Managed database transaction. More...

#include <mdbx.h++>

Public Member Functions
MDBX_CXX11_CONSTEXPR	txn_managed () noexcept=default

	txn_managed (txn_managed &&)=default

txn_managed &	operator= (txn_managed &&other)

	txn_managed (const txn_managed &)=delete

txn_managed &	operator= (const txn_managed &)=delete

	~txn_managed () noexcept

void	abort ()
	Abandon all the operations of the transaction instead of saving them. More...

void	commit ()
	Commit all the operations of a transaction into the database. More...

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

	txn (const txn &) noexcept=default

txn &	operator= (txn &&other) noexcept

	txn (txn &&other) noexcept

	~txn () noexcept

MDBX_CXX14_CONSTEXPR	operator bool () const noexcept

MDBX_CXX14_CONSTEXPR	operator const MDBX_txn * () const

MDBX_CXX14_CONSTEXPR	operator MDBX_txn * ()

inline ::mdbx::env	env () const noexcept
	Returns the transaction's environment. More...

MDBX_txn_flags_t	flags () const
	Returns transaction's flags. More...

uint64_t	id () const
	Return the transaction's ID. More...

bool	is_dirty (const void *ptr) const
	Checks whether the given data is on a dirty page. More...

bool	is_readonly () const
	Checks whether the transaction is read-only. More...

bool	is_readwrite () const
	Checks whether the transaction is read-write. More...

info	get_info (bool scan_reader_lock_table=false) const
	Returns information about the MDBX transaction. More...

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

size_t	size_current () const
	Returns current write transaction size (i.e.summary volume of dirty pages) in bytes. More...

void	reset_reading ()
	Reset a read-only transaction. More...

void	renew_reading ()
	Renew a read-only transaction. More...

txn_managed	start_nested ()
	Start nested write transaction. More...

cursor_managed	open_cursor (map_handle map)
	Opens cursor for specified key-value map handle. More...

map_handle	open_map (const char *name, const ::mdbx::key_mode key_mode=::mdbx::key_mode::usual, const ::mdbx::value_mode value_mode=::mdbx::value_mode::single) const
	Open existing key-value map. More...

map_handle	open_map (const ::std::string &name, const ::mdbx::key_mode key_mode=::mdbx::key_mode::usual, const ::mdbx::value_mode value_mode=::mdbx::value_mode::single) const
	Open existing key-value map. More...

map_handle	create_map (const char *name, const ::mdbx::key_mode key_mode=::mdbx::key_mode::usual, const ::mdbx::value_mode value_mode=::mdbx::value_mode::single)
	Create new or open existing key-value map. More...

map_handle	create_map (const ::std::string &name, const ::mdbx::key_mode key_mode=::mdbx::key_mode::usual, const ::mdbx::value_mode value_mode=::mdbx::value_mode::single)
	Create new or open existing key-value map. More...

void	drop_map (map_handle map)
	Drops key-value map using handle. More...

bool	drop_map (const char *name, bool throw_if_absent=false)
	Drops key-value map using name. More...

bool	drop_map (const ::std::string &name, bool throw_if_absent=false)
	Drop key-value map. More...

void	clear_map (map_handle map)
	Clear key-value map. More...

bool	clear_map (const char *name, bool throw_if_absent=false)

bool	clear_map (const ::std::string &name, bool throw_if_absent=false)

map_stat	get_map_stat (map_handle map) const
	Returns statistics for a sub-database. More...

uint32_t	get_tree_deepmask (map_handle map) const
	Returns depth (bitmask) information of nested dupsort (multi-value) B+trees for given database. More...

map_handle::info	get_handle_info (map_handle map) const
	Returns information about key-value map (aka sub-database) handle. More...

txn &	put_canary (const canary &)
	Set integers markers (aka "canary") associated with the environment. More...

canary	get_canary () const
	Returns fours integers markers (aka "canary") associated with the environment. More...

uint64_t	sequence (map_handle map) const

uint64_t	sequence (map_handle map, uint64_t increment)
	Reads and increment sequence generator associated with a key-value map (aka sub-database). More...

int	compare_keys (map_handle map, const slice &a, const slice &b) const noexcept
	Compare two keys according to a particular key-value map (aka sub-database). More...

int	compare_values (map_handle map, const slice &a, const slice &b) const noexcept
	Compare two values according to a particular key-value map (aka sub-database). More...

int	compare_keys (map_handle map, const pair &a, const pair &b) const noexcept
	Compare keys of two pairs according to a particular key-value map (aka sub-database). More...

int	compare_values (map_handle map, const pair &a, const pair &b) const noexcept
	Compare values of two pairs according to a particular key-value map (aka sub-database). More...

slice	get (map_handle map, const slice &key) const
	Get value by key from a key-value map (aka sub-database). More...

slice	get (map_handle map, slice key, size_t &values_count) const
	Get first of multi-value and values count by key from a key-value multimap (aka sub-database). More...

slice	get (map_handle map, const slice &key, const slice &value_at_absence) const
	Get value by key from a key-value map (aka sub-database). More...

slice	get (map_handle map, slice key, size_t &values_count, const slice &value_at_absence) const
	Get first of multi-value and values count by key from a key-value multimap (aka sub-database). More...

pair_result	get_equal_or_great (map_handle map, const slice &key) const
	Get value for equal or great key from a database. More...

pair_result	get_equal_or_great (map_handle map, const slice &key, const slice &value_at_absence) const
	Get value for equal or great key from a database. More...

MDBX_error_t	put (map_handle map, const slice &key, slice *value, MDBX_put_flags_t flags) noexcept

void	put (map_handle map, const slice &key, slice value, put_mode mode)

void	insert (map_handle map, const slice &key, slice value)

value_result	try_insert (map_handle map, const slice &key, slice value)

slice	insert_reserve (map_handle map, const slice &key, size_t value_length)

value_result	try_insert_reserve (map_handle map, const slice &key, size_t value_length)

void	upsert (map_handle map, const slice &key, const slice &value)

slice	upsert_reserve (map_handle map, const slice &key, size_t value_length)

void	update (map_handle map, const slice &key, const slice &value)

bool	try_update (map_handle map, const slice &key, const slice &value)

slice	update_reserve (map_handle map, const slice &key, size_t value_length)

value_result	try_update_reserve (map_handle map, const slice &key, size_t value_length)

bool	erase (map_handle map, const slice &key)
	Removes all values for given key. More...

bool	erase (map_handle map, const slice &key, const slice &value)
	Removes the particular multi-value entry of the key. More...

void	replace (map_handle map, const slice &key, slice old_value, const slice &new_value)
	Replaces the particular multi-value of the key with a new value. More...

template<class ALLOCATOR , typename CAPACITY_POLICY >
buffer< ALLOCATOR, CAPACITY_POLICY >	extract (map_handle map, const slice &key, const typename buffer< ALLOCATOR, CAPACITY_POLICY >::allocator_type &allocator=buffer< ALLOCATOR, CAPACITY_POLICY >::allocator_type())
	Removes and return a value of the key. More...

template<class ALLOCATOR , typename CAPACITY_POLICY >
buffer< ALLOCATOR, CAPACITY_POLICY >	replace (map_handle map, const slice &key, const slice &new_value, const typename buffer< ALLOCATOR, CAPACITY_POLICY >::allocator_type &allocator=buffer< ALLOCATOR, CAPACITY_POLICY >::allocator_type())
	Replaces and returns a value of the key with new one. More...

template<class ALLOCATOR , typename CAPACITY_POLICY >
buffer< ALLOCATOR, CAPACITY_POLICY >	replace_reserve (map_handle map, const slice &key, slice &new_value, const typename buffer< ALLOCATOR, CAPACITY_POLICY >::allocator_type &allocator=buffer< ALLOCATOR, CAPACITY_POLICY >::allocator_type())

void	append (map_handle map, const slice &key, const slice &value, bool multivalue_order_preserved=true)
	Adding a key-value pair, provided that ascending order of the keys and (optionally) values are preserved. More...

size_t	put_multiple (map_handle map, const slice &key, const size_t value_length, const void *values_array, size_t values_count, put_mode mode, bool allow_partial=false)

template<typename VALUE >
void	put_multiple (map_handle map, const slice &key, const ::std::vector< VALUE > &vector, put_mode mode)

ptrdiff_t	estimate (map_handle map, pair from, pair to) const

ptrdiff_t	estimate (map_handle map, slice from, slice to) const

ptrdiff_t	estimate_from_first (map_handle map, slice to) const

ptrdiff_t	estimate_to_last (map_handle map, slice from) const

Friends
class	env

class	txn

Additional Inherited Members
Public Types inherited from mdbx::txn
using	info = ::MDBX_txn_info

using	map_stat = ::MDBX_stat

using	canary = ::MDBX_canary

Protected Member Functions inherited from mdbx::txn
MDBX_CXX11_CONSTEXPR	txn (MDBX_txn *ptr) noexcept

Protected Attributes inherited from mdbx::txn
MDBX_txn *	handle_ {nullptr}

Detailed Description

Managed database transaction.

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

All database operations require a transaction handle. Transactions may be read-only or read-write.

Constructor & Destructor Documentation

◆ txn_managed() [1/3]

MDBX_CXX11_CONSTEXPR mdbx::txn_managed::txn_managed ( )

defaultnoexcept

◆ txn_managed() [2/3]

mdbx::txn_managed::txn_managed ( txn_managed && )

default

◆ txn_managed() [3/3]

mdbx::txn_managed::txn_managed ( const txn_managed & )

delete

◆ ~txn_managed()

mdbx::txn_managed::~txn_managed ( )

noexcept

Member Function Documentation

◆ abort()

void mdbx::txn_managed::abort ( )

Abandon all the operations of the transaction instead of saving them.

◆ commit()

void mdbx::txn_managed::commit ( )

Commit all the operations of a transaction into the database.

◆ operator=() [1/2]

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

delete

◆ operator=() [2/2]

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

inline

Friends And Related Function Documentation

◆ env

friend class env

friend

◆ txn

friend class txn