C++ BSONElementSet::count方法代码示例

    bool AllMatchExpression::_match( const BSONElementSet& all ) const {

        if ( all.size() == 0 )
            return _arrayEntries.singleNull();

        const BSONElementSet& equalities = _arrayEntries.equalities();
        for ( BSONElementSet::const_iterator i = equalities.begin(); i != equalities.end(); ++i ) {
            BSONElement foo = *i;
            if ( all.count( foo ) == 0 )
                return false;
        }

        for ( size_t i = 0; i < _arrayEntries.numRegexes(); i++ ) {

            bool found = false;
            for ( BSONElementSet::const_iterator j = all.begin(); j != all.end(); ++j ) {
                BSONElement bar = *j;
                if ( _arrayEntries.regex(i)->matchesSingleElement( bar ) ) {
                    found = true;
                    break;
                }
            }
            if ( ! found )
                return false;

        }

        return true;
    }

        bool run(const string& dbname, BSONObj& cmdObj, int, string& errmsg, BSONObjBuilder& result, bool fromRepl ) {
            Timer t;
            string ns = dbname + '.' + cmdObj.firstElement().valuestr();

            string key = cmdObj["key"].valuestrsafe();
            BSONObj keyPattern = BSON( key << 1 );

            BSONObj query = getQuery( cmdObj );

            int bufSize = BSONObjMaxUserSize - 4096;
            BufBuilder bb( bufSize );
            char * start = bb.buf();

            BSONArrayBuilder arr( bb );
            BSONElementSet values;

            long long nscanned = 0; // locations looked at
            long long nscannedObjects = 0; // full objects looked at
            long long n = 0; // matches
            MatchDetails md;

            Collection *cl = getCollection( ns );

            if ( ! cl ) {
                result.appendArray( "values" , BSONObj() );
                result.append( "stats" , BSON( "n" << 0 << "nscanned" << 0 << "nscannedObjects" << 0 ) );
                return true;
            }

            shared_ptr<Cursor> cursor;
            if ( ! query.isEmpty() ) {
                cursor = getOptimizedCursor(ns.c_str() , query , BSONObj() );
            }
            else {

                // query is empty, so lets see if we can find an index
                // with the key so we don't have to hit the raw data
                for (int i = 0; i < cl->nIndexes(); i++) {
                    IndexDetails &idx = cl->idx(i);
                    if (cl->isMultikey(i)) {
                        continue;
                    }

                    if ( idx.inKeyPattern( key ) ) {
                        cursor = getBestGuessCursor( ns.c_str() ,
                                                     BSONObj() ,
                                                     idx.keyPattern() );
                        if( cursor.get() ) break;
                    }

                }

                if ( ! cursor.get() ) {
                    cursor = getOptimizedCursor(ns.c_str() , query , BSONObj() );
                }

            }

            
            verify( cursor );
            string cursorName = cursor->toString();
            
            auto_ptr<ClientCursor> cc (new ClientCursor(QueryOption_NoCursorTimeout, cursor, ns));

            for ( ; cursor->ok(); cursor->advance() ) {
                nscanned++;
                bool loadedRecord = false;

                if ( cursor->currentMatches( &md ) && !cursor->getsetdup( cursor->currPK() ) ) {
                    n++;

                    BSONObj holder;
                    BSONElementSet temp;
                    loadedRecord = ! cc->getFieldsDotted( key , temp, holder );

                    for ( BSONElementSet::iterator i=temp.begin(); i!=temp.end(); ++i ) {
                        BSONElement e = *i;
                        if ( values.count( e ) )
                            continue;

                        int now = bb.len();

                        uassert(10044,  "distinct too big, 16mb cap", ( now + e.size() + 1024 ) < bufSize );

                        arr.append( e );
                        BSONElement x( start + now );

                        values.insert( x );
                    }
                }

                if ( loadedRecord || md.hasLoadedRecord() )
                    nscannedObjects++;

                RARELY killCurrentOp.checkForInterrupt();
            }

            verify( start == bb.buf() );

            result.appendArray( "values" , arr.done() );
//.........这里部分代码省略.........

        bool run(const string& dbname, BSONObj& cmdObj, int, string& errmsg, BSONObjBuilder& result,
                 bool fromRepl ) {

            Timer t;
            string ns = dbname + '.' + cmdObj.firstElement().valuestr();

            string key = cmdObj["key"].valuestrsafe();
            BSONObj keyPattern = BSON( key << 1 );

            BSONObj query = getQuery( cmdObj );

            int bufSize = BSONObjMaxUserSize - 4096;
            BufBuilder bb( bufSize );
            char * start = bb.buf();

            BSONArrayBuilder arr( bb );
            BSONElementSet values;

            long long nscanned = 0; // locations looked at
            long long nscannedObjects = 0; // full objects looked at
            long long n = 0; // matches

            NamespaceDetails * d = nsdetails( ns );

            string cursorName;

            if (!d) {
                result.appendArray( "values" , BSONObj() );
                result.append("stats", BSON("n" << 0 <<
                                            "nscanned" << 0 <<
                                            "nscannedObjects" << 0));
                return true;
            }

            CanonicalQuery* cq;
            // XXX: project out just the field we're distinct-ing.  May be covered...
            if (!CanonicalQuery::canonicalize(ns, query, &cq).isOK()) {
                uasserted(17215, "Can't canonicalize query " + query.toString());
                return 0;
            }

            Runner* rawRunner;
            if (!getRunner(cq, &rawRunner).isOK()) {
                uasserted(17216, "Can't get runner for query " + query.toString());
                return 0;
            }

            auto_ptr<Runner> runner(rawRunner);
            auto_ptr<DeregisterEvenIfUnderlyingCodeThrows> safety;
            ClientCursor::registerRunner(runner.get());
            runner->setYieldPolicy(Runner::YIELD_AUTO);
            safety.reset(new DeregisterEvenIfUnderlyingCodeThrows(runner.get()));

            BSONObj obj;
            Runner::RunnerState state;
            while (Runner::RUNNER_ADVANCED == (state = runner->getNext(&obj, NULL))) {
                BSONElementSet elts;
                obj.getFieldsDotted(key, elts);

                for (BSONElementSet::iterator it = elts.begin(); it != elts.end(); ++it) {
                    BSONElement elt = *it;
                    if (values.count(elt)) { continue; }
                    int currentBufPos = bb.len();

                    uassert(17217, "distinct too big, 16mb cap",
                            (currentBufPos + elt.size() + 1024) < bufSize);

                    arr.append(elt);
                    BSONElement x(start + currentBufPos);
                    values.insert(x);
                }
            }
            TypeExplain* bareExplain;
            Status res = runner->getExplainPlan(&bareExplain);
            if (res.isOK()) {
                auto_ptr<TypeExplain> explain(bareExplain);
                if (explain->isCursorSet()) {
                    cursorName = explain->getCursor();
                }
                n = explain->getN();
                nscanned = explain->getNScanned();
                nscannedObjects = explain->getNScannedObjects();
            }

            verify( start == bb.buf() );

            result.appendArray( "values" , arr.done() );

            {
                BSONObjBuilder b;
                b.appendNumber( "n" , n );
                b.appendNumber( "nscanned" , nscanned );
                b.appendNumber( "nscannedObjects" , nscannedObjects );
                b.appendNumber( "timems" , t.millis() );
                b.append( "cursor" , cursorName );
                result.append( "stats" , b.obj() );
            }

            return true;
        }

    bool run(OperationContext* txn,
             const string& dbname,
             BSONObj& cmdObj,
             int,
             string& errmsg,
             BSONObjBuilder& result) {
        Timer t;

        // ensure that the key is a string
        uassert(18510,
                mongoutils::str::stream() << "The first argument to the distinct command "
                                          << "must be a string but was a "
                                          << typeName(cmdObj["key"].type()),
                cmdObj["key"].type() == mongo::String);

        // ensure that the where clause is a document
        if (cmdObj["query"].isNull() == false && cmdObj["query"].eoo() == false) {
            uassert(18511,
                    mongoutils::str::stream() << "The query for the distinct command must be a "
                                              << "document but was a "
                                              << typeName(cmdObj["query"].type()),
                    cmdObj["query"].type() == mongo::Object);
        }

        string key = cmdObj["key"].valuestrsafe();
        BSONObj keyPattern = BSON(key << 1);

        BSONObj query = getQuery(cmdObj);

        int bufSize = BSONObjMaxUserSize - 4096;
        BufBuilder bb(bufSize);
        char* start = bb.buf();

        BSONArrayBuilder arr(bb);
        BSONElementSet values;

        const string ns = parseNs(dbname, cmdObj);
        AutoGetCollectionForRead ctx(txn, ns);

        Collection* collection = ctx.getCollection();
        if (!collection) {
            result.appendArray("values", BSONObj());
            result.append("stats", BSON("n" << 0 << "nscanned" << 0 << "nscannedObjects" << 0));
            return true;
        }

        auto statusWithPlanExecutor =
            getExecutorDistinct(txn, collection, query, key, PlanExecutor::YIELD_AUTO);
        if (!statusWithPlanExecutor.isOK()) {
            uasserted(17216,
                      mongoutils::str::stream() << "Can't get executor for query " << query << ": "
                                                << statusWithPlanExecutor.getStatus().toString());
            return 0;
        }

        unique_ptr<PlanExecutor> exec = std::move(statusWithPlanExecutor.getValue());

        BSONObj obj;
        PlanExecutor::ExecState state;
        while (PlanExecutor::ADVANCED == (state = exec->getNext(&obj, NULL))) {
            // Distinct expands arrays.
            //
            // If our query is covered, each value of the key should be in the index key and
            // available to us without this.  If a collection scan is providing the data, we may
            // have to expand an array.
            BSONElementSet elts;
            obj.getFieldsDotted(key, elts);

            for (BSONElementSet::iterator it = elts.begin(); it != elts.end(); ++it) {
                BSONElement elt = *it;
                if (values.count(elt)) {
                    continue;
                }
                int currentBufPos = bb.len();

                uassert(17217,
                        "distinct too big, 16mb cap",
                        (currentBufPos + elt.size() + 1024) < bufSize);

                arr.append(elt);
                BSONElement x(start + currentBufPos);
                values.insert(x);
            }
        }

        // Get summary information about the plan.
        PlanSummaryStats stats;
        Explain::getSummaryStats(*exec, &stats);

        verify(start == bb.buf());

        result.appendArray("values", arr.done());

        {
            BSONObjBuilder b;
            b.appendNumber("n", stats.nReturned);
            b.appendNumber("nscanned", stats.totalKeysExamined);
            b.appendNumber("nscannedObjects", stats.totalDocsExamined);
            b.appendNumber("timems", t.millis());
            b.append("planSummary", Explain::getPlanSummary(exec.get()));
//.........这里部分代码省略.........

        bool run(const string& dbname, BSONObj& cmdObj, int, string& errmsg, BSONObjBuilder& result, bool fromRepl ) {
            Timer t;
            string ns = dbname + '.' + cmdObj.firstElement().valuestr();

            string key = cmdObj["key"].valuestrsafe();
            BSONObj keyPattern = BSON( key << 1 );

            BSONObj query = getQuery( cmdObj );

            int bufSize = BSONObjMaxUserSize - 4096;
            BufBuilder bb( bufSize );
            char * start = bb.buf();

            BSONArrayBuilder arr( bb );
            BSONElementSet values;

            long long nscanned = 0; // locations looked at
            long long nscannedObjects = 0; // full objects looked at
            long long n = 0; // matches
            MatchDetails md;

            NamespaceDetails * d = nsdetails( ns );

            if ( ! d ) {
                result.appendArray( "values" , BSONObj() );
                result.append( "stats" , BSON( "n" << 0 << "nscanned" << 0 << "nscannedObjects" << 0 ) );
                return true;
            }

            shared_ptr<Cursor> cursor;
            if ( ! query.isEmpty() ) {
                cursor = getOptimizedCursor( ns.c_str(), query, BSONObj() );
            }
            else {

                // query is empty, so lets see if we can find an index
                // with the key so we don't have to hit the raw data
                NamespaceDetails::IndexIterator ii = d->ii();
                while ( ii.more() ) {
                    IndexDetails& idx = ii.next();

                    if ( d->isMultikey( ii.pos() - 1 ) )
                        continue;

                    if ( idx.inKeyPattern( key ) ) {
                        cursor = getBestGuessCursor( ns.c_str(), BSONObj(), idx.keyPattern() );
                        if( cursor.get() ) break;
                    }

                }

                if ( ! cursor.get() )
                    cursor = getOptimizedCursor(ns.c_str() , query , BSONObj() );

            }

            
            verify( cursor );
            string cursorName = cursor->toString();
            
            auto_ptr<ClientCursor> cc (new ClientCursor(QueryOption_NoCursorTimeout, cursor, ns));

            // map from indexed field to offset in key object
            map<string, int> indexedFields;  
            if (!cursor->modifiedKeys()) {
                // store index information so we can decide if we can
                // get something out of the index key rather than full object

                int x = 0;
                BSONObjIterator i( cursor->indexKeyPattern() );
                while ( i.more() ) {
                    BSONElement e = i.next();
                    if ( e.isNumber() ) {
                        // only want basic index fields, not "2d" etc
                        indexedFields[e.fieldName()] = x;
                    }
                    x++;
                }
            }

            while ( cursor->ok() ) {
                nscanned++;
                bool loadedRecord = false;

                if ( cursor->currentMatches( &md ) && !cursor->getsetdup( cursor->currLoc() ) ) {
                    n++;

                    BSONObj holder;
                    BSONElementSet temp;
                    // Try to get the record from the key fields.
                    loadedRecord = !getFieldsDotted(indexedFields, cursor, key, temp, holder);

                    for ( BSONElementSet::iterator i=temp.begin(); i!=temp.end(); ++i ) {
                        BSONElement e = *i;
                        if ( values.count( e ) )
                            continue;

                        int now = bb.len();

                        uassert(10044,  "distinct too big, 16mb cap", ( now + e.size() + 1024 ) < bufSize );
//.........这里部分代码省略.........

        bool run(const string& dbname, BSONObj& cmdObj, int, string& errmsg, BSONObjBuilder& result,
                 bool fromRepl ) {

            Timer t;
            string ns = dbname + '.' + cmdObj.firstElement().valuestr();

            string key = cmdObj["key"].valuestrsafe();
            BSONObj keyPattern = BSON( key << 1 );

            BSONObj query = getQuery( cmdObj );

            int bufSize = BSONObjMaxUserSize - 4096;
            BufBuilder bb( bufSize );
            char * start = bb.buf();

            BSONArrayBuilder arr( bb );
            BSONElementSet values;

            long long nscanned = 0; // locations looked at
            long long nscannedObjects = 0; // full objects looked at
            long long n = 0; // matches

            Collection* collection = cc().database()->getCollection( ns );

            if (!collection) {
                result.appendArray( "values" , BSONObj() );
                result.append("stats", BSON("n" << 0 <<
                                            "nscanned" << 0 <<
                                            "nscannedObjects" << 0));
                return true;
            }

            Runner* rawRunner;
            Status status = getRunnerDistinct(collection, query, key, &rawRunner);
            if (!status.isOK()) {
                uasserted(17216, mongoutils::str::stream() << "Can't get runner for query "
                              << query << ": " << status.toString());
                return 0;
            }

            auto_ptr<Runner> runner(rawRunner);
            const ScopedRunnerRegistration safety(runner.get());
            runner->setYieldPolicy(Runner::YIELD_AUTO);

            string cursorName;
            BSONObj obj;
            Runner::RunnerState state;
            while (Runner::RUNNER_ADVANCED == (state = runner->getNext(&obj, NULL))) {
                // Distinct expands arrays.
                //
                // If our query is covered, each value of the key should be in the index key and
                // available to us without this.  If a collection scan is providing the data, we may
                // have to expand an array.
                BSONElementSet elts;
                obj.getFieldsDotted(key, elts);

                for (BSONElementSet::iterator it = elts.begin(); it != elts.end(); ++it) {
                    BSONElement elt = *it;
                    if (values.count(elt)) { continue; }
                    int currentBufPos = bb.len();

                    uassert(17217, "distinct too big, 16mb cap",
                            (currentBufPos + elt.size() + 1024) < bufSize);

                    arr.append(elt);
                    BSONElement x(start + currentBufPos);
                    values.insert(x);
                }
            }
            TypeExplain* bareExplain;
            Status res = runner->getInfo(&bareExplain, NULL);
            if (res.isOK()) {
                auto_ptr<TypeExplain> explain(bareExplain);
                if (explain->isCursorSet()) {
                    cursorName = explain->getCursor();
                }
                n = explain->getN();
                nscanned = explain->getNScanned();
                nscannedObjects = explain->getNScannedObjects();
            }

            verify( start == bb.buf() );

            result.appendArray( "values" , arr.done() );

            {
                BSONObjBuilder b;
                b.appendNumber( "n" , n );
                b.appendNumber( "nscanned" , nscanned );
                b.appendNumber( "nscannedObjects" , nscannedObjects );
                b.appendNumber( "timems" , t.millis() );
                b.append( "cursor" , cursorName );
                result.append( "stats" , b.obj() );
            }

            return true;
        }

        bool run(const string& dbname, BSONObj& cmdObj, string& errmsg, BSONObjBuilder& result, bool fromRepl ) {
            Timer t;
            string ns = dbname + '.' + cmdObj.firstElement().valuestr();

            string key = cmdObj["key"].valuestrsafe();
            BSONObj keyPattern = BSON( key << 1 );

            BSONObj query = getQuery( cmdObj );

            int bufSize = BSONObjMaxUserSize - 4096;
            BufBuilder bb( bufSize );
            char * start = bb.buf();

            BSONArrayBuilder arr( bb );
            BSONElementSet values;

            long long nscanned = 0; // locations looked at
            long long nscannedObjects = 0; // full objects looked at
            long long n = 0; // matches
            MatchDetails md;

            NamespaceDetails * d = nsdetails( ns.c_str() );

            if ( ! d ) {
                result.appendArray( "values" , BSONObj() );
                result.append( "stats" , BSON( "n" << 0 << "nscanned" << 0 << "nscannedObjects" << 0 ) );
                return true;
            }

            shared_ptr<Cursor> cursor;
            if ( ! query.isEmpty() ) {
                cursor = NamespaceDetailsTransient::getCursor(ns.c_str() , query , BSONObj() );
            }
            else {

                // query is empty, so lets see if we can find an index
                // with the key so we don't have to hit the raw data
                NamespaceDetails::IndexIterator ii = d->ii();
                while ( ii.more() ) {
                    IndexDetails& idx = ii.next();

                    if ( d->isMultikey( ii.pos() - 1 ) )
                        continue;

                    if ( idx.inKeyPattern( key ) ) {
                        cursor = bestGuessCursor( ns.c_str() , BSONObj() , idx.keyPattern() );
                        if( cursor.get() ) break;
                    }

                }

                if ( ! cursor.get() )
                    cursor = NamespaceDetailsTransient::getCursor(ns.c_str() , query , BSONObj() );

            }

            
            assert( cursor );
            string cursorName = cursor->toString();
            
            auto_ptr<ClientCursor> cc (new ClientCursor(QueryOption_NoCursorTimeout, cursor, ns));

            while ( cursor->ok() ) {
                nscanned++;
                bool loadedObject = false;

                if ( ( !cursor->matcher() || cursor->matcher()->matchesCurrent( cursor.get() , &md ) ) &&
                    !cursor->getsetdup( cursor->currLoc() ) ) {
                    n++;

                    BSONElementSet temp;
                    loadedObject = ! cc->getFieldsDotted( key , temp );

                    for ( BSONElementSet::iterator i=temp.begin(); i!=temp.end(); ++i ) {
                        BSONElement e = *i;
                        if ( values.count( e ) )
                            continue;

                        int now = bb.len();

                        uassert(10044,  "distinct too big, 16mb cap", ( now + e.size() + 1024 ) < bufSize );

                        arr.append( e );
                        BSONElement x( start + now );

                        values.insert( x );
                    }
                }

                if ( loadedObject || md._loadedObject )
                    nscannedObjects++;

                cursor->advance();

                if (!cc->yieldSometimes( ClientCursor::MaybeCovered )) {
                    cc.release();
                    break;
                }

                RARELY killCurrentOp.checkForInterrupt();
//.........这里部分代码省略.........

    bool run(OperationContext* txn,
             const string& dbname,
             BSONObj& cmdObj,
             int,
             string& errmsg,
             BSONObjBuilder& result) {
        Timer t;

        const string ns = parseNs(dbname, cmdObj);
        AutoGetCollectionForRead ctx(txn, ns);

        Collection* collection = ctx.getCollection();

        auto executor = getPlanExecutor(txn, collection, ns, cmdObj, false);
        if (!executor.isOK()) {
            return appendCommandStatus(result, executor.getStatus());
        }

        string key = cmdObj[kKeyField].valuestrsafe();

        int bufSize = BSONObjMaxUserSize - 4096;
        BufBuilder bb(bufSize);
        char* start = bb.buf();

        BSONArrayBuilder arr(bb);
        BSONElementSet values;

        BSONObj obj;
        PlanExecutor::ExecState state;
        while (PlanExecutor::ADVANCED == (state = executor.getValue()->getNext(&obj, NULL))) {
            // Distinct expands arrays.
            //
            // If our query is covered, each value of the key should be in the index key and
            // available to us without this.  If a collection scan is providing the data, we may
            // have to expand an array.
            BSONElementSet elts;
            obj.getFieldsDotted(key, elts);

            for (BSONElementSet::iterator it = elts.begin(); it != elts.end(); ++it) {
                BSONElement elt = *it;
                if (values.count(elt)) {
                    continue;
                }
                int currentBufPos = bb.len();

                uassert(17217,
                        "distinct too big, 16mb cap",
                        (currentBufPos + elt.size() + 1024) < bufSize);

                arr.append(elt);
                BSONElement x(start + currentBufPos);
                values.insert(x);
            }
        }

        // Return an error if execution fails for any reason.
        if (PlanExecutor::FAILURE == state || PlanExecutor::DEAD == state) {
            const std::unique_ptr<PlanStageStats> stats(executor.getValue()->getStats());
            log() << "Plan executor error during distinct command: "
                  << PlanExecutor::statestr(state) << ", stats: " << Explain::statsToBSON(*stats);

            return appendCommandStatus(result,
                                       Status(ErrorCodes::OperationFailed,
                                              str::stream()
                                                  << "Executor error during distinct command: "
                                                  << WorkingSetCommon::toStatusString(obj)));
        }


        // Get summary information about the plan.
        PlanSummaryStats stats;
        Explain::getSummaryStats(*executor.getValue(), &stats);
        collection->infoCache()->notifyOfQuery(txn, stats.indexesUsed);
        CurOp::get(txn)->debug().fromMultiPlanner = stats.fromMultiPlanner;
        CurOp::get(txn)->debug().replanned = stats.replanned;

        verify(start == bb.buf());

        result.appendArray("values", arr.done());

        {
            BSONObjBuilder b;
            b.appendNumber("n", stats.nReturned);
            b.appendNumber("nscanned", stats.totalKeysExamined);
            b.appendNumber("nscannedObjects", stats.totalDocsExamined);
            b.appendNumber("timems", t.millis());
            b.append("planSummary", Explain::getPlanSummary(executor.getValue().get()));
            result.append("stats", b.obj());
        }

        return true;
    }