diff options
Diffstat (limited to 'src/mongo/db/ops/delete.cpp')
| -rw-r--r-- | src/mongo/db/ops/delete.cpp | 158 |
1 files changed, 158 insertions, 0 deletions
diff --git a/src/mongo/db/ops/delete.cpp b/src/mongo/db/ops/delete.cpp new file mode 100644 index 00000000000..e33611c151e --- /dev/null +++ b/src/mongo/db/ops/delete.cpp @@ -0,0 +1,158 @@ +// delete.cpp + +/** +* Copyright (C) 2008 10gen Inc. +* +* This program is free software: you can redistribute it and/or modify +* it under the terms of the GNU Affero General Public License, version 3, +* as published by the Free Software Foundation. +* +* This program is distributed in the hope that it will be useful, +* but WITHOUT ANY WARRANTY; without even the implied warranty of +* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +* GNU Affero General Public License for more details. +* +* You should have received a copy of the GNU Affero General Public License +* along with this program. If not, see <http://www.gnu.org/licenses/>. +*/ + +#include "pch.h" +#include "delete.h" +#include "../queryoptimizer.h" +#include "../oplog.h" + +namespace mongo { + + /* ns: namespace, e.g. <database>.<collection> + pattern: the "where" clause / criteria + justOne: stop after 1 match + god: allow access to system namespaces, and don't yield + */ + long long deleteObjects(const char *ns, BSONObj pattern, bool justOneOrig, bool logop, bool god, RemoveSaver * rs ) { + if( !god ) { + if ( strstr(ns, ".system.") ) { + /* note a delete from system.indexes would corrupt the db + if done here, as there are pointers into those objects in + NamespaceDetails. + */ + uassert(12050, "cannot delete from system namespace", legalClientSystemNS( ns , true ) ); + } + if ( strchr( ns , '$' ) ) { + log() << "cannot delete from collection with reserved $ in name: " << ns << endl; + uassert( 10100 , "cannot delete from collection with reserved $ in name", strchr(ns, '$') == 0 ); + } + } + + { + NamespaceDetails *d = nsdetails( ns ); + if ( ! d ) + return 0; + uassert( 10101 , "can't remove from a capped collection" , ! d->capped ); + } + + long long nDeleted = 0; + + shared_ptr< Cursor > creal = NamespaceDetailsTransient::getCursor( ns, pattern, BSONObj(), false, 0 ); + + if( !creal->ok() ) + return nDeleted; + + shared_ptr< Cursor > cPtr = creal; + auto_ptr<ClientCursor> cc( new ClientCursor( QueryOption_NoCursorTimeout, cPtr, ns) ); + cc->setDoingDeletes( true ); + + CursorId id = cc->cursorid(); + + bool justOne = justOneOrig; + bool canYield = !god && !(creal->matcher() && creal->matcher()->docMatcher().atomic()); + + do { + // TODO: we can generalize this I believe + // + bool willNeedRecord = (creal->matcher() && creal->matcher()->needRecord()) || pattern.isEmpty() || isSimpleIdQuery( pattern ); + if ( ! willNeedRecord ) { + // TODO: this is a total hack right now + // check if the index full encompasses query + + if ( pattern.nFields() == 1 && + str::equals( pattern.firstElement().fieldName() , creal->indexKeyPattern().firstElement().fieldName() ) ) + willNeedRecord = true; + } + + if ( canYield && ! cc->yieldSometimes( willNeedRecord ? ClientCursor::WillNeed : ClientCursor::MaybeCovered ) ) { + cc.release(); // has already been deleted elsewhere + // TODO should we assert or something? + break; + } + if ( !cc->ok() ) { + break; // if we yielded, could have hit the end + } + + // this way we can avoid calling updateLocation() every time (expensive) + // as well as some other nuances handled + cc->setDoingDeletes( true ); + + DiskLoc rloc = cc->currLoc(); + BSONObj key = cc->currKey(); + + bool match = creal->currentMatches(); + bool dup = cc->c()->getsetdup(rloc); + + if ( ! cc->advance() ) + justOne = true; + + if ( ! match ) + continue; + + assert( !dup ); // can't be a dup, we deleted it! + + if ( !justOne ) { + /* NOTE: this is SLOW. this is not good, noteLocation() was designed to be called across getMore + blocks. here we might call millions of times which would be bad. + */ + cc->c()->prepareToTouchEarlierIterate(); + } + + if ( logop ) { + BSONElement e; + if( BSONObj( rloc.rec() ).getObjectID( e ) ) { + BSONObjBuilder b; + b.append( e ); + bool replJustOne = true; + logOp( "d", ns, b.done(), 0, &replJustOne ); + } + else { + problem() << "deleted object without id, not logging" << endl; + } + } + + if ( rs ) + rs->goingToDelete( rloc.obj() /*cc->c->current()*/ ); + + theDataFileMgr.deleteRecord(ns, rloc.rec(), rloc); + nDeleted++; + if ( justOne ) { + break; + } + cc->c()->recoverFromTouchingEarlierIterate(); + + if( !god ) + getDur().commitIfNeeded(); + + if( debug && god && nDeleted == 100 ) + log() << "warning high number of deletes with god=true which could use significant memory" << endl; + } + while ( cc->ok() ); + + if ( cc.get() && ClientCursor::find( id , false ) == 0 ) { + // TODO: remove this and the id declaration above if this doesn't trigger + // if it does, then i'm very confused (ERH 06/2011) + error() << "this should be impossible" << endl; + printStackTrace(); + cc.release(); + } + + return nDeleted; + } + +} |