue;+        if (m3->mc_pg[0] == mp) {+          m3->mc_snum = 0;+          m3->mc_top = 0;+          m3->mc_flags &= ~C_INITIALIZED;+        }+      }+      mc->mc_snum = 0;+      mc->mc_top = 0;+      mc->mc_flags &= ~C_INITIALIZED;++      rc = mdbx_page_retire(mc, mp);+      if (unlikely(rc != MDBX_SUCCESS))+        return rc;+    } else if (IS_BRANCH(mp) && nkeys == 1) {+      mdbx_debug("%s", "collapsing root page!");+      mc->mc_db->md_root = node_pgno(page_node(mp, 0));+      rc = mdbx_page_get(mc, mc->mc_db->md_root, &mc->mc_pg[0], NULL,+                         pp_txnid4chk(mp, mc->mc_txn));+      if (unlikely(rc != MDBX_SUCCESS))+        return rc;+      mc->mc_db->md_depth--;+      mc->mc_ki[0] = mc->mc_ki[1];+      for (int i = 1; i < mc->mc_db->md_depth; i++) {+        mc->mc_pg[i] = mc->mc_pg[i + 1];+        mc->mc_ki[i] = mc->mc_ki[i + 1];+      }++      /* Adjust other cursors pointing to mp */+      for (MDBX_cursor *m2 = mc->mc_txn->tw.cursors[mc->mc_dbi]; m2;+           m2 = m2->mc_next) {+        MDBX_cursor *m3 =+            (mc->mc_flags & C_SUB) ? &m2->mc_xcursor->mx_cursor : m2;+        if (m3 == mc || !(m3->mc_flags & C_INITIALIZED))+          continue;+        if (m3->mc_pg[0] == mp) {+          for (int i = 0; i < mc->mc_db->md_depth; i++) {+            m3->mc_pg[i] = m3->mc_pg[i + 1];+            m3->mc_ki[i] = m3->mc_ki[i + 1];+          }+          m3->mc_snum--;+          m3->mc_top--;+        }+      }+      mdbx_cassert(mc, IS_LEAF(mc->mc_pg[mc->mc_top]) ||+                           PAGETYPE(mc->mc_pg[mc->mc_top]) == pagetype);+      mdbx_cassert(mc, mc->mc_snum < mc->mc_db->md_depth ||+                           IS_LEAF(mc->mc_pg[mc->mc_db->md_depth - 1]));++      rc = mdbx_page_retire(mc, mp);+      if (unlikely(rc != MDBX_SUCCESS))+        return rc;+    } else {+      mdbx_debug("root page %" PRIaPGNO+                 " doesn't need rebalancing (flags 0x%x)",+                 mp->mp_pgno, mp->mp_flags);+    }+    return MDBX_SUCCESS;+  }++  /* The parent (branch page) must have at least 2 pointers,+   * otherwise the tree is invalid. */+  const unsigned pre_top = mc->mc_top - 1;+  mdbx_cassert(mc, IS_BRANCH(mc->mc_pg[pre_top]));+  mdbx_cassert(mc, !IS_SUBP(mc->mc_pg[0]));+  mdbx_cassert(mc, page_numkeys(mc->mc_pg[pre_top]) > 1);++  /* Leaf page fill factor is below the threshold.+   * Try to move keys from left or right neighbor, or+   * merge with a neighbor page. */++  /* Find neighbors. */+  MDBX_cursor mn;+  cursor_copy_internal(mc, &mn);+  mn.mc_xcursor = NULL;++  MDBX_page *left = nullptr, *right = nullptr;+  if (mn.mc_ki[pre_top] > 0) {+    rc = mdbx_page_get(+        &mn, node_pgno(page_node(mn.mc_pg[pre_top], mn.mc_ki[pre_top] - 1)),+        &left, NULL, pp_txnid4chk(mn.mc_pg[pre_top], mc->mc_txn));+    if (unlikely(rc != MDBX_SUCCESS))+      return rc;+    mdbx_cassert(mc, PAGETYPE(left) == PAGETYPE(mc->mc_pg[mc->mc_top]));+  }+  if (mn.mc_ki[pre_top] + 1u < page_numkeys(mn.mc_pg[pre_top])) {+    rc = mdbx_page_get(+        &mn, node_pgno(page_node(mn.mc_pg[pre_top], mn.mc_ki[pre_top] + 1)),+        &right, NULL, pp_txnid4chk(mn.mc_pg[pre_top], mc->mc_txn));+    if (unlikely(rc != MDBX_SUCCESS))+      return rc;+    mdbx_cassert(mc, PAGETYPE(right) == PAGETYPE(mc->mc_pg[mc->mc_top]));+  }++  const unsigned ki_top = mc->mc_ki[mc->mc_top];+  const unsigned ki_pre_top = mn.mc_ki[pre_top];+  const unsigned nkeys = page_numkeys(mn.mc_pg[mn.mc_top]);++  const unsigned left_room = left ? page_room(left) : 0;+  const unsigned right_room = right ? page_room(right) : 0;+retry:+  if (left_room > room_threshold && left_room >= right_room) {+    /* try merge with left */+    mdbx_cassert(mc, page_numkeys(left) >= minkeys);+    mn.mc_pg[mn.mc_top] = left;+    mn.mc_ki[mn.mc_top - 1] = (indx_t)(ki_pre_top - 1);+    mn.mc_ki[mn.mc_top] = (indx_t)(page_numkeys(left) - 1);+    mc->mc_ki[mc->mc_top] = 0;+    const unsigned new_ki = ki_top + page_numkeys(left);+    mn.mc_ki[mn.mc_top] += mc->mc_ki[mn.mc_top] + 1;+    /* We want mdbx_rebalance to find mn when doing fixups */+    WITH_CURSOR_TRACKING(mn, rc = mdbx_page_merge(mc, &mn));+    if (likely(rc != MDBX_RESULT_TRUE)) {+      cursor_copy_internal(&mn, mc);+      mc->mc_ki[mc->mc_top] = (indx_t)new_ki;+      mdbx_cassert(mc, rc || page_numkeys(mc->mc_pg[mc->mc_top]) >= minkeys);+      return rc;+    }+  }+  if (right_room > room_threshold) {+    /* try merge with right */+    mdbx_cassert(mc, page_numkeys(right) >= minkeys);+    mn.mc_pg[mn.mc_top] = right;+    mn.mc_ki[mn.mc_top - 1] = (indx_t)(ki_pre_top + 1);+    mn.mc_ki[mn.mc_top] = 0;+    mc->mc_ki[mc->mc_top] = (indx_t)nkeys;+    WITH_CURSOR_TRACKING(mn, rc = mdbx_page_merge(&mn, mc));+    if (likely(rc != MDBX_RESULT_TRUE)) {+      mc->mc_ki[mc->mc_top] = (indx_t)ki_top;+      mdbx_cassert(mc, rc || page_numkeys(mc->mc_pg[mc->mc_top]) >= minkeys);+      return rc;+    }+  }++  const unsigned left_nkeys = left ? page_numkeys(left) : 0;+  const unsigned right_nkeys = right ? page_numkeys(right) : 0;+  if (left_nkeys > minkeys &&+      (right_nkeys <= left_nkeys || right_room >= left_room)) {+    /* try move from left */+    mn.mc_pg[mn.mc_top] = left;+    mn.mc_ki[mn.mc_top - 1] = (indx_t)(ki_pre_top - 1);+    mn.mc_ki[mn.mc_top] = (indx_t)(page_numkeys(left) - 1);+    mc->mc_ki[mc->mc_top] = 0;+    WITH_CURSOR_TRACKING(mn, rc = mdbx_node_move(&mn, mc, true));+    if (likely(rc != MDBX_RESULT_TRUE)) {+      mc->mc_ki[mc->mc_top] = (indx_t)(ki_top + 1);+      mdbx_cassert(mc, rc || page_numkeys(mc->mc_pg[mc->mc_top]) >= minkeys);+      return rc;+    }+  }+  if (right_nkeys > minkeys) {+    /* try move from right */+    mn.mc_pg[mn.mc_top] = right;+    mn.mc_ki[mn.mc_top - 1] = (indx_t)(ki_pre_top + 1);+    mn.mc_ki[mn.mc_top] = 0;+    mc->mc_ki[mc->mc_top] = (indx_t)nkeys;+    WITH_CURSOR_TRACKING(mn, rc = mdbx_node_move(&mn, mc, false));+    if (likely(rc != MDBX_RESULT_TRUE)) {+      mc->mc_ki[mc->mc_top] = (indx_t)ki_top;+      mdbx_cassert(mc, rc || page_numkeys(mc->mc_pg[mc->mc_top]) >= minkeys);+      return rc;+    }+  }++  if (nkeys >= minkeys) {+    mc->mc_ki[mc->mc_top] = (indx_t)ki_top;+    if (!mdbx_audit_enabled())+      return MDBX_SUCCESS;+    return mdbx_cursor_check(mc, C_UPDATING);+  }++  if (likely(room_threshold > 0)) {+    room_threshold = 0;+    goto retry;+  }+  return MDBX_PROBLEM;+}++static __cold int mdbx_page_check(MDBX_cursor *const mc,+                                  const MDBX_page *const mp, unsigned options) {+  options |= mc->mc_flags & (C_COPYING | C_UPDATING | C_RETIRING | C_SKIPORD);+  MDBX_env *const env = mc->mc_txn->mt_env;+  const unsigned nkeys = page_numkeys(mp);+  char *const end_of_page = (char *)mp + env->me_psize;+  if (unlikely(mp->mp_pgno < MIN_PAGENO || mp->mp_pgno > MAX_PAGENO))+    return bad_page(mp, "invalid pgno (%u)\n", mp->mp_pgno);+  if (IS_OVERFLOW(mp)) {+    if (unlikely(mp->mp_pages < 1 && mp->mp_pages >= MAX_PAGENO / 2))+      return bad_page(mp, "invalid overflow n-pages (%u)\n", mp->mp_pages);+    if (unlikely(mp->mp_pgno + mp->mp_pages > mc->mc_txn->mt_next_pgno))+      return bad_page(mp, "overflow page beyond (%u) next-pgno\n",+                      mp->mp_pgno + mp->mp_pages);+    return MDBX_SUCCESS;+  }++  int rc = MDBX_SUCCESS;+  if ((options & C_UPDATING) == 0 || !IS_DIRTY(mp)) {+    if (unlikely(nkeys < 2 && IS_BRANCH(mp)))+      rc = bad_page(mp, "branch-page nkey (%u) < 2\n", nkeys);+  }++  MDBX_val here, prev = {0, 0};+  for (unsigned i = 0; i < nkeys; ++i) {+    if (IS_LEAF2(mp)) {+      const size_t ksize = mp->mp_leaf2_ksize;+      char *const key = page_leaf2key(mp, i, ksize);+      if (unlikely(end_of_page < key + ksize)) {+        rc = bad_page(mp, "leaf2-key beyond (%zu) page-end\n",+                      key + ksize - end_of_page);+        continue;+      }++      if ((options & C_COPYING) == 0) {+        if (unlikely(ksize != mc->mc_dbx->md_klen_min)) {+          if (unlikely(ksize < mc->mc_dbx->md_klen_min ||+                       ksize > mc->mc_dbx->md_klen_max))+            rc = bad_page(+                mp, "leaf2-key size (%zu) <> min/max key-length (%zu/%zu)\n",+                ksize, mc->mc_dbx->md_klen_min, mc->mc_dbx->md_klen_max);+          else+            mc->mc_dbx->md_klen_min = mc->mc_dbx->md_klen_max = ksize;+        }+        if ((options & C_SKIPORD) == 0) {+          here.iov_len = ksize;+          here.iov_base = key;+          if (prev.iov_base && unlikely(mc->mc_dbx->md_cmp(&here, &prev) <= 0))+            rc = bad_page(mp, "leaf2-key #%u wrong order\n", i);+          prev = here;+        }+      }+    } else {+      const MDBX_node *const node = page_node(mp, i);+      const char *node_end = (char *)node + NODESIZE;+      if (unlikely(node_end > end_of_page)) {+        rc = bad_page(mp, "node (%zu) beyond page-end\n",+                      node_end - end_of_page);+        continue;+      }+      if (IS_LEAF(mp) || i > 0) {+        size_t ksize = node_ks(node);+        char *key = node_key(node);+        if (unlikely(end_of_page < key + ksize)) {+          rc = bad_page(mp, "node-key (%zu) beyond page-end\n",+                        key + ksize - end_of_page);+          continue;+        }++        if ((options & C_COPYING) == 0) {+          if (unlikely(ksize < mc->mc_dbx->md_klen_min ||+                       ksize > mc->mc_dbx->md_klen_max))+            rc = bad_page(+                mp, "node-key size (%zu) <> min/max key-length (%zu/%zu)\n",+                ksize, mc->mc_dbx->md_klen_min, mc->mc_dbx->md_klen_max);++          if ((options & C_SKIPORD) == 0) {+            here.iov_base = key;+            here.iov_len = ksize;+            if (prev.iov_base &&+                unlikely(mc->mc_dbx->md_cmp(&here, &prev) <= 0))+              rc = bad_page(mp, "node-key #%u wrong order\n", i);+            prev = here;+          }+        }+      }+      if (IS_BRANCH(mp)) {+        if ((options & C_RETIRING) == 0) {+          const pgno_t ref = node_pgno(node);+          if (unlikely(ref < MIN_PAGENO || ref >= mc->mc_txn->mt_next_pgno))+            rc = bad_page(mp, "branch-node wrong pgno (%u)\n", ref);+        }+        continue;+      }++      switch (node_flags(node)) {+      default:+        rc = bad_page(mp, "invalid node flags (%u)\n", node_flags(node));+        break;+      case F_BIGDATA /* data on large-page */:+      case 0 /* usual */:+      case F_SUBDATA /* sub-db */:+      case F_SUBDATA | F_DUPDATA /* dupsorted sub-tree */:+      case F_DUPDATA /* short sub-page */:+        break;+      }++      if (node_flags(node) & F_BIGDATA) {+        const size_t dsize = node_ds(node);+        if ((options & C_COPYING) == 0) {+          if (unlikely(dsize <= mc->mc_dbx->md_vlen_min ||+                       dsize > mc->mc_dbx->md_vlen_max))+            rc = bad_page(+                mp,+                "big-node data size (%zu) <> min/max value-length (%zu/%zu)\n",+                dsize, mc->mc_dbx->md_vlen_min, mc->mc_dbx->md_vlen_max);+        }+        if ((options & C_RETIRING) == 0) {+          MDBX_page *lp;+          int err = mdbx_page_get(mc, node_largedata_pgno(node), &lp, NULL,+                                  pp_txnid4chk(mp, mc->mc_txn));+          if (unlikely(err != MDBX_SUCCESS))+            return err;+          if (unlikely(!IS_OVERFLOW(lp))) {+            rc = bad_page(mp, "big-node refs to non-overflow page (%u)\n",+                          lp->mp_pgno);+            continue;+          }+          if (unlikely(number_of_ovpages(env, dsize) > lp->mp_pages))+            rc =+                bad_page(mp, "big-node size (%zu) mismatch n-pages size (%u)\n",+                         dsize, lp->mp_pages);+        }+        continue;+      }++      const size_t dsize = node_ds(node);+      const char *const data = node_data(node);+      if (unlikely(end_of_page < data + dsize)) {+        rc = bad_page(mp,+                      "node-data(%u of %u, %zu bytes) beyond (%zu) page-end\n",+                      i, nkeys, dsize, data + dsize - end_of_page);+        continue;+      }++      switch (node_flags(node)) {+      default:+        /* wrong, but already handled */+        continue;+      case 0 /* usual */:+        if ((options & C_COPYING) == 0) {+          if (unlikely(dsize < mc->mc_dbx->md_vlen_min ||+                       dsize > mc->mc_dbx->md_vlen_max)) {+            rc = bad_page(+                mp, "node-data size (%zu) <> min/max value-length (%zu/%zu)\n",+                dsize, mc->mc_dbx->md_vlen_min, mc->mc_dbx->md_vlen_max);+            continue;+          }+        }+        break;+      case F_SUBDATA /* sub-db */:+        if (unlikely(dsize != sizeof(MDBX_db))) {+          rc = bad_page(mp, "invalid sub-db record size (%zu)\n", dsize);+          continue;+        }+        break;+      case F_SUBDATA | F_DUPDATA /* dupsorted sub-tree */:+        if (unlikely(dsize != sizeof(MDBX_db))) {+          rc = bad_page(mp, "invalid nested-db record size (%zu)\n", dsize);+          continue;+        }+        break;+      case F_DUPDATA /* short sub-page */:+        if (unlikely(dsize <= PAGEHDRSZ)) {+          rc = bad_page(mp, "invalid nested-page record size (%zu)\n", dsize);+          continue;+        } else {+          const MDBX_page *const sp = (MDBX_page *)data;+          const char *const end_of_subpage = data + dsize;+          const int nsubkeys = page_numkeys(sp);+          switch (sp->mp_flags & ~P_DIRTY /* ignore for sub-pages */) {+          case P_LEAF | P_SUBP:+          case P_LEAF | P_LEAF2 | P_SUBP:+            break;+          default:+            rc = bad_page(mp, "invalid nested-page flags (%u)\n", sp->mp_flags);+            continue;+          }++          MDBX_val sub_here, sub_prev = {0, 0};+          for (int j = 0; j < nsubkeys; j++) {+            if (IS_LEAF2(sp)) {+              /* LEAF2 pages have no mp_ptrs[] or node headers */+              size_t sub_ksize = sp->mp_leaf2_ksize;+              char *sub_key = page_leaf2key(sp, j, sub_ksize);+              if (unlikely(end_of_subpage < sub_key + sub_ksize)) {+                rc = bad_page(mp, "nested-leaf2-key beyond (%zu) nested-page\n",+                              sub_key + sub_ksize - end_of_subpage);+                continue;+              }++              if ((options & C_COPYING) == 0) {+                if (unlikely(sub_ksize != mc->mc_dbx->md_vlen_min)) {+                  if (unlikely(sub_ksize < mc->mc_dbx->md_vlen_min ||+                               sub_ksize > mc->mc_dbx->md_vlen_max)) {+                    rc = bad_page(mp,+                                  "nested-leaf2-key size (%zu) <> min/max "+                                  "value-length (%zu/%zu)\n",+                                  sub_ksize, mc->mc_dbx->md_vlen_min,+                                  mc->mc_dbx->md_vlen_max);+                    continue;+                  }+                  mc->mc_dbx->md_vlen_min = mc->mc_dbx->md_vlen_max = sub_ksize;+                }+                if ((options & C_SKIPORD) == 0) {+                  sub_here.iov_len = sub_ksize;+                  sub_here.iov_base = sub_key;+                  if (sub_prev.iov_base &&+                      unlikely(mc->mc_dbx->md_dcmp(&sub_prev, &sub_here) >= 0))+                    rc = bad_page(mp, "nested-leaf2-key #%u wrong order\n", j);+                  sub_prev = sub_here;+                }+              }+            } else {+              const MDBX_node *const sub_node = page_node(sp, j);+              const char *sub_node_end = (char *)sub_node + NODESIZE;+              if (unlikely(sub_node_end > end_of_subpage)) {+                rc = bad_page(mp, "nested-node beyond (%zu) nested-page\n",+                              end_of_subpage - sub_node_end);+                continue;+              }+              if (unlikely(node_flags(sub_node) != 0))+                rc = bad_page(mp, "nested-node invalid flags (%u)\n",+                              node_flags(sub_node));++              size_t sub_ksize = node_ks(sub_node);+              char *sub_key = node_key(sub_node);+              size_t sub_dsize = node_ds(sub_node);+              /* char *sub_data = node_data(sub_node); */++              if ((options & C_COPYING) == 0) {+                if (unlikely(sub_ksize < mc->mc_dbx->md_vlen_min ||+                             sub_ksize > mc->mc_dbx->md_vlen_max))+                  rc = bad_page(mp,+                                "nested-node-key size (%zu) <> min/max "+                                "value-length (%zu/%zu)\n",+                                sub_ksize, mc->mc_dbx->md_vlen_min,+                                mc->mc_dbx->md_vlen_max);++                if ((options & C_SKIPORD) == 0) {+                  sub_here.iov_len = sub_ksize;+                  sub_here.iov_base = sub_key;+                  if (sub_prev.iov_base &&+                      unlikely(mc->mc_dbx->md_dcmp(&sub_prev, &sub_here) >= 0))+                    rc = bad_page(mp, "nested-node-key #%u wrong order\n", j);+                  sub_prev = sub_here;+                }+              }+              if (unlikely(sub_dsize != 0))+                rc = bad_page(mp, "nested-node non-empty data size (%zu)\n",+                              sub_dsize);+              if (unlikely(end_of_subpage < sub_key + sub_ksize))+                rc = bad_page(mp, "nested-node-key beyond (%zu) nested-page\n",+                              sub_key + sub_ksize - end_of_subpage);+            }+          }+        }+        break;+      }+    }+  }+  return rc;+}++static __cold int mdbx_cursor_check(MDBX_cursor *mc, unsigned options) {+  mdbx_tassert(mc->mc_txn, mc->mc_txn->mt_parent ||+                               mc->mc_txn->tw.dirtyroom ++                                       mc->mc_txn->tw.dirtylist->length ==+                                   mc->mc_txn->mt_env->me_options.dp_limit);+  mdbx_cassert(mc, mc->mc_top == mc->mc_snum - 1);+  if (unlikely(mc->mc_top != mc->mc_snum - 1))+    return MDBX_CURSOR_FULL;+  mdbx_cassert(mc, (options & C_UPDATING) ? mc->mc_snum <= mc->mc_db->md_depth+                                          : mc->mc_snum == mc->mc_db->md_depth);+  if (unlikely((options & C_UPDATING) ? mc->mc_snum > mc->mc_db->md_depth+                                      : mc->mc_snum != mc->mc_db->md_depth))+    return MDBX_CURSOR_FULL;++  for (int n = 0; n < (int)mc->mc_snum; ++n) {+    MDBX_page *mp = mc->mc_pg[n];+    const unsigned nkeys = page_numkeys(mp);+    const bool expect_branch = (n < mc->mc_db->md_depth - 1) ? true : false;+    const bool expect_nested_leaf =+        (n + 1 == mc->mc_db->md_depth - 1) ? true : false;+    const bool branch = IS_BRANCH(mp) ? true : false;+    mdbx_cassert(mc, branch == expect_branch);+    if (unlikely(branch != expect_branch))+      return MDBX_CURSOR_FULL;+    if ((options & C_UPDATING) == 0) {+      mdbx_cassert(mc,+                   nkeys > mc->mc_ki[n] || (!branch && nkeys == mc->mc_ki[n] &&+                                            (mc->mc_flags & C_EOF) != 0));+      if (unlikely(nkeys <= mc->mc_ki[n] &&+                   !(!branch && nkeys == mc->mc_ki[n] &&+                     (mc->mc_flags & C_EOF) != 0)))+        return MDBX_CURSOR_FULL;+    } else {+      mdbx_cassert(mc, nkeys + 1 >= mc->mc_ki[n]);+      if (unlikely(nkeys + 1 < mc->mc_ki[n]))+        return MDBX_CURSOR_FULL;+    }++    int err = mdbx_page_check(mc, mp, options);+    if (unlikely(err != MDBX_SUCCESS))+      return err;++    for (unsigned i = 0; i < nkeys; ++i) {+      if (branch) {+        MDBX_node *node = page_node(mp, i);+        mdbx_cassert(mc, node_flags(node) == 0);+        if (unlikely(node_flags(node) != 0))+          return MDBX_CURSOR_FULL;+        pgno_t pgno = node_pgno(node);+        MDBX_page *np;+        int rc =+            mdbx_page_get(mc, pgno, &np, NULL, pp_txnid4chk(mp, mc->mc_txn));+        mdbx_cassert(mc, rc == MDBX_SUCCESS);+        if (unlikely(rc != MDBX_SUCCESS))+          return rc;+        const bool nested_leaf = IS_LEAF(np) ? true : false;+        mdbx_cassert(mc, nested_leaf == expect_nested_leaf);+        if (unlikely(nested_leaf != expect_nested_leaf))+          return MDBX_CURSOR_FULL;+        err = mdbx_page_check(mc, np, options);+        if (unlikely(err != MDBX_SUCCESS))+          return err;+      }+    }+  }+  return MDBX_SUCCESS;+}++/* Complete a delete operation started by mdbx_cursor_del(). */+static int mdbx_cursor_del0(MDBX_cursor *mc) {+  int rc;+  MDBX_page *mp;+  indx_t ki;+  unsigned nkeys;+  MDBX_dbi dbi = mc->mc_dbi;++  mdbx_cassert(mc, cursor_is_tracked(mc));+  mdbx_cassert(mc, IS_LEAF(mc->mc_pg[mc->mc_top]));+  ki = mc->mc_ki[mc->mc_top];+  mp = mc->mc_pg[mc->mc_top];+  mdbx_node_del(mc, mc->mc_db->md_xsize);+  mc->mc_db->md_entries--;++  /* Adjust other cursors pointing to mp */+  for (MDBX_cursor *m2 = mc->mc_txn->tw.cursors[dbi]; m2; m2 = m2->mc_next) {+    MDBX_cursor *m3 = (mc->mc_flags & C_SUB) ? &m2->mc_xcursor->mx_cursor : m2;+    if (m3 == mc || !(m2->mc_flags & m3->mc_flags & C_INITIALIZED))+      continue;+    if (m3->mc_snum < mc->mc_snum)+      continue;+    if (m3->mc_pg[mc->mc_top] == mp) {+      if (m3->mc_ki[mc->mc_top] == ki) {+        m3->mc_flags |= C_DEL;+        if (mc->mc_db->md_flags & MDBX_DUPSORT) {+          /* Sub-cursor referred into dataset which is gone */+          m3->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED | C_EOF);+        }+        continue;+      } else if (m3->mc_ki[mc->mc_top] > ki) {+        m3->mc_ki[mc->mc_top]--;+      }+      if (XCURSOR_INITED(m3))+        XCURSOR_REFRESH(m3, m3->mc_pg[mc->mc_top], m3->mc_ki[mc->mc_top]);+    }+  }++  rc = mdbx_rebalance(mc);+  if (unlikely(rc != MDBX_SUCCESS))+    goto bailout;++  if (unlikely(!mc->mc_snum)) {+    /* DB is totally empty now, just bail out.+     * Other cursors adjustments were already done+     * by mdbx_rebalance and aren't needed here. */+    mdbx_cassert(mc, mc->mc_db->md_entries == 0 && mc->mc_db->md_depth == 0 &&+                         mc->mc_db->md_root == P_INVALID);+    mc->mc_flags |= C_EOF;+    return MDBX_SUCCESS;+  }++  ki = mc->mc_ki[mc->mc_top];+  mp = mc->mc_pg[mc->mc_top];+  mdbx_cassert(mc, IS_LEAF(mc->mc_pg[mc->mc_top]));+  nkeys = page_numkeys(mp);+  mdbx_cassert(mc, (mc->mc_db->md_entries > 0 && nkeys > 0) ||+                       ((mc->mc_flags & C_SUB) && mc->mc_db->md_entries == 0 &&+                        nkeys == 0));++  /* Adjust this and other cursors pointing to mp */+  for (MDBX_cursor *m2 = mc->mc_txn->tw.cursors[dbi]; m2; m2 = m2->mc_next) {+    MDBX_cursor *m3 = (mc->mc_flags & C_SUB) ? &m2->mc_xcursor->mx_cursor : m2;+    if (!(m2->mc_flags & m3->mc_flags & C_INITIALIZED))+      continue;+    if (m3->mc_snum < mc->mc_snum)+      continue;+    if (m3->mc_pg[mc->mc_top] == mp) {+      /* if m3 points past last node in page, find next sibling */+      if (m3->mc_ki[mc->mc_top] >= nkeys) {+        rc = mdbx_cursor_sibling(m3, SIBLING_RIGHT);+        if (rc == MDBX_NOTFOUND) {+          m3->mc_flags |= C_EOF;+          rc = MDBX_SUCCESS;+          continue;+        }+        if (unlikely(rc != MDBX_SUCCESS))+          goto bailout;+      }+      if (m3->mc_ki[mc->mc_top] >= ki ||+          /* moved to right sibling */ m3->mc_pg[mc->mc_top] != mp) {+        if (m3->mc_xcursor && !(m3->mc_flags & C_EOF)) {+          MDBX_node *node =+              page_node(m3->mc_pg[m3->mc_top], m3->mc_ki[m3->mc_top]);+          /* If this node has dupdata, it may need to be reinited+           * because its data has moved.+           * If the xcursor was not inited it must be reinited.+           * Else if node points to a subDB, nothing is needed. */+          if (node_flags(node) & F_DUPDATA) {+            if (m3->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) {+              if (!(node_flags(node) & F_SUBDATA))+                m3->mc_xcursor->mx_cursor.mc_pg[0] = node_data(node);+            } else {+              rc = mdbx_xcursor_init1(m3, node, m3->mc_pg[m3->mc_top]);+              if (unlikely(rc != MDBX_SUCCESS))+                goto bailout;+              rc = mdbx_cursor_first(&m3->mc_xcursor->mx_cursor, NULL, NULL);+              if (unlikely(rc != MDBX_SUCCESS))+                goto bailout;+            }+          }+          m3->mc_xcursor->mx_cursor.mc_flags |= C_DEL;+        }+        m3->mc_flags |= C_DEL;+      }+    }+  }++  mdbx_cassert(mc, rc == MDBX_SUCCESS);+  if (mdbx_audit_enabled())+    rc = mdbx_cursor_check(mc, 0);+  return rc;++bailout:+  mc->mc_txn->mt_flags |= MDBX_TXN_ERROR;+  return rc;+}++int mdbx_del(MDBX_txn *txn, MDBX_dbi dbi, const MDBX_val *key,+             const MDBX_val *data) {+  int rc = check_txn_rw(txn, MDBX_TXN_BLOCKED);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  if (unlikely(!key))+    return MDBX_EINVAL;++  if (unlikely(!mdbx_txn_dbi_exists(txn, dbi, DBI_USRVALID)))+    return MDBX_BAD_DBI;++  if (unlikely(txn->mt_flags & (MDBX_TXN_RDONLY | MDBX_TXN_BLOCKED)))+    return (txn->mt_flags & MDBX_TXN_RDONLY) ? MDBX_EACCESS : MDBX_BAD_TXN;++  return mdbx_del0(txn, dbi, key, data, 0);+}++static int mdbx_del0(MDBX_txn *txn, MDBX_dbi dbi, const MDBX_val *key,+                     const MDBX_val *data, unsigned flags) {+  MDBX_cursor_couple cx;+  MDBX_cursor_op op;+  MDBX_val rdata;+  int rc, exact = 0;+  DKBUF;++  mdbx_debug("====> delete db %u key [%s], data [%s]", dbi, DKEY(key),+             DVAL(data));++  rc = mdbx_cursor_init(&cx.outer, txn, dbi);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  if (data) {+    op = MDBX_GET_BOTH;+    rdata = *data;+    data = &rdata;+  } else {+    op = MDBX_SET;+    flags |= MDBX_ALLDUPS;+  }+  rc =+      mdbx_cursor_set(&cx.outer, (MDBX_val *)key, (MDBX_val *)data, op, &exact);+  if (likely(rc == MDBX_SUCCESS)) {+    /* let mdbx_page_split know about this cursor if needed:+     * delete will trigger a rebalance; if it needs to move+     * a node from one page to another, it will have to+     * update the parent's separator key(s). If the new sepkey+     * is larger than the current one, the parent page may+     * run out of space, triggering a split. We need this+     * cursor to be consistent until the end of the rebalance. */+    cx.outer.mc_next = txn->tw.cursors[dbi];+    txn->tw.cursors[dbi] = &cx.outer;+    rc = mdbx_cursor_del(&cx.outer, flags);+    txn->tw.cursors[dbi] = cx.outer.mc_next;+  }+  return rc;+}++/* Split a page and insert a new node.+ * Set MDBX_TXN_ERROR on failure.+ * [in,out] mc Cursor pointing to the page and desired insertion index.+ * The cursor will be updated to point to the actual page and index where+ * the node got inserted after the split.+ * [in] newkey The key for the newly inserted node.+ * [in] newdata The data for the newly inserted node.+ * [in] newpgno The page number, if the new node is a branch node.+ * [in] nflags The NODE_ADD_FLAGS for the new node.+ * Returns 0 on success, non-zero on failure. */+static int mdbx_page_split(MDBX_cursor *mc, const MDBX_val *newkey,+                           MDBX_val *newdata, pgno_t newpgno, unsigned nflags) {+  unsigned flags;+  int rc = MDBX_SUCCESS, foliage = 0, did_split = 0;+  pgno_t pgno = 0;+  unsigned i, ptop;+  MDBX_env *env = mc->mc_txn->mt_env;+  MDBX_val sepkey, rkey, xdata;+  MDBX_page *copy = NULL;+  MDBX_page *rp, *pp;+  MDBX_cursor mn;+  DKBUF;++  MDBX_page *mp = mc->mc_pg[mc->mc_top];+  unsigned newindx = mc->mc_ki[mc->mc_top];+  unsigned nkeys = page_numkeys(mp);+  if (mdbx_audit_enabled()) {+    rc = mdbx_cursor_check(mc, C_UPDATING);+    if (unlikely(rc != MDBX_SUCCESS))+      return rc;+  }++  mdbx_cassert(mc,+               nkeys >= (unsigned)(IS_BRANCH(mp) ? MDBX_MINKEYS * 2 - 1 : 1));+  mdbx_debug("-----> splitting %s page %" PRIaPGNO+             " and adding [%s] at index %i/%i",+             IS_LEAF(mp) ? "leaf" : "branch", mp->mp_pgno, DKEY(newkey),+             mc->mc_ki[mc->mc_top], nkeys);++  /* Create a right sibling. */+  if ((rc = mdbx_page_new(mc, mp->mp_flags, 1, &rp)))+    return rc;+  rp->mp_leaf2_ksize = mp->mp_leaf2_ksize;+  mdbx_debug("new right sibling: page %" PRIaPGNO, rp->mp_pgno);++  /* Usually when splitting the root page, the cursor+   * height is 1. But when called from mdbx_update_key,+   * the cursor height may be greater because it walks+   * up the stack while finding the branch slot to update. */+  if (mc->mc_top < 1) {+    if ((rc = mdbx_page_new(mc, P_BRANCH, 1, &pp)))+      goto done;+    /* shift current top to make room for new parent */+    mdbx_cassert(mc, mc->mc_snum < 2 && mc->mc_db->md_depth > 0);+    mc->mc_pg[2] = mc->mc_pg[1];+    mc->mc_ki[2] = mc->mc_ki[1];+    mc->mc_pg[1] = mc->mc_pg[0];+    mc->mc_ki[1] = mc->mc_ki[0];+    mc->mc_pg[0] = pp;+    mc->mc_ki[0] = 0;+    mc->mc_db->md_root = pp->mp_pgno;+    mdbx_debug("root split! new root = %" PRIaPGNO, pp->mp_pgno);+    foliage = mc->mc_db->md_depth++;++    /* Add left (implicit) pointer. */+    if (unlikely((rc = mdbx_node_add_branch(mc, 0, NULL, mp->mp_pgno)) !=+                 MDBX_SUCCESS)) {+      /* undo the pre-push */+      mc->mc_pg[0] = mc->mc_pg[1];+      mc->mc_ki[0] = mc->mc_ki[1];+      mc->mc_db->md_root = mp->mp_pgno;+      mc->mc_db->md_depth--;+      goto done;+    }+    mc->mc_snum++;+    mc->mc_top++;+    ptop = 0;+  } else {+    ptop = mc->mc_top - 1;+    mdbx_debug("parent branch page is %" PRIaPGNO, mc->mc_pg[ptop]->mp_pgno);+  }++  cursor_copy_internal(mc, &mn);+  mn.mc_xcursor = NULL;+  mn.mc_pg[mn.mc_top] = rp;+  mn.mc_ki[mn.mc_top] = 0;+  mn.mc_ki[ptop] = mc->mc_ki[ptop] + 1;++  unsigned split_indx;+  if (nflags & MDBX_APPEND) {+    mn.mc_ki[mn.mc_top] = 0;+    sepkey = *newkey;+    split_indx = newindx;+    nkeys = 0;+  } else {+    split_indx = (nkeys + 1) / 2;+    if (IS_LEAF2(rp)) {+      char *split, *ins;+      unsigned lsize, rsize, ksize;+      /* Move half of the keys to the right sibling */+      const int x = mc->mc_ki[mc->mc_top] - split_indx;+      ksize = mc->mc_db->md_xsize;+      split = page_leaf2key(mp, split_indx, ksize);+      rsize = (nkeys - split_indx) * ksize;+      lsize = (nkeys - split_indx) * sizeof(indx_t);+      mdbx_cassert(mc, mp->mp_lower >= lsize);+      mp->mp_lower -= (indx_t)lsize;+      mdbx_cassert(mc, rp->mp_lower + lsize <= UINT16_MAX);+      rp->mp_lower += (indx_t)lsize;+      mdbx_cassert(mc, mp->mp_upper + rsize - lsize <= UINT16_MAX);+      mp->mp_upper += (indx_t)(rsize - lsize);+      mdbx_cassert(mc, rp->mp_upper >= rsize - lsize);+      rp->mp_upper -= (indx_t)(rsize - lsize);+      sepkey.iov_len = ksize;+      if (newindx == split_indx) {+        sepkey.iov_base = newkey->iov_base;+      } else {+        sepkey.iov_base = split;+      }+      if (x < 0) {+        mdbx_cassert(mc, ksize >= sizeof(indx_t));+        ins = page_leaf2key(mp, mc->mc_ki[mc->mc_top], ksize);+        memcpy(rp->mp_ptrs, split, rsize);+        sepkey.iov_base = rp->mp_ptrs;+        memmove(ins + ksize, ins, (split_indx - mc->mc_ki[mc->mc_top]) * ksize);+        memcpy(ins, newkey->iov_base, ksize);+        mdbx_cassert(mc, UINT16_MAX - mp->mp_lower >= (int)sizeof(indx_t));+        mp->mp_lower += sizeof(indx_t);+        mdbx_cassert(mc, mp->mp_upper >= ksize - sizeof(indx_t));+        mp->mp_upper -= (indx_t)(ksize - sizeof(indx_t));+      } else {+        memcpy(rp->mp_ptrs, split, x * ksize);+        ins = page_leaf2key(rp, x, ksize);+        memcpy(ins, newkey->iov_base, ksize);+        memcpy(ins + ksize, split + x * ksize, rsize - x * ksize);+        mdbx_cassert(mc, UINT16_MAX - rp->mp_lower >= (int)sizeof(indx_t));+        rp->mp_lower += sizeof(indx_t);+        mdbx_cassert(mc, rp->mp_upper >= ksize - sizeof(indx_t));+        rp->mp_upper -= (indx_t)(ksize - sizeof(indx_t));+        mdbx_cassert(mc, x <= (int)UINT16_MAX);+        mc->mc_ki[mc->mc_top] = (indx_t)x;+      }+    } else {+      /* Maximum free space in an empty page */+      const unsigned pmax = page_space(env);+      const size_t nsize = IS_LEAF(mp) ? leaf_size(env, newkey, newdata)+                                       : branch_size(env, newkey);++      /* grab a page to hold a temporary copy */+      copy = mdbx_page_malloc(mc->mc_txn, 1);+      if (unlikely(copy == NULL)) {+        rc = MDBX_ENOMEM;+        goto done;+      }+      copy->mp_pgno = mp->mp_pgno;+      copy->mp_flags = mp->mp_flags;+      copy->mp_txnid = INVALID_TXNID;+      copy->mp_lower = 0;+      copy->mp_upper = (indx_t)page_space(env);++      /* prepare to insert */+      for (unsigned j = i = 0; i < nkeys; i++) {+        if (i == newindx)+          copy->mp_ptrs[j++] = 0;+        copy->mp_ptrs[j++] = mp->mp_ptrs[i];+      }++      /* When items are relatively large the split point needs+       * to be checked, because being off-by-one will make the+       * difference between success or failure in mdbx_node_add.+       *+       * It's also relevant if a page happens to be laid out+       * such that one half of its nodes are all "small" and+       * the other half of its nodes are "large." If the new+       * item is also "large" and falls on the half with+       * "large" nodes, it also may not fit.+       *+       * As a final tweak, if the new item goes on the last+       * spot on the page (and thus, onto the new page), bias+       * the split so the new page is emptier than the old page.+       * This yields better packing during sequential inserts. */+      if (nkeys < 32 || nsize > pmax / 16 || newindx >= nkeys) {+        /* Find split point */+        int dir;+        size_t psize = 0;+        unsigned k;+        if (newindx <= split_indx || newindx >= nkeys) {+          i = 0;+          dir = 1;+          k = (newindx >= nkeys) ? nkeys : split_indx + 1 + IS_LEAF(mp);+          split_indx = k - 1;+        } else {+          i = nkeys;+          dir = -1;+          k = split_indx - 1;+          split_indx += 1;+        }+        do {+          if (i == newindx) {+            psize += nsize;+          } else {+            MDBX_node *node =+                (MDBX_node *)((char *)mp + copy->mp_ptrs[i] + PAGEHDRSZ);+            psize += NODESIZE + node_ks(node) + sizeof(indx_t);+            if (IS_LEAF(mp))+              psize += F_ISSET(node_flags(node), F_BIGDATA) ? sizeof(pgno_t)+                                                            : node_ds(node);+            psize = EVEN(psize);+          }+          if (psize > pmax) {+            split_indx = i + (dir < 0);+            break;+          }+          i += dir;+        } while (i != k);+      }++      if (split_indx == newindx) {+        sepkey.iov_len = newkey->iov_len;+        sepkey.iov_base = newkey->iov_base;+      } else {+        MDBX_node *node =+            (MDBX_node *)((char *)mp + copy->mp_ptrs[split_indx] + PAGEHDRSZ);+        sepkey.iov_len = node_ks(node);+        sepkey.iov_base = node_key(node);+      }+    }+  }++  mdbx_debug("separator is %d [%s]", split_indx, DKEY(&sepkey));+  if (mdbx_audit_enabled()) {+    rc = mdbx_cursor_check(mc, C_UPDATING);+    if (unlikely(rc != MDBX_SUCCESS))+      goto done;+    rc = mdbx_cursor_check(&mn, C_UPDATING);+    if (unlikely(rc != MDBX_SUCCESS))+      goto done;+  }++  /* Copy separator key to the parent. */+  if (page_room(mn.mc_pg[ptop]) < branch_size(env, &sepkey)) {+    const int snum = mc->mc_snum;+    const int depth = mc->mc_db->md_depth;+    mn.mc_snum--;+    mn.mc_top--;+    did_split = 1;+    /* We want other splits to find mn when doing fixups */+    WITH_CURSOR_TRACKING(+        mn, rc = mdbx_page_split(&mn, &sepkey, NULL, rp->mp_pgno, 0));+    if (unlikely(rc != MDBX_SUCCESS))+      goto done;+    mdbx_cassert(mc, (int)mc->mc_snum - snum == mc->mc_db->md_depth - depth);+    if (mdbx_audit_enabled()) {+      rc = mdbx_cursor_check(mc, C_UPDATING);+      if (unlikely(rc != MDBX_SUCCESS))+        goto done;+    }++    /* root split? */+    ptop += mc->mc_snum - snum;++    /* Right page might now have changed parent.+     * Check if left page also changed parent. */+    if (mn.mc_pg[ptop] != mc->mc_pg[ptop] &&+        mc->mc_ki[ptop] >= page_numkeys(mc->mc_pg[ptop])) {+      for (i = 0; i < ptop; i++) {+        mc->mc_pg[i] = mn.mc_pg[i];+        mc->mc_ki[i] = mn.mc_ki[i];+      }+      mc->mc_pg[ptop] = mn.mc_pg[ptop];+      if (mn.mc_ki[ptop]) {+        mc->mc_ki[ptop] = mn.mc_ki[ptop] - 1;+      } else {+        /* find right page's left sibling */+        mc->mc_ki[ptop] = mn.mc_ki[ptop];+        rc = mdbx_cursor_sibling(mc, SIBLING_LEFT);+      }+    }+  } else {+    mn.mc_top--;+    rc = mdbx_node_add_branch(&mn, mn.mc_ki[ptop], &sepkey, rp->mp_pgno);+    mn.mc_top++;+  }+  if (unlikely(rc != MDBX_SUCCESS)) {+    if (rc == MDBX_NOTFOUND) /* improper mdbx_cursor_sibling() result */ {+      mdbx_error("unexpected %s", "MDBX_NOTFOUND");+      rc = MDBX_PROBLEM;+    }+    goto done;+  }++  if (nflags & MDBX_APPEND) {+    mc->mc_pg[mc->mc_top] = rp;+    mc->mc_ki[mc->mc_top] = 0;+    switch (PAGETYPE(rp)) {+    case P_BRANCH: {+      mdbx_cassert(mc, (nflags & (F_BIGDATA | F_SUBDATA | F_DUPDATA)) == 0);+      mdbx_cassert(mc, newpgno != 0 && newpgno != P_INVALID);+      rc = mdbx_node_add_branch(mc, 0, newkey, newpgno);+    } break;+    case P_LEAF: {+      mdbx_cassert(mc, newpgno == 0 || newpgno == P_INVALID);+      rc = mdbx_node_add_leaf(mc, 0, newkey, newdata, nflags);+    } break;+    case P_LEAF | P_LEAF2: {+      mdbx_cassert(mc, (nflags & (F_BIGDATA | F_SUBDATA | F_DUPDATA)) == 0);+      mdbx_cassert(mc, newpgno == 0 || newpgno == P_INVALID);+      rc = mdbx_node_add_leaf2(mc, 0, newkey);+    } break;+    default:+      rc = bad_page(rp, "wrong page-type %u\n", PAGETYPE(rp));+    }+    if (rc)+      goto done;+    for (i = 0; i < mc->mc_top; i++)+      mc->mc_ki[i] = mn.mc_ki[i];+  } else if (!IS_LEAF2(mp)) {+    /* Move nodes */+    mc->mc_pg[mc->mc_top] = rp;+    i = split_indx;+    indx_t n = 0;+    do {+      MDBX_val *rdata = NULL;+      if (i == newindx) {+        rkey.iov_base = newkey->iov_base;+        rkey.iov_len = newkey->iov_len;+        if (IS_LEAF(mp)) {+          rdata = newdata;+        } else+          pgno = newpgno;+        flags = nflags;+        /* Update index for the new key. */+        mc->mc_ki[mc->mc_top] = n;+      } else {+        MDBX_node *node =+            (MDBX_node *)((char *)mp + copy->mp_ptrs[i] + PAGEHDRSZ);+        rkey.iov_base = node_key(node);+        rkey.iov_len = node_ks(node);+        if (IS_LEAF(mp)) {+          xdata.iov_base = node_data(node);+          xdata.iov_len = node_ds(node);+          rdata = &xdata;+        } else+          pgno = node_pgno(node);+        flags = node_flags(node);+      }++      switch (PAGETYPE(rp)) {+      case P_BRANCH: {+        mdbx_cassert(mc, 0 == (uint16_t)flags);+        if (n == 0) {+          /* First branch index doesn't need key data. */+          rkey.iov_len = 0;+        }+        rc = mdbx_node_add_branch(mc, n, &rkey, pgno);+      } break;+      case P_LEAF: {+        mdbx_cassert(mc, pgno == 0);+        mdbx_cassert(mc, rdata != NULL);+        rc = mdbx_node_add_leaf(mc, n, &rkey, rdata, flags);+      } break;+      /* case P_LEAF | P_LEAF2: {+        mdbx_cassert(mc, (nflags & (F_BIGDATA | F_SUBDATA | F_DUPDATA)) == 0);+        mdbx_cassert(mc, gno == 0);+        rc = mdbx_node_add_leaf2(mc, n, &rkey);+      } break; */+      default:+        rc = bad_page(rp, "wrong page-type %u\n", PAGETYPE(rp));+      }+      if (rc)+        goto done;++      if (i == nkeys) {+        i = 0;+        n = 0;+        mc->mc_pg[mc->mc_top] = copy;+      } else {+        i++;+        n++;+      }+    } while (i != split_indx);++    nkeys = page_numkeys(copy);+    for (i = 0; i < nkeys; i++)+      mp->mp_ptrs[i] = copy->mp_ptrs[i];+    mp->mp_lower = copy->mp_lower;+    mp->mp_upper = copy->mp_upper;+    memcpy(page_node(mp, nkeys - 1), page_node(copy, nkeys - 1),+           env->me_psize - copy->mp_upper - PAGEHDRSZ);++    /* reset back to original page */+    if (newindx < split_indx) {+      mc->mc_pg[mc->mc_top] = mp;+    } else {+      mc->mc_pg[mc->mc_top] = rp;+      mc->mc_ki[ptop]++;+      /* Make sure mc_ki is still valid. */+      if (mn.mc_pg[ptop] != mc->mc_pg[ptop] &&+          mc->mc_ki[ptop] >= page_numkeys(mc->mc_pg[ptop])) {+        for (i = 0; i <= ptop; i++) {+          mc->mc_pg[i] = mn.mc_pg[i];+          mc->mc_ki[i] = mn.mc_ki[i];+        }+      }+    }+    if (nflags & MDBX_RESERVE) {+      MDBX_node *node = page_node(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);+      if (!(node_flags(node) & F_BIGDATA))+        newdata->iov_base = node_data(node);+    }+  } else {+    if (newindx >= split_indx) {+      mc->mc_pg[mc->mc_top] = rp;+      mc->mc_ki[ptop]++;+      /* Make sure mc_ki is still valid. */+      if (mn.mc_pg[ptop] != mc->mc_pg[ptop] &&+          mc->mc_ki[ptop] >= page_numkeys(mc->mc_pg[ptop])) {+        for (i = 0; i <= ptop; i++) {+          mc->mc_pg[i] = mn.mc_pg[i];+          mc->mc_ki[i] = mn.mc_ki[i];+        }+      }+    }+  }++  {+    /* Adjust other cursors pointing to mp */+    MDBX_cursor *m2, *m3;+    MDBX_dbi dbi = mc->mc_dbi;+    nkeys = page_numkeys(mp);++    for (m2 = mc->mc_txn->tw.cursors[dbi]; m2; m2 = m2->mc_next) {+      m3 = (mc->mc_flags & C_SUB) ? &m2->mc_xcursor->mx_cursor : m2;+      if (m3 == mc)+        continue;+      if (!(m2->mc_flags & m3->mc_flags & C_INITIALIZED))+        continue;+      if (foliage) {+        int k;+        /* sub cursors may be on different DB */+        if (m3->mc_pg[0] != mp)+          continue;+        /* root split */+        for (k = foliage; k >= 0; k--) {+          m3->mc_ki[k + 1] = m3->mc_ki[k];+          m3->mc_pg[k + 1] = m3->mc_pg[k];+        }+        m3->mc_ki[0] = (m3->mc_ki[0] >= nkeys) ? 1 : 0;+        m3->mc_pg[0] = mc->mc_pg[0];+        m3->mc_snum++;+        m3->mc_top++;+      }+      if (m3->mc_top >= mc->mc_top && m3->mc_pg[mc->mc_top] == mp) {+        if (m3->mc_ki[mc->mc_top] >= newindx && !(nflags & MDBX_SPLIT_REPLACE))+          m3->mc_ki[mc->mc_top]++;+        if (m3->mc_ki[mc->mc_top] >= nkeys) {+          m3->mc_pg[mc->mc_top] = rp;+          mdbx_cassert(mc, m3->mc_ki[mc->mc_top] >= nkeys);+          m3->mc_ki[mc->mc_top] -= (indx_t)nkeys;+          for (i = 0; i < mc->mc_top; i++) {+            m3->mc_ki[i] = mn.mc_ki[i];+            m3->mc_pg[i] = mn.mc_pg[i];+          }+        }+      } else if (!did_split && m3->mc_top >= ptop &&+                 m3->mc_pg[ptop] == mc->mc_pg[ptop] &&+                 m3->mc_ki[ptop] >= mc->mc_ki[ptop]) {+        m3->mc_ki[ptop]++;+      }+      if (XCURSOR_INITED(m3) && IS_LEAF(mp))+        XCURSOR_REFRESH(m3, m3->mc_pg[mc->mc_top], m3->mc_ki[mc->mc_top]);+    }+  }+  mdbx_debug("mp left: %d, rp left: %d", page_room(mp), page_room(rp));++done:+  if (copy) /* tmp page */+    mdbx_dpage_free(env, copy, 1);+  if (unlikely(rc))+    mc->mc_txn->mt_flags |= MDBX_TXN_ERROR;+  return rc;+}++int mdbx_put(MDBX_txn *txn, MDBX_dbi dbi, const MDBX_val *key, MDBX_val *data,+             unsigned flags) {+  int rc = check_txn_rw(txn, MDBX_TXN_BLOCKED);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  if (unlikely(!key || !data))+    return MDBX_EINVAL;++  if (unlikely(!mdbx_txn_dbi_exists(txn, dbi, DBI_USRVALID)))+    return MDBX_BAD_DBI;++  if (unlikely(flags & ~(MDBX_NOOVERWRITE | MDBX_NODUPDATA | MDBX_ALLDUPS |+                         MDBX_ALLDUPS | MDBX_RESERVE | MDBX_APPEND |+                         MDBX_APPENDDUP | MDBX_CURRENT | MDBX_MULTIPLE)))+    return MDBX_EINVAL;++  if (unlikely(txn->mt_flags & (MDBX_TXN_RDONLY | MDBX_TXN_BLOCKED)))+    return (txn->mt_flags & MDBX_TXN_RDONLY) ? MDBX_EACCESS : MDBX_BAD_TXN;++  MDBX_cursor_couple cx;+  rc = mdbx_cursor_init(&cx.outer, txn, dbi);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;+  cx.outer.mc_next = txn->tw.cursors[dbi];+  txn->tw.cursors[dbi] = &cx.outer;++  /* LY: support for update (explicit overwrite) */+  if (flags & MDBX_CURRENT) {+    rc = mdbx_cursor_get(&cx.outer, (MDBX_val *)key, NULL, MDBX_SET);+    if (likely(rc == MDBX_SUCCESS) &&+        (txn->mt_dbs[dbi].md_flags & MDBX_DUPSORT) &&+        (flags & MDBX_ALLDUPS) == 0) {+      /* LY: allows update (explicit overwrite) only for unique keys */+      MDBX_node *node = page_node(cx.outer.mc_pg[cx.outer.mc_top],+                                  cx.outer.mc_ki[cx.outer.mc_top]);+      if (F_ISSET(node_flags(node), F_DUPDATA)) {+        mdbx_tassert(txn, XCURSOR_INITED(&cx.outer) &&+                              cx.outer.mc_xcursor->mx_db.md_entries > 1);+        rc = MDBX_EMULTIVAL;+      }+    }+  }++  if (likely(rc == MDBX_SUCCESS))+    rc = mdbx_cursor_put(&cx.outer, key, data, flags);+  txn->tw.cursors[dbi] = cx.outer.mc_next;++  return rc;+}++/**** COPYING *****************************************************************/++#ifndef MDBX_WBUF+#define MDBX_WBUF ((size_t)1024 * 1024)+#endif++/* State needed for a double-buffering compacting copy. */+typedef struct mdbx_copy {+  MDBX_env *mc_env;+  MDBX_txn *mc_txn;+  mdbx_condpair_t mc_condpair;+  uint8_t *mc_wbuf[2];+  uint8_t *mc_over[2];+  size_t mc_wlen[2];+  size_t mc_olen[2];+  mdbx_filehandle_t mc_fd;+  /* Error code.  Never cleared if set.  Both threads can set nonzero+   * to fail the copy.  Not mutex-protected, MDBX expects atomic int. */+  volatile int mc_error;+  pgno_t mc_next_pgno;+  volatile unsigned mc_head;+  volatile unsigned mc_tail;+} mdbx_copy;++/* Dedicated writer thread for compacting copy. */+static THREAD_RESULT __cold THREAD_CALL mdbx_env_copythr(void *arg) {+  mdbx_copy *my = arg;++#if defined(EPIPE) && !(defined(_WIN32) || defined(_WIN64))+  sigset_t sigset;+  sigemptyset(&sigset);+  sigaddset(&sigset, SIGPIPE);+  my->mc_error = pthread_sigmask(SIG_BLOCK, &sigset, NULL);+#endif /* EPIPE */++  mdbx_condpair_lock(&my->mc_condpair);+  while (!my->mc_error) {+    while (my->mc_tail == my->mc_head && !my->mc_error) {+      int err = mdbx_condpair_wait(&my->mc_condpair, true);+      if (err != MDBX_SUCCESS) {+        my->mc_error = err;+        goto bailout;+      }+    }+    const unsigned toggle = my->mc_tail & 1;+    size_t wsize = my->mc_wlen[toggle];+    if (wsize == 0) {+      my->mc_tail += 1;+      break /* EOF */;+    }+    my->mc_wlen[toggle] = 0;+    uint8_t *ptr = my->mc_wbuf[toggle];+  again:+    if (!my->mc_error) {+      int err = mdbx_write(my->mc_fd, ptr, wsize);+      if (err != MDBX_SUCCESS) {+#if defined(EPIPE) && !(defined(_WIN32) || defined(_WIN64))+        if (err == EPIPE) {+          /* Collect the pending SIGPIPE,+           * otherwise at least OS X gives it to the process on thread-exit. */+          int unused;+          sigwait(&sigset, &unused);+        }+#endif /* EPIPE */+        my->mc_error = err;+        goto bailout;+      }+    }++    /* If there's an overflow page tail, write it too */+    wsize = my->mc_olen[toggle];+    if (wsize) {+      my->mc_olen[toggle] = 0;+      ptr = my->mc_over[toggle];+      goto again;+    }+    my->mc_tail += 1;+    mdbx_condpair_signal(&my->mc_condpair, false);+  }+bailout:+  mdbx_condpair_unlock(&my->mc_condpair);+  return (THREAD_RESULT)0;+}++/* Give buffer and/or MDBX_EOF to writer thread, await unused buffer. */+static __cold int mdbx_env_cthr_toggle(mdbx_copy *my) {+  mdbx_condpair_lock(&my->mc_condpair);+  mdbx_assert(my->mc_env, my->mc_head - my->mc_tail < 2 || my->mc_error);+  my->mc_head += 1;+  mdbx_condpair_signal(&my->mc_condpair, true);+  while (!my->mc_error &&+         my->mc_head - my->mc_tail == 2 /* both buffers in use */) {+    int err = mdbx_condpair_wait(&my->mc_condpair, false);+    if (err != MDBX_SUCCESS)+      my->mc_error = err;+  }+  mdbx_condpair_unlock(&my->mc_condpair);+  return my->mc_error;+}++/* Depth-first tree traversal for compacting copy.+ * [in] my control structure.+ * [in,out] pg database root.+ * [in] flags includes F_DUPDATA if it is a sorted-duplicate sub-DB. */+static __cold int mdbx_env_cwalk(mdbx_copy *my, pgno_t *pg, int flags) {+  MDBX_cursor_couple couple;+  MDBX_page *mo, *mp, *leaf;+  char *buf, *ptr;+  int rc;+  unsigned i;++  /* Empty DB, nothing to do */+  if (*pg == P_INVALID)+    return MDBX_SUCCESS;++  memset(&couple, 0, sizeof(couple));+  couple.outer.mc_snum = 1;+  couple.outer.mc_txn = my->mc_txn;+  couple.outer.mc_flags = couple.inner.mx_cursor.mc_flags =+      C_COPYING | C_SKIPORD;++  rc = mdbx_page_get(&couple.outer, *pg, &couple.outer.mc_pg[0], NULL,+                     my->mc_txn->mt_txnid);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;+  rc = mdbx_page_search_root(&couple.outer, NULL, MDBX_PS_FIRST);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  /* Make cursor pages writable */+  buf = ptr = mdbx_malloc(pgno2bytes(my->mc_env, couple.outer.mc_snum));+  if (buf == NULL)+    return MDBX_ENOMEM;++  for (i = 0; i < couple.outer.mc_top; i++) {+    mdbx_page_copy((MDBX_page *)ptr, couple.outer.mc_pg[i],+                   my->mc_env->me_psize);+    couple.outer.mc_pg[i] = (MDBX_page *)ptr;+    ptr += my->mc_env->me_psize;+  }++  /* This is writable space for a leaf page. Usually not needed. */+  leaf = (MDBX_page *)ptr;++  while (couple.outer.mc_snum > 0) {+    mp = couple.outer.mc_pg[couple.outer.mc_top];+    unsigned n = page_numkeys(mp);++    if (IS_LEAF(mp)) {+      if (!IS_LEAF2(mp) && !(flags & F_DUPDATA)) {+        for (i = 0; i < n; i++) {+          MDBX_node *node = page_node(mp, i);+          if (node_flags(node) & F_BIGDATA) {+            MDBX_page *omp;++            /* Need writable leaf */+            if (mp != leaf) {+              couple.outer.mc_pg[couple.outer.mc_top] = leaf;+              mdbx_page_copy(leaf, mp, my->mc_env->me_psize);+              mp = leaf;+              node = page_node(mp, i);+            }++            const pgno_t pgno = node_largedata_pgno(node);+            poke_pgno(node_data(node), my->mc_next_pgno);+            rc = mdbx_page_get(&couple.outer, pgno, &omp, NULL,+                               pp_txnid4chk(mp, my->mc_txn));+            if (unlikely(rc != MDBX_SUCCESS))+              goto done;+            unsigned toggle = my->mc_head & 1;+            if (my->mc_wlen[toggle] + my->mc_env->me_psize > MDBX_WBUF) {+              rc = mdbx_env_cthr_toggle(my);+              if (unlikely(rc != MDBX_SUCCESS))+                goto done;+              toggle = my->mc_head & 1;+            }+            mo = (MDBX_page *)(my->mc_wbuf[toggle] + my->mc_wlen[toggle]);+            memcpy(mo, omp, my->mc_env->me_psize);+            mo->mp_pgno = my->mc_next_pgno;+            my->mc_next_pgno += omp->mp_pages;+            my->mc_wlen[toggle] += my->mc_env->me_psize;+            if (omp->mp_pages > 1) {+              my->mc_olen[toggle] = pgno2bytes(my->mc_env, omp->mp_pages - 1);+              my->mc_over[toggle] = (uint8_t *)omp + my->mc_env->me_psize;+              rc = mdbx_env_cthr_toggle(my);+              if (unlikely(rc != MDBX_SUCCESS))+                goto done;+              toggle = my->mc_head & 1;+            }+          } else if (node_flags(node) & F_SUBDATA) {+            if (!MDBX_DISABLE_PAGECHECKS &&+                unlikely(node_ds(node) != sizeof(MDBX_db))) {+              rc = MDBX_CORRUPTED;+              goto done;+            }++            /* Need writable leaf */+            if (mp != leaf) {+              couple.outer.mc_pg[couple.outer.mc_top] = leaf;+              mdbx_page_copy(leaf, mp, my->mc_env->me_psize);+              mp = leaf;+              node = page_node(mp, i);+            }++            MDBX_db db;+            memcpy(&db, node_data(node), sizeof(MDBX_db));+            rc = mdbx_env_cwalk(my, &db.md_root, node_flags(node) & F_DUPDATA);+            if (rc)+              goto done;+            memcpy(node_data(node), &db, sizeof(MDBX_db));+          }+        }+      }+    } else {+      couple.outer.mc_ki[couple.outer.mc_top]++;+      if (couple.outer.mc_ki[couple.outer.mc_top] < n) {+      again:+        rc = mdbx_page_get(+            &couple.outer,+            node_pgno(page_node(mp, couple.outer.mc_ki[couple.outer.mc_top])),+            &mp, NULL, pp_txnid4chk(mp, my->mc_txn));+        if (unlikely(rc != MDBX_SUCCESS))+          goto done;+        couple.outer.mc_top++;+        couple.outer.mc_snum++;+        couple.outer.mc_ki[couple.outer.mc_top] = 0;+        if (IS_BRANCH(mp)) {+          /* Whenever we advance to a sibling branch page,+           * we must proceed all the way down to its first leaf. */+          mdbx_page_copy(couple.outer.mc_pg[couple.outer.mc_top], mp,+                         my->mc_env->me_psize);+          goto again;+        } else+          couple.outer.mc_pg[couple.outer.mc_top] = mp;+        continue;+      }+    }+    unsigned toggle = my->mc_head & 1;+    if (my->mc_wlen[toggle] + my->mc_wlen[toggle] > MDBX_WBUF) {+      rc = mdbx_env_cthr_toggle(my);+      if (unlikely(rc != MDBX_SUCCESS))+        goto done;+      toggle = my->mc_head & 1;+    }+    mo = (MDBX_page *)(my->mc_wbuf[toggle] + my->mc_wlen[toggle]);+    mdbx_page_copy(mo, mp, my->mc_env->me_psize);+    mo->mp_pgno = my->mc_next_pgno++;+    my->mc_wlen[toggle] += my->mc_env->me_psize;+    if (couple.outer.mc_top) {+      /* Update parent if there is one */+      node_set_pgno(page_node(couple.outer.mc_pg[couple.outer.mc_top - 1],+                              couple.outer.mc_ki[couple.outer.mc_top - 1]),+                    mo->mp_pgno);+      mdbx_cursor_pop(&couple.outer);+    } else {+      /* Otherwise we're done */+      *pg = mo->mp_pgno;+      break;+    }+  }+done:+  mdbx_free(buf);+  return rc;+}++static __cold void compact_fixup_meta(MDBX_env *env, MDBX_meta *meta) {+  /* Calculate filesize taking in account shrink/growing thresholds */+  if (meta->mm_geo.next != meta->mm_geo.now) {+    meta->mm_geo.now = meta->mm_geo.next;+    const pgno_t aligner = pv2pages(+        meta->mm_geo.grow_pv ? meta->mm_geo.grow_pv : meta->mm_geo.shrink_pv);+    if (aligner) {+      const pgno_t aligned = pgno_align2os_pgno(+          env, meta->mm_geo.next + aligner - meta->mm_geo.next % aligner);+      meta->mm_geo.now = aligned;+    }+  }++  if (meta->mm_geo.now < meta->mm_geo.lower)+    meta->mm_geo.now = meta->mm_geo.lower;+  if (meta->mm_geo.now > meta->mm_geo.upper)+    meta->mm_geo.now = meta->mm_geo.upper;++  /* Update signature */+  assert(meta->mm_geo.now >= meta->mm_geo.next);+  unaligned_poke_u64(4, meta->mm_datasync_sign, mdbx_meta_sign(meta));+}++/* Make resizeable */+static __cold void make_sizeable(MDBX_meta *meta) {+  meta->mm_geo.lower = MIN_PAGENO;+  if (meta->mm_geo.grow_pv == 0) {+    const pgno_t step = 1 + (meta->mm_geo.upper - meta->mm_geo.lower) / 42;+    meta->mm_geo.grow_pv = pages2pv(step);+  }+  if (meta->mm_geo.shrink_pv == 0) {+    const pgno_t step = pv2pages(meta->mm_geo.grow_pv) << 1;+    meta->mm_geo.shrink_pv = pages2pv(step);+  }+}++/* Copy environment with compaction. */+static __cold int mdbx_env_compact(MDBX_env *env, MDBX_txn *read_txn,+                                   mdbx_filehandle_t fd, uint8_t *buffer,+                                   const bool dest_is_pipe, const int flags) {+  const size_t meta_bytes = pgno2bytes(env, NUM_METAS);+  uint8_t *const data_buffer =+      buffer + ceil_powerof2(meta_bytes, env->me_os_psize);+  MDBX_meta *const meta = mdbx_init_metas(env, buffer);+  mdbx_meta_set_txnid(env, meta, read_txn->mt_txnid);++  if (flags & MDBX_CP_FORCE_DYNAMIC_SIZE)+    make_sizeable(meta);++  /* copy canary sequences if present */+  if (read_txn->mt_canary.v) {+    meta->mm_canary = read_txn->mt_canary;+    meta->mm_canary.v = mdbx_meta_txnid_stable(env, meta);+  }++  /* Set metapage 1 with current main DB */+  pgno_t new_root, root = read_txn->mt_dbs[MAIN_DBI].md_root;+  if ((new_root = root) == P_INVALID) {+    /* When the DB is empty, handle it specially to+     * fix any breakage like page leaks from ITS#8174. */+    meta->mm_dbs[MAIN_DBI].md_flags = read_txn->mt_dbs[MAIN_DBI].md_flags;+    compact_fixup_meta(env, meta);+    if (dest_is_pipe) {+      int rc = mdbx_write(fd, buffer, meta_bytes);+      if (rc != MDBX_SUCCESS)+        return rc;+    }+  } else {+    /* Count free pages + GC pages.  Subtract from last_pg+     * to find the new last_pg, which also becomes the new root. */+    pgno_t freecount = 0;+    MDBX_cursor_couple couple;+    MDBX_val key, data;++    int rc = mdbx_cursor_init(&couple.outer, read_txn, FREE_DBI);+    if (unlikely(rc != MDBX_SUCCESS))+      return rc;+    while ((rc = mdbx_cursor_get(&couple.outer, &key, &data, MDBX_NEXT)) == 0)+      freecount += *(pgno_t *)data.iov_base;+    if (unlikely(rc != MDBX_NOTFOUND))+      return rc;++    freecount += read_txn->mt_dbs[FREE_DBI].md_branch_pages ++                 read_txn->mt_dbs[FREE_DBI].md_leaf_pages ++                 read_txn->mt_dbs[FREE_DBI].md_overflow_pages;++    new_root = read_txn->mt_next_pgno - 1 - freecount;+    meta->mm_geo.next = new_root + 1;+    meta->mm_dbs[MAIN_DBI] = read_txn->mt_dbs[MAIN_DBI];+    meta->mm_dbs[MAIN_DBI].md_root = new_root;++    mdbx_copy ctx;+    memset(&ctx, 0, sizeof(ctx));+    rc = mdbx_condpair_init(&ctx.mc_condpair);+    if (unlikely(rc != MDBX_SUCCESS))+      return rc;++    memset(data_buffer, 0, MDBX_WBUF * 2);+    ctx.mc_wbuf[0] = data_buffer;+    ctx.mc_wbuf[1] = data_buffer + MDBX_WBUF;+    ctx.mc_next_pgno = NUM_METAS;+    ctx.mc_env = env;+    ctx.mc_fd = fd;+    ctx.mc_txn = read_txn;++    mdbx_thread_t thread;+    int thread_err = mdbx_thread_create(&thread, mdbx_env_copythr, &ctx);+    if (likely(thread_err == MDBX_SUCCESS)) {+      if (dest_is_pipe) {+        compact_fixup_meta(env, meta);+        rc = mdbx_write(fd, buffer, meta_bytes);+      }+      if (rc == MDBX_SUCCESS)+        rc = mdbx_env_cwalk(&ctx, &root, 0);+      mdbx_env_cthr_toggle(&ctx);+      mdbx_env_cthr_toggle(&ctx);+      thread_err = mdbx_thread_join(thread);+      mdbx_assert(env, (ctx.mc_tail == ctx.mc_head &&+                        ctx.mc_wlen[ctx.mc_head & 1] == 0) ||+                           ctx.mc_error);+      mdbx_condpair_destroy(&ctx.mc_condpair);+    }+    if (unlikely(thread_err != MDBX_SUCCESS))+      return thread_err;+    if (unlikely(rc != MDBX_SUCCESS))+      return rc;+    if (unlikely(ctx.mc_error != MDBX_SUCCESS))+      return ctx.mc_error;++    if (dest_is_pipe) {+      if (unlikely(root != new_root)) {+        mdbx_error("post-compactification root %" PRIaPGNO+                   " NE expected %" PRIaPGNO+                   " (source DB corrupted or has a page leak(s))",+                   root, new_root);+        return MDBX_CORRUPTED; /* page leak or corrupt DB */+      }+    } else {+      if (unlikely(root > new_root)) {+        mdbx_error("post-compactification root %" PRIaPGNO+                   " GT expected %" PRIaPGNO " (source DB corrupted)",+                   root, new_root);+        return MDBX_CORRUPTED; /* page leak or corrupt DB */+      }+      if (unlikely(root < new_root)) {+        mdbx_warning("post-compactification root %" PRIaPGNO+                     " LT expected %" PRIaPGNO " (page leak(s) in source DB)",+                     root, new_root);+        /* fixup meta */+        meta->mm_dbs[MAIN_DBI].md_root = root;+        meta->mm_geo.next = root + 1;+      }+      compact_fixup_meta(env, meta);+    }+  }++  /* Extend file if required */+  if (meta->mm_geo.now != meta->mm_geo.next) {+    const size_t whole_size = pgno2bytes(env, meta->mm_geo.now);+    if (!dest_is_pipe)+      return mdbx_ftruncate(fd, whole_size);++    const size_t used_size = pgno2bytes(env, meta->mm_geo.next);+    memset(data_buffer, 0, MDBX_WBUF);+    for (size_t offset = used_size; offset < whole_size;) {+      const size_t chunk =+          (MDBX_WBUF < whole_size - offset) ? MDBX_WBUF : whole_size - offset;+      /* copy to avoid EFAULT in case swapped-out */+      int rc = mdbx_write(fd, data_buffer, chunk);+      if (unlikely(rc != MDBX_SUCCESS))+        return rc;+      offset += chunk;+    }+  }+  return MDBX_SUCCESS;+}++/* Copy environment as-is. */+static __cold int mdbx_env_copy_asis(MDBX_env *env, MDBX_txn *read_txn,+                                     mdbx_filehandle_t fd, uint8_t *buffer,+                                     const bool dest_is_pipe, const int flags) {+  /* We must start the actual read txn after blocking writers */+  int rc = mdbx_txn_end(read_txn, MDBX_END_RESET_TMP);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  /* Temporarily block writers until we snapshot the meta pages */+  rc = mdbx_txn_lock(env, false);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  rc = mdbx_txn_renew0(read_txn, MDBX_TXN_RDONLY);+  if (unlikely(rc != MDBX_SUCCESS)) {+    mdbx_txn_unlock(env);+    return rc;+  }++  mdbx_jitter4testing(false);+  const size_t meta_bytes = pgno2bytes(env, NUM_METAS);+  /* Make a snapshot of meta-pages,+   * but writing ones after the data was flushed */+  memcpy(buffer, env->me_map, meta_bytes);+  MDBX_meta *const headcopy = /* LY: get pointer to the snapshot copy */+      (MDBX_meta *)(buffer + ((uint8_t *)mdbx_meta_head(env) - env->me_map));+  mdbx_txn_unlock(env);++  if (flags & MDBX_CP_FORCE_DYNAMIC_SIZE)+    make_sizeable(headcopy);+  /* Update signature to steady */+  unaligned_poke_u64(4, headcopy->mm_datasync_sign, mdbx_meta_sign(headcopy));++  /* Copy the data */+  const size_t whole_size = pgno_align2os_bytes(env, read_txn->mt_end_pgno);+  const size_t used_size = pgno2bytes(env, read_txn->mt_next_pgno);+  mdbx_jitter4testing(false);++  if (dest_is_pipe)+    rc = mdbx_write(fd, buffer, meta_bytes);++  uint8_t *const data_buffer =+      buffer + ceil_powerof2(meta_bytes, env->me_os_psize);+  for (size_t offset = meta_bytes; rc == MDBX_SUCCESS && offset < used_size;) {+#if MDBX_USE_SENDFILE+    static bool sendfile_unavailable;+    if (dest_is_pipe && likely(!sendfile_unavailable)) {+      off_t in_offset = offset;+      const ssize_t written =+          sendfile(fd, env->me_lazy_fd, &in_offset, used_size - offset);+      if (likely(written > 0)) {+        offset = in_offset;+        continue;+      }+      rc = MDBX_ENODATA;+      if (written == 0 || ignore_enosys(rc = errno) != MDBX_RESULT_TRUE)+        break;+      sendfile_unavailable = true;+    }+#endif /* MDBX_USE_SENDFILE */++#if MDBX_USE_COPYFILERANGE+    static bool copyfilerange_unavailable;+    if (!dest_is_pipe && likely(!copyfilerange_unavailable)) {+      off_t in_offset = offset, out_offset = offset;+      ssize_t bytes_copied = copy_file_range(+          env->me_lazy_fd, &in_offset, fd, &out_offset, used_size - offset, 0);+      if (likely(bytes_copied > 0)) {+        offset = in_offset;+        continue;+      }+      rc = MDBX_ENODATA;+      if (bytes_copied == 0 || ignore_enosys(rc = errno) != MDBX_RESULT_TRUE)+        break;+      copyfilerange_unavailable = true;+    }+#endif /* MDBX_USE_COPYFILERANGE */++    /* fallback to portable */+    const size_t chunk =+        (MDBX_WBUF < used_size - offset) ? MDBX_WBUF : used_size - offset;+    /* copy to avoid EFAULT in case swapped-out */+    memcpy(data_buffer, env->me_map + offset, chunk);+    rc = mdbx_write(fd, data_buffer, chunk);+    offset += chunk;+  }++  /* Extend file if required */+  if (likely(rc == MDBX_SUCCESS) && whole_size != used_size) {+    if (!dest_is_pipe)+      rc = mdbx_ftruncate(fd, whole_size);+    else {+      memset(data_buffer, 0, MDBX_WBUF);+      for (size_t offset = used_size;+           rc == MDBX_SUCCESS && offset < whole_size;) {+        const size_t chunk =+            (MDBX_WBUF < whole_size - offset) ? MDBX_WBUF : whole_size - offset;+        /* copy to avoid EFAULT in case swapped-out */+        rc = mdbx_write(fd, data_buffer, chunk);+        offset += chunk;+      }+    }+  }++  return rc;+}++__cold int mdbx_env_copy2fd(MDBX_env *env, mdbx_filehandle_t fd,+                            unsigned flags) {+  int rc = check_env(env, true);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  const int dest_is_pipe = mdbx_is_pipe(fd);+  if (MDBX_IS_ERROR(dest_is_pipe))+    return dest_is_pipe;++  if (!dest_is_pipe) {+    rc = mdbx_fseek(fd, 0);+    if (unlikely(rc != MDBX_SUCCESS))+      return rc;+  }++  const size_t buffer_size =+      pgno_align2os_bytes(env, NUM_METAS) ++      ceil_powerof2(((flags & MDBX_CP_COMPACT) ? MDBX_WBUF * 2 : MDBX_WBUF),+                    env->me_os_psize);++  uint8_t *buffer = NULL;+  rc = mdbx_memalign_alloc(env->me_os_psize, buffer_size, (void **)&buffer);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  MDBX_txn *read_txn = NULL;+  /* Do the lock/unlock of the reader mutex before starting the+   * write txn. Otherwise other read txns could block writers. */+  rc = mdbx_txn_begin(env, NULL, MDBX_TXN_RDONLY, &read_txn);+  if (unlikely(rc != MDBX_SUCCESS)) {+    mdbx_memalign_free(buffer);+    return rc;+  }++  if (!dest_is_pipe) {+    /* Firstly write a stub to meta-pages.+     * Now we sure to incomplete copy will not be used. */+    memset(buffer, -1, pgno2bytes(env, NUM_METAS));+    rc = mdbx_write(fd, buffer, pgno2bytes(env, NUM_METAS));+  }++  if (likely(rc == MDBX_SUCCESS)) {+    memset(buffer, 0, pgno2bytes(env, NUM_METAS));+    rc = ((flags & MDBX_CP_COMPACT) ? mdbx_env_compact : mdbx_env_copy_asis)(+        env, read_txn, fd, buffer, dest_is_pipe, flags);+  }+  mdbx_txn_abort(read_txn);++  if (!dest_is_pipe) {+    if (likely(rc == MDBX_SUCCESS))+      rc = mdbx_fsync(fd, MDBX_SYNC_DATA | MDBX_SYNC_SIZE);++    /* Write actual meta */+    if (likely(rc == MDBX_SUCCESS))+      rc = mdbx_pwrite(fd, buffer, pgno2bytes(env, NUM_METAS), 0);++    if (likely(rc == MDBX_SUCCESS))+      rc = mdbx_fsync(fd, MDBX_SYNC_DATA | MDBX_SYNC_IODQ);+  }++  mdbx_memalign_free(buffer);+  return rc;+}++__cold int mdbx_env_copy(MDBX_env *env, const char *dest_path,+                         MDBX_copy_flags_t flags) {+  int rc = check_env(env, true);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  if (unlikely(!dest_path))+    return MDBX_EINVAL;++  /* The destination path must exist, but the destination file must not.+   * We don't want the OS to cache the writes, since the source data is+   * already in the OS cache. */+  mdbx_filehandle_t newfd;+  rc = mdbx_openfile(MDBX_OPEN_COPY, env, dest_path, &newfd,+#if defined(_WIN32) || defined(_WIN64)+                     (mdbx_mode_t)-1+#else+                     S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP+#endif+  );++  if (rc == MDBX_SUCCESS) {+#if defined(_WIN32) || defined(_WIN64)+    OVERLAPPED ov;+    memset(&ov, 0, sizeof(ov));+    if (!LockFileEx(newfd, LOCKFILE_EXCLUSIVE_LOCK | LOCKFILE_FAIL_IMMEDIATELY,+                    0, 0, INT32_MAX, &ov))+      rc = GetLastError();+#else+    struct flock lock_op;+    memset(&lock_op, 0, sizeof(lock_op));+    lock_op.l_type = F_WRLCK;+    lock_op.l_whence = SEEK_SET;+    lock_op.l_start = 0;+    lock_op.l_len =+        (sizeof(lock_op.l_len) > 4 ? INT64_MAX : INT32_MAX) & ~(size_t)0xffff;+    if (fcntl(newfd, F_SETLK, &lock_op)+#if (defined(__linux__) || defined(__gnu_linux__)) && defined(LOCK_EX) &&      \+    (!defined(__ANDROID_API__) || __ANDROID_API__ >= 24)+        || flock(newfd, LOCK_EX | LOCK_NB)+#endif /* Linux */+    )+      rc = errno;+#endif /* Windows / POSIX */+  }++  if (rc == MDBX_SUCCESS)+    rc = mdbx_env_copy2fd(env, newfd, flags);++  if (newfd != INVALID_HANDLE_VALUE) {+    int err = mdbx_closefile(newfd);+    if (rc == MDBX_SUCCESS && err != rc)+      rc = err;+    if (rc != MDBX_SUCCESS)+      (void)mdbx_removefile(dest_path);+  }++  return rc;+}++/******************************************************************************/++__cold int mdbx_env_set_flags(MDBX_env *env, MDBX_env_flags_t flags,+                              bool onoff) {+  int rc = check_env(env, false);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  if (unlikely(flags &+               ((env->me_flags & MDBX_ENV_ACTIVE) ? ~ENV_CHANGEABLE_FLAGS+                                                  : ~ENV_USABLE_FLAGS)))+    return MDBX_EPERM;++  if (unlikely(env->me_flags & MDBX_RDONLY))+    return MDBX_EACCESS;++  if (unlikely(env->me_txn0->mt_owner == mdbx_thread_self()))+    return MDBX_BUSY;++  const bool lock_needed = (env->me_map && env->me_txn0 &&+                            env->me_txn0->mt_owner != mdbx_thread_self());+  bool should_unlock = false;+  if (lock_needed) {+    rc = mdbx_txn_lock(env, false);+    if (unlikely(rc))+      return rc;+    should_unlock = true;+  }++  if (onoff)+    env->me_flags = merge_sync_flags(env->me_flags, flags);+  else+    env->me_flags &= ~flags;++  if (should_unlock)+    mdbx_txn_unlock(env);+  return MDBX_SUCCESS;+}++__cold int mdbx_env_get_flags(const MDBX_env *env, unsigned *arg) {+  int rc = check_env(env, false);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  if (unlikely(!arg))+    return MDBX_EINVAL;++  *arg = env->me_flags & ENV_USABLE_FLAGS;+  return MDBX_SUCCESS;+}++__cold int mdbx_env_set_userctx(MDBX_env *env, void *ctx) {+  int rc = check_env(env, false);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  env->me_userctx = ctx;+  return MDBX_SUCCESS;+}++void *__cold mdbx_env_get_userctx(const MDBX_env *env) {+  return env ? env->me_userctx : NULL;+}++__cold int mdbx_env_set_assert(MDBX_env *env, MDBX_assert_func *func) {+  int rc = check_env(env, false);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++#if MDBX_DEBUG+  env->me_assert_func = func;+  return MDBX_SUCCESS;+#else+  (void)func;+  return MDBX_ENOSYS;+#endif+}++__cold int mdbx_env_get_path(const MDBX_env *env, const char **arg) {+  int rc = check_env(env, true);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  if (unlikely(!arg))+    return MDBX_EINVAL;++  *arg = env->me_pathname;+  return MDBX_SUCCESS;+}++__cold int mdbx_env_get_fd(const MDBX_env *env, mdbx_filehandle_t *arg) {+  int rc = check_env(env, true);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  if (unlikely(!arg))+    return MDBX_EINVAL;++  *arg = env->me_lazy_fd;+  return MDBX_SUCCESS;+}++/* Common code for mdbx_dbi_stat() and mdbx_env_stat().+ * [in] env the environment to operate in.+ * [in] db the MDBX_db record containing the stats to return.+ * [out] arg the address of an MDBX_stat structure to receive the stats.+ * Returns 0, this function always succeeds. */+static void mdbx_stat0(const MDBX_env *env, const MDBX_db *db, MDBX_stat *dest,+                       size_t bytes) {+  dest->ms_psize = env->me_psize;+  dest->ms_depth = db->md_depth;+  dest->ms_branch_pages = db->md_branch_pages;+  dest->ms_leaf_pages = db->md_leaf_pages;+  dest->ms_overflow_pages = db->md_overflow_pages;+  dest->ms_entries = db->md_entries;+  if (likely(bytes >=+             offsetof(MDBX_stat, ms_mod_txnid) + sizeof(dest->ms_mod_txnid)))+    dest->ms_mod_txnid = db->md_mod_txnid;+}++#ifndef LIBMDBX_NO_EXPORTS_LEGACY_API+__cold int mdbx_env_stat(const MDBX_env *env, MDBX_stat *stat, size_t bytes) {+  return __inline_mdbx_env_stat(env, stat, bytes);+}+#endif /* LIBMDBX_NO_EXPORTS_LEGACY_API */++__cold int mdbx_env_stat_ex(const MDBX_env *env, const MDBX_txn *txn,+                            MDBX_stat *dest, size_t bytes) {+  if (unlikely((env == NULL && txn == NULL) || dest == NULL))+    return MDBX_EINVAL;++  if (txn) {+    int err = check_txn(txn, MDBX_TXN_BLOCKED);+    if (unlikely(err != MDBX_SUCCESS))+      return err;+  }+  if (env) {+    int err = check_env(env, true);+    if (unlikely(err != MDBX_SUCCESS))+      return err;+    if (txn && unlikely(txn->mt_env != env))+      return MDBX_EINVAL;+  }++  const size_t size_before_modtxnid = offsetof(MDBX_stat, ms_mod_txnid);+  if (unlikely(bytes != sizeof(MDBX_stat)) && bytes != size_before_modtxnid)+    return MDBX_EINVAL;++  if (txn) {+    mdbx_stat0(txn->mt_env, &txn->mt_dbs[MAIN_DBI], dest, bytes);+    return MDBX_SUCCESS;+  }++  while (1) {+    const MDBX_meta *const recent_meta = mdbx_meta_head(env);+    const txnid_t txnid = mdbx_meta_txnid_fluid(env, recent_meta);+    mdbx_stat0(env, &recent_meta->mm_dbs[MAIN_DBI], dest, bytes);+    mdbx_compiler_barrier();+    if (likely(txnid == mdbx_meta_txnid_fluid(env, recent_meta) &&+               recent_meta == mdbx_meta_head(env)))+      return MDBX_SUCCESS;+  }+}++__cold int mdbx_dbi_dupsort_depthmask(MDBX_txn *txn, MDBX_dbi dbi,+                                      uint32_t *mask) {+  int rc = check_txn(txn, MDBX_TXN_BLOCKED);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  if (unlikely(!mask))+    return MDBX_EINVAL;++  if (unlikely(!mdbx_txn_dbi_exists(txn, dbi, DBI_VALID)))+    return MDBX_BAD_DBI;++  MDBX_cursor_couple cx;+  rc = mdbx_cursor_init(&cx.outer, txn, dbi);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;+  if ((cx.outer.mc_db->md_flags & MDBX_DUPSORT) == 0)+    return MDBX_RESULT_TRUE;++  MDBX_val key, data;+  rc = mdbx_cursor_first(&cx.outer, &key, &data);+  *mask = 0;+  while (rc == MDBX_SUCCESS) {+    const MDBX_node *node = page_node(cx.outer.mc_pg[cx.outer.mc_top],+                                      cx.outer.mc_ki[cx.outer.mc_top]);+    const MDBX_db *db = node_data(node);+    const unsigned flags = node_flags(node);+    switch (flags) {+    case F_BIGDATA:+    case 0:+      /* single-value entry, deep = 0 */+      *mask |= 1 << 0;+      break;+    case F_DUPDATA:+      /* single sub-page, deep = 1 */+      *mask |= 1 << 1;+      break;+    case F_DUPDATA | F_SUBDATA:+      /* sub-tree */+      *mask |= 1 << unaligned_peek_u16(1, &db->md_depth);+      break;+    default:+      mdbx_error("wrong node-flags %u", flags);+      return MDBX_CORRUPTED;+    }+    rc = mdbx_cursor_next(&cx.outer, &key, &data, MDBX_NEXT_NODUP);+  }++  return (rc == MDBX_NOTFOUND) ? MDBX_SUCCESS : rc;+}++#ifndef LIBMDBX_NO_EXPORTS_LEGACY_API+__cold int mdbx_env_info(const MDBX_env *env, MDBX_envinfo *info,+                         size_t bytes) {+  return __inline_mdbx_env_info(env, info, bytes);+}+#endif /* LIBMDBX_NO_EXPORTS_LEGACY_API */++__cold int mdbx_env_info_ex(const MDBX_env *env, const MDBX_txn *txn,+                            MDBX_envinfo *arg, size_t bytes) {+  if (unlikely((env == NULL && txn == NULL) || arg == NULL))+    return MDBX_EINVAL;++  if (txn) {+    int err = check_txn(txn, MDBX_TXN_BLOCKED);+    if (unlikely(err != MDBX_SUCCESS))+      return err;+  }+  if (env) {+    int err = check_env(env, false);+    if (unlikely(err != MDBX_SUCCESS))+      return err;+    if (txn && unlikely(txn->mt_env != env))+      return MDBX_EINVAL;+  } else {+    env = txn->mt_env;+  }++  const size_t size_before_bootid = offsetof(MDBX_envinfo, mi_bootid);+  if (unlikely(bytes != sizeof(MDBX_envinfo)) && bytes != size_before_bootid)+    return MDBX_EINVAL;++  /* is the environment open? (https://github.com/erthink/libmdbx/issues/171) */+  if (unlikely(!env->me_map)) {+    /* environment not yet opened */+#if 1+    /* default behavior: returns the available info but zeroed the rest */+    memset(arg, 0, bytes);+    arg->mi_geo.lower = env->me_dbgeo.lower;+    arg->mi_geo.upper = env->me_dbgeo.upper;+    arg->mi_geo.shrink = env->me_dbgeo.shrink;+    arg->mi_geo.grow = env->me_dbgeo.grow;+    arg->mi_geo.current = env->me_dbgeo.now;+    arg->mi_maxreaders = env->me_maxreaders;+    arg->mi_dxb_pagesize = env->me_psize;+    arg->mi_sys_pagesize = env->me_os_psize;+    if (likely(bytes > size_before_bootid)) {+      arg->mi_bootid.current.x = bootid.x;+      arg->mi_bootid.current.y = bootid.y;+    }+    return MDBX_SUCCESS;+#else+    /* some users may prefer this behavior: return appropriate error */+    return MDBX_EPERM;+#endif+  }++  const MDBX_meta *const meta0 = METAPAGE(env, 0);+  const MDBX_meta *const meta1 = METAPAGE(env, 1);+  const MDBX_meta *const meta2 = METAPAGE(env, 2);+  pgno_t unsynced_pages;+  while (1) {+    if (unlikely(env->me_flags & MDBX_FATAL_ERROR))+      return MDBX_PANIC;++    const MDBX_meta *const recent_meta = mdbx_meta_head(env);+    arg->mi_recent_txnid = mdbx_meta_txnid_fluid(env, recent_meta);+    arg->mi_meta0_txnid = mdbx_meta_txnid_fluid(env, meta0);+    arg->mi_meta0_sign = unaligned_peek_u64(4, meta0->mm_datasync_sign);+    arg->mi_meta1_txnid = mdbx_meta_txnid_fluid(env, meta1);+    arg->mi_meta1_sign = unaligned_peek_u64(4, meta1->mm_datasync_sign);+    arg->mi_meta2_txnid = mdbx_meta_txnid_fluid(env, meta2);+    arg->mi_meta2_sign = unaligned_peek_u64(4, meta2->mm_datasync_sign);+    if (likely(bytes > size_before_bootid)) {+      memcpy(&arg->mi_bootid.meta0, &meta0->mm_bootid, 16);+      memcpy(&arg->mi_bootid.meta1, &meta1->mm_bootid, 16);+      memcpy(&arg->mi_bootid.meta2, &meta2->mm_bootid, 16);+    }++    const MDBX_meta *txn_meta = recent_meta;+    arg->mi_last_pgno = txn_meta->mm_geo.next - 1;+    arg->mi_geo.current = pgno2bytes(env, txn_meta->mm_geo.now);+    if (txn) {+      arg->mi_last_pgno = txn->mt_next_pgno - 1;+      arg->mi_geo.current = pgno2bytes(env, txn->mt_end_pgno);++      const txnid_t wanna_meta_txnid = (txn->mt_flags & MDBX_TXN_RDONLY)+                                           ? txn->mt_txnid+                                           : txn->mt_txnid - MDBX_TXNID_STEP;+      txn_meta = (arg->mi_meta0_txnid == wanna_meta_txnid) ? meta0 : txn_meta;+      txn_meta = (arg->mi_meta1_txnid == wanna_meta_txnid) ? meta1 : txn_meta;+      txn_meta = (arg->mi_meta2_txnid == wanna_meta_txnid) ? meta2 : txn_meta;+    }+    arg->mi_geo.lower = pgno2bytes(env, txn_meta->mm_geo.lower);+    arg->mi_geo.upper = pgno2bytes(env, txn_meta->mm_geo.upper);+    arg->mi_geo.shrink = pgno2bytes(env, pv2pages(txn_meta->mm_geo.shrink_pv));+    arg->mi_geo.grow = pgno2bytes(env, pv2pages(txn_meta->mm_geo.grow_pv));+    unsynced_pages = atomic_load32(env->me_unsynced_pages, mo_Relaxed) ++                     (atomic_load32(env->me_meta_sync_txnid, mo_Relaxed) !=+                      (uint32_t)arg->mi_last_pgno);++    arg->mi_mapsize = env->me_dxb_mmap.limit;+    mdbx_compiler_barrier();+    if (likely(arg->mi_meta0_txnid == mdbx_meta_txnid_fluid(env, meta0) &&+               arg->mi_meta0_sign ==+                   unaligned_peek_u64(4, meta0->mm_datasync_sign) &&+               arg->mi_meta1_txnid == mdbx_meta_txnid_fluid(env, meta1) &&+               arg->mi_meta1_sign ==+                   unaligned_peek_u64(4, meta1->mm_datasync_sign) &&+               arg->mi_meta2_txnid == mdbx_meta_txnid_fluid(env, meta2) &&+               arg->mi_meta2_sign ==+                   unaligned_peek_u64(4, meta2->mm_datasync_sign) &&+               recent_meta == mdbx_meta_head(env) &&+               arg->mi_recent_txnid == mdbx_meta_txnid_fluid(env, recent_meta)))+      break;+  }++  arg->mi_maxreaders = env->me_maxreaders;+  arg->mi_numreaders =+      env->me_lck ? atomic_load32(&env->me_lck->mti_numreaders, mo_Relaxed)+                  : INT32_MAX;+  arg->mi_dxb_pagesize = env->me_psize;+  arg->mi_sys_pagesize = env->me_os_psize;++  const MDBX_lockinfo *const lck = env->me_lck;+  if (likely(bytes > size_before_bootid)) {+    arg->mi_unsync_volume = pgno2bytes(env, unsynced_pages);+    const uint64_t monotime_now = mdbx_osal_monotime();+    arg->mi_since_sync_seconds16dot16 = mdbx_osal_monotime_to_16dot16(+        monotime_now - atomic_load64(env->me_sync_timestamp, mo_Relaxed));+    arg->mi_since_reader_check_seconds16dot16 =+        lck ? mdbx_osal_monotime_to_16dot16(+                  monotime_now -+                  atomic_load64(&lck->mti_reader_check_timestamp, mo_Relaxed))+            : 0;+    arg->mi_autosync_threshold =+        pgno2bytes(env, atomic_load32(env->me_autosync_threshold, mo_Relaxed));+    arg->mi_autosync_period_seconds16dot16 = mdbx_osal_monotime_to_16dot16(+        atomic_load64(env->me_autosync_period, mo_Relaxed));+    arg->mi_bootid.current.x = bootid.x;+    arg->mi_bootid.current.y = bootid.y;+    arg->mi_mode = lck ? lck->mti_envmode.weak : env->me_flags;+  }++  arg->mi_self_latter_reader_txnid = arg->mi_latter_reader_txnid = 0;+  if (lck) {+    arg->mi_self_latter_reader_txnid = arg->mi_latter_reader_txnid =+        arg->mi_recent_txnid;+    for (unsigned i = 0; i < arg->mi_numreaders; ++i) {+      const uint32_t pid =+          atomic_load32(&lck->mti_readers[i].mr_pid, mo_AcquireRelease);+      if (pid) {+        const txnid_t txnid = safe64_read(&lck->mti_readers[i].mr_txnid);+        if (arg->mi_latter_reader_txnid > txnid)+          arg->mi_latter_reader_txnid = txnid;+        if (pid == env->me_pid && arg->mi_self_latter_reader_txnid > txnid)+          arg->mi_self_latter_reader_txnid = txnid;+      }+    }+  }++  return MDBX_SUCCESS;+}++static __inline MDBX_cmp_func *get_default_keycmp(unsigned flags) {+  return (flags & MDBX_REVERSEKEY)+             ? cmp_reverse+             : (flags & MDBX_INTEGERKEY) ? cmp_int_align2 : cmp_lexical;+}++static __inline MDBX_cmp_func *get_default_datacmp(unsigned flags) {+  return !(flags & MDBX_DUPSORT)+             ? cmp_lenfast+             : ((flags & MDBX_INTEGERDUP)+                    ? cmp_int_unaligned+                    : ((flags & MDBX_REVERSEDUP) ? cmp_reverse : cmp_lexical));+}++static int mdbx_dbi_bind(MDBX_txn *txn, const MDBX_dbi dbi, unsigned user_flags,+                         MDBX_cmp_func *keycmp, MDBX_cmp_func *datacmp) {+  /* LY: so, accepting only three cases for the table's flags:+   * 1) user_flags and both comparators are zero+   *    = assume that a by-default mode/flags is requested for reading;+   * 2) user_flags exactly the same+   *    = assume that the target mode/flags are requested properly;+   * 3) user_flags differs, but table is empty and MDBX_CREATE is provided+   *    = assume that a properly create request with custom flags;+   */+  if ((user_flags ^ txn->mt_dbs[dbi].md_flags) & DB_PERSISTENT_FLAGS) {+    /* flags are differs, check other conditions */+    if ((!user_flags && (!keycmp || keycmp == txn->mt_dbxs[dbi].md_cmp) &&+         (!datacmp || datacmp == txn->mt_dbxs[dbi].md_dcmp)) ||+        user_flags == MDBX_ACCEDE) {+      /* no comparators were provided and flags are zero,+       * seems that is case #1 above */+      user_flags = txn->mt_dbs[dbi].md_flags;+    } else if ((user_flags & MDBX_CREATE) && txn->mt_dbs[dbi].md_entries == 0) {+      if (txn->mt_flags & MDBX_TXN_RDONLY)+        return /* FIXME: return extended info */ MDBX_EACCESS;+      /* make sure flags changes get committed */+      txn->mt_dbs[dbi].md_flags = user_flags & DB_PERSISTENT_FLAGS;+      txn->mt_flags |= MDBX_TXN_DIRTY;+    } else {+      return /* FIXME: return extended info */ MDBX_INCOMPATIBLE;+    }+  }++  if (!keycmp)+    keycmp = txn->mt_dbxs[dbi].md_cmp ? txn->mt_dbxs[dbi].md_cmp+                                      : get_default_keycmp(user_flags);+  if (txn->mt_dbxs[dbi].md_cmp != keycmp) {+    if (txn->mt_dbxs[dbi].md_cmp)+      return MDBX_EINVAL;+    txn->mt_dbxs[dbi].md_cmp = keycmp;+  }++  if (!datacmp)+    datacmp = txn->mt_dbxs[dbi].md_dcmp ? txn->mt_dbxs[dbi].md_dcmp+                                        : get_default_datacmp(user_flags);+  if (txn->mt_dbxs[dbi].md_dcmp != datacmp) {+    if (txn->mt_dbxs[dbi].md_dcmp)+      return MDBX_EINVAL;+    txn->mt_dbxs[dbi].md_dcmp = datacmp;+  }++  return MDBX_SUCCESS;+}++static int dbi_open(MDBX_txn *txn, const char *table_name, unsigned user_flags,+                    MDBX_dbi *dbi, MDBX_cmp_func *keycmp,+                    MDBX_cmp_func *datacmp) {+  int rc = MDBX_EINVAL;+  if (unlikely(!dbi))+    return rc;++  if (unlikely((user_flags & ~DB_USABLE_FLAGS) != 0)) {+  early_bailout:+    *dbi = 0;+    return rc;+  }++  rc = check_txn(txn, MDBX_TXN_BLOCKED);+  if (unlikely(rc != MDBX_SUCCESS))+    goto early_bailout;++  switch (user_flags & (MDBX_INTEGERDUP | MDBX_DUPFIXED | MDBX_DUPSORT |+                        MDBX_REVERSEDUP | MDBX_ACCEDE)) {+  case MDBX_ACCEDE:+    if ((user_flags & MDBX_CREATE) == 0)+      break;+    __fallthrough /* fall through */;+  default:+    rc = MDBX_EINVAL;+    goto early_bailout;++  case MDBX_DUPSORT:+  case MDBX_DUPSORT | MDBX_REVERSEDUP:+  case MDBX_DUPSORT | MDBX_DUPFIXED:+  case MDBX_DUPSORT | MDBX_DUPFIXED | MDBX_REVERSEDUP:+  case MDBX_DUPSORT | MDBX_DUPFIXED | MDBX_INTEGERDUP:+  case MDBX_DUPSORT | MDBX_DUPFIXED | MDBX_INTEGERDUP | MDBX_REVERSEDUP:+  case 0:+    break;+  }++  /* main table? */+  if (!table_name) {+    rc = mdbx_dbi_bind(txn, MAIN_DBI, user_flags, keycmp, datacmp);+    if (unlikely(rc != MDBX_SUCCESS))+      goto early_bailout;+    *dbi = MAIN_DBI;+    return rc;+  }++  if (txn->mt_dbxs[MAIN_DBI].md_cmp == NULL) {+    txn->mt_dbxs[MAIN_DBI].md_cmp =+        get_default_keycmp(txn->mt_dbs[MAIN_DBI].md_flags);+    txn->mt_dbxs[MAIN_DBI].md_dcmp =+        get_default_datacmp(txn->mt_dbs[MAIN_DBI].md_flags);+  }++  /* Is the DB already open? */+  size_t len = strlen(table_name);+  MDBX_dbi scan, slot;+  for (slot = scan = txn->mt_numdbs; --scan >= CORE_DBS;) {+    if (!txn->mt_dbxs[scan].md_name.iov_len) {+      /* Remember this free slot */+      slot = scan;+      continue;+    }+    if (len == txn->mt_dbxs[scan].md_name.iov_len &&+        !strncmp(table_name, txn->mt_dbxs[scan].md_name.iov_base, len)) {+      rc = mdbx_dbi_bind(txn, scan, user_flags, keycmp, datacmp);+      if (unlikely(rc != MDBX_SUCCESS))+        goto early_bailout;+      *dbi = scan;+      return rc;+    }+  }++  /* Fail, if no free slot and max hit */+  MDBX_env *env = txn->mt_env;+  if (unlikely(slot >= env->me_maxdbs)) {+    rc = MDBX_DBS_FULL;+    goto early_bailout;+  }++  /* Cannot mix named table with some main-table flags */+  if (unlikely(txn->mt_dbs[MAIN_DBI].md_flags &+               (MDBX_DUPSORT | MDBX_INTEGERKEY))) {+    rc = (user_flags & MDBX_CREATE) ? MDBX_INCOMPATIBLE : MDBX_NOTFOUND;+    goto early_bailout;+  }++  /* Find the DB info */+  int exact = 0;+  MDBX_val key, data;+  key.iov_len = len;+  key.iov_base = (void *)table_name;+  MDBX_cursor_couple couple;+  rc = mdbx_cursor_init(&couple.outer, txn, MAIN_DBI);+  if (unlikely(rc != MDBX_SUCCESS))+    goto early_bailout;+  rc = mdbx_cursor_set(&couple.outer, &key, &data, MDBX_SET, &exact);+  if (unlikely(rc != MDBX_SUCCESS)) {+    if (rc != MDBX_NOTFOUND || !(user_flags & MDBX_CREATE))+      goto early_bailout;+  } else {+    /* make sure this is actually a table */+    MDBX_node *node = page_node(couple.outer.mc_pg[couple.outer.mc_top],+                                couple.outer.mc_ki[couple.outer.mc_top]);+    if (unlikely((node_flags(node) & (F_DUPDATA | F_SUBDATA)) != F_SUBDATA)) {+      rc = MDBX_INCOMPATIBLE;+      goto early_bailout;+    }+    if (!MDBX_DISABLE_PAGECHECKS && unlikely(data.iov_len != sizeof(MDBX_db))) {+      rc = MDBX_CORRUPTED;+      goto early_bailout;+    }+  }++  if (rc != MDBX_SUCCESS && unlikely(txn->mt_flags & MDBX_TXN_RDONLY)) {+    rc = MDBX_EACCESS;+    goto early_bailout;+  }++  /* Done here so we cannot fail after creating a new DB */+  char *namedup = mdbx_strdup(table_name);+  if (unlikely(!namedup)) {+    rc = MDBX_ENOMEM;+    goto early_bailout;+  }++  int err = mdbx_fastmutex_acquire(&env->me_dbi_lock);+  if (unlikely(err != MDBX_SUCCESS)) {+    rc = err;+    mdbx_free(namedup);+    goto early_bailout;+  }++  /* Import handles from env */+  dbi_import_locked(txn);++  /* Rescan after mutex acquisition & import handles */+  for (slot = scan = txn->mt_numdbs; --scan >= CORE_DBS;) {+    if (!txn->mt_dbxs[scan].md_name.iov_len) {+      /* Remember this free slot */+      slot = scan;+      continue;+    }+    if (len == txn->mt_dbxs[scan].md_name.iov_len &&+        !strncmp(table_name, txn->mt_dbxs[scan].md_name.iov_base, len)) {+      rc = mdbx_dbi_bind(txn, scan, user_flags, keycmp, datacmp);+      if (unlikely(rc != MDBX_SUCCESS))+        goto later_bailout;+      *dbi = scan;+      goto later_exit;+    }+  }++  if (unlikely(slot >= env->me_maxdbs)) {+    rc = MDBX_DBS_FULL;+    goto later_bailout;+  }++  unsigned dbiflags = DBI_FRESH | DBI_VALID | DBI_USRVALID;+  MDBX_db db_dummy;+  if (unlikely(rc)) {+    /* MDBX_NOTFOUND and MDBX_CREATE: Create new DB */+    mdbx_tassert(txn, rc == MDBX_NOTFOUND);+    memset(&db_dummy, 0, sizeof(db_dummy));+    db_dummy.md_root = P_INVALID;+    db_dummy.md_flags = user_flags & DB_PERSISTENT_FLAGS;+    data.iov_len = sizeof(db_dummy);+    data.iov_base = &db_dummy;+    WITH_CURSOR_TRACKING(couple.outer,+                         rc = mdbx_cursor_put(&couple.outer, &key, &data,+                                              F_SUBDATA | MDBX_NOOVERWRITE));++    if (unlikely(rc != MDBX_SUCCESS))+      goto later_bailout;++    dbiflags |= DBI_DIRTY | DBI_CREAT;+    txn->mt_flags |= MDBX_TXN_DIRTY;+  }++  /* Got info, register DBI in this txn */+  memset(txn->mt_dbxs + slot, 0, sizeof(MDBX_dbx));+  txn->mt_dbs[slot] = *(MDBX_db *)data.iov_base;+  env->me_dbflags[slot] = 0;+  rc = mdbx_dbi_bind(txn, slot, user_flags, keycmp, datacmp);+  if (unlikely(rc != MDBX_SUCCESS)) {+    mdbx_tassert(txn, (dbiflags & DBI_CREAT) == 0);+  later_bailout:+    *dbi = 0;+  later_exit:+    mdbx_free(namedup);+  } else {+    txn->mt_dbistate[slot] = (uint8_t)dbiflags;+    txn->mt_dbxs[slot].md_name.iov_base = namedup;+    txn->mt_dbxs[slot].md_name.iov_len = len;+    txn->mt_dbiseqs[slot] = ++env->me_dbiseqs[slot];+    if (!(dbiflags & DBI_CREAT))+      env->me_dbflags[slot] = txn->mt_dbs[slot].md_flags | DB_VALID;+    if (txn->mt_numdbs == slot) {+      mdbx_compiler_barrier();+      txn->mt_numdbs = env->me_numdbs = slot + 1;+      if (!(txn->mt_flags & MDBX_TXN_RDONLY))+        txn->tw.cursors[slot] = NULL;+    }+    mdbx_assert(env, env->me_numdbs > slot);+    *dbi = slot;+  }++  mdbx_ensure(env, mdbx_fastmutex_release(&env->me_dbi_lock) == MDBX_SUCCESS);+  return rc;+}++int mdbx_dbi_open(MDBX_txn *txn, const char *table_name,+                  MDBX_db_flags_t table_flags, MDBX_dbi *dbi) {+  return dbi_open(txn, table_name, table_flags, dbi, nullptr, nullptr);+}++int mdbx_dbi_open_ex(MDBX_txn *txn, const char *table_name,+                     MDBX_db_flags_t table_flags, MDBX_dbi *dbi,+                     MDBX_cmp_func *keycmp, MDBX_cmp_func *datacmp) {+  return dbi_open(txn, table_name, table_flags, dbi, keycmp, datacmp);+}++__cold int mdbx_dbi_stat(MDBX_txn *txn, MDBX_dbi dbi, MDBX_stat *dest,+                         size_t bytes) {+  int rc = check_txn(txn, MDBX_TXN_BLOCKED);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  if (unlikely(!dest))+    return MDBX_EINVAL;++  if (unlikely(!mdbx_txn_dbi_exists(txn, dbi, DBI_VALID)))+    return MDBX_BAD_DBI;++  const size_t size_before_modtxnid = offsetof(MDBX_stat, ms_mod_txnid);+  if (unlikely(bytes != sizeof(MDBX_stat)) && bytes != size_before_modtxnid)+    return MDBX_EINVAL;++  if (unlikely(txn->mt_flags & MDBX_TXN_BLOCKED))+    return MDBX_BAD_TXN;++  if (unlikely(txn->mt_dbistate[dbi] & DBI_STALE)) {+    rc = mdbx_fetch_sdb(txn, dbi);+    if (unlikely(rc != MDBX_SUCCESS))+      return rc;+  }+  mdbx_stat0(txn->mt_env, &txn->mt_dbs[dbi], dest, bytes);+  return MDBX_SUCCESS;+}++static int mdbx_dbi_close_locked(MDBX_env *env, MDBX_dbi dbi) {+  mdbx_assert(env, dbi >= CORE_DBS);+  if (unlikely(dbi >= env->me_numdbs))+    return MDBX_BAD_DBI;++  char *ptr = env->me_dbxs[dbi].md_name.iov_base;+  /* If there was no name, this was already closed */+  if (unlikely(!ptr))+    return MDBX_BAD_DBI;++  env->me_dbflags[dbi] = 0;+  env->me_dbiseqs[dbi]++;+  env->me_dbxs[dbi].md_name.iov_len = 0;+  mdbx_memory_fence(mo_AcquireRelease, true);+  env->me_dbxs[dbi].md_name.iov_base = NULL;+  mdbx_free(ptr);++  if (env->me_numdbs == dbi + 1) {+    unsigned i = env->me_numdbs;+    do+      --i;+    while (i > CORE_DBS && !env->me_dbxs[i - 1].md_name.iov_base);+    env->me_numdbs = i;+  }++  return MDBX_SUCCESS;+}++int mdbx_dbi_close(MDBX_env *env, MDBX_dbi dbi) {+  int rc = check_env(env, true);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  if (unlikely(dbi < CORE_DBS || dbi >= env->me_maxdbs))+    return MDBX_BAD_DBI;++  rc = mdbx_fastmutex_acquire(&env->me_dbi_lock);+  if (likely(rc == MDBX_SUCCESS)) {+    rc = (dbi < env->me_maxdbs && (env->me_dbflags[dbi] & DB_VALID))+             ? mdbx_dbi_close_locked(env, dbi)+             : MDBX_BAD_DBI;+    mdbx_ensure(env, mdbx_fastmutex_release(&env->me_dbi_lock) == MDBX_SUCCESS);+  }+  return rc;+}++int mdbx_dbi_flags_ex(MDBX_txn *txn, MDBX_dbi dbi, unsigned *flags,+                      unsigned *state) {+  int rc = check_txn(txn, MDBX_TXN_BLOCKED);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  if (unlikely(!flags || !state))+    return MDBX_EINVAL;++  if (unlikely(!mdbx_txn_dbi_exists(txn, dbi, DBI_VALID)))+    return MDBX_BAD_DBI;++  *flags = txn->mt_dbs[dbi].md_flags & DB_PERSISTENT_FLAGS;+  *state =+      txn->mt_dbistate[dbi] & (DBI_FRESH | DBI_CREAT | DBI_DIRTY | DBI_STALE);++  return MDBX_SUCCESS;+}++#ifndef LIBMDBX_NO_EXPORTS_LEGACY_API+int mdbx_dbi_flags(MDBX_txn *txn, MDBX_dbi dbi, unsigned *flags) {+  return __inline_mdbx_dbi_flags(txn, dbi, flags);+}+#endif /* LIBMDBX_NO_EXPORTS_LEGACY_API */++/* Add all the DB's pages to the free list.+ * [in] mc Cursor on the DB to free.+ * [in] subs non-Zero to check for sub-DBs in this DB.+ * Returns 0 on success, non-zero on failure. */+static int mdbx_drop0(MDBX_cursor *mc, bool subs) {+  int rc = mdbx_page_search(mc, NULL, MDBX_PS_FIRST);+  if (likely(rc == MDBX_SUCCESS)) {+    MDBX_txn *txn = mc->mc_txn;+    MDBX_cursor mx;+    unsigned i;++    /* DUPSORT sub-DBs have no ovpages/DBs. Omit scanning leaves.+     * This also avoids any P_LEAF2 pages, which have no nodes.+     * Also if the DB doesn't have sub-DBs and has no overflow+     * pages, omit scanning leaves. */+    if ((mc->mc_flags & C_SUB) || (subs | mc->mc_db->md_overflow_pages) == 0)+      mdbx_cursor_pop(mc);++    rc = mdbx_pnl_need(&txn->tw.retired_pages,+                       mc->mc_db->md_branch_pages + mc->mc_db->md_leaf_pages ++                           mc->mc_db->md_overflow_pages);+    if (unlikely(rc))+      goto done;++    cursor_copy_internal(mc, &mx);+    while (mc->mc_snum > 0) {+      MDBX_page *mp = mc->mc_pg[mc->mc_top];+      unsigned n = page_numkeys(mp);+      if (IS_LEAF(mp)) {+        for (i = 0; i < n; i++) {+          MDBX_node *node = page_node(mp, i);+          if (node_flags(node) & F_BIGDATA) {+            MDBX_page *omp;+            rc = mdbx_page_get(mc, node_largedata_pgno(node), &omp, NULL,+                               pp_txnid4chk(mp, mc->mc_txn));+            if (unlikely(rc))+              goto done;+            mdbx_cassert(mc, IS_OVERFLOW(omp));+            rc = mdbx_page_retire(mc, omp);+            if (unlikely(rc))+              goto done;+            if (!mc->mc_db->md_overflow_pages && !subs)+              break;+          } else if (subs && (node_flags(node) & F_SUBDATA)) {+            if (unlikely((node_flags(node) & F_DUPDATA) == 0)) {+              rc = /* disallowing implicit subDB deletion */ MDBX_INCOMPATIBLE;+              goto done;+            }+            rc = mdbx_xcursor_init1(mc, node, mp);+            if (unlikely(rc != MDBX_SUCCESS))+              goto done;+            rc = mdbx_drop0(&mc->mc_xcursor->mx_cursor, false);+            if (unlikely(rc))+              goto done;+          }+        }+        if (!subs && !mc->mc_db->md_overflow_pages)+          goto pop;+      } else {+        for (i = 0; i < n; i++) {+          /* free it */+          rc = mdbx_retire_pgno(mc, node_pgno(page_node(mp, i)));+          if (unlikely(rc))+            goto done;+        }+      }+      if (!mc->mc_top)+        break;+      mdbx_cassert(mc, i <= UINT16_MAX);+      mc->mc_ki[mc->mc_top] = (indx_t)i;+      rc = mdbx_cursor_sibling(mc, SIBLING_RIGHT);+      if (rc) {+        if (unlikely(rc != MDBX_NOTFOUND))+          goto done;+      /* no more siblings, go back to beginning+       * of previous level. */+      pop:+        mdbx_cursor_pop(mc);+        mc->mc_ki[0] = 0;+        for (i = 1; i < mc->mc_snum; i++) {+          mc->mc_ki[i] = 0;+          mc->mc_pg[i] = mx.mc_pg[i];+        }+      }+    }+    /* free it */+    rc = mdbx_retire_pgno(mc, mc->mc_db->md_root);+  done:+    if (unlikely(rc))+      txn->mt_flags |= MDBX_TXN_ERROR;+  } else if (rc == MDBX_NOTFOUND) {+    rc = MDBX_SUCCESS;+  }+  mc->mc_flags &= ~C_INITIALIZED;+  return rc;+}++int mdbx_drop(MDBX_txn *txn, MDBX_dbi dbi, bool del) {+  int rc = check_txn_rw(txn, MDBX_TXN_BLOCKED);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  if (unlikely(!mdbx_txn_dbi_exists(txn, dbi, DBI_USRVALID)))+    return MDBX_BAD_DBI;++  if (unlikely(TXN_DBI_CHANGED(txn, dbi)))+    return MDBX_BAD_DBI;++  MDBX_cursor *mc;+  rc = mdbx_cursor_open(txn, dbi, &mc);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  if (unlikely(!mdbx_txn_dbi_exists(txn, dbi, DBI_USRVALID))) {+    rc = MDBX_BAD_DBI;+    goto bailout;+  }++  if (unlikely(TXN_DBI_CHANGED(txn, dbi))) {+    rc = MDBX_BAD_DBI;+    goto bailout;+  }++  rc = mdbx_drop0(mc,+                  dbi == MAIN_DBI || (mc->mc_db->md_flags & MDBX_DUPSORT) != 0);+  /* Invalidate the dropped DB's cursors */+  for (MDBX_cursor *m2 = txn->tw.cursors[dbi]; m2; m2 = m2->mc_next)+    m2->mc_flags &= ~(C_INITIALIZED | C_EOF);+  if (unlikely(rc))+    goto bailout;++  /* Can't delete the main DB */+  if (del && dbi >= CORE_DBS) {+    rc = mdbx_del0(txn, MAIN_DBI, &mc->mc_dbx->md_name, NULL, F_SUBDATA);+    if (likely(rc == MDBX_SUCCESS)) {+      mdbx_tassert(txn, txn->mt_dbistate[MAIN_DBI] & DBI_DIRTY);+      mdbx_tassert(txn, txn->mt_flags & MDBX_TXN_DIRTY);+      txn->mt_dbistate[dbi] = DBI_STALE;+      MDBX_env *env = txn->mt_env;+      rc = mdbx_fastmutex_acquire(&env->me_dbi_lock);+      if (unlikely(rc != MDBX_SUCCESS)) {+        txn->mt_flags |= MDBX_TXN_ERROR;+        goto bailout;+      }+      mdbx_dbi_close_locked(env, dbi);+      mdbx_ensure(env,+                  mdbx_fastmutex_release(&env->me_dbi_lock) == MDBX_SUCCESS);+    } else {+      txn->mt_flags |= MDBX_TXN_ERROR;+    }+  } else {+    /* reset the DB record, mark it dirty */+    txn->mt_dbistate[dbi] |= DBI_DIRTY;+    txn->mt_dbs[dbi].md_depth = 0;+    txn->mt_dbs[dbi].md_branch_pages = 0;+    txn->mt_dbs[dbi].md_leaf_pages = 0;+    txn->mt_dbs[dbi].md_overflow_pages = 0;+    txn->mt_dbs[dbi].md_entries = 0;+    txn->mt_dbs[dbi].md_root = P_INVALID;+    txn->mt_dbs[dbi].md_seq = 0;+    txn->mt_flags |= MDBX_TXN_DIRTY;+  }++bailout:+  mdbx_cursor_close(mc);+  return rc;+}++int mdbx_set_compare(MDBX_txn *txn, MDBX_dbi dbi, MDBX_cmp_func *cmp) {+  int rc = check_txn(txn, MDBX_TXN_BLOCKED);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  if (unlikely(!mdbx_txn_dbi_exists(txn, dbi, DBI_USRVALID)))+    return MDBX_BAD_DBI;++  txn->mt_dbxs[dbi].md_cmp = cmp;+  return MDBX_SUCCESS;+}++int mdbx_set_dupsort(MDBX_txn *txn, MDBX_dbi dbi, MDBX_cmp_func *cmp) {+  int rc = check_txn(txn, MDBX_TXN_BLOCKED);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  if (unlikely(!mdbx_txn_dbi_exists(txn, dbi, DBI_USRVALID)))+    return MDBX_BAD_DBI;++  txn->mt_dbxs[dbi].md_dcmp = cmp;+  return MDBX_SUCCESS;+}++__cold int mdbx_reader_list(const MDBX_env *env, MDBX_reader_list_func *func,+                            void *ctx) {+  int rc = check_env(env, true);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  if (unlikely(!func))+    return MDBX_EINVAL;++  rc = MDBX_RESULT_TRUE;+  int serial = 0;+  if (likely(env->me_lck)) {+    const unsigned snap_nreaders =+        atomic_load32(&env->me_lck->mti_numreaders, mo_AcquireRelease);+    for (unsigned i = 0; i < snap_nreaders; i++) {+      const MDBX_reader *r = env->me_lck->mti_readers + i;+    retry_reader:;+      const uint32_t pid = atomic_load32(&r->mr_pid, mo_AcquireRelease);+      if (!pid)+        continue;+      txnid_t txnid = safe64_read(&r->mr_txnid);+      const uint64_t tid = atomic_load64(&r->mr_tid, mo_Relaxed);+      const pgno_t pages_used =+          atomic_load32(&r->mr_snapshot_pages_used, mo_Relaxed);+      const uint64_t reader_pages_retired =+          atomic_load64(&r->mr_snapshot_pages_retired, mo_Relaxed);+      if (unlikely(+              txnid != safe64_read(&r->mr_txnid) ||+              pid != atomic_load32(&r->mr_pid, mo_AcquireRelease) ||+              tid != atomic_load64(&r->mr_tid, mo_Relaxed) ||+              pages_used !=+                  atomic_load32(&r->mr_snapshot_pages_used, mo_Relaxed) ||+              reader_pages_retired !=+                  atomic_load64(&r->mr_snapshot_pages_retired, mo_Relaxed)))+        goto retry_reader;++      mdbx_assert(env, txnid > 0);+      if (txnid >= SAFE64_INVALID_THRESHOLD)+        txnid = 0;++      size_t bytes_used = 0;+      size_t bytes_retained = 0;+      uint64_t lag = 0;+      if (txnid) {+      retry_header:;+        const MDBX_meta *const recent_meta = mdbx_meta_head(env);+        const uint64_t head_pages_retired =+            unaligned_peek_u64(4, recent_meta->mm_pages_retired);+        const txnid_t head_txnid = mdbx_meta_txnid_fluid(env, recent_meta);+        mdbx_compiler_barrier();+        if (unlikely(+                recent_meta != mdbx_meta_head(env) ||+                head_pages_retired !=+                    unaligned_peek_u64(4, recent_meta->mm_pages_retired)) ||+            head_txnid != mdbx_meta_txnid_fluid(env, recent_meta))+          goto retry_header;++        lag = (head_txnid - txnid) / MDBX_TXNID_STEP;+        bytes_used = pgno2bytes(env, pages_used);+        bytes_retained = (head_pages_retired > reader_pages_retired)+                             ? pgno2bytes(env, (pgno_t)(head_pages_retired -+                                                        reader_pages_retired))+                             : 0;+      }+      rc = func(ctx, ++serial, i, pid, (mdbx_tid_t)tid, txnid, lag, bytes_used,+                bytes_retained);+      if (unlikely(rc != MDBX_SUCCESS))+        break;+    }+  }++  return rc;+}++/* Insert pid into list if not already present.+ * return -1 if already present. */+static bool __cold mdbx_pid_insert(uint32_t *ids, uint32_t pid) {+  /* binary search of pid in list */+  unsigned base = 0;+  unsigned cursor = 1;+  int val = 0;+  unsigned n = ids[0];++  while (n > 0) {+    unsigned pivot = n >> 1;+    cursor = base + pivot + 1;+    val = pid - ids[cursor];++    if (val < 0) {+      n = pivot;+    } else if (val > 0) {+      base = cursor;+      n -= pivot + 1;+    } else {+      /* found, so it's a duplicate */+      return false;+    }+  }++  if (val > 0)+    ++cursor;++  ids[0]++;+  for (n = ids[0]; n > cursor; n--)+    ids[n] = ids[n - 1];+  ids[n] = pid;+  return true;+}++__cold int mdbx_reader_check(MDBX_env *env, int *dead) {+  if (dead)+    *dead = 0;+  return mdbx_cleanup_dead_readers(env, false, dead);+}++/* Return:+ *  MDBX_RESULT_TRUE - done and mutex recovered+ *  MDBX_SUCCESS     - done+ *  Otherwise errcode. */+MDBX_INTERNAL_FUNC __cold int+mdbx_cleanup_dead_readers(MDBX_env *env, int rdt_locked, int *dead) {+  int rc = check_env(env, true);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  mdbx_assert(env, rdt_locked >= 0);+  MDBX_lockinfo *const lck = env->me_lck;+  if (unlikely(lck == NULL)) {+    /* exclusive mode */+    if (dead)+      *dead = 0;+    return MDBX_SUCCESS;+  }++  const unsigned snap_nreaders =+      atomic_load32(&lck->mti_numreaders, mo_AcquireRelease);+  uint32_t pidsbuf_onstask[142];+  uint32_t *const pids =+      (snap_nreaders < ARRAY_LENGTH(pidsbuf_onstask))+          ? pidsbuf_onstask+          : mdbx_malloc((snap_nreaders + 1) * sizeof(uint32_t));+  if (unlikely(!pids))+    return MDBX_ENOMEM;++  pids[0] = 0;+  int count = 0;+  for (unsigned i = 0; i < snap_nreaders; i++) {+    const uint32_t pid =+        atomic_load32(&lck->mti_readers[i].mr_pid, mo_AcquireRelease);+    if (pid == 0)+      continue /* skip empty */;+    if (pid == env->me_pid)+      continue /* skip self */;+    if (!mdbx_pid_insert(pids, pid))+      continue /* such pid already processed */;++    int err = mdbx_rpid_check(env, pid);+    if (err == MDBX_RESULT_TRUE)+      continue /* reader is live */;++    if (err != MDBX_SUCCESS) {+      rc = err;+      break /* mdbx_rpid_check() failed */;+    }++    /* stale reader found */+    if (!rdt_locked) {+      err = mdbx_rdt_lock(env);+      if (MDBX_IS_ERROR(err)) {+        rc = err;+        break;+      }++      rdt_locked = -1;+      if (err == MDBX_RESULT_TRUE) {+        /* mutex recovered, the mdbx_ipclock_failed() checked all readers */+        rc = MDBX_RESULT_TRUE;+        break;+      }++      /* a other process may have clean and reused slot, recheck */+      if (lck->mti_readers[i].mr_pid.weak != pid)+        continue;++      err = mdbx_rpid_check(env, pid);+      if (MDBX_IS_ERROR(err)) {+        rc = err;+        break;+      }++      if (err != MDBX_SUCCESS)+        continue /* the race with other process, slot reused */;+    }++    /* clean it */+    for (unsigned j = i; j < snap_nreaders; j++) {+      if (lck->mti_readers[j].mr_pid.weak == pid) {+        mdbx_debug("clear stale reader pid %" PRIuPTR " txn %" PRIaTXN,+                   (size_t)pid, lck->mti_readers[j].mr_txnid.weak);+        atomic_store32(&lck->mti_readers[j].mr_pid, 0, mo_Relaxed);+        atomic_store32(&lck->mti_readers_refresh_flag, true, mo_AcquireRelease);+        count++;+      }+    }+  }++  if (likely(!MDBX_IS_ERROR(rc)))+    atomic_store64(&lck->mti_reader_check_timestamp, mdbx_osal_monotime(),+                   mo_Relaxed);++  if (rdt_locked < 0)+    mdbx_rdt_unlock(env);++  if (pids != pidsbuf_onstask)+    mdbx_free(pids);++  if (dead)+    *dead = count;+  return rc;+}++__cold int mdbx_setup_debug(int loglevel, int flags, MDBX_debug_func *logger) {+  const int rc = mdbx_runtime_flags | (mdbx_loglevel << 16);++  if (loglevel != MDBX_LOG_DONTCHANGE)+    mdbx_loglevel = (uint8_t)loglevel;++  if (flags != MDBX_DBG_DONTCHANGE) {+    flags &=+#if MDBX_DEBUG+        MDBX_DBG_ASSERT | MDBX_DBG_AUDIT | MDBX_DBG_JITTER |+#endif+        MDBX_DBG_DUMP | MDBX_DBG_LEGACY_MULTIOPEN | MDBX_DBG_LEGACY_OVERLAP;+    mdbx_runtime_flags = (uint8_t)flags;+  }++  if (logger != MDBX_LOGGER_DONTCHANGE)+    mdbx_debug_logger = logger;+  return rc;+}++static txnid_t __cold mdbx_kick_longlived_readers(MDBX_env *env,+                                                  const txnid_t laggard) {+  mdbx_debug("DB size maxed out by reading #%" PRIaTXN, laggard);++  int retry;+  for (retry = 0; retry < INT_MAX; ++retry) {+    txnid_t oldest = mdbx_recent_steady_txnid(env);+    mdbx_assert(env, oldest < env->me_txn0->mt_txnid);+    mdbx_assert(env, oldest >= laggard);+    mdbx_assert(env, oldest >= env->me_oldest->weak);+    if (oldest == laggard || unlikely(!env->me_lck /* without-LCK mode */))+      return oldest;++    if (MDBX_IS_ERROR(mdbx_cleanup_dead_readers(env, false, NULL)))+      break;++    MDBX_reader *asleep = nullptr;+    MDBX_lockinfo *const lck = env->me_lck;+    uint64_t oldest_retired = UINT64_MAX;+    const unsigned snap_nreaders =+        atomic_load32(&lck->mti_numreaders, mo_AcquireRelease);+    for (unsigned i = 0; i < snap_nreaders; ++i) {+    retry:+      if (atomic_load32(&lck->mti_readers[i].mr_pid, mo_AcquireRelease)) {+        /* mdbx_jitter4testing(true); */+        const uint64_t snap_retired = atomic_load64(+            &lck->mti_readers[i].mr_snapshot_pages_retired, mo_Relaxed);+        const txnid_t snap_txnid = safe64_read(&lck->mti_readers[i].mr_txnid);+        if (unlikely(snap_retired !=+                         atomic_load64(+                             &lck->mti_readers[i].mr_snapshot_pages_retired,+                             mo_AcquireRelease) ||+                     snap_txnid != safe64_read(&lck->mti_readers[i].mr_txnid)))+          goto retry;+        if (oldest > snap_txnid &&+            laggard <= /* ignore pending updates */ snap_txnid) {+          oldest = snap_txnid;+          oldest_retired = snap_retired;+          asleep = &lck->mti_readers[i];+        }+      }+    }++    if (laggard < oldest || !asleep) {+      if (retry && env->me_hsr_callback) {+        /* LY: notify end of hsr-loop */+        const txnid_t gap = oldest - laggard;+        env->me_hsr_callback(env, env->me_txn, 0, 0, laggard,+                             (gap < UINT_MAX) ? (unsigned)gap : UINT_MAX, 0,+                             -retry);+      }+      mdbx_notice("hsr-kick: update oldest %" PRIaTXN " -> %" PRIaTXN,+                  env->me_oldest->weak, oldest);+      mdbx_assert(env, env->me_oldest->weak <= oldest);+      return atomic_store64(env->me_oldest, oldest, mo_Relaxed);+    }++    if (!env->me_hsr_callback)+      break;++    uint32_t pid = atomic_load32(&asleep->mr_pid, mo_AcquireRelease);+    uint64_t tid = asleep->mr_tid.weak;+    if (safe64_read(&asleep->mr_txnid) != laggard || pid <= 0)+      continue;++    const MDBX_meta *head_meta = mdbx_meta_head(env);+    const txnid_t gap =+        (mdbx_meta_txnid_stable(env, head_meta) - laggard) / MDBX_TXNID_STEP;+    const uint64_t head_retired =+        unaligned_peek_u64(4, head_meta->mm_pages_retired);+    const size_t space =+        (oldest_retired > head_retired)+            ? pgno2bytes(env, (pgno_t)(oldest_retired - head_retired))+            : 0;+    int rc = env->me_hsr_callback(+        env, env->me_txn, pid, (mdbx_tid_t)tid, laggard,+        (gap < UINT_MAX) ? (unsigned)gap : UINT_MAX, space, retry);+    if (rc < 0)+      break;++    if (rc > 0) {+      if (rc == 1) {+        safe64_reset_compare(&asleep->mr_txnid, laggard);+      } else {+        safe64_reset(&asleep->mr_txnid, true);+        atomic_store64(&asleep->mr_tid, 0, mo_Relaxed);+        atomic_store32(&asleep->mr_pid, 0, mo_Relaxed);+      }+      atomic_store32(&lck->mti_readers_refresh_flag, true, mo_Relaxed);+    }+  }++  if (retry && env->me_hsr_callback) {+    /* LY: notify end of hsr-loop */+    env->me_hsr_callback(env, env->me_txn, 0, 0, laggard, 0, 0, -retry);+  }+  return mdbx_find_oldest(env->me_txn);+}++#ifndef LIBMDBX_NO_EXPORTS_LEGACY_API+__cold int mdbx_env_set_syncbytes(MDBX_env *env, size_t threshold) {+  return __inline_mdbx_env_set_syncbytes(env, threshold);+}++__cold int mdbx_env_set_syncperiod(MDBX_env *env, unsigned seconds_16dot16) {+  return __inline_mdbx_env_set_syncperiod(env, seconds_16dot16);+}+#endif /* LIBMDBX_NO_EXPORTS_LEGACY_API */++__cold int mdbx_env_set_hsr(MDBX_env *env, MDBX_hsr_func *hsr) {+  int rc = check_env(env, false);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  env->me_hsr_callback = hsr;+  return MDBX_SUCCESS;+}++MDBX_hsr_func *__cold mdbx_env_get_hsr(const MDBX_env *env) {+  return likely(env && env->me_signature.weak == MDBX_ME_SIGNATURE)+             ? env->me_hsr_callback+             : NULL;+}++#ifdef __SANITIZE_THREAD__+/* LY: avoid tsan-trap by me_txn, mm_last_pg and mt_next_pgno */+__attribute__((__no_sanitize_thread__, __noinline__))+#endif+int mdbx_txn_straggler(const MDBX_txn *txn, int *percent)+{+  int rc = check_txn(txn, MDBX_TXN_BLOCKED);+  if (unlikely(rc != MDBX_SUCCESS))+    return (rc > 0) ? -rc : rc;++  MDBX_env *env = txn->mt_env;+  if (unlikely((txn->mt_flags & MDBX_TXN_RDONLY) == 0)) {+    if (percent)+      *percent =+          (int)((txn->mt_next_pgno * UINT64_C(100) + txn->mt_end_pgno / 2) /+                txn->mt_end_pgno);+    return 0;+  }++  txnid_t recent;+  MDBX_meta *meta;+  do {+    meta = mdbx_meta_head(env);+    recent = mdbx_meta_txnid_fluid(env, meta);+    if (percent) {+      const pgno_t maxpg = meta->mm_geo.now;+      *percent = (int)((meta->mm_geo.next * UINT64_C(100) + maxpg / 2) / maxpg);+    }+  } while (unlikely(recent != mdbx_meta_txnid_fluid(env, meta)));++  txnid_t lag = (recent - txn->mt_txnid) / MDBX_TXNID_STEP;+  return (lag > INT_MAX) ? INT_MAX : (int)lag;+}++typedef struct mdbx_walk_ctx {+  void *mw_user;+  MDBX_pgvisitor_func *mw_visitor;+  MDBX_txn *mw_txn;+  MDBX_cursor *mw_cursor;+  bool mw_dont_check_keys_ordering;+} mdbx_walk_ctx_t;++static __cold int mdbx_walk_sdb(mdbx_walk_ctx_t *ctx, MDBX_db *const db,+                                const char *name, int deep);++static MDBX_page_type_t walk_page_type(const MDBX_page *mp) {+  if (mp)+    switch (mp->mp_flags) {+    case P_BRANCH:+      return MDBX_page_branch;+    case P_LEAF:+      return MDBX_page_leaf;+    case P_LEAF | P_LEAF2:+      return MDBX_page_dupfixed_leaf;+    case P_OVERFLOW:+      return MDBX_page_large;+    case P_META:+      return MDBX_page_meta;+    }+  return MDBX_page_broken;+}++/* Depth-first tree traversal. */+static __cold int mdbx_walk_tree(mdbx_walk_ctx_t *ctx, const pgno_t pgno,+                                 const char *name, int deep,+                                 txnid_t parent_txnid) {+  assert(pgno != P_INVALID);+  MDBX_page *mp = nullptr;+  int rc, err = mdbx_page_get(ctx->mw_cursor, pgno, &mp, NULL, parent_txnid);+  if (err == MDBX_SUCCESS)+    err = mdbx_page_check(ctx->mw_cursor, mp, 0);++  MDBX_page_type_t type = walk_page_type(mp);+  const int nentries = (mp && !IS_OVERFLOW(mp)) ? page_numkeys(mp) : 1;+  unsigned npages = (mp && IS_OVERFLOW(mp)) ? mp->mp_pages : 1;+  size_t pagesize = pgno2bytes(ctx->mw_txn->mt_env, npages);+  size_t header_size = (mp && !IS_LEAF2(mp) && !IS_OVERFLOW(mp))+                           ? PAGEHDRSZ + mp->mp_lower+                           : PAGEHDRSZ;+  size_t payload_size = 0;+  size_t unused_size =+      (mp && !IS_OVERFLOW(mp) ? page_room(mp) : pagesize - header_size) -+      payload_size;+  size_t align_bytes = 0;++  if (err == MDBX_SUCCESS) {+    /* LY: Don't use mask here, e.g bitwise+     * (P_BRANCH|P_LEAF|P_LEAF2|P_META|P_OVERFLOW|P_SUBP).+     * Pages should not me marked dirty/loose or otherwise. */+    switch (mp->mp_flags) {+    default:+      err = MDBX_CORRUPTED;+      break;+    case P_BRANCH:+      if (unlikely(nentries < 2))+        err = MDBX_CORRUPTED;+    case P_LEAF:+    case P_LEAF | P_LEAF2:+      break;+    }+  }++  for (int i = 0; err == MDBX_SUCCESS && i < nentries;+       align_bytes += ((payload_size + align_bytes) & 1), i++) {+    if (type == MDBX_page_dupfixed_leaf) {+      /* LEAF2 pages have no mp_ptrs[] or node headers */+      payload_size += mp->mp_leaf2_ksize;+      continue;+    }++    MDBX_node *node = page_node(mp, i);+    payload_size += NODESIZE + node_ks(node);++    if (type == MDBX_page_branch) {+      assert(i > 0 || node_ks(node) == 0);+      continue;+    }++    assert(type == MDBX_page_leaf);+    switch (node_flags(node)) {+    case 0 /* usual node */:+      payload_size += node_ds(node);+      break;++    case F_BIGDATA /* long data on the large/overflow page */: {+      payload_size += sizeof(pgno_t);+      const pgno_t large_pgno = node_largedata_pgno(node);+      const size_t over_payload = node_ds(node);+      const size_t over_header = PAGEHDRSZ;+      npages = 1;++      MDBX_page *op;+      err = mdbx_page_get(ctx->mw_cursor, large_pgno, &op, NULL,+                          pp_txnid4chk(mp, ctx->mw_txn));+      if (err == MDBX_SUCCESS)+        err = mdbx_page_check(ctx->mw_cursor, op, 0);+      if (err == MDBX_SUCCESS) {+        /* LY: Don't use mask here, e.g bitwise+         * (P_BRANCH|P_LEAF|P_LEAF2|P_META|P_OVERFLOW|P_SUBP).+         * Pages should not me marked dirty/loose or otherwise. */+        if (unlikely(P_OVERFLOW != op->mp_flags))+          err = bad_page(mp, "wrong page type %d for large data", op->mp_flags);+        else+          npages = op->mp_pages;+      }++      pagesize = pgno2bytes(ctx->mw_txn->mt_env, npages);+      const size_t over_unused = pagesize - over_payload - over_header;+      rc = ctx->mw_visitor(large_pgno, npages, ctx->mw_user, deep, name,+                           pagesize, MDBX_page_large, err, 1, over_payload,+                           over_header, over_unused);+      if (unlikely(rc != MDBX_SUCCESS))+        return (rc == MDBX_RESULT_TRUE) ? MDBX_SUCCESS : rc;+    } break;++    case F_SUBDATA /* sub-db */: {+      const size_t namelen = node_ks(node);+      payload_size += node_ds(node);+      if (unlikely(namelen == 0 || node_ds(node) != sizeof(MDBX_db)))+        err = MDBX_CORRUPTED;+    } break;++    case F_SUBDATA | F_DUPDATA /* dupsorted sub-tree */:+      payload_size += sizeof(MDBX_db);+      if (unlikely(node_ds(node) != sizeof(MDBX_db)))+        err = MDBX_CORRUPTED;+      break;++    case F_DUPDATA /* short sub-page */: {+      if (unlikely(node_ds(node) <= PAGEHDRSZ)) {+        err = MDBX_CORRUPTED;+        break;+      }++      MDBX_page *sp = node_data(node);+      const int nsubkeys = page_numkeys(sp);+      size_t subheader_size =+          IS_LEAF2(sp) ? PAGEHDRSZ : PAGEHDRSZ + sp->mp_lower;+      size_t subunused_size = page_room(sp);+      size_t subpayload_size = 0;+      size_t subalign_bytes = 0;+      MDBX_page_type_t subtype;++      switch (sp->mp_flags & ~P_DIRTY /* ignore for sub-pages */) {+      case P_LEAF | P_SUBP:+        subtype = MDBX_subpage_leaf;+        break;+      case P_LEAF | P_LEAF2 | P_SUBP:+        subtype = MDBX_subpage_dupfixed_leaf;+        break;+      default:+        subtype = MDBX_subpage_broken;+        err = MDBX_CORRUPTED;+      }++      for (int j = 0; err == MDBX_SUCCESS && j < nsubkeys;+           subalign_bytes += ((subpayload_size + subalign_bytes) & 1), j++) {++        if (subtype == MDBX_subpage_dupfixed_leaf) {+          /* LEAF2 pages have no mp_ptrs[] or node headers */+          subpayload_size += sp->mp_leaf2_ksize;+        } else {+          assert(subtype == MDBX_subpage_leaf);+          MDBX_node *subnode = page_node(sp, j);+          subpayload_size += NODESIZE + node_ks(subnode) + node_ds(subnode);+          if (unlikely(node_flags(subnode) != 0))+            err = MDBX_CORRUPTED;+        }+      }++      rc = ctx->mw_visitor(pgno, 0, ctx->mw_user, deep + 1, name, node_ds(node),+                           subtype, err, nsubkeys, subpayload_size,+                           subheader_size, subunused_size + subalign_bytes);+      if (unlikely(rc != MDBX_SUCCESS))+        return (rc == MDBX_RESULT_TRUE) ? MDBX_SUCCESS : rc;+      header_size += subheader_size;+      unused_size += subunused_size;+      payload_size += subpayload_size;+      align_bytes += subalign_bytes;+    } break;++    default:+      err = MDBX_CORRUPTED;+    }+  }++  rc = ctx->mw_visitor(pgno, 1, ctx->mw_user, deep, name,+                       ctx->mw_txn->mt_env->me_psize, type, err, nentries,+                       payload_size, header_size, unused_size + align_bytes);+  if (unlikely(rc != MDBX_SUCCESS))+    return (rc == MDBX_RESULT_TRUE) ? MDBX_SUCCESS : rc;++  for (int i = 0; err == MDBX_SUCCESS && i < nentries; i++) {+    if (type == MDBX_page_dupfixed_leaf)+      continue;++    MDBX_node *node = page_node(mp, i);+    if (type == MDBX_page_branch) {+      err = mdbx_walk_tree(ctx, node_pgno(node), name, deep + 1,+                           pp_txnid4chk(mp, ctx->mw_txn));+      if (unlikely(err != MDBX_SUCCESS)) {+        if (err == MDBX_RESULT_TRUE)+          break;+        return err;+      }+      continue;+    }++    assert(type == MDBX_page_leaf);+    MDBX_db db;+    switch (node_flags(node)) {+    default:+      continue;++    case F_SUBDATA /* sub-db */: {+      const size_t namelen = node_ks(node);+      if (unlikely(namelen == 0 || node_ds(node) != sizeof(MDBX_db))) {+        err = MDBX_CORRUPTED;+        break;+      }++      char namebuf_onstask[64];+      char *const sub_name = (namelen < sizeof(namebuf_onstask))+                                 ? namebuf_onstask+                                 : mdbx_malloc(namelen + 1);+      if (sub_name) {+        memcpy(sub_name, node_key(node), namelen);+        sub_name[namelen] = 0;+        memcpy(&db, node_data(node), sizeof(db));+        err = mdbx_walk_sdb(ctx, &db, sub_name, deep + 1);+        if (sub_name != namebuf_onstask)+          mdbx_free(sub_name);+      } else {+        err = MDBX_ENOMEM;+      }+    } break;++    case F_SUBDATA | F_DUPDATA /* dupsorted sub-tree */:+      if (unlikely(node_ds(node) != sizeof(MDBX_db) ||+                   ctx->mw_cursor->mc_xcursor == NULL))+        err = MDBX_CORRUPTED;+      else {+        memcpy(&db, node_data(node), sizeof(db));+        assert(ctx->mw_cursor->mc_xcursor ==+               &container_of(ctx->mw_cursor, MDBX_cursor_couple, outer)->inner);+        ctx->mw_cursor = &ctx->mw_cursor->mc_xcursor->mx_cursor;+        err = mdbx_walk_tree(ctx, db.md_root, name, deep + 1,+                             pp_txnid4chk(mp, ctx->mw_txn));+        MDBX_xcursor *inner_xcursor =+            container_of(ctx->mw_cursor, MDBX_xcursor, mx_cursor);+        MDBX_cursor_couple *couple =+            container_of(inner_xcursor, MDBX_cursor_couple, inner);+        ctx->mw_cursor = &couple->outer;+      }+      break;+    }+  }++  return MDBX_SUCCESS;+}++static __cold int mdbx_walk_sdb(mdbx_walk_ctx_t *ctx, MDBX_db *const db,+                                const char *name, int deep) {+  if (unlikely(db->md_root == P_INVALID))+    return MDBX_SUCCESS; /* empty db */++  MDBX_cursor_couple couple;+  MDBX_dbx dbx = {.md_klen_min = INT_MAX};+  uint8_t dbistate = DBI_VALID | DBI_AUDITED;+  int rc = mdbx_couple_init(&couple, ~0u, ctx->mw_txn, db, &dbx, &dbistate);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  if (ctx->mw_dont_check_keys_ordering) {+    couple.outer.mc_flags |= C_SKIPORD;+    couple.inner.mx_cursor.mc_flags |= C_SKIPORD;+  }+  couple.outer.mc_next = ctx->mw_cursor;+  ctx->mw_cursor = &couple.outer;+  rc = mdbx_walk_tree(ctx, db->md_root, name, deep, ctx->mw_txn->mt_txnid);+  ctx->mw_cursor = couple.outer.mc_next;+  return rc;+}++__cold int mdbx_env_pgwalk(MDBX_txn *txn, MDBX_pgvisitor_func *visitor,+                           void *user, bool dont_check_keys_ordering) {+  int rc = check_txn(txn, MDBX_TXN_BLOCKED);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  mdbx_walk_ctx_t ctx;+  memset(&ctx, 0, sizeof(ctx));+  ctx.mw_txn = txn;+  ctx.mw_user = user;+  ctx.mw_visitor = visitor;+  ctx.mw_dont_check_keys_ordering = dont_check_keys_ordering;++  rc = visitor(0, NUM_METAS, user, 0, MDBX_PGWALK_META,+               pgno2bytes(txn->mt_env, NUM_METAS), MDBX_page_meta, MDBX_SUCCESS,+               NUM_METAS, sizeof(MDBX_meta) * NUM_METAS, PAGEHDRSZ * NUM_METAS,+               (txn->mt_env->me_psize - sizeof(MDBX_meta) - PAGEHDRSZ) *+                   NUM_METAS);+  if (!MDBX_IS_ERROR(rc))+    rc = mdbx_walk_sdb(&ctx, &txn->mt_dbs[FREE_DBI], MDBX_PGWALK_GC, 0);+  if (!MDBX_IS_ERROR(rc))+    rc = mdbx_walk_sdb(&ctx, &txn->mt_dbs[MAIN_DBI], MDBX_PGWALK_MAIN, 0);+  return rc;+}++int mdbx_canary_put(MDBX_txn *txn, const MDBX_canary *canary) {+  int rc = check_txn_rw(txn, MDBX_TXN_BLOCKED);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  if (likely(canary)) {+    if (txn->mt_canary.x == canary->x && txn->mt_canary.y == canary->y &&+        txn->mt_canary.z == canary->z)+      return MDBX_SUCCESS;+    txn->mt_canary.x = canary->x;+    txn->mt_canary.y = canary->y;+    txn->mt_canary.z = canary->z;+  }+  txn->mt_canary.v = txn->mt_txnid;+  txn->mt_flags |= MDBX_TXN_DIRTY;++  return MDBX_SUCCESS;+}++int mdbx_canary_get(const MDBX_txn *txn, MDBX_canary *canary) {+  int rc = check_txn(txn, MDBX_TXN_BLOCKED);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  if (unlikely(canary == NULL))+    return MDBX_EINVAL;++  *canary = txn->mt_canary;+  return MDBX_SUCCESS;+}++int mdbx_cursor_on_first(const MDBX_cursor *mc) {+  if (unlikely(mc == NULL))+    return MDBX_EINVAL;++  if (unlikely(mc->mc_signature != MDBX_MC_LIVE))+    return (mc->mc_signature == MDBX_MC_READY4CLOSE) ? MDBX_EINVAL+                                                     : MDBX_EBADSIGN;++  if (!(mc->mc_flags & C_INITIALIZED))+    return mc->mc_db->md_entries ? MDBX_RESULT_FALSE : MDBX_RESULT_TRUE;++  for (unsigned i = 0; i < mc->mc_snum; ++i) {+    if (mc->mc_ki[i])+      return MDBX_RESULT_FALSE;+  }++  return MDBX_RESULT_TRUE;+}++int mdbx_cursor_on_last(const MDBX_cursor *mc) {+  if (unlikely(mc == NULL))+    return MDBX_EINVAL;++  if (unlikely(mc->mc_signature != MDBX_MC_LIVE))+    return (mc->mc_signature == MDBX_MC_READY4CLOSE) ? MDBX_EINVAL+                                                     : MDBX_EBADSIGN;++  if (!(mc->mc_flags & C_INITIALIZED))+    return mc->mc_db->md_entries ? MDBX_RESULT_FALSE : MDBX_RESULT_TRUE;++  for (unsigned i = 0; i < mc->mc_snum; ++i) {+    unsigned nkeys = page_numkeys(mc->mc_pg[i]);+    if (mc->mc_ki[i] < nkeys - 1)+      return MDBX_RESULT_FALSE;+  }++  return MDBX_RESULT_TRUE;+}++int mdbx_cursor_eof(const MDBX_cursor *mc) {+  if (unlikely(mc == NULL))+    return MDBX_EINVAL;++  if (unlikely(mc->mc_signature != MDBX_MC_LIVE))+    return (mc->mc_signature == MDBX_MC_READY4CLOSE) ? MDBX_EINVAL+                                                     : MDBX_EBADSIGN;++  if ((mc->mc_flags & C_INITIALIZED) == 0)+    return MDBX_RESULT_TRUE;++  if (mc->mc_snum == 0)+    return MDBX_RESULT_TRUE;++  if ((mc->mc_flags & C_EOF) &&+      mc->mc_ki[mc->mc_top] >= page_numkeys(mc->mc_pg[mc->mc_top]))+    return MDBX_RESULT_TRUE;++  return MDBX_RESULT_FALSE;+}++//------------------------------------------------------------------------------++struct diff_result {+  ptrdiff_t diff;+  unsigned level;+  int root_nkeys;+};++/* calculates: r = x - y */+__hot static int cursor_diff(const MDBX_cursor *const __restrict x,+                             const MDBX_cursor *const __restrict y,+                             struct diff_result *const __restrict r) {+  r->diff = 0;+  r->level = 0;+  r->root_nkeys = 0;++  if (unlikely(x->mc_signature != MDBX_MC_LIVE))+    return (x->mc_signature == MDBX_MC_READY4CLOSE) ? MDBX_EINVAL+                                                    : MDBX_EBADSIGN;++  if (unlikely(y->mc_signature != MDBX_MC_LIVE))+    return (y->mc_signature == MDBX_MC_READY4CLOSE) ? MDBX_EINVAL+                                                    : MDBX_EBADSIGN;++  int rc = check_txn(x->mc_txn, MDBX_TXN_BLOCKED);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  if (unlikely(x->mc_txn != y->mc_txn))+    return MDBX_BAD_TXN;++  if (unlikely(y->mc_dbi != x->mc_dbi))+    return MDBX_EINVAL;++  if (unlikely(!(y->mc_flags & x->mc_flags & C_INITIALIZED)))+    return MDBX_ENODATA;++  while (likely(r->level < y->mc_snum && r->level < x->mc_snum)) {+    if (unlikely(y->mc_pg[r->level] != x->mc_pg[r->level]))+      return MDBX_PROBLEM;++    int nkeys = page_numkeys(y->mc_pg[r->level]);+    assert(nkeys > 0);+    if (r->level == 0)+      r->root_nkeys = nkeys;++    const int limit_ki = nkeys - 1;+    const int x_ki = x->mc_ki[r->level];+    const int y_ki = y->mc_ki[r->level];+    r->diff = ((x_ki < limit_ki) ? x_ki : limit_ki) -+              ((y_ki < limit_ki) ? y_ki : limit_ki);+    if (r->diff == 0) {+      r->level += 1;+      continue;+    }++    while (unlikely(r->diff == 1) &&+           likely(r->level + 1 < y->mc_snum && r->level + 1 < x->mc_snum)) {+      r->level += 1;+      /*   DB'PAGEs: 0------------------>MAX+       *+       *    CURSORs:       y < x+       *  STACK[i ]:         |+       *  STACK[+1]:  ...y++N|0++x...+       */+      nkeys = page_numkeys(y->mc_pg[r->level]);+      r->diff = (nkeys - y->mc_ki[r->level]) + x->mc_ki[r->level];+      assert(r->diff > 0);+    }++    while (unlikely(r->diff == -1) &&+           likely(r->level + 1 < y->mc_snum && r->level + 1 < x->mc_snum)) {+      r->level += 1;+      /*   DB'PAGEs: 0------------------>MAX+       *+       *    CURSORs:       x < y+       *  STACK[i ]:         |+       *  STACK[+1]:  ...x--N|0--y...+       */+      nkeys = page_numkeys(x->mc_pg[r->level]);+      r->diff = -(nkeys - x->mc_ki[r->level]) - y->mc_ki[r->level];+      assert(r->diff < 0);+    }++    return MDBX_SUCCESS;+  }++  r->diff = CMP2INT(x->mc_flags & C_EOF, y->mc_flags & C_EOF);+  return MDBX_SUCCESS;+}++__hot static ptrdiff_t estimate(const MDBX_db *db,+                                struct diff_result *const __restrict dr) {+  /*        root: branch-page    => scale = leaf-factor * branch-factor^(N-1)+   *     level-1: branch-page(s) => scale = leaf-factor * branch-factor^2+   *     level-2: branch-page(s) => scale = leaf-factor * branch-factor+   *     level-N: branch-page(s) => scale = leaf-factor+   *  leaf-level: leaf-page(s)   => scale = 1+   */+  ptrdiff_t btree_power = (ptrdiff_t)db->md_depth - 2 - (ptrdiff_t)dr->level;+  if (btree_power < 0)+    return dr->diff;++  ptrdiff_t estimated =+      (ptrdiff_t)db->md_entries * dr->diff / (ptrdiff_t)db->md_leaf_pages;+  if (btree_power == 0)+    return estimated;++  if (db->md_depth < 4) {+    assert(dr->level == 0 && btree_power == 1);+    return (ptrdiff_t)db->md_entries * dr->diff / (ptrdiff_t)dr->root_nkeys;+  }++  /* average_branchpage_fillfactor = total(branch_entries) / branch_pages+     total(branch_entries) = leaf_pages + branch_pages - 1 (root page) */+  const size_t log2_fixedpoint = sizeof(size_t) - 1;+  const size_t half = UINT64_C(1) << (log2_fixedpoint - 1);+  const size_t factor =+      ((db->md_leaf_pages + db->md_branch_pages - 1) << log2_fixedpoint) /+      db->md_branch_pages;+  while (1) {+    switch ((size_t)btree_power) {+    default: {+      const size_t square = (factor * factor + half) >> log2_fixedpoint;+      const size_t quad = (square * square + half) >> log2_fixedpoint;+      do {+        estimated = estimated * quad + half;+        estimated >>= log2_fixedpoint;+        btree_power -= 4;+      } while (btree_power >= 4);+      continue;+    }+    case 3:+      estimated = estimated * factor + half;+      estimated >>= log2_fixedpoint;+      __fallthrough /* fall through */;+    case 2:+      estimated = estimated * factor + half;+      estimated >>= log2_fixedpoint;+      __fallthrough /* fall through */;+    case 1:+      estimated = estimated * factor + half;+      estimated >>= log2_fixedpoint;+      __fallthrough /* fall through */;+    case 0:+      if (unlikely(estimated > (ptrdiff_t)db->md_entries))+        return (ptrdiff_t)db->md_entries;+      if (unlikely(estimated < -(ptrdiff_t)db->md_entries))+        return -(ptrdiff_t)db->md_entries;+      return estimated;+    }+  }+}++int mdbx_estimate_distance(const MDBX_cursor *first, const MDBX_cursor *last,+                           ptrdiff_t *distance_items) {+  if (unlikely(first == NULL || last == NULL || distance_items == NULL))+    return MDBX_EINVAL;++  *distance_items = 0;+  struct diff_result dr;+  int rc = cursor_diff(last, first, &dr);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  if (unlikely(dr.diff == 0) &&+      F_ISSET(first->mc_db->md_flags & last->mc_db->md_flags,+              MDBX_DUPSORT | C_INITIALIZED)) {+    first = &first->mc_xcursor->mx_cursor;+    last = &last->mc_xcursor->mx_cursor;+    rc = cursor_diff(first, last, &dr);+    if (unlikely(rc != MDBX_SUCCESS))+      return rc;+  }++  if (likely(dr.diff != 0))+    *distance_items = estimate(first->mc_db, &dr);++  return MDBX_SUCCESS;+}++int mdbx_estimate_move(const MDBX_cursor *cursor, MDBX_val *key, MDBX_val *data,+                       MDBX_cursor_op move_op, ptrdiff_t *distance_items) {+  if (unlikely(cursor == NULL || distance_items == NULL ||+               move_op == MDBX_GET_CURRENT || move_op == MDBX_GET_MULTIPLE))+    return MDBX_EINVAL;++  if (unlikely(cursor->mc_signature != MDBX_MC_LIVE))+    return (cursor->mc_signature == MDBX_MC_READY4CLOSE) ? MDBX_EINVAL+                                                         : MDBX_EBADSIGN;++  int rc = check_txn(cursor->mc_txn, MDBX_TXN_BLOCKED);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  if (!(cursor->mc_flags & C_INITIALIZED))+    return MDBX_ENODATA;++  MDBX_cursor_couple next;+  cursor_copy_internal(cursor, &next.outer);+  next.outer.mc_xcursor = NULL;+  if (cursor->mc_db->md_flags & MDBX_DUPSORT) {+    next.outer.mc_xcursor = &next.inner;+    rc = mdbx_xcursor_init0(&next.outer);+    if (unlikely(rc != MDBX_SUCCESS))+      return rc;+    MDBX_xcursor *mx = &container_of(cursor, MDBX_cursor_couple, outer)->inner;+    cursor_copy_internal(&mx->mx_cursor, &next.inner.mx_cursor);+  }++  MDBX_val stub = {0, 0};+  if (data == NULL) {+    const unsigned mask =+        1 << MDBX_GET_BOTH | 1 << MDBX_GET_BOTH_RANGE | 1 << MDBX_SET_KEY;+    if (unlikely(mask & (1 << move_op)))+      return MDBX_EINVAL;+    data = &stub;+  }++  if (key == NULL) {+    const unsigned mask = 1 << MDBX_GET_BOTH | 1 << MDBX_GET_BOTH_RANGE |+                          1 << MDBX_SET_KEY | 1 << MDBX_SET |+                          1 << MDBX_SET_RANGE;+    if (unlikely(mask & (1 << move_op)))+      return MDBX_EINVAL;+    key = &stub;+  }++  rc = mdbx_cursor_get(&next.outer, key, data, move_op);+  if (unlikely(rc != MDBX_SUCCESS &&+               (rc != MDBX_NOTFOUND || !(next.outer.mc_flags & C_INITIALIZED))))+    return rc;++  return mdbx_estimate_distance(cursor, &next.outer, distance_items);+}++int mdbx_estimate_range(MDBX_txn *txn, MDBX_dbi dbi, MDBX_val *begin_key,+                        MDBX_val *begin_data, MDBX_val *end_key,+                        MDBX_val *end_data, ptrdiff_t *size_items) {+  int rc = check_txn(txn, MDBX_TXN_BLOCKED);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  if (unlikely(!size_items))+    return MDBX_EINVAL;++  if (unlikely(begin_data && (begin_key == NULL || begin_key == MDBX_EPSILON)))+    return MDBX_EINVAL;++  if (unlikely(end_data && (end_key == NULL || end_key == MDBX_EPSILON)))+    return MDBX_EINVAL;++  if (unlikely(begin_key == MDBX_EPSILON && end_key == MDBX_EPSILON))+    return MDBX_EINVAL;++  if (unlikely(!mdbx_txn_dbi_exists(txn, dbi, DBI_USRVALID)))+    return MDBX_BAD_DBI;++  MDBX_cursor_couple begin;+  /* LY: first, initialize cursor to refresh a DB in case it have DB_STALE */+  rc = mdbx_cursor_init(&begin.outer, txn, dbi);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  if (unlikely(begin.outer.mc_db->md_entries == 0)) {+    *size_items = 0;+    return MDBX_SUCCESS;+  }++  if (!begin_key) {+    if (unlikely(!end_key)) {+      /* LY: FIRST..LAST case */+      *size_items = (ptrdiff_t)begin.outer.mc_db->md_entries;+      return MDBX_SUCCESS;+    }+    MDBX_val stub = {0, 0};+    rc = mdbx_cursor_first(&begin.outer, &stub, &stub);+    if (unlikely(end_key == MDBX_EPSILON)) {+      /* LY: FIRST..+epsilon case */+      return (rc == MDBX_SUCCESS)+                 ? mdbx_cursor_count(&begin.outer, (size_t *)size_items)+                 : rc;+    }+  } else {+    if (unlikely(begin_key == MDBX_EPSILON)) {+      if (end_key == NULL) {+        /* LY: -epsilon..LAST case */+        MDBX_val stub = {0, 0};+        rc = mdbx_cursor_last(&begin.outer, &stub, &stub);+        return (rc == MDBX_SUCCESS)+                   ? mdbx_cursor_count(&begin.outer, (size_t *)size_items)+                   : rc;+      }+      /* LY: -epsilon..value case */+      assert(end_key != MDBX_EPSILON);+      begin_key = end_key;+    } else if (unlikely(end_key == MDBX_EPSILON)) {+      /* LY: value..+epsilon case */+      assert(begin_key != MDBX_EPSILON);+      end_key = begin_key;+    }+    if (end_key && !begin_data && !end_data &&+        (begin_key == end_key ||+         begin.outer.mc_dbx->md_cmp(begin_key, end_key) == 0)) {+      /* LY: single key case */+      int exact = 0;+      rc = mdbx_cursor_set(&begin.outer, begin_key, NULL, MDBX_SET, &exact);+      if (unlikely(rc != MDBX_SUCCESS)) {+        *size_items = 0;+        return (rc == MDBX_NOTFOUND) ? MDBX_SUCCESS : rc;+      }+      *size_items = 1;+      if (begin.outer.mc_xcursor != NULL) {+        MDBX_node *node = page_node(begin.outer.mc_pg[begin.outer.mc_top],+                                    begin.outer.mc_ki[begin.outer.mc_top]);+        if (F_ISSET(node_flags(node), F_DUPDATA)) {+          /* LY: return the number of duplicates for given key */+          mdbx_tassert(txn,+                       begin.outer.mc_xcursor == &begin.inner &&+                           (begin.inner.mx_cursor.mc_flags & C_INITIALIZED));+          *size_items =+              (sizeof(*size_items) >= sizeof(begin.inner.mx_db.md_entries) ||+               begin.inner.mx_db.md_entries <= PTRDIFF_MAX)+                  ? (size_t)begin.inner.mx_db.md_entries+                  : PTRDIFF_MAX;+        }+      }+      return MDBX_SUCCESS;+    } else {+      rc = mdbx_cursor_set(&begin.outer, begin_key, begin_data,+                           begin_data ? MDBX_GET_BOTH_RANGE : MDBX_SET_RANGE,+                           NULL);+    }+  }++  if (unlikely(rc != MDBX_SUCCESS)) {+    if (rc != MDBX_NOTFOUND || !(begin.outer.mc_flags & C_INITIALIZED))+      return rc;+  }++  MDBX_cursor_couple end;+  rc = mdbx_cursor_init(&end.outer, txn, dbi);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;+  if (!end_key) {+    MDBX_val stub = {0, 0};+    rc = mdbx_cursor_last(&end.outer, &stub, &stub);+  } else {+    rc = mdbx_cursor_set(&end.outer, end_key, end_data,+                         end_data ? MDBX_GET_BOTH_RANGE : MDBX_SET_RANGE, NULL);+  }+  if (unlikely(rc != MDBX_SUCCESS)) {+    if (rc != MDBX_NOTFOUND || !(end.outer.mc_flags & C_INITIALIZED))+      return rc;+  }++  rc = mdbx_estimate_distance(&begin.outer, &end.outer, size_items);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;+  assert(*size_items >= -(ptrdiff_t)begin.outer.mc_db->md_entries &&+         *size_items <= (ptrdiff_t)begin.outer.mc_db->md_entries);++#if 0 /* LY: Was decided to returns as-is (i.e. negative) the estimation       \+       * results for an inverted ranges. */++  /* Commit 8ddfd1f34ad7cf7a3c4aa75d2e248ca7e639ed63+     Change-Id: If59eccf7311123ab6384c4b93f9b1fed5a0a10d1 */++  if (*size_items < 0) {+    /* LY: inverted range case */+    *size_items += (ptrdiff_t)begin.outer.mc_db->md_entries;+  } else if (*size_items == 0 && begin_key && end_key) {+    int cmp = begin.outer.mc_dbx->md_cmp(&origin_begin_key, &origin_end_key);+    if (cmp == 0 && (begin.inner.mx_cursor.mc_flags & C_INITIALIZED) &&+        begin_data && end_data)+      cmp = begin.outer.mc_dbx->md_dcmp(&origin_begin_data, &origin_end_data);+    if (cmp > 0) {+      /* LY: inverted range case with empty scope */+      *size_items = (ptrdiff_t)begin.outer.mc_db->md_entries;+    }+  }+  assert(*size_items >= 0 &&+         *size_items <= (ptrdiff_t)begin.outer.mc_db->md_entries);+#endif++  return MDBX_SUCCESS;+}++//------------------------------------------------------------------------------++/* Позволяет обновить или удалить существующую запись с получением+ * в old_data предыдущего значения данных. При этом если new_data равен+ * нулю, то выполняется удаление, иначе обновление/вставка.+ *+ * Текущее значение может находиться в уже измененной (грязной) странице.+ * В этом случае страница будет перезаписана при обновлении, а само старое+ * значение утрачено. Поэтому исходно в old_data должен быть передан+ * дополнительный буфер для копирования старого значения.+ * Если переданный буфер слишком мал, то функция вернет -1, установив+ * old_data->iov_len в соответствующее значение.+ *+ * Для не-уникальных ключей также возможен второй сценарий использования,+ * когда посредством old_data из записей с одинаковым ключом для+ * удаления/обновления выбирается конкретная. Для выбора этого сценария+ * во flags следует одновременно указать MDBX_CURRENT и MDBX_NOOVERWRITE.+ * Именно эта комбинация выбрана, так как она лишена смысла, и этим позволяет+ * идентифицировать запрос такого сценария.+ *+ * Функция может быть замещена соответствующими операциями с курсорами+ * после двух доработок (TODO):+ *  - внешняя аллокация курсоров, в том числе на стеке (без malloc).+ *  - получения статуса страницы по адресу (знать о P_DIRTY).+ */++int mdbx_replace_ex(MDBX_txn *txn, MDBX_dbi dbi, const MDBX_val *key,+                    MDBX_val *new_data, MDBX_val *old_data,+                    MDBX_put_flags_t flags, MDBX_preserve_func preserver,+                    void *preserver_context) {+  int rc = check_txn_rw(txn, MDBX_TXN_BLOCKED);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  if (unlikely(!key || !old_data || old_data == new_data))+    return MDBX_EINVAL;++  if (unlikely(old_data->iov_base == NULL && old_data->iov_len))+    return MDBX_EINVAL;++  if (unlikely(new_data == NULL &&+               (flags & (MDBX_CURRENT | MDBX_RESERVE)) != MDBX_CURRENT))+    return MDBX_EINVAL;++  if (unlikely(!mdbx_txn_dbi_exists(txn, dbi, DBI_USRVALID)))+    return MDBX_BAD_DBI;++  if (unlikely(flags &+               ~(MDBX_NOOVERWRITE | MDBX_NODUPDATA | MDBX_ALLDUPS |+                 MDBX_RESERVE | MDBX_APPEND | MDBX_APPENDDUP | MDBX_CURRENT)))+    return MDBX_EINVAL;++  MDBX_cursor_couple cx;+  rc = mdbx_cursor_init(&cx.outer, txn, dbi);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;+  cx.outer.mc_next = txn->tw.cursors[dbi];+  txn->tw.cursors[dbi] = &cx.outer;++  MDBX_val present_key = *key;+  if (F_ISSET(flags, MDBX_CURRENT | MDBX_NOOVERWRITE)) {+    /* в old_data значение для выбора конкретного дубликата */+    if (unlikely(!(txn->mt_dbs[dbi].md_flags & MDBX_DUPSORT))) {+      rc = MDBX_EINVAL;+      goto bailout;+    }++    /* убираем лишний бит, он был признаком запрошенного режима */+    flags -= MDBX_NOOVERWRITE;++    rc = mdbx_cursor_get(&cx.outer, &present_key, old_data, MDBX_GET_BOTH);+    if (rc != MDBX_SUCCESS)+      goto bailout;+  } else {+    /* в old_data буфер для сохранения предыдущего значения */+    if (unlikely(new_data && old_data->iov_base == new_data->iov_base))+      return MDBX_EINVAL;+    MDBX_val present_data;+    rc = mdbx_cursor_get(&cx.outer, &present_key, &present_data, MDBX_SET_KEY);+    if (unlikely(rc != MDBX_SUCCESS)) {+      old_data->iov_base = NULL;+      old_data->iov_len = 0;+      if (rc != MDBX_NOTFOUND || (flags & MDBX_CURRENT))+        goto bailout;+    } else if (flags & MDBX_NOOVERWRITE) {+      rc = MDBX_KEYEXIST;+      *old_data = present_data;+      goto bailout;+    } else {+      MDBX_page *page = cx.outer.mc_pg[cx.outer.mc_top];+      if (txn->mt_dbs[dbi].md_flags & MDBX_DUPSORT) {+        if (flags & MDBX_CURRENT) {+          /* disallow update/delete for multi-values */+          MDBX_node *node = page_node(page, cx.outer.mc_ki[cx.outer.mc_top]);+          if (F_ISSET(node_flags(node), F_DUPDATA)) {+            mdbx_tassert(txn, XCURSOR_INITED(&cx.outer) &&+                                  cx.outer.mc_xcursor->mx_db.md_entries > 1);+            if (cx.outer.mc_xcursor->mx_db.md_entries > 1) {+              rc = MDBX_EMULTIVAL;+              goto bailout;+            }+          }+          /* В оригинальной LMDB флажок MDBX_CURRENT здесь приведет+           * к замене данных без учета MDBX_DUPSORT сортировки,+           * но здесь это в любом случае допустимо, так как мы+           * проверили что для ключа есть только одно значение. */+        }+      }++      if (IS_DIRTY(page)) {+        if (new_data && cmp_lenfast(&present_data, new_data) == 0) {+          /* если данные совпадают, то ничего делать не надо */+          *old_data = *new_data;+          goto bailout;+        }+        rc = preserver ? preserver(preserver_context, old_data,+                                   present_data.iov_base, present_data.iov_len)+                       : MDBX_SUCCESS;+        if (unlikely(rc != MDBX_SUCCESS))+          goto bailout;+      } else {+        *old_data = present_data;+      }+      flags |= MDBX_CURRENT;+    }+  }++  if (likely(new_data))+    rc = mdbx_cursor_put(&cx.outer, key, new_data, flags);+  else+    rc = mdbx_cursor_del(&cx.outer, flags & MDBX_ALLDUPS);++bailout:+  txn->tw.cursors[dbi] = cx.outer.mc_next;+  return rc;+}++static int default_value_preserver(void *context, MDBX_val *target,+                                   const void *src, size_t bytes) {+  (void)context;+  if (unlikely(target->iov_len < bytes)) {+    target->iov_base = nullptr;+    target->iov_len = bytes;+    return MDBX_RESULT_TRUE;+  }+  memcpy(target->iov_base, src, target->iov_len = bytes);+  return MDBX_SUCCESS;+}++int mdbx_replace(MDBX_txn *txn, MDBX_dbi dbi, const MDBX_val *key,+                 MDBX_val *new_data, MDBX_val *old_data,+                 MDBX_put_flags_t flags) {+  return mdbx_replace_ex(txn, dbi, key, new_data, old_data, flags,+                         default_value_preserver, nullptr);+}++/* Функция сообщает находится ли указанный адрес в "грязной" странице у+ * заданной пишущей транзакции. В конечном счете это позволяет избавиться от+ * лишнего копирования данных из НЕ-грязных страниц.+ *+ * "Грязные" страницы - это те, которые уже были изменены в ходе пишущей+ * транзакции. Соответственно, какие-либо дальнейшие изменения могут привести+ * к перезаписи таких страниц. Поэтому все функции, выполняющие изменения, в+ * качестве аргументов НЕ должны получать указатели на данные в таких+ * страницах. В свою очередь "НЕ грязные" страницы перед модификацией будут+ * скопированы.+ *+ * Другими словами, данные из "грязных" страниц должны быть либо скопированы+ * перед передачей в качестве аргументов для дальнейших модификаций, либо+ * отвергнуты на стадии проверки корректности аргументов.+ *+ * Таким образом, функция позволяет как избавиться от лишнего копирования,+ * так и выполнить более полную проверку аргументов.+ *+ * ВАЖНО: Передаваемый указатель должен указывать на начало данных. Только+ * так гарантируется что актуальный заголовок страницы будет физически+ * расположен в той-же странице памяти, в том числе для многостраничных+ * P_OVERFLOW страниц с длинными данными. */+int mdbx_is_dirty(const MDBX_txn *txn, const void *ptr) {+  int rc = check_txn(txn, MDBX_TXN_BLOCKED);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  const MDBX_env *env = txn->mt_env;+  const ptrdiff_t offset = (uint8_t *)ptr - env->me_map;+  if (offset >= 0) {+    const pgno_t pgno = bytes2pgno(env, offset);+    if (likely(pgno < txn->mt_next_pgno)) {+      if (txn->mt_flags & MDBX_TXN_RDONLY)+        return MDBX_RESULT_FALSE;++      const MDBX_page *page = pgno2page(env, pgno);+      if (unlikely(page->mp_pgno != pgno)) {+        /* The ptr pointed into middle of a large page,+         * not to the beginning of a data. */+        return MDBX_EINVAL;+      }+      if (unlikely(page->mp_flags & (P_DIRTY | P_LOOSE | P_KEEP | P_META)))+        return MDBX_RESULT_TRUE;+      if (likely(txn->tw.spill_pages == nullptr))+        return MDBX_RESULT_FALSE;+      return mdbx_pnl_exist(txn->tw.spill_pages, pgno << 1) ? MDBX_RESULT_TRUE+                                                            : MDBX_RESULT_FALSE;+    }+    if ((size_t)offset < env->me_dxb_mmap.limit) {+      /* Указатель адресует что-то в пределах mmap, но за границей+       * распределенных страниц. Такое может случится если mdbx_is_dirty()+       * вызывается после операции, в ходе которой грязная страница попала+       * в loose и затем была возвращена в нераспределенное пространство. */+      return MDBX_RESULT_TRUE;+    }+  }++  /* Страница вне используемого mmap-диапазона, т.е. либо в функцию был+   * передан некорректный адрес, либо адрес в теневой странице, которая была+   * выделена посредством malloc().+   *+   * Для режима WRITE_MAP режима страница однозначно "не грязная",+   * а для режимов без WRITE_MAP следует просматривать списки dirty+   * и spilled страниц у каких-либо транзакций (в том числе дочерних).+   *+   * Поэтому для WRITE_MAP возвращаем false, а для остальных режимов+   * всегда true. Такая логика имеет ряд преимуществ:+   *  - не тратим время на просмотр списков;+   *  - результат всегда безопасен (может быть ложно-положительным,+   *    но не ложно-отрицательным);+   *  - результат не зависит от вложенности транзакций и от относительного+   *    положения переданной транзакции в этой рекурсии. */+  return (env->me_flags & MDBX_WRITEMAP) ? MDBX_RESULT_FALSE : MDBX_RESULT_TRUE;+}++int mdbx_dbi_sequence(MDBX_txn *txn, MDBX_dbi dbi, uint64_t *result,+                      uint64_t increment) {+  int rc = check_txn(txn, MDBX_TXN_BLOCKED);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  if (unlikely(!mdbx_txn_dbi_exists(txn, dbi, DBI_USRVALID)))+    return MDBX_BAD_DBI;++  if (unlikely(TXN_DBI_CHANGED(txn, dbi)))+    return MDBX_BAD_DBI;++  if (unlikely(txn->mt_dbistate[dbi] & DBI_STALE)) {+    rc = mdbx_fetch_sdb(txn, dbi);+    if (unlikely(rc != MDBX_SUCCESS))+      return rc;+  }++  MDBX_db *dbs = &txn->mt_dbs[dbi];+  if (likely(result))+    *result = dbs->md_seq;++  if (likely(increment > 0)) {+    if (unlikely(txn->mt_flags & MDBX_TXN_RDONLY))+      return MDBX_EACCESS;++    uint64_t new = dbs->md_seq + increment;+    if (unlikely(new < increment))+      return MDBX_RESULT_TRUE;++    mdbx_tassert(txn, new > dbs->md_seq);+    dbs->md_seq = new;+    txn->mt_flags |= MDBX_TXN_DIRTY;+    txn->mt_dbistate[dbi] |= DBI_DIRTY;+  }++  return MDBX_SUCCESS;+}++/*----------------------------------------------------------------------------*/++#ifndef LIBMDBX_NO_EXPORTS_LEGACY_API+__cold MDBX_NOTHROW_CONST_FUNCTION intptr_t mdbx_limits_pgsize_min(void) {+  return __inline_mdbx_limits_pgsize_min();+}++__cold MDBX_NOTHROW_CONST_FUNCTION intptr_t mdbx_limits_pgsize_max(void) {+  return __inline_mdbx_limits_pgsize_max();+}+#endif /* LIBMDBX_NO_EXPORTS_LEGACY_API */++__cold intptr_t mdbx_limits_dbsize_min(intptr_t pagesize) {+  if (pagesize < 1)+    pagesize = (intptr_t)mdbx_default_pagesize();+  else if (unlikely(pagesize < (intptr_t)MIN_PAGESIZE ||+                    pagesize > (intptr_t)MAX_PAGESIZE ||+                    !is_powerof2((size_t)pagesize)))+    return -1;++  return MIN_PAGENO * pagesize;+}++__cold intptr_t mdbx_limits_dbsize_max(intptr_t pagesize) {+  if (pagesize < 1)+    pagesize = (intptr_t)mdbx_default_pagesize();+  else if (unlikely(pagesize < (intptr_t)MIN_PAGESIZE ||+                    pagesize > (intptr_t)MAX_PAGESIZE ||+                    !is_powerof2((size_t)pagesize)))+    return -1;++  STATIC_ASSERT(MAX_MAPSIZE < INTPTR_MAX);+  const uint64_t limit = MAX_PAGENO * (uint64_t)pagesize;+  return (limit < (intptr_t)MAX_MAPSIZE) ? (intptr_t)limit+                                         : (intptr_t)MAX_MAPSIZE;+}++__cold intptr_t mdbx_limits_txnsize_max(intptr_t pagesize) {+  if (pagesize < 1)+    pagesize = (intptr_t)mdbx_default_pagesize();+  else if (unlikely(pagesize < (intptr_t)MIN_PAGESIZE ||+                    pagesize > (intptr_t)MAX_PAGESIZE ||+                    !is_powerof2((size_t)pagesize)))+    return -1;++  STATIC_ASSERT(MAX_MAPSIZE < INTPTR_MAX);+  const uint64_t limit = pagesize * (uint64_t)(MDBX_PGL_LIMIT - 1);+  return (limit < (intptr_t)MAX_MAPSIZE) ? (intptr_t)limit+                                         : (intptr_t)MAX_MAPSIZE;+}++/*** Key-making functions to avoid custom comparators *************************/++static __always_inline double key2double(const int64_t key) {+  union {+    uint64_t u;+    double f;+  } casting;++  casting.u = (key < 0) ? key + UINT64_C(0x8000000000000000)+                        : UINT64_C(0xffffFFFFffffFFFF) - key;+  return casting.f;+}++static __always_inline uint64_t double2key(const double *const ptr) {+  STATIC_ASSERT(sizeof(double) == sizeof(int64_t));+  const int64_t i = *(const int64_t *)ptr;+  const uint64_t u = (i < 0) ? UINT64_C(0xffffFFFFffffFFFF) - i+                             : i + UINT64_C(0x8000000000000000);+  if (mdbx_assert_enabled()) {+    const double f = key2double(u);+    assert(memcmp(&f, ptr, 8) == 0);+  }+  return u;+}++static __always_inline float key2float(const int32_t key) {+  union {+    uint32_t u;+    float f;+  } casting;++  casting.u =+      (key < 0) ? key + UINT32_C(0x80000000) : UINT32_C(0xffffFFFF) - key;+  return casting.f;+}++static __always_inline uint32_t float2key(const float *const ptr) {+  STATIC_ASSERT(sizeof(float) == sizeof(int32_t));+  const int32_t i = *(const int32_t *)ptr;+  const uint32_t u =+      (i < 0) ? UINT32_C(0xffffFFFF) - i : i + UINT32_C(0x80000000);+  if (mdbx_assert_enabled()) {+    const float f = key2float(u);+    assert(memcmp(&f, ptr, 4) == 0);+  }+  return u;+}++uint64_t mdbx_key_from_double(const double ieee754_64bit) {+  return double2key(&ieee754_64bit);+}++uint64_t mdbx_key_from_ptrdouble(const double *const ieee754_64bit) {+  return double2key(ieee754_64bit);+}++uint32_t mdbx_key_from_float(const float ieee754_32bit) {+  return float2key(&ieee754_32bit);+}++uint32_t mdbx_key_from_ptrfloat(const float *const ieee754_32bit) {+  return float2key(ieee754_32bit);+}++#ifndef LIBMDBX_NO_EXPORTS_LEGACY_API+MDBX_NOTHROW_CONST_FUNCTION uint64_t mdbx_key_from_int64(const int64_t i64) {+  return __inline_mdbx_key_from_int64(i64);+}++MDBX_NOTHROW_CONST_FUNCTION uint32_t mdbx_key_from_int32(const int32_t i32) {+  return __inline_mdbx_key_from_int32(i32);+}+#endif /* LIBMDBX_NO_EXPORTS_LEGACY_API */++#define IEEE754_DOUBLE_MANTISSA_SIZE 52+#define IEEE754_DOUBLE_EXPONENTA_BIAS 0x3FF+#define IEEE754_DOUBLE_EXPONENTA_MAX 0x7FF+#define IEEE754_DOUBLE_IMPLICIT_LEAD UINT64_C(0x0010000000000000)+#define IEEE754_DOUBLE_MANTISSA_MASK UINT64_C(0x000FFFFFFFFFFFFF)+#define IEEE754_DOUBLE_MANTISSA_AMAX UINT64_C(0x001FFFFFFFFFFFFF)++static __inline int clz64(uint64_t value) {+#if __GNUC_PREREQ(4, 1) || __has_builtin(__builtin_clzl)+  if (sizeof(value) == sizeof(int))+    return __builtin_clz(value);+  if (sizeof(value) == sizeof(long))+    return __builtin_clzl(value);+#if (defined(__SIZEOF_LONG_LONG__) && __SIZEOF_LONG_LONG__ == 8) ||            \+    __has_builtin(__builtin_clzll)+  return __builtin_clzll(value);+#endif /* have(long long) && long long == uint64_t */+#endif /* GNU C */++#if defined(_MSC_VER)+  unsigned long index;+#if defined(_M_AMD64) || defined(_M_ARM64) || defined(_M_X64)+  _BitScanReverse64(&index, value);+  return 63 - index;+#else+  if (value > UINT32_MAX) {+    _BitScanReverse(&index, (uint32_t)(value >> 32));+    return 31 - index;+  }+  _BitScanReverse(&index, (uint32_t)value);+  return 63 - index;+#endif+#endif /* MSVC */++  value |= value >> 1;+  value |= value >> 2;+  value |= value >> 4;+  value |= value >> 8;+  value |= value >> 16;+  value |= value >> 32;+  static const uint8_t debruijn_clz64[64] = {+      63, 16, 62, 7,  15, 36, 61, 3,  6,  14, 22, 26, 35, 47, 60, 2,+      9,  5,  28, 11, 13, 21, 42, 19, 25, 31, 34, 40, 46, 52, 59, 1,+      17, 8,  37, 4,  23, 27, 48, 10, 29, 12, 43, 20, 32, 41, 53, 18,+      38, 24, 49, 30, 44, 33, 54, 39, 50, 45, 55, 51, 56, 57, 58, 0};+  return debruijn_clz64[value * UINT64_C(0x03F79D71B4CB0A89) >> 58];+}++static __inline uint64_t round_mantissa(const uint64_t u64, int shift) {+  assert(shift < 0 && u64 > 0);+  shift = -shift;+  const unsigned half = 1 << (shift - 1);+  const unsigned lsb = 1 & (unsigned)(u64 >> shift);+  const unsigned tie2even = 1 ^ lsb;+  return (u64 + half - tie2even) >> shift;+}++uint64_t mdbx_key_from_jsonInteger(const int64_t json_integer) {+  const uint64_t bias = UINT64_C(0x8000000000000000);+  if (json_integer > 0) {+    const uint64_t u64 = json_integer;+    int shift = clz64(u64) - (64 - IEEE754_DOUBLE_MANTISSA_SIZE - 1);+    uint64_t mantissa = u64 << shift;+    if (unlikely(shift < 0)) {+      mantissa = round_mantissa(u64, shift);+      if (mantissa > IEEE754_DOUBLE_MANTISSA_AMAX)+        mantissa = round_mantissa(u64, --shift);+    }++    assert(mantissa >= IEEE754_DOUBLE_IMPLICIT_LEAD &&+           mantissa <= IEEE754_DOUBLE_MANTISSA_AMAX);+    const uint64_t exponent =+        IEEE754_DOUBLE_EXPONENTA_BIAS + IEEE754_DOUBLE_MANTISSA_SIZE - shift;+    assert(exponent > 0 && exponent <= IEEE754_DOUBLE_EXPONENTA_MAX);+    const uint64_t key = bias + (exponent << IEEE754_DOUBLE_MANTISSA_SIZE) ++                         (mantissa - IEEE754_DOUBLE_IMPLICIT_LEAD);+#if !defined(_MSC_VER) ||                                                      \+    defined(                                                                   \+        _DEBUG) /* Workaround for MSVC error LNK2019: unresolved external      \+                   symbol __except1 referenced in function __ftol3_except */+    assert(key == mdbx_key_from_double((double)json_integer));+#endif /* Workaround for MSVC */+    return key;+  }++  if (json_integer < 0) {+    const uint64_t u64 = -json_integer;+    int shift = clz64(u64) - (64 - IEEE754_DOUBLE_MANTISSA_SIZE - 1);+    uint64_t mantissa = u64 << shift;+    if (unlikely(shift < 0)) {+      mantissa = round_mantissa(u64, shift);+      if (mantissa > IEEE754_DOUBLE_MANTISSA_AMAX)+        mantissa = round_mantissa(u64, --shift);+    }++    assert(mantissa >= IEEE754_DOUBLE_IMPLICIT_LEAD &&+           mantissa <= IEEE754_DOUBLE_MANTISSA_AMAX);+    const uint64_t exponent =+        IEEE754_DOUBLE_EXPONENTA_BIAS + IEEE754_DOUBLE_MANTISSA_SIZE - shift;+    assert(exponent > 0 && exponent <= IEEE754_DOUBLE_EXPONENTA_MAX);+    const uint64_t key = bias - 1 - (exponent << IEEE754_DOUBLE_MANTISSA_SIZE) -+                         (mantissa - IEEE754_DOUBLE_IMPLICIT_LEAD);+#if !defined(_MSC_VER) ||                                                      \+    defined(                                                                   \+        _DEBUG) /* Workaround for MSVC error LNK2019: unresolved external      \+                   symbol __except1 referenced in function __ftol3_except */+    assert(key == mdbx_key_from_double((double)json_integer));+#endif /* Workaround for MSVC */+    return key;+  }++  return bias;+}++int64_t mdbx_jsonInteger_from_key(const MDBX_val v) {+  assert(v.iov_len == 8);+  const uint64_t key = unaligned_peek_u64(2, v.iov_base);+  const uint64_t bias = UINT64_C(0x8000000000000000);+  const uint64_t covalent = (key > bias) ? key - bias : bias - key - 1;+  const int shift = IEEE754_DOUBLE_EXPONENTA_BIAS + 63 -+                    (IEEE754_DOUBLE_EXPONENTA_MAX &+                     (int)(covalent >> IEEE754_DOUBLE_MANTISSA_SIZE));+  if (unlikely(shift < 1))+    return (key < bias) ? INT64_MIN : INT64_MAX;+  if (unlikely(shift > 63))+    return 0;++  const uint64_t unscaled = ((covalent & IEEE754_DOUBLE_MANTISSA_MASK)+                             << (63 - IEEE754_DOUBLE_MANTISSA_SIZE)) ++                            bias;+  const int64_t absolute = unscaled >> shift;+  const int64_t value = (key < bias) ? -absolute : absolute;+  assert(key == mdbx_key_from_jsonInteger(value) ||+         (mdbx_key_from_jsonInteger(value - 1) < key &&+          key < mdbx_key_from_jsonInteger(value + 1)));+  return value;+}++double mdbx_double_from_key(const MDBX_val v) {+  assert(v.iov_len == 8);+  return key2double(unaligned_peek_u64(2, v.iov_base));+}++float mdbx_float_from_key(const MDBX_val v) {+  assert(v.iov_len == 4);+  return key2float(unaligned_peek_u32(2, v.iov_base));+}++int32_t mdbx_int32_from_key(const MDBX_val v) {+  assert(v.iov_len == 4);+  return (int32_t)(unaligned_peek_u32(2, v.iov_base) - UINT32_C(0x80000000));+}++int64_t mdbx_int64_from_key(const MDBX_val v) {+  assert(v.iov_len == 8);+  return (int64_t)(unaligned_peek_u64(2, v.iov_base) -+                   UINT64_C(0x8000000000000000));+}++__cold MDBX_cmp_func *mdbx_get_keycmp(unsigned flags) {+  return get_default_keycmp(flags);+}++__cold MDBX_cmp_func *mdbx_get_datacmp(unsigned flags) {+  return get_default_datacmp(flags);+}++__cold int mdbx_env_set_option(MDBX_env *env, const MDBX_option_t option,+                               const uint64_t value) {+  int err = check_env(env, false);+  if (unlikely(err != MDBX_SUCCESS))+    return err;++  const bool lock_needed = (env->me_map && env->me_txn0 &&+                            env->me_txn0->mt_owner != mdbx_thread_self());+  bool should_unlock = false;+  switch (option) {+  case MDBX_opt_sync_bytes:+    if (unlikely(env->me_flags & MDBX_RDONLY))+      return MDBX_EACCESS;+    if (unlikely(!env->me_autosync_threshold))+      return MDBX_EPERM;+    if (sizeof(value) > sizeof(size_t) && unlikely(value != (size_t)value))+      return MDBX_TOO_LARGE;+    if (atomic_store32(env->me_autosync_threshold,+                       bytes2pgno(env, (size_t)value + env->me_psize - 1),+                       mo_Relaxed) != 0) {+      err = mdbx_env_sync_poll(env);+      if (unlikely(MDBX_IS_ERROR(err)))+        return err;+    }+    break;++  case MDBX_opt_sync_period:+    if (unlikely(env->me_flags & MDBX_RDONLY))+      return MDBX_EACCESS;+    if (unlikely(!env->me_autosync_period))+      return MDBX_EPERM;+    if (unlikely(value > UINT32_MAX))+      return MDBX_TOO_LARGE;+    if (atomic_store64(env->me_autosync_period,+                       mdbx_osal_16dot16_to_monotime((uint32_t)value),+                       mo_Relaxed) != 0) {+      err = mdbx_env_sync_poll(env);+      if (unlikely(MDBX_IS_ERROR(err)))+        return err;+    }+    break;++  case MDBX_opt_max_db:+    if (unlikely(value > MDBX_MAX_DBI))+      return MDBX_EINVAL;+    if (unlikely(env->me_map))+      return MDBX_EPERM;+    env->me_maxdbs = (unsigned)value + CORE_DBS;+    break;++  case MDBX_opt_max_readers:+    if (unlikely(value < 1 || value > MDBX_READERS_LIMIT))+      return MDBX_EINVAL;+    if (unlikely(env->me_map))+      return MDBX_EPERM;+    env->me_maxreaders = (unsigned)value;+    break;++  case MDBX_opt_dp_reserve_limit:+    if (unlikely(value > INT_MAX))+      return MDBX_EINVAL;+    if (env->me_options.dp_reserve_limit != (unsigned)value) {+      if (lock_needed) {+        err = mdbx_txn_lock(env, false);+        if (unlikely(err != MDBX_SUCCESS))+          return err;+        should_unlock = true;+      }+      env->me_options.dp_reserve_limit = (unsigned)value;+      while (env->me_dp_reserve_len > env->me_options.dp_reserve_limit) {+        mdbx_assert(env, env->me_dp_reserve != NULL);+        MDBX_page *dp = env->me_dp_reserve;+        ASAN_UNPOISON_MEMORY_REGION(dp, env->me_psize);+        VALGRIND_MAKE_MEM_DEFINED(&dp->mp_next, sizeof(dp->mp_next));+        env->me_dp_reserve = dp->mp_next;+        VALGRIND_MEMPOOL_FREE(env, dp);+        mdbx_free(dp);+        env->me_dp_reserve_len -= 1;+      }+    }+    break;++  case MDBX_opt_rp_augment_limit:+    if (unlikely(value > MDBX_PGL_LIMIT))+      return MDBX_EINVAL;+    env->me_options.rp_augment_limit = (unsigned)value;+    break;++  case MDBX_opt_txn_dp_limit:+  case MDBX_opt_txn_dp_initial:+    if (unlikely(value > MDBX_PGL_LIMIT || value < CURSOR_STACK * 4))+      return MDBX_EINVAL;+    if (unlikely(env->me_txn0 == NULL))+      return MDBX_EACCESS;+    if (lock_needed) {+      err = mdbx_txn_lock(env, false);+      if (unlikely(err != MDBX_SUCCESS))+        return err;+      should_unlock = true;+    }+    if (env->me_txn)+      err = MDBX_EPERM /* unable change during transaction */;+    else {+      mdbx_dpl_clear(env->me_txn0->tw.dirtylist);+      const unsigned value32 = (unsigned)value;+      if (option == MDBX_opt_txn_dp_initial &&+          env->me_options.dp_initial != value32) {+        if (env->me_options.dp_limit < value32)+          env->me_options.dp_limit = value32;+        if (env->me_txn0->tw.dirtylist->detent < value32 &&+            !mdbx_dpl_reserve(env->me_txn0, value32))+          err = MDBX_ENOMEM;+        else+          env->me_options.dp_initial = value32;+      }+      if (option == MDBX_opt_txn_dp_limit &&+          env->me_options.dp_limit != value32) {+        if (env->me_txn0->tw.dirtylist->detent > value32 &&+            !mdbx_dpl_reserve(env->me_txn0, value32))+          err = MDBX_ENOMEM;+        else {+          if (env->me_options.dp_initial > value32)+            env->me_options.dp_initial = value32;+          env->me_options.dp_limit = value32;+        }+      }+    }+    break;++  case MDBX_opt_spill_max_denominator:+    if (unlikely(value > 255))+      return MDBX_EINVAL;+    env->me_options.spill_max_denominator = (uint8_t)value;+    break;+  case MDBX_opt_spill_min_denominator:+    if (unlikely(value > 255))+      return MDBX_EINVAL;+    env->me_options.spill_min_denominator = (uint8_t)value;+    break;+  case MDBX_opt_spill_parent4child_denominator:+    if (unlikely(value > 255))+      return MDBX_EINVAL;+    env->me_options.spill_parent4child_denominator = (uint8_t)value;+    break;++  case MDBX_opt_loose_limit:+    if (unlikely(value > 255))+      return MDBX_EINVAL;+    env->me_options.dp_loose_limit = (uint8_t)value;+    break;++  default:+    return MDBX_EINVAL;+  }++  if (should_unlock)+    mdbx_txn_unlock(env);+  return err;+}++__cold int mdbx_env_get_option(const MDBX_env *env, const MDBX_option_t option,+                               uint64_t *value) {+  int err = check_env(env, false);+  if (unlikely(err != MDBX_SUCCESS))+    return err;+  if (unlikely(!value))+    return MDBX_EINVAL;++  switch (option) {+  case MDBX_opt_sync_bytes:+    if (unlikely(!env->me_autosync_threshold))+      return MDBX_EPERM;+    *value =+        pgno2bytes(env, atomic_load32(env->me_autosync_threshold, mo_Relaxed));+    break;++  case MDBX_opt_sync_period:+    if (unlikely(!env->me_autosync_period))+      return MDBX_EPERM;+    *value = mdbx_osal_monotime_to_16dot16(+        atomic_load64(env->me_autosync_period, mo_Relaxed));+    break;++  case MDBX_opt_max_db:+    *value = env->me_maxdbs - CORE_DBS;+    break;++  case MDBX_opt_max_readers:+    *value = env->me_maxreaders;+    break;++  case MDBX_opt_dp_reserve_limit:+    *value = env->me_options.dp_reserve_limit;+    break;++  case MDBX_opt_rp_augment_limit:+    *value = env->me_options.rp_augment_limit;+    break;++  case MDBX_opt_txn_dp_limit:+    *value = env->me_options.dp_limit;+    break;+  case MDBX_opt_txn_dp_initial:+    *value = env->me_options.dp_initial;+    break;++  case MDBX_opt_spill_max_denominator:+    *value = env->me_options.spill_max_denominator;+    break;+  case MDBX_opt_spill_min_denominator:+    *value = env->me_options.spill_min_denominator;+    break;+  case MDBX_opt_spill_parent4child_denominator:+    *value = env->me_options.spill_parent4child_denominator;+    break;++  case MDBX_opt_loose_limit:+    *value = env->me_options.dp_loose_limit;+    break;++  default:+    return MDBX_EINVAL;+  }++  return MDBX_SUCCESS;+}++/*** Attribute support functions for Nexenta **********************************/+#ifdef MDBX_NEXENTA_ATTRS++static __inline int mdbx_attr_peek(MDBX_val *data, mdbx_attr_t *attrptr) {+  if (unlikely(data->iov_len < sizeof(mdbx_attr_t)))+    return MDBX_INCOMPATIBLE;++  if (likely(attrptr != NULL))+    *attrptr = *(mdbx_attr_t *)data->iov_base;+  data->iov_len -= sizeof(mdbx_attr_t);+  data->iov_base =+      likely(data->iov_len > 0) ? ((mdbx_attr_t *)data->iov_base) + 1 : NULL;++  return MDBX_SUCCESS;+}++static __inline int mdbx_attr_poke(MDBX_val *reserved, MDBX_val *data,+                                   mdbx_attr_t attr, MDBX_put_flags_t flags) {+  mdbx_attr_t *space = reserved->iov_base;+  if (flags & MDBX_RESERVE) {+    if (likely(data != NULL)) {+      data->iov_base = data->iov_len ? space + 1 : NULL;+    }+  } else {+    *space = attr;+    if (likely(data != NULL)) {+      memcpy(space + 1, data->iov_base, data->iov_len);+    }+  }++  return MDBX_SUCCESS;+}++int mdbx_cursor_get_attr(MDBX_cursor *mc, MDBX_val *key, MDBX_val *data,+                         mdbx_attr_t *attrptr, MDBX_cursor_op op) {+  int rc = mdbx_cursor_get(mc, key, data, op);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  return mdbx_attr_peek(data, attrptr);+}++int mdbx_get_attr(MDBX_txn *txn, MDBX_dbi dbi, MDBX_val *key, MDBX_val *data,+                  uint64_t *attrptr) {+  int rc = mdbx_get(txn, dbi, key, data);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  return mdbx_attr_peek(data, attrptr);+}++int mdbx_put_attr(MDBX_txn *txn, MDBX_dbi dbi, MDBX_val *key, MDBX_val *data,+                  mdbx_attr_t attr, MDBX_put_flags_t flags) {+  MDBX_val reserve;+  reserve.iov_base = NULL;+  reserve.iov_len = (data ? data->iov_len : 0) + sizeof(mdbx_attr_t);++  int rc = mdbx_put(txn, dbi, key, &reserve, flags | MDBX_RESERVE);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  return mdbx_attr_poke(&reserve, data, attr, flags);+}++int mdbx_cursor_put_attr(MDBX_cursor *cursor, MDBX_val *key, MDBX_val *data,+                         mdbx_attr_t attr, MDBX_put_flags_t flags) {+  MDBX_val reserve;+  reserve.iov_base = NULL;+  reserve.iov_len = (data ? data->iov_len : 0) + sizeof(mdbx_attr_t);++  int rc = mdbx_cursor_put(cursor, key, &reserve, flags | MDBX_RESERVE);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  return mdbx_attr_poke(&reserve, data, attr, flags);+}++int mdbx_set_attr(MDBX_txn *txn, MDBX_dbi dbi, MDBX_val *key, MDBX_val *data,+                  mdbx_attr_t attr) {+  if (unlikely(!key || !txn))+    return MDBX_EINVAL;++  if (unlikely(txn->mt_signature != MDBX_MT_SIGNATURE))+    return MDBX_EBADSIGN;++  if (unlikely(!TXN_DBI_EXIST(txn, dbi, DB_USRVALID)))+    return MDBX_BAD_DBI;++  if (unlikely(txn->mt_flags & (MDBX_TXN_RDONLY | MDBX_TXN_BLOCKED)))+    return (txn->mt_flags & MDBX_TXN_RDONLY) ? MDBX_EACCESS : MDBX_BAD_TXN;++  MDBX_cursor_couple cx;+  MDBX_val old_data;+  int rc = mdbx_cursor_init(&cx.outer, txn, dbi);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;+  rc = mdbx_cursor_set(&cx.outer, key, &old_data, MDBX_SET, NULL);+  if (unlikely(rc != MDBX_SUCCESS)) {+    if (rc == MDBX_NOTFOUND && data) {+      cx.outer.mc_next = txn->tw.cursors[dbi];+      txn->tw.cursors[dbi] = &cx.outer;+      rc = mdbx_cursor_put_attr(&cx.outer, key, data, attr, 0);+      txn->tw.cursors[dbi] = cx.outer.mc_next;+    }+    return rc;+  }++  mdbx_attr_t old_attr = 0;+  rc = mdbx_attr_peek(&old_data, &old_attr);+  if (unlikely(rc != MDBX_SUCCESS))+    return rc;++  if (old_attr == attr && (!data || (data->iov_len == old_data.iov_len &&+                                     memcmp(data->iov_base, old_data.iov_base,+                                            old_data.iov_len) == 0)))+    return MDBX_SUCCESS;++  cx.outer.mc_next = txn->tw.cursors[dbi];+  txn->tw.cursors[dbi] = &cx.outer;+  rc = mdbx_cursor_put_attr(&cx.outer, key, data ? data : &old_data, attr,+                            MDBX_CURRENT);+  txn->tw.cursors[dbi] = cx.outer.mc_next;+  return rc;+}+#endif /* MDBX_NEXENTA_ATTRS */++/******************************************************************************/+/* *INDENT-OFF* */+/* clang-format off */++__dll_export+#ifdef __attribute_used__+    __attribute_used__+#elif defined(__GNUC__) || __has_attribute(__used__)+    __attribute__((__used__))+#endif+#ifdef __attribute_externally_visible__+        __attribute_externally_visible__+#elif (defined(__GNUC__) && !defined(__clang__)) ||                            \+    __has_attribute(__externally_visible__)+    __attribute__((__externally_visible__))+#endif+    const struct MDBX_build_info mdbx_build = {+#ifdef MDBX_BUILD_TIMESTAMP+    MDBX_BUILD_TIMESTAMP+#else+    __DATE__ " " __TIME__+#endif /* MDBX_BUILD_TIMESTAMP */++    ,+#ifdef MDBX_BUILD_TARGET+    MDBX_BUILD_TARGET+#else+  #if defined(__ANDROID_API__)+    "Android" STRINGIFY(__ANDROID_API__)+  #elif defined(__linux__) || defined(__gnu_linux__)+    "Linux"+  #elif defined(EMSCRIPTEN) || defined(__EMSCRIPTEN__)+    "webassembly"+  #elif defined(__CYGWIN__)+    "CYGWIN"+  #elif defined(_WIN64) || defined(_WIN32) || defined(__TOS_WIN__) \+      || defined(__WINDOWS__)+    "Windows"+  #elif defined(__APPLE__)+    #if (defined(TARGET_OS_IPHONE) && TARGET_OS_IPHONE) \+      || (defined(TARGET_IPHONE_SIMULATOR) && TARGET_IPHONE_SIMULATOR)+      "iOS"+    #else+      "MacOS"+    #endif+  #elif defined(__FreeBSD__)+    "FreeBSD"+  #elif defined(__DragonFly__)+    "DragonFlyBSD"+  #elif defined(__NetBSD__)+    "NetBSD"+  #elif defined(__OpenBSD__)+    "OpenBSD"+  #elif defined(__bsdi__)+    "UnixBSDI"+  #elif defined(__MACH__)+    "MACH"+  #elif (defined(_HPUX_SOURCE) || defined(__hpux) || defined(__HP_aCC))+    "HPUX"+  #elif defined(_AIX)+    "AIX"+  #elif defined(__sun) && defined(__SVR4)+    "Solaris"+  #elif defined(__BSD__) || defined(BSD)+    "UnixBSD"+  #elif defined(__unix__) || defined(UNIX) || defined(__unix) \+      || defined(__UNIX) || defined(__UNIX__)+    "UNIX"+  #elif defined(_POSIX_VERSION)+    "POSIX" STRINGIFY(_POSIX_VERSION)+  #else+    "UnknownOS"+  #endif /* Target OS */++    "-"++  #if defined(__amd64__)+    "AMD64"+  #elif defined(__ia32__)+    "IA32"+  #elif defined(__e2k__) || defined(__elbrus__)+    "Elbrus"+  #elif defined(__alpha__) || defined(__alpha) || defined(_M_ALPHA)+    "Alpha"+  #elif defined(__aarch64__) || defined(_M_ARM64)+    "ARM64"+  #elif defined(__arm__) || defined(__thumb__) || defined(__TARGET_ARCH_ARM) \+      || defined(__TARGET_ARCH_THUMB) || defined(_ARM) || defined(_M_ARM) \+      || defined(_M_ARMT) || defined(__arm)+    "ARM"+  #elif defined(__mips64) || defined(__mips64__) || (defined(__mips) && (__mips >= 64))+    "MIPS64"+  #elif defined(__mips__) || defined(__mips) || defined(_R4000) || defined(__MIPS__)+    "MIPS"+  #elif defined(__hppa64__) || defined(__HPPA64__) || defined(__hppa64)+    "PARISC64"+  #elif defined(__hppa__) || defined(__HPPA__) || defined(__hppa)+    "PARISC"+  #elif defined(__ia64__) || defined(__ia64) || defined(_IA64) \+      || defined(__IA64__) || defined(_M_IA64) || defined(__itanium__)+    "Itanium"+  #elif defined(__powerpc64__) || defined(__ppc64__) || defined(__ppc64) \+      || defined(__powerpc64) || defined(_ARCH_PPC64)+    "PowerPC64"+  #elif defined(__powerpc__) || defined(__ppc__) || defined(__powerpc) \+      || defined(__ppc) || defined(_ARCH_PPC) || defined(__PPC__) || defined(__POWERPC__)+    "PowerPC"+  #elif defined(__sparc64__) || defined(__sparc64)+    "SPARC64"+  #elif defined(__sparc__) || defined(__sparc)+    "SPARC"+  #elif defined(__s390__) || defined(__s390) || defined(__zarch__) || defined(__zarch)+    "S390"+  #else+    "UnknownARCH"+  #endif+#endif /* MDBX_BUILD_TARGET */++#ifdef MDBX_BUILD_TYPE+# if defined(_MSC_VER)+#   pragma message("Configuration-depended MDBX_BUILD_TYPE: " MDBX_BUILD_TYPE)+# endif+    "-" MDBX_BUILD_TYPE+#endif /* MDBX_BUILD_TYPE */+    ,+    "MDBX_DEBUG=" STRINGIFY(MDBX_DEBUG)+    " MDBX_WORDBITS=" STRINGIFY(MDBX_WORDBITS)+    " BYTE_ORDER="+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__+    "LITTLE_ENDIAN"+#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__+    "BIG_ENDIAN"+#else+    #error "FIXME: Unsupported byte order"+#endif /* __BYTE_ORDER__ */+    " MDBX_ENV_CHECKPID=" MDBX_ENV_CHECKPID_CONFIG+    " MDBX_TXN_CHECKOWNER=" MDBX_TXN_CHECKOWNER_CONFIG+    " MDBX_64BIT_ATOMIC=" MDBX_64BIT_ATOMIC_CONFIG+    " MDBX_64BIT_CAS=" MDBX_64BIT_CAS_CONFIG+    " MDBX_TRUST_RTC=" MDBX_TRUST_RTC_CONFIG+    " MDBX_ENABLE_REFUND=" STRINGIFY(MDBX_ENABLE_REFUND)+#if MDBX_DISABLE_PAGECHECKS+    " MDBX_DISABLE_PAGECHECKS=YES"+#endif /* MDBX_DISABLE_PAGECHECKS */+#ifdef __SANITIZE_ADDRESS__+    " SANITIZE_ADDRESS=YES"+#endif /* __SANITIZE_ADDRESS__ */+#ifdef MDBX_USE_VALGRIND+    " MDBX_USE_VALGRIND=YES"+#endif /* MDBX_USE_VALGRIND */+#ifdef MDBX_FORCE_ASSERTIONS+    " MDBX_FORCE_ASSERTIONS=YES"+#endif /* MDBX_FORCE_ASSERTIONS */+#ifdef _GNU_SOURCE+    " _GNU_SOURCE=YES"+#else+    " _GNU_SOURCE=NO"+#endif /* _GNU_SOURCE */+#ifdef __APPLE__+    " MDBX_OSX_SPEED_INSTEADOF_DURABILITY=" STRINGIFY(MDBX_OSX_SPEED_INSTEADOF_DURABILITY)+#endif /* MacOS */+#if defined(_WIN32) || defined(_WIN64)+    " MDBX_AVOID_CRT=" STRINGIFY(MDBX_AVOID_CRT)+    " MDBX_CONFIG_MANUAL_TLS_CALLBACK=" STRINGIFY(MDBX_CONFIG_MANUAL_TLS_CALLBACK)+    " MDBX_BUILD_SHARED_LIBRARY=" STRINGIFY(MDBX_BUILD_SHARED_LIBRARY)+    " WINVER=" STRINGIFY(WINVER)+#else /* Windows */+    " MDBX_LOCKING=" MDBX_LOCKING_CONFIG+    " MDBX_USE_OFDLOCKS=" MDBX_USE_OFDLOCKS_CONFIG+#endif /* !Windows */+    " MDBX_CACHELINE_SIZE=" STRINGIFY(MDBX_CACHELINE_SIZE)+    " MDBX_CPU_WRITEBACK_INCOHERENT=" STRINGIFY(MDBX_CPU_WRITEBACK_INCOHERENT)+    " MDBX_MMAP_INCOHERENT_CPU_CACHE=" STRINGIFY(MDBX_MMAP_INCOHERENT_CPU_CACHE)+    " MDBX_MMAP_INCOHERENT_FILE_WRITE=" STRINGIFY(MDBX_MMAP_INCOHERENT_FILE_WRITE)+    " MDBX_UNALIGNED_OK=" STRINGIFY(MDBX_UNALIGNED_OK)+    " MDBX_PNL_ASCENDING=" STRINGIFY(MDBX_PNL_ASCENDING)+    ,+#ifdef MDBX_BUILD_COMPILER+    MDBX_BUILD_COMPILER+#else+  #ifdef __INTEL_COMPILER+    "Intel C/C++ " STRINGIFY(__INTEL_COMPILER)+  #elsif defined(__apple_build_version__)+    "Apple clang " STRINGIFY(__apple_build_version__)+  #elif defined(__ibmxl__)+    "IBM clang C " STRINGIFY(__ibmxl_version__) "." STRINGIFY(__ibmxl_release__)+    "." STRINGIFY(__ibmxl_modification__) "." STRINGIFY(__ibmxl_ptf_fix_level__)+  #elif defined(__clang__)+    "clang " STRINGIFY(__clang_version__)+  #elif defined(__MINGW64__)+    "MINGW-64 " STRINGIFY(__MINGW64_MAJOR_VERSION) "." STRINGIFY(__MINGW64_MINOR_VERSION)+  #elif defined(__MINGW32__)+    "MINGW-32 " STRINGIFY(__MINGW32_MAJOR_VERSION) "." STRINGIFY(__MINGW32_MINOR_VERSION)+  #elif defined(__IBMC__)+    "IBM C " STRINGIFY(__IBMC__)+  #elif defined(__GNUC__)+    "GNU C/C++ "+    #ifdef __VERSION__+      __VERSION__+    #else+      STRINGIFY(__GNUC__) "." STRINGIFY(__GNUC_MINOR__) "." STRINGIFY(__GNUC_PATCHLEVEL__)+    #endif+  #elif defined(_MSC_VER)+    "MSVC " STRINGIFY(_MSC_FULL_VER) "-" STRINGIFY(_MSC_BUILD)+  #else+    "Unknown compiler"+  #endif+#endif /* MDBX_BUILD_COMPILER */+    ,+#ifdef MDBX_BUILD_FLAGS_CONFIG+    MDBX_BUILD_FLAGS_CONFIG+#endif /* MDBX_BUILD_FLAGS_CONFIG */+#ifdef MDBX_BUILD_FLAGS+    MDBX_BUILD_FLAGS+#endif /* MDBX_BUILD_FLAGS */+#if !(defined(MDBX_BUILD_FLAGS_CONFIG) || defined(MDBX_BUILD_FLAGS))+    "undefined (please use correct build script)"+#ifdef _MSC_VER+#pragma message("warning: Build flags undefined. Please use correct build script")+#else+#warning "Build flags undefined. Please use correct build script"+#endif // _MSC_VER+#endif+};++#ifdef __SANITIZE_ADDRESS__+LIBMDBX_API __attribute__((__weak__)) const char *__asan_default_options() {+  return "symbolize=1:allow_addr2line=1:"+#ifdef _DEBUG+         "debug=1:"+#endif /* _DEBUG */+         "report_globals=1:"+         "replace_str=1:replace_intrin=1:"+         "malloc_context_size=9:"+         "detect_leaks=1:"+         "check_printf=1:"+         "detect_deadlocks=1:"+#ifndef LTO_ENABLED+         "check_initialization_order=1:"+#endif+         "detect_stack_use_after_return=1:"+         "intercept_tls_get_addr=1:"+         "decorate_proc_maps=1:"+         "abort_on_error=1";+}+#endif /* __SANITIZE_ADDRESS__ */++/* *INDENT-ON* */+/* clang-format on */+/* https://en.wikipedia.org/wiki/Operating_system_abstraction_layer */++/*+ * Copyright 2015-2021 Leonid Yuriev <leo@yuriev.ru>+ * and other libmdbx authors: please see AUTHORS file.+ * All rights reserved.+ *+ * Redistribution and use in source and binary forms, with or without+ * modification, are permitted only as authorized by the OpenLDAP+ * Public License.+ *+ * A copy of this license is available in the file LICENSE in the+ * top-level directory of the distribution or, alternatively, at+ * <http://www.OpenLDAP.org/license.html>.+ */+++#if defined(_WIN32) || defined(_WIN64)++#include <winioctl.h>++static int waitstatus2errcode(DWORD result) {+  switch (result) {+  case WAIT_OBJECT_0:+    return MDBX_SUCCESS;+  case WAIT_FAILED:+    return GetLastError();+  case WAIT_ABANDONED:+    return ERROR_ABANDONED_WAIT_0;+  case WAIT_IO_COMPLETION:+    return ERROR_USER_APC;+  case WAIT_TIMEOUT:+    return ERROR_TIMEOUT;+  default:+    return ERROR_UNHANDLED_ERROR;+  }+}++/* Map a result from an NTAPI call to WIN32 error code. */+static int ntstatus2errcode(NTSTATUS status) {+  DWORD dummy;+  OVERLAPPED ov;+  memset(&ov, 0, sizeof(ov));+  ov.Internal = status;+  return GetOverlappedResult(NULL, &ov, &dummy, FALSE) ? MDBX_SUCCESS+                                                       : GetLastError();+}++/* We use native NT APIs to setup the memory map, so that we can+ * let the DB file grow incrementally instead of always preallocating+ * the full size. These APIs are defined in <wdm.h> and <ntifs.h>+ * but those headers are meant for driver-level development and+ * conflict with the regular user-level headers, so we explicitly+ * declare them here. Using these APIs also means we must link to+ * ntdll.dll, which is not linked by default in user code. */++extern NTSTATUS NTAPI NtCreateSection(+    OUT PHANDLE SectionHandle, IN ACCESS_MASK DesiredAccess,+    IN OPTIONAL POBJECT_ATTRIBUTES ObjectAttributes,+    IN OPTIONAL PLARGE_INTEGER MaximumSize, IN ULONG SectionPageProtection,+    IN ULONG AllocationAttributes, IN OPTIONAL HANDLE FileHandle);++typedef struct _SECTION_BASIC_INFORMATION {+  ULONG Unknown;+  ULONG SectionAttributes;+  LARGE_INTEGER SectionSize;+} SECTION_BASIC_INFORMATION, *PSECTION_BASIC_INFORMATION;++extern NTSTATUS NTAPI NtMapViewOfSection(+    IN HANDLE SectionHandle, IN HANDLE ProcessHandle, IN OUT PVOID *BaseAddress,+    IN ULONG_PTR ZeroBits, IN SIZE_T CommitSize,+    IN OUT OPTIONAL PLARGE_INTEGER SectionOffset, IN OUT PSIZE_T ViewSize,+    IN SECTION_INHERIT InheritDisposition, IN ULONG AllocationType,+    IN ULONG Win32Protect);++extern NTSTATUS NTAPI NtUnmapViewOfSection(IN HANDLE ProcessHandle,+                                           IN OPTIONAL PVOID BaseAddress);++extern NTSTATUS NTAPI NtClose(HANDLE Handle);++extern NTSTATUS NTAPI NtAllocateVirtualMemory(+    IN HANDLE ProcessHandle, IN OUT PVOID *BaseAddress, IN ULONG_PTR ZeroBits,+    IN OUT PSIZE_T RegionSize, IN ULONG AllocationType, IN ULONG Protect);++extern NTSTATUS NTAPI NtFreeVirtualMemory(IN HANDLE ProcessHandle,+                                          IN PVOID *BaseAddress,+                                          IN OUT PSIZE_T RegionSize,+                                          IN ULONG FreeType);++#ifndef WOF_CURRENT_VERSION+typedef struct _WOF_EXTERNAL_INFO {+  DWORD Version;+  DWORD Provider;+} WOF_EXTERNAL_INFO, *PWOF_EXTERNAL_INFO;+#endif /* WOF_CURRENT_VERSION */++#ifndef WIM_PROVIDER_CURRENT_VERSION+#define WIM_PROVIDER_HASH_SIZE 20++typedef struct _WIM_PROVIDER_EXTERNAL_INFO {+  DWORD Version;+  DWORD Flags;+  LARGE_INTEGER DataSourceId;+  BYTE ResourceHash[WIM_PROVIDER_HASH_SIZE];+} WIM_PROVIDER_EXTERNAL_INFO, *PWIM_PROVIDER_EXTERNAL_INFO;+#endif /* WIM_PROVIDER_CURRENT_VERSION */++#ifndef FILE_PROVIDER_CURRENT_VERSION+typedef struct _FILE_PROVIDER_EXTERNAL_INFO_V1 {+  ULONG Version;+  ULONG Algorithm;+  ULONG Flags;+} FILE_PROVIDER_EXTERNAL_INFO_V1, *PFILE_PROVIDER_EXTERNAL_INFO_V1;+#endif /* FILE_PROVIDER_CURRENT_VERSION */++#ifndef STATUS_OBJECT_NOT_EXTERNALLY_BACKED+#define STATUS_OBJECT_NOT_EXTERNALLY_BACKED ((NTSTATUS)0xC000046DL)+#endif+#ifndef STATUS_INVALID_DEVICE_REQUEST+#define STATUS_INVALID_DEVICE_REQUEST ((NTSTATUS)0xC0000010L)+#endif+#ifndef STATUS_NOT_SUPPORTED+#define STATUS_NOT_SUPPORTED ((NTSTATUS)0xC00000BBL)+#endif++#ifndef FILE_DEVICE_FILE_SYSTEM+#define FILE_DEVICE_FILE_SYSTEM 0x00000009+#endif++#ifndef FSCTL_GET_EXTERNAL_BACKING+#define FSCTL_GET_EXTERNAL_BACKING                                             \+  CTL_CODE(FILE_DEVICE_FILE_SYSTEM, 196, METHOD_BUFFERED, FILE_ANY_ACCESS)+#endif++#endif /* _WIN32 || _WIN64 */++/*----------------------------------------------------------------------------*/++#if defined(__UCLIBC__)+__extern_C void __assert(const char *, const char *, unsigned int, const char *)+#ifdef __THROW+    __THROW+#else+    __nothrow+#endif /* __THROW */+    MDBX_NORETURN;+#define __assert_fail(assertion, file, line, function)                         \+  __assert(assertion, file, line, function)++#elif _POSIX_C_SOURCE > 200212 &&                                              \+    /* workaround for avoid musl libc wrong prototype */ (                     \+        defined(__GLIBC__) || defined(__GNU_LIBRARY__))+/* Prototype should match libc runtime. ISO POSIX (2003) & LSB 1.x-3.x */+__extern_C void __assert_fail(const char *assertion, const char *file,+                              unsigned line, const char *function)+#ifdef __THROW+    __THROW+#else+    __nothrow+#endif /* __THROW */+    MDBX_NORETURN;++#elif defined(__APPLE__) || defined(__MACH__)+__extern_C void __assert_rtn(const char *function, const char *file, int line,+                             const char *assertion) /* __nothrow */+#ifdef __dead2+    __dead2+#else+    MDBX_NORETURN+#endif /* __dead2 */+#ifdef __disable_tail_calls+    __disable_tail_calls+#endif /* __disable_tail_calls */+    ;++#define __assert_fail(assertion, file, line, function)                         \+  __assert_rtn(function, file, line, assertion)+#elif defined(__sun) || defined(__SVR4) || defined(__svr4__)+__extern_C void __assert_c99(const char *assection, const char *file, int line,+                             const char *function) MDBX_NORETURN;+#define __assert_fail(assertion, file, line, function)                         \+  __assert_c99(assertion, file, line, function)+#elif defined(__OpenBSD__)+__extern_C __dead void __assert2(const char *file, int line,+                                 const char *function,+                                 const char *assertion) /* __nothrow */;+#define __assert_fail(assertion, file, line, function)                         \+  __assert2(file, line, function, assertion)+#elif defined(__NetBSD__)+__extern_C __dead void __assert13(const char *file, int line,+                                  const char *function,+                                  const char *assertion) /* __nothrow */;+#define __assert_fail(assertion, file, line, function)                         \+  __assert13(file, line, function, assertion)+#elif defined(__FreeBSD__) || defined(__BSD__) || defined(__bsdi__) ||         \+    defined(__DragonFly__)+__extern_C void __assert(const char *function, const char *file, int line,+                         const char *assertion) /* __nothrow */+#ifdef __dead2+    __dead2+#else+    MDBX_NORETURN+#endif /* __dead2 */+#ifdef __disable_tail_calls+    __disable_tail_calls+#endif /* __disable_tail_calls */+    ;+#define __assert_fail(assertion, file, line, function)                         \+  __assert(function, file, line, assertion)++#endif /* __assert_fail */++#if !defined(__ANDROID_API__) || MDBX_DEBUG++void __cold mdbx_assert_fail(const MDBX_env *env, const char *msg,+                             const char *func, int line) {+#if MDBX_DEBUG+  if (env && env->me_assert_func) {+    env->me_assert_func(env, msg, func, line);+    return;+  }+#else+  (void)env;+#endif /* MDBX_DEBUG */++  if (mdbx_debug_logger)+    mdbx_debug_log(MDBX_LOG_FATAL, func, line, "assert: %s\n", msg);+  else {+#if defined(_WIN32) || defined(_WIN64)+    char *message = nullptr;+    const int num = mdbx_asprintf(&message, "\r\nMDBX-ASSERTION: %s, %s:%u",+                                  msg, func ? func : "unknown", line);+    if (num < 1 || !message)+      message = "<troubles with assertion-message preparation>";+    OutputDebugStringA(message);+    if (IsDebuggerPresent())+      DebugBreak();+#elif defined(__ANDROID_API__)+    __android_log_assert(msg, "mdbx", "%s:%u", func, line);+#else+    __assert_fail(msg, "mdbx", line, func);+#endif+  }++#if defined(_WIN32) || defined(_WIN64)+  FatalExit(ERROR_UNHANDLED_ERROR);+#else+  abort();+#endif+}++#endif /* __ANDROID_API__ || MDBX_DEBUG */++__cold void mdbx_panic(const char *fmt, ...) {+  va_list ap;+  va_start(ap, fmt);++  char *message = nullptr;+  const int num = mdbx_vasprintf(&message, fmt, ap);+  va_end(ap);+  const char *const const_message =+      (num < 1 || !message) ? "<troubles with panic-message preparation>"+                            : message;++#if defined(_WIN32) || defined(_WIN64)+  OutputDebugStringA("\r\nMDBX-PANIC: ");+  OutputDebugStringA(const_message);+  if (IsDebuggerPresent())+    DebugBreak();+  FatalExit(ERROR_UNHANDLED_ERROR);+#else+#if defined(__ANDROID_API__)+  __android_log_assert("panic", "mdbx", "%s", const_message);+#else+  __assert_fail(const_message, "mdbx", 0, "panic");+#endif /* __ANDROID_API__ */+  abort();+#endif+}++/*----------------------------------------------------------------------------*/++#ifndef mdbx_vasprintf+MDBX_INTERNAL_FUNC int mdbx_vasprintf(char **strp, const char *fmt,+                                      va_list ap) {+  va_list ones;+  va_copy(ones, ap);+  int needed = vsnprintf(nullptr, 0, fmt, ap);++  if (unlikely(needed < 0 || needed >= INT_MAX)) {+    *strp = nullptr;+    va_end(ones);+    return needed;+  }++  *strp = mdbx_malloc(needed + 1);+  if (unlikely(*strp == nullptr)) {+    va_end(ones);+#if defined(_WIN32) || defined(_WIN64)+    SetLastError(MDBX_ENOMEM);+#else+    errno = MDBX_ENOMEM;+#endif+    return -1;+  }++  int actual = vsnprintf(*strp, needed + 1, fmt, ones);+  va_end(ones);++  assert(actual == needed);+  if (unlikely(actual < 0)) {+    mdbx_free(*strp);+    *strp = nullptr;+  }+  return actual;+}+#endif /* mdbx_vasprintf */++#ifndef mdbx_asprintf+MDBX_INTERNAL_FUNC int mdbx_asprintf(char **strp, const char *fmt, ...) {+  va_list ap;+  va_start(ap, fmt);+  int rc = mdbx_vasprintf(strp, fmt, ap);+  va_end(ap);+  return rc;+}+#endif /* mdbx_asprintf */++#ifndef mdbx_memalign_alloc+MDBX_INTERNAL_FUNC int mdbx_memalign_alloc(size_t alignment, size_t bytes,+                                           void **result) {+  assert(is_powerof2(alignment) && alignment >= sizeof(void *));+#if defined(_WIN32) || defined(_WIN64)+  (void)alignment;+  *result = VirtualAlloc(NULL, bytes, MEM_COMMIT | MEM_RESERVE, PAGE_READWRITE);+  return *result ? MDBX_SUCCESS : MDBX_ENOMEM /* ERROR_OUTOFMEMORY */;+#elif defined(_ISOC11_SOURCE)+  *result = aligned_alloc(alignment, ceil_powerof2(bytes, alignment));+  return *result ? MDBX_SUCCESS : errno;+#elif _POSIX_VERSION >= 200112L &&                                             \+    (!defined(__ANDROID_API__) || __ANDROID_API__ >= 17)+  *result = nullptr;+  return posix_memalign(result, alignment, bytes);+#elif __GLIBC_PREREQ(2, 16) || __STDC_VERSION__ >= 201112L+  *result = memalign(alignment, bytes);+  return *result ? MDBX_SUCCESS : errno;+#else+#error FIXME+#endif+}+#endif /* mdbx_memalign_alloc */++#ifndef mdbx_memalign_free+MDBX_INTERNAL_FUNC void mdbx_memalign_free(void *ptr) {+#if defined(_WIN32) || defined(_WIN64)+  VirtualFree(ptr, 0, MEM_RELEASE);+#else+  mdbx_free(ptr);+#endif+}+#endif /* mdbx_memalign_free */++#ifndef mdbx_strdup+char *mdbx_strdup(const char *str) {+  if (!str)+    return NULL;+  size_t bytes = strlen(str) + 1;+  char *dup = mdbx_malloc(bytes);+  if (dup)+    memcpy(dup, str, bytes);+  return dup;+}+#endif /* mdbx_strdup */++/*----------------------------------------------------------------------------*/++MDBX_INTERNAL_FUNC int mdbx_condpair_init(mdbx_condpair_t *condpair) {+  int rc;+  memset(condpair, 0, sizeof(mdbx_condpair_t));+#if defined(_WIN32) || defined(_WIN64)+  if ((condpair->mutex = CreateMutexW(NULL, FALSE, NULL)) == NULL) {+    rc = GetLastError();+    goto bailout_mutex;+  }+  if ((condpair->event[0] = CreateEventW(NULL, FALSE, FALSE, NULL)) == NULL) {+    rc = GetLastError();+    goto bailout_event;+  }+  if ((condpair->event[1] = CreateEventW(NULL, FALSE, FALSE, NULL)) != NULL)+    return MDBX_SUCCESS;++  rc = GetLastError();+  (void)CloseHandle(condpair->event[0]);+bailout_event:+  (void)CloseHandle(condpair->mutex);+#else+  rc = pthread_mutex_init(&condpair->mutex, NULL);+  if (unlikely(rc != 0))+    goto bailout_mutex;+  rc = pthread_cond_init(&condpair->cond[0], NULL);+  if (unlikely(rc != 0))+    goto bailout_cond;+  rc = pthread_cond_init(&condpair->cond[1], NULL);+  if (likely(rc == 0))+    return MDBX_SUCCESS;++  (void)pthread_cond_destroy(&condpair->cond[0]);+bailout_cond:+  (void)pthread_mutex_destroy(&condpair->mutex);+#endif+bailout_mutex:+  memset(condpair, 0, sizeof(mdbx_condpair_t));+  return rc;+}++MDBX_INTERNAL_FUNC int mdbx_condpair_destroy(mdbx_condpair_t *condpair) {+#if defined(_WIN32) || defined(_WIN64)+  int rc = CloseHandle(condpair->mutex) ? MDBX_SUCCESS : GetLastError();+  rc = CloseHandle(condpair->event[0]) ? rc : GetLastError();+  rc = CloseHandle(condpair->event[1]) ? rc : GetLastError();+#else+  int err, rc = pthread_mutex_destroy(&condpair->mutex);+  rc = (err = pthread_cond_destroy(&condpair->cond[0])) ? err : rc;+  rc = (err = pthread_cond_destroy(&condpair->cond[1])) ? err : rc;+#endif+  memset(condpair, 0, sizeof(mdbx_condpair_t));+  return rc;+}++MDBX_INTERNAL_FUNC int mdbx_condpair_lock(mdbx_condpair_t *condpair) {+#if defined(_WIN32) || defined(_WIN64)+  DWORD code = WaitForSingleObject(condpair->mutex, INFINITE);+  return waitstatus2errcode(code);+#else+  return pthread_mutex_lock(&condpair->mutex);+#endif+}++MDBX_INTERNAL_FUNC int mdbx_condpair_unlock(mdbx_condpair_t *condpair) {+#if defined(_WIN32) || defined(_WIN64)+  return ReleaseMutex(condpair->mutex) ? MDBX_SUCCESS : GetLastError();+#else+  return pthread_mutex_unlock(&condpair->mutex);+#endif+}++MDBX_INTERNAL_FUNC int mdbx_condpair_signal(mdbx_condpair_t *condpair,+                                            bool part) {+#if defined(_WIN32) || defined(_WIN64)+  return SetEvent(condpair->event[part]) ? MDBX_SUCCESS : GetLastError();+#else+  return pthread_cond_signal(&condpair->cond[part]);+#endif+}++MDBX_INTERNAL_FUNC int mdbx_condpair_wait(mdbx_condpair_t *condpair,+                                          bool part) {+#if defined(_WIN32) || defined(_WIN64)+  DWORD code = SignalObjectAndWait(condpair->mutex, condpair->event[part],+                                   INFINITE, FALSE);+  if (code == WAIT_OBJECT_0) {+    code = WaitForSingleObject(condpair->mutex, INFINITE);+    if (code == WAIT_OBJECT_0)+      return MDBX_SUCCESS;+  }+  return waitstatus2errcode(code);+#else+  return pthread_cond_wait(&condpair->cond[part], &condpair->mutex);+#endif+}++/*----------------------------------------------------------------------------*/++MDBX_INTERNAL_FUNC int mdbx_fastmutex_init(mdbx_fastmutex_t *fastmutex) {+#if defined(_WIN32) || defined(_WIN64)+  InitializeCriticalSection(fastmutex);+  return MDBX_SUCCESS;+#else+  return pthread_mutex_init(fastmutex, NULL);+#endif+}++MDBX_INTERNAL_FUNC int mdbx_fastmutex_destroy(mdbx_fastmutex_t *fastmutex) {+#if defined(_WIN32) || defined(_WIN64)+  DeleteCriticalSection(fastmutex);+  return MDBX_SUCCESS;+#else+  return pthread_mutex_destroy(fastmutex);+#endif+}++MDBX_INTERNAL_FUNC int mdbx_fastmutex_acquire(mdbx_fastmutex_t *fastmutex) {+#if defined(_WIN32) || defined(_WIN64)+  __try {+    EnterCriticalSection(fastmutex);+  } __except (+      (GetExceptionCode() ==+       0xC0000194 /* STATUS_POSSIBLE_DEADLOCK / EXCEPTION_POSSIBLE_DEADLOCK */)+          ? EXCEPTION_EXECUTE_HANDLER+          : EXCEPTION_CONTINUE_SEARCH) {+    return ERROR_POSSIBLE_DEADLOCK;+  }+  return MDBX_SUCCESS;+#else+  return pthread_mutex_lock(fastmutex);+#endif+}++MDBX_INTERNAL_FUNC int mdbx_fastmutex_release(mdbx_fastmutex_t *fastmutex) {+#if defined(_WIN32) || defined(_WIN64)+  LeaveCriticalSection(fastmutex);+  return MDBX_SUCCESS;+#else+  return pthread_mutex_unlock(fastmutex);+#endif+}++/*----------------------------------------------------------------------------*/++MDBX_INTERNAL_FUNC int mdbx_removefile(const char *pathname) {+#if defined(_WIN32) || defined(_WIN64)+  const size_t wlen = mbstowcs(nullptr, pathname, INT_MAX);+  if (wlen < 1 || wlen > /* MAX_PATH */ INT16_MAX)+    return ERROR_INVALID_NAME;+  wchar_t *const pathnameW = _alloca((wlen + 1) * sizeof(wchar_t));+  if (wlen != mbstowcs(pathnameW, pathname, wlen + 1))+    return ERROR_INVALID_NAME;+  return DeleteFileW(pathnameW) ? MDBX_SUCCESS : GetLastError();+#else+  return unlink(pathname) ? errno : MDBX_SUCCESS;+#endif+}++#if !(defined(_WIN32) || defined(_WIN64))+static bool is_valid_fd(int fd) { return !(isatty(fd) < 0 && errno == EBADF); }+#endif /*! Windows */++MDBX_INTERNAL_FUNC int mdbx_removedirectory(const char *pathname) {+#if defined(_WIN32) || defined(_WIN64)+  const size_t wlen = mbstowcs(nullptr, pathname, INT_MAX);+  if (wlen < 1 || wlen > /* MAX_PATH */ INT16_MAX)+    return ERROR_INVALID_NAME;+  wchar_t *const pathnameW = _alloca((wlen + 1) * sizeof(wchar_t));+  if (wlen != mbstowcs(pathnameW, pathname, wlen + 1))+    return ERROR_INVALID_NAME;+  return RemoveDirectoryW(pathnameW) ? MDBX_SUCCESS : GetLastError();+#else+  return rmdir(pathname) ? errno : MDBX_SUCCESS;+#endif+}++MDBX_INTERNAL_FUNC int mdbx_openfile(const enum mdbx_openfile_purpose purpose,+                                     const MDBX_env *env, const char *pathname,+                                     mdbx_filehandle_t *fd,+                                     mdbx_mode_t unix_mode_bits) {+  *fd = INVALID_HANDLE_VALUE;++#if defined(_WIN32) || defined(_WIN64)+  const size_t wlen = mbstowcs(nullptr, pathname, INT_MAX);+  if (wlen < 1 || wlen > /* MAX_PATH */ INT16_MAX)+    return ERROR_INVALID_NAME;+  wchar_t *const pathnameW = _alloca((wlen + 1) * sizeof(wchar_t));+  if (wlen != mbstowcs(pathnameW, pathname, wlen + 1))+    return ERROR_INVALID_NAME;++  DWORD CreationDisposition = unix_mode_bits ? OPEN_ALWAYS : OPEN_EXISTING;+  DWORD FlagsAndAttributes =+      FILE_FLAG_POSIX_SEMANTICS | FILE_ATTRIBUTE_NOT_CONTENT_INDEXED;+  DWORD DesiredAccess = FILE_READ_ATTRIBUTES;+  DWORD ShareMode = (env->me_flags & MDBX_EXCLUSIVE)+                        ? 0+                        : (FILE_SHARE_READ | FILE_SHARE_WRITE);++  switch (purpose) {+  default:+    return ERROR_INVALID_PARAMETER;+  case MDBX_OPEN_LCK:+    CreationDisposition = OPEN_ALWAYS;+    DesiredAccess |= GENERIC_READ | GENERIC_WRITE;+    FlagsAndAttributes |= FILE_ATTRIBUTE_HIDDEN | FILE_ATTRIBUTE_TEMPORARY;+    break;+  case MDBX_OPEN_DXB_READ:+    CreationDisposition = OPEN_EXISTING;+    DesiredAccess |= GENERIC_READ;+    ShareMode |= FILE_SHARE_READ;+    break;+  case MDBX_OPEN_DXB_LAZY:+    DesiredAccess |= GENERIC_READ | GENERIC_WRITE;+    break;+  case MDBX_OPEN_DXB_DSYNC:+    CreationDisposition = OPEN_EXISTING;+    DesiredAccess |= GENERIC_WRITE;+    FlagsAndAttributes |= FILE_FLAG_WRITE_THROUGH;+    break;+  case MDBX_OPEN_COPY:+    CreationDisposition = CREATE_NEW;+    ShareMode = 0;+    DesiredAccess |= GENERIC_WRITE;+    FlagsAndAttributes |=+        (env->me_psize < env->me_os_psize) ? 0 : FILE_FLAG_NO_BUFFERING;+    break;+  case MDBX_OPEN_DELETE:+    CreationDisposition = OPEN_EXISTING;+    ShareMode |= FILE_SHARE_DELETE;+    DesiredAccess =+        FILE_READ_ATTRIBUTES | FILE_WRITE_ATTRIBUTES | DELETE | SYNCHRONIZE;+    break;+  }++  *fd = CreateFileW(pathnameW, DesiredAccess, ShareMode, NULL,+                    CreationDisposition, FlagsAndAttributes, NULL);+  if (*fd == INVALID_HANDLE_VALUE)+    return GetLastError();++  BY_HANDLE_FILE_INFORMATION info;+  if (!GetFileInformationByHandle(*fd, &info)) {+    int err = GetLastError();+    CloseHandle(*fd);+    *fd = INVALID_HANDLE_VALUE;+    return err;+  }+  const DWORD AttributesDiff =+      (info.dwFileAttributes ^ FlagsAndAttributes) &+      (FILE_ATTRIBUTE_HIDDEN | FILE_ATTRIBUTE_NOT_CONTENT_INDEXED |+       FILE_ATTRIBUTE_TEMPORARY | FILE_ATTRIBUTE_COMPRESSED);+  if (AttributesDiff)+    (void)SetFileAttributesW(pathnameW, info.dwFileAttributes ^ AttributesDiff);++#else+  int flags = unix_mode_bits ? O_CREAT : 0;+  switch (purpose) {+  default:+    return EINVAL;+  case MDBX_OPEN_LCK:+    flags |= O_RDWR;+    break;+  case MDBX_OPEN_DXB_READ:+    flags = O_RDONLY;+    break;+  case MDBX_OPEN_DXB_LAZY:+    flags |= O_RDWR;+    break;+  case MDBX_OPEN_COPY:+    flags = O_CREAT | O_WRONLY | O_EXCL;+    break;+  case MDBX_OPEN_DXB_DSYNC:+    flags |= O_WRONLY;+#if defined(O_DSYNC)+    flags |= O_DSYNC;+#elif defined(O_SYNC)+    flags |= O_SYNC;+#elif defined(O_FSYNC)+    flags |= O_FSYNC;+#endif+    break;+  case MDBX_OPEN_DELETE:+    flags = O_RDWR;+    break;+  }++  const bool direct_nocache_for_copy =+      env->me_psize >= env->me_os_psize && purpose == MDBX_OPEN_COPY;+  if (direct_nocache_for_copy) {+#if defined(O_DIRECT)+    flags |= O_DIRECT;+#endif /* O_DIRECT */+#if defined(O_NOCACHE)+    flags |= O_NOCACHE;+#endif /* O_NOCACHE */+  }++#ifdef O_CLOEXEC+  flags |= O_CLOEXEC;+#endif /* O_CLOEXEC */++  /* Safeguard for https://github.com/erthink/libmdbx/issues/144 */+#if STDIN_FILENO == 0 && STDOUT_FILENO == 1 && STDERR_FILENO == 2+  int stub_fd0 = -1, stub_fd1 = -1, stub_fd2 = -1;+  static const char dev_null[] = "/dev/null";+  if (!is_valid_fd(STDIN_FILENO)) {+    mdbx_warning("STD%s_FILENO/%d is invalid, open %s for temporary stub", "IN",+                 STDIN_FILENO, dev_null);+    stub_fd0 = open(dev_null, O_RDONLY | O_NOCTTY);+  }+  if (!is_valid_fd(STDOUT_FILENO)) {+    mdbx_warning("STD%s_FILENO/%d is invalid, open %s for temporary stub",+                 "OUT", STDOUT_FILENO, dev_null);+    stub_fd1 = open(dev_null, O_WRONLY | O_NOCTTY);+  }+  if (!is_valid_fd(STDERR_FILENO)) {+    mdbx_warning("STD%s_FILENO/%d is invalid, open %s for temporary stub",+                 "ERR", STDERR_FILENO, dev_null);+    stub_fd2 = open(dev_null, O_WRONLY | O_NOCTTY);+  }+#else+#error "Unexpected or unsupported UNIX or POSIX system"+#endif /* STDIN_FILENO == 0 && STDERR_FILENO == 2 */++  *fd = open(pathname, flags, unix_mode_bits);+#if defined(O_DIRECT)+  if (*fd < 0 && (flags & O_DIRECT) &&+      (errno == EINVAL || errno == EAFNOSUPPORT)) {+    flags &= ~(O_DIRECT | O_EXCL);+    *fd = open(pathname, flags, unix_mode_bits);+  }+#endif /* O_DIRECT */++  /* Safeguard for https://github.com/erthink/libmdbx/issues/144 */+#if STDIN_FILENO == 0 && STDOUT_FILENO == 1 && STDERR_FILENO == 2+  if (*fd == STDIN_FILENO) {+    mdbx_warning("Got STD%s_FILENO/%d, avoid using it by dup(fd)", "IN",+                 STDIN_FILENO);+    assert(stub_fd0 == -1);+    *fd = dup(stub_fd0 = *fd);+  }+  if (*fd == STDOUT_FILENO) {+    mdbx_warning("Got STD%s_FILENO/%d, avoid using it by dup(fd)", "OUT",+                 STDOUT_FILENO);+    assert(stub_fd1 == -1);+    *fd = dup(stub_fd1 = *fd);+  }+  if (*fd == STDERR_FILENO) {+    mdbx_warning("Got STD%s_FILENO/%d, avoid using it by dup(fd)", "ERR",+                 STDERR_FILENO);+    assert(stub_fd2 == -1);+    *fd = dup(stub_fd2 = *fd);+  }+  if (stub_fd0 != -1)+    close(stub_fd0);+  if (stub_fd1 != -1)+    close(stub_fd1);+  if (stub_fd2 != -1)+    close(stub_fd2);+  if (*fd >= STDIN_FILENO && *fd <= STDERR_FILENO) {+    mdbx_error(+        "Rejecting the use of a FD in the range "+        "STDIN_FILENO/%d..STDERR_FILENO/%d to prevent database corruption",+        STDIN_FILENO, STDERR_FILENO);+    close(*fd);+    return EBADF;+  }+#else+#error "Unexpected or unsupported UNIX or POSIX system"+#endif /* STDIN_FILENO == 0 && STDERR_FILENO == 2 */++  if (*fd < 0)+    return errno;++#if defined(FD_CLOEXEC) && !defined(O_CLOEXEC)+  const int fd_flags = fcntl(*fd, F_GETFD);+  if (fd_flags != -1)+    (void)fcntl(*fd, F_SETFD, fd_flags | FD_CLOEXEC);+#endif /* FD_CLOEXEC && !O_CLOEXEC */++  if (direct_nocache_for_copy) {+#if defined(F_NOCACHE) && !defined(O_NOCACHE)+    (void)fcntl(*fd, F_NOCACHE, 1);+#endif /* F_NOCACHE */+  }++#endif+  return MDBX_SUCCESS;+}++MDBX_INTERNAL_FUNC int mdbx_closefile(mdbx_filehandle_t fd) {+#if defined(_WIN32) || defined(_WIN64)+  return CloseHandle(fd) ? MDBX_SUCCESS : GetLastError();+#else+  assert(fd > STDERR_FILENO);+  return (close(fd) == 0) ? MDBX_SUCCESS : errno;+#endif+}++MDBX_INTERNAL_FUNC int mdbx_pread(mdbx_filehandle_t fd, void *buf, size_t bytes,+                                  uint64_t offset) {+  if (bytes > MAX_WRITE)+    return MDBX_EINVAL;+#if defined(_WIN32) || defined(_WIN64)+  OVERLAPPED ov;+  ov.hEvent = 0;+  ov.Offset = (DWORD)offset;+  ov.OffsetHigh = HIGH_DWORD(offset);++  DWORD read = 0;+  if (unlikely(!ReadFile(fd, buf, (DWORD)bytes, &read, &ov))) {+    int rc = GetLastError();+    return (rc == MDBX_SUCCESS) ? /* paranoia */ ERROR_READ_FAULT : rc;+  }+#else+  STATIC_ASSERT_MSG(sizeof(off_t) >= sizeof(size_t),+                    "libmdbx requires 64-bit file I/O on 64-bit systems");+  intptr_t read = pread(fd, buf, bytes, offset);+  if (read < 0) {+    int rc = errno;+    return (rc == MDBX_SUCCESS) ? /* paranoia */ MDBX_EIO : rc;+  }+#endif+  return (bytes == (size_t)read) ? MDBX_SUCCESS : MDBX_ENODATA;+}++MDBX_INTERNAL_FUNC int mdbx_pwrite(mdbx_filehandle_t fd, const void *buf,+                                   size_t bytes, uint64_t offset) {+  while (true) {+#if defined(_WIN32) || defined(_WIN64)+    OVERLAPPED ov;+    ov.hEvent = 0;+    ov.Offset = (DWORD)offset;+    ov.OffsetHigh = HIGH_DWORD(offset);++    DWORD written;+    if (unlikely(!WriteFile(+            fd, buf, likely(bytes <= MAX_WRITE) ? (DWORD)bytes : MAX_WRITE,+            &written, &ov)))+      return GetLastError();+    if (likely(bytes == written))+      return MDBX_SUCCESS;+#else+    STATIC_ASSERT_MSG(sizeof(off_t) >= sizeof(size_t),+                      "libmdbx requires 64-bit file I/O on 64-bit systems");+    const intptr_t written =+        pwrite(fd, buf, likely(bytes <= MAX_WRITE) ? bytes : MAX_WRITE, offset);+    if (likely(bytes == (size_t)written))+      return MDBX_SUCCESS;+    if (written < 0) {+      const int rc = errno;+      if (rc != EINTR)+        return rc;+      continue;+    }+#endif+    bytes -= written;+    offset += written;+    buf = (char *)buf + written;+  }+}++MDBX_INTERNAL_FUNC int mdbx_write(mdbx_filehandle_t fd, const void *buf,+                                  size_t bytes) {+  while (true) {+#if defined(_WIN32) || defined(_WIN64)+    DWORD written;+    if (unlikely(!WriteFile(+            fd, buf, likely(bytes <= MAX_WRITE) ? (DWORD)bytes : MAX_WRITE,+            &written, nullptr)))+      return GetLastError();+    if (likely(bytes == written))+      return MDBX_SUCCESS;+#else+    STATIC_ASSERT_MSG(sizeof(off_t) >= sizeof(size_t),+                      "libmdbx requires 64-bit file I/O on 64-bit systems");+    const intptr_t written =+        write(fd, buf, likely(bytes <= MAX_WRITE) ? bytes : MAX_WRITE);+    if (likely(bytes == (size_t)written))+      return MDBX_SUCCESS;+    if (written < 0) {+      const int rc = errno;+      if (rc != EINTR)+        return rc;+      continue;+    }+#endif+    bytes -= written;+    buf = (char *)buf + written;+  }+}++int mdbx_pwritev(mdbx_filehandle_t fd, struct iovec *iov, int iovcnt,+                 uint64_t offset, size_t expected_written) {+#if defined(_WIN32) || defined(_WIN64) || defined(__APPLE__) ||                \+    (defined(__ANDROID_API__) && __ANDROID_API__ < 24)+  size_t written = 0;+  for (int i = 0; i < iovcnt; ++i) {+    int rc = mdbx_pwrite(fd, iov[i].iov_base, iov[i].iov_len, offset);+    if (unlikely(rc != MDBX_SUCCESS))+      return rc;+    written += iov[i].iov_len;+    offset += iov[i].iov_len;+  }+  return (expected_written == written) ? MDBX_SUCCESS+                                       : MDBX_EIO /* ERROR_WRITE_FAULT */;+#else+  int rc;+  intptr_t written;+  do {+    STATIC_ASSERT_MSG(sizeof(off_t) >= sizeof(size_t),+                      "libmdbx requires 64-bit file I/O on 64-bit systems");+    written = pwritev(fd, iov, iovcnt, offset);+    if (likely(expected_written == (size_t)written))+      return MDBX_SUCCESS;+    rc = errno;+  } while (rc == EINTR);+  return (written < 0) ? rc : MDBX_EIO /* Use which error code? */;+#endif+}++MDBX_INTERNAL_FUNC int mdbx_fsync(mdbx_filehandle_t fd,+                                  enum mdbx_syncmode_bits mode_bits) {+#if defined(_WIN32) || defined(_WIN64)+  if ((mode_bits & (MDBX_SYNC_DATA | MDBX_SYNC_IODQ)) && !FlushFileBuffers(fd))+    return GetLastError();+  return MDBX_SUCCESS;+#else++#if defined(__APPLE__) &&                                                      \+    MDBX_OSX_SPEED_INSTEADOF_DURABILITY == MDBX_OSX_WANNA_DURABILITY+  if (mode_bits & MDBX_SYNC_IODQ)+    return likely(fcntl(fd, F_FULLFSYNC) != -1) ? MDBX_SUCCESS : errno;+#endif /* MacOS */++  /* LY: This approach is always safe and without appreciable performance+   * degradation, even on a kernel with fdatasync's bug.+   *+   * For more info about of a corresponding fdatasync() bug+   * see http://www.spinics.net/lists/linux-ext4/msg33714.html */+  while (1) {+    switch (mode_bits & (MDBX_SYNC_DATA | MDBX_SYNC_SIZE)) {+    case MDBX_SYNC_NONE:+      return MDBX_SUCCESS /* nothing to do */;+#if defined(_POSIX_SYNCHRONIZED_IO) && _POSIX_SYNCHRONIZED_IO > 0+    case MDBX_SYNC_DATA:+      if (fdatasync(fd) == 0)+        return MDBX_SUCCESS;+      break /* error */;+#if defined(__linux__) || defined(__gnu_linux__)+    case MDBX_SYNC_SIZE:+      if (mdbx_linux_kernel_version >= 0x03060000)+        return MDBX_SUCCESS;+      __fallthrough /* fall through */;+#endif /* Linux */+#endif /* _POSIX_SYNCHRONIZED_IO > 0 */+    default:+      if (fsync(fd) == 0)+        return MDBX_SUCCESS;+    }++    int rc = errno;+    if (rc != EINTR)+      return rc;+  }+#endif+}++int mdbx_filesize(mdbx_filehandle_t fd, uint64_t *length) {+#if defined(_WIN32) || defined(_WIN64)+  BY_HANDLE_FILE_INFORMATION info;+  if (!GetFileInformationByHandle(fd, &info))+    return GetLastError();+  *length = info.nFileSizeLow | (uint64_t)info.nFileSizeHigh << 32;+#else+  struct stat st;++  STATIC_ASSERT_MSG(sizeof(off_t) <= sizeof(uint64_t),+                    "libmdbx requires 64-bit file I/O on 64-bit systems");+  if (fstat(fd, &st))+    return errno;++  *length = st.st_size;+#endif+  return MDBX_SUCCESS;+}++MDBX_INTERNAL_FUNC int mdbx_is_pipe(mdbx_filehandle_t fd) {+#if defined(_WIN32) || defined(_WIN64)+  switch (GetFileType(fd)) {+  case FILE_TYPE_DISK:+    return MDBX_RESULT_FALSE;+  case FILE_TYPE_CHAR:+  case FILE_TYPE_PIPE:+    return MDBX_RESULT_TRUE;+  default:+    return GetLastError();+  }+#else+  struct stat info;+  if (fstat(fd, &info))+    return errno;+  switch (info.st_mode & S_IFMT) {+  case S_IFBLK:+  case S_IFREG:+    return MDBX_RESULT_FALSE;+  case S_IFCHR:+  case S_IFIFO:+  case S_IFSOCK:+    return MDBX_RESULT_TRUE;+  case S_IFDIR:+  case S_IFLNK:+  default:+    return MDBX_INCOMPATIBLE;+  }+#endif+}++MDBX_INTERNAL_FUNC int mdbx_ftruncate(mdbx_filehandle_t fd, uint64_t length) {+#if defined(_WIN32) || defined(_WIN64)+  if (mdbx_SetFileInformationByHandle) {+    FILE_END_OF_FILE_INFO EndOfFileInfo;+    EndOfFileInfo.EndOfFile.QuadPart = length;+    return mdbx_SetFileInformationByHandle(fd, FileEndOfFileInfo,+                                           &EndOfFileInfo,+                                           sizeof(FILE_END_OF_FILE_INFO))+               ? MDBX_SUCCESS+               : GetLastError();+  } else {+    LARGE_INTEGER li;+    li.QuadPart = length;+    return (SetFilePointerEx(fd, li, NULL, FILE_BEGIN) && SetEndOfFile(fd))+               ? MDBX_SUCCESS+               : GetLastError();+  }+#else+  STATIC_ASSERT_MSG(sizeof(off_t) >= sizeof(size_t),+                    "libmdbx requires 64-bit file I/O on 64-bit systems");+  return ftruncate(fd, length) == 0 ? MDBX_SUCCESS : errno;+#endif+}++MDBX_INTERNAL_FUNC int mdbx_fseek(mdbx_filehandle_t fd, uint64_t pos) {+#if defined(_WIN32) || defined(_WIN64)+  LARGE_INTEGER li;+  li.QuadPart = pos;+  return SetFilePointerEx(fd, li, NULL, FILE_BEGIN) ? MDBX_SUCCESS+                                                    : GetLastError();+#else+  STATIC_ASSERT_MSG(sizeof(off_t) >= sizeof(size_t),+                    "libmdbx requires 64-bit file I/O on 64-bit systems");+  return (lseek(fd, pos, SEEK_SET) < 0) ? errno : MDBX_SUCCESS;+#endif+}++/*----------------------------------------------------------------------------*/++MDBX_INTERNAL_FUNC int+mdbx_thread_create(mdbx_thread_t *thread,+                   THREAD_RESULT(THREAD_CALL *start_routine)(void *),+                   void *arg) {+#if defined(_WIN32) || defined(_WIN64)+  *thread = CreateThread(NULL, 0, start_routine, arg, 0, NULL);+  return *thread ? MDBX_SUCCESS : GetLastError();+#else+  return pthread_create(thread, NULL, start_routine, arg);+#endif+}++MDBX_INTERNAL_FUNC int mdbx_thread_join(mdbx_thread_t thread) {+#if defined(_WIN32) || defined(_WIN64)+  DWORD code = WaitForSingleObject(thread, INFINITE);+  return waitstatus2errcode(code);+#else+  void *unused_retval = &unused_retval;+  return pthread_join(thread, &unused_retval);+#endif+}++/*----------------------------------------------------------------------------*/++MDBX_INTERNAL_FUNC int mdbx_msync(mdbx_mmap_t *map, size_t offset,+                                  size_t length,+                                  enum mdbx_syncmode_bits mode_bits) {+  uint8_t *ptr = (uint8_t *)map->address + offset;+#if defined(_WIN32) || defined(_WIN64)+  if (!FlushViewOfFile(ptr, length))+    return GetLastError();+#else+#if defined(__linux__) || defined(__gnu_linux__)+  if (mode_bits == MDBX_SYNC_NONE && mdbx_linux_kernel_version > 0x02061300)+    /* Since Linux 2.6.19, MS_ASYNC is in fact a no-op. The kernel properly+     * tracks dirty pages and flushes them to storage as necessary. */+    return MDBX_SUCCESS;+#endif /* Linux */+  if (msync(ptr, length, (mode_bits & MDBX_SYNC_DATA) ? MS_SYNC : MS_ASYNC))+    return errno;+  mode_bits &= ~MDBX_SYNC_DATA;+#endif+  return mdbx_fsync(map->fd, mode_bits);+}++MDBX_INTERNAL_FUNC int mdbx_check_fs_rdonly(mdbx_filehandle_t handle,+                                            const char *pathname, int err) {+#if defined(_WIN32) || defined(_WIN64)+  (void)pathname;+  (void)err;+  if (!mdbx_GetVolumeInformationByHandleW)+    return MDBX_ENOSYS;+  DWORD unused, flags;+  if (!mdbx_GetVolumeInformationByHandleW(handle, nullptr, 0, nullptr, &unused,+                                          &flags, nullptr, 0))+    return GetLastError();+  if ((flags & FILE_READ_ONLY_VOLUME) == 0)+    return MDBX_EACCESS;+#else+  struct statvfs info;+  if (err != MDBX_ENOFILE) {+    if (statvfs(pathname, &info))+      return errno;+    if ((info.f_flag & ST_RDONLY) == 0)+      return err;+  }+  if (fstatvfs(handle, &info))+    return errno;+  if ((info.f_flag & ST_RDONLY) == 0)+    return (err == MDBX_ENOFILE) ? MDBX_EACCESS : err;+#endif /* !Windows */+  return MDBX_SUCCESS;+}++static int mdbx_check_fs_local(mdbx_filehandle_t handle, int flags) {+#if defined(_WIN32) || defined(_WIN64)+  if (mdbx_RunningUnderWine() && !(flags & MDBX_EXCLUSIVE))+    return ERROR_NOT_CAPABLE /* workaround for Wine */;++  if (GetFileType(handle) != FILE_TYPE_DISK)+    return ERROR_FILE_OFFLINE;++  if (mdbx_GetFileInformationByHandleEx) {+    FILE_REMOTE_PROTOCOL_INFO RemoteProtocolInfo;+    if (mdbx_GetFileInformationByHandleEx(handle, FileRemoteProtocolInfo,+                                          &RemoteProtocolInfo,+                                          sizeof(RemoteProtocolInfo))) {+      if ((RemoteProtocolInfo.Flags & REMOTE_PROTOCOL_INFO_FLAG_OFFLINE) &&+          !(flags & MDBX_RDONLY))+        return ERROR_FILE_OFFLINE;+      if (!(RemoteProtocolInfo.Flags & REMOTE_PROTOCOL_INFO_FLAG_LOOPBACK) &&+          !(flags & MDBX_EXCLUSIVE))+        return ERROR_REMOTE_STORAGE_MEDIA_ERROR;+    }+  }++  if (mdbx_NtFsControlFile) {+    NTSTATUS rc;+    struct {+      WOF_EXTERNAL_INFO wof_info;+      union {+        WIM_PROVIDER_EXTERNAL_INFO wim_info;+        FILE_PROVIDER_EXTERNAL_INFO_V1 file_info;+      };+      size_t reserved_for_microsoft_madness[42];+    } GetExternalBacking_OutputBuffer;+    IO_STATUS_BLOCK StatusBlock;+    rc = mdbx_NtFsControlFile(handle, NULL, NULL, NULL, &StatusBlock,+                              FSCTL_GET_EXTERNAL_BACKING, NULL, 0,+                              &GetExternalBacking_OutputBuffer,+                              sizeof(GetExternalBacking_OutputBuffer));+    if (NT_SUCCESS(rc)) {+      if (!(flags & MDBX_EXCLUSIVE))+        return ERROR_REMOTE_STORAGE_MEDIA_ERROR;+    } else if (rc != STATUS_OBJECT_NOT_EXTERNALLY_BACKED &&+               rc != STATUS_INVALID_DEVICE_REQUEST &&+               rc != STATUS_NOT_SUPPORTED)+      return ntstatus2errcode(rc);+  }++  if (mdbx_GetVolumeInformationByHandleW && mdbx_GetFinalPathNameByHandleW) {+    WCHAR *PathBuffer = mdbx_malloc(sizeof(WCHAR) * INT16_MAX);+    if (!PathBuffer)+      return MDBX_ENOMEM;++    int rc = MDBX_SUCCESS;+    DWORD VolumeSerialNumber, FileSystemFlags;+    if (!mdbx_GetVolumeInformationByHandleW(handle, PathBuffer, INT16_MAX,+                                            &VolumeSerialNumber, NULL,+                                            &FileSystemFlags, NULL, 0)) {+      rc = GetLastError();+      goto bailout;+    }++    if ((flags & MDBX_RDONLY) == 0) {+      if (FileSystemFlags &+          (FILE_SEQUENTIAL_WRITE_ONCE | FILE_READ_ONLY_VOLUME |+           FILE_VOLUME_IS_COMPRESSED)) {+        rc = ERROR_REMOTE_STORAGE_MEDIA_ERROR;+        goto bailout;+      }+    }++    if (!mdbx_GetFinalPathNameByHandleW(handle, PathBuffer, INT16_MAX,+                                        FILE_NAME_NORMALIZED |+                                            VOLUME_NAME_NT)) {+      rc = GetLastError();+      goto bailout;+    }++    if (_wcsnicmp(PathBuffer, L"\\Device\\Mup\\", 12) == 0) {+      if (!(flags & MDBX_EXCLUSIVE)) {+        rc = ERROR_REMOTE_STORAGE_MEDIA_ERROR;+        goto bailout;+      }+    } else if (mdbx_GetFinalPathNameByHandleW(handle, PathBuffer, INT16_MAX,+                                              FILE_NAME_NORMALIZED |+                                                  VOLUME_NAME_DOS)) {+      UINT DriveType = GetDriveTypeW(PathBuffer);+      if (DriveType == DRIVE_NO_ROOT_DIR &&+          _wcsnicmp(PathBuffer, L"\\\\?\\", 4) == 0 &&+          _wcsnicmp(PathBuffer + 5, L":\\", 2) == 0) {+        PathBuffer[7] = 0;+        DriveType = GetDriveTypeW(PathBuffer + 4);+      }+      switch (DriveType) {+      case DRIVE_CDROM:+        if (flags & MDBX_RDONLY)+          break;+      // fall through+      case DRIVE_UNKNOWN:+      case DRIVE_NO_ROOT_DIR:+      case DRIVE_REMOTE:+      default:+        if (!(flags & MDBX_EXCLUSIVE))+          rc = ERROR_REMOTE_STORAGE_MEDIA_ERROR;+      // fall through+      case DRIVE_REMOVABLE:+      case DRIVE_FIXED:+      case DRIVE_RAMDISK:+        break;+      }+    }+  bailout:+    mdbx_free(PathBuffer);+    return rc;+  }++#else++  struct statvfs statvfs_info;+  if (fstatvfs(handle, &statvfs_info))+    return errno;+#if defined(ST_LOCAL) || defined(ST_EXPORTED)+  const unsigned long st_flags = statvfs_info.f_flag;+#endif /* ST_LOCAL || ST_EXPORTED */++#if defined(__NetBSD__)+  const unsigned type = 0;+  const char *const name = statvfs_info.f_fstypename;+  const size_t name_len = VFS_NAMELEN;+#elif defined(_AIX) || defined(__OS400__)+  const char *const name = statvfs_info.f_basetype;+  const size_t name_len = sizeof(statvfs_info.f_basetype);+  struct stat st;+  if (fstat(handle, &st))+    return errno;+  const unsigned type = st.st_vfstype;+  if ((st.st_flag & FS_REMOTE) != 0 && !(flags & MDBX_EXCLUSIVE))+    return MDBX_EREMOTE;+#elif defined(FSTYPSZ) || defined(_FSTYPSZ)+  const unsigned type = 0;+  const char *const name = statvfs_info.f_basetype;+  const size_t name_len = sizeof(statvfs_info.f_basetype);+#elif defined(__sun) || defined(__SVR4) || defined(__svr4__) ||                \+    defined(ST_FSTYPSZ) || defined(_ST_FSTYPSZ)+  const unsigned type = 0;+  struct stat st;+  if (fstat(handle, &st))+    return errno;+  const char *const name = st.st_fstype;+  const size_t name_len = strlen(name);+#else+  struct statfs statfs_info;+  if (fstatfs(handle, &statfs_info))+    return errno;+#if defined(__OpenBSD__)+  const unsigned type = 0;+#else+  const unsigned type = statfs_info.f_type;+#endif+#if defined(MNT_LOCAL) || defined(MNT_EXPORTED)+  const unsigned long mnt_flags = statfs_info.f_flags;+#endif /* MNT_LOCAL || MNT_EXPORTED */+#if defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__) ||     \+    defined(__BSD__) || defined(__bsdi__) || defined(__DragonFly__) ||         \+    defined(__APPLE__) || defined(__MACH__) || defined(MFSNAMELEN) ||          \+    defined(MFSTYPENAMELEN) || defined(VFS_NAMELEN)+  const char *const name = statfs_info.f_fstypename;+  const size_t name_len = sizeof(statfs_info.f_fstypename);+#elif defined(__ANDROID_API__) && __ANDROID_API__ < 21+  const char *const name = "";+  const unsigned name_len = 0;+#else++  const char *name = "";+  unsigned name_len = 0;++  struct stat st;+  if (fstat(handle, &st))+    return errno;++  char pathbuf[PATH_MAX];+  FILE *mounted = nullptr;+#if defined(__linux__) || defined(__gnu_linux__)+  mounted = setmntent("/proc/mounts", "r");+#endif /* Linux */+  if (!mounted)+    mounted = setmntent("/etc/mtab", "r");+  if (mounted) {+    const struct mntent *ent;+#if defined(_BSD_SOURCE) || defined(_SVID_SOURCE) || defined(__BIONIC__) ||    \+    (defined(_DEFAULT_SOURCE) && __GLIBC_PREREQ(2, 19))+    struct mntent entbuf;+    const bool should_copy = false;+    while (nullptr !=+           (ent = getmntent_r(mounted, &entbuf, pathbuf, sizeof(pathbuf))))+#else+    const bool should_copy = true;+    while (nullptr != (ent = getmntent(mounted)))+#endif+    {+      struct stat mnt;+      if (!stat(ent->mnt_dir, &mnt) && mnt.st_dev == st.st_dev) {+        if (should_copy) {+          name =+              strncpy(pathbuf, ent->mnt_fsname, name_len = sizeof(pathbuf) - 1);+          pathbuf[name_len] = 0;+        } else {+          name = ent->mnt_fsname;+          name_len = strlen(name);+        }+        break;+      }+    }+    endmntent(mounted);+  }+#endif /* !xBSD && !Android/Bionic */+#endif++  if (name_len) {+    if (((name_len > 2 && strncasecmp("nfs", name, 3) == 0) ||+         strncasecmp("cifs", name, name_len) == 0 ||+         strncasecmp("ncpfs", name, name_len) == 0 ||+         strncasecmp("smbfs", name, name_len) == 0 ||+         ((name_len > 3 && strncasecmp("fuse", name, 4) == 0) &&+          strncasecmp("fuseblk", name, name_len) != 0)) &&+        !(flags & MDBX_EXCLUSIVE))+      return MDBX_EREMOTE;+    if (strcasecmp("ftp", name) == 0 || strcasecmp("http", name) == 0 ||+        strcasecmp("sshfs", name) == 0)+      return MDBX_EREMOTE;+  }++#ifdef ST_LOCAL+  if ((st_flags & ST_LOCAL) == 0 && !(flags & MDBX_EXCLUSIVE))+    return MDBX_EREMOTE;+#elif defined(MNT_LOCAL)+  if ((mnt_flags & MNT_LOCAL) == 0 && !(flags & MDBX_EXCLUSIVE))+    return MDBX_EREMOTE;+#endif /* ST/MNT_LOCAL */++#ifdef ST_EXPORTED+  if ((st_flags & ST_EXPORTED) != 0 && !(flags & MDBX_RDONLY))+    return MDBX_EREMOTE;+#elif defined(MNT_EXPORTED)+  if ((mnt_flags & MNT_EXPORTED) != 0 && !(flags & MDBX_RDONLY))+    return MDBX_EREMOTE;+#endif /* ST/MNT_EXPORTED */++  switch (type) {+  case 0xFF534D42 /* CIFS_MAGIC_NUMBER */:+  case 0x6969 /* NFS_SUPER_MAGIC */:+  case 0x564c /* NCP_SUPER_MAGIC */:+  case 0x517B /* SMB_SUPER_MAGIC */:+#if defined(__digital__) || defined(__osf__) || defined(__osf)+  case 0x0E /* Tru64 NFS */:+#endif+#ifdef ST_FST_NFS+  case ST_FST_NFS:+#endif+    if ((flags & MDBX_EXCLUSIVE) == 0)+      return MDBX_EREMOTE;+  case 0:+  default:+    break;+  }+#endif /* Unix */++  return MDBX_SUCCESS;+}++MDBX_INTERNAL_FUNC int mdbx_mmap(const int flags, mdbx_mmap_t *map,+                                 const size_t size, const size_t limit,+                                 const unsigned options) {+  assert(size <= limit);+  map->limit = 0;+  map->current = 0;+  map->address = nullptr;+#if defined(_WIN32) || defined(_WIN64)+  map->section = NULL;+  map->filesize = 0;+#endif /* Windows */++  int err = mdbx_check_fs_local(map->fd, flags);+  if (unlikely(err != MDBX_SUCCESS))+    return err;++  if ((flags & MDBX_RDONLY) == 0 && (options & MMAP_OPTION_TRUNCATE) != 0) {+    err = mdbx_ftruncate(map->fd, size);+    if (err != MDBX_SUCCESS)+      return err;+#if defined(_WIN32) || defined(_WIN64)+    map->filesize = size;+#else+    map->current = size;+#endif+  } else {+    uint64_t filesize = 0;+    err = mdbx_filesize(map->fd, &filesize);+    if (err != MDBX_SUCCESS)+      return err;+#if defined(_WIN32) || defined(_WIN64)+    map->filesize = filesize;+#else+    map->current = (filesize > limit) ? limit : (size_t)filesize;+#endif+  }++#if defined(_WIN32) || defined(_WIN64)+  LARGE_INTEGER SectionSize;+  SectionSize.QuadPart = size;+  err = NtCreateSection(+      &map->section,+      /* DesiredAccess */+      (flags & MDBX_WRITEMAP)+          ? SECTION_QUERY | SECTION_MAP_READ | SECTION_EXTEND_SIZE |+                SECTION_MAP_WRITE+          : SECTION_QUERY | SECTION_MAP_READ | SECTION_EXTEND_SIZE,+      /* ObjectAttributes */ NULL, /* MaximumSize (InitialSize) */ &SectionSize,+      /* SectionPageProtection */+      (flags & MDBX_RDONLY) ? PAGE_READONLY : PAGE_READWRITE,+      /* AllocationAttributes */ SEC_RESERVE, map->fd);+  if (!NT_SUCCESS(err))+    return ntstatus2errcode(err);++  SIZE_T ViewSize =+      (flags & MDBX_RDONLY) ? 0 : mdbx_RunningUnderWine() ? size : limit;+  err = NtMapViewOfSection(+      map->section, GetCurrentProcess(), &map->address,+      /* ZeroBits */ 0,+      /* CommitSize */ 0,+      /* SectionOffset */ NULL, &ViewSize,+      /* InheritDisposition */ ViewUnmap,+      /* AllocationType */ (flags & MDBX_RDONLY) ? 0 : MEM_RESERVE,+      /* Win32Protect */+      (flags & MDBX_WRITEMAP) ? PAGE_READWRITE : PAGE_READONLY);+  if (!NT_SUCCESS(err)) {+    NtClose(map->section);+    map->section = 0;+    map->address = nullptr;+    return ntstatus2errcode(err);+  }+  assert(map->address != MAP_FAILED);++  map->current = (size_t)SectionSize.QuadPart;+  map->limit = ViewSize;++#else++#ifndef MAP_TRYFIXED+#define MAP_TRYFIXED 0+#endif++#ifndef MAP_HASSEMAPHORE+#define MAP_HASSEMAPHORE 0+#endif++#ifndef MAP_CONCEAL+#define MAP_CONCEAL 0+#endif++#ifndef MAP_NOSYNC+#define MAP_NOSYNC 0+#endif++  map->address = mmap(+      NULL, limit, (flags & MDBX_WRITEMAP) ? PROT_READ | PROT_WRITE : PROT_READ,+      MAP_SHARED | MAP_FILE |+          (F_ISSET(flags, MDBX_UTTERLY_NOSYNC) ? MAP_NOSYNC : 0) |+          ((options & MMAP_OPTION_SEMAPHORE) ? MAP_HASSEMAPHORE | MAP_NOSYNC+                                             : MAP_CONCEAL),+      map->fd, 0);++  if (unlikely(map->address == MAP_FAILED)) {+    map->limit = 0;+    map->current = 0;+    map->address = nullptr;+    return errno;+  }+  map->limit = limit;++#ifdef MADV_DONTFORK+  if (unlikely(madvise(map->address, map->limit, MADV_DONTFORK) != 0))+    return errno;+#endif+#ifdef MADV_NOHUGEPAGE+  (void)madvise(map->address, map->limit, MADV_NOHUGEPAGE);+#endif++#endif++  VALGRIND_MAKE_MEM_DEFINED(map->address, map->current);+  ASAN_UNPOISON_MEMORY_REGION(map->address, map->current);+  return MDBX_SUCCESS;+}++MDBX_INTERNAL_FUNC int mdbx_munmap(mdbx_mmap_t *map) {+  VALGRIND_MAKE_MEM_NOACCESS(map->address, map->current);+  /* Unpoisoning is required for ASAN to avoid false-positive diagnostic+   * when this memory will re-used by malloc or another mmapping.+   * See https://github.com/erthink/libmdbx/pull/93#issuecomment-613687203 */+  ASAN_UNPOISON_MEMORY_REGION(map->address, map->limit);+#if defined(_WIN32) || defined(_WIN64)+  if (map->section)+    NtClose(map->section);+  NTSTATUS rc = NtUnmapViewOfSection(GetCurrentProcess(), map->address);+  if (!NT_SUCCESS(rc))+    ntstatus2errcode(rc);+#else+  if (unlikely(munmap(map->address, map->limit)))+    return errno;+#endif++  map->limit = 0;+  map->current = 0;+  map->address = nullptr;+  return MDBX_SUCCESS;+}++MDBX_INTERNAL_FUNC int mdbx_mresize(int flags, mdbx_mmap_t *map, size_t size,+                                    size_t limit, const bool may_move) {+  assert(size <= limit);+#if defined(_WIN32) || defined(_WIN64)+  assert(size != map->current || limit != map->limit || size < map->filesize);++  NTSTATUS status;+  LARGE_INTEGER SectionSize;+  int err, rc = MDBX_SUCCESS;++  if (!(flags & MDBX_RDONLY) && limit == map->limit && size > map->current &&+      /* workaround for Wine */ mdbx_NtExtendSection) {+    /* growth rw-section */+    SectionSize.QuadPart = size;+    status = mdbx_NtExtendSection(map->section, &SectionSize);+    if (!NT_SUCCESS(status))+      return ntstatus2errcode(status);+    map->current = size;+    if (map->filesize < size)+      map->filesize = size;+    return MDBX_SUCCESS;+  }++  if (limit > map->limit) {+    /* check ability of address space for growth before unmap */+    PVOID BaseAddress = (PBYTE)map->address + map->limit;+    SIZE_T RegionSize = limit - map->limit;+    status = NtAllocateVirtualMemory(GetCurrentProcess(), &BaseAddress, 0,+                                     &RegionSize, MEM_RESERVE, PAGE_NOACCESS);+    if (status == /* STATUS_CONFLICTING_ADDRESSES */ 0xC0000018)+      return MDBX_UNABLE_EXTEND_MAPSIZE;+    if (!NT_SUCCESS(status))+      return ntstatus2errcode(status);++    status = NtFreeVirtualMemory(GetCurrentProcess(), &BaseAddress, &RegionSize,+                                 MEM_RELEASE);+    if (!NT_SUCCESS(status))+      return ntstatus2errcode(status);+  }++  /* Windows unable:+   *  - shrink a mapped file;+   *  - change size of mapped view;+   *  - extend read-only mapping;+   * Therefore we should unmap/map entire section. */+  status = NtUnmapViewOfSection(GetCurrentProcess(), map->address);+  if (!NT_SUCCESS(status))+    return ntstatus2errcode(status);+  status = NtClose(map->section);+  map->section = NULL;+  PVOID ReservedAddress = NULL;+  SIZE_T ReservedSize = limit;++  if (!NT_SUCCESS(status)) {+  bailout_ntstatus:+    err = ntstatus2errcode(status);+  bailout:+    map->address = NULL;+    map->current = map->limit = 0;+    if (ReservedAddress) {+      ReservedSize = 0;+      status = NtFreeVirtualMemory(GetCurrentProcess(), &ReservedAddress,+                                   &ReservedSize, MEM_RELEASE);+      assert(NT_SUCCESS(status));+      (void)status;+    }+    return err;+  }++retry_file_and_section:+  /* resizing of the file may take a while,+   * therefore we reserve address space to avoid occupy it by other threads */+  ReservedAddress = map->address;+  status = NtAllocateVirtualMemory(GetCurrentProcess(), &ReservedAddress, 0,+                                   &ReservedSize, MEM_RESERVE, PAGE_NOACCESS);+  if (!NT_SUCCESS(status)) {+    ReservedAddress = NULL;+    if (status != /* STATUS_CONFLICTING_ADDRESSES */ 0xC0000018)+      goto bailout_ntstatus /* no way to recovery */;++    if (may_move)+      /* the base address could be changed */+      map->address = NULL;+  }++  err = mdbx_filesize(map->fd, &map->filesize);+  if (err != MDBX_SUCCESS)+    goto bailout;++  if ((flags & MDBX_RDONLY) == 0 && map->filesize != size) {+    err = mdbx_ftruncate(map->fd, size);+    if (err == MDBX_SUCCESS)+      map->filesize = size;+    /* ignore error, because Windows unable shrink file+     * that already mapped (by another process) */+  }++  SectionSize.QuadPart = size;+  status = NtCreateSection(+      &map->section,+      /* DesiredAccess */+      (flags & MDBX_WRITEMAP)+          ? SECTION_QUERY | SECTION_MAP_READ | SECTION_EXTEND_SIZE |+                SECTION_MAP_WRITE+          : SECTION_QUERY | SECTION_MAP_READ | SECTION_EXTEND_SIZE,+      /* ObjectAttributes */ NULL,+      /* MaximumSize (InitialSize) */ &SectionSize,+      /* SectionPageProtection */+      (flags & MDBX_RDONLY) ? PAGE_READONLY : PAGE_READWRITE,+      /* AllocationAttributes */ SEC_RESERVE, map->fd);++  if (!NT_SUCCESS(status))+    goto bailout_ntstatus;++  if (ReservedAddress) {+    /* release reserved address space */+    ReservedSize = 0;+    status = NtFreeVirtualMemory(GetCurrentProcess(), &ReservedAddress,+                                 &ReservedSize, MEM_RELEASE);+    ReservedAddress = NULL;+    if (!NT_SUCCESS(status))+      goto bailout_ntstatus;+  }++retry_mapview:;+  SIZE_T ViewSize = (flags & MDBX_RDONLY) ? size : limit;+  status = NtMapViewOfSection(+      map->section, GetCurrentProcess(), &map->address,+      /* ZeroBits */ 0,+      /* CommitSize */ 0,+      /* SectionOffset */ NULL, &ViewSize,+      /* InheritDisposition */ ViewUnmap,+      /* AllocationType */ (flags & MDBX_RDONLY) ? 0 : MEM_RESERVE,+      /* Win32Protect */+      (flags & MDBX_WRITEMAP) ? PAGE_READWRITE : PAGE_READONLY);++  if (!NT_SUCCESS(status)) {+    if (status == /* STATUS_CONFLICTING_ADDRESSES */ 0xC0000018 &&+        map->address && may_move) {+      /* try remap at another base address */+      map->address = NULL;+      goto retry_mapview;+    }+    NtClose(map->section);+    map->section = NULL;++    if (map->address && (size != map->current || limit != map->limit)) {+      /* try remap with previously size and limit,+       * but will return MDBX_UNABLE_EXTEND_MAPSIZE on success */+      rc = MDBX_UNABLE_EXTEND_MAPSIZE;+      size = map->current;+      ReservedSize = limit = map->limit;+      goto retry_file_and_section;+    }++    /* no way to recovery */+    goto bailout_ntstatus;+  }+  assert(map->address != MAP_FAILED);++  map->current = (size_t)SectionSize.QuadPart;+  map->limit = ViewSize;++#else++  uint64_t filesize = 0;+  int rc = mdbx_filesize(map->fd, &filesize);+  if (rc != MDBX_SUCCESS)+    return rc;++  if (flags & MDBX_RDONLY) {+    map->current = (filesize > limit) ? limit : (size_t)filesize;+    if (map->current != size)+      rc = MDBX_UNABLE_EXTEND_MAPSIZE;+  } else if (filesize != size) {+    rc = mdbx_ftruncate(map->fd, size);+    if (rc != MDBX_SUCCESS)+      return rc;+    map->current = size;+  }++  if (limit == map->limit)+    return MDBX_SUCCESS;++  if (limit < map->limit) {+    /* unmap an excess at end of mapping. */+    if (unlikely(munmap(map->dxb + limit, map->limit - limit)))+      return errno;+    map->limit = limit;+    return MDBX_SUCCESS;+  }++  assert(limit > map->limit);+  uint8_t *ptr = MAP_FAILED;++#if defined(MREMAP_MAYMOVE)+  ptr = mremap(map->address, map->limit, limit, may_move ? MREMAP_MAYMOVE : 0);+  if (ptr == MAP_FAILED) {+    const int err = errno;+    switch (err) {+    default:+      return err;+    case EAGAIN:+    case ENOMEM:+      return MDBX_UNABLE_EXTEND_MAPSIZE;+    case EFAULT /* MADV_DODUMP / MADV_DONTDUMP are mixed for mmap-range */:+      break;+    }+  }+#endif /* MREMAP_MAYMOVE */++  const unsigned mmap_flags =+      MAP_CONCEAL | MAP_SHARED | MAP_FILE |+      (F_ISSET(flags, MDBX_UTTERLY_NOSYNC) ? MAP_NOSYNC : 0);+  const unsigned mmap_prot =+      (flags & MDBX_WRITEMAP) ? PROT_READ | PROT_WRITE : PROT_READ;++  if (ptr == MAP_FAILED) {+    /* Try to mmap additional space beyond the end of mapping. */+    ptr = mmap(map->dxb + map->limit, limit - map->limit, mmap_prot,+               mmap_flags+#if defined(MAP_FIXED_NOREPLACE)+                   | MAP_FIXED_NOREPLACE+#endif /* MAP_FIXED_NOREPLACE */+               ,+               map->fd, map->limit);+    if (ptr == map->dxb + map->limit)+      ptr = map->dxb;+    else if (ptr != MAP_FAILED) {+      /* the desired address is busy, unmap unsuitable one */+      if (unlikely(munmap(ptr, limit - map->limit)))+        return errno;+      ptr = MAP_FAILED;+    } else {+      const int err = errno;+      switch (err) {+      default:+        return err;+      case EAGAIN:+      case ENOMEM:+        return MDBX_UNABLE_EXTEND_MAPSIZE;+      case EEXIST: /* address busy */+      case EINVAL: /* kernel don't support MAP_FIXED_NOREPLACE */+        break;+      }+    }+  }++  if (ptr == MAP_FAILED) {+    /* unmap and map again whole region */+    if (!may_move) {+      /* TODO: Perhaps here it is worth to implement suspend/resume threads+       * and perform unmap/map as like for Windows. */+      return MDBX_UNABLE_EXTEND_MAPSIZE;+    }++    if (unlikely(munmap(map->address, map->limit)))+      return errno;++    ptr = mmap(map->address, limit, mmap_prot, mmap_flags, map->fd, 0);+    if (unlikely(ptr == MAP_FAILED)) {+      ptr = mmap(map->address, map->limit, mmap_prot, mmap_flags, map->fd, 0);+      if (unlikely(ptr == MAP_FAILED)) {+        VALGRIND_MAKE_MEM_NOACCESS(map->address, map->current);+        /* Unpoisoning is required for ASAN to avoid false-positive diagnostic+         * when this memory will re-used by malloc or another mmapping.+         * See https://github.com/erthink/libmdbx/pull/93#issuecomment-613687203+         */+        ASAN_UNPOISON_MEMORY_REGION(map->address, map->limit);+        map->limit = 0;+        map->current = 0;+        map->address = nullptr;+        return errno;+      }+      rc = MDBX_UNABLE_EXTEND_MAPSIZE;+      limit = map->limit;+    }+  }++  assert(ptr && ptr != MAP_FAILED);+  if (map->address != ptr) {+    VALGRIND_MAKE_MEM_NOACCESS(map->address, map->current);+    /* Unpoisoning is required for ASAN to avoid false-positive diagnostic+     * when this memory will re-used by malloc or another mmapping.+     * See https://github.com/erthink/libmdbx/pull/93#issuecomment-613687203+     */+    ASAN_UNPOISON_MEMORY_REGION(map->address, map->limit);++    VALGRIND_MAKE_MEM_DEFINED(ptr, map->current);+    ASAN_UNPOISON_MEMORY_REGION(ptr, map->current);+    map->address = ptr;+  }+  map->limit = limit;++#ifdef MADV_DONTFORK+  if (unlikely(madvise(map->address, map->limit, MADV_DONTFORK) != 0))+    return errno;+#endif /* MADV_DONTFORK */++#ifdef MADV_NOHUGEPAGE+  (void)madvise(map->address, map->limit, MADV_NOHUGEPAGE);+#endif /* MADV_NOHUGEPAGE */++#endif /* POSIX / Windows */++  return rc;+}++/*----------------------------------------------------------------------------*/++MDBX_INTERNAL_FUNC __cold void mdbx_osal_jitter(bool tiny) {+  for (;;) {+#if defined(_M_IX86) || defined(_M_X64) || defined(__i386__) ||                \+    defined(__x86_64__)+    const unsigned salt = 277u * (unsigned)__rdtsc();+#else+    const unsigned salt = rand();+#endif++    const unsigned coin = salt % (tiny ? 29u : 43u);+    if (coin < 43 / 3)+      break;+#if defined(_WIN32) || defined(_WIN64)+    SwitchToThread();+    if (coin > 43 * 2 / 3)+      Sleep(1);+#else+    sched_yield();+    if (coin > 43 * 2 / 3)+      usleep(coin);+#endif+  }+}++#if defined(_WIN32) || defined(_WIN64)+#elif defined(__APPLE__) || defined(__MACH__)+#include <mach/mach_time.h>+#elif defined(__linux__) || defined(__gnu_linux__)+static __cold clockid_t choice_monoclock(void) {+  struct timespec probe;+#if defined(CLOCK_BOOTTIME)+  if (clock_gettime(CLOCK_BOOTTIME, &probe) == 0)+    return CLOCK_BOOTTIME;+#elif defined(CLOCK_MONOTONIC_RAW)+  if (clock_gettime(CLOCK_MONOTONIC_RAW, &probe) == 0)+    return CLOCK_MONOTONIC_RAW;+#elif defined(CLOCK_MONOTONIC_COARSE)+  if (clock_gettime(CLOCK_MONOTONIC_COARSE, &probe) == 0)+    return CLOCK_MONOTONIC_COARSE;+#endif+  return CLOCK_MONOTONIC;+}+#endif++/*----------------------------------------------------------------------------*/++#if defined(_WIN32) || defined(_WIN64)+static LARGE_INTEGER performance_frequency;+#elif defined(__APPLE__) || defined(__MACH__)+static uint64_t ratio_16dot16_to_monotine;+#endif++MDBX_INTERNAL_FUNC uint64_t+mdbx_osal_16dot16_to_monotime(uint32_t seconds_16dot16) {+#if defined(_WIN32) || defined(_WIN64)+  if (unlikely(performance_frequency.QuadPart == 0))+    QueryPerformanceFrequency(&performance_frequency);+  const uint64_t ratio = performance_frequency.QuadPart;+#elif defined(__APPLE__) || defined(__MACH__)+  if (unlikely(ratio_16dot16_to_monotine == 0)) {+    mach_timebase_info_data_t ti;+    mach_timebase_info(&ti);+    ratio_16dot16_to_monotine = UINT64_C(1000000000) * ti.denom / ti.numer;+  }+  const uint64_t ratio = ratio_16dot16_to_monotine;+#else+  const uint64_t ratio = UINT64_C(1000000000);+#endif+  return (ratio * seconds_16dot16 + 32768) >> 16;+}++MDBX_INTERNAL_FUNC uint32_t mdbx_osal_monotime_to_16dot16(uint64_t monotime) {+  static uint64_t limit;+  if (unlikely(monotime > limit)) {+    if (limit != 0)+      return UINT32_MAX;+    limit = mdbx_osal_16dot16_to_monotime(UINT32_MAX - 1);+    if (monotime > limit)+      return UINT32_MAX;+  }+#if defined(_WIN32) || defined(_WIN64)+  return (uint32_t)((monotime << 16) / performance_frequency.QuadPart);+#elif defined(__APPLE__) || defined(__MACH__)+  return (uint32_t)((monotime << 16) / ratio_16dot16_to_monotine);+#else+  return (uint32_t)(monotime * 128 / 1953125);+#endif+}++MDBX_INTERNAL_FUNC uint64_t mdbx_osal_monotime(void) {+#if defined(_WIN32) || defined(_WIN64)+  LARGE_INTEGER counter;+  counter.QuadPart = 0;+  QueryPerformanceCounter(&counter);+  return counter.QuadPart;+#elif defined(__APPLE__) || defined(__MACH__)+  return mach_absolute_time();+#else++#if defined(__linux__) || defined(__gnu_linux__)+  static clockid_t posix_clockid = -1;+  if (unlikely(posix_clockid < 0))+    posix_clockid = choice_monoclock();+#elif defined(CLOCK_MONOTONIC)+#define posix_clockid CLOCK_MONOTONIC+#else+#define posix_clockid CLOCK_REALTIME+#endif++  struct timespec ts;+  if (unlikely(clock_gettime(posix_clockid, &ts) != 0)) {+    ts.tv_nsec = 0;+    ts.tv_sec = 0;+  }+  return ts.tv_sec * UINT64_C(1000000000) + ts.tv_nsec;+#endif+}++/*----------------------------------------------------------------------------*/++static void bootid_shake(bin128_t *p) {+  /* Bob Jenkins's PRNG: https://burtleburtle.net/bob/rand/smallprng.html */+  const uint32_t e = p->a - (p->b << 23 | p->b >> 9);+  p->a = p->b ^ (p->c << 16 | p->c >> 16);+  p->b = p->c + (p->d << 11 | p->d >> 21);+  p->c = p->d + e;+  p->d = e + p->a;+}++static void bootid_collect(bin128_t *p, const void *s, size_t n) {+  p->y += UINT64_C(64526882297375213);+  bootid_shake(p);+  for (size_t i = 0; i < n; ++i) {+    bootid_shake(p);+    p->y ^= UINT64_C(48797879452804441) * ((const uint8_t *)s)[i];+    bootid_shake(p);+    p->y += 14621231;+  }+  bootid_shake(p);++  /* minor non-linear tomfoolery */+  const unsigned z = p->x % 61;+  p->y = p->y << z | p->y >> (64 - z);+  bootid_shake(p);+  bootid_shake(p);+  const unsigned q = p->x % 59;+  p->y = p->y << q | p->y >> (64 - q);+  bootid_shake(p);+  bootid_shake(p);+  bootid_shake(p);+}++#if defined(_WIN32) || defined(_WIN64)++static uint64_t windows_systemtime_ms() {+  FILETIME ft;+  GetSystemTimeAsFileTime(&ft);+  return ((uint64_t)ft.dwHighDateTime << 32 | ft.dwLowDateTime) / 10000ul;+}++static uint64_t windows_bootime(void) {+  unsigned confirmed = 0;+  uint64_t boottime = 0;+  uint64_t up0 = mdbx_GetTickCount64();+  uint64_t st0 = windows_systemtime_ms();+  for (uint64_t fuse = st0; up0 && st0 < fuse + 1000 * 1000u / 42;) {+    YieldProcessor();+    const uint64_t up1 = mdbx_GetTickCount64();+    const uint64_t st1 = windows_systemtime_ms();+    if (st1 > fuse && st1 == st0 && up1 == up0) {+      uint64_t diff = st1 - up1;+      if (boottime == diff) {+        if (++confirmed > 4)+          return boottime;+      } else {+        confirmed = 0;+        boottime = diff;+      }+      fuse = st1;+      Sleep(1);+    }+    st0 = st1;+    up0 = up1;+  }+  return 0;+}++static LSTATUS mdbx_RegGetValue(HKEY hKey, LPCSTR lpSubKey, LPCSTR lpValue,+                                PVOID pvData, LPDWORD pcbData) {+  LSTATUS rc;+  if (!mdbx_RegGetValueA) {+    /* an old Windows 2000/XP */+    HKEY hSubKey;+    rc = RegOpenKeyA(hKey, lpSubKey, &hSubKey);+    if (rc == ERROR_SUCCESS) {+      rc = RegQueryValueExA(hSubKey, lpValue, NULL, NULL, pvData, pcbData);+      RegCloseKey(hSubKey);+    }+    return rc;+  }++  rc = mdbx_RegGetValueA(hKey, lpSubKey, lpValue, RRF_RT_ANY, NULL, pvData,+                         pcbData);+  if (rc != ERROR_FILE_NOT_FOUND)+    return rc;++  rc = mdbx_RegGetValueA(hKey, lpSubKey, lpValue,+                         RRF_RT_ANY | 0x00010000 /* RRF_SUBKEY_WOW6464KEY */,+                         NULL, pvData, pcbData);+  if (rc != ERROR_FILE_NOT_FOUND)+    return rc;+  return mdbx_RegGetValueA(hKey, lpSubKey, lpValue,+                           RRF_RT_ANY | 0x00020000 /* RRF_SUBKEY_WOW6432KEY */,+                           NULL, pvData, pcbData);+}+#endif++static __cold __maybe_unused bool bootid_parse_uuid(bin128_t *s, const void *p,+                                                    const size_t n) {+  if (n > 31) {+    unsigned bits = 0;+    for (unsigned i = 0; i < n; ++i) /* try parse an UUID in text form */ {+      uint8_t c = ((const uint8_t *)p)[i];+      if (c >= '0' && c <= '9')+        c -= '0';+      else if (c >= 'a' && c <= 'f')+        c -= 'a' - 10;+      else if (c >= 'A' && c <= 'F')+        c -= 'A' - 10;+      else+        continue;+      assert(c <= 15);+      c ^= s->y >> 60;+      s->y = s->y << 4 | s->x >> 60;+      s->x = s->x << 4 | c;+      bits += 4;+    }+    if (bits > 42 * 3)+      /* UUID parsed successfully */+      return true;+  }++  if (n > 15) /* is enough handle it as a binary? */ {+    if (n == sizeof(bin128_t)) {+      bin128_t aligned;+      memcpy(&aligned, p, sizeof(bin128_t));+      s->x += aligned.x;+      s->y += aligned.y;+    } else+      bootid_collect(s, p, n);+    return true;+  }++  if (n)+    bootid_collect(s, p, n);+  return false;+}++__cold MDBX_INTERNAL_FUNC bin128_t mdbx_osal_bootid(void) {+  bin128_t bin = {{0, 0}};+  bool got_machineid = false, got_boottime = false, got_bootseq = false;++#if defined(__linux__) || defined(__gnu_linux__)+  {+    const int fd =+        open("/proc/sys/kernel/random/boot_id", O_RDONLY | O_NOFOLLOW);+    if (fd != -1) {+      struct statfs fs;+      char buf[42];+      const ssize_t len =+          (fstatfs(fd, &fs) == 0 && fs.f_type == /* procfs */ 0x9FA0)+              ? read(fd, buf, sizeof(buf))+              : -1;+      const int err = close(fd);+      assert(err == 0);+      (void)err;+      if (len > 0 && bootid_parse_uuid(&bin, buf, len))+        return bin;+    }+  }+#endif /* Linux */++#if defined(__APPLE__) || defined(__MACH__)+  {+    char buf[42];+    size_t len = sizeof(buf);+    if (!sysctlbyname("kern.bootsessionuuid", buf, &len, nullptr, 0) &&+        bootid_parse_uuid(&bin, buf, len))+      return bin;++#if defined(__MAC_OS_X_VERSION_MIN_REQUIRED) &&                                \+    __MAC_OS_X_VERSION_MIN_REQUIRED > 1050+    uuid_t uuid;+    struct timespec wait = {0, 1000000000u / 42};+    if (!gethostuuid(uuid, &wait) &&+        bootid_parse_uuid(&bin, uuid, sizeof(uuid)))+      got_machineid = true;+#endif /* > 10.5 */++    struct timeval boottime;+    len = sizeof(boottime);+    if (!sysctlbyname("kern.boottime", &boottime, &len, nullptr, 0) &&+        len == sizeof(boottime) && boottime.tv_sec)+      got_boottime = true;+  }+#endif /* Apple/Darwin */++#if defined(_WIN32) || defined(_WIN64)+  {+    union buf {+      DWORD BootId;+      DWORD BaseTime;+      SYSTEM_TIMEOFDAY_INFORMATION SysTimeOfDayInfo;+      struct {+        LARGE_INTEGER BootTime;+        LARGE_INTEGER CurrentTime;+        LARGE_INTEGER TimeZoneBias;+        ULONG TimeZoneId;+        ULONG Reserved;+        ULONGLONG BootTimeBias;+        ULONGLONG SleepTimeBias;+      } SysTimeOfDayInfoHacked;+      wchar_t MachineGuid[42];+      char DigitalProductId[248];+    } buf;++    static const char HKLM_MicrosoftCryptography[] =+        "SOFTWARE\\Microsoft\\Cryptography";+    DWORD len = sizeof(buf);+    /* Windows is madness and must die */+    if (mdbx_RegGetValue(HKEY_LOCAL_MACHINE, HKLM_MicrosoftCryptography,+                         "MachineGuid", &buf.MachineGuid,+                         &len) == ERROR_SUCCESS &&+        len > 42 && len < sizeof(buf))+      got_machineid = bootid_parse_uuid(&bin, &buf.MachineGuid, len);++    if (!got_machineid) {+      /* again, Windows is madness */+      static const char HKLM_WindowsNT[] =+          "SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion";+      static const char HKLM_WindowsNT_DPK[] =+          "SOFTWARE\\Microsoft\\Windows "+          "NT\\CurrentVersion\\DefaultProductKey";+      static const char HKLM_WindowsNT_DPK2[] =+          "SOFTWARE\\Microsoft\\Windows "+          "NT\\CurrentVersion\\DefaultProductKey2";++      len = sizeof(buf);+      if (mdbx_RegGetValue(HKEY_LOCAL_MACHINE, HKLM_WindowsNT,+                           "DigitalProductId", &buf.DigitalProductId,+                           &len) == ERROR_SUCCESS &&+          len > 42 && len < sizeof(buf)) {+        bootid_collect(&bin, &buf.DigitalProductId, len);+        got_machineid = true;+      }+      len = sizeof(buf);+      if (mdbx_RegGetValue(HKEY_LOCAL_MACHINE, HKLM_WindowsNT_DPK,+                           "DigitalProductId", &buf.DigitalProductId,+                           &len) == ERROR_SUCCESS &&+          len > 42 && len < sizeof(buf)) {+        bootid_collect(&bin, &buf.DigitalProductId, len);+        got_machineid = true;+      }+      len = sizeof(buf);+      if (mdbx_RegGetValue(HKEY_LOCAL_MACHINE, HKLM_WindowsNT_DPK2,+                           "DigitalProductId", &buf.DigitalProductId,+                           &len) == ERROR_SUCCESS &&+          len > 42 && len < sizeof(buf)) {+        bootid_collect(&bin, &buf.DigitalProductId, len);+        got_machineid = true;+      }+    }++    static const char HKLM_PrefetcherParams[] =+        "SYSTEM\\CurrentControlSet\\Control\\Session Manager\\Memory "+        "Management\\PrefetchParameters";+    len = sizeof(buf);+    if (mdbx_RegGetValue(HKEY_LOCAL_MACHINE, HKLM_PrefetcherParams, "BootId",+                         &buf.BootId, &len) == ERROR_SUCCESS &&+        len > 1 && len < sizeof(buf)) {+      bootid_collect(&bin, &buf.BootId, len);+      got_bootseq = true;+    }++    len = sizeof(buf);+    if (mdbx_RegGetValue(HKEY_LOCAL_MACHINE, HKLM_PrefetcherParams, "BaseTime",+                         &buf.BaseTime, &len) == ERROR_SUCCESS &&+        len >= sizeof(buf.BaseTime) && buf.BaseTime) {+      bootid_collect(&bin, &buf.BaseTime, len);+      got_boottime = true;+    }++    /* BootTime from SYSTEM_TIMEOFDAY_INFORMATION */+    NTSTATUS status = NtQuerySystemInformation(+        0x03 /* SystemTmeOfDayInformation */, &buf.SysTimeOfDayInfo,+        sizeof(buf.SysTimeOfDayInfo), &len);+    if (NT_SUCCESS(status) &&+        len >= offsetof(union buf, SysTimeOfDayInfoHacked.BootTime) ++                   sizeof(buf.SysTimeOfDayInfoHacked.BootTime) &&+        buf.SysTimeOfDayInfoHacked.BootTime.QuadPart) {+      bootid_collect(&bin, &buf.SysTimeOfDayInfoHacked.BootTime,+                     sizeof(buf.SysTimeOfDayInfoHacked.BootTime));+      got_boottime = true;+    }++    if (!got_boottime) {+      uint64_t boottime = windows_bootime();+      if (boottime) {+        bootid_collect(&bin, &boottime, sizeof(boottime));+        got_boottime = true;+      }+    }+  }+#endif /* Windows */++#if defined(CTL_HW) && defined(HW_UUID)+  if (!got_machineid) {+    static const int mib[] = {CTL_HW, HW_UUID};+    char buf[42];+    size_t len = sizeof(buf);+    if (sysctl(+#ifdef SYSCTL_LEGACY_NONCONST_MIB+            (int *)+#endif+                mib,+            ARRAY_LENGTH(mib), &buf, &len, NULL, 0) == 0)+      got_machineid = bootid_parse_uuid(&bin, buf, len);+  }+#endif /* CTL_HW && HW_UUID */++#if defined(CTL_KERN) && defined(KERN_HOSTUUID)+  if (!got_machineid) {+    static const int mib[] = {CTL_KERN, KERN_HOSTUUID};+    char buf[42];+    size_t len = sizeof(buf);+    if (sysctl(+#ifdef SYSCTL_LEGACY_NONCONST_MIB+            (int *)+#endif+                mib,+            ARRAY_LENGTH(mib), &buf, &len, NULL, 0) == 0)+      got_machineid = bootid_parse_uuid(&bin, buf, len);+  }+#endif /* CTL_KERN && KERN_HOSTUUID */++#if defined(__NetBSD__)+  if (!got_machineid) {+    char buf[42];+    size_t len = sizeof(buf);+    if (sysctlbyname("machdep.dmi.system-uuid", buf, &len, NULL, 0) == 0)+      got_machineid = bootid_parse_uuid(&bin, buf, len);+  }+#endif /* __NetBSD__ */++#if _XOPEN_SOURCE_EXTENDED+  if (!got_machineid) {+    const int hostid = gethostid();+    if (hostid > 0) {+      bootid_collect(&bin, &hostid, sizeof(hostid));+      got_machineid = true;+    }+  }+#endif /* _XOPEN_SOURCE_EXTENDED */++  if (!got_machineid) {+  lack:+    bin.x = bin.y = 0;+    return bin;+  }++  /*--------------------------------------------------------------------------*/++#if defined(CTL_KERN) && defined(KERN_BOOTTIME)+  if (!got_boottime) {+    static const int mib[] = {CTL_KERN, KERN_BOOTTIME};+    struct timeval boottime;+    size_t len = sizeof(boottime);+    if (sysctl(+#ifdef SYSCTL_LEGACY_NONCONST_MIB+            (int *)+#endif+                mib,+            ARRAY_LENGTH(mib), &boottime, &len, NULL, 0) == 0 &&+        len == sizeof(boottime) && boottime.tv_sec) {+      bootid_collect(&bin, &boottime, len);+      got_boottime = true;+    }+  }+#endif /* CTL_KERN && KERN_BOOTTIME */++#if defined(__sun) || defined(__SVR4) || defined(__svr4__)+  if (!got_boottime) {+    kstat_ctl_t *kc = kstat_open();+    if (kc) {+      kstat_t *kp = kstat_lookup(kc, "unix", 0, "system_misc");+      if (kp && kstat_read(kc, kp, 0) != -1) {+        kstat_named_t *kn = (kstat_named_t *)kstat_data_lookup(kp, "boot_time");+        if (kn) {+          switch (kn->data_type) {+          case KSTAT_DATA_INT32:+          case KSTAT_DATA_UINT32:+            bootid_collect(&bin, &kn->value, sizeof(int32_t));+            got_boottime = true;+          case KSTAT_DATA_INT64:+          case KSTAT_DATA_UINT64:+            bootid_collect(&bin, &kn->value, sizeof(int64_t));+            got_boottime = true;+          }+        }+      }+      kstat_close(kc);+    }+  }+#endif /* SunOS / Solaris */++#if _XOPEN_SOURCE_EXTENDED && defined(BOOT_TIME)+  if (!got_boottime) {+    setutxent();+    const struct utmpx id = {.ut_type = BOOT_TIME};+    const struct utmpx *entry = getutxid(&id);+    if (entry) {+      bootid_collect(&bin, entry, sizeof(*entry));+      got_boottime = true;+      while (unlikely((entry = getutxid(&id)) != nullptr)) {+        /* have multiple reboot records, assuming we can distinguish next+         * bootsession even if RTC is wrong or absent */+        bootid_collect(&bin, entry, sizeof(*entry));+        got_bootseq = true;+      }+    }+    endutxent();+  }+#endif /* _XOPEN_SOURCE_EXTENDED && BOOT_TIME */++  if (!got_bootseq) {+    if (!got_boottime || !MDBX_TRUST_RTC)+      goto lack;++#if defined(_WIN32) || defined(_WIN64)+    FILETIME now;+    GetSystemTimeAsFileTime(&now);+    if (0x1CCCCCC > now.dwHighDateTime)+#else+    struct timespec mono, real;+    if (clock_gettime(CLOCK_MONOTONIC, &mono) ||+        clock_gettime(CLOCK_REALTIME, &real) ||+        /* wrong time, RTC is mad or absent */+        1555555555l > real.tv_sec ||+        /* seems no adjustment by RTC/NTP, i.e. a fake time */+        real.tv_sec < mono.tv_sec || 1234567890l > real.tv_sec - mono.tv_sec ||+        (real.tv_sec - mono.tv_sec) % 900u == 0)+#endif+      goto lack;+  }++  return bin;+}+/* This is CMake-template for libmdbx's version.c+ ******************************************************************************/+++#if MDBX_VERSION_MAJOR != 0 ||                             \+    MDBX_VERSION_MINOR != 9+#error "API version mismatch! Had `git fetch --tags` done?"+#endif++static const char sourcery[] = STRINGIFY(MDBX_BUILD_SOURCERY);++__dll_export+#ifdef __attribute_used__+    __attribute_used__+#elif defined(__GNUC__) || __has_attribute(__used__)+    __attribute__((__used__))+#endif+#ifdef __attribute_externally_visible__+        __attribute_externally_visible__+#elif (defined(__GNUC__) && !defined(__clang__)) ||                            \+    __has_attribute(__externally_visible__)+    __attribute__((__externally_visible__))+#endif+    const struct MDBX_version_info mdbx_version = {+        0,+        9,+        3,+        44,+        {"2021-03-15T03:36:51+03:00", "a21683ceb45327600291f68b32878035e3d432ba", "0e0682ff7ada5d96fdcaa405ab58d90358e2c661",+         "v0.9.3-44-g0e0682f"},+        sourcery};++__dll_export+#ifdef __attribute_used__+    __attribute_used__+#elif defined(__GNUC__) || __has_attribute(__used__)+    __attribute__((__used__))+#endif+#ifdef __attribute_externally_visible__+        __attribute_externally_visible__+#elif (defined(__GNUC__) && !defined(__clang__)) ||                            \+    __has_attribute(__externally_visible__)+    __attribute__((__externally_visible__))+#endif+    const char *const mdbx_sourcery_anchor = sourcery;+/*+ * Copyright 2015-2021 Leonid Yuriev <leo@yuriev.ru>+ * and other libmdbx authors: please see AUTHORS file.+ * All rights reserved.+ *+ * Redistribution and use in source and binary forms, with or without+ * modification, are permitted only as authorized by the OpenLDAP+ * Public License.+ *+ * A copy of this license is available in the file LICENSE in the+ * top-level directory of the distribution or, alternatively, at+ * <http://www.OpenLDAP.org/license.html>.+ */++#if defined(_WIN32) || defined(_WIN64) /* Windows LCK-implementation */++/* PREAMBLE FOR WINDOWS:+ *+ * We are not concerned for performance here.+ * If you are running Windows a performance could NOT be the goal.+ * Otherwise please use Linux. */+++static void mdbx_winnt_import(void);++#if MDBX_BUILD_SHARED_LIBRARY+#if MDBX_AVOID_CRT && defined(NDEBUG)+/* DEBUG/CHECKED builds still require MSVC's CRT for runtime checks.+ *+ * Define dll's entry point only for Release build when NDEBUG is defined and+ * MDBX_AVOID_CRT=ON. if the entry point isn't defined then MSVC's will+ * automatically use DllMainCRTStartup() from CRT library, which also+ * automatically call DllMain() from our mdbx.dll */+#pragma comment(linker, "/ENTRY:DllMain")+#endif /* MDBX_AVOID_CRT */++BOOL APIENTRY DllMain(HANDLE module, DWORD reason, LPVOID reserved)+#else+#if !MDBX_CONFIG_MANUAL_TLS_CALLBACK+static+#endif /* !MDBX_CONFIG_MANUAL_TLS_CALLBACK */+    void NTAPI+    mdbx_dll_handler(PVOID module, DWORD reason, PVOID reserved)+#endif /* MDBX_BUILD_SHARED_LIBRARY */+{+  (void)reserved;+  switch (reason) {+  case DLL_PROCESS_ATTACH:+    mdbx_winnt_import();+    mdbx_rthc_global_init();+    break;+  case DLL_PROCESS_DETACH:+    mdbx_rthc_global_dtor();+    break;++  case DLL_THREAD_ATTACH:+    break;+  case DLL_THREAD_DETACH:+    mdbx_rthc_thread_dtor(module);+    break;+  }+#if MDBX_BUILD_SHARED_LIBRARY+  return TRUE;+#endif+}++#if !MDBX_BUILD_SHARED_LIBRARY && !MDBX_CONFIG_MANUAL_TLS_CALLBACK+/* *INDENT-OFF* */+/* clang-format off */+#if defined(_MSC_VER)+#  pragma const_seg(push)+#  pragma data_seg(push)++#  ifdef _WIN64+     /* kick a linker to create the TLS directory if not already done */+#    pragma comment(linker, "/INCLUDE:_tls_used")+     /* Force some symbol references. */+#    pragma comment(linker, "/INCLUDE:mdbx_tls_anchor")+     /* specific const-segment for WIN64 */+#    pragma const_seg(".CRT$XLB")+     const+#  else+     /* kick a linker to create the TLS directory if not already done */+#    pragma comment(linker, "/INCLUDE:__tls_used")+     /* Force some symbol references. */+#    pragma comment(linker, "/INCLUDE:_mdbx_tls_anchor")+     /* specific data-segment for WIN32 */+#    pragma data_seg(".CRT$XLB")+#  endif++   __declspec(allocate(".CRT$XLB")) PIMAGE_TLS_CALLBACK mdbx_tls_anchor = mdbx_dll_handler;+#  pragma data_seg(pop)+#  pragma const_seg(pop)++#elif defined(__GNUC__)+#  ifdef _WIN64+     const+#  endif+   PIMAGE_TLS_CALLBACK mdbx_tls_anchor __attribute__((__section__(".CRT$XLB"), used)) = mdbx_dll_handler;+#else+#  error FIXME+#endif+/* *INDENT-ON* */+/* clang-format on */+#endif /* !MDBX_BUILD_SHARED_LIBRARY && !MDBX_CONFIG_MANUAL_TLS_CALLBACK */++/*----------------------------------------------------------------------------*/++#define LCK_SHARED 0+#define LCK_EXCLUSIVE LOCKFILE_EXCLUSIVE_LOCK+#define LCK_WAITFOR 0+#define LCK_DONTWAIT LOCKFILE_FAIL_IMMEDIATELY++static __inline BOOL flock(mdbx_filehandle_t fd, DWORD flags, uint64_t offset,+                           size_t bytes) {+  OVERLAPPED ov;+  ov.hEvent = 0;+  ov.Offset = (DWORD)offset;+  ov.OffsetHigh = HIGH_DWORD(offset);+  return LockFileEx(fd, flags, 0, (DWORD)bytes, HIGH_DWORD(bytes), &ov);+}++static __inline BOOL funlock(mdbx_filehandle_t fd, uint64_t offset,+                             size_t bytes) {+  return UnlockFile(fd, (DWORD)offset, HIGH_DWORD(offset), (DWORD)bytes,+                    HIGH_DWORD(bytes));+}++/*----------------------------------------------------------------------------*/+/* global `write` lock for write-txt processing,+ * exclusive locking both meta-pages) */++#define LCK_MAXLEN (1u + (size_t)(MAXSSIZE_T))+#define LCK_META_OFFSET 0+#define LCK_META_LEN (MAX_PAGESIZE * NUM_METAS)+#define LCK_BODY_OFFSET LCK_META_LEN+#define LCK_BODY_LEN (LCK_MAXLEN - LCK_BODY_OFFSET)+#define LCK_BODY LCK_BODY_OFFSET, LCK_BODY_LEN+#define LCK_WHOLE 0, LCK_MAXLEN++int mdbx_txn_lock(MDBX_env *env, bool dontwait) {+  if (dontwait) {+    if (!TryEnterCriticalSection(&env->me_windowsbug_lock))+      return MDBX_BUSY;+  } else {+    __try {+      EnterCriticalSection(&env->me_windowsbug_lock);+    }+    __except ((GetExceptionCode() ==+                 0xC0000194 /* STATUS_POSSIBLE_DEADLOCK / EXCEPTION_POSSIBLE_DEADLOCK */)+                    ? EXCEPTION_EXECUTE_HANDLER+                    : EXCEPTION_CONTINUE_SEARCH) {+      return ERROR_POSSIBLE_DEADLOCK;+    }+  }++  if ((env->me_flags & MDBX_EXCLUSIVE) ||+      flock(env->me_lazy_fd,+            dontwait ? (LCK_EXCLUSIVE | LCK_DONTWAIT)+                     : (LCK_EXCLUSIVE | LCK_WAITFOR),+            LCK_BODY))+    return MDBX_SUCCESS;+  int rc = GetLastError();+  LeaveCriticalSection(&env->me_windowsbug_lock);+  return (!dontwait || rc != ERROR_LOCK_VIOLATION) ? rc : MDBX_BUSY;+}++void mdbx_txn_unlock(MDBX_env *env) {+  int rc = (env->me_flags & MDBX_EXCLUSIVE)+               ? TRUE+               : funlock(env->me_lazy_fd, LCK_BODY);+  LeaveCriticalSection(&env->me_windowsbug_lock);+  if (!rc)+    mdbx_panic("%s failed: err %u", __func__, GetLastError());+}++/*----------------------------------------------------------------------------*/+/* global `read` lock for readers registration,+ * exclusive locking `mti_numreaders` (second) cacheline */++#define LCK_LO_OFFSET 0+#define LCK_LO_LEN offsetof(MDBX_lockinfo, mti_numreaders)+#define LCK_UP_OFFSET LCK_LO_LEN+#define LCK_UP_LEN (sizeof(MDBX_lockinfo) - LCK_UP_OFFSET)+#define LCK_LOWER LCK_LO_OFFSET, LCK_LO_LEN+#define LCK_UPPER LCK_UP_OFFSET, LCK_UP_LEN++MDBX_INTERNAL_FUNC int mdbx_rdt_lock(MDBX_env *env) {+  mdbx_srwlock_AcquireShared(&env->me_remap_guard);+  if (env->me_lfd == INVALID_HANDLE_VALUE)+    return MDBX_SUCCESS; /* readonly database in readonly filesystem */++  /* transition from S-? (used) to S-E (locked),+   * e.g. exclusive lock upper-part */+  if ((env->me_flags & MDBX_EXCLUSIVE) ||+      flock(env->me_lfd, LCK_EXCLUSIVE | LCK_WAITFOR, LCK_UPPER))+    return MDBX_SUCCESS;++  int rc = GetLastError();+  mdbx_srwlock_ReleaseShared(&env->me_remap_guard);+  return rc;+}++MDBX_INTERNAL_FUNC void mdbx_rdt_unlock(MDBX_env *env) {+  if (env->me_lfd != INVALID_HANDLE_VALUE) {+    /* transition from S-E (locked) to S-? (used), e.g. unlock upper-part */+    if ((env->me_flags & MDBX_EXCLUSIVE) == 0 &&+        !funlock(env->me_lfd, LCK_UPPER))+      mdbx_panic("%s failed: err %u", __func__, GetLastError());+  }+  mdbx_srwlock_ReleaseShared(&env->me_remap_guard);+}++MDBX_INTERNAL_FUNC int mdbx_lockfile(mdbx_filehandle_t fd, bool wait) {+  return flock(fd,+               wait ? LCK_EXCLUSIVE | LCK_WAITFOR+                    : LCK_EXCLUSIVE | LCK_DONTWAIT,+               0, LCK_MAXLEN)+             ? MDBX_SUCCESS+             : GetLastError();+}++static int suspend_and_append(mdbx_handle_array_t **array,+                              const DWORD ThreadId) {+  const unsigned limit = (*array)->limit;+  if ((*array)->count == limit) {+    void *ptr = mdbx_realloc(+        (limit > ARRAY_LENGTH((*array)->handles))+            ? *array+            : /* don't free initial array on the stack */ NULL,+        sizeof(mdbx_handle_array_t) ++            sizeof(HANDLE) * (limit * 2 - ARRAY_LENGTH((*array)->handles)));+    if (!ptr)+      return MDBX_ENOMEM;+    if (limit == ARRAY_LENGTH((*array)->handles))+      memcpy(ptr, *array, sizeof(mdbx_handle_array_t));+    *array = (mdbx_handle_array_t *)ptr;+    (*array)->limit = limit * 2;+  }++  HANDLE hThread = OpenThread(THREAD_SUSPEND_RESUME | THREAD_QUERY_INFORMATION,+                              FALSE, ThreadId);+  if (hThread == NULL)+    return GetLastError();++  if (SuspendThread(hThread) == -1) {+    int err = GetLastError();+    DWORD ExitCode;+    if (err == /* workaround for Win10 UCRT bug */ ERROR_ACCESS_DENIED ||+        !GetExitCodeThread(hThread, &ExitCode) || ExitCode != STILL_ACTIVE)+      err = MDBX_SUCCESS;+    CloseHandle(hThread);+    return err;+  }++  (*array)->handles[(*array)->count++] = hThread;+  return MDBX_SUCCESS;+}++MDBX_INTERNAL_FUNC int+mdbx_suspend_threads_before_remap(MDBX_env *env, mdbx_handle_array_t **array) {+  const uintptr_t CurrentTid = GetCurrentThreadId();+  int rc;+  if (env->me_lck) {+    /* Scan LCK for threads of the current process */+    const MDBX_reader *const begin = env->me_lck->mti_readers;+    const MDBX_reader *const end =+        begin + atomic_load32(&env->me_lck->mti_numreaders, mo_AcquireRelease);+    const uintptr_t WriteTxnOwner = env->me_txn0 ? env->me_txn0->mt_owner : 0;+    for (const MDBX_reader *reader = begin; reader < end; ++reader) {+      if (reader->mr_pid.weak != env->me_pid || !reader->mr_tid.weak) {+      skip_lck:+        continue;+      }+      if (reader->mr_tid.weak == CurrentTid ||+          reader->mr_tid.weak == WriteTxnOwner)+        goto skip_lck;+      if (env->me_flags & MDBX_NOTLS) {+        /* Skip duplicates in no-tls mode */+        for (const MDBX_reader *scan = reader; --scan >= begin;)+          if (scan->mr_tid.weak == reader->mr_tid.weak)+            goto skip_lck;+      }++      rc = suspend_and_append(array, (mdbx_tid_t)reader->mr_tid.weak);+      if (rc != MDBX_SUCCESS) {+      bailout_lck:+        (void)mdbx_resume_threads_after_remap(*array);+        return rc;+      }+    }+    if (WriteTxnOwner && WriteTxnOwner != CurrentTid) {+      rc = suspend_and_append(array, (mdbx_tid_t)WriteTxnOwner);+      if (rc != MDBX_SUCCESS)+        goto bailout_lck;+    }+  } else {+    /* Without LCK (i.e. read-only mode).+     * Walk through a snapshot of all running threads */+    mdbx_assert(env,+                env->me_txn0 == NULL || (env->me_flags & MDBX_EXCLUSIVE) != 0);+    const HANDLE hSnapshot = CreateToolhelp32Snapshot(TH32CS_SNAPTHREAD, 0);+    if (hSnapshot == INVALID_HANDLE_VALUE)+      return GetLastError();++    THREADENTRY32 entry;+    entry.dwSize = sizeof(THREADENTRY32);++    if (!Thread32First(hSnapshot, &entry)) {+      rc = GetLastError();+    bailout_toolhelp:+      CloseHandle(hSnapshot);+      (void)mdbx_resume_threads_after_remap(*array);+      return rc;+    }++    do {+      if (entry.th32OwnerProcessID != env->me_pid ||+          entry.th32ThreadID == CurrentTid)+        continue;++      rc = suspend_and_append(array, entry.th32ThreadID);+      if (rc != MDBX_SUCCESS)+        goto bailout_toolhelp;++    } while (Thread32Next(hSnapshot, &entry));++    rc = GetLastError();+    if (rc != ERROR_NO_MORE_FILES)+      goto bailout_toolhelp;+    CloseHandle(hSnapshot);+  }++  return MDBX_SUCCESS;+}++MDBX_INTERNAL_FUNC int+mdbx_resume_threads_after_remap(mdbx_handle_array_t *array) {+  int rc = MDBX_SUCCESS;+  for (unsigned i = 0; i < array->count; ++i) {+    const HANDLE hThread = array->handles[i];+    if (ResumeThread(hThread) == -1) {+      const int err = GetLastError();+      DWORD ExitCode;+      if (err != /* workaround for Win10 UCRT bug */ ERROR_ACCESS_DENIED &&+          GetExitCodeThread(hThread, &ExitCode) && ExitCode == STILL_ACTIVE)+        rc = err;+    }+    CloseHandle(hThread);+  }+  return rc;+}++/*----------------------------------------------------------------------------*/+/* global `initial` lock for lockfile initialization,+ * exclusive/shared locking first cacheline */++/* Briefly description of locking schema/algorithm:+ *  - Windows does not support upgrading or downgrading for file locking.+ *  - Therefore upgrading/downgrading is emulated by shared and exclusive+ *    locking of upper and lower halves.+ *  - In other words, we have FSM with possible 9 states,+ *    i.e. free/shared/exclusive x free/shared/exclusive == 9.+ *    Only 6 states of FSM are used, which 2 of ones are transitive.+ *+ * States:+ *   ?-?  = free, i.e. unlocked+ *   S-?  = used, i.e. shared lock+ *   E-?  = exclusive-read, i.e. operational exclusive+ *   ?-S+ *   ?-E  = middle (transitive state)+ *   S-S+ *   S-E  = locked (transitive state)+ *   E-S+ *   E-E  = exclusive-write, i.e. exclusive due (re)initialization+ *+ *  The mdbx_lck_seize() moves the locking-FSM from the initial free/unlocked+ *  state to the "exclusive write" (and returns MDBX_RESULT_TRUE) if possible,+ *  or to the "used" (and returns MDBX_RESULT_FALSE).+ *+ *  The mdbx_lck_downgrade() moves the locking-FSM from "exclusive write"+ *  state to the "used" (i.e. shared) state.+ *+ *  The mdbx_lck_upgrade() moves the locking-FSM from "used" (i.e. shared)+ *  state to the "exclusive write" state.+ */++static void lck_unlock(MDBX_env *env) {+  int err;++  if (env->me_lfd != INVALID_HANDLE_VALUE) {+    /* double `unlock` for robustly remove overlapped shared/exclusive locks */+    while (funlock(env->me_lfd, LCK_LOWER))+      ;+    err = GetLastError();+    assert(err == ERROR_NOT_LOCKED ||+           (mdbx_RunningUnderWine() && err == ERROR_LOCK_VIOLATION));+    (void)err;+    SetLastError(ERROR_SUCCESS);++    while (funlock(env->me_lfd, LCK_UPPER))+      ;+    err = GetLastError();+    assert(err == ERROR_NOT_LOCKED ||+           (mdbx_RunningUnderWine() && err == ERROR_LOCK_VIOLATION));+    (void)err;+    SetLastError(ERROR_SUCCESS);+  }++  if (env->me_lazy_fd != INVALID_HANDLE_VALUE) {+    /* explicitly unlock to avoid latency for other processes (windows kernel+     * releases such locks via deferred queues) */+    while (funlock(env->me_lazy_fd, LCK_BODY))+      ;+    err = GetLastError();+    assert(err == ERROR_NOT_LOCKED ||+           (mdbx_RunningUnderWine() && err == ERROR_LOCK_VIOLATION));+    (void)err;+    SetLastError(ERROR_SUCCESS);++    while (funlock(env->me_lazy_fd, LCK_WHOLE))+      ;+    err = GetLastError();+    assert(err == ERROR_NOT_LOCKED ||+           (mdbx_RunningUnderWine() && err == ERROR_LOCK_VIOLATION));+    (void)err;+    SetLastError(ERROR_SUCCESS);+  }+}++/* Seize state as 'exclusive-write' (E-E and returns MDBX_RESULT_TRUE)+ * or as 'used' (S-? and returns MDBX_RESULT_FALSE).+ * Otherwise returns an error. */+static int internal_seize_lck(HANDLE lfd) {+  int rc;+  assert(lfd != INVALID_HANDLE_VALUE);++  /* 1) now on ?-? (free), get ?-E (middle) */+  mdbx_jitter4testing(false);+  if (!flock(lfd, LCK_EXCLUSIVE | LCK_WAITFOR, LCK_UPPER)) {+    rc = GetLastError() /* 2) something went wrong, give up */;+    mdbx_error("%s, err %u", "?-?(free) >> ?-E(middle)", rc);+    return rc;+  }++  /* 3) now on ?-E (middle), try E-E (exclusive-write) */+  mdbx_jitter4testing(false);+  if (flock(lfd, LCK_EXCLUSIVE | LCK_DONTWAIT, LCK_LOWER))+    return MDBX_RESULT_TRUE /* 4) got E-E (exclusive-write), done */;++  /* 5) still on ?-E (middle) */+  rc = GetLastError();+  mdbx_jitter4testing(false);+  if (rc != ERROR_SHARING_VIOLATION && rc != ERROR_LOCK_VIOLATION) {+    /* 6) something went wrong, give up */+    if (!funlock(lfd, LCK_UPPER))+      mdbx_panic("%s(%s) failed: err %u", __func__, "?-E(middle) >> ?-?(free)",+                 GetLastError());+    return rc;+  }++  /* 7) still on ?-E (middle), try S-E (locked) */+  mdbx_jitter4testing(false);+  rc = flock(lfd, LCK_SHARED | LCK_DONTWAIT, LCK_LOWER) ? MDBX_RESULT_FALSE+                                                        : GetLastError();++  mdbx_jitter4testing(false);+  if (rc != MDBX_RESULT_FALSE)+    mdbx_error("%s, err %u", "?-E(middle) >> S-E(locked)", rc);++  /* 8) now on S-E (locked) or still on ?-E (middle),+   *    transition to S-? (used) or ?-? (free) */+  if (!funlock(lfd, LCK_UPPER))+    mdbx_panic("%s(%s) failed: err %u", __func__,+               "X-E(locked/middle) >> X-?(used/free)", GetLastError());++  /* 9) now on S-? (used, DONE) or ?-? (free, FAILURE) */+  return rc;+}++MDBX_INTERNAL_FUNC int mdbx_lck_seize(MDBX_env *env) {+  int rc;++  assert(env->me_lazy_fd != INVALID_HANDLE_VALUE);+  if (env->me_flags & MDBX_EXCLUSIVE)+    return MDBX_RESULT_TRUE /* nope since files were must be opened+                               non-shareable */+        ;++  if (env->me_lfd == INVALID_HANDLE_VALUE) {+    /* LY: without-lck mode (e.g. on read-only filesystem) */+    mdbx_jitter4testing(false);+    if (!flock(env->me_lazy_fd, LCK_SHARED | LCK_DONTWAIT, LCK_WHOLE)) {+      rc = GetLastError();+      mdbx_error("%s, err %u", "without-lck", rc);+      return rc;+    }+    return MDBX_RESULT_FALSE;+  }++  rc = internal_seize_lck(env->me_lfd);+  mdbx_jitter4testing(false);+  if (rc == MDBX_RESULT_TRUE && (env->me_flags & MDBX_RDONLY) == 0) {+    /* Check that another process don't operates in without-lck mode.+     * Doing such check by exclusive locking the body-part of db. Should be+     * noted:+     *  - we need an exclusive lock for do so;+     *  - we can't lock meta-pages, otherwise other process could get an error+     *    while opening db in valid (non-conflict) mode. */+    if (!flock(env->me_lazy_fd, LCK_EXCLUSIVE | LCK_DONTWAIT, LCK_BODY)) {+      rc = GetLastError();+      mdbx_error("%s, err %u", "lock-against-without-lck", rc);+      mdbx_jitter4testing(false);+      lck_unlock(env);+    } else {+      mdbx_jitter4testing(false);+      if (!funlock(env->me_lazy_fd, LCK_BODY))+        mdbx_panic("%s(%s) failed: err %u", __func__,+                   "unlock-against-without-lck", GetLastError());+    }+  }++  return rc;+}++MDBX_INTERNAL_FUNC int mdbx_lck_downgrade(MDBX_env *env) {+  /* Transite from exclusive-write state (E-E) to used (S-?) */+  assert(env->me_lazy_fd != INVALID_HANDLE_VALUE);+  assert(env->me_lfd != INVALID_HANDLE_VALUE);++  if (env->me_flags & MDBX_EXCLUSIVE)+    return MDBX_SUCCESS /* nope since files were must be opened non-shareable */+        ;+  /* 1) now at E-E (exclusive-write), transition to ?_E (middle) */+  if (!funlock(env->me_lfd, LCK_LOWER))+    mdbx_panic("%s(%s) failed: err %u", __func__,+               "E-E(exclusive-write) >> ?-E(middle)", GetLastError());++  /* 2) now at ?-E (middle), transition to S-E (locked) */+  if (!flock(env->me_lfd, LCK_SHARED | LCK_DONTWAIT, LCK_LOWER)) {+    int rc = GetLastError() /* 3) something went wrong, give up */;+    mdbx_error("%s, err %u", "?-E(middle) >> S-E(locked)", rc);+    return rc;+  }++  /* 4) got S-E (locked), continue transition to S-? (used) */+  if (!funlock(env->me_lfd, LCK_UPPER))+    mdbx_panic("%s(%s) failed: err %u", __func__, "S-E(locked) >> S-?(used)",+               GetLastError());++  return MDBX_SUCCESS /* 5) now at S-? (used), done */;+}++MDBX_INTERNAL_FUNC int mdbx_lck_upgrade(MDBX_env *env) {+  /* Transite from used state (S-?) to exclusive-write (E-E) */+  assert(env->me_lfd != INVALID_HANDLE_VALUE);++  if (env->me_flags & MDBX_EXCLUSIVE)+    return MDBX_SUCCESS /* nope since files were must be opened non-shareable */+        ;++  int rc;+  /* 1) now on S-? (used), try S-E (locked) */+  mdbx_jitter4testing(false);+  if (!flock(env->me_lfd, LCK_EXCLUSIVE | LCK_DONTWAIT, LCK_UPPER)) {+    rc = GetLastError() /* 2) something went wrong, give up */;+    mdbx_verbose("%s, err %u", "S-?(used) >> S-E(locked)", rc);+    return rc;+  }++  /* 3) now on S-E (locked), transition to ?-E (middle) */+  if (!funlock(env->me_lfd, LCK_LOWER))+    mdbx_panic("%s(%s) failed: err %u", __func__, "S-E(locked) >> ?-E(middle)",+               GetLastError());++  /* 4) now on ?-E (middle), try E-E (exclusive-write) */+  mdbx_jitter4testing(false);+  if (!flock(env->me_lfd, LCK_EXCLUSIVE | LCK_DONTWAIT, LCK_LOWER)) {+    rc = GetLastError() /* 5) something went wrong, give up */;+    mdbx_verbose("%s, err %u", "?-E(middle) >> E-E(exclusive-write)", rc);+    return rc;+  }++  return MDBX_SUCCESS /* 6) now at E-E (exclusive-write), done */;+}++MDBX_INTERNAL_FUNC int mdbx_lck_init(MDBX_env *env,+                                     MDBX_env *inprocess_neighbor,+                                     int global_uniqueness_flag) {+  (void)env;+  (void)inprocess_neighbor;+  (void)global_uniqueness_flag;+  return MDBX_SUCCESS;+}++MDBX_INTERNAL_FUNC int mdbx_lck_destroy(MDBX_env *env,+                                        MDBX_env *inprocess_neighbor) {+  /* LY: should unmap before releasing the locks to avoid race condition and+   * STATUS_USER_MAPPED_FILE/ERROR_USER_MAPPED_FILE */+  if (env->me_map)+    mdbx_munmap(&env->me_dxb_mmap);+  if (env->me_lck) {+    const bool synced = env->me_lck_mmap.lck->mti_unsynced_pages.weak == 0;+    mdbx_munmap(&env->me_lck_mmap);+    if (synced && !inprocess_neighbor && env->me_lfd != INVALID_HANDLE_VALUE &&+        mdbx_lck_upgrade(env) == MDBX_SUCCESS)+      /* this will fail if LCK is used/mmapped by other process(es) */+      mdbx_ftruncate(env->me_lfd, 0);+  }+  lck_unlock(env);+  return MDBX_SUCCESS;+}++/*----------------------------------------------------------------------------*/+/* reader checking (by pid) */++MDBX_INTERNAL_FUNC int mdbx_rpid_set(MDBX_env *env) {+  (void)env;+  return MDBX_SUCCESS;+}++MDBX_INTERNAL_FUNC int mdbx_rpid_clear(MDBX_env *env) {+  (void)env;+  return MDBX_SUCCESS;+}++/* Checks reader by pid.+ *+ * Returns:+ *   MDBX_RESULT_TRUE, if pid is live (unable to acquire lock)+ *   MDBX_RESULT_FALSE, if pid is dead (lock acquired)+ *   or otherwise the errcode. */+MDBX_INTERNAL_FUNC int mdbx_rpid_check(MDBX_env *env, uint32_t pid) {+  (void)env;+  HANDLE hProcess = OpenProcess(SYNCHRONIZE, FALSE, pid);+  int rc;+  if (likely(hProcess)) {+    rc = WaitForSingleObject(hProcess, 0);+    if (unlikely(rc == WAIT_FAILED))+      rc = GetLastError();+    CloseHandle(hProcess);+  } else {+    rc = GetLastError();+  }++  switch (rc) {+  case ERROR_INVALID_PARAMETER:+    /* pid seems invalid */+    return MDBX_RESULT_FALSE;+  case WAIT_OBJECT_0:+    /* process just exited */+    return MDBX_RESULT_FALSE;+  case ERROR_ACCESS_DENIED:+    /* The ERROR_ACCESS_DENIED would be returned for CSRSS-processes, etc.+     * assume pid exists */+    return MDBX_RESULT_TRUE;+  case WAIT_TIMEOUT:+    /* pid running */+    return MDBX_RESULT_TRUE;+  default:+    /* failure */+    return rc;+  }+}++//----------------------------------------------------------------------------+// Stub for slim read-write lock+// Copyright (C) 1995-2002 Brad Wilson++static void WINAPI stub_srwlock_Init(MDBX_srwlock *srwl) {+  srwl->readerCount = srwl->writerCount = 0;+}++static void WINAPI stub_srwlock_AcquireShared(MDBX_srwlock *srwl) {+  while (true) {+    assert(srwl->writerCount >= 0 && srwl->readerCount >= 0);++    //  If there's a writer already, spin without unnecessarily+    //  interlocking the CPUs+    if (srwl->writerCount != 0) {+      YieldProcessor();+      continue;+    }++    //  Add to the readers list+    _InterlockedIncrement(&srwl->readerCount);++    // Check for writers again (we may have been preempted). If+    // there are no writers writing or waiting, then we're done.+    if (srwl->writerCount == 0)+      break;++    // Remove from the readers list, spin, try again+    _InterlockedDecrement(&srwl->readerCount);+    YieldProcessor();+  }+}++static void WINAPI stub_srwlock_ReleaseShared(MDBX_srwlock *srwl) {+  assert(srwl->readerCount > 0);+  _InterlockedDecrement(&srwl->readerCount);+}++static void WINAPI stub_srwlock_AcquireExclusive(MDBX_srwlock *srwl) {+  while (true) {+    assert(srwl->writerCount >= 0 && srwl->readerCount >= 0);++    //  If there's a writer already, spin without unnecessarily+    //  interlocking the CPUs+    if (srwl->writerCount != 0) {+      YieldProcessor();+      continue;+    }++    // See if we can become the writer (expensive, because it inter-+    // locks the CPUs, so writing should be an infrequent process)+    if (_InterlockedExchange(&srwl->writerCount, 1) == 0)+      break;+  }++  // Now we're the writer, but there may be outstanding readers.+  // Spin until there aren't any more; new readers will wait now+  // that we're the writer.+  while (srwl->readerCount != 0) {+    assert(srwl->writerCount >= 0 && srwl->readerCount >= 0);+    YieldProcessor();+  }+}++static void WINAPI stub_srwlock_ReleaseExclusive(MDBX_srwlock *srwl) {+  assert(srwl->writerCount == 1 && srwl->readerCount >= 0);+  srwl->writerCount = 0;+}++MDBX_srwlock_function mdbx_srwlock_Init, mdbx_srwlock_AcquireShared,+    mdbx_srwlock_ReleaseShared, mdbx_srwlock_AcquireExclusive,+    mdbx_srwlock_ReleaseExclusive;++/*----------------------------------------------------------------------------*/++#if 0  /* LY: unused for now */+static DWORD WINAPI stub_DiscardVirtualMemory(PVOID VirtualAddress,+                                              SIZE_T Size) {+  return VirtualAlloc(VirtualAddress, Size, MEM_RESET, PAGE_NOACCESS)+             ? ERROR_SUCCESS+	  : GetLastError();+}+#endif /* unused for now */++static uint64_t WINAPI stub_GetTickCount64(void) {+  LARGE_INTEGER Counter, Frequency;+  return (QueryPerformanceFrequency(&Frequency) &&+          QueryPerformanceCounter(&Counter))+             ? Counter.QuadPart * 1000ul / Frequency.QuadPart+             : 0;+}++/*----------------------------------------------------------------------------*/+#ifndef MDBX_ALLOY+MDBX_NtExtendSection mdbx_NtExtendSection;+MDBX_GetFileInformationByHandleEx mdbx_GetFileInformationByHandleEx;+MDBX_GetVolumeInformationByHandleW mdbx_GetVolumeInformationByHandleW;+MDBX_GetFinalPathNameByHandleW mdbx_GetFinalPathNameByHandleW;+MDBX_SetFileInformationByHandle mdbx_SetFileInformationByHandle;+MDBX_NtFsControlFile mdbx_NtFsControlFile;+MDBX_PrefetchVirtualMemory mdbx_PrefetchVirtualMemory;+MDBX_GetTickCount64 mdbx_GetTickCount64;+MDBX_RegGetValueA mdbx_RegGetValueA;+#if 0  /* LY: unused for now */+MDBX_DiscardVirtualMemory mdbx_DiscardVirtualMemory;+MDBX_OfferVirtualMemory mdbx_OfferVirtualMemory;+MDBX_ReclaimVirtualMemory mdbx_ReclaimVirtualMemory;+#endif /* unused for now */+#endif /* MDBX_ALLOY */++static void mdbx_winnt_import(void) {+  const HINSTANCE hNtdll = GetModuleHandleA("ntdll.dll");++#define GET_PROC_ADDR(dll, ENTRY)                                              \+  mdbx_##ENTRY = (MDBX_##ENTRY)GetProcAddress(dll, #ENTRY)++  if (GetProcAddress(hNtdll, "wine_get_version")) {+    assert(mdbx_RunningUnderWine());+  } else {+    GET_PROC_ADDR(hNtdll, NtFsControlFile);+    GET_PROC_ADDR(hNtdll, NtExtendSection);+    assert(!mdbx_RunningUnderWine());+  }++  const HINSTANCE hKernel32dll = GetModuleHandleA("kernel32.dll");+  GET_PROC_ADDR(hKernel32dll, GetFileInformationByHandleEx);+  GET_PROC_ADDR(hKernel32dll, GetTickCount64);+  if (!mdbx_GetTickCount64)+    mdbx_GetTickCount64 = stub_GetTickCount64;+  if (!mdbx_RunningUnderWine()) {+    GET_PROC_ADDR(hKernel32dll, SetFileInformationByHandle);+    GET_PROC_ADDR(hKernel32dll, GetVolumeInformationByHandleW);+    GET_PROC_ADDR(hKernel32dll, GetFinalPathNameByHandleW);+    GET_PROC_ADDR(hKernel32dll, PrefetchVirtualMemory);+  }++  const HINSTANCE hAdvapi32dll = GetModuleHandleA("advapi32.dll");+  GET_PROC_ADDR(hAdvapi32dll, RegGetValueA);++#if 0  /* LY: unused for now */+  if (!mdbx_RunningUnderWine()) {+    GET_PROC_ADDR(hKernel32dll, DiscardVirtualMemory);+    GET_PROC_ADDR(hKernel32dll, OfferVirtualMemory);+    GET_PROC_ADDR(hKernel32dll, ReclaimVirtualMemory);+  }+  if (!mdbx_DiscardVirtualMemory)+    mdbx_DiscardVirtualMemory = stub_DiscardVirtualMemory;+  if (!mdbx_OfferVirtualMemory)+    mdbx_OfferVirtualMemory = stub_OfferVirtualMemory;+  if (!mdbx_ReclaimVirtualMemory)+    mdbx_ReclaimVirtualMemory = stub_ReclaimVirtualMemory;+#endif /* unused for now */++#undef GET_PROC_ADDR++  const MDBX_srwlock_function init =+      (MDBX_srwlock_function)GetProcAddress(hKernel32dll, "InitializeSRWLock");+  if (init != NULL) {+    mdbx_srwlock_Init = init;+    mdbx_srwlock_AcquireShared = (MDBX_srwlock_function)GetProcAddress(+        hKernel32dll, "AcquireSRWLockShared");+    mdbx_srwlock_ReleaseShared = (MDBX_srwlock_function)GetProcAddress(+        hKernel32dll, "ReleaseSRWLockShared");+    mdbx_srwlock_AcquireExclusive = (MDBX_srwlock_function)GetProcAddress(+        hKernel32dll, "AcquireSRWLockExclusive");+    mdbx_srwlock_ReleaseExclusive = (MDBX_srwlock_function)GetProcAddress(+        hKernel32dll, "ReleaseSRWLockExclusive");+  } else {+    mdbx_srwlock_Init = stub_srwlock_Init;+    mdbx_srwlock_AcquireShared = stub_srwlock_AcquireShared;+    mdbx_srwlock_ReleaseShared = stub_srwlock_ReleaseShared;+    mdbx_srwlock_AcquireExclusive = stub_srwlock_AcquireExclusive;+    mdbx_srwlock_ReleaseExclusive = stub_srwlock_ReleaseExclusive;+  }+}++#endif /* Windows LCK-implementation */+/*+ * Copyright 2015-2021 Leonid Yuriev <leo@yuriev.ru>+ * and other libmdbx authors: please see AUTHORS file.+ * All rights reserved.+ *+ * Redistribution and use in source and binary forms, with or without+ * modification, are permitted only as authorized by the OpenLDAP+ * Public License.+ *+ * A copy of this license is available in the file LICENSE in the+ * top-level directory of the distribution or, alternatively, at+ * <http://www.OpenLDAP.org/license.html>.+ */++#if !(defined(_WIN32) || defined(_WIN64)) /* !Windows LCK-implementation */++#include <sys/sem.h>++/*----------------------------------------------------------------------------*/+/* global constructor/destructor */++#if defined(__linux__) || defined(__gnu_linux__)++#include <sys/utsname.h>++#ifndef MDBX_ALLOY+uint32_t mdbx_linux_kernel_version;+bool mdbx_RunningOnWSL1;+#endif /* MDBX_ALLOY */++static __cold uint8_t probe_for_WSL(const char *tag) {+  const char *const WSL = strstr(tag, "WSL");+  if (WSL && WSL[3] >= '2' && WSL[3] <= '9')+    return WSL[3] - '0';+  const char *const wsl = strstr(tag, "wsl");+  if (wsl && wsl[3] >= '2' && wsl[3] <= '9')+    return wsl[3] - '0';+  return (WSL || wsl || strcasestr(tag, "Microsoft")) ? 1 : 0;+}++#endif /* Linux */++static __cold __attribute__((__constructor__)) void+mdbx_global_constructor(void) {+#if defined(__linux__) || defined(__gnu_linux__)+  struct utsname buffer;+  if (uname(&buffer) == 0) {+    /* "Official" way of detecting WSL1 but not WSL2+     * https://github.com/Microsoft/WSL/issues/423#issuecomment-221627364+     *+     * WARNING: False negative detection of WSL1 will result in DATA LOSS!+     * So, the REQUIREMENTS for this code:+     *  1. MUST detect WSL1 without false-negatives.+     *  2. DESIRABLE detect WSL2 but without the risk of violating the first. */+    mdbx_RunningOnWSL1 = probe_for_WSL(buffer.version) == 1 ||+                         probe_for_WSL(buffer.sysname) == 1 ||+                         probe_for_WSL(buffer.release) == 1;+    int i = 0;+    char *p = buffer.release;+    while (*p && i < 4) {+      if (*p >= '0' && *p <= '9') {+        long number = strtol(p, &p, 10);+        if (number > 0) {+          if (number > 255)+            number = 255;+          mdbx_linux_kernel_version += number << (24 - i * 8);+        }+        ++i;+      } else {+        ++p;+      }+    }+  }+#endif /* Linux */++  mdbx_rthc_global_init();+}++static __cold __attribute__((__destructor__)) void+mdbx_global_destructor(void) {+  mdbx_rthc_global_dtor();+}++/*----------------------------------------------------------------------------*/+/* lck */++/* Описание реализации блокировок для POSIX & Linux:+ *+ * lck-файл отображается в память, в нём организуется таблица читателей и+ * размещаются совместно используемые posix-мьютексы (futex). Посредством+ * этих мьютексов (см struct MDBX_lockinfo) реализуются:+ *  - Блокировка таблицы читателей для регистрации,+ *    т.е. функции mdbx_rdt_lock() и mdbx_rdt_unlock().+ *  - Блокировка БД для пишущих транзакций,+ *    т.е. функции mdbx_txn_lock() и mdbx_txn_unlock().+ *+ * Остальной функционал реализуется отдельно посредством файловых блокировок:+ *  - Первоначальный захват БД в режиме exclusive/shared и последующий перевод+ *    в операционный режим, функции mdbx_lck_seize() и mdbx_lck_downgrade().+ *  - Проверка присутствие процессов-читателей,+ *    т.е. функции mdbx_rpid_set(), mdbx_rpid_clear() и mdbx_rpid_check().+ *+ * Для блокировки файлов используется fcntl(F_SETLK), так как:+ *  - lockf() оперирует только эксклюзивной блокировкой и требует+ *    открытия файла в RW-режиме.+ *  - flock() не гарантирует атомарности при смене блокировок+ *    и оперирует только всем файлом целиком.+ *  - Для контроля процессов-читателей используются однобайтовые+ *    range-блокировки lck-файла посредством fcntl(F_SETLK). При этом+ *    в качестве позиции используется pid процесса-читателя.+ *  - Для первоначального захвата и shared/exclusive выполняется блокировка+ *    основного файла БД и при успехе lck-файла.+ *+ * ----------------------------------------------------------------------------+ * УДЕРЖИВАЕМЫЕ БЛОКИРОВКИ В ЗАВИСИМОСТИ ОТ РЕЖИМА И СОСТОЯНИЯ+ *+ * Эксклюзивный режим без lck-файла:+ *   = заблокирован весь dxb-файл посредством F_RDLCK или F_WRLCK,+ *     в зависимости от MDBX_RDONLY.+ *+ * Не-операционный режим на время пере-инициализации и разрушении lck-файла:+ *   = F_WRLCK блокировка первого байта lck-файла, другие процессы ждут её+ *     снятия при получении F_RDLCK через F_SETLKW.+ *   - блокировки dxb-файла могут меняться до снятие эксклюзивной блокировки+ *    lck-файла:+ *       + для НЕ-эксклюзивного режима блокировка pid-байта в dxb-файле+ *         посредством F_RDLCK или F_WRLCK, в зависимости от MDBX_RDONLY.+ *       + для ЭКСКЛЮЗИВНОГО режима блокировка pid-байта всего dxb-файла+ *         посредством F_RDLCK или F_WRLCK, в зависимости от MDBX_RDONLY.+ *+ * ОПЕРАЦИОННЫЙ режим с lck-файлом:+ *   = F_RDLCK блокировка первого байта lck-файла, другие процессы не могут+ *     получить F_WRLCK и таким образом видят что БД используется.+ *   + F_WRLCK блокировка pid-байта в clk-файле после первой транзакции чтения.+ *   + для НЕ-эксклюзивного режима блокировка pid-байта в dxb-файле+ *     посредством F_RDLCK или F_WRLCK, в зависимости от MDBX_RDONLY.+ *   + для ЭКСКЛЮЗИВНОГО режима блокировка pid-байта всего dxb-файла+ *     посредством F_RDLCK или F_WRLCK, в зависимости от MDBX_RDONLY.+ */++#if MDBX_USE_OFDLOCKS+static int op_setlk, op_setlkw, op_getlk;+static void __cold choice_fcntl() {+  assert(!op_setlk && !op_setlkw && !op_getlk);+  if ((mdbx_runtime_flags & MDBX_DBG_LEGACY_MULTIOPEN) == 0+#if defined(__linux__) || defined(__gnu_linux__)+      && mdbx_linux_kernel_version >+             0x030f0000 /* OFD locks are available since 3.15, but engages here+                           only for 3.16 and later kernels (i.e. LTS) because+                           of reliability reasons */+#endif                  /* linux */+  ) {+    op_setlk = F_OFD_SETLK;+    op_setlkw = F_OFD_SETLKW;+    op_getlk = F_OFD_GETLK;+    return;+  }+  op_setlk = F_SETLK;+  op_setlkw = F_SETLKW;+  op_getlk = F_GETLK;+}+#else+#define op_setlk F_SETLK+#define op_setlkw F_SETLKW+#define op_getlk F_GETLK+#endif /* MDBX_USE_OFDLOCKS */++#ifndef OFF_T_MAX+#define OFF_T_MAX                                                              \+  ((sizeof(off_t) > 4 ? INT64_MAX : INT32_MAX) & ~(size_t)0xffff)+#endif++static int lck_op(mdbx_filehandle_t fd, int cmd, int lck, off_t offset,+                  off_t len) {+  mdbx_jitter4testing(true);+  for (;;) {+    struct flock lock_op;+    memset(&lock_op, 0, sizeof(lock_op));+    lock_op.l_type = lck;+    lock_op.l_whence = SEEK_SET;+    lock_op.l_start = offset;+    lock_op.l_len = len;+    int rc = fcntl(fd, cmd, &lock_op);+    mdbx_jitter4testing(true);+    if (rc != -1) {+      if (cmd == op_getlk) {+        /* Checks reader by pid. Returns:+         *   MDBX_RESULT_TRUE   - if pid is live (reader holds a lock).+         *   MDBX_RESULT_FALSE  - if pid is dead (a lock could be placed). */+        return (lock_op.l_type == F_UNLCK) ? MDBX_RESULT_FALSE+                                           : MDBX_RESULT_TRUE;+      }+      return MDBX_SUCCESS;+    }+    rc = errno;+    if (rc != EINTR || cmd == op_setlkw) {+      mdbx_assert(nullptr, MDBX_IS_ERROR(rc));+      return rc;+    }+  }+}++MDBX_INTERNAL_FUNC int mdbx_lockfile(mdbx_filehandle_t fd, bool wait) {+#if MDBX_USE_OFDLOCKS+  if (unlikely(op_setlk == 0))+    choice_fcntl();+#endif /* MDBX_USE_OFDLOCKS */+  return lck_op(fd, wait ? op_setlkw : op_setlk, F_WRLCK, 0, OFF_T_MAX);+}++MDBX_INTERNAL_FUNC int mdbx_rpid_set(MDBX_env *env) {+  assert(env->me_lfd != INVALID_HANDLE_VALUE);+  assert(env->me_pid > 0);+  if (unlikely(mdbx_getpid() != env->me_pid))+    return MDBX_PANIC;+  return lck_op(env->me_lfd, op_setlk, F_WRLCK, env->me_pid, 1);+}++MDBX_INTERNAL_FUNC int mdbx_rpid_clear(MDBX_env *env) {+  assert(env->me_lfd != INVALID_HANDLE_VALUE);+  assert(env->me_pid > 0);+  return lck_op(env->me_lfd, op_setlk, F_UNLCK, env->me_pid, 1);+}++MDBX_INTERNAL_FUNC int mdbx_rpid_check(MDBX_env *env, uint32_t pid) {+  assert(env->me_lfd != INVALID_HANDLE_VALUE);+  assert(pid > 0);+  return lck_op(env->me_lfd, op_getlk, F_WRLCK, pid, 1);+}++/*---------------------------------------------------------------------------*/++#if MDBX_LOCKING > MDBX_LOCKING_SYSV+MDBX_INTERNAL_FUNC int mdbx_ipclock_stub(mdbx_ipclock_t *ipc) {+#if MDBX_LOCKING == MDBX_LOCKING_POSIX1988+  return sem_init(ipc, false, 1) ? errno : 0;+#elif MDBX_LOCKING == MDBX_LOCKING_POSIX2001 ||                                \+    MDBX_LOCKING == MDBX_LOCKING_POSIX2008+  return pthread_mutex_init(ipc, nullptr);+#else+#error "FIXME"+#endif+}++MDBX_INTERNAL_FUNC int mdbx_ipclock_destroy(mdbx_ipclock_t *ipc) {+#if MDBX_LOCKING == MDBX_LOCKING_POSIX1988+  return sem_destroy(ipc) ? errno : 0;+#elif MDBX_LOCKING == MDBX_LOCKING_POSIX2001 ||                                \+    MDBX_LOCKING == MDBX_LOCKING_POSIX2008+  return pthread_mutex_destroy(ipc);+#else+#error "FIXME"+#endif+}+#endif /* MDBX_LOCKING > MDBX_LOCKING_SYSV */++static int check_fstat(MDBX_env *env) {+  struct stat st;++  int rc = MDBX_SUCCESS;+  if (fstat(env->me_lazy_fd, &st)) {+    rc = errno;+    mdbx_error("fstat(%s), err %d", "DXB", rc);+    return rc;+  }++  if (!S_ISREG(st.st_mode) || st.st_nlink < 1) {+#ifdef EBADFD+    rc = EBADFD;+#else+    rc = EPERM;+#endif+    mdbx_error("%s %s, err %d", "DXB",+               (st.st_nlink < 1) ? "file was removed" : "not a regular file",+               rc);+    return rc;+  }++  if (st.st_size < (off_t)(MDBX_MIN_PAGESIZE * NUM_METAS)) {+    mdbx_verbose("dxb-file is too short (%u), exclusive-lock needed",+                 (unsigned)st.st_size);+    rc = MDBX_RESULT_TRUE;+  }++  //----------------------------------------------------------------------------++  if (fstat(env->me_lfd, &st)) {+    rc = errno;+    mdbx_error("fstat(%s), err %d", "LCK", rc);+    return rc;+  }++  if (!S_ISREG(st.st_mode) || st.st_nlink < 1) {+#ifdef EBADFD+    rc = EBADFD;+#else+    rc = EPERM;+#endif+    mdbx_error("%s %s, err %d", "LCK",+               (st.st_nlink < 1) ? "file was removed" : "not a regular file",+               rc);+    return rc;+  }++  /* Checking file size for detect the situation when we got the shared lock+   * immediately after mdbx_lck_destroy(). */+  if (st.st_size < (off_t)(sizeof(MDBX_lockinfo) + sizeof(MDBX_reader))) {+    mdbx_verbose("lck-file is too short (%u), exclusive-lock needed",+                 (unsigned)st.st_size);+    rc = MDBX_RESULT_TRUE;+  }++  return rc;+}++MDBX_INTERNAL_FUNC int __cold mdbx_lck_seize(MDBX_env *env) {+  assert(env->me_lazy_fd != INVALID_HANDLE_VALUE);+  if (unlikely(mdbx_getpid() != env->me_pid))+    return MDBX_PANIC;+#if MDBX_USE_OFDLOCKS+  if (unlikely(op_setlk == 0))+    choice_fcntl();+#endif /* MDBX_USE_OFDLOCKS */++  int rc = MDBX_SUCCESS;+#if defined(__linux__) || defined(__gnu_linux__)+  if (unlikely(mdbx_RunningOnWSL1)) {+    rc = ENOLCK /* No record locks available */;+    mdbx_error("%s, err %u",+               "WSL1 (Windows Subsystem for Linux) is mad and trouble-full, "+               "injecting failure to avoid data loss",+               rc);+    return rc;+  }+#endif /* Linux */++  if (env->me_lfd == INVALID_HANDLE_VALUE) {+    /* LY: without-lck mode (e.g. exclusive or on read-only filesystem) */+    rc =+        lck_op(env->me_lazy_fd, op_setlk,+               (env->me_flags & MDBX_RDONLY) ? F_RDLCK : F_WRLCK, 0, OFF_T_MAX);+    if (rc != MDBX_SUCCESS) {+      mdbx_error("%s, err %u", "without-lck", rc);+      mdbx_assert(env, MDBX_IS_ERROR(rc));+      return rc;+    }+    return MDBX_RESULT_TRUE /* Done: return with exclusive locking. */;+  }+#if defined(_POSIX_PRIORITY_SCHEDULING) && _POSIX_PRIORITY_SCHEDULING > 0+  sched_yield();+#endif++retry:+  if (rc == MDBX_RESULT_TRUE) {+    rc = lck_op(env->me_lfd, op_setlk, F_UNLCK, 0, 1);+    if (rc != MDBX_SUCCESS) {+      mdbx_error("%s, err %u", "unlock-before-retry", rc);+      mdbx_assert(env, MDBX_IS_ERROR(rc));+      return rc;+    }+  }++  /* Firstly try to get exclusive locking.  */+  rc = lck_op(env->me_lfd, op_setlk, F_WRLCK, 0, 1);+  if (rc == MDBX_SUCCESS) {+    rc = check_fstat(env);+    if (MDBX_IS_ERROR(rc))+      return rc;++  continue_dxb_exclusive:+    rc =+        lck_op(env->me_lazy_fd, op_setlk,+               (env->me_flags & MDBX_RDONLY) ? F_RDLCK : F_WRLCK, 0, OFF_T_MAX);+    if (rc == MDBX_SUCCESS)+      return MDBX_RESULT_TRUE /* Done: return with exclusive locking. */;++    int err = check_fstat(env);+    if (MDBX_IS_ERROR(err))+      return err;++    /* the cause may be a collision with POSIX's file-lock recovery. */+    if (!(rc == EAGAIN || rc == EACCES || rc == EBUSY || rc == EWOULDBLOCK ||+          rc == EDEADLK)) {+      mdbx_error("%s, err %u", "dxb-exclusive", rc);+      mdbx_assert(env, MDBX_IS_ERROR(rc));+      return rc;+    }++    /* Fallback to lck-shared */+  } else if (!(rc == EAGAIN || rc == EACCES || rc == EBUSY ||+               rc == EWOULDBLOCK || rc == EDEADLK)) {+    mdbx_error("%s, err %u", "try-exclusive", rc);+    mdbx_assert(env, MDBX_IS_ERROR(rc));+    return rc;+  }++  /* Here could be one of two:+   *  - mdbx_lck_destroy() from the another process was hold the lock+   *    during a destruction.+   *  - either mdbx_lck_seize() from the another process was got the exclusive+   *    lock and doing initialization.+   * For distinguish these cases will use size of the lck-file later. */++  /* Wait for lck-shared now. */+  /* Here may be await during transient processes, for instance until another+   * competing process doesn't call lck_downgrade(). */+  rc = lck_op(env->me_lfd, op_setlkw, F_RDLCK, 0, 1);+  if (rc != MDBX_SUCCESS) {+    mdbx_error("%s, err %u", "try-shared", rc);+    mdbx_assert(env, MDBX_IS_ERROR(rc));+    return rc;+  }++  rc = check_fstat(env);+  if (rc == MDBX_RESULT_TRUE)+    goto retry;+  if (rc != MDBX_SUCCESS) {+    mdbx_error("%s, err %u", "lck_fstat", rc);+    return rc;+  }++  /* got shared, retry exclusive */+  rc = lck_op(env->me_lfd, op_setlk, F_WRLCK, 0, 1);+  if (rc == MDBX_SUCCESS)+    goto continue_dxb_exclusive;++  if (!(rc == EAGAIN || rc == EACCES || rc == EBUSY || rc == EWOULDBLOCK ||+        rc == EDEADLK)) {+    mdbx_error("%s, err %u", "try-exclusive", rc);+    mdbx_assert(env, MDBX_IS_ERROR(rc));+    return rc;+  }++  /* Lock against another process operating in without-lck or exclusive mode. */+  rc =+      lck_op(env->me_lazy_fd, op_setlk,+             (env->me_flags & MDBX_RDONLY) ? F_RDLCK : F_WRLCK, env->me_pid, 1);+  if (rc != MDBX_SUCCESS) {+    mdbx_error("%s, err %u", "lock-against-without-lck", rc);+    mdbx_assert(env, MDBX_IS_ERROR(rc));+    return rc;+  }++  /* Done: return with shared locking. */+  return MDBX_RESULT_FALSE;+}++MDBX_INTERNAL_FUNC int mdbx_lck_downgrade(MDBX_env *env) {+  assert(env->me_lfd != INVALID_HANDLE_VALUE);+  if (unlikely(mdbx_getpid() != env->me_pid))+    return MDBX_PANIC;++  int rc = MDBX_SUCCESS;+  if ((env->me_flags & MDBX_EXCLUSIVE) == 0) {+    rc = lck_op(env->me_lazy_fd, op_setlk, F_UNLCK, 0, env->me_pid);+    if (rc == MDBX_SUCCESS)+      rc = lck_op(env->me_lazy_fd, op_setlk, F_UNLCK, env->me_pid + 1,+                  OFF_T_MAX - env->me_pid - 1);+  }+  if (rc == MDBX_SUCCESS)+    rc = lck_op(env->me_lfd, op_setlk, F_RDLCK, 0, 1);+  if (unlikely(rc != 0)) {+    mdbx_error("%s, err %u", "lck", rc);+    assert(MDBX_IS_ERROR(rc));+  }+  return rc;+}++MDBX_INTERNAL_FUNC int __cold mdbx_lck_destroy(MDBX_env *env,+                                               MDBX_env *inprocess_neighbor) {+  if (unlikely(mdbx_getpid() != env->me_pid))+    return MDBX_PANIC;++  int rc = MDBX_SUCCESS;+  struct stat lck_info;+  if (env->me_lfd != INVALID_HANDLE_VALUE && !inprocess_neighbor &&+      env->me_lck &&+      /* try get exclusive access */+      lck_op(env->me_lfd, op_setlk, F_WRLCK, 0, OFF_T_MAX) == 0 &&+      /* if LCK was not removed */+      fstat(env->me_lfd, &lck_info) == 0 && lck_info.st_nlink > 0 &&+      lck_op(env->me_lazy_fd, op_setlk,+             (env->me_flags & MDBX_RDONLY) ? F_RDLCK : F_WRLCK, 0,+             OFF_T_MAX) == 0) {++    mdbx_verbose("%p got exclusive, drown locks", (void *)env);+#if MDBX_LOCKING == MDBX_LOCKING_SYSV+    if (env->me_sysv_ipc.semid != -1)+      rc = semctl(env->me_sysv_ipc.semid, 2, IPC_RMID) ? errno : 0;+#else+    rc = mdbx_ipclock_destroy(&env->me_lck->mti_rlock);+    if (rc == 0)+      rc = mdbx_ipclock_destroy(&env->me_lck->mti_wlock);+#endif /* MDBX_LOCKING */++    mdbx_assert(env, rc == 0);+    if (rc == 0) {+      const bool synced = env->me_lck_mmap.lck->mti_unsynced_pages.weak == 0;+      mdbx_munmap(&env->me_lck_mmap);+      if (synced)+        rc = ftruncate(env->me_lfd, 0) ? errno : 0;+    }++    mdbx_jitter4testing(false);+  }++  /* 1) POSIX's fcntl() locks (i.e. when op_setlk == F_SETLK) should be restored+   * after file was closed.+   *+   * 2) File locks would be released (by kernel) while the file-descriptors will+   * be closed. But to avoid false-positive EACCESS and EDEADLK from the kernel,+   * locks should be released here explicitly with properly order. */++  /* close dxb and restore lock */+  if (env->me_dsync_fd != INVALID_HANDLE_VALUE) {+    if (unlikely(close(env->me_dsync_fd) != 0) && rc == MDBX_SUCCESS)+      rc = errno;+    env->me_dsync_fd = INVALID_HANDLE_VALUE;+  }+  if (env->me_lazy_fd != INVALID_HANDLE_VALUE) {+    if (unlikely(close(env->me_lazy_fd) != 0) && rc == MDBX_SUCCESS)+      rc = errno;+    env->me_lazy_fd = INVALID_HANDLE_VALUE;+    if (op_setlk == F_SETLK && inprocess_neighbor && rc == MDBX_SUCCESS) {+      /* restore file-lock */+      rc = lck_op(+          inprocess_neighbor->me_lazy_fd, F_SETLKW,+          (inprocess_neighbor->me_flags & MDBX_RDONLY) ? F_RDLCK : F_WRLCK,+          (inprocess_neighbor->me_flags & MDBX_EXCLUSIVE)+              ? 0+              : inprocess_neighbor->me_pid,+          (inprocess_neighbor->me_flags & MDBX_EXCLUSIVE) ? OFF_T_MAX : 1);+    }+  }++  /* close clk and restore locks */+  if (env->me_lfd != INVALID_HANDLE_VALUE) {+    if (unlikely(close(env->me_lfd) != 0) && rc == MDBX_SUCCESS)+      rc = errno;+    env->me_lfd = INVALID_HANDLE_VALUE;+    if (op_setlk == F_SETLK && inprocess_neighbor && rc == MDBX_SUCCESS) {+      /* restore file-locks */+      rc = lck_op(inprocess_neighbor->me_lfd, F_SETLKW, F_RDLCK, 0, 1);+      if (rc == MDBX_SUCCESS && inprocess_neighbor->me_live_reader)+        rc = mdbx_rpid_set(inprocess_neighbor);+    }+  }++  if (inprocess_neighbor && rc != MDBX_SUCCESS)+    inprocess_neighbor->me_flags |= MDBX_FATAL_ERROR;+  return rc;+}++/*---------------------------------------------------------------------------*/++MDBX_INTERNAL_FUNC int __cold mdbx_lck_init(MDBX_env *env,+                                            MDBX_env *inprocess_neighbor,+                                            int global_uniqueness_flag) {+#if MDBX_LOCKING == MDBX_LOCKING_SYSV+  int semid = -1;+  /* don't initialize semaphores twice */+  (void)inprocess_neighbor;+  if (global_uniqueness_flag == MDBX_RESULT_TRUE) {+    struct stat st;+    if (fstat(env->me_lazy_fd, &st))+      return errno;+  sysv_retry_create:+    semid = semget(env->me_sysv_ipc.key, 2,+                   IPC_CREAT | IPC_EXCL |+                       (st.st_mode & (S_IRWXU | S_IRWXG | S_IRWXO)));+    if (unlikely(semid == -1)) {+      int err = errno;+      if (err != EEXIST)+        return err;++      /* remove and re-create semaphore set */+      semid = semget(env->me_sysv_ipc.key, 2, 0);+      if (semid == -1) {+        err = errno;+        if (err != ENOENT)+          return err;+        goto sysv_retry_create;+      }+      if (semctl(semid, 2, IPC_RMID)) {+        err = errno;+        if (err != EIDRM)+          return err;+      }+      goto sysv_retry_create;+    }++    unsigned short val_array[2] = {1, 1};+    if (semctl(semid, 2, SETALL, val_array))+      return errno;+  } else {+    semid = semget(env->me_sysv_ipc.key, 2, 0);+    if (semid == -1)+      return errno;++    /* check read & write access */+    struct semid_ds data[2];+    if (semctl(semid, 2, IPC_STAT, data) || semctl(semid, 2, IPC_SET, data))+      return errno;+  }++  env->me_sysv_ipc.semid = semid;+  return MDBX_SUCCESS;++#elif MDBX_LOCKING == MDBX_LOCKING_FUTEX+  (void)inprocess_neighbor;+  if (global_uniqueness_flag != MDBX_RESULT_TRUE)+    return MDBX_SUCCESS;+#error "FIXME: Not implemented"+#elif MDBX_LOCKING == MDBX_LOCKING_POSIX1988++  /* don't initialize semaphores twice */+  (void)inprocess_neighbor;+  if (global_uniqueness_flag == MDBX_RESULT_TRUE) {+    if (sem_init(&env->me_lck->mti_rlock, true, 1))+      return errno;+    if (sem_init(&env->me_lck->mti_wlock, true, 1))+      return errno;+  }+  return MDBX_SUCCESS;++#elif MDBX_LOCKING == MDBX_LOCKING_POSIX2001 ||                                \+    MDBX_LOCKING == MDBX_LOCKING_POSIX2008+  if (inprocess_neighbor)+    return MDBX_SUCCESS /* don't need any initialization for mutexes+      if LCK already opened/used inside current process */+        ;++    /* FIXME: Unfortunately, there is no other reliable way but to long testing+     * on each platform. On the other hand, behavior like FreeBSD is incorrect+     * and we can expect it to be rare. Moreover, even on FreeBSD without+     * additional in-process initialization, the probability of an problem+     * occurring is vanishingly small, and the symptom is a return of EINVAL+     * while locking a mutex. In other words, in the worst case, the problem+     * results in an EINVAL error at the start of the transaction, but NOT data+     * loss, nor database corruption, nor other fatal troubles. Thus, the code+     * below I am inclined to think the workaround for erroneous platforms (like+     * FreeBSD), rather than a defect of libmdbx. */+#if defined(__FreeBSD__)+  /* seems that shared mutexes on FreeBSD required in-process initialization */+  (void)global_uniqueness_flag;+#else+  /* shared mutexes on many other platforms (including Darwin and Linux's+   * futexes) doesn't need any addition in-process initialization */+  if (global_uniqueness_flag != MDBX_RESULT_TRUE)+    return MDBX_SUCCESS;+#endif++  pthread_mutexattr_t ma;+  int rc = pthread_mutexattr_init(&ma);+  if (rc)+    return rc;++  rc = pthread_mutexattr_setpshared(&ma, PTHREAD_PROCESS_SHARED);+  if (rc)+    goto bailout;++#if MDBX_LOCKING == MDBX_LOCKING_POSIX2008+#if defined(PTHREAD_MUTEX_ROBUST) || defined(pthread_mutexattr_setrobust)+  rc = pthread_mutexattr_setrobust(&ma, PTHREAD_MUTEX_ROBUST);+#elif defined(PTHREAD_MUTEX_ROBUST_NP) ||                                      \+    defined(pthread_mutexattr_setrobust_np)+  rc = pthread_mutexattr_setrobust_np(&ma, PTHREAD_MUTEX_ROBUST_NP);+#elif _POSIX_THREAD_PROCESS_SHARED < 200809L+  rc = pthread_mutexattr_setrobust_np(&ma, PTHREAD_MUTEX_ROBUST_NP);+#else+  rc = pthread_mutexattr_setrobust(&ma, PTHREAD_MUTEX_ROBUST);+#endif+  if (rc)+    goto bailout;+#endif /* MDBX_LOCKING == MDBX_LOCKING_POSIX2008 */++#if defined(_POSIX_THREAD_PRIO_INHERIT) && _POSIX_THREAD_PRIO_INHERIT >= 0 &&  \+    !defined(MDBX_SAFE4QEMU)+  rc = pthread_mutexattr_setprotocol(&ma, PTHREAD_PRIO_INHERIT);+  if (rc == ENOTSUP)+    rc = pthread_mutexattr_setprotocol(&ma, PTHREAD_PRIO_NONE);+  if (rc && rc != ENOTSUP)+    goto bailout;+#endif /* PTHREAD_PRIO_INHERIT */++  rc = pthread_mutexattr_settype(&ma, PTHREAD_MUTEX_ERRORCHECK);+  if (rc && rc != ENOTSUP)+    goto bailout;++  rc = pthread_mutex_init(&env->me_lck->mti_rlock, &ma);+  if (rc)+    goto bailout;+  rc = pthread_mutex_init(&env->me_lck->mti_wlock, &ma);++bailout:+  pthread_mutexattr_destroy(&ma);+  return rc;+#else+#error "FIXME"+#endif /* MDBX_LOCKING > 0 */+}++static int __cold mdbx_ipclock_failed(MDBX_env *env, mdbx_ipclock_t *ipc,+                                      const int err) {+  int rc = err;+#if MDBX_LOCKING == MDBX_LOCKING_POSIX2008 || MDBX_LOCKING == MDBX_LOCKING_SYSV+  if (err == EOWNERDEAD) {+    /* We own the mutex. Clean up after dead previous owner. */++    const bool rlocked = (env->me_lck && ipc == &env->me_lck->mti_rlock);+    rc = MDBX_SUCCESS;+    if (!rlocked) {+      if (unlikely(env->me_txn)) {+        /* env is hosed if the dead thread was ours */+        env->me_flags |= MDBX_FATAL_ERROR;+        env->me_txn = NULL;+        rc = MDBX_PANIC;+      }+    }+    mdbx_warning("%clock owner died, %s", (rlocked ? 'r' : 'w'),+                 (rc ? "this process' env is hosed" : "recovering"));++    int check_rc = mdbx_cleanup_dead_readers(env, rlocked, NULL);+    check_rc = (check_rc == MDBX_SUCCESS) ? MDBX_RESULT_TRUE : check_rc;++#if MDBX_LOCKING == MDBX_LOCKING_SYSV+    rc = (rc == MDBX_SUCCESS) ? check_rc : rc;+#else+#if defined(PTHREAD_MUTEX_ROBUST) || defined(pthread_mutex_consistent)+    int mreco_rc = pthread_mutex_consistent(ipc);+#elif defined(PTHREAD_MUTEX_ROBUST_NP) || defined(pthread_mutex_consistent_np)+    int mreco_rc = pthread_mutex_consistent_np(ipc);+#elif _POSIX_THREAD_PROCESS_SHARED < 200809L+    int mreco_rc = pthread_mutex_consistent_np(ipc);+#else+    int mreco_rc = pthread_mutex_consistent(ipc);+#endif+    check_rc = (mreco_rc == 0) ? check_rc : mreco_rc;++    if (unlikely(mreco_rc))+      mdbx_error("lock recovery failed, %s", mdbx_strerror(mreco_rc));++    rc = (rc == MDBX_SUCCESS) ? check_rc : rc;+    if (MDBX_IS_ERROR(rc))+      pthread_mutex_unlock(ipc);+#endif /* MDBX_LOCKING == MDBX_LOCKING_POSIX2008 */+    return rc;+  }+#elif MDBX_LOCKING == MDBX_LOCKING_POSIX2001+  (void)ipc;+#elif MDBX_LOCKING == MDBX_LOCKING_POSIX1988+  (void)ipc;+#elif MDBX_LOCKING == MDBX_LOCKING_FUTEX+#ifdef _MSC_VER+#pragma message("warning: TODO")+#else+#warning "TODO"+#endif+  (void)ipc;+#else+#error "FIXME"+#endif /* MDBX_LOCKING */++  mdbx_error("mutex (un)lock failed, %s", mdbx_strerror(err));+  if (rc != EDEADLK)+    env->me_flags |= MDBX_FATAL_ERROR;+  return rc;+}++static int mdbx_ipclock_lock(MDBX_env *env, mdbx_ipclock_t *ipc,+                             const bool dont_wait) {+#if MDBX_LOCKING == MDBX_LOCKING_POSIX2001 ||                                  \+    MDBX_LOCKING == MDBX_LOCKING_POSIX2008+  int rc = dont_wait ? pthread_mutex_trylock(ipc) : pthread_mutex_lock(ipc);+  rc = (rc == EBUSY && dont_wait) ? MDBX_BUSY : rc;+#elif MDBX_LOCKING == MDBX_LOCKING_POSIX1988+  int rc = MDBX_SUCCESS;+  if (dont_wait) {+    if (sem_trywait(ipc)) {+      rc = errno;+      if (rc == EAGAIN)+        rc = MDBX_BUSY;+    }+  } else if (sem_wait(ipc))+    rc = errno;+#elif MDBX_LOCKING == MDBX_LOCKING_SYSV+  struct sembuf op = {.sem_num = (ipc != env->me_wlock),+                      .sem_op = -1,+                      .sem_flg = dont_wait ? IPC_NOWAIT | SEM_UNDO : SEM_UNDO};+  int rc;+  if (semop(env->me_sysv_ipc.semid, &op, 1)) {+    rc = errno;+    if (dont_wait && rc == EAGAIN)+      rc = MDBX_BUSY;+  } else {+    rc = *ipc ? EOWNERDEAD : MDBX_SUCCESS;+    *ipc = env->me_pid;+  }+#else+#error "FIXME"+#endif /* MDBX_LOCKING */++  if (unlikely(rc != MDBX_SUCCESS && rc != MDBX_BUSY))+    rc = mdbx_ipclock_failed(env, ipc, rc);+  return rc;+}++static int mdbx_ipclock_unlock(MDBX_env *env, mdbx_ipclock_t *ipc) {+#if MDBX_LOCKING == MDBX_LOCKING_POSIX2001 ||                                  \+    MDBX_LOCKING == MDBX_LOCKING_POSIX2008+  int rc = pthread_mutex_unlock(ipc);+  (void)env;+#elif MDBX_LOCKING == MDBX_LOCKING_POSIX1988+  int rc = sem_post(ipc) ? errno : MDBX_SUCCESS;+  (void)env;+#elif MDBX_LOCKING == MDBX_LOCKING_SYSV+  if (unlikely(*ipc != (pid_t)env->me_pid))+    return EPERM;+  *ipc = 0;+  struct sembuf op = {+      .sem_num = (ipc != env->me_wlock), .sem_op = 1, .sem_flg = SEM_UNDO};+  int rc = semop(env->me_sysv_ipc.semid, &op, 1) ? errno : MDBX_SUCCESS;+#else+#error "FIXME"+#endif /* MDBX_LOCKING */+  return rc;+}++MDBX_INTERNAL_FUNC int mdbx_rdt_lock(MDBX_env *env) {+  mdbx_trace("%s", ">>");+  mdbx_jitter4testing(true);+  int rc = mdbx_ipclock_lock(env, &env->me_lck->mti_rlock, false);+  mdbx_trace("<< rc %d", rc);+  return rc;+}++MDBX_INTERNAL_FUNC void mdbx_rdt_unlock(MDBX_env *env) {+  mdbx_trace("%s", ">>");+  int rc = mdbx_ipclock_unlock(env, &env->me_lck->mti_rlock);+  mdbx_trace("<< rc %d", rc);+  if (unlikely(rc != MDBX_SUCCESS))+    mdbx_panic("%s() failed: err %d\n", __func__, rc);+  mdbx_jitter4testing(true);+}++int mdbx_txn_lock(MDBX_env *env, bool dont_wait) {+  mdbx_trace("%swait %s", dont_wait ? "dont-" : "", ">>");+  mdbx_jitter4testing(true);+  int rc = mdbx_ipclock_lock(env, env->me_wlock, dont_wait);+  mdbx_trace("<< rc %d", rc);+  return MDBX_IS_ERROR(rc) ? rc : MDBX_SUCCESS;+}++void mdbx_txn_unlock(MDBX_env *env) {+  mdbx_trace("%s", ">>");+  int rc = mdbx_ipclock_unlock(env, env->me_wlock);+  mdbx_trace("<< rc %d", rc);+  if (unlikely(rc != MDBX_SUCCESS))+    mdbx_panic("%s() failed: err %d\n", __func__, rc);+  mdbx_jitter4testing(true);+}++#else+#ifdef _MSC_VER+#pragma warning(disable : 4206) /* nonstandard extension used: translation     \+                                   unit is empty */+#endif                          /* _MSC_VER (warnings) */+#endif                          /* !Windows LCK-implementation */
+ libmdbx.cabal view
@@ -0,0 +1,83 @@+cabal-version: 1.12++-- This file has been generated from package.yaml by hpack version 0.34.4.+--+-- see: https://github.com/sol/hpack++name:           libmdbx+version:        0.1.0.0+synopsis:       Bindings for libmdbx, an embedded key/value store+description:    Haskell bindings for [libmdbx](https://github.com/erthink/libmdbx).+                .+                See documentation in the main module or check the README on GitHub at+                <https://github.com/fjvallarino/libmdbx-hs#readme>.+category:       Database+homepage:       https://github.com/fjvallarino/libmdbx-hs#readme+bug-reports:    https://github.com/fjvallarino/libmdbx-hs/issues+author:         Francisco Vallarino+maintainer:     fjvallarino@gmail.com+copyright:      2021 Francisco Vallarino+license:        BSD3+license-file:   LICENSE+build-type:     Simple+extra-source-files:+    README.md+    ChangeLog.md++source-repository head+  type: git+  location: https://github.com/fjvallarino/libmdbx-hs++library+  exposed-modules:+      Mdbx+      Mdbx.API+      Mdbx.Database+      Mdbx.FFI+      Mdbx.Types+  other-modules:+      Paths_libmdbx+  hs-source-dirs:+      src+  include-dirs:+      cbits/libmdbx+  c-sources:+      cbits/libmdbx/mdbx.c+  build-depends:+      base >=4.7 && <5+    , mtl >=2.1 && <2.3+    , text ==1.2.*+  default-language: Haskell2010++executable libmdbx-exe+  main-is: Main.hs+  other-modules:+      Mdbx.Store+      Paths_libmdbx+  hs-source-dirs:+      app+  ghc-options: -threaded -rtsopts -with-rtsopts=-N+  build-depends:+      base >=4.7 && <5+    , bytestring >=0.10 && <0.12+    , libmdbx+    , mtl >=2.1 && <2.3+    , store ==0.7.*+    , string-interpolate >=0.2 && <0.4+    , text ==1.2.*+  default-language: Haskell2010++test-suite libmdbx-hs-test+  type: exitcode-stdio-1.0+  main-is: Spec.hs+  other-modules:+      Paths_libmdbx+  hs-source-dirs:+      test+  ghc-options: -threaded -rtsopts -with-rtsopts=-N+  build-depends:+      base >=4.7 && <5+    , libmdbx+    , mtl >=2.1 && <2.3+    , text ==1.2.*+  default-language: Haskell2010
+ src/Mdbx.hs view
@@ -0,0 +1,32 @@+{-|+Module      : Mdbx+Copyright   : (c) 2021 Francisco Vallarino+License     : BSD-3-Clause (see the LICENSE file)+Maintainer  : fjvallarino@gmail.com+Stability   : experimental+Portability : non-portable++Main module for libmdbx-hs. This is what most applications should import.++In case you only need to store, update and retrieve data, check the+`Mdbx.Database` module.++You will also want to check `Mdbx.Types` in order to be able to store your data+types. In general, you will also want to use a serialization library such as+[store](https://hackage.haskell.org/package/store) or+[cereal](https://hackage.haskell.org/package/cereal).++If you want fine grained control or using cursors, check `Mdbx.API`.++The `Mdbx.FFI` (not exported by this module) provides direct, low level,+bindings to libmdbx.+-}+module Mdbx (+  module Mdbx.API,+  module Mdbx.Database,+  module Mdbx.Types+) where++import Mdbx.API+import Mdbx.Database+import Mdbx.Types
+ src/Mdbx/API.hs view
@@ -0,0 +1,279 @@+{-|+Module      : Mdbx.API+Copyright   : (c) 2021 Francisco Vallarino+License     : BSD-3-Clause (see the LICENSE file)+Maintainer  : fjvallarino@gmail.com+Stability   : experimental+Portability : non-portable++Thin wrappers over the low level API to provide MonadIO support and exception+based error handling.+-}+{-# LANGUAGE FlexibleContexts #-}++module Mdbx.API (+  -- Keys+  keyCmp,+  -- Env+  envOpen,+  envClose,+  -- Txn+  txnBegin,+  txnCommit,+  txnAbort,+  -- Dbi+  dbiOpen,+  dbiClose,+  -- Val+  itemPut,+  itemGet,+  itemDel,+  -- Cursor+  cursorOpen,+  cursorClose,+  cursorPut,+  cursorDel,+  cursorFirst,+  cursorLast,+  cursorAt,+  cursorRange,+  cursorNext,+  cursorPrev,+  cursorMove+) where++import Control.Monad.IO.Class (MonadIO, liftIO)++import Mdbx.FFI++{-|+Compares two keys and returns -1, 0 or 1 if key1 is lower, equal or greater than+key2.+-}+keyCmp+  :: MonadIO m+  => MdbxTxn+  -> MdbxDbi+  -> MdbxVal+  -> MdbxVal+  -> m Int+keyCmp txn dbi key1 key2 = liftIO $ mdbx_cmp txn dbi key1 key2++-- | Opens an environment.+envOpen+  :: (MonadIO m, MonadFail m)+  => String+  -> [MdbxEnvFlags]+  -> m MdbxEnv+envOpen path flags = do+  (retCreate, env) <- liftIO mdbx_env_create+  checkError () retCreate+  retOpen <- liftIO $ mdbx_env_open env path flags 0o644+  checkError env retOpen++-- | Close an environment.+envClose+  :: (MonadIO m, MonadFail m)+  => MdbxEnv+  -> m ()+envClose env = do+  ret <- liftIO $ mdbx_env_close env+  checkError () ret++-- | Begins a transaction.+txnBegin+  :: (MonadIO m, MonadFail m)+  => MdbxEnv+  -> Maybe MdbxTxn+  -> [MdbxTxnFlags]+  -> m MdbxTxn+txnBegin env parent flags = do+  (ret, txn) <- liftIO $ mdbx_txn_begin env parent flags+  checkError txn ret++-- | Commits a transaction.+txnCommit+  :: (MonadIO m, MonadFail m)+  => MdbxTxn+  -> m ()+txnCommit txn = do+  ret <- liftIO $ mdbx_txn_commit txn+  checkError () ret++-- | Aborts a transaction.+txnAbort+  :: (MonadIO m, MonadFail m)+  => MdbxTxn+  -> m ()+txnAbort txn = do+  ret <- liftIO $ mdbx_txn_abort txn+  checkError () ret++-- | Opens a database (table).+dbiOpen+  :: (MonadIO m, MonadFail m)+  => MdbxEnv+  -> Maybe String+  -> [MdbxDbFlags]+  -> m MdbxDbi+dbiOpen env name flags = do+  txn <- txnBegin env Nothing []+  (ret, dbi) <- liftIO $ mdbx_dbi_open txn name flags+  txnAbort txn+  checkError dbi ret++-- | Closes a database.+dbiClose+  :: (MonadIO m, MonadFail m)+  => MdbxEnv+  -> MdbxDbi+  -> m ()+dbiClose env dbi = do+  ret <- liftIO $ mdbx_dbi_close env dbi+  checkError () ret++-- | Returns the value associated to the given key, if any.+itemGet+  :: (MonadIO m, MonadFail m)+  => MdbxTxn+  -> MdbxDbi+  -> MdbxVal+  -> m (Maybe MdbxVal)+itemGet txn db key = do+  (ret, val) <- liftIO $ mdbx_get txn db key+  if ret == fromEnum MdbxNotfound+    then return Nothing+    else checkError (Just val) ret++-- | Saves the provided key/value pair.+itemPut+  :: (MonadIO m, MonadFail m)+  => MdbxTxn+  -> MdbxDbi+  -> MdbxVal+  -> MdbxVal+  -> [MdbxPutFlags]+  -> m ()+itemPut txn db key val flags = do+  ret <- liftIO $ mdbx_put txn db key val flags+  checkError () ret++-- | Deletes the value associated with the given key, if any.+itemDel+  :: (MonadIO m, MonadFail m)+  => MdbxTxn+  -> MdbxDbi+  -> MdbxVal+  -> Maybe MdbxVal+  -> m ()+itemDel txn db key mval = do+  ret <- liftIO $ mdbx_del txn db key mval+  checkError () ret++-- | Opens a cursor.+cursorOpen+  :: (MonadIO m, MonadFail m)+  => MdbxTxn+  -> MdbxDbi+  -> m MdbxCursor+cursorOpen txn dbi = do+  (ret, cur) <- liftIO $ mdbx_cursor_open txn dbi+  checkError cur ret++-- | Closes a cursor.+cursorClose+  :: (MonadIO m, MonadFail m)+  => MdbxCursor+  -> m ()+cursorClose cur = do+  liftIO $ mdbx_cursor_close cur++-- | Stores the provided value at the given key, positioning the cursor on it.+cursorPut+  :: (MonadIO m, MonadFail m)+  => MdbxCursor+  -> MdbxVal+  -> MdbxVal+  -> [MdbxPutFlags]+  -> m ()+cursorPut cur key val flags = do+  ret <- liftIO $ mdbx_cursor_put cur key val flags+  checkError () ret++-- | Deletes the value at the current position.+cursorDel+  :: (MonadIO m, MonadFail m)+  => MdbxCursor+  -> [MdbxPutFlags]+  -> m ()+cursorDel cur flags = do+  ret <- liftIO $ mdbx_cursor_del cur flags+  checkError () ret++-- | Moves to the first key on the database.+cursorFirst+  :: (MonadIO m, MonadFail m)+  => MdbxCursor+  -> m (Maybe (MdbxVal, MdbxVal))+cursorFirst cur = cursorMove cur emptyMdbxVal MdbxFirst++-- | Moves to the last key on the database.+cursorLast+  :: (MonadIO m, MonadFail m)+  => MdbxCursor+  -> m (Maybe (MdbxVal, MdbxVal))+cursorLast cur = cursorMove cur emptyMdbxVal MdbxLast++-- | Moves to the given key.+cursorAt+  :: (MonadIO m, MonadFail m)+  => MdbxCursor+  -> MdbxVal+  -> m (Maybe (MdbxVal, MdbxVal))+cursorAt cur key = cursorMove cur key MdbxSetKey++-- | Moves to the given key or first greater than it. Useful for searching.+cursorRange+  :: (MonadIO m, MonadFail m)+  => MdbxCursor+  -> MdbxVal+  -> m (Maybe (MdbxVal, MdbxVal))+cursorRange cur key = cursorMove cur key MdbxSetRange++-- | Moves to the next key.+cursorNext+  :: (MonadIO m, MonadFail m)+  => MdbxCursor+  -> m (Maybe (MdbxVal, MdbxVal))+cursorNext cur = cursorMove cur emptyMdbxVal MdbxNext++-- | Moves to the previous key.+cursorPrev+  :: (MonadIO m, MonadFail m)+  => MdbxCursor+  -> m (Maybe (MdbxVal, MdbxVal))+cursorPrev cur = cursorMove cur emptyMdbxVal MdbxPrev++-- | Moves the cursor using the provided operation.+cursorMove+  :: (MonadIO m, MonadFail m)+  => MdbxCursor+  -> MdbxVal+  -> MdbxCursorOp+  -> m (Maybe (MdbxVal, MdbxVal))+cursorMove cur baseKey op = do+  (ret, key, val) <- liftIO $ mdbx_cursor_get cur baseKey op+  if ret == fromEnum MdbxNotfound+    then return Nothing+    else checkError (Just (key, val)) ret++-- Helpers+checkError+  :: (MonadIO m, MonadFail m)+  => a+  -> Int+  -> m a+checkError val 0 = return val+checkError _ code = do+  msg <- liftIO $ mdbx_strerror code+  fail msg
+ src/Mdbx/Database.hs view
@@ -0,0 +1,169 @@+{-|+Module      : Mdbx.Database+Copyright   : (c) 2021 Francisco Vallarino+License     : BSD-3-Clause (see the LICENSE file)+Maintainer  : fjvallarino@gmail.com+Stability   : experimental+Portability : non-portable++High level API to create, update, delete and query an MDBX database.+-}+module Mdbx.Database (+  -- * Get+  getItem,+  getItems,+  -- * Query+  getRange,+  -- * Save+  putItem,+  putItems,+  -- * Delete+  delItem,+  delItems+) where++import Control.Monad (forM, forM_, void)+import Control.Monad.IO.Class (MonadIO, liftIO)+import Data.Function (fix)+import Data.Maybe (catMaybes, fromJust)++import Mdbx.API+import Mdbx.Types++-- | Returns the value associated with the given key, if any.+getItem+  :: (MonadIO m, MonadFail m, MdbxItem k, MdbxItem v)+  => MdbxEnv       -- ^ The environment.+  -> MdbxDbi       -- ^ The database.+  -> k             -- ^ The key to lookup.+  -> m (Maybe v)   -- ^ The matching value, if any.+getItem env dbi key = do+  txn <- txnBegin env Nothing [MdbxTxnRdonly]++  resp <- liftIO $ toMdbxVal key $ \mkey -> do+    mval <- itemGet txn dbi mkey+    mapM fromMdbxVal mval+  void $ txnCommit txn+  return resp++{-|+Returns the values associated to a list of keys. Returned length may not match+that of provided keys in case some of them are not found.+-}+getItems+  :: (MonadIO m, MonadFail m, MdbxItem k, MdbxItem v)+  => MdbxEnv       -- ^ The environment.+  -> MdbxDbi       -- ^ The database.+  -> [k]           -- ^ The keys to lookup.+  -> m [v]         -- ^ The matching values. Length may not match that of keys.+getItems env dbi keys = do+  txn <- txnBegin env Nothing [MdbxTxnRdonly]++  resp <- forM keys $ \key ->+    liftIO $ toMdbxVal key $ \mkey -> do+      mval <- itemGet txn dbi mkey+      mapM fromMdbxVal mval+  void $ txnCommit txn+  return $ catMaybes resp++-- | Returns the list of values whose keys lie between the provided range.+getRange+  :: (MonadIO m, MonadFail m, MdbxItem k, MdbxItem v)+  => MdbxEnv       -- ^ The environment.+  -> MdbxDbi       -- ^ The database.+  -> k             -- ^ The start of the range (inclusive).+  -> k             -- ^ The end of the range (inclusive).+  -> m [v]         -- ^ The matching values.+getRange env dbi start end = do+  txn <- txnBegin env Nothing [MdbxTxnRdonly]+  cursor <- cursorOpen txn dbi++  pairs <- liftIO $ toMdbxVal start $ \skey ->+    liftIO $ toMdbxVal end $ \ekey -> do+      pair1 <- cursorRange cursor skey+      flip fix (pair1, []) $ \loop (pair, items) -> do+        isValid <- pairLEKey txn dbi ekey pair++        if isValid+          then do+            val <- fromMdbxVal . snd . fromJust $ pair+            newPair <- cursorNext cursor++            loop (newPair, val : items)+          else return items++  void $ txnCommit txn+  return $ reverse pairs++-- | Saves the given key/value pair.+putItem+  :: (MonadIO m, MonadFail m, MdbxItem k, MdbxItem v)+  => MdbxEnv       -- ^ The environment.+  -> MdbxDbi       -- ^ The database.+  -> k             -- ^ The key.+  -> v             -- ^ The value.+  -> m ()+putItem env dbi key item = do+  txn <- txnBegin env Nothing []+  liftIO $ toMdbxVal key $ \mkey ->+    liftIO $ toMdbxVal item $ \mitem ->+      itemPut txn dbi mkey mitem []+  void $ txnCommit txn++-- | Saves the given key/value pairs. Runs in a single transaction.+putItems+  :: (MonadIO m, MonadFail m, MdbxItem k, MdbxItem v)+  => MdbxEnv       -- ^ The environment.+  -> MdbxDbi       -- ^ The database.+  -> [(k, v)]      -- ^ The list of key/value pairs.+  -> m ()+putItems env dbi items = do+  txn <- txnBegin env Nothing []+  forM_ items $ \(key, item) ->+    liftIO $ toMdbxVal key $ \mkey ->+      liftIO $ toMdbxVal item $ \mitem ->+        itemPut txn dbi mkey mitem []+  void $ txnCommit txn++-- | Deletes the item associated with the given key, if any.+delItem+  :: (MonadIO m, MonadFail m, MdbxItem k)+  => MdbxEnv       -- ^ The environment.+  -> MdbxDbi       -- ^ The database.+  -> k             -- ^ The key to delete.+  -> m ()+delItem env dbi key = do+  txn <- txnBegin env Nothing []+  liftIO $ toMdbxVal key $ \mkey ->+    itemDel txn dbi mkey Nothing+  void $ txnCommit txn++{-|+Deletes the items associated with the given keys, if any. Runs in a single+transaction.+-}+delItems+  :: (MonadIO m, MonadFail m, MdbxItem k)+  => MdbxEnv       -- ^ The environment.+  -> MdbxDbi       -- ^ The database.+  -> [k]           -- ^ The keys to delete.+  -> m ()+delItems env dbi keys = do+  txn <- txnBegin env Nothing []+  forM_ keys $ \key ->+    liftIO $ toMdbxVal key $ \mkey ->+      itemDel txn dbi mkey Nothing+  void $ txnCommit txn++-- Helpers++-- | Checks if the key of the key/value pair is lower than the provided key.+pairLEKey+  :: (MonadIO m, MonadFail m)+  => MdbxTxn       -- ^ The active transaction.+  -> MdbxDbi       -- ^ The database.+  -> MdbxVal       -- ^ The reference key.+  -> Maybe (MdbxVal, MdbxVal)  -- ^ The key/value pair to check+  -> m Bool        -- ^ True if the key/value is lower or equal than the key.+pairLEKey txn dbi end Nothing = return False+pairLEKey txn dbi end (Just (key, _)) = (<= 0) <$> keyCmp txn dbi key end
+ src/Mdbx/FFI.chs view
@@ -0,0 +1,366 @@+{-|+Module      : Mdbx.FFI+Copyright   : (c) 2021 Francisco Vallarino+License     : BSD-3-Clause (see the LICENSE file)+Maintainer  : fjvallarino@gmail.com+Stability   : experimental+Portability : non-portable++Low level bindings to libmdbx functions.+-}+{-# LANGUAGE DerivingStrategies #-}+{-# LANGUAGE GeneralisedNewtypeDeriving #-}+{-# LANGUAGE StandaloneDeriving #-}++module Mdbx.FFI (+  -- * Environment+  MdbxEnvFlags(..),+  MdbxEnv(..),+  MdbxEnvMode(..),+  mdbx_env_create,+  mdbx_env_open,+  mdbx_env_close,++  -- * Transaction+  MdbxTxnFlags(..),+  MdbxTxn(..),+  mdbx_txn_begin,+  mdbx_txn_commit,+  mdbx_txn_abort,+  mdbx_txn_env,++  -- * Database+  MdbxDbFlags(..),+  MdbxDbi(..),+  mdbx_dbi_open,+  mdbx_dbi_close,++  -- * Data+  MdbxVal(..),+  emptyMdbxVal,++  -- * CRUD+  MdbxPutFlags(..),+  mdbx_put,+  mdbx_get,+  mdbx_del,++  -- * Cursor+  MdbxCursorOp(..),+  MdbxCursor(..),+  mdbx_cursor_open,+  mdbx_cursor_close,+  mdbx_cursor_del,+  mdbx_cursor_get,+  mdbx_cursor_put,+  mdbx_cursor_count,+  mdbx_strerror,+  mdbx_cmp,++  -- * Error+  MdbxError(..)+) where++import Foreign+import Foreign.C++#include "mdbx.h"++-- Common+{# typedef size_t CSize #}++-- | Error codes for the different operations.+{# enum MDBX_error_t as MdbxError {underscoreToCase} deriving (Show, Eq, Ord) #}++-- Environment++-- | Environment object, needed for all the operations.+{# pointer *MDBX_env as MdbxEnv newtype #}+deriving instance Storable MdbxEnv++-- | Flags for opening and environment.+data MdbxEnvFlags+  = MdbxEnvDefaults+  | MdbxSyncDurable+  | MdbxNosubdir+  | MdbxSafeNosync+  | MdbxMapasync+  | MdbxRdonly+  | MdbxNometasync+  | MdbxWritemap+  | MdbxUtterlyNosync+  | MdbxNotls+  | MdbxExclusive+  | MdbxNordahead+  | MdbxNomeminit+  | MdbxCoalesce+  | MdbxLiforeclaim+  | MdbxPageperturb+  | MdbxAccede+  deriving (Show, Eq, Ord)++--{# enum MDBX_env_flags_t as MdbxEnvFlags {underscoreToCase} deriving (Show, Eq, Ord) #}+{# enum MDBX_env_flags_t as MdbxEnvFlags nocode {underscoreToCase} #}++-- | UNIX permissions to set on created files. Zero value means to open existing, but do not create.+type MdbxEnvMode = {# type mdbx_mode_t  #}+{# typedef mdbx_mode_t MdbxEnvMode #}++-- Opening and closing.++-- | Creates an environment. Represents a database in the file system.+{# fun unsafe mdbx_env_create {alloca- `MdbxEnv' peek*} -> `Int' #}++-- | Opens an environment. Receives name, flags and mode.+{# fun unsafe mdbx_env_open {`MdbxEnv', `String', bitMask`[MdbxEnvFlags]', `MdbxEnvMode'} -> `Int' #}++-- | Closes an environment.+{# fun unsafe mdbx_env_close {`MdbxEnv'} -> `Int' #}++{-- Closes an env (env, dontSync) --}+-- Fails under ghci+-- {# fun unsafe mdbx_env_close_ex {`MdbxEnv', `Bool'} -> `Int' #}++-- Transaction++-- | Transaction instance. Needed for all operations with data, even reading.+{# pointer *MDBX_txn as MdbxTxn newtype #}+deriving instance Storable MdbxTxn++-- | Flags for a transaction.+data MdbxTxnFlags+  = MdbxTxnReadwrite+  | MdbxTxnNosync+  | MdbxTxnRdonly+  | MdbxTxnNometasync+  | MdbxTxnRdonlyPrepare+  | MdbxTxnTry+  deriving (Show, Eq, Ord)++-- {# enum MDBX_txn_flags_t as MdbxTxnFlags {underscoreToCase} deriving (Show, Eq, Ord) #}+{# enum MDBX_txn_flags_t as MdbxTxnFlags nocode {underscoreToCase} #}++{-|+Begins a new transaction.++Arguments:++- Environment.+- Parent transaction, or Nothing.+- Flags.+-}+{# fun unsafe mdbx_txn_begin {`MdbxEnv', maybeTxn* `Maybe MdbxTxn', bitMask`[MdbxTxnFlags]', alloca- `MdbxTxn' peek*} -> `Int' #}++-- | Commits a transaction.+{# fun unsafe mdbx_txn_commit {`MdbxTxn'} -> `Int' #}++-- | Aborts a transaction.+{# fun unsafe mdbx_txn_abort {`MdbxTxn'} -> `Int' #}++-- | Gets the environment from a transaction.+{# fun unsafe mdbx_txn_env {`MdbxTxn'} -> `MdbxEnv' #}++-- MdbxEnv* mdbx_txn_env	(	const MdbxTxn * 	txn	)++-- Database++-- | Database instance. Represents a logical table in the database.+type MdbxDbi = {# type MDBX_dbi #}+{# typedef MDBX_dbi MdbxDbi #}++-- | Flags for a database.+data MdbxDbFlags+  = MdbxDbDefaults+  | MdbxReversekey+  | MdbxDupsort+  | MdbxIntegerkey+  | MdbxDupfixed+  | MdbxIntegerdup+  | MdbxReversedup+  | MdbxCreate+  | MdbxDbAccede+  deriving (Show, Eq, Ord)++--{# enum MDBX_db_flags_t as MdbxDbFlags {underscoreToCase} deriving (Show, Eq, Ord) #}+{# enum MDBX_db_flags_t as MdbxDbFlags nocode {underscoreToCase} #}++{-|+Opens a database.++Arguments:++- Transaction.+- Name.+- Flags.+-}+{# fun unsafe mdbx_dbi_open {`MdbxTxn', maybeString* `Maybe String', bitMask`[MdbxDbFlags]', alloca- `MdbxDbi' peek*} -> `Int' #}++-- | Closes a database.+{# fun unsafe mdbx_dbi_close {`MdbxEnv', `MdbxDbi'} -> `Int' #}++-- CRUD++-- | Binary blob representing a key or value in the database.+data MdbxVal = MdbxVal {+  mvlSize :: {-# UNPACK #-} !{# type size_t #},+  mvlData :: {-# UNPACK #-} !(Ptr ())+} deriving (Eq, Show)++--instance Show MdbxVal where+--  show (MdbxVal sz dt) = "MdbxVal { size = " ++ show sz ++ ", data = " ++ show dt ++ " }"++instance Storable MdbxVal where+  sizeOf _ = {# sizeof MDBX_val #}+  alignment _ = {# alignof MDBX_val #}+  peek ptr = do+    sz <- {# get MDBX_val->iov_len #} ptr+    pd <- {# get MDBX_val->iov_base #} ptr+    return $! MdbxVal sz pd+  poke ptr (MdbxVal sz pd) = do+    {# set MDBX_val->iov_len #} ptr sz+    {# set MDBX_val->iov_base #} ptr pd++-- | Sample empty value+emptyMdbxVal :: MdbxVal+emptyMdbxVal = MdbxVal 0 nullPtr++{# pointer *MDBX_val as MdbxValPtr -> MdbxVal #}++-- | Flags for all data related operations.+data MdbxPutFlags+  = MdbxUpsert+  | MdbxNooverwrite+  | MdbxNodupdata+  | MdbxCurrent+  | MdbxAlldups+  | MdbxReserve+  | MdbxAppend+  | MdbxAppenddup+  | MdbxMultiple+  deriving (Show, Eq, Ord)++--{# enum MDBX_put_flags_t as MdbxPutFlags {underscoreToCase} deriving (Show, Eq, Ord) #}+{# enum MDBX_put_flags_t as MdbxPutFlags nocode {underscoreToCase} #}++{-|+Stores a key/value pair.++Arguments:++- Transaction.+- Database.+- Key.+- Value.+-}+{# fun unsafe mdbx_put {`MdbxTxn', `MdbxDbi', with* `MdbxVal', with* `MdbxVal', bitMask`[MdbxPutFlags]'} -> `Int' #}++{-|+Gets a value with the given key.++Arguments:++- Transaction.+- Database.+- Key.+-}+{# fun unsafe mdbx_get {`MdbxTxn', `MdbxDbi', with* `MdbxVal', alloca- `MdbxVal' peek*} -> `Int' #}++{-|+Gets a value with the given key.++Arguments:++- Transaction.+- Database.+- Key.+-}+{# fun unsafe mdbx_del {`MdbxTxn', `MdbxDbi', with* `MdbxVal', withMaybe* `Maybe MdbxVal'} -> `Int' #}++-- Cursor++-- | Cursor instance. Used for efficient navigation in a database.+{# pointer *MDBX_cursor as MdbxCursor newtype #}+deriving instance Storable MdbxCursor++-- | Flags for cursor operations.+data MdbxCursorOp+  = MdbxFirst+  | MdbxFirstDup+  | MdbxGetBoth+  | MdbxGetBothRange+  | MdbxGetCurrent+  | MdbxGetMultiple+  | MdbxLast+  | MdbxLastDup+  | MdbxNext+  | MdbxNextDup+  | MdbxNextMultiple+  | MdbxNextNodup+  | MdbxPrev+  | MdbxPrevDup+  | MdbxPrevNodup+  | MdbxSet+  | MdbxSetKey+  | MdbxSetRange+  | MdbxPrevMultiple+  | MdbxSetLowerbound+  deriving (Show, Eq, Ord)++--{# enum MDBX_cursor_op as MdbxCursorOp {underscoreToCase} deriving (Show, Eq, Ord) #}+{# enum MDBX_cursor_op as MdbxCursorOp nocode {underscoreToCase} #}++{-|+Opens a new cursor.++Arguments:++- Transaction.+- Database.+-}+{# fun unsafe mdbx_cursor_open {`MdbxTxn', `MdbxDbi', alloca- `MdbxCursor' peek*} -> `Int' #}++-- | Closes a cursor.+{# fun unsafe mdbx_cursor_close {`MdbxCursor'} -> `()' #}++-- | Removes the current key/value pair.+{# fun unsafe mdbx_cursor_del {`MdbxCursor', bitMask`[MdbxPutFlags]'} -> `Int' #}++-- | Returns the current key/value pair.+{# fun unsafe mdbx_cursor_get {`MdbxCursor', with* `MdbxVal' peek*, alloca- `MdbxVal' peek*, `MdbxCursorOp'} -> `Int' #}++{-| Sets the value for the current key.++Arguments:++- Cursor.+- Key.+- Value.+- FLags.+-}+{# fun unsafe mdbx_cursor_put {`MdbxCursor', with* `MdbxVal', with* `MdbxVal', bitMask`[MdbxPutFlags]'} -> `Int' #}++-- | Returns the count of duplicates in the current key.+{# fun unsafe mdbx_cursor_count {`MdbxCursor', alloca- `CSize' peek*} -> `Int' #}++-- Helpers++-- | Returns the description of a given error number.+{# fun unsafe mdbx_strerror {`Int'} -> `String' #}++-- | Compares two values as a binary blob.+{# fun unsafe mdbx_cmp {`MdbxTxn', `MdbxDbi', with* `MdbxVal', with* `MdbxVal'} -> `Int' #}++bitMask :: Enum a => [a] -> C2HSImp.CInt+bitMask = foldl (.|.) 0 . fmap (fromIntegral . fromEnum)++maybeString :: Maybe String -> (Ptr CChar -> IO c) -> IO c+maybeString Nothing fn = fn nullPtr+maybeString (Just val) fn = withCString val fn++maybeTxn :: Maybe MdbxTxn -> (MdbxTxn -> IO c) -> IO c+maybeTxn Nothing fn = fn (MdbxTxn nullPtr)+maybeTxn (Just val) fn = fn val++withMaybe :: Storable a => Maybe a -> (Ptr a -> IO c) -> IO c+withMaybe Nothing fn = fn nullPtr+withMaybe (Just val) fn = with val fn
+ src/Mdbx/Types.hs view
@@ -0,0 +1,108 @@+{-|+Module      : Mdbx.Types+Copyright   : (c) 2021 Francisco Vallarino+License     : BSD-3-Clause (see the LICENSE file)+Maintainer  : fjvallarino@gmail.com+Stability   : experimental+Portability : non-portable++Types used by the library. Mainly re exports the types generated by c2hs in the+FFI module, while also adding some types used by the high level interface.+-}+module Mdbx.Types (+  -- * Re-exported from FFI+  MdbxEnv,+  MdbxTxn,+  MdbxDbi,+  MdbxVal(..),+  MdbxEnvMode(..),+  MdbxEnvFlags(..),+  MdbxTxnFlags(..),+  MdbxDbFlags(..),+  MdbxPutFlags(..),+  MdbxCursorOp(..),+  -- * High level interface+  MdbxItem(..)+) where++import Data.Text (Text)+import Data.Text.Foreign (fromPtr, useAsPtr)+import Foreign.Ptr (castPtr)++import Mdbx.FFI++{-|+Converts an instance to/from the representation needed by libmdbx. This type is+used for both keys and values.++Only the Text instance is provided, since it is commonly used as the key when+storing/retrieving a value.++For your own types, in general, you will want to use a serialization library+such as store, cereal, etc, and apply the newtype deriving via trick. ++For store (this can be found in the example application), the instance can be+defined as:++@+newtype MdbxItemStore a = MdbxItemStore {+  unwrapStore :: a+}++instance Store a => MdbxItem (MdbxItemStore a) where+  fromMdbxVal item = MdbxItemStore <$> fromMdbxStore item+  toMdbxVal item = withMdbxStore (unwrapStore item)++fromMdbxStore :: Store v => MdbxVal -> IO v+fromMdbxStore (MdbxVal size ptr) = do+  bs <- unsafePackCStringLen (castPtr ptr, fromIntegral size)+  decodeIO bs++withMdbxStore :: Store v => v -> (MdbxVal -> IO a) -> IO a+withMdbxStore val fn =+  unsafeUseAsCStringLen bsV $ \(ptrV, sizeV) -> do+    let mval = MdbxVal (fromIntegral sizeV) (castPtr ptrV)+    fn mval+  where+    bsV = encode val+@++This code can be adaptad to other serialization libraries. It is not provided as+part of libmdbx-hs itself to avoid forcing dependencies.++Then, to derive the instance for your owwn type:++@+data User = User {+  _username :: Text,+  _password :: Text+} deriving (Eq, Show, Generic, Store)++deriving via (MdbxItemStore User) instance MdbxItem User+@++Note: if you plan on using a custom type as the key, be careful if it contains+Text or Bytestring instances, since these types have a length field which is,+in general, before the data. This can issues when using cursors, since those+depend on key ordering and the length field will make shorter instances lower+than longer ones, even if the content indicates the opposite. In general, it is+simpler to use Text as the key.+-}+class MdbxItem i where+  {-|+  Converts a block of memory provided by libmdbx to a user data type. There are+  no guarantees provided by the library that the block of memory matches the+  expected type, and a crash can happen if not careful.+  -}+  fromMdbxVal :: MdbxVal -> IO i+  {-+  Converts a user data type to a block of memory.+  -}+  toMdbxVal :: i -> (MdbxVal -> IO b) -> IO b++instance MdbxItem Text where+  fromMdbxVal (MdbxVal sz ptr) =+    fromPtr (castPtr ptr) (fromIntegral sz `div` 2)++  toMdbxVal val fn = useAsPtr val $ \ptr size ->+    fn $ MdbxVal (fromIntegral size * 2) (castPtr ptr)
+ test/Spec.hs view
@@ -0,0 +1,2 @@+main :: IO ()+main = putStrLn "Test suite not yet implemented"