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¶

Generated automatically by Doxygen for LMDB from the source code.

Wed Aug 16 2023

LMDB

Source file:	mdb_lmdb.h.3.en.gz (from lmdb-doc 0.9.31-1)
Source last updated:	2023-08-16T11:53:43Z
Converted to HTML:	2024-10-21T18:21:51Z