X-Git-Url: https://git.sur5r.net/?a=blobdiff_plain;f=libraries%2Fliblmdb%2Flmdb.h;h=fb512bf9d8165b12dd30984c53454a06167d9b1c;hb=c3d84bcd06d0017a7fad5f1d7932c590605e6369;hp=2c4c126b4a93e900c8e0887047cd50766b3ff765;hpb=8d8ad7002683689fe17b659969a6db0d300f857e;p=openldap diff --git a/libraries/liblmdb/lmdb.h b/libraries/liblmdb/lmdb.h index 2c4c126b4a..fb512bf9d8 100644 --- a/libraries/liblmdb/lmdb.h +++ b/libraries/liblmdb/lmdb.h @@ -66,6 +66,20 @@ * BSD systems or when otherwise configured with MDB_USE_POSIX_SEM. * Multiple users can cause startup to fail later, as noted above. * + * - There is normally no pure read-only mode, since readers need write + * access to locks and lock file. Exceptions: On read-only filesystems + * or with the #MDB_NOLOCK flag described under #mdb_env_open(). + * + * - By default, in versions before 0.9.10, unused portions of the data + * file might receive garbage data from memory freed by other code. + * (This does not happen when using the #MDB_WRITEMAP flag.) As of + * 0.9.10 the default behavior is to initialize such memory before + * writing to the data file. Since there may be a slight performance + * cost due to this initialization, applications may disable it using + * the #MDB_NOMEMINIT flag. Applications handling sensitive data + * which must not be written should not use this flag. This flag is + * irrelevant when using #MDB_WRITEMAP. + * * - A thread can only use one transaction at a time, plus any child * transactions. Each transaction belongs to one thread. See below. * The #MDB_NOTLS flag changes this for read-only transactions. @@ -170,7 +184,7 @@ typedef int mdb_filehandle_t; /** Library minor version */ #define MDB_VERSION_MINOR 9 /** Library patch version */ -#define MDB_VERSION_PATCH 8 +#define MDB_VERSION_PATCH 10 /** Combine args a,b,c into a single integer for easy version comparisons */ #define MDB_VERINT(a,b,c) (((a) << 24) | ((b) << 16) | (c)) @@ -180,7 +194,7 @@ 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 "August 29, 2013" +#define MDB_VERSION_DATE "November 11, 2013" /** A stringifier for the version info */ #define MDB_VERSTR(a,b,c,d) "MDB " #a "." #b "." #c ": (" d ")" @@ -216,13 +230,13 @@ typedef struct MDB_cursor MDB_cursor; /** @brief Generic structure used for passing keys and data in and out * of the database. * - * Key sizes must be between 1 and the liblmdb build-time constant - * #MDB_MAXKEYSIZE inclusive. This currently defaults to 511. The - * same applies to data sizes in databases with the #MDB_DUPSORT flag. - * Other data items can in theory be from 0 to 0xffffffff bytes long. - * * Values returned from the database are valid only until a subsequent - * update operation, or the end of the transaction. + * update operation, or the end of the transaction. Do not modify or + * free them, they commonly point into the database itself. + * + * Key sizes must be between 1 and #mdb_env_get_maxkeysize() inclusive. + * The same applies to data sizes in databases with the #MDB_DUPSORT flag. + * Other data items can in theory be from 0 to 0xffffffff bytes long. */ typedef struct MDB_val { size_t mv_size; /**< size of the data item */ @@ -265,10 +279,16 @@ typedef void (MDB_rel_func)(MDB_val *item, void *oldptr, void *newptr, void *rel #define MDB_NOMETASYNC 0x40000 /** use writable mmap */ #define MDB_WRITEMAP 0x80000 - /** use asynchronous msync when MDB_WRITEMAP is used */ + /** use asynchronous msync when #MDB_WRITEMAP is used */ #define MDB_MAPASYNC 0x100000 /** tie reader locktable slots to #MDB_txn objects instead of to threads */ #define MDB_NOTLS 0x200000 + /** don't do any locking, caller must manage their own locks */ +#define MDB_NOLOCK 0x400000 + /** don't do readahead (no effect on Windows) */ +#define MDB_NORDAHEAD 0x800000 + /** don't initialize malloc'd memory before writing to datafile */ +#define MDB_NOMEMINIT 0x1000000 /** @} */ /** @defgroup mdb_dbi_open Database Flags @@ -486,6 +506,8 @@ int mdb_env_create(MDB_env **env); * and uses fewer mallocs, but loses protection from application bugs * like wild pointer writes and other bad updates into the database. * Incompatible with nested transactions. + * Processes with and without MDB_WRITEMAP on the same environment do + * not cooperate well. *