This class iterates over a capped collection identified by 'ns'. More...

#include <record_store_v1_capped_iterator.h>

Inheritance diagram for mongo::CappedRecordStoreV1Iterator:

Detailed Description

This class iterates over a capped collection identified by 'ns'.

The collection must exist when the constructor is called.

Public Member Functions
	CappedRecordStoreV1Iterator (OperationContext opCtx, const CappedRecordStoreV1 collection, bool forward)

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

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

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

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

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

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

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

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

std::unique_ptr< RecordFetcher >	fetcherForId (const RecordId &id) const final
	Returns a RecordFetcher if needed to fetch the provided Record or none if unneeded. More...

Public Member Functions inherited from mongo::SeekableRecordCursor
virtual void	saveUnpositioned ()
	Prepares for state changes in underlying data without necessarily saving the current state. More...

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

Private Member Functions
void	advance ()

bool	isEOF ()

DiskLoc	getNextCapped (const DiskLoc &dl)
	Internal collection navigation helper methods. More...

DiskLoc	prevLoop (const DiskLoc &curr)

DiskLoc	nextLoop (const DiskLoc &prev)

Extent *	_getExtent (const DiskLoc &loc)

DiskLoc	_getNextRecord (const DiskLoc &loc)

DiskLoc	_getPrevRecord (const DiskLoc &loc)

Private Attributes
OperationContext *	_opCtx

const CappedRecordStoreV1 *const	_recordStore

DiskLoc	_curr

const bool	_forward

bool	_killedByInvalidate = false

Constructor & Destructor Documentation

◆ CappedRecordStoreV1Iterator()

mongo::CappedRecordStoreV1Iterator::CappedRecordStoreV1Iterator	(	OperationContext *	opCtx,
		const CappedRecordStoreV1 *	collection,
		bool	forward
	)

Member Function Documentation

◆ _getExtent()

Extent * mongo::CappedRecordStoreV1Iterator::_getExtent ( const DiskLoc & loc )

private

◆ _getNextRecord()

DiskLoc mongo::CappedRecordStoreV1Iterator::_getNextRecord ( const DiskLoc & loc )

private

◆ _getPrevRecord()

DiskLoc mongo::CappedRecordStoreV1Iterator::_getPrevRecord ( const DiskLoc & loc )

private

◆ advance()

void mongo::CappedRecordStoreV1Iterator::advance ( )

private

◆ detachFromOperationContext()

void mongo::CappedRecordStoreV1Iterator::detachFromOperationContext ( )

inlinefinalvirtual

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.

◆ fetcherForId()

std::unique_ptr< RecordFetcher > mongo::CappedRecordStoreV1Iterator::fetcherForId ( const RecordId & id ) const

finalvirtual

Returns a RecordFetcher if needed to fetch the provided Record or none if unneeded.

Reimplemented from mongo::SeekableRecordCursor.

◆ fetcherForNext()

std::unique_ptr< RecordFetcher > mongo::CappedRecordStoreV1Iterator::fetcherForNext ( ) const

finalvirtual

Returns a RecordFetcher if needed for a call to next() or none if unneeded.

Reimplemented from mongo::RecordCursor.

◆ getNextCapped()

DiskLoc mongo::CappedRecordStoreV1Iterator::getNextCapped ( const DiskLoc & dl )

private

Internal collection navigation helper methods.

◆ invalidate()

void mongo::CappedRecordStoreV1Iterator::invalidate	(	OperationContext *	opCtx,
		const RecordId &	id
	)

finalvirtual

Inform the cursor that this id is being invalidated.

Must be called between save and restore. The opCtx is that of the operation causing the invalidation, not the opCtx using the cursor.

WARNING: Storage engines other than MMAPv1 should use the default implementation, and not depend on this being called.

Reimplemented from mongo::RecordCursor.

◆ isEOF()

bool mongo::CappedRecordStoreV1Iterator::isEOF ( )

inlineprivate

◆ next()

boost::optional< Record > mongo::CappedRecordStoreV1Iterator::next ( )

finalvirtual

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.

◆ nextLoop()

DiskLoc mongo::CappedRecordStoreV1Iterator::nextLoop ( const DiskLoc & prev )

private

◆ prevLoop()

DiskLoc mongo::CappedRecordStoreV1Iterator::prevLoop ( const DiskLoc & curr )

private

◆ reattachToOperationContext()

void mongo::CappedRecordStoreV1Iterator::reattachToOperationContext ( OperationContext * opCtx )

inlinefinalvirtual

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::CappedRecordStoreV1Iterator::restore ( )

finalvirtual

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::CappedRecordStoreV1Iterator::save ( )

finalvirtual

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.

◆ seekExact()

boost::optional< Record > mongo::CappedRecordStoreV1Iterator::seekExact ( const RecordId & id )

finalvirtual

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.

Member Data Documentation

◆ _curr

DiskLoc mongo::CappedRecordStoreV1Iterator::_curr

private

◆ _forward

const bool mongo::CappedRecordStoreV1Iterator::_forward

private

◆ _killedByInvalidate

bool mongo::CappedRecordStoreV1Iterator::_killedByInvalidate = false

private

◆ _opCtx

OperationContext* mongo::CappedRecordStoreV1Iterator::_opCtx

private

◆ _recordStore

const CappedRecordStoreV1* const mongo::CappedRecordStoreV1Iterator::_recordStore

private

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

/home/louis/git/mongodbsource.github.io/src/src/mongo/db/storage/mmap_v1/record_store_v1_capped_iterator.h
/home/louis/git/mongodbsource.github.io/src/src/mongo/db/storage/mmap_v1/record_store_v1_capped_iterator.cpp

Detailed Description

Public Member Functions

Private Member Functions

Private Attributes

Constructor & Destructor Documentation

◆ CappedRecordStoreV1Iterator()

Member Function Documentation

◆ _getExtent()

◆ _getNextRecord()

◆ _getPrevRecord()

◆ advance()

◆ detachFromOperationContext()

◆ fetcherForId()

◆ fetcherForNext()

◆ getNextCapped()

◆ invalidate()

◆ isEOF()

◆ next()

◆ nextLoop()

◆ prevLoop()

◆ reattachToOperationContext()

◆ restore()

◆ save()

◆ seekExact()

Member Data Documentation

◆ _curr

◆ _forward

◆ _killedByInvalidate

◆ _opCtx

◆ _recordStore