C++ BSONObj::nFields方法代码示例

    // static
    Status ParsedProjection::make(const BSONObj& spec, 
                                  const MatchExpression* const query,
                                  ParsedProjection** out,
                                  const MatchExpressionParser::WhereCallback& whereCallback) {
        // Are we including or excluding fields?  Values:
        // -1 when we haven't initialized it.
        // 1 when we're including
        // 0 when we're excluding.
        int include_exclude = -1;

        // If any of these are 'true' the projection isn't covered.
        bool include = true;
        bool hasNonSimple = false;
        bool hasDottedField = false;

        bool includeID = true;

        bool hasIndexKeyProjection = false;

        bool wantGeoNearPoint = false;
        bool wantGeoNearDistance = false;

        // Until we see a positional or elemMatch operator we're normal.
        ArrayOpType arrayOpType = ARRAY_OP_NORMAL;

        BSONObjIterator it(spec);
        while (it.more()) {
            BSONElement e = it.next();

            if (!e.isNumber() && !e.isBoolean()) {
                hasNonSimple = true;
            }

            if (Object == e.type()) {
                BSONObj obj = e.embeddedObject();
                if (1 != obj.nFields()) {
                    return Status(ErrorCodes::BadValue, ">1 field in obj: " + obj.toString());
                }

                BSONElement e2 = obj.firstElement();
                if (mongoutils::str::equals(e2.fieldName(), "$slice")) {
                    if (e2.isNumber()) {
                        // This is A-OK.
                    }
                    else if (e2.type() == Array) {
                        BSONObj arr = e2.embeddedObject();
                        if (2 != arr.nFields()) {
                            return Status(ErrorCodes::BadValue, "$slice array wrong size");
                        }

                        BSONObjIterator it(arr);
                        // Skip over 'skip'.
                        it.next();
                        int limit = it.next().numberInt();
                        if (limit <= 0) {
                            return Status(ErrorCodes::BadValue, "$slice limit must be positive");
                        }
                    }
                    else {
                        return Status(ErrorCodes::BadValue,
                                      "$slice only supports numbers and [skip, limit] arrays");
                    }
                }
                else if (mongoutils::str::equals(e2.fieldName(), "$elemMatch")) {
                    // Validate $elemMatch arguments and dependencies.
                    if (Object != e2.type()) {
                        return Status(ErrorCodes::BadValue,
                                      "elemMatch: Invalid argument, object required.");
                    }

                    if (ARRAY_OP_POSITIONAL == arrayOpType) {
                        return Status(ErrorCodes::BadValue,
                                      "Cannot specify positional operator and $elemMatch.");
                    }

                    if (mongoutils::str::contains(e.fieldName(), '.')) {
                        return Status(ErrorCodes::BadValue,
                                      "Cannot use $elemMatch projection on a nested field.");
                    }

                    arrayOpType = ARRAY_OP_ELEM_MATCH;

                    // Create a MatchExpression for the elemMatch.
                    BSONObj elemMatchObj = e.wrap();
                    verify(elemMatchObj.isOwned());

                    // TODO: Is there a faster way of validating the elemMatchObj?
                    StatusWithMatchExpression swme = MatchExpressionParser::parse(elemMatchObj,
                                                                                  whereCallback);
                    if (!swme.isOK()) {
                        return swme.getStatus();
                    }
                    delete swme.getValue();
                }
                else if (mongoutils::str::equals(e2.fieldName(), "$meta")) {
                    // Field for meta must be top level.  We can relax this at some point.
                    if (mongoutils::str::contains(e.fieldName(), '.')) {
                        return Status(ErrorCodes::BadValue, "field for $meta cannot be nested");
                    }
//.........这里部分代码省略.........

ProjectionExec::ProjectionExec(const BSONObj& spec,
                               const MatchExpression* queryExpression,
                               const CollatorInterface* collator,
                               const ExtensionsCallback& extensionsCallback)
    : _include(true),
      _special(false),
      _source(spec),
      _includeID(true),
      _skip(0),
      _limit(-1),
      _arrayOpType(ARRAY_OP_NORMAL),
      _queryExpression(queryExpression),
      _hasReturnKey(false),
      _collator(collator) {
    // Whether we're including or excluding fields.
    enum class IncludeExclude { kUninitialized, kInclude, kExclude };
    IncludeExclude includeExclude = IncludeExclude::kUninitialized;

    BSONObjIterator it(_source);
    while (it.more()) {
        BSONElement e = it.next();

        if (Object == e.type()) {
            BSONObj obj = e.embeddedObject();
            verify(1 == obj.nFields());

            BSONElement e2 = obj.firstElement();
            if (mongoutils::str::equals(e2.fieldName(), "$slice")) {
                if (e2.isNumber()) {
                    int i = e2.numberInt();
                    if (i < 0) {
                        add(e.fieldName(), i, -i);  // limit is now positive
                    } else {
                        add(e.fieldName(), 0, i);
                    }
                } else {
                    verify(e2.type() == Array);
                    BSONObj arr = e2.embeddedObject();
                    verify(2 == arr.nFields());

                    BSONObjIterator it(arr);
                    int skip = it.next().numberInt();
                    int limit = it.next().numberInt();

                    verify(limit > 0);

                    add(e.fieldName(), skip, limit);
                }
            } else if (mongoutils::str::equals(e2.fieldName(), "$elemMatch")) {
                _arrayOpType = ARRAY_OP_ELEM_MATCH;

                // Create a MatchExpression for the elemMatch.
                BSONObj elemMatchObj = e.wrap();
                verify(elemMatchObj.isOwned());
                _elemMatchObjs.push_back(elemMatchObj);
                StatusWithMatchExpression statusWithMatcher =
                    MatchExpressionParser::parse(elemMatchObj, extensionsCallback, _collator);
                verify(statusWithMatcher.isOK());
                // And store it in _matchers.
                _matchers[mongoutils::str::before(e.fieldName(), '.').c_str()] =
                    statusWithMatcher.getValue().release();

                add(e.fieldName(), true);
            } else if (mongoutils::str::equals(e2.fieldName(), "$meta")) {
                verify(String == e2.type());
                if (e2.valuestr() == QueryRequest::metaTextScore) {
                    _meta[e.fieldName()] = META_TEXT_SCORE;
                } else if (e2.valuestr() == QueryRequest::metaSortKey) {
                    _sortKeyMetaFields.push_back(e.fieldName());
                    _meta[_sortKeyMetaFields.back()] = META_SORT_KEY;
                } else if (e2.valuestr() == QueryRequest::metaRecordId) {
                    _meta[e.fieldName()] = META_RECORDID;
                } else if (e2.valuestr() == QueryRequest::metaGeoNearPoint) {
                    _meta[e.fieldName()] = META_GEONEAR_POINT;
                } else if (e2.valuestr() == QueryRequest::metaGeoNearDistance) {
                    _meta[e.fieldName()] = META_GEONEAR_DIST;
                } else if (e2.valuestr() == QueryRequest::metaIndexKey) {
                    _hasReturnKey = true;
                } else {
                    // This shouldn't happen, should be caught by parsing.
                    verify(0);
                }
            } else {
                verify(0);
            }
        } else if (mongoutils::str::equals(e.fieldName(), "_id") && !e.trueValue()) {
            _includeID = false;
        } else {
            add(e.fieldName(), e.trueValue());

            // If we haven't specified an include/exclude, initialize includeExclude.
            if (includeExclude == IncludeExclude::kUninitialized) {
                includeExclude =
                    e.trueValue() ? IncludeExclude::kInclude : IncludeExclude::kExclude;
                _include = !e.trueValue();
            }
        }

        if (mongoutils::str::contains(e.fieldName(), ".$")) {
            _arrayOpType = ARRAY_OP_POSITIONAL;
//.........这里部分代码省略.........

        void _update( Request& r , DbMessage& d, ChunkManager* manager ){
            int flags = d.pullInt();
            
            BSONObj query = d.nextJsObj();
            uassert( 10201 ,  "invalid update" , d.moreJSObjs() );
            BSONObj toupdate = d.nextJsObj();

            BSONObj chunkFinder = query;
            
            bool upsert = flags & UpdateOption_Upsert;
            bool multi = flags & UpdateOption_Multi;

            if ( multi )
                uassert( 10202 ,  "can't mix multi and upsert and sharding" , ! upsert );

            if ( upsert && !(manager->hasShardKey(toupdate) ||
                             (toupdate.firstElement().fieldName()[0] == '$' && manager->hasShardKey(query))))
            {
                throw UserException( 8012 , "can't upsert something without shard key" );
            }

            bool save = false;
            if ( ! manager->hasShardKey( query ) ){
                if ( multi ){
                }
                else if ( query.nFields() != 1 || strcmp( query.firstElement().fieldName() , "_id" ) ){
                    throw UserException( 8013 , "can't do update with query that doesn't have the shard key" );
                }
                else {
                    save = true;
                    chunkFinder = toupdate;
                }
            }

            
            if ( ! save ){
                if ( toupdate.firstElement().fieldName()[0] == '$' ){
                    // TODO: check for $set, etc.. on shard key
                }
                else if ( manager->hasShardKey( toupdate ) && manager->getShardKey().compare( query , toupdate ) ){
                    throw UserException( 8014 , "change would move shards!" );
                }
            }
            
            if ( multi ){
                vector<Chunk*> chunks;
                manager->getChunksForQuery( chunks , chunkFinder );
                set<string> seen;
                for ( vector<Chunk*>::iterator i=chunks.begin(); i!=chunks.end(); i++){
                    Chunk * c = *i;
                    if ( seen.count( c->getShard() ) )
                        continue;
                    doWrite( dbUpdate , r , c->getShard() );
                    seen.insert( c->getShard() );
                }
            }
            else {
                Chunk& c = manager->findChunk( chunkFinder );
                doWrite( dbUpdate , r , c.getShard() );
                c.splitIfShould( d.msg().data->dataLen() );
            }

        }

 BSONObj interpreterVersion(const BSONObj& a, void* data) {
     uassert( 16453, "interpreterVersion accepts no arguments", a.nFields() == 0 );
     return BSON( "" << globalScriptEngine->getInterpreterVersionString() );
 }

//.........这里部分代码省略.........
                        mss->applyModsInPlace( true );// const_cast<BSONObj&>(onDisk) );

                        DEBUGUPDATE( "\t\t\t doing in place update" );
                        if ( profile && !multi )
                            debug.fastmod = true;

                        if ( modsIsIndexed ) {
                            seenObjects.insert( loc );
                        }

                        d->paddingFits();
                    }
                    else {
                        if ( rs )
                            rs->goingToDelete( onDisk );

                        BSONObj newObj = mss->createNewFromMods();
                        checkTooLarge(newObj);
                        DiskLoc newLoc = theDataFileMgr.updateRecord(ns,
                                                                     d,
                                                                     nsdt,
                                                                     r,
                                                                     loc,
                                                                     newObj.objdata(),
                                                                     newObj.objsize(),
                                                                     debug);

                        if ( newLoc != loc || modsIsIndexed ){
                            // log() << "Moved obj " << newLoc.obj()["_id"] << " from " << loc << " to " << newLoc << endl;
                            // object moved, need to make sure we don' get again
                            seenObjects.insert( newLoc );
                        }

                    }

                    if ( logop ) {
                        DEV verify( mods->size() );
                        BSONObj logObj = mss->getOpLogRewrite();
                        DEBUGUPDATE( "\t rewrite update: " << logObj );

                        // It is possible that the entire mod set was a no-op over this
                        // document.  We would have an empty log record in that case. If we
                        // call logOp, with an empty record, that would be replicated as "clear
                        // this record", which is not what we want. Therefore, to get a no-op
                        // in the replica, we simply don't log.
                        if ( logObj.nFields() ) {
                            logOp("u", ns, logObj , &pattern, 0, fromMigrate );
                        }
                    }
                    numModded++;
                    if ( ! multi )
                        return UpdateResult( 1 , 1 , numModded , BSONObj() );
                    if ( willAdvanceCursor )
                        c->recoverFromTouchingEarlierIterate();

                    getDur().commitIfNeeded();

                    continue;
                }

                uassert( 10158 ,  "multi update only works with $ operators" , ! multi );

                BSONElementManipulator::lookForTimestamps( updateobj );
                checkNoMods( updateobj );
                theDataFileMgr.updateRecord(ns, d, nsdt, r, loc , updateobj.objdata(), updateobj.objsize(), debug, su);
                if ( logop ) {
                    DEV wassert( !su ); // super used doesn't get logged, this would be bad.
                    logOp("u", ns, updateobj, &pattern, 0, fromMigrate );
                }
                return UpdateResult( 1 , 0 , 1 , BSONObj() );
            } while ( c->ok() );
        } // endif

        if ( numModded )
            return UpdateResult( 1 , 1 , numModded , BSONObj() );

        if ( upsert ) {
            if ( updateobj.firstElementFieldName()[0] == '$' ) {
                // upsert of an $operation. build a default object
                BSONObj newObj = mods->createNewFromQuery( patternOrig );
                checkNoMods( newObj );
                debug.fastmodinsert = true;
                theDataFileMgr.insertWithObjMod(ns, newObj, false, su);
                if ( logop )
                    logOp( "i", ns, newObj, 0, 0, fromMigrate );

                return UpdateResult( 0 , 1 , 1 , newObj );
            }
            uassert( 10159 ,  "multi update only works with $ operators" , ! multi );
            checkNoMods( updateobj );
            debug.upsert = true;
            BSONObj no = updateobj;
            theDataFileMgr.insertWithObjMod(ns, no, false, su);
            if ( logop )
                logOp( "i", ns, no, 0, 0, fromMigrate );
            return UpdateResult( 0 , 0 , 1 , no );
        }

        return UpdateResult( 0 , isOperatorUpdate , 0 , BSONObj() );
    }

    void IndexScanNode::computeProperties() {
        _sorts.clear();

        BSONObj sortPattern;
        {
            BSONObjBuilder sortBob;
            BSONObj normalizedIndexKeyPattern(LiteParsedQuery::normalizeSortOrder(indexKeyPattern));
            BSONObjIterator it(normalizedIndexKeyPattern);
            while (it.more()) {
                BSONElement elt = it.next();
                // Zero is returned if elt is not a number.  This happens when elt is hashed or
                // 2dsphere, our two projection indices.  We want to drop those from the sort
                // pattern.
                int val = elt.numberInt() * direction;
                if (0 != val) {
                    sortBob.append(elt.fieldName(), val);
                }
            }
            sortPattern = sortBob.obj();
        }
        _sorts.insert(sortPattern);

        const int nFields = sortPattern.nFields();
        if (nFields > 1) {
            // We're sorted not only by sortPattern but also by all prefixes of it.
            for (int i = 0; i < nFields; ++i) {
                // Make obj out of fields [0,i]
                BSONObjIterator it(sortPattern);
                BSONObjBuilder prefixBob;
                for (int j = 0; j <= i; ++j) {
                    prefixBob.append(it.next());
                }
                _sorts.insert(prefixBob.obj());
            }
        }

        // If we are using the index {a:1, b:1} to answer the predicate {a: 10}, it's sorted
        // both by the index key pattern and by the pattern {b: 1}.

        // See if there are any fields with equalities for bounds.  We can drop these
        // from any sort orders created.
        set<string> equalityFields;
        if (!bounds.isSimpleRange) {
            // Figure out how many fields are point intervals.
            for (size_t i = 0; i < bounds.fields.size(); ++i) {
                const OrderedIntervalList& oil = bounds.fields[i];
                if (oil.intervals.size() != 1) {
                    continue;
                }
                const Interval& ival = oil.intervals[0];
                if (!ival.isPoint()) {
                    continue;
                }
                equalityFields.insert(oil.name);
            }
        }

        if (equalityFields.empty()) {
            return;
        }

        // TODO: Each field in equalityFields could be dropped from the sort order since it is
        // a point interval.  The full set of sort orders is as follows:
        // For each sort in _sorts:
        //    For each drop in powerset(equalityFields):
        //        Remove fields in 'drop' from 'sort' and add resulting sort to output.

        // Since this involves a powerset, we only remove point intervals that the prior sort
        // planning code removed, namely the contiguous prefix of the key pattern.
        BSONObjIterator it(sortPattern);
        BSONObjBuilder prefixBob;
        while (it.more()) {
            BSONElement elt = it.next();
            // TODO: string slowness.  fix when bounds are stringdata not string.
            if (equalityFields.end() == equalityFields.find(string(elt.fieldName()))) {
                prefixBob.append(elt);
                // This field isn't a point interval, can't drop.
                break;
            }
        }

        while (it.more()) {
            prefixBob.append(it.next());
        }

        // If we have an index {a:1} and an equality on 'a' don't append an empty sort order.
        BSONObj filterPointsObj = prefixBob.obj();
        if (!filterPointsObj.isEmpty()) {
            _sorts.insert(filterPointsObj);
        }
    }

    ProjectionExec::ProjectionExec(const BSONObj& spec, const MatchExpression* queryExpression)
        : _include(true),
          _special(false),
          _source(spec),
          _includeID(true),
          _skip(0),
          _limit(-1),
          _arrayOpType(ARRAY_OP_NORMAL),
          _hasNonSimple(false),
          _hasDottedField(false),
          _queryExpression(queryExpression),
          _hasReturnKey(false) {

        // Are we including or excluding fields?
        // -1 when we haven't initialized it.
        // 1 when we're including
        // 0 when we're excluding.
        int include_exclude = -1;

        BSONObjIterator it(_source);
        while (it.more()) {
            BSONElement e = it.next();

            if (!e.isNumber() && !e.isBoolean()) {
                _hasNonSimple = true;
            }

            if (Object == e.type()) {
                BSONObj obj = e.embeddedObject();
                verify(1 == obj.nFields());

                BSONElement e2 = obj.firstElement();
                if (mongoutils::str::equals(e2.fieldName(), "$slice")) {
                    if (e2.isNumber()) {
                        int i = e2.numberInt();
                        if (i < 0) {
                            add(e.fieldName(), i, -i); // limit is now positive
                        }
                        else {
                            add(e.fieldName(), 0, i);
                        }
                    }
                    else {
                        verify(e2.type() == Array);
                        BSONObj arr = e2.embeddedObject();
                        verify(2 == arr.nFields());

                        BSONObjIterator it(arr);
                        int skip = it.next().numberInt();
                        int limit = it.next().numberInt();

                        verify(limit > 0);

                        add(e.fieldName(), skip, limit);
                    }
                }
                else if (mongoutils::str::equals(e2.fieldName(), "$elemMatch")) {
                    _arrayOpType = ARRAY_OP_ELEM_MATCH;

                    // Create a MatchExpression for the elemMatch.
                    BSONObj elemMatchObj = e.wrap();
                    verify(elemMatchObj.isOwned());
                    _elemMatchObjs.push_back(elemMatchObj);
                    StatusWithMatchExpression swme = MatchExpressionParser::parse(elemMatchObj);
                    verify(swme.isOK());
                    // And store it in _matchers.
                    _matchers[mongoutils::str::before(e.fieldName(), '.').c_str()]
                        = swme.getValue();

                    add(e.fieldName(), true);
                }
                else if (mongoutils::str::equals(e2.fieldName(), "$meta")) {
                    verify(String == e2.type());
                    if (mongoutils::str::equals(e2.valuestr(), "text")) {
                        _meta[e.fieldName()] = META_TEXT;
                    }
                    else if (mongoutils::str::equals(e2.valuestr(), "diskloc")) {
                        _meta[e.fieldName()] = META_DISKLOC;
                    }
                    else if (mongoutils::str::equals(e2.valuestr(), "indexKey")) {
                        _hasReturnKey = true;
                        // The index key clobbers everything so just stop parsing here.
                        return;
                    }
                    else {
                        // This shouldn't happen, should be caught by parsing.
                        verify(0);
                    }
                }
                else {
                    verify(0);
                }
            }
            else if (mongoutils::str::equals(e.fieldName(), "_id") && !e.trueValue()) {
                _includeID = false;
            }
            else {
                add(e.fieldName(), e.trueValue());

                // Projections of dotted fields aren't covered.
//.........这里部分代码省略.........

    void Projection::init( const BSONObj& o ) {
        massert( 10371 , "can only add to Projection once", _source.isEmpty());
        _source = o;

        BSONObjIterator i( o );
        int true_false = -1;
        while ( i.more() ) {
            BSONElement e = i.next();

            if ( ! e.isNumber() )
                _hasNonSimple = true;

            if (e.type() == Object) {
                BSONObj obj = e.embeddedObject();
                BSONElement e2 = obj.firstElement();
                if ( mongoutils::str::equals( e2.fieldName(), "$slice" ) ) {
                    if (e2.isNumber()) {
                        int i = e2.numberInt();
                        if (i < 0)
                            add(e.fieldName(), i, -i); // limit is now positive
                        else
                            add(e.fieldName(), 0, i);

                    }
                    else if (e2.type() == Array) {
                        BSONObj arr = e2.embeddedObject();
                        uassert(13099, "$slice array wrong size", arr.nFields() == 2 );

                        BSONObjIterator it(arr);
                        int skip = it.next().numberInt();
                        int limit = it.next().numberInt();
                        uassert(13100, "$slice limit must be positive", limit > 0 );
                        add(e.fieldName(), skip, limit);

                    }
                    else {
                        uassert(13098, "$slice only supports numbers and [skip, limit] arrays", false);
                    }
                }
                else if ( mongoutils::str::equals( e2.fieldName(), "$elemMatch" ) ) {
                    // validate $elemMatch arguments and dependencies
                    uassert( 16342, "elemMatch: invalid argument.  object required.",
                             e2.type() == Object );
                    uassert( 16343, "Cannot specify positional operator and $elemMatch"
                                    " (currently unsupported).",
                             _arrayOpType != ARRAY_OP_POSITIONAL );
                    uassert( 16344, "Cannot use $elemMatch projection on a nested field"
                                    " (currently unsupported).",
                             ! mongoutils::str::contains( e.fieldName(), '.' ) );
                    _arrayOpType = ARRAY_OP_ELEM_MATCH;

                    // initialize new Matcher object(s)

                    _matchers.insert( make_pair( mongoutils::str::before( e.fieldName(), '.' ),
                                                 boost::make_shared<Matcher>( e.wrap(), true ) ) );
                    add( e.fieldName(), true );
                }
                else {
                    uasserted(13097, string("Unsupported projection option: ") +
                                     obj.firstElementFieldName() );
                }

            }
            else if (!strcmp(e.fieldName(), "_id") && !e.trueValue()) {
                _includeID = false;
            }
            else {
                add( e.fieldName(), e.trueValue() );

                // validate input
                if (true_false == -1) {
                    true_false = e.trueValue();
                    _include = !e.trueValue();
                }
                else {
                    uassert( 10053 , "You cannot currently mix including and excluding fields. "
                                     "Contact us if this is an issue." ,
                             (bool)true_false == e.trueValue() );
                }
            }
            if ( mongoutils::str::contains( e.fieldName(), ".$" ) ) {
                // positional op found; verify dependencies
                uassert( 16345, "Cannot exclude array elements with the positional operator"
                                " (currently unsupported).", e.trueValue() );
                uassert( 16346, "Cannot specify more than one positional array element per query"
                                " (currently unsupported).", _arrayOpType != ARRAY_OP_POSITIONAL );
                uassert( 16347, "Cannot specify positional operator and $elemMatch"
                                " (currently unsupported).", _arrayOpType != ARRAY_OP_ELEM_MATCH );
                _arrayOpType = ARRAY_OP_POSITIONAL;
            }
        }
    }

        void _update( Request& r , DbMessage& d, ChunkManagerPtr manager ){
            int flags = d.pullInt();
            
            BSONObj query = d.nextJsObj();
            uassert( 10201 ,  "invalid update" , d.moreJSObjs() );
            BSONObj toupdate = d.nextJsObj();

            BSONObj chunkFinder = query;
            
            bool upsert = flags & UpdateOption_Upsert;
            bool multi = flags & UpdateOption_Multi;

            if ( multi )
                uassert( 10202 ,  "can't mix multi and upsert and sharding" , ! upsert );

            if ( upsert && !(manager->hasShardKey(toupdate) ||
                             (toupdate.firstElement().fieldName()[0] == '$' && manager->hasShardKey(query))))
            {
                throw UserException( 8012 , "can't upsert something without shard key" );
            }

            bool save = false;
            if ( ! manager->hasShardKey( query ) ){
                if ( multi ){
                }
                else if ( query.nFields() != 1 || strcmp( query.firstElement().fieldName() , "_id" ) ){
                    throw UserException( 8013 , "can't do update with query that doesn't have the shard key" );
                }
                else {
                    save = true;
                    chunkFinder = toupdate;
                }
            }

            
            if ( ! save ){
                if ( toupdate.firstElement().fieldName()[0] == '$' ){
                    BSONObjIterator ops(toupdate);
                    while(ops.more()){
                        BSONElement op(ops.next());
                        if (op.type() != Object)
                            continue;
                        BSONObjIterator fields(op.embeddedObject());
                        while(fields.more()){
                            const string field = fields.next().fieldName();
                            uassert(13123, "Can't modify shard key's value", ! manager->getShardKey().partOfShardKey(field));
                        }
                    }
                } else if ( manager->hasShardKey( toupdate ) ){
                    uassert( 8014, "change would move shards!", manager->getShardKey().compare( query , toupdate ) == 0 );
                } else {
                    uasserted(12376, "shard key must be in update object");
                }
            }
            
            if ( multi ){
                vector<shared_ptr<ChunkRange> > chunks;
                manager->getChunksForQuery( chunks , chunkFinder );
                set<Shard> seen;
                for ( vector<shared_ptr<ChunkRange> >::iterator i=chunks.begin(); i!=chunks.end(); i++){
                    shared_ptr<ChunkRange> c = *i;
                    if ( seen.count( c->getShard() ) )
                        continue;
                    doWrite( dbUpdate , r , c->getShard() );
                    seen.insert( c->getShard() );
                }
            }
            else {
                ChunkPtr c = manager->findChunk( chunkFinder );
                doWrite( dbUpdate , r , c->getShard() );
                c->splitIfShould( d.msg().header()->dataLen() );
            }

        }

// static
bool WorkingSetCommon::isValidStatusMemberObject(const BSONObj& obj) {
    return obj.nFields() == 3 && obj.hasField("ok") && obj.hasField("code") &&
        obj.hasField("errmsg");
}

    void Projection::init( const BSONObj& o ) {
        massert( 10371 , "can only add to Projection once", _source.isEmpty());
        _source = o;

        BSONObjIterator i( o );
        int true_false = -1;
        while ( i.more() ) {
            BSONElement e = i.next();

            if ( ! e.isNumber() )
                _hasNonSimple = true;

            if (e.type() == Object) {
                BSONObj obj = e.embeddedObject();
                BSONElement e2 = obj.firstElement();
                if ( strcmp(e2.fieldName(), "$slice") == 0 ) {
                    if (e2.isNumber()) {
                        int i = e2.numberInt();
                        if (i < 0)
                            add(e.fieldName(), i, -i); // limit is now positive
                        else
                            add(e.fieldName(), 0, i);

                    }
                    else if (e2.type() == Array) {
                        BSONObj arr = e2.embeddedObject();
                        uassert(13099, "$slice array wrong size", arr.nFields() == 2 );

                        BSONObjIterator it(arr);
                        int skip = it.next().numberInt();
                        int limit = it.next().numberInt();
                        uassert(13100, "$slice limit must be positive", limit > 0 );
                        add(e.fieldName(), skip, limit);

                    }
                    else {
                        uassert(13098, "$slice only supports numbers and [skip, limit] arrays", false);
                    }
                }
                else {
                    uassert(13097, string("Unsupported projection option: ") + obj.firstElementFieldName(), false);
                }

            }
            else if (!strcmp(e.fieldName(), "_id") && !e.trueValue()) {
                _includeID = false;

            }
            else {

                add (e.fieldName(), e.trueValue());

                // validate input
                if (true_false == -1) {
                    true_false = e.trueValue();
                    _include = !e.trueValue();
                }
                else {
                    uassert( 10053 , "You cannot currently mix including and excluding fields. Contact us if this is an issue." ,
                             (bool)true_false == e.trueValue() );
                }
            }
        }
    }

intrusive_ptr<DocumentSourceSort> DocumentSourceSort::create(
    const intrusive_ptr<ExpressionContext>& pExpCtx,
    BSONObj sortOrder,
    long long limit,
    boost::optional<uint64_t> maxMemoryUsageBytes) {
    intrusive_ptr<DocumentSourceSort> pSort(new DocumentSourceSort(pExpCtx));
    pSort->_maxMemoryUsageBytes = maxMemoryUsageBytes
        ? *maxMemoryUsageBytes
        : internalDocumentSourceSortMaxBlockingSortBytes.load();
    pSort->_rawSort = sortOrder.getOwned();

    for (auto&& keyField : sortOrder) {
        auto fieldName = keyField.fieldNameStringData();

        SortPatternPart patternPart;

        if (keyField.type() == Object) {
            BSONObj metaDoc = keyField.Obj();
            // this restriction is due to needing to figure out sort direction
            uassert(17312,
                    "$meta is the only expression supported by $sort right now",
                    metaDoc.firstElement().fieldNameStringData() == "$meta");

            uassert(ErrorCodes::FailedToParse,
                    "Cannot have additional keys in a $meta sort specification",
                    metaDoc.nFields() == 1);

            VariablesParseState vps = pExpCtx->variablesParseState;
            patternPart.expression = ExpressionMeta::parse(pExpCtx, metaDoc.firstElement(), vps);

            // If sorting by textScore, sort highest scores first. If sorting by randVal, order
            // doesn't matter, so just always use descending.
            patternPart.isAscending = false;

            pSort->_sortPattern.push_back(std::move(patternPart));
            continue;
        }

        uassert(15974,
                "$sort key ordering must be specified using a number or {$meta: 'textScore'}",
                keyField.isNumber());

        int sortOrder = keyField.numberInt();

        uassert(15975,
                "$sort key ordering must be 1 (for ascending) or -1 (for descending)",
                ((sortOrder == 1) || (sortOrder == -1)));

        patternPart.fieldPath = FieldPath{fieldName};
        patternPart.isAscending = (sortOrder > 0);
        pSort->_paths.insert(patternPart.fieldPath->fullPath());
        pSort->_sortPattern.push_back(std::move(patternPart));
    }

    uassert(15976, "$sort stage must have at least one sort key", !pSort->_sortPattern.empty());

    pSort->_sortKeyGen = SortKeyGenerator{
        // The SortKeyGenerator expects the expressions to be serialized in order to detect a sort
        // by a metadata field.
        pSort->sortKeyPattern(SortKeySerialization::kForPipelineSerialization).toBson(),
        pExpCtx->getCollator()};

    if (limit > 0) {
        pSort->setLimitSrc(DocumentSourceLimit::create(pExpCtx, limit));
    }

    return pSort;
}

    jsval toval( const BSONElement& e ) {

        switch( e.type() ) {
        case EOO:
        case jstNULL:
        case Undefined:
            return JSVAL_NULL;
        case NumberDouble:
        case NumberInt:
            return toval( e.number() );
        case Symbol: // TODO: should we make a special class for this
        case String:
            return toval( e.valuestr() );
        case Bool:
            return e.boolean() ? JSVAL_TRUE : JSVAL_FALSE;
        case Object: {
            BSONObj embed = e.embeddedObject().getOwned();
            return toval( &embed );
        }
        case Array: {

            BSONObj embed = e.embeddedObject().getOwned();

            if ( embed.isEmpty() ) {
                return OBJECT_TO_JSVAL( JS_NewArrayObject( _context , 0 , 0 ) );
            }

            int n = embed.nFields();

            JSObject * array = JS_NewArrayObject( _context , n , 0 );
            assert( array );

            jsval myarray = OBJECT_TO_JSVAL( array );

            for ( int i=0; i<n; i++ ) {
                jsval v = toval( embed[i] );
                assert( JS_SetElement( _context , array , i , &v ) );
            }

            return myarray;
        }
        case jstOID: {
            OID oid = e.__oid();
            JSObject * o = JS_NewObject( _context , &object_id_class , 0 , 0 );
            setProperty( o , "str" , toval( oid.str().c_str() ) );
            return OBJECT_TO_JSVAL( o );
        }
        case RegEx: {
            const char * flags = e.regexFlags();
            uintN flagNumber = 0;
            while ( *flags ) {
                switch ( *flags ) {
                case 'g':
                    flagNumber |= JSREG_GLOB;
                    break;
                case 'i':
                    flagNumber |= JSREG_FOLD;
                    break;
                case 'm':
                    flagNumber |= JSREG_MULTILINE;
                    break;
                //case 'y': flagNumber |= JSREG_STICKY; break;

                default:
                    log() << "warning: unknown regex flag:" << *flags << endl;
                }
                flags++;
            }

            JSObject * r = JS_NewRegExpObject( _context , (char*)e.regex() , strlen( e.regex() ) , flagNumber );
            assert( r );
            return OBJECT_TO_JSVAL( r );
        }
        case Code: {
            JSFunction * func = compileFunction( e.valuestr() );
            return OBJECT_TO_JSVAL( JS_GetFunctionObject( func ) );
        }
        case CodeWScope: {
            JSFunction * func = compileFunction( e.codeWScopeCode() );

            BSONObj extraScope = e.codeWScopeObject();
            if ( ! extraScope.isEmpty() ) {
                log() << "warning: CodeWScope doesn't transfer to db.eval" << endl;
            }

            return OBJECT_TO_JSVAL( JS_GetFunctionObject( func ) );
        }
        case Date:
            return OBJECT_TO_JSVAL( js_NewDateObjectMsec( _context , (jsdouble) e.date().millis ) );

        case MinKey:
            return OBJECT_TO_JSVAL( JS_NewObject( _context , &minkey_class , 0 , 0 ) );

        case MaxKey:
            return OBJECT_TO_JSVAL( JS_NewObject( _context , &maxkey_class , 0 , 0 ) );

        case Timestamp: {
            JSObject * o = JS_NewObject( _context , &timestamp_class , 0 , 0 );
            setProperty( o , "t" , toval( (double)(e.timestampTime()) ) );
            setProperty( o , "i" , toval( (double)(e.timestampInc()) ) );
//.........这里部分代码省略.........

    int IndexCursor::skipToNextKey( const BSONObj &currentKey ) {
        int skipPrefixIndex = _boundsIterator->advance( currentKey );
        if ( skipPrefixIndex == -2 ) { 
            // We are done iterating completely.
            _ok = false;
            return -2;
        }
        else if ( skipPrefixIndex == -1 ) { 
            // We should skip nothing.
            return -1;
        }
    
        // We should skip to a further key, efficiently.
        //
        // If after(), skip to the first key greater/less than the key comprised
        // of the first "skipPrefixIndex" elements of currentKey, and the rest
        // set to MaxKey/MinKey for direction > 0 and direction < 0 respectively.
        // eg: skipPrefixIndex = 1, currKey {a:1, b:2, c:1}, direction > 0,  so we skip
        // to the first key greater than {a:1, b:maxkey, c:maxkey}
        //
        // If after() is false, we use the same key prefix but set the reamining
        // elements to the elements described by cmp(), in order.
        // eg: skipPrefixIndex = 1, currKey {a:1, b:2, c:1}) and cmp() [b:5, c:11]
        // so we use skip to {a:1, b:5, c:11}, also noting direction.
        if ( _boundsIterator->after() ) {
            skipPrefix( currentKey, skipPrefixIndex );
        } else {
            BSONObjBuilder b(currentKey.objsize());
            BSONObjIterator it = currentKey.begin();
            const vector<const BSONElement *> &endKeys = _boundsIterator->cmp();
            const int nFields = currentKey.nFields();
            for ( int i = 0; i < nFields; i++ ) {
                if ( i < skipPrefixIndex ) {
                    verify( it.more() );
                    b.append( it.next() );
                } else {
                    b.appendAs( *endKeys[i] , "" );
                }
            }
            findKey( b.done() );

            // Skip passed key prefixes that are not supposed to be inclusive
            // as described by _boundsIterator->inc() and endKeys
            //
            // We'll spend at worst nFields^2 time ensuring all key elements
            // are properly set if all the inclusive bits are false and we
            // keep landing on keys where the ith element of curr == endkeys[i].
            //
            // This complexity is usually ok, since this skipping is supposed to
            // save us from really big linear scans across the key space in
            // some pathological cases. It's not clear whether or not small
            // cases are hurt too badly by this algorithm.
            bool allInclusive = true;
            const vector<bool> &inclusive = _boundsIterator->inc();
            for ( int i = 0; i < nFields; i++ ) {
                if ( !inclusive[i] ) {
                    allInclusive = false;
                    break;
                }
            }
again:      while ( !allInclusive && ok() ) {
                BSONObj key = _currKey;
                it = key.begin();
                dassert( nFields == key.nFields() );
                for ( int i = 0; i < nFields; i++ ) {
                    const BSONElement e = it.next();
                    if ( i >= skipPrefixIndex && !inclusive[i] && e.valuesEqual(*endKeys[i]) ) {
                        // The ith element equals the ith endKey but it's not supposed to be inclusive.
                        // Skipping to the next value for the ith element involves skipping a prefix 
                        // with i + 1 elements.
                        skipPrefix( key, i + 1 );
                        goto again;
                    }
                }
                break;
            }
        }
        return 0;
    }

void ExpressionKeysPrivate::getS2Keys(const BSONObj& obj,
                                      const BSONObj& keyPattern,
                                      const S2IndexingParams& params,
                                      BSONObjSet* keys,
                                      MultikeyPaths* multikeyPaths) {
    BSONObjSet keysToAdd = SimpleBSONObjComparator::kInstance.makeBSONObjSet();

    // Does one of our documents have a geo field?
    bool haveGeoField = false;

    if (multikeyPaths) {
        invariant(multikeyPaths->empty());
        multikeyPaths->resize(keyPattern.nFields());
    }

    size_t posInIdx = 0;

    // We output keys in the same order as the fields we index.
    for (const auto keyElem : keyPattern) {
        // First, we get the keys that this field adds.  Either they're added literally from
        // the value of the field, or they're transformed if the field is geo.
        BSONElementSet fieldElements;
        const bool expandArrayOnTrailingField = false;
        std::set<size_t>* arrayComponents = multikeyPaths ? &(*multikeyPaths)[posInIdx] : nullptr;
        dps::extractAllElementsAlongPath(
            obj, keyElem.fieldName(), fieldElements, expandArrayOnTrailingField, arrayComponents);

        // Trailing array values aren't being expanded, so we still need to determine whether the
        // last component of the indexed path 'keyElem.fieldName()' causes the index to be multikey.
        // We say that it does if
        //   (a) the last component of the indexed path ever refers to an array value (regardless of
        //       the number of array elements)
        //   (b) the last component of the indexed path ever refers to GeoJSON data that requires
        //       multiple cells for its covering.
        bool lastPathComponentCausesIndexToBeMultikey;
        BSONObjSet keysForThisField = SimpleBSONObjComparator::kInstance.makeBSONObjSet();
        if (IndexNames::GEO_2DSPHERE == keyElem.valuestr()) {
            if (params.indexVersion >= S2_INDEX_VERSION_2) {
                // For >= V2,
                // geo: null,
                // geo: undefined
                // geo: []
                // should all behave like there is no geo field.  So we look for these cases and
                // throw out the field elements if we find them.
                if (1 == fieldElements.size()) {
                    BSONElement elt = *fieldElements.begin();
                    // Get the :null and :undefined cases.
                    if (elt.isNull() || Undefined == elt.type()) {
                        fieldElements.clear();
                    } else if (elt.isABSONObj()) {
                        // And this is the :[] case.
                        BSONObj obj = elt.Obj();
                        if (0 == obj.nFields()) {
                            fieldElements.clear();
                        }
                    }
                }

                // >= V2 2dsphere indices require that at least one geo field to be present in a
                // document in order to index it.
                if (fieldElements.size() > 0) {
                    haveGeoField = true;
                }
            }

            lastPathComponentCausesIndexToBeMultikey =
                getS2GeoKeys(obj, fieldElements, params, &keysForThisField);
        } else {
            lastPathComponentCausesIndexToBeMultikey =
                getS2LiteralKeys(fieldElements, params.collator, &keysForThisField);
        }

        // We expect there to be the missing field element present in the keys if data is
        // missing.  So, this should be non-empty.
        verify(!keysForThisField.empty());

        if (multikeyPaths && lastPathComponentCausesIndexToBeMultikey) {
            const size_t pathLengthOfThisField = FieldRef{keyElem.fieldNameStringData()}.numParts();
            invariant(pathLengthOfThisField > 0);
            (*multikeyPaths)[posInIdx].insert(pathLengthOfThisField - 1);
        }

        // We take the Cartesian product of all of the keys.  This requires that we have
        // some keys to take the Cartesian product with.  If keysToAdd.empty(), we
        // initialize it.
        if (keysToAdd.empty()) {
            keysToAdd = keysForThisField;
            ++posInIdx;
            continue;
        }

        BSONObjSet updatedKeysToAdd = SimpleBSONObjComparator::kInstance.makeBSONObjSet();
        for (BSONObjSet::const_iterator it = keysToAdd.begin(); it != keysToAdd.end(); ++it) {
            for (BSONObjSet::const_iterator newIt = keysForThisField.begin();
                 newIt != keysForThisField.end();
                 ++newIt) {
                BSONObjBuilder b;
                b.appendElements(*it);
                b.append(newIt->firstElement());
                updatedKeysToAdd.insert(b.obj());
//.........这里部分代码省略.........