void RecordStoreV1Base::deleteRecord( TransactionExperiment* txn, const DiskLoc& dl ) { Record* todelete = recordFor( dl ); /* remove ourself from the record next/prev chain */ { if ( todelete->prevOfs() != DiskLoc::NullOfs ) { DiskLoc prev = getPrevRecordInExtent( dl ); Record* prevRecord = recordFor( prev ); txn->writingInt( prevRecord->nextOfs() ) = todelete->nextOfs(); } if ( todelete->nextOfs() != DiskLoc::NullOfs ) { DiskLoc next = getNextRecord( dl ); Record* nextRecord = recordFor( next ); txn->writingInt( nextRecord->prevOfs() ) = todelete->prevOfs(); } } /* remove ourself from extent pointers */ { Extent *e = txn->writing( _getExtent( _getExtentLocForRecord( dl ) ) ); if ( e->firstRecord == dl ) { if ( todelete->nextOfs() == DiskLoc::NullOfs ) e->firstRecord.Null(); else e->firstRecord.set(dl.a(), todelete->nextOfs() ); } if ( e->lastRecord == dl ) { if ( todelete->prevOfs() == DiskLoc::NullOfs ) e->lastRecord.Null(); else e->lastRecord.set(dl.a(), todelete->prevOfs() ); } } /* add to the free list */ { _details->incrementStats( txn, -1 * todelete->netLength(), -1 ); if ( _isSystemIndexes ) { /* temp: if in system.indexes, don't reuse, and zero out: we want to be careful until validated more, as IndexDetails has pointers to this disk location. so an incorrectly done remove would cause a lot of problems. */ memset( txn->writingPtr(todelete, todelete->lengthWithHeaders() ), 0, todelete->lengthWithHeaders() ); } else { DEV { unsigned long long *p = reinterpret_cast<unsigned long long *>( todelete->data() ); *txn->writing(p) = 0; } addDeletedRec(txn, dl); } } }
DiskLoc ExtentManager::getPrevRecord( const DiskLoc& loc ) const { DiskLoc prev = getPrevRecordInExtent( loc ); if ( !prev.isNull() ) return prev; // now traverse extents Extent *e = extentFor(loc); while ( 1 ) { if ( e->xprev.isNull() ) return DiskLoc(); // end of collection e = e->xprev.ext(); if ( !e->firstRecord.isNull() ) break; // entire extent could be empty, keep looking } return e->firstRecord; }
DiskLoc RecordStoreV1Base::getPrevRecord( const DiskLoc& loc ) const { DiskLoc prev = getPrevRecordInExtent( loc ); if ( !prev.isNull() ) return prev; // now traverse extents Extent *e = _getExtent(_getExtentLocForRecord(loc)); while ( 1 ) { if ( e->xprev.isNull() ) return DiskLoc(); // end of collection e = _getExtent( e->xprev ); if ( !e->firstRecord.isNull() ) break; // entire extent could be empty, keep looking } return e->lastRecord; }
void RecordStoreV1Base::deleteRecord( OperationContext* txn, const DiskLoc& dl ) { Record* todelete = recordFor( dl ); invariant( todelete->netLength() >= 4 ); // this is required for defensive code /* remove ourself from the record next/prev chain */ { if ( todelete->prevOfs() != DiskLoc::NullOfs ) { DiskLoc prev = getPrevRecordInExtent( txn, dl ); Record* prevRecord = recordFor( prev ); txn->recoveryUnit()->writingInt( prevRecord->nextOfs() ) = todelete->nextOfs(); } if ( todelete->nextOfs() != DiskLoc::NullOfs ) { DiskLoc next = getNextRecord( txn, dl ); Record* nextRecord = recordFor( next ); txn->recoveryUnit()->writingInt( nextRecord->prevOfs() ) = todelete->prevOfs(); } } /* remove ourself from extent pointers */ { DiskLoc extentLoc = todelete->myExtentLoc(dl); Extent *e = _getExtent( txn, extentLoc ); if ( e->firstRecord == dl ) { txn->recoveryUnit()->writing(&e->firstRecord); if ( todelete->nextOfs() == DiskLoc::NullOfs ) e->firstRecord.Null(); else e->firstRecord.set(dl.a(), todelete->nextOfs() ); } if ( e->lastRecord == dl ) { txn->recoveryUnit()->writing(&e->lastRecord); if ( todelete->prevOfs() == DiskLoc::NullOfs ) e->lastRecord.Null(); else e->lastRecord.set(dl.a(), todelete->prevOfs() ); } } /* add to the free list */ { _details->incrementStats( txn, -1 * todelete->netLength(), -1 ); if ( _isSystemIndexes ) { /* temp: if in system.indexes, don't reuse, and zero out: we want to be careful until validated more, as IndexDetails has pointers to this disk location. so an incorrectly done remove would cause a lot of problems. */ memset( txn->recoveryUnit()->writingPtr(todelete, todelete->lengthWithHeaders() ), 0, todelete->lengthWithHeaders() ); } else { // this is defensive so we can detect if we are still using a location // that was deleted memset(txn->recoveryUnit()->writingPtr(todelete->data(), 4), 0xee, 4); addDeletedRec(txn, dl); } } }