mongo::WiredTigerSnapshotManager Class Reference

#include <wiredtiger_snapshot_manager.h>

Inheritance diagram for mongo::WiredTigerSnapshotManager:

Public Member Functions
	WiredTigerSnapshotManager ()=default
void	setCommittedSnapshot (const Timestamp &timestamp) final
	Sets the snapshot to be used for committed reads. More...
void	setLocalSnapshot (const Timestamp &timestamp) final
	Sets the snapshot for the last stable timestamp for reading on secondaries. More...
boost::optional< Timestamp >	getLocalSnapshot () final
	Returns the local snapshot timestamp. More...
void	dropAllSnapshots () final
	Drops all snapshots and clears the "committed" snapshot. More...
Timestamp	beginTransactionOnCommittedSnapshot (WT_SESSION *session) const
	Starts a transaction and returns the SnapshotName used. More...
Timestamp	beginTransactionOnLocalSnapshot (WT_SESSION *session, WiredTigerBeginTxnBlock::IgnorePrepared ignorePrepared) const
	Starts a transaction on the last stable local timestamp, set by setLocalSnapshot. More...
boost::optional< Timestamp >	getMinSnapshotForNextCommittedRead () const
	Returns lowest SnapshotName that could possibly be used by a future call to beginTransactionOnCommittedSnapshot, or boost::none if there is currently no committed snapshot. More...

Private Member Functions
	MONGO_DISALLOW_COPYING (WiredTigerSnapshotManager)

Private Attributes
stdx::mutex	_committedSnapshotMutex
boost::optional< Timestamp >	_committedSnapshot
stdx::mutex	_localSnapshotMutex
boost::optional< Timestamp >	_localSnapshot

Additional Inherited Members
Protected Member Functions inherited from mongo::SnapshotManager
virtual	~SnapshotManager ()=default
	SnapshotManagers are not intended to be deleted through pointers to base type. More...

Constructor & Destructor Documentation

WiredTigerSnapshotManager()

mongo::WiredTigerSnapshotManager::WiredTigerSnapshotManager ( )

default

Member Function Documentation

beginTransactionOnCommittedSnapshot()

Timestamp mongo::WiredTigerSnapshotManager::beginTransactionOnCommittedSnapshot

(

WT_SESSION *

session

)

const

Starts a transaction and returns the SnapshotName used.

Throws if there is currently no committed snapshot.

beginTransactionOnLocalSnapshot()

Timestamp mongo::WiredTigerSnapshotManager::beginTransactionOnLocalSnapshot	(	WT_SESSION *	session,
		WiredTigerBeginTxnBlock::IgnorePrepared	ignorePrepared
	)		const

Starts a transaction on the last stable local timestamp, set by setLocalSnapshot.

Throws if no local snapshot has been set.

dropAllSnapshots()

void mongo::WiredTigerSnapshotManager::dropAllSnapshots ( )

finalvirtual

Drops all snapshots and clears the "committed" snapshot.

Implements mongo::SnapshotManager.

getLocalSnapshot()

boost::optional< Timestamp > mongo::WiredTigerSnapshotManager::getLocalSnapshot ( )

finalvirtual

Returns the local snapshot timestamp.

Implements mongo::SnapshotManager.

getMinSnapshotForNextCommittedRead()

boost::optional< Timestamp > mongo::WiredTigerSnapshotManager::getMinSnapshotForNextCommittedRead

(

)

const

Returns lowest SnapshotName that could possibly be used by a future call to beginTransactionOnCommittedSnapshot, or boost::none if there is currently no committed snapshot.

This should not be used for starting a transaction on this SnapshotName since the named snapshot may be deleted by the time you start the transaction.

MONGO_DISALLOW_COPYING()

mongo::WiredTigerSnapshotManager::MONGO_DISALLOW_COPYING ( WiredTigerSnapshotManager  )

private

setCommittedSnapshot()

void mongo::WiredTigerSnapshotManager::setCommittedSnapshot ( const Timestamp &  timestamp )

finalvirtual

Sets the snapshot to be used for committed reads.

Implementations are allowed to assume that all older snapshots have names that compare less than the passed in name, and newer ones compare greater.

This is called while holding a very hot mutex. Therefore it should avoid doing any work that can be done later.

Implements mongo::SnapshotManager.

setLocalSnapshot()

void mongo::WiredTigerSnapshotManager::setLocalSnapshot ( const Timestamp &  timestamp )

finalvirtual

Sets the snapshot for the last stable timestamp for reading on secondaries.

Implements mongo::SnapshotManager.

Member Data Documentation

_committedSnapshot

boost::optional<Timestamp> mongo::WiredTigerSnapshotManager::_committedSnapshot

private

_committedSnapshotMutex

stdx::mutex mongo::WiredTigerSnapshotManager::_committedSnapshotMutex

mutableprivate

_localSnapshot

boost::optional<Timestamp> mongo::WiredTigerSnapshotManager::_localSnapshot

private

_localSnapshotMutex

stdx::mutex mongo::WiredTigerSnapshotManager::_localSnapshotMutex

mutableprivate

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

• /home/louis/git/mongodbsource.github.io/src/src/mongo/db/storage/wiredtiger/wiredtiger_snapshot_manager.h
• /home/louis/git/mongodbsource.github.io/src/src/mongo/db/storage/wiredtiger/wiredtiger_snapshot_manager.cpp