SOLIBS =
PROGS = mdb_stat mdb_copy mtest mtest2 mtest3 mtest4 mtest5
-all: libmdb.a libmdb.so $(PROGS)
+all: liblmdb.a liblmdb.so $(PROGS)
clean:
rm -rf $(PROGS) *.[ao] *.so *~ testdb
mkdir testdb
./mtest && ./mdb_stat testdb
-libmdb.a: mdb.o midl.o
+liblmdb.a: mdb.o midl.o
ar rs $@ mdb.o midl.o
-libmdb.so: mdb.o midl.o
+liblmdb.so: mdb.o midl.o
gcc -pthread -shared -o $@ mdb.o midl.o $(SOLIBS)
-mdb_stat: mdb_stat.o libmdb.a
-mdb_copy: mdb_copy.o libmdb.a
-mtest: mtest.o libmdb.a
-mtest2: mtest2.o libmdb.a
-mtest3: mtest3.o libmdb.a
-mtest4: mtest4.o libmdb.a
-mtest5: mtest5.o libmdb.a
-mtest6: mtest6.o libmdb.a
-mfree: mfree.o libmdb.a
-
-mdb.o: mdb.c mdb.h midl.h
+mdb_stat: mdb_stat.o liblmdb.a
+mdb_copy: mdb_copy.o liblmdb.a
+mtest: mtest.o liblmdb.a
+mtest2: mtest2.o liblmdb.a
+mtest3: mtest3.o liblmdb.a
+mtest4: mtest4.o liblmdb.a
+mtest5: mtest5.o liblmdb.a
+mtest6: mtest6.o liblmdb.a
+mfree: mfree.o liblmdb.a
+
+mdb.o: mdb.c lmdb.h midl.h
$(CC) $(CFLAGS) -fPIC $(CPPFLAGS) -c mdb.c
midl.o: midl.c midl.h
%: %.o
$(CC) $(CFLAGS) $(LDFLAGS) $^ $(LDLIBS) -o $@
-%.o: %.c mdb.h
+%.o: %.c lmdb.h
$(CC) $(CFLAGS) $(CPPFLAGS) -c $<
--- /dev/null
+/** @file lmdb.h
+ * @brief Lightning memory-mapped database library
+ *
+ * @mainpage MDB Lightning Memory-Mapped Database Manager
+ *
+ * @section intro_sec Introduction
+ * MDB 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, MDB 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. MDB 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.
+ *
+ * @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: Terminate all programs using the database, or make
+ * them close it. Next database user will reset the lockfile.
+ *
+ * - On BSD systems or others configured with MDB_USE_POSIX_SEM,
+ * startup can fail due to semaphores owned by another userid.
+ *
+ * Fix: Open and close the database as the user which owns the
+ * semaphores (likely last user) or as root, while no other
+ * process is using the database.
+ *
+ * Restrictions/caveats (in addition to those listed for some functions):
+ *
+ * - Only the database owner should normally use the database on
+ * BSD systems or when otherwise configured with MDB_USE_POSIX_SEM.
+ * Multiple users can cause startup to fail later, as noted above.
+ *
+ * - A thread can only use one transaction at a time, plus any child
+ * transactions. Each transaction belongs to one thread. See below.
+ *
+ * - Use an MDB_env* in the process which opened it, without fork()ing.
+ *
+ * - Do not have open an MDB database twice in the same process at
+ * the same time. Not even from a plain open() call - close()ing it
+ * breaks flock() advisory locking.
+ *
+ * - 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.
+ *
+ * ...when several processes can use a database concurrently:
+ *
+ * - Avoid suspending a process with active transactions. These
+ * would then be "long-lived" as above.
+ *
+ * - Avoid aborting a process with an active transaction.
+ * The transaction becomes "long-lived" as above until the lockfile
+ * is reset, since the process may not remove it from the lockfile.
+ *
+ * - If you do that anyway, close the environment once in a while,
+ * so the lockfile can get reset.
+ *
+ * - Do not use MDB 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 2011-2012 Howard Chu, Symas Corp. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted only as authorized by the OpenLDAP
+ * Public License.
+ *
+ * A copy of this license is available in the file LICENSE in the
+ * top-level directory of the distribution or, alternatively, at
+ * <http://www.OpenLDAP.org/license.html>.
+ *
+ * @par Derived From:
+ * This code is derived from btree.c written by Martin Hedenfalk.
+ *
+ * Copyright (c) 2009, 2010 Martin Hedenfalk <martin@bzero.se>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+#ifndef _LMDB_H_
+#define _LMDB_H_
+
+#include <sys/types.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** @defgroup mdb MDB 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 5
+
+/** 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 "November 30, 2012"
+
+/** A stringifier for the version info */
+#define MDB_VERSTR(a,b,c,d) "MDB " #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. */
+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
+ *
+ * Values do not overlap Database Flags.
+ * @{
+ */
+ /** mmap at a fixed address */
+#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 */
+#define MDB_MAPASYNC 0x100000
+/** @} */
+
+/** @defgroup mdb_open Database Flags
+ *
+ * Values do not overlap Environment Flags.
+ * @{
+ */
+ /** use reverse string keys */
+#define MDB_REVERSEKEY 0x02
+ /** use sorted duplicates */
+#define MDB_DUPSORT 0x04
+ /** numeric keys in native byte order.
+ * 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 numeric in native byte order */
+#define MDB_INTEGERDUP 0x20
+ /** with #MDB_DUPSORT, use reverse string dups */
+#define MDB_REVERSEDUP 0x40
+ /** create DB if not already existing */
+#define MDB_CREATE 0x40000
+/** @} */
+
+/** @defgroup mdb_put Write Flags
+ * @{
+ */
+/** For put: Don't write if the key already exists. */
+#define MDB_NOOVERWRITE 0x10
+/** Only for #MDB_DUPSORT<br>
+ * For put: don't write if the key and data pair already exist.<br>
+ * For mdb_cursor_del: remove all duplicate data items.
+ */
+#define MDB_NODUPDATA 0x20
+/** For mdb_cursor_put: overwrite the current key/data pair */
+#define MDB_CURRENT 0x40
+/** For put: Just reserve space for data, don't copy it. Return a
+ * pointer to the reserved space.
+ */
+#define MDB_RESERVE 0x10000
+/** Data is being appended, don't split full pages. */
+#define MDB_APPEND 0x20000
+/** Duplicate data is being appended, don't split full pages. */
+#define MDB_APPENDDUP 0x40000
+/** Store multiple data items in one call. */
+#define MDB_MULTIPLE 0x80000
+/* @} */
+
+/** @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 all the duplicate data items at the current
+ cursor position. 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 all duplicate data items at the next
+ cursor position. Only for #MDB_DUPFIXED */
+ MDB_NEXT_NODUP, /**< Position at first data item of next key.
+ Only for #MDB_DUPSORT */
+ 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.
+ Only for #MDB_DUPSORT */
+ 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_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, probably I/O error */
+#define MDB_PANIC (-30795)
+ /** Environment version mismatch */
+#define MDB_VERSION_MISMATCH (-30794)
+ /** File is not a valid MDB 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)
+ /** Nested 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)
+#define MDB_LAST_ERRCODE MDB_PAGE_FULL
+/** @} */
+
+/** @brief Statistics for a database in the environment */
+typedef struct MDB_stat {
+ unsigned int ms_psize; /**< Size of a database page.
+ This is currently the same for all databases. */
+ unsigned int ms_depth; /**< Depth (height) of the B-tree */
+ size_t ms_branch_pages; /**< Number of internal (non-leaf) pages */
+ size_t ms_leaf_pages; /**< Number of leaf pages */
+ size_t ms_overflow_pages; /**< Number of overflow pages */
+ size_t ms_entries; /**< Number of data items */
+} MDB_stat;
+
+/** @brief Information about the environment */
+typedef struct MDB_envinfo {
+ void *me_mapaddr; /**< Address of map, if fixed */
+ size_t me_mapsize; /**< Size of the data memory map */
+ size_t me_last_pgno; /**< ID of the last used page */
+ size_t me_last_txnid; /**< ID of the last committed transaction */
+ unsigned int me_maxreaders; /**< maximum number of threads for the environment */
+ unsigned int me_numreaders; /**< maximum number of threads used in the environment */
+} MDB_envinfo;
+
+ /** @brief Return the mdb 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 MDB library error is
+ * returned. See @ref errors for a list of MDB-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 MDB environment handle.
+ *
+ * This function allocates memory for a #MDB_env structure. To release
+ * the allocated memory and discard the handle, call #mdb_env_close().
+ * Before the handle may be used, it must be opened using #mdb_env_open().
+ * Various other options may also need to be set before opening the handle,
+ * e.g. #mdb_env_set_mapsize(), #mdb_env_set_maxreaders(), #mdb_env_set_maxdbs(),
+ * depending on usage requirements.
+ * @param[out] env The address where the new handle will be stored
+ * @return A non-zero error value on failure and 0 on success.
+ */
+int mdb_env_create(MDB_env **env);
+
+ /** @brief Open an environment handle.
+ *
+ * If this function fails, #mdb_env_close() must be called to discard the #MDB_env handle.
+ * @param[in] env An environment handle returned by #mdb_env_create()
+ * @param[in] path The directory in which the database files reside. This
+ * directory must already exist and be writable.
+ * @param[in] flags Special options for this environment. This parameter
+ * must be set to 0 or by bitwise OR'ing together one or more of the
+ * values described here.
+ * Flags set by mdb_env_set_flags() are also used.
+ * <ul>
+ * <li>#MDB_FIXEDMAP
+ * use a fixed address for the mmap region. This flag must be specified
+ * when creating the environment, and is stored persistently in the environment.
+ * If successful, the memory map will always reside at the same virtual address
+ * and pointers used to reference data items in the database will be constant
+ * across multiple invocations. This option may not always work, depending on
+ * how the operating system has allocated memory to shared libraries and other uses.
+ * The feature is highly experimental.
+ * <li>#MDB_NOSUBDIR
+ * By default, MDB creates its environment in a directory whose
+ * pathname is given in \b path, and creates its data and lock files
+ * under that directory. With this option, \b path is used as-is for
+ * the database main data file. The database lock file is the \b path
+ * with "-lock" appended.
+ * <li>#MDB_NOSYNC
+ * Don't perform a synchronous flush after committing a transaction. This means
+ * transactions will exhibit the ACI (atomicity, consistency, and isolation)
+ * properties, but not D (durability); that is database integrity will be
+ * maintained but it is possible some number of the most recently committed
+ * transactions may be undone after a system crash. The number of transactions
+ * at risk is governed by how often the system flushes dirty buffers to disk
+ * and how often #mdb_env_sync() is called. This flag may be changed
+ * at any time using #mdb_env_set_flags().
+ * <li>#MDB_NOMETASYNC
+ * Don't perform a synchronous flush of the meta page after committing
+ * a transaction. This is similar to the #MDB_NOSYNC case, but safer
+ * because the transaction data is still flushed. The meta page for any
+ * transaction N will be flushed by the data flush of transaction N+1.
+ * In case of a system crash, the last committed transaction may be
+ * lost. This flag may be changed at any time using #mdb_env_set_flags().
+ * <li>#MDB_RDONLY
+ * Open the environment in read-only mode. No write operations will be allowed.
+ * </ul>
+ * @param[in] mode The UNIX permissions to set on created files. This parameter
+ * is ignored on Windows.
+ * @return A non-zero error value on failure and 0 on success. Some possible
+ * errors are:
+ * <ul>
+ * <li>#MDB_VERSION_MISMATCH - the version of the MDB library doesn't match the
+ * version that created the database environment.
+ * <li>EINVAL - the environment file headers are corrupted.
+ * <li>ENOENT - the directory specified by the path parameter doesn't exist.
+ * <li>EACCES - the user didn't have permission to access the environment files.
+ * <li>EAGAIN - the environment was locked by another process.
+ * </ul>
+ */
+int mdb_env_open(MDB_env *env, const char *path, unsigned int flags, mode_t mode);
+
+ /** @brief Copy an MDB environment to the specified path.
+ *
+ * This function may be used to make a backup of an existing environment.
+ * @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 Return statistics about the MDB 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 MDB 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. MDB always flushes
+ * the OS buffers upon commit as well, unless the environment was
+ * opened with #MDB_NOSYNC.
+ * @param[in] env An environment handle returned by #mdb_env_create()
+ * @param[in] force If non-zero, force a synchronous flush. Otherwise
+ * if the environment has the #MDB_NOSYNC flag set the flushes
+ * will be omitted, and with #MDB_MAPASYNC they will be asynchronous.
+ * @return A non-zero error value on failure and 0 on success. Some possible
+ * errors are:
+ * <ul>
+ * <li>EINVAL - an invalid parameter was specified.
+ * <li>EIO - an error occurred during synchronization.
+ * </ul>
+ */
+int mdb_env_sync(MDB_env *env, int force);
+
+ /** @brief Close the environment and release the memory map.
+ *
+ * Only a single thread may call this function. All transactions, databases,
+ * and cursors must already be closed before calling this function. Attempts to
+ * use any such handles after calling this function will cause a SIGSEGV.
+ * The environment handle will be freed and must not be used again after this call.
+ * @param[in] env An environment handle returned by #mdb_env_create()
+ */
+void mdb_env_close(MDB_env *env);
+
+ /** @brief Set environment flags.
+ *
+ * This may be used to set some flags in addition to those from
+ * #mdb_env_open(), or to unset these flags.
+ * @param[in] env An environment handle returned by #mdb_env_create()
+ * @param[in] flags The flags to change, bitwise OR'ed together
+ * @param[in] onoff A non-zero value sets the flags, zero clears them.
+ * @return A non-zero error value on failure and 0 on success. Some possible
+ * errors are:
+ * <ul>
+ * <li>EINVAL - an invalid parameter was specified.
+ * </ul>
+ */
+int mdb_env_set_flags(MDB_env *env, unsigned int flags, int onoff);
+
+ /** @brief Get environment flags.
+ *
+ * @param[in] env An environment handle returned by #mdb_env_create()
+ * @param[out] flags The address of an integer to store the flags
+ * @return A non-zero error value on failure and 0 on success. Some possible
+ * errors are:
+ * <ul>
+ * <li>EINVAL - an invalid parameter was specified.
+ * </ul>
+ */
+int mdb_env_get_flags(MDB_env *env, unsigned int *flags);
+
+ /** @brief Return the path that was used in #mdb_env_open().
+ *
+ * @param[in] env An environment handle returned by #mdb_env_create()
+ * @param[out] path Address of a string pointer to contain the path. This
+ * is the actual string in the environment, not a copy. It should not be
+ * altered in any way.
+ * @return A non-zero error value on failure and 0 on success. Some possible
+ * errors are:
+ * <ul>
+ * <li>EINVAL - an invalid parameter was specified.
+ * </ul>
+ */
+int mdb_env_get_path(MDB_env *env, const char **path);
+
+ /** @brief 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 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] size The size in bytes
+ * @return A non-zero error value on failure and 0 on success. Some possible
+ * errors are:
+ * <ul>
+ * <li>EINVAL - an invalid parameter was specified, or the environment is already open.
+ * </ul>
+ */
+int mdb_env_set_mapsize(MDB_env *env, size_t size);
+
+ /** @brief Set the maximum number of threads 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.
+ * 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 threads
+ * @return A non-zero error value on failure and 0 on success. Some possible
+ * errors are:
+ * <ul>
+ * <li>EINVAL - an invalid parameter was specified, or the environment is already open.
+ * </ul>
+ */
+int mdb_env_set_maxreaders(MDB_env *env, unsigned int readers);
+
+ /** @brief Get the maximum number of threads for the environment.
+ *
+ * @param[in] env An environment handle returned by #mdb_env_create()
+ * @param[out] readers Address of an integer to store the number of readers
+ * @return A non-zero error value on failure and 0 on success. Some possible
+ * errors are:
+ * <ul>
+ * <li>EINVAL - an invalid parameter was specified.
+ * </ul>
+ */
+int mdb_env_get_maxreaders(MDB_env *env, unsigned int *readers);
+
+ /** @brief Set the maximum number of named databases for the environment.
+ *
+ * This function is only needed if multiple databases will be used in the
+ * environment. Simpler applications that use the environment as a single
+ * unnamed database can ignore this option.
+ * This function may only be called after #mdb_env_create() and before #mdb_env_open().
+ * @param[in] env An environment handle returned by #mdb_env_create()
+ * @param[in] dbs The maximum number of databases
+ * @return A non-zero error value on failure and 0 on success. Some possible
+ * errors are:
+ * <ul>
+ * <li>EINVAL - an invalid parameter was specified, or the environment is already open.
+ * </ul>
+ */
+int mdb_env_set_maxdbs(MDB_env *env, MDB_dbi dbs);
+
+ /** @brief Create a transaction for use with the environment.
+ *
+ * The transaction handle may be discarded using #mdb_txn_abort() or #mdb_txn_commit().
+ * @note Transactions may not span threads; a transaction must only be used by a
+ * single thread. Also, a thread may only have a single transaction.
+ * @note Cursors may not span transactions; each cursor must be opened and closed
+ * within a single transaction.
+ * @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 may not issue any other operations besides mdb_txn_begin,
+ * mdb_txn_abort, or mdb_txn_commit while it has active child transactions.
+ * @param[in] flags Special options for this transaction. This parameter
+ * must be set to 0 or by bitwise OR'ing together one or more of the
+ * values described here.
+ * <ul>
+ * <li>#MDB_RDONLY
+ * This transaction will not perform any write operations.
+ * </ul>
+ * @param[out] txn Address where the new #MDB_txn handle will be stored
+ * @return A non-zero error value on failure and 0 on success. Some possible
+ * errors are:
+ * <ul>
+ * <li>#MDB_PANIC - a fatal error occurred earlier and the environment
+ * must be shut down.
+ * <li>ENOMEM - out of memory, or a read-only transaction was requested and
+ * the reader lock table is full. See #mdb_env_set_maxreaders().
+ * </ul>
+ */
+int mdb_txn_begin(MDB_env *env, MDB_txn *parent, unsigned int flags, MDB_txn **txn);
+
+ /** @brief Commit all the operations of a transaction into the database.
+ *
+ * All cursors opened within the transaction will be closed by this call. The cursors
+ * and transaction handle will be freed and must not be used again after this call.
+ * @param[in] txn A transaction handle returned by #mdb_txn_begin()
+ * @return A non-zero error value on failure and 0 on success. Some possible
+ * errors are:
+ * <ul>
+ * <li>EINVAL - an invalid parameter was specified.
+ * <li>ENOSPC - no more disk space.
+ * <li>EIO - a low-level I/O error occurred while writing.
+ * <li>ENOMEM - the transaction is nested and could not be merged into its parent.
+ * </ul>
+ */
+int mdb_txn_commit(MDB_txn *txn);
+
+ /** @brief Abandon all the operations of the transaction instead of saving them.
+ *
+ * All cursors opened within the transaction will be closed by this call. The cursors
+ * and transaction handle will be freed and must not be used again after this call.
+ * @param[in] txn A transaction handle returned by #mdb_txn_begin()
+ */
+void mdb_txn_abort(MDB_txn *txn);
+
+ /** @brief Reset a read-only transaction.
+ *
+ * This releases the current reader lock but doesn't free the
+ * transaction handle, allowing it to be used again later by #mdb_txn_renew().
+ * It otherwise has the same effect as #mdb_txn_abort() but saves some memory
+ * allocation/deallocation overhead if a thread is going to start a new
+ * read-only transaction again soon.
+ * All cursors opened within the transaction must be closed before the transaction
+ * is reset.
+ * Reader locks generally don't interfere with writers, but they keep old
+ * versions of database pages allocated. Thus they prevent the old pages
+ * from being reused when writers commit new data, and so under heavy load
+ * the database size may grow much more rapidly than otherwise.
+ * @param[in] txn A transaction handle returned by #mdb_txn_begin()
+ */
+void mdb_txn_reset(MDB_txn *txn);
+
+ /** @brief Renew a read-only transaction.
+ *
+ * This acquires a new reader lock for a transaction handle that had been
+ * released by #mdb_txn_reset(). It must be called before a reset transaction
+ * may be used again.
+ * @param[in] txn A transaction handle returned by #mdb_txn_begin()
+ * @return A non-zero error value on failure and 0 on success. Some possible
+ * errors are:
+ * <ul>
+ * <li>#MDB_PANIC - a fatal error occurred earlier and the environment
+ * must be shut down.
+ * <li>EINVAL - an invalid parameter was specified.
+ * </ul>
+ */
+int mdb_txn_renew(MDB_txn *txn);
+
+ /** @brief Open a database in the environment.
+ *
+ * The database handle may be discarded by calling #mdb_close(). The
+ * database handle resides in the shared environment, it is not owned
+ * by the given transaction. Only one thread should call this function;
+ * it is not mutex-protected in a read-only transaction.
+ * To use named databases (with name != NULL), #mdb_env_set_maxdbs()
+ * must be called before opening the enviorment.
+ * @param[in] txn A transaction handle returned by #mdb_txn_begin()
+ * @param[in] name The name of the database to open. If only a single
+ * database is needed in the environment, this value may be NULL.
+ * @param[in] flags Special options for this database. This parameter
+ * must be set to 0 or by bitwise OR'ing together one or more of the
+ * values described here.
+ * <ul>
+ * <li>#MDB_REVERSEKEY
+ * Keys are strings to be compared in reverse order, from the end
+ * of the strings to the beginning. By default, Keys are treated as strings and
+ * compared from beginning to end.
+ * <li>#MDB_DUPSORT
+ * Duplicate keys may be used in the database. (Or, from another perspective,
+ * keys may have multiple data items, stored in sorted order.) By default
+ * keys must be unique and may have only a single data item.
+ * <li>#MDB_INTEGERKEY
+ * Keys are binary integers in native byte order. Setting this option
+ * requires all keys to be the same size, typically sizeof(int)
+ * or sizeof(size_t).
+ * <li>#MDB_DUPFIXED
+ * This flag may only be used in combination with #MDB_DUPSORT. This option
+ * tells the library that the data items for this database are all the same
+ * size, which allows further optimizations in storage and retrieval. When
+ * all data items are the same size, the #MDB_GET_MULTIPLE and #MDB_NEXT_MULTIPLE
+ * cursor operations may be used to retrieve multiple items at once.
+ * <li>#MDB_INTEGERDUP
+ * This option specifies that duplicate data items are also integers, and
+ * should be sorted as such.
+ * <li>#MDB_REVERSEDUP
+ * This option specifies that duplicate data items should be compared as
+ * strings in reverse order.
+ * <li>#MDB_CREATE
+ * Create the named database if it doesn't exist. This option is not
+ * allowed in a read-only transaction or a read-only environment.
+ * </ul>
+ * @param[out] dbi Address where the new #MDB_dbi handle will be stored
+ * @return A non-zero error value on failure and 0 on success. Some possible
+ * errors are:
+ * <ul>
+ * <li>#MDB_NOTFOUND - the specified database doesn't exist in the environment
+ * and #MDB_CREATE was not specified.
+ * <li>ENFILE - too many databases have been opened. See #mdb_env_set_maxdbs().
+ * </ul>
+ */
+int mdb_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_open()
+ * @param[out] stat The address of an #MDB_stat structure
+ * where the statistics will be copied
+ * @return A non-zero error value on failure and 0 on success. Some possible
+ * errors are:
+ * <ul>
+ * <li>EINVAL - an invalid parameter was specified.
+ * </ul>
+ */
+int mdb_stat(MDB_txn *txn, MDB_dbi dbi, MDB_stat *stat);
+
+ /** @brief Close a database handle.
+ *
+ * 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 any further.
+ * @param[in] env An environment handle returned by #mdb_env_create()
+ * @param[in] dbi A database handle returned by #mdb_open()
+ */
+void mdb_close(MDB_env *env, MDB_dbi dbi);
+
+ /** @brief Delete a database and/or free all its pages.
+ *
+ * If the \b del parameter is 1, the DB handle will be closed
+ * and the DB will be deleted.
+ * @param[in] txn A transaction handle returned by #mdb_txn_begin()
+ * @param[in] dbi A database handle returned by #mdb_open()
+ * @param[in] del 1 to delete the DB from the environment,
+ * 0 to just free its pages.
+ * @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_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_open()
+ * @param[in] cmp A #MDB_cmp_func function
+ * @return A non-zero error value on failure and 0 on success. Some possible
+ * errors are:
+ * <ul>
+ * <li>EINVAL - an invalid parameter was specified.
+ * </ul>
+ */
+int mdb_set_compare(MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp);
+
+ /** @brief Set a custom data comparison function for a #MDB_DUPSORT database.
+ *
+ * This comparison function is called whenever it is necessary to compare a data
+ * item specified by the application with a data item currently stored in the database.
+ * This function only takes effect if the database was opened with the #MDB_DUPSORT
+ * flag.
+ * If no comparison function is specified, and no special key flags were specified
+ * with #mdb_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_open()
+ * @param[in] cmp A #MDB_cmp_func function
+ * @return A non-zero error value on failure and 0 on success. Some possible
+ * errors are:
+ * <ul>
+ * <li>EINVAL - an invalid parameter was specified.
+ * </ul>
+ */
+int mdb_set_dupsort(MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp);
+
+ /** @brief Set a relocation function for a #MDB_FIXEDMAP database.
+ *
+ * @todo The relocation function is called whenever it is necessary to move the data
+ * of an item to a different position in the database (e.g. through tree
+ * balancing operations, shifts as a result of adds or deletes, etc.). It is
+ * intended to allow address/position-dependent data items to be stored in
+ * a database in an environment opened with the #MDB_FIXEDMAP option.
+ * Currently the relocation feature is unimplemented and setting
+ * this function has no effect.
+ * @param[in] txn A transaction handle returned by #mdb_txn_begin()
+ * @param[in] dbi A database handle returned by #mdb_open()
+ * @param[in] rel A #MDB_rel_func function
+ * @return A non-zero error value on failure and 0 on success. Some possible
+ * errors are:
+ * <ul>
+ * <li>EINVAL - an invalid parameter was specified.
+ * </ul>
+ */
+int mdb_set_relfunc(MDB_txn *txn, MDB_dbi dbi, MDB_rel_func *rel);
+
+ /** @brief Set a context pointer for a #MDB_FIXEDMAP database's relocation function.
+ *
+ * See #mdb_set_relfunc and #MDB_rel_func for more details.
+ * @param[in] txn A transaction handle returned by #mdb_txn_begin()
+ * @param[in] dbi A database handle returned by #mdb_open()
+ * @param[in] ctx An arbitrary pointer for whatever the application needs.
+ * It will be passed to the callback function set by #mdb_set_relfunc
+ * as its \b relctx parameter whenever the callback is invoked.
+ * @return A non-zero error value on failure and 0 on success. Some possible
+ * errors are:
+ * <ul>
+ * <li>EINVAL - an invalid parameter was specified.
+ * </ul>
+ */
+int mdb_set_relctx(MDB_txn *txn, MDB_dbi dbi, void *ctx);
+
+ /** @brief Get items from a database.
+ *
+ * This function retrieves key/data pairs from the database. The address
+ * and length of the data associated with the specified \b key are returned
+ * in the structure to which \b data refers.
+ * If the database supports duplicate keys (#MDB_DUPSORT) then the
+ * first data item for the key will be returned. Retrieval of other
+ * items requires the use of #mdb_cursor_get().
+ *
+ * @note The memory pointed to by the returned values is owned by the
+ * database. The caller need not dispose of the memory, and may not
+ * modify it in any way. For values returned in a read-only transaction
+ * any modification attempts will cause a SIGSEGV.
+ * @param[in] txn A transaction handle returned by #mdb_txn_begin()
+ * @param[in] dbi A database handle returned by #mdb_open()
+ * @param[in] key The key to search for in the database
+ * @param[out] data The data corresponding to the key
+ * @return A non-zero error value on failure and 0 on success. Some possible
+ * errors are:
+ * <ul>
+ * <li>#MDB_NOTFOUND - the key was not in the database.
+ * <li>EINVAL - an invalid parameter was specified.
+ * </ul>
+ */
+int mdb_get(MDB_txn *txn, MDB_dbi dbi, MDB_val *key, MDB_val *data);
+
+ /** @brief Store items into a database.
+ *
+ * This function stores key/data pairs in the database. The default behavior
+ * is to enter the new key/data pair, replacing any previously existing key
+ * if duplicates are disallowed, or adding a duplicate data item if
+ * duplicates are allowed (#MDB_DUPSORT).
+ * @param[in] txn A transaction handle returned by #mdb_txn_begin()
+ * @param[in] dbi A database handle returned by #mdb_open()
+ * @param[in] key The key to store in the database
+ * @param[in,out] data The data to store
+ * @param[in] flags Special options for this operation. This parameter
+ * must be set to 0 or by bitwise OR'ing together one or more of the
+ * values described here.
+ * <ul>
+ * <li>#MDB_NODUPDATA - enter the new key/data pair only if it does not
+ * already appear in the database. This flag may only be specified
+ * if the database was opened with #MDB_DUPSORT. The function will
+ * return #MDB_KEYEXIST if the key/data pair already appears in the
+ * database.
+ * <li>#MDB_NOOVERWRITE - enter the new key/data pair only if the key
+ * does not already appear in the database. The function will return
+ * #MDB_KEYEXIST if the key already appears in the database, even if
+ * the database supports duplicates (#MDB_DUPSORT). The \b data
+ * parameter will be set to point to the existing item.
+ * <li>#MDB_RESERVE - reserve space for data of the given size, but
+ * don't copy the given data. Instead, return a pointer to the
+ * reserved space, which the caller can fill in later. This saves
+ * an extra memcpy if the data is being generated later.
+ * <li>#MDB_APPEND - append the given key/data pair to the end of the
+ * database. No key comparisons are performed. This option allows
+ * fast bulk loading when keys are already known to be in the
+ * correct order. Loading unsorted keys with this flag will cause
+ * data corruption.
+ * <li>#MDB_APPENDDUP - as above, but for sorted dup data.
+ * </ul>
+ * @return A non-zero error value on failure and 0 on success. Some possible
+ * errors are:
+ * <ul>
+ * <li>EACCES - an attempt was made to write in a read-only transaction.
+ * <li>EINVAL - an invalid parameter was specified.
+ * <li>ENOMEM - the database is full, see #mdb_env_set_mapsize().
+ * </ul>
+ */
+int mdb_put(MDB_txn *txn, MDB_dbi dbi, MDB_val *key, MDB_val *data,
+ unsigned int flags);
+
+ /** @brief Delete items from a database.
+ *
+ * This function removes key/data pairs from the database.
+ * If the database does not support sorted duplicate data items
+ * (#MDB_DUPSORT) the data parameter is ignored.
+ * If the database supports sorted duplicates and the data parameter
+ * is NULL, all of the duplicate data items for the key will be
+ * deleted. Otherwise, if the data parameter is non-NULL
+ * only the matching data item will be deleted.
+ * This function will return #MDB_NOTFOUND if the specified key/data
+ * pair is not in the database.
+ * @param[in] txn A transaction handle returned by #mdb_txn_begin()
+ * @param[in] dbi A database handle returned by #mdb_open()
+ * @param[in] key The key to delete from the database
+ * @param[in] data The data to delete
+ * @return A non-zero error value on failure and 0 on success. Some possible
+ * errors are:
+ * <ul>
+ * <li>EACCES - an attempt was made to write in a read-only transaction.
+ * <li>EINVAL - an invalid parameter was specified.
+ * </ul>
+ */
+int mdb_del(MDB_txn *txn, MDB_dbi dbi, MDB_val *key, MDB_val *data);
+
+ /** @brief Create a cursor handle.
+ *
+ * Cursors are associated with a specific transaction and database and
+ * may not span threads.
+ * @param[in] txn A transaction handle returned by #mdb_txn_begin()
+ * @param[in] dbi A database handle returned by #mdb_open()
+ * @param[out] cursor Address where the new #MDB_cursor handle will be stored
+ * @return A non-zero error value on failure and 0 on success. Some possible
+ * errors are:
+ * <ul>
+ * <li>EINVAL - an invalid parameter was specified.
+ * </ul>
+ */
+int mdb_cursor_open(MDB_txn *txn, MDB_dbi dbi, MDB_cursor **cursor);
+
+ /** @brief Close a cursor handle.
+ *
+ * The cursor handle will be freed and must not be used again after this call.
+ * @param[in] cursor A cursor handle returned by #mdb_cursor_open()
+ */
+void mdb_cursor_close(MDB_cursor *cursor);
+
+ /** @brief Renew a cursor handle.
+ *
+ * Cursors are associated with a specific transaction and database and
+ * may not span threads. 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.
+ * @param[in] txn A transaction handle returned by #mdb_txn_begin()
+ * @param[in] cursor A cursor handle returned by #mdb_cursor_open()
+ * @return A non-zero error value on failure and 0 on success. Some possible
+ * errors are:
+ * <ul>
+ * <li>EINVAL - an invalid parameter was specified.
+ * </ul>
+ */
+int mdb_cursor_renew(MDB_txn *txn, MDB_cursor *cursor);
+
+ /** @brief Return the cursor's transaction handle.
+ *
+ * @param[in] cursor A cursor handle returned by #mdb_cursor_open()
+ */
+MDB_txn *mdb_cursor_txn(MDB_cursor *cursor);
+
+ /** @brief Return the cursor's database handle.
+ *
+ * @param[in] cursor A cursor handle returned by #mdb_cursor_open()
+ */
+MDB_dbi mdb_cursor_dbi(MDB_cursor *cursor);
+
+ /** @brief Retrieve by cursor.
+ *
+ * This function retrieves key/data pairs from the database. The address and length
+ * of the key are returned in the object to which \b key refers (except for the
+ * case of the #MDB_SET option, in which the \b key object is unchanged), and
+ * the address and length of the data are returned in the object to which \b data
+ * refers.
+ * @param[in] cursor A cursor handle returned by #mdb_cursor_open()
+ * @param[in,out] key The key for a retrieved item
+ * @param[in,out] data The data of a retrieved item
+ * @param[in] op A cursor operation #MDB_cursor_op
+ * @return A non-zero error value on failure and 0 on success. Some possible
+ * errors are:
+ * <ul>
+ * <li>#MDB_NOTFOUND - no matching key found.
+ * <li>EINVAL - an invalid parameter was specified.
+ * </ul>
+ */
+int mdb_cursor_get(MDB_cursor *cursor, MDB_val *key, MDB_val *data,
+ MDB_cursor_op op);
+
+ /** @brief Store by cursor.
+ *
+ * This function stores key/data pairs into the database.
+ * If the function fails for any reason, the state of the cursor will be
+ * unchanged. If the function succeeds and an item is inserted into the
+ * database, the cursor is always positioned to refer to the newly inserted item.
+ * @param[in] cursor A cursor handle returned by #mdb_cursor_open()
+ * @param[in] key The key operated on.
+ * @param[in] data The data operated on.
+ * @param[in] flags Options for this operation. This parameter
+ * must be set to 0 or one of the values described here.
+ * <ul>
+ * <li>#MDB_CURRENT - overwrite the data of the key/data pair to which
+ * the cursor refers with the specified data item. The \b key
+ * parameter is ignored.
+ * <li>#MDB_NODUPDATA - enter the new key/data pair only if it does not
+ * already appear in the database. This flag may only be specified
+ * if the database was opened with #MDB_DUPSORT. The function will
+ * return #MDB_KEYEXIST if the key/data pair already appears in the
+ * database.
+ * <li>#MDB_NOOVERWRITE - enter the new key/data pair only if the key
+ * does not already appear in the database. The function will return
+ * #MDB_KEYEXIST if the key already appears in the database, even if
+ * the database supports duplicates (#MDB_DUPSORT).
+ * <li>#MDB_RESERVE - reserve space for data of the given size, but
+ * don't copy the given data. Instead, return a pointer to the
+ * reserved space, which the caller can fill in later. This saves
+ * an extra memcpy if the data is being generated later.
+ * <li>#MDB_APPEND - append the given key/data pair to the end of the
+ * database. No key comparisons are performed. This option allows
+ * fast bulk loading when keys are already known to be in the
+ * correct order. Loading unsorted keys with this flag will cause
+ * data corruption.
+ * <li>#MDB_APPENDDUP - as above, but for sorted dup data.
+ * </ul>
+ * @return A non-zero error value on failure and 0 on success. Some possible
+ * errors are:
+ * <ul>
+ * <li>EACCES - an attempt was made to modify a read-only database.
+ * <li>EINVAL - an invalid parameter was specified.
+ * </ul>
+ */
+int mdb_cursor_put(MDB_cursor *cursor, MDB_val *key, MDB_val *data,
+ unsigned int flags);
+
+ /** @brief Delete current key/data pair
+ *
+ * This function deletes the key/data pair to which the cursor refers.
+ * @param[in] cursor A cursor handle returned by #mdb_cursor_open()
+ * @param[in] flags Options for this operation. This parameter
+ * must be set to 0 or one of the values described here.
+ * <ul>
+ * <li>#MDB_NODUPDATA - delete all of the data items for the current key.
+ * This flag may only be specified if the database was opened with #MDB_DUPSORT.
+ * </ul>
+ * @return A non-zero error value on failure and 0 on success. Some possible
+ * errors are:
+ * <ul>
+ * <li>EACCES - an attempt was made to modify a read-only database.
+ * <li>EINVAL - an invalid parameter was specified.
+ * </ul>
+ */
+int mdb_cursor_del(MDB_cursor *cursor, unsigned int flags);
+
+ /** @brief Return count of duplicates for current key.
+ *
+ * This call is only valid on databases that support sorted duplicate
+ * data items #MDB_DUPSORT.
+ * @param[in] cursor A cursor handle returned by #mdb_cursor_open()
+ * @param[out] countp Address where the count will be stored
+ * @return A non-zero error value on failure and 0 on success. Some possible
+ * errors are:
+ * <ul>
+ * <li>EINVAL - cursor is not initialized, or an invalid parameter was specified.
+ * </ul>
+ */
+int mdb_cursor_count(MDB_cursor *cursor, size_t *countp);
+
+ /** @brief Compare two data items according to a particular database.
+ *
+ * This returns a comparison as if the two data items were keys in the
+ * specified database.
+ * @param[in] txn A transaction handle returned by #mdb_txn_begin()
+ * @param[in] dbi A database handle returned by #mdb_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
+ * a sorted duplicates #MDB_DUPSORT database.
+ * @param[in] txn A transaction handle returned by #mdb_txn_begin()
+ * @param[in] dbi A database handle returned by #mdb_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);
+/** @} */
+
+#ifdef __cplusplus
+}
+#endif
+#endif /* _LMDB_H_ */
#define MISALIGNED_OK 1
#endif
-#include "mdb.h"
+#include "lmdb.h"
#include "midl.h"
#if (BYTE_ORDER == LITTLE_ENDIAN) == (BYTE_ORDER == BIG_ENDIAN)
+++ /dev/null
-/** @file mdb.h
- * @brief memory-mapped database library
- *
- * @mainpage MDB Memory-Mapped Database Manager
- *
- * @section intro_sec Introduction
- * MDB 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, MDB 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. MDB 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.
- *
- * @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: Terminate all programs using the database, or make
- * them close it. Next database user will reset the lockfile.
- *
- * - On BSD systems or others configured with MDB_USE_POSIX_SEM,
- * startup can fail due to semaphores owned by another userid.
- *
- * Fix: Open and close the database as the user which owns the
- * semaphores (likely last user) or as root, while no other
- * process is using the database.
- *
- * Restrictions/caveats (in addition to those listed for some functions):
- *
- * - Only the database owner should normally use the database on
- * BSD systems or when otherwise configured with MDB_USE_POSIX_SEM.
- * Multiple users can cause startup to fail later, as noted above.
- *
- * - A thread can only use one transaction at a time, plus any child
- * transactions. Each transaction belongs to one thread. See below.
- *
- * - Use an MDB_env* in the process which opened it, without fork()ing.
- *
- * - Do not have open an MDB database twice in the same process at
- * the same time. Not even from a plain open() call - close()ing it
- * breaks flock() advisory locking.
- *
- * - 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.
- *
- * ...when several processes can use a database concurrently:
- *
- * - Avoid suspending a process with active transactions. These
- * would then be "long-lived" as above.
- *
- * - Avoid aborting a process with an active transaction.
- * The transaction becomes "long-lived" as above until the lockfile
- * is reset, since the process may not remove it from the lockfile.
- *
- * - If you do that anyway, close the environment once in a while,
- * so the lockfile can get reset.
- *
- * - Do not use MDB 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 2011-2012 Howard Chu, Symas Corp. All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted only as authorized by the OpenLDAP
- * Public License.
- *
- * A copy of this license is available in the file LICENSE in the
- * top-level directory of the distribution or, alternatively, at
- * <http://www.OpenLDAP.org/license.html>.
- *
- * @par Derived From:
- * This code is derived from btree.c written by Martin Hedenfalk.
- *
- * Copyright (c) 2009, 2010 Martin Hedenfalk <martin@bzero.se>
- *
- * Permission to use, copy, modify, and distribute this software for any
- * purpose with or without fee is hereby granted, provided that the above
- * copyright notice and this permission notice appear in all copies.
- *
- * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
- * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
- * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
- * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
- * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
- * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
- * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
- */
-#ifndef _MDB_H_
-#define _MDB_H_
-
-#include <sys/types.h>
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-/** @defgroup mdb MDB API
- * @{
- * @brief OpenLDAP 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 4
-
-/** 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 "September 14, 2012"
-
-/** A stringifier for the version info */
-#define MDB_VERSTR(a,b,c,d) "MDB " #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. */
-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
- *
- * Values do not overlap Database Flags.
- * @{
- */
- /** mmap at a fixed address */
-#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 */
-#define MDB_MAPASYNC 0x100000
-/** @} */
-
-/** @defgroup mdb_open Database Flags
- *
- * Values do not overlap Environment Flags.
- * @{
- */
- /** use reverse string keys */
-#define MDB_REVERSEKEY 0x02
- /** use sorted duplicates */
-#define MDB_DUPSORT 0x04
- /** numeric keys in native byte order.
- * 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 numeric in native byte order */
-#define MDB_INTEGERDUP 0x20
- /** with #MDB_DUPSORT, use reverse string dups */
-#define MDB_REVERSEDUP 0x40
- /** create DB if not already existing */
-#define MDB_CREATE 0x40000
-/** @} */
-
-/** @defgroup mdb_put Write Flags
- * @{
- */
-/** For put: Don't write if the key already exists. */
-#define MDB_NOOVERWRITE 0x10
-/** Only for #MDB_DUPSORT<br>
- * For put: don't write if the key and data pair already exist.<br>
- * For mdb_cursor_del: remove all duplicate data items.
- */
-#define MDB_NODUPDATA 0x20
-/** For mdb_cursor_put: overwrite the current key/data pair */
-#define MDB_CURRENT 0x40
-/** For put: Just reserve space for data, don't copy it. Return a
- * pointer to the reserved space.
- */
-#define MDB_RESERVE 0x10000
-/** Data is being appended, don't split full pages. */
-#define MDB_APPEND 0x20000
-/** Duplicate data is being appended, don't split full pages. */
-#define MDB_APPENDDUP 0x40000
-/** Store multiple data items in one call. */
-#define MDB_MULTIPLE 0x80000
-/* @} */
-
-/** @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 all the duplicate data items at the current
- cursor position. 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 all duplicate data items at the next
- cursor position. Only for #MDB_DUPFIXED */
- MDB_NEXT_NODUP, /**< Position at first data item of next key.
- Only for #MDB_DUPSORT */
- 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.
- Only for #MDB_DUPSORT */
- 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_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, probably I/O error */
-#define MDB_PANIC (-30795)
- /** Environment version mismatch */
-#define MDB_VERSION_MISMATCH (-30794)
- /** File is not a valid MDB 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)
- /** Nested 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)
-#define MDB_LAST_ERRCODE MDB_PAGE_FULL
-/** @} */
-
-/** @brief Statistics for a database in the environment */
-typedef struct MDB_stat {
- unsigned int ms_psize; /**< Size of a database page.
- This is currently the same for all databases. */
- unsigned int ms_depth; /**< Depth (height) of the B-tree */
- size_t ms_branch_pages; /**< Number of internal (non-leaf) pages */
- size_t ms_leaf_pages; /**< Number of leaf pages */
- size_t ms_overflow_pages; /**< Number of overflow pages */
- size_t ms_entries; /**< Number of data items */
-} MDB_stat;
-
-/** @brief Information about the environment */
-typedef struct MDB_envinfo {
- void *me_mapaddr; /**< Address of map, if fixed */
- size_t me_mapsize; /**< Size of the data memory map */
- size_t me_last_pgno; /**< ID of the last used page */
- size_t me_last_txnid; /**< ID of the last committed transaction */
- unsigned int me_maxreaders; /**< maximum number of threads for the environment */
- unsigned int me_numreaders; /**< maximum number of threads used in the environment */
-} MDB_envinfo;
-
- /** @brief Return the mdb 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 MDB library error is
- * returned. See @ref errors for a list of MDB-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 MDB environment handle.
- *
- * This function allocates memory for a #MDB_env structure. To release
- * the allocated memory and discard the handle, call #mdb_env_close().
- * Before the handle may be used, it must be opened using #mdb_env_open().
- * Various other options may also need to be set before opening the handle,
- * e.g. #mdb_env_set_mapsize(), #mdb_env_set_maxreaders(), #mdb_env_set_maxdbs(),
- * depending on usage requirements.
- * @param[out] env The address where the new handle will be stored
- * @return A non-zero error value on failure and 0 on success.
- */
-int mdb_env_create(MDB_env **env);
-
- /** @brief Open an environment handle.
- *
- * If this function fails, #mdb_env_close() must be called to discard the #MDB_env handle.
- * @param[in] env An environment handle returned by #mdb_env_create()
- * @param[in] path The directory in which the database files reside. This
- * directory must already exist and be writable.
- * @param[in] flags Special options for this environment. This parameter
- * must be set to 0 or by bitwise OR'ing together one or more of the
- * values described here.
- * Flags set by mdb_env_set_flags() are also used.
- * <ul>
- * <li>#MDB_FIXEDMAP
- * use a fixed address for the mmap region. This flag must be specified
- * when creating the environment, and is stored persistently in the environment.
- * If successful, the memory map will always reside at the same virtual address
- * and pointers used to reference data items in the database will be constant
- * across multiple invocations. This option may not always work, depending on
- * how the operating system has allocated memory to shared libraries and other uses.
- * The feature is highly experimental.
- * <li>#MDB_NOSUBDIR
- * By default, MDB creates its environment in a directory whose
- * pathname is given in \b path, and creates its data and lock files
- * under that directory. With this option, \b path is used as-is for
- * the database main data file. The database lock file is the \b path
- * with "-lock" appended.
- * <li>#MDB_NOSYNC
- * Don't perform a synchronous flush after committing a transaction. This means
- * transactions will exhibit the ACI (atomicity, consistency, and isolation)
- * properties, but not D (durability); that is database integrity will be
- * maintained but it is possible some number of the most recently committed
- * transactions may be undone after a system crash. The number of transactions
- * at risk is governed by how often the system flushes dirty buffers to disk
- * and how often #mdb_env_sync() is called. This flag may be changed
- * at any time using #mdb_env_set_flags().
- * <li>#MDB_NOMETASYNC
- * Don't perform a synchronous flush of the meta page after committing
- * a transaction. This is similar to the #MDB_NOSYNC case, but safer
- * because the transaction data is still flushed. The meta page for any
- * transaction N will be flushed by the data flush of transaction N+1.
- * In case of a system crash, the last committed transaction may be
- * lost. This flag may be changed at any time using #mdb_env_set_flags().
- * <li>#MDB_RDONLY
- * Open the environment in read-only mode. No write operations will be allowed.
- * </ul>
- * @param[in] mode The UNIX permissions to set on created files. This parameter
- * is ignored on Windows.
- * @return A non-zero error value on failure and 0 on success. Some possible
- * errors are:
- * <ul>
- * <li>#MDB_VERSION_MISMATCH - the version of the MDB library doesn't match the
- * version that created the database environment.
- * <li>EINVAL - the environment file headers are corrupted.
- * <li>ENOENT - the directory specified by the path parameter doesn't exist.
- * <li>EACCES - the user didn't have permission to access the environment files.
- * <li>EAGAIN - the environment was locked by another process.
- * </ul>
- */
-int mdb_env_open(MDB_env *env, const char *path, unsigned int flags, mode_t mode);
-
- /** @brief Copy an MDB environment to the specified path.
- *
- * This function may be used to make a backup of an existing environment.
- * @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 Return statistics about the MDB 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 MDB 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. MDB always flushes
- * the OS buffers upon commit as well, unless the environment was
- * opened with #MDB_NOSYNC.
- * @param[in] env An environment handle returned by #mdb_env_create()
- * @param[in] force If non-zero, force a synchronous flush. Otherwise
- * if the environment has the #MDB_NOSYNC flag set the flushes
- * will be omitted, and with #MDB_MAPASYNC they will be asynchronous.
- * @return A non-zero error value on failure and 0 on success. Some possible
- * errors are:
- * <ul>
- * <li>EINVAL - an invalid parameter was specified.
- * <li>EIO - an error occurred during synchronization.
- * </ul>
- */
-int mdb_env_sync(MDB_env *env, int force);
-
- /** @brief Close the environment and release the memory map.
- *
- * Only a single thread may call this function. All transactions, databases,
- * and cursors must already be closed before calling this function. Attempts to
- * use any such handles after calling this function will cause a SIGSEGV.
- * The environment handle will be freed and must not be used again after this call.
- * @param[in] env An environment handle returned by #mdb_env_create()
- */
-void mdb_env_close(MDB_env *env);
-
- /** @brief Set environment flags.
- *
- * This may be used to set some flags in addition to those from
- * #mdb_env_open(), or to unset these flags.
- * @param[in] env An environment handle returned by #mdb_env_create()
- * @param[in] flags The flags to change, bitwise OR'ed together
- * @param[in] onoff A non-zero value sets the flags, zero clears them.
- * @return A non-zero error value on failure and 0 on success. Some possible
- * errors are:
- * <ul>
- * <li>EINVAL - an invalid parameter was specified.
- * </ul>
- */
-int mdb_env_set_flags(MDB_env *env, unsigned int flags, int onoff);
-
- /** @brief Get environment flags.
- *
- * @param[in] env An environment handle returned by #mdb_env_create()
- * @param[out] flags The address of an integer to store the flags
- * @return A non-zero error value on failure and 0 on success. Some possible
- * errors are:
- * <ul>
- * <li>EINVAL - an invalid parameter was specified.
- * </ul>
- */
-int mdb_env_get_flags(MDB_env *env, unsigned int *flags);
-
- /** @brief Return the path that was used in #mdb_env_open().
- *
- * @param[in] env An environment handle returned by #mdb_env_create()
- * @param[out] path Address of a string pointer to contain the path. This
- * is the actual string in the environment, not a copy. It should not be
- * altered in any way.
- * @return A non-zero error value on failure and 0 on success. Some possible
- * errors are:
- * <ul>
- * <li>EINVAL - an invalid parameter was specified.
- * </ul>
- */
-int mdb_env_get_path(MDB_env *env, const char **path);
-
- /** @brief 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 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] size The size in bytes
- * @return A non-zero error value on failure and 0 on success. Some possible
- * errors are:
- * <ul>
- * <li>EINVAL - an invalid parameter was specified, or the environment is already open.
- * </ul>
- */
-int mdb_env_set_mapsize(MDB_env *env, size_t size);
-
- /** @brief Set the maximum number of threads 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.
- * 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 threads
- * @return A non-zero error value on failure and 0 on success. Some possible
- * errors are:
- * <ul>
- * <li>EINVAL - an invalid parameter was specified, or the environment is already open.
- * </ul>
- */
-int mdb_env_set_maxreaders(MDB_env *env, unsigned int readers);
-
- /** @brief Get the maximum number of threads for the environment.
- *
- * @param[in] env An environment handle returned by #mdb_env_create()
- * @param[out] readers Address of an integer to store the number of readers
- * @return A non-zero error value on failure and 0 on success. Some possible
- * errors are:
- * <ul>
- * <li>EINVAL - an invalid parameter was specified.
- * </ul>
- */
-int mdb_env_get_maxreaders(MDB_env *env, unsigned int *readers);
-
- /** @brief Set the maximum number of named databases for the environment.
- *
- * This function is only needed if multiple databases will be used in the
- * environment. Simpler applications that use the environment as a single
- * unnamed database can ignore this option.
- * This function may only be called after #mdb_env_create() and before #mdb_env_open().
- * @param[in] env An environment handle returned by #mdb_env_create()
- * @param[in] dbs The maximum number of databases
- * @return A non-zero error value on failure and 0 on success. Some possible
- * errors are:
- * <ul>
- * <li>EINVAL - an invalid parameter was specified, or the environment is already open.
- * </ul>
- */
-int mdb_env_set_maxdbs(MDB_env *env, MDB_dbi dbs);
-
- /** @brief Create a transaction for use with the environment.
- *
- * The transaction handle may be discarded using #mdb_txn_abort() or #mdb_txn_commit().
- * @note Transactions may not span threads; a transaction must only be used by a
- * single thread. Also, a thread may only have a single transaction.
- * @note Cursors may not span transactions; each cursor must be opened and closed
- * within a single transaction.
- * @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 may not issue any other operations besides mdb_txn_begin,
- * mdb_txn_abort, or mdb_txn_commit while it has active child transactions.
- * @param[in] flags Special options for this transaction. This parameter
- * must be set to 0 or by bitwise OR'ing together one or more of the
- * values described here.
- * <ul>
- * <li>#MDB_RDONLY
- * This transaction will not perform any write operations.
- * </ul>
- * @param[out] txn Address where the new #MDB_txn handle will be stored
- * @return A non-zero error value on failure and 0 on success. Some possible
- * errors are:
- * <ul>
- * <li>#MDB_PANIC - a fatal error occurred earlier and the environment
- * must be shut down.
- * <li>ENOMEM - out of memory, or a read-only transaction was requested and
- * the reader lock table is full. See #mdb_env_set_maxreaders().
- * </ul>
- */
-int mdb_txn_begin(MDB_env *env, MDB_txn *parent, unsigned int flags, MDB_txn **txn);
-
- /** @brief Commit all the operations of a transaction into the database.
- *
- * All cursors opened within the transaction will be closed by this call. The cursors
- * and transaction handle will be freed and must not be used again after this call.
- * @param[in] txn A transaction handle returned by #mdb_txn_begin()
- * @return A non-zero error value on failure and 0 on success. Some possible
- * errors are:
- * <ul>
- * <li>EINVAL - an invalid parameter was specified.
- * <li>ENOSPC - no more disk space.
- * <li>EIO - a low-level I/O error occurred while writing.
- * <li>ENOMEM - the transaction is nested and could not be merged into its parent.
- * </ul>
- */
-int mdb_txn_commit(MDB_txn *txn);
-
- /** @brief Abandon all the operations of the transaction instead of saving them.
- *
- * All cursors opened within the transaction will be closed by this call. The cursors
- * and transaction handle will be freed and must not be used again after this call.
- * @param[in] txn A transaction handle returned by #mdb_txn_begin()
- */
-void mdb_txn_abort(MDB_txn *txn);
-
- /** @brief Reset a read-only transaction.
- *
- * This releases the current reader lock but doesn't free the
- * transaction handle, allowing it to be used again later by #mdb_txn_renew().
- * It otherwise has the same effect as #mdb_txn_abort() but saves some memory
- * allocation/deallocation overhead if a thread is going to start a new
- * read-only transaction again soon.
- * All cursors opened within the transaction must be closed before the transaction
- * is reset.
- * Reader locks generally don't interfere with writers, but they keep old
- * versions of database pages allocated. Thus they prevent the old pages
- * from being reused when writers commit new data, and so under heavy load
- * the database size may grow much more rapidly than otherwise.
- * @param[in] txn A transaction handle returned by #mdb_txn_begin()
- */
-void mdb_txn_reset(MDB_txn *txn);
-
- /** @brief Renew a read-only transaction.
- *
- * This acquires a new reader lock for a transaction handle that had been
- * released by #mdb_txn_reset(). It must be called before a reset transaction
- * may be used again.
- * @param[in] txn A transaction handle returned by #mdb_txn_begin()
- * @return A non-zero error value on failure and 0 on success. Some possible
- * errors are:
- * <ul>
- * <li>#MDB_PANIC - a fatal error occurred earlier and the environment
- * must be shut down.
- * <li>EINVAL - an invalid parameter was specified.
- * </ul>
- */
-int mdb_txn_renew(MDB_txn *txn);
-
- /** @brief Open a database in the environment.
- *
- * The database handle may be discarded by calling #mdb_close(). The
- * database handle resides in the shared environment, it is not owned
- * by the given transaction. Only one thread should call this function;
- * it is not mutex-protected in a read-only transaction.
- * To use named databases (with name != NULL), #mdb_env_set_maxdbs()
- * must be called before opening the enviorment.
- * @param[in] txn A transaction handle returned by #mdb_txn_begin()
- * @param[in] name The name of the database to open. If only a single
- * database is needed in the environment, this value may be NULL.
- * @param[in] flags Special options for this database. This parameter
- * must be set to 0 or by bitwise OR'ing together one or more of the
- * values described here.
- * <ul>
- * <li>#MDB_REVERSEKEY
- * Keys are strings to be compared in reverse order, from the end
- * of the strings to the beginning. By default, Keys are treated as strings and
- * compared from beginning to end.
- * <li>#MDB_DUPSORT
- * Duplicate keys may be used in the database. (Or, from another perspective,
- * keys may have multiple data items, stored in sorted order.) By default
- * keys must be unique and may have only a single data item.
- * <li>#MDB_INTEGERKEY
- * Keys are binary integers in native byte order. Setting this option
- * requires all keys to be the same size, typically sizeof(int)
- * or sizeof(size_t).
- * <li>#MDB_DUPFIXED
- * This flag may only be used in combination with #MDB_DUPSORT. This option
- * tells the library that the data items for this database are all the same
- * size, which allows further optimizations in storage and retrieval. When
- * all data items are the same size, the #MDB_GET_MULTIPLE and #MDB_NEXT_MULTIPLE
- * cursor operations may be used to retrieve multiple items at once.
- * <li>#MDB_INTEGERDUP
- * This option specifies that duplicate data items are also integers, and
- * should be sorted as such.
- * <li>#MDB_REVERSEDUP
- * This option specifies that duplicate data items should be compared as
- * strings in reverse order.
- * <li>#MDB_CREATE
- * Create the named database if it doesn't exist. This option is not
- * allowed in a read-only transaction or a read-only environment.
- * </ul>
- * @param[out] dbi Address where the new #MDB_dbi handle will be stored
- * @return A non-zero error value on failure and 0 on success. Some possible
- * errors are:
- * <ul>
- * <li>#MDB_NOTFOUND - the specified database doesn't exist in the environment
- * and #MDB_CREATE was not specified.
- * <li>ENFILE - too many databases have been opened. See #mdb_env_set_maxdbs().
- * </ul>
- */
-int mdb_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_open()
- * @param[out] stat The address of an #MDB_stat structure
- * where the statistics will be copied
- * @return A non-zero error value on failure and 0 on success. Some possible
- * errors are:
- * <ul>
- * <li>EINVAL - an invalid parameter was specified.
- * </ul>
- */
-int mdb_stat(MDB_txn *txn, MDB_dbi dbi, MDB_stat *stat);
-
- /** @brief Close a database handle.
- *
- * 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 any further.
- * @param[in] env An environment handle returned by #mdb_env_create()
- * @param[in] dbi A database handle returned by #mdb_open()
- */
-void mdb_close(MDB_env *env, MDB_dbi dbi);
-
- /** @brief Delete a database and/or free all its pages.
- *
- * If the \b del parameter is 1, the DB handle will be closed
- * and the DB will be deleted.
- * @param[in] txn A transaction handle returned by #mdb_txn_begin()
- * @param[in] dbi A database handle returned by #mdb_open()
- * @param[in] del 1 to delete the DB from the environment,
- * 0 to just free its pages.
- * @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_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_open()
- * @param[in] cmp A #MDB_cmp_func function
- * @return A non-zero error value on failure and 0 on success. Some possible
- * errors are:
- * <ul>
- * <li>EINVAL - an invalid parameter was specified.
- * </ul>
- */
-int mdb_set_compare(MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp);
-
- /** @brief Set a custom data comparison function for a #MDB_DUPSORT database.
- *
- * This comparison function is called whenever it is necessary to compare a data
- * item specified by the application with a data item currently stored in the database.
- * This function only takes effect if the database was opened with the #MDB_DUPSORT
- * flag.
- * If no comparison function is specified, and no special key flags were specified
- * with #mdb_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_open()
- * @param[in] cmp A #MDB_cmp_func function
- * @return A non-zero error value on failure and 0 on success. Some possible
- * errors are:
- * <ul>
- * <li>EINVAL - an invalid parameter was specified.
- * </ul>
- */
-int mdb_set_dupsort(MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp);
-
- /** @brief Set a relocation function for a #MDB_FIXEDMAP database.
- *
- * @todo The relocation function is called whenever it is necessary to move the data
- * of an item to a different position in the database (e.g. through tree
- * balancing operations, shifts as a result of adds or deletes, etc.). It is
- * intended to allow address/position-dependent data items to be stored in
- * a database in an environment opened with the #MDB_FIXEDMAP option.
- * Currently the relocation feature is unimplemented and setting
- * this function has no effect.
- * @param[in] txn A transaction handle returned by #mdb_txn_begin()
- * @param[in] dbi A database handle returned by #mdb_open()
- * @param[in] rel A #MDB_rel_func function
- * @return A non-zero error value on failure and 0 on success. Some possible
- * errors are:
- * <ul>
- * <li>EINVAL - an invalid parameter was specified.
- * </ul>
- */
-int mdb_set_relfunc(MDB_txn *txn, MDB_dbi dbi, MDB_rel_func *rel);
-
- /** @brief Set a context pointer for a #MDB_FIXEDMAP database's relocation function.
- *
- * See #mdb_set_relfunc and #MDB_rel_func for more details.
- * @param[in] txn A transaction handle returned by #mdb_txn_begin()
- * @param[in] dbi A database handle returned by #mdb_open()
- * @param[in] ctx An arbitrary pointer for whatever the application needs.
- * It will be passed to the callback function set by #mdb_set_relfunc
- * as its \b relctx parameter whenever the callback is invoked.
- * @return A non-zero error value on failure and 0 on success. Some possible
- * errors are:
- * <ul>
- * <li>EINVAL - an invalid parameter was specified.
- * </ul>
- */
-int mdb_set_relctx(MDB_txn *txn, MDB_dbi dbi, void *ctx);
-
- /** @brief Get items from a database.
- *
- * This function retrieves key/data pairs from the database. The address
- * and length of the data associated with the specified \b key are returned
- * in the structure to which \b data refers.
- * If the database supports duplicate keys (#MDB_DUPSORT) then the
- * first data item for the key will be returned. Retrieval of other
- * items requires the use of #mdb_cursor_get().
- *
- * @note The memory pointed to by the returned values is owned by the
- * database. The caller need not dispose of the memory, and may not
- * modify it in any way. For values returned in a read-only transaction
- * any modification attempts will cause a SIGSEGV.
- * @param[in] txn A transaction handle returned by #mdb_txn_begin()
- * @param[in] dbi A database handle returned by #mdb_open()
- * @param[in] key The key to search for in the database
- * @param[out] data The data corresponding to the key
- * @return A non-zero error value on failure and 0 on success. Some possible
- * errors are:
- * <ul>
- * <li>#MDB_NOTFOUND - the key was not in the database.
- * <li>EINVAL - an invalid parameter was specified.
- * </ul>
- */
-int mdb_get(MDB_txn *txn, MDB_dbi dbi, MDB_val *key, MDB_val *data);
-
- /** @brief Store items into a database.
- *
- * This function stores key/data pairs in the database. The default behavior
- * is to enter the new key/data pair, replacing any previously existing key
- * if duplicates are disallowed, or adding a duplicate data item if
- * duplicates are allowed (#MDB_DUPSORT).
- * @param[in] txn A transaction handle returned by #mdb_txn_begin()
- * @param[in] dbi A database handle returned by #mdb_open()
- * @param[in] key The key to store in the database
- * @param[in,out] data The data to store
- * @param[in] flags Special options for this operation. This parameter
- * must be set to 0 or by bitwise OR'ing together one or more of the
- * values described here.
- * <ul>
- * <li>#MDB_NODUPDATA - enter the new key/data pair only if it does not
- * already appear in the database. This flag may only be specified
- * if the database was opened with #MDB_DUPSORT. The function will
- * return #MDB_KEYEXIST if the key/data pair already appears in the
- * database.
- * <li>#MDB_NOOVERWRITE - enter the new key/data pair only if the key
- * does not already appear in the database. The function will return
- * #MDB_KEYEXIST if the key already appears in the database, even if
- * the database supports duplicates (#MDB_DUPSORT). The \b data
- * parameter will be set to point to the existing item.
- * <li>#MDB_RESERVE - reserve space for data of the given size, but
- * don't copy the given data. Instead, return a pointer to the
- * reserved space, which the caller can fill in later. This saves
- * an extra memcpy if the data is being generated later.
- * <li>#MDB_APPEND - append the given key/data pair to the end of the
- * database. No key comparisons are performed. This option allows
- * fast bulk loading when keys are already known to be in the
- * correct order. Loading unsorted keys with this flag will cause
- * data corruption.
- * <li>#MDB_APPENDDUP - as above, but for sorted dup data.
- * </ul>
- * @return A non-zero error value on failure and 0 on success. Some possible
- * errors are:
- * <ul>
- * <li>EACCES - an attempt was made to write in a read-only transaction.
- * <li>EINVAL - an invalid parameter was specified.
- * <li>ENOMEM - the database is full, see #mdb_env_set_mapsize().
- * </ul>
- */
-int mdb_put(MDB_txn *txn, MDB_dbi dbi, MDB_val *key, MDB_val *data,
- unsigned int flags);
-
- /** @brief Delete items from a database.
- *
- * This function removes key/data pairs from the database.
- * If the database does not support sorted duplicate data items
- * (#MDB_DUPSORT) the data parameter is ignored.
- * If the database supports sorted duplicates and the data parameter
- * is NULL, all of the duplicate data items for the key will be
- * deleted. Otherwise, if the data parameter is non-NULL
- * only the matching data item will be deleted.
- * This function will return #MDB_NOTFOUND if the specified key/data
- * pair is not in the database.
- * @param[in] txn A transaction handle returned by #mdb_txn_begin()
- * @param[in] dbi A database handle returned by #mdb_open()
- * @param[in] key The key to delete from the database
- * @param[in] data The data to delete
- * @return A non-zero error value on failure and 0 on success. Some possible
- * errors are:
- * <ul>
- * <li>EACCES - an attempt was made to write in a read-only transaction.
- * <li>EINVAL - an invalid parameter was specified.
- * </ul>
- */
-int mdb_del(MDB_txn *txn, MDB_dbi dbi, MDB_val *key, MDB_val *data);
-
- /** @brief Create a cursor handle.
- *
- * Cursors are associated with a specific transaction and database and
- * may not span threads.
- * @param[in] txn A transaction handle returned by #mdb_txn_begin()
- * @param[in] dbi A database handle returned by #mdb_open()
- * @param[out] cursor Address where the new #MDB_cursor handle will be stored
- * @return A non-zero error value on failure and 0 on success. Some possible
- * errors are:
- * <ul>
- * <li>EINVAL - an invalid parameter was specified.
- * </ul>
- */
-int mdb_cursor_open(MDB_txn *txn, MDB_dbi dbi, MDB_cursor **cursor);
-
- /** @brief Close a cursor handle.
- *
- * The cursor handle will be freed and must not be used again after this call.
- * @param[in] cursor A cursor handle returned by #mdb_cursor_open()
- */
-void mdb_cursor_close(MDB_cursor *cursor);
-
- /** @brief Renew a cursor handle.
- *
- * Cursors are associated with a specific transaction and database and
- * may not span threads. 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.
- * @param[in] txn A transaction handle returned by #mdb_txn_begin()
- * @param[in] cursor A cursor handle returned by #mdb_cursor_open()
- * @return A non-zero error value on failure and 0 on success. Some possible
- * errors are:
- * <ul>
- * <li>EINVAL - an invalid parameter was specified.
- * </ul>
- */
-int mdb_cursor_renew(MDB_txn *txn, MDB_cursor *cursor);
-
- /** @brief Return the cursor's transaction handle.
- *
- * @param[in] cursor A cursor handle returned by #mdb_cursor_open()
- */
-MDB_txn *mdb_cursor_txn(MDB_cursor *cursor);
-
- /** @brief Return the cursor's database handle.
- *
- * @param[in] cursor A cursor handle returned by #mdb_cursor_open()
- */
-MDB_dbi mdb_cursor_dbi(MDB_cursor *cursor);
-
- /** @brief Retrieve by cursor.
- *
- * This function retrieves key/data pairs from the database. The address and length
- * of the key are returned in the object to which \b key refers (except for the
- * case of the #MDB_SET option, in which the \b key object is unchanged), and
- * the address and length of the data are returned in the object to which \b data
- * refers.
- * @param[in] cursor A cursor handle returned by #mdb_cursor_open()
- * @param[in,out] key The key for a retrieved item
- * @param[in,out] data The data of a retrieved item
- * @param[in] op A cursor operation #MDB_cursor_op
- * @return A non-zero error value on failure and 0 on success. Some possible
- * errors are:
- * <ul>
- * <li>#MDB_NOTFOUND - no matching key found.
- * <li>EINVAL - an invalid parameter was specified.
- * </ul>
- */
-int mdb_cursor_get(MDB_cursor *cursor, MDB_val *key, MDB_val *data,
- MDB_cursor_op op);
-
- /** @brief Store by cursor.
- *
- * This function stores key/data pairs into the database.
- * If the function fails for any reason, the state of the cursor will be
- * unchanged. If the function succeeds and an item is inserted into the
- * database, the cursor is always positioned to refer to the newly inserted item.
- * @param[in] cursor A cursor handle returned by #mdb_cursor_open()
- * @param[in] key The key operated on.
- * @param[in] data The data operated on.
- * @param[in] flags Options for this operation. This parameter
- * must be set to 0 or one of the values described here.
- * <ul>
- * <li>#MDB_CURRENT - overwrite the data of the key/data pair to which
- * the cursor refers with the specified data item. The \b key
- * parameter is ignored.
- * <li>#MDB_NODUPDATA - enter the new key/data pair only if it does not
- * already appear in the database. This flag may only be specified
- * if the database was opened with #MDB_DUPSORT. The function will
- * return #MDB_KEYEXIST if the key/data pair already appears in the
- * database.
- * <li>#MDB_NOOVERWRITE - enter the new key/data pair only if the key
- * does not already appear in the database. The function will return
- * #MDB_KEYEXIST if the key already appears in the database, even if
- * the database supports duplicates (#MDB_DUPSORT).
- * <li>#MDB_RESERVE - reserve space for data of the given size, but
- * don't copy the given data. Instead, return a pointer to the
- * reserved space, which the caller can fill in later. This saves
- * an extra memcpy if the data is being generated later.
- * <li>#MDB_APPEND - append the given key/data pair to the end of the
- * database. No key comparisons are performed. This option allows
- * fast bulk loading when keys are already known to be in the
- * correct order. Loading unsorted keys with this flag will cause
- * data corruption.
- * <li>#MDB_APPENDDUP - as above, but for sorted dup data.
- * </ul>
- * @return A non-zero error value on failure and 0 on success. Some possible
- * errors are:
- * <ul>
- * <li>EACCES - an attempt was made to modify a read-only database.
- * <li>EINVAL - an invalid parameter was specified.
- * </ul>
- */
-int mdb_cursor_put(MDB_cursor *cursor, MDB_val *key, MDB_val *data,
- unsigned int flags);
-
- /** @brief Delete current key/data pair
- *
- * This function deletes the key/data pair to which the cursor refers.
- * @param[in] cursor A cursor handle returned by #mdb_cursor_open()
- * @param[in] flags Options for this operation. This parameter
- * must be set to 0 or one of the values described here.
- * <ul>
- * <li>#MDB_NODUPDATA - delete all of the data items for the current key.
- * This flag may only be specified if the database was opened with #MDB_DUPSORT.
- * </ul>
- * @return A non-zero error value on failure and 0 on success. Some possible
- * errors are:
- * <ul>
- * <li>EACCES - an attempt was made to modify a read-only database.
- * <li>EINVAL - an invalid parameter was specified.
- * </ul>
- */
-int mdb_cursor_del(MDB_cursor *cursor, unsigned int flags);
-
- /** @brief Return count of duplicates for current key.
- *
- * This call is only valid on databases that support sorted duplicate
- * data items #MDB_DUPSORT.
- * @param[in] cursor A cursor handle returned by #mdb_cursor_open()
- * @param[out] countp Address where the count will be stored
- * @return A non-zero error value on failure and 0 on success. Some possible
- * errors are:
- * <ul>
- * <li>EINVAL - cursor is not initialized, or an invalid parameter was specified.
- * </ul>
- */
-int mdb_cursor_count(MDB_cursor *cursor, size_t *countp);
-
- /** @brief Compare two data items according to a particular database.
- *
- * This returns a comparison as if the two data items were keys in the
- * specified database.
- * @param[in] txn A transaction handle returned by #mdb_txn_begin()
- * @param[in] dbi A database handle returned by #mdb_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
- * a sorted duplicates #MDB_DUPSORT database.
- * @param[in] txn A transaction handle returned by #mdb_txn_begin()
- * @param[in] dbi A database handle returned by #mdb_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);
-/** @} */
-
-#ifdef __cplusplus
-}
-#endif
-#endif /* _MDB_H_ */
*/
#include <stdio.h>
#include <stdlib.h>
-#include "mdb.h"
+#include "lmdb.h"
int main(int argc,char * argv[])
{
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
-#include "mdb.h"
+#include "lmdb.h"
static void prstat(MDB_stat *ms)
{
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
-#include "mdb.h"
+#include "lmdb.h"
#include "midl.h"
int main(int argc,char * argv[])
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
-#include "mdb.h"
+#include "lmdb.h"
int main(int argc,char * argv[])
{
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
-#include "mdb.h"
+#include "lmdb.h"
int main(int argc,char * argv[])
{
#include <stdlib.h>
#include <string.h>
#include <time.h>
-#include "mdb.h"
+#include "lmdb.h"
int main(int argc,char * argv[])
{
#include <stdlib.h>
#include <string.h>
#include <time.h>
-#include "mdb.h"
+#include "lmdb.h"
int main(int argc,char * argv[])
{
#include <stdlib.h>
#include <string.h>
#include <time.h>
-#include "mdb.h"
+#include "lmdb.h"
int main(int argc,char * argv[])
{
#include <stdlib.h>
#include <string.h>
#include <time.h>
-#include "mdb.h"
+#include "lmdb.h"
char dkbuf[1024];
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