Lightning memory-mapped database library. More...

#include <sys/types.h>

Data Structures
struct	MDB_val
	Generic structure used for passing keys and data in and out of the database. More...

struct	MDB_stat
	Statistics for a database in the environment. More...

struct	MDB_envinfo
	Information about the environment. More...

Macros
#define	MDB_VERSION_MAJOR 0

#define	MDB_VERSION_MINOR 9

#define	MDB_VERSION_PATCH 18

#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 "December 19, 2015"

#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. More...

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.

Data Structures

Macros

Typedefs

Enumerations

Functions

Detailed Description

Typedef Documentation