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ppad-lmdb (empty) → 0.1.0

raw patch · 13 files changed

+13823/−0 lines, 13 filesdep +QuickCheckdep +basedep +bytestring

Dependencies added: QuickCheck, base, bytestring, containers, criterion, directory, filepath, ppad-lmdb, tasty, tasty-hunit, tasty-quickcheck, weigh

Files

+ CHANGELOG view
@@ -0,0 +1,6 @@+# Changelog++- 0.1.0 (2026-05-24)+  * Initial release, consisting of support for LMDB environments,+    transactions, basic row operations (get, put, del), and range scans.+
+ LICENSE view
@@ -0,0 +1,20 @@+Copyright (c) 2026 Jared Tobin++Permission is hereby granted, free of charge, to any person obtaining+a copy of this software and associated documentation files (the+"Software"), to deal in the Software without restriction, including+without limitation the rights to use, copy, modify, merge, publish,+distribute, sublicense, and/or sell copies of the Software, and to+permit persons to whom the Software is furnished to do so, subject to+the following conditions:++The above copyright notice and this permission notice shall be included+in all copies or substantial portions of the Software.++THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.+IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY+CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,+TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE+SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ bench/Main.hs view
@@ -0,0 +1,84 @@+{-# LANGUAGE BangPatterns      #-}+{-# LANGUAGE OverloadedStrings #-}++module Main where++import Control.Monad (forM_)+import Criterion.Main+import qualified Data.ByteString as BS+import qualified Data.ByteString.Builder as BB+import qualified Data.ByteString.Lazy as BSL+import qualified Database.LMDB as L+import System.Directory+  ( createDirectory+  , doesDirectoryExist+  , getTemporaryDirectory+  , removeDirectoryRecursive+  )+import System.FilePath ((</>))++main :: IO ()+main = do+  tmpRoot <- getTemporaryDirectory+  let dir = tmpRoot </> "ppad-lmdb-bench"+  exists <- doesDirectoryExist dir+  if exists then removeDirectoryRecursive dir else pure ()+  createDirectory dir+  let flags = L.defaultEnvFlags+                { L.envMapSize = 128 * 1024 * 1024+                , L.envMaxDbs  = 4+                }+  L.withEnv dir flags $ \env -> do+    -- pre-populate+    L.withWriteTxn env $ \txn -> do+      dbi <- L.openDbi txn Nothing True+      forM_ (kvs 10000) $ \(k, v) -> L.put txn dbi k v+    defaultMain+      [ bgroup "put"+          [ bench "1k inserts (one txn)"  $ whnfIO (insert env 1000)+          , bench "10k inserts (one txn)" $ whnfIO (insert env 10000)+          ]+      , bgroup "get"+          [ bench "1k random hits"        $ whnfIO (readN env 1000)+          , bench "10k random hits"       $ whnfIO (readN env 10000)+          ]+      , bgroup "cursor"+          [ bench "scan 10k entries"      $ whnfIO (scanAll env)+          ]+      ]+  removeDirectoryRecursive dir++-- key/value helpers ----------------------------------------------------------++kvs :: Int -> [(BS.ByteString, BS.ByteString)]+kvs n = [ (mkKey i, mkVal i) | i <- [0 .. n - 1] ]++mkKey :: Int -> BS.ByteString+mkKey i = BSL.toStrict (BB.toLazyByteString (BB.string7 "k" <> BB.intDec i))++mkVal :: Int -> BS.ByteString+mkVal i = BSL.toStrict (BB.toLazyByteString (BB.string7 "v" <> BB.intDec i))++-- workloads ------------------------------------------------------------------++insert :: L.Env -> Int -> IO ()+insert env n = L.withWriteTxn env $ \txn -> do+  dbi <- L.openDbi txn Nothing False+  forM_ (kvs n) $ \(k, v) -> L.put txn dbi k v++readN :: L.Env -> Int -> IO ()+readN env n = L.withReadTxn env $ \txn -> do+  dbi <- L.openDbi txn Nothing False+  forM_ [0 .. n - 1] $ \i -> do+    _ <- L.get txn dbi (mkKey i)+    pure ()++scanAll :: L.Env -> IO Int+scanAll env = L.withReadTxn env $ \txn -> do+  dbi <- L.openDbi txn Nothing False+  L.withCursor txn dbi $ \cur -> do+    let go !acc Nothing  = pure acc+        go !acc (Just _) = L.cursorNext cur >>= go (acc + 1)+    mfirst <- L.cursorFirst cur+    go (0 :: Int) mfirst+
+ bench/Weight.hs view
@@ -0,0 +1,70 @@+{-# LANGUAGE BangPatterns      #-}+{-# LANGUAGE OverloadedStrings #-}++module Main where++import Control.Monad (forM_)+import qualified Data.ByteString as BS+import qualified Data.ByteString.Builder as BB+import qualified Data.ByteString.Lazy as BSL+import qualified Database.LMDB as L+import System.Directory+  ( createDirectory+  , doesDirectoryExist+  , getTemporaryDirectory+  , removeDirectoryRecursive+  )+import System.FilePath ((</>))+import Weigh++main :: IO ()+main = do+  tmpRoot <- getTemporaryDirectory+  let dir = tmpRoot </> "ppad-lmdb-weigh"+  exists <- doesDirectoryExist dir+  if exists then removeDirectoryRecursive dir else pure ()+  createDirectory dir+  let envFlags = L.defaultEnvFlags+                   { L.envMapSize = 64 * 1024 * 1024+                   , L.envMaxDbs  = 4+                   }+  L.withEnv dir envFlags $ \env -> do+    L.withWriteTxn env $ \txn -> do+      dbi <- L.openDbi txn Nothing True+      forM_ (kvs 1000) $ \(k, v) -> L.put txn dbi k v+    mainWith $ do+      io "1k put (one txn)"  (insert env) 1000+      io "1k get (one txn)"  (readN env)  1000+      io "scan 1k entries"   scanAll      env+  existsAfter <- doesDirectoryExist dir+  if existsAfter then removeDirectoryRecursive dir else pure ()++kvs :: Int -> [(BS.ByteString, BS.ByteString)]+kvs n = [ (mkKey i, mkVal i) | i <- [0 .. n - 1] ]++mkKey :: Int -> BS.ByteString+mkKey i = BSL.toStrict (BB.toLazyByteString (BB.string7 "k" <> BB.intDec i))++mkVal :: Int -> BS.ByteString+mkVal i = BSL.toStrict (BB.toLazyByteString (BB.string7 "v" <> BB.intDec i))++insert :: L.Env -> Int -> IO ()+insert env n = L.withWriteTxn env $ \txn -> do+  dbi <- L.openDbi txn Nothing False+  forM_ (kvs n) $ \(k, v) -> L.put txn dbi k v++readN :: L.Env -> Int -> IO ()+readN env n = L.withReadTxn env $ \txn -> do+  dbi <- L.openDbi txn Nothing False+  forM_ [0 .. n - 1] $ \i -> do+    _ <- L.get txn dbi (mkKey i)+    pure ()++scanAll :: L.Env -> IO Int+scanAll env = L.withReadTxn env $ \txn -> do+  dbi <- L.openDbi txn Nothing False+  L.withCursor txn dbi $ \cur -> do+    mfirst <- L.cursorFirst cur+    let go !acc Nothing  = pure acc+        go !acc (Just _) = L.cursorNext cur >>= go (acc + 1)+    go (0 :: Int) mfirst
+ cbits/LICENSE view
@@ -0,0 +1,47 @@+The OpenLDAP Public License+  Version 2.8, 17 August 2003++Redistribution and use of this software and associated documentation+("Software"), with or without modification, are permitted provided+that the following conditions are met:++1. Redistributions in source form must retain copyright statements+   and notices,++2. Redistributions in binary form must reproduce applicable copyright+   statements and notices, this list of conditions, and the following+   disclaimer in the documentation and/or other materials provided+   with the distribution, and++3. Redistributions must contain a verbatim copy of this document.++The OpenLDAP Foundation may revise this license from time to time.+Each revision is distinguished by a version number.  You may use+this Software under terms of this license revision or under the+terms of any subsequent revision of the license.++THIS SOFTWARE IS PROVIDED BY THE OPENLDAP FOUNDATION AND ITS+CONTRIBUTORS ``AS IS'' AND ANY EXPRESSED 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 OPENLDAP FOUNDATION, ITS CONTRIBUTORS, OR THE AUTHOR(S)+OR OWNER(S) OF THE SOFTWARE 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.++The names of the authors and copyright holders must not be used in+advertising or otherwise to promote the sale, use or other dealing+in this Software without specific, written prior permission.  Title+to copyright in this Software shall at all times remain with copyright+holders.++OpenLDAP is a registered trademark of the OpenLDAP Foundation.++Copyright 1999-2003 The OpenLDAP Foundation, Redwood City,+California, USA.  All Rights Reserved.  Permission to copy and+distribute verbatim copies of this document is granted.
+ cbits/lmdb.h view
@@ -0,0 +1,1608 @@+/** @file lmdb.h+ *	@brief Lightning memory-mapped database library+ *+ *	@mainpage	Lightning Memory-Mapped Database Manager (LMDB)+ *+ *	@section intro_sec Introduction+ *	LMDB is a Btree-based database management library modeled loosely on the+ *	BerkeleyDB API, but much simplified. The entire database is exposed+ *	in a memory map, and all data fetches return data directly+ *	from the mapped memory, so no malloc's or memcpy's occur during+ *	data fetches. As such, the library is extremely simple because it+ *	requires no page caching layer of its own, and it is extremely high+ *	performance and memory-efficient. It is also fully transactional with+ *	full ACID semantics, and when the memory map is read-only, the+ *	database integrity cannot be corrupted by stray pointer writes from+ *	application code.+ *+ *	The library is fully thread-aware and supports concurrent read/write+ *	access from multiple processes and threads. Data pages use a copy-on-+ *	write strategy so no active data pages are ever overwritten, which+ *	also provides resistance to corruption and eliminates the need of any+ *	special recovery procedures after a system crash. Writes are fully+ *	serialized; only one write transaction may be active at a time, which+ *	guarantees that writers can never deadlock. The database structure is+ *	multi-versioned so readers run with no locks; writers cannot block+ *	readers, and readers don't block writers.+ *+ *	Unlike other well-known database mechanisms which use either write-ahead+ *	transaction logs or append-only data writes, LMDB requires no maintenance+ *	during operation. Both write-ahead loggers and append-only databases+ *	require periodic checkpointing and/or compaction of their log or database+ *	files otherwise they grow without bound. LMDB tracks free pages within+ *	the database and re-uses them for new write operations, so the database+ *	size does not grow without bound in normal use.+ *+ *	The memory map can be used as a read-only or read-write map. It is+ *	read-only by default as this provides total immunity to corruption.+ *	Using read-write mode offers much higher write performance, but adds+ *	the possibility for stray application writes thru pointers to silently+ *	corrupt the database. Of course if your application code is known to+ *	be bug-free (...) then this is not an issue.+ *+ *	If this is your first time using a transactional embedded key/value+ *	store, you may find the \ref starting page to be helpful.+ *+ *	@section caveats_sec Caveats+ *	Troubleshooting the lock file, plus semaphores on BSD systems:+ *+ *	- A broken lockfile can cause sync issues.+ *	  Stale reader transactions left behind by an aborted program+ *	  cause further writes to grow the database quickly, and+ *	  stale locks can block further operation.+ *+ *	  Fix: Check for stale readers periodically, using the+ *	  #mdb_reader_check function or the \ref mdb_stat_1 "mdb_stat" tool.+ *	  Stale writers will be cleared automatically on some systems:+ *	  - Windows - automatic+ *	  - Linux, systems using POSIX mutexes with Robust option - automatic+ *	  - not on BSD, systems using POSIX semaphores.+ *	  Otherwise just make all programs using the database close it;+ *	  the lockfile is always reset on first open of the environment.+ *+ *	- On BSD systems or others configured with MDB_USE_POSIX_SEM,+ *	  startup can fail due to semaphores owned by another userid.+ *+ *	  Fix: Open and close the database as the user which owns the+ *	  semaphores (likely last user) or as root, while no other+ *	  process is using the database.+ *+ *	Restrictions/caveats (in addition to those listed for some functions):+ *+ *	- Only the database owner should normally use the database on+ *	  BSD systems or when otherwise configured with MDB_USE_POSIX_SEM.+ *	  Multiple users can cause startup to fail later, as noted above.+ *+ *	- There is normally no pure read-only mode, since readers need write+ *	  access to locks and lock file. Exceptions: On read-only filesystems+ *	  or with the #MDB_NOLOCK flag described under #mdb_env_open().+ *+ *	- An LMDB configuration will often reserve considerable \b unused+ *	  memory address space and maybe file size for future growth.+ *	  This does not use actual memory or disk space, but users may need+ *	  to understand the difference so they won't be scared off.+ *+ *	- By default, in versions before 0.9.10, unused portions of the data+ *	  file might receive garbage data from memory freed by other code.+ *	  (This does not happen when using the #MDB_WRITEMAP flag.) As of+ *	  0.9.10 the default behavior is to initialize such memory before+ *	  writing to the data file. Since there may be a slight performance+ *	  cost due to this initialization, applications may disable it using+ *	  the #MDB_NOMEMINIT flag. Applications handling sensitive data+ *	  which must not be written should not use this flag. This flag is+ *	  irrelevant when using #MDB_WRITEMAP.+ *+ *	- A thread can only use one transaction at a time, plus any child+ *	  transactions.  Each transaction belongs to one thread.  See below.+ *	  The #MDB_NOTLS flag changes this for read-only transactions.+ *+ *	- Use an MDB_env* in the process which opened it, not after fork().+ *+ *	- Do not have open an LMDB database twice in the same process at+ *	  the same time.  Not even from a plain open() call - close()ing it+ *	  breaks fcntl() advisory locking.  (It is OK to reopen it after+ *	  fork() - exec*(), since the lockfile has FD_CLOEXEC set.)+ *+ *	- Avoid long-lived transactions.  Read transactions prevent+ *	  reuse of pages freed by newer write transactions, thus the+ *	  database can grow quickly.  Write transactions prevent+ *	  other write transactions, since writes are serialized.+ *+ *	- Avoid suspending a process with active transactions.  These+ *	  would then be "long-lived" as above.  Also read transactions+ *	  suspended when writers commit could sometimes see wrong data.+ *+ *	...when several processes can use a database concurrently:+ *+ *	- Avoid aborting a process with an active transaction.+ *	  The transaction becomes "long-lived" as above until a check+ *	  for stale readers is performed or the lockfile is reset,+ *	  since the process may not remove it from the lockfile.+ *+ *	  This does not apply to write transactions if the system clears+ *	  stale writers, see above.+ *+ *	- If you do that anyway, do a periodic check for stale readers. Or+ *	  close the environment once in a while, so the lockfile can get reset.+ *+ *	- Do not use LMDB databases on remote filesystems, even between+ *	  processes on the same host.  This breaks flock() on some OSes,+ *	  possibly memory map sync, and certainly sync between programs+ *	  on different hosts.+ *+ *	- Opening a database can fail if another process is opening or+ *	  closing it at exactly the same time.+ *+ *	@author	Howard Chu, Symas Corporation.+ *+ *	@copyright Copyright 2011-2021 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>.+ *+ *	@par Derived From:+ * This code is derived from btree.c written by Martin Hedenfalk.+ *+ * 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.+ */+#ifndef _LMDB_H_+#define _LMDB_H_++#include <sys/types.h>++#ifdef __cplusplus+extern "C" {+#endif++/** Unix permissions for creating files, or dummy definition for Windows */+#ifdef _MSC_VER+typedef	int	mdb_mode_t;+#else+typedef	mode_t	mdb_mode_t;+#endif++/** An abstraction for a file handle.+ *	On POSIX systems file handles are small integers. On Windows+ *	they're opaque pointers.+ */+#ifdef _WIN32+typedef	void *mdb_filehandle_t;+#else+typedef int mdb_filehandle_t;+#endif++/** @defgroup mdb LMDB API+ *	@{+ *	@brief OpenLDAP Lightning Memory-Mapped Database Manager+ */+/** @defgroup Version Version Macros+ *	@{+ */+/** Library major version */+#define MDB_VERSION_MAJOR	0+/** Library minor version */+#define MDB_VERSION_MINOR	9+/** Library patch version */+#define MDB_VERSION_PATCH	33++/** Combine args a,b,c into a single integer for easy version comparisons */+#define MDB_VERINT(a,b,c)	(((a) << 24) | ((b) << 16) | (c))++/** The full library version as a single integer */+#define MDB_VERSION_FULL	\+	MDB_VERINT(MDB_VERSION_MAJOR,MDB_VERSION_MINOR,MDB_VERSION_PATCH)++/** The release date of this library version */+#define MDB_VERSION_DATE	"May 21, 2024"++/** A stringifier for the version info */+#define MDB_VERSTR(a,b,c,d)	"LMDB " #a "." #b "." #c ": (" d ")"++/** A helper for the stringifier macro */+#define MDB_VERFOO(a,b,c,d)	MDB_VERSTR(a,b,c,d)++/** The full library version as a C string */+#define	MDB_VERSION_STRING	\+	MDB_VERFOO(MDB_VERSION_MAJOR,MDB_VERSION_MINOR,MDB_VERSION_PATCH,MDB_VERSION_DATE)+/**	@} */++/** @brief Opaque structure for a database environment.+ *+ * A DB environment supports multiple databases, all residing in the same+ * shared-memory map.+ */+typedef struct MDB_env MDB_env;++/** @brief Opaque structure for a transaction handle.+ *+ * All database operations require a transaction handle. Transactions may be+ * read-only or read-write.+ */+typedef struct MDB_txn MDB_txn;++/** @brief A handle for an individual database in the DB environment. */+typedef unsigned int	MDB_dbi;++/** @brief Opaque structure for navigating through a database */+typedef struct MDB_cursor MDB_cursor;++/** @brief Generic structure used for passing keys and data in and out+ * of the database.+ *+ * Values returned from the database are valid only until a subsequent+ * update operation, or the end of the transaction. Do not modify or+ * free them, they commonly point into the database itself.+ *+ * Key sizes must be between 1 and #mdb_env_get_maxkeysize() inclusive.+ * The same applies to data sizes in databases with the #MDB_DUPSORT flag.+ * Other data items can in theory be from 0 to 0xffffffff bytes long.+ */+typedef struct MDB_val {+	size_t		 mv_size;	/**< size of the data item */+	void		*mv_data;	/**< address of the data item */+} MDB_val;++/** @brief A callback function used to compare two keys in a database */+typedef int  (MDB_cmp_func)(const MDB_val *a, const MDB_val *b);++/** @brief A callback function used to relocate a position-dependent data item+ * in a fixed-address database.+ *+ * The \b newptr gives the item's desired address in+ * the memory map, and \b oldptr gives its previous address. The item's actual+ * data resides at the address in \b item.  This callback is expected to walk+ * through the fields of the record in \b item and modify any+ * values based at the \b oldptr address to be relative to the \b newptr address.+ * @param[in,out] item The item that is to be relocated.+ * @param[in] oldptr The previous address.+ * @param[in] newptr The new address to relocate to.+ * @param[in] relctx An application-provided context, set by #mdb_set_relctx().+ * @todo This feature is currently unimplemented.+ */+typedef void (MDB_rel_func)(MDB_val *item, void *oldptr, void *newptr, void *relctx);++/** @defgroup	mdb_env	Environment Flags+ *	@{+ */+	/** mmap at a fixed address (experimental) */+#define MDB_FIXEDMAP	0x01+	/** no environment directory */+#define MDB_NOSUBDIR	0x4000+	/** don't fsync after commit */+#define MDB_NOSYNC		0x10000+	/** read only */+#define MDB_RDONLY		0x20000+	/** don't fsync metapage after commit */+#define MDB_NOMETASYNC		0x40000+	/** use writable mmap */+#define MDB_WRITEMAP		0x80000+	/** use asynchronous msync when #MDB_WRITEMAP is used */+#define MDB_MAPASYNC		0x100000+	/** tie reader locktable slots to #MDB_txn objects instead of to threads */+#define MDB_NOTLS		0x200000+	/** don't do any locking, caller must manage their own locks */+#define MDB_NOLOCK		0x400000+	/** don't do readahead (no effect on Windows) */+#define MDB_NORDAHEAD	0x800000+	/** don't initialize malloc'd memory before writing to datafile */+#define MDB_NOMEMINIT	0x1000000+/** @} */++/**	@defgroup	mdb_dbi_open	Database Flags+ *	@{+ */+	/** use reverse string keys */+#define MDB_REVERSEKEY	0x02+	/** use sorted duplicates */+#define MDB_DUPSORT		0x04+	/** numeric keys in native byte order: either unsigned int or size_t.+	 *  The keys must all be of the same size. */+#define MDB_INTEGERKEY	0x08+	/** with #MDB_DUPSORT, sorted dup items have fixed size */+#define MDB_DUPFIXED	0x10+	/** with #MDB_DUPSORT, dups are #MDB_INTEGERKEY-style integers */+#define MDB_INTEGERDUP	0x20+	/** with #MDB_DUPSORT, use reverse string dups */+#define MDB_REVERSEDUP	0x40+	/** create DB if not already existing */+#define MDB_CREATE		0x40000+/** @} */++/**	@defgroup mdb_put	Write Flags+ *	@{+ */+/** For put: Don't write if the key already exists. */+#define MDB_NOOVERWRITE	0x10+/** Only for #MDB_DUPSORT<br>+ * For put: don't write if the key and data pair already exist.<br>+ * For mdb_cursor_del: remove all duplicate data items.+ */+#define MDB_NODUPDATA	0x20+/** For mdb_cursor_put: overwrite the current key/data pair */+#define MDB_CURRENT	0x40+/** For put: Just reserve space for data, don't copy it. Return a+ * pointer to the reserved space.+ */+#define MDB_RESERVE	0x10000+/** Data is being appended, don't split full pages. */+#define MDB_APPEND	0x20000+/** Duplicate data is being appended, don't split full pages. */+#define MDB_APPENDDUP	0x40000+/** Store multiple data items in one call. Only for #MDB_DUPFIXED. */+#define MDB_MULTIPLE	0x80000+/*	@} */++/**	@defgroup mdb_copy	Copy Flags+ *	@{+ */+/** Compacting copy: Omit free space from copy, and renumber all+ * pages sequentially.+ */+#define MDB_CP_COMPACT	0x01+/*	@} */++/** @brief Cursor Get operations.+ *+ *	This is the set of all operations for retrieving data+ *	using a cursor.+ */+typedef enum MDB_cursor_op {+	MDB_FIRST,				/**< Position at first key/data item */+	MDB_FIRST_DUP,			/**< Position at first data item of current key.+								Only for #MDB_DUPSORT */+	MDB_GET_BOTH,			/**< Position at key/data pair. Only for #MDB_DUPSORT */+	MDB_GET_BOTH_RANGE,		/**< position at key, nearest data. Only for #MDB_DUPSORT */+	MDB_GET_CURRENT,		/**< Return key/data at current cursor position */+	MDB_GET_MULTIPLE,		/**< Return up to a page of duplicate data items+								from current cursor position. Move cursor to prepare+								for #MDB_NEXT_MULTIPLE. Only for #MDB_DUPFIXED */+	MDB_LAST,				/**< Position at last key/data item */+	MDB_LAST_DUP,			/**< Position at last data item of current key.+								Only for #MDB_DUPSORT */+	MDB_NEXT,				/**< Position at next data item */+	MDB_NEXT_DUP,			/**< Position at next data item of current key.+								Only for #MDB_DUPSORT */+	MDB_NEXT_MULTIPLE,		/**< Return up to a page of duplicate data items+								from next cursor position. Move cursor to prepare+								for #MDB_NEXT_MULTIPLE. Only for #MDB_DUPFIXED */+	MDB_NEXT_NODUP,			/**< Position at first data item of next key */+	MDB_PREV,				/**< Position at previous data item */+	MDB_PREV_DUP,			/**< Position at previous data item of current key.+								Only for #MDB_DUPSORT */+	MDB_PREV_NODUP,			/**< Position at last data item of previous key */+	MDB_SET,				/**< Position at specified key */+	MDB_SET_KEY,			/**< Position at specified key, return key + data */+	MDB_SET_RANGE,			/**< Position at first key greater than or equal to specified key. */+	MDB_PREV_MULTIPLE		/**< Position at previous page and return up to+								a page of duplicate data items. Only for #MDB_DUPFIXED */+} MDB_cursor_op;++/** @defgroup  errors	Return Codes+ *+ *	BerkeleyDB uses -30800 to -30999, we'll go under them+ *	@{+ */+	/**	Successful result */+#define MDB_SUCCESS	 0+	/** key/data pair already exists */+#define MDB_KEYEXIST	(-30799)+	/** key/data pair not found (EOF) */+#define MDB_NOTFOUND	(-30798)+	/** Requested page not found - this usually indicates corruption */+#define MDB_PAGE_NOTFOUND	(-30797)+	/** Located page was wrong type */+#define MDB_CORRUPTED	(-30796)+	/** Update of meta page failed or environment had fatal error */+#define MDB_PANIC		(-30795)+	/** Environment version mismatch */+#define MDB_VERSION_MISMATCH	(-30794)+	/** File is not a valid LMDB file */+#define MDB_INVALID	(-30793)+	/** Environment mapsize reached */+#define MDB_MAP_FULL	(-30792)+	/** Environment maxdbs reached */+#define MDB_DBS_FULL	(-30791)+	/** Environment maxreaders reached */+#define MDB_READERS_FULL	(-30790)+	/** Too many TLS keys in use - Windows only */+#define MDB_TLS_FULL	(-30789)+	/** Txn has too many dirty pages */+#define MDB_TXN_FULL	(-30788)+	/** Cursor stack too deep - internal error */+#define MDB_CURSOR_FULL	(-30787)+	/** Page has not enough space - internal error */+#define MDB_PAGE_FULL	(-30786)+	/** Database contents grew beyond environment mapsize */+#define MDB_MAP_RESIZED	(-30785)+	/** Operation and DB incompatible, or DB type changed. This can mean:+	 *	<ul>+	 *	<li>The operation expects an #MDB_DUPSORT / #MDB_DUPFIXED database.+	 *	<li>Opening a named DB when the unnamed DB has #MDB_DUPSORT / #MDB_INTEGERKEY.+	 *	<li>Accessing a data record as a database, or vice versa.+	 *	<li>The database was dropped and recreated with different flags.+	 *	</ul>+	 */+#define MDB_INCOMPATIBLE	(-30784)+	/** Invalid reuse of reader locktable slot */+#define MDB_BAD_RSLOT		(-30783)+	/** Transaction must abort, has a child, or is invalid */+#define MDB_BAD_TXN			(-30782)+	/** Unsupported size of key/DB name/data, or wrong DUPFIXED size */+#define MDB_BAD_VALSIZE		(-30781)+	/** The specified DBI was changed unexpectedly */+#define MDB_BAD_DBI		(-30780)+	/** The last defined error code */+#define MDB_LAST_ERRCODE	MDB_BAD_DBI+/** @} */++/** @brief Statistics for a database in the environment */+typedef struct MDB_stat {+	unsigned int	ms_psize;			/**< Size of a database page.+											This is currently the same for all databases. */+	unsigned int	ms_depth;			/**< Depth (height) of the B-tree */+	size_t		ms_branch_pages;	/**< Number of internal (non-leaf) pages */+	size_t		ms_leaf_pages;		/**< Number of leaf pages */+	size_t		ms_overflow_pages;	/**< Number of overflow pages */+	size_t		ms_entries;			/**< Number of data items */+} MDB_stat;++/** @brief Information about the environment */+typedef struct MDB_envinfo {+	void	*me_mapaddr;			/**< Address of map, if fixed */+	size_t	me_mapsize;				/**< Size of the data memory map */+	size_t	me_last_pgno;			/**< ID of the last used page */+	size_t	me_last_txnid;			/**< ID of the last committed transaction */+	unsigned int me_maxreaders;		/**< max reader slots in the environment */+	unsigned int me_numreaders;		/**< max reader slots used in the environment */+} MDB_envinfo;++	/** @brief Return the LMDB library version information.+	 *+	 * @param[out] major if non-NULL, the library major version number is copied here+	 * @param[out] minor if non-NULL, the library minor version number is copied here+	 * @param[out] patch if non-NULL, the library patch version number is copied here+	 * @retval "version string" The library version as a string+	 */+char *mdb_version(int *major, int *minor, int *patch);++	/** @brief Return a string describing a given error code.+	 *+	 * This function is a superset of the ANSI C X3.159-1989 (ANSI C) strerror(3)+	 * function. If the error code is greater than or equal to 0, then the string+	 * returned by the system function strerror(3) is returned. If the error code+	 * is less than 0, an error string corresponding to the LMDB library error is+	 * returned. See @ref errors for a list of LMDB-specific error codes.+	 * @param[in] err The error code+	 * @retval "error message" The description of the error+	 */+char *mdb_strerror(int err);++	/** @brief Create an LMDB environment handle.+	 *+	 * This function allocates memory for a #MDB_env structure. To release+	 * the allocated memory and discard the handle, call #mdb_env_close().+	 * Before the handle may be used, it must be opened using #mdb_env_open().+	 * Various other options may also need to be set before opening the handle,+	 * e.g. #mdb_env_set_mapsize(), #mdb_env_set_maxreaders(), #mdb_env_set_maxdbs(),+	 * depending on usage requirements.+	 * @param[out] env The address where the new handle will be stored+	 * @return A non-zero error value on failure and 0 on success.+	 */+int  mdb_env_create(MDB_env **env);++	/** @brief Open an environment handle.+	 *+	 * If this function fails, #mdb_env_close() must be called to discard the #MDB_env handle.+	 * @param[in] env An environment handle returned by #mdb_env_create()+	 * @param[in] path The directory in which the database files reside. This+	 * directory must already exist and be writable.+	 * @param[in] flags Special options for this environment. This parameter+	 * must be set to 0 or by bitwise OR'ing together one or more of the+	 * values described here.+	 * Flags set by mdb_env_set_flags() are also used.+	 * <ul>+	 *	<li>#MDB_FIXEDMAP+	 *      use a fixed address for the mmap region. This flag must be specified+	 *      when creating the environment, and is stored persistently in the environment.+	 *		If successful, the memory map will always reside at the same virtual address+	 *		and pointers used to reference data items in the database will be constant+	 *		across multiple invocations. This option may not always work, depending on+	 *		how the operating system has allocated memory to shared libraries and other uses.+	 *		The feature is highly experimental.+	 *	<li>#MDB_NOSUBDIR+	 *		By default, LMDB creates its environment in a directory whose+	 *		pathname is given in \b path, and creates its data and lock files+	 *		under that directory. With this option, \b path is used as-is for+	 *		the database main data file. The database lock file is the \b path+	 *		with "-lock" appended.+	 *	<li>#MDB_RDONLY+	 *		Open the environment in read-only mode. No write operations will be+	 *		allowed. LMDB will still modify the lock file - except on read-only+	 *		filesystems, where LMDB does not use locks.+	 *	<li>#MDB_WRITEMAP+	 *		Use a writeable memory map unless MDB_RDONLY is set. This uses+	 *		fewer mallocs but loses protection from application bugs+	 *		like wild pointer writes and other bad updates into the database.+	 *		This may be slightly faster for DBs that fit entirely in RAM, but+	 *		is slower for DBs larger than RAM.+	 *		Incompatible with nested transactions.+	 *		Do not mix processes with and without MDB_WRITEMAP on the same+	 *		environment.  This can defeat durability (#mdb_env_sync etc).+	 *	<li>#MDB_NOMETASYNC+	 *		Flush system buffers to disk only once per transaction, omit the+	 *		metadata flush. Defer that until the system flushes files to disk,+	 *		or next non-MDB_RDONLY commit or #mdb_env_sync(). This optimization+	 *		maintains database integrity, but a system crash may undo the last+	 *		committed transaction. I.e. it preserves the ACI (atomicity,+	 *		consistency, isolation) but not D (durability) database property.+	 *		This flag may be changed at any time using #mdb_env_set_flags().+	 *	<li>#MDB_NOSYNC+	 *		Don't flush system buffers to disk when committing a transaction.+	 *		This optimization means a system crash can corrupt the database or+	 *		lose the last transactions if buffers are not yet flushed to disk.+	 *		The risk is governed by how often the system flushes dirty buffers+	 *		to disk and how often #mdb_env_sync() is called.  However, if the+	 *		filesystem preserves write order and the #MDB_WRITEMAP flag is not+	 *		used, transactions exhibit ACI (atomicity, consistency, isolation)+	 *		properties and only lose D (durability).  I.e. database integrity+	 *		is maintained, but a system crash may undo the final transactions.+	 *		Note that (#MDB_NOSYNC | #MDB_WRITEMAP) leaves the system with no+	 *		hint for when to write transactions to disk, unless #mdb_env_sync()+	 *		is called. (#MDB_MAPASYNC | #MDB_WRITEMAP) may be preferable.+	 *		This flag may be changed at any time using #mdb_env_set_flags().+	 *	<li>#MDB_MAPASYNC+	 *		When using #MDB_WRITEMAP, use asynchronous flushes to disk.+	 *		As with #MDB_NOSYNC, a system crash can then corrupt the+	 *		database or lose the last transactions. Calling #mdb_env_sync()+	 *		ensures on-disk database integrity until next commit.+	 *		This flag may be changed at any time using #mdb_env_set_flags().+	 *	<li>#MDB_NOTLS+	 *		Don't use Thread-Local Storage. Tie reader locktable slots to+	 *		#MDB_txn objects instead of to threads. I.e. #mdb_txn_reset() keeps+	 *		the slot reserved for the #MDB_txn object. A thread may use parallel+	 *		read-only transactions. A read-only transaction may span threads if+	 *		the user synchronizes its use. Applications that multiplex many+	 *		user threads over individual OS threads need this option. Such an+	 *		application must also serialize the write transactions in an OS+	 *		thread, since LMDB's write locking is unaware of the user threads.+	 *	<li>#MDB_NOLOCK+	 *		Don't do any locking. If concurrent access is anticipated, the+	 *		caller must manage all concurrency itself. For proper operation+	 *		the caller must enforce single-writer semantics, and must ensure+	 *		that no readers are using old transactions while a writer is+	 *		active. The simplest approach is to use an exclusive lock so that+	 *		no readers may be active at all when a writer begins.+	 *	<li>#MDB_NORDAHEAD+	 *		Turn off readahead. Most operating systems perform readahead on+	 *		read requests by default. This option turns it off if the OS+	 *		supports it. Turning it off may help random read performance+	 *		when the DB is larger than RAM and system RAM is full.+	 *		The option is not implemented on Windows.+	 *	<li>#MDB_NOMEMINIT+	 *		Don't initialize malloc'd memory before writing to unused spaces+	 *		in the data file. By default, memory for pages written to the data+	 *		file is obtained using malloc. While these pages may be reused in+	 *		subsequent transactions, freshly malloc'd pages will be initialized+	 *		to zeroes before use. This avoids persisting leftover data from other+	 *		code (that used the heap and subsequently freed the memory) into the+	 *		data file. Note that many other system libraries may allocate+	 *		and free memory from the heap for arbitrary uses. E.g., stdio may+	 *		use the heap for file I/O buffers. This initialization step has a+	 *		modest performance cost so some applications may want to disable+	 *		it using this flag. This option can be a problem for applications+	 *		which handle sensitive data like passwords, and it makes memory+	 *		checkers like Valgrind noisy. This flag is not needed with #MDB_WRITEMAP,+	 *		which writes directly to the mmap instead of using malloc for pages. The+	 *		initialization is also skipped if #MDB_RESERVE is used; the+	 *		caller is expected to overwrite all of the memory that was+	 *		reserved in that case.+	 *		This flag may be changed at any time using #mdb_env_set_flags().+	 * </ul>+	 * @param[in] mode The UNIX permissions to set on created files and semaphores.+	 * This parameter is ignored on Windows.+	 * @return A non-zero error value on failure and 0 on success. Some possible+	 * errors are:+	 * <ul>+	 *	<li>#MDB_VERSION_MISMATCH - the version of the LMDB library doesn't match the+	 *	version that created the database environment.+	 *	<li>#MDB_INVALID - the environment file headers are corrupted.+	 *	<li>ENOENT - the directory specified by the path parameter doesn't exist.+	 *	<li>EACCES - the user didn't have permission to access the environment files.+	 *	<li>EAGAIN - the environment was locked by another process.+	 * </ul>+	 */+int  mdb_env_open(MDB_env *env, const char *path, unsigned int flags, mdb_mode_t mode);++	/** @brief Copy an LMDB environment to the specified path.+	 *+	 * This function may be used to make a backup of an existing environment.+	 * No lockfile is created, since it gets recreated at need.+	 * @note This call can trigger significant file size growth if run in+	 * parallel with write transactions, because it employs a read-only+	 * transaction. See long-lived transactions under @ref caveats_sec.+	 * @param[in] env An environment handle returned by #mdb_env_create(). It+	 * must have already been opened successfully.+	 * @param[in] path The directory in which the copy will reside. This+	 * directory must already exist and be writable but must otherwise be+	 * empty.+	 * @return A non-zero error value on failure and 0 on success.+	 */+int  mdb_env_copy(MDB_env *env, const char *path);++	/** @brief Copy an LMDB environment to the specified file descriptor.+	 *+	 * This function may be used to make a backup of an existing environment.+	 * No lockfile is created, since it gets recreated at need.+	 * @note This call can trigger significant file size growth if run in+	 * parallel with write transactions, because it employs a read-only+	 * transaction. See long-lived transactions under @ref caveats_sec.+	 * @param[in] env An environment handle returned by #mdb_env_create(). It+	 * must have already been opened successfully.+	 * @param[in] fd The filedescriptor to write the copy to. It must+	 * have already been opened for Write access.+	 * @return A non-zero error value on failure and 0 on success.+	 */+int  mdb_env_copyfd(MDB_env *env, mdb_filehandle_t fd);++	/** @brief Copy an LMDB environment to the specified path, with options.+	 *+	 * This function may be used to make a backup of an existing environment.+	 * No lockfile is created, since it gets recreated at need.+	 * @note This call can trigger significant file size growth if run in+	 * parallel with write transactions, because it employs a read-only+	 * transaction. See long-lived transactions under @ref caveats_sec.+	 * @param[in] env An environment handle returned by #mdb_env_create(). It+	 * must have already been opened successfully.+	 * @param[in] path The directory in which the copy will reside. This+	 * directory must already exist and be writable but must otherwise be+	 * empty.+	 * @param[in] flags Special options for this operation. This parameter+	 * must be set to 0 or by bitwise OR'ing together one or more of the+	 * values described here.+	 * <ul>+	 *	<li>#MDB_CP_COMPACT - Perform compaction while copying: omit free+	 *		pages and sequentially renumber all pages in output. This option+	 *		consumes more CPU and runs more slowly than the default.+	 *		Currently it fails if the environment has suffered a page leak.+	 * </ul>+	 * @return A non-zero error value on failure and 0 on success.+	 */+int  mdb_env_copy2(MDB_env *env, const char *path, unsigned int flags);++	/** @brief Copy an LMDB environment to the specified file descriptor,+	 *	with options.+	 *+	 * This function may be used to make a backup of an existing environment.+	 * No lockfile is created, since it gets recreated at need. See+	 * #mdb_env_copy2() for further details.+	 * @note This call can trigger significant file size growth if run in+	 * parallel with write transactions, because it employs a read-only+	 * transaction. See long-lived transactions under @ref caveats_sec.+	 * @param[in] env An environment handle returned by #mdb_env_create(). It+	 * must have already been opened successfully.+	 * @param[in] fd The filedescriptor to write the copy to. It must+	 * have already been opened for Write access.+	 * @param[in] flags Special options for this operation.+	 * See #mdb_env_copy2() for options.+	 * @return A non-zero error value on failure and 0 on success.+	 */+int  mdb_env_copyfd2(MDB_env *env, mdb_filehandle_t fd, unsigned int flags);++	/** @brief Return statistics about the LMDB environment.+	 *+	 * @param[in] env An environment handle returned by #mdb_env_create()+	 * @param[out] stat The address of an #MDB_stat structure+	 * 	where the statistics will be copied+	 */+int  mdb_env_stat(MDB_env *env, MDB_stat *stat);++	/** @brief Return information about the LMDB environment.+	 *+	 * @param[in] env An environment handle returned by #mdb_env_create()+	 * @param[out] stat The address of an #MDB_envinfo structure+	 * 	where the information will be copied+	 */+int  mdb_env_info(MDB_env *env, MDB_envinfo *stat);++	/** @brief Flush the data buffers to disk.+	 *+	 * Data is always written to disk when #mdb_txn_commit() is called,+	 * but the operating system may keep it buffered. LMDB always flushes+	 * the OS buffers upon commit as well, unless the environment was+	 * opened with #MDB_NOSYNC or in part #MDB_NOMETASYNC. This call is+	 * not valid if the environment was opened with #MDB_RDONLY.+	 * @param[in] env An environment handle returned by #mdb_env_create()+	 * @param[in] force If non-zero, force a synchronous flush.  Otherwise+	 *  if the environment has the #MDB_NOSYNC flag set the flushes+	 *	will be omitted, and with #MDB_MAPASYNC they will be asynchronous.+	 * @return A non-zero error value on failure and 0 on success. Some possible+	 * errors are:+	 * <ul>+	 *	<li>EACCES - the environment is read-only.+	 *	<li>EINVAL - an invalid parameter was specified.+	 *	<li>EIO - an error occurred during synchronization.+	 * </ul>+	 */+int  mdb_env_sync(MDB_env *env, int force);++	/** @brief Close the environment and release the memory map.+	 *+	 * Only a single thread may call this function. All transactions, databases,+	 * and cursors must already be closed before calling this function. Attempts to+	 * use any such handles after calling this function will cause a SIGSEGV.+	 * The environment handle will be freed and must not be used again after this call.+	 * @param[in] env An environment handle returned by #mdb_env_create()+	 */+void mdb_env_close(MDB_env *env);++	/** @brief Set environment flags.+	 *+	 * This may be used to set some flags in addition to those from+	 * #mdb_env_open(), or to unset these flags.  If several threads+	 * change the flags at the same time, the result is undefined.+	 * @param[in] env An environment handle returned by #mdb_env_create()+	 * @param[in] flags The flags to change, bitwise OR'ed together+	 * @param[in] onoff A non-zero value sets the flags, zero clears them.+	 * @return A non-zero error value on failure and 0 on success. Some possible+	 * errors are:+	 * <ul>+	 *	<li>EINVAL - an invalid parameter was specified.+	 * </ul>+	 */+int  mdb_env_set_flags(MDB_env *env, unsigned int flags, int onoff);++	/** @brief Get environment flags.+	 *+	 * @param[in] env An environment handle returned by #mdb_env_create()+	 * @param[out] flags The address of an integer to store the flags+	 * @return A non-zero error value on failure and 0 on success. Some possible+	 * errors are:+	 * <ul>+	 *	<li>EINVAL - an invalid parameter was specified.+	 * </ul>+	 */+int  mdb_env_get_flags(MDB_env *env, unsigned int *flags);++	/** @brief Return the path that was used in #mdb_env_open().+	 *+	 * @param[in] env An environment handle returned by #mdb_env_create()+	 * @param[out] path Address of a string pointer to contain the path. This+	 * is the actual string in the environment, not a copy. It should not be+	 * altered in any way.+	 * @return A non-zero error value on failure and 0 on success. Some possible+	 * errors are:+	 * <ul>+	 *	<li>EINVAL - an invalid parameter was specified.+	 * </ul>+	 */+int  mdb_env_get_path(MDB_env *env, const char **path);++	/** @brief Return the filedescriptor for the given environment.+	 *+	 * This function may be called after fork(), so the descriptor can be+	 * closed before exec*().  Other LMDB file descriptors have FD_CLOEXEC.+	 * (Until LMDB 0.9.18, only the lockfile had that.)+	 *+	 * @param[in] env An environment handle returned by #mdb_env_create()+	 * @param[out] fd Address of a mdb_filehandle_t to contain the descriptor.+	 * @return A non-zero error value on failure and 0 on success. Some possible+	 * errors are:+	 * <ul>+	 *	<li>EINVAL - an invalid parameter was specified.+	 * </ul>+	 */+int  mdb_env_get_fd(MDB_env *env, mdb_filehandle_t *fd);++	/** @brief Set the size of the memory map to use for this environment.+	 *+	 * The size should be a multiple of the OS page size. The default is+	 * 10485760 bytes. The size of the memory map is also the maximum size+	 * of the database. The value should be chosen as large as possible,+	 * to accommodate future growth of the database.+	 * This function should be called after #mdb_env_create() and before #mdb_env_open().+	 * It may be called at later times if no transactions are active in+	 * this process. Note that the library does not check for this condition,+	 * the caller must ensure it explicitly.+	 *+	 * The new size takes effect immediately for the current process but+	 * will not be persisted to any others until a write transaction has been+	 * committed by the current process. Also, only mapsize increases are+	 * persisted into the environment.+	 *+	 * If the mapsize is increased by another process, and data has grown+	 * beyond the range of the current mapsize, #mdb_txn_begin() will+	 * return #MDB_MAP_RESIZED. This function may be called with a size+	 * of zero to adopt the new size.+	 *+	 * Any attempt to set a size smaller than the space already consumed+	 * by the environment will be silently changed to the current size of the used space.+	 * @param[in] env An environment handle returned by #mdb_env_create()+	 * @param[in] size The size in bytes+	 * @return A non-zero error value on failure and 0 on success. Some possible+	 * errors are:+	 * <ul>+	 *	<li>EINVAL - an invalid parameter was specified, or the environment has+	 *   	an active write transaction.+	 * </ul>+	 */+int  mdb_env_set_mapsize(MDB_env *env, size_t size);++	/** @brief Set the maximum number of threads/reader slots for the environment.+	 *+	 * This defines the number of slots in the lock table that is used to track readers in the+	 * the environment. The default is 126.+	 * Starting a read-only transaction normally ties a lock table slot to the+	 * current thread until the environment closes or the thread exits. If+	 * MDB_NOTLS is in use, #mdb_txn_begin() instead ties the slot to the+	 * MDB_txn object until it or the #MDB_env object is destroyed.+	 * This function may only be called after #mdb_env_create() and before #mdb_env_open().+	 * @param[in] env An environment handle returned by #mdb_env_create()+	 * @param[in] readers The maximum number of reader lock table slots+	 * @return A non-zero error value on failure and 0 on success. Some possible+	 * errors are:+	 * <ul>+	 *	<li>EINVAL - an invalid parameter was specified, or the environment is already open.+	 * </ul>+	 */+int  mdb_env_set_maxreaders(MDB_env *env, unsigned int readers);++	/** @brief Get the maximum number of threads/reader slots for the environment.+	 *+	 * @param[in] env An environment handle returned by #mdb_env_create()+	 * @param[out] readers Address of an integer to store the number of readers+	 * @return A non-zero error value on failure and 0 on success. Some possible+	 * errors are:+	 * <ul>+	 *	<li>EINVAL - an invalid parameter was specified.+	 * </ul>+	 */+int  mdb_env_get_maxreaders(MDB_env *env, unsigned int *readers);++	/** @brief Set the maximum number of named databases for the environment.+	 *+	 * This function is only needed if multiple databases will be used in the+	 * environment. Simpler applications that use the environment as a single+	 * unnamed database can ignore this option.+	 * This function may only be called after #mdb_env_create() and before #mdb_env_open().+	 *+	 * Currently a moderate number of slots are cheap but a huge number gets+	 * expensive: 7-120 words per transaction, and every #mdb_dbi_open()+	 * does a linear search of the opened slots.+	 * @param[in] env An environment handle returned by #mdb_env_create()+	 * @param[in] dbs The maximum number of databases+	 * @return A non-zero error value on failure and 0 on success. Some possible+	 * errors are:+	 * <ul>+	 *	<li>EINVAL - an invalid parameter was specified, or the environment is already open.+	 * </ul>+	 */+int  mdb_env_set_maxdbs(MDB_env *env, MDB_dbi dbs);++	/** @brief Get the maximum size of keys and #MDB_DUPSORT data we can write.+	 *+	 * Depends on the compile-time constant #MDB_MAXKEYSIZE. Default 511.+	 * See @ref MDB_val.+	 * @param[in] env An environment handle returned by #mdb_env_create()+	 * @return The maximum size of a key we can write+	 */+int  mdb_env_get_maxkeysize(MDB_env *env);++	/** @brief Set application information associated with the #MDB_env.+	 *+	 * @param[in] env An environment handle returned by #mdb_env_create()+	 * @param[in] ctx An arbitrary pointer for whatever the application needs.+	 * @return A non-zero error value on failure and 0 on success.+	 */+int  mdb_env_set_userctx(MDB_env *env, void *ctx);++	/** @brief Get the application information associated with the #MDB_env.+	 *+	 * @param[in] env An environment handle returned by #mdb_env_create()+	 * @return The pointer set by #mdb_env_set_userctx().+	 */+void *mdb_env_get_userctx(MDB_env *env);++	/** @brief A callback function for most LMDB assert() failures,+	 * called before printing the message and aborting.+	 *+	 * @param[in] env An environment handle returned by #mdb_env_create().+	 * @param[in] msg The assertion message, not including newline.+	 */+typedef void MDB_assert_func(MDB_env *env, const char *msg);++	/** Set or reset the assert() callback of the environment.+	 * Disabled if liblmdb is built with NDEBUG.+	 * @note This hack should become obsolete as lmdb's error handling matures.+	 * @param[in] env An environment handle returned by #mdb_env_create().+	 * @param[in] func An #MDB_assert_func function, or 0.+	 * @return A non-zero error value on failure and 0 on success.+	 */+int  mdb_env_set_assert(MDB_env *env, MDB_assert_func *func);++	/** @brief Create a transaction for use with the environment.+	 *+	 * The transaction handle may be discarded using #mdb_txn_abort() or #mdb_txn_commit().+	 * @note A transaction and its cursors must only be used by a single+	 * thread, and a thread may only have a single transaction at a time.+	 * If #MDB_NOTLS is in use, this does not apply to read-only transactions.+	 * @note Cursors may not span transactions.+	 * @param[in] env An environment handle returned by #mdb_env_create()+	 * @param[in] parent If this parameter is non-NULL, the new transaction+	 * will be a nested transaction, with the transaction indicated by \b parent+	 * as its parent. Transactions may be nested to any level. A parent+	 * transaction and its cursors may not issue any other operations than+	 * mdb_txn_commit and mdb_txn_abort while it has active child transactions.+	 * @param[in] flags Special options for this transaction. This parameter+	 * must be set to 0 or by bitwise OR'ing together one or more of the+	 * values described here.+	 * <ul>+	 *	<li>#MDB_RDONLY+	 *		This transaction will not perform any write operations.+	 * </ul>+	 * @param[out] txn Address where the new #MDB_txn handle will be stored+	 * @return A non-zero error value on failure and 0 on success. Some possible+	 * errors are:+	 * <ul>+	 *	<li>#MDB_PANIC - a fatal error occurred earlier and the environment+	 *		must be shut down.+	 *	<li>#MDB_MAP_RESIZED - another process wrote data beyond this MDB_env's+	 *		mapsize and this environment's map must be resized as well.+	 *		See #mdb_env_set_mapsize().+	 *	<li>#MDB_READERS_FULL - a read-only transaction was requested and+	 *		the reader lock table is full. See #mdb_env_set_maxreaders().+	 *	<li>ENOMEM - out of memory.+	 * </ul>+	 */+int  mdb_txn_begin(MDB_env *env, MDB_txn *parent, unsigned int flags, MDB_txn **txn);++	/** @brief Returns the transaction's #MDB_env+	 *+	 * @param[in] txn A transaction handle returned by #mdb_txn_begin()+	 */+MDB_env *mdb_txn_env(MDB_txn *txn);++	/** @brief Return the transaction's ID.+	 *+	 * This returns the identifier associated with this transaction. For a+	 * read-only transaction, this corresponds to the snapshot being read;+	 * concurrent readers will frequently have the same transaction ID.+	 *+	 * @param[in] txn A transaction handle returned by #mdb_txn_begin()+	 * @return A transaction ID, valid if input is an active transaction.+	 */+size_t mdb_txn_id(MDB_txn *txn);++	/** @brief Commit all the operations of a transaction into the database.+	 *+	 * The transaction handle is freed. It and its cursors must not be used+	 * again after this call, except with #mdb_cursor_renew().+	 * @note Earlier documentation incorrectly said all cursors would be freed.+	 * Only write-transactions free cursors.+	 * @param[in] txn A transaction handle returned by #mdb_txn_begin()+	 * @return A non-zero error value on failure and 0 on success. Some possible+	 * errors are:+	 * <ul>+	 *	<li>EINVAL - an invalid parameter was specified.+	 *	<li>ENOSPC - no more disk space.+	 *	<li>EIO - a low-level I/O error occurred while writing.+	 *	<li>ENOMEM - out of memory.+	 * </ul>+	 */+int  mdb_txn_commit(MDB_txn *txn);++	/** @brief Abandon all the operations of the transaction instead of saving them.+	 *+	 * The transaction handle is freed. It and its cursors must not be used+	 * again after this call, except with #mdb_cursor_renew().+	 * @note Earlier documentation incorrectly said all cursors would be freed.+	 * Only write-transactions free cursors.+	 * @param[in] txn A transaction handle returned by #mdb_txn_begin()+	 */+void mdb_txn_abort(MDB_txn *txn);++	/** @brief Reset a read-only transaction.+	 *+	 * Abort the transaction like #mdb_txn_abort(), but keep the transaction+	 * handle. #mdb_txn_renew() may reuse the handle. This saves allocation+	 * overhead if the process will start a new read-only transaction soon,+	 * and also locking overhead if #MDB_NOTLS is in use. The reader table+	 * lock is released, but the table slot stays tied to its thread or+	 * #MDB_txn. Use mdb_txn_abort() to discard a reset handle, and to free+	 * its lock table slot if MDB_NOTLS is in use.+	 * Cursors opened within the transaction must not be used+	 * again after this call, except with #mdb_cursor_renew().+	 * Reader locks generally don't interfere with writers, but they keep old+	 * versions of database pages allocated. Thus they prevent the old pages+	 * from being reused when writers commit new data, and so under heavy load+	 * the database size may grow much more rapidly than otherwise.+	 * @param[in] txn A transaction handle returned by #mdb_txn_begin()+	 */+void mdb_txn_reset(MDB_txn *txn);++	/** @brief Renew a read-only transaction.+	 *+	 * This acquires a new reader lock for a transaction handle that had been+	 * released by #mdb_txn_reset(). It must be called before a reset transaction+	 * may be used again.+	 * @param[in] txn A transaction handle returned by #mdb_txn_begin()+	 * @return A non-zero error value on failure and 0 on success. Some possible+	 * errors are:+	 * <ul>+	 *	<li>#MDB_PANIC - a fatal error occurred earlier and the environment+	 *		must be shut down.+	 *	<li>EINVAL - an invalid parameter was specified.+	 * </ul>+	 */+int  mdb_txn_renew(MDB_txn *txn);++/** Compat with version <= 0.9.4, avoid clash with libmdb from MDB Tools project */+#define mdb_open(txn,name,flags,dbi)	mdb_dbi_open(txn,name,flags,dbi)+/** Compat with version <= 0.9.4, avoid clash with libmdb from MDB Tools project */+#define mdb_close(env,dbi)				mdb_dbi_close(env,dbi)++	/** @brief Open a database in the environment.+	 *+	 * A database handle denotes the name and parameters of a database,+	 * independently of whether such a database exists.+	 * The database handle may be discarded by calling #mdb_dbi_close().+	 * The old database handle is returned if the database was already open.+	 * The handle may only be closed once.+	 *+	 * The database handle will be private to the current transaction until+	 * the transaction is successfully committed. If the transaction is+	 * aborted the handle will be closed automatically.+	 * After a successful commit the handle will reside in the shared+	 * environment, and may be used by other transactions.+	 *+	 * This function must not be called from multiple concurrent+	 * transactions in the same process. A transaction that uses+	 * this function must finish (either commit or abort) before+	 * any other transaction in the process may use this function.+	 *+	 * To use named databases (with name != NULL), #mdb_env_set_maxdbs()+	 * must be called before opening the environment.  Database names are+	 * keys in the unnamed database, and may be read but not written.+	 *+	 * @param[in] txn A transaction handle returned by #mdb_txn_begin()+	 * @param[in] name The name of the database to open. If only a single+	 * 	database is needed in the environment, this value may be NULL.+	 * @param[in] flags Special options for this database. This parameter+	 * must be set to 0 or by bitwise OR'ing together one or more of the+	 * values described here.+	 * <ul>+	 *	<li>#MDB_REVERSEKEY+	 *		Keys are strings to be compared in reverse order, from the end+	 *		of the strings to the beginning. By default, Keys are treated as strings and+	 *		compared from beginning to end.+	 *	<li>#MDB_DUPSORT+	 *		Duplicate keys may be used in the database. (Or, from another perspective,+	 *		keys may have multiple data items, stored in sorted order.) By default+	 *		keys must be unique and may have only a single data item.+	 *	<li>#MDB_INTEGERKEY+	 *		Keys are binary integers in native byte order, either unsigned int+	 *		or size_t, and will be sorted as such.+	 *		The keys must all be of the same size.+	 *	<li>#MDB_DUPFIXED+	 *		This flag may only be used in combination with #MDB_DUPSORT. This option+	 *		tells the library that the data items for this database are all the same+	 *		size, which allows further optimizations in storage and retrieval. When+	 *		all data items are the same size, the #MDB_GET_MULTIPLE, #MDB_NEXT_MULTIPLE+	 *		and #MDB_PREV_MULTIPLE cursor operations may be used to retrieve multiple+	 *		items at once.+	 *	<li>#MDB_INTEGERDUP+	 *		This option specifies that duplicate data items are binary integers,+	 *		similar to #MDB_INTEGERKEY keys.+	 *	<li>#MDB_REVERSEDUP+	 *		This option specifies that duplicate data items should be compared as+	 *		strings in reverse order.+	 *	<li>#MDB_CREATE+	 *		Create the named database if it doesn't exist. This option is not+	 *		allowed in a read-only transaction or a read-only environment.+	 * </ul>+	 * @param[out] dbi Address where the new #MDB_dbi handle will be stored+	 * @return A non-zero error value on failure and 0 on success. Some possible+	 * errors are:+	 * <ul>+	 *	<li>#MDB_NOTFOUND - the specified database doesn't exist in the environment+	 *		and #MDB_CREATE was not specified.+	 *	<li>#MDB_DBS_FULL - too many databases have been opened. See #mdb_env_set_maxdbs().+	 * </ul>+	 */+int  mdb_dbi_open(MDB_txn *txn, const char *name, unsigned int flags, MDB_dbi *dbi);++	/** @brief Retrieve statistics for a database.+	 *+	 * @param[in] txn A transaction handle returned by #mdb_txn_begin()+	 * @param[in] dbi A database handle returned by #mdb_dbi_open()+	 * @param[out] stat The address of an #MDB_stat structure+	 * 	where the statistics will be copied+	 * @return A non-zero error value on failure and 0 on success. Some possible+	 * errors are:+	 * <ul>+	 *	<li>EINVAL - an invalid parameter was specified.+	 * </ul>+	 */+int  mdb_stat(MDB_txn *txn, MDB_dbi dbi, MDB_stat *stat);++	/** @brief Retrieve the DB flags for a database handle.+	 *+	 * @param[in] txn A transaction handle returned by #mdb_txn_begin()+	 * @param[in] dbi A database handle returned by #mdb_dbi_open()+	 * @param[out] flags Address where the flags will be returned.+	 * @return A non-zero error value on failure and 0 on success.+	 */+int mdb_dbi_flags(MDB_txn *txn, MDB_dbi dbi, unsigned int *flags);++	/** @brief Close a database handle. Normally unnecessary. Use with care:+	 *+	 * This call is not mutex protected. Handles should only be closed by+	 * a single thread, and only if no other threads are going to reference+	 * the database handle or one of its cursors any further. Do not close+	 * a handle if an existing transaction has modified its database.+	 * Doing so can cause misbehavior from database corruption to errors+	 * like MDB_BAD_VALSIZE (since the DB name is gone).+	 *+	 * Closing a database handle is not necessary, but lets #mdb_dbi_open()+	 * reuse the handle value.  Usually it's better to set a bigger+	 * #mdb_env_set_maxdbs(), unless that value would be large.+	 *+	 * @param[in] env An environment handle returned by #mdb_env_create()+	 * @param[in] dbi A database handle returned by #mdb_dbi_open()+	 */+void mdb_dbi_close(MDB_env *env, MDB_dbi dbi);++	/** @brief Empty or delete+close a database.+	 *+	 * See #mdb_dbi_close() for restrictions about closing the DB handle.+	 * @param[in] txn A transaction handle returned by #mdb_txn_begin()+	 * @param[in] dbi A database handle returned by #mdb_dbi_open()+	 * @param[in] del 0 to empty the DB, 1 to delete it from the+	 * environment and close the DB handle.+	 * @return A non-zero error value on failure and 0 on success.+	 */+int  mdb_drop(MDB_txn *txn, MDB_dbi dbi, int del);++	/** @brief Set a custom key comparison function for a database.+	 *+	 * The comparison function is called whenever it is necessary to compare a+	 * key specified by the application with a key currently stored in the database.+	 * If no comparison function is specified, and no special key flags were specified+	 * with #mdb_dbi_open(), the keys are compared lexically, with shorter keys collating+	 * before longer keys.+	 * @warning This function must be called before any data access functions are used,+	 * otherwise data corruption may occur. The same comparison function must be used by every+	 * program accessing the database, every time the database is used.+	 * @param[in] txn A transaction handle returned by #mdb_txn_begin()+	 * @param[in] dbi A database handle returned by #mdb_dbi_open()+	 * @param[in] cmp A #MDB_cmp_func function+	 * @return A non-zero error value on failure and 0 on success. Some possible+	 * errors are:+	 * <ul>+	 *	<li>EINVAL - an invalid parameter was specified.+	 * </ul>+	 */+int  mdb_set_compare(MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp);++	/** @brief Set a custom data comparison function for a #MDB_DUPSORT database.+	 *+	 * This comparison function is called whenever it is necessary to compare a data+	 * item specified by the application with a data item currently stored in the database.+	 * This function only takes effect if the database was opened with the #MDB_DUPSORT+	 * flag.+	 * If no comparison function is specified, and no special key flags were specified+	 * with #mdb_dbi_open(), the data items are compared lexically, with shorter items collating+	 * before longer items.+	 * @warning This function must be called before any data access functions are used,+	 * otherwise data corruption may occur. The same comparison function must be used by every+	 * program accessing the database, every time the database is used.+	 * @param[in] txn A transaction handle returned by #mdb_txn_begin()+	 * @param[in] dbi A database handle returned by #mdb_dbi_open()+	 * @param[in] cmp A #MDB_cmp_func function+	 * @return A non-zero error value on failure and 0 on success. Some possible+	 * errors are:+	 * <ul>+	 *	<li>EINVAL - an invalid parameter was specified.+	 * </ul>+	 */+int  mdb_set_dupsort(MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp);++	/** @brief Set a relocation function for a #MDB_FIXEDMAP database.+	 *+	 * @todo The relocation function is called whenever it is necessary to move the data+	 * of an item to a different position in the database (e.g. through tree+	 * balancing operations, shifts as a result of adds or deletes, etc.). It is+	 * intended to allow address/position-dependent data items to be stored in+	 * a database in an environment opened with the #MDB_FIXEDMAP option.+	 * Currently the relocation feature is unimplemented and setting+	 * this function has no effect.+	 * @param[in] txn A transaction handle returned by #mdb_txn_begin()+	 * @param[in] dbi A database handle returned by #mdb_dbi_open()+	 * @param[in] rel A #MDB_rel_func function+	 * @return A non-zero error value on failure and 0 on success. Some possible+	 * errors are:+	 * <ul>+	 *	<li>EINVAL - an invalid parameter was specified.+	 * </ul>+	 */+int  mdb_set_relfunc(MDB_txn *txn, MDB_dbi dbi, MDB_rel_func *rel);++	/** @brief Set a context pointer for a #MDB_FIXEDMAP database's relocation function.+	 *+	 * See #mdb_set_relfunc and #MDB_rel_func for more details.+	 * @param[in] txn A transaction handle returned by #mdb_txn_begin()+	 * @param[in] dbi A database handle returned by #mdb_dbi_open()+	 * @param[in] ctx An arbitrary pointer for whatever the application needs.+	 * It will be passed to the callback function set by #mdb_set_relfunc+	 * as its \b relctx parameter whenever the callback is invoked.+	 * @return A non-zero error value on failure and 0 on success. Some possible+	 * errors are:+	 * <ul>+	 *	<li>EINVAL - an invalid parameter was specified.+	 * </ul>+	 */+int  mdb_set_relctx(MDB_txn *txn, MDB_dbi dbi, void *ctx);++	/** @brief Get items from a database.+	 *+	 * This function retrieves key/data pairs from the database. The address+	 * and length of the data associated with the specified \b key are returned+	 * in the structure to which \b data refers.+	 * If the database supports duplicate keys (#MDB_DUPSORT) then the+	 * first data item for the key will be returned. Retrieval of other+	 * items requires the use of #mdb_cursor_get().+	 *+	 * @note The memory pointed to by the returned values is owned by the+	 * database. The caller need not dispose of the memory, and may not+	 * modify it in any way. For values returned in a read-only transaction+	 * any modification attempts will cause a SIGSEGV.+	 * @note Values returned from the database are valid only until a+	 * subsequent update operation, or the end of the transaction.+	 * @param[in] txn A transaction handle returned by #mdb_txn_begin()+	 * @param[in] dbi A database handle returned by #mdb_dbi_open()+	 * @param[in] key The key to search for in the database+	 * @param[out] data The data corresponding to the key+	 * @return A non-zero error value on failure and 0 on success. Some possible+	 * errors are:+	 * <ul>+	 *	<li>#MDB_NOTFOUND - the key was not in the database.+	 *	<li>EINVAL - an invalid parameter was specified.+	 * </ul>+	 */+int  mdb_get(MDB_txn *txn, MDB_dbi dbi, MDB_val *key, MDB_val *data);++	/** @brief Store items into a database.+	 *+	 * This function stores key/data pairs in the database. The default behavior+	 * is to enter the new key/data pair, replacing any previously existing key+	 * if duplicates are disallowed, or adding a duplicate data item if+	 * duplicates are allowed (#MDB_DUPSORT).+	 * @param[in] txn A transaction handle returned by #mdb_txn_begin()+	 * @param[in] dbi A database handle returned by #mdb_dbi_open()+	 * @param[in] key The key to store in the database+	 * @param[in,out] data The data to store+	 * @param[in] flags Special options for this operation. This parameter+	 * must be set to 0 or by bitwise OR'ing together one or more of the+	 * values described here.+	 * <ul>+	 *	<li>#MDB_NODUPDATA - enter the new key/data pair only if it does not+	 *		already appear in the database. This flag may only be specified+	 *		if the database was opened with #MDB_DUPSORT. The function will+	 *		return #MDB_KEYEXIST if the key/data pair already appears in the+	 *		database.+	 *	<li>#MDB_NOOVERWRITE - enter the new key/data pair only if the key+	 *		does not already appear in the database. The function will return+	 *		#MDB_KEYEXIST if the key already appears in the database, even if+	 *		the database supports duplicates (#MDB_DUPSORT). The \b data+	 *		parameter will be set to point to the existing item.+	 *	<li>#MDB_RESERVE - reserve space for data of the given size, but+	 *		don't copy the given data. Instead, return a pointer to the+	 *		reserved space, which the caller can fill in later - before+	 *		the next update operation or the transaction ends. This saves+	 *		an extra memcpy if the data is being generated later.+	 *		LMDB does nothing else with this memory, the caller is expected+	 *		to modify all of the space requested. This flag must not be+	 *		specified if the database was opened with #MDB_DUPSORT.+	 *	<li>#MDB_APPEND - append the given key/data pair to the end of the+	 *		database. This option allows fast bulk loading when keys are+	 *		already known to be in the correct order. Loading unsorted keys+	 *		with this flag will cause a #MDB_KEYEXIST error.+	 *	<li>#MDB_APPENDDUP - as above, but for sorted dup data.+	 * </ul>+	 * @return A non-zero error value on failure and 0 on success. Some possible+	 * errors are:+	 * <ul>+	 *	<li>#MDB_MAP_FULL - the database is full, see #mdb_env_set_mapsize().+	 *	<li>#MDB_TXN_FULL - the transaction has too many dirty pages.+	 *	<li>EACCES - an attempt was made to write in a read-only transaction.+	 *	<li>EINVAL - an invalid parameter was specified.+	 * </ul>+	 */+int  mdb_put(MDB_txn *txn, MDB_dbi dbi, MDB_val *key, MDB_val *data,+			    unsigned int flags);++	/** @brief Delete items from a database.+	 *+	 * This function removes key/data pairs from the database.+	 * If the database does not support sorted duplicate data items+	 * (#MDB_DUPSORT) the data parameter is ignored.+	 * If the database supports sorted duplicates and the data parameter+	 * is NULL, all of the duplicate data items for the key will be+	 * deleted. Otherwise, if the data parameter is non-NULL+	 * only the matching data item will be deleted.+	 * This function will return #MDB_NOTFOUND if the specified key/data+	 * pair is not in the database.+	 * @param[in] txn A transaction handle returned by #mdb_txn_begin()+	 * @param[in] dbi A database handle returned by #mdb_dbi_open()+	 * @param[in] key The key to delete from the database+	 * @param[in] data The data to delete+	 * @return A non-zero error value on failure and 0 on success. Some possible+	 * errors are:+	 * <ul>+	 *	<li>EACCES - an attempt was made to write in a read-only transaction.+	 *	<li>EINVAL - an invalid parameter was specified.+	 * </ul>+	 */+int  mdb_del(MDB_txn *txn, MDB_dbi dbi, MDB_val *key, MDB_val *data);++	/** @brief Create a cursor handle.+	 *+	 * A cursor is associated with a specific transaction and database.+	 * A cursor cannot be used when its database handle is closed.  Nor+	 * when its transaction has ended, except with #mdb_cursor_renew().+	 * It can be discarded with #mdb_cursor_close().+	 * A cursor in a write-transaction can be closed before its transaction+	 * ends, and will otherwise be closed when its transaction ends.+	 * A cursor in a read-only transaction must be closed explicitly, before+	 * or after its transaction ends. It can be reused with+	 * #mdb_cursor_renew() before finally closing it.+	 * @note Earlier documentation said that cursors in every transaction+	 * were closed when the transaction committed or aborted.+	 * @param[in] txn A transaction handle returned by #mdb_txn_begin()+	 * @param[in] dbi A database handle returned by #mdb_dbi_open()+	 * @param[out] cursor Address where the new #MDB_cursor handle will be stored+	 * @return A non-zero error value on failure and 0 on success. Some possible+	 * errors are:+	 * <ul>+	 *	<li>EINVAL - an invalid parameter was specified.+	 * </ul>+	 */+int  mdb_cursor_open(MDB_txn *txn, MDB_dbi dbi, MDB_cursor **cursor);++	/** @brief Close a cursor handle.+	 *+	 * The cursor handle will be freed and must not be used again after this call.+	 * Its transaction must still be live if it is a write-transaction.+	 * @param[in] cursor A cursor handle returned by #mdb_cursor_open()+	 */+void mdb_cursor_close(MDB_cursor *cursor);++	/** @brief Renew a cursor handle.+	 *+	 * A cursor is associated with a specific transaction and database.+	 * Cursors that are only used in read-only+	 * transactions may be re-used, to avoid unnecessary malloc/free overhead.+	 * The cursor may be associated with a new read-only transaction, and+	 * referencing the same database handle as it was created with.+	 * This may be done whether the previous transaction is live or dead.+	 * @param[in] txn A transaction handle returned by #mdb_txn_begin()+	 * @param[in] cursor A cursor handle returned by #mdb_cursor_open()+	 * @return A non-zero error value on failure and 0 on success. Some possible+	 * errors are:+	 * <ul>+	 *	<li>EINVAL - an invalid parameter was specified.+	 * </ul>+	 */+int  mdb_cursor_renew(MDB_txn *txn, MDB_cursor *cursor);++	/** @brief Return the cursor's transaction handle.+	 *+	 * @param[in] cursor A cursor handle returned by #mdb_cursor_open()+	 */+MDB_txn *mdb_cursor_txn(MDB_cursor *cursor);++	/** @brief Return the cursor's database handle.+	 *+	 * @param[in] cursor A cursor handle returned by #mdb_cursor_open()+	 */+MDB_dbi mdb_cursor_dbi(MDB_cursor *cursor);++	/** @brief Retrieve by cursor.+	 *+	 * This function retrieves key/data pairs from the database. The address and length+	 * of the key are returned in the object to which \b key refers (except for the+	 * case of the #MDB_SET option, in which the \b key object is unchanged), and+	 * the address and length of the data are returned in the object to which \b data+	 * refers.+	 * See #mdb_get() for restrictions on using the output values.+	 * @param[in] cursor A cursor handle returned by #mdb_cursor_open()+	 * @param[in,out] key The key for a retrieved item+	 * @param[in,out] data The data of a retrieved item+	 * @param[in] op A cursor operation #MDB_cursor_op+	 * @return A non-zero error value on failure and 0 on success. Some possible+	 * errors are:+	 * <ul>+	 *	<li>#MDB_NOTFOUND - no matching key found.+	 *	<li>EINVAL - an invalid parameter was specified.+	 * </ul>+	 */+int  mdb_cursor_get(MDB_cursor *cursor, MDB_val *key, MDB_val *data,+			    MDB_cursor_op op);++	/** @brief Store by cursor.+	 *+	 * This function stores key/data pairs into the database.+	 * The cursor is positioned at the new item, or on failure usually near it.+	 * @note Earlier documentation incorrectly said errors would leave the+	 * state of the cursor unchanged.+	 * @param[in] cursor A cursor handle returned by #mdb_cursor_open()+	 * @param[in] key The key operated on.+	 * @param[in] data The data operated on.+	 * @param[in] flags Options for this operation. This parameter+	 * must be set to 0 or one of the values described here.+	 * <ul>+	 *	<li>#MDB_CURRENT - replace the item at the current cursor position.+	 *		The \b key parameter must still be provided, and must match it.+	 *		If using sorted duplicates (#MDB_DUPSORT) the data item must still+	 *		sort into the same place. This is intended to be used when the+	 *		new data is the same size as the old. Otherwise it will simply+	 *		perform a delete of the old record followed by an insert.+	 *	<li>#MDB_NODUPDATA - enter the new key/data pair only if it does not+	 *		already appear in the database. This flag may only be specified+	 *		if the database was opened with #MDB_DUPSORT. The function will+	 *		return #MDB_KEYEXIST if the key/data pair already appears in the+	 *		database.+	 *	<li>#MDB_NOOVERWRITE - enter the new key/data pair only if the key+	 *		does not already appear in the database. The function will return+	 *		#MDB_KEYEXIST if the key already appears in the database, even if+	 *		the database supports duplicates (#MDB_DUPSORT).+	 *	<li>#MDB_RESERVE - reserve space for data of the given size, but+	 *		don't copy the given data. Instead, return a pointer to the+	 *		reserved space, which the caller can fill in later - before+	 *		the next update operation or the transaction ends. This saves+	 *		an extra memcpy if the data is being generated later. This flag+	 *		must not be specified if the database was opened with #MDB_DUPSORT.+	 *	<li>#MDB_APPEND - append the given key/data pair to the end of the+	 *		database. No key comparisons are performed. This option allows+	 *		fast bulk loading when keys are already known to be in the+	 *		correct order. Loading unsorted keys with this flag will cause+	 *		a #MDB_KEYEXIST error.+	 *	<li>#MDB_APPENDDUP - as above, but for sorted dup data.+	 *	<li>#MDB_MULTIPLE - store multiple contiguous data elements in a+	 *		single request. This flag may only be specified if the database+	 *		was opened with #MDB_DUPFIXED. The \b data argument must be an+	 *		array of two MDB_vals. The mv_size of the first MDB_val must be+	 *		the size of a single data element. The mv_data of the first MDB_val+	 *		must point to the beginning of the array of contiguous data elements.+	 *		The mv_size of the second MDB_val must be the count of the number+	 *		of data elements to store. On return this field will be set to+	 *		the count of the number of elements actually written. The mv_data+	 *		of the second MDB_val is unused.+	 * </ul>+	 * @return A non-zero error value on failure and 0 on success. Some possible+	 * errors are:+	 * <ul>+	 *	<li>#MDB_MAP_FULL - the database is full, see #mdb_env_set_mapsize().+	 *	<li>#MDB_TXN_FULL - the transaction has too many dirty pages.+	 *	<li>EACCES - an attempt was made to write in a read-only transaction.+	 *	<li>EINVAL - an invalid parameter was specified.+	 * </ul>+	 */+int  mdb_cursor_put(MDB_cursor *cursor, MDB_val *key, MDB_val *data,+				unsigned int flags);++	/** @brief Delete current key/data pair+	 *+	 * This function deletes the key/data pair to which the cursor refers.+	 * This does not invalidate the cursor, so operations such as MDB_NEXT+	 * can still be used on it.+	 * Both MDB_NEXT and MDB_GET_CURRENT will return the same record after+	 * this operation.+	 * @param[in] cursor A cursor handle returned by #mdb_cursor_open()+	 * @param[in] flags Options for this operation. This parameter+	 * must be set to 0 or one of the values described here.+	 * <ul>+	 *	<li>#MDB_NODUPDATA - delete all of the data items for the current key.+	 *		This flag may only be specified if the database was opened with #MDB_DUPSORT.+	 * </ul>+	 * @return A non-zero error value on failure and 0 on success. Some possible+	 * errors are:+	 * <ul>+	 *	<li>EACCES - an attempt was made to write in a read-only transaction.+	 *	<li>EINVAL - an invalid parameter was specified.+	 * </ul>+	 */+int  mdb_cursor_del(MDB_cursor *cursor, unsigned int flags);++	/** @brief Return count of duplicates for current key.+	 *+	 * This call is only valid on databases that support sorted duplicate+	 * data items #MDB_DUPSORT.+	 * @param[in] cursor A cursor handle returned by #mdb_cursor_open()+	 * @param[out] countp Address where the count will be stored+	 * @return A non-zero error value on failure and 0 on success. Some possible+	 * errors are:+	 * <ul>+	 *	<li>EINVAL - cursor is not initialized, or an invalid parameter was specified.+	 * </ul>+	 */+int  mdb_cursor_count(MDB_cursor *cursor, size_t *countp);++	/** @brief Compare two data items according to a particular database.+	 *+	 * This returns a comparison as if the two data items were keys in the+	 * specified database.+	 * @param[in] txn A transaction handle returned by #mdb_txn_begin()+	 * @param[in] dbi A database handle returned by #mdb_dbi_open()+	 * @param[in] a The first item to compare+	 * @param[in] b The second item to compare+	 * @return < 0 if a < b, 0 if a == b, > 0 if a > b+	 */+int  mdb_cmp(MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b);++	/** @brief Compare two data items according to a particular database.+	 *+	 * This returns a comparison as if the two items were data items of+	 * the specified database. The database must have the #MDB_DUPSORT flag.+	 * @param[in] txn A transaction handle returned by #mdb_txn_begin()+	 * @param[in] dbi A database handle returned by #mdb_dbi_open()+	 * @param[in] a The first item to compare+	 * @param[in] b The second item to compare+	 * @return < 0 if a < b, 0 if a == b, > 0 if a > b+	 */+int  mdb_dcmp(MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b);++	/** @brief A callback function used to print a message from the library.+	 *+	 * @param[in] msg The string to be printed.+	 * @param[in] ctx An arbitrary context pointer for the callback.+	 * @return < 0 on failure, >= 0 on success.+	 */+typedef int (MDB_msg_func)(const char *msg, void *ctx);++	/** @brief Dump the entries in the reader lock table.+	 *+	 * @param[in] env An environment handle returned by #mdb_env_create()+	 * @param[in] func A #MDB_msg_func function+	 * @param[in] ctx Anything the message function needs+	 * @return < 0 on failure, >= 0 on success.+	 */+int	mdb_reader_list(MDB_env *env, MDB_msg_func *func, void *ctx);++	/** @brief Check for stale entries in the reader lock table.+	 *+	 * @param[in] env An environment handle returned by #mdb_env_create()+	 * @param[out] dead Number of stale slots that were cleared+	 * @return 0 on success, non-zero on failure.+	 */+int	mdb_reader_check(MDB_env *env, int *dead);+/**	@} */++#ifdef __cplusplus+}+#endif+/** @page tools LMDB Command Line Tools+	The following describes the command line tools that are available for LMDB.+	\li \ref mdb_copy_1+	\li \ref mdb_dump_1+	\li \ref mdb_load_1+	\li \ref mdb_stat_1+*/++#endif /* _LMDB_H_ */
+ cbits/mdb.c view
@@ -0,0 +1,10434 @@+/** @file mdb.c+ *	@brief Lightning memory-mapped database library+ *+ *	A Btree-based database management library modeled loosely on the+ *	BerkeleyDB API, but much simplified.+ */+/*+ * Copyright 2011-2021 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>.+ *+ * This code is derived from btree.c written by Martin Hedenfalk.+ *+ * 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.+ */+#ifndef _GNU_SOURCE+#define _GNU_SOURCE 1+#endif+#if defined(__WIN64__)+#define _FILE_OFFSET_BITS	64+#endif+#ifdef _WIN32+#include <malloc.h>+#include <windows.h>+#include <wchar.h>				/* get wcscpy() */++/** getpid() returns int; MinGW defines pid_t but MinGW64 typedefs it+ *  as int64 which is wrong. MSVC doesn't define it at all, so just+ *  don't use it.+ */+#define MDB_PID_T	int+#define MDB_THR_T	DWORD+#include <sys/types.h>+#include <sys/stat.h>+#ifdef __GNUC__+# include <sys/param.h>+#else+# define LITTLE_ENDIAN	1234+# define BIG_ENDIAN	4321+# define BYTE_ORDER	LITTLE_ENDIAN+# ifndef SSIZE_MAX+#  define SSIZE_MAX	INT_MAX+# endif+#endif+#else+#include <sys/types.h>+#include <sys/stat.h>+#define MDB_PID_T	pid_t+#define MDB_THR_T	pthread_t+#include <sys/param.h>+#include <sys/uio.h>+#include <sys/mman.h>+#ifdef HAVE_SYS_FILE_H+#include <sys/file.h>+#endif+#include <fcntl.h>+#endif++#if defined(__mips) && defined(__linux)+/* MIPS has cache coherency issues, requires explicit cache control */+#include <sys/cachectl.h>+#define CACHEFLUSH(addr, bytes, cache)	cacheflush(addr, bytes, cache)+#else+#define CACHEFLUSH(addr, bytes, cache)+#endif++#if defined(__linux) && !defined(MDB_FDATASYNC_WORKS)+/** fdatasync is broken on ext3/ext4fs on older kernels, see+ *	description in #mdb_env_open2 comments. You can safely+ *	define MDB_FDATASYNC_WORKS if this code will only be run+ *	on kernels 3.6 and newer.+ */+#define	BROKEN_FDATASYNC+#endif++#include <errno.h>+#include <limits.h>+#include <stddef.h>+#include <inttypes.h>+#include <stdio.h>+#include <stdlib.h>+#include <string.h>+#include <time.h>++#ifdef _MSC_VER+#include <io.h>+typedef SSIZE_T	ssize_t;+#else+#include <unistd.h>+#endif++#if defined(__sun) || defined(ANDROID)+/* Most platforms have posix_memalign, older may only have memalign */+#define HAVE_MEMALIGN	1+#include <malloc.h>+/* On Solaris, we need the POSIX sigwait function */+#if defined (__sun)+# define _POSIX_PTHREAD_SEMANTICS	1+#endif+#endif++#if !(defined(BYTE_ORDER) || defined(__BYTE_ORDER))+#include <netinet/in.h>+#include <resolv.h>	/* defines BYTE_ORDER on HPUX and Solaris */+#endif++#if defined(__FreeBSD__) && defined(__FreeBSD_version) && __FreeBSD_version >= 1100110+# define MDB_USE_POSIX_MUTEX	1+# define MDB_USE_ROBUST	1+#elif defined(__APPLE__) || defined (BSD) || defined(__FreeBSD_kernel__)+# define MDB_USE_POSIX_SEM	1+# define MDB_FDATASYNC		fsync+#elif defined(ANDROID)+# define MDB_FDATASYNC		fsync+#endif++#ifndef _WIN32+#include <pthread.h>+#include <signal.h>+#ifdef MDB_USE_POSIX_SEM+# define MDB_USE_HASH		1+#include <semaphore.h>+#else+#define MDB_USE_POSIX_MUTEX	1+#endif+#endif++#if defined(_WIN32) + defined(MDB_USE_POSIX_SEM) \+	+ defined(MDB_USE_POSIX_MUTEX) != 1+# error "Ambiguous shared-lock implementation"+#endif++#ifdef USE_VALGRIND+#include <valgrind/memcheck.h>+#define VGMEMP_CREATE(h,r,z)    VALGRIND_CREATE_MEMPOOL(h,r,z)+#define VGMEMP_ALLOC(h,a,s) VALGRIND_MEMPOOL_ALLOC(h,a,s)+#define VGMEMP_FREE(h,a) VALGRIND_MEMPOOL_FREE(h,a)+#define VGMEMP_DESTROY(h)	VALGRIND_DESTROY_MEMPOOL(h)+#define VGMEMP_DEFINED(a,s)	VALGRIND_MAKE_MEM_DEFINED(a,s)+#else+#define VGMEMP_CREATE(h,r,z)+#define VGMEMP_ALLOC(h,a,s)+#define VGMEMP_FREE(h,a)+#define VGMEMP_DESTROY(h)+#define VGMEMP_DEFINED(a,s)+#endif++#ifndef BYTE_ORDER+# if (defined(_LITTLE_ENDIAN) || defined(_BIG_ENDIAN)) && !(defined(_LITTLE_ENDIAN) && defined(_BIG_ENDIAN))+/* Solaris just defines one or the other */+#  define LITTLE_ENDIAN	1234+#  define BIG_ENDIAN	4321+#  ifdef _LITTLE_ENDIAN+#   define BYTE_ORDER  LITTLE_ENDIAN+#  else+#   define BYTE_ORDER  BIG_ENDIAN+#  endif+# else+#  define BYTE_ORDER   __BYTE_ORDER+# endif+#endif++#ifndef LITTLE_ENDIAN+#define LITTLE_ENDIAN	__LITTLE_ENDIAN+#endif+#ifndef BIG_ENDIAN+#define BIG_ENDIAN	__BIG_ENDIAN+#endif++#if defined(__i386) || defined(__x86_64) || defined(_M_IX86)+#define MISALIGNED_OK	1+#endif++#include "lmdb.h"+#include "midl.h"++#if (BYTE_ORDER == LITTLE_ENDIAN) == (BYTE_ORDER == BIG_ENDIAN)+# error "Unknown or unsupported endianness (BYTE_ORDER)"+#elif (-6 & 5) || CHAR_BIT != 8 || UINT_MAX < 0xffffffff || ULONG_MAX % 0xFFFF+# error "Two's complement, reasonably sized integer types, please"+#endif++#if (((__clang_major__ << 8) | __clang_minor__) >= 0x0302) || (((__GNUC__ << 8) | __GNUC_MINOR__) >= 0x0403)+/** Mark infrequently used env functions as cold. This puts them in a separate+ *  section, and optimizes them for size */+#define ESECT __attribute__ ((cold))+#else+/* On older compilers, use a separate section */+# ifdef __GNUC__+#  ifdef __APPLE__+#   define      ESECT   __attribute__ ((section("__TEXT,text_env")))+#  else+#   define      ESECT   __attribute__ ((section("text_env")))+#  endif+# else+#  define ESECT+# endif+#endif++#ifdef _WIN32+#define CALL_CONV WINAPI+#else+#define CALL_CONV+#endif++/** @defgroup internal	LMDB Internals+ *	@{+ */+/** @defgroup compat	Compatibility Macros+ *	A bunch of macros to minimize the amount of platform-specific ifdefs+ *	needed throughout the rest of the code. When the features this library+ *	needs are similar enough to POSIX to be hidden in a one-or-two line+ *	replacement, this macro approach is used.+ *	@{+ */++	/** Features under development */+#ifndef MDB_DEVEL+#define MDB_DEVEL 0+#endif++	/** Wrapper around __func__, which is a C99 feature */+#if __STDC_VERSION__ >= 199901L+# define mdb_func_	__func__+#elif __GNUC__ >= 2 || _MSC_VER >= 1300+# define mdb_func_	__FUNCTION__+#else+/* If a debug message says <mdb_unknown>(), update the #if statements above */+# define mdb_func_	"<mdb_unknown>"+#endif++/* Internal error codes, not exposed outside liblmdb */+#define	MDB_NO_ROOT		(MDB_LAST_ERRCODE + 10)+#ifdef _WIN32+#define MDB_OWNERDEAD	((int) WAIT_ABANDONED)+#elif defined(MDB_USE_POSIX_MUTEX) && defined(EOWNERDEAD)+#define MDB_OWNERDEAD	EOWNERDEAD	/**< #LOCK_MUTEX0() result if dead owner */+#endif++#ifdef __GLIBC__+#define	GLIBC_VER	((__GLIBC__ << 16 )| __GLIBC_MINOR__)+#endif+/** Some platforms define the EOWNERDEAD error code+ * even though they don't support Robust Mutexes.+ * Compile with -DMDB_USE_ROBUST=0, or use some other+ * mechanism like -DMDB_USE_POSIX_SEM instead of+ * -DMDB_USE_POSIX_MUTEX.+ * (Posix semaphores are not robust.)+ */+#ifndef MDB_USE_ROBUST+/* Android currently lacks Robust Mutex support. So does glibc < 2.4. */+# if defined(MDB_USE_POSIX_MUTEX) && (defined(ANDROID) || \+	(defined(__GLIBC__) && GLIBC_VER < 0x020004))+#  define MDB_USE_ROBUST	0+# else+#  define MDB_USE_ROBUST	1+# endif+#endif /* !MDB_USE_ROBUST */++#if defined(MDB_USE_POSIX_MUTEX) && (MDB_USE_ROBUST)+/* glibc < 2.12 only provided _np API */+#  if (defined(__GLIBC__) && GLIBC_VER < 0x02000c) || \+	(defined(PTHREAD_MUTEX_ROBUST_NP) && !defined(PTHREAD_MUTEX_ROBUST))+#   define PTHREAD_MUTEX_ROBUST	PTHREAD_MUTEX_ROBUST_NP+#   define pthread_mutexattr_setrobust(attr, flag)	pthread_mutexattr_setrobust_np(attr, flag)+#   define pthread_mutex_consistent(mutex)	pthread_mutex_consistent_np(mutex)+#  endif+#endif /* MDB_USE_POSIX_MUTEX && MDB_USE_ROBUST */++#if defined(MDB_OWNERDEAD) && (MDB_USE_ROBUST)+#define MDB_ROBUST_SUPPORTED	1+#endif++#ifdef _WIN32+#define MDB_USE_HASH	1+#define MDB_PIDLOCK	0+#define THREAD_RET	DWORD+#define pthread_t	HANDLE+#define pthread_mutex_t	HANDLE+#define pthread_cond_t	HANDLE+typedef HANDLE mdb_mutex_t, mdb_mutexref_t;+#define pthread_key_t	DWORD+#define pthread_self()	GetCurrentThreadId()+#define pthread_key_create(x,y)	\+	((*(x) = TlsAlloc()) == TLS_OUT_OF_INDEXES ? ErrCode() : 0)+#define pthread_key_delete(x)	TlsFree(x)+#define pthread_getspecific(x)	TlsGetValue(x)+#define pthread_setspecific(x,y)	(TlsSetValue(x,y) ? 0 : ErrCode())+#define pthread_mutex_unlock(x)	ReleaseMutex(*x)+#define pthread_mutex_lock(x)	WaitForSingleObject(*x, INFINITE)+#define pthread_cond_signal(x)	SetEvent(*x)+#define pthread_cond_wait(cond,mutex)	do{SignalObjectAndWait(*mutex, *cond, INFINITE, FALSE); WaitForSingleObject(*mutex, INFINITE);}while(0)+#define THREAD_CREATE(thr,start,arg) \+	(((thr) = CreateThread(NULL, 0, start, arg, 0, NULL)) ? 0 : ErrCode())+#define THREAD_FINISH(thr) \+	(WaitForSingleObject(thr, INFINITE) ? ErrCode() : 0)+#define LOCK_MUTEX0(mutex)		WaitForSingleObject(mutex, INFINITE)+#define UNLOCK_MUTEX(mutex)		ReleaseMutex(mutex)+#define mdb_mutex_consistent(mutex)	0+#define getpid()	GetCurrentProcessId()+#define	MDB_FDATASYNC(fd)	(!FlushFileBuffers(fd))+#define	MDB_MSYNC(addr,len,flags)	(!FlushViewOfFile(addr,len))+#define	ErrCode()	GetLastError()+#define GET_PAGESIZE(x) {SYSTEM_INFO si; GetSystemInfo(&si); (x) = si.dwPageSize;}+#define	close(fd)	(CloseHandle(fd) ? 0 : -1)+#define	munmap(ptr,len)	UnmapViewOfFile(ptr)+#ifdef PROCESS_QUERY_LIMITED_INFORMATION+#define MDB_PROCESS_QUERY_LIMITED_INFORMATION PROCESS_QUERY_LIMITED_INFORMATION+#else+#define MDB_PROCESS_QUERY_LIMITED_INFORMATION 0x1000+#endif+#define	Z	"I"+#else+#define THREAD_RET	void *+#define THREAD_CREATE(thr,start,arg)	pthread_create(&thr,NULL,start,arg)+#define THREAD_FINISH(thr)	pthread_join(thr,NULL)+#define	Z	"z"			/**< printf format modifier for size_t */++	/** For MDB_LOCK_FORMAT: True if readers take a pid lock in the lockfile */+#define MDB_PIDLOCK			1++#ifdef MDB_USE_POSIX_SEM++typedef sem_t *mdb_mutex_t, *mdb_mutexref_t;+#define LOCK_MUTEX0(mutex)		mdb_sem_wait(mutex)+#define UNLOCK_MUTEX(mutex)		sem_post(mutex)++static int+mdb_sem_wait(sem_t *sem)+{+   int rc;+   while ((rc = sem_wait(sem)) && (rc = errno) == EINTR) ;+   return rc;+}++#else	/* MDB_USE_POSIX_MUTEX: */+	/** Shared mutex/semaphore as the original is stored.+	 *+	 *	Not for copies.  Instead it can be assigned to an #mdb_mutexref_t.+	 *	When mdb_mutexref_t is a pointer and mdb_mutex_t is not, then it+	 *	is array[size 1] so it can be assigned to the pointer.+	 */+typedef pthread_mutex_t mdb_mutex_t[1];+	/** Reference to an #mdb_mutex_t */+typedef pthread_mutex_t *mdb_mutexref_t;+	/** Lock the reader or writer mutex.+	 *	Returns 0 or a code to give #mdb_mutex_failed(), as in #LOCK_MUTEX().+	 */+#define LOCK_MUTEX0(mutex)	pthread_mutex_lock(mutex)+	/** Unlock the reader or writer mutex.+	 */+#define UNLOCK_MUTEX(mutex)	pthread_mutex_unlock(mutex)+	/** Mark mutex-protected data as repaired, after death of previous owner.+	 */+#define mdb_mutex_consistent(mutex)	pthread_mutex_consistent(mutex)+#endif	/* MDB_USE_POSIX_SEM */++	/** Get the error code for the last failed system function.+	 */+#define	ErrCode()	errno++	/** An abstraction for a file handle.+	 *	On POSIX systems file handles are small integers. On Windows+	 *	they're opaque pointers.+	 */+#define	HANDLE	int++	/**	A value for an invalid file handle.+	 *	Mainly used to initialize file variables and signify that they are+	 *	unused.+	 */+#define INVALID_HANDLE_VALUE	(-1)++	/** 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.+	 */+#define	GET_PAGESIZE(x)	((x) = sysconf(_SC_PAGE_SIZE))+#endif++#if defined(_WIN32) || defined(MDB_USE_POSIX_SEM)+#define MNAME_LEN	32+#else+#define MNAME_LEN	(sizeof(pthread_mutex_t))+#endif++/** @} */++#ifdef MDB_ROBUST_SUPPORTED+	/** Lock mutex, handle any error, set rc = result.+	 *	Return 0 on success, nonzero (not rc) on error.+	 */+#define LOCK_MUTEX(rc, env, mutex) \+	(((rc) = LOCK_MUTEX0(mutex)) && \+	 ((rc) = mdb_mutex_failed(env, mutex, rc)))+static int mdb_mutex_failed(MDB_env *env, mdb_mutexref_t mutex, int rc);+#else+#define LOCK_MUTEX(rc, env, mutex) ((rc) = LOCK_MUTEX0(mutex))+#define mdb_mutex_failed(env, mutex, rc) (rc)+#endif++#ifndef _WIN32+/**	A flag for opening a file and requesting synchronous data writes.+ *	This is only used when writing a meta page. It's not strictly needed;+ *	we could just do a normal write and then immediately perform a flush.+ *	But if this flag is available it saves us an extra system call.+ *+ *	@note If O_DSYNC is undefined but exists in /usr/include,+ * preferably set some compiler flag to get the definition.+ */+#ifndef MDB_DSYNC+# ifdef O_DSYNC+# define MDB_DSYNC	O_DSYNC+# else+# define MDB_DSYNC	O_SYNC+# endif+#endif+#endif++/** Function for flushing the data of a file. Define this to fsync+ *	if fdatasync() is not supported.+ */+#ifndef MDB_FDATASYNC+# define MDB_FDATASYNC	fdatasync+#endif++#ifndef MDB_MSYNC+# define MDB_MSYNC(addr,len,flags)	msync(addr,len,flags)+#endif++#ifndef MS_SYNC+#define	MS_SYNC	1+#endif++#ifndef MS_ASYNC+#define	MS_ASYNC	0+#endif++	/** A page number in the database.+	 *	Note that 64 bit page numbers are overkill, since pages themselves+	 *	already represent 12-13 bits of addressable memory, and the OS will+	 *	always limit applications to a maximum of 63 bits of address space.+	 *+	 *	@note In the #MDB_node structure, we only store 48 bits of this value,+	 *	which thus limits us to only 60 bits of addressable data.+	 */+typedef MDB_ID	pgno_t;++	/** A transaction ID.+	 *	See struct MDB_txn.mt_txnid for details.+	 */+typedef MDB_ID	txnid_t;++/** @defgroup debug	Debug Macros+ *	@{+ */+#ifndef MDB_DEBUG+	/**	Enable debug output.  Needs variable argument macros (a C99 feature).+	 *	Set this to 1 for copious tracing. Set to 2 to add dumps of all IDLs+	 *	read from and written to the database (used for free space management).+	 */+#define MDB_DEBUG 0+#endif++#define MDB_DBG_INFO	1+#define MDB_DBG_TRACE	2++#if MDB_DEBUG+static int mdb_debug = MDB_DBG_TRACE;+static txnid_t mdb_debug_start;++	/**	Print a debug message with printf formatting.+	 *	Requires double parenthesis around 2 or more args.+	 */+# define DPRINTF(args) ((void) ((mdb_debug & MDB_DBG_INFO) && DPRINTF0 args))+# define DPRINTF0(fmt, ...) \+	fprintf(stderr, "%s:%d " fmt "\n", mdb_func_, __LINE__, __VA_ARGS__)+	/** Trace info for replaying */+# define MDB_TRACE(args)	((void) ((mdb_debug & MDB_DBG_TRACE) && DPRINTF1 args))+# define DPRINTF1(fmt, ...) \+	fprintf(stderr, ">%d:%s: " fmt "\n", getpid(), mdb_func_, __VA_ARGS__)+#else+# define DPRINTF(args)	((void) 0)+# define MDB_TRACE(args)	((void) 0)+#endif+	/**	Print a debug string.+	 *	The string is printed literally, with no format processing.+	 */+#define DPUTS(arg)	DPRINTF(("%s", arg))+	/** 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)+/** @} */++	/**	@brief The maximum size of a database page.+	 *+	 *	It is 32k or 64k, since value-PAGEBASE must fit in+	 *	#MDB_page.%mp_upper.+	 *+	 *	LMDB 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	 (PAGEBASE ? 0x10000 : 0x8000)++	/** 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 MDB_MINKEYS	 2++	/**	A stamp that identifies a file as an LMDB file.+	 *	There's nothing special about this value other than that it is easily+	 *	recognizable, and it will reflect any byte order mismatches.+	 */+#define MDB_MAGIC	 0xBEEFC0DE++	/**	The version number for a database's datafile format. */+#define MDB_DATA_VERSION	 ((MDB_DEVEL) ? 999 : 1)+	/**	The version number for a database's lockfile format. */+#define MDB_LOCK_VERSION	 1++	/**	@brief The max size of a key we can write, or 0 for computed max.+	 *+	 *	This macro should normally be left alone or set to 0.+	 *	Note that a database with big keys or dupsort data cannot be+	 *	reliably modified by a liblmdb which uses a smaller max.+	 *	The default is 511 for backwards compat, or 0 when #MDB_DEVEL.+	 *+	 *	Other values are allowed, for backwards compat.  However:+	 *	A value bigger than the computed max can break if you do not+	 *	know what you are doing, and liblmdb <= 0.9.10 can break when+	 *	modifying a DB with keys/dupsort data bigger than its max.+	 *+	 *	Data items in an #MDB_DUPSORT database are also limited to+	 *	this size, since they're actually keys of a sub-DB.  Keys and+	 *	#MDB_DUPSORT data items must fit on a node in a regular page.+	 */+#ifndef MDB_MAXKEYSIZE+#define MDB_MAXKEYSIZE	 ((MDB_DEVEL) ? 0 : 511)+#endif++	/**	The maximum size of a key we can write to the environment. */+#if MDB_MAXKEYSIZE+#define ENV_MAXKEY(env)	(MDB_MAXKEYSIZE)+#else+#define ENV_MAXKEY(env)	((env)->me_maxkey)+#endif++	/**	@brief The maximum size of a data item.+	 *+	 *	We only store a 32 bit value for node sizes.+	 */+#define MAXDATASIZE	0xffffffffUL++#if MDB_DEBUG+	/**	Key size which fits in a #DKBUF.+	 *	@ingroup debug+	 */+#define DKBUF_MAXKEYSIZE ((MDB_MAXKEYSIZE) > 0 ? (MDB_MAXKEYSIZE) : 511)+	/**	A key buffer.+	 *	@ingroup debug+	 *	This is used for printing a hex dump of a key's contents.+	 */+#define DKBUF	char kbuf[DKBUF_MAXKEYSIZE*2+1]+	/**	A data value buffer.+	 *	@ingroup debug+	 *	This is used for printing a hex dump of a #MDB_DUPSORT value's contents.+	 */+#define DDBUF	char dbuf[DKBUF_MAXKEYSIZE*2+1+2]+	/**	Display a key in hex.+	 *	@ingroup debug+	 *	Invoke a function to display a key in hex.+	 */+#define	DKEY(x)	mdb_dkey(x, kbuf)+#else+#define	DKBUF+#define	DDBUF+#define DKEY(x)	0+#endif++	/** An invalid page number.+	 *	Mainly used to denote an empty tree.+	 */+#define P_INVALID	 (~(pgno_t)0)++	/** Test if the flags \b f are set in a flag word \b w. */+#define F_ISSET(w, f)	 (((w) & (f)) == (f))++	/** Round \b n up to an even number. */+#define EVEN(n)		(((n) + 1U) & -2) /* sign-extending -2 to match n+1U */++	/**	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;++	/**	Default size of memory map.+	 *	This is certainly too small for any actual applications. Apps should always set+	 *	the size explicitly using #mdb_env_set_mapsize().+	 */+#define DEFAULT_MAPSIZE	1048576++/**	@defgroup readers	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 #MDB_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, or+ *	if #MDB_NOLOCK is set.+ *+ *	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.+ *	@{+ */+	/**	Number of slots in the reader table.+	 *	This value was chosen somewhat arbitrarily. 126 readers plus a+	 *	couple mutexes fit exactly into 8KB on my development machine.+	 *	Applications should set the table size using #mdb_env_set_maxreaders().+	 */+#define DEFAULT_READERS	126++	/**	The size of a CPU cache line in bytes. We want our lock structures+	 *	aligned to this size to avoid false cache line sharing in the+	 *	lock table.+	 *	This value works for most CPUs. For Itanium this should be 128.+	 */+#ifndef CACHELINE+#define CACHELINE	64+#endif++	/**	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.+	 */+typedef struct MDB_rxbody {+	/**	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.+	 */+	volatile txnid_t		mrb_txnid;+	/** The process ID of the process owning this reader txn. */+	volatile MDB_PID_T	mrb_pid;+	/** The thread ID of the thread owning this txn. */+	volatile MDB_THR_T	mrb_tid;+} MDB_rxbody;++	/** The actual reader record, with cacheline padding. */+typedef struct MDB_reader {+	union {+		MDB_rxbody mrx;+		/** shorthand for mrb_txnid */+#define	mr_txnid	mru.mrx.mrb_txnid+#define	mr_pid	mru.mrx.mrb_pid+#define	mr_tid	mru.mrx.mrb_tid+		/** cache line alignment */+		char pad[(sizeof(MDB_rxbody)+CACHELINE-1) & ~(CACHELINE-1)];+	} mru;+} MDB_reader;++	/** The header for the reader table.+	 *	The table resides in a memory-mapped file. (This is a different file+	 *	than is used for the main database.)+	 *+	 *	For POSIX the actual mutexes reside in the shared memory of this+	 *	mapped file. On Windows, mutexes are named objects allocated by the+	 *	kernel; we store the mutex names in this mapped file so that other+	 *	processes can grab them. This same approach is also used on+	 *	MacOSX/Darwin (using named semaphores) since MacOSX doesn't support+	 *	process-shared POSIX mutexes. For these cases where a named object+	 *	is used, the object name is derived from a 64 bit FNV hash of the+	 *	environment pathname. As such, naming collisions are extremely+	 *	unlikely. If a collision occurs, the results are unpredictable.+	 */+typedef struct MDB_txbody {+		/** Stamp identifying this as an LMDB file. It must be set+		 *	to #MDB_MAGIC. */+	uint32_t	mtb_magic;+		/** Format of this lock file. Must be set to #MDB_LOCK_FORMAT. */+	uint32_t	mtb_format;+#if defined(_WIN32) || defined(MDB_USE_POSIX_SEM)+	char	mtb_rmname[MNAME_LEN];+#else+		/** Mutex protecting access to this table.+		 *	This is the reader table lock used with LOCK_MUTEX().+		 */+	mdb_mutex_t	mtb_rmutex;+#endif+		/**	The ID of the last transaction committed to the database.+		 *	This is recorded here only for convenience; the value can always+		 *	be determined by reading the main database meta pages.+		 */+	volatile txnid_t		mtb_txnid;+		/** 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.+		 */+	volatile unsigned	mtb_numreaders;+} MDB_txbody;++	/** The actual reader table definition. */+typedef struct MDB_txninfo {+	union {+		MDB_txbody mtb;+#define mti_magic	mt1.mtb.mtb_magic+#define mti_format	mt1.mtb.mtb_format+#define mti_rmutex	mt1.mtb.mtb_rmutex+#define mti_rmname	mt1.mtb.mtb_rmname+#define mti_txnid	mt1.mtb.mtb_txnid+#define mti_numreaders	mt1.mtb.mtb_numreaders+		char pad[(sizeof(MDB_txbody)+CACHELINE-1) & ~(CACHELINE-1)];+	} mt1;+	union {+#if defined(_WIN32) || defined(MDB_USE_POSIX_SEM)+		char mt2_wmname[MNAME_LEN];+#define	mti_wmname	mt2.mt2_wmname+#else+		mdb_mutex_t	mt2_wmutex;+#define mti_wmutex	mt2.mt2_wmutex+#endif+		char pad[(MNAME_LEN+CACHELINE-1) & ~(CACHELINE-1)];+	} mt2;+	MDB_reader	mti_readers[1];+} MDB_txninfo;++	/** Lockfile format signature: version, features and field layout */+#define MDB_LOCK_FORMAT \+	((uint32_t) \+	 ((MDB_LOCK_VERSION) \+	  /* Flags which describe functionality */ \+	  + (((MDB_PIDLOCK) != 0) << 16)))+/** @} */++/** Common header for all page types. The page type depends on #mp_flags.+ *+ * #P_BRANCH and #P_LEAF pages have unsorted '#MDB_node's at the end, with+ * sorted #mp_ptrs[] entries referring to them. Exception: #P_LEAF2 pages+ * omit mp_ptrs and pack sorted #MDB_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 #MDB_meta, the start point of an LMDB snapshot.+ *+ * Each non-metapage up to #MDB_meta.%mm_last_pg is reachable exactly once+ * in the snapshot: Either used by a database or listed in a freeDB record.+ */+typedef struct MDB_page {+#define	mp_pgno	mp_p.p_pgno+#define	mp_next	mp_p.p_next+	union {+		pgno_t		p_pgno;	/**< page number */+		struct MDB_page *p_next; /**< for in-memory list of freed pages */+	} mp_p;+	uint16_t	mp_pad;			/**< key size if this is a LEAF2 page */+/**	@defgroup mdb_page	Page Flags+ *	@ingroup internal+ *	Flags for the page headers.+ *	@{+ */+#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 #MDB_DUPFIXED records */+#define	P_SUBP		 0x40		/**< for #MDB_DUPSORT sub-pages */+#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;		/**< @ref mdb_page */+#define mp_lower	mp_pb.pb.pb_lower+#define mp_upper	mp_pb.pb.pb_upper+#define mp_pages	mp_pb.pb_pages+	union {+		struct {+			indx_t		pb_lower;		/**< lower bound of free space */+			indx_t		pb_upper;		/**< upper bound of free space */+		} pb;+		uint32_t	pb_pages;	/**< number of overflow pages */+	} mp_pb;+	indx_t		mp_ptrs[0];		/**< dynamic size */+} MDB_page;++/** Alternate page header, for 2-byte aligned access */+typedef struct MDB_page2 {+	uint16_t	mp2_p[sizeof(pgno_t)/2];+	uint16_t	mp2_pad;+	uint16_t	mp2_flags;+	indx_t		mp2_lower;+	indx_t		mp2_upper;+	indx_t		mp2_ptrs[0];+} MDB_page2;++#define MP_PGNO(p)	(((MDB_page2 *)(void *)(p))->mp2_p)+#define MP_PAD(p)	(((MDB_page2 *)(void *)(p))->mp2_pad)+#define MP_FLAGS(p)	(((MDB_page2 *)(void *)(p))->mp2_flags)+#define MP_LOWER(p)	(((MDB_page2 *)(void *)(p))->mp2_lower)+#define MP_UPPER(p)	(((MDB_page2 *)(void *)(p))->mp2_upper)+#define MP_PTRS(p)	(((MDB_page2 *)(void *)(p))->mp2_ptrs)++	/** Size of the page header, excluding dynamic data at the end */+#define PAGEHDRSZ	 ((unsigned) offsetof(MDB_page, mp_ptrs))++	/** Address of first usable data byte in a page, after the header */+#define METADATA(p)	 ((void *)((char *)(p) + PAGEHDRSZ))++	/** ITS#7713, change PAGEBASE to handle 65536 byte pages */+#define	PAGEBASE	((MDB_DEVEL) ? PAGEHDRSZ : 0)++	/** Number of nodes on a page */+#define NUMKEYS(p)	 ((MP_LOWER(p) - (PAGEHDRSZ-PAGEBASE)) >> 1)++	/** The amount of space remaining in the page */+#define SIZELEFT(p)	 (indx_t)(MP_UPPER(p) - MP_LOWER(p))++	/** The percentage of space used in the page, in tenths of a percent. */+#define PAGEFILL(env, p) (1000L * ((env)->me_psize - PAGEHDRSZ - SIZELEFT(p)) / \+				((env)->me_psize - PAGEHDRSZ))+	/** The minimum page fill factor, in tenths of a percent.+	 *	Pages emptier than this are candidates for merging.+	 */+#define FILL_THRESHOLD	 250++	/** Test if a page is a leaf page */+#define IS_LEAF(p)	 F_ISSET(MP_FLAGS(p), P_LEAF)+	/** Test if a page is a LEAF2 page */+#define IS_LEAF2(p)	 F_ISSET(MP_FLAGS(p), P_LEAF2)+	/** Test if a page is a branch page */+#define IS_BRANCH(p)	 F_ISSET(MP_FLAGS(p), P_BRANCH)+	/** Test if a page is an overflow page */+#define IS_OVERFLOW(p)	 F_ISSET(MP_FLAGS(p), P_OVERFLOW)+	/** Test if a page is a sub page */+#define IS_SUBP(p)	 F_ISSET(MP_FLAGS(p), P_SUBP)++	/** The number of overflow pages needed to store the given size. */+#define OVPAGES(size, psize)	((PAGEHDRSZ-1 + (size)) / (psize) + 1)++	/** Link in #MDB_txn.%mt_loose_pgs list.+	 *  Kept outside the page header, which is needed when reusing the page.+	 */+#define NEXT_LOOSE_PAGE(p)		(*(MDB_page **)((p) + 2))++	/** 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 'MDB_node's.+	 *+	 * #mn_lo and #mn_hi are used for data size on leaf nodes, and for child+	 * pgno on branch nodes.  On 64 bit platforms, #mn_flags is also used+	 * for pgno.  (Branch nodes have no flags).  Lo and hi are in host byte+	 * order in case some accesses can be optimized to 32-bit word access.+	 *+	 * 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 MDB_node {+	/** part of data size or pgno+	 *	@{ */+#if BYTE_ORDER == LITTLE_ENDIAN+	unsigned short	mn_lo, mn_hi;+#else+	unsigned short	mn_hi, mn_lo;+#endif+	/** @} */+/** @defgroup mdb_node Node Flags+ *	@ingroup internal+ *	Flags for node headers.+ *	@{+ */+#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 #mdb_node_add() */+#define	NODE_ADD_FLAGS	(F_DUPDATA|F_SUBDATA|MDB_RESERVE|MDB_APPEND)++/** @} */+	unsigned short	mn_flags;		/**< @ref mdb_node */+	unsigned short	mn_ksize;		/**< key size */+	char		mn_data[1];			/**< key and data are appended here */+} MDB_node;++	/** Size of the node header, excluding dynamic data at the end */+#define NODESIZE	 offsetof(MDB_node, mn_data)++	/** Bit position of top word in page number, for shifting mn_flags */+#define PGNO_TOPWORD ((pgno_t)-1 > 0xffffffffu ? 32 : 0)++	/** 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.+	 */+#define INDXSIZE(k)	 (NODESIZE + ((k) == NULL ? 0 : (k)->mv_size))++	/** Size of a node in a leaf page with a given key and data.+	 *	This is node header plus key plus data size.+	 */+#define LEAFSIZE(k, d)	 (NODESIZE + (k)->mv_size + (d)->mv_size)++	/** Address of node \b i in page \b p */+#define NODEPTR(p, i)	 ((MDB_node *)((char *)(p) + MP_PTRS(p)[i] + PAGEBASE))++	/** Address of the key for the node */+#define NODEKEY(node)	 (void *)((node)->mn_data)++	/** Address of the data for a node */+#define NODEDATA(node)	 (void *)((char *)(node)->mn_data + (node)->mn_ksize)++	/** Get the page number pointed to by a branch node */+#define NODEPGNO(node) \+	((node)->mn_lo | ((pgno_t) (node)->mn_hi << 16) | \+	 (PGNO_TOPWORD ? ((pgno_t) (node)->mn_flags << PGNO_TOPWORD) : 0))+	/** Set the page number in a branch node */+#define SETPGNO(node,pgno)	do { \+	(node)->mn_lo = (pgno) & 0xffff; (node)->mn_hi = (pgno) >> 16; \+	if (PGNO_TOPWORD) (node)->mn_flags = (pgno) >> PGNO_TOPWORD; } while(0)++	/** Get the size of the data in a leaf node */+#define NODEDSZ(node)	 ((node)->mn_lo | ((unsigned)(node)->mn_hi << 16))+	/** Set the size of the data for a leaf node */+#define SETDSZ(node,size)	do { \+	(node)->mn_lo = (size) & 0xffff; (node)->mn_hi = (size) >> 16;} while(0)+	/** The size of a key in a node */+#define NODEKSZ(node)	 ((node)->mn_ksize)++	/** Copy a page number from src to dst */+#ifdef MISALIGNED_OK+#define COPY_PGNO(dst,src)	dst = src+#undef MP_PGNO+#define MP_PGNO(p)	((p)->mp_pgno)+#else+#if SIZE_MAX > 4294967295UL+#define COPY_PGNO(dst,src)	do { \+	unsigned short *s, *d;	\+	s = (unsigned short *)&(src);	\+	d = (unsigned short *)&(dst);	\+	*d++ = *s++;	\+	*d++ = *s++;	\+	*d++ = *s++;	\+	*d = *s;	\+} while (0)+#else+#define COPY_PGNO(dst,src)	do { \+	unsigned short *s, *d;	\+	s = (unsigned short *)&(src);	\+	d = (unsigned short *)&(dst);	\+	*d++ = *s++;	\+	*d = *s;	\+} while (0)+#endif+#endif+	/** The address of a key in a LEAF2 page.+	 *	LEAF2 pages are used for #MDB_DUPFIXED sorted-duplicate sub-DBs.+	 *	There are no node headers, keys are stored contiguously.+	 */+#define LEAF2KEY(p, i, ks)	((char *)(p) + PAGEHDRSZ + ((i)*(ks)))++	/** Set the \b node's key into \b keyptr, if requested. */+#define MDB_GET_KEY(node, keyptr)	{ if ((keyptr) != NULL) { \+	(keyptr)->mv_size = NODEKSZ(node); (keyptr)->mv_data = NODEKEY(node); } }++	/** Set the \b node's key into \b key. */+#define MDB_GET_KEY2(node, key)	{ key.mv_size = NODEKSZ(node); key.mv_data = NODEKEY(node); }++	/** Information about a single database in the environment. */+typedef struct MDB_db {+	uint32_t	md_pad;		/**< also ksize for LEAF2 pages */+	uint16_t	md_flags;	/**< @ref mdb_dbi_open */+	uint16_t	md_depth;	/**< depth 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 */+	size_t		md_entries;		/**< number of data items */+	pgno_t		md_root;		/**< the root page of this tree */+} MDB_db;++#define MDB_VALID	0x8000		/**< DB handle is valid, for me_dbflags */+#define PERSISTENT_FLAGS	(0xffff & ~(MDB_VALID))+	/** #mdb_dbi_open() flags */+#define VALID_FLAGS	(MDB_REVERSEKEY|MDB_DUPSORT|MDB_INTEGERKEY|MDB_DUPFIXED|\+	MDB_INTEGERDUP|MDB_REVERSEDUP|MDB_CREATE)++	/** 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	2++	/** 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 MDB_meta {+		/** Stamp identifying this as an LMDB file. It must be set+		 *	to #MDB_MAGIC. */+	uint32_t	mm_magic;+		/** Version number of this file. Must be set to #MDB_DATA_VERSION. */+	uint32_t	mm_version;+	void		*mm_address;		/**< address for fixed mapping */+	size_t		mm_mapsize;			/**< size of mmap region */+	MDB_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_pad+	/** Any persistent environment flags. @ref mdb_env */+#define	mm_flags	mm_dbs[FREE_DBI].md_flags+	/** Last used page in the datafile.+	 *	Actually the file may be shorter if the freeDB lists the final pages.+	 */+	pgno_t		mm_last_pg;+	volatile txnid_t	mm_txnid;	/**< txnid that committed this page */+} MDB_meta;++	/** Buffer for a stack-allocated meta page.+	 *	The members define size and alignment, and silence type+	 *	aliasing warnings.  They are not used directly; that could+	 *	mean incorrectly using several union members in parallel.+	 */+typedef union MDB_metabuf {+	MDB_page	mb_page;+	struct {+		char		mm_pad[PAGEHDRSZ];+		MDB_meta	mm_meta;+	} mb_metabuf;+} MDB_metabuf;++	/** 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 MDB_dbx {+	MDB_val		md_name;		/**< name of the database */+	MDB_cmp_func	*md_cmp;	/**< function for comparing keys */+	MDB_cmp_func	*md_dcmp;	/**< function for comparing data items */+	MDB_rel_func	*md_rel;	/**< user relocate function */+	void		*md_relctx;		/**< user-provided context for md_rel */+} MDB_dbx;++	/** A database transaction.+	 *	Every operation requires a transaction handle.+	 */+struct MDB_txn {+	MDB_txn		*mt_parent;		/**< parent of a nested txn */+	/** Nested txn under this txn, set together with flag #MDB_TXN_HAS_CHILD */+	MDB_txn		*mt_child;+	pgno_t		mt_next_pgno;	/**< next unallocated page */+	/** 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;+	MDB_env		*mt_env;		/**< the DB environment */+	/** The list of pages that became unused during this transaction.+	 */+	MDB_IDL		mt_free_pgs;+	/** The list of loose pages that became unused and may be reused+	 *	in this transaction, linked through #NEXT_LOOSE_PAGE(page).+	 */+	MDB_page	*mt_loose_pgs;+	/** Number of loose pages (#mt_loose_pgs) */+	int			mt_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.+	 */+	MDB_IDL		mt_spill_pgs;+	union {+		/** For write txns: Modified pages. Sorted when not MDB_WRITEMAP. */+		MDB_ID2L	dirty_list;+		/** For read txns: This thread/txn's reader table slot, or NULL. */+		MDB_reader	*reader;+	} mt_u;+	/** Array of records for each DB known in the environment. */+	MDB_dbx		*mt_dbxs;+	/** Array of MDB_db records for each known DB */+	MDB_db		*mt_dbs;+	/** Array of sequence numbers for each DB handle */+	unsigned int	*mt_dbiseqs;+/** @defgroup mt_dbflag	Transaction DB Flags+ *	@ingroup internal+ * @{+ */+#define DB_DIRTY	0x01		/**< DB was written in this txn */+#define DB_STALE	0x02		/**< Named-DB record is older than txnID */+#define DB_NEW		0x04		/**< Named-DB handle opened in this txn */+#define DB_VALID	0x08		/**< DB handle is valid, see also #MDB_VALID */+#define DB_USRVALID	0x10		/**< As #DB_VALID, but not set for #FREE_DBI */+#define DB_DUPDATA	0x20		/**< DB is #MDB_DUPSORT data */+/** @} */+	/** In write txns, array of cursors for each DB */+	MDB_cursor	**mt_cursors;+	/** Array of flags for each DB */+	unsigned char	*mt_dbflags;+	/**	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.+	 */+	MDB_dbi		mt_numdbs;++/** @defgroup mdb_txn	Transaction Flags+ *	@ingroup internal+ *	@{+ */+	/** #mdb_txn_begin() flags */+#define MDB_TXN_BEGIN_FLAGS	MDB_RDONLY+#define MDB_TXN_RDONLY		MDB_RDONLY	/**< read-only transaction */+	/* internal txn flags */+#define MDB_TXN_WRITEMAP	MDB_WRITEMAP	/**< copy of #MDB_env flag in writers */+#define MDB_TXN_FINISHED	0x01		/**< txn is finished or never began */+#define MDB_TXN_ERROR		0x02		/**< txn is unusable after an error */+#define MDB_TXN_DIRTY		0x04		/**< must write, even if dirty list is empty */+#define MDB_TXN_SPILLS		0x08		/**< txn or a parent has spilled pages */+#define MDB_TXN_HAS_CHILD	0x10		/**< txn has an #MDB_txn.%mt_child */+	/** most operations on the txn are currently illegal */+#define MDB_TXN_BLOCKED		(MDB_TXN_FINISHED|MDB_TXN_ERROR|MDB_TXN_HAS_CHILD)+/** @} */+	unsigned int	mt_flags;		/**< @ref mdb_txn */+	/** #dirty_list room: 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+	 *	dirty_list into mt_parent after freeing hidden mt_parent pages.+	 */+	unsigned int	mt_dirty_room;+};++/** Enough space for 2^32 nodes with minimum of 2 keys per node. I.e., plenty.+ * At 4 keys per node, enough for 2^64 nodes, so there's probably no need to+ * raise this on a 64 bit machine.+ */+#define CURSOR_STACK		 32++struct MDB_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. #MDB_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 MDB_cursor {+	/** Next cursor on this DB in this txn */+	MDB_cursor	*mc_next;+	/** Backup of the original cursor if this cursor is a shadow */+	MDB_cursor	*mc_backup;+	/** Context used for databases with #MDB_DUPSORT, otherwise NULL */+	struct MDB_xcursor	*mc_xcursor;+	/** The transaction that owns this cursor */+	MDB_txn		*mc_txn;+	/** The database handle this cursor operates on */+	MDB_dbi		mc_dbi;+	/** The database record for this cursor */+	MDB_db		*mc_db;+	/** The database auxiliary record for this cursor */+	MDB_dbx		*mc_dbx;+	/** The @ref mt_dbflag for this database */+	unsigned char	*mc_dbflag;+	unsigned short 	mc_snum;	/**< number of pushed pages */+	unsigned short	mc_top;		/**< index of top page, normally mc_snum-1 */+/** @defgroup mdb_cursor	Cursor Flags+ *	@ingroup internal+ *	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	0x40		/**< Un-track cursor when closing */+/** @} */+	unsigned int	mc_flags;	/**< @ref mdb_cursor */+	MDB_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 MDB_xcursor {+	/** A sub-cursor for traversing the Dup DB */+	MDB_cursor mx_cursor;+	/** The database record for this Dup DB */+	MDB_db	mx_db;+	/**	The auxiliary DB record for this Dup DB */+	MDB_dbx	mx_dbx;+	/** The @ref mt_dbflag for this Dup DB */+	unsigned char mx_dbflag;+} MDB_xcursor;++	/** Check if there is an inited xcursor */+#define XCURSOR_INITED(mc) \+	((mc)->mc_xcursor && ((mc)->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED))++	/** Update the xcursor's sub-page pointer, if any, in \b mc.  Needed+	 *	when the node which contains the sub-page may have moved.  Called+	 *	with leaf page \b mp = mc->mc_pg[\b top].+	 */+#define XCURSOR_REFRESH(mc, top, mp) do { \+	MDB_page *xr_pg = (mp); \+	MDB_node *xr_node; \+	if (!XCURSOR_INITED(mc) || (mc)->mc_ki[top] >= NUMKEYS(xr_pg)) break; \+	xr_node = NODEPTR(xr_pg, (mc)->mc_ki[top]); \+	if ((xr_node->mn_flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA) \+		(mc)->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(xr_node); \+} while (0)++	/** State of FreeDB old pages, stored in the MDB_env */+typedef struct MDB_pgstate {+	pgno_t		*mf_pghead;	/**< Reclaimed freeDB pages, or NULL before use */+	txnid_t		mf_pglast;	/**< ID of last used record, or 0 if !mf_pghead */+} MDB_pgstate;++	/** The database environment. */+struct MDB_env {+	HANDLE		me_fd;		/**< The main data file */+	HANDLE		me_lfd;		/**< The lock file */+	HANDLE		me_mfd;		/**< For writing and syncing the meta pages */+	/** Failed to update the meta page. Probably an I/O error. */+#define	MDB_FATAL_ERROR	0x80000000U+	/** Some fields are initialized. */+#define	MDB_ENV_ACTIVE	0x20000000U+	/** me_txkey is set */+#define	MDB_ENV_TXKEY	0x10000000U+	/** fdatasync is unreliable */+#define	MDB_FSYNCONLY	0x08000000U+	uint32_t 	me_flags;		/**< @ref mdb_env */+	unsigned int	me_psize;	/**< DB page size, inited from me_os_psize */+	unsigned int	me_os_psize;	/**< OS page size, from #GET_PAGESIZE */+	unsigned int	me_maxreaders;	/**< size of the reader table */+	/** Max #MDB_txninfo.%mti_numreaders of interest to #mdb_env_close() */+	volatile int	me_close_readers;+	MDB_dbi		me_numdbs;		/**< number of DBs opened */+	MDB_dbi		me_maxdbs;		/**< size of the DB table */+	MDB_PID_T	me_pid;		/**< process ID of this env */+	char		*me_path;		/**< path to the DB files */+	char		*me_map;		/**< the memory map of the data file */+	MDB_txninfo	*me_txns;		/**< the memory map of the lock file or NULL */+	MDB_meta	*me_metas[NUM_METAS];	/**< pointers to the two meta pages */+	void		*me_pbuf;		/**< scratch area for DUPSORT put() */+	MDB_txn		*me_txn;		/**< current write transaction */+	MDB_txn		*me_txn0;		/**< prealloc'd write transaction */+	size_t		me_mapsize;		/**< size of the data memory map */+	off_t		me_size;		/**< current file size */+	pgno_t		me_maxpg;		/**< me_mapsize / me_psize */+	MDB_dbx		*me_dbxs;		/**< array of static DB info */+	uint16_t	*me_dbflags;	/**< array of flags from MDB_db.md_flags */+	unsigned int	*me_dbiseqs;	/**< array of dbi sequence numbers */+	pthread_key_t	me_txkey;	/**< thread-key for readers */+	txnid_t		me_pgoldest;	/**< ID of oldest reader last time we looked */+	MDB_pgstate	me_pgstate;		/**< state of old pages from freeDB */+#	define		me_pglast	me_pgstate.mf_pglast+#	define		me_pghead	me_pgstate.mf_pghead+	MDB_page	*me_dpages;		/**< list of malloc'd blocks for re-use */+	/** IDL of pages that became unused in a write txn */+	MDB_IDL		me_free_pgs;+	/** ID2L of pages written during a write txn. Length MDB_IDL_UM_SIZE. */+	MDB_ID2L	me_dirty_list;+	/** Max number of freelist items that can fit in a single overflow page */+	int			me_maxfree_1pg;+	/** Max size of a node on a page */+	unsigned int	me_nodemax;+#if !(MDB_MAXKEYSIZE)+	unsigned int	me_maxkey;	/**< max size of a key */+#endif+	int		me_live_reader;		/**< have liveness lock in reader table */+#ifdef _WIN32+	int		me_pidquery;		/**< Used in OpenProcess */+#endif+#ifdef MDB_USE_POSIX_MUTEX	/* Posix mutexes reside in shared mem */+#	define		me_rmutex	me_txns->mti_rmutex /**< Shared reader lock */+#	define		me_wmutex	me_txns->mti_wmutex /**< Shared writer lock */+#else+	mdb_mutex_t	me_rmutex;+	mdb_mutex_t	me_wmutex;+#endif+	void		*me_userctx;	 /**< User-settable context */+	MDB_assert_func *me_assert_func; /**< Callback for assertion failures */+};++	/** Nested transaction */+typedef struct MDB_ntxn {+	MDB_txn		mnt_txn;		/**< the transaction */+	MDB_pgstate	mnt_pgstate;	/**< parent transaction's saved freestate */+} MDB_ntxn;++	/** max number of pages to commit in one writev() call */+#define MDB_COMMIT_PAGES	 64+#if defined(IOV_MAX) && IOV_MAX < MDB_COMMIT_PAGES+#undef MDB_COMMIT_PAGES+#define MDB_COMMIT_PAGES	IOV_MAX+#endif++	/** max bytes to write in one call */+#define MAX_WRITE		(0x40000000U >> (sizeof(ssize_t) == 4))++	/** Check \b txn and \b dbi arguments to a function */+#define TXN_DBI_EXIST(txn, dbi, validity) \+	((txn) && (dbi)<(txn)->mt_numdbs && ((txn)->mt_dbflags[dbi] & (validity)))++	/** Check for misused \b dbi handles */+#define TXN_DBI_CHANGED(txn, dbi) \+	((txn)->mt_dbiseqs[dbi] != (txn)->mt_env->me_dbiseqs[dbi])++static int  mdb_page_alloc(MDB_cursor *mc, int num, MDB_page **mp);+static int  mdb_page_new(MDB_cursor *mc, uint32_t flags, int num, MDB_page **mp);+static int  mdb_page_touch(MDB_cursor *mc);++#define MDB_END_NAMES {"committed", "empty-commit", "abort", "reset", \+	"reset-tmp", "fail-begin", "fail-beginchild"}+enum {+	/* mdb_txn_end operation number, for logging */+	MDB_END_COMMITTED, MDB_END_EMPTY_COMMIT, MDB_END_ABORT, MDB_END_RESET,+	MDB_END_RESET_TMP, MDB_END_FAIL_BEGIN, MDB_END_FAIL_BEGINCHILD+};+#define MDB_END_OPMASK	0x0F	/**< mask for #mdb_txn_end() operation number */+#define MDB_END_UPDATE	0x10	/**< update env state (DBIs) */+#define MDB_END_FREE	0x20	/**< free txn unless it is #MDB_env.%me_txn0 */+#define MDB_END_SLOT MDB_NOTLS	/**< release any reader slot if #MDB_NOTLS */+static void mdb_txn_end(MDB_txn *txn, unsigned mode);++static int  mdb_page_get(MDB_cursor *mc, pgno_t pgno, MDB_page **mp, int *lvl);+static int  mdb_page_search_root(MDB_cursor *mc,+			    MDB_val *key, int modify);+#define MDB_PS_MODIFY	1+#define MDB_PS_ROOTONLY	2+#define MDB_PS_FIRST	4+#define MDB_PS_LAST		8+static int  mdb_page_search(MDB_cursor *mc,+			    MDB_val *key, int flags);+static int	mdb_page_merge(MDB_cursor *csrc, MDB_cursor *cdst);++#define MDB_SPLIT_REPLACE	MDB_APPENDDUP	/**< newkey is not new */+static int	mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata,+				pgno_t newpgno, unsigned int nflags);++static int  mdb_env_read_header(MDB_env *env, MDB_meta *meta);+static MDB_meta *mdb_env_pick_meta(const MDB_env *env);+static int  mdb_env_write_meta(MDB_txn *txn);+#if defined(MDB_USE_POSIX_MUTEX) && !defined(MDB_ROBUST_SUPPORTED) /* Drop unused excl arg */+# define mdb_env_close0(env, excl) mdb_env_close1(env)+#endif+static void mdb_env_close0(MDB_env *env, int excl);++static MDB_node *mdb_node_search(MDB_cursor *mc, MDB_val *key, int *exactp);+static int  mdb_node_add(MDB_cursor *mc, indx_t indx,+			    MDB_val *key, MDB_val *data, pgno_t pgno, unsigned int flags);+static void mdb_node_del(MDB_cursor *mc, int ksize);+static void mdb_node_shrink(MDB_page *mp, indx_t indx);+static int	mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst, int fromleft);+static int  mdb_node_read(MDB_cursor *mc, MDB_node *leaf, MDB_val *data);+static size_t	mdb_leaf_size(MDB_env *env, MDB_val *key, MDB_val *data);+static size_t	mdb_branch_size(MDB_env *env, MDB_val *key);++static int	mdb_rebalance(MDB_cursor *mc);+static int	mdb_update_key(MDB_cursor *mc, MDB_val *key);++static void	mdb_cursor_pop(MDB_cursor *mc);+static int	mdb_cursor_push(MDB_cursor *mc, MDB_page *mp);++static int	_mdb_cursor_del(MDB_cursor *mc, unsigned int flags);+static int	_mdb_cursor_put(MDB_cursor *mc, MDB_val *key, MDB_val *data, unsigned int flags);++static int	mdb_cursor_del0(MDB_cursor *mc);+static int	mdb_del0(MDB_txn *txn, MDB_dbi dbi, MDB_val *key, MDB_val *data, unsigned flags);+static int	mdb_cursor_sibling(MDB_cursor *mc, int move_right);+static int	mdb_cursor_next(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op);+static int	mdb_cursor_prev(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op);+static int	mdb_cursor_set(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op,+				int *exactp);+static int	mdb_cursor_first(MDB_cursor *mc, MDB_val *key, MDB_val *data);+static int	mdb_cursor_last(MDB_cursor *mc, MDB_val *key, MDB_val *data);++static void	mdb_cursor_init(MDB_cursor *mc, MDB_txn *txn, MDB_dbi dbi, MDB_xcursor *mx);+static void	mdb_xcursor_init0(MDB_cursor *mc);+static void	mdb_xcursor_init1(MDB_cursor *mc, MDB_node *node);+static void	mdb_xcursor_init2(MDB_cursor *mc, MDB_xcursor *src_mx, int force);++static int	mdb_drop0(MDB_cursor *mc, int subs);+static void mdb_default_cmp(MDB_txn *txn, MDB_dbi dbi);+static int mdb_reader_check0(MDB_env *env, int rlocked, int *dead);++/** @cond */+static MDB_cmp_func	mdb_cmp_memn, mdb_cmp_memnr, mdb_cmp_int, mdb_cmp_cint, mdb_cmp_long;+/** @endcond */++/** Compare two items pointing at size_t's of unknown alignment. */+#ifdef MISALIGNED_OK+# define mdb_cmp_clong mdb_cmp_long+#else+# define mdb_cmp_clong mdb_cmp_cint+#endif++#ifdef _WIN32+static SECURITY_DESCRIPTOR mdb_null_sd;+static SECURITY_ATTRIBUTES mdb_all_sa;+static int mdb_sec_inited;++struct MDB_name;+static int utf8_to_utf16(const char *src, struct MDB_name *dst, int xtra);+#endif++/** Return the library version info. */+char * ESECT+mdb_version(int *major, int *minor, int *patch)+{+	if (major) *major = MDB_VERSION_MAJOR;+	if (minor) *minor = MDB_VERSION_MINOR;+	if (patch) *patch = MDB_VERSION_PATCH;+	return MDB_VERSION_STRING;+}++/** Table of descriptions for LMDB @ref errors */+static char *const mdb_errstr[] = {+	"MDB_KEYEXIST: Key/data pair already exists",+	"MDB_NOTFOUND: No matching key/data pair found",+	"MDB_PAGE_NOTFOUND: Requested page not found",+	"MDB_CORRUPTED: Located page was wrong type",+	"MDB_PANIC: Update of meta page failed or environment had fatal error",+	"MDB_VERSION_MISMATCH: Database environment version mismatch",+	"MDB_INVALID: File is not an LMDB file",+	"MDB_MAP_FULL: Environment mapsize limit reached",+	"MDB_DBS_FULL: Environment maxdbs limit reached",+	"MDB_READERS_FULL: Environment maxreaders limit reached",+	"MDB_TLS_FULL: Thread-local storage keys full - too many environments open",+	"MDB_TXN_FULL: Transaction has too many dirty pages - transaction too big",+	"MDB_CURSOR_FULL: Internal error - cursor stack limit reached",+	"MDB_PAGE_FULL: Internal error - page has no more space",+	"MDB_MAP_RESIZED: Database contents grew beyond environment mapsize",+	"MDB_INCOMPATIBLE: Operation and DB incompatible, or DB flags changed",+	"MDB_BAD_RSLOT: Invalid reuse of reader locktable slot",+	"MDB_BAD_TXN: Transaction must abort, has a child, or is invalid",+	"MDB_BAD_VALSIZE: Unsupported size of key/DB name/data, or wrong DUPFIXED size",+	"MDB_BAD_DBI: The specified DBI handle was closed/changed unexpectedly",+};++char *+mdb_strerror(int err)+{+#ifdef _WIN32+	/** HACK: pad 4KB on stack over the buf. Return system msgs in buf.+	 *	This works as long as no function between the call to mdb_strerror+	 *	and the actual use of the message uses more than 4K of stack.+	 */+#define MSGSIZE	1024+#define PADSIZE	4096+	char buf[MSGSIZE+PADSIZE], *ptr = buf;+#endif+	int i;+	if (!err)+		return ("Successful return: 0");++	if (err >= MDB_KEYEXIST && err <= MDB_LAST_ERRCODE) {+		i = err - MDB_KEYEXIST;+		return mdb_errstr[i];+	}++#ifdef _WIN32+	/* These are the C-runtime error codes we use. The comment indicates+	 * their numeric value, and the Win32 error they would correspond to+	 * if the error actually came from a Win32 API. A major mess, we should+	 * have used LMDB-specific error codes for everything.+	 */+	switch(err) {+	case ENOENT:	/* 2, FILE_NOT_FOUND */+	case EIO:		/* 5, ACCESS_DENIED */+	case ENOMEM:	/* 12, INVALID_ACCESS */+	case EACCES:	/* 13, INVALID_DATA */+	case EBUSY:		/* 16, CURRENT_DIRECTORY */+	case EINVAL:	/* 22, BAD_COMMAND */+	case ENOSPC:	/* 28, OUT_OF_PAPER */+		return strerror(err);+	default:+		;+	}+	buf[0] = 0;+	FormatMessageA(FORMAT_MESSAGE_FROM_SYSTEM |+		FORMAT_MESSAGE_IGNORE_INSERTS,+		NULL, err, 0, ptr, MSGSIZE, NULL);+	return ptr;+#else+	if (err < 0)+		return "Invalid error code";+	return strerror(err);+#endif+}++/** assert(3) variant in cursor context */+#define mdb_cassert(mc, expr)	mdb_assert0((mc)->mc_txn->mt_env, expr, #expr)+/** assert(3) variant in transaction context */+#define mdb_tassert(txn, expr)	mdb_assert0((txn)->mt_env, expr, #expr)+/** assert(3) variant in environment context */+#define mdb_eassert(env, expr)	mdb_assert0(env, expr, #expr)++#ifndef NDEBUG+# define mdb_assert0(env, expr, expr_txt) ((expr) ? (void)0 : \+		mdb_assert_fail(env, expr_txt, mdb_func_, __FILE__, __LINE__))++static void ESECT+mdb_assert_fail(MDB_env *env, const char *expr_txt,+	const char *func, const char *file, int line)+{+	char buf[400];+	sprintf(buf, "%.100s:%d: Assertion '%.200s' failed in %.40s()",+		file, line, expr_txt, func);+	if (env->me_assert_func)+		env->me_assert_func(env, buf);+	fprintf(stderr, "%s\n", buf);+	abort();+}+#else+# define mdb_assert0(env, expr, expr_txt) ((void) 0)+#endif /* NDEBUG */++#if MDB_DEBUG+/** Return the page number of \b mp which may be sub-page, for debug output */+static pgno_t+mdb_dbg_pgno(MDB_page *mp)+{+	pgno_t ret;+	COPY_PGNO(ret, MP_PGNO(mp));+	return ret;+}++/** Display a key in hexadecimal and return the address of the result.+ * @param[in] key the key to display+ * @param[in] buf the buffer to write into. Should always be #DKBUF.+ * @return The key in hexadecimal form.+ */+char *+mdb_dkey(MDB_val *key, char *buf)+{+	char *ptr = buf;+	unsigned char *c = key->mv_data;+	unsigned int i;++	if (!key)+		return "";++	if (key->mv_size > DKBUF_MAXKEYSIZE)+		return "MDB_MAXKEYSIZE";+	/* may want to make this a dynamic check: if the key is mostly+	 * printable characters, print it as-is instead of converting to hex.+	 */+#if 1+	buf[0] = '\0';+	for (i=0; i<key->mv_size; i++)+		ptr += sprintf(ptr, "%02x", *c++);+#else+	sprintf(buf, "%.*s", key->mv_size, key->mv_data);+#endif+	return buf;+}++static char *+mdb_dval(MDB_txn *txn, MDB_dbi dbi, MDB_val *data, char *buf)+{+	if (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT) {+		mdb_dkey(data, buf+1);+		*buf = '[';+		strcpy(buf + data->mv_size * 2 + 1, "]");+	} else+		*buf = '\0';+	return buf;+}++static const char *+mdb_leafnode_type(MDB_node *n)+{+	static char *const tp[2][2] = {{"", ": DB"}, {": sub-page", ": sub-DB"}};+	return F_ISSET(n->mn_flags, F_BIGDATA) ? ": overflow page" :+		tp[F_ISSET(n->mn_flags, F_DUPDATA)][F_ISSET(n->mn_flags, F_SUBDATA)];+}++/** Display all the keys in the page. */+void+mdb_page_list(MDB_page *mp)+{+	pgno_t pgno = mdb_dbg_pgno(mp);+	const char *type, *state = (MP_FLAGS(mp) & P_DIRTY) ? ", dirty" : "";+	MDB_node *node;+	unsigned int i, nkeys, nsize, total = 0;+	MDB_val key;+	DKBUF;++	switch (MP_FLAGS(mp) & (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 = "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:+		fprintf(stderr, "Overflow page %"Z"u pages %u%s\n",+			pgno, mp->mp_pages, state);+		return;+	case P_META:+		fprintf(stderr, "Meta-page %"Z"u txnid %"Z"u\n",+			pgno, ((MDB_meta *)METADATA(mp))->mm_txnid);+		return;+	default:+		fprintf(stderr, "Bad page %"Z"u flags 0x%X\n", pgno, MP_FLAGS(mp));+		return;+	}++	nkeys = NUMKEYS(mp);+	fprintf(stderr, "%s %"Z"u numkeys %d%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.mv_size = nsize = mp->mp_pad;+			key.mv_data = LEAF2KEY(mp, i, nsize);+			total += nsize;+			fprintf(stderr, "key %d: nsize %d, %s\n", i, nsize, DKEY(&key));+			continue;+		}+		node = NODEPTR(mp, i);+		key.mv_size = node->mn_ksize;+		key.mv_data = node->mn_data;+		nsize = NODESIZE + key.mv_size;+		if (IS_BRANCH(mp)) {+			fprintf(stderr, "key %d: page %"Z"u, %s\n", i, NODEPGNO(node),+				DKEY(&key));+			total += nsize;+		} else {+			if (F_ISSET(node->mn_flags, F_BIGDATA))+				nsize += sizeof(pgno_t);+			else+				nsize += NODEDSZ(node);+			total += nsize;+			nsize += sizeof(indx_t);+			fprintf(stderr, "key %d: nsize %d, %s%s\n",+				i, nsize, DKEY(&key), mdb_leafnode_type(node));+		}+		total = EVEN(total);+	}+	fprintf(stderr, "Total: header %d + contents %d + unused %d\n",+		IS_LEAF2(mp) ? PAGEHDRSZ : PAGEBASE + MP_LOWER(mp), total, SIZELEFT(mp));+}++void+mdb_cursor_chk(MDB_cursor *mc)+{+	unsigned int i;+	MDB_node *node;+	MDB_page *mp;++	if (!mc->mc_snum || !(mc->mc_flags & C_INITIALIZED)) return;+	for (i=0; i<mc->mc_top; i++) {+		mp = mc->mc_pg[i];+		node = NODEPTR(mp, mc->mc_ki[i]);+		if (NODEPGNO(node) != mc->mc_pg[i+1]->mp_pgno)+			printf("oops!\n");+	}+	if (mc->mc_ki[i] >= NUMKEYS(mc->mc_pg[i]))+		printf("ack!\n");+	if (XCURSOR_INITED(mc)) {+		node = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);+		if (((node->mn_flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA) &&+			mc->mc_xcursor->mx_cursor.mc_pg[0] != NODEDATA(node)) {+			printf("blah!\n");+		}+	}+}+#endif++#if (MDB_DEBUG) > 2+/** 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 void mdb_audit(MDB_txn *txn)+{+	MDB_cursor mc;+	MDB_val key, data;+	MDB_ID freecount, count;+	MDB_dbi i;+	int rc;++	freecount = 0;+	mdb_cursor_init(&mc, txn, FREE_DBI, NULL);+	while ((rc = mdb_cursor_get(&mc, &key, &data, MDB_NEXT)) == 0)+		freecount += *(MDB_ID *)data.mv_data;+	mdb_tassert(txn, rc == MDB_NOTFOUND);++	count = 0;+	for (i = 0; i<txn->mt_numdbs; i++) {+		MDB_xcursor mx;+		if (!(txn->mt_dbflags[i] & DB_VALID))+			continue;+		mdb_cursor_init(&mc, txn, i, &mx);+		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 (txn->mt_dbs[i].md_flags & MDB_DUPSORT) {+			rc = mdb_page_search(&mc, NULL, MDB_PS_FIRST);+			for (; rc == MDB_SUCCESS; rc = mdb_cursor_sibling(&mc, 1)) {+				unsigned j;+				MDB_page *mp;+				mp = mc.mc_pg[mc.mc_top];+				for (j=0; j<NUMKEYS(mp); j++) {+					MDB_node *leaf = NODEPTR(mp, j);+					if (leaf->mn_flags & F_SUBDATA) {+						MDB_db db;+						memcpy(&db, NODEDATA(leaf), sizeof(db));+						count += db.md_branch_pages + db.md_leaf_pages ++							db.md_overflow_pages;+					}+				}+			}+			mdb_tassert(txn, rc == MDB_NOTFOUND);+		}+	}+	if (freecount + count + NUM_METAS != txn->mt_next_pgno) {+		fprintf(stderr, "audit: %"Z"u freecount: %"Z"u count: %"Z"u total: %"Z"u next_pgno: %"Z"u\n",+			txn->mt_txnid, freecount, count+NUM_METAS,+			freecount+count+NUM_METAS, txn->mt_next_pgno);+	}+}+#endif++int+mdb_cmp(MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b)+{+	return txn->mt_dbxs[dbi].md_cmp(a, b);+}++int+mdb_dcmp(MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b)+{+	MDB_cmp_func *dcmp = txn->mt_dbxs[dbi].md_dcmp;+#if UINT_MAX < SIZE_MAX+	if (dcmp == mdb_cmp_int && a->mv_size == sizeof(size_t))+		dcmp = mdb_cmp_clong;+#endif+	return dcmp(a, b);+}++/** Allocate memory for a page.+ * Re-use old malloc'd pages first for singletons, otherwise just malloc.+ * Set #MDB_TXN_ERROR on failure.+ */+static MDB_page *+mdb_page_malloc(MDB_txn *txn, unsigned num)+{+	MDB_env *env = txn->mt_env;+	MDB_page *ret = env->me_dpages;+	size_t psize = env->me_psize, sz = psize, off;+	/* For ! #MDB_NOMEMINIT, psize counts how much to init.+	 * 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.+	 */+	if (num == 1) {+		if (ret) {+			VGMEMP_ALLOC(env, ret, sz);+			VGMEMP_DEFINED(ret, sizeof(ret->mp_next));+			env->me_dpages = ret->mp_next;+			return ret;+		}+		psize -= off = PAGEHDRSZ;+	} else {+		sz *= num;+		off = sz - psize;+	}+	if ((ret = malloc(sz)) != NULL) {+		VGMEMP_ALLOC(env, ret, sz);+		if (!(env->me_flags & MDB_NOMEMINIT)) {+			memset((char *)ret + off, 0, psize);+			ret->mp_pad = 0;+		}+	} else {+		txn->mt_flags |= MDB_TXN_ERROR;+	}+	return ret;+}+/** Free a single page.+ * Saves single pages to a list, for future reuse.+ * (This is not used for multi-page overflow pages.)+ */+static void+mdb_page_free(MDB_env *env, MDB_page *mp)+{+	mp->mp_next = env->me_dpages;+	VGMEMP_FREE(env, mp);+	env->me_dpages = mp;+}++/** Free a dirty page */+static void+mdb_dpage_free(MDB_env *env, MDB_page *dp)+{+	if (!IS_OVERFLOW(dp) || dp->mp_pages == 1) {+		mdb_page_free(env, dp);+	} else {+		/* large pages just get freed directly */+		VGMEMP_FREE(env, dp);+		free(dp);+	}+}++/**	Return all dirty pages to dpage list */+static void+mdb_dlist_free(MDB_txn *txn)+{+	MDB_env *env = txn->mt_env;+	MDB_ID2L dl = txn->mt_u.dirty_list;+	unsigned i, n = dl[0].mid;++	for (i = 1; i <= n; i++) {+		mdb_dpage_free(env, dl[i].mptr);+	}+	dl[0].mid = 0;+}++/** 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 freeDB+ * and already resides on the dirty list, but has been+ * deleted. Use these pages first before pulling again+ * from the freeDB.+ *+ * If the page wasn't dirtied in this txn, just add it+ * to this txn's free list.+ */+static int+mdb_page_loose(MDB_cursor *mc, MDB_page *mp)+{+	int loose = 0;+	pgno_t pgno = mp->mp_pgno;+	MDB_txn *txn = mc->mc_txn;++	if ((mp->mp_flags & P_DIRTY) && mc->mc_dbi != FREE_DBI) {+		if (txn->mt_parent) {+			MDB_ID2 *dl = txn->mt_u.dirty_list;+			/* If txn has a parent, make sure the page is in our+			 * dirty list.+			 */+			if (dl[0].mid) {+				unsigned x = mdb_mid2l_search(dl, pgno);+				if (x <= dl[0].mid && dl[x].mid == pgno) {+					if (mp != dl[x].mptr) { /* bad cursor? */+						mc->mc_flags &= ~(C_INITIALIZED|C_EOF);+						txn->mt_flags |= MDB_TXN_ERROR;+						return MDB_CORRUPTED;+					}+					/* ok, it's ours */+					loose = 1;+				}+			}+		} else {+			/* no parent txn, so it's just ours */+			loose = 1;+		}+	}+	if (loose) {+		DPRINTF(("loosen db %d page %"Z"u", DDBI(mc),+			mp->mp_pgno));+		NEXT_LOOSE_PAGE(mp) = txn->mt_loose_pgs;+		txn->mt_loose_pgs = mp;+		txn->mt_loose_count++;+		mp->mp_flags |= P_LOOSE;+	} else {+		int rc = mdb_midl_append(&txn->mt_free_pgs, pgno);+		if (rc)+			return rc;+	}++	return MDB_SUCCESS;+}++/** Set or clear P_KEEP in dirty, non-overflow, non-sub pages watched by txn.+ * @param[in] mc A cursor handle for the current operation.+ * @param[in] pflags Flags of the pages to update:+ * P_DIRTY to set P_KEEP, P_DIRTY|P_KEEP to clear it.+ * @param[in] all No shortcuts. Needed except after a full #mdb_page_flush().+ * @return 0 on success, non-zero on failure.+ */+static int+mdb_pages_xkeep(MDB_cursor *mc, unsigned pflags, int all)+{+	enum { Mask = P_SUBP|P_DIRTY|P_LOOSE|P_KEEP };+	MDB_txn *txn = mc->mc_txn;+	MDB_cursor *m3, *m0 = mc;+	MDB_xcursor *mx;+	MDB_page *dp, *mp;+	MDB_node *leaf;+	unsigned i, j;+	int rc = MDB_SUCCESS, level;++	/* Mark pages seen by cursors */+	if (mc->mc_flags & C_UNTRACK)+		mc = NULL;				/* will find mc in mt_cursors */+	for (i = txn->mt_numdbs;; mc = txn->mt_cursors[--i]) {+		for (; mc; mc=mc->mc_next) {+			if (!(mc->mc_flags & C_INITIALIZED))+				continue;+			for (m3 = mc;; m3 = &mx->mx_cursor) {+				mp = NULL;+				for (j=0; j<m3->mc_snum; j++) {+					mp = m3->mc_pg[j];+					if ((mp->mp_flags & Mask) == pflags)+						mp->mp_flags ^= P_KEEP;+				}+				mx = m3->mc_xcursor;+				/* Proceed to mx if it is at a sub-database */+				if (! (mx && (mx->mx_cursor.mc_flags & C_INITIALIZED)))+					break;+				if (! (mp && (mp->mp_flags & P_LEAF)))+					break;+				leaf = NODEPTR(mp, m3->mc_ki[j-1]);+				if (!(leaf->mn_flags & F_SUBDATA))+					break;+			}+		}+		if (i == 0)+			break;+	}++	if (all) {+		/* Mark dirty root pages */+		for (i=0; i<txn->mt_numdbs; i++) {+			if (txn->mt_dbflags[i] & DB_DIRTY) {+				pgno_t pgno = txn->mt_dbs[i].md_root;+				if (pgno == P_INVALID)+					continue;+				if ((rc = mdb_page_get(m0, pgno, &dp, &level)) != MDB_SUCCESS)+					break;+				if ((dp->mp_flags & Mask) == pflags && level <= 1)+					dp->mp_flags ^= P_KEEP;+			}+		}+	}++	return rc;+}++static int mdb_page_flush(MDB_txn *txn, int keep);++/**	Spill pages from the dirty list back to disk.+ * This is intended to prevent running into #MDB_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 #MDB_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 #mdb_txn_begin() of a child txn, if+ *	 the parent's dirty_room is below a given threshold.+ *+ * Otherwise, if not using nested txns, it is expected that apps will+ * not run into #MDB_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 #mdb_page_touch(). Such references are+ * handled by #mdb_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.+ *+ * @param[in] m0 cursor A cursor handle identifying the transaction and+ *	database for which we are checking space.+ * @param[in] key For a put operation, the key being stored.+ * @param[in] data For a put operation, the data being stored.+ * @return 0 on success, non-zero on failure.+ */+static int+mdb_page_spill(MDB_cursor *m0, MDB_val *key, MDB_val *data)+{+	MDB_txn *txn = m0->mc_txn;+	MDB_page *dp;+	MDB_ID2L dl = txn->mt_u.dirty_list;+	unsigned int i, j, need;+	int rc;++	if (m0->mc_flags & C_SUB)+		return MDB_SUCCESS;++	/* Estimate how much space this op will take */+	i = m0->mc_db->md_depth;+	/* Named DBs also dirty the main DB */+	if (m0->mc_dbi >= CORE_DBS)+		i += txn->mt_dbs[MAIN_DBI].md_depth;+	/* For puts, roughly factor in the key+data size */+	if (key)+		i += (LEAFSIZE(key, data) + txn->mt_env->me_psize) / txn->mt_env->me_psize;+	i += i;	/* double it for good measure */+	need = i;++	if (txn->mt_dirty_room > i)+		return MDB_SUCCESS;++	if (!txn->mt_spill_pgs) {+		txn->mt_spill_pgs = mdb_midl_alloc(MDB_IDL_UM_MAX);+		if (!txn->mt_spill_pgs)+			return ENOMEM;+	} else {+		/* purge deleted slots */+		MDB_IDL sl = txn->mt_spill_pgs;+		unsigned int num = sl[0];+		j=0;+		for (i=1; i<=num; i++) {+			if (!(sl[i] & 1))+				sl[++j] = sl[i];+		}+		sl[0] = j;+	}++	/* Preserve pages which may soon be dirtied again */+	if ((rc = mdb_pages_xkeep(m0, P_DIRTY, 1)) != MDB_SUCCESS)+		goto done;++	/* Less aggressive spill - we originally spilled the entire dirty list,+	 * with a few exceptions for cursor pages and DB root pages. But this+	 * turns out to be a lot of wasted effort because in a large txn many+	 * of those pages will need to be used again. So now we spill only 1/8th+	 * of the dirty pages. Testing revealed this to be a good tradeoff,+	 * better than 1/2, 1/4, or 1/10.+	 */+	if (need < MDB_IDL_UM_MAX / 8)+		need = MDB_IDL_UM_MAX / 8;++	/* Save the page IDs of all the pages we're flushing */+	/* flush from the tail forward, this saves a lot of shifting later on. */+	for (i=dl[0].mid; i && need; i--) {+		MDB_ID pn = dl[i].mid << 1;+		dp = dl[i].mptr;+		if (dp->mp_flags & (P_LOOSE|P_KEEP))+			continue;+		/* Can't spill twice, make sure it's not already in a parent's+		 * spill list.+		 */+		if (txn->mt_parent) {+			MDB_txn *tx2;+			for (tx2 = txn->mt_parent; tx2; tx2 = tx2->mt_parent) {+				if (tx2->mt_spill_pgs) {+					j = mdb_midl_search(tx2->mt_spill_pgs, pn);+					if (j <= tx2->mt_spill_pgs[0] && tx2->mt_spill_pgs[j] == pn) {+						dp->mp_flags |= P_KEEP;+						break;+					}+				}+			}+			if (tx2)+				continue;+		}+		if ((rc = mdb_midl_append(&txn->mt_spill_pgs, pn)))+			goto done;+		need--;+	}+	mdb_midl_sort(txn->mt_spill_pgs);++	/* Flush the spilled part of dirty list */+	if ((rc = mdb_page_flush(txn, i)) != MDB_SUCCESS)+		goto done;++	/* Reset any dirty pages we kept that page_flush didn't see */+	rc = mdb_pages_xkeep(m0, P_DIRTY|P_KEEP, i);++done:+	txn->mt_flags |= rc ? MDB_TXN_ERROR : MDB_TXN_SPILLS;+	return rc;+}++/** Find oldest txnid still referenced. Expects txn->mt_txnid > 0. */+static txnid_t+mdb_find_oldest(MDB_txn *txn)+{+	int i;+	txnid_t mr, oldest = txn->mt_txnid - 1;+	if (txn->mt_env->me_txns) {+		MDB_reader *r = txn->mt_env->me_txns->mti_readers;+		for (i = txn->mt_env->me_txns->mti_numreaders; --i >= 0; ) {+			if (r[i].mr_pid) {+				mr = r[i].mr_txnid;+				if (oldest > mr)+					oldest = mr;+			}+		}+	}+	return oldest;+}++/** Add a page to the txn's dirty list */+static void+mdb_page_dirty(MDB_txn *txn, MDB_page *mp)+{+	MDB_ID2 mid;+	int rc, (*insert)(MDB_ID2L, MDB_ID2 *);++	if (txn->mt_flags & MDB_TXN_WRITEMAP) {+		insert = mdb_mid2l_append;+	} else {+		insert = mdb_mid2l_insert;+	}+	mid.mid = mp->mp_pgno;+	mid.mptr = mp;+	rc = insert(txn->mt_u.dirty_list, &mid);+	mdb_tassert(txn, rc == 0);+	txn->mt_dirty_room--;+}++/** Allocate page numbers and memory for writing.  Maintain me_pglast,+ * me_pghead and mt_next_pgno.  Set #MDB_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 freedB, just merge freeDB records into me_pghead[]+ * and move me_pglast to say which records were consumed.  Only this+ * function can create me_pghead and move me_pglast/mt_next_pgno.+ * @param[in] mc cursor A cursor handle identifying the transaction and+ *	database for which we are allocating.+ * @param[in] num the number of pages to allocate.+ * @param[out] mp Address of the allocated page(s). Requests for multiple pages+ *  will always be satisfied by a single contiguous chunk of memory.+ * @return 0 on success, non-zero on failure.+ */+static int+mdb_page_alloc(MDB_cursor *mc, int num, MDB_page **mp)+{+#ifdef MDB_PARANOID	/* Seems like we can ignore this now */+	/* Get at most <Max_retries> more freeDB records once me_pghead+	 * has enough pages.  If not enough, use new pages from the map.+	 * If <Paranoid> and mc is updating the freeDB, only get new+	 * records if me_pghead is empty. Then the freelist cannot play+	 * catch-up with itself by growing while trying to save it.+	 */+	enum { Paranoid = 1, Max_retries = 500 };+#else+	enum { Paranoid = 0, Max_retries = INT_MAX /*infinite*/ };+#endif+	int rc, retry = num * 60;+	MDB_txn *txn = mc->mc_txn;+	MDB_env *env = txn->mt_env;+	pgno_t pgno, *mop = env->me_pghead;+	unsigned i, j, mop_len = mop ? mop[0] : 0, n2 = num-1;+	MDB_page *np;+	txnid_t oldest = 0, last;+	MDB_cursor_op op;+	MDB_cursor m2;+	int found_old = 0;++	/* If there are any loose pages, just use them */+	if (num == 1 && txn->mt_loose_pgs) {+		np = txn->mt_loose_pgs;+		txn->mt_loose_pgs = NEXT_LOOSE_PAGE(np);+		txn->mt_loose_count--;+		DPRINTF(("db %d use loose page %"Z"u", DDBI(mc),+				np->mp_pgno));+		*mp = np;+		return MDB_SUCCESS;+	}++	*mp = NULL;++	/* If our dirty list is already full, we can't do anything */+	if (txn->mt_dirty_room == 0) {+		rc = MDB_TXN_FULL;+		goto fail;+	}++	for (op = MDB_FIRST;; op = MDB_NEXT) {+		MDB_val key, data;+		MDB_node *leaf;+		pgno_t *idl;++		/* Seek a big enough contiguous page range. Prefer+		 * pages at the tail, just truncating the list.+		 */+		if (mop_len > n2) {+			i = mop_len;+			do {+				pgno = mop[i];+				if (mop[i-n2] == pgno+n2)+					goto search_done;+			} while (--i > n2);+			if (--retry < 0)+				break;+		}++		if (op == MDB_FIRST) {	/* 1st iteration */+			/* Prepare to fetch more and coalesce */+			last = env->me_pglast;+			oldest = env->me_pgoldest;+			mdb_cursor_init(&m2, txn, FREE_DBI, NULL);+			if (last) {+				op = MDB_SET_RANGE;+				key.mv_data = &last; /* will look up last+1 */+				key.mv_size = sizeof(last);+			}+			if (Paranoid && mc->mc_dbi == FREE_DBI)+				retry = -1;+		}+		if (Paranoid && retry < 0 && mop_len)+			break;++		last++;+		/* Do not fetch more if the record will be too recent */+		if (oldest <= last) {+			if (!found_old) {+				oldest = mdb_find_oldest(txn);+				env->me_pgoldest = oldest;+				found_old = 1;+			}+			if (oldest <= last)+				break;+		}+		rc = mdb_cursor_get(&m2, &key, NULL, op);+		if (rc) {+			if (rc == MDB_NOTFOUND)+				break;+			goto fail;+		}+		last = *(txnid_t*)key.mv_data;+		if (oldest <= last) {+			if (!found_old) {+				oldest = mdb_find_oldest(txn);+				env->me_pgoldest = oldest;+				found_old = 1;+			}+			if (oldest <= last)+				break;+		}+		np = m2.mc_pg[m2.mc_top];+		leaf = NODEPTR(np, m2.mc_ki[m2.mc_top]);+		if ((rc = mdb_node_read(&m2, leaf, &data)) != MDB_SUCCESS)+			goto fail;++		idl = (MDB_ID *) data.mv_data;+		i = idl[0];+		if (!mop) {+			if (!(env->me_pghead = mop = mdb_midl_alloc(i))) {+				rc = ENOMEM;+				goto fail;+			}+		} else {+			if ((rc = mdb_midl_need(&env->me_pghead, i)) != 0)+				goto fail;+			mop = env->me_pghead;+		}+		env->me_pglast = last;+#if (MDB_DEBUG) > 1+		DPRINTF(("IDL read txn %"Z"u root %"Z"u num %u",+			last, txn->mt_dbs[FREE_DBI].md_root, i));+		for (j = i; j; j--)+			DPRINTF(("IDL %"Z"u", idl[j]));+#endif+		/* Merge in descending sorted order */+		mdb_midl_xmerge(mop, idl);+		mop_len = mop[0];+	}++	/* Use new pages from the map when nothing suitable in the freeDB */+	i = 0;+	pgno = txn->mt_next_pgno;+	if (pgno + num >= env->me_maxpg) {+			DPUTS("DB size maxed out");+			rc = MDB_MAP_FULL;+			goto fail;+	}++search_done:+	if (env->me_flags & MDB_WRITEMAP) {+		np = (MDB_page *)(env->me_map + env->me_psize * pgno);+	} else {+		if (!(np = mdb_page_malloc(txn, num))) {+			rc = ENOMEM;+			goto fail;+		}+	}+	if (i) {+		mop[0] = mop_len -= num;+		/* Move any stragglers down */+		for (j = i-num; j < mop_len; )+			mop[++j] = mop[++i];+	} else {+		txn->mt_next_pgno = pgno + num;+	}+	np->mp_pgno = pgno;+	mdb_page_dirty(txn, np);+	*mp = np;++	return MDB_SUCCESS;++fail:+	txn->mt_flags |= MDB_TXN_ERROR;+	return rc;+}++/** Copy the used portions of a non-overflow page.+ * @param[in] dst page to copy into+ * @param[in] src page to copy from+ * @param[in] psize size of a page+ */+static void+mdb_page_copy(MDB_page *dst, MDB_page *src, unsigned int psize)+{+	enum { Align = sizeof(pgno_t) };+	indx_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 &= -Align) && !IS_LEAF2(src)) {+		upper = (upper + PAGEBASE) & -Align;+		memcpy(dst, src, (lower + PAGEBASE + (Align-1)) & -Align);+		memcpy((pgno_t *)((char *)dst+upper), (pgno_t *)((char *)src+upper),+			psize - upper);+	} else {+		memcpy(dst, src, psize - unused);+	}+}++/** 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.+ * @param[in] txn the transaction handle.+ * @param[in] mp the page being referenced. It must not be dirty.+ * @param[out] ret the writable page, if any. ret is unchanged if+ * mp wasn't spilled.+ */+static int+mdb_page_unspill(MDB_txn *txn, MDB_page *mp, MDB_page **ret)+{+	MDB_env *env = txn->mt_env;+	const MDB_txn *tx2;+	unsigned x;+	pgno_t pgno = mp->mp_pgno, pn = pgno << 1;++	for (tx2 = txn; tx2; tx2=tx2->mt_parent) {+		if (!tx2->mt_spill_pgs)+			continue;+		x = mdb_midl_search(tx2->mt_spill_pgs, pn);+		if (x <= tx2->mt_spill_pgs[0] && tx2->mt_spill_pgs[x] == pn) {+			MDB_page *np;+			int num;+			if (txn->mt_dirty_room == 0)+				return MDB_TXN_FULL;+			if (IS_OVERFLOW(mp))+				num = mp->mp_pages;+			else+				num = 1;+			if (env->me_flags & MDB_WRITEMAP) {+				np = mp;+			} else {+				np = mdb_page_malloc(txn, num);+				if (!np)+					return ENOMEM;+				if (num > 1)+					memcpy(np, mp, num * env->me_psize);+				else+					mdb_page_copy(np, mp, env->me_psize);+			}+			if (tx2 == 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.+				 */+				if (x == txn->mt_spill_pgs[0])+					txn->mt_spill_pgs[0]--;+				else+					txn->mt_spill_pgs[x] |= 1;+			}	/* otherwise, if belonging to a parent txn, the+				 * page remains spilled until child commits+				 */++			mdb_page_dirty(txn, np);+			np->mp_flags |= P_DIRTY;+			*ret = np;+			break;+		}+	}+	return MDB_SUCCESS;+}++/** Touch a page: make it dirty and re-insert into tree with updated pgno.+ * Set #MDB_TXN_ERROR on failure.+ * @param[in] mc cursor pointing to the page to be touched+ * @return 0 on success, non-zero on failure.+ */+static int+mdb_page_touch(MDB_cursor *mc)+{+	MDB_page *mp = mc->mc_pg[mc->mc_top], *np;+	MDB_txn *txn = mc->mc_txn;+	MDB_cursor *m2, *m3;+	pgno_t	pgno;+	int rc;++	if (!F_ISSET(MP_FLAGS(mp), P_DIRTY)) {+		if (txn->mt_flags & MDB_TXN_SPILLS) {+			np = NULL;+			rc = mdb_page_unspill(txn, mp, &np);+			if (rc)+				goto fail;+			if (np)+				goto done;+		}+		if ((rc = mdb_midl_need(&txn->mt_free_pgs, 1)) ||+			(rc = mdb_page_alloc(mc, 1, &np)))+			goto fail;+		pgno = np->mp_pgno;+		DPRINTF(("touched db %d page %"Z"u -> %"Z"u", DDBI(mc),+			mp->mp_pgno, pgno));+		mdb_cassert(mc, mp->mp_pgno != pgno);+		mdb_midl_xappend(txn->mt_free_pgs, mp->mp_pgno);+		/* Update the parent page, if any, to point to the new page */+		if (mc->mc_top) {+			MDB_page *parent = mc->mc_pg[mc->mc_top-1];+			MDB_node *node = NODEPTR(parent, mc->mc_ki[mc->mc_top-1]);+			SETPGNO(node, pgno);+		} else {+			mc->mc_db->md_root = pgno;+		}+	} else if (txn->mt_parent && !IS_SUBP(mp)) {+		MDB_ID2 mid, *dl = txn->mt_u.dirty_list;+		pgno = mp->mp_pgno;+		/* If txn has a parent, make sure the page is in our+		 * dirty list.+		 */+		if (dl[0].mid) {+			unsigned x = mdb_mid2l_search(dl, pgno);+			if (x <= dl[0].mid && dl[x].mid == pgno) {+				if (mp != dl[x].mptr) { /* bad cursor? */+					mc->mc_flags &= ~(C_INITIALIZED|C_EOF);+					txn->mt_flags |= MDB_TXN_ERROR;+					return MDB_CORRUPTED;+				}+				return 0;+			}+		}+		mdb_cassert(mc, dl[0].mid < MDB_IDL_UM_MAX);+		/* No - copy it */+		np = mdb_page_malloc(txn, 1);+		if (!np)+			return ENOMEM;+		mid.mid = pgno;+		mid.mptr = np;+		rc = mdb_mid2l_insert(dl, &mid);+		mdb_cassert(mc, rc == 0);+	} else {+		return 0;+	}++	mdb_page_copy(np, mp, txn->mt_env->me_psize);+	np->mp_pgno = pgno;+	np->mp_flags |= P_DIRTY;++done:+	/* Adjust cursors pointing to mp */+	mc->mc_pg[mc->mc_top] = np;+	m2 = txn->mt_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 (IS_LEAF(np))+					XCURSOR_REFRESH(m2, mc->mc_top, np);+			}+		}+	}+	return 0;++fail:+	txn->mt_flags |= MDB_TXN_ERROR;+	return rc;+}++int+mdb_env_sync(MDB_env *env, int force)+{+	int rc = 0;+	if (env->me_flags & MDB_RDONLY)+		return EACCES;+	if (force || !F_ISSET(env->me_flags, MDB_NOSYNC)) {+		if (env->me_flags & MDB_WRITEMAP) {+			int flags = ((env->me_flags & MDB_MAPASYNC) && !force)+				? MS_ASYNC : MS_SYNC;+			if (MDB_MSYNC(env->me_map, env->me_mapsize, flags))+				rc = ErrCode();+#ifdef _WIN32+			else if (flags == MS_SYNC && MDB_FDATASYNC(env->me_fd))+				rc = ErrCode();+#endif+		} else {+#ifdef BROKEN_FDATASYNC+			if (env->me_flags & MDB_FSYNCONLY) {+				if (fsync(env->me_fd))+					rc = ErrCode();+			} else+#endif+			if (MDB_FDATASYNC(env->me_fd))+				rc = ErrCode();+		}+	}+	return rc;+}++/** Back up parent txn's cursors, then grab the originals for tracking */+static int+mdb_cursor_shadow(MDB_txn *src, MDB_txn *dst)+{+	MDB_cursor *mc, *bk;+	MDB_xcursor *mx;+	size_t size;+	int i;++	for (i = src->mt_numdbs; --i >= 0; ) {+		if ((mc = src->mt_cursors[i]) != NULL) {+			size = sizeof(MDB_cursor);+			if (mc->mc_xcursor)+				size += sizeof(MDB_xcursor);+			for (; mc; mc = bk->mc_next) {+				bk = malloc(size);+				if (!bk)+					return ENOMEM;+				*bk = *mc;+				mc->mc_backup = bk;+				mc->mc_db = &dst->mt_dbs[i];+				/* 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    = dst;+				mc->mc_dbflag = &dst->mt_dbflags[i];+				if ((mx = mc->mc_xcursor) != NULL) {+					*(MDB_xcursor *)(bk+1) = *mx;+					mx->mx_cursor.mc_txn = dst;+				}+				mc->mc_next = dst->mt_cursors[i];+				dst->mt_cursors[i] = mc;+			}+		}+	}+	return MDB_SUCCESS;+}++/** Close this write txn's cursors, give parent txn's cursors back to parent.+ * @param[in] txn the transaction handle.+ * @param[in] merge true to keep changes to parent cursors, false to revert.+ * @return 0 on success, non-zero on failure.+ */+static void+mdb_cursors_close(MDB_txn *txn, unsigned merge)+{+	MDB_cursor **cursors = txn->mt_cursors, *mc, *next, *bk;+	MDB_xcursor *mx;+	int i;++	for (i = txn->mt_numdbs; --i >= 0; ) {+		for (mc = cursors[i]; mc; mc = next) {+			next = mc->mc_next;+			if ((bk = mc->mc_backup) != NULL) {+				if (merge) {+					/* Commit changes 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_dbflag = bk->mc_dbflag;+					if ((mx = mc->mc_xcursor) != NULL)+						mx->mx_cursor.mc_txn = bk->mc_txn;+				} else {+					/* Abort nested txn */+					*mc = *bk;+					if ((mx = mc->mc_xcursor) != NULL)+						*mx = *(MDB_xcursor *)(bk+1);+				}+				mc = bk;+			}+			/* Only malloced cursors are permanently tracked. */+			free(mc);+		}+		cursors[i] = NULL;+	}+}++#if !(MDB_PIDLOCK)		/* Currently the same as defined(_WIN32) */+enum Pidlock_op {+	Pidset, Pidcheck+};+#else+enum Pidlock_op {+	Pidset = F_SETLK, Pidcheck = F_GETLK+};+#endif++/** Set or check a pid lock. Set returns 0 on success.+ * Check returns 0 if the process is certainly dead, nonzero if it may+ * be alive (the lock exists or an error happened so we do not know).+ *+ * On Windows Pidset is a no-op, we merely check for the existence+ * of the process with the given pid. On POSIX we use a single byte+ * lock on the lockfile, set at an offset equal to the pid.+ */+static int+mdb_reader_pid(MDB_env *env, enum Pidlock_op op, MDB_PID_T pid)+{+#if !(MDB_PIDLOCK)		/* Currently the same as defined(_WIN32) */+	int ret = 0;+	HANDLE h;+	if (op == Pidcheck) {+		h = OpenProcess(env->me_pidquery, FALSE, pid);+		/* No documented "no such process" code, but other program use this: */+		if (!h)+			return ErrCode() != ERROR_INVALID_PARAMETER;+		/* A process exists until all handles to it close. Has it exited? */+		ret = WaitForSingleObject(h, 0) != 0;+		CloseHandle(h);+	}+	return ret;+#else+	for (;;) {+		int rc;+		struct flock lock_info;+		memset(&lock_info, 0, sizeof(lock_info));+		lock_info.l_type = F_WRLCK;+		lock_info.l_whence = SEEK_SET;+		lock_info.l_start = pid;+		lock_info.l_len = 1;+		if ((rc = fcntl(env->me_lfd, op, &lock_info)) == 0) {+			if (op == F_GETLK && lock_info.l_type != F_UNLCK)+				rc = -1;+		} else if ((rc = ErrCode()) == EINTR) {+			continue;+		}+		return rc;+	}+#endif+}++/** Common code for #mdb_txn_begin() and #mdb_txn_renew().+ * @param[in] txn the transaction handle to initialize+ * @return 0 on success, non-zero on failure.+ */+static int+mdb_txn_renew0(MDB_txn *txn)+{+	MDB_env *env = txn->mt_env;+	MDB_txninfo *ti = env->me_txns;+	MDB_meta *meta;+	unsigned int i, nr, flags = txn->mt_flags;+	uint16_t x;+	int rc, new_notls = 0;++	if ((flags &= MDB_TXN_RDONLY) != 0) {+		if (!ti) {+			meta = mdb_env_pick_meta(env);+			txn->mt_txnid = meta->mm_txnid;+			txn->mt_u.reader = NULL;+		} else {+			MDB_reader *r = (env->me_flags & MDB_NOTLS) ? txn->mt_u.reader :+				pthread_getspecific(env->me_txkey);+			if (r) {+				if (r->mr_pid != env->me_pid || r->mr_txnid != (txnid_t)-1)+					return MDB_BAD_RSLOT;+			} else {+				MDB_PID_T pid = env->me_pid;+				MDB_THR_T tid = pthread_self();+				mdb_mutexref_t rmutex = env->me_rmutex;++				if (!env->me_live_reader) {+					rc = mdb_reader_pid(env, Pidset, pid);+					if (rc)+						return rc;+					env->me_live_reader = 1;+				}++				if (LOCK_MUTEX(rc, env, rmutex))+					return rc;+				nr = ti->mti_numreaders;+				for (i=0; i<nr; i++)+					if (ti->mti_readers[i].mr_pid == 0)+						break;+				if (i == env->me_maxreaders) {+					UNLOCK_MUTEX(rmutex);+					return MDB_READERS_FULL;+				}+				r = &ti->mti_readers[i];+				/* Claim the reader slot, carefully since other code+				 * uses the reader table un-mutexed: First reset the+				 * slot, next publish it in mti_numreaders.  After+				 * that, it is safe for mdb_env_close() to touch it.+				 * When it will be closed, we can finally claim it.+				 */+				r->mr_pid = 0;+				r->mr_txnid = (txnid_t)-1;+				r->mr_tid = tid;+				if (i == nr)+					ti->mti_numreaders = ++nr;+				env->me_close_readers = nr;+				r->mr_pid = pid;+				UNLOCK_MUTEX(rmutex);++				new_notls = (env->me_flags & MDB_NOTLS);+				if (!new_notls && (rc=pthread_setspecific(env->me_txkey, r))) {+					r->mr_pid = 0;+					return rc;+				}+			}+			do /* LY: Retry on a race, ITS#7970. */+				r->mr_txnid = ti->mti_txnid;+			while(r->mr_txnid != ti->mti_txnid);+			if (!r->mr_txnid && (env->me_flags & MDB_RDONLY)) {+				meta = mdb_env_pick_meta(env);+				r->mr_txnid = meta->mm_txnid;+			} else {+				meta = env->me_metas[r->mr_txnid & 1];+			}+			txn->mt_txnid = r->mr_txnid;+			txn->mt_u.reader = r;+		}++	} else {+		/* Not yet touching txn == env->me_txn0, it may be active */+		if (ti) {+			if (LOCK_MUTEX(rc, env, env->me_wmutex))+				return rc;+			txn->mt_txnid = ti->mti_txnid;+			meta = env->me_metas[txn->mt_txnid & 1];+		} else {+			meta = mdb_env_pick_meta(env);+			txn->mt_txnid = meta->mm_txnid;+		}+		txn->mt_txnid++;+#if MDB_DEBUG+		if (txn->mt_txnid == mdb_debug_start)+			mdb_debug = MDB_DBG_INFO;+#endif+		txn->mt_child = NULL;+		txn->mt_loose_pgs = NULL;+		txn->mt_loose_count = 0;+		txn->mt_dirty_room = MDB_IDL_UM_MAX;+		txn->mt_u.dirty_list = env->me_dirty_list;+		txn->mt_u.dirty_list[0].mid = 0;+		txn->mt_free_pgs = env->me_free_pgs;+		txn->mt_free_pgs[0] = 0;+		txn->mt_spill_pgs = NULL;+		env->me_txn = txn;+		memcpy(txn->mt_dbiseqs, env->me_dbiseqs, env->me_maxdbs * sizeof(unsigned int));+	}++	/* Copy the DB info and flags */+	memcpy(txn->mt_dbs, meta->mm_dbs, CORE_DBS * sizeof(MDB_db));++	/* Moved to here to avoid a data race in read TXNs */+	txn->mt_next_pgno = meta->mm_last_pg+1;++	txn->mt_flags = flags;++	/* Setup db info */+	txn->mt_numdbs = env->me_numdbs;+	for (i=CORE_DBS; i<txn->mt_numdbs; i++) {+		x = env->me_dbflags[i];+		txn->mt_dbs[i].md_flags = x & PERSISTENT_FLAGS;+		txn->mt_dbflags[i] = (x & MDB_VALID) ? DB_VALID|DB_USRVALID|DB_STALE : 0;+	}+	txn->mt_dbflags[MAIN_DBI] = DB_VALID|DB_USRVALID;+	txn->mt_dbflags[FREE_DBI] = DB_VALID;++	if (env->me_flags & MDB_FATAL_ERROR) {+		DPUTS("environment had fatal error, must shutdown!");+		rc = MDB_PANIC;+	} else if (env->me_maxpg < txn->mt_next_pgno) {+		rc = MDB_MAP_RESIZED;+	} else {+		return MDB_SUCCESS;+	}+	mdb_txn_end(txn, new_notls /*0 or MDB_END_SLOT*/ | MDB_END_FAIL_BEGIN);+	return rc;+}++int+mdb_txn_renew(MDB_txn *txn)+{+	int rc;++	if (!txn || !F_ISSET(txn->mt_flags, MDB_TXN_RDONLY|MDB_TXN_FINISHED))+		return EINVAL;++	rc = mdb_txn_renew0(txn);+	if (rc == MDB_SUCCESS) {+		DPRINTF(("renew txn %"Z"u%c %p on mdbenv %p, root page %"Z"u",+			txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w',+			(void *)txn, (void *)txn->mt_env, txn->mt_dbs[MAIN_DBI].md_root));+	}+	return rc;+}++int+mdb_txn_begin(MDB_env *env, MDB_txn *parent, unsigned int flags, MDB_txn **ret)+{+	MDB_txn *txn;+	MDB_ntxn *ntxn;+	int rc, size, tsize;++	flags &= MDB_TXN_BEGIN_FLAGS;+	flags |= env->me_flags & MDB_WRITEMAP;++	if (env->me_flags & MDB_RDONLY & ~flags) /* write txn in RDONLY env */+		return EACCES;++	if (parent) {+		/* Nested transactions: Max 1 child, write txns only, no writemap */+		flags |= parent->mt_flags;+		if (flags & (MDB_RDONLY|MDB_WRITEMAP|MDB_TXN_BLOCKED)) {+			return (parent->mt_flags & MDB_TXN_RDONLY) ? EINVAL : MDB_BAD_TXN;+		}+		/* Child txns save MDB_pgstate and use own copy of cursors */+		size = env->me_maxdbs * (sizeof(MDB_db)+sizeof(MDB_cursor *)+1);+		size += tsize = sizeof(MDB_ntxn);+	} else if (flags & MDB_RDONLY) {+		size = env->me_maxdbs * (sizeof(MDB_db)+1);+		size += tsize = sizeof(MDB_txn);+	} else {+		/* Reuse preallocated write txn. However, do not touch it until+		 * mdb_txn_renew0() succeeds, since it currently may be active.+		 */+		txn = env->me_txn0;+		goto renew;+	}+	if ((txn = calloc(1, size)) == NULL) {+		DPRINTF(("calloc: %s", strerror(errno)));+		return ENOMEM;+	}+	txn->mt_dbxs = env->me_dbxs;	/* static */+	txn->mt_dbs = (MDB_db *) ((char *)txn + tsize);+	txn->mt_dbflags = (unsigned char *)txn + size - env->me_maxdbs;+	txn->mt_flags = flags;+	txn->mt_env = env;++	if (parent) {+		unsigned int i;+		txn->mt_cursors = (MDB_cursor **)(txn->mt_dbs + env->me_maxdbs);+		txn->mt_dbiseqs = parent->mt_dbiseqs;+		txn->mt_u.dirty_list = malloc(sizeof(MDB_ID2)*MDB_IDL_UM_SIZE);+		if (!txn->mt_u.dirty_list ||+			!(txn->mt_free_pgs = mdb_midl_alloc(MDB_IDL_UM_MAX)))+		{+			free(txn->mt_u.dirty_list);+			free(txn);+			return ENOMEM;+		}+		txn->mt_txnid = parent->mt_txnid;+		txn->mt_dirty_room = parent->mt_dirty_room;+		txn->mt_u.dirty_list[0].mid = 0;+		txn->mt_spill_pgs = NULL;+		txn->mt_next_pgno = parent->mt_next_pgno;+		parent->mt_flags |= MDB_TXN_HAS_CHILD;+		parent->mt_child = txn;+		txn->mt_parent = parent;+		txn->mt_numdbs = parent->mt_numdbs;+		memcpy(txn->mt_dbs, parent->mt_dbs, txn->mt_numdbs * sizeof(MDB_db));+		/* Copy parent's mt_dbflags, but clear DB_NEW */+		for (i=0; i<txn->mt_numdbs; i++)+			txn->mt_dbflags[i] = parent->mt_dbflags[i] & ~DB_NEW;+		rc = 0;+		ntxn = (MDB_ntxn *)txn;+		ntxn->mnt_pgstate = env->me_pgstate; /* save parent me_pghead & co */+		if (env->me_pghead) {+			size = MDB_IDL_SIZEOF(env->me_pghead);+			env->me_pghead = mdb_midl_alloc(env->me_pghead[0]);+			if (env->me_pghead)+				memcpy(env->me_pghead, ntxn->mnt_pgstate.mf_pghead, size);+			else+				rc = ENOMEM;+		}+		if (!rc)+			rc = mdb_cursor_shadow(parent, txn);+		if (rc)+			mdb_txn_end(txn, MDB_END_FAIL_BEGINCHILD);+	} else { /* MDB_RDONLY */+		txn->mt_dbiseqs = env->me_dbiseqs;+renew:+		rc = mdb_txn_renew0(txn);+	}+	if (rc) {+		if (txn != env->me_txn0)+			free(txn);+	} else {+		txn->mt_flags |= flags;	/* could not change txn=me_txn0 earlier */+		*ret = txn;+		DPRINTF(("begin txn %"Z"u%c %p on mdbenv %p, root page %"Z"u",+			txn->mt_txnid, (flags & MDB_RDONLY) ? 'r' : 'w',+			(void *) txn, (void *) env, txn->mt_dbs[MAIN_DBI].md_root));+	}+	MDB_TRACE(("%p, %p, %u = %p", env, parent, flags, txn));++	return rc;+}++MDB_env *+mdb_txn_env(MDB_txn *txn)+{+	if(!txn) return NULL;+	return txn->mt_env;+}++size_t+mdb_txn_id(MDB_txn *txn)+{+    if(!txn) return 0;+    return txn->mt_txnid;+}++/** Export or close DBI handles opened in this txn. */+static void+mdb_dbis_update(MDB_txn *txn, int keep)+{+	int i;+	MDB_dbi n = txn->mt_numdbs;+	MDB_env *env = txn->mt_env;+	unsigned char *tdbflags = txn->mt_dbflags;++	for (i = n; --i >= CORE_DBS;) {+		if (tdbflags[i] & DB_NEW) {+			if (keep) {+				env->me_dbflags[i] = txn->mt_dbs[i].md_flags | MDB_VALID;+			} else {+				char *ptr = env->me_dbxs[i].md_name.mv_data;+				if (ptr) {+					env->me_dbxs[i].md_name.mv_data = NULL;+					env->me_dbxs[i].md_name.mv_size = 0;+					env->me_dbflags[i] = 0;+					env->me_dbiseqs[i]++;+					free(ptr);+				}+			}+		}+	}+	if (keep && env->me_numdbs < n)+		env->me_numdbs = n;+}++/** End a transaction, except successful commit of a nested transaction.+ * May be called twice for readonly txns: First reset it, then abort.+ * @param[in] txn the transaction handle to end+ * @param[in] mode why and how to end the transaction+ */+static void+mdb_txn_end(MDB_txn *txn, unsigned mode)+{+	MDB_env	*env = txn->mt_env;+#if MDB_DEBUG+	static const char *const names[] = MDB_END_NAMES;+#endif++	/* Export or close DBI handles opened in this txn */+	mdb_dbis_update(txn, mode & MDB_END_UPDATE);++	DPRINTF(("%s txn %"Z"u%c %p on mdbenv %p, root page %"Z"u",+		names[mode & MDB_END_OPMASK],+		txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w',+		(void *) txn, (void *)env, txn->mt_dbs[MAIN_DBI].md_root));++	if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {+		if (txn->mt_u.reader) {+			txn->mt_u.reader->mr_txnid = (txnid_t)-1;+			if (!(env->me_flags & MDB_NOTLS)) {+				txn->mt_u.reader = NULL; /* txn does not own reader */+			} else if (mode & MDB_END_SLOT) {+				txn->mt_u.reader->mr_pid = 0;+				txn->mt_u.reader = NULL;+			} /* else txn owns the slot until it does MDB_END_SLOT */+		}+		txn->mt_numdbs = 0;		/* prevent further DBI activity */+		txn->mt_flags |= MDB_TXN_FINISHED;++	} else if (!F_ISSET(txn->mt_flags, MDB_TXN_FINISHED)) {+		pgno_t *pghead = env->me_pghead;++		if (!(mode & MDB_END_UPDATE)) /* !(already closed cursors) */+			mdb_cursors_close(txn, 0);+		if (!(env->me_flags & MDB_WRITEMAP)) {+			mdb_dlist_free(txn);+		}++		txn->mt_numdbs = 0;+		txn->mt_flags = MDB_TXN_FINISHED;++		if (!txn->mt_parent) {+			mdb_midl_shrink(&txn->mt_free_pgs);+			env->me_free_pgs = txn->mt_free_pgs;+			/* me_pgstate: */+			env->me_pghead = NULL;+			env->me_pglast = 0;++			env->me_txn = NULL;+			mode = 0;	/* txn == env->me_txn0, do not free() it */++			/* The writer mutex was locked in mdb_txn_begin. */+			if (env->me_txns)+				UNLOCK_MUTEX(env->me_wmutex);+		} else {+			txn->mt_parent->mt_child = NULL;+			txn->mt_parent->mt_flags &= ~MDB_TXN_HAS_CHILD;+			env->me_pgstate = ((MDB_ntxn *)txn)->mnt_pgstate;+			mdb_midl_free(txn->mt_free_pgs);+			free(txn->mt_u.dirty_list);+		}+		mdb_midl_free(txn->mt_spill_pgs);++		mdb_midl_free(pghead);+	}++	if (mode & MDB_END_FREE)+		free(txn);+}++void+mdb_txn_reset(MDB_txn *txn)+{+	if (txn == NULL)+		return;++	/* This call is only valid for read-only txns */+	if (!(txn->mt_flags & MDB_TXN_RDONLY))+		return;++	mdb_txn_end(txn, MDB_END_RESET);+}++static void+_mdb_txn_abort(MDB_txn *txn)+{+	if (txn == NULL)+		return;++	if (txn->mt_child)+		_mdb_txn_abort(txn->mt_child);++	mdb_txn_end(txn, MDB_END_ABORT|MDB_END_SLOT|MDB_END_FREE);+}++void+mdb_txn_abort(MDB_txn *txn)+{+	MDB_TRACE(("%p", txn));+	_mdb_txn_abort(txn);+}++/** Save the freelist as of this transaction to the freeDB.+ * This changes the freelist. Keep trying until it stabilizes.+ */+static int+mdb_freelist_save(MDB_txn *txn)+{+	/* env->me_pghead[] can grow and shrink during this call.+	 * env->me_pglast and txn->mt_free_pgs[] can only grow.+	 * Page numbers cannot disappear from txn->mt_free_pgs[].+	 */+	MDB_cursor mc;+	MDB_env	*env = txn->mt_env;+	int rc, maxfree_1pg = env->me_maxfree_1pg, more = 1;+	txnid_t	pglast = 0, head_id = 0;+	pgno_t	freecnt = 0, *free_pgs, *mop;+	ssize_t	head_room = 0, total_room = 0, mop_len, clean_limit;++	mdb_cursor_init(&mc, txn, FREE_DBI, NULL);++	if (env->me_pghead) {+		/* Make sure first page of freeDB is touched and on freelist */+		rc = mdb_page_search(&mc, NULL, MDB_PS_FIRST|MDB_PS_MODIFY);+		if (rc && rc != MDB_NOTFOUND)+			return rc;+	}++	if (!env->me_pghead && txn->mt_loose_pgs) {+		/* Put loose page numbers in mt_free_pgs, since+		 * we may be unable to return them to me_pghead.+		 */+		MDB_page *mp = txn->mt_loose_pgs;+		MDB_ID2 *dl = txn->mt_u.dirty_list;+		unsigned x;+		if ((rc = mdb_midl_need(&txn->mt_free_pgs, txn->mt_loose_count)) != 0)+			return rc;+		for (; mp; mp = NEXT_LOOSE_PAGE(mp)) {+			mdb_midl_xappend(txn->mt_free_pgs, mp->mp_pgno);+			/* must also remove from dirty list */+			if (txn->mt_flags & MDB_TXN_WRITEMAP) {+				for (x=1; x<=dl[0].mid; x++)+					if (dl[x].mid == mp->mp_pgno)+						break;+				mdb_tassert(txn, x <= dl[0].mid);+			} else {+				x = mdb_mid2l_search(dl, mp->mp_pgno);+				mdb_tassert(txn, dl[x].mid == mp->mp_pgno);+				mdb_dpage_free(env, mp);+			}+			dl[x].mptr = NULL;+		}+		{+			/* squash freed slots out of the dirty list */+			unsigned y;+			for (y=1; dl[y].mptr && y <= dl[0].mid; y++);+			if (y <= dl[0].mid) {+				for(x=y, y++;;) {+					while (!dl[y].mptr && y <= dl[0].mid) y++;+					if (y > dl[0].mid) break;+					dl[x++] = dl[y++];+				}+				dl[0].mid = x-1;+			} else {+				/* all slots freed */+				dl[0].mid = 0;+			}+		}+		txn->mt_loose_pgs = NULL;+		txn->mt_loose_count = 0;+	}++	/* MDB_RESERVE cancels meminit in ovpage malloc (when no WRITEMAP) */+	clean_limit = (env->me_flags & (MDB_NOMEMINIT|MDB_WRITEMAP))+		? SSIZE_MAX : maxfree_1pg;++	for (;;) {+		/* Come back here after each Put() in case freelist changed */+		MDB_val key, data;+		pgno_t *pgs;+		ssize_t j;++		/* If using records from freeDB which we have not yet+		 * deleted, delete them and any we reserved for me_pghead.+		 */+		while (pglast < env->me_pglast) {+			rc = mdb_cursor_first(&mc, &key, NULL);+			if (rc)+				return rc;+			pglast = head_id = *(txnid_t *)key.mv_data;+			total_room = head_room = 0;+			mdb_tassert(txn, pglast <= env->me_pglast);+			rc = _mdb_cursor_del(&mc, 0);+			if (rc)+				return rc;+		}++		/* Save the IDL of pages freed by this txn, to a single record */+		if (freecnt < txn->mt_free_pgs[0]) {+			if (!freecnt) {+				/* Make sure last page of freeDB is touched and on freelist */+				rc = mdb_page_search(&mc, NULL, MDB_PS_LAST|MDB_PS_MODIFY);+				if (rc && rc != MDB_NOTFOUND)+					return rc;+			}+			free_pgs = txn->mt_free_pgs;+			/* Write to last page of freeDB */+			key.mv_size = sizeof(txn->mt_txnid);+			key.mv_data = &txn->mt_txnid;+			do {+				freecnt = free_pgs[0];+				data.mv_size = MDB_IDL_SIZEOF(free_pgs);+				rc = _mdb_cursor_put(&mc, &key, &data, MDB_RESERVE);+				if (rc)+					return rc;+				/* Retry if mt_free_pgs[] grew during the Put() */+				free_pgs = txn->mt_free_pgs;+			} while (freecnt < free_pgs[0]);+			mdb_midl_sort(free_pgs);+			memcpy(data.mv_data, free_pgs, data.mv_size);+#if (MDB_DEBUG) > 1+			{+				unsigned int i = free_pgs[0];+				DPRINTF(("IDL write txn %"Z"u root %"Z"u num %u",+					txn->mt_txnid, txn->mt_dbs[FREE_DBI].md_root, i));+				for (; i; i--)+					DPRINTF(("IDL %"Z"u", free_pgs[i]));+			}+#endif+			continue;+		}++		mop = env->me_pghead;+		mop_len = (mop ? mop[0] : 0) + txn->mt_loose_count;++		/* Reserve records for me_pghead[]. Split it if multi-page,+		 * to avoid searching freeDB for a page range. Use keys in+		 * range [1,me_pglast]: Smaller than txnid of oldest reader.+		 */+		if (total_room >= mop_len) {+			if (total_room == mop_len || --more < 0)+				break;+		} else if (head_room >= maxfree_1pg && head_id > 1) {+			/* Keep current record (overflow page), add a new one */+			head_id--;+			head_room = 0;+		}+		/* (Re)write {key = head_id, IDL length = head_room} */+		total_room -= head_room;+		head_room = mop_len - total_room;+		if (head_room > maxfree_1pg && head_id > 1) {+			/* Overflow multi-page for part of me_pghead */+			head_room /= head_id; /* amortize page sizes */+			head_room += maxfree_1pg - head_room % (maxfree_1pg + 1);+		} else if (head_room < 0) {+			/* Rare case, not bothering to delete this record */+			head_room = 0;+		}+		key.mv_size = sizeof(head_id);+		key.mv_data = &head_id;+		data.mv_size = (head_room + 1) * sizeof(pgno_t);+		rc = _mdb_cursor_put(&mc, &key, &data, MDB_RESERVE);+		if (rc)+			return rc;+		/* IDL is initially empty, zero out at least the length */+		pgs = (pgno_t *)data.mv_data;+		j = head_room > clean_limit ? head_room : 0;+		do {+			pgs[j] = 0;+		} while (--j >= 0);+		total_room += head_room;+	}++	/* Return loose page numbers to me_pghead, though usually none are+	 * left at this point.  The pages themselves remain in dirty_list.+	 */+	if (txn->mt_loose_pgs) {+		MDB_page *mp = txn->mt_loose_pgs;+		unsigned count = txn->mt_loose_count;+		MDB_IDL loose;+		/* Room for loose pages + temp IDL with same */+		if ((rc = mdb_midl_need(&env->me_pghead, 2*count+1)) != 0)+			return rc;+		mop = env->me_pghead;+		loose = mop + MDB_IDL_ALLOCLEN(mop) - count;+		for (count = 0; mp; mp = NEXT_LOOSE_PAGE(mp))+			loose[ ++count ] = mp->mp_pgno;+		loose[0] = count;+		mdb_midl_sort(loose);+		mdb_midl_xmerge(mop, loose);+		txn->mt_loose_pgs = NULL;+		txn->mt_loose_count = 0;+		mop_len = mop[0];+	}++	/* Fill in the reserved me_pghead records */+	rc = MDB_SUCCESS;+	if (mop_len) {+		MDB_val key, data;++		mop += mop_len;+		rc = mdb_cursor_first(&mc, &key, &data);+		for (; !rc; rc = mdb_cursor_next(&mc, &key, &data, MDB_NEXT)) {+			txnid_t id = *(txnid_t *)key.mv_data;+			ssize_t	len = (ssize_t)(data.mv_size / sizeof(MDB_ID)) - 1;+			MDB_ID save;++			mdb_tassert(txn, len >= 0 && id <= env->me_pglast);+			key.mv_data = &id;+			if (len > mop_len) {+				len = mop_len;+				data.mv_size = (len + 1) * sizeof(MDB_ID);+			}+			data.mv_data = mop -= len;+			save = mop[0];+			mop[0] = len;+			rc = _mdb_cursor_put(&mc, &key, &data, MDB_CURRENT);+			mop[0] = save;+			if (rc || !(mop_len -= len))+				break;+		}+	}+	return rc;+}++/** Flush (some) dirty pages to the map, after clearing their dirty flag.+ * @param[in] txn the transaction that's being committed+ * @param[in] keep number of initial pages in dirty_list to keep dirty.+ * @return 0 on success, non-zero on failure.+ */+static int+mdb_page_flush(MDB_txn *txn, int keep)+{+	MDB_env		*env = txn->mt_env;+	MDB_ID2L	dl = txn->mt_u.dirty_list;+	unsigned	psize = env->me_psize, j;+	int			i, pagecount = dl[0].mid, rc;+	size_t		size = 0, pos = 0;+	pgno_t		pgno = 0;+	MDB_page	*dp = NULL;+#ifdef _WIN32+	OVERLAPPED	ov;+#else+	struct iovec iov[MDB_COMMIT_PAGES];+	ssize_t		wpos = 0, wsize = 0, wres;+	size_t		next_pos = 1; /* impossible pos, so pos != next_pos */+	int			n = 0;+#endif++	j = i = keep;++	if (env->me_flags & MDB_WRITEMAP) {+		/* Clear dirty flags */+		while (++i <= pagecount) {+			dp = dl[i].mptr;+			/* Don't flush this page yet */+			if (dp->mp_flags & (P_LOOSE|P_KEEP)) {+				dp->mp_flags &= ~P_KEEP;+				dl[++j] = dl[i];+				continue;+			}+			dp->mp_flags &= ~P_DIRTY;+		}+		goto done;+	}++	/* Write the pages */+	for (;;) {+		if (++i <= pagecount) {+			dp = dl[i].mptr;+			/* Don't flush this page yet */+			if (dp->mp_flags & (P_LOOSE|P_KEEP)) {+				dp->mp_flags &= ~P_KEEP;+				dl[i].mid = 0;+				continue;+			}+			pgno = dl[i].mid;+			/* clear dirty flag */+			dp->mp_flags &= ~P_DIRTY;+			pos = pgno * psize;+			size = psize;+			if (IS_OVERFLOW(dp)) size *= dp->mp_pages;+		}+#ifdef _WIN32+		else break;++		/* Windows actually supports scatter/gather I/O, but only on+		 * unbuffered file handles. Since we're relying on the OS page+		 * cache for all our data, that's self-defeating. So we just+		 * write pages one at a time. We use the ov structure to set+		 * the write offset, to at least save the overhead of a Seek+		 * system call.+		 */+		DPRINTF(("committing page %"Z"u", pgno));+		memset(&ov, 0, sizeof(ov));+		ov.Offset = pos & 0xffffffff;+		ov.OffsetHigh = pos >> 16 >> 16;+		if (!WriteFile(env->me_fd, dp, size, NULL, &ov)) {+			rc = ErrCode();+			DPRINTF(("WriteFile: %d", rc));+			return rc;+		}+#else+		/* Write up to MDB_COMMIT_PAGES dirty pages at a time. */+		if (pos!=next_pos || n==MDB_COMMIT_PAGES || wsize+size>MAX_WRITE) {+			if (n) {+retry_write:+				/* Write previous page(s) */+#ifdef MDB_USE_PWRITEV+				wres = pwritev(env->me_fd, iov, n, wpos);+#else+				if (n == 1) {+					wres = pwrite(env->me_fd, iov[0].iov_base, wsize, wpos);+				} else {+retry_seek:+					if (lseek(env->me_fd, wpos, SEEK_SET) == -1) {+						rc = ErrCode();+						if (rc == EINTR)+							goto retry_seek;+						DPRINTF(("lseek: %s", strerror(rc)));+						return rc;+					}+					wres = writev(env->me_fd, iov, n);+				}+#endif+				if (wres != wsize) {+					if (wres < 0) {+						rc = ErrCode();+						if (rc == EINTR)+							goto retry_write;+						DPRINTF(("Write error: %s", strerror(rc)));+					} else {+						rc = EIO; /* TODO: Use which error code? */+						DPUTS("short write, filesystem full?");+					}+					return rc;+				}+				n = 0;+			}+			if (i > pagecount)+				break;+			wpos = pos;+			wsize = 0;+		}+		DPRINTF(("committing page %"Z"u", pgno));+		next_pos = pos + size;+		iov[n].iov_len = size;+		iov[n].iov_base = (char *)dp;+		wsize += size;+		n++;+#endif	/* _WIN32 */+	}++	/* MIPS has cache coherency issues, this is a no-op everywhere else+	 * Note: for any size >= on-chip cache size, entire on-chip cache is+	 * flushed.+	 */+	CACHEFLUSH(env->me_map, txn->mt_next_pgno * env->me_psize, DCACHE);++	for (i = keep; ++i <= pagecount; ) {+		dp = dl[i].mptr;+		/* This is a page we skipped above */+		if (!dl[i].mid) {+			dl[++j] = dl[i];+			dl[j].mid = dp->mp_pgno;+			continue;+		}+		mdb_dpage_free(env, dp);+	}++done:+	i--;+	txn->mt_dirty_room += i - j;+	dl[0].mid = j;+	return MDB_SUCCESS;+}++static int+_mdb_txn_commit(MDB_txn *txn)+{+	int		rc;+	unsigned int i, end_mode;+	MDB_env	*env;++	if (txn == NULL)+		return EINVAL;++	/* mdb_txn_end() mode for a commit which writes nothing */+	end_mode = MDB_END_EMPTY_COMMIT|MDB_END_UPDATE|MDB_END_SLOT|MDB_END_FREE;++	if (txn->mt_child) {+		rc = _mdb_txn_commit(txn->mt_child);+		if (rc)+			goto fail;+	}++	env = txn->mt_env;++	if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {+		goto done;+	}++	if (txn->mt_flags & (MDB_TXN_FINISHED|MDB_TXN_ERROR)) {+		DPUTS("txn has failed/finished, can't commit");+		if (txn->mt_parent)+			txn->mt_parent->mt_flags |= MDB_TXN_ERROR;+		rc = MDB_BAD_TXN;+		goto fail;+	}++	if (txn->mt_parent) {+		MDB_txn *parent = txn->mt_parent;+		MDB_page **lp;+		MDB_ID2L dst, src;+		MDB_IDL pspill;+		unsigned x, y, len, ps_len;++		/* Append our free list to parent's */+		rc = mdb_midl_append_list(&parent->mt_free_pgs, txn->mt_free_pgs);+		if (rc)+			goto fail;+		mdb_midl_free(txn->mt_free_pgs);+		/* Failures after this must either undo the changes+		 * to the parent or set MDB_TXN_ERROR in the parent.+		 */++		parent->mt_next_pgno = txn->mt_next_pgno;+		parent->mt_flags = txn->mt_flags;++		/* Merge our cursors into parent's and close them */+		mdb_cursors_close(txn, 1);++		/* Update parent's DB table. */+		memcpy(parent->mt_dbs, txn->mt_dbs, txn->mt_numdbs * sizeof(MDB_db));+		parent->mt_numdbs = txn->mt_numdbs;+		parent->mt_dbflags[FREE_DBI] = txn->mt_dbflags[FREE_DBI];+		parent->mt_dbflags[MAIN_DBI] = txn->mt_dbflags[MAIN_DBI];+		for (i=CORE_DBS; i<txn->mt_numdbs; i++) {+			/* preserve parent's DB_NEW status */+			x = parent->mt_dbflags[i] & DB_NEW;+			parent->mt_dbflags[i] = txn->mt_dbflags[i] | x;+		}++		dst = parent->mt_u.dirty_list;+		src = txn->mt_u.dirty_list;+		/* Remove anything in our dirty list from parent's spill list */+		if ((pspill = parent->mt_spill_pgs) && (ps_len = pspill[0])) {+			x = y = ps_len;+			pspill[0] = (pgno_t)-1;+			/* Mark our dirty pages as deleted in parent spill list */+			for (i=0, len=src[0].mid; ++i <= len; ) {+				MDB_ID pn = src[i].mid << 1;+				while (pn > pspill[x])+					x--;+				if (pn == pspill[x]) {+					pspill[x] = 1;+					y = --x;+				}+			}+			/* Squash deleted pagenums if we deleted any */+			for (x=y; ++x <= ps_len; )+				if (!(pspill[x] & 1))+					pspill[++y] = pspill[x];+			pspill[0] = y;+		}++		/* Remove anything in our spill list from parent's dirty list */+		if (txn->mt_spill_pgs && txn->mt_spill_pgs[0]) {+			for (i=1; i<=txn->mt_spill_pgs[0]; i++) {+				MDB_ID pn = txn->mt_spill_pgs[i];+				if (pn & 1)+					continue;	/* deleted spillpg */+				pn >>= 1;+				y = mdb_mid2l_search(dst, pn);+				if (y <= dst[0].mid && dst[y].mid == pn) {+					free(dst[y].mptr);+					while (y < dst[0].mid) {+						dst[y] = dst[y+1];+						y++;+					}+					dst[0].mid--;+				}+			}+		}++		/* Find len = length of merging our dirty list with parent's */+		x = dst[0].mid;+		dst[0].mid = 0;		/* simplify loops */+		if (parent->mt_parent) {+			len = x + src[0].mid;+			y = mdb_mid2l_search(src, dst[x].mid + 1) - 1;+			for (i = x; y && i; y--) {+				pgno_t yp = src[y].mid;+				while (yp < dst[i].mid)+					i--;+				if (yp == dst[i].mid) {+					i--;+					len--;+				}+			}+		} else { /* Simplify the above for single-ancestor case */+			len = MDB_IDL_UM_MAX - txn->mt_dirty_room;+		}+		/* Merge our dirty list with parent's */+		y = src[0].mid;+		for (i = len; y; dst[i--] = src[y--]) {+			pgno_t yp = src[y].mid;+			while (yp < dst[x].mid)+				dst[i--] = dst[x--];+			if (yp == dst[x].mid)+				free(dst[x--].mptr);+		}+		mdb_tassert(txn, i == x);+		dst[0].mid = len;+		free(txn->mt_u.dirty_list);+		parent->mt_dirty_room = txn->mt_dirty_room;+		if (txn->mt_spill_pgs) {+			if (parent->mt_spill_pgs) {+				/* TODO: Prevent failure here, so parent does not fail */+				rc = mdb_midl_append_list(&parent->mt_spill_pgs, txn->mt_spill_pgs);+				if (rc)+					parent->mt_flags |= MDB_TXN_ERROR;+				mdb_midl_free(txn->mt_spill_pgs);+				mdb_midl_sort(parent->mt_spill_pgs);+			} else {+				parent->mt_spill_pgs = txn->mt_spill_pgs;+			}+		}++		/* Append our loose page list to parent's */+		for (lp = &parent->mt_loose_pgs; *lp; lp = &NEXT_LOOSE_PAGE(*lp))+			;+		*lp = txn->mt_loose_pgs;+		parent->mt_loose_count += txn->mt_loose_count;++		parent->mt_child = NULL;+		mdb_midl_free(((MDB_ntxn *)txn)->mnt_pgstate.mf_pghead);+		free(txn);+		return rc;+	}++	if (txn != env->me_txn) {+		DPUTS("attempt to commit unknown transaction");+		rc = EINVAL;+		goto fail;+	}++	mdb_cursors_close(txn, 0);++	if (!txn->mt_u.dirty_list[0].mid &&+		!(txn->mt_flags & (MDB_TXN_DIRTY|MDB_TXN_SPILLS)))+		goto done;++	DPRINTF(("committing txn %"Z"u %p on mdbenv %p, root page %"Z"u",+	    txn->mt_txnid, (void*)txn, (void*)env, txn->mt_dbs[MAIN_DBI].md_root));++	/* Update DB root pointers */+	if (txn->mt_numdbs > CORE_DBS) {+		MDB_cursor mc;+		MDB_dbi i;+		MDB_val data;+		data.mv_size = sizeof(MDB_db);++		mdb_cursor_init(&mc, txn, MAIN_DBI, NULL);+		for (i = CORE_DBS; i < txn->mt_numdbs; i++) {+			if (txn->mt_dbflags[i] & DB_DIRTY) {+				if (TXN_DBI_CHANGED(txn, i)) {+					rc = MDB_BAD_DBI;+					goto fail;+				}+				data.mv_data = &txn->mt_dbs[i];+				rc = _mdb_cursor_put(&mc, &txn->mt_dbxs[i].md_name, &data,+					F_SUBDATA);+				if (rc)+					goto fail;+			}+		}+	}++	rc = mdb_freelist_save(txn);+	if (rc)+		goto fail;++	mdb_midl_free(env->me_pghead);+	env->me_pghead = NULL;+	mdb_midl_shrink(&txn->mt_free_pgs);++#if (MDB_DEBUG) > 2+	mdb_audit(txn);+#endif++	if ((rc = mdb_page_flush(txn, 0)) ||+		(rc = mdb_env_sync(env, 0)) ||+		(rc = mdb_env_write_meta(txn)))+		goto fail;+	end_mode = MDB_END_COMMITTED|MDB_END_UPDATE;++done:+	mdb_txn_end(txn, end_mode);+	return MDB_SUCCESS;++fail:+	_mdb_txn_abort(txn);+	return rc;+}++int+mdb_txn_commit(MDB_txn *txn)+{+	MDB_TRACE(("%p", txn));+	return _mdb_txn_commit(txn);+}++/** Read the environment parameters of a DB environment before+ * mapping it into memory.+ * @param[in] env the environment handle+ * @param[out] meta address of where to store the meta information+ * @return 0 on success, non-zero on failure.+ */+static int ESECT+mdb_env_read_header(MDB_env *env, MDB_meta *meta)+{+	MDB_metabuf	pbuf;+	MDB_page	*p;+	MDB_meta	*m;+	int			i, rc, off;+	enum { Size = sizeof(pbuf) };++	/* We don't know the page size yet, so use a minimum value.+	 * Read both meta pages so we can use the latest one.+	 */++	for (i=off=0; i<NUM_METAS; i++, off += meta->mm_psize) {+#ifdef _WIN32+		DWORD len;+		OVERLAPPED ov;+		memset(&ov, 0, sizeof(ov));+		ov.Offset = off;+		rc = ReadFile(env->me_fd, &pbuf, Size, &len, &ov) ? (int)len : -1;+		if (rc == -1 && ErrCode() == ERROR_HANDLE_EOF)+			rc = 0;+#else+		rc = pread(env->me_fd, &pbuf, Size, off);+#endif+		if (rc != Size) {+			if (rc == 0 && off == 0)+				return ENOENT;+			rc = rc < 0 ? (int) ErrCode() : MDB_INVALID;+			DPRINTF(("read: %s", mdb_strerror(rc)));+			return rc;+		}++		p = (MDB_page *)&pbuf;++		if (!F_ISSET(p->mp_flags, P_META)) {+			DPRINTF(("page %"Z"u not a meta page", p->mp_pgno));+			return MDB_INVALID;+		}++		m = METADATA(p);+		if (m->mm_magic != MDB_MAGIC) {+			DPUTS("meta has invalid magic");+			return MDB_INVALID;+		}++		if (m->mm_version != MDB_DATA_VERSION) {+			DPRINTF(("database is version %u, expected version %u",+				m->mm_version, MDB_DATA_VERSION));+			return MDB_VERSION_MISMATCH;+		}++		if (off == 0 || m->mm_txnid > meta->mm_txnid)+			*meta = *m;+	}+	return 0;+}++/** Fill in most of the zeroed #MDB_meta for an empty database environment */+static void ESECT+mdb_env_init_meta0(MDB_env *env, MDB_meta *meta)+{+	meta->mm_magic = MDB_MAGIC;+	meta->mm_version = MDB_DATA_VERSION;+	meta->mm_mapsize = env->me_mapsize;+	meta->mm_psize = env->me_psize;+	meta->mm_last_pg = NUM_METAS-1;+	meta->mm_flags = env->me_flags & 0xffff;+	meta->mm_flags |= MDB_INTEGERKEY; /* this is mm_dbs[FREE_DBI].md_flags */+	meta->mm_dbs[FREE_DBI].md_root = P_INVALID;+	meta->mm_dbs[MAIN_DBI].md_root = P_INVALID;+}++/** Write the environment parameters of a freshly created DB environment.+ * @param[in] env the environment handle+ * @param[in] meta the #MDB_meta to write+ * @return 0 on success, non-zero on failure.+ */+static int ESECT+mdb_env_init_meta(MDB_env *env, MDB_meta *meta)+{+	MDB_page *p, *q;+	int rc;+	unsigned int	 psize;+#ifdef _WIN32+	DWORD len;+	OVERLAPPED ov;+	memset(&ov, 0, sizeof(ov));+#define DO_PWRITE(rc, fd, ptr, size, len, pos)	do { \+	ov.Offset = pos;	\+	rc = WriteFile(fd, ptr, size, &len, &ov);	} while(0)+#else+	int len;+#define DO_PWRITE(rc, fd, ptr, size, len, pos)	do { \+	len = pwrite(fd, ptr, size, pos);	\+	if (len == -1 && ErrCode() == EINTR) continue; \+	rc = (len >= 0); break; } while(1)+#endif++	DPUTS("writing new meta page");++	psize = env->me_psize;++	p = calloc(NUM_METAS, psize);+	if (!p)+		return ENOMEM;++	p->mp_pgno = 0;+	p->mp_flags = P_META;+	*(MDB_meta *)METADATA(p) = *meta;++	q = (MDB_page *)((char *)p + psize);+	q->mp_pgno = 1;+	q->mp_flags = P_META;+	*(MDB_meta *)METADATA(q) = *meta;++	DO_PWRITE(rc, env->me_fd, p, psize * NUM_METAS, len, 0);+	if (!rc)+		rc = ErrCode();+	else if ((unsigned) len == psize * NUM_METAS)+		rc = MDB_SUCCESS;+	else+		rc = ENOSPC;+	free(p);+	return rc;+}++/** Update the environment info to commit a transaction.+ * @param[in] txn the transaction that's being committed+ * @return 0 on success, non-zero on failure.+ */+static int+mdb_env_write_meta(MDB_txn *txn)+{+	MDB_env *env;+	MDB_meta	meta, metab, *mp;+	unsigned flags;+	size_t mapsize;+	off_t off;+	int rc, len, toggle;+	char *ptr;+	HANDLE mfd;+#ifdef _WIN32+	OVERLAPPED ov;+#else+	int r2;+#endif++	toggle = txn->mt_txnid & 1;+	DPRINTF(("writing meta page %d for root page %"Z"u",+		toggle, txn->mt_dbs[MAIN_DBI].md_root));++	env = txn->mt_env;+	flags = env->me_flags;+	mp = env->me_metas[toggle];+	mapsize = env->me_metas[toggle ^ 1]->mm_mapsize;+	/* Persist any increases of mapsize config */+	if (mapsize < env->me_mapsize)+		mapsize = env->me_mapsize;++	if (flags & MDB_WRITEMAP) {+		mp->mm_mapsize = mapsize;+		mp->mm_dbs[FREE_DBI] = txn->mt_dbs[FREE_DBI];+		mp->mm_dbs[MAIN_DBI] = txn->mt_dbs[MAIN_DBI];+		mp->mm_last_pg = txn->mt_next_pgno - 1;+#if (__GNUC__ * 100 + __GNUC_MINOR__ >= 404) && /* TODO: portability */	\+	!(defined(__i386__) || defined(__x86_64__))+		/* LY: issue a memory barrier, if not x86. ITS#7969 */+		__sync_synchronize();+#endif+		mp->mm_txnid = txn->mt_txnid;+		if (!(flags & (MDB_NOMETASYNC|MDB_NOSYNC))) {+			unsigned meta_size = env->me_psize;+			rc = (env->me_flags & MDB_MAPASYNC) ? MS_ASYNC : MS_SYNC;+			ptr = (char *)mp - PAGEHDRSZ;+#ifndef _WIN32	/* POSIX msync() requires ptr = start of OS page */+			r2 = (ptr - env->me_map) & (env->me_os_psize - 1);+			ptr -= r2;+			meta_size += r2;+#endif+			if (MDB_MSYNC(ptr, meta_size, rc)) {+				rc = ErrCode();+				goto fail;+			}+		}+		goto done;+	}+	metab.mm_txnid = mp->mm_txnid;+	metab.mm_last_pg = mp->mm_last_pg;++	meta.mm_mapsize = mapsize;+	meta.mm_dbs[FREE_DBI] = txn->mt_dbs[FREE_DBI];+	meta.mm_dbs[MAIN_DBI] = txn->mt_dbs[MAIN_DBI];+	meta.mm_last_pg = txn->mt_next_pgno - 1;+	meta.mm_txnid = txn->mt_txnid;++	off = offsetof(MDB_meta, mm_mapsize);+	ptr = (char *)&meta + off;+	len = sizeof(MDB_meta) - off;+	off += (char *)mp - env->me_map;++	/* Write to the SYNC fd unless MDB_NOSYNC/MDB_NOMETASYNC.+	 * (me_mfd goes to the same file as me_fd, but writing to it+	 * also syncs to disk.  Avoids a separate fdatasync() call.)+	 */+	mfd = (flags & (MDB_NOSYNC|MDB_NOMETASYNC)) ? env->me_fd : env->me_mfd;+#ifdef _WIN32+	{+		memset(&ov, 0, sizeof(ov));+		ov.Offset = off;+		if (!WriteFile(mfd, ptr, len, (DWORD *)&rc, &ov))+			rc = -1;+	}+#else+retry_write:+	rc = pwrite(mfd, ptr, len, off);+#endif+	if (rc != len) {+		rc = rc < 0 ? ErrCode() : EIO;+#ifndef _WIN32+		if (rc == EINTR)+			goto retry_write;+#endif+		DPUTS("write failed, disk error?");+		/* On a failure, the pagecache still contains the new data.+		 * Write some old data back, to prevent it from being used.+		 * Use the non-SYNC fd; we know it will fail anyway.+		 */+		meta.mm_last_pg = metab.mm_last_pg;+		meta.mm_txnid = metab.mm_txnid;+#ifdef _WIN32+		memset(&ov, 0, sizeof(ov));+		ov.Offset = off;+		WriteFile(env->me_fd, ptr, len, NULL, &ov);+#else+		r2 = pwrite(env->me_fd, ptr, len, off);+		(void)r2;	/* Silence warnings. We don't care about pwrite's return value */+#endif+fail:+		env->me_flags |= MDB_FATAL_ERROR;+		return rc;+	}+	/* MIPS has cache coherency issues, this is a no-op everywhere else */+	CACHEFLUSH(env->me_map + off, len, DCACHE);+done:+	/* Memory ordering issues are irrelevant; since the entire writer+	 * is wrapped by wmutex, all of these changes will become visible+	 * after the wmutex is unlocked. Since the DB is multi-version,+	 * readers will get consistent data regardless of how fresh or+	 * how stale their view of these values is.+	 */+	if (env->me_txns)+		env->me_txns->mti_txnid = txn->mt_txnid;++	return MDB_SUCCESS;+}++/** Check both meta pages to see which one is newer.+ * @param[in] env the environment handle+ * @return newest #MDB_meta.+ */+static MDB_meta *+mdb_env_pick_meta(const MDB_env *env)+{+	MDB_meta *const *metas = env->me_metas;+	return metas[ metas[0]->mm_txnid < metas[1]->mm_txnid ];+}++int ESECT+mdb_env_create(MDB_env **env)+{+	MDB_env *e;++	e = calloc(1, sizeof(MDB_env));+	if (!e)+		return ENOMEM;++	e->me_maxreaders = DEFAULT_READERS;+	e->me_maxdbs = e->me_numdbs = CORE_DBS;+	e->me_fd = INVALID_HANDLE_VALUE;+	e->me_lfd = INVALID_HANDLE_VALUE;+	e->me_mfd = INVALID_HANDLE_VALUE;+#ifdef MDB_USE_POSIX_SEM+	e->me_rmutex = SEM_FAILED;+	e->me_wmutex = SEM_FAILED;+#endif+	e->me_pid = getpid();+	GET_PAGESIZE(e->me_os_psize);+	VGMEMP_CREATE(e,0,0);+	*env = e;+	MDB_TRACE(("%p", e));+	return MDB_SUCCESS;+}++static int ESECT+mdb_env_map(MDB_env *env, void *addr)+{+	MDB_page *p;+	unsigned int flags = env->me_flags;+#ifdef _WIN32+	int rc;+	HANDLE mh;+	LONG sizelo, sizehi;+	size_t msize;++	if (flags & MDB_RDONLY) {+		/* Don't set explicit map size, use whatever exists */+		msize = 0;+		sizelo = 0;+		sizehi = 0;+	} else {+		msize = env->me_mapsize;+		sizelo = msize & 0xffffffff;+		sizehi = msize >> 16 >> 16; /* only needed on Win64 */++		/* Windows won't create mappings for zero length files.+		 * and won't map more than the file size.+		 * Just set the maxsize right now.+		 */+		if (!(flags & MDB_WRITEMAP) && (SetFilePointer(env->me_fd, sizelo, &sizehi, 0) != (DWORD)sizelo+			|| !SetEndOfFile(env->me_fd)+			|| SetFilePointer(env->me_fd, 0, NULL, 0) != 0))+			return ErrCode();+	}++	mh = CreateFileMapping(env->me_fd, NULL, flags & MDB_WRITEMAP ?+		PAGE_READWRITE : PAGE_READONLY,+		sizehi, sizelo, NULL);+	if (!mh)+		return ErrCode();+	env->me_map = MapViewOfFileEx(mh, flags & MDB_WRITEMAP ?+		FILE_MAP_WRITE : FILE_MAP_READ,+		0, 0, msize, addr);+	rc = env->me_map ? 0 : ErrCode();+	CloseHandle(mh);+	if (rc)+		return rc;+#else+	int mmap_flags = MAP_SHARED;+	int prot = PROT_READ;+#ifdef MAP_NOSYNC	/* Used on FreeBSD */+	if (flags & MDB_NOSYNC)+		mmap_flags |= MAP_NOSYNC;+#endif+	if (flags & MDB_WRITEMAP) {+		prot |= PROT_WRITE;+		if (ftruncate(env->me_fd, env->me_mapsize) < 0)+			return ErrCode();+	}+	env->me_map = mmap(addr, env->me_mapsize, prot, mmap_flags,+		env->me_fd, 0);+	if (env->me_map == MAP_FAILED) {+		env->me_map = NULL;+		return ErrCode();+	}++	if (flags & MDB_NORDAHEAD) {+		/* Turn off readahead. It's harmful when the DB is larger than RAM. */+#ifdef MADV_RANDOM+		madvise(env->me_map, env->me_mapsize, MADV_RANDOM);+#else+#ifdef POSIX_MADV_RANDOM+		posix_madvise(env->me_map, env->me_mapsize, POSIX_MADV_RANDOM);+#endif /* POSIX_MADV_RANDOM */+#endif /* MADV_RANDOM */+	}+#endif /* _WIN32 */++	/* Can happen because the address argument to mmap() is just a+	 * hint.  mmap() can pick another, e.g. if the range is in use.+	 * The MAP_FIXED flag would prevent that, but then mmap could+	 * instead unmap existing pages to make room for the new map.+	 */+	if (addr && env->me_map != addr)+		return EBUSY;	/* TODO: Make a new MDB_* error code? */++	p = (MDB_page *)env->me_map;+	env->me_metas[0] = METADATA(p);+	env->me_metas[1] = (MDB_meta *)((char *)env->me_metas[0] + env->me_psize);++	return MDB_SUCCESS;+}++int ESECT+mdb_env_set_mapsize(MDB_env *env, size_t size)+{+	/* If env is already open, caller is responsible for making+	 * sure there are no active txns.+	 */+	if (env->me_map) {+		int rc;+		MDB_meta *meta;+		void *old;+		if (env->me_txn)+			return EINVAL;+		meta = mdb_env_pick_meta(env);+		if (!size)+			size = meta->mm_mapsize;+		{+			/* Silently round up to minimum if the size is too small */+			size_t minsize = (meta->mm_last_pg + 1) * env->me_psize;+			if (size < minsize)+				size = minsize;+		}+		munmap(env->me_map, env->me_mapsize);+		env->me_mapsize = size;+		old = (env->me_flags & MDB_FIXEDMAP) ? env->me_map : NULL;+		rc = mdb_env_map(env, old);+		if (rc)+			return rc;+	}+	env->me_mapsize = size;+	if (env->me_psize)+		env->me_maxpg = env->me_mapsize / env->me_psize;+	MDB_TRACE(("%p, %"Yu"", env, size));+	return MDB_SUCCESS;+}++int ESECT+mdb_env_set_maxdbs(MDB_env *env, MDB_dbi dbs)+{+	if (env->me_map)+		return EINVAL;+	env->me_maxdbs = dbs + CORE_DBS;+	MDB_TRACE(("%p, %u", env, dbs));+	return MDB_SUCCESS;+}++int ESECT+mdb_env_set_maxreaders(MDB_env *env, unsigned int readers)+{+	if (env->me_map || readers < 1)+		return EINVAL;+	env->me_maxreaders = readers;+	MDB_TRACE(("%p, %u", env, readers));+	return MDB_SUCCESS;+}++int ESECT+mdb_env_get_maxreaders(MDB_env *env, unsigned int *readers)+{+	if (!env || !readers)+		return EINVAL;+	*readers = env->me_maxreaders;+	return MDB_SUCCESS;+}++static int ESECT+mdb_fsize(HANDLE fd, size_t *size)+{+#ifdef _WIN32+	LARGE_INTEGER fsize;++	if (!GetFileSizeEx(fd, &fsize))+		return ErrCode();++	*size = fsize.QuadPart;+#else+	struct stat st;++	if (fstat(fd, &st))+		return ErrCode();++	*size = st.st_size;+#endif+	return MDB_SUCCESS;+}+++#ifdef _WIN32+typedef wchar_t	mdb_nchar_t;+# define MDB_NAME(str)	L##str+# define mdb_name_cpy	wcscpy+#else+/** Character type for file names: char on Unix, wchar_t on Windows */+typedef char	mdb_nchar_t;+# define MDB_NAME(str)	str		/**< #mdb_nchar_t[] string literal */+# define mdb_name_cpy	strcpy	/**< Copy name (#mdb_nchar_t string) */+#endif++/** Filename - string of #mdb_nchar_t[] */+typedef struct MDB_name {+	int mn_len;					/**< Length  */+	int mn_alloced;				/**< True if #mn_val was malloced */+	mdb_nchar_t	*mn_val;		/**< Contents */+} MDB_name;++/** Filename suffixes [datafile,lockfile][without,with MDB_NOSUBDIR] */+static const mdb_nchar_t *const mdb_suffixes[2][2] = {+	{ MDB_NAME("/data.mdb"), MDB_NAME("")      },+	{ MDB_NAME("/lock.mdb"), MDB_NAME("-lock") }+};++#define MDB_SUFFLEN 9	/**< Max string length in #mdb_suffixes[] */++/** Set up filename + scratch area for filename suffix, for opening files.+ * It should be freed with #mdb_fname_destroy().+ * On Windows, paths are converted from char *UTF-8 to wchar_t *UTF-16.+ *+ * @param[in] path Pathname for #mdb_env_open().+ * @param[in] envflags Whether a subdir and/or lockfile will be used.+ * @param[out] fname Resulting filename, with room for a suffix if necessary.+ */+static int ESECT+mdb_fname_init(const char *path, unsigned envflags, MDB_name *fname)+{+	int no_suffix = F_ISSET(envflags, MDB_NOSUBDIR|MDB_NOLOCK);+	fname->mn_alloced = 0;+#ifdef _WIN32+	return utf8_to_utf16(path, fname, no_suffix ? 0 : MDB_SUFFLEN);+#else+	fname->mn_len = strlen(path);+	if (no_suffix)+		fname->mn_val = (char *) path;+	else if ((fname->mn_val = malloc(fname->mn_len + MDB_SUFFLEN+1)) != NULL) {+		fname->mn_alloced = 1;+		strcpy(fname->mn_val, path);+	}+	else+		return ENOMEM;+	return MDB_SUCCESS;+#endif+}++/** Destroy \b fname from #mdb_fname_init() */+#define mdb_fname_destroy(fname) \+	do { if ((fname).mn_alloced) free((fname).mn_val); } while (0)++#ifdef O_CLOEXEC /* POSIX.1-2008: Set FD_CLOEXEC atomically at open() */+# define MDB_CLOEXEC		O_CLOEXEC+#else+# define MDB_CLOEXEC		0+#endif++/** File type, access mode etc. for #mdb_fopen() */+enum mdb_fopen_type {+#ifdef _WIN32+	MDB_O_RDONLY, MDB_O_RDWR, MDB_O_META, MDB_O_COPY, MDB_O_LOCKS+#else+	/* A comment in mdb_fopen() explains some O_* flag choices. */+	MDB_O_RDONLY= O_RDONLY,                            /**< for RDONLY me_fd */+	MDB_O_RDWR  = O_RDWR  |O_CREAT,                    /**< for me_fd */+	MDB_O_META  = O_WRONLY|MDB_DSYNC     |MDB_CLOEXEC, /**< for me_mfd */+	MDB_O_COPY  = O_WRONLY|O_CREAT|O_EXCL|MDB_CLOEXEC, /**< for #mdb_env_copy() */+	/** Bitmask for open() flags in enum #mdb_fopen_type.  The other bits+	 * distinguish otherwise-equal MDB_O_* constants from each other.+	 */+	MDB_O_MASK  = MDB_O_RDWR|MDB_CLOEXEC | MDB_O_RDONLY|MDB_O_META|MDB_O_COPY,+	MDB_O_LOCKS = MDB_O_RDWR|MDB_CLOEXEC | ((MDB_O_MASK+1) & ~MDB_O_MASK) /**< for me_lfd */+#endif+};++/** Open an LMDB file.+ * @param[in] env	The LMDB environment.+ * @param[in,out] fname	Path from from #mdb_fname_init().  A suffix is+ * appended if necessary to create the filename, without changing mn_len.+ * @param[in] which	Determines file type, access mode, etc.+ * @param[in] mode	The Unix permissions for the file, if we create it.+ * @param[out] res	Resulting file handle.+ * @return 0 on success, non-zero on failure.+ */+static int ESECT+mdb_fopen(const MDB_env *env, MDB_name *fname,+	enum mdb_fopen_type which, mdb_mode_t mode,+	HANDLE *res)+{+	int rc = MDB_SUCCESS;+	HANDLE fd;+#ifdef _WIN32+	DWORD acc, share, disp, attrs;+#else+	int flags;+#endif++	if (fname->mn_alloced)		/* modifiable copy */+		mdb_name_cpy(fname->mn_val + fname->mn_len,+			mdb_suffixes[which==MDB_O_LOCKS][F_ISSET(env->me_flags, MDB_NOSUBDIR)]);++	/* The directory must already exist.  Usually the file need not.+	 * MDB_O_META requires the file because we already created it using+	 * MDB_O_RDWR.  MDB_O_COPY must not overwrite an existing file.+	 *+	 * With MDB_O_COPY we do not want the OS to cache the writes, since+	 * the source data is already in the OS cache.+	 *+	 * The lockfile needs FD_CLOEXEC (close file descriptor on exec*())+	 * to avoid the flock() issues noted under Caveats in lmdb.h.+	 * Also set it for other filehandles which the user cannot get at+	 * and close himself, which he may need after fork().  I.e. all but+	 * me_fd, which programs do use via mdb_env_get_fd().+	 */++#ifdef _WIN32+	acc = GENERIC_READ|GENERIC_WRITE;+	share = FILE_SHARE_READ|FILE_SHARE_WRITE;+	disp = OPEN_ALWAYS;+	attrs = FILE_ATTRIBUTE_NORMAL;+	switch (which) {+	case MDB_O_RDONLY:			/* read-only datafile */+		acc = GENERIC_READ;+		disp = OPEN_EXISTING;+		break;+	case MDB_O_META:			/* for writing metapages */+		acc = GENERIC_WRITE;+		disp = OPEN_EXISTING;+		attrs = FILE_ATTRIBUTE_NORMAL|FILE_FLAG_WRITE_THROUGH;+		break;+	case MDB_O_COPY:			/* mdb_env_copy() & co */+		acc = GENERIC_WRITE;+		share = 0;+		disp = CREATE_NEW;+		attrs = FILE_FLAG_NO_BUFFERING|FILE_FLAG_WRITE_THROUGH;+		break;+	default: break;	/* silence gcc -Wswitch (not all enum values handled) */+	}+	fd = CreateFileW(fname->mn_val, acc, share, NULL, disp, attrs, NULL);+#else+	fd = open(fname->mn_val, which & MDB_O_MASK, mode);+#endif++	if (fd == INVALID_HANDLE_VALUE)+		rc = ErrCode();+#ifndef _WIN32+	else {+		if (which != MDB_O_RDONLY && which != MDB_O_RDWR) {+			/* Set CLOEXEC if we could not pass it to open() */+			if (!MDB_CLOEXEC && (flags = fcntl(fd, F_GETFD)) != -1)+				(void) fcntl(fd, F_SETFD, flags | FD_CLOEXEC);+		}+		if (which == MDB_O_COPY && env->me_psize >= env->me_os_psize) {+			/* This may require buffer alignment.  There is no portable+			 * way to ask how much, so we require OS pagesize alignment.+			 */+# ifdef F_NOCACHE	/* __APPLE__ */+			(void) fcntl(fd, F_NOCACHE, 1);+# elif defined O_DIRECT+			/* open(...O_DIRECT...) would break on filesystems without+			 * O_DIRECT support (ITS#7682). Try to set it here instead.+			 */+			if ((flags = fcntl(fd, F_GETFL)) != -1)+				(void) fcntl(fd, F_SETFL, flags | O_DIRECT);+# endif+		}+	}+#endif	/* !_WIN32 */++	*res = fd;+	return rc;+}+++#ifdef BROKEN_FDATASYNC+#include <sys/utsname.h>+#include <sys/vfs.h>+#endif++/** Further setup required for opening an LMDB environment+ */+static int ESECT+mdb_env_open2(MDB_env *env)+{+	unsigned int flags = env->me_flags;+	int i, newenv = 0, rc;+	MDB_meta meta;++#ifdef _WIN32+	/* See if we should use QueryLimited */+	rc = GetVersion();+	if ((rc & 0xff) > 5)+		env->me_pidquery = MDB_PROCESS_QUERY_LIMITED_INFORMATION;+	else+		env->me_pidquery = PROCESS_QUERY_INFORMATION;+#endif /* _WIN32 */++#ifdef BROKEN_FDATASYNC+	/* ext3/ext4 fdatasync is broken on some older Linux kernels.+	 * https://lkml.org/lkml/2012/9/3/83+	 * Kernels after 3.6-rc6 are known good.+	 * https://lkml.org/lkml/2012/9/10/556+	 * See if the DB is on ext3/ext4, then check for new enough kernel+	 * Kernels 2.6.32.60, 2.6.34.15, 3.2.30, and 3.5.4 are also known+	 * to be patched.+	 */+	{+		struct statfs st;+		fstatfs(env->me_fd, &st);+		while (st.f_type == 0xEF53) {+			struct utsname uts;+			int i;+			uname(&uts);+			if (uts.release[0] < '3') {+				if (!strncmp(uts.release, "2.6.32.", 7)) {+					i = atoi(uts.release+7);+					if (i >= 60)+						break;	/* 2.6.32.60 and newer is OK */+				} else if (!strncmp(uts.release, "2.6.34.", 7)) {+					i = atoi(uts.release+7);+					if (i >= 15)+						break;	/* 2.6.34.15 and newer is OK */+				}+			} else if (uts.release[0] == '3') {+				i = atoi(uts.release+2);+				if (i > 5)+					break;	/* 3.6 and newer is OK */+				if (i == 5) {+					i = atoi(uts.release+4);+					if (i >= 4)+						break;	/* 3.5.4 and newer is OK */+				} else if (i == 2) {+					i = atoi(uts.release+4);+					if (i >= 30)+						break;	/* 3.2.30 and newer is OK */+				}+			} else {	/* 4.x and newer is OK */+				break;+			}+			env->me_flags |= MDB_FSYNCONLY;+			break;+		}+	}+#endif++	if ((i = mdb_env_read_header(env, &meta)) != 0) {+		if (i != ENOENT)+			return i;+		DPUTS("new mdbenv");+		newenv = 1;+		env->me_psize = env->me_os_psize;+		if (env->me_psize > MAX_PAGESIZE)+			env->me_psize = MAX_PAGESIZE;+		memset(&meta, 0, sizeof(meta));+		mdb_env_init_meta0(env, &meta);+		meta.mm_mapsize = DEFAULT_MAPSIZE;+	} else {+		env->me_psize = meta.mm_psize;+	}++	/* Was a mapsize configured? */+	if (!env->me_mapsize) {+		env->me_mapsize = meta.mm_mapsize;+	}+	{+		/* Make sure mapsize >= committed data size.  Even when using+		 * mm_mapsize, which could be broken in old files (ITS#7789).+		 */+		size_t minsize = (meta.mm_last_pg + 1) * meta.mm_psize;+		if (env->me_mapsize < minsize)+			env->me_mapsize = minsize;+	}+	meta.mm_mapsize = env->me_mapsize;++	if (newenv && !(flags & MDB_FIXEDMAP)) {+		/* mdb_env_map() may grow the datafile.  Write the metapages+		 * first, so the file will be valid if initialization fails.+		 * Except with FIXEDMAP, since we do not yet know mm_address.+		 * We could fill in mm_address later, but then a different+		 * program might end up doing that - one with a memory layout+		 * and map address which does not suit the main program.+		 */+		rc = mdb_env_init_meta(env, &meta);+		if (rc)+			return rc;+		newenv = 0;+	}++	rc = mdb_env_map(env, (flags & MDB_FIXEDMAP) ? meta.mm_address : NULL);+	if (rc)+		return rc;++	if (newenv) {+		if (flags & MDB_FIXEDMAP)+			meta.mm_address = env->me_map;+		i = mdb_env_init_meta(env, &meta);+		if (i != MDB_SUCCESS) {+			return i;+		}+	}++	env->me_maxfree_1pg = (env->me_psize - PAGEHDRSZ) / sizeof(pgno_t) - 1;+	env->me_nodemax = (((env->me_psize - PAGEHDRSZ) / MDB_MINKEYS) & -2)+		- sizeof(indx_t);+#if !(MDB_MAXKEYSIZE)+	env->me_maxkey = env->me_nodemax - (NODESIZE + sizeof(MDB_db));+#endif+	env->me_maxpg = env->me_mapsize / env->me_psize;++#if MDB_DEBUG+	{+		MDB_meta *meta = mdb_env_pick_meta(env);+		MDB_db *db = &meta->mm_dbs[MAIN_DBI];++		DPRINTF(("opened database version %u, pagesize %u",+			meta->mm_version, env->me_psize));+		DPRINTF(("using meta page %d",    (int) (meta->mm_txnid & 1)));+		DPRINTF(("depth: %u",             db->md_depth));+		DPRINTF(("entries: %"Z"u",        db->md_entries));+		DPRINTF(("branch pages: %"Z"u",   db->md_branch_pages));+		DPRINTF(("leaf pages: %"Z"u",     db->md_leaf_pages));+		DPRINTF(("overflow pages: %"Z"u", db->md_overflow_pages));+		DPRINTF(("root: %"Z"u",           db->md_root));+	}+#endif++	return MDB_SUCCESS;+}+++/** Release a reader thread's slot in the reader lock table.+ *	This function is called automatically when a thread exits.+ * @param[in] ptr This points to the slot in the reader lock table.+ */+static void+mdb_env_reader_dest(void *ptr)+{+	MDB_reader *reader = ptr;++#ifndef _WIN32+	if (reader->mr_pid == getpid()) /* catch pthread_exit() in child process */+#endif+		/* We omit the mutex, so do this atomically (i.e. skip mr_txnid) */+		reader->mr_pid = 0;+}++#ifdef _WIN32+/** Junk for arranging thread-specific callbacks on Windows. This is+ *	necessarily platform and compiler-specific. Windows supports up+ *	to 1088 keys. Let's assume nobody opens more than 64 environments+ *	in a single process, for now. They can override this if needed.+ */+#ifndef MAX_TLS_KEYS+#define MAX_TLS_KEYS	64+#endif+static pthread_key_t mdb_tls_keys[MAX_TLS_KEYS];+static int mdb_tls_nkeys;++static void NTAPI mdb_tls_callback(PVOID module, DWORD reason, PVOID ptr)+{+	int i;+	switch(reason) {+	case DLL_PROCESS_ATTACH: break;+	case DLL_THREAD_ATTACH: break;+	case DLL_THREAD_DETACH:+		for (i=0; i<mdb_tls_nkeys; i++) {+			MDB_reader *r = pthread_getspecific(mdb_tls_keys[i]);+			if (r) {+				mdb_env_reader_dest(r);+			}+		}+		break;+	case DLL_PROCESS_DETACH: break;+	}+}+#ifdef __GNUC__+#ifdef _WIN64+const PIMAGE_TLS_CALLBACK mdb_tls_cbp __attribute__((section (".CRT$XLB"))) = mdb_tls_callback;+#else+PIMAGE_TLS_CALLBACK mdb_tls_cbp __attribute__((section (".CRT$XLB"))) = mdb_tls_callback;+#endif+#else+#ifdef _WIN64+/* Force some symbol references.+ *	_tls_used forces the linker to create the TLS directory if not already done+ *	mdb_tls_cbp prevents whole-program-optimizer from dropping the symbol.+ */+#pragma comment(linker, "/INCLUDE:_tls_used")+#pragma comment(linker, "/INCLUDE:mdb_tls_cbp")+#pragma const_seg(".CRT$XLB")+extern const PIMAGE_TLS_CALLBACK mdb_tls_cbp;+const PIMAGE_TLS_CALLBACK mdb_tls_cbp = mdb_tls_callback;+#pragma const_seg()+#else	/* _WIN32 */+#pragma comment(linker, "/INCLUDE:__tls_used")+#pragma comment(linker, "/INCLUDE:_mdb_tls_cbp")+#pragma data_seg(".CRT$XLB")+PIMAGE_TLS_CALLBACK mdb_tls_cbp = mdb_tls_callback;+#pragma data_seg()+#endif	/* WIN 32/64 */+#endif	/* !__GNUC__ */+#endif++/** Downgrade the exclusive lock on the region back to shared */+static int ESECT+mdb_env_share_locks(MDB_env *env, int *excl)+{+	int rc = 0;+	MDB_meta *meta = mdb_env_pick_meta(env);++	env->me_txns->mti_txnid = meta->mm_txnid;++#ifdef _WIN32+	{+		OVERLAPPED ov;+		/* First acquire a shared lock. The Unlock will+		 * then release the existing exclusive lock.+		 */+		memset(&ov, 0, sizeof(ov));+		if (!LockFileEx(env->me_lfd, 0, 0, 1, 0, &ov)) {+			rc = ErrCode();+		} else {+			UnlockFile(env->me_lfd, 0, 0, 1, 0);+			*excl = 0;+		}+	}+#else+	{+		struct flock lock_info;+		/* The shared lock replaces the existing lock */+		memset((void *)&lock_info, 0, sizeof(lock_info));+		lock_info.l_type = F_RDLCK;+		lock_info.l_whence = SEEK_SET;+		lock_info.l_start = 0;+		lock_info.l_len = 1;+		while ((rc = fcntl(env->me_lfd, F_SETLK, &lock_info)) &&+				(rc = ErrCode()) == EINTR) ;+		*excl = rc ? -1 : 0;	/* error may mean we lost the lock */+	}+#endif++	return rc;+}++/** Try to get exclusive lock, otherwise shared.+ *	Maintain *excl = -1: no/unknown lock, 0: shared, 1: exclusive.+ */+static int ESECT+mdb_env_excl_lock(MDB_env *env, int *excl)+{+	int rc = 0;+#ifdef _WIN32+	if (LockFile(env->me_lfd, 0, 0, 1, 0)) {+		*excl = 1;+	} else {+		OVERLAPPED ov;+		memset(&ov, 0, sizeof(ov));+		if (LockFileEx(env->me_lfd, 0, 0, 1, 0, &ov)) {+			*excl = 0;+		} else {+			rc = ErrCode();+		}+	}+#else+	struct flock lock_info;+	memset((void *)&lock_info, 0, sizeof(lock_info));+	lock_info.l_type = F_WRLCK;+	lock_info.l_whence = SEEK_SET;+	lock_info.l_start = 0;+	lock_info.l_len = 1;+	while ((rc = fcntl(env->me_lfd, F_SETLK, &lock_info)) &&+			(rc = ErrCode()) == EINTR) ;+	if (!rc) {+		*excl = 1;+	} else+# ifndef MDB_USE_POSIX_MUTEX+	if (*excl < 0) /* always true when MDB_USE_POSIX_MUTEX */+# endif+	{+		lock_info.l_type = F_RDLCK;+		while ((rc = fcntl(env->me_lfd, F_SETLKW, &lock_info)) &&+				(rc = ErrCode()) == EINTR) ;+		if (rc == 0)+			*excl = 0;+	}+#endif+	return rc;+}++#ifdef MDB_USE_HASH+/*+ * hash_64 - 64 bit Fowler/Noll/Vo-0 FNV-1a hash code+ *+ * @(#) $Revision: 5.1 $+ * @(#) $Id: hash_64a.c,v 5.1 2009/06/30 09:01:38 chongo Exp $+ * @(#) $Source: /usr/local/src/cmd/fnv/RCS/hash_64a.c,v $+ *+ *	  http://www.isthe.com/chongo/tech/comp/fnv/index.html+ *+ ***+ *+ * Please do not copyright this code.  This code is in the public domain.+ *+ * LANDON CURT NOLL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,+ * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO+ * EVENT SHALL LANDON CURT NOLL BE LIABLE FOR ANY SPECIAL, 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.+ *+ * By:+ *	chongo <Landon Curt Noll> /\oo/\+ *	  http://www.isthe.com/chongo/+ *+ * Share and Enjoy!	:-)+ */++typedef unsigned long long	mdb_hash_t;+#define MDB_HASH_INIT ((mdb_hash_t)0xcbf29ce484222325ULL)++/** perform a 64 bit Fowler/Noll/Vo FNV-1a hash on a buffer+ * @param[in] val	value to hash+ * @param[in] hval	initial value for hash+ * @return 64 bit hash+ *+ * NOTE: To use the recommended 64 bit FNV-1a hash, use MDB_HASH_INIT as the+ * 	 hval arg on the first call.+ */+static mdb_hash_t+mdb_hash_val(MDB_val *val, mdb_hash_t hval)+{+	unsigned char *s = (unsigned char *)val->mv_data;	/* unsigned string */+	unsigned char *end = s + val->mv_size;+	/*+	 * FNV-1a hash each octet of the string+	 */+	while (s < end) {+		/* xor the bottom with the current octet */+		hval ^= (mdb_hash_t)*s++;++		/* multiply by the 64 bit FNV magic prime mod 2^64 */+		hval += (hval << 1) + (hval << 4) + (hval << 5) ++			(hval << 7) + (hval << 8) + (hval << 40);+	}+	/* return our new hash value */+	return hval;+}++/** Hash the string and output the encoded hash.+ * This uses modified RFC1924 Ascii85 encoding to accommodate systems with+ * very short name limits. We don't care about the encoding being reversible,+ * we just want to preserve as many bits of the input as possible in a+ * small printable string.+ * @param[in] str string to hash+ * @param[out] encbuf an array of 11 chars to hold the hash+ */+static const char mdb_a85[]= "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz!#$%&()*+-;<=>?@^_`{|}~";++static void ESECT+mdb_pack85(unsigned long l, char *out)+{+	int i;++	for (i=0; i<5; i++) {+		*out++ = mdb_a85[l % 85];+		l /= 85;+	}+}++static void ESECT+mdb_hash_enc(MDB_val *val, char *encbuf)+{+	mdb_hash_t h = mdb_hash_val(val, MDB_HASH_INIT);++	mdb_pack85(h, encbuf);+	mdb_pack85(h>>32, encbuf+5);+	encbuf[10] = '\0';+}+#endif++/** Open and/or initialize the lock region for the environment.+ * @param[in] env The LMDB environment.+ * @param[in] fname Filename + scratch area, from #mdb_fname_init().+ * @param[in] mode The Unix permissions for the file, if we create it.+ * @param[in,out] excl In -1, out lock type: -1 none, 0 shared, 1 exclusive+ * @return 0 on success, non-zero on failure.+ */+static int ESECT+mdb_env_setup_locks(MDB_env *env, MDB_name *fname, int mode, int *excl)+{+#ifdef _WIN32+#	define MDB_ERRCODE_ROFS	ERROR_WRITE_PROTECT+#else+#	define MDB_ERRCODE_ROFS	EROFS+#endif+	int rc;+	off_t size, rsize;++	rc = mdb_fopen(env, fname, MDB_O_LOCKS, mode, &env->me_lfd);+	if (rc) {+		/* Omit lockfile if read-only env on read-only filesystem */+		if (rc == MDB_ERRCODE_ROFS && (env->me_flags & MDB_RDONLY)) {+			return MDB_SUCCESS;+		}+		goto fail;+	}++	if (!(env->me_flags & MDB_NOTLS)) {+		rc = pthread_key_create(&env->me_txkey, mdb_env_reader_dest);+		if (rc)+			goto fail;+		env->me_flags |= MDB_ENV_TXKEY;+#ifdef _WIN32+		/* Windows TLS callbacks need help finding their TLS info. */+		if (mdb_tls_nkeys >= MAX_TLS_KEYS) {+			rc = MDB_TLS_FULL;+			goto fail;+		}+		mdb_tls_keys[mdb_tls_nkeys++] = env->me_txkey;+#endif+	}++	/* Try to get exclusive lock. If we succeed, then+	 * nobody is using the lock region and we should initialize it.+	 */+	if ((rc = mdb_env_excl_lock(env, excl))) goto fail;++#ifdef _WIN32+	size = GetFileSize(env->me_lfd, NULL);+#else+	size = lseek(env->me_lfd, 0, SEEK_END);+	if (size == -1) goto fail_errno;+#endif+	rsize = (env->me_maxreaders-1) * sizeof(MDB_reader) + sizeof(MDB_txninfo);+	if (size < rsize && *excl > 0) {+#ifdef _WIN32+		if (SetFilePointer(env->me_lfd, rsize, NULL, FILE_BEGIN) != (DWORD)rsize+			|| !SetEndOfFile(env->me_lfd))+			goto fail_errno;+#else+		if (ftruncate(env->me_lfd, rsize) != 0) goto fail_errno;+#endif+	} else {+		rsize = size;+		size = rsize - sizeof(MDB_txninfo);+		env->me_maxreaders = size/sizeof(MDB_reader) + 1;+	}+	{+#ifdef _WIN32+		HANDLE mh;+		mh = CreateFileMapping(env->me_lfd, NULL, PAGE_READWRITE,+			0, 0, NULL);+		if (!mh) goto fail_errno;+		env->me_txns = MapViewOfFileEx(mh, FILE_MAP_WRITE, 0, 0, rsize, NULL);+		CloseHandle(mh);+		if (!env->me_txns) goto fail_errno;+#else+		void *m = mmap(NULL, rsize, PROT_READ|PROT_WRITE, MAP_SHARED,+			env->me_lfd, 0);+		if (m == MAP_FAILED) goto fail_errno;+		env->me_txns = m;+#endif+	}+	if (*excl > 0) {+#ifdef _WIN32+		BY_HANDLE_FILE_INFORMATION stbuf;+		struct {+			DWORD volume;+			DWORD nhigh;+			DWORD nlow;+		} idbuf;+		MDB_val val;+		char encbuf[11];++		if (!mdb_sec_inited) {+			InitializeSecurityDescriptor(&mdb_null_sd,+				SECURITY_DESCRIPTOR_REVISION);+			SetSecurityDescriptorDacl(&mdb_null_sd, TRUE, 0, FALSE);+			mdb_all_sa.nLength = sizeof(SECURITY_ATTRIBUTES);+			mdb_all_sa.bInheritHandle = FALSE;+			mdb_all_sa.lpSecurityDescriptor = &mdb_null_sd;+			mdb_sec_inited = 1;+		}+		if (!GetFileInformationByHandle(env->me_lfd, &stbuf)) goto fail_errno;+		idbuf.volume = stbuf.dwVolumeSerialNumber;+		idbuf.nhigh  = stbuf.nFileIndexHigh;+		idbuf.nlow   = stbuf.nFileIndexLow;+		val.mv_data = &idbuf;+		val.mv_size = sizeof(idbuf);+		mdb_hash_enc(&val, encbuf);+		sprintf(env->me_txns->mti_rmname, "Global\\MDBr%s", encbuf);+		sprintf(env->me_txns->mti_wmname, "Global\\MDBw%s", encbuf);+		env->me_rmutex = CreateMutexA(&mdb_all_sa, FALSE, env->me_txns->mti_rmname);+		if (!env->me_rmutex) goto fail_errno;+		env->me_wmutex = CreateMutexA(&mdb_all_sa, FALSE, env->me_txns->mti_wmname);+		if (!env->me_wmutex) goto fail_errno;+#elif defined(MDB_USE_POSIX_SEM)+		struct stat stbuf;+		struct {+			dev_t dev;+			ino_t ino;+		} idbuf;+		MDB_val val;+		char encbuf[11];++#if defined(__NetBSD__)+#define	MDB_SHORT_SEMNAMES	1	/* limited to 14 chars */+#endif+		if (fstat(env->me_lfd, &stbuf)) goto fail_errno;+		idbuf.dev = stbuf.st_dev;+		idbuf.ino = stbuf.st_ino;+		val.mv_data = &idbuf;+		val.mv_size = sizeof(idbuf);+		mdb_hash_enc(&val, encbuf);+#ifdef MDB_SHORT_SEMNAMES+		encbuf[9] = '\0';	/* drop name from 15 chars to 14 chars */+#endif+		sprintf(env->me_txns->mti_rmname, "/MDBr%s", encbuf);+		sprintf(env->me_txns->mti_wmname, "/MDBw%s", encbuf);+		/* Clean up after a previous run, if needed:  Try to+		 * remove both semaphores before doing anything else.+		 */+		sem_unlink(env->me_txns->mti_rmname);+		sem_unlink(env->me_txns->mti_wmname);+		env->me_rmutex = sem_open(env->me_txns->mti_rmname,+			O_CREAT|O_EXCL, mode, 1);+		if (env->me_rmutex == SEM_FAILED) goto fail_errno;+		env->me_wmutex = sem_open(env->me_txns->mti_wmname,+			O_CREAT|O_EXCL, mode, 1);+		if (env->me_wmutex == SEM_FAILED) goto fail_errno;+#else	/* MDB_USE_POSIX_MUTEX: */+		pthread_mutexattr_t mattr;++		/* Solaris needs this before initing a robust mutex.  Otherwise+		 * it may skip the init and return EBUSY "seems someone already+		 * inited" or EINVAL "it was inited differently".+		 */+		memset(env->me_txns->mti_rmutex, 0, sizeof(*env->me_txns->mti_rmutex));+		memset(env->me_txns->mti_wmutex, 0, sizeof(*env->me_txns->mti_wmutex));++		if ((rc = pthread_mutexattr_init(&mattr)))+			goto fail;++		rc = pthread_mutexattr_setpshared(&mattr, PTHREAD_PROCESS_SHARED);+#ifdef MDB_ROBUST_SUPPORTED+		if (!rc) rc = pthread_mutexattr_setrobust(&mattr, PTHREAD_MUTEX_ROBUST);+#endif+		if (!rc) rc = pthread_mutex_init(env->me_txns->mti_rmutex, &mattr);+		if (!rc) rc = pthread_mutex_init(env->me_txns->mti_wmutex, &mattr);+		pthread_mutexattr_destroy(&mattr);+		if (rc)+			goto fail;+#endif	/* _WIN32 || MDB_USE_POSIX_SEM */++		env->me_txns->mti_magic = MDB_MAGIC;+		env->me_txns->mti_format = MDB_LOCK_FORMAT;+		env->me_txns->mti_txnid = 0;+		env->me_txns->mti_numreaders = 0;++	} else {+		if (env->me_txns->mti_magic != MDB_MAGIC) {+			DPUTS("lock region has invalid magic");+			rc = MDB_INVALID;+			goto fail;+		}+		if (env->me_txns->mti_format != MDB_LOCK_FORMAT) {+			DPRINTF(("lock region has format+version 0x%x, expected 0x%x",+				env->me_txns->mti_format, MDB_LOCK_FORMAT));+			rc = MDB_VERSION_MISMATCH;+			goto fail;+		}+		rc = ErrCode();+		if (rc && rc != EACCES && rc != EAGAIN) {+			goto fail;+		}+#ifdef _WIN32+		env->me_rmutex = OpenMutexA(SYNCHRONIZE, FALSE, env->me_txns->mti_rmname);+		if (!env->me_rmutex) goto fail_errno;+		env->me_wmutex = OpenMutexA(SYNCHRONIZE, FALSE, env->me_txns->mti_wmname);+		if (!env->me_wmutex) goto fail_errno;+#elif defined(MDB_USE_POSIX_SEM)+		env->me_rmutex = sem_open(env->me_txns->mti_rmname, 0);+		if (env->me_rmutex == SEM_FAILED) goto fail_errno;+		env->me_wmutex = sem_open(env->me_txns->mti_wmname, 0);+		if (env->me_wmutex == SEM_FAILED) goto fail_errno;+#endif+	}+	return MDB_SUCCESS;++fail_errno:+	rc = ErrCode();+fail:+	return rc;+}++	/** Only a subset of the @ref mdb_env flags can be changed+	 *	at runtime. Changing other flags requires closing the+	 *	environment and re-opening it with the new flags.+	 */+#define	CHANGEABLE	(MDB_NOSYNC|MDB_NOMETASYNC|MDB_MAPASYNC|MDB_NOMEMINIT)+#define	CHANGELESS	(MDB_FIXEDMAP|MDB_NOSUBDIR|MDB_RDONLY| \+	MDB_WRITEMAP|MDB_NOTLS|MDB_NOLOCK|MDB_NORDAHEAD)++#if VALID_FLAGS & PERSISTENT_FLAGS & (CHANGEABLE|CHANGELESS)+# error "Persistent DB flags & env flags overlap, but both go in mm_flags"+#endif++int ESECT+mdb_env_open(MDB_env *env, const char *path, unsigned int flags, mdb_mode_t mode)+{+	int rc, excl = -1;+	MDB_name fname;++	if (env->me_fd!=INVALID_HANDLE_VALUE || (flags & ~(CHANGEABLE|CHANGELESS)))+		return EINVAL;++	flags |= env->me_flags;++	rc = mdb_fname_init(path, flags, &fname);+	if (rc)+		return rc;++	if (flags & MDB_RDONLY) {+		/* silently ignore WRITEMAP when we're only getting read access */+		flags &= ~MDB_WRITEMAP;+	} else {+		if (!((env->me_free_pgs = mdb_midl_alloc(MDB_IDL_UM_MAX)) &&+			  (env->me_dirty_list = calloc(MDB_IDL_UM_SIZE, sizeof(MDB_ID2)))))+			rc = ENOMEM;+	}+	env->me_flags = flags |= MDB_ENV_ACTIVE;+	if (rc)+		goto leave;++	env->me_path = strdup(path);+	env->me_dbxs = calloc(env->me_maxdbs, sizeof(MDB_dbx));+	env->me_dbflags = calloc(env->me_maxdbs, sizeof(uint16_t));+	env->me_dbiseqs = calloc(env->me_maxdbs, sizeof(unsigned int));+	if (!(env->me_dbxs && env->me_path && env->me_dbflags && env->me_dbiseqs)) {+		rc = ENOMEM;+		goto leave;+	}+	env->me_dbxs[FREE_DBI].md_cmp = mdb_cmp_long; /* aligned MDB_INTEGERKEY */++	/* For RDONLY, get lockfile after we know datafile exists */+	if (!(flags & (MDB_RDONLY|MDB_NOLOCK))) {+		rc = mdb_env_setup_locks(env, &fname, mode, &excl);+		if (rc)+			goto leave;+	}++	rc = mdb_fopen(env, &fname,+		(flags & MDB_RDONLY) ? MDB_O_RDONLY : MDB_O_RDWR,+		mode, &env->me_fd);+	if (rc)+		goto leave;++	if ((flags & (MDB_RDONLY|MDB_NOLOCK)) == MDB_RDONLY) {+		rc = mdb_env_setup_locks(env, &fname, mode, &excl);+		if (rc)+			goto leave;+	}++	if ((rc = mdb_env_open2(env)) == MDB_SUCCESS) {+		if (!(flags & (MDB_RDONLY|MDB_WRITEMAP))) {+			/* Synchronous fd for meta writes. Needed even with+			 * MDB_NOSYNC/MDB_NOMETASYNC, in case these get reset.+			 */+			rc = mdb_fopen(env, &fname, MDB_O_META, mode, &env->me_mfd);+			if (rc)+				goto leave;+		}+		DPRINTF(("opened dbenv %p", (void *) env));+		if (excl > 0) {+			rc = mdb_env_share_locks(env, &excl);+			if (rc)+				goto leave;+		}+		if (!(flags & MDB_RDONLY)) {+			MDB_txn *txn;+			int tsize = sizeof(MDB_txn), size = tsize + env->me_maxdbs *+				(sizeof(MDB_db)+sizeof(MDB_cursor *)+sizeof(unsigned int)+1);+			if ((env->me_pbuf = calloc(1, env->me_psize)) &&+				(txn = calloc(1, size)))+			{+				txn->mt_dbs = (MDB_db *)((char *)txn + tsize);+				txn->mt_cursors = (MDB_cursor **)(txn->mt_dbs + env->me_maxdbs);+				txn->mt_dbiseqs = (unsigned int *)(txn->mt_cursors + env->me_maxdbs);+				txn->mt_dbflags = (unsigned char *)(txn->mt_dbiseqs + env->me_maxdbs);+				txn->mt_env = env;+				txn->mt_dbxs = env->me_dbxs;+				txn->mt_flags = MDB_TXN_FINISHED;+				env->me_txn0 = txn;+			} else {+				rc = ENOMEM;+			}+		}+	}++leave:+	MDB_TRACE(("%p, %s, %u, %04o", env, path, flags & (CHANGEABLE|CHANGELESS), mode));+	if (rc) {+		mdb_env_close0(env, excl);+	}+	mdb_fname_destroy(fname);+	return rc;+}++/** Destroy resources from mdb_env_open(), clear our readers & DBIs */+static void ESECT+mdb_env_close0(MDB_env *env, int excl)+{+	int i;++	if (!(env->me_flags & MDB_ENV_ACTIVE))+		return;++	/* Doing this here since me_dbxs may not exist during mdb_env_close */+	if (env->me_dbxs) {+		for (i = env->me_maxdbs; --i >= CORE_DBS; )+			free(env->me_dbxs[i].md_name.mv_data);+		free(env->me_dbxs);+	}++	free(env->me_pbuf);+	free(env->me_dbiseqs);+	free(env->me_dbflags);+	free(env->me_path);+	free(env->me_dirty_list);+	free(env->me_txn0);+	mdb_midl_free(env->me_free_pgs);++	if (env->me_flags & MDB_ENV_TXKEY) {+		pthread_key_delete(env->me_txkey);+#ifdef _WIN32+		/* Delete our key from the global list */+		for (i=0; i<mdb_tls_nkeys; i++)+			if (mdb_tls_keys[i] == env->me_txkey) {+				mdb_tls_keys[i] = mdb_tls_keys[mdb_tls_nkeys-1];+				mdb_tls_nkeys--;+				break;+			}+#endif+	}++	if (env->me_map) {+		munmap(env->me_map, env->me_mapsize);+	}+	if (env->me_mfd != INVALID_HANDLE_VALUE)+		(void) close(env->me_mfd);+	if (env->me_fd != INVALID_HANDLE_VALUE)+		(void) close(env->me_fd);+	if (env->me_txns) {+		MDB_PID_T pid = getpid();+		/* Clearing readers is done in this function because+		 * me_txkey with its destructor must be disabled first.+		 *+		 * We skip the the reader mutex, so we touch only+		 * data owned by this process (me_close_readers and+		 * our readers), and clear each reader atomically.+		 */+		for (i = env->me_close_readers; --i >= 0; )+			if (env->me_txns->mti_readers[i].mr_pid == pid)+				env->me_txns->mti_readers[i].mr_pid = 0;+#ifdef _WIN32+		if (env->me_rmutex) {+			CloseHandle(env->me_rmutex);+			if (env->me_wmutex) CloseHandle(env->me_wmutex);+		}+		/* Windows automatically destroys the mutexes when+		 * the last handle closes.+		 */+#elif defined(MDB_USE_POSIX_SEM)+		if (env->me_rmutex != SEM_FAILED) {+			sem_close(env->me_rmutex);+			if (env->me_wmutex != SEM_FAILED)+				sem_close(env->me_wmutex);+			/* If we have the filelock:  If we are the+			 * only remaining user, clean up semaphores.+			 */+			if (excl == 0)+				mdb_env_excl_lock(env, &excl);+			if (excl > 0) {+				sem_unlink(env->me_txns->mti_rmname);+				sem_unlink(env->me_txns->mti_wmname);+			}+		}+#endif+		munmap((void *)env->me_txns, (env->me_maxreaders-1)*sizeof(MDB_reader)+sizeof(MDB_txninfo));+	}+	if (env->me_lfd != INVALID_HANDLE_VALUE) {+#ifdef _WIN32+		if (excl >= 0) {+			/* Unlock the lockfile.  Windows would have unlocked it+			 * after closing anyway, but not necessarily at once.+			 */+			UnlockFile(env->me_lfd, 0, 0, 1, 0);+		}+#endif+		(void) close(env->me_lfd);+	}++	env->me_flags &= ~(MDB_ENV_ACTIVE|MDB_ENV_TXKEY);+}++void ESECT+mdb_env_close(MDB_env *env)+{+	MDB_page *dp;++	if (env == NULL)+		return;++	MDB_TRACE(("%p", env));+	VGMEMP_DESTROY(env);+	while ((dp = env->me_dpages) != NULL) {+		VGMEMP_DEFINED(&dp->mp_next, sizeof(dp->mp_next));+		env->me_dpages = dp->mp_next;+		free(dp);+	}++	mdb_env_close0(env, 0);+	free(env);+}++/** Compare two items pointing at aligned size_t's */+static int+mdb_cmp_long(const MDB_val *a, const MDB_val *b)+{+	return (*(size_t *)a->mv_data < *(size_t *)b->mv_data) ? -1 :+		*(size_t *)a->mv_data > *(size_t *)b->mv_data;+}++/** Compare two items pointing at aligned unsigned int's.+ *+ *	This is also set as #MDB_INTEGERDUP|#MDB_DUPFIXED's #MDB_dbx.%md_dcmp,+ *	but #mdb_cmp_clong() is called instead if the data type is size_t.+ */+static int+mdb_cmp_int(const MDB_val *a, const MDB_val *b)+{+	return (*(unsigned int *)a->mv_data < *(unsigned int *)b->mv_data) ? -1 :+		*(unsigned int *)a->mv_data > *(unsigned int *)b->mv_data;+}++/** Compare two items pointing at unsigned ints of unknown alignment.+ *	Nodes and keys are guaranteed to be 2-byte aligned.+ */+static int+mdb_cmp_cint(const MDB_val *a, const MDB_val *b)+{+#if BYTE_ORDER == LITTLE_ENDIAN+	unsigned short *u, *c;+	int x;++	u = (unsigned short *) ((char *) a->mv_data + a->mv_size);+	c = (unsigned short *) ((char *) b->mv_data + a->mv_size);+	do {+		x = *--u - *--c;+	} while(!x && u > (unsigned short *)a->mv_data);+	return x;+#else+	unsigned short *u, *c, *end;+	int x;++	end = (unsigned short *) ((char *) a->mv_data + a->mv_size);+	u = (unsigned short *)a->mv_data;+	c = (unsigned short *)b->mv_data;+	do {+		x = *u++ - *c++;+	} while(!x && u < end);+	return x;+#endif+}++/** Compare two items lexically */+static int+mdb_cmp_memn(const MDB_val *a, const MDB_val *b)+{+	int diff;+	ssize_t len_diff;+	unsigned int len;++	len = a->mv_size;+	len_diff = (ssize_t) a->mv_size - (ssize_t) b->mv_size;+	if (len_diff > 0) {+		len = b->mv_size;+		len_diff = 1;+	}++	diff = memcmp(a->mv_data, b->mv_data, len);+	return diff ? diff : len_diff<0 ? -1 : len_diff;+}++/** Compare two items in reverse byte order */+static int+mdb_cmp_memnr(const MDB_val *a, const MDB_val *b)+{+	const unsigned char	*p1, *p2, *p1_lim;+	ssize_t len_diff;+	int diff;++	p1_lim = (const unsigned char *)a->mv_data;+	p1 = (const unsigned char *)a->mv_data + a->mv_size;+	p2 = (const unsigned char *)b->mv_data + b->mv_size;++	len_diff = (ssize_t) a->mv_size - (ssize_t) b->mv_size;+	if (len_diff > 0) {+		p1_lim += len_diff;+		len_diff = 1;+	}++	while (p1 > p1_lim) {+		diff = *--p1 - *--p2;+		if (diff)+			return diff;+	}+	return len_diff<0 ? -1 : len_diff;+}++/** 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 MDB_node *+mdb_node_search(MDB_cursor *mc, MDB_val *key, int *exactp)+{+	unsigned int	 i = 0, nkeys;+	int		 low, high;+	int		 rc = 0;+	MDB_page *mp = mc->mc_pg[mc->mc_top];+	MDB_node	*node = NULL;+	MDB_val	 nodekey;+	MDB_cmp_func *cmp;+	DKBUF;++	nkeys = NUMKEYS(mp);++	DPRINTF(("searching %u keys in %s %spage %"Z"u",+	    nkeys, IS_LEAF(mp) ? "leaf" : "branch", IS_SUBP(mp) ? "sub-" : "",+	    mdb_dbg_pgno(mp)));++	low = IS_LEAF(mp) ? 0 : 1;+	high = nkeys - 1;+	cmp = mc->mc_dbx->md_cmp;++	/* Branch pages have no data, so if using integer keys,+	 * alignment is guaranteed. Use faster mdb_cmp_int.+	 */+	if (cmp == mdb_cmp_cint && IS_BRANCH(mp)) {+		if (NODEPTR(mp, 1)->mn_ksize == sizeof(size_t))+			cmp = mdb_cmp_long;+		else+			cmp = mdb_cmp_int;+	}++	if (IS_LEAF2(mp)) {+		nodekey.mv_size = mc->mc_db->md_pad;+		node = NODEPTR(mp, 0);	/* fake */+		while (low <= high) {+			i = (low + high) >> 1;+			nodekey.mv_data = LEAF2KEY(mp, i, nodekey.mv_size);+			rc = cmp(key, &nodekey);+			DPRINTF(("found leaf index %u [%s], rc = %i",+			    i, DKEY(&nodekey), rc));+			if (rc == 0)+				break;+			if (rc > 0)+				low = i + 1;+			else+				high = i - 1;+		}+	} else {+		while (low <= high) {+			i = (low + high) >> 1;++			node = NODEPTR(mp, i);+			nodekey.mv_size = NODEKSZ(node);+			nodekey.mv_data = NODEKEY(node);++			rc = cmp(key, &nodekey);+#if MDB_DEBUG+			if (IS_LEAF(mp))+				DPRINTF(("found leaf index %u [%s], rc = %i",+				    i, DKEY(&nodekey), rc));+			else+				DPRINTF(("found branch index %u [%s -> %"Z"u], rc = %i",+				    i, DKEY(&nodekey), NODEPGNO(node), rc));+#endif+			if (rc == 0)+				break;+			if (rc > 0)+				low = i + 1;+			else+				high = i - 1;+		}+	}++	if (rc > 0) {	/* Found entry is less than the key. */+		i++;	/* Skip to get the smallest entry larger than key. */+		if (!IS_LEAF2(mp))+			node = NODEPTR(mp, i);+	}+	if (exactp)+		*exactp = (rc == 0 && nkeys > 0);+	/* store the key index */+	mc->mc_ki[mc->mc_top] = i;+	if (i >= nkeys)+		/* There is no entry larger or equal to the key. */+		return NULL;++	/* nodeptr is fake for LEAF2 */+	return node;+}++#if 0+static void+mdb_cursor_adjust(MDB_cursor *mc, func)+{+	MDB_cursor *m2;++	for (m2 = mc->mc_txn->mt_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 void+mdb_cursor_pop(MDB_cursor *mc)+{+	if (mc->mc_snum) {+		DPRINTF(("popping page %"Z"u off db %d cursor %p",+			mc->mc_pg[mc->mc_top]->mp_pgno, DDBI(mc), (void *) mc));++		mc->mc_snum--;+		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 #MDB_TXN_ERROR on failure.+ */+static int+mdb_cursor_push(MDB_cursor *mc, MDB_page *mp)+{+	DPRINTF(("pushing page %"Z"u on db %d cursor %p", mp->mp_pgno,+		DDBI(mc), (void *) mc));++	if (mc->mc_snum >= CURSOR_STACK) {+		mc->mc_txn->mt_flags |= MDB_TXN_ERROR;+		return MDB_CURSOR_FULL;+	}++	mc->mc_top = mc->mc_snum++;+	mc->mc_pg[mc->mc_top] = mp;+	mc->mc_ki[mc->mc_top] = 0;++	return MDB_SUCCESS;+}++/** Find the address of the page corresponding to a given page number.+ * Set #MDB_TXN_ERROR on failure.+ * @param[in] mc the cursor accessing the page.+ * @param[in] pgno the page number for the page to retrieve.+ * @param[out] ret address of a pointer where the page's address will be stored.+ * @param[out] lvl dirty_list inheritance level of found page. 1=current txn, 0=mapped page.+ * @return 0 on success, non-zero on failure.+ */+static int+mdb_page_get(MDB_cursor *mc, pgno_t pgno, MDB_page **ret, int *lvl)+{+	MDB_txn *txn = mc->mc_txn;+	MDB_env *env = txn->mt_env;+	MDB_page *p = NULL;+	int level;++	if (! (txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_WRITEMAP))) {+		MDB_txn *tx2 = txn;+		level = 1;+		do {+			MDB_ID2L dl = tx2->mt_u.dirty_list;+			unsigned x;+			/* 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 (tx2->mt_spill_pgs) {+				MDB_ID pn = pgno << 1;+				x = mdb_midl_search(tx2->mt_spill_pgs, pn);+				if (x <= tx2->mt_spill_pgs[0] && tx2->mt_spill_pgs[x] == pn) {+					p = (MDB_page *)(env->me_map + env->me_psize * pgno);+					goto done;+				}+			}+			if (dl[0].mid) {+				unsigned x = mdb_mid2l_search(dl, pgno);+				if (x <= dl[0].mid && dl[x].mid == pgno) {+					p = dl[x].mptr;+					goto done;+				}+			}+			level++;+		} while ((tx2 = tx2->mt_parent) != NULL);+	}++	if (pgno < txn->mt_next_pgno) {+		level = 0;+		p = (MDB_page *)(env->me_map + env->me_psize * pgno);+	} else {+		DPRINTF(("page %"Z"u not found", pgno));+		txn->mt_flags |= MDB_TXN_ERROR;+		return MDB_PAGE_NOTFOUND;+	}++done:+	*ret = p;+	if (lvl)+		*lvl = level;+	return MDB_SUCCESS;+}++/** Finish #mdb_page_search() / #mdb_page_search_lowest().+ *	The cursor is at the root page, set up the rest of it.+ */+static int+mdb_page_search_root(MDB_cursor *mc, MDB_val *key, int flags)+{+	MDB_page	*mp = mc->mc_pg[mc->mc_top];+	int rc;+	DKBUF;++	while (IS_BRANCH(mp)) {+		MDB_node	*node;+		indx_t		i;++		DPRINTF(("branch page %"Z"u has %u keys", mp->mp_pgno, NUMKEYS(mp)));+		/* Don't assert on branch pages in the FreeDB. We can get here+		 * while in the process of rebalancing a FreeDB branch page; we must+		 * let that proceed. ITS#8336+		 */+		mdb_cassert(mc, !mc->mc_dbi || NUMKEYS(mp) > 1);+		DPRINTF(("found index 0 to page %"Z"u", NODEPGNO(NODEPTR(mp, 0))));++		if (flags & (MDB_PS_FIRST|MDB_PS_LAST)) {+			i = 0;+			if (flags & MDB_PS_LAST) {+				i = 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 = mdb_node_search(mc, key, &exact);+			if (node == NULL)+				i = NUMKEYS(mp) - 1;+			else {+				i = mc->mc_ki[mc->mc_top];+				if (!exact) {+					mdb_cassert(mc, i > 0);+					i--;+				}+			}+			DPRINTF(("following index %u for key [%s]", i, DKEY(key)));+		}++		mdb_cassert(mc, i < NUMKEYS(mp));+		node = NODEPTR(mp, i);++		if ((rc = mdb_page_get(mc, NODEPGNO(node), &mp, NULL)) != 0)+			return rc;++		mc->mc_ki[mc->mc_top] = i;+		if ((rc = mdb_cursor_push(mc, mp)))+			return rc;++ready:+		if (flags & MDB_PS_MODIFY) {+			if ((rc = mdb_page_touch(mc)) != 0)+				return rc;+			mp = mc->mc_pg[mc->mc_top];+		}+	}++	if (!IS_LEAF(mp)) {+		DPRINTF(("internal error, index points to a %02X page!?",+		    mp->mp_flags));+		mc->mc_txn->mt_flags |= MDB_TXN_ERROR;+		return MDB_CORRUPTED;+	}++	DPRINTF(("found leaf page %"Z"u for key [%s]", mp->mp_pgno,+	    key ? DKEY(key) : "null"));+	mc->mc_flags |= C_INITIALIZED;+	mc->mc_flags &= ~C_EOF;++	return MDB_SUCCESS;+}++/** Search for the lowest key under the current branch page.+ * This just bypasses a NUMKEYS check in the current page+ * before calling mdb_page_search_root(), because the callers+ * are all in situations where the current page is known to+ * be underfilled.+ */+static int+mdb_page_search_lowest(MDB_cursor *mc)+{+	MDB_page	*mp = mc->mc_pg[mc->mc_top];+	MDB_node	*node = NODEPTR(mp, 0);+	int rc;++	if ((rc = mdb_page_get(mc, NODEPGNO(node), &mp, NULL)) != 0)+		return rc;++	mc->mc_ki[mc->mc_top] = 0;+	if ((rc = mdb_cursor_push(mc, mp)))+		return rc;+	return mdb_page_search_root(mc, NULL, MDB_PS_FIRST);+}++/** Search for the page a given key should be in.+ * Push it and its parent pages on the cursor stack.+ * @param[in,out] mc the cursor for this operation.+ * @param[in] key the key to search for, or NULL for first/last page.+ * @param[in] flags If MDB_PS_MODIFY is set, visited pages in the DB+ *   are touched (updated with new page numbers).+ *   If MDB_PS_FIRST or MDB_PS_LAST is set, find first or last leaf.+ *   This is used by #mdb_cursor_first() and #mdb_cursor_last().+ *   If MDB_PS_ROOTONLY set, just fetch root node, no further lookups.+ * @return 0 on success, non-zero on failure.+ */+static int+mdb_page_search(MDB_cursor *mc, MDB_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 (mc->mc_txn->mt_flags & MDB_TXN_BLOCKED) {+		DPUTS("transaction may not be used now");+		return MDB_BAD_TXN;+	} else {+		/* Make sure we're using an up-to-date root */+		if (*mc->mc_dbflag & DB_STALE) {+				MDB_cursor mc2;+				if (TXN_DBI_CHANGED(mc->mc_txn, mc->mc_dbi))+					return MDB_BAD_DBI;+				mdb_cursor_init(&mc2, mc->mc_txn, MAIN_DBI, NULL);+				rc = mdb_page_search(&mc2, &mc->mc_dbx->md_name, 0);+				if (rc)+					return rc;+				{+					MDB_val data;+					int exact = 0;+					uint16_t flags;+					MDB_node *leaf = mdb_node_search(&mc2,+						&mc->mc_dbx->md_name, &exact);+					if (!exact)+						return MDB_BAD_DBI;+					if ((leaf->mn_flags & (F_DUPDATA|F_SUBDATA)) != F_SUBDATA)+						return MDB_INCOMPATIBLE; /* not a named DB */+					rc = mdb_node_read(&mc2, leaf, &data);+					if (rc)+						return rc;+					memcpy(&flags, ((char *) data.mv_data + offsetof(MDB_db, md_flags)),+						sizeof(uint16_t));+					/* The txn may not know this DBI, or another process may+					 * have dropped and recreated the DB with other flags.+					 */+					if ((mc->mc_db->md_flags & PERSISTENT_FLAGS) != flags)+						return MDB_INCOMPATIBLE;+					memcpy(mc->mc_db, data.mv_data, sizeof(MDB_db));+				}+				*mc->mc_dbflag &= ~DB_STALE;+		}+		root = mc->mc_db->md_root;++		if (root == P_INVALID) {		/* Tree is empty. */+			DPUTS("tree is empty");+			return MDB_NOTFOUND;+		}+	}++	mdb_cassert(mc, root > 1);+	if (!mc->mc_pg[0] || mc->mc_pg[0]->mp_pgno != root)+		if ((rc = mdb_page_get(mc, root, &mc->mc_pg[0], NULL)) != 0)+			return rc;++	mc->mc_snum = 1;+	mc->mc_top = 0;++	DPRINTF(("db %d root page %"Z"u has flags 0x%X",+		DDBI(mc), root, mc->mc_pg[0]->mp_flags));++	if (flags & MDB_PS_MODIFY) {+		if ((rc = mdb_page_touch(mc)))+			return rc;+	}++	if (flags & MDB_PS_ROOTONLY)+		return MDB_SUCCESS;++	return mdb_page_search_root(mc, key, flags);+}++static int+mdb_ovpage_free(MDB_cursor *mc, MDB_page *mp)+{+	MDB_txn *txn = mc->mc_txn;+	pgno_t pg = mp->mp_pgno;+	unsigned x = 0, ovpages = mp->mp_pages;+	MDB_env *env = txn->mt_env;+	MDB_IDL sl = txn->mt_spill_pgs;+	MDB_ID pn = pg << 1;+	int rc;++	DPRINTF(("free ov page %"Z"u (%d)", pg, ovpages));+	/* If the page is dirty or on the spill list we just acquired it,+	 * so we should give it back to our current free list, if any.+	 * Otherwise put it onto the list of pages we freed in this txn.+	 *+	 * Won't create me_pghead: me_pglast must be inited along with it.+	 * Unsupported in nested txns: They would need to hide the page+	 * range in ancestor txns' dirty and spilled lists.+	 */+	if (env->me_pghead &&+		!txn->mt_parent &&+		((mp->mp_flags & P_DIRTY) ||+		 (sl && (x = mdb_midl_search(sl, pn)) <= sl[0] && sl[x] == pn)))+	{+		unsigned i, j;+		pgno_t *mop;+		MDB_ID2 *dl, ix, iy;+		rc = mdb_midl_need(&env->me_pghead, ovpages);+		if (rc)+			return rc;+		if (!(mp->mp_flags & P_DIRTY)) {+			/* This page is no longer spilled */+			if (x == sl[0])+				sl[0]--;+			else+				sl[x] |= 1;+			goto release;+		}+		/* Remove from dirty list */+		dl = txn->mt_u.dirty_list;+		x = dl[0].mid--;+		for (ix = dl[x]; ix.mptr != mp; ix = iy) {+			if (x > 1) {+				x--;+				iy = dl[x];+				dl[x] = ix;+			} else {+				mdb_cassert(mc, x > 1);+				j = ++(dl[0].mid);+				dl[j] = ix;		/* Unsorted. OK when MDB_TXN_ERROR. */+				txn->mt_flags |= MDB_TXN_ERROR;+				return MDB_CORRUPTED;+			}+		}+		txn->mt_dirty_room++;+		if (!(env->me_flags & MDB_WRITEMAP))+			mdb_dpage_free(env, mp);+release:+		/* Insert in me_pghead */+		mop = env->me_pghead;+		j = mop[0] + ovpages;+		for (i = mop[0]; i && mop[i] < pg; i--)+			mop[j--] = mop[i];+		while (j>i)+			mop[j--] = pg++;+		mop[0] += ovpages;+	} else {+		rc = mdb_midl_append_range(&txn->mt_free_pgs, pg, ovpages);+		if (rc)+			return rc;+	}+	mc->mc_db->md_overflow_pages -= ovpages;+	return 0;+}++/** Return the data associated with a given node.+ * @param[in] mc The cursor for this operation.+ * @param[in] leaf The node being read.+ * @param[out] data Updated to point to the node's data.+ * @return 0 on success, non-zero on failure.+ */+static int+mdb_node_read(MDB_cursor *mc, MDB_node *leaf, MDB_val *data)+{+	MDB_page	*omp;		/* overflow page */+	pgno_t		 pgno;+	int rc;++	if (!F_ISSET(leaf->mn_flags, F_BIGDATA)) {+		data->mv_size = NODEDSZ(leaf);+		data->mv_data = NODEDATA(leaf);+		return MDB_SUCCESS;+	}++	/* Read overflow data.+	 */+	data->mv_size = NODEDSZ(leaf);+	memcpy(&pgno, NODEDATA(leaf), sizeof(pgno));+	if ((rc = mdb_page_get(mc, pgno, &omp, NULL)) != 0) {+		DPRINTF(("read overflow page %"Z"u failed", pgno));+		return rc;+	}+	data->mv_data = METADATA(omp);++	return MDB_SUCCESS;+}++int+mdb_get(MDB_txn *txn, MDB_dbi dbi,+    MDB_val *key, MDB_val *data)+{+	MDB_cursor	mc;+	MDB_xcursor	mx;+	int exact = 0;+	DKBUF;++	DPRINTF(("===> get db %u key [%s]", dbi, DKEY(key)));++	if (!key || !data || !TXN_DBI_EXIST(txn, dbi, DB_USRVALID))+		return EINVAL;++	if (txn->mt_flags & MDB_TXN_BLOCKED)+		return MDB_BAD_TXN;++	mdb_cursor_init(&mc, txn, dbi, &mx);+	return mdb_cursor_set(&mc, key, data, MDB_SET, &exact);+}++/** Find a sibling for a page.+ * Replaces the page at the top of the cursor's stack with the+ * specified sibling, if one exists.+ * @param[in] mc The cursor for this operation.+ * @param[in] move_right Non-zero if the right sibling is requested,+ * otherwise the left sibling.+ * @return 0 on success, non-zero on failure.+ */+static int+mdb_cursor_sibling(MDB_cursor *mc, int move_right)+{+	int		 rc;+	MDB_node	*indx;+	MDB_page	*mp;++	if (mc->mc_snum < 2) {+		return MDB_NOTFOUND;		/* root has no siblings */+	}++	mdb_cursor_pop(mc);+	DPRINTF(("parent page is page %"Z"u, index %u",+		mc->mc_pg[mc->mc_top]->mp_pgno, mc->mc_ki[mc->mc_top]));++	if (move_right ? (mc->mc_ki[mc->mc_top] + 1u >= NUMKEYS(mc->mc_pg[mc->mc_top]))+		       : (mc->mc_ki[mc->mc_top] == 0)) {+		DPRINTF(("no more keys left, moving to %s sibling",+		    move_right ? "right" : "left"));+		if ((rc = mdb_cursor_sibling(mc, move_right)) != MDB_SUCCESS) {+			/* undo cursor_pop before returning */+			mc->mc_top++;+			mc->mc_snum++;+			return rc;+		}+	} else {+		if (move_right)+			mc->mc_ki[mc->mc_top]++;+		else+			mc->mc_ki[mc->mc_top]--;+		DPRINTF(("just moving to %s index key %u",+		    move_right ? "right" : "left", mc->mc_ki[mc->mc_top]));+	}+	mdb_cassert(mc, IS_BRANCH(mc->mc_pg[mc->mc_top]));++	indx = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);+	if ((rc = mdb_page_get(mc, NODEPGNO(indx), &mp, NULL)) != 0) {+		/* mc will be inconsistent if caller does mc_snum++ as above */+		mc->mc_flags &= ~(C_INITIALIZED|C_EOF);+		return rc;+	}++	mdb_cursor_push(mc, mp);+	if (!move_right)+		mc->mc_ki[mc->mc_top] = NUMKEYS(mp)-1;++	return MDB_SUCCESS;+}++/** Move the cursor to the next data item. */+static int+mdb_cursor_next(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op)+{+	MDB_page	*mp;+	MDB_node	*leaf;+	int rc;++	if ((mc->mc_flags & C_DEL && op == MDB_NEXT_DUP))+		return MDB_NOTFOUND;++	if (!(mc->mc_flags & C_INITIALIZED))+		return mdb_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] >= NUMKEYS(mp)-1)+			return MDB_NOTFOUND;+		mc->mc_flags ^= C_EOF;+	}++	if (mc->mc_db->md_flags & MDB_DUPSORT) {+		leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);+		if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {+			if (op == MDB_NEXT || op == MDB_NEXT_DUP) {+				rc = mdb_cursor_next(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_NEXT);+				if (op != MDB_NEXT || rc != MDB_NOTFOUND) {+					if (rc == MDB_SUCCESS)+						MDB_GET_KEY(leaf, key);+					return rc;+				}+			}+		} else {+			mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);+			if (op == MDB_NEXT_DUP)+				return MDB_NOTFOUND;+		}+	}++	DPRINTF(("cursor_next: top page is %"Z"u in cursor %p",+		mdb_dbg_pgno(mp), (void *) mc));+	if (mc->mc_flags & C_DEL) {+		mc->mc_flags ^= C_DEL;+		goto skip;+	}++	if (mc->mc_ki[mc->mc_top] + 1u >= NUMKEYS(mp)) {+		DPUTS("=====> move to next sibling page");+		if ((rc = mdb_cursor_sibling(mc, 1)) != MDB_SUCCESS) {+			mc->mc_flags |= C_EOF;+			return rc;+		}+		mp = mc->mc_pg[mc->mc_top];+		DPRINTF(("next page is %"Z"u, key index %u", mp->mp_pgno, mc->mc_ki[mc->mc_top]));+	} else+		mc->mc_ki[mc->mc_top]++;++skip:+	DPRINTF(("==> cursor points to page %"Z"u with %u keys, key index %u",+	    mdb_dbg_pgno(mp), NUMKEYS(mp), mc->mc_ki[mc->mc_top]));++	if (IS_LEAF2(mp)) {+		key->mv_size = mc->mc_db->md_pad;+		key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);+		return MDB_SUCCESS;+	}++	mdb_cassert(mc, IS_LEAF(mp));+	leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);++	if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {+		mdb_xcursor_init1(mc, leaf);+		rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL);+		if (rc != MDB_SUCCESS)+			return rc;+	} else if (data) {+		if ((rc = mdb_node_read(mc, leaf, data)) != MDB_SUCCESS)+			return rc;+	}++	MDB_GET_KEY(leaf, key);+	return MDB_SUCCESS;+}++/** Move the cursor to the previous data item. */+static int+mdb_cursor_prev(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op)+{+	MDB_page	*mp;+	MDB_node	*leaf;+	int rc;++	if (!(mc->mc_flags & C_INITIALIZED)) {+		rc = mdb_cursor_last(mc, key, data);+		if (rc)+			return rc;+		mc->mc_ki[mc->mc_top]++;+	}++	mp = mc->mc_pg[mc->mc_top];++	if ((mc->mc_db->md_flags & MDB_DUPSORT) &&+		mc->mc_ki[mc->mc_top] < NUMKEYS(mp)) {+		leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);+		if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {+			if (op == MDB_PREV || op == MDB_PREV_DUP) {+				rc = mdb_cursor_prev(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_PREV);+				if (op != MDB_PREV || rc != MDB_NOTFOUND) {+					if (rc == MDB_SUCCESS) {+						MDB_GET_KEY(leaf, key);+						mc->mc_flags &= ~C_EOF;+					}+					return rc;+				}+			}+		} else {+			mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);+			if (op == MDB_PREV_DUP)+				return MDB_NOTFOUND;+		}+	}++	DPRINTF(("cursor_prev: top page is %"Z"u in cursor %p",+		mdb_dbg_pgno(mp), (void *) mc));++	mc->mc_flags &= ~(C_EOF|C_DEL);++	if (mc->mc_ki[mc->mc_top] == 0)  {+		DPUTS("=====> move to prev sibling page");+		if ((rc = mdb_cursor_sibling(mc, 0)) != MDB_SUCCESS) {+			return rc;+		}+		mp = mc->mc_pg[mc->mc_top];+		mc->mc_ki[mc->mc_top] = NUMKEYS(mp) - 1;+		DPRINTF(("prev page is %"Z"u, key index %u", mp->mp_pgno, mc->mc_ki[mc->mc_top]));+	} else+		mc->mc_ki[mc->mc_top]--;++	DPRINTF(("==> cursor points to page %"Z"u with %u keys, key index %u",+	    mdb_dbg_pgno(mp), NUMKEYS(mp), mc->mc_ki[mc->mc_top]));++	if (!IS_LEAF(mp))+		return MDB_CORRUPTED;++	if (IS_LEAF2(mp)) {+		key->mv_size = mc->mc_db->md_pad;+		key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);+		return MDB_SUCCESS;+	}++	leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);++	if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {+		mdb_xcursor_init1(mc, leaf);+		rc = mdb_cursor_last(&mc->mc_xcursor->mx_cursor, data, NULL);+		if (rc != MDB_SUCCESS)+			return rc;+	} else if (data) {+		if ((rc = mdb_node_read(mc, leaf, data)) != MDB_SUCCESS)+			return rc;+	}++	MDB_GET_KEY(leaf, key);+	return MDB_SUCCESS;+}++/** Set the cursor on a specific data item. */+static int+mdb_cursor_set(MDB_cursor *mc, MDB_val *key, MDB_val *data,+    MDB_cursor_op op, int *exactp)+{+	int		 rc;+	MDB_page	*mp;+	MDB_node	*leaf = NULL;+	DKBUF;++	if (key->mv_size == 0)+		return MDB_BAD_VALSIZE;++	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) {+		MDB_val nodekey;++		mp = mc->mc_pg[mc->mc_top];+		if (!NUMKEYS(mp)) {+			mc->mc_ki[mc->mc_top] = 0;+			return MDB_NOTFOUND;+		}+		if (MP_FLAGS(mp) & P_LEAF2) {+			nodekey.mv_size = mc->mc_db->md_pad;+			nodekey.mv_data = LEAF2KEY(mp, 0, nodekey.mv_size);+		} else {+			leaf = NODEPTR(mp, 0);+			MDB_GET_KEY2(leaf, nodekey);+		}+		rc = mc->mc_dbx->md_cmp(key, &nodekey);+		if (rc == 0) {+			/* Probably happens rarely, but first node on the page+			 * was the one we wanted.+			 */+			mc->mc_ki[mc->mc_top] = 0;+			if (exactp)+				*exactp = 1;+			goto set1;+		}+		if (rc > 0) {+			unsigned int i;+			unsigned int nkeys = NUMKEYS(mp);+			if (nkeys > 1) {+				if (MP_FLAGS(mp) & P_LEAF2) {+					nodekey.mv_data = LEAF2KEY(mp,+						 nkeys-1, nodekey.mv_size);+				} else {+					leaf = NODEPTR(mp, nkeys-1);+					MDB_GET_KEY2(leaf, nodekey);+				}+				rc = mc->mc_dbx->md_cmp(key, &nodekey);+				if (rc == 0) {+					/* last node was the one we wanted */+					mc->mc_ki[mc->mc_top] = nkeys-1;+					if (exactp)+						*exactp = 1;+					goto set1;+				}+				if (rc < 0) {+					if (mc->mc_ki[mc->mc_top] < NUMKEYS(mp)) {+						/* This is definitely the right page, skip search_page */+						if (MP_FLAGS(mp) & P_LEAF2) {+							nodekey.mv_data = LEAF2KEY(mp,+								 mc->mc_ki[mc->mc_top], nodekey.mv_size);+						} else {+							leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);+							MDB_GET_KEY2(leaf, nodekey);+						}+						rc = mc->mc_dbx->md_cmp(key, &nodekey);+						if (rc == 0) {+							/* current node was the one we wanted */+							if (exactp)+								*exactp = 1;+							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] <+					NUMKEYS(mc->mc_pg[i])-1)+					break;+			if (i == mc->mc_top) {+				/* There are no other pages */+				mc->mc_ki[mc->mc_top] = nkeys;+				return MDB_NOTFOUND;+			}+		}+		if (!mc->mc_top) {+			/* There are no other pages */+			mc->mc_ki[mc->mc_top] = 0;+			if (op == MDB_SET_RANGE && !exactp) {+				rc = 0;+				goto set1;+			} else+				return MDB_NOTFOUND;+		}+	} else {+		mc->mc_pg[0] = 0;+	}++	rc = mdb_page_search(mc, key, 0);+	if (rc != MDB_SUCCESS)+		return rc;++	mp = mc->mc_pg[mc->mc_top];+	mdb_cassert(mc, IS_LEAF(mp));++set2:+	leaf = mdb_node_search(mc, key, exactp);+	if (exactp != NULL && !*exactp) {+		/* MDB_SET specified and not an exact match. */+		return MDB_NOTFOUND;+	}++	if (leaf == NULL) {+		DPUTS("===> inexact leaf not found, goto sibling");+		if ((rc = mdb_cursor_sibling(mc, 1)) != MDB_SUCCESS) {+			mc->mc_flags |= C_EOF;+			return rc;		/* no entries matched */+		}+		mp = mc->mc_pg[mc->mc_top];+		mdb_cassert(mc, IS_LEAF(mp));+		leaf = NODEPTR(mp, 0);+	}++set1:+	mc->mc_flags |= C_INITIALIZED;+	mc->mc_flags &= ~C_EOF;++	if (IS_LEAF2(mp)) {+		if (op == MDB_SET_RANGE || op == MDB_SET_KEY) {+			key->mv_size = mc->mc_db->md_pad;+			key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);+		}+		return MDB_SUCCESS;+	}++	if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {+		mdb_xcursor_init1(mc, leaf);+		if (op == MDB_SET || op == MDB_SET_KEY || op == MDB_SET_RANGE) {+			rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL);+		} else {+			int ex2, *ex2p;+			if (op == MDB_GET_BOTH) {+				ex2p = &ex2;+				ex2 = 0;+			} else {+				ex2p = NULL;+			}+			rc = mdb_cursor_set(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_SET_RANGE, ex2p);+			if (rc != MDB_SUCCESS)+				return rc;+		}+	} else if (data) {+		if (op == MDB_GET_BOTH || op == MDB_GET_BOTH_RANGE) {+			MDB_val olddata;+			MDB_cmp_func *dcmp;+			if ((rc = mdb_node_read(mc, leaf, &olddata)) != MDB_SUCCESS)+				return rc;+			dcmp = mc->mc_dbx->md_dcmp;+#if UINT_MAX < SIZE_MAX+			if (dcmp == mdb_cmp_int && olddata.mv_size == sizeof(size_t))+				dcmp = mdb_cmp_clong;+#endif+			rc = dcmp(data, &olddata);+			if (rc) {+				if (op == MDB_GET_BOTH || rc > 0)+					return MDB_NOTFOUND;+				rc = 0;+			}+			*data = olddata;++		} else {+			if (mc->mc_xcursor)+				mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);+			if ((rc = mdb_node_read(mc, leaf, data)) != MDB_SUCCESS)+				return rc;+		}+	}++	/* The key already matches in all other cases */+	if (op == MDB_SET_RANGE || op == MDB_SET_KEY)+		MDB_GET_KEY(leaf, key);+	DPRINTF(("==> cursor placed on key [%s]", DKEY(key)));++	return rc;+}++/** Move the cursor to the first item in the database. */+static int+mdb_cursor_first(MDB_cursor *mc, MDB_val *key, MDB_val *data)+{+	int		 rc;+	MDB_node	*leaf;++	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 = mdb_page_search(mc, NULL, MDB_PS_FIRST);+		if (rc != MDB_SUCCESS)+			return rc;+	}+	mdb_cassert(mc, IS_LEAF(mc->mc_pg[mc->mc_top]));++	leaf = NODEPTR(mc->mc_pg[mc->mc_top], 0);+	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 ( key ) {+			key->mv_size = mc->mc_db->md_pad;+			key->mv_data = LEAF2KEY(mc->mc_pg[mc->mc_top], 0, key->mv_size);+		}+		return MDB_SUCCESS;+	}++	if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {+		mdb_xcursor_init1(mc, leaf);+		rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL);+		if (rc)+			return rc;+	} else if (data) {+		if ((rc = mdb_node_read(mc, leaf, data)) != MDB_SUCCESS)+			return rc;+	}++	MDB_GET_KEY(leaf, key);+	return MDB_SUCCESS;+}++/** Move the cursor to the last item in the database. */+static int+mdb_cursor_last(MDB_cursor *mc, MDB_val *key, MDB_val *data)+{+	int		 rc;+	MDB_node	*leaf;++	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 = mdb_page_search(mc, NULL, MDB_PS_LAST);+		if (rc != MDB_SUCCESS)+			return rc;+	}+	mdb_cassert(mc, IS_LEAF(mc->mc_pg[mc->mc_top]));++	mc->mc_ki[mc->mc_top] = NUMKEYS(mc->mc_pg[mc->mc_top]) - 1;+	mc->mc_flags |= C_INITIALIZED|C_EOF;+	leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);++	if (IS_LEAF2(mc->mc_pg[mc->mc_top])) {+		if (key) {+			key->mv_size = mc->mc_db->md_pad;+			key->mv_data = LEAF2KEY(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], key->mv_size);+		}+		return MDB_SUCCESS;+	}++	if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {+		mdb_xcursor_init1(mc, leaf);+		rc = mdb_cursor_last(&mc->mc_xcursor->mx_cursor, data, NULL);+		if (rc)+			return rc;+	} else if (data) {+		if ((rc = mdb_node_read(mc, leaf, data)) != MDB_SUCCESS)+			return rc;+	}++	MDB_GET_KEY(leaf, key);+	return MDB_SUCCESS;+}++int+mdb_cursor_get(MDB_cursor *mc, MDB_val *key, MDB_val *data,+    MDB_cursor_op op)+{+	int		 rc;+	int		 exact = 0;+	int		 (*mfunc)(MDB_cursor *mc, MDB_val *key, MDB_val *data);++	if (mc == NULL)+		return EINVAL;++	if (mc->mc_txn->mt_flags & MDB_TXN_BLOCKED)+		return MDB_BAD_TXN;++	switch (op) {+	case MDB_GET_CURRENT:+		if (!(mc->mc_flags & C_INITIALIZED)) {+			rc = EINVAL;+		} else {+			MDB_page *mp = mc->mc_pg[mc->mc_top];+			int nkeys = NUMKEYS(mp);+			if (!nkeys || mc->mc_ki[mc->mc_top] >= nkeys) {+				mc->mc_ki[mc->mc_top] = nkeys;+				rc = MDB_NOTFOUND;+				break;+			}+			rc = MDB_SUCCESS;+			if (IS_LEAF2(mp)) {+				key->mv_size = mc->mc_db->md_pad;+				key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);+			} else {+				MDB_node *leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);+				MDB_GET_KEY(leaf, key);+				if (data) {+					if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {+						rc = mdb_cursor_get(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_GET_CURRENT);+					} else {+						rc = mdb_node_read(mc, leaf, data);+					}+				}+			}+		}+		break;+	case MDB_GET_BOTH:+	case MDB_GET_BOTH_RANGE:+		if (data == NULL) {+			rc = EINVAL;+			break;+		}+		if (mc->mc_xcursor == NULL) {+			rc = MDB_INCOMPATIBLE;+			break;+		}+		/* FALLTHRU */+	case MDB_SET:+	case MDB_SET_KEY:+	case MDB_SET_RANGE:+		if (key == NULL) {+			rc = EINVAL;+		} else {+			rc = mdb_cursor_set(mc, key, data, op,+				op == MDB_SET_RANGE ? NULL : &exact);+		}+		break;+	case MDB_GET_MULTIPLE:+		if (data == NULL || !(mc->mc_flags & C_INITIALIZED)) {+			rc = EINVAL;+			break;+		}+		if (!(mc->mc_db->md_flags & MDB_DUPFIXED)) {+			rc = MDB_INCOMPATIBLE;+			break;+		}+		rc = MDB_SUCCESS;+		if (!(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) ||+			(mc->mc_xcursor->mx_cursor.mc_flags & C_EOF))+			break;+		goto fetchm;+	case MDB_NEXT_MULTIPLE:+		if (data == NULL) {+			rc = EINVAL;+			break;+		}+		if (!(mc->mc_db->md_flags & MDB_DUPFIXED)) {+			rc = MDB_INCOMPATIBLE;+			break;+		}+		rc = mdb_cursor_next(mc, key, data, MDB_NEXT_DUP);+		if (rc == MDB_SUCCESS) {+			if (mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) {+				MDB_cursor *mx;+fetchm:+				mx = &mc->mc_xcursor->mx_cursor;+				data->mv_size = NUMKEYS(mx->mc_pg[mx->mc_top]) *+					mx->mc_db->md_pad;+				data->mv_data = METADATA(mx->mc_pg[mx->mc_top]);+				mx->mc_ki[mx->mc_top] = NUMKEYS(mx->mc_pg[mx->mc_top])-1;+			} else {+				rc = MDB_NOTFOUND;+			}+		}+		break;+	case MDB_PREV_MULTIPLE:+		if (data == NULL) {+			rc = EINVAL;+			break;+		}+		if (!(mc->mc_db->md_flags & MDB_DUPFIXED)) {+			rc = MDB_INCOMPATIBLE;+			break;+		}+		if (!(mc->mc_flags & C_INITIALIZED))+			rc = mdb_cursor_last(mc, key, data);+		else+			rc = MDB_SUCCESS;+		if (rc == MDB_SUCCESS) {+			MDB_cursor *mx = &mc->mc_xcursor->mx_cursor;+			if (mx->mc_flags & C_INITIALIZED) {+				rc = mdb_cursor_sibling(mx, 0);+				if (rc == MDB_SUCCESS)+					goto fetchm;+			} else {+				rc = MDB_NOTFOUND;+			}+		}+		break;+	case MDB_NEXT:+	case MDB_NEXT_DUP:+	case MDB_NEXT_NODUP:+		rc = mdb_cursor_next(mc, key, data, op);+		break;+	case MDB_PREV:+	case MDB_PREV_DUP:+	case MDB_PREV_NODUP:+		rc = mdb_cursor_prev(mc, key, data, op);+		break;+	case MDB_FIRST:+		rc = mdb_cursor_first(mc, key, data);+		break;+	case MDB_FIRST_DUP:+		mfunc = mdb_cursor_first;+	mmove:+		if (data == NULL || !(mc->mc_flags & C_INITIALIZED)) {+			rc = EINVAL;+			break;+		}+		if (mc->mc_xcursor == NULL) {+			rc = MDB_INCOMPATIBLE;+			break;+		}+		if (mc->mc_ki[mc->mc_top] >= NUMKEYS(mc->mc_pg[mc->mc_top])) {+			mc->mc_ki[mc->mc_top] = NUMKEYS(mc->mc_pg[mc->mc_top]);+			rc = MDB_NOTFOUND;+			break;+		}+		mc->mc_flags &= ~C_EOF;+		{+			MDB_node *leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);+			if (!F_ISSET(leaf->mn_flags, F_DUPDATA)) {+				MDB_GET_KEY(leaf, key);+				rc = mdb_node_read(mc, leaf, data);+				break;+			}+		}+		if (!(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED)) {+			rc = EINVAL;+			break;+		}+		rc = mfunc(&mc->mc_xcursor->mx_cursor, data, NULL);+		break;+	case MDB_LAST:+		rc = mdb_cursor_last(mc, key, data);+		break;+	case MDB_LAST_DUP:+		mfunc = mdb_cursor_last;+		goto mmove;+	default:+		DPRINTF(("unhandled/unimplemented cursor operation %u", op));+		rc = EINVAL;+		break;+	}++	if (mc->mc_flags & C_DEL)+		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.+ * @param[in] mc The cursor to operate on.+ */+static int+mdb_cursor_touch(MDB_cursor *mc)+{+	int rc = MDB_SUCCESS;++	if (mc->mc_dbi >= CORE_DBS && !(*mc->mc_dbflag & (DB_DIRTY|DB_DUPDATA))) {+		/* Touch DB record of named DB */+		MDB_cursor mc2;+		MDB_xcursor mcx;+		if (TXN_DBI_CHANGED(mc->mc_txn, mc->mc_dbi))+			return MDB_BAD_DBI;+		mdb_cursor_init(&mc2, mc->mc_txn, MAIN_DBI, &mcx);+		rc = mdb_page_search(&mc2, &mc->mc_dbx->md_name, MDB_PS_MODIFY);+		if (rc)+			 return rc;+		*mc->mc_dbflag |= DB_DIRTY;+	}+	mc->mc_top = 0;+	if (mc->mc_snum) {+		do {+			rc = mdb_page_touch(mc);+		} while (!rc && ++(mc->mc_top) < mc->mc_snum);+		mc->mc_top = mc->mc_snum-1;+	}+	return rc;+}++/** Do not spill pages to disk if txn is getting full, may fail instead */+#define MDB_NOSPILL	0x8000++static int+_mdb_cursor_put(MDB_cursor *mc, MDB_val *key, MDB_val *data,+    unsigned int flags)+{+	MDB_env		*env;+	MDB_node	*leaf = NULL;+	MDB_page	*fp, *mp, *sub_root = NULL;+	uint16_t	fp_flags;+	MDB_val		xdata, *rdata, dkey, olddata;+	MDB_db dummy;+	int do_sub = 0, insert_key, insert_data;+	unsigned int mcount = 0, dcount = 0, nospill;+	size_t nsize;+	int rc, rc2;+	unsigned int nflags;+	DKBUF;++	if (mc == NULL || key == NULL)+		return EINVAL;++	env = mc->mc_txn->mt_env;++	/* Check this first so counter will always be zero on any+	 * early failures.+	 */+	if (flags & MDB_MULTIPLE) {+		dcount = data[1].mv_size;+		data[1].mv_size = 0;+		if (!F_ISSET(mc->mc_db->md_flags, MDB_DUPFIXED))+			return MDB_INCOMPATIBLE;+	}++	nospill = flags & MDB_NOSPILL;+	flags &= ~MDB_NOSPILL;++	if (mc->mc_txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_BLOCKED))+		return (mc->mc_txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN;++	if (key->mv_size-1 >= ENV_MAXKEY(env))+		return MDB_BAD_VALSIZE;++#if SIZE_MAX > MAXDATASIZE+	if (data->mv_size > ((mc->mc_db->md_flags & MDB_DUPSORT) ? ENV_MAXKEY(env) : MAXDATASIZE))+		return MDB_BAD_VALSIZE;+#else+	if ((mc->mc_db->md_flags & MDB_DUPSORT) && data->mv_size > ENV_MAXKEY(env))+		return MDB_BAD_VALSIZE;+#endif++	DPRINTF(("==> put db %d key [%s], size %"Z"u, data size %"Z"u",+		DDBI(mc), DKEY(key), key ? key->mv_size : 0, data->mv_size));++	dkey.mv_size = 0;++	if (flags & MDB_CURRENT) {+		if (!(mc->mc_flags & C_INITIALIZED))+			return EINVAL;+		rc = MDB_SUCCESS;+	} else 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 = MDB_NO_ROOT;+	} else {+		int exact = 0;+		MDB_val d2;+		if (flags & MDB_APPEND) {+			MDB_val k2;+			rc = mdb_cursor_last(mc, &k2, &d2);+			if (rc == 0) {+				rc = mc->mc_dbx->md_cmp(key, &k2);+				if (rc > 0) {+					rc = MDB_NOTFOUND;+					mc->mc_ki[mc->mc_top]++;+				} else {+					/* new key is <= last key */+					rc = MDB_KEYEXIST;+				}+			}+		} else {+			rc = mdb_cursor_set(mc, key, &d2, MDB_SET, &exact);+		}+		if ((flags & MDB_NOOVERWRITE) && rc == 0) {+			DPRINTF(("duplicate key [%s]", DKEY(key)));+			*data = d2;+			return MDB_KEYEXIST;+		}+		if (rc && rc != MDB_NOTFOUND)+			return rc;+	}++	if (mc->mc_flags & C_DEL)+		mc->mc_flags ^= C_DEL;++	/* Cursor is positioned, check for room in the dirty list */+	if (!nospill) {+		if (flags & MDB_MULTIPLE) {+			rdata = &xdata;+			xdata.mv_size = data->mv_size * dcount;+		} else {+			rdata = data;+		}+		if ((rc2 = mdb_page_spill(mc, key, rdata)))+			return rc2;+	}++	if (rc == MDB_NO_ROOT) {+		MDB_page *np;+		/* new database, write a root leaf page */+		DPUTS("allocating new root leaf page");+		if ((rc2 = mdb_page_new(mc, P_LEAF, 1, &np))) {+			return rc2;+		}+		mdb_cursor_push(mc, np);+		mc->mc_db->md_root = np->mp_pgno;+		mc->mc_db->md_depth++;+		*mc->mc_dbflag |= DB_DIRTY;+		if ((mc->mc_db->md_flags & (MDB_DUPSORT|MDB_DUPFIXED))+			== MDB_DUPFIXED)+			MP_FLAGS(np) |= P_LEAF2;+		mc->mc_flags |= C_INITIALIZED;+	} else {+		/* make sure all cursor pages are writable */+		rc2 = mdb_cursor_touch(mc);+		if (rc2)+			return rc2;+	}++	insert_key = insert_data = rc;+	if (insert_key) {+		/* The key does not exist */+		DPRINTF(("inserting key at index %i", mc->mc_ki[mc->mc_top]));+		if ((mc->mc_db->md_flags & MDB_DUPSORT) &&+			LEAFSIZE(key, data) > env->me_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_flags = P_LEAF|P_DIRTY;+			fp = env->me_pbuf;+			fp->mp_pad = data->mv_size; /* used if MDB_DUPFIXED */+			MP_LOWER(fp) = MP_UPPER(fp) = (PAGEHDRSZ-PAGEBASE);+			olddata.mv_size = 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 int ksize = mc->mc_db->md_pad;+			if (key->mv_size != ksize)+				return MDB_BAD_VALSIZE;+			ptr = LEAF2KEY(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], ksize);+			memcpy(ptr, key->mv_data, 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 short 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 = mdb_update_key(mc, key);+				else+					rc2 = MDB_SUCCESS;+				mc->mc_top += dtop;+				if (rc2)+					return rc2;+			}+			return MDB_SUCCESS;+		}++more:+		leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);+		olddata.mv_size = NODEDSZ(leaf);+		olddata.mv_data = NODEDATA(leaf);++		/* DB has dups? */+		if (F_ISSET(mc->mc_db->md_flags, MDB_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, offset = 0;+			mp = fp = xdata.mv_data = 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(leaf->mn_flags, F_DUPDATA)) {+				MDB_cmp_func *dcmp;+				/* Just overwrite the current item */+				if (flags == MDB_CURRENT)+					goto current;+				dcmp = mc->mc_dbx->md_dcmp;+#if UINT_MAX < SIZE_MAX+				if (dcmp == mdb_cmp_int && olddata.mv_size == sizeof(size_t))+					dcmp = mdb_cmp_clong;+#endif+				/* does data match? */+				if (!dcmp(data, &olddata)) {+					if (flags & (MDB_NODUPDATA|MDB_APPENDDUP))+						return MDB_KEYEXIST;+					/* overwrite it */+					goto current;+				}++				/* Back up original data item */+				dkey.mv_size = olddata.mv_size;+				dkey.mv_data = memcpy(fp+1, olddata.mv_data, olddata.mv_size);++				/* Make sub-page header for the dup items, with dummy body */+				MP_FLAGS(fp) = P_LEAF|P_DIRTY|P_SUBP;+				MP_LOWER(fp) = (PAGEHDRSZ-PAGEBASE);+				xdata.mv_size = PAGEHDRSZ + dkey.mv_size + data->mv_size;+				if (mc->mc_db->md_flags & MDB_DUPFIXED) {+					MP_FLAGS(fp) |= P_LEAF2;+					fp->mp_pad = data->mv_size;+					xdata.mv_size += 2 * data->mv_size;	/* leave space for 2 more */+				} else {+					xdata.mv_size += 2 * (sizeof(indx_t) + NODESIZE) ++						(dkey.mv_size & 1) + (data->mv_size & 1);+				}+				MP_UPPER(fp) = xdata.mv_size - PAGEBASE;+				olddata.mv_size = xdata.mv_size; /* pretend olddata is fp */+			} else if (leaf->mn_flags & 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.mv_data;+				switch (flags) {+				default:+					if (!(mc->mc_db->md_flags & MDB_DUPFIXED)) {+						offset = EVEN(NODESIZE + sizeof(indx_t) ++							data->mv_size);+						break;+					}+					offset = fp->mp_pad;+					if (SIZELEFT(fp) < offset) {+						offset *= 4; /* space for 4 more */+						break;+					}+					/* FALLTHRU */ /* Big enough MDB_DUPFIXED sub-page */+				case MDB_CURRENT:+					MP_FLAGS(fp) |= P_DIRTY;+					COPY_PGNO(MP_PGNO(fp), MP_PGNO(mp));+					mc->mc_xcursor->mx_cursor.mc_pg[0] = fp;+					flags |= F_DUPDATA;+					goto put_sub;+				}+				xdata.mv_size = olddata.mv_size + offset;+			}++			fp_flags = MP_FLAGS(fp);+			if (NODESIZE + NODEKSZ(leaf) + xdata.mv_size > env->me_nodemax) {+					/* Too big for a sub-page, convert to sub-DB */+					fp_flags &= ~P_SUBP;+prep_subDB:+					if (mc->mc_db->md_flags & MDB_DUPFIXED) {+						fp_flags |= P_LEAF2;+						dummy.md_pad = fp->mp_pad;+						dummy.md_flags = MDB_DUPFIXED;+						if (mc->mc_db->md_flags & MDB_INTEGERDUP)+							dummy.md_flags |= MDB_INTEGERKEY;+					} else {+						dummy.md_pad = 0;+						dummy.md_flags = 0;+					}+					dummy.md_depth = 1;+					dummy.md_branch_pages = 0;+					dummy.md_leaf_pages = 1;+					dummy.md_overflow_pages = 0;+					dummy.md_entries = NUMKEYS(fp);+					xdata.mv_size = sizeof(MDB_db);+					xdata.mv_data = &dummy;+					if ((rc = mdb_page_alloc(mc, 1, &mp)))+						return rc;+					offset = env->me_psize - olddata.mv_size;+					flags |= F_DUPDATA|F_SUBDATA;+					dummy.md_root = mp->mp_pgno;+					sub_root = mp;+			}+			if (mp != fp) {+				MP_FLAGS(mp) = fp_flags | P_DIRTY;+				MP_PAD(mp)   = MP_PAD(fp);+				MP_LOWER(mp) = MP_LOWER(fp);+				MP_UPPER(mp) = MP_UPPER(fp) + offset;+				if (fp_flags & P_LEAF2) {+					memcpy(METADATA(mp), METADATA(fp), NUMKEYS(fp) * fp->mp_pad);+				} else {+					memcpy((char *)mp + MP_UPPER(mp) + PAGEBASE, (char *)fp + MP_UPPER(fp) + PAGEBASE,+						olddata.mv_size - MP_UPPER(fp) - PAGEBASE);+					memcpy((char *)MP_PTRS(mp), (char *)MP_PTRS(fp), NUMKEYS(fp) * sizeof(mp->mp_ptrs[0]));+					for (i=0; i<NUMKEYS(fp); i++)+						mp->mp_ptrs[i] += offset;+				}+			}++			rdata = &xdata;+			flags |= F_DUPDATA;+			do_sub = 1;+			if (!insert_key)+				mdb_node_del(mc, 0);+			goto new_sub;+		}+current:+		/* LMDB passes F_SUBDATA in 'flags' to write a DB record */+		if ((leaf->mn_flags ^ flags) & F_SUBDATA)+			return MDB_INCOMPATIBLE;+		/* overflow page overwrites need special handling */+		if (F_ISSET(leaf->mn_flags, F_BIGDATA)) {+			MDB_page *omp;+			pgno_t pg;+			int level, ovpages, dpages = OVPAGES(data->mv_size, env->me_psize);++			memcpy(&pg, olddata.mv_data, sizeof(pg));+			if ((rc2 = mdb_page_get(mc, pg, &omp, &level)) != 0)+				return rc2;+			ovpages = omp->mp_pages;++			/* Is the ov page large enough? */+			if (ovpages >= dpages) {+			  if (!(omp->mp_flags & P_DIRTY) &&+				  (level || (env->me_flags & MDB_WRITEMAP)))+			  {+				rc = mdb_page_unspill(mc->mc_txn, omp, &omp);+				if (rc)+					return rc;+				level = 0;		/* dirty in this txn or clean */+			  }+			  /* Is it dirty? */+			  if (omp->mp_flags & P_DIRTY) {+				/* 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 (level > 1) {+					/* It is writable only in a parent txn */+					size_t sz = (size_t) env->me_psize * ovpages, off;+					MDB_page *np = mdb_page_malloc(mc->mc_txn, ovpages);+					MDB_ID2 id2;+					if (!np)+						return ENOMEM;+					id2.mid = pg;+					id2.mptr = np;+					/* Note - this page is already counted in parent's dirty_room */+					rc2 = mdb_mid2l_insert(mc->mc_txn->mt_u.dirty_list, &id2);+					mdb_cassert(mc, rc2 == 0);+					/* Currently we make the page look as with put() in the+					 * parent txn, in case the user peeks at MDB_RESERVEd+					 * or unused parts. Some users treat ovpages specially.+					 */+					if (!(flags & MDB_RESERVE)) {+						/* Skip the part where LMDB will put *data.+						 * Copy end of page, adjusting alignment so+						 * compiler may copy words instead of bytes.+						 */+						off = (PAGEHDRSZ + data->mv_size) & -(int)sizeof(size_t);+						memcpy((size_t *)((char *)np + off),+							(size_t *)((char *)omp + off), sz - off);+						sz = PAGEHDRSZ;+					}+					memcpy(np, omp, sz); /* Copy beginning of page */+					omp = np;+				}+				SETDSZ(leaf, data->mv_size);+				if (F_ISSET(flags, MDB_RESERVE))+					data->mv_data = METADATA(omp);+				else+					memcpy(METADATA(omp), data->mv_data, data->mv_size);+				return MDB_SUCCESS;+			  }+			}+			if ((rc2 = mdb_ovpage_free(mc, omp)) != MDB_SUCCESS)+				return rc2;+		} else if (data->mv_size == olddata.mv_size) {+			/* 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, MDB_RESERVE))+				data->mv_data = olddata.mv_data;+			else if (!(mc->mc_flags & C_SUB))+				memcpy(olddata.mv_data, data->mv_data, data->mv_size);+			else {+				if (key->mv_size != NODEKSZ(leaf))+					goto new_ksize;+				memcpy(NODEKEY(leaf), key->mv_data, key->mv_size);+				goto fix_parent;+			}+			return MDB_SUCCESS;+		}+new_ksize:+		mdb_node_del(mc, 0);+	}++	rdata = data;++new_sub:+	nflags = flags & NODE_ADD_FLAGS;+	nsize = IS_LEAF2(mc->mc_pg[mc->mc_top]) ? key->mv_size : mdb_leaf_size(env, key, rdata);+	if (SIZELEFT(mc->mc_pg[mc->mc_top]) < nsize) {+		if (( flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA )+			nflags &= ~MDB_APPEND; /* sub-page may need room to grow */+		if (!insert_key)+			nflags |= MDB_SPLIT_REPLACE;+		rc = mdb_page_split(mc, key, rdata, P_INVALID, nflags);+	} else {+		/* There is room already in this leaf page. */+		rc = mdb_node_add(mc, mc->mc_ki[mc->mc_top], key, rdata, 0, nflags);+		if (rc == 0) {+			/* Adjust other cursors pointing to mp */+			MDB_cursor *m2, *m3;+			MDB_dbi dbi = mc->mc_dbi;+			unsigned i = mc->mc_top;+			MDB_page *mp = mc->mc_pg[i];++			for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {+				if (mc->mc_flags & C_SUB)+					m3 = &m2->mc_xcursor->mx_cursor;+				else+					m3 = 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] && insert_key) {+					m3->mc_ki[i]++;+				}+				XCURSOR_REFRESH(m3, i, mp);+			}+		}+	}++	if (rc == MDB_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, new_dupdata;+			size_t ecount;+put_sub:+			xdata.mv_size = 0;+			xdata.mv_data = "";+			leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);+			if ((flags & (MDB_CURRENT|MDB_APPENDDUP)) == MDB_CURRENT) {+				xflags = MDB_CURRENT|MDB_NOSPILL;+			} else {+				mdb_xcursor_init1(mc, leaf);+				xflags = (flags & MDB_NODUPDATA) ?+					MDB_NOOVERWRITE|MDB_NOSPILL : MDB_NOSPILL;+			}+			if (sub_root)+				mc->mc_xcursor->mx_cursor.mc_pg[0] = sub_root;+			new_dupdata = (int)dkey.mv_size;+			/* converted, write the original data first */+			if (dkey.mv_size) {+				rc = _mdb_cursor_put(&mc->mc_xcursor->mx_cursor, &dkey, &xdata, xflags);+				if (rc)+					goto bad_sub;+				/* we've done our job */+				dkey.mv_size = 0;+			}+			if (!(leaf->mn_flags & F_SUBDATA) || sub_root) {+				/* Adjust other cursors pointing to mp */+				MDB_cursor *m2;+				MDB_xcursor *mx = mc->mc_xcursor;+				unsigned i = mc->mc_top;+				MDB_page *mp = mc->mc_pg[i];++				for (m2 = mc->mc_txn->mt_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]) {+							mdb_xcursor_init2(m2, mx, new_dupdata);+						} else if (!insert_key) {+							XCURSOR_REFRESH(m2, i, mp);+						}+					}+				}+			}+			ecount = mc->mc_xcursor->mx_db.md_entries;+			if (flags & MDB_APPENDDUP)+				xflags |= MDB_APPEND;+			rc = _mdb_cursor_put(&mc->mc_xcursor->mx_cursor, data, &xdata, xflags);+			if (flags & F_SUBDATA) {+				void *db = NODEDATA(leaf);+				memcpy(db, &mc->mc_xcursor->mx_db, sizeof(MDB_db));+			}+			insert_data = mc->mc_xcursor->mx_db.md_entries - ecount;+		}+		/* 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 (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 & MDB_MULTIPLE) {+			if (!rc) {+				mcount++;+				/* let caller know how many succeeded, if any */+				data[1].mv_size = mcount;+				if (mcount < dcount) {+					data[0].mv_data = (char *)data[0].mv_data + data[0].mv_size;+					insert_key = insert_data = 0;+					goto more;+				}+			}+		}+		return rc;+bad_sub:+		if (rc == MDB_KEYEXIST)	/* should not happen, we deleted that item */+			rc = MDB_CORRUPTED;+	}+	mc->mc_txn->mt_flags |= MDB_TXN_ERROR;+	return rc;+}++int+mdb_cursor_put(MDB_cursor *mc, MDB_val *key, MDB_val *data,+    unsigned int flags)+{+	DKBUF;+	DDBUF;+	int rc = _mdb_cursor_put(mc, key, data, flags);+	MDB_TRACE(("%p, %"Z"u[%s], %"Z"u%s, %u",+		mc, key ? key->mv_size:0, DKEY(key), data ? data->mv_size:0,+			data ? mdb_dval(mc->mc_txn, mc->mc_dbi, data, dbuf):"", flags));+	return rc;+}++static int+_mdb_cursor_del(MDB_cursor *mc, unsigned int flags)+{+	MDB_node	*leaf;+	MDB_page	*mp;+	int rc;++	if (mc->mc_txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_BLOCKED))+		return (mc->mc_txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN;++	if (!(mc->mc_flags & C_INITIALIZED))+		return EINVAL;++	if (mc->mc_ki[mc->mc_top] >= NUMKEYS(mc->mc_pg[mc->mc_top]))+		return MDB_NOTFOUND;++	if (!(flags & MDB_NOSPILL) && (rc = mdb_page_spill(mc, NULL, NULL)))+		return rc;++	rc = mdb_cursor_touch(mc);+	if (rc)+		return rc;++	mp = mc->mc_pg[mc->mc_top];+	if (!IS_LEAF(mp))+		return MDB_CORRUPTED;+	if (IS_LEAF2(mp))+		goto del_key;+	leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);++	if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {+		if (flags & MDB_NODUPDATA) {+			/* mdb_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(leaf->mn_flags, F_SUBDATA)) {+				mc->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf);+			}+			rc = _mdb_cursor_del(&mc->mc_xcursor->mx_cursor, MDB_NOSPILL);+			if (rc)+				return rc;+			/* If sub-DB still has entries, we're done */+			if (mc->mc_xcursor->mx_db.md_entries) {+				if (leaf->mn_flags & F_SUBDATA) {+					/* update subDB info */+					void *db = NODEDATA(leaf);+					memcpy(db, &mc->mc_xcursor->mx_db, sizeof(MDB_db));+				} else {+					MDB_cursor *m2;+					/* shrink fake page */+					mdb_node_shrink(mp, mc->mc_ki[mc->mc_top]);+					leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);+					mc->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf);+					/* fix other sub-DB cursors pointed at fake pages on this page */+					for (m2 = mc->mc_txn->mt_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) {+							XCURSOR_REFRESH(m2, mc->mc_top, mp);+						}+					}+				}+				mc->mc_db->md_entries--;+				return rc;+			} else {+				mc->mc_xcursor->mx_cursor.mc_flags &= ~C_INITIALIZED;+			}+			/* otherwise fall thru and delete the sub-DB */+		}++		if (leaf->mn_flags & F_SUBDATA) {+			/* add all the child DB's pages to the free list */+			rc = mdb_drop0(&mc->mc_xcursor->mx_cursor, 0);+			if (rc)+				goto fail;+		}+	}+	/* LMDB passes F_SUBDATA in 'flags' to delete a DB record */+	else if ((leaf->mn_flags ^ flags) & F_SUBDATA) {+		rc = MDB_INCOMPATIBLE;+		goto fail;+	}++	/* add overflow pages to free list */+	if (F_ISSET(leaf->mn_flags, F_BIGDATA)) {+		MDB_page *omp;+		pgno_t pg;++		memcpy(&pg, NODEDATA(leaf), sizeof(pg));+		if ((rc = mdb_page_get(mc, pg, &omp, NULL)) ||+			(rc = mdb_ovpage_free(mc, omp)))+			goto fail;+	}++del_key:+	return mdb_cursor_del0(mc);++fail:+	mc->mc_txn->mt_flags |= MDB_TXN_ERROR;+	return rc;+}++int+mdb_cursor_del(MDB_cursor *mc, unsigned int flags)+{+	MDB_TRACE(("%p, %u",+		mc, flags));+	return _mdb_cursor_del(mc, flags);+}++/** Allocate and initialize new pages for a database.+ * Set #MDB_TXN_ERROR on failure.+ * @param[in] mc a cursor on the database being added to.+ * @param[in] flags flags defining what type of page is being allocated.+ * @param[in] num the number of pages to allocate. This is usually 1,+ * unless allocating overflow pages for a large record.+ * @param[out] mp Address of a page, or NULL on failure.+ * @return 0 on success, non-zero on failure.+ */+static int+mdb_page_new(MDB_cursor *mc, uint32_t flags, int num, MDB_page **mp)+{+	MDB_page	*np;+	int rc;++	if ((rc = mdb_page_alloc(mc, num, &np)))+		return rc;+	DPRINTF(("allocated new mpage %"Z"u, page size %u",+	    np->mp_pgno, mc->mc_txn->mt_env->me_psize));+	np->mp_flags = flags | P_DIRTY;+	np->mp_lower = (PAGEHDRSZ-PAGEBASE);+	np->mp_upper = mc->mc_txn->mt_env->me_psize - PAGEBASE;++	if (IS_BRANCH(np))+		mc->mc_db->md_branch_pages++;+	else if (IS_LEAF(np))+		mc->mc_db->md_leaf_pages++;+	else if (IS_OVERFLOW(np)) {+		mc->mc_db->md_overflow_pages += num;+		np->mp_pages = num;+	}+	*mp = np;++	return 0;+}++/** 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 #MDB_node headers.+ * @param[in] env The environment handle.+ * @param[in] key The key for the node.+ * @param[in] data The data for the node.+ * @return The number of bytes needed to store the node.+ */+static size_t+mdb_leaf_size(MDB_env *env, MDB_val *key, MDB_val *data)+{+	size_t		 sz;++	sz = LEAFSIZE(key, data);+	if (sz > env->me_nodemax) {+		/* put on overflow page */+		sz -= data->mv_size - sizeof(pgno_t);+	}++	return EVEN(sz + 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 #MDB_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 #MDB_node headers.+ * @param[in] env The environment handle.+ * @param[in] key The key for the node.+ * @return The number of bytes needed to store the node.+ */+static size_t+mdb_branch_size(MDB_env *env, MDB_val *key)+{+	size_t		 sz;++	sz = INDXSIZE(key);+	if (sz > env->me_nodemax) {+		/* put on overflow page */+		/* not implemented */+		/* sz -= key->size - sizeof(pgno_t); */+	}++	return sz + sizeof(indx_t);+}++/** Add a node to the page pointed to by the cursor.+ * Set #MDB_TXN_ERROR on failure.+ * @param[in] mc The cursor for this operation.+ * @param[in] indx The index on the page where the new node should be added.+ * @param[in] key The key for the new node.+ * @param[in] data The data for the new node, if any.+ * @param[in] pgno The page number, if adding a branch node.+ * @param[in] flags Flags for the node.+ * @return 0 on success, non-zero on failure. Possible errors are:+ * <ul>+ *	<li>ENOMEM - failed to allocate overflow pages for the node.+ *	<li>MDB_PAGE_FULL - there is insufficient room in the page. This error+ *	should never happen since all callers already calculate the+ *	page's free space before calling this function.+ * </ul>+ */+static int+mdb_node_add(MDB_cursor *mc, indx_t indx,+    MDB_val *key, MDB_val *data, pgno_t pgno, unsigned int flags)+{+	unsigned int	 i;+	size_t		 node_size = NODESIZE;+	ssize_t		 room;+	indx_t		 ofs;+	MDB_node	*node;+	MDB_page	*mp = mc->mc_pg[mc->mc_top];+	MDB_page	*ofp = NULL;		/* overflow page */+	void		*ndata;+	DKBUF;++	mdb_cassert(mc, MP_UPPER(mp) >= MP_LOWER(mp));++	DPRINTF(("add to %s %spage %"Z"u index %i, data size %"Z"u key size %"Z"u [%s]",+	    IS_LEAF(mp) ? "leaf" : "branch",+		IS_SUBP(mp) ? "sub-" : "",+		mdb_dbg_pgno(mp), indx, data ? data->mv_size : 0,+		key ? key->mv_size : 0, key ? DKEY(key) : "null"));++	if (IS_LEAF2(mp)) {+		/* Move higher keys up one slot. */+		int ksize = mc->mc_db->md_pad, dif;+		char *ptr = LEAF2KEY(mp, indx, ksize);+		dif = NUMKEYS(mp) - indx;+		if (dif > 0)+			memmove(ptr+ksize, ptr, dif*ksize);+		/* insert new key */+		memcpy(ptr, key->mv_data, ksize);++		/* Just using these for counting */+		MP_LOWER(mp) += sizeof(indx_t);+		MP_UPPER(mp) -= ksize - sizeof(indx_t);+		return MDB_SUCCESS;+	}++	room = (ssize_t)SIZELEFT(mp) - (ssize_t)sizeof(indx_t);+	if (key != NULL)+		node_size += key->mv_size;+	if (IS_LEAF(mp)) {+		mdb_cassert(mc, key && data);+		if (F_ISSET(flags, F_BIGDATA)) {+			/* Data already on overflow page. */+			node_size += sizeof(pgno_t);+		} else if (node_size + data->mv_size > mc->mc_txn->mt_env->me_nodemax) {+			int ovpages = OVPAGES(data->mv_size, mc->mc_txn->mt_env->me_psize);+			int rc;+			/* Put data on overflow page. */+			DPRINTF(("data size is %"Z"u, node would be %"Z"u, put data on overflow page",+			    data->mv_size, node_size+data->mv_size));+			node_size = EVEN(node_size + sizeof(pgno_t));+			if ((ssize_t)node_size > room)+				goto full;+			if ((rc = mdb_page_new(mc, P_OVERFLOW, ovpages, &ofp)))+				return rc;+			DPRINTF(("allocated overflow page %"Z"u", ofp->mp_pgno));+			flags |= F_BIGDATA;+			goto update;+		} else {+			node_size += data->mv_size;+		}+	}+	node_size = EVEN(node_size);+	if ((ssize_t)node_size > room)+		goto full;++update:+	/* Move higher pointers up one slot. */+	for (i = NUMKEYS(mp); i > indx; i--)+		MP_PTRS(mp)[i] = MP_PTRS(mp)[i - 1];++	/* Adjust free space offsets. */+	ofs = MP_UPPER(mp) - node_size;+	mdb_cassert(mc, ofs >= MP_LOWER(mp) + sizeof(indx_t));+	MP_PTRS(mp)[indx] = ofs;+	MP_UPPER(mp) = ofs;+	MP_LOWER(mp) += sizeof(indx_t);++	/* Write the node data. */+	node = NODEPTR(mp, indx);+	node->mn_ksize = (key == NULL) ? 0 : key->mv_size;+	node->mn_flags = flags;+	if (IS_LEAF(mp))+		SETDSZ(node,data->mv_size);+	else+		SETPGNO(node,pgno);++	if (key)+		memcpy(NODEKEY(node), key->mv_data, key->mv_size);++	if (IS_LEAF(mp)) {+		ndata = NODEDATA(node);+		if (ofp == NULL) {+			if (F_ISSET(flags, F_BIGDATA))+				memcpy(ndata, data->mv_data, sizeof(pgno_t));+			else if (F_ISSET(flags, MDB_RESERVE))+				data->mv_data = ndata;+			else+				memcpy(ndata, data->mv_data, data->mv_size);+		} else {+			memcpy(ndata, &ofp->mp_pgno, sizeof(pgno_t));+			ndata = METADATA(ofp);+			if (F_ISSET(flags, MDB_RESERVE))+				data->mv_data = ndata;+			else+				memcpy(ndata, data->mv_data, data->mv_size);+		}+	}++	return MDB_SUCCESS;++full:+	DPRINTF(("not enough room in page %"Z"u, got %u ptrs",+		mdb_dbg_pgno(mp), NUMKEYS(mp)));+	DPRINTF(("upper-lower = %u - %u = %"Z"d", MP_UPPER(mp),MP_LOWER(mp),room));+	DPRINTF(("node size = %"Z"u", node_size));+	mc->mc_txn->mt_flags |= MDB_TXN_ERROR;+	return MDB_PAGE_FULL;+}++/** Delete the specified node from a page.+ * @param[in] mc Cursor pointing to the node to delete.+ * @param[in] ksize The size of a node. Only used if the page is+ * part of a #MDB_DUPFIXED database.+ */+static void+mdb_node_del(MDB_cursor *mc, int ksize)+{+	MDB_page *mp = mc->mc_pg[mc->mc_top];+	indx_t	indx = mc->mc_ki[mc->mc_top];+	unsigned int	 sz;+	indx_t		 i, j, numkeys, ptr;+	MDB_node	*node;+	char		*base;++	DPRINTF(("delete node %u on %s page %"Z"u", indx,+	    IS_LEAF(mp) ? "leaf" : "branch", mdb_dbg_pgno(mp)));+	numkeys = NUMKEYS(mp);+	mdb_cassert(mc, indx < numkeys);++	if (IS_LEAF2(mp)) {+		int x = numkeys - 1 - indx;+		base = LEAF2KEY(mp, indx, ksize);+		if (x)+			memmove(base, base + ksize, x * ksize);+		MP_LOWER(mp) -= sizeof(indx_t);+		MP_UPPER(mp) += ksize - sizeof(indx_t);+		return;+	}++	node = NODEPTR(mp, indx);+	sz = NODESIZE + node->mn_ksize;+	if (IS_LEAF(mp)) {+		if (F_ISSET(node->mn_flags, F_BIGDATA))+			sz += sizeof(pgno_t);+		else+			sz += NODEDSZ(node);+	}+	sz = EVEN(sz);++	ptr = MP_PTRS(mp)[indx];+	for (i = j = 0; i < numkeys; i++) {+		if (i != indx) {+			MP_PTRS(mp)[j] = MP_PTRS(mp)[i];+			if (MP_PTRS(mp)[i] < ptr)+				MP_PTRS(mp)[j] += sz;+			j++;+		}+	}++	base = (char *)mp + MP_UPPER(mp) + PAGEBASE;+	memmove(base + sz, base, ptr - MP_UPPER(mp));++	MP_LOWER(mp) -= sizeof(indx_t);+	MP_UPPER(mp) += sz;+}++/** Compact the main page after deleting a node on a subpage.+ * @param[in] mp The main page to operate on.+ * @param[in] indx The index of the subpage on the main page.+ */+static void+mdb_node_shrink(MDB_page *mp, indx_t indx)+{+	MDB_node *node;+	MDB_page *sp, *xp;+	char *base;+	indx_t delta, nsize, len, ptr;+	int i;++	node = NODEPTR(mp, indx);+	sp = (MDB_page *)NODEDATA(node);+	delta = SIZELEFT(sp);+	nsize = NODEDSZ(node) - delta;++	/* Prepare to shift upward, set len = length(subpage part to shift) */+	if (IS_LEAF2(sp)) {+		len = nsize;+		if (nsize & 1)+			return;		/* do not make the node uneven-sized */+	} else {+		xp = (MDB_page *)((char *)sp + delta); /* destination subpage */+		for (i = NUMKEYS(sp); --i >= 0; )+			MP_PTRS(xp)[i] = MP_PTRS(sp)[i] - delta;+		len = PAGEHDRSZ;+	}+	MP_UPPER(sp) = MP_LOWER(sp);+	COPY_PGNO(MP_PGNO(sp), mp->mp_pgno);+	SETDSZ(node, nsize);++	/* Shift <lower nodes...initial part of subpage> upward */+	base = (char *)mp + mp->mp_upper + PAGEBASE;+	memmove(base + delta, base, (char *)sp + len - base);++	ptr = mp->mp_ptrs[indx];+	for (i = NUMKEYS(mp); --i >= 0; ) {+		if (mp->mp_ptrs[i] <= ptr)+			mp->mp_ptrs[i] += delta;+	}+	mp->mp_upper += 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.+ * @param[in] mc The main cursor whose sorted-dups cursor is to be initialized.+ */+static void+mdb_xcursor_init0(MDB_cursor *mc)+{+	MDB_xcursor *mx = mc->mc_xcursor;++	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_dbflag = &mx->mx_dbflag;+	mx->mx_cursor.mc_snum = 0;+	mx->mx_cursor.mc_top = 0;+	mx->mx_cursor.mc_flags = C_SUB;+	mx->mx_dbx.md_name.mv_size = 0;+	mx->mx_dbx.md_name.mv_data = NULL;+	mx->mx_dbx.md_cmp = mc->mc_dbx->md_dcmp;+	mx->mx_dbx.md_dcmp = NULL;+	mx->mx_dbx.md_rel = mc->mc_dbx->md_rel;+}++/** Final setup of a sorted-dups cursor.+ *	Sets up the fields that depend on the data from the main cursor.+ * @param[in] mc The main cursor whose sorted-dups cursor is to be initialized.+ * @param[in] node The data containing the #MDB_db record for the+ * sorted-dup database.+ */+static void+mdb_xcursor_init1(MDB_cursor *mc, MDB_node *node)+{+	MDB_xcursor *mx = mc->mc_xcursor;++	if (node->mn_flags & F_SUBDATA) {+		memcpy(&mx->mx_db, NODEDATA(node), sizeof(MDB_db));+		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;+	} else {+		MDB_page *fp = NODEDATA(node);+		mx->mx_db.md_pad = 0;+		mx->mx_db.md_flags = 0;+		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 = NUMKEYS(fp);+		COPY_PGNO(mx->mx_db.md_root, MP_PGNO(fp));+		mx->mx_cursor.mc_snum = 1;+		mx->mx_cursor.mc_top = 0;+		mx->mx_cursor.mc_flags = C_INITIALIZED|C_SUB;+		mx->mx_cursor.mc_pg[0] = fp;+		mx->mx_cursor.mc_ki[0] = 0;+		if (mc->mc_db->md_flags & MDB_DUPFIXED) {+			mx->mx_db.md_flags = MDB_DUPFIXED;+			mx->mx_db.md_pad = fp->mp_pad;+			if (mc->mc_db->md_flags & MDB_INTEGERDUP)+				mx->mx_db.md_flags |= MDB_INTEGERKEY;+		}+	}+	DPRINTF(("Sub-db -%u root page %"Z"u", mx->mx_cursor.mc_dbi,+		mx->mx_db.md_root));+	mx->mx_dbflag = DB_VALID|DB_USRVALID|DB_DUPDATA;+#if UINT_MAX < SIZE_MAX+	if (mx->mx_dbx.md_cmp == mdb_cmp_int && mx->mx_db.md_pad == sizeof(size_t))+		mx->mx_dbx.md_cmp = mdb_cmp_clong;+#endif+}+++/** 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.+ * @param[in] mc The main cursor whose sorted-dups cursor is to be fixed up.+ * @param[in] src_mx The xcursor of an up-to-date cursor.+ * @param[in] new_dupdata True if converting from a non-#F_DUPDATA item.+ */+static void+mdb_xcursor_init2(MDB_cursor *mc, MDB_xcursor *src_mx, int new_dupdata)+{+	MDB_xcursor *mx = mc->mc_xcursor;++	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_dbflag = DB_VALID|DB_USRVALID|DB_DUPDATA;+#if UINT_MAX < SIZE_MAX+		mx->mx_dbx.md_cmp = src_mx->mx_dbx.md_cmp;+#endif+	} else if (!(mx->mx_cursor.mc_flags & C_INITIALIZED)) {+		return;+	}+	mx->mx_db = src_mx->mx_db;+	mx->mx_cursor.mc_pg[0] = src_mx->mx_cursor.mc_pg[0];+	DPRINTF(("Sub-db -%u root page %"Z"u", mx->mx_cursor.mc_dbi,+		mx->mx_db.md_root));+}++/** Initialize a cursor for a given transaction and database. */+static void+mdb_cursor_init(MDB_cursor *mc, MDB_txn *txn, MDB_dbi dbi, MDB_xcursor *mx)+{+	mc->mc_next = NULL;+	mc->mc_backup = NULL;+	mc->mc_dbi = dbi;+	mc->mc_txn = txn;+	mc->mc_db = &txn->mt_dbs[dbi];+	mc->mc_dbx = &txn->mt_dbxs[dbi];+	mc->mc_dbflag = &txn->mt_dbflags[dbi];+	mc->mc_snum = 0;+	mc->mc_top = 0;+	mc->mc_pg[0] = 0;+	mc->mc_ki[0] = 0;+	mc->mc_flags = 0;+	if (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT) {+		mdb_tassert(txn, mx != NULL);+		mc->mc_xcursor = mx;+		mdb_xcursor_init0(mc);+	} else {+		mc->mc_xcursor = NULL;+	}+	if (*mc->mc_dbflag & DB_STALE) {+		mdb_page_search(mc, NULL, MDB_PS_ROOTONLY);+	}+}++int+mdb_cursor_open(MDB_txn *txn, MDB_dbi dbi, MDB_cursor **ret)+{+	MDB_cursor	*mc;+	size_t size = sizeof(MDB_cursor);++	if (!ret || !TXN_DBI_EXIST(txn, dbi, DB_VALID))+		return EINVAL;++	if (txn->mt_flags & MDB_TXN_BLOCKED)+		return MDB_BAD_TXN;++	if (dbi == FREE_DBI && !F_ISSET(txn->mt_flags, MDB_TXN_RDONLY))+		return EINVAL;++	if (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT)+		size += sizeof(MDB_xcursor);++	if ((mc = malloc(size)) != NULL) {+		mdb_cursor_init(mc, txn, dbi, (MDB_xcursor *)(mc + 1));+		if (txn->mt_cursors) {+			mc->mc_next = txn->mt_cursors[dbi];+			txn->mt_cursors[dbi] = mc;+			mc->mc_flags |= C_UNTRACK;+		}+	} else {+		return ENOMEM;+	}++	MDB_TRACE(("%p, %u = %p", txn, dbi, mc));+	*ret = mc;++	return MDB_SUCCESS;+}++int+mdb_cursor_renew(MDB_txn *txn, MDB_cursor *mc)+{+	if (!mc || !TXN_DBI_EXIST(txn, mc->mc_dbi, DB_VALID))+		return EINVAL;++	if ((mc->mc_flags & C_UNTRACK) || txn->mt_cursors)+		return EINVAL;++	if (txn->mt_flags & MDB_TXN_BLOCKED)+		return MDB_BAD_TXN;++	mdb_cursor_init(mc, txn, mc->mc_dbi, mc->mc_xcursor);+	return MDB_SUCCESS;+}++/* Return the count of duplicate data items for the current key */+int+mdb_cursor_count(MDB_cursor *mc, size_t *countp)+{+	MDB_node	*leaf;++	if (mc == NULL || countp == NULL)+		return EINVAL;++	if (mc->mc_xcursor == NULL)+		return MDB_INCOMPATIBLE;++	if (mc->mc_txn->mt_flags & MDB_TXN_BLOCKED)+		return MDB_BAD_TXN;++	if (!(mc->mc_flags & C_INITIALIZED))+		return EINVAL;++	if (!mc->mc_snum)+		return MDB_NOTFOUND;++	if (mc->mc_flags & C_EOF) {+		if (mc->mc_ki[mc->mc_top] >= NUMKEYS(mc->mc_pg[mc->mc_top]))+			return MDB_NOTFOUND;+		mc->mc_flags ^= C_EOF;+	}++	leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);+	if (!F_ISSET(leaf->mn_flags, F_DUPDATA)) {+		*countp = 1;+	} else {+		if (!(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED))+			return EINVAL;++		*countp = mc->mc_xcursor->mx_db.md_entries;+	}+	return MDB_SUCCESS;+}++void+mdb_cursor_close(MDB_cursor *mc)+{+	MDB_TRACE(("%p", mc));+	if (mc && !mc->mc_backup) {+		/* remove from txn, if tracked */+		if ((mc->mc_flags & C_UNTRACK) && mc->mc_txn->mt_cursors) {+			MDB_cursor **prev = &mc->mc_txn->mt_cursors[mc->mc_dbi];+			while (*prev && *prev != mc) prev = &(*prev)->mc_next;+			if (*prev == mc)+				*prev = mc->mc_next;+		}+		free(mc);+	}+}++MDB_txn *+mdb_cursor_txn(MDB_cursor *mc)+{+	if (!mc) return NULL;+	return mc->mc_txn;+}++MDB_dbi+mdb_cursor_dbi(MDB_cursor *mc)+{+	return mc->mc_dbi;+}++/** Replace the key for a branch node with a new key.+ * Set #MDB_TXN_ERROR on failure.+ * @param[in] mc Cursor pointing to the node to operate on.+ * @param[in] key The new key to use.+ * @return 0 on success, non-zero on failure.+ */+static int+mdb_update_key(MDB_cursor *mc, MDB_val *key)+{+	MDB_page		*mp;+	MDB_node		*node;+	char			*base;+	size_t			 len;+	int				 delta, ksize, oksize;+	indx_t			 ptr, i, numkeys, indx;+	DKBUF;++	indx = mc->mc_ki[mc->mc_top];+	mp = mc->mc_pg[mc->mc_top];+	node = NODEPTR(mp, indx);+	ptr = mp->mp_ptrs[indx];+#if MDB_DEBUG+	{+		MDB_val	k2;+		char kbuf2[DKBUF_MAXKEYSIZE*2+1];+		k2.mv_data = NODEKEY(node);+		k2.mv_size = node->mn_ksize;+		DPRINTF(("update key %u (ofs %u) [%s] to [%s] on page %"Z"u",+			indx, ptr,+			mdb_dkey(&k2, kbuf2),+			DKEY(key),+			mp->mp_pgno));+	}+#endif++	/* Sizes must be 2-byte aligned. */+	ksize = EVEN(key->mv_size);+	oksize = EVEN(node->mn_ksize);+	delta = ksize - oksize;++	/* Shift node contents if EVEN(key length) changed. */+	if (delta) {+		if (delta > 0 && SIZELEFT(mp) < delta) {+			pgno_t pgno;+			/* not enough space left, do a delete and split */+			DPRINTF(("Not enough room, delta = %d, splitting...", delta));+			pgno = NODEPGNO(node);+			mdb_node_del(mc, 0);+			return mdb_page_split(mc, key, NULL, pgno, MDB_SPLIT_REPLACE);+		}++		numkeys = NUMKEYS(mp);+		for (i = 0; i < numkeys; i++) {+			if (mp->mp_ptrs[i] <= ptr)+				mp->mp_ptrs[i] -= delta;+		}++		base = (char *)mp + mp->mp_upper + PAGEBASE;+		len = ptr - mp->mp_upper + NODESIZE;+		memmove(base - delta, base, len);+		mp->mp_upper -= delta;++		node = NODEPTR(mp, indx);+	}++	/* But even if no shift was needed, update ksize */+	if (node->mn_ksize != key->mv_size)+		node->mn_ksize = key->mv_size;++	if (key->mv_size)+		memcpy(NODEKEY(node), key->mv_data, key->mv_size);++	return MDB_SUCCESS;+}++static void+mdb_cursor_copy(const MDB_cursor *csrc, MDB_cursor *cdst);++/** Perform \b act while tracking temporary cursor \b mn */+#define WITH_CURSOR_TRACKING(mn, act) do { \+	MDB_cursor dummy, *tracked, **tp = &(mn).mc_txn->mt_cursors[mn.mc_dbi]; \+	if ((mn).mc_flags & C_SUB) { \+		dummy.mc_flags =  C_INITIALIZED; \+		dummy.mc_xcursor = (MDB_xcursor *)&(mn);	\+		tracked = &dummy; \+	} else { \+		tracked = &(mn); \+	} \+	tracked->mc_next = *tp; \+	*tp = tracked; \+	{ act; } \+	*tp = tracked->mc_next; \+} while (0)++/** Move a node from csrc to cdst.+ */+static int+mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst, int fromleft)+{+	MDB_node		*srcnode;+	MDB_val		 key, data;+	pgno_t	srcpg;+	MDB_cursor mn;+	int			 rc;+	unsigned short flags;++	DKBUF;++	/* Mark src and dst as dirty. */+	if ((rc = mdb_page_touch(csrc)) ||+	    (rc = mdb_page_touch(cdst)))+		return rc;++	if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {+		key.mv_size = csrc->mc_db->md_pad;+		key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], csrc->mc_ki[csrc->mc_top], key.mv_size);+		data.mv_size = 0;+		data.mv_data = NULL;+		srcpg = 0;+		flags = 0;+	} else {+		srcnode = NODEPTR(csrc->mc_pg[csrc->mc_top], csrc->mc_ki[csrc->mc_top]);+		mdb_cassert(csrc, !((size_t)srcnode & 1));+		srcpg = NODEPGNO(srcnode);+		flags = srcnode->mn_flags;+		if (csrc->mc_ki[csrc->mc_top] == 0 && IS_BRANCH(csrc->mc_pg[csrc->mc_top])) {+			unsigned int snum = csrc->mc_snum;+			MDB_node *s2;+			/* must find the lowest key below src */+			rc = mdb_page_search_lowest(csrc);+			if (rc)+				return rc;+			if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {+				key.mv_size = csrc->mc_db->md_pad;+				key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], 0, key.mv_size);+			} else {+				s2 = NODEPTR(csrc->mc_pg[csrc->mc_top], 0);+				key.mv_size = NODEKSZ(s2);+				key.mv_data = NODEKEY(s2);+			}+			csrc->mc_snum = snum--;+			csrc->mc_top = snum;+		} else {+			key.mv_size = NODEKSZ(srcnode);+			key.mv_data = NODEKEY(srcnode);+		}+		data.mv_size = NODEDSZ(srcnode);+		data.mv_data = NODEDATA(srcnode);+	}+	mn.mc_xcursor = NULL;+	if (IS_BRANCH(cdst->mc_pg[cdst->mc_top]) && cdst->mc_ki[cdst->mc_top] == 0) {+		unsigned int snum = cdst->mc_snum;+		MDB_node *s2;+		MDB_val bkey;+		/* must find the lowest key below dst */+		mdb_cursor_copy(cdst, &mn);+		rc = mdb_page_search_lowest(&mn);+		if (rc)+			return rc;+		if (IS_LEAF2(mn.mc_pg[mn.mc_top])) {+			bkey.mv_size = mn.mc_db->md_pad;+			bkey.mv_data = LEAF2KEY(mn.mc_pg[mn.mc_top], 0, bkey.mv_size);+		} else {+			s2 = NODEPTR(mn.mc_pg[mn.mc_top], 0);+			bkey.mv_size = NODEKSZ(s2);+			bkey.mv_data = NODEKEY(s2);+		}+		mn.mc_snum = snum--;+		mn.mc_top = snum;+		mn.mc_ki[snum] = 0;+		rc = mdb_update_key(&mn, &bkey);+		if (rc)+			return rc;+	}++	DPRINTF(("moving %s node %u [%s] on page %"Z"u to node %u on page %"Z"u",+	    IS_LEAF(csrc->mc_pg[csrc->mc_top]) ? "leaf" : "branch",+	    csrc->mc_ki[csrc->mc_top],+		DKEY(&key),+	    csrc->mc_pg[csrc->mc_top]->mp_pgno,+	    cdst->mc_ki[cdst->mc_top], cdst->mc_pg[cdst->mc_top]->mp_pgno));++	/* Add the node to the destination page.+	 */+	rc = mdb_node_add(cdst, cdst->mc_ki[cdst->mc_top], &key, &data, srcpg, flags);+	if (rc != MDB_SUCCESS)+		return rc;++	/* Delete the node from the source page.+	 */+	mdb_node_del(csrc, key.mv_size);++	{+		/* Adjust other cursors pointing to mp */+		MDB_cursor *m2, *m3;+		MDB_dbi dbi = csrc->mc_dbi;+		MDB_page *mpd, *mps;++		mps = csrc->mc_pg[csrc->mc_top];+		/* If we're adding on the left, bump others up */+		if (fromleft) {+			mpd = cdst->mc_pg[csrc->mc_top];+			for (m2 = csrc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {+				if (csrc->mc_flags & C_SUB)+					m3 = &m2->mc_xcursor->mx_cursor;+				else+					m3 = m2;+				if (!(m3->mc_flags & C_INITIALIZED) || m3->mc_top < csrc->mc_top)+					continue;+				if (m3 != cdst &&+					m3->mc_pg[csrc->mc_top] == mpd &&+					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] == mps &&+					m3->mc_ki[csrc->mc_top] == csrc->mc_ki[csrc->mc_top]) {+					m3->mc_pg[csrc->mc_top] = cdst->mc_pg[cdst->mc_top];+					m3->mc_ki[csrc->mc_top] = cdst->mc_ki[cdst->mc_top];+					m3->mc_ki[csrc->mc_top-1]++;+				}+				if (IS_LEAF(mps))+					XCURSOR_REFRESH(m3, csrc->mc_top, m3->mc_pg[csrc->mc_top]);+			}+		} else+		/* Adding on the right, bump others down */+		{+			for (m2 = csrc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {+				if (csrc->mc_flags & C_SUB)+					m3 = &m2->mc_xcursor->mx_cursor;+				else+					m3 = 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] == mps) {+					if (!m3->mc_ki[csrc->mc_top]) {+						m3->mc_pg[csrc->mc_top] = cdst->mc_pg[cdst->mc_top];+						m3->mc_ki[csrc->mc_top] = cdst->mc_ki[cdst->mc_top];+						m3->mc_ki[csrc->mc_top-1]--;+					} else {+						m3->mc_ki[csrc->mc_top]--;+					}+					if (IS_LEAF(mps))+						XCURSOR_REFRESH(m3, csrc->mc_top, m3->mc_pg[csrc->mc_top]);+				}+			}+		}+	}++	/* Update the parent separators.+	 */+	if (csrc->mc_ki[csrc->mc_top] == 0) {+		if (csrc->mc_ki[csrc->mc_top-1] != 0) {+			if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {+				key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], 0, key.mv_size);+			} else {+				srcnode = NODEPTR(csrc->mc_pg[csrc->mc_top], 0);+				key.mv_size = NODEKSZ(srcnode);+				key.mv_data = NODEKEY(srcnode);+			}+			DPRINTF(("update separator for source page %"Z"u to [%s]",+				csrc->mc_pg[csrc->mc_top]->mp_pgno, DKEY(&key)));+			mdb_cursor_copy(csrc, &mn);+			mn.mc_snum--;+			mn.mc_top--;+			/* We want mdb_rebalance to find mn when doing fixups */+			WITH_CURSOR_TRACKING(mn,+				rc = mdb_update_key(&mn, &key));+			if (rc)+				return rc;+		}+		if (IS_BRANCH(csrc->mc_pg[csrc->mc_top])) {+			MDB_val	 nullkey;+			indx_t	ix = csrc->mc_ki[csrc->mc_top];+			nullkey.mv_size = 0;+			csrc->mc_ki[csrc->mc_top] = 0;+			rc = mdb_update_key(csrc, &nullkey);+			csrc->mc_ki[csrc->mc_top] = ix;+			mdb_cassert(csrc, rc == MDB_SUCCESS);+		}+	}++	if (cdst->mc_ki[cdst->mc_top] == 0) {+		if (cdst->mc_ki[cdst->mc_top-1] != 0) {+			if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {+				key.mv_data = LEAF2KEY(cdst->mc_pg[cdst->mc_top], 0, key.mv_size);+			} else {+				srcnode = NODEPTR(cdst->mc_pg[cdst->mc_top], 0);+				key.mv_size = NODEKSZ(srcnode);+				key.mv_data = NODEKEY(srcnode);+			}+			DPRINTF(("update separator for destination page %"Z"u to [%s]",+				cdst->mc_pg[cdst->mc_top]->mp_pgno, DKEY(&key)));+			mdb_cursor_copy(cdst, &mn);+			mn.mc_snum--;+			mn.mc_top--;+			/* We want mdb_rebalance to find mn when doing fixups */+			WITH_CURSOR_TRACKING(mn,+				rc = mdb_update_key(&mn, &key));+			if (rc)+				return rc;+		}+		if (IS_BRANCH(cdst->mc_pg[cdst->mc_top])) {+			MDB_val	 nullkey;+			indx_t	ix = cdst->mc_ki[cdst->mc_top];+			nullkey.mv_size = 0;+			cdst->mc_ki[cdst->mc_top] = 0;+			rc = mdb_update_key(cdst, &nullkey);+			cdst->mc_ki[cdst->mc_top] = ix;+			mdb_cassert(cdst, rc == MDB_SUCCESS);+		}+	}++	return MDB_SUCCESS;+}++/** Merge one page into another.+ *  The nodes from the page pointed to by \b csrc will+ *	be copied to the page pointed to by \b cdst and then+ *	the \b csrc page will be freed.+ * @param[in] csrc Cursor pointing to the source page.+ * @param[in] cdst Cursor pointing to the destination page.+ * @return 0 on success, non-zero on failure.+ */+static int+mdb_page_merge(MDB_cursor *csrc, MDB_cursor *cdst)+{+	MDB_page	*psrc, *pdst;+	MDB_node	*srcnode;+	MDB_val		 key, data;+	unsigned	 nkeys;+	int			 rc;+	indx_t		 i, j;++	psrc = csrc->mc_pg[csrc->mc_top];+	pdst = cdst->mc_pg[cdst->mc_top];++	DPRINTF(("merging page %"Z"u into %"Z"u", psrc->mp_pgno, pdst->mp_pgno));++	mdb_cassert(csrc, csrc->mc_snum > 1);	/* can't merge root page */+	mdb_cassert(csrc, cdst->mc_snum > 1);++	/* Mark dst as dirty. */+	if ((rc = mdb_page_touch(cdst)))+		return rc;++	/* get dst page again now that we've touched it. */+	pdst = cdst->mc_pg[cdst->mc_top];++	/* Move all nodes from src to dst.+	 */+	j = nkeys = NUMKEYS(pdst);+	if (IS_LEAF2(psrc)) {+		key.mv_size = csrc->mc_db->md_pad;+		key.mv_data = METADATA(psrc);+		for (i = 0; i < NUMKEYS(psrc); i++, j++) {+			rc = mdb_node_add(cdst, j, &key, NULL, 0, 0);+			if (rc != MDB_SUCCESS)+				return rc;+			key.mv_data = (char *)key.mv_data + key.mv_size;+		}+	} else {+		for (i = 0; i < NUMKEYS(psrc); i++, j++) {+			srcnode = NODEPTR(psrc, i);+			if (i == 0 && IS_BRANCH(psrc)) {+				MDB_cursor mn;+				MDB_node *s2;+				mdb_cursor_copy(csrc, &mn);+				mn.mc_xcursor = NULL;+				/* must find the lowest key below src */+				rc = mdb_page_search_lowest(&mn);+				if (rc)+					return rc;+				if (IS_LEAF2(mn.mc_pg[mn.mc_top])) {+					key.mv_size = mn.mc_db->md_pad;+					key.mv_data = LEAF2KEY(mn.mc_pg[mn.mc_top], 0, key.mv_size);+				} else {+					s2 = NODEPTR(mn.mc_pg[mn.mc_top], 0);+					key.mv_size = NODEKSZ(s2);+					key.mv_data = NODEKEY(s2);+				}+			} else {+				key.mv_size = srcnode->mn_ksize;+				key.mv_data = NODEKEY(srcnode);+			}++			data.mv_size = NODEDSZ(srcnode);+			data.mv_data = NODEDATA(srcnode);+			rc = mdb_node_add(cdst, j, &key, &data, NODEPGNO(srcnode), srcnode->mn_flags);+			if (rc != MDB_SUCCESS)+				return rc;+		}+	}++	DPRINTF(("dst page %"Z"u now has %u keys (%.1f%% filled)",+	    pdst->mp_pgno, NUMKEYS(pdst),+		(float)PAGEFILL(cdst->mc_txn->mt_env, pdst) / 10));++	/* Unlink the src page from parent and add to free list.+	 */+	csrc->mc_top--;+	mdb_node_del(csrc, 0);+	if (csrc->mc_ki[csrc->mc_top] == 0) {+		key.mv_size = 0;+		rc = mdb_update_key(csrc, &key);+		if (rc) {+			csrc->mc_top++;+			return rc;+		}+	}+	csrc->mc_top++;++	psrc = csrc->mc_pg[csrc->mc_top];+	/* If not operating on FreeDB, allow this page to be reused+	 * in this txn. Otherwise just add to free list.+	 */+	rc = mdb_page_loose(csrc, psrc);+	if (rc)+		return rc;+	if (IS_LEAF(psrc))+		csrc->mc_db->md_leaf_pages--;+	else+		csrc->mc_db->md_branch_pages--;+	{+		/* Adjust other cursors pointing to mp */+		MDB_cursor *m2, *m3;+		MDB_dbi dbi = csrc->mc_dbi;+		unsigned int top = csrc->mc_top;++		for (m2 = csrc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {+			if (csrc->mc_flags & C_SUB)+				m3 = &m2->mc_xcursor->mx_cursor;+			else+				m3 = m2;+			if (m3 == csrc) continue;+			if (m3->mc_snum < csrc->mc_snum) continue;+			if (m3->mc_pg[top] == psrc) {+				m3->mc_pg[top] = pdst;+				m3->mc_ki[top] += 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 (IS_LEAF(psrc))+				XCURSOR_REFRESH(m3, top, m3->mc_pg[top]);+		}+	}+	{+		unsigned int snum = cdst->mc_snum;+		uint16_t depth = cdst->mc_db->md_depth;+		mdb_cursor_pop(cdst);+		rc = mdb_rebalance(cdst);+		/* Did the tree height change? */+		if (depth != cdst->mc_db->md_depth)+			snum += cdst->mc_db->md_depth - depth;+		cdst->mc_snum = snum;+		cdst->mc_top = snum-1;+	}+	return rc;+}++/** Copy the contents of a cursor.+ * @param[in] csrc The cursor to copy from.+ * @param[out] cdst The cursor to copy to.+ */+static void+mdb_cursor_copy(const MDB_cursor *csrc, MDB_cursor *cdst)+{+	unsigned int i;++	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;++	for (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.+ * @param[in] mc Cursor pointing to the page where rebalancing+ * should begin.+ * @return 0 on success, non-zero on failure.+ */+static int+mdb_rebalance(MDB_cursor *mc)+{+	MDB_node	*node;+	int rc, fromleft;+	unsigned int ptop, minkeys, thresh;+	MDB_cursor	mn;+	indx_t oldki;++	if (IS_BRANCH(mc->mc_pg[mc->mc_top])) {+		minkeys = 2;+		thresh = 1;+	} else {+		minkeys = 1;+		thresh = FILL_THRESHOLD;+	}+	DPRINTF(("rebalancing %s page %"Z"u (has %u keys, %.1f%% full)",+	    IS_LEAF(mc->mc_pg[mc->mc_top]) ? "leaf" : "branch",+	    mdb_dbg_pgno(mc->mc_pg[mc->mc_top]), NUMKEYS(mc->mc_pg[mc->mc_top]),+		(float)PAGEFILL(mc->mc_txn->mt_env, mc->mc_pg[mc->mc_top]) / 10));++	if (PAGEFILL(mc->mc_txn->mt_env, mc->mc_pg[mc->mc_top]) >= thresh &&+		NUMKEYS(mc->mc_pg[mc->mc_top]) >= minkeys) {+		DPRINTF(("no need to rebalance page %"Z"u, above fill threshold",+		    mdb_dbg_pgno(mc->mc_pg[mc->mc_top])));+		return MDB_SUCCESS;+	}++	if (mc->mc_snum < 2) {+		MDB_page *mp = mc->mc_pg[0];+		if (IS_SUBP(mp)) {+			DPUTS("Can't rebalance a subpage, ignoring");+			return MDB_SUCCESS;+		}+		if (NUMKEYS(mp) == 0) {+			DPUTS("tree is completely empty");+			mc->mc_db->md_root = P_INVALID;+			mc->mc_db->md_depth = 0;+			mc->mc_db->md_leaf_pages = 0;+			rc = mdb_midl_append(&mc->mc_txn->mt_free_pgs, mp->mp_pgno);+			if (rc)+				return rc;+			/* Adjust cursors pointing to mp */+			mc->mc_snum = 0;+			mc->mc_top = 0;+			mc->mc_flags &= ~C_INITIALIZED;+			{+				MDB_cursor *m2, *m3;+				MDB_dbi dbi = mc->mc_dbi;++				for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {+					if (mc->mc_flags & C_SUB)+						m3 = &m2->mc_xcursor->mx_cursor;+					else+						m3 = m2;+					if (!(m3->mc_flags & C_INITIALIZED) || (m3->mc_snum < mc->mc_snum))+						continue;+					if (m3->mc_pg[0] == mp) {+						m3->mc_snum = 0;+						m3->mc_top = 0;+						m3->mc_flags &= ~C_INITIALIZED;+					}+				}+			}+		} else if (IS_BRANCH(mp) && NUMKEYS(mp) == 1) {+			int i;+			DPUTS("collapsing root page!");+			rc = mdb_midl_append(&mc->mc_txn->mt_free_pgs, mp->mp_pgno);+			if (rc)+				return rc;+			mc->mc_db->md_root = NODEPGNO(NODEPTR(mp, 0));+			rc = mdb_page_get(mc, mc->mc_db->md_root, &mc->mc_pg[0], NULL);+			if (rc)+				return rc;+			mc->mc_db->md_depth--;+			mc->mc_db->md_branch_pages--;+			mc->mc_ki[0] = mc->mc_ki[1];+			for (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 */+				MDB_cursor *m2, *m3;+				MDB_dbi dbi = mc->mc_dbi;++				for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {+					if (mc->mc_flags & C_SUB)+						m3 = &m2->mc_xcursor->mx_cursor;+					else+						m3 = m2;+					if (m3 == mc) continue;+					if (!(m3->mc_flags & C_INITIALIZED))+						continue;+					if (m3->mc_pg[0] == mp) {+						for (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--;+					}+				}+			}+		} else+			DPUTS("root page doesn't need rebalancing");+		return MDB_SUCCESS;+	}++	/* The parent (branch page) must have at least 2 pointers,+	 * otherwise the tree is invalid.+	 */+	ptop = mc->mc_top-1;+	mdb_cassert(mc, NUMKEYS(mc->mc_pg[ptop]) > 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.+	 */+	mdb_cursor_copy(mc, &mn);+	mn.mc_xcursor = NULL;++	oldki = mc->mc_ki[mc->mc_top];+	if (mc->mc_ki[ptop] == 0) {+		/* We're the leftmost leaf in our parent.+		 */+		DPUTS("reading right neighbor");+		mn.mc_ki[ptop]++;+		node = NODEPTR(mc->mc_pg[ptop], mn.mc_ki[ptop]);+		rc = mdb_page_get(mc, NODEPGNO(node), &mn.mc_pg[mn.mc_top], NULL);+		if (rc)+			return rc;+		mn.mc_ki[mn.mc_top] = 0;+		mc->mc_ki[mc->mc_top] = NUMKEYS(mc->mc_pg[mc->mc_top]);+		fromleft = 0;+	} else {+		/* There is at least one neighbor to the left.+		 */+		DPUTS("reading left neighbor");+		mn.mc_ki[ptop]--;+		node = NODEPTR(mc->mc_pg[ptop], mn.mc_ki[ptop]);+		rc = mdb_page_get(mc, NODEPGNO(node), &mn.mc_pg[mn.mc_top], NULL);+		if (rc)+			return rc;+		mn.mc_ki[mn.mc_top] = NUMKEYS(mn.mc_pg[mn.mc_top]) - 1;+		mc->mc_ki[mc->mc_top] = 0;+		fromleft = 1;+	}++	DPRINTF(("found neighbor page %"Z"u (%u keys, %.1f%% full)",+	    mn.mc_pg[mn.mc_top]->mp_pgno, NUMKEYS(mn.mc_pg[mn.mc_top]),+		(float)PAGEFILL(mc->mc_txn->mt_env, mn.mc_pg[mn.mc_top]) / 10));++	/* If the neighbor page is above threshold and has enough keys,+	 * move one key from it. Otherwise we should try to merge them.+	 * (A branch page must never have less than 2 keys.)+	 */+	if (PAGEFILL(mc->mc_txn->mt_env, mn.mc_pg[mn.mc_top]) >= thresh && NUMKEYS(mn.mc_pg[mn.mc_top]) > minkeys) {+		rc = mdb_node_move(&mn, mc, fromleft);+		if (fromleft) {+			/* if we inserted on left, bump position up */+			oldki++;+		}+	} else {+		if (!fromleft) {+			rc = mdb_page_merge(&mn, mc);+		} else {+			oldki += NUMKEYS(mn.mc_pg[mn.mc_top]);+			mn.mc_ki[mn.mc_top] += mc->mc_ki[mn.mc_top] + 1;+			/* We want mdb_rebalance to find mn when doing fixups */+			WITH_CURSOR_TRACKING(mn,+				rc = mdb_page_merge(mc, &mn));+			mdb_cursor_copy(&mn, mc);+		}+		mc->mc_flags &= ~C_EOF;+	}+	mc->mc_ki[mc->mc_top] = oldki;+	return rc;+}++/** Complete a delete operation started by #mdb_cursor_del(). */+static int+mdb_cursor_del0(MDB_cursor *mc)+{+	int rc;+	MDB_page *mp;+	indx_t ki;+	unsigned int nkeys;+	MDB_cursor *m2, *m3;+	MDB_dbi dbi = mc->mc_dbi;++	ki = mc->mc_ki[mc->mc_top];+	mp = mc->mc_pg[mc->mc_top];+	mdb_node_del(mc, mc->mc_db->md_pad);+	mc->mc_db->md_entries--;+	{+		/* Adjust other cursors pointing to mp */+		for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {+			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 || 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 & MDB_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]--;+				}+				XCURSOR_REFRESH(m3, mc->mc_top, mp);+			}+		}+	}+	rc = mdb_rebalance(mc);+	if (rc)+		goto fail;++	/* DB is totally empty now, just bail out.+	 * Other cursors adjustments were already done+	 * by mdb_rebalance and aren't needed here.+	 */+	if (!mc->mc_snum) {+		mc->mc_flags |= C_EOF;+		return rc;+	}++	mp = mc->mc_pg[mc->mc_top];+	nkeys = NUMKEYS(mp);++	/* Adjust other cursors pointing to mp */+	for (m2 = mc->mc_txn->mt_cursors[dbi]; !rc && m2; m2=m2->mc_next) {+		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->mc_ki[mc->mc_top] >= mc->mc_ki[mc->mc_top]) {+			/* if m3 points past last node in page, find next sibling */+				if (m3->mc_ki[mc->mc_top] >= nkeys) {+					rc = mdb_cursor_sibling(m3, 1);+					if (rc == MDB_NOTFOUND) {+						m3->mc_flags |= C_EOF;+						rc = MDB_SUCCESS;+						continue;+					}+					if (rc)+						goto fail;+				}+				if (m3->mc_xcursor && !(m3->mc_flags & C_EOF)) {+					MDB_node *node = NODEPTR(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 initd it must be reinited.+					 * Else if node points to a subDB, nothing is needed.+					 * Else (xcursor was initd, not a subDB) needs mc_pg[0] reset.+					 */+					if (node->mn_flags & F_DUPDATA) {+						if (m3->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) {+							if (!(node->mn_flags & F_SUBDATA))+								m3->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(node);+						} else {+							mdb_xcursor_init1(m3, node);+							rc = mdb_cursor_first(&m3->mc_xcursor->mx_cursor, NULL, NULL);+							if (rc)+								goto fail;+						}+					}+					m3->mc_xcursor->mx_cursor.mc_flags |= C_DEL;+				}+			}+		}+	}+	mc->mc_flags |= C_DEL;++fail:+	if (rc)+		mc->mc_txn->mt_flags |= MDB_TXN_ERROR;+	return rc;+}++int+mdb_del(MDB_txn *txn, MDB_dbi dbi,+    MDB_val *key, MDB_val *data)+{+	DKBUF;+	DDBUF;+	if (!key || !TXN_DBI_EXIST(txn, dbi, DB_USRVALID))+		return EINVAL;++	if (txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_BLOCKED))+		return (txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN;++	if (!F_ISSET(txn->mt_dbs[dbi].md_flags, MDB_DUPSORT)) {+		/* must ignore any data */+		data = NULL;+	}++	MDB_TRACE(("%p, %u, %"Z"u[%s], %"Z"u%s",+		txn, dbi, key ? key->mv_size:0, DKEY(key), data ? data->mv_size:0,+		data ? mdb_dval(txn, dbi, data, dbuf):""));+	return mdb_del0(txn, dbi, key, data, 0);+}++static int+mdb_del0(MDB_txn *txn, MDB_dbi dbi,+	MDB_val *key, MDB_val *data, unsigned flags)+{+	MDB_cursor mc;+	MDB_xcursor mx;+	MDB_cursor_op op;+	MDB_val rdata, *xdata;+	int		 rc, exact = 0;+	DKBUF;++	DPRINTF(("====> delete db %u key [%s]", dbi, DKEY(key)));++	mdb_cursor_init(&mc, txn, dbi, &mx);++	if (data) {+		op = MDB_GET_BOTH;+		rdata = *data;+		xdata = &rdata;+	} else {+		op = MDB_SET;+		xdata = NULL;+		flags |= MDB_NODUPDATA;+	}+	rc = mdb_cursor_set(&mc, key, xdata, op, &exact);+	if (rc == 0) {+		/* let mdb_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.+		 */+		mc.mc_flags |= C_UNTRACK;+		mc.mc_next = txn->mt_cursors[dbi];+		txn->mt_cursors[dbi] = &mc;+		rc = _mdb_cursor_del(&mc, flags);+		txn->mt_cursors[dbi] = mc.mc_next;+	}+	return rc;+}++/** Split a page and insert a new node.+ * Set #MDB_TXN_ERROR on failure.+ * @param[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.+ * @param[in] newkey The key for the newly inserted node.+ * @param[in] newdata The data for the newly inserted node.+ * @param[in] newpgno The page number, if the new node is a branch node.+ * @param[in] nflags The #NODE_ADD_FLAGS for the new node.+ * @return 0 on success, non-zero on failure.+ */+static int+mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata, pgno_t newpgno,+	unsigned int nflags)+{+	unsigned int flags;+	int		 rc = MDB_SUCCESS, new_root = 0, did_split = 0;+	indx_t		 newindx;+	pgno_t		 pgno = 0;+	int	 i, j, split_indx, nkeys, pmax;+	MDB_env 	*env = mc->mc_txn->mt_env;+	MDB_node	*node;+	MDB_val	 sepkey, rkey, xdata, *rdata = &xdata;+	MDB_page	*copy = NULL;+	MDB_page	*mp, *rp, *pp;+	int ptop;+	MDB_cursor	mn;+	DKBUF;++	mp = mc->mc_pg[mc->mc_top];+	newindx = mc->mc_ki[mc->mc_top];+	nkeys = NUMKEYS(mp);++	DPRINTF(("-----> splitting %s page %"Z"u 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 = mdb_page_new(mc, mp->mp_flags, 1, &rp)))+		return rc;+	rp->mp_pad = mp->mp_pad;+	DPRINTF(("new right sibling: page %"Z"u", rp->mp_pgno));++	/* Usually when splitting the root page, the cursor+	 * height is 1. But when called from mdb_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 = mdb_page_new(mc, P_BRANCH, 1, &pp)))+			goto done;+		/* shift current top to make room for new parent */+		for (i=mc->mc_snum; i>0; i--) {+			mc->mc_pg[i] = mc->mc_pg[i-1];+			mc->mc_ki[i] = mc->mc_ki[i-1];+		}+		mc->mc_pg[0] = pp;+		mc->mc_ki[0] = 0;+		mc->mc_db->md_root = pp->mp_pgno;+		DPRINTF(("root split! new root = %"Z"u", pp->mp_pgno));+		new_root = mc->mc_db->md_depth++;++		/* Add left (implicit) pointer. */+		if ((rc = mdb_node_add(mc, 0, NULL, NULL, mp->mp_pgno, 0)) != MDB_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;+		DPRINTF(("parent branch page is %"Z"u", mc->mc_pg[ptop]->mp_pgno));+	}++	mdb_cursor_copy(mc, &mn);+	mn.mc_xcursor = NULL;+	mn.mc_pg[mn.mc_top] = rp;+	mn.mc_ki[ptop] = mc->mc_ki[ptop]+1;++	if (nflags & MDB_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;+			int x;+			unsigned int lsize, rsize, ksize;+			/* Move half of the keys to the right sibling */+			x = mc->mc_ki[mc->mc_top] - split_indx;+			ksize = mc->mc_db->md_pad;+			split = LEAF2KEY(mp, split_indx, ksize);+			rsize = (nkeys - split_indx) * ksize;+			lsize = (nkeys - split_indx) * sizeof(indx_t);+			mp->mp_lower -= lsize;+			rp->mp_lower += lsize;+			mp->mp_upper += rsize - lsize;+			rp->mp_upper -= rsize - lsize;+			sepkey.mv_size = ksize;+			if (newindx == split_indx) {+				sepkey.mv_data = newkey->mv_data;+			} else {+				sepkey.mv_data = split;+			}+			if (x<0) {+				ins = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], ksize);+				memcpy(rp->mp_ptrs, split, rsize);+				sepkey.mv_data = rp->mp_ptrs;+				memmove(ins+ksize, ins, (split_indx - mc->mc_ki[mc->mc_top]) * ksize);+				memcpy(ins, newkey->mv_data, ksize);+				mp->mp_lower += sizeof(indx_t);+				mp->mp_upper -= ksize - sizeof(indx_t);+			} else {+				if (x)+					memcpy(rp->mp_ptrs, split, x * ksize);+				ins = LEAF2KEY(rp, x, ksize);+				memcpy(ins, newkey->mv_data, ksize);+				memcpy(ins+ksize, split + x * ksize, rsize - x * ksize);+				rp->mp_lower += sizeof(indx_t);+				rp->mp_upper -= ksize - sizeof(indx_t);+				mc->mc_ki[mc->mc_top] = x;+			}+		} else {+			int psize, nsize, k, keythresh;++			/* Maximum free space in an empty page */+			pmax = env->me_psize - PAGEHDRSZ;+			/* Threshold number of keys considered "small" */+			keythresh = env->me_psize >> 7;++			if (IS_LEAF(mp))+				nsize = mdb_leaf_size(env, newkey, newdata);+			else+				nsize = mdb_branch_size(env, newkey);+			nsize = EVEN(nsize);++			/* grab a page to hold a temporary copy */+			copy = mdb_page_malloc(mc->mc_txn, 1);+			if (copy == NULL) {+				rc = ENOMEM;+				goto done;+			}+			copy->mp_pgno  = mp->mp_pgno;+			copy->mp_flags = mp->mp_flags;+			copy->mp_lower = (PAGEHDRSZ-PAGEBASE);+			copy->mp_upper = env->me_psize - PAGEBASE;++			/* prepare to insert */+			for (i=0, j=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 mdb_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 < keythresh || nsize > pmax/16 || newindx >= nkeys) {+				/* Find split point */+				psize = 0;+				if (newindx <= split_indx || newindx >= nkeys) {+					i = 0; j = 1;+					k = newindx >= nkeys ? nkeys : split_indx+1+IS_LEAF(mp);+				} else {+					i = nkeys; j = -1;+					k = split_indx-1;+				}+				for (; i!=k; i+=j) {+					if (i == newindx) {+						psize += nsize;+						node = NULL;+					} else {+						node = (MDB_node *)((char *)mp + copy->mp_ptrs[i] + PAGEBASE);+						psize += NODESIZE + NODEKSZ(node) + sizeof(indx_t);+						if (IS_LEAF(mp)) {+							if (F_ISSET(node->mn_flags, F_BIGDATA))+								psize += sizeof(pgno_t);+							else+								psize += NODEDSZ(node);+						}+						psize = EVEN(psize);+					}+					if (psize > pmax || i == k-j) {+						split_indx = i + (j<0);+						break;+					}+				}+			}+			if (split_indx == newindx) {+				sepkey.mv_size = newkey->mv_size;+				sepkey.mv_data = newkey->mv_data;+			} else {+				node = (MDB_node *)((char *)mp + copy->mp_ptrs[split_indx] + PAGEBASE);+				sepkey.mv_size = node->mn_ksize;+				sepkey.mv_data = NODEKEY(node);+			}+		}+	}++	DPRINTF(("separator is %d [%s]", split_indx, DKEY(&sepkey)));++	/* Copy separator key to the parent.+	 */+	if (SIZELEFT(mn.mc_pg[ptop]) < mdb_branch_size(env, &sepkey)) {+		int snum = mc->mc_snum;+		mn.mc_snum--;+		mn.mc_top--;+		did_split = 1;+		/* We want other splits to find mn when doing fixups */+		WITH_CURSOR_TRACKING(mn,+			rc = mdb_page_split(&mn, &sepkey, NULL, rp->mp_pgno, 0));+		if (rc)+			goto done;++		/* root split? */+		if (mc->mc_snum > snum) {+			ptop++;+		}+		/* 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] >= 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];+				mdb_cursor_sibling(mc, 0);+			}+		}+	} else {+		mn.mc_top--;+		rc = mdb_node_add(&mn, mn.mc_ki[ptop], &sepkey, NULL, rp->mp_pgno, 0);+		mn.mc_top++;+	}+	if (rc != MDB_SUCCESS) {+		goto done;+	}+	if (nflags & MDB_APPEND) {+		mc->mc_pg[mc->mc_top] = rp;+		mc->mc_ki[mc->mc_top] = 0;+		rc = mdb_node_add(mc, 0, newkey, newdata, newpgno, nflags);+		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;+		j = 0;+		do {+			if (i == newindx) {+				rkey.mv_data = newkey->mv_data;+				rkey.mv_size = newkey->mv_size;+				if (IS_LEAF(mp)) {+					rdata = newdata;+				} else+					pgno = newpgno;+				flags = nflags;+				/* Update index for the new key. */+				mc->mc_ki[mc->mc_top] = j;+			} else {+				node = (MDB_node *)((char *)mp + copy->mp_ptrs[i] + PAGEBASE);+				rkey.mv_data = NODEKEY(node);+				rkey.mv_size = node->mn_ksize;+				if (IS_LEAF(mp)) {+					xdata.mv_data = NODEDATA(node);+					xdata.mv_size = NODEDSZ(node);+					rdata = &xdata;+				} else+					pgno = NODEPGNO(node);+				flags = node->mn_flags;+			}++			if (!IS_LEAF(mp) && j == 0) {+				/* First branch index doesn't need key data. */+				rkey.mv_size = 0;+			}++			rc = mdb_node_add(mc, j, &rkey, rdata, pgno, flags);+			if (rc)+				goto done;+			if (i == nkeys) {+				i = 0;+				j = 0;+				mc->mc_pg[mc->mc_top] = copy;+			} else {+				i++;+				j++;+			}+		} while (i != split_indx);++		nkeys = 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(NODEPTR(mp, nkeys-1), NODEPTR(copy, nkeys-1),+			env->me_psize - copy->mp_upper - PAGEBASE);++		/* 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] >= 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 & MDB_RESERVE) {+			node = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);+			if (!(node->mn_flags & F_BIGDATA))+				newdata->mv_data = NODEDATA(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] >= 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 */+		MDB_cursor *m2, *m3;+		MDB_dbi dbi = mc->mc_dbi;+		nkeys = NUMKEYS(mp);++		for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {+			if (mc->mc_flags & C_SUB)+				m3 = &m2->mc_xcursor->mx_cursor;+			else+				m3 = m2;+			if (m3 == mc)+				continue;+			if (!(m2->mc_flags & m3->mc_flags & C_INITIALIZED))+				continue;+			if (new_root) {+				int k;+				/* sub cursors may be on different DB */+				if (m3->mc_pg[0] != mp)+					continue;+				/* root split */+				for (k=new_root; k>=0; k--) {+					m3->mc_ki[k+1] = m3->mc_ki[k];+					m3->mc_pg[k+1] = m3->mc_pg[k];+				}+				if (m3->mc_ki[0] >= nkeys) {+					m3->mc_ki[0] = 1;+				} else {+					m3->mc_ki[0] = 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 & MDB_SPLIT_REPLACE))+					m3->mc_ki[mc->mc_top]++;+				if (m3->mc_ki[mc->mc_top] >= nkeys) {+					m3->mc_pg[mc->mc_top] = rp;+					m3->mc_ki[mc->mc_top] -= 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 (IS_LEAF(mp))+				XCURSOR_REFRESH(m3, mc->mc_top, m3->mc_pg[mc->mc_top]);+		}+	}+	DPRINTF(("mp left: %d, rp left: %d", SIZELEFT(mp), SIZELEFT(rp)));++done:+	if (copy)					/* tmp page */+		mdb_page_free(env, copy);+	if (rc)+		mc->mc_txn->mt_flags |= MDB_TXN_ERROR;+	return rc;+}++int+mdb_put(MDB_txn *txn, MDB_dbi dbi,+    MDB_val *key, MDB_val *data, unsigned int flags)+{+	MDB_cursor mc;+	MDB_xcursor mx;+	int rc;+	DKBUF;+	DDBUF;++	if (!key || !data || !TXN_DBI_EXIST(txn, dbi, DB_USRVALID))+		return EINVAL;++	if (flags & ~(MDB_NOOVERWRITE|MDB_NODUPDATA|MDB_RESERVE|MDB_APPEND|MDB_APPENDDUP))+		return EINVAL;++	if (txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_BLOCKED))+		return (txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN;++	MDB_TRACE(("%p, %u, %"Z"u[%s], %"Z"u%s, %u",+		txn, dbi, key ? key->mv_size:0, DKEY(key), data->mv_size, mdb_dval(txn, dbi, data, dbuf), flags));+	mdb_cursor_init(&mc, txn, dbi, &mx);+	mc.mc_next = txn->mt_cursors[dbi];+	txn->mt_cursors[dbi] = &mc;+	rc = _mdb_cursor_put(&mc, key, data, flags);+	txn->mt_cursors[dbi] = mc.mc_next;+	return rc;+}++#ifndef MDB_WBUF+#define MDB_WBUF	(1024*1024)+#endif+#define MDB_EOF		0x10	/**< #mdb_env_copyfd1() is done reading */++	/** State needed for a double-buffering compacting copy. */+typedef struct mdb_copy {+	MDB_env *mc_env;+	MDB_txn *mc_txn;+	pthread_mutex_t mc_mutex;+	pthread_cond_t mc_cond;	/**< Condition variable for #mc_new */+	char *mc_wbuf[2];+	char *mc_over[2];+	int mc_wlen[2];+	int mc_olen[2];+	pgno_t mc_next_pgno;+	HANDLE mc_fd;+	int mc_toggle;			/**< Buffer number in provider */+	int mc_new;				/**< (0-2 buffers to write) | (#MDB_EOF at end) */+	/** Error code.  Never cleared if set.  Both threads can set nonzero+	 *	to fail the copy.  Not mutex-protected, LMDB expects atomic int.+	 */+	volatile int mc_error;+} mdb_copy;++	/** Dedicated writer thread for compacting copy. */+static THREAD_RET ESECT CALL_CONV+mdb_env_copythr(void *arg)+{+	mdb_copy *my = arg;+	char *ptr;+	int toggle = 0, wsize, rc;+#ifdef _WIN32+	DWORD len;+#define DO_WRITE(rc, fd, ptr, w2, len)	rc = WriteFile(fd, ptr, w2, &len, NULL)+#else+	int len;+#define DO_WRITE(rc, fd, ptr, w2, len)	len = write(fd, ptr, w2); rc = (len >= 0)+#ifdef SIGPIPE+	sigset_t set;+	sigemptyset(&set);+	sigaddset(&set, SIGPIPE);+	if ((rc = pthread_sigmask(SIG_BLOCK, &set, NULL)) != 0)+		my->mc_error = rc;+#endif+#endif++	pthread_mutex_lock(&my->mc_mutex);+	for(;;) {+		while (!my->mc_new)+			pthread_cond_wait(&my->mc_cond, &my->mc_mutex);+		if (my->mc_new == 0 + MDB_EOF) /* 0 buffers, just EOF */+			break;+		wsize = my->mc_wlen[toggle];+		ptr = my->mc_wbuf[toggle];+again:+		rc = MDB_SUCCESS;+		while (wsize > 0 && !my->mc_error) {+			DO_WRITE(rc, my->mc_fd, ptr, wsize, len);+			if (!rc) {+				rc = ErrCode();+#if defined(SIGPIPE) && !defined(_WIN32)+				if (rc == EPIPE) {+					/* Collect the pending SIGPIPE, otherwise at least OS X+					 * gives it to the process on thread-exit (ITS#8504).+					 */+					int tmp;+					sigwait(&set, &tmp);+				}+#endif+				break;+			} else if (len > 0) {+				rc = MDB_SUCCESS;+				ptr += len;+				wsize -= len;+				continue;+			} else {+				rc = EIO;+				break;+			}+		}+		if (rc) {+			my->mc_error = rc;+		}+		/* If there's an overflow page tail, write it too */+		if (my->mc_olen[toggle]) {+			wsize = my->mc_olen[toggle];+			ptr = my->mc_over[toggle];+			my->mc_olen[toggle] = 0;+			goto again;+		}+		my->mc_wlen[toggle] = 0;+		toggle ^= 1;+		/* Return the empty buffer to provider */+		my->mc_new--;+		pthread_cond_signal(&my->mc_cond);+	}+	pthread_mutex_unlock(&my->mc_mutex);+	return (THREAD_RET)0;+#undef DO_WRITE+}++	/** Give buffer and/or #MDB_EOF to writer thread, await unused buffer.+	 *+	 * @param[in] my control structure.+	 * @param[in] adjust (1 to hand off 1 buffer) | (MDB_EOF when ending).+	 */+static int ESECT+mdb_env_cthr_toggle(mdb_copy *my, int adjust)+{+	pthread_mutex_lock(&my->mc_mutex);+	my->mc_new += adjust;+	pthread_cond_signal(&my->mc_cond);+	while (my->mc_new & 2)		/* both buffers in use */+		pthread_cond_wait(&my->mc_cond, &my->mc_mutex);+	pthread_mutex_unlock(&my->mc_mutex);++	my->mc_toggle ^= (adjust & 1);+	/* Both threads reset mc_wlen, to be safe from threading errors */+	my->mc_wlen[my->mc_toggle] = 0;+	return my->mc_error;+}++	/** Depth-first tree traversal for compacting copy.+	 * @param[in] my control structure.+	 * @param[in,out] pg database root.+	 * @param[in] flags includes #F_DUPDATA if it is a sorted-duplicate sub-DB.+	 */+static int ESECT+mdb_env_cwalk(mdb_copy *my, pgno_t *pg, int flags)+{+	MDB_cursor mc = {0};+	MDB_node *ni;+	MDB_page *mo, *mp, *leaf;+	char *buf, *ptr;+	int rc, toggle;+	unsigned int i;++	/* Empty DB, nothing to do */+	if (*pg == P_INVALID)+		return MDB_SUCCESS;++	mc.mc_snum = 1;+	mc.mc_txn = my->mc_txn;++	rc = mdb_page_get(&mc, *pg, &mc.mc_pg[0], NULL);+	if (rc)+		return rc;+	rc = mdb_page_search_root(&mc, NULL, MDB_PS_FIRST);+	if (rc)+		return rc;++	/* Make cursor pages writable */+	buf = ptr = malloc(my->mc_env->me_psize * mc.mc_snum);+	if (buf == NULL)+		return ENOMEM;++	for (i=0; i<mc.mc_top; i++) {+		mdb_page_copy((MDB_page *)ptr, mc.mc_pg[i], my->mc_env->me_psize);+		mc.mc_pg[i] = (MDB_page *)ptr;+		ptr += my->mc_env->me_psize;+	}++	/* This is writable space for a leaf page. Usually not needed. */+	leaf = (MDB_page *)ptr;++	toggle = my->mc_toggle;+	while (mc.mc_snum > 0) {+		unsigned n;+		mp = mc.mc_pg[mc.mc_top];+		n = NUMKEYS(mp);++		if (IS_LEAF(mp)) {+			if (!IS_LEAF2(mp) && !(flags & F_DUPDATA)) {+				for (i=0; i<n; i++) {+					ni = NODEPTR(mp, i);+					if (ni->mn_flags & F_BIGDATA) {+						MDB_page *omp;+						pgno_t pg;++						/* Need writable leaf */+						if (mp != leaf) {+							mc.mc_pg[mc.mc_top] = leaf;+							mdb_page_copy(leaf, mp, my->mc_env->me_psize);+							mp = leaf;+							ni = NODEPTR(mp, i);+						}++						memcpy(&pg, NODEDATA(ni), sizeof(pg));+						memcpy(NODEDATA(ni), &my->mc_next_pgno, sizeof(pgno_t));+						rc = mdb_page_get(&mc, pg, &omp, NULL);+						if (rc)+							goto done;+						if (my->mc_wlen[toggle] >= MDB_WBUF) {+							rc = mdb_env_cthr_toggle(my, 1);+							if (rc)+								goto done;+							toggle = my->mc_toggle;+						}+						mo = (MDB_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] = my->mc_env->me_psize * (omp->mp_pages - 1);+							my->mc_over[toggle] = (char *)omp + my->mc_env->me_psize;+							rc = mdb_env_cthr_toggle(my, 1);+							if (rc)+								goto done;+							toggle = my->mc_toggle;+						}+					} else if (ni->mn_flags & F_SUBDATA) {+						MDB_db db;++						/* Need writable leaf */+						if (mp != leaf) {+							mc.mc_pg[mc.mc_top] = leaf;+							mdb_page_copy(leaf, mp, my->mc_env->me_psize);+							mp = leaf;+							ni = NODEPTR(mp, i);+						}++						memcpy(&db, NODEDATA(ni), sizeof(db));+						my->mc_toggle = toggle;+						rc = mdb_env_cwalk(my, &db.md_root, ni->mn_flags & F_DUPDATA);+						if (rc)+							goto done;+						toggle = my->mc_toggle;+						memcpy(NODEDATA(ni), &db, sizeof(db));+					}+				}+			}+		} else {+			mc.mc_ki[mc.mc_top]++;+			if (mc.mc_ki[mc.mc_top] < n) {+				pgno_t pg;+again:+				ni = NODEPTR(mp, mc.mc_ki[mc.mc_top]);+				pg = NODEPGNO(ni);+				rc = mdb_page_get(&mc, pg, &mp, NULL);+				if (rc)+					goto done;+				mc.mc_top++;+				mc.mc_snum++;+				mc.mc_ki[mc.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.+					 */+					mdb_page_copy(mc.mc_pg[mc.mc_top], mp, my->mc_env->me_psize);+					goto again;+				} else+					mc.mc_pg[mc.mc_top] = mp;+				continue;+			}+		}+		if (my->mc_wlen[toggle] >= MDB_WBUF) {+			rc = mdb_env_cthr_toggle(my, 1);+			if (rc)+				goto done;+			toggle = my->mc_toggle;+		}+		mo = (MDB_page *)(my->mc_wbuf[toggle] + my->mc_wlen[toggle]);+		mdb_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 (mc.mc_top) {+			/* Update parent if there is one */+			ni = NODEPTR(mc.mc_pg[mc.mc_top-1], mc.mc_ki[mc.mc_top-1]);+			SETPGNO(ni, mo->mp_pgno);+			mdb_cursor_pop(&mc);+		} else {+			/* Otherwise we're done */+			*pg = mo->mp_pgno;+			break;+		}+	}+done:+	free(buf);+	return rc;+}++	/** Copy environment with compaction. */+static int ESECT+mdb_env_copyfd1(MDB_env *env, HANDLE fd)+{+	MDB_meta *mm;+	MDB_page *mp;+	mdb_copy my = {0};+	MDB_txn *txn = NULL;+	pthread_t thr;+	pgno_t root, new_root;+	int rc = MDB_SUCCESS;++#ifdef _WIN32+	if (!(my.mc_mutex = CreateMutex(NULL, FALSE, NULL)) ||+		!(my.mc_cond = CreateEvent(NULL, FALSE, FALSE, NULL))) {+		rc = ErrCode();+		goto done;+	}+	my.mc_wbuf[0] = _aligned_malloc(MDB_WBUF*2, env->me_os_psize);+	if (my.mc_wbuf[0] == NULL) {+		/* _aligned_malloc() sets errno, but we use Windows error codes */+		rc = ERROR_NOT_ENOUGH_MEMORY;+		goto done;+	}+#else+	if ((rc = pthread_mutex_init(&my.mc_mutex, NULL)) != 0)+		return rc;+	if ((rc = pthread_cond_init(&my.mc_cond, NULL)) != 0)+		goto done2;+#ifdef HAVE_MEMALIGN+	my.mc_wbuf[0] = memalign(env->me_os_psize, MDB_WBUF*2);+	if (my.mc_wbuf[0] == NULL) {+		rc = errno;+		goto done;+	}+#else+	{+		void *p;+		if ((rc = posix_memalign(&p, env->me_os_psize, MDB_WBUF*2)) != 0)+			goto done;+		my.mc_wbuf[0] = p;+	}+#endif+#endif+	memset(my.mc_wbuf[0], 0, MDB_WBUF*2);+	my.mc_wbuf[1] = my.mc_wbuf[0] + MDB_WBUF;+	my.mc_next_pgno = NUM_METAS;+	my.mc_env = env;+	my.mc_fd = fd;+	rc = THREAD_CREATE(thr, mdb_env_copythr, &my);+	if (rc)+		goto done;++	rc = mdb_txn_begin(env, NULL, MDB_RDONLY, &txn);+	if (rc)+		goto finish;++	mp = (MDB_page *)my.mc_wbuf[0];+	memset(mp, 0, NUM_METAS * env->me_psize);+	mp->mp_pgno = 0;+	mp->mp_flags = P_META;+	mm = (MDB_meta *)METADATA(mp);+	mdb_env_init_meta0(env, mm);+	mm->mm_address = env->me_metas[0]->mm_address;++	mp = (MDB_page *)(my.mc_wbuf[0] + env->me_psize);+	mp->mp_pgno = 1;+	mp->mp_flags = P_META;+	*(MDB_meta *)METADATA(mp) = *mm;+	mm = (MDB_meta *)METADATA(mp);++	/* Set metapage 1 with current main DB */+	root = new_root = txn->mt_dbs[MAIN_DBI].md_root;+	if (root != P_INVALID) {+		/* Count free pages + freeDB pages.  Subtract from last_pg+		 * to find the new last_pg, which also becomes the new root.+		 */+		MDB_ID freecount = 0;+		MDB_cursor mc;+		MDB_val key, data;+		mdb_cursor_init(&mc, txn, FREE_DBI, NULL);+		while ((rc = mdb_cursor_get(&mc, &key, &data, MDB_NEXT)) == 0)+			freecount += *(MDB_ID *)data.mv_data;+		if (rc != MDB_NOTFOUND)+			goto finish;+		freecount += txn->mt_dbs[FREE_DBI].md_branch_pages ++			txn->mt_dbs[FREE_DBI].md_leaf_pages ++			txn->mt_dbs[FREE_DBI].md_overflow_pages;++		new_root = txn->mt_next_pgno - 1 - freecount;+		mm->mm_last_pg = new_root;+		mm->mm_dbs[MAIN_DBI] = txn->mt_dbs[MAIN_DBI];+		mm->mm_dbs[MAIN_DBI].md_root = new_root;+	} else {+		/* When the DB is empty, handle it specially to+		 * fix any breakage like page leaks from ITS#8174.+		 */+		mm->mm_dbs[MAIN_DBI].md_flags = txn->mt_dbs[MAIN_DBI].md_flags;+	}+	if (root != P_INVALID || mm->mm_dbs[MAIN_DBI].md_flags) {+		mm->mm_txnid = 1;		/* use metapage 1 */+	}++	my.mc_wlen[0] = env->me_psize * NUM_METAS;+	my.mc_txn = txn;+	rc = mdb_env_cwalk(&my, &root, 0);+	if (rc == MDB_SUCCESS && root != new_root) {+		rc = MDB_INCOMPATIBLE;	/* page leak or corrupt DB */+	}++finish:+	if (rc)+		my.mc_error = rc;+	mdb_env_cthr_toggle(&my, 1 | MDB_EOF);+	rc = THREAD_FINISH(thr);+	_mdb_txn_abort(txn);++done:+#ifdef _WIN32+	if (my.mc_wbuf[0]) _aligned_free(my.mc_wbuf[0]);+	if (my.mc_cond)  CloseHandle(my.mc_cond);+	if (my.mc_mutex) CloseHandle(my.mc_mutex);+#else+	free(my.mc_wbuf[0]);+	pthread_cond_destroy(&my.mc_cond);+done2:+	pthread_mutex_destroy(&my.mc_mutex);+#endif+	return rc ? rc : my.mc_error;+}++	/** Copy environment as-is. */+static int ESECT+mdb_env_copyfd0(MDB_env *env, HANDLE fd)+{+	MDB_txn *txn = NULL;+	mdb_mutexref_t wmutex = NULL;+	int rc;+	size_t wsize, w3;+	char *ptr;+#ifdef _WIN32+	DWORD len, w2;+#define DO_WRITE(rc, fd, ptr, w2, len)	rc = WriteFile(fd, ptr, w2, &len, NULL)+#else+	ssize_t len;+	size_t w2;+#define DO_WRITE(rc, fd, ptr, w2, len)	len = write(fd, ptr, w2); rc = (len >= 0)+#endif++	/* Do the lock/unlock of the reader mutex before starting the+	 * write txn.  Otherwise other read txns could block writers.+	 */+	rc = mdb_txn_begin(env, NULL, MDB_RDONLY, &txn);+	if (rc)+		return rc;++	if (env->me_txns) {+		/* We must start the actual read txn after blocking writers */+		mdb_txn_end(txn, MDB_END_RESET_TMP);++		/* Temporarily block writers until we snapshot the meta pages */+		wmutex = env->me_wmutex;+		if (LOCK_MUTEX(rc, env, wmutex))+			goto leave;++		rc = mdb_txn_renew0(txn);+		if (rc) {+			UNLOCK_MUTEX(wmutex);+			goto leave;+		}+	}++	wsize = env->me_psize * NUM_METAS;+	ptr = env->me_map;+	w2 = wsize;+	while (w2 > 0) {+		DO_WRITE(rc, fd, ptr, w2, len);+		if (!rc) {+			rc = ErrCode();+			break;+		} else if (len > 0) {+			rc = MDB_SUCCESS;+			ptr += len;+			w2 -= len;+			continue;+		} else {+			/* Non-blocking or async handles are not supported */+			rc = EIO;+			break;+		}+	}+	if (wmutex)+		UNLOCK_MUTEX(wmutex);++	if (rc)+		goto leave;++	w3 = txn->mt_next_pgno * env->me_psize;+	{+		size_t fsize = 0;+		if ((rc = mdb_fsize(env->me_fd, &fsize)))+			goto leave;+		if (w3 > fsize)+			w3 = fsize;+	}+	wsize = w3 - wsize;+	while (wsize > 0) {+		if (wsize > MAX_WRITE)+			w2 = MAX_WRITE;+		else+			w2 = wsize;+		DO_WRITE(rc, fd, ptr, w2, len);+		if (!rc) {+			rc = ErrCode();+			break;+		} else if (len > 0) {+			rc = MDB_SUCCESS;+			ptr += len;+			wsize -= len;+			continue;+		} else {+			rc = EIO;+			break;+		}+	}++leave:+	_mdb_txn_abort(txn);+	return rc;+}++int ESECT+mdb_env_copyfd2(MDB_env *env, HANDLE fd, unsigned int flags)+{+	if (flags & MDB_CP_COMPACT)+		return mdb_env_copyfd1(env, fd);+	else+		return mdb_env_copyfd0(env, fd);+}++int ESECT+mdb_env_copyfd(MDB_env *env, HANDLE fd)+{+	return mdb_env_copyfd2(env, fd, 0);+}++int ESECT+mdb_env_copy2(MDB_env *env, const char *path, unsigned int flags)+{+	int rc;+	MDB_name fname;+	HANDLE newfd = INVALID_HANDLE_VALUE;++	rc = mdb_fname_init(path, env->me_flags | MDB_NOLOCK, &fname);+	if (rc == MDB_SUCCESS) {+		rc = mdb_fopen(env, &fname, MDB_O_COPY, 0666, &newfd);+		mdb_fname_destroy(fname);+	}+	if (rc == MDB_SUCCESS) {+		rc = mdb_env_copyfd2(env, newfd, flags);+		if (close(newfd) < 0 && rc == MDB_SUCCESS)+			rc = ErrCode();+	}+	return rc;+}++int ESECT+mdb_env_copy(MDB_env *env, const char *path)+{+	return mdb_env_copy2(env, path, 0);+}++int ESECT+mdb_env_set_flags(MDB_env *env, unsigned int flag, int onoff)+{+	if (flag & ~CHANGEABLE)+		return EINVAL;+	if (onoff)+		env->me_flags |= flag;+	else+		env->me_flags &= ~flag;+	return MDB_SUCCESS;+}++int ESECT+mdb_env_get_flags(MDB_env *env, unsigned int *arg)+{+	if (!env || !arg)+		return EINVAL;++	*arg = env->me_flags & (CHANGEABLE|CHANGELESS);+	return MDB_SUCCESS;+}++int ESECT+mdb_env_set_userctx(MDB_env *env, void *ctx)+{+	if (!env)+		return EINVAL;+	env->me_userctx = ctx;+	return MDB_SUCCESS;+}++void * ESECT+mdb_env_get_userctx(MDB_env *env)+{+	return env ? env->me_userctx : NULL;+}++int ESECT+mdb_env_set_assert(MDB_env *env, MDB_assert_func *func)+{+	if (!env)+		return EINVAL;+#ifndef NDEBUG+	env->me_assert_func = func;+#endif+	return MDB_SUCCESS;+}++int ESECT+mdb_env_get_path(MDB_env *env, const char **arg)+{+	if (!env || !arg)+		return EINVAL;++	*arg = env->me_path;+	return MDB_SUCCESS;+}++int ESECT+mdb_env_get_fd(MDB_env *env, mdb_filehandle_t *arg)+{+	if (!env || !arg)+		return EINVAL;++	*arg = env->me_fd;+	return MDB_SUCCESS;+}++/** Common code for #mdb_stat() and #mdb_env_stat().+ * @param[in] env the environment to operate in.+ * @param[in] db the #MDB_db record containing the stats to return.+ * @param[out] arg the address of an #MDB_stat structure to receive the stats.+ * @return 0, this function always succeeds.+ */+static int ESECT+mdb_stat0(MDB_env *env, MDB_db *db, MDB_stat *arg)+{+	arg->ms_psize = env->me_psize;+	arg->ms_depth = db->md_depth;+	arg->ms_branch_pages = db->md_branch_pages;+	arg->ms_leaf_pages = db->md_leaf_pages;+	arg->ms_overflow_pages = db->md_overflow_pages;+	arg->ms_entries = db->md_entries;++	return MDB_SUCCESS;+}++int ESECT+mdb_env_stat(MDB_env *env, MDB_stat *arg)+{+	MDB_meta *meta;++	if (env == NULL || arg == NULL)+		return EINVAL;++	meta = mdb_env_pick_meta(env);++	return mdb_stat0(env, &meta->mm_dbs[MAIN_DBI], arg);+}++int ESECT+mdb_env_info(MDB_env *env, MDB_envinfo *arg)+{+	MDB_meta *meta;++	if (env == NULL || arg == NULL)+		return EINVAL;++	meta = mdb_env_pick_meta(env);+	arg->me_mapaddr = meta->mm_address;+	arg->me_last_pgno = meta->mm_last_pg;+	arg->me_last_txnid = meta->mm_txnid;++	arg->me_mapsize = env->me_mapsize;+	arg->me_maxreaders = env->me_maxreaders;+	arg->me_numreaders = env->me_txns ? env->me_txns->mti_numreaders : 0;+	return MDB_SUCCESS;+}++/** Set the default comparison functions for a database.+ * Called immediately after a database is opened to set the defaults.+ * The user can then override them with #mdb_set_compare() or+ * #mdb_set_dupsort().+ * @param[in] txn A transaction handle returned by #mdb_txn_begin()+ * @param[in] dbi A database handle returned by #mdb_dbi_open()+ */+static void+mdb_default_cmp(MDB_txn *txn, MDB_dbi dbi)+{+	uint16_t f = txn->mt_dbs[dbi].md_flags;++	txn->mt_dbxs[dbi].md_cmp =+		(f & MDB_REVERSEKEY) ? mdb_cmp_memnr :+		(f & MDB_INTEGERKEY) ? mdb_cmp_cint  : mdb_cmp_memn;++	txn->mt_dbxs[dbi].md_dcmp =+		!(f & MDB_DUPSORT) ? 0 :+		((f & MDB_INTEGERDUP)+		 ? ((f & MDB_DUPFIXED)   ? mdb_cmp_int   : mdb_cmp_cint)+		 : ((f & MDB_REVERSEDUP) ? mdb_cmp_memnr : mdb_cmp_memn));+}++int mdb_dbi_open(MDB_txn *txn, const char *name, unsigned int flags, MDB_dbi *dbi)+{+	MDB_val key, data;+	MDB_dbi i;+	MDB_cursor mc;+	MDB_db dummy;+	int rc, dbflag, exact;+	unsigned int unused = 0, seq;+	char *namedup;+	size_t len;++	if (flags & ~VALID_FLAGS)+		return EINVAL;+	if (txn->mt_flags & MDB_TXN_BLOCKED)+		return MDB_BAD_TXN;++	/* main DB? */+	if (!name) {+		*dbi = MAIN_DBI;+		if (flags & PERSISTENT_FLAGS) {+			uint16_t f2 = flags & PERSISTENT_FLAGS;+			/* make sure flag changes get committed */+			if ((txn->mt_dbs[MAIN_DBI].md_flags | f2) != txn->mt_dbs[MAIN_DBI].md_flags) {+				txn->mt_dbs[MAIN_DBI].md_flags |= f2;+				txn->mt_flags |= MDB_TXN_DIRTY;+			}+		}+		mdb_default_cmp(txn, MAIN_DBI);+		MDB_TRACE(("%p, (null), %u = %u", txn, flags, MAIN_DBI));+		return MDB_SUCCESS;+	}++	if (txn->mt_dbxs[MAIN_DBI].md_cmp == NULL) {+		mdb_default_cmp(txn, MAIN_DBI);+	}++	/* Is the DB already open? */+	len = strlen(name);+	for (i=CORE_DBS; i<txn->mt_numdbs; i++) {+		if (!txn->mt_dbxs[i].md_name.mv_size) {+			/* Remember this free slot */+			if (!unused) unused = i;+			continue;+		}+		if (len == txn->mt_dbxs[i].md_name.mv_size &&+			!strncmp(name, txn->mt_dbxs[i].md_name.mv_data, len)) {+			*dbi = i;+			return MDB_SUCCESS;+		}+	}++	/* If no free slot and max hit, fail */+	if (!unused && txn->mt_numdbs >= txn->mt_env->me_maxdbs)+		return MDB_DBS_FULL;++	/* Cannot mix named databases with some mainDB flags */+	if (txn->mt_dbs[MAIN_DBI].md_flags & (MDB_DUPSORT|MDB_INTEGERKEY))+		return (flags & MDB_CREATE) ? MDB_INCOMPATIBLE : MDB_NOTFOUND;++	/* Find the DB info */+	dbflag = DB_NEW|DB_VALID|DB_USRVALID;+	exact = 0;+	key.mv_size = len;+	key.mv_data = (void *)name;+	mdb_cursor_init(&mc, txn, MAIN_DBI, NULL);+	rc = mdb_cursor_set(&mc, &key, &data, MDB_SET, &exact);+	if (rc == MDB_SUCCESS) {+		/* make sure this is actually a DB */+		MDB_node *node = NODEPTR(mc.mc_pg[mc.mc_top], mc.mc_ki[mc.mc_top]);+		if ((node->mn_flags & (F_DUPDATA|F_SUBDATA)) != F_SUBDATA)+			return MDB_INCOMPATIBLE;+	} else {+		if (rc != MDB_NOTFOUND || !(flags & MDB_CREATE))+			return rc;+		if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY))+			return EACCES;+	}++	/* Done here so we cannot fail after creating a new DB */+	if ((namedup = strdup(name)) == NULL)+		return ENOMEM;++	if (rc) {+		/* MDB_NOTFOUND and MDB_CREATE: Create new DB */+		data.mv_size = sizeof(MDB_db);+		data.mv_data = &dummy;+		memset(&dummy, 0, sizeof(dummy));+		dummy.md_root = P_INVALID;+		dummy.md_flags = flags & PERSISTENT_FLAGS;+		WITH_CURSOR_TRACKING(mc,+			rc = _mdb_cursor_put(&mc, &key, &data, F_SUBDATA));+		dbflag |= DB_DIRTY;+	}++	if (rc) {+		free(namedup);+	} else {+		/* Got info, register DBI in this txn */+		unsigned int slot = unused ? unused : txn->mt_numdbs;+		txn->mt_dbxs[slot].md_name.mv_data = namedup;+		txn->mt_dbxs[slot].md_name.mv_size = len;+		txn->mt_dbxs[slot].md_rel = NULL;+		txn->mt_dbflags[slot] = dbflag;+		/* txn-> and env-> are the same in read txns, use+		 * tmp variable to avoid undefined assignment+		 */+		seq = ++txn->mt_env->me_dbiseqs[slot];+		txn->mt_dbiseqs[slot] = seq;++		memcpy(&txn->mt_dbs[slot], data.mv_data, sizeof(MDB_db));+		*dbi = slot;+		mdb_default_cmp(txn, slot);+		if (!unused) {+			txn->mt_numdbs++;+		}+		MDB_TRACE(("%p, %s, %u = %u", txn, name, flags, slot));+	}++	return rc;+}++int ESECT+mdb_stat(MDB_txn *txn, MDB_dbi dbi, MDB_stat *arg)+{+	if (!arg || !TXN_DBI_EXIST(txn, dbi, DB_VALID))+		return EINVAL;++	if (txn->mt_flags & MDB_TXN_BLOCKED)+		return MDB_BAD_TXN;++	if (txn->mt_dbflags[dbi] & DB_STALE) {+		MDB_cursor mc;+		MDB_xcursor mx;+		/* Stale, must read the DB's root. cursor_init does it for us. */+		mdb_cursor_init(&mc, txn, dbi, &mx);+	}+	return mdb_stat0(txn->mt_env, &txn->mt_dbs[dbi], arg);+}++void mdb_dbi_close(MDB_env *env, MDB_dbi dbi)+{+	char *ptr;+	if (dbi < CORE_DBS || dbi >= env->me_maxdbs)+		return;+	ptr = env->me_dbxs[dbi].md_name.mv_data;+	/* If there was no name, this was already closed */+	if (ptr) {+		MDB_TRACE(("%p, %u", env, dbi));+		env->me_dbxs[dbi].md_name.mv_data = NULL;+		env->me_dbxs[dbi].md_name.mv_size = 0;+		env->me_dbflags[dbi] = 0;+		env->me_dbiseqs[dbi]++;+		free(ptr);+	}+}++int mdb_dbi_flags(MDB_txn *txn, MDB_dbi dbi, unsigned int *flags)+{+	/* We could return the flags for the FREE_DBI too but what's the point? */+	if (!TXN_DBI_EXIST(txn, dbi, DB_USRVALID))+		return EINVAL;+	*flags = txn->mt_dbs[dbi].md_flags & PERSISTENT_FLAGS;+	return MDB_SUCCESS;+}++/** Add all the DB's pages to the free list.+ * @param[in] mc Cursor on the DB to free.+ * @param[in] subs non-Zero to check for sub-DBs in this DB.+ * @return 0 on success, non-zero on failure.+ */+static int+mdb_drop0(MDB_cursor *mc, int subs)+{+	int rc;++	rc = mdb_page_search(mc, NULL, MDB_PS_FIRST);+	if (rc == MDB_SUCCESS) {+		MDB_txn *txn = mc->mc_txn;+		MDB_node *ni;+		MDB_cursor mx;+		unsigned int 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))+			mdb_cursor_pop(mc);++		mdb_cursor_copy(mc, &mx);+		while (mc->mc_snum > 0) {+			MDB_page *mp = mc->mc_pg[mc->mc_top];+			unsigned n = NUMKEYS(mp);+			if (IS_LEAF(mp)) {+				for (i=0; i<n; i++) {+					ni = NODEPTR(mp, i);+					if (ni->mn_flags & F_BIGDATA) {+						MDB_page *omp;+						pgno_t pg;+						memcpy(&pg, NODEDATA(ni), sizeof(pg));+						rc = mdb_page_get(mc, pg, &omp, NULL);+						if (rc != 0)+							goto done;+						mdb_cassert(mc, IS_OVERFLOW(omp));+						rc = mdb_midl_append_range(&txn->mt_free_pgs,+							pg, omp->mp_pages);+						if (rc)+							goto done;+						mc->mc_db->md_overflow_pages -= omp->mp_pages;+						if (!mc->mc_db->md_overflow_pages && !subs)+							break;+					} else if (subs && (ni->mn_flags & F_SUBDATA)) {+						mdb_xcursor_init1(mc, ni);+						rc = mdb_drop0(&mc->mc_xcursor->mx_cursor, 0);+						if (rc)+							goto done;+					}+				}+				if (!subs && !mc->mc_db->md_overflow_pages)+					goto pop;+			} else {+				if ((rc = mdb_midl_need(&txn->mt_free_pgs, n)) != 0)+					goto done;+				for (i=0; i<n; i++) {+					pgno_t pg;+					ni = NODEPTR(mp, i);+					pg = NODEPGNO(ni);+					/* free it */+					mdb_midl_xappend(txn->mt_free_pgs, pg);+				}+			}+			if (!mc->mc_top)+				break;+			mc->mc_ki[mc->mc_top] = i;+			rc = mdb_cursor_sibling(mc, 1);+			if (rc) {+				if (rc != MDB_NOTFOUND)+					goto done;+				/* no more siblings, go back to beginning+				 * of previous level.+				 */+pop:+				mdb_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 = mdb_midl_append(&txn->mt_free_pgs, mc->mc_db->md_root);+done:+		if (rc)+			txn->mt_flags |= MDB_TXN_ERROR;+	} else if (rc == MDB_NOTFOUND) {+		rc = MDB_SUCCESS;+	}+	mc->mc_flags &= ~C_INITIALIZED;+	return rc;+}++int mdb_drop(MDB_txn *txn, MDB_dbi dbi, int del)+{+	MDB_cursor *mc, *m2;+	int rc;++	if ((unsigned)del > 1 || !TXN_DBI_EXIST(txn, dbi, DB_USRVALID))+		return EINVAL;++	if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY))+		return EACCES;++	if (TXN_DBI_CHANGED(txn, dbi))+		return MDB_BAD_DBI;++	rc = mdb_cursor_open(txn, dbi, &mc);+	if (rc)+		return rc;++	MDB_TRACE(("%u, %d", dbi, del));+	rc = mdb_drop0(mc, mc->mc_db->md_flags & MDB_DUPSORT);+	/* Invalidate the dropped DB's cursors */+	for (m2 = txn->mt_cursors[dbi]; m2; m2 = m2->mc_next)+		m2->mc_flags &= ~(C_INITIALIZED|C_EOF);+	if (rc)+		goto leave;++	/* Can't delete the main DB */+	if (del && dbi >= CORE_DBS) {+		rc = mdb_del0(txn, MAIN_DBI, &mc->mc_dbx->md_name, NULL, F_SUBDATA);+		if (!rc) {+			txn->mt_dbflags[dbi] = DB_STALE;+			mdb_dbi_close(txn->mt_env, dbi);+		} else {+			txn->mt_flags |= MDB_TXN_ERROR;+		}+	} else {+		/* reset the DB record, mark it dirty */+		txn->mt_dbflags[dbi] |= DB_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_flags |= MDB_TXN_DIRTY;+	}+leave:+	mdb_cursor_close(mc);+	return rc;+}++int mdb_set_compare(MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp)+{+	if (!TXN_DBI_EXIST(txn, dbi, DB_USRVALID))+		return EINVAL;++	txn->mt_dbxs[dbi].md_cmp = cmp;+	return MDB_SUCCESS;+}++int mdb_set_dupsort(MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp)+{+	if (!TXN_DBI_EXIST(txn, dbi, DB_USRVALID))+		return EINVAL;++	txn->mt_dbxs[dbi].md_dcmp = cmp;+	return MDB_SUCCESS;+}++int mdb_set_relfunc(MDB_txn *txn, MDB_dbi dbi, MDB_rel_func *rel)+{+	if (!TXN_DBI_EXIST(txn, dbi, DB_USRVALID))+		return EINVAL;++	txn->mt_dbxs[dbi].md_rel = rel;+	return MDB_SUCCESS;+}++int mdb_set_relctx(MDB_txn *txn, MDB_dbi dbi, void *ctx)+{+	if (!TXN_DBI_EXIST(txn, dbi, DB_USRVALID))+		return EINVAL;++	txn->mt_dbxs[dbi].md_relctx = ctx;+	return MDB_SUCCESS;+}++int ESECT+mdb_env_get_maxkeysize(MDB_env *env)+{+	return ENV_MAXKEY(env);+}++int ESECT+mdb_reader_list(MDB_env *env, MDB_msg_func *func, void *ctx)+{+	unsigned int i, rdrs;+	MDB_reader *mr;+	char buf[64];+	int rc = 0, first = 1;++	if (!env || !func)+		return -1;+	if (!env->me_txns) {+		return func("(no reader locks)\n", ctx);+	}+	rdrs = env->me_txns->mti_numreaders;+	mr = env->me_txns->mti_readers;+	for (i=0; i<rdrs; i++) {+		if (mr[i].mr_pid) {+			txnid_t	txnid = mr[i].mr_txnid;+			sprintf(buf, txnid == (txnid_t)-1 ?+				"%10d %"Z"x -\n" : "%10d %"Z"x %"Z"u\n",+				(int)mr[i].mr_pid, (size_t)mr[i].mr_tid, txnid);+			if (first) {+				first = 0;+				rc = func("    pid     thread     txnid\n", ctx);+				if (rc < 0)+					break;+			}+			rc = func(buf, ctx);+			if (rc < 0)+				break;+		}+	}+	if (first) {+		rc = func("(no active readers)\n", ctx);+	}+	return rc;+}++/** Insert pid into list if not already present.+ * return -1 if already present.+ */+static int ESECT+mdb_pid_insert(MDB_PID_T *ids, MDB_PID_T pid)+{+	/* binary search of pid in list */+	unsigned base = 0;+	unsigned cursor = 1;+	int val = 0;+	unsigned n = ids[0];++	while( 0 < n ) {+		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 -1;+		}+	}++	if( val > 0 ) {+		++cursor;+	}+	ids[0]++;+	for (n = ids[0]; n > cursor; n--)+		ids[n] = ids[n-1];+	ids[n] = pid;+	return 0;+}++int ESECT+mdb_reader_check(MDB_env *env, int *dead)+{+	if (!env)+		return EINVAL;+	if (dead)+		*dead = 0;+	return env->me_txns ? mdb_reader_check0(env, 0, dead) : MDB_SUCCESS;+}++/** As #mdb_reader_check(). \b rlocked is set if caller locked #me_rmutex. */+static int ESECT+mdb_reader_check0(MDB_env *env, int rlocked, int *dead)+{+	mdb_mutexref_t rmutex = rlocked ? NULL : env->me_rmutex;+	unsigned int i, j, rdrs;+	MDB_reader *mr;+	MDB_PID_T *pids, pid;+	int rc = MDB_SUCCESS, count = 0;++	rdrs = env->me_txns->mti_numreaders;+	pids = malloc((rdrs+1) * sizeof(MDB_PID_T));+	if (!pids)+		return ENOMEM;+	pids[0] = 0;+	mr = env->me_txns->mti_readers;+	for (i=0; i<rdrs; i++) {+		pid = mr[i].mr_pid;+		if (pid && pid != env->me_pid) {+			if (mdb_pid_insert(pids, pid) == 0) {+				if (!mdb_reader_pid(env, Pidcheck, pid)) {+					/* Stale reader found */+					j = i;+					if (rmutex) {+						if ((rc = LOCK_MUTEX0(rmutex)) != 0) {+							if ((rc = mdb_mutex_failed(env, rmutex, rc)))+								break;+							rdrs = 0; /* the above checked all readers */+						} else {+							/* Recheck, a new process may have reused pid */+							if (mdb_reader_pid(env, Pidcheck, pid))+								j = rdrs;+						}+					}+					for (; j<rdrs; j++)+							if (mr[j].mr_pid == pid) {+								DPRINTF(("clear stale reader pid %u txn %"Z"d",+									(unsigned) pid, mr[j].mr_txnid));+								mr[j].mr_pid = 0;+								count++;+							}+					if (rmutex)+						UNLOCK_MUTEX(rmutex);+				}+			}+		}+	}+	free(pids);+	if (dead)+		*dead = count;+	return rc;+}++#ifdef MDB_ROBUST_SUPPORTED+/** Handle #LOCK_MUTEX0() failure.+ * Try to repair the lock file if the mutex owner died.+ * @param[in] env	the environment handle+ * @param[in] mutex	LOCK_MUTEX0() mutex+ * @param[in] rc	LOCK_MUTEX0() error (nonzero)+ * @return 0 on success with the mutex locked, or an error code on failure.+ */+static int ESECT+mdb_mutex_failed(MDB_env *env, mdb_mutexref_t mutex, int rc)+{+	int rlocked, rc2;+	MDB_meta *meta;++	if (rc == MDB_OWNERDEAD) {+		/* We own the mutex. Clean up after dead previous owner. */+		rc = MDB_SUCCESS;+		rlocked = (mutex == env->me_rmutex);+		if (!rlocked) {+			/* Keep mti_txnid updated, otherwise next writer can+			 * overwrite data which latest meta page refers to.+			 */+			meta = mdb_env_pick_meta(env);+			env->me_txns->mti_txnid = meta->mm_txnid;+			/* env is hosed if the dead thread was ours */+			if (env->me_txn) {+				env->me_flags |= MDB_FATAL_ERROR;+				env->me_txn = NULL;+				rc = MDB_PANIC;+			}+		}+		DPRINTF(("%cmutex owner died, %s", (rlocked ? 'r' : 'w'),+			(rc ? "this process' env is hosed" : "recovering")));+		rc2 = mdb_reader_check0(env, rlocked, NULL);+		if (rc2 == 0)+			rc2 = mdb_mutex_consistent(mutex);+		if (rc || (rc = rc2)) {+			DPRINTF(("LOCK_MUTEX recovery failed, %s", mdb_strerror(rc)));+			UNLOCK_MUTEX(mutex);+		}+	} else {+#ifdef _WIN32+		rc = ErrCode();+#endif+		DPRINTF(("LOCK_MUTEX failed, %s", mdb_strerror(rc)));+	}++	return rc;+}+#endif	/* MDB_ROBUST_SUPPORTED */++#if defined(_WIN32)+/** Convert \b src to new wchar_t[] string with room for \b xtra extra chars */+static int ESECT+utf8_to_utf16(const char *src, MDB_name *dst, int xtra)+{+	int rc, need = 0;+	wchar_t *result = NULL;+	for (;;) {					/* malloc result, then fill it in */+		need = MultiByteToWideChar(CP_UTF8, 0, src, -1, result, need);+		if (!need) {+			rc = ErrCode();+			free(result);+			return rc;+		}+		if (!result) {+			result = malloc(sizeof(wchar_t) * (need + xtra));+			if (!result)+				return ENOMEM;+			continue;+		}+		dst->mn_alloced = 1;+		dst->mn_len = need - 1;+		dst->mn_val = result;+		return MDB_SUCCESS;+	}+}+#endif /* defined(_WIN32) */+/** @} */
+ cbits/midl.c view
@@ -0,0 +1,359 @@+/**	@file midl.c+ *	@brief ldap bdb back-end ID List functions */+/* $OpenLDAP$ */+/* This work is part of OpenLDAP Software <http://www.openldap.org/>.+ *+ * Copyright 2000-2021 The OpenLDAP Foundation.+ * Portions Copyright 2001-2021 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>.+ */++#include <limits.h>+#include <string.h>+#include <stdlib.h>+#include <errno.h>+#include <sys/types.h>+#include "midl.h"++/** @defgroup internal	LMDB Internals+ *	@{+ */+/** @defgroup idls	ID List Management+ *	@{+ */+#define CMP(x,y)	 ( (x) < (y) ? -1 : (x) > (y) )++unsigned mdb_midl_search( MDB_IDL ids, MDB_ID id )+{+	/*+	 * binary search of id in ids+	 * if found, returns position of id+	 * if not found, returns first position greater than id+	 */+	unsigned base = 0;+	unsigned cursor = 1;+	int val = 0;+	unsigned n = ids[0];++	while( 0 < n ) {+		unsigned pivot = n >> 1;+		cursor = base + pivot + 1;+		val = CMP( ids[cursor], id );++		if( val < 0 ) {+			n = pivot;++		} else if ( val > 0 ) {+			base = cursor;+			n -= pivot + 1;++		} else {+			return cursor;+		}+	}++	if( val > 0 ) {+		++cursor;+	}+	return cursor;+}++#if 0	/* superseded by append/sort */+int mdb_midl_insert( MDB_IDL ids, MDB_ID id )+{+	unsigned x, i;++	x = mdb_midl_search( ids, id );+	assert( x > 0 );++	if( x < 1 ) {+		/* internal error */+		return -2;+	}++	if ( x <= ids[0] && ids[x] == id ) {+		/* duplicate */+		assert(0);+		return -1;+	}++	if ( ++ids[0] >= MDB_IDL_DB_MAX ) {+		/* no room */+		--ids[0];+		return -2;++	} else {+		/* insert id */+		for (i=ids[0]; i>x; i--)+			ids[i] = ids[i-1];+		ids[x] = id;+	}++	return 0;+}+#endif++MDB_IDL mdb_midl_alloc(int num)+{+	MDB_IDL ids = malloc((num+2) * sizeof(MDB_ID));+	if (ids) {+		*ids++ = num;+		*ids = 0;+	}+	return ids;+}++void mdb_midl_free(MDB_IDL ids)+{+	if (ids)+		free(ids-1);+}++void mdb_midl_shrink( MDB_IDL *idp )+{+	MDB_IDL ids = *idp;+	if (*(--ids) > MDB_IDL_UM_MAX &&+		(ids = realloc(ids, (MDB_IDL_UM_MAX+2) * sizeof(MDB_ID))))+	{+		*ids++ = MDB_IDL_UM_MAX;+		*idp = ids;+	}+}++static int mdb_midl_grow( MDB_IDL *idp, int num )+{+	MDB_IDL idn = *idp-1;+	/* grow it */+	idn = realloc(idn, (*idn + num + 2) * sizeof(MDB_ID));+	if (!idn)+		return ENOMEM;+	*idn++ += num;+	*idp = idn;+	return 0;+}++int mdb_midl_need( MDB_IDL *idp, unsigned num )+{+	MDB_IDL ids = *idp;+	num += ids[0];+	if (num > ids[-1]) {+		num = (num + num/4 + (256 + 2)) & -256;+		if (!(ids = realloc(ids-1, num * sizeof(MDB_ID))))+			return ENOMEM;+		*ids++ = num - 2;+		*idp = ids;+	}+	return 0;+}++int mdb_midl_append( MDB_IDL *idp, MDB_ID id )+{+	MDB_IDL ids = *idp;+	/* Too big? */+	if (ids[0] >= ids[-1]) {+		if (mdb_midl_grow(idp, MDB_IDL_UM_MAX))+			return ENOMEM;+		ids = *idp;+	}+	ids[0]++;+	ids[ids[0]] = id;+	return 0;+}++int mdb_midl_append_list( MDB_IDL *idp, MDB_IDL app )+{+	MDB_IDL ids = *idp;+	/* Too big? */+	if (ids[0] + app[0] >= ids[-1]) {+		if (mdb_midl_grow(idp, app[0]))+			return ENOMEM;+		ids = *idp;+	}+	memcpy(&ids[ids[0]+1], &app[1], app[0] * sizeof(MDB_ID));+	ids[0] += app[0];+	return 0;+}++int mdb_midl_append_range( MDB_IDL *idp, MDB_ID id, unsigned n )+{+	MDB_ID *ids = *idp, len = ids[0];+	/* Too big? */+	if (len + n > ids[-1]) {+		if (mdb_midl_grow(idp, n | MDB_IDL_UM_MAX))+			return ENOMEM;+		ids = *idp;+	}+	ids[0] = len + n;+	ids += len;+	while (n)+		ids[n--] = id++;+	return 0;+}++void mdb_midl_xmerge( MDB_IDL idl, MDB_IDL merge )+{+	MDB_ID old_id, merge_id, i = merge[0], j = idl[0], k = i+j, total = k;+	idl[0] = (MDB_ID)-1;		/* delimiter for idl scan below */+	old_id = idl[j];+	while (i) {+		merge_id = merge[i--];+		for (; old_id < merge_id; old_id = idl[--j])+			idl[k--] = old_id;+		idl[k--] = merge_id;+	}+	idl[0] = total;+}++/* Quicksort + Insertion sort for small arrays */++#define SMALL	8+#define	MIDL_SWAP(a,b)	{ itmp=(a); (a)=(b); (b)=itmp; }++void+mdb_midl_sort( MDB_IDL ids )+{+	/* Max possible depth of int-indexed tree * 2 items/level */+	int istack[sizeof(int)*CHAR_BIT * 2];+	int i,j,k,l,ir,jstack;+	MDB_ID a, itmp;++	ir = (int)ids[0];+	l = 1;+	jstack = 0;+	for(;;) {+		if (ir - l < SMALL) {	/* Insertion sort */+			for (j=l+1;j<=ir;j++) {+				a = ids[j];+				for (i=j-1;i>=1;i--) {+					if (ids[i] >= a) break;+					ids[i+1] = ids[i];+				}+				ids[i+1] = a;+			}+			if (jstack == 0) break;+			ir = istack[jstack--];+			l = istack[jstack--];+		} else {+			k = (l + ir) >> 1;	/* Choose median of left, center, right */+			MIDL_SWAP(ids[k], ids[l+1]);+			if (ids[l] < ids[ir]) {+				MIDL_SWAP(ids[l], ids[ir]);+			}+			if (ids[l+1] < ids[ir]) {+				MIDL_SWAP(ids[l+1], ids[ir]);+			}+			if (ids[l] < ids[l+1]) {+				MIDL_SWAP(ids[l], ids[l+1]);+			}+			i = l+1;+			j = ir;+			a = ids[l+1];+			for(;;) {+				do i++; while(ids[i] > a);+				do j--; while(ids[j] < a);+				if (j < i) break;+				MIDL_SWAP(ids[i],ids[j]);+			}+			ids[l+1] = ids[j];+			ids[j] = a;+			jstack += 2;+			if (ir-i+1 >= j-l) {+				istack[jstack] = ir;+				istack[jstack-1] = i;+				ir = j-1;+			} else {+				istack[jstack] = j-1;+				istack[jstack-1] = l;+				l = i;+			}+		}+	}+}++unsigned mdb_mid2l_search( MDB_ID2L ids, MDB_ID id )+{+	/*+	 * binary search of id in ids+	 * if found, returns position of id+	 * if not found, returns first position greater than id+	 */+	unsigned base = 0;+	unsigned cursor = 1;+	int val = 0;+	unsigned n = (unsigned)ids[0].mid;++	while( 0 < n ) {+		unsigned pivot = n >> 1;+		cursor = base + pivot + 1;+		val = CMP( id, ids[cursor].mid );++		if( val < 0 ) {+			n = pivot;++		} else if ( val > 0 ) {+			base = cursor;+			n -= pivot + 1;++		} else {+			return cursor;+		}+	}++	if( val > 0 ) {+		++cursor;+	}+	return cursor;+}++int mdb_mid2l_insert( MDB_ID2L ids, MDB_ID2 *id )+{+	unsigned x, i;++	x = mdb_mid2l_search( ids, id->mid );++	if( x < 1 ) {+		/* internal error */+		return -2;+	}++	if ( x <= ids[0].mid && ids[x].mid == id->mid ) {+		/* duplicate */+		return -1;+	}++	if ( ids[0].mid >= MDB_IDL_UM_MAX ) {+		/* too big */+		return -2;++	} else {+		/* insert id */+		ids[0].mid++;+		for (i=(unsigned)ids[0].mid; i>x; i--)+			ids[i] = ids[i-1];+		ids[x] = *id;+	}++	return 0;+}++int mdb_mid2l_append( MDB_ID2L ids, MDB_ID2 *id )+{+	/* Too big? */+	if (ids[0].mid >= MDB_IDL_UM_MAX) {+		return -2;+	}+	ids[0].mid++;+	ids[ids[0].mid] = *id;+	return 0;+}++/** @} */+/** @} */
+ cbits/midl.h view
@@ -0,0 +1,188 @@+/**	@file midl.h+ *	@brief LMDB ID List header file.+ *+ *	This file was originally part of back-bdb but has been+ *	modified for use in libmdb. Most of the macros defined+ *	in this file are unused, just left over from the original.+ *+ *	This file is only used internally in libmdb and its definitions+ *	are not exposed publicly.+ */+/* $OpenLDAP$ */+/* This work is part of OpenLDAP Software <http://www.openldap.org/>.+ *+ * Copyright 2000-2021 The OpenLDAP Foundation.+ * Portions Copyright 2001-2021 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>.+ */++#ifndef _MDB_MIDL_H_+#define _MDB_MIDL_H_++#include <stddef.h>++#ifdef __cplusplus+extern "C" {+#endif++/** @defgroup internal	LMDB Internals+ *	@{+ */++/** @defgroup idls	ID List Management+ *	@{+ */+	/** A generic unsigned ID number. These were entryIDs in back-bdb.+	 *	Preferably it should have the same size as a pointer.+	 */+typedef size_t MDB_ID;++	/** An IDL is an ID List, a sorted array of IDs. The first+	 * element of the array is a counter for how many actual+	 * IDs are in the list. In the original back-bdb code, IDLs are+	 * sorted in ascending order. For libmdb IDLs are sorted in+	 * descending order.+	 */+typedef MDB_ID *MDB_IDL;++/* IDL sizes - likely should be even bigger+ *   limiting factors: sizeof(ID), thread stack size+ */+#ifndef MDB_IDL_LOGN+#define	MDB_IDL_LOGN	16	/* DB_SIZE is 2^16, UM_SIZE is 2^17 */+#endif+#define MDB_IDL_DB_SIZE		(1<<MDB_IDL_LOGN)+#define MDB_IDL_UM_SIZE		(1<<(MDB_IDL_LOGN+1))++#define MDB_IDL_DB_MAX		(MDB_IDL_DB_SIZE-1)+#define MDB_IDL_UM_MAX		(MDB_IDL_UM_SIZE-1)++#define MDB_IDL_SIZEOF(ids)		(((ids)[0]+1) * sizeof(MDB_ID))+#define MDB_IDL_IS_ZERO(ids) ( (ids)[0] == 0 )+#define MDB_IDL_CPY( dst, src ) (memcpy( dst, src, MDB_IDL_SIZEOF( src ) ))+#define MDB_IDL_FIRST( ids )	( (ids)[1] )+#define MDB_IDL_LAST( ids )		( (ids)[(ids)[0]] )++	/** Current max length of an #mdb_midl_alloc()ed IDL */+#define MDB_IDL_ALLOCLEN( ids )	( (ids)[-1] )++	/** Append ID to IDL. The IDL must be big enough. */+#define mdb_midl_xappend(idl, id) do { \+		MDB_ID *xidl = (idl), xlen = ++(xidl[0]); \+		xidl[xlen] = (id); \+	} while (0)++	/** Search for an ID in an IDL.+	 * @param[in] ids	The IDL to search.+	 * @param[in] id	The ID to search for.+	 * @return	The index of the first ID greater than or equal to \b id.+	 */+unsigned mdb_midl_search( MDB_IDL ids, MDB_ID id );++	/** Allocate an IDL.+	 * Allocates memory for an IDL of the given size.+	 * @return	IDL on success, NULL on failure.+	 */+MDB_IDL mdb_midl_alloc(int num);++	/** Free an IDL.+	 * @param[in] ids	The IDL to free.+	 */+void mdb_midl_free(MDB_IDL ids);++	/** Shrink an IDL.+	 * Return the IDL to the default size if it has grown larger.+	 * @param[in,out] idp	Address of the IDL to shrink.+	 */+void mdb_midl_shrink(MDB_IDL *idp);++	/** Make room for num additional elements in an IDL.+	 * @param[in,out] idp	Address of the IDL.+	 * @param[in] num	Number of elements to make room for.+	 * @return	0 on success, ENOMEM on failure.+	 */+int mdb_midl_need(MDB_IDL *idp, unsigned num);++	/** Append an ID onto an IDL.+	 * @param[in,out] idp	Address of the IDL to append to.+	 * @param[in] id	The ID to append.+	 * @return	0 on success, ENOMEM if the IDL is too large.+	 */+int mdb_midl_append( MDB_IDL *idp, MDB_ID id );++	/** Append an IDL onto an IDL.+	 * @param[in,out] idp	Address of the IDL to append to.+	 * @param[in] app	The IDL to append.+	 * @return	0 on success, ENOMEM if the IDL is too large.+	 */+int mdb_midl_append_list( MDB_IDL *idp, MDB_IDL app );++	/** Append an ID range onto an IDL.+	 * @param[in,out] idp	Address of the IDL to append to.+	 * @param[in] id	The lowest ID to append.+	 * @param[in] n		Number of IDs to append.+	 * @return	0 on success, ENOMEM if the IDL is too large.+	 */+int mdb_midl_append_range( MDB_IDL *idp, MDB_ID id, unsigned n );++	/** Merge an IDL onto an IDL. The destination IDL must be big enough.+	 * @param[in] idl	The IDL to merge into.+	 * @param[in] merge	The IDL to merge.+	 */+void mdb_midl_xmerge( MDB_IDL idl, MDB_IDL merge );++	/** Sort an IDL.+	 * @param[in,out] ids	The IDL to sort.+	 */+void mdb_midl_sort( MDB_IDL ids );++	/** An ID2 is an ID/pointer pair.+	 */+typedef struct MDB_ID2 {+	MDB_ID mid;		/**< The ID */+	void *mptr;		/**< The pointer */+} MDB_ID2;++	/** An ID2L is an ID2 List, a sorted array of ID2s.+	 * The first element's \b mid member is a count of how many actual+	 * elements are in the array. The \b mptr member of the first element is unused.+	 * The array is sorted in ascending order by \b mid.+	 */+typedef MDB_ID2 *MDB_ID2L;++	/** Search for an ID in an ID2L.+	 * @param[in] ids	The ID2L to search.+	 * @param[in] id	The ID to search for.+	 * @return	The index of the first ID2 whose \b mid member is greater than or equal to \b id.+	 */+unsigned mdb_mid2l_search( MDB_ID2L ids, MDB_ID id );+++	/** Insert an ID2 into a ID2L.+	 * @param[in,out] ids	The ID2L to insert into.+	 * @param[in] id	The ID2 to insert.+	 * @return	0 on success, -1 if the ID was already present in the ID2L.+	 */+int mdb_mid2l_insert( MDB_ID2L ids, MDB_ID2 *id );++	/** Append an ID2 into a ID2L.+	 * @param[in,out] ids	The ID2L to append into.+	 * @param[in] id	The ID2 to append.+	 * @return	0 on success, -2 if the ID2L is too big.+	 */+int mdb_mid2l_append( MDB_ID2L ids, MDB_ID2 *id );++/** @} */+/** @} */+#ifdef __cplusplus+}+#endif+#endif	/* _MDB_MIDL_H_ */
+ lib/Database/LMDB.hs view
@@ -0,0 +1,442 @@+{-# OPTIONS_HADDOCK prune #-}+{-# LANGUAGE BangPatterns   #-}+{-# LANGUAGE EmptyDataDecls #-}++-- |+-- Module: Database.LMDB+-- Copyright: (c) 2026 Jared Tobin+-- License: MIT+-- Maintainer: Jared Tobin <jared@ppad.tech>+--+-- Minimal bindings to+-- [LMDB](https://www.symas.com/lmdb), an embedded ACID key-value+-- store. The upstream LMDB C source is vendored under @cbits\/@ at+-- release @LMDB_0.9.33@; no external @liblmdb@ is needed.+--+-- LMDB has a single-writer, many-reader transaction model and uses+-- memory mapping for zero-copy reads. This module presents that as a+-- bracketed @IO@-only interface.+--+-- Read-only and read-write transactions are distinguished at the type+-- level via a phantom parameter on 'Txn', so using a write primitive+-- (e.g. 'put') on a read transaction is a compile-time error.+--+-- Most operations throw 'LMDBException' on error. 'get' and 'del' are+-- the exceptions: they map a missing key onto 'Nothing' and 'False'+-- respectively, since absence is normal control flow.++module Database.LMDB (+  -- * Environments+    Env+  , EnvFlags(..)+  , defaultEnvFlags+  , open+  , close+  , withEnv++  -- * Transactions+  , Txn+  , RO+  , RW+  , withReadTxn+  , withWriteTxn++  -- * Databases+  , Dbi+  , openDbi++  -- * Key-value operations+  , get+  , put+  , del++  -- * Cursors+  , Cursor+  , withCursor+  , cursorFirst+  , cursorLast+  , cursorNext+  , cursorPrev+  , cursorSeek++  -- * Errors+  , LMDBException(..)+  ) where++import Control.Exception+  ( Exception, bracket, bracketOnError, mask, onException, throwIO)+import qualified Data.ByteString as BS+import qualified Data.ByteString.Unsafe as BU+import Foreign.C.String (peekCString, withCString)+import Foreign.C.Types (CInt, CSize, CUInt)+import Foreign.Marshal.Alloc (alloca, allocaBytes)+import Foreign.Ptr (Ptr, nullPtr, plusPtr)+import Foreign.Storable (peek, peekByteOff, pokeByteOff)+import Database.LMDB.Internal++-- handles --------------------------------------------------------------------++-- | An LMDB environment. Roughly, an open database file (or, with+--   'envNoSubdir' off, a directory containing one).+newtype Env = Env (Ptr MDB_env)++-- | Phantom tag for read-only transactions.+data RO++-- | Phantom tag for read-write transactions.+data RW++-- | A transaction. The phantom @s@ distinguishes 'RO' from 'RW' so+--   that write operations refuse to type-check against read-only+--   transactions.+newtype Txn s = Txn (Ptr MDB_txn)++-- | A database identifier within an 'Env'.+newtype Dbi = Dbi MDB_dbi++-- | A cursor for range-scanning a 'Dbi'.+newtype Cursor s = Cursor (Ptr MDB_cursor)++-- environment flags ----------------------------------------------------------++-- | Configuration for 'open'.+data EnvFlags = EnvFlags+  { envMapSize  :: !Int+    -- ^ map size in bytes; LMDB will refuse writes beyond this. The+    --   default of 10 MiB is intentionally small — set it to something+    --   appropriate for your workload before opening.+  , envMaxDbs   :: !Int+    -- ^ maximum number of named sub-databases. Default 1.+  , envNoSubdir :: !Bool+    -- ^ if 'True', treat the path as a regular file rather than a+    --   directory containing @data.mdb@ and @lock.mdb@.+  , envReadOnly :: !Bool+    -- ^ open the environment read-only.+  , envNoSync   :: !Bool+    -- ^ skip @fsync@ at commit time. Faster, but a crash may lose+    --   the last transaction. The database remains internally+    --   consistent.+  } deriving Show++-- | Default 'EnvFlags': 10 MiB map, one database, directory layout,+--   read-write, syncing at commit.+--+--   >>> envMapSize defaultEnvFlags+--   10485760+defaultEnvFlags :: EnvFlags+defaultEnvFlags = EnvFlags+  { envMapSize  = 10 * 1024 * 1024+  , envMaxDbs   = 1+  , envNoSubdir = False+  , envReadOnly = False+  , envNoSync   = False+  }++envFlagBits :: EnvFlags -> CUInt+envFlagBits EnvFlags { envNoSubdir = nsd, envReadOnly = ro, envNoSync = ns } =+  (if nsd then _MDB_NOSUBDIR else 0)+    + (if ro then _MDB_RDONLY   else 0)+    + (if ns then _MDB_NOSYNC   else 0)++-- error handling -------------------------------------------------------------++-- | A typed wrapper around LMDB error codes. 'LMDBOther' carries the+--   raw error code plus the message from @mdb_strerror@.+data LMDBException+  = LMDBKeyExist+  | LMDBNotFound          -- ^ Only seen via "Database.LMDB.Internal";+                          --   the safe layer maps this to 'Nothing'+                          --   or 'False' instead of throwing.+  | LMDBMapFull+  | LMDBCorrupted+  | LMDBPanic+  | LMDBVersionMismatch+  | LMDBOther !Int !String+  deriving Show++instance Exception LMDBException++throwLmdb :: CInt -> IO a+throwLmdb code+  | code == _MDB_KEYEXIST         = throwIO LMDBKeyExist+  | code == _MDB_NOTFOUND         = throwIO LMDBNotFound+  | code == _MDB_MAP_FULL         = throwIO LMDBMapFull+  | code == _MDB_CORRUPTED        = throwIO LMDBCorrupted+  | code == _MDB_PANIC            = throwIO LMDBPanic+  | code == _MDB_VERSION_MISMATCH = throwIO LMDBVersionMismatch+  | otherwise = do+      msg <- mdb_strerror code >>= peekCString+      throwIO (LMDBOther (fromIntegral code) msg)++check :: CInt -> IO ()+check 0 = pure ()+check c = throwLmdb c+{-# INLINE check #-}++-- environment lifecycle ------------------------------------------------------++-- | Open an LMDB environment at the given path. The path must already+--   exist (as a directory unless 'envNoSubdir' is set, in which case+--   the file's parent directory must exist).+--+--   Throws 'LMDBException' on failure.+--+--   >>> env <- open "/tmp/mydb" defaultEnvFlags { envNoSubdir = True }+open :: FilePath -> EnvFlags -> IO Env+open path flags = mask $ \restore -> do+  envp <- alloca $ \pp -> do+    check =<< mdb_env_create pp+    peek pp+  let env = Env envp+  flip onException (close env) . restore $ do+    check =<< mdb_env_set_mapsize envp+                  (fromIntegral (envMapSize flags))+    check =<< mdb_env_set_maxdbs envp+                  (fromIntegral (envMaxDbs flags))+    withCString path $ \cpath ->+      check =<< mdb_env_open envp cpath (envFlagBits flags) 0o644+  pure env++-- | Close an environment. Must not be called while transactions are+--   live.+close :: Env -> IO ()+close (Env envp) = mdb_env_close envp++-- | Bracketed environment lifecycle: 'open' the environment, run the+--   action, 'close' on exit (including async exceptions).+--+--   >>> withEnv "/tmp/mydb" defaultEnvFlags $ \env -> ...+withEnv :: FilePath -> EnvFlags -> (Env -> IO a) -> IO a+withEnv path flags = bracket (open path flags) close++-- transactions ---------------------------------------------------------------++beginTxn :: Env -> CUInt -> IO (Ptr MDB_txn)+beginTxn (Env envp) flags = alloca $ \pp -> do+  check =<< mdb_txn_begin envp nullPtr flags pp+  peek pp++-- | Run an action in a read-only transaction. The transaction is+--   aborted on exit; read transactions have no work to commit.+--+--   >>> withReadTxn env $ \txn -> ...+withReadTxn :: Env -> (Txn RO -> IO a) -> IO a+withReadTxn env act = bracketOnError+  (beginTxn env _MDB_RDONLY)+  mdb_txn_abort+  (\txnp -> do+      r <- act (Txn txnp)+      mdb_txn_abort txnp+      pure r)++-- | Run an action in a read-write transaction. Commits if the action+--   returns normally; aborts on exception.+--+--   >>> withWriteTxn env $ \txn -> ...+withWriteTxn :: Env -> (Txn RW -> IO a) -> IO a+withWriteTxn env act = bracketOnError+  (beginTxn env 0)+  mdb_txn_abort+  (\txnp -> do+      r <- act (Txn txnp)+      check =<< mdb_txn_commit txnp+      pure r)++-- databases ------------------------------------------------------------------++-- | Open a database within a transaction. Pass 'Nothing' for the+--   unnamed default database. If the @create@ flag is 'True', the+--   database is created if it does not already exist — and the+--   transaction must be a read-write transaction.+--+--   >>> dbi <- openDbi txn Nothing True+openDbi+  :: Txn s+  -> Maybe BS.ByteString -- ^ database name; 'Nothing' for the default+  -> Bool                -- ^ create if not present+  -> IO Dbi+openDbi (Txn txnp) mname create = alloca $ \pp -> do+  let flags = if create then _MDB_CREATE else 0+      go cstr = do+        check =<< mdb_dbi_open txnp cstr flags pp+        Dbi <$> peek pp+  case mname of+    Nothing -> go nullPtr+    Just nm -> BU.unsafeUseAsCString nm go++-- bytestring <-> MDB_val helpers --------------------------------------------++-- An MDB_val is two words: a CSize length at offset 0, a payload Ptr+-- at offset 8 (on 64-bit). We poke fields directly rather than going+-- through the Storable instance so hot paths don't depend on it being+-- inlined.++withBSAsVal :: BS.ByteString -> (Ptr MDB_val -> IO a) -> IO a+withBSAsVal bs k =+  BU.unsafeUseAsCStringLen bs $ \(p, n) ->+  allocaBytes 16 $ \vp -> do+    pokeByteOff vp 0 (fromIntegral n :: CSize)+    pokeByteOff vp 8 p+    k vp+{-# INLINE withBSAsVal #-}++peekVal :: Ptr MDB_val -> IO BS.ByteString+peekVal vp = do+  sz <- peekByteOff vp 0 :: IO CSize+  pd <- peekByteOff vp 8+  BS.packCStringLen (pd, fromIntegral sz)+{-# INLINE peekVal #-}++-- key-value ops --------------------------------------------------------------++-- | Look up a key. Returns 'Nothing' if not found. Other LMDB errors+--   throw 'LMDBException'.+--+--   The returned 'BS.ByteString' is a copy of the data; LMDB's+--   memory-mapped buffer is not aliased into Haskell.+--+--   >>> get txn dbi "hello"+--   Just "world"+get+  :: Txn s+  -> Dbi+  -> BS.ByteString               -- ^ key+  -> IO (Maybe BS.ByteString)    -- ^ value, if present+get (Txn txnp) (Dbi dbi) k =+  BU.unsafeUseAsCStringLen k $ \(kdata, klen) ->+  allocaBytes 32 $ \kp -> do+    let !vp = kp `plusPtr` 16+    pokeByteOff kp 0 (fromIntegral klen :: CSize)+    pokeByteOff kp 8 kdata+    code <- mdb_get txnp dbi kp vp+    if   code == _MDB_NOTFOUND+    then pure Nothing+    else do+      check code+      Just <$> peekVal vp+{-# INLINE get #-}++-- | Insert or replace a key. Throws 'LMDBException' on failure.+--+--   >>> put txn dbi "hello" "world"+put+  :: Txn RW+  -> Dbi+  -> BS.ByteString -- ^ key+  -> BS.ByteString -- ^ value+  -> IO ()+put (Txn txnp) (Dbi dbi) k v =+  BU.unsafeUseAsCStringLen k $ \(kdata, klen) ->+  BU.unsafeUseAsCStringLen v $ \(vdata, vlen) ->+  allocaBytes 32 $ \kp -> do+    let !vp = kp `plusPtr` 16+    pokeByteOff kp 0 (fromIntegral klen :: CSize)+    pokeByteOff kp 8 kdata+    pokeByteOff vp 0 (fromIntegral vlen :: CSize)+    pokeByteOff vp 8 vdata+    check =<< mdb_put txnp dbi kp vp 0+{-# INLINE put #-}++-- | Delete a key. Returns 'True' if the key existed and was removed,+--   'False' if it was already absent.+--+--   >>> del txn dbi "hello"+--   True+del+  :: Txn RW+  -> Dbi+  -> BS.ByteString -- ^ key+  -> IO Bool       -- ^ 'True' if the key was present and removed+del (Txn txnp) (Dbi dbi) k =+  withBSAsVal k $ \kp -> do+    code <- mdb_del txnp dbi kp nullPtr+    if   code == _MDB_NOTFOUND then pure False+    else do+      check code+      pure True+{-# INLINE del #-}++-- cursors --------------------------------------------------------------------++-- | Bracketed cursor lifecycle: open a cursor over the given 'Dbi',+--   run the action, close the cursor on exit (including async+--   exceptions).+--+--   >>> withCursor txn dbi $ \cur -> ...+withCursor :: Txn s -> Dbi -> (Cursor s -> IO a) -> IO a+withCursor (Txn txnp) (Dbi dbi) act = bracket open' mdb_cursor_close use'+  where+    open' = alloca $ \pp -> do+      check =<< mdb_cursor_open txnp dbi pp+      peek pp+    use' p = act (Cursor p)++-- Scan-position helper (no input key): one 32-byte buffer for both+-- output MDB_vals.+cursorMove+  :: Cursor s+  -> CInt              -- MDB_cursor_op+  -> IO (Maybe (BS.ByteString, BS.ByteString))+cursorMove (Cursor cp) op =+  allocaBytes 32 $ \kp -> do+    let !vp = kp `plusPtr` 16+    code <- mdb_cursor_get cp kp vp op+    if   code == _MDB_NOTFOUND+    then pure Nothing+    else do+      check code+      k <- peekVal kp+      v <- peekVal vp+      pure (Just (k, v))+{-# INLINE cursorMove #-}++-- | Position at the first key/value pair, or 'Nothing' on an empty+--   database.+--+--   >>> cursorFirst cur+--   Just ("a","alpha")+cursorFirst :: Cursor s -> IO (Maybe (BS.ByteString, BS.ByteString))+cursorFirst c = cursorMove c _MDB_FIRST+{-# INLINE cursorFirst #-}++-- | Position at the last key/value pair, or 'Nothing' on an empty+--   database.+cursorLast :: Cursor s -> IO (Maybe (BS.ByteString, BS.ByteString))+cursorLast c = cursorMove c _MDB_LAST+{-# INLINE cursorLast #-}++-- | Advance to the next key/value pair, or 'Nothing' if already at+--   the end.+cursorNext :: Cursor s -> IO (Maybe (BS.ByteString, BS.ByteString))+cursorNext c = cursorMove c _MDB_NEXT+{-# INLINE cursorNext #-}++-- | Step back to the previous key/value pair, or 'Nothing' if already+--   at the start.+cursorPrev :: Cursor s -> IO (Maybe (BS.ByteString, BS.ByteString))+cursorPrev c = cursorMove c _MDB_PREV+{-# INLINE cursorPrev #-}++-- | Position at the first key /greater than or equal to/ the given+--   key, or 'Nothing' if no such key exists.+--+--   >>> cursorSeek cur "m"+--   Just ("n","november")+cursorSeek+  :: Cursor s+  -> BS.ByteString+  -> IO (Maybe (BS.ByteString, BS.ByteString))+cursorSeek (Cursor cp) k =+  BU.unsafeUseAsCStringLen k $ \(kdata, klen) ->+  allocaBytes 32 $ \kp -> do+    let !vp = kp `plusPtr` 16+    pokeByteOff kp 0 (fromIntegral klen :: CSize)+    pokeByteOff kp 8 kdata+    code <- mdb_cursor_get cp kp vp _MDB_SET_RANGE+    if   code == _MDB_NOTFOUND+    then pure Nothing+    else do+      check code+      ok <- peekVal kp+      ov <- peekVal vp+      pure (Just (ok, ov))
+ lib/Database/LMDB/Internal.hs view
@@ -0,0 +1,280 @@+{-# OPTIONS_HADDOCK not-home #-}+{-# LANGUAGE CApiFFI #-}++-- |+-- Module: Database.LMDB.Internal+-- Copyright: (c) 2026 Jared Tobin+-- License: MIT+-- Maintainer: Jared Tobin <jared@ppad.tech>+--+-- Raw FFI declarations and constants for the LMDB C API. This module+-- is exposed for power users; prefer "Database.LMDB" for the safe,+-- bracketed interface.++module Database.LMDB.Internal (+  -- * Opaque handles+    MDB_env+  , MDB_txn+  , MDB_dbi+  , MDB_cursor++  -- * Value pair+  , MDB_val(..)++  -- * Environment flags+  , _MDB_NOSUBDIR+  , _MDB_NOSYNC+  , _MDB_RDONLY+  , _MDB_NOMETASYNC+  , _MDB_NOTLS++  -- * Database open flags+  , _MDB_CREATE++  -- * Put flags+  , _MDB_NOOVERWRITE+  , _MDB_APPEND++  -- * Cursor operations+  , _MDB_FIRST+  , _MDB_LAST+  , _MDB_NEXT+  , _MDB_PREV+  , _MDB_SET+  , _MDB_SET_RANGE+  , _MDB_GET_CURRENT++  -- * Error codes+  , _MDB_SUCCESS+  , _MDB_KEYEXIST+  , _MDB_NOTFOUND+  , _MDB_MAP_FULL+  , _MDB_CORRUPTED+  , _MDB_PANIC+  , _MDB_VERSION_MISMATCH+  , _MDB_INVALID+  , _MDB_BAD_TXN+  , _MDB_BAD_VALSIZE+  , _MDB_BAD_DBI++  -- * Environment lifecycle+  , mdb_env_create+  , mdb_env_open+  , mdb_env_close+  , mdb_env_set_mapsize+  , mdb_env_set_maxdbs+  , mdb_env_sync++  -- * Transactions+  , mdb_txn_begin+  , mdb_txn_commit+  , mdb_txn_abort++  -- * Databases+  , mdb_dbi_open+  , mdb_dbi_close++  -- * Key-value operations+  , mdb_get+  , mdb_put+  , mdb_del++  -- * Cursors+  , mdb_cursor_open+  , mdb_cursor_close+  , mdb_cursor_get++  -- * Diagnostics+  , mdb_strerror+  ) where++import Foreign.C.String (CString)+import Foreign.C.Types+  (CInt(..), CUInt(..), CSize(..), CChar(..))+import Foreign.Ptr (Ptr)+import Foreign.Storable (Storable(..))+import System.Posix.Types (CMode(..))++-- opaque handles -------------------------------------------------------------++data MDB_env+data MDB_txn+data MDB_cursor++-- | LMDB's database identifier is a plain @unsigned int@ value type,+--   not a pointer.+type MDB_dbi = CUInt++-- value pair -----------------------------------------------------------------++-- | The key-or-value pair LMDB passes across the FFI boundary.+data MDB_val = MDB_val+  { mvSize :: !CSize+  , mvData :: !(Ptr CChar)+  }++instance Storable MDB_val where+  sizeOf    _ = 2 * sizeOf (undefined :: Ptr ())+  {-# INLINE sizeOf #-}+  alignment _ = alignment   (undefined :: Ptr ())+  {-# INLINE alignment #-}+  peek p = do+    sz <- peekByteOff p 0+    pd <- peekByteOff p (sizeOf (undefined :: Ptr ()))+    pure (MDB_val sz pd)+  {-# INLINE peek #-}+  poke p (MDB_val sz pd) = do+    pokeByteOff p 0 sz+    pokeByteOff p (sizeOf (undefined :: Ptr ())) pd+  {-# INLINE poke #-}++-- environment flags ----------------------------------------------------------++_MDB_NOSUBDIR, _MDB_NOSYNC, _MDB_RDONLY, _MDB_NOMETASYNC, _MDB_NOTLS+  :: CUInt+_MDB_NOSUBDIR    = 0x4000+_MDB_NOSYNC      = 0x10000+_MDB_RDONLY      = 0x20000+_MDB_NOMETASYNC  = 0x40000+_MDB_NOTLS       = 0x200000++-- database open flags --------------------------------------------------------++_MDB_CREATE :: CUInt+_MDB_CREATE = 0x40000++-- put flags ------------------------------------------------------------------++_MDB_NOOVERWRITE, _MDB_APPEND :: CUInt+_MDB_NOOVERWRITE = 0x10+_MDB_APPEND      = 0x20000++-- cursor ops -----------------------------------------------------------------++-- These mirror the enum MDB_cursor_op declared in lmdb.h. We only+-- bind the operations the safe wrapper currently uses; add more as+-- needed.++_MDB_FIRST, _MDB_LAST, _MDB_NEXT, _MDB_PREV+  , _MDB_SET, _MDB_SET_RANGE, _MDB_GET_CURRENT :: CInt+_MDB_FIRST       = 0+_MDB_LAST        = 6+_MDB_NEXT        = 8+_MDB_PREV        = 12+_MDB_SET         = 15+_MDB_SET_RANGE   = 17  -- index per MDB_cursor_op enum (post-DUP entries)+_MDB_GET_CURRENT = 4++-- error codes ----------------------------------------------------------------++_MDB_SUCCESS, _MDB_KEYEXIST, _MDB_NOTFOUND, _MDB_MAP_FULL+  , _MDB_CORRUPTED, _MDB_PANIC, _MDB_VERSION_MISMATCH, _MDB_INVALID+  , _MDB_BAD_TXN, _MDB_BAD_VALSIZE, _MDB_BAD_DBI :: CInt+_MDB_SUCCESS          = 0+_MDB_KEYEXIST         = -30799+_MDB_NOTFOUND         = -30798+_MDB_CORRUPTED        = -30796+_MDB_PANIC            = -30795+_MDB_VERSION_MISMATCH = -30794+_MDB_INVALID          = -30793+_MDB_MAP_FULL         = -30792+_MDB_BAD_TXN          = -30782+_MDB_BAD_VALSIZE      = -30781+_MDB_BAD_DBI          = -30780++-- foreign imports ------------------------------------------------------------++-- environment lifecycle++foreign import capi "lmdb.h mdb_env_create"+  mdb_env_create :: Ptr (Ptr MDB_env) -> IO CInt++foreign import capi "lmdb.h mdb_env_open"+  mdb_env_open+    :: Ptr MDB_env -> CString -> CUInt -> CMode -> IO CInt++foreign import capi "lmdb.h mdb_env_close"+  mdb_env_close :: Ptr MDB_env -> IO ()++foreign import capi "lmdb.h mdb_env_set_mapsize"+  mdb_env_set_mapsize :: Ptr MDB_env -> CSize -> IO CInt++foreign import capi "lmdb.h mdb_env_set_maxdbs"+  mdb_env_set_maxdbs :: Ptr MDB_env -> MDB_dbi -> IO CInt++foreign import capi "lmdb.h mdb_env_sync"+  mdb_env_sync :: Ptr MDB_env -> CInt -> IO CInt++-- transactions++foreign import capi "lmdb.h mdb_txn_begin"+  mdb_txn_begin+    :: Ptr MDB_env+    -> Ptr MDB_txn      -- parent (NULL for top-level)+    -> CUInt            -- flags+    -> Ptr (Ptr MDB_txn)+    -> IO CInt++foreign import capi "lmdb.h mdb_txn_commit"+  mdb_txn_commit :: Ptr MDB_txn -> IO CInt++foreign import capi "lmdb.h mdb_txn_abort"+  mdb_txn_abort :: Ptr MDB_txn -> IO ()++-- databases++foreign import capi "lmdb.h mdb_dbi_open"+  mdb_dbi_open+    :: Ptr MDB_txn+    -> CString          -- name; NULL for the default unnamed db+    -> CUInt            -- flags+    -> Ptr MDB_dbi+    -> IO CInt++foreign import capi "lmdb.h mdb_dbi_close"+  mdb_dbi_close :: Ptr MDB_env -> MDB_dbi -> IO ()++-- key-value ops++foreign import capi "lmdb.h mdb_get"+  mdb_get+    :: Ptr MDB_txn -> MDB_dbi -> Ptr MDB_val -> Ptr MDB_val -> IO CInt++foreign import capi "lmdb.h mdb_put"+  mdb_put+    :: Ptr MDB_txn+    -> MDB_dbi+    -> Ptr MDB_val      -- key+    -> Ptr MDB_val      -- data+    -> CUInt            -- flags+    -> IO CInt++foreign import capi "lmdb.h mdb_del"+  mdb_del+    :: Ptr MDB_txn+    -> MDB_dbi+    -> Ptr MDB_val      -- key+    -> Ptr MDB_val      -- data; NULL except for MDB_DUPSORT+    -> IO CInt++-- cursors++foreign import capi "lmdb.h mdb_cursor_open"+  mdb_cursor_open+    :: Ptr MDB_txn -> MDB_dbi -> Ptr (Ptr MDB_cursor) -> IO CInt++foreign import capi "lmdb.h mdb_cursor_close"+  mdb_cursor_close :: Ptr MDB_cursor -> IO ()++foreign import capi "lmdb.h mdb_cursor_get"+  mdb_cursor_get+    :: Ptr MDB_cursor+    -> Ptr MDB_val      -- key (in/out)+    -> Ptr MDB_val      -- data (out)+    -> CInt             -- MDB_cursor_op+    -> IO CInt++-- diagnostics++foreign import capi "lmdb.h mdb_strerror"+  mdb_strerror :: CInt -> IO CString
+ ppad-lmdb.cabal view
@@ -0,0 +1,104 @@+cabal-version:      3.0+name:               ppad-lmdb+version:            0.1.0+synopsis:           Minimal bindings to LMDB.+license:            MIT+license-file:       LICENSE+author:             Jared Tobin+maintainer:         jared@ppad.tech+category:           Database+build-type:         Simple+tested-with:        GHC == 9.10.3+extra-doc-files:    CHANGELOG+extra-source-files: cbits/LICENSE+                  , cbits/lmdb.h+                  , cbits/mdb.c+                  , cbits/midl.c+                  , cbits/midl.h+description:+  Minimal bindings to+  [LMDB](https://www.symas.com/lmdb) (Lightning Memory-Mapped+  Database), an embedded ACID key-value store. The upstream LMDB C+  source is vendored at release @LMDB_0.9.33@ under @cbits/@; no+  external @liblmdb@ is required.++flag llvm+  description: Use GHC's LLVM backend.+  default:     False+  manual:      True++source-repository head+  type:     git+  location: git.ppad.tech/lmdb.git++library+  default-language: Haskell2010+  hs-source-dirs:   lib+  include-dirs:     cbits+  c-sources:        cbits/mdb.c+                  , cbits/midl.c+  cc-options:       -w+  ghc-options:+      -Wall+      -optc-Wno-incompatible-pointer-types+  if flag(llvm)+    ghc-options: -fllvm -O2+  if !os(windows)+    extra-libraries: pthread+  exposed-modules:+      Database.LMDB+      Database.LMDB.Internal+  build-depends:+      base       >= 4.9  && < 5+    , bytestring >= 0.9  && < 0.13++test-suite lmdb-tests+  type:                exitcode-stdio-1.0+  default-language:    Haskell2010+  hs-source-dirs:      test+  main-is:             Main.hs+  ghc-options:+      -rtsopts -Wall -O2+  build-depends:+      base+    , bytestring+    , containers+    , directory+    , filepath+    , ppad-lmdb+    , QuickCheck+    , tasty+    , tasty-hunit+    , tasty-quickcheck++benchmark lmdb-bench+  type:                exitcode-stdio-1.0+  default-language:    Haskell2010+  hs-source-dirs:      bench+  main-is:             Main.hs+  ghc-options:+      -rtsopts -O2 -Wall+  build-depends:+      base+    , bytestring+    , criterion+    , directory+    , filepath+    , ppad-lmdb++benchmark lmdb-weigh+  type:                exitcode-stdio-1.0+  default-language:    Haskell2010+  hs-source-dirs:      bench+  main-is:             Weight.hs+  ghc-options:+      -rtsopts -O2 -Wall -fno-warn-orphans+  if flag(llvm)+    ghc-options: -fllvm+  build-depends:+      base+    , bytestring+    , directory+    , filepath+    , ppad-lmdb+    , weigh
+ test/Main.hs view
@@ -0,0 +1,181 @@+{-# LANGUAGE OverloadedStrings #-}++module Main where++import qualified Control.Exception as E+import Control.Monad (forM_)+import qualified Data.ByteString as BS+import qualified Data.ByteString.Char8 as BSC+import qualified Data.Map.Strict as Map+import qualified Database.LMDB as L+import System.Directory+  ( createDirectory+  , doesDirectoryExist+  , getTemporaryDirectory+  , removeDirectoryRecursive+  )+import System.FilePath ((</>))+import Test.Tasty+import Test.Tasty.HUnit+import Test.Tasty.QuickCheck as QC++main :: IO ()+main = defaultMain $ testGroup "ppad-lmdb"+  [ unitTests+  , propTests+  ]++-- helpers --------------------------------------------------------------------++-- | Run an action against a fresh temporary db directory. The+--   directory is created (clean) before the action and removed after.+withTmpEnv :: L.EnvFlags -> (L.Env -> IO a) -> IO a+withTmpEnv envFlags k = do+  tmpRoot <- getTemporaryDirectory+  let dir = tmpRoot </> "ppad-lmdb-test"+  exists <- doesDirectoryExist dir+  if exists then removeDirectoryRecursive dir else pure ()+  createDirectory dir+  result <- L.withEnv dir envFlags k+  removeDirectoryRecursive dir+  pure result++-- shared bigger map for tests+flags :: L.EnvFlags+flags = L.defaultEnvFlags+  { L.envMapSize = 64 * 1024 * 1024+  , L.envMaxDbs  = 4+  }++writeKV+  :: L.Env -> [(BS.ByteString, BS.ByteString)] -> IO ()+writeKV env kvs = L.withWriteTxn env $ \txn -> do+  dbi <- L.openDbi txn Nothing True+  forM_ kvs $ \(k, v) -> L.put txn dbi k v++-- unit tests -----------------------------------------------------------------++unitTests :: TestTree+unitTests = testGroup "unit"+  [ testCase "put then get roundtrip" $+      withTmpEnv flags $ \env -> do+        writeKV env [("hello", "world")]+        v <- L.withReadTxn env $ \txn -> do+          dbi <- L.openDbi txn Nothing False+          L.get txn dbi "hello"+        v @?= Just "world"++  , testCase "get on missing key returns Nothing" $+      withTmpEnv flags $ \env -> do+        writeKV env [("a", "1")]+        v <- L.withReadTxn env $ \txn -> do+          dbi <- L.openDbi txn Nothing False+          L.get txn dbi "absent"+        v @?= Nothing++  , testCase "del returns True only when key existed" $+      withTmpEnv flags $ \env -> do+        writeKV env [("a", "1"), ("b", "2")]+        (existed, repeated, missing) <- L.withWriteTxn env $ \txn -> do+          dbi <- L.openDbi txn Nothing False+          e   <- L.del txn dbi "a"+          e2  <- L.del txn dbi "a"+          m   <- L.del txn dbi "never-existed"+          pure (e, e2, m)+        existed  @?= True+        repeated @?= False+        missing  @?= False++  , testCase "write txn aborted on exception" $+      withTmpEnv flags $ \env -> do+        -- attempt that throws after a write+        let attempt = L.withWriteTxn env $ \txn -> do+              dbi <- L.openDbi txn Nothing True+              L.put txn dbi "k" "v"+              E.throwIO (userError "boom")+        r <- E.try attempt :: IO (Either IOError ())+        case r of+          Left _  -> pure ()+          Right _ -> assertFailure "expected the user error"+        -- key must not be visible to a fresh read txn+        v <- L.withReadTxn env $ \txn -> do+          dbi <- L.openDbi txn Nothing True+          L.get txn dbi "k"+        v @?= Nothing++  , testCase "cursor walks keys in ascending order" $+      withTmpEnv flags $ \env -> do+        let kvs = [ (BSC.pack [c], BSC.pack [c])+                  | c <- "abcdefghij" ]+        writeKV env kvs+        seen <- L.withReadTxn env $ \txn -> do+          dbi <- L.openDbi txn Nothing False+          L.withCursor txn dbi (cursorWalk [])+        seen @?= kvs++  , testCase "cursorSeek lands on first >= key" $+      withTmpEnv flags $ \env -> do+        writeKV env [ ("a","1"), ("c","3"), ("e","5") ]+        r <- L.withReadTxn env $ \txn -> do+          dbi <- L.openDbi txn Nothing False+          L.withCursor txn dbi $ \cur ->+            L.cursorSeek cur "b"+        r @?= Just ("c", "3")+  ]++-- walk a cursor, accumulating pairs from current position to end+cursorWalk+  :: [(BS.ByteString, BS.ByteString)]+  -> L.Cursor s+  -> IO [(BS.ByteString, BS.ByteString)]+cursorWalk acc cur = do+  step <- L.cursorFirst cur+  go (reverse acc) step+  where+    go ys Nothing      = pure (reverse ys)+    go ys (Just kv)    = do+      next <- L.cursorNext cur+      go (kv : ys) next++-- properties -----------------------------------------------------------------++newtype Key = Key BS.ByteString deriving Show+newtype Val = Val BS.ByteString deriving Show++-- LMDB rejects empty keys; restrict to non-empty bounded strings.+instance Arbitrary Key where+  arbitrary = do+    n <- QC.chooseInt (1, 32)+    Key . BS.pack <$> QC.vectorOf n QC.arbitrary++instance Arbitrary Val where+  arbitrary = do+    n <- QC.chooseInt (0, 64)+    Val . BS.pack <$> QC.vectorOf n QC.arbitrary++propTests :: TestTree+propTests = testGroup "props"+  [ QC.testProperty "put / get roundtrip" $ \(Key k) (Val v) ->+      QC.ioProperty $ withTmpEnv flags $ \env -> do+        writeKV env [(k, v)]+        got <- L.withReadTxn env $ \txn -> do+          dbi <- L.openDbi txn Nothing False+          L.get txn dbi k+        pure (got == Just v)++  , QC.testProperty "cursor enumerates Map.toAscList" $ \kvs0 ->+      let kvs = uniqueKeys [(k, v) | (Key k, Val v) <- kvs0]+      in  QC.ioProperty $ withTmpEnv flags $ \env -> do+            writeKV env kvs+            seen <- L.withReadTxn env $ \txn -> do+              dbi <- L.openDbi txn Nothing False+              L.withCursor txn dbi (cursorWalk [])+            pure (seen == Map.toAscList (Map.fromList kvs))+  ]++-- keep only the last write for each key, matching LMDB's overwrite+-- semantics under MDB_NOOVERWRITE-not-set+uniqueKeys+  :: [(BS.ByteString, BS.ByteString)]+  -> [(BS.ByteString, BS.ByteString)]+uniqueKeys = Map.toList . Map.fromList