lmdb::txn Class Reference

Resource class for MDB_txn* handles. More...

#include <lmdb++.h>

Public Member Functions
	txn (MDB_txn *const handle) noexcept
	Constructor.
	txn (txn &&other) noexcept
	Move constructor.
txn &	operator= (txn &&other) noexcept
	Move assignment operator.
	~txn () noexcept
	Destructor.
	operator MDB_txn * () const noexcept
	Returns the underlying MDB_txn* handle.
MDB_txn *	handle () const noexcept
	Returns the underlying MDB_txn* handle.
MDB_env *	env () const noexcept
	Returns the transaction's MDB_env* handle.
void	commit ()
	Commits this transaction.
void	abort () noexcept
	Aborts this transaction.
void	reset () noexcept
	Resets this read-only transaction.
void	renew ()
	Renews this read-only transaction.

Static Public Member Functions
static txn	begin (MDB_env *const env, MDB_txn *const parent=nullptr, const unsigned int flags=default_flags)
	Creates a new LMDB transaction.

Static Public Attributes
static constexpr unsigned int	default_flags = 0

Protected Attributes
MDB_txn *	_handle {nullptr}

Detailed Description

Resource class for MDB_txn* handles.

Note

Instances of this class are movable, but not copyable.

See also

http://symas.com/mdb/doc/group__internal.html#structMDB__txn

Constructor & Destructor Documentation

txn() [1/2]

lmdb::txn::txn ( MDB_txn *const  handle )

inlinenoexcept

Constructor.

Parameters

handle

a valid MDB_txn* handle

txn() [2/2]

lmdb::txn::txn ( txn &&  other )

inlinenoexcept

Move constructor.

~txn()

lmdb::txn::~txn ( )

inlinenoexcept

Destructor.

Member Function Documentation

abort()

void lmdb::txn::abort ( )

inlinenoexcept

Aborts this transaction.

Postcondition

handle() == nullptr

begin()

static txn lmdb::txn::begin ( MDB_env *const  env, MDB_txn *const  parent = nullptr, const unsigned int  flags = default_flags  )

inlinestatic

Creates a new LMDB transaction.

Parameters

env	the environment handle
parent
flags

Exceptions

lmdb::error

on failure

commit()

void lmdb::txn::commit ( )

inline

Commits this transaction.

Exceptions

lmdb::error

on failure

Postcondition

handle() == nullptr

env()

MDB_env * lmdb::txn::env ( ) const

inlinenoexcept

Returns the transaction's MDB_env* handle.

handle()

MDB_txn * lmdb::txn::handle ( ) const

inlinenoexcept

Returns the underlying MDB_txn* handle.

operator MDB_txn *()

lmdb::txn::operator MDB_txn * ( ) const

inlinenoexcept

Returns the underlying MDB_txn* handle.

operator=()

txn & lmdb::txn::operator= ( txn &&  other )

inlinenoexcept

Move assignment operator.

renew()

void lmdb::txn::renew ( )

inline

Renews this read-only transaction.

Exceptions

lmdb::error

on failure

reset()

void lmdb::txn::reset ( )

inlinenoexcept

Resets this read-only transaction.

Member Data Documentation

_handle

MDB_txn* lmdb::txn::_handle {nullptr}

protected

default_flags

constexpr unsigned int lmdb::txn::default_flags = 0

staticconstexpr

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

• lmdb++.h