Storage Engine API
Public Member Functions | Private Member Functions | Private Attributes | List of all members
mongo::RecordStoreV1Base::IntraExtentIterator Class Referencefinal

Iterates over all records within a single extent. More...

#include <record_store_v1_base.h>

Inheritance diagram for mongo::RecordStoreV1Base::IntraExtentIterator:
mongo::RecordCursor

Detailed Description

Iterates over all records within a single extent.

EOF at end of extent, even if there are more extents.

Public Member Functions

 IntraExtentIterator (OperationContext *opCtx, DiskLoc start, const RecordStoreV1Base *rs, bool forward=true)
 
boost::optional< Record > next () final
 Moves forward and returns the new data or boost::none if there is no more data. More...
 
void invalidate (OperationContext *opCtx, const RecordId &dl) final
 Inform the cursor that this id is being invalidated. 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...
 
std::unique_ptr< RecordFetcher > fetcherForNext () const final
 Returns a RecordFetcher if needed for a call to next() or none if unneeded. More...
 
- Public Member Functions inherited from mongo::RecordCursor
virtual ~RecordCursor ()=default
 

Private Member Functions

virtual const MmapV1RecordHeader * recordFor (const DiskLoc &loc) const
 
void advance ()
 

Private Attributes

OperationContext * _opCtx
 
DiskLoc _curr
 
const RecordStoreV1Base * _rs
 
bool _forward
 

Constructor & Destructor Documentation

◆ IntraExtentIterator()

mongo::RecordStoreV1Base::IntraExtentIterator::IntraExtentIterator ( OperationContext *  opCtx,
DiskLoc  start,
const RecordStoreV1Base *  rs,
bool  forward = true 
)
inline

Member Function Documentation

◆ advance()

void mongo::RecordStoreV1Base::IntraExtentIterator::advance ( )
private

◆ detachFromOperationContext()

void mongo::RecordStoreV1Base::IntraExtentIterator::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.

◆ fetcherForNext()

std::unique_ptr< RecordFetcher > mongo::RecordStoreV1Base::IntraExtentIterator::fetcherForNext ( ) const
finalvirtual

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

Reimplemented from mongo::RecordCursor.

◆ invalidate()

void mongo::RecordStoreV1Base::IntraExtentIterator::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.

◆ next()

boost::optional< Record > mongo::RecordStoreV1Base::IntraExtentIterator::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.

◆ reattachToOperationContext()

void mongo::RecordStoreV1Base::IntraExtentIterator::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.

◆ recordFor()

virtual const MmapV1RecordHeader* mongo::RecordStoreV1Base::IntraExtentIterator::recordFor ( const DiskLoc &  loc) const
inlineprivatevirtual

◆ restore()

bool mongo::RecordStoreV1Base::IntraExtentIterator::restore ( )
inlinefinalvirtual

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::RecordStoreV1Base::IntraExtentIterator::save ( )
inlinefinalvirtual

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.

Member Data Documentation

◆ _curr

DiskLoc mongo::RecordStoreV1Base::IntraExtentIterator::_curr
private

◆ _forward

bool mongo::RecordStoreV1Base::IntraExtentIterator::_forward
private

◆ _opCtx

OperationContext* mongo::RecordStoreV1Base::IntraExtentIterator::_opCtx
private

◆ _rs

const RecordStoreV1Base* mongo::RecordStoreV1Base::IntraExtentIterator::_rs
private
The documentation for this class was generated from the following files: