#include <wiredtiger_record_store.h>

Inheritance diagram for mongo::WiredTigerRecordStoreCursorBase:

Public Member Functions
	WiredTigerRecordStoreCursorBase (OperationContext *opCtx, const WiredTigerRecordStore &rs, bool forward)

boost::optional< Record >	next ()
	Moves forward and returns the new data or boost::none if there is no more data. More...

boost::optional< Record >	seekExact (const RecordId &id)
	Seeks to a Record with the provided id. More...

void	save ()
	Prepares for state changes in underlying data in a way that allows the cursor's current position to be restored. More...

void	saveUnpositioned ()
	Prepares for state changes in underlying data without necessarily saving the current state. More...

bool	restore ()
	Recovers from potential state changes in underlying data. More...

void	detachFromOperationContext ()
	Detaches from the OperationContext and releases any storage-engine state. More...

void	reattachToOperationContext (OperationContext *opCtx)
	Reattaches to the OperationContext and reacquires any storage-engine state. More...

Public Member Functions inherited from mongo::SeekableRecordCursor
virtual std::unique_ptr< RecordFetcher >	fetcherForId (const RecordId &id) const
	Returns a RecordFetcher if needed to fetch the provided Record or none if unneeded. More...

Public Member Functions inherited from mongo::RecordCursor
virtual	~RecordCursor ()=default

virtual void	invalidate (OperationContext *opCtx, const RecordId &id)
	Inform the cursor that this id is being invalidated. More...

virtual std::unique_ptr< RecordFetcher >	fetcherForNext () const
	Returns a RecordFetcher if needed for a call to next() or none if unneeded. More...

Protected Member Functions
virtual RecordId	getKey (WT_CURSOR *cursor) const =0

virtual void	setKey (WT_CURSOR *cursor, RecordId id) const =0

virtual bool	hasWrongPrefix (WT_CURSOR cursor, RecordId id) const =0
	Callers must have already checked the return value of a positioning method against 'WT_NOTFOUND'. More...

virtual void	initCursorToBeginning ()=0
	Called when restoring a cursor that has not been advanced. More...

Protected Attributes
const WiredTigerRecordStore &	_rs

OperationContext *	_opCtx

const bool	_forward

bool	_skipNextAdvance = false

boost::optional< WiredTigerCursor >	_cursor

bool	_eof = false

RecordId	_lastReturnedId

Private Member Functions
bool	isVisible (const RecordId &id)

Constructor & Destructor Documentation

◆ WiredTigerRecordStoreCursorBase()

mongo::WiredTigerRecordStoreCursorBase::WiredTigerRecordStoreCursorBase	(	OperationContext *	opCtx,
		const WiredTigerRecordStore &	rs,
		bool	forward
	)

Member Function Documentation

◆ detachFromOperationContext()

void mongo::WiredTigerRecordStoreCursorBase::detachFromOperationContext ( )

virtual

Detaches from the OperationContext and releases any storage-engine state.

It is only legal to call this when in a "saved" state. While in the "detached" state, it is only legal to call reattachToOperationContext or the destructor. It is not legal to call detachFromOperationContext() while already in the detached state.

Implements mongo::RecordCursor.

◆ getKey()

virtual RecordId mongo::WiredTigerRecordStoreCursorBase::getKey ( WT_CURSOR * cursor ) const

protectedpure virtual

Implemented in mongo::WiredTigerRecordStorePrefixedCursor, and mongo::WiredTigerRecordStoreStandardCursor.

◆ hasWrongPrefix()

virtual bool mongo::WiredTigerRecordStoreCursorBase::hasWrongPrefix	(	WT_CURSOR *	cursor,
		RecordId *	id
	)		const

protectedpure virtual

Callers must have already checked the return value of a positioning method against 'WT_NOTFOUND'.

This method allows for additional predicates to be considered on a validly positioned cursor. 'id' is an out parameter. Implementations are not required to fill it in. It's simply a possible optimization to avoid a future 'getKey' call if 'hasWrongPrefix' already did one.

Implemented in mongo::WiredTigerRecordStorePrefixedCursor, and mongo::WiredTigerRecordStoreStandardCursor.

◆ initCursorToBeginning()

virtual void mongo::WiredTigerRecordStoreCursorBase::initCursorToBeginning ( )

protectedpure virtual

Called when restoring a cursor that has not been advanced.

Implemented in mongo::WiredTigerRecordStorePrefixedCursor, and mongo::WiredTigerRecordStoreStandardCursor.

◆ isVisible()

bool mongo::WiredTigerRecordStoreCursorBase::isVisible ( const RecordId & id )

private

◆ next()

boost::optional< Record > mongo::WiredTigerRecordStoreCursorBase::next ( )

virtual

Moves forward and returns the new data or boost::none if there is no more data.

Continues returning boost::none once it reaches EOF.

Implements mongo::RecordCursor.

◆ reattachToOperationContext()

void mongo::WiredTigerRecordStoreCursorBase::reattachToOperationContext ( OperationContext * opCtx )

virtual

Reattaches to the OperationContext and reacquires any storage-engine state.

It is only legal to call this in the "detached" state. On return, the cursor is left in a "saved" state, so callers must still call restoreState to use this object.

Implements mongo::RecordCursor.

◆ restore()

bool mongo::WiredTigerRecordStoreCursorBase::restore ( )

virtual

Recovers from potential state changes in underlying data.

Returns false if it is invalid to continue using this iterator. This usually means that capped deletes have caught up to the position of this iterator and continuing could result in missed data.

If the former position no longer exists, but it is safe to continue iterating, the following call to next() will return the next closest position in the direction of the scan, if any.

This handles restoring after either save() or SeekableRecordCursor::saveUnpositioned().

Implements mongo::RecordCursor.

◆ save()

void mongo::WiredTigerRecordStoreCursorBase::save ( )

virtual

Prepares for state changes in underlying data in a way that allows the cursor's current position to be restored.

It is safe to call save multiple times in a row. No other method (excluding destructor) may be called until successfully restored.

Implements mongo::RecordCursor.

◆ saveUnpositioned()

void mongo::WiredTigerRecordStoreCursorBase::saveUnpositioned ( )

virtual

Prepares for state changes in underlying data without necessarily saving the current state.

The cursor's position when restored is unspecified. Caller is expected to seek rather than call next() following the restore.

It is safe to call saveUnpositioned multiple times in a row. No other method (excluding destructor) may be called until successfully restored.

Reimplemented from mongo::SeekableRecordCursor.

◆ seekExact()

boost::optional< Record > mongo::WiredTigerRecordStoreCursorBase::seekExact ( const RecordId & id )

virtual

Seeks to a Record with the provided id.

If an exact match can't be found, boost::none will be returned and the resulting position of the cursor is unspecified.

Implements mongo::SeekableRecordCursor.

◆ setKey()

virtual void mongo::WiredTigerRecordStoreCursorBase::setKey	(	WT_CURSOR *	cursor,
		RecordId	id
	)		const

protectedpure virtual

Implemented in mongo::WiredTigerRecordStorePrefixedCursor, and mongo::WiredTigerRecordStoreStandardCursor.

Member Data Documentation

◆ _cursor

boost::optional<WiredTigerCursor> mongo::WiredTigerRecordStoreCursorBase::_cursor

protected

◆ _eof

bool mongo::WiredTigerRecordStoreCursorBase::_eof = false

protected

◆ _forward

const bool mongo::WiredTigerRecordStoreCursorBase::_forward

protected

◆ _lastReturnedId

RecordId mongo::WiredTigerRecordStoreCursorBase::_lastReturnedId

protected

◆ _opCtx

OperationContext* mongo::WiredTigerRecordStoreCursorBase::_opCtx

protected

◆ _rs

const WiredTigerRecordStore& mongo::WiredTigerRecordStoreCursorBase::_rs

protected

◆ _skipNextAdvance

bool mongo::WiredTigerRecordStoreCursorBase::_skipNextAdvance = false

protected

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

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

Public Member Functions

Protected Member Functions

Protected Attributes

Private Member Functions

Constructor & Destructor Documentation

◆ WiredTigerRecordStoreCursorBase()

Member Function Documentation

◆ detachFromOperationContext()

◆ getKey()

◆ hasWrongPrefix()

◆ initCursorToBeginning()

◆ isVisible()

◆ next()

◆ reattachToOperationContext()

◆ restore()

◆ save()

◆ saveUnpositioned()

◆ seekExact()

◆ setKey()

Member Data Documentation

◆ _cursor

◆ _eof

◆ _forward

◆ _lastReturnedId

◆ _opCtx

◆ _rs

◆ _skipNextAdvance