Classes
struct	MDBX_stat
	Statistics for a database in the environment. More...

struct	MDBX_envinfo
	Information about the environment. More...

struct	MDBX_txn_info
	Information about the transaction. More...

Typedefs
typedef enum MDBX_dbi_state_t	MDBX_dbi_state_t

typedef int()	MDBX_reader_list_func(void *ctx, int num, int slot, mdbx_pid_t pid, mdbx_tid_t thread, uint64_t txnid, uint64_t lag, size_t bytes_used, size_t bytes_retained) MDBX_CXX17_NOEXCEPT
	A callback function used to enumerate the reader lock table. More...

Enumerations
enum	MDBX_dbi_state_t { MDBX_DBI_DIRTY = 0x01, MDBX_DBI_STALE = 0x02, MDBX_DBI_FRESH = 0x04, MDBX_DBI_CREAT = 0x08 }
	DBI state bits returted by mdbx_dbi_flags_ex() More...

Functions
LIBMDBX_API int	mdbx_env_stat_ex (const MDBX_env env, const MDBX_txn txn, MDBX_stat *stat, size_t bytes)
	Return statistics about the MDBX environment. More...

MDBX_DEPRECATED int	mdbx_env_stat (const MDBX_env env, MDBX_stat stat, size_t bytes)
	Return statistics about the MDBX environment. More...

LIBMDBX_API int	mdbx_env_info_ex (const MDBX_env env, const MDBX_txn txn, MDBX_envinfo *info, size_t bytes)
	Return information about the MDBX environment. More...

MDBX_DEPRECATED int	mdbx_env_info (const MDBX_env env, MDBX_envinfo info, size_t bytes)
	Return information about the MDBX environment. More...

int	mdbx_env_get_syncbytes (const MDBX_env env, size_t threshold)
	Get threshold to force flush the data buffers to disk, even any of MDBX_SAFE_NOSYNC flag in the environment. More...

int	mdbx_env_get_syncperiod (const MDBX_env env, unsigned period_seconds_16dot16)
	Get relative period since the last unsteady commit to force flush the data buffers to disk, even of MDBX_SAFE_NOSYNC flag in the environment. More...

LIBMDBX_API int	mdbx_env_get_flags (const MDBX_env env, unsigned flags)
	Get environment flags. More...

LIBMDBX_API int	mdbx_env_get_path (const MDBX_env env, const char *dest)
	Return the path that was used in mdbx_env_open(). More...

LIBMDBX_API int	mdbx_env_get_fd (const MDBX_env env, mdbx_filehandle_t fd)
	Return the file descriptor for the given environment. More...

MDBX_NOTHROW_CONST_FUNCTION intptr_t	mdbx_limits_pgsize_min (void)
	Returns the minimal database page size in bytes. More...

MDBX_NOTHROW_CONST_FUNCTION intptr_t	mdbx_limits_pgsize_max (void)
	Returns the maximal database page size in bytes. More...

MDBX_NOTHROW_CONST_FUNCTION LIBMDBX_API intptr_t	mdbx_limits_dbsize_min (intptr_t pagesize)
	Returns minimal database size in bytes for given page size, or -1 if pagesize is invalid. More...

MDBX_NOTHROW_CONST_FUNCTION LIBMDBX_API intptr_t	mdbx_limits_dbsize_max (intptr_t pagesize)
	Returns maximal database size in bytes for given page size, or -1 if pagesize is invalid. More...

MDBX_NOTHROW_CONST_FUNCTION LIBMDBX_API intptr_t	mdbx_limits_keysize_max (intptr_t pagesize, MDBX_db_flags_t flags)
	Returns maximal key size in bytes for given page size and database flags, or -1 if pagesize is invalid. More...

MDBX_NOTHROW_CONST_FUNCTION LIBMDBX_API intptr_t	mdbx_limits_valsize_max (intptr_t pagesize, MDBX_db_flags_t flags)
	Returns maximal data size in bytes for given page size and database flags, or -1 if pagesize is invalid. More...

MDBX_NOTHROW_CONST_FUNCTION LIBMDBX_API intptr_t	mdbx_limits_txnsize_max (intptr_t pagesize)
	Returns maximal write transaction size (i.e. limit for summary volume of dirty pages) in bytes for given page size, or -1 if pagesize is invalid. More...

int	mdbx_env_get_maxreaders (const MDBX_env env, unsigned readers)
	Get the maximum number of threads/reader slots for the environment. More...

int	mdbx_env_get_maxdbs (const MDBX_env env, MDBX_dbi dbs)
	Get the maximum number of named databases for the environment. More...

MDBX_NOTHROW_PURE_FUNCTION LIBMDBX_API size_t	mdbx_default_pagesize (void)
	Returns the default size of database page for the current system. More...

LIBMDBX_API int	mdbx_get_sysraminfo (intptr_t page_size, intptr_t total_pages, intptr_t *avail_pages)
	Returns basic information about system RAM. This function provides a portable way to get information about available RAM and can be useful in that it returns the same information that libmdbx uses internally to adjust various options and control readahead. More...

MDBX_NOTHROW_PURE_FUNCTION LIBMDBX_API int	mdbx_env_get_maxkeysize_ex (const MDBX_env *env, MDBX_db_flags_t flags)
	Returns the maximum size of keys can put. More...

MDBX_NOTHROW_PURE_FUNCTION LIBMDBX_API int	mdbx_env_get_maxvalsize_ex (const MDBX_env *env, MDBX_db_flags_t flags)
	Returns the maximum size of data we can put. More...

MDBX_NOTHROW_PURE_FUNCTION MDBX_DEPRECATED LIBMDBX_API int	mdbx_env_get_maxkeysize (const MDBX_env *env)

MDBX_NOTHROW_PURE_FUNCTION LIBMDBX_API void *	mdbx_env_get_userctx (const MDBX_env *env)
	Returns an application information (a context pointer) associated with the environment. More...

LIBMDBX_API int	mdbx_txn_info (const MDBX_txn txn, MDBX_txn_info info, bool scan_rlt)
	Return information about the MDBX transaction. More...

MDBX_NOTHROW_PURE_FUNCTION LIBMDBX_API uint64_t	mdbx_txn_id (const MDBX_txn *txn)
	Return the transaction's ID. More...

LIBMDBX_API int	mdbx_txn_commit_ex (MDBX_txn txn, MDBX_commit_latency latency)
	Commit all the operations of a transaction into the database and collect latency information. More...

LIBMDBX_API int	mdbx_dbi_stat (MDBX_txn txn, MDBX_dbi dbi, MDBX_stat stat, size_t bytes)
	Retrieve statistics for a database. More...

LIBMDBX_API int	mdbx_dbi_dupsort_depthmask (MDBX_txn txn, MDBX_dbi dbi, uint32_t mask)
	Retrieve depth (bitmask) information of nested dupsort (multi-value) B+trees for given database. More...

LIBMDBX_API int	mdbx_dbi_flags_ex (MDBX_txn txn, MDBX_dbi dbi, unsigned flags, unsigned *state)
	Retrieve the DB flags and status for a database handle. More...

int	mdbx_dbi_flags (MDBX_txn txn, MDBX_dbi dbi, unsigned flags)
	The shortcut to calling mdbx_dbi_flags_ex() with `state=NULL` for discarding it result. More...

MDBX_NOTHROW_PURE_FUNCTION LIBMDBX_API int	mdbx_is_dirty (const MDBX_txn txn, const void ptr)
	Determines whether the given address is on a dirty database page of the transaction or not. More...

LIBMDBX_API int	mdbx_reader_list (const MDBX_env env, MDBX_reader_list_func func, void *ctx)
	Enumerate the entries in the reader lock table. More...

MDBX_DEPRECATED LIBMDBX_API int	mdbx_txn_straggler (const MDBX_txn txn, int percent)
	Returns a lag of the reading for the given transaction. More...

Detailed Description

Typedef Documentation

◆ MDBX_dbi_state_t

typedef enum MDBX_dbi_state_t MDBX_dbi_state_t

◆ MDBX_reader_list_func

typedef int() MDBX_reader_list_func(void *ctx, int num, int slot, mdbx_pid_t pid, mdbx_tid_t thread, uint64_t txnid, uint64_t lag, size_t bytes_used, size_t bytes_retained) MDBX_CXX17_NOEXCEPT

A callback function used to enumerate the reader lock table.

Parameters

[in]	ctx	An arbitrary context pointer for the callback.
[in]	num	The serial number during enumeration, starting from 1.
[in]	slot	The reader lock table slot number.
[in]	txnid	The ID of the transaction being read, i.e. the MVCC-snapshot number.
[in]	lag	The lag from a recent MVCC-snapshot, i.e. the number of committed write transactions since the current read transaction started.
[in]	pid	The reader process ID.
[in]	thread	The reader thread ID.
[in]	bytes_used	The number of last used page in the MVCC-snapshot which being read, i.e. database file can't shrinked beyond this.
[in]	bytes_retired	The total size of the database pages that were retired by committed write transactions after the reader's MVCC-snapshot, i.e. the space which would be freed after the Reader releases the MVCC-snapshot for reuse by completion read transaction.

Returns: < 0 on failure, >= 0 on success.

See also: mdbx_reader_list()

Enumeration Type Documentation

◆ MDBX_dbi_state_t

enum MDBX_dbi_state_t

DBI state bits returted by mdbx_dbi_flags_ex()

See also: mdbx_dbi_flags_ex()

Enumerator
MDBX_DBI_DIRTY	DB was written in this txn
MDBX_DBI_STALE	Named-DB record is older than txnID
MDBX_DBI_FRESH	Named-DB handle opened in this txn
MDBX_DBI_CREAT	Named-DB handle created in this txn

Function Documentation

◆ mdbx_dbi_dupsort_depthmask()

LIBMDBX_API int mdbx_dbi_dupsort_depthmask	(	MDBX_txn *	txn,
		MDBX_dbi	dbi,
		uint32_t *	mask
	)

Retrieve depth (bitmask) information of nested dupsort (multi-value) B+trees for given database.

Parameters

[in]	txn	A transaction handle returned by mdbx_txn_begin().
[in]	dbi	A database handle returned by mdbx_dbi_open().
[out]	mask	The address of an uint32_t value where the bitmask will be stored.

Returns: A non-zero error value on failure and 0 on success, some possible errors are:

Return values

MDBX_THREAD_MISMATCH	Given transaction is not owned by current thread.
MDBX_EINVAL	An invalid parameter was specified.
MDBX_RESULT_TRUE	The dbi isn't a dupsort (multi-value) database.

◆ mdbx_dbi_flags()

int mdbx_dbi_flags	(	MDBX_txn *	txn,
		MDBX_dbi	dbi,
		unsigned *	flags
	)

inline

The shortcut to calling mdbx_dbi_flags_ex() with state=NULL for discarding it result.

◆ mdbx_dbi_flags_ex()

LIBMDBX_API int mdbx_dbi_flags_ex	(	MDBX_txn *	txn,
		MDBX_dbi	dbi,
		unsigned *	flags,
		unsigned *	state
	)

Retrieve the DB flags and status for a database handle.

Parameters

[in]	txn	A transaction handle returned by mdbx_txn_begin().
[in]	dbi	A database handle returned by mdbx_dbi_open().
[out]	flags	Address where the flags will be returned.
[out]	state	Address where the state will be returned.

Returns: A non-zero error value on failure and 0 on success.

◆ mdbx_dbi_stat()

LIBMDBX_API int mdbx_dbi_stat	(	MDBX_txn *	txn,
		MDBX_dbi	dbi,
		MDBX_stat *	stat,
		size_t	bytes
	)

Retrieve statistics for a database.

Parameters

[in]	txn	A transaction handle returned by mdbx_txn_begin().
[in]	dbi	A database handle returned by mdbx_dbi_open().
[out]	stat	The address of an MDBX_stat structure where the statistics will be copied.
[in]	bytes	The size of MDBX_stat.

Returns: A non-zero error value on failure and 0 on success, some possible errors are:

Return values

MDBX_THREAD_MISMATCH	Given transaction is not owned by current thread.
MDBX_EINVAL	An invalid parameter was specified.

◆ mdbx_default_pagesize()

MDBX_NOTHROW_PURE_FUNCTION LIBMDBX_API size_t mdbx_default_pagesize ( void )

Returns the default size of database page for the current system.

Default size of database page depends on the size of the system page and usually exactly match it.

◆ mdbx_env_get_fd()

LIBMDBX_API int mdbx_env_get_fd	(	const MDBX_env *	env,
		mdbx_filehandle_t *	fd
	)

Return the file descriptor for the given environment.

Note: All MDBX file descriptors have FD_CLOEXEC and couldn't be used after exec() and or fork().

Parameters

[in]	env	An environment handle returned by mdbx_env_create().
[out]	fd	Address of a int to contain the descriptor.

Returns: A non-zero error value on failure and 0 on success, some possible errors are:

Return values

MDBX_EINVAL An invalid parameter was specified.

◆ mdbx_env_get_flags()

LIBMDBX_API int mdbx_env_get_flags	(	const MDBX_env *	env,
		unsigned *	flags
	)

Get environment flags.

See also: mdbx_env_set_flags()

Parameters

[in]	env	An environment handle returned by mdbx_env_create().
[out]	flags	The address of an integer to store the flags.

Returns: A non-zero error value on failure and 0 on success, some possible errors are:

Return values

MDBX_EINVAL An invalid parameter was specified.

◆ mdbx_env_get_maxdbs()

int mdbx_env_get_maxdbs	(	const MDBX_env *	env,
		MDBX_dbi *	dbs
	)

inline

Get the maximum number of named databases for the environment.

See also: mdbx_env_set_maxdbs()

Parameters

[in]	env	An environment handle returned by mdbx_env_create().
[out]	dbs	Address to store the maximum number of databases.

Returns: A non-zero error value on failure and 0 on success, some possible errors are:

Return values

MDBX_EINVAL An invalid parameter was specified.

◆ mdbx_env_get_maxkeysize()

MDBX_NOTHROW_PURE_FUNCTION MDBX_DEPRECATED LIBMDBX_API int mdbx_env_get_maxkeysize ( const MDBX_env * env )

Deprecated:: Please use mdbx_env_get_maxkeysize_ex() and/or mdbx_env_get_maxvalsize_ex()

◆ mdbx_env_get_maxkeysize_ex()

MDBX_NOTHROW_PURE_FUNCTION LIBMDBX_API int mdbx_env_get_maxkeysize_ex	(	const MDBX_env *	env,
		MDBX_db_flags_t	flags
	)

Returns the maximum size of keys can put.

Parameters

[in]	env	An environment handle returned by mdbx_env_create().
[in]	flags	Database options (MDBX_DUPSORT, MDBX_INTEGERKEY and so on).

See also: db_flags

Returns: The maximum size of a key can write, or -1 if something is wrong.

◆ mdbx_env_get_maxreaders()

int mdbx_env_get_maxreaders	(	const MDBX_env *	env,
		unsigned *	readers
	)

inline

Get the maximum number of threads/reader slots for the environment.

See also: mdbx_env_set_maxreaders()

Parameters

[in]	env	An environment handle returned by mdbx_env_create().
[out]	readers	Address of an integer to store the number of readers.

Returns: A non-zero error value on failure and 0 on success, some possible errors are:

Return values

MDBX_EINVAL An invalid parameter was specified.

◆ mdbx_env_get_maxvalsize_ex()

MDBX_NOTHROW_PURE_FUNCTION LIBMDBX_API int mdbx_env_get_maxvalsize_ex	(	const MDBX_env *	env,
		MDBX_db_flags_t	flags
	)

Returns the maximum size of data we can put.

Parameters

[in]	env	An environment handle returned by mdbx_env_create().
[in]	flags	Database options (MDBX_DUPSORT, MDBX_INTEGERKEY and so on).

See also: db_flags

Returns: The maximum size of a data can write, or -1 if something is wrong.

◆ mdbx_env_get_path()

LIBMDBX_API int mdbx_env_get_path	(	const MDBX_env *	env,
		const char **	dest
	)

Return the path that was used in mdbx_env_open().

Parameters

[in]	env	An environment handle returned by mdbx_env_create()
[out]	dest	Address of a string pointer to contain the path. This is the actual string in the environment, not a copy. It should not be altered in any way.

Returns: A non-zero error value on failure and 0 on success, some possible errors are:

Return values

MDBX_EINVAL An invalid parameter was specified.

◆ mdbx_env_get_syncbytes()

int mdbx_env_get_syncbytes	(	const MDBX_env *	env,
		size_t *	threshold
	)

inline

Get threshold to force flush the data buffers to disk, even any of MDBX_SAFE_NOSYNC flag in the environment.

See also: mdbx_env_set_syncbytes(); MDBX_opt_sync_bytes

Parameters

[in]	env	An environment handle returned by mdbx_env_create().
[out]	threshold	Address of an size_t to store the number of bytes of summary changes when a synchronous flush would be made.

Returns: A non-zero error value on failure and 0 on success, some possible errors are:

Return values

MDBX_EINVAL An invalid parameter was specified.

◆ mdbx_env_get_syncperiod()

int mdbx_env_get_syncperiod	(	const MDBX_env *	env,
		unsigned *	period_seconds_16dot16
	)

inline

Get relative period since the last unsteady commit to force flush the data buffers to disk, even of MDBX_SAFE_NOSYNC flag in the environment.

See also: mdbx_env_set_syncperiod(); MDBX_opt_sync_period

Parameters

[in]	env	An environment handle returned by mdbx_env_create().
[out]	period_seconds_16dot16	Address of an size_t to store the period in 1/65536 of second when a synchronous flush would be made since the last unsteady commit.

Returns: A non-zero error value on failure and 0 on success, some possible errors are:

Return values

MDBX_EINVAL An invalid parameter was specified.

◆ mdbx_env_get_userctx()

MDBX_NOTHROW_PURE_FUNCTION LIBMDBX_API void* mdbx_env_get_userctx ( const MDBX_env * env )

Returns an application information (a context pointer) associated with the environment.

See also: mdbx_env_set_userctx()

Parameters

[in] env An environment handle returned by mdbx_env_create()

Returns: The pointer set by mdbx_env_set_userctx() or NULL if something wrong.

◆ mdbx_env_info()

MDBX_DEPRECATED int mdbx_env_info	(	const MDBX_env *	env,
		MDBX_envinfo *	info,
		size_t	bytes
	)

inline

Return information about the MDBX environment.

Deprecated:: Please use mdbx_env_info_ex() instead.

◆ mdbx_env_info_ex()

LIBMDBX_API int mdbx_env_info_ex	(	const MDBX_env *	env,
		const MDBX_txn *	txn,
		MDBX_envinfo *	info,
		size_t	bytes
	)

Return information about the MDBX environment.

At least one of env or txn argument must be non-null. If txn is passed non-null then stat will be filled accordingly to the given transaction. Otherwise, if txn is null, then stat will be populated by a snapshot from the last committed write transaction, and at next time, other information can be returned.

Legacy mdbx_env_info() correspond to calling mdbx_env_info_ex() with the null txn argument.

Parameters

[in]	env	An environment handle returned by mdbx_env_create()
[in]	txn	A transaction handle returned by mdbx_txn_begin()
[out]	info	The address of an MDBX_envinfo structure where the information will be copied
[in]	bytes	The size of MDBX_envinfo.

Returns: A non-zero error value on failure and 0 on success.

◆ mdbx_env_stat()

MDBX_DEPRECATED int mdbx_env_stat	(	const MDBX_env *	env,
		MDBX_stat *	stat,
		size_t	bytes
	)

inline

Return statistics about the MDBX environment.

Deprecated:: Please use mdbx_env_stat_ex() instead.

◆ mdbx_env_stat_ex()

LIBMDBX_API int mdbx_env_stat_ex	(	const MDBX_env *	env,
		const MDBX_txn *	txn,
		MDBX_stat *	stat,
		size_t	bytes
	)

Return statistics about the MDBX environment.

At least one of env or txn argument must be non-null. If txn is passed non-null then stat will be filled accordingly to the given transaction. Otherwise, if txn is null, then stat will be populated by a snapshot from the last committed write transaction, and at next time, other information can be returned.

Legacy mdbx_env_stat() correspond to calling mdbx_env_stat_ex() with the null txn argument.

Parameters

[in]	env	An environment handle returned by mdbx_env_create()
[in]	txn	A transaction handle returned by mdbx_txn_begin()
[out]	stat	The address of an MDBX_stat structure where the statistics will be copied
[in]	bytes	The size of MDBX_stat.

Returns: A non-zero error value on failure and 0 on success.

◆ mdbx_get_sysraminfo()

LIBMDBX_API int mdbx_get_sysraminfo	(	intptr_t *	page_size,
		intptr_t *	total_pages,
		intptr_t *	avail_pages
	)

Returns basic information about system RAM. This function provides a portable way to get information about available RAM and can be useful in that it returns the same information that libmdbx uses internally to adjust various options and control readahead.

Parameters

[out]	page_size	Optional address where the system page size will be stored.
[out]	total_pages	Optional address where the number of total RAM pages will be stored.
[out]	avail_pages	Optional address where the number of available/free RAM pages will be stored.

Returns: A non-zero error value on failure and 0 on success.

◆ mdbx_is_dirty()

MDBX_NOTHROW_PURE_FUNCTION LIBMDBX_API int mdbx_is_dirty	(	const MDBX_txn *	txn,
		const void *	ptr
	)

Determines whether the given address is on a dirty database page of the transaction or not.

Ultimately, this allows to avoid copy data from non-dirty pages.

"Dirty" pages are those that have already been changed during a write transaction. Accordingly, any further changes may result in such pages being overwritten. Therefore, all functions libmdbx performing changes inside the database as arguments should NOT get pointers to data in those pages. In turn, "not dirty" pages before modification will be copied.

In other words, data from dirty pages must either be copied before being passed as arguments for further processing or rejected at the argument validation stage. Thus, mdbx_is_dirty() allows you to get rid of unnecessary copying, and perform a more complete check of the arguments.

Note: The address passed must point to the beginning of the data. This is the only way to ensure that the actual page header is physically located in the same memory page, including for multi-pages with long data.; In rare cases the function may return a false positive answer (MDBX_RESULT_TRUE when data is NOT on a dirty page), but never a false negative if the arguments are correct.

Parameters

[in]	txn	A transaction handle returned by mdbx_txn_begin().
[in]	ptr	The address of data to check.

Returns: A MDBX_RESULT_TRUE or MDBX_RESULT_FALSE value, otherwise the error code:

Return values

MDBX_RESULT_TRUE	Given address is on the dirty page.
MDBX_RESULT_FALSE	Given address is NOT on the dirty page.
Otherwise	the error code.

◆ mdbx_limits_dbsize_max()

MDBX_NOTHROW_CONST_FUNCTION LIBMDBX_API intptr_t mdbx_limits_dbsize_max ( intptr_t pagesize )

Returns maximal database size in bytes for given page size, or -1 if pagesize is invalid.

◆ mdbx_limits_dbsize_min()

MDBX_NOTHROW_CONST_FUNCTION LIBMDBX_API intptr_t mdbx_limits_dbsize_min ( intptr_t pagesize )

Returns minimal database size in bytes for given page size, or -1 if pagesize is invalid.

◆ mdbx_limits_keysize_max()

MDBX_NOTHROW_CONST_FUNCTION LIBMDBX_API intptr_t mdbx_limits_keysize_max	(	intptr_t	pagesize,
		MDBX_db_flags_t	flags
	)

Returns maximal key size in bytes for given page size and database flags, or -1 if pagesize is invalid.

See also: db_flags

◆ mdbx_limits_pgsize_max()

MDBX_NOTHROW_CONST_FUNCTION intptr_t mdbx_limits_pgsize_max ( void )

inline

Returns the maximal database page size in bytes.

◆ mdbx_limits_pgsize_min()

MDBX_NOTHROW_CONST_FUNCTION intptr_t mdbx_limits_pgsize_min ( void )

inline

Returns the minimal database page size in bytes.

◆ mdbx_limits_txnsize_max()

MDBX_NOTHROW_CONST_FUNCTION LIBMDBX_API intptr_t mdbx_limits_txnsize_max ( intptr_t pagesize )

Returns maximal write transaction size (i.e. limit for summary volume of dirty pages) in bytes for given page size, or -1 if pagesize is invalid.

◆ mdbx_limits_valsize_max()

MDBX_NOTHROW_CONST_FUNCTION LIBMDBX_API intptr_t mdbx_limits_valsize_max	(	intptr_t	pagesize,
		MDBX_db_flags_t	flags
	)

Returns maximal data size in bytes for given page size and database flags, or -1 if pagesize is invalid.

See also: db_flags

◆ mdbx_reader_list()

LIBMDBX_API int mdbx_reader_list	(	const MDBX_env *	env,
		MDBX_reader_list_func *	func,
		void *	ctx
	)

Enumerate the entries in the reader lock table.

Parameters

[in]	env	An environment handle returned by mdbx_env_create().
[in]	func	A MDBX_reader_list_func function.
[in]	ctx	An arbitrary context pointer for the enumeration function.

Returns: A non-zero error value on failure and 0 on success, or MDBX_RESULT_TRUE if the reader lock table is empty.

◆ mdbx_txn_commit_ex()

LIBMDBX_API int mdbx_txn_commit_ex	(	MDBX_txn *	txn,
		MDBX_commit_latency *	latency
	)

Commit all the operations of a transaction into the database and collect latency information.

See also: mdbx_txn_commit()

Warning: This function may be changed in future releases.

◆ mdbx_txn_id()

MDBX_NOTHROW_PURE_FUNCTION LIBMDBX_API uint64_t mdbx_txn_id ( const MDBX_txn * txn )

Return the transaction's ID.

This returns the identifier associated with this transaction. For a read-only transaction, this corresponds to the snapshot being read; concurrent readers will frequently have the same transaction ID.

Parameters

[in] txn A transaction handle returned by mdbx_txn_begin().

Returns: A transaction ID, valid if input is an active transaction, otherwise 0.

◆ mdbx_txn_info()

LIBMDBX_API int mdbx_txn_info	(	const MDBX_txn *	txn,
		MDBX_txn_info *	info,
		bool	scan_rlt
	)

Return information about the MDBX transaction.

Parameters

[in]	txn	A transaction handle returned by mdbx_txn_begin()
[out]	info	The address of an MDBX_txn_info structure where the information will be copied.
[in]	scan_rlt	The boolean flag controls the scan of the read lock table to provide complete information. Such scan is relatively expensive and you can avoid it if corresponding fields are not needed. See description of MDBX_txn_info.

Returns: A non-zero error value on failure and 0 on success.

◆ mdbx_txn_straggler()

MDBX_DEPRECATED LIBMDBX_API int mdbx_txn_straggler	(	const MDBX_txn *	txn,
		int *	percent
	)

Returns a lag of the reading for the given transaction.

Returns an information for estimate how much given read-only transaction is lagging relative the to actual head.

Deprecated:: Please use mdbx_txn_info() instead.

Parameters

[in]	txn	A transaction handle returned by mdbx_txn_begin().
[out]	percent	Percentage of page allocation in the database.

Returns: Number of transactions committed after the given was started for read, or negative value on failure.

Classes

Typedefs

Enumerations

Functions

Detailed Description

Typedef Documentation

◆ MDBX_dbi_state_t

◆ MDBX_reader_list_func

Enumeration Type Documentation

◆ MDBX_dbi_state_t

Function Documentation

◆ mdbx_dbi_dupsort_depthmask()

◆ mdbx_dbi_flags()

◆ mdbx_dbi_flags_ex()

◆ mdbx_dbi_stat()

◆ mdbx_default_pagesize()

◆ mdbx_env_get_fd()

◆ mdbx_env_get_flags()

◆ mdbx_env_get_maxdbs()

◆ mdbx_env_get_maxkeysize()

◆ mdbx_env_get_maxkeysize_ex()

◆ mdbx_env_get_maxreaders()

◆ mdbx_env_get_maxvalsize_ex()

◆ mdbx_env_get_path()

◆ mdbx_env_get_syncbytes()

◆ mdbx_env_get_syncperiod()

◆ mdbx_env_get_userctx()

◆ mdbx_env_info()

◆ mdbx_env_info_ex()

◆ mdbx_env_stat()

◆ mdbx_env_stat_ex()

◆ mdbx_get_sysraminfo()

◆ mdbx_is_dirty()

◆ mdbx_limits_dbsize_max()

◆ mdbx_limits_dbsize_min()

◆ mdbx_limits_keysize_max()

◆ mdbx_limits_pgsize_max()

◆ mdbx_limits_pgsize_min()

◆ mdbx_limits_txnsize_max()

◆ mdbx_limits_valsize_max()

◆ mdbx_reader_list()

◆ mdbx_txn_commit_ex()

◆ mdbx_txn_id()

◆ mdbx_txn_info()

◆ mdbx_txn_straggler()