Managed database environment. More...

#include <mdbx.h++>

Classes
struct	create_parameters
	Additional parameters for creating a new database. More...

Public Member Functions
MDBX_CXX11_CONSTEXPR	env_managed () noexcept=default

	env_managed (const MDBX_STD_FILESYSTEM_PATH &, const operate_parameters &, bool accede=true)
	Open existing database. More...

	env_managed (const ::std::string &, const operate_parameters &, bool accede=true)

	env_managed (const MDBX_STD_FILESYSTEM_PATH &, const create_parameters &, const operate_parameters &, bool accede=true)
	Create new or open existing database. More...

	env_managed (const ::std::string &, const create_parameters &, const operate_parameters &, bool accede=true)

void	close (bool dont_sync=false)
	Explicitly closes the environment and release the memory map. More...

	env_managed (env_managed &&)=default

env_managed &	operator= (env_managed &&other)

	env_managed (const env_managed &)=delete

env_managed &	operator= (const env_managed &)=delete

virtual	~env_managed () noexcept

Public Member Functions inherited from mdbx::env
MDBX_CXX11_CONSTEXPR	env () noexcept=default

	env (const env &) noexcept=default

env &	operator= (env &&other) noexcept

	env (env &&other) noexcept

	~env () noexcept

MDBX_CXX14_CONSTEXPR	operator bool () const noexcept

MDBX_CXX14_CONSTEXPR	operator const MDBX_env * () const

MDBX_CXX14_CONSTEXPR	operator MDBX_env * ()

env::operate_parameters	get_operation_parameters () const
	Returns current operation parameters. More...

env::mode	get_mode () const
	Returns current operation mode. More...

env::durability	get_durability () const
	Returns current durability mode. More...

env::reclaiming_options	get_reclaiming () const
	Returns current reclaiming options. More...

env::operate_options	get_options () const
	Returns current operate options. More...

bool	is_pristine () const
	Returns `true` for a freshly created database, but `false` if at least one transaction was committed. More...

bool	is_empty () const
	Checks whether the database is empty. More...

size_t	dbsize_min () const
	Returns the minimal database size in bytes for the environment. More...

size_t	dbsize_max () const
	Returns the maximal database size in bytes for the environment. More...

size_t	key_min (key_mode mode) const noexcept
	Returns the minimal key size in bytes for specified keys mode. More...

size_t	key_max (key_mode mode) const
	Returns the maximal key size in bytes for specified keys mode. More...

size_t	value_min (value_mode mode) const noexcept
	Returns the minimal value size in bytes for specified values mode. More...

size_t	value_max (value_mode mode) const
	Returns the maximal value size in bytes for specified values mode. More...

size_t	transaction_size_max () const
	Returns the maximal write transaction size (i.e. limit for summary volume of dirty pages) in bytes. More...

env &	copy (const MDBX_STD_FILESYSTEM_PATH &destination, bool compactify, bool force_dynamic_size=false)
	Make a copy (backup) of an existing environment to the specified path. More...

env &	copy (const ::std::string &destination, bool compactify, bool force_dynamic_size=false)

env &	copy (filehandle fd, bool compactify, bool force_dynamic_size=false)
	Copy an environment to the specified file descriptor. More...

stat	get_stat () const
	Returns snapshot statistics about the MDBX environment. More...

size_t	get_pagesize () const
	Returns pagesize of this MDBX environment. More...

info	get_info () const
	Return snapshot information about the MDBX environment. More...

stat	get_stat (const txn &) const
	Return statistics about the MDBX environment accordingly to the specified transaction. More...

info	get_info (const txn &) const
	Return information about the MDBX environment accordingly to the specified transaction. More...

filehandle	get_filehandle () const
	Returns the file descriptor for the DXB file of MDBX environment. More...

path	get_path () const
	Return the path that was used for opening the environment. More...

MDBX_env_flags_t	get_flags () const
	Returns environment flags. More...

unsigned	max_readers () const
	Returns the maximum number of threads/reader slots for the environment. More...

unsigned	max_maps () const
	Returns the maximum number of named databases for the environment. More...

void *	get_context () const noexcept
	Returns the application context associated with the environment. More...

env &	set_context (void *)
	Sets the application context associated with the environment. More...

env &	set_sync_threshold (size_t bytes)
	Sets threshold to force flush the data buffers to disk, for non-sync durability modes. More...

env &	set_sync_period (unsigned seconds_16dot16)
	Sets relative period since the last unsteady commit to force flush the data buffers to disk, for non-sync durability modes. More...

env &	set_sync_period (double seconds)
	Sets relative period since the last unsteady commit to force flush the data buffers to disk, for non-sync durability modes. More...

env &	alter_flags (MDBX_env_flags_t flags, bool on_off)
	Alter environment flags. More...

env &	set_geometry (const geometry &size)
	Set all size-related parameters of environment. More...

bool	sync_to_disk (bool force=true, bool nonblock=false)
	Flush the environment data buffers. More...

bool	poll_sync_to_disk ()
	Performs non-blocking polling of sync-to-disk thresholds. More...

void	close_map (const map_handle &)
	Close a key-value map (aka sub-database) handle. Normally unnecessary. More...

template<typename VISITOR >
int	enumerate_readers (VISITOR &visitor)
	Enumerate readers. More...

unsigned	check_readers ()
	Checks for stale readers in the lock table and return number of cleared slots. More...

env &	set_HandleSlowReaders (MDBX_hsr_func *)
	Sets a Handle-Slow-Readers callback to resolve database full/overflow issue due to a reader(s) which prevents the old data from being recycled. More...

MDBX_hsr_func *	get_HandleSlowReaders () const noexcept
	Returns the current Handle-Slow-Readers callback used to resolve database full/overflow issue due to a reader(s) which prevents the old data from being recycled. More...

txn_managed	start_read () const
	Starts read (read-only) transaction. More...

txn_managed	prepare_read () const
	Creates but not start read transaction. More...

txn_managed	start_write (bool dont_wait=false)
	Starts write (read-write) transaction. More...

txn_managed	try_start_write ()
	Tries to start write (read-write) transaction without blocking. More...

Additional Inherited Members
Public Types inherited from mdbx::env
enum	mode { readonly, write_file_io, write_mapped_io }
	Operation mode. More...

enum	durability { robust_synchronous, half_synchronous_weak_last, lazy_weak_tail, whole_fragile }
	Durability level. More...

enum	remove_mode { just_remove = MDBX_ENV_JUST_DELETE, ensure_unused = MDBX_ENV_ENSURE_UNUSED, wait_for_unused = MDBX_ENV_WAIT_FOR_UNUSED }
	Deletion modes for remove(). More...

using	stat = ::MDBX_stat
	Statistics for a database in the MDBX environment. More...

using	info = ::MDBX_envinfo
	Information about the environment. More...

Static Public Member Functions inherited from mdbx::env
static size_t	default_pagesize () noexcept
	Returns default page size for current system/platform. More...

static bool	remove (const MDBX_STD_FILESYSTEM_PATH &, const remove_mode mode=just_remove)
	Removes the environment's files in a proper and multiprocess-safe way. More...

static bool	remove (const ::std::string &, const remove_mode mode=just_remove)

Protected Member Functions inherited from mdbx::env
MDBX_CXX11_CONSTEXPR	env (MDBX_env *ptr) noexcept

Protected Attributes inherited from mdbx::env
MDBX_env *	handle_ {nullptr}

Detailed Description

Managed database environment.

As other managed classes, env_managed destroys the represented underlying object from the own class destructor, but disallows copying and assignment for instances.

An environment supports multiple key-value databases (aka key-value spaces or tables), all residing in the same shared-memory map.

Constructor & Destructor Documentation

◆ env_managed() [1/7]

MDBX_CXX11_CONSTEXPR mdbx::env_managed::env_managed ( )

defaultnoexcept

◆ env_managed() [2/7]

mdbx::env_managed::env_managed	(	const MDBX_STD_FILESYSTEM_PATH &	,
		const operate_parameters &	,
		bool	accede = `true`
	)

Open existing database.

◆ env_managed() [3/7]

mdbx::env_managed::env_managed	(	const ::std::string &	,
		const operate_parameters &	,
		bool	accede = `true`
	)

◆ env_managed() [4/7]

mdbx::env_managed::env_managed	(	const MDBX_STD_FILESYSTEM_PATH &	,
		const create_parameters &	,
		const operate_parameters &	,
		bool	accede = `true`
	)

Create new or open existing database.

◆ env_managed() [5/7]

mdbx::env_managed::env_managed	(	const ::std::string &	,
		const create_parameters &	,
		const operate_parameters &	,
		bool	accede = `true`
	)

◆ env_managed() [6/7]

mdbx::env_managed::env_managed ( env_managed && )

default

◆ env_managed() [7/7]

mdbx::env_managed::env_managed ( const env_managed & )

delete

◆ ~env_managed()

virtual mdbx::env_managed::~env_managed ( )

virtualnoexcept

Member Function Documentation

◆ close()

void mdbx::env_managed::close ( bool dont_sync = false )

Explicitly closes the environment and release the memory map.

Only a single thread may call this function. All transactions, databases, and cursors must already be closed before calling this function. Attempts to use any such handles after calling this function will cause a SIGSEGV. The environment handle will be freed and must not be used again after this call.

Parameters

[in] dont_sync A dont'sync flag, if non-zero the last checkpoint will be kept "as is" and may be still "weak" in the lazy_weak_tail or whole_fragile modes. Such "weak" checkpoint will be ignored on opening next time, and transactions since the last non-weak checkpoint (meta-page update) will rolledback for consistency guarantee.

◆ operator=() [1/2]

env_managed& mdbx::env_managed::operator= ( const env_managed & )

delete

◆ operator=() [2/2]

env_managed& mdbx::env_managed::operator= ( env_managed && other )

inline

The documentation for this class was generated from the following file:

mdbx.h++

Classes

Public Member Functions

Additional Inherited Members