示例#1
0
        bool group( string realdbname , const string& ns , const BSONObj& query ,
                    BSONObj keyPattern , string keyFunctionCode , string reduceCode , const char * reduceScope ,
                    BSONObj initial , string finalize ,
                    string& errmsg , BSONObjBuilder& result ) {


            auto_ptr<Scope> s = globalScriptEngine->getPooledScope( realdbname );
            s->localConnect( realdbname.c_str() );

            if ( reduceScope )
                s->init( reduceScope );

            s->setObject( "$initial" , initial , true );

            s->exec( "$reduce = " + reduceCode , "reduce setup" , false , true , true , 100 );
            s->exec( "$arr = [];" , "reduce setup 2" , false , true , true , 100 );
            ScriptingFunction f = s->createFunction(
                                      "function(){ "
                                      "  if ( $arr[n] == null ){ "
                                      "    next = {}; "
                                      "    Object.extend( next , $key ); "
                                      "    Object.extend( next , $initial , true ); "
                                      "    $arr[n] = next; "
                                      "    next = null; "
                                      "  } "
                                      "  $reduce( obj , $arr[n] ); "
                                      "}" );

            ScriptingFunction keyFunction = 0;
            if ( keyFunctionCode.size() ) {
                keyFunction = s->createFunction( keyFunctionCode.c_str() );
            }


            double keysize = keyPattern.objsize() * 3;
            double keynum = 1;

            map<BSONObj,int,BSONObjCmp> map;
            list<BSONObj> blah;

            shared_ptr<Cursor> cursor = NamespaceDetailsTransient::getCursor(ns.c_str() , query);
            ClientCursor::CleanupPointer ccPointer;
            ccPointer.reset( new ClientCursor( QueryOption_NoCursorTimeout, cursor, ns ) );

            while ( cursor->ok() ) {
                
                if ( !ccPointer->yieldSometimes( ClientCursor::MaybeCovered ) ||
                    !cursor->ok() ) {
                    break;
                }
                
                if ( !cursor->currentMatches() || cursor->getsetdup( cursor->currLoc() ) ) {
                    cursor->advance();
                    continue;
                }

                if ( !ccPointer->yieldSometimes( ClientCursor::WillNeed ) ||
                    !cursor->ok() ) {
                    break;
                }
                
                BSONObj obj = cursor->current();
                cursor->advance();

                BSONObj key = getKey( obj , keyPattern , keyFunction , keysize / keynum , s.get() );
                keysize += key.objsize();
                keynum++;

                int& n = map[key];
                if ( n == 0 ) {
                    n = map.size();
                    s->setObject( "$key" , key , true );

                    uassert( 10043 ,  "group() can't handle more than 20000 unique keys" , n <= 20000 );
                }

                s->setObject( "obj" , obj , true );
                s->setNumber( "n" , n - 1 );
                if ( s->invoke( f , 0, 0 , 0 , true ) ) {
                    throw UserException( 9010 , (string)"reduce invoke failed: " + s->getError() );
                }
            }
            ccPointer.reset();

            if (!finalize.empty()) {
                s->exec( "$finalize = " + finalize , "finalize define" , false , true , true , 100 );
                ScriptingFunction g = s->createFunction(
                                          "function(){ "
                                          "  for(var i=0; i < $arr.length; i++){ "
                                          "  var ret = $finalize($arr[i]); "
                                          "  if (ret !== undefined) "
                                          "    $arr[i] = ret; "
                                          "  } "
                                          "}" );
                s->invoke( g , 0, 0 , 0 , true );
            }

            result.appendArray( "retval" , s->getObject( "$arr" ) );
            result.append( "count" , keynum - 1 );
            result.append( "keys" , (int)(map.size()) );
            s->exec( "$arr = [];" , "reduce setup 2" , false , true , true , 100 );
            s->gc();

            return true;
        }
示例#2
0
    /**
     * Run a query with a cursor provided by the query optimizer, or FindingStartCursor.
     * @yields the db lock.
     */
    const char *queryWithQueryOptimizer( Message &m, int queryOptions, const char *ns,
                                        const BSONObj &jsobj, CurOp& curop,
                                        const BSONObj &query, const BSONObj &order,
                                        const shared_ptr<ParsedQuery> &pq_shared,
                                        const BSONObj &oldPlan,
                                        const ConfigVersion &shardingVersionAtStart,
                                        Message &result ) {

        const ParsedQuery &pq( *pq_shared );
        shared_ptr<Cursor> cursor;
        QueryPlanSummary queryPlan;
        
        if ( pq.hasOption( QueryOption_OplogReplay ) ) {
            cursor = FindingStartCursor::getCursor( ns, query, order );
        }
        else {
            cursor =
            NamespaceDetailsTransient::getCursor( ns, query, order, QueryPlanSelectionPolicy::any(),
                                                 0, pq_shared, &queryPlan );
        }
        verify( cursor );
        
        QueryResponseBuilder queryResponseBuilder( pq, cursor, queryPlan, oldPlan );
        bool saveClientCursor = false;
        const char *exhaust = 0;
        OpTime slaveReadTill;
        ClientCursor::CleanupPointer ccPointer;
        ccPointer.reset( new ClientCursor( QueryOption_NoCursorTimeout, cursor, ns ) );
        
        for( ; cursor->ok(); cursor->advance() ) {

            bool yielded = false;
            if ( !ccPointer->yieldSometimes( ClientCursor::MaybeCovered, &yielded ) ||
                !cursor->ok() ) {
                cursor.reset();
                queryResponseBuilder.noteYield();
                // !!! TODO The queryResponseBuilder still holds cursor.  Currently it will not do
                // anything unsafe with the cursor in handoff(), but this is very fragile.
                //
                // We don't fail the query since we're fine with returning partial data if the
                // collection was dropped.
                // NOTE see SERVER-2454.
                // TODO This is wrong.  The cursor could be gone if the closeAllDatabases command
                // just ran.
                break;
            }

            if ( yielded ) {
                queryResponseBuilder.noteYield();
            }
            
            if ( pq.getMaxScan() && cursor->nscanned() > pq.getMaxScan() ) {
                break;
            }
            
            if ( !queryResponseBuilder.addMatch() ) {
                continue;
            }
            
            // Note slave's position in the oplog.
            if ( pq.hasOption( QueryOption_OplogReplay ) ) {
                BSONObj current = cursor->current();
                BSONElement e = current["ts"];
                if ( e.type() == Date || e.type() == Timestamp ) {
                    slaveReadTill = e._opTime();
                }
            }
            
            if ( !cursor->supportGetMore() || pq.isExplain() ) {
                if ( queryResponseBuilder.enoughTotalResults() ) {
                    break;
                }
            }
            else if ( queryResponseBuilder.enoughForFirstBatch() ) {
                // if only 1 requested, no cursor saved for efficiency...we assume it is findOne()
                if ( pq.wantMore() && pq.getNumToReturn() != 1 ) {
                    queryResponseBuilder.finishedFirstBatch();
                    if ( cursor->advance() ) {
                        saveClientCursor = true;
                    }
                }
                break;
            }
        }
        
        if ( cursor ) {
            if ( pq.hasOption( QueryOption_CursorTailable ) && pq.getNumToReturn() != 1 ) {
                cursor->setTailable();
            }
            
            // If the tailing request succeeded.
            if ( cursor->tailable() ) {
                saveClientCursor = true;
            }
        }
        
        if ( shardingState.getVersion( ns ) != shardingVersionAtStart ) {
            // if the version changed during the query
            // we might be missing some data
            // and its safe to send this as mongos can resend
            // at this point
            throw SendStaleConfigException( ns , "version changed during initial query", shardingVersionAtStart, shardingState.getVersion( ns ) );
        }

        int nReturned = queryResponseBuilder.handoff( result );

        ccPointer.reset();
        long long cursorid = 0;
        if ( saveClientCursor ) {
            // Create a new ClientCursor, with a default timeout.
            ccPointer.reset( new ClientCursor( queryOptions, cursor, ns,
                                              jsobj.getOwned() ) );
            cursorid = ccPointer->cursorid();
            DEV tlog(2) << "query has more, cursorid: " << cursorid << endl;
            if ( cursor->supportYields() ) {
                ClientCursor::YieldData data;
                ccPointer->prepareToYield( data );
            }
            else {
                ccPointer->c()->noteLocation();
            }
            
            // !!! Save the original message buffer, so it can be referenced in getMore.
            ccPointer->originalMessage = m;

            // Save slave's position in the oplog.
            if ( pq.hasOption( QueryOption_OplogReplay ) && !slaveReadTill.isNull() ) {
                ccPointer->slaveReadTill( slaveReadTill );
            }
            
            if ( !ccPointer->ok() && ccPointer->c()->tailable() ) {
                DEV tlog() << "query has no more but tailable, cursorid: " << cursorid << endl;
            }
            
            if( queryOptions & QueryOption_Exhaust ) {
                exhaust = ns;
                curop.debug().exhaust = true;
            }
            
            // Set attributes for getMore.
            ccPointer->setChunkManager( queryResponseBuilder.chunkManager() );
            ccPointer->setPos( nReturned );
            ccPointer->pq = pq_shared;
            ccPointer->fields = pq.getFieldPtr();
            ccPointer.release();
        }
        
        QueryResult *qr = (QueryResult *) result.header();
        qr->cursorId = cursorid;
        curop.debug().cursorid = ( cursorid == 0 ? -1 : qr->cursorId );
        qr->setResultFlagsToOk();
        // qr->len is updated automatically by appendData()
        curop.debug().responseLength = qr->len;
        qr->setOperation(opReply);
        qr->startingFrom = 0;
        qr->nReturned = nReturned;
        
        int duration = curop.elapsedMillis();
        bool dbprofile = curop.shouldDBProfile( duration );
        if ( dbprofile || duration >= cmdLine.slowMS ) {
            curop.debug().nscanned = (int)( cursor ? cursor->nscanned() : 0 );
            curop.debug().ntoskip = pq.getSkip();
        }
        curop.debug().nreturned = nReturned;

        return exhaust;
    }