Provided by: lmdb-doc_0.9.31-1_all
NAME
lmdb.h - Lightning memory-mapped database library.
SYNOPSIS
#include <sys/types.h> Data Structures struct MDB_val Generic structure used for passing keys and data in and out of the database. struct MDB_stat Statistics for a database in the environment. struct MDB_envinfo Information about the environment. Macros #define MDB_VERSION_MAJOR 0 #define MDB_VERSION_MINOR 9 #define MDB_VERSION_PATCH 31 #define MDB_VERINT(a, b, c) (((a) << 24) | ((b) << 16) | (c)) #define MDB_VERSION_FULL MDB_VERINT(MDB_VERSION_MAJOR,MDB_VERSION_MINOR,MDB_VERSION_PATCH) #define MDB_VERSION_DATE 'July 10, 2023' #define MDB_VERSTR(a, b, c, d) 'LMDB ' #a '.' #b '.' #c ': (' d ')' #define MDB_VERFOO(a, b, c, d) MDB_VERSTR(a,b,c,d) #define MDB_VERSION_STRING MDB_VERFOO(MDB_VERSION_MAJOR,MDB_VERSION_MINOR,MDB_VERSION_PATCH,MDB_VERSION_DATE) #define MDB_FIXEDMAP 0x01 #define MDB_NOSUBDIR 0x4000 #define MDB_NOSYNC 0x10000 #define MDB_RDONLY 0x20000 #define MDB_NOMETASYNC 0x40000 #define MDB_WRITEMAP 0x80000 #define MDB_MAPASYNC 0x100000 #define MDB_NOTLS 0x200000 #define MDB_NOLOCK 0x400000 #define MDB_NORDAHEAD 0x800000 #define MDB_NOMEMINIT 0x1000000 #define MDB_REVERSEKEY 0x02 #define MDB_DUPSORT 0x04 #define MDB_INTEGERKEY 0x08 #define MDB_DUPFIXED 0x10 #define MDB_INTEGERDUP 0x20 #define MDB_REVERSEDUP 0x40 #define MDB_CREATE 0x40000 #define MDB_NOOVERWRITE 0x10 #define MDB_NODUPDATA 0x20 #define MDB_CURRENT 0x40 #define MDB_RESERVE 0x10000 #define MDB_APPEND 0x20000 #define MDB_APPENDDUP 0x40000 #define MDB_MULTIPLE 0x80000 #define MDB_CP_COMPACT 0x01 #define MDB_SUCCESS 0 #define MDB_KEYEXIST (-30799) #define MDB_NOTFOUND (-30798) #define MDB_PAGE_NOTFOUND (-30797) #define MDB_CORRUPTED (-30796) #define MDB_PANIC (-30795) #define MDB_VERSION_MISMATCH (-30794) #define MDB_INVALID (-30793) #define MDB_MAP_FULL (-30792) #define MDB_DBS_FULL (-30791) #define MDB_READERS_FULL (-30790) #define MDB_TLS_FULL (-30789) #define MDB_TXN_FULL (-30788) #define MDB_CURSOR_FULL (-30787) #define MDB_PAGE_FULL (-30786) #define MDB_MAP_RESIZED (-30785) #define MDB_INCOMPATIBLE (-30784) #define MDB_BAD_RSLOT (-30783) #define MDB_BAD_TXN (-30782) #define MDB_BAD_VALSIZE (-30781) #define MDB_BAD_DBI (-30780) #define MDB_LAST_ERRCODE MDB_BAD_DBI #define mdb_open(txn, name, flags, dbi) mdb_dbi_open(txn,name,flags,dbi) #define mdb_close(env, dbi) mdb_dbi_close(env,dbi) Typedefs typedef mode_t mdb_mode_t typedef int mdb_filehandle_t typedef unsigned int MDB_dbi A handle for an individual database in the DB environment. typedef int() MDB_cmp_func(const MDB_val *a, const MDB_val *b) A callback function used to compare two keys in a database. typedef void() MDB_rel_func(MDB_val *item, void *oldptr, void *newptr, void *relctx) A callback function used to relocate a position-dependent data item in a fixed-address database. typedef void MDB_assert_func(MDB_env *env, const char *msg) A callback function for most LMDB assert() failures, called before printing the message and aborting. typedef int() MDB_msg_func(const char *msg, void *ctx) A callback function used to print a message from the library. Enumerations enum MDB_cursor_op { MDB_FIRST, MDB_FIRST_DUP, MDB_GET_BOTH, MDB_GET_BOTH_RANGE, MDB_GET_CURRENT, MDB_GET_MULTIPLE, MDB_LAST, MDB_LAST_DUP, MDB_NEXT, MDB_NEXT_DUP, MDB_NEXT_MULTIPLE, MDB_NEXT_NODUP, MDB_PREV, MDB_PREV_DUP, MDB_PREV_NODUP, MDB_SET, MDB_SET_KEY, MDB_SET_RANGE, MDB_PREV_MULTIPLE } Cursor Get operations. Functions char * mdb_version (int *major, int *minor, int *patch) Return the LMDB library version information. char * mdb_strerror (int err) Return a string describing a given error code. int mdb_env_create (MDB_env **env) Create an LMDB environment handle. int mdb_env_open (MDB_env *env, const char *path, unsigned int flags, mdb_mode_t mode) Open an environment handle. int mdb_env_copy (MDB_env *env, const char *path) Copy an LMDB environment to the specified path. int mdb_env_copyfd (MDB_env *env, mdb_filehandle_t fd) Copy an LMDB environment to the specified file descriptor. int mdb_env_copy2 (MDB_env *env, const char *path, unsigned int flags) Copy an LMDB environment to the specified path, with options. int mdb_env_copyfd2 (MDB_env *env, mdb_filehandle_t fd, unsigned int flags) Copy an LMDB environment to the specified file descriptor, with options. int mdb_env_stat (MDB_env *env, MDB_stat *stat) Return statistics about the LMDB environment. int mdb_env_info (MDB_env *env, MDB_envinfo *stat) Return information about the LMDB environment. int mdb_env_sync (MDB_env *env, int force) Flush the data buffers to disk. void mdb_env_close (MDB_env *env) Close the environment and release the memory map. int mdb_env_set_flags (MDB_env *env, unsigned int flags, int onoff) Set environment flags. int mdb_env_get_flags (MDB_env *env, unsigned int *flags) Get environment flags. int mdb_env_get_path (MDB_env *env, const char **path) Return the path that was used in mdb_env_open(). int mdb_env_get_fd (MDB_env *env, mdb_filehandle_t *fd) Return the filedescriptor for the given environment. int mdb_env_set_mapsize (MDB_env *env, size_t size) Set the size of the memory map to use for this environment. int mdb_env_set_maxreaders (MDB_env *env, unsigned int readers) Set the maximum number of threads/reader slots for the environment. int mdb_env_get_maxreaders (MDB_env *env, unsigned int *readers) Get the maximum number of threads/reader slots for the environment. int mdb_env_set_maxdbs (MDB_env *env, MDB_dbi dbs) Set the maximum number of named databases for the environment. int mdb_env_get_maxkeysize (MDB_env *env) Get the maximum size of keys and MDB_DUPSORT data we can write. int mdb_env_set_userctx (MDB_env *env, void *ctx) Set application information associated with the MDB_env. void * mdb_env_get_userctx (MDB_env *env) Get the application information associated with the MDB_env. int mdb_env_set_assert (MDB_env *env, MDB_assert_func *func) int mdb_txn_begin (MDB_env *env, MDB_txn *parent, unsigned int flags, MDB_txn **txn) Create a transaction for use with the environment. MDB_env * mdb_txn_env (MDB_txn *txn) Returns the transaction's MDB_env. size_t mdb_txn_id (MDB_txn *txn) Return the transaction's ID. int mdb_txn_commit (MDB_txn *txn) Commit all the operations of a transaction into the database. void mdb_txn_abort (MDB_txn *txn) Abandon all the operations of the transaction instead of saving them. void mdb_txn_reset (MDB_txn *txn) Reset a read-only transaction. int mdb_txn_renew (MDB_txn *txn) Renew a read-only transaction. int mdb_dbi_open (MDB_txn *txn, const char *name, unsigned int flags, MDB_dbi *dbi) Open a database in the environment. int mdb_stat (MDB_txn *txn, MDB_dbi dbi, MDB_stat *stat) Retrieve statistics for a database. int mdb_dbi_flags (MDB_txn *txn, MDB_dbi dbi, unsigned int *flags) Retrieve the DB flags for a database handle. void mdb_dbi_close (MDB_env *env, MDB_dbi dbi) Close a database handle. Normally unnecessary. Use with care: int mdb_drop (MDB_txn *txn, MDB_dbi dbi, int del) Empty or delete+close a database. int mdb_set_compare (MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp) Set a custom key comparison function for a database. int mdb_set_dupsort (MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp) Set a custom data comparison function for a MDB_DUPSORT database. int mdb_set_relfunc (MDB_txn *txn, MDB_dbi dbi, MDB_rel_func *rel) Set a relocation function for a MDB_FIXEDMAP database. int mdb_set_relctx (MDB_txn *txn, MDB_dbi dbi, void *ctx) Set a context pointer for a MDB_FIXEDMAP database's relocation function. int mdb_get (MDB_txn *txn, MDB_dbi dbi, MDB_val *key, MDB_val *data) Get items from a database. int mdb_put (MDB_txn *txn, MDB_dbi dbi, MDB_val *key, MDB_val *data, unsigned int flags) Store items into a database. int mdb_del (MDB_txn *txn, MDB_dbi dbi, MDB_val *key, MDB_val *data) Delete items from a database. int mdb_cursor_open (MDB_txn *txn, MDB_dbi dbi, MDB_cursor **cursor) Create a cursor handle. void mdb_cursor_close (MDB_cursor *cursor) Close a cursor handle. int mdb_cursor_renew (MDB_txn *txn, MDB_cursor *cursor) Renew a cursor handle. MDB_txn * mdb_cursor_txn (MDB_cursor *cursor) Return the cursor's transaction handle. MDB_dbi mdb_cursor_dbi (MDB_cursor *cursor) Return the cursor's database handle. int mdb_cursor_get (MDB_cursor *cursor, MDB_val *key, MDB_val *data, MDB_cursor_op op) Retrieve by cursor. int mdb_cursor_put (MDB_cursor *cursor, MDB_val *key, MDB_val *data, unsigned int flags) Store by cursor. int mdb_cursor_del (MDB_cursor *cursor, unsigned int flags) Delete current key/data pair. int mdb_cursor_count (MDB_cursor *cursor, size_t *countp) Return count of duplicates for current key. int mdb_cmp (MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b) Compare two data items according to a particular database. int mdb_dcmp (MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b) Compare two data items according to a particular database. int mdb_reader_list (MDB_env *env, MDB_msg_func *func, void *ctx) Dump the entries in the reader lock table. int mdb_reader_check (MDB_env *env, int *dead) Check for stale entries in the reader lock table.
Detailed Description
Lightning memory-mapped database library.
Typedef Documentation
typedef mode_t mdb_mode_t Unix permissions for creating files, or dummy definition for Windows typedef int mdb_filehandle_t An abstraction for a file handle. On POSIX systems file handles are small integers. On Windows they're opaque pointers.
Author
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