diff --git a/LICENSE b/LICENSE new file mode 100644 --- /dev/null +++ b/LICENSE @@ -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. diff --git a/lmdb-clib.cabal b/lmdb-clib.cabal new file mode 100644 --- /dev/null +++ b/lmdb-clib.cabal @@ -0,0 +1,56 @@ +cabal-version: 3.4 +name: lmdb-clib +version: 0.9.31 +synopsis: Lightning Memory-Mapped Database +author: Howard Chu, Symas Corporation. +maintainer: Simon Marlow +copyright: Copyright 2011-2021 Howard Chu, Symas Corp. +homepage: https://www.symas.com/mdb +license: BSD-3-Clause +license-files: LICENSE +build-type: Simple + +Description: + Cabal wrapper around the LMDB C library, with one tweak to increase + the default max key size from 511 bytes to ~2kB. + +source-repository head + type: git + location: https://git.openldap.org/openldap/openldap/tree/mdb.master + +-- Note: if you import a new version, copy the local change to +-- #define PAGEBASE that is needed to increase the max key size. + +common fb-cpp + cxx-options: -std=c++20 -Wno-nullability-completeness -fno-omit-frame-pointer + if !flag(clang) + cxx-options: -fcoroutines + if arch(x86_64) + cxx-options: -march=haswell + if flag(opt) && !flag(asan) + cxx-options: -O3 -DNDEBUG + else + cc-options: -g + cxx-options: -g + +flag clang + default: False + +flag asan + default: False + +flag opt + default: True + +library + import: fb-cpp + default-language: Haskell2010 + c-sources: + mdb.c + midl.c + cc-options: -DMDB_MAXKEYSIZE=0 + include-dirs: . + install-includes: + lmdb.h + midl.h + diff --git a/lmdb.h b/lmdb.h new file mode 100644 --- /dev/null +++ b/lmdb.h @@ -0,0 +1,1680 @@ +/** @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 most systems: + * - Windows - automatic + * - BSD, systems using SysV semaphores - automatic + * - Linux, systems using POSIX mutexes with Robust option - automatic + * 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_SYSV_SEM or + * 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 + * . + * + * @par Derived From: + * This code is derived from btree.c written by Martin Hedenfalk. + * + * Copyright (c) 2009, 2010 Martin Hedenfalk + * + * 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 +#include +#include + +#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 + +#ifdef _WIN32 +#define MDB_FMT_Z "I" +#else +#define MDB_FMT_Z "z" /**< printf/scanf format modifier for size_t */ +#endif + +#ifndef MDB_VL32 +/** Unsigned type used for mapsize, entry counts and page/transaction IDs. + * + * It is normally size_t, hence the name. Defining MDB_VL32 makes it + * uint64_t, but do not try this unless you know what you are doing. + */ +typedef size_t mdb_size_t; +#define MDB_SIZE_MAX SIZE_MAX /**< max #mdb_size_t */ +/** #mdb_size_t printf formats, \b t = one of [diouxX] without quotes */ +#define MDB_PRIy(t) MDB_FMT_Z #t +/** #mdb_size_t scanf formats, \b t = one of [dioux] without quotes */ +#define MDB_SCNy(t) MDB_FMT_Z #t +#else +typedef uint64_t mdb_size_t; +#define MDB_SIZE_MAX UINT64_MAX +#define MDB_PRIy(t) PRI##t##64 +#define MDB_SCNy(t) SCN##t##64 +#define mdb_env_create \ + mdb_env_create_vl32 /**< Prevent mixing with non-VL32 builds */ +#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 70 + +/** 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 "December 19, 2015" + +/** 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 +/** use the previous snapshot rather than the latest one */ +#define MDB_PREVSNAPSHOT 0x2000000 +/** @} */ + +/** @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 #mdb_size_t. + * (lmdb expects 32-bit int <= size_t <= 32/64-bit mdb_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
+ * For put: don't write if the key and data pair already exist.
+ * 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: + *
    + *
  • The operation expects an #MDB_DUPSORT / #MDB_DUPFIXED database. + *
  • Opening a named DB when the unnamed DB has #MDB_DUPSORT / + * #MDB_INTEGERKEY.
  • Accessing a data record as a database, or vice versa. + *
  • The database was dropped and recreated with different flags. + *
+ */ +#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) +/** Unexpected problem - txn should abort */ +#define MDB_PROBLEM (-30779) +/** The last defined error code */ +#define MDB_LAST_ERRCODE MDB_PROBLEM +/** @} */ + +/** @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 */ + mdb_size_t ms_branch_pages; /**< Number of internal (non-leaf) pages */ + mdb_size_t ms_leaf_pages; /**< Number of leaf pages */ + mdb_size_t ms_overflow_pages; /**< Number of overflow pages */ + mdb_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 */ + mdb_size_t me_mapsize; /**< Size of the data memory map */ + mdb_size_t me_last_pgno; /**< ID of the last used page */ + mdb_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. + *
    + *
  • #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. + *
  • #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.
  • #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.
  • #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). + *
  • #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(). + *
  • #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().
  • #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(). + *
  • #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.
  • #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.
  • #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. + *
  • #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(). + *
  • #MDB_PREVSNAPSHOT + * Open the environment with the previous snapshot rather than the + * latest one. This loses the latest transaction, but may help work around some + * types of corruption. If opened with write access, this must be + * the only process using the environment. This flag is automatically reset + * after a write transaction is successfully committed. + *
+ * @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: + *
    + *
  • #MDB_VERSION_MISMATCH - the version of the LMDB library doesn't + * match the version that created the database environment.
  • #MDB_INVALID - + * the environment file headers are corrupted.
  • ENOENT - the directory + * specified by the path parameter doesn't exist.
  • EACCES - the user didn't + * have permission to access the environment files.
  • EAGAIN - the environment + * was locked by another process. + *
+ */ +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. + *
    + *
  • #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. + *
+ * @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: + *
    + *
  • EACCES - the environment is read-only. + *
  • EINVAL - an invalid parameter was specified. + *
  • EIO - an error occurred during synchronization. + *
+ */ +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: + *
    + *
  • EINVAL - an invalid parameter was specified. + *
+ */ +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: + *
    + *
  • EINVAL - an invalid parameter was specified. + *
+ */ +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: + *
    + *
  • EINVAL - an invalid parameter was specified. + *
+ */ +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: + *
    + *
  • EINVAL - an invalid parameter was specified. + *
+ */ +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: + *
    + *
  • EINVAL - an invalid parameter was specified, or the environment has + * an active write transaction. + *
+ */ +int mdb_env_set_mapsize(MDB_env* env, mdb_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: + *
    + *
  • EINVAL - an invalid parameter was specified, or the environment is + * already open. + *
+ */ +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: + *
    + *
  • EINVAL - an invalid parameter was specified. + *
+ */ +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: + *
    + *
  • EINVAL - an invalid parameter was specified, or the environment is + * already open. + *
+ */ +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. + *
    + *
  • #MDB_RDONLY + * This transaction will not perform any write operations. + *
  • #MDB_NOSYNC + * Don't flush system buffers to disk when committing this + * transaction.
  • #MDB_NOMETASYNC Flush system buffers but omit metadata flush + * when committing this transaction. + *
+ * @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: + *
    + *
  • #MDB_PANIC - a fatal error occurred earlier and the environment + * must be shut down. + *
  • #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(). + *
  • #MDB_READERS_FULL - a read-only transaction was requested and + * the reader lock table is full. See #mdb_env_set_maxreaders(). + *
  • ENOMEM - out of memory. + *
+ */ +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. + */ +mdb_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: + *
    + *
  • EINVAL - an invalid parameter was specified. + *
  • ENOSPC - no more disk space. + *
  • EIO - a low-level I/O error occurred while writing. + *
  • ENOMEM - out of memory. + *
+ */ +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: + *
    + *
  • #MDB_PANIC - a fatal error occurred earlier and the environment + * must be shut down. + *
  • EINVAL - an invalid parameter was specified. + *
+ */ +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. + *
    + *
  • #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.
  • #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.
  • #MDB_INTEGERKEY Keys are binary + * integers in native byte order, either unsigned int or #mdb_size_t, and will + * be sorted as such. (lmdb expects 32-bit int <= size_t <= 32/64-bit + * mdb_size_t.) The keys must all be of the same size.
  • #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.
  • #MDB_INTEGERDUP This option specifies that duplicate data items + * are binary integers, similar to #MDB_INTEGERKEY keys.
  • #MDB_REVERSEDUP + * This option specifies that duplicate data items should be + * compared as strings in reverse order.
  • #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. + *
+ * @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: + *
    + *
  • #MDB_NOTFOUND - the specified database doesn't exist in the + * environment and #MDB_CREATE was not specified.
  • #MDB_DBS_FULL - too many + * databases have been opened. See #mdb_env_set_maxdbs(). + *
+ */ +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: + *
    + *
  • EINVAL - an invalid parameter was specified. + *
+ */ +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: + *
    + *
  • EINVAL - an invalid parameter was specified. + *
+ */ +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: + *
    + *
  • EINVAL - an invalid parameter was specified. + *
+ */ +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: + *
    + *
  • EINVAL - an invalid parameter was specified. + *
+ */ +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: + *
    + *
  • EINVAL - an invalid parameter was specified. + *
+ */ +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: + *
    + *
  • #MDB_NOTFOUND - the key was not in the database. + *
  • EINVAL - an invalid parameter was specified. + *
+ */ +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. + *
    + *
  • #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. + *
  • #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.
  • #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.
  • #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. + *
  • #MDB_APPENDDUP - as above, but for sorted dup data. + *
+ * @return A non-zero error value on failure and 0 on success. Some possible + * errors are: + *
    + *
  • #MDB_MAP_FULL - the database is full, see #mdb_env_set_mapsize(). + *
  • #MDB_TXN_FULL - the transaction has too many dirty pages. + *
  • EACCES - an attempt was made to write in a read-only transaction. + *
  • EINVAL - an invalid parameter was specified. + *
+ */ +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: + *
    + *
  • EACCES - an attempt was made to write in a read-only transaction. + *
  • EINVAL - an invalid parameter was specified. + *
+ */ +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: + *
    + *
  • EINVAL - an invalid parameter was specified. + *
+ */ +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: + *
    + *
  • EINVAL - an invalid parameter was specified. + *
+ */ +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: + *
    + *
  • #MDB_NOTFOUND - no matching key found. + *
  • EINVAL - an invalid parameter was specified. + *
+ */ +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. + *
    + *
  • #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.
  • #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. + *
  • #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).
  • #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.
  • #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. + *
  • #MDB_APPENDDUP - as above, but for sorted dup data. + *
  • #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. + *
+ * @return A non-zero error value on failure and 0 on success. Some possible + * errors are: + *
    + *
  • #MDB_MAP_FULL - the database is full, see #mdb_env_set_mapsize(). + *
  • #MDB_TXN_FULL - the transaction has too many dirty pages. + *
  • EACCES - an attempt was made to write in a read-only transaction. + *
  • EINVAL - an invalid parameter was specified. + *
+ */ +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. + *
    + *
  • #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. + *
+ * @return A non-zero error value on failure and 0 on success. Some possible + * errors are: + *
    + *
  • EACCES - an attempt was made to write in a read-only transaction. + *
  • EINVAL - an invalid parameter was specified. + *
+ */ +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: + *
    + *
  • EINVAL - cursor is not initialized, or an invalid parameter was + * specified. + *
+ */ +int mdb_cursor_count(MDB_cursor* cursor, mdb_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_ */ diff --git a/mdb.c b/mdb.c new file mode 100644 --- /dev/null +++ b/mdb.c @@ -0,0 +1,11609 @@ +/** @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 + * . + * + * This code is derived from btree.c written by Martin Hedenfalk. + * + * Copyright (c) 2009, 2010 Martin Hedenfalk + * + * 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(MDB_VL32) || defined(__WIN64__) +#define _FILE_OFFSET_BITS 64 +#endif +#ifdef _WIN32 +#include +#include /* get wcscpy() */ +#include + +/* We use native NT APIs to setup the memory map, so that we can + * let the DB file grow incrementally instead of always preallocating + * the full size. These APIs are defined in and + * but those headers are meant for driver-level development and + * conflict with the regular user-level headers, so we explicitly + * declare them here. We get pointers to these functions from + * NTDLL.DLL at runtime, to avoid buildtime dependencies on any + * NTDLL import libraries. + */ +typedef NTSTATUS(WINAPI NtCreateSectionFunc)( + OUT PHANDLE sh, + IN ACCESS_MASK acc, + IN void* oa OPTIONAL, + IN PLARGE_INTEGER ms OPTIONAL, + IN ULONG pp, + IN ULONG aa, + IN HANDLE fh OPTIONAL); + +static NtCreateSectionFunc* NtCreateSection; + +typedef enum _SECTION_INHERIT { ViewShare = 1, ViewUnmap = 2 } SECTION_INHERIT; + +typedef NTSTATUS(WINAPI NtMapViewOfSectionFunc)( + IN PHANDLE sh, + IN HANDLE ph, + IN OUT PVOID* addr, + IN ULONG_PTR zbits, + IN SIZE_T cs, + IN OUT PLARGE_INTEGER off OPTIONAL, + IN OUT PSIZE_T vs, + IN SECTION_INHERIT ih, + IN ULONG at, + IN ULONG pp); + +static NtMapViewOfSectionFunc* NtMapViewOfSection; + +typedef NTSTATUS(WINAPI NtCloseFunc)(HANDLE h); + +static NtCloseFunc* NtClose; + +/** 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 +#include +#ifdef __GNUC__ +#include +#else +#define LITTLE_ENDIAN 1234 +#define BIG_ENDIAN 4321 +#define BYTE_ORDER LITTLE_ENDIAN +#ifndef SSIZE_MAX +#define SSIZE_MAX INT_MAX +#endif +#endif +#define MDB_OFF_T int64_t +#else +#include +#include +#define MDB_PID_T pid_t +#define MDB_THR_T pthread_t +#include +#include +#include +#ifdef HAVE_SYS_FILE_H +#include +#endif +#include +#define MDB_OFF_T off_t +#endif + +#if defined(__mips) && defined(__linux) +/* MIPS has cache coherency issues, requires explicit cache control */ +#include +#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 +#include +#include +#include +#include +#include +#include +#include + +#ifdef _MSC_VER +#include +typedef SSIZE_T ssize_t; +#else +#include +#endif + +#if defined(__sun) || defined(__ANDROID__) +/* Most platforms have posix_memalign, older may only have memalign */ +#define HAVE_MEMALIGN 1 +#include +/* 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 +#include /* 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__) +#if !(defined(MDB_USE_POSIX_MUTEX) || defined(MDB_USE_POSIX_SEM)) +#define MDB_USE_SYSV_SEM 1 +#endif +#if defined(__APPLE__) +#define MDB_FDATASYNC(fd) fcntl(fd, F_FULLFSYNC) +#else +#define MDB_FDATASYNC fsync +#endif +#elif defined(__ANDROID__) +#define MDB_FDATASYNC fsync +#endif + +#ifndef _WIN32 +#include +#include +#ifdef MDB_USE_POSIX_SEM +#define MDB_USE_HASH 1 +#include +#elif defined(MDB_USE_SYSV_SEM) +#include +#include +#ifdef _SEM_SEMUN_UNDEFINED +union semun { + int val; + struct semid_ds* buf; + unsigned short* array; +}; +#endif /* _SEM_SEMUN_UNDEFINED */ +#else +#define MDB_USE_POSIX_MUTEX 1 +#endif /* MDB_USE_POSIX_SEM */ +#endif /* !_WIN32 */ + +#if defined(_WIN32) + defined(MDB_USE_POSIX_SEM) + defined(MDB_USE_SYSV_SEM) + \ + defined(MDB_USE_POSIX_MUTEX) != \ + 1 +#error "Ambiguous shared-lock implementation" +#endif + +#ifdef USE_VALGRIND +#include +#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 || \ + MDB_SIZE_MAX % UINT_MAX +#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 (), update the #if statements above */ +#define mdb_func_ "" +#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_SYSV_SEM +#define MDB_OWNERDEAD (MDB_LAST_ERRCODE + 11) +#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_SYSV_SEM instead of + * -DMDB_USE_POSIX_MUTEX. (SysV semaphores are + * also Robust, but some systems don't support them + * either.) + */ +#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 +#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) + +/** 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; +} + +#elif defined MDB_USE_SYSV_SEM + +typedef struct mdb_mutex { + int semid; + int semnum; + int* locked; +} mdb_mutex_t[1], *mdb_mutexref_t; + +#define LOCK_MUTEX0(mutex) mdb_sem_wait(mutex) +#define UNLOCK_MUTEX(mutex) \ + do { \ + struct sembuf sb = {0, 1, SEM_UNDO}; \ + sb.sem_num = (mutex)->semnum; \ + *(mutex)->locked = 0; \ + semop((mutex)->semid, &sb, 1); \ + } while (0) + +static int mdb_sem_wait(mdb_mutexref_t sem) { + int rc, *locked = sem->locked; + struct sembuf sb = {0, -1, SEM_UNDO}; + sb.sem_num = sem->semnum; + do { + if (!semop(sem->semid, &sb, 1)) { + rc = *locked ? MDB_OWNERDEAD : MDB_SUCCESS; + *locked = 1; + break; + } + } while ((rc = errno) == EINTR); + return rc; +} + +#define mdb_mutex_consistent(mutex) 0 + +#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 || MDB_USE_SYSV_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)) +// #define GET_PAGESIZE(x) ((x) = 65536) +#endif + +#define Z MDB_FMT_Z /**< printf/scanf format modifier for size_t */ +#define Yu MDB_PRIy(u) /**< printf format for #mdb_size_t */ +#define Yd MDB_PRIy(d) /**< printf format for 'signed #mdb_size_t' */ + +#ifdef MDB_USE_SYSV_SEM +#define MNAME_LEN (sizeof(int)) +#else +#define MNAME_LEN (sizeof(pthread_mutex_t)) +#endif + +/** Initial part of #MDB_env.me_mutexname[]. + * Changes to this code must be reflected in #MDB_LOCK_FORMAT. + */ +#ifdef _WIN32 +#define MUTEXNAME_PREFIX "Global\\MDB" +#elif defined MDB_USE_POSIX_SEM +#define MUTEXNAME_PREFIX "/MDB" +#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 ((MDB_DEVEL) ? 999 : 2) +/** Number of bits representing #MDB_LOCK_VERSION in #MDB_LOCK_FORMAT. + * The remaining bits must leave room for #MDB_lock_desc. + */ +#define MDB_LOCK_VERSION_BITS 12 + +/** @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 */ + +/** Least significant 1-bit of \b n. n must be of an unsigned type. */ +#define LOW_BIT(n) ((n) & (-(n))) + +/** (log2(\b p2) % \b n), for p2 = power of 2 and 0 < n < 8. */ +#define LOG2_MOD(p2, n) (7 - 86 / ((p2) % ((1U << (n)) - 1) + 11)) +/* Explanation: Let p2 = 2**(n*y + x), x> (CACHELINE > 64), 5)) + + 6 * (sizeof(MDB_PID_T) / 4 % 3) /* legacy(2) to word(4/8)? */ + + 18 * (sizeof(pthread_t) / 4 % 5) /* can be struct{id, active data} */ + + 90 * (sizeof(MDB_txbody) / CACHELINE % 3) + + 270 * (MDB_LOCK_TYPE % 120) + /* The above is < 270*120 < 2**15 */ + + ((sizeof(txnid_t) == 8) << 15) /* 32bit/64bit */ + + ((sizeof(MDB_reader) > CACHELINE) << 16) + /* Not really needed - implied by MDB_LOCK_TYPE != (_WIN32 locking) */ + + (((MDB_PIDLOCK) != 0) << 17) + /* 18 bits total: Must be <= (32 - MDB_LOCK_VERSION_BITS). */ +}; +/** @} */ + +/** 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 PAGEHDRSZ +// #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 MDB_SIZE_MAX > 0xffffffffU +#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 */ + mdb_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; +#ifdef MDB_VL32 + union { /* always zero since we don't support fixed mapping in MDB_VL32 */ + MDB_ID mmun_ull; + void* mmun_address; + } mm_un; +#define mm_address mm_un.mmun_address +#else + void* mm_address; /**< address for fixed mapping */ +#endif + mdb_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 */ +#ifdef MDB_VL32 + pgno_t mt_last_pgno; /**< last written page */ +#endif + /** 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; +#ifdef MDB_VL32 + /** List of read-only pages (actually chunks) */ + MDB_ID3L mt_rpages; + /** We map chunks of 16 pages. Even though Windows uses 4KB pages, all + * mappings must begin on 64KB boundaries. So we round off all pgnos to + * a chunk boundary. We do the same on Linux for symmetry, and also to + * reduce the frequency of mmap/munmap calls. + */ +#define MDB_RPAGE_CHUNK 16 +#define MDB_TRPAGE_SIZE 4096 /**< size of #mt_rpages array of chunks */ +#define MDB_TRPAGE_MAX (MDB_TRPAGE_SIZE - 1) /**< maximum chunk index */ + unsigned int mt_rpcheck; /**< threshold for reclaiming unref'd chunks */ +#endif + /** 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_NOMETASYNC | MDB_NOSYNC | MDB_RDONLY) +#define MDB_TXN_NOMETASYNC \ + MDB_NOMETASYNC /**< don't sync meta for this txn on commit */ +#define MDB_TXN_NOSYNC MDB_NOSYNC /**< don't sync this txn on commit */ +#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 */ +#define C_WRITEMAP MDB_TXN_WRITEMAP /**< Copy of txn flag */ +/** Read-only cursor into the txn's original snapshot in the map. + * Set for read-only txns, and in #mdb_page_alloc() for #FREE_DBI when + * #MDB_DEVEL & 2. Only implements code which is necessary for this. + */ +#define C_ORIG_RDONLY MDB_TXN_RDONLY + /** @} */ + 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 */ +#ifdef MDB_VL32 + MDB_page* mc_ovpg; /**< a referenced overflow page */ +#define MC_OVPG(mc) ((mc)->mc_ovpg) +#define MC_SET_OVPG(mc, pg) ((mc)->mc_ovpg = (pg)) +#else +#define MC_OVPG(mc) ((MDB_page*)0) +#define MC_SET_OVPG(mc, pg) ((void)0) +#endif +}; + +/** 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 */ +#ifdef _WIN32 +#ifdef MDB_VL32 + HANDLE me_fmh; /**< File Mapping handle */ +#endif /* MDB_VL32 */ + HANDLE me_ovfd; /**< Overlapped/async with write-through file handle */ +#endif /* _WIN32 */ + /** 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 */ + mdb_size_t me_mapsize; /**< size of the data memory map */ + MDB_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 */ + OVERLAPPED* ov; /**< Used for for overlapping I/O requests */ + int ovs; /**< Count of OVERLAPPEDs */ +#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; +#if defined(_WIN32) || defined(MDB_USE_POSIX_SEM) + /** Half-initialized name of mutexes, to be completed by #MUTEXNAME() */ + char me_mutexname[sizeof(MUTEXNAME_PREFIX) + 11]; +#endif +#endif +#ifdef MDB_VL32 + MDB_ID3L me_rpages; /**< like #mt_rpages, but global to env */ + pthread_mutex_t me_rpmutex; /**< control access to #me_rpages */ +#define MDB_ERPAGE_SIZE 16384 +#define MDB_ERPAGE_MAX (MDB_ERPAGE_SIZE - 1) + unsigned int me_rpcheck; +#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, int prev, 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 '#mdb_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 + +/** True if we need #mdb_cmp_clong() instead of \b cmp for #MDB_INTEGERDUP */ +#define NEED_CMP_CLONG(cmp, ksize) \ + (UINT_MAX < MDB_SIZE_MAX && (cmp) == mdb_cmp_int && \ + (ksize) == sizeof(mdb_size_t)) + +#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", + "MDB_PROBLEM: Unexpected problem - txn should abort", +}; + +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 %" Yu " pages %u%s\n", + pgno, + mp->mp_pages, + state); + return; + case P_META: + fprintf( + stderr, + "Meta-page %" Yu " txnid %" Yu "\n", + pgno, + ((MDB_meta*)METADATA(mp))->mm_txnid); + return; + default: + fprintf(stderr, "Bad page %" Yu " flags 0x%X\n", pgno, MP_FLAGS(mp)); + return; + } + + nkeys = NUMKEYS(mp); + fprintf(stderr, "%s %" Yu " 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 %" Yu ", %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: %" Yu " freecount: %" Yu " count: %" Yu " total: %" Yu + " next_pgno: %" Yu "\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 (NEED_CMP_CLONG(dcmp, a->mv_size)) + dcmp = mdb_cmp_clong; + 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; +} + +#ifdef MDB_VL32 +static void mdb_page_unref(MDB_txn* txn, MDB_page* mp) { + pgno_t pgno; + MDB_ID3L tl = txn->mt_rpages; + unsigned x, rem; + if (mp->mp_flags & (P_SUBP | P_DIRTY)) + return; + rem = mp->mp_pgno & (MDB_RPAGE_CHUNK - 1); + pgno = mp->mp_pgno ^ rem; + x = mdb_mid3l_search(tl, pgno); + if (x != tl[0].mid && tl[x + 1].mid == mp->mp_pgno) + x++; + if (tl[x].mref) + tl[x].mref--; +} +#define MDB_PAGE_UNREF(txn, mp) mdb_page_unref(txn, mp) + +static void mdb_cursor_unref(MDB_cursor* mc) { + int i; + if (mc->mc_txn->mt_rpages[0].mid) { + if (!mc->mc_snum || !mc->mc_pg[0] || IS_SUBP(mc->mc_pg[0])) + return; + for (i = 0; i < mc->mc_snum; i++) + mdb_page_unref(mc->mc_txn, mc->mc_pg[i]); + if (mc->mc_ovpg) { + mdb_page_unref(mc->mc_txn, mc->mc_ovpg); + mc->mc_ovpg = 0; + } + } + mc->mc_snum = mc->mc_top = 0; + mc->mc_pg[0] = NULL; + mc->mc_flags &= ~C_INITIALIZED; +} +#define MDB_CURSOR_UNREF(mc, force) \ + (((force) || ((mc)->mc_flags & C_INITIALIZED)) ? mdb_cursor_unref(mc) \ + : (void)0) + +#else +#define MDB_PAGE_UNREF(txn, mp) +#define MDB_CURSOR_UNREF(mc, force) ((void)0) +#endif /* MDB_VL32 */ + +/** 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_PROBLEM; + } + /* ok, it's ours */ + loose = 1; + } + } + } else { + /* no parent txn, so it's just ours */ + loose = 1; + } + } + if (loose) { + DPRINTF(("loosen db %d page %" Yu, 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: First m0, then tracked cursors */ + for (i = txn->mt_numdbs;;) { + if (mc->mc_flags & C_INITIALIZED) { + 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; + } + } + mc = mc->mc_next; + for (; !mc || mc == m0; mc = txn->mt_cursors[--i]) + if (i == 0) + goto mark_done; + } + +mark_done: + 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*); +#ifdef _WIN32 /* With Windows we always write dirty pages with WriteFile, \ + * so we always want them ordered */ + insert = mdb_mid2l_insert; +#else /* but otherwise with writemaps, we just use msync, we \ + * don't need the ordering and just append */ + if (txn->mt_flags & MDB_TXN_WRITEMAP) + insert = mdb_mid2l_append; + else + insert = mdb_mid2l_insert; +#endif + 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. + * When #MDB_DEVEL & 2, it is not affected by #mdb_freelist_save(): it + * then uses the transaction's original snapshot of the freeDB. + * @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 more freeDB records once me_pghead + * has enough pages. If not enough, use new pages from the map. + * If 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 %" Yu, 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 (MDB_DEVEL) & 2 /* "& 2" so MDB_DEVEL=1 won't hide bugs breaking freeDB */ + /* Use original snapshot. TODO: Should need less care in code + * which modifies the database. Maybe we can delete some code? + */ + m2.mc_flags |= C_ORIG_RDONLY; + m2.mc_db = &env->me_metas[(txn->mt_txnid - 1) & 1]->mm_dbs[FREE_DBI]; + m2.mc_dbflag = (unsigned char*)""; /* probably unnecessary */ +#endif + 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 %" Yu " root %" Yu " num %u", + last, + txn->mt_dbs[FREE_DBI].md_root, + i)); + for (j = i; j; j--) + DPRINTF(("IDL %" Yu, 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; + } +#if defined(_WIN32) && !defined(MDB_VL32) + if (!(env->me_flags & MDB_RDONLY)) { + void* p; + p = (MDB_page*)(env->me_map + env->me_psize * pgno); + p = VirtualAlloc( + p, + env->me_psize * num, + MEM_COMMIT, + (env->me_flags & MDB_WRITEMAP) ? PAGE_READWRITE : PAGE_READONLY); + if (!p) { + DPUTS("VirtualAlloc failed"); + rc = ErrCode(); + goto fail; + } + } +#endif + +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 %" Yu " -> %" Yu, 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_PROBLEM; + } + 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); + } + } + } + MDB_PAGE_UNREF(mc->mc_txn, mp); + return 0; + +fail: + txn->mt_flags |= MDB_TXN_ERROR; + return rc; +} + +int mdb_env_sync0(MDB_env* env, int force, pgno_t numpgs) { + int rc = 0; + if (env->me_flags & MDB_RDONLY) + return EACCES; + if (force +#ifndef _WIN32 /* Sync is normally achieved in Windows by doing WRITE_THROUGH \ + writes */ + || !(env->me_flags & MDB_NOSYNC) +#endif + ) { + 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_psize * numpgs, flags)) + rc = ErrCode(); +#if defined(_WIN32) || defined(__APPLE__) + 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; +} + +int mdb_env_sync(MDB_env* env, int force) { + MDB_meta* m = mdb_env_pick_meta(env); + return mdb_env_sync0(env, force, m->mm_last_pg + 1); +} + +/** 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; +#ifdef MDB_VL32 + txn->mt_last_pgno = txn->mt_next_pgno - 1; +#endif + + 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 %" Yu "%c %p on mdbenv %p, root page %" Yu, + 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; + } +#ifdef MDB_VL32 + if (!parent) { + txn->mt_rpages = malloc(MDB_TRPAGE_SIZE * sizeof(MDB_ID3)); + if (!txn->mt_rpages) { + free(txn); + return ENOMEM; + } + txn->mt_rpages[0].mid = 0; + txn->mt_rpcheck = MDB_TRPAGE_SIZE / 2; + } +#endif + 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; +#ifdef MDB_VL32 + txn->mt_rpages = parent->mt_rpages; +#endif + 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) { + /* mt_rpages is owned by parent */ + free(txn->mt_u.dirty_list); + free(txn); + } + } else { + txn->mt_flags |= flags; /* could not change txn=me_txn0 earlier */ + *ret = txn; + DPRINTF( + ("begin txn %" Yu "%c %p on mdbenv %p, root page %" Yu, + 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; +} + +mdb_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 %" Yu "%c %p on mdbenv %p, root page %" Yu, + 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; + mdb_midl_free(txn->mt_spill_pgs); + + 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(pghead); + } +#ifdef MDB_VL32 + if (!txn->mt_parent) { + MDB_ID3L el = env->me_rpages, tl = txn->mt_rpages; + unsigned i, x, n = tl[0].mid; + pthread_mutex_lock(&env->me_rpmutex); + for (i = 1; i <= n; i++) { + if (tl[i].mid & (MDB_RPAGE_CHUNK - 1)) { + /* tmp overflow pages that we didn't share in env */ + munmap(tl[i].mptr, tl[i].mcnt * env->me_psize); + } else { + x = mdb_mid3l_search(el, tl[i].mid); + if (tl[i].mptr == el[x].mptr) { + el[x].mref--; + } else { + /* another tmp overflow page */ + munmap(tl[i].mptr, tl[i].mcnt * env->me_psize); + } + } + } + pthread_mutex_unlock(&env->me_rpmutex); + tl[0].mid = 0; + if (mode & MDB_END_FREE) + free(tl); + } +#endif + 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. + * + * When (MDB_DEVEL) & 2, the changes do not affect #mdb_page_alloc(), + * it then uses the transaction's original snapshot of the freeDB. + */ +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 %" Yu " root %" Yu " num %u", + txn->mt_txnid, + txn->mt_dbs[FREE_DBI].md_root, + i)); + for (; i; i--) + DPRINTF(("IDL %" Yu, 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; + MDB_OFF_T pos = 0; + pgno_t pgno = 0; + MDB_page* dp = NULL; +#ifdef _WIN32 + OVERLAPPED* ov = env->ov; + MDB_page* wdp; + int async_i = 0; + HANDLE fd = (env->me_flags & MDB_NOSYNC) ? env->me_fd : env->me_ovfd; +#else + struct iovec iov[MDB_COMMIT_PAGES]; + HANDLE fd = env->me_fd; +#endif + ssize_t wsize = 0, wres; + MDB_OFF_T wpos = 0, next_pos = 1; /* impossible pos, so pos != next_pos */ + int n = 0; + + j = i = keep; + if (env->me_flags & MDB_WRITEMAP +#ifdef _WIN32 + /* In windows, we still do writes to the file (with write-through enabled + * in sync mode), as this is faster than FlushViewOfFile/FlushFileBuffers + */ + && (env->me_flags & MDB_NOSYNC) +#endif + ) { + /* 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; + } + +#ifdef _WIN32 + if (pagecount - keep >= env->ovs) { + /* ran out of room in ov array, and re-malloc, copy handles and free + * previous */ + int ovs = (pagecount - keep) * + 1.5; /* provide extra padding to reduce number of re-allocations */ + int new_size = ovs * sizeof(OVERLAPPED); + ov = malloc(new_size); + if (ov == NULL) + return ENOMEM; + int previous_size = env->ovs * sizeof(OVERLAPPED); + memcpy(ov, env->ov, previous_size); /* Copy previous OVERLAPPED data to + retain event handles */ + /* And clear rest of memory */ + memset(&ov[env->ovs], 0, new_size - previous_size); + if (env->ovs > 0) { + free(env->ov); /* release previous allocation */ + } + + env->ov = ov; + env->ovs = ovs; + } +#endif + + /* 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; + } + /* Write up to MDB_COMMIT_PAGES dirty pages at a time. */ + if (pos != next_pos || n == MDB_COMMIT_PAGES || + wsize + size > MAX_WRITE +#ifdef _WIN32 + /* If writemap is enabled, consecutive page positions infer + * contiguous (mapped) memory. + * Otherwise force write pages one at a time. + * 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. + */ + || !(env->me_flags & MDB_WRITEMAP) +#endif + ) { + if (n) { + retry_write: + /* Write previous page(s) */ + DPRINTF(("committing page %" Z "u", pgno)); +#ifdef _WIN32 + OVERLAPPED* this_ov = &ov[async_i]; + /* Clear status, and keep hEvent, we reuse that */ + this_ov->Internal = 0; + this_ov->Offset = wpos & 0xffffffff; + this_ov->OffsetHigh = wpos >> 16 >> 16; + if (!F_ISSET(env->me_flags, MDB_NOSYNC) && !this_ov->hEvent) { + HANDLE event = CreateEvent(NULL, FALSE, FALSE, NULL); + if (!event) { + rc = ErrCode(); + DPRINTF(("CreateEvent: %s", strerror(rc))); + return rc; + } + this_ov->hEvent = event; + } + if (!WriteFile(fd, wdp, wsize, NULL, this_ov)) { + rc = ErrCode(); + if (rc != ERROR_IO_PENDING) { + DPRINTF(("WriteFile: %d", rc)); + return rc; + } + } + async_i++; +#else +#ifdef MDB_USE_PWRITEV + wres = pwritev(fd, iov, n, wpos); +#else + if (n == 1) { + wres = pwrite(fd, iov[0].iov_base, wsize, wpos); + } else { + retry_seek: + if (lseek(fd, wpos, SEEK_SET) == -1) { + rc = ErrCode(); + if (rc == EINTR) + goto retry_seek; + DPRINTF(("lseek: %s", strerror(rc))); + return rc; + } + wres = writev(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; + } +#endif /* _WIN32 */ + n = 0; + } + if (i > pagecount) + break; + wpos = pos; + wsize = 0; +#ifdef _WIN32 + wdp = dp; + } +#else + } + iov[n].iov_len = size; + iov[n].iov_base = (char*)dp; +#endif /* _WIN32 */ + DPRINTF(("committing page %" Yu, pgno)); + next_pos = pos + size; + wsize += size; + n++; + } +#ifdef MDB_VL32 + if (pgno > txn->mt_last_pgno) + txn->mt_last_pgno = pgno; +#endif + +#ifdef _WIN32 + if (!F_ISSET(env->me_flags, MDB_NOSYNC)) { + /* Now wait for all the asynchronous/overlapped sync/write-through writes to + * complete. We start with the last one so that all the others should + * already be complete and we reduce thread suspend/resuming (in practice, + * typically about 99.5% of writes are done after the last write is done) */ + rc = 0; + while (--async_i >= 0) { + if (ov[async_i].hEvent) { + DWORD temp_wres; + if (!GetOverlappedResult(fd, &ov[async_i], &temp_wres, TRUE)) { + rc = ErrCode(); /* Continue on so that all the event signals are reset + */ + } + wres = temp_wres; + } + } + if (rc) { /* any error on GetOverlappedResult, exit now */ + return rc; + } + } +#endif /* _WIN32 */ + + if (!(env->me_flags & MDB_WRITEMAP)) { + /* Don't free pages when using writemap (can only get here in NOSYNC mode in + * Windows) 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 ESECT mdb_env_share_locks(MDB_env* env, int* excl); + +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 %" Yu " %p on mdbenv %p, root page %" Yu, + 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))) + goto fail; + if (!F_ISSET(txn->mt_flags, MDB_TXN_NOSYNC) && + (rc = mdb_env_sync0(env, 0, txn->mt_next_pgno))) + goto fail; + if ((rc = mdb_env_write_meta(txn))) + goto fail; + end_mode = MDB_END_COMMITTED | MDB_END_UPDATE; + if (env->me_flags & MDB_PREVSNAPSHOT) { + if (!(env->me_flags & MDB_NOLOCK)) { + int excl; + rc = mdb_env_share_locks(env, &excl); + if (rc) + goto fail; + } + env->me_flags ^= MDB_PREVSNAPSHOT; + } + +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[in] prev whether to read the backup meta page + * @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, int prev, 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 %" Yu " 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 || + (prev ? m->mm_txnid < meta->mm_txnid : 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; + mdb_size_t mapsize; + MDB_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 %" Yu, + toggle, + txn->mt_dbs[MAIN_DBI].md_root)); + + env = txn->mt_env; + flags = txn->mt_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; + +#ifndef _WIN32 /* We don't want to ever use MSYNC/FlushViewOfFile in Windows \ + */ + 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; + /* POSIX msync() requires ptr = start of OS page */ + r2 = (ptr - env->me_map) & (env->me_os_psize - 1); + ptr -= r2; + meta_size += r2; + if (MDB_MSYNC(ptr, meta_size, rc)) { + rc = ErrCode(); + goto fail; + } + } + goto done; + } +#endif + 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) ^ + ((env->me_flags & MDB_PREVSNAPSHOT) != 0)]; +} + +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; +#elif defined MDB_USE_SYSV_SEM + e->me_rmutex->semid = -1; + e->me_wmutex->semid = -1; +#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; +} + +#ifdef _WIN32 +/** @brief Map a result from an NTAPI call to WIN32. */ +static DWORD mdb_nt2win32(NTSTATUS st) { + OVERLAPPED o = {0}; + DWORD br; + o.Internal = st; + GetOverlappedResult(NULL, &o, &br, FALSE); + return GetLastError(); +} +#endif + +static int ESECT mdb_env_map(MDB_env* env, void* addr) { + MDB_page* p; + unsigned int flags = env->me_flags; +#ifdef _WIN32 + int rc; + int access = SECTION_MAP_READ; + HANDLE mh; + void* map; + SIZE_T msize; + ULONG pageprot = PAGE_READONLY, secprot, alloctype; + + if (flags & MDB_WRITEMAP) { + access |= SECTION_MAP_WRITE; + pageprot = PAGE_READWRITE; + } + if (flags & MDB_RDONLY) { + secprot = PAGE_READONLY; + msize = 0; + alloctype = 0; + } else { + secprot = PAGE_READWRITE; + msize = env->me_mapsize; + alloctype = MEM_RESERVE; + } + + /** Some users are afraid of seeing their disk space getting used + * all at once, so the default is now to do incremental file growth. + * But that has a large performance impact, so give the option of + * allocating the file up front. + */ +#ifdef MDB_FIXEDSIZE + LARGE_INTEGER fsize; + fsize.LowPart = msize & 0xffffffff; + fsize.HighPart = msize >> 16 >> 16; + rc = NtCreateSection( + &mh, access, NULL, &fsize, secprot, SEC_RESERVE, env->me_fd); +#else + rc = NtCreateSection( + &mh, access, NULL, NULL, secprot, SEC_RESERVE, env->me_fd); +#endif + if (rc) + return mdb_nt2win32(rc); + map = addr; +#ifdef MDB_VL32 + msize = NUM_METAS * env->me_psize; +#endif + rc = NtMapViewOfSection( + mh, + GetCurrentProcess(), + &map, + 0, + 0, + NULL, + &msize, + ViewUnmap, + alloctype, + pageprot); +#ifdef MDB_VL32 + env->me_fmh = mh; +#else + NtClose(mh); +#endif + if (rc) + return mdb_nt2win32(rc); + env->me_map = map; +#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 +#ifdef MDB_VL32 + (void)flags; + env->me_map = + mmap(addr, NUM_METAS * env->me_psize, prot, mmap_flags, env->me_fd, 0); + if (env->me_map == MAP_FAILED) { + env->me_map = NULL; + return ErrCode(); + } +#else + 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? */ +#endif + + 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, mdb_size_t size) { + /* If env is already open, caller is responsible for making + * sure there are no active txns. + */ + if (env->me_map) { + MDB_meta* meta; +#ifndef MDB_VL32 + void* old; + int rc; +#endif + 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 */ + mdb_size_t minsize = (meta->mm_last_pg + 1) * env->me_psize; + if (size < minsize) + size = minsize; + } +#ifndef MDB_VL32 + /* For MDB_VL32 this bit is a noop since we dynamically remap + * chunks of the DB anyway. + */ + 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; +#endif /* !MDB_VL32 */ + } + 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, mdb_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")}}; + +/** Filename suffix lengths (excluding null terminator) + * [datafile,lockfile][without,with MDB_NOSUBDIR] */ +static const size_t mdb_suffix_lens[2][2] = {{9, 0}, {9, 5}}; + +#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; + memcpy(fname->mn_val, path, fname->mn_len + 1); + } 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_OVERLAPPED, + 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 */ + const mdb_nchar_t* suffix = mdb_suffixes[which == MDB_O_LOCKS][F_ISSET( + env->me_flags, MDB_NOSUBDIR)]; + size_t suffix_len = mdb_suffix_lens[which == MDB_O_LOCKS] + [F_ISSET(env->me_flags, MDB_NOSUBDIR)] + + 1; + memcpy(fname->mn_val + fname->mn_len, suffix, suffix_len * sizeof(mdb_nchar_t)); + } + + /* 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_OVERLAPPED: /* for unbuffered asynchronous writes (write-through + mode)*/ + acc = GENERIC_WRITE; + disp = OPEN_EXISTING; + attrs = FILE_FLAG_OVERLAPPED | FILE_FLAG_WRITE_THROUGH; + break; + 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 +#include +#endif + +/** Further setup required for opening an LMDB environment + */ +static int ESECT mdb_env_open2(MDB_env* env, int prev) { + 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; + /* Grab functions we need from NTDLL */ + if (!NtCreateSection) { + HMODULE h = GetModuleHandleW(L"NTDLL.DLL"); + if (!h) + return MDB_PROBLEM; + NtClose = (NtCloseFunc*)GetProcAddress(h, "NtClose"); + if (!NtClose) + return MDB_PROBLEM; + NtMapViewOfSection = + (NtMapViewOfSectionFunc*)GetProcAddress(h, "NtMapViewOfSection"); + if (!NtMapViewOfSection) + return MDB_PROBLEM; + NtCreateSection = + (NtCreateSectionFunc*)GetProcAddress(h, "NtCreateSection"); + if (!NtCreateSection) + return MDB_PROBLEM; + } + env->ovs = 0; +#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, prev, &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). + */ + mdb_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; + } +#ifdef _WIN32 + /* For FIXEDMAP, make sure the file is non-empty before we attempt to map it + */ + if (newenv) { + char dummy = 0; + DWORD len; + rc = WriteFile(env->me_fd, &dummy, 1, &len, NULL); + if (!rc) { + rc = ErrCode(); + return rc; + } + } +#endif + + 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 (prev && env->me_txns) + env->me_txns->mti_txnid = meta.mm_txnid; + +#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: %" Yu, db->md_entries)); + DPRINTF(("branch pages: %" Yu, db->md_branch_pages)); + DPRINTF(("leaf pages: %" Yu, db->md_leaf_pages)); + DPRINTF(("overflow pages: %" Yu, db->md_overflow_pages)); + DPRINTF(("root: %" Yu, 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 /\oo/\ + * http://www.isthe.com/chongo/ + * + * Share and Enjoy! :-) + */ + +/** perform a 64 bit Fowler/Noll/Vo FNV-1a hash on a buffer + * @param[in] val value to hash + * @param[in] len length of value + * @return 64 bit hash + */ +static mdb_hash_t mdb_hash(const void* val, size_t len) { + const unsigned char *s = (const unsigned char*)val, *end = s + len; + mdb_hash_t hval = 0xcbf29ce484222325ULL; + /* + * FNV-1a hash each octet of the buffer + */ + while (s < end) { + hval = (hval ^ *s++) * 0x100000001b3ULL; + } + /* 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 long l, char* out) { + int i; + + for (i = 0; i < 10 && l; i++) { + *out++ = mdb_a85[l % 85]; + l /= 85; + } + *out = '\0'; +} + +/** Init #MDB_env.me_mutexname[] except the char which #MUTEXNAME() will set. + * Changes to this code must be reflected in #MDB_LOCK_FORMAT. + */ +static void ESECT mdb_env_mname_init(MDB_env* env) { + char* nm = env->me_mutexname; + strcpy(nm, MUTEXNAME_PREFIX); + mdb_pack85(env->me_txns->mti_mutexid, nm + sizeof(MUTEXNAME_PREFIX)); +} + +/** Return env->me_mutexname after filling in ch ('r'/'w') for convenience */ +#define MUTEXNAME(env, ch) \ + ((void)((env)->me_mutexname[sizeof(MUTEXNAME_PREFIX) - 1] = (ch)), \ + (env)->me_mutexname) + +#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 +#ifdef MDB_USE_SYSV_SEM + int semid; + union semun semu; +#endif + int rc; + MDB_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; + + 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; + env->me_txns->mti_mutexid = mdb_hash(&idbuf, sizeof(idbuf)); + mdb_env_mname_init(env); + env->me_rmutex = CreateMutexA(&mdb_all_sa, FALSE, MUTEXNAME(env, 'r')); + if (!env->me_rmutex) + goto fail_errno; + env->me_wmutex = CreateMutexA(&mdb_all_sa, FALSE, MUTEXNAME(env, 'w')); + if (!env->me_wmutex) + goto fail_errno; +#elif defined(MDB_USE_POSIX_SEM) + struct stat stbuf; + struct { + dev_t dev; + ino_t ino; + } idbuf; + +#if defined(__NetBSD__) +#define MDB_SHORT_SEMNAMES 1 /* limited to 14 chars */ +#endif + if (fstat(env->me_lfd, &stbuf)) + goto fail_errno; + memset(&idbuf, 0, sizeof(idbuf)); + idbuf.dev = stbuf.st_dev; + idbuf.ino = stbuf.st_ino; + env->me_txns->mti_mutexid = mdb_hash(&idbuf, sizeof(idbuf)) +#ifdef MDB_SHORT_SEMNAMES + /* Max 9 base85-digits. We truncate here instead of in + * mdb_env_mname_init() to keep the latter portable. + */ + % ((mdb_hash_t)85 * 85 * 85 * 85 * 85 * 85 * 85 * 85 * 85) +#endif + ; + mdb_env_mname_init(env); + /* Clean up after a previous run, if needed: Try to + * remove both semaphores before doing anything else. + */ + sem_unlink(MUTEXNAME(env, 'r')); + sem_unlink(MUTEXNAME(env, 'w')); + env->me_rmutex = sem_open(MUTEXNAME(env, 'r'), O_CREAT | O_EXCL, mode, 1); + if (env->me_rmutex == SEM_FAILED) + goto fail_errno; + env->me_wmutex = sem_open(MUTEXNAME(env, 'w'), O_CREAT | O_EXCL, mode, 1); + if (env->me_wmutex == SEM_FAILED) + goto fail_errno; +#elif defined(MDB_USE_SYSV_SEM) + unsigned short vals[2] = {1, 1}; + key_t key = ftok(fname->mn_val, 'M'); /* fname is lockfile path now */ + if (key == -1) + goto fail_errno; + semid = semget(key, 2, (mode & 0777) | IPC_CREAT); + if (semid < 0) + goto fail_errno; + semu.array = vals; + if (semctl(semid, 0, SETALL, semu) < 0) + goto fail_errno; + env->me_txns->mti_semid = semid; + env->me_txns->mti_rlocked = 0; + env->me_txns->mti_wlocked = 0; +#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)) != 0) + 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 || ... */ + + 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 { +#ifdef MDB_USE_SYSV_SEM + struct semid_ds buf; +#endif + 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 + mdb_env_mname_init(env); + env->me_rmutex = OpenMutexA(SYNCHRONIZE, FALSE, MUTEXNAME(env, 'r')); + if (!env->me_rmutex) + goto fail_errno; + env->me_wmutex = OpenMutexA(SYNCHRONIZE, FALSE, MUTEXNAME(env, 'w')); + if (!env->me_wmutex) + goto fail_errno; +#elif defined(MDB_USE_POSIX_SEM) + mdb_env_mname_init(env); + env->me_rmutex = sem_open(MUTEXNAME(env, 'r'), 0); + if (env->me_rmutex == SEM_FAILED) + goto fail_errno; + env->me_wmutex = sem_open(MUTEXNAME(env, 'w'), 0); + if (env->me_wmutex == SEM_FAILED) + goto fail_errno; +#elif defined(MDB_USE_SYSV_SEM) + semid = env->me_txns->mti_semid; + semu.buf = &buf; + /* check for read access */ + if (semctl(semid, 0, IPC_STAT, semu) < 0) + goto fail_errno; + /* check for write access */ + if (semctl(semid, 0, IPC_SET, semu) < 0) + goto fail_errno; +#endif + } +#ifdef MDB_USE_SYSV_SEM + env->me_rmutex->semid = semid; + env->me_wmutex->semid = semid; + env->me_rmutex->semnum = 0; + env->me_wmutex->semnum = 1; + env->me_rmutex->locked = &env->me_txns->mti_rlocked; + env->me_wmutex->locked = &env->me_txns->mti_wlocked; +#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 | MDB_PREVSNAPSHOT) + +#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; + +#ifdef MDB_VL32 + if (flags & MDB_WRITEMAP) { + /* silently ignore WRITEMAP in 32 bit mode */ + flags ^= MDB_WRITEMAP; + } + if (flags & MDB_FIXEDMAP) { + /* cannot support FIXEDMAP */ + return EINVAL; + } +#endif + flags |= env->me_flags; + + rc = mdb_fname_init(path, flags, &fname); + if (rc) + return rc; + +#ifdef MDB_VL32 +#ifdef _WIN32 + env->me_rpmutex = CreateMutex(NULL, FALSE, NULL); + if (!env->me_rpmutex) { + rc = ErrCode(); + goto leave; + } +#else + rc = pthread_mutex_init(&env->me_rpmutex, NULL); + if (rc) + goto leave; +#endif +#endif + flags |= MDB_ENV_ACTIVE; /* tell mdb_env_close0() to clean up */ + + 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; + if (rc) + goto leave; + +#ifdef MDB_VL32 + { + env->me_rpages = malloc(MDB_ERPAGE_SIZE * sizeof(MDB_ID3)); + if (!env->me_rpages) { + rc = ENOMEM; + goto leave; + } + env->me_rpages[0].mid = 0; + env->me_rpcheck = MDB_ERPAGE_SIZE / 2; + } +#endif + + 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; + if ((flags & MDB_PREVSNAPSHOT) && !excl) { + rc = EAGAIN; + goto leave; + } + } + + rc = mdb_fopen( + env, + &fname, + (flags & MDB_RDONLY) ? MDB_O_RDONLY : MDB_O_RDWR, + mode, + &env->me_fd); + if (rc) + goto leave; +#ifdef _WIN32 + rc = mdb_fopen(env, &fname, MDB_O_OVERLAPPED, mode, &env->me_ovfd); + if (rc) + goto leave; +#endif + + 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, flags & MDB_PREVSNAPSHOT)) == MDB_SUCCESS) { + /* Synchronous fd for meta writes. Needed even with + * MDB_NOSYNC/MDB_NOMETASYNC, in case these get reset. + */ + if (!(flags & (MDB_RDONLY | MDB_WRITEMAP))) { + 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 && !(flags & MDB_PREVSNAPSHOT)) { + 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; +#ifdef MDB_VL32 + txn->mt_rpages = malloc(MDB_TRPAGE_SIZE * sizeof(MDB_ID3)); + if (!txn->mt_rpages) { + free(txn); + rc = ENOMEM; + goto leave; + } + txn->mt_rpages[0].mid = 0; + txn->mt_rpcheck = MDB_TRPAGE_SIZE / 2; +#endif + 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); +#ifdef MDB_VL32 + if (env->me_txn0 && env->me_txn0->mt_rpages) + free(env->me_txn0->mt_rpages); + if (env->me_rpages) { + MDB_ID3L el = env->me_rpages; + unsigned int x; + for (x = 1; x <= el[0].mid; x++) + munmap(el[x].mptr, el[x].mcnt * env->me_psize); + free(el); + } +#endif + 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) { +#ifdef MDB_VL32 + munmap(env->me_map, NUM_METAS * env->me_psize); +#else + munmap(env->me_map, env->me_mapsize); +#endif + } + if (env->me_mfd != INVALID_HANDLE_VALUE) + (void)close(env->me_mfd); +#ifdef _WIN32 + if (env->ovs > 0) { + for (i = 0; i < env->ovs; i++) { + CloseHandle(env->ov[i].hEvent); + } + free(env->ov); + } + if (env->me_ovfd != INVALID_HANDLE_VALUE) + (void)close(env->me_ovfd); +#endif + 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(MUTEXNAME(env, 'r')); + sem_unlink(MUTEXNAME(env, 'w')); + } + } +#elif defined(MDB_USE_SYSV_SEM) + if (env->me_rmutex->semid != -1) { + /* 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) + semctl(env->me_rmutex->semid, 0, IPC_RMID); + } +#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); + } +#ifdef MDB_VL32 +#ifdef _WIN32 + if (env->me_fmh) + CloseHandle(env->me_fmh); + if (env->me_rpmutex) + CloseHandle(env->me_rpmutex); +#else + pthread_mutex_destroy(&env->me_rpmutex); +#endif +#endif + + 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 #mdb_size_t's */ +static int mdb_cmp_long(const MDB_val* a, const MDB_val* b) { + return (*(mdb_size_t*)a->mv_data < *(mdb_size_t*)b->mv_data) + ? -1 + : *(mdb_size_t*)a->mv_data > *(mdb_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 #mdb_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 %" Yu, + 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(mdb_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 -> %" Yu "], 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 %" Yu " 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 %" Yu " 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; +} + +#ifdef MDB_VL32 +/** Map a read-only page. + * There are two levels of tracking in use, a per-txn list and a per-env list. + * ref'ing and unref'ing the per-txn list is faster since it requires no + * locking. Pages are cached in the per-env list for global reuse, and a lock + * is required. Pages are not immediately unmapped when their refcnt goes to + * zero; they hang around in case they will be reused again soon. + * + * When the per-txn list gets full, all pages with refcnt=0 are purged from the + * list and their refcnts in the per-env list are decremented. + * + * When the per-env list gets full, all pages with refcnt=0 are purged from the + * list and their pages are unmapped. + * + * @note "full" means the list has reached its respective rpcheck threshold. + * This threshold slowly raises if no pages could be purged on a given check, + * and returns to its original value when enough pages were purged. + * + * If purging doesn't free any slots, filling the per-txn list will return + * MDB_TXN_FULL, and filling the per-env list returns MDB_MAP_FULL. + * + * Reference tracking in a txn is imperfect, pages can linger with non-zero + * refcnt even without active references. It was deemed to be too invasive + * to add unrefs in every required location. However, all pages are unref'd + * at the end of the transaction. This guarantees that no stale references + * linger in the per-env list. + * + * Usually we map chunks of 16 pages at a time, but if an overflow page begins + * at the tail of the chunk we extend the chunk to include the entire overflow + * page. Unfortunately, pages can be turned into overflow pages after their + * chunk was already mapped. In that case we must remap the chunk if the + * overflow page is referenced. If the chunk's refcnt is 0 we can just remap + * it, otherwise we temporarily map a new chunk just for the overflow page. + * + * @note this chunk handling means we cannot guarantee that a data item + * returned from the DB will stay alive for the duration of the transaction: + * We unref pages as soon as a cursor moves away from the page + * A subsequent op may cause a purge, which may unmap any unref'd chunks + * The caller must copy the data if it must be used later in the same txn. + * + * Also - our reference counting revolves around cursors, but overflow pages + * aren't pointed to by a cursor's page stack. We have to remember them + * explicitly, in the added mc_ovpg field. A single cursor can only hold a + * reference to one overflow page at a time. + * + * @param[in] txn the transaction for this access. + * @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. + * @return 0 on success, non-zero on failure. + */ +static int mdb_rpage_get(MDB_txn* txn, pgno_t pg0, MDB_page** ret) { + MDB_env* env = txn->mt_env; + MDB_page* p; + MDB_ID3L tl = txn->mt_rpages; + MDB_ID3L el = env->me_rpages; + MDB_ID3 id3; + unsigned x, rem; + pgno_t pgno; + int rc, retries = 1; +#ifdef _WIN32 + LARGE_INTEGER off; + SIZE_T len; +#define SET_OFF(off, val) off.QuadPart = val +#define MAP(rc, env, addr, len, off) \ + addr = NULL; \ + rc = NtMapViewOfSection( \ + env->me_fmh, \ + GetCurrentProcess(), \ + &addr, \ + 0, \ + len, \ + &off, \ + &len, \ + ViewUnmap, \ + (env->me_flags & MDB_RDONLY) ? 0 : MEM_RESERVE, \ + PAGE_READONLY); \ + if (rc) \ + rc = mdb_nt2win32(rc) +#else + off_t off; + size_t len; +#define SET_OFF(off, val) off = val +#define MAP(rc, env, addr, len, off) \ + addr = mmap(NULL, len, PROT_READ, MAP_SHARED, env->me_fd, off); \ + rc = (addr == MAP_FAILED) ? errno : 0 +#endif + + /* remember the offset of the actual page number, so we can + * return the correct pointer at the end. + */ + rem = pg0 & (MDB_RPAGE_CHUNK - 1); + pgno = pg0 ^ rem; + + id3.mid = 0; + x = mdb_mid3l_search(tl, pgno); + if (x <= tl[0].mid && tl[x].mid == pgno) { + if (x != tl[0].mid && tl[x + 1].mid == pg0) + x++; + /* check for overflow size */ + p = (MDB_page*)((char*)tl[x].mptr + rem * env->me_psize); + if (IS_OVERFLOW(p) && p->mp_pages + rem > tl[x].mcnt) { + id3.mcnt = p->mp_pages + rem; + len = id3.mcnt * env->me_psize; + SET_OFF(off, pgno * env->me_psize); + MAP(rc, env, id3.mptr, len, off); + if (rc) + return rc; + /* check for local-only page */ + if (rem) { + mdb_tassert(txn, tl[x].mid != pg0); + /* hope there's room to insert this locally. + * setting mid here tells later code to just insert + * this id3 instead of searching for a match. + */ + id3.mid = pg0; + goto notlocal; + } else { + /* ignore the mapping we got from env, use new one */ + tl[x].mptr = id3.mptr; + tl[x].mcnt = id3.mcnt; + /* if no active ref, see if we can replace in env */ + if (!tl[x].mref) { + unsigned i; + pthread_mutex_lock(&env->me_rpmutex); + i = mdb_mid3l_search(el, tl[x].mid); + if (el[i].mref == 1) { + /* just us, replace it */ + munmap(el[i].mptr, el[i].mcnt * env->me_psize); + el[i].mptr = tl[x].mptr; + el[i].mcnt = tl[x].mcnt; + } else { + /* there are others, remove ourself */ + el[i].mref--; + } + pthread_mutex_unlock(&env->me_rpmutex); + } + } + } + id3.mptr = tl[x].mptr; + id3.mcnt = tl[x].mcnt; + tl[x].mref++; + goto ok; + } + +notlocal: + if (tl[0].mid >= MDB_TRPAGE_MAX - txn->mt_rpcheck) { + unsigned i, y; + /* purge unref'd pages from our list and unref in env */ + pthread_mutex_lock(&env->me_rpmutex); + retry: + y = 0; + for (i = 1; i <= tl[0].mid; i++) { + if (!tl[i].mref) { + if (!y) + y = i; + /* tmp overflow pages don't go to env */ + if (tl[i].mid & (MDB_RPAGE_CHUNK - 1)) { + munmap(tl[i].mptr, tl[i].mcnt * env->me_psize); + continue; + } + x = mdb_mid3l_search(el, tl[i].mid); + el[x].mref--; + } + } + pthread_mutex_unlock(&env->me_rpmutex); + if (!y) { + /* we didn't find any unref'd chunks. + * if we're out of room, fail. + */ + if (tl[0].mid >= MDB_TRPAGE_MAX) + return MDB_TXN_FULL; + /* otherwise, raise threshold for next time around + * and let this go. + */ + txn->mt_rpcheck /= 2; + } else { + /* we found some unused; consolidate the list */ + for (i = y + 1; i <= tl[0].mid; i++) + if (tl[i].mref) + tl[y++] = tl[i]; + tl[0].mid = y - 1; + /* decrease the check threshold toward its original value */ + if (!txn->mt_rpcheck) + txn->mt_rpcheck = 1; + while (txn->mt_rpcheck < tl[0].mid && + txn->mt_rpcheck < MDB_TRPAGE_SIZE / 2) + txn->mt_rpcheck *= 2; + } + } + if (tl[0].mid < MDB_TRPAGE_SIZE) { + id3.mref = 1; + if (id3.mid) + goto found; + /* don't map past last written page in read-only envs */ + if ((env->me_flags & MDB_RDONLY) && + pgno + MDB_RPAGE_CHUNK - 1 > txn->mt_last_pgno) + id3.mcnt = txn->mt_last_pgno + 1 - pgno; + else + id3.mcnt = MDB_RPAGE_CHUNK; + len = id3.mcnt * env->me_psize; + id3.mid = pgno; + + /* search for page in env */ + pthread_mutex_lock(&env->me_rpmutex); + x = mdb_mid3l_search(el, pgno); + if (x <= el[0].mid && el[x].mid == pgno) { + id3.mptr = el[x].mptr; + id3.mcnt = el[x].mcnt; + /* check for overflow size */ + p = (MDB_page*)((char*)id3.mptr + rem * env->me_psize); + if (IS_OVERFLOW(p) && p->mp_pages + rem > id3.mcnt) { + id3.mcnt = p->mp_pages + rem; + len = id3.mcnt * env->me_psize; + SET_OFF(off, pgno * env->me_psize); + MAP(rc, env, id3.mptr, len, off); + if (rc) + goto fail; + if (!el[x].mref) { + munmap(el[x].mptr, env->me_psize * el[x].mcnt); + el[x].mptr = id3.mptr; + el[x].mcnt = id3.mcnt; + } else { + id3.mid = pg0; + pthread_mutex_unlock(&env->me_rpmutex); + goto found; + } + } + el[x].mref++; + pthread_mutex_unlock(&env->me_rpmutex); + goto found; + } + if (el[0].mid >= MDB_ERPAGE_MAX - env->me_rpcheck) { + /* purge unref'd pages */ + unsigned i, y = 0; + for (i = 1; i <= el[0].mid; i++) { + if (!el[i].mref) { + if (!y) + y = i; + munmap(el[i].mptr, env->me_psize * el[i].mcnt); + } + } + if (!y) { + if (retries) { + /* see if we can unref some local pages */ + retries--; + id3.mid = 0; + goto retry; + } + if (el[0].mid >= MDB_ERPAGE_MAX) { + pthread_mutex_unlock(&env->me_rpmutex); + return MDB_MAP_FULL; + } + env->me_rpcheck /= 2; + } else { + for (i = y + 1; i <= el[0].mid; i++) + if (el[i].mref) + el[y++] = el[i]; + el[0].mid = y - 1; + if (!env->me_rpcheck) + env->me_rpcheck = 1; + while (env->me_rpcheck < el[0].mid && + env->me_rpcheck < MDB_ERPAGE_SIZE / 2) + env->me_rpcheck *= 2; + } + } + SET_OFF(off, pgno * env->me_psize); + MAP(rc, env, id3.mptr, len, off); + if (rc) { + fail: + pthread_mutex_unlock(&env->me_rpmutex); + return rc; + } + /* check for overflow size */ + p = (MDB_page*)((char*)id3.mptr + rem * env->me_psize); + if (IS_OVERFLOW(p) && p->mp_pages + rem > id3.mcnt) { + id3.mcnt = p->mp_pages + rem; + munmap(id3.mptr, len); + len = id3.mcnt * env->me_psize; + MAP(rc, env, id3.mptr, len, off); + if (rc) + goto fail; + } + mdb_mid3l_insert(el, &id3); + pthread_mutex_unlock(&env->me_rpmutex); + found: + mdb_mid3l_insert(tl, &id3); + } else { + return MDB_TXN_FULL; + } +ok: + p = (MDB_page*)((char*)id3.mptr + rem * env->me_psize); +#if MDB_DEBUG /* we don't need this check any more */ + if (IS_OVERFLOW(p)) { + mdb_tassert(txn, p->mp_pages + rem <= id3.mcnt); + } +#endif + *ret = p; + return MDB_SUCCESS; +} +#endif + +/** 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_page* p = NULL; + int level; + + if (!(mc->mc_flags & (C_ORIG_RDONLY | C_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) { + goto mapped; + } + } + 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) { + DPRINTF(("page %" Yu " not found", pgno)); + txn->mt_flags |= MDB_TXN_ERROR; + return MDB_PAGE_NOTFOUND; + } + + level = 0; + +mapped: { +#ifdef MDB_VL32 + int rc = mdb_rpage_get(txn, pgno, &p); + if (rc) { + txn->mt_flags |= MDB_TXN_ERROR; + return rc; + } +#else + MDB_env* env = txn->mt_env; + p = (MDB_page*)(env->me_map + env->me_psize * pgno); +#endif +} + +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 %" Yu " 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 %" Yu, 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 %" Yu " 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) { +#ifdef MDB_VL32 + if (mc->mc_pg[0]) + MDB_PAGE_UNREF(mc->mc_txn, mc->mc_pg[0]); +#endif + if ((rc = mdb_page_get(mc, root, &mc->mc_pg[0], NULL)) != 0) + return rc; + } + +#ifdef MDB_VL32 + { + int i; + for (i = 1; i < mc->mc_snum; i++) + MDB_PAGE_UNREF(mc->mc_txn, mc->mc_pg[i]); + } +#endif + mc->mc_snum = 1; + mc->mc_top = 0; + + DPRINTF( + ("db %d root page %" Yu " 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 %" Yu " (%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_PROBLEM; + } + } + 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; + } +#ifdef MDB_VL32 + if (mc->mc_ovpg == mp) + mc->mc_ovpg = NULL; +#endif + 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 (MC_OVPG(mc)) { + MDB_PAGE_UNREF(mc->mc_txn, MC_OVPG(mc)); + MC_SET_OVPG(mc, NULL); + } + 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 %" Yu " failed", pgno)); + return rc; + } + data->mv_data = METADATA(omp); + MC_SET_OVPG(mc, 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, rc; + 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); + rc = mdb_cursor_set(&mc, key, data, MDB_SET, &exact); + /* unref all the pages when MDB_VL32 - caller must copy the data + * before doing anything else + */ + MDB_CURSOR_UNREF(&mc, 1); + return rc; +} + +/** 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; +#ifdef MDB_VL32 + MDB_page* op; +#endif + + if (mc->mc_snum < 2) { + return MDB_NOTFOUND; /* root has no siblings */ + } + +#ifdef MDB_VL32 + op = mc->mc_pg[mc->mc_top]; +#endif + mdb_cursor_pop(mc); + DPRINTF( + ("parent page is page %" Yu ", 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])); + + MDB_PAGE_UNREF(mc->mc_txn, op); + + 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 { + MDB_CURSOR_UNREF(&mc->mc_xcursor->mx_cursor, 0); + } + } 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 %" Yu " 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 %" Yu ", 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 %" Yu " 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 { + MDB_CURSOR_UNREF(&mc->mc_xcursor->mx_cursor, 0); + } + } 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 %" Yu " 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 %" Yu ", key index %u", + mp->mp_pgno, + mc->mc_ki[mc->mc_top])); + } else + mc->mc_ki[mc->mc_top]--; + + DPRINTF( + ("==> cursor points to page %" Yu " 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) { + MDB_CURSOR_UNREF(&mc->mc_xcursor->mx_cursor, 0); + 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 (NEED_CMP_CLONG(dcmp, olddata.mv_size)) + dcmp = mdb_cmp_clong; + 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) { + MDB_CURSOR_UNREF(&mc->mc_xcursor->mx_cursor, 0); + 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) { + MDB_CURSOR_UNREF(&mc->mc_xcursor->mx_cursor, 0); + 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 (NEED_CMP_CLONG(dcmp, olddata.mv_size)) + dcmp = mdb_cmp_clong; + /* 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; + mdb_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_PROBLEM; + } + 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 %" Yu ", 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: + *
    + *
  • ENOMEM - failed to allocate overflow pages for the node. + *
  • 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. + *
+ */ +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 %" Yu " 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 %" Yu, 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 %" Yu ", 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 %" Yu, + 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 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; + MC_SET_OVPG(&mx->mx_cursor, NULL); + mx->mx_cursor.mc_flags = + C_SUB | (mc->mc_flags & (C_ORIG_RDONLY | C_WRITEMAP)); + 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; + + mx->mx_cursor.mc_flags &= C_SUB | C_ORIG_RDONLY | C_WRITEMAP; + 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; + } 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; + 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 %" Yu, mx->mx_cursor.mc_dbi, mx->mx_db.md_root)); + mx->mx_dbflag = DB_VALID | DB_USRVALID | DB_DUPDATA; + if (NEED_CMP_CLONG(mx->mx_dbx.md_cmp, mx->mx_db.md_pad)) + mx->mx_dbx.md_cmp = mdb_cmp_clong; +} + +/** 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 < MDB_SIZE_MAX /* matches mdb_xcursor_init1:NEED_CMP_CLONG() */ + 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 %" Yu, 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_SET_OVPG(mc, NULL); + mc->mc_flags = txn->mt_flags & (C_ORIG_RDONLY | C_WRITEMAP); + 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, mdb_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) { + MDB_CURSOR_UNREF(mc, 0); + } + if (mc && !mc->mc_backup) { + /* Remove from txn, if tracked. + * A read-only txn (!C_UNTRACK) may have been freed already, + * so do not peek inside it. Only write txns track cursors. + */ + if ((mc->mc_flags & C_UNTRACK) && 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 %" Yu, + 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 %" Yu " to node %u on page %" Yu, + 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 %" Yu " 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 %" Yu " 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 %" Yu " into %" Yu, 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 %" Yu " 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; + MC_SET_OVPG(cdst, MC_OVPG(csrc)); + + 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 %" Yu " (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 %" Yu ", 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 %" Yu " (%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[mc->mc_top], m3->mc_ki[mc->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_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 %" Yu " 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 %" Yu, 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 = %" Yu, 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 %" Yu, 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]; + rc = 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) { + if (rc == MDB_NOTFOUND) /* improper mdb_cursor_sibling() result */ + rc = MDB_PROBLEM; + 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]; + size_t mc_wlen[2]; + size_t 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, rc; + size_t wsize; +#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; + mc.mc_flags = my->mc_txn->mt_flags & (C_ORIG_RDONLY | C_WRITEMAP); + + 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; + mdb_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; + { + mdb_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); +#ifdef MDB_VL32 + /* bump refcount for mx's pages */ + for (i = 0; i < mc->mc_snum; i++) + mdb_page_get(&mx, mc->mc_pg[i]->mp_pgno, &mx.mc_pg[i], NULL); +#endif + 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; + /* drop refcount for mx's pages */ + MDB_CURSOR_UNREF(&mx, 0); + } 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; + snprintf( + buf, + sizeof(buf), + txnid == (txnid_t)-1 ? "%10d %" Z "x -\n" : "%10d %" Z "x %" Yu "\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 %" Yd, + (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) */ +/** @} */ diff --git a/midl.c b/midl.c new file mode 100644 --- /dev/null +++ b/midl.c @@ -0,0 +1,415 @@ +/** @file midl.c + * @brief ldap bdb back-end ID List functions */ +/* $OpenLDAP$ */ +/* This work is part of OpenLDAP Software . + * + * 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 + * . + */ + +#include "midl.h" +#include +#include +#include +#include +#include + +/** @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; +} + +#ifdef MDB_VL32 +unsigned mdb_mid3l_search(MDB_ID3L 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_mid3l_insert(MDB_ID3L ids, MDB_ID3* id) { + unsigned x, i; + + x = mdb_mid3l_search(ids, id->mid); + + if (x < 1) { + /* internal error */ + return -2; + } + + if (x <= ids[0].mid && ids[x].mid == id->mid) { + /* duplicate */ + return -1; + } + + /* insert id */ + ids[0].mid++; + for (i = (unsigned)ids[0].mid; i > x; i--) + ids[i] = ids[i - 1]; + ids[x] = *id; + + return 0; +} +#endif /* MDB_VL32 */ + +/** @} */ +/** @} */ diff --git a/midl.h b/midl.h new file mode 100644 --- /dev/null +++ b/midl.h @@ -0,0 +1,203 @@ +/** @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 . + * + * 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 + * . + */ + +#ifndef _MDB_MIDL_H_ +#define _MDB_MIDL_H_ + +#include "lmdb.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 mdb_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 MDB_VL32 +typedef struct MDB_ID3 { + MDB_ID mid; /**< The ID */ + void* mptr; /**< The pointer */ + unsigned int mcnt; /**< Number of pages */ + unsigned int mref; /**< Refcounter */ +} MDB_ID3; + +typedef MDB_ID3* MDB_ID3L; + +unsigned mdb_mid3l_search(MDB_ID3L ids, MDB_ID id); +int mdb_mid3l_insert(MDB_ID3L ids, MDB_ID3* id); + +#endif /* MDB_VL32 */ +/** @} */ +/** @} */ +#ifdef __cplusplus +} +#endif +#endif /* _MDB_MIDL_H_ */