mdb_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 14

#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 'September 20, 2014'

#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 }

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. 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.

mdb_lmdb.h (3)

SYNOPSIS

Data Structures

Macros

Typedefs

Enumerations

Functions

Detailed Description

Typedef Documentation

typedef mode_t \fBmdb_mode_t\fP

typedef int \fBmdb_filehandle_t\fP

Author