diff options
Diffstat (limited to 'contrib/lmdb/lmdb.h')
| -rw-r--r-- | contrib/lmdb/lmdb.h | 30 |
1 files changed, 22 insertions, 8 deletions
diff --git a/contrib/lmdb/lmdb.h b/contrib/lmdb/lmdb.h index c4d05d17..29135b7f 100644 --- a/contrib/lmdb/lmdb.h +++ b/contrib/lmdb/lmdb.h @@ -77,6 +77,11 @@ * access to locks and lock file. Exceptions: On read-only filesystems * or with the #MDB_NOLOCK flag described under #mdb_env_open(). * + * - An LMDB configuration will often reserve considerable \b unused + * memory address space and maybe file size for future growth. + * This does not use actual memory or disk space, but users may need + * to understand the difference so they won't be scared off. + * * - By default, in versions before 0.9.10, unused portions of the data * file might receive garbage data from memory freed by other code. * (This does not happen when using the #MDB_WRITEMAP flag.) As of @@ -91,11 +96,12 @@ * transactions. Each transaction belongs to one thread. See below. * The #MDB_NOTLS flag changes this for read-only transactions. * - * - Use an MDB_env* in the process which opened it, without fork()ing. + * - Use an MDB_env* in the process which opened it, not after fork(). * * - Do not have open an LMDB database twice in the same process at * the same time. Not even from a plain open() call - close()ing it - * breaks flock() advisory locking. + * breaks fcntl() advisory locking. (It is OK to reopen it after + * fork() - exec*(), since the lockfile has FD_CLOEXEC set.) * * - Avoid long-lived transactions. Read transactions prevent * reuse of pages freed by newer write transactions, thus the @@ -129,7 +135,7 @@ * * @author Howard Chu, Symas Corporation. * - * @copyright Copyright 2011-2016 Howard Chu, Symas Corp. All rights reserved. + * @copyright Copyright 2011-2017 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 @@ -194,7 +200,7 @@ typedef int mdb_filehandle_t; /** Library minor version */ #define MDB_VERSION_MINOR 9 /** Library patch version */ -#define MDB_VERSION_PATCH 18 +#define MDB_VERSION_PATCH 21 /** Combine args a,b,c into a single integer for easy version comparisons */ #define MDB_VERINT(a,b,c) (((a) << 24) | ((b) << 16) | (c)) @@ -204,7 +210,7 @@ typedef int mdb_filehandle_t; MDB_VERINT(MDB_VERSION_MAJOR,MDB_VERSION_MINOR,MDB_VERSION_PATCH) /** The release date of this library version */ -#define MDB_VERSION_DATE "February 5, 2016" +#define MDB_VERSION_DATE "June 1, 2017" /** A stringifier for the version info */ #define MDB_VERSTR(a,b,c,d) "LMDB " #a "." #b "." #c ": (" d ")" @@ -383,7 +389,9 @@ typedef enum MDB_cursor_op { MDB_PREV_NODUP, /**< Position at last data item of previous key */ MDB_SET, /**< Position at specified key */ MDB_SET_KEY, /**< Position at specified key, return key + data */ - MDB_SET_RANGE /**< Position at first key greater than or equal to specified key. */ + MDB_SET_RANGE, /**< Position at first key greater than or equal to specified key. */ + MDB_PREV_MULTIPLE /**< Position at previous page and return key and up to + a page of duplicate data items. Only for #MDB_DUPFIXED */ } MDB_cursor_op; /** @defgroup errors Return Codes @@ -672,6 +680,7 @@ int mdb_env_copyfd(MDB_env *env, mdb_filehandle_t fd); * <li>#MDB_CP_COMPACT - Perform compaction while copying: omit free * pages and sequentially renumber all pages in output. This option * consumes more CPU and runs more slowly than the default. + * Currently it fails if the environment has suffered a page leak. * </ul> * @return A non-zero error value on failure and 0 on success. */ @@ -787,6 +796,10 @@ int mdb_env_get_path(MDB_env *env, const char **path); /** @brief Return the filedescriptor for the given environment. * + * This function may be called after fork(), so the descriptor can be + * closed before exec*(). Other LMDB file descriptors have FD_CLOEXEC. + * (Until LMDB 0.9.18, only the lockfile had that.) + * * @param[in] env An environment handle returned by #mdb_env_create() * @param[out] fd Address of a mdb_filehandle_t to contain the descriptor. * @return A non-zero error value on failure and 0 on success. Some possible @@ -1090,8 +1103,9 @@ int mdb_txn_renew(MDB_txn *txn); * 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. + * all data items are the same size, the #MDB_GET_MULTIPLE, #MDB_NEXT_MULTIPLE + * and #MDB_PREV_MULTIPLE cursor operations may be used to retrieve multiple + * items at once. * <li>#MDB_INTEGERDUP * This option specifies that duplicate data items are binary integers, * similar to #MDB_INTEGERKEY keys. |