C++ BSONObjBuilder::append方法代码示例

    bool run(OperationContext* txn,
             const string& dbname,
             BSONObj& cmdObj,
             int,
             string& errmsg,
             BSONObjBuilder& result) {
        int numSet = 0;
        bool found = false;

        const ServerParameter::Map& parameterMap = ServerParameterSet::getGlobal()->getMap();

        // First check that we aren't setting the same parameter twice and that we actually are
        // setting parameters that we have registered and can change at runtime
        BSONObjIterator parameterCheckIterator(cmdObj);

        // We already know that "setParameter" will be the first element in this object, so skip
        // past that
        parameterCheckIterator.next();

        // Set of all the parameters the user is attempting to change
        std::map<std::string, BSONElement> parametersToSet;

        // Iterate all parameters the user passed in to do the initial validation checks,
        // including verifying that we are not setting the same parameter twice.
        while (parameterCheckIterator.more()) {
            BSONElement parameter = parameterCheckIterator.next();
            std::string parameterName = parameter.fieldName();

            ServerParameter::Map::const_iterator foundParameter = parameterMap.find(parameterName);

            // Check to see if this is actually a valid parameter
            if (foundParameter == parameterMap.end()) {
                errmsg = str::stream() << "attempted to set unrecognized parameter ["
                                       << parameterName << "], use help:true to see options ";
                return false;
            }

            // Make sure we are allowed to change this parameter
            if (!foundParameter->second->allowedToChangeAtRuntime()) {
                errmsg = str::stream() << "not allowed to change [" << parameterName
                                       << "] at runtime";
                return false;
            }

            // Make sure we are only setting this parameter once
            if (parametersToSet.count(parameterName)) {
                errmsg = str::stream()
                    << "attempted to set parameter [" << parameterName
                    << "] twice in the same setParameter command, "
                    << "once to value: [" << parametersToSet[parameterName].toString(false)
                    << "], and once to value: [" << parameter.toString(false) << "]";
                return false;
            }

            parametersToSet[parameterName] = parameter;
        }

        // Iterate the parameters that we have confirmed we are setting and actually set them.
        // Not that if setting any one parameter fails, the command will fail, but the user
        // won't see what has been set and what hasn't.  See SERVER-8552.
        for (std::map<std::string, BSONElement>::iterator it = parametersToSet.begin();
             it != parametersToSet.end();
             ++it) {
            BSONElement parameter = it->second;
            std::string parameterName = it->first;

            ServerParameter::Map::const_iterator foundParameter = parameterMap.find(parameterName);

            if (foundParameter == parameterMap.end()) {
                errmsg = str::stream() << "Parameter: " << parameterName << " that was "
                                       << "avaliable during our first lookup in the registered "
                                       << "parameters map is no longer available.";
                return false;
            }

            if (numSet == 0) {
                foundParameter->second->append(txn, result, "was");
            }

            Status status = foundParameter->second->set(parameter);
            if (status.isOK()) {
                numSet++;
                continue;
            }

            errmsg = status.reason();
            result.append("code", status.code());
            return false;
        }

        if (numSet == 0 && !found) {
            errmsg = "no option found to set, use help:true to see options ";
            return false;
        }

        return true;
    }

void NetworkCounter::append(BSONObjBuilder& b) {
    b.append("bytesIn", static_cast<long long>(_bytesIn.loadRelaxed()));
    b.append("bytesOut", static_cast<long long>(_bytesOut.loadRelaxed()));
    b.append("numRequests", static_cast<long long>(_requests.loadRelaxed()));
}

      inline void kill_wrapper( ProcessId pid, int sig, int port, const BSONObj& opt ) {
#ifdef _WIN32
            if (sig == SIGKILL || port == 0) {
                verify( registry._handles.count(pid) );
                TerminateProcess(registry._handles[pid], 1); // returns failure for "zombie" processes.
                return;
            }

            std::string eventName = getShutdownSignalName(pid.asUInt32());

            HANDLE event = OpenEventA(EVENT_MODIFY_STATE, FALSE, eventName.c_str());
            if (event == NULL) {
                int gle = GetLastError();
                if (gle != ERROR_FILE_NOT_FOUND) {
                    warning() << "kill_wrapper OpenEvent failed: " << errnoWithDescription();
                }
                else {
                    log() << "kill_wrapper OpenEvent failed to open event to the process "
                        << pid.asUInt32()
                        << ". It has likely died already or server is running an older version."
                        << " Attempting to shutdown through admin command.";

                    // Back-off to the old way of shutting down the server on Windows, in case we
                    // are managing a pre-2.6.0rc0 service, which did not have the event.
                    //
                    try {
                        DBClientConnection conn;
                        conn.connect("127.0.0.1:" + BSONObjBuilder::numStr(port));

                        BSONElement authObj = opt["auth"];

                        if (!authObj.eoo()){
                            string errMsg;
                            conn.auth("admin", authObj["user"].String(),
                                authObj["pwd"].String(), errMsg);

                            if (!errMsg.empty()) {
                                cout << "Failed to authenticate before shutdown: "
                                    << errMsg << endl;
                            }
                        }

                        BSONObj info;
                        BSONObjBuilder b;
                        b.append("shutdown", 1);
                        b.append("force", 1);
                        conn.runCommand("admin", b.done(), info);
                    }
                    catch (...) {
                        // Do nothing. This command never returns data to the client and the driver
                        // doesn't like that.
                        //
                    }
                }
                return;
            }

            ON_BLOCK_EXIT(CloseHandle, event);

            bool result = SetEvent(event);
            if (!result) {
                error() << "kill_wrapper SetEvent failed: " << errnoWithDescription();
                return;
            }
#else
            int x = kill( pid.toNative(), sig );
            if ( x ) {
                if ( errno == ESRCH ) {
                }
                else {
                    log() << "killFailed: " << errnoWithDescription() << endl;
                    verify( x == 0 );
                }
            }

#endif
        }

 virtual bool run(const string&, BSONObj& cmdObj, int, string& errmsg, BSONObjBuilder& result, bool fromRepl) {
     result.append("argv", CmdLine::getArgvArray());
     result.append("parsed", CmdLine::getParsedOpts());
     return true;
 }

    static bool receivedQuery(Client& c, DbResponse& dbresponse, Message& m ) {
        bool ok = true;
        MSGID responseTo = m.header()->id;

        DbMessage d(m);
        QueryMessage q(d);
        auto_ptr< Message > resp( new Message() );

        CurOp& op = *(c.curop());

        shared_ptr<AssertionException> ex;

        try {
            dbresponse.exhaust = runQuery(m, q, op, *resp);
            verify( !resp->empty() );
        }
        catch ( SendStaleConfigException& e ){
            ex.reset( new SendStaleConfigException( e.getns(), e.getInfo().msg, e.getVersionReceived(), e.getVersionWanted() ) );
            ok = false;
        }
        catch ( AssertionException& e ) {
            ex.reset( new AssertionException( e.getInfo().msg, e.getCode() ) );
            ok = false;
        }

        if( ex ){

            op.debug().exceptionInfo = ex->getInfo();
            LOGWITHRATELIMIT {
                log() << "assertion " << ex->toString() << " ns:" << q.ns << " query:" <<
                (q.query.valid() ? q.query.toString() : "query object is corrupt") << endl;
                if( q.ntoskip || q.ntoreturn )
                    log() << " ntoskip:" << q.ntoskip << " ntoreturn:" << q.ntoreturn << endl;
            }

            SendStaleConfigException* scex = NULL;
            if ( ex->getCode() == SendStaleConfigCode ) scex = static_cast<SendStaleConfigException*>( ex.get() );

            BSONObjBuilder err;
            ex->getInfo().append( err );
            if( scex ){
                err.append( "ns", scex->getns() );
                err.appendTimestamp( "vReceived", scex->getVersionReceived() );
                err.appendTimestamp( "vWanted", scex->getVersionWanted() );
            }
            BSONObj errObj = err.done();

            log() << errObj << endl;

            BufBuilder b;
            b.skip(sizeof(QueryResult));
            b.appendBuf((void*) errObj.objdata(), errObj.objsize());

            // todo: call replyToQuery() from here instead of this!!! see dbmessage.h
            QueryResult * msgdata = (QueryResult *) b.buf();
            b.decouple();
            QueryResult *qr = msgdata;
            qr->_resultFlags() = ResultFlag_ErrSet;
            if( scex ) qr->_resultFlags() |= ResultFlag_ShardConfigStale;
            qr->len = b.len();
            qr->setOperation(opReply);
            qr->cursorId = 0;
            qr->startingFrom = 0;
            qr->nReturned = 1;
            resp.reset( new Message() );
            resp->setData( msgdata, true );

        }

        op.debug().responseLength = resp->header()->dataLen();

        dbresponse.response = resp.release();
        dbresponse.responseTo = responseTo;

        return ok;
    }

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

                if ( ! okForConfigChanges( errmsg ) )
                    return false;

                ShardConnection::sync();

                Timer t;
                string ns = cmdObj.firstElement().valuestrsafe();
                if ( ns.size() == 0 ) {
                    errmsg = "no ns";
                    return false;
                }

                DBConfigPtr config = grid.getDBConfig( ns );
                if ( ! config->isSharded( ns ) ) {
                    config->reload();
                    if ( ! config->isSharded( ns ) ) {
                        errmsg = "ns not sharded.  have to shard before we can move a chunk";
                        return false;
                    }
                }

                BSONObj find = cmdObj.getObjectField( "find" );
                if ( find.isEmpty() ) {
                    errmsg = "need to specify find.  see help";
                    return false;
                }

                string toString = cmdObj["to"].valuestrsafe();
                if ( ! toString.size()  ) {
                    errmsg = "you have to specify where you want to move the chunk";
                    return false;
                }

                Shard to = Shard::make( toString );

                // so far, chunk size serves test purposes; it may or may not become a supported parameter
                long long maxChunkSizeBytes = cmdObj["maxChunkSizeBytes"].numberLong();
                if ( maxChunkSizeBytes == 0 ) {
                    maxChunkSizeBytes = Chunk::MaxChunkSize;
                }

                tlog() << "CMD: movechunk: " << cmdObj << endl;

                ChunkManagerPtr info = config->getChunkManager( ns );
                ChunkPtr c = info->findChunk( find );
                const Shard& from = c->getShard();

                if ( from == to ) {
                    errmsg = "that chunk is already on that shard";
                    return false;
                }

                BSONObj res;
                if ( ! c->moveAndCommit( to , maxChunkSizeBytes , res ) ) {
                    errmsg = "move failed";
                    result.append( "cause" , res );
                    return false;
                }
                
                // preemptively reload the config to get new version info
                config->getChunkManager( ns , true );

                result.append( "millis" , t.millis() );
                return true;
            }

 static BSONObj simpleKey( char c, int n = 1 ) {
     BSONObjBuilder builder;
     string val( n, c );
     builder.append( "a", val );
     return builder.obj();
 }

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

            if ( cmdObj.firstElement().type() != Array ) {
                errmsg = "ops has to be an array";
                return false;
            }

            BSONObj ops = cmdObj.firstElement().Obj();

            {
                // check input
                BSONObjIterator i( ops );
                while ( i.more() ) {
                    BSONElement e = i.next();
                    if (!_checkOperation(e, errmsg)) {
                        return false;
                    }
                }
            }

            // SERVER-4328 todo : is global ok or does this take a long time? i believe multiple 
            // ns used so locking individually requires more analysis
            ScopedTransaction scopedXact(txn, MODE_X);
            Lock::GlobalWrite globalWriteLock(txn->lockState());

            if (!fromRepl &&
                !repl::getGlobalReplicationCoordinator()->canAcceptWritesForDatabase(dbname)) {
                return appendCommandStatus(result, Status(ErrorCodes::NotMaster, str::stream()
                    << "Not primary while applying ops to database " << dbname));
            }

            // Preconditions check reads the database state, so needs to be done locked
            if ( cmdObj["preCondition"].type() == Array ) {
                BSONObjIterator i( cmdObj["preCondition"].Obj() );
                while ( i.more() ) {
                    BSONObj f = i.next().Obj();

                    DBDirectClient db( txn );
                    BSONObj realres = db.findOne( f["ns"].String() , f["q"].Obj() );

                    // Apply-ops would never have a $where matcher, so use the default callback,
                    // which will throw an error if $where is found.
                    Matcher m(f["res"].Obj());
                    if ( ! m.matches( realres ) ) {
                        result.append( "got" , realres );
                        result.append( "whatFailed" , f );
                        errmsg = "pre-condition failed";
                        return false;
                    }
                }
            }

            // apply
            int num = 0;
            int errors = 0;
            
            BSONObjIterator i( ops );
            BSONArrayBuilder ab;
            const bool alwaysUpsert = cmdObj.hasField("alwaysUpsert") ?
                    cmdObj["alwaysUpsert"].trueValue() : true;
            
            while ( i.more() ) {
                BSONElement e = i.next();
                const BSONObj& temp = e.Obj();

                // Ignore 'n' operations.
                const char *opType = temp["op"].valuestrsafe();
                if (*opType == 'n') continue;

                const string ns = temp["ns"].String();

                // Run operations under a nested lock as a hack to prevent yielding.
                //
                // The list of operations is supposed to be applied atomically; yielding
                // would break atomicity by allowing an interruption or a shutdown to occur
                // after only some operations are applied.  We are already locked globally
                // at this point, so taking a DBLock on the namespace creates a nested lock,
                // and yields are disallowed for operations that hold a nested lock.
                //
                // We do not have a wrapping WriteUnitOfWork so it is possible for a journal
                // commit to happen with a subset of ops applied.
                // TODO figure out what to do about this.
                Lock::GlobalWrite globalWriteLockDisallowTempRelease(txn->lockState());

                // Ensures that yielding will not happen (see the comment above).
                DEV {
                    Locker::LockSnapshot lockSnapshot;
                    invariant(!txn->lockState()->saveLockStateAndUnlock(&lockSnapshot));
                };

                OldClientContext ctx(txn, ns);

                Status status(ErrorCodes::InternalError, "");
                while (true) {
                    try {
                        // We assume that in the WriteConflict retry case, either the op rolls back
                        // any changes it makes or is otherwise safe to rerun.
                        status =
                            repl::applyOperation_inlock(txn, ctx.db(), temp, false, alwaysUpsert);
                        break;
//.........这里部分代码省略.........

        bool wrappedRun(OperationContext* txn,
                        const string& dbname,
                        BSONObj& jsobj,
                        string& errmsg,
                        BSONObjBuilder& anObjBuilder) {
            BSONElement e = jsobj.firstElement();
            const string toDeleteNs = dbname + '.' + e.valuestr();
            if (!serverGlobalParams.quiet) {
                MONGO_TLOG(0) << "CMD: dropIndexes " << toDeleteNs << endl;
            }

            Client::Context ctx(toDeleteNs);
            Database* db = ctx.db();

            Collection* collection = db->getCollection( toDeleteNs );
            if ( ! collection ) {
                errmsg = "ns not found";
                return false;
            }

            stopIndexBuilds(db, jsobj);

            IndexCatalog* indexCatalog = collection->getIndexCatalog();
            anObjBuilder.appendNumber("nIndexesWas", indexCatalog->numIndexesTotal() );


            BSONElement f = jsobj.getField("index");
            if ( f.type() == String ) {

                string indexToDelete = f.valuestr();

                if ( indexToDelete == "*" ) {
                    Status s = indexCatalog->dropAllIndexes(txn, false);
                    if ( !s.isOK() ) {
                        appendCommandStatus( anObjBuilder, s );
                        return false;
                    }
                    anObjBuilder.append("msg", "non-_id indexes dropped for collection");
                    return true;
                }

                IndexDescriptor* desc = collection->getIndexCatalog()->findIndexByName( indexToDelete );
                if ( desc == NULL ) {
                    errmsg = str::stream() << "index not found with name [" << indexToDelete << "]";
                    return false;
                }

                if ( desc->isIdIndex() ) {
                    errmsg = "cannot drop _id index";
                    return false;
                }

                Status s = indexCatalog->dropIndex(txn, desc);
                if ( !s.isOK() ) {
                    appendCommandStatus( anObjBuilder, s );
                    return false;
                }

                return true;
            }

            if ( f.type() == Object ) {
                IndexDescriptor* desc = collection->getIndexCatalog()->findIndexByKeyPattern( f.embeddedObject() );
                if ( desc == NULL ) {
                    errmsg = "can't find index with key:";
                    errmsg += f.embeddedObject().toString();
                    return false;
                }

                if ( desc->isIdIndex() ) {
                    errmsg = "cannot drop _id index";
                    return false;
                }

                Status s = indexCatalog->dropIndex(txn, desc);
                if ( !s.isOK() ) {
                    appendCommandStatus( anObjBuilder, s );
                    return false;
                }

                return true;
            }

            errmsg = "invalid index name spec";
            return false;
        }

        bool run(OperationContext* txn, const string& dbname , BSONObj& jsobj, int, string& errmsg, BSONObjBuilder& result, bool /*fromRepl*/) {
            static DBDirectClient db;

            BSONElement e = jsobj.firstElement();
            string toDeleteNs = dbname + '.' + e.valuestr();

            MONGO_TLOG(0) << "CMD: reIndex " << toDeleteNs << endl;

            Lock::DBWrite dbXLock(dbname);
            Client::Context ctx(toDeleteNs);

            Collection* collection = ctx.db()->getCollection( toDeleteNs );

            if ( !collection ) {
                errmsg = "ns not found";
                return false;
            }

            BackgroundOperation::assertNoBgOpInProgForNs( toDeleteNs );

            std::vector<BSONObj> indexesInProg = stopIndexBuilds(ctx.db(), jsobj);

            list<BSONObj> all;
            auto_ptr<DBClientCursor> i = db.query( dbname + ".system.indexes" , BSON( "ns" << toDeleteNs ) , 0 , 0 , 0 , QueryOption_SlaveOk );
            BSONObjBuilder b;
            while ( i->more() ) {
                const BSONObj spec = i->next().removeField("v").getOwned();
                const BSONObj key = spec.getObjectField("key");
                const Status keyStatus = validateKeyPattern(key);
                if (!keyStatus.isOK()) {
                    errmsg = str::stream()
                        << "Cannot rebuild index " << spec << ": " << keyStatus.reason()
                        << " For more info see http://dochub.mongodb.org/core/index-validation";
                    return false;
                }

                b.append( BSONObjBuilder::numStr( all.size() ) , spec );
                all.push_back( spec );
            }
            result.appendNumber( "nIndexesWas", collection->getIndexCatalog()->numIndexesTotal() );

            Status s = collection->getIndexCatalog()->dropAllIndexes(txn, true);
            if ( !s.isOK() ) {
                errmsg = "dropIndexes failed";
                return appendCommandStatus( result, s );
            }

            for ( list<BSONObj>::iterator i=all.begin(); i!=all.end(); i++ ) {
                BSONObj o = *i;
                LOG(1) << "reIndex ns: " << toDeleteNs << " index: " << o << endl;
                Status s = collection->getIndexCatalog()->createIndex(txn, o, false);
                if ( !s.isOK() )
                    return appendCommandStatus( result, s );
            }

            result.append( "nIndexes" , (int)all.size() );
            result.appendArray( "indexes" , b.obj() );

            IndexBuilder::restoreIndexes(indexesInProg);
            return true;
        }

//.........这里部分代码省略.........
                if ( mods.get() && mods->hasDynamicArray() ) {
                    // The Cursor must have a Matcher to record an elemMatchKey.  But currently
                    // a modifier on a dynamic array field may be applied even if there is no
                    // elemMatchKey, so a matcher cannot be required.
                    //verify( c->matcher() );
                    details.requestElemMatchKey();
                }

                if ( !c->currentMatches( &details ) ) {
                    c->advance();
                    continue;
                }

                Record* r = c->_current();
                DiskLoc loc = c->currLoc();

                if ( c->getsetdup( loc ) && autoDedup ) {
                    c->advance();
                    continue;
                }

                BSONObj js = BSONObj::make(r);

                BSONObj pattern = patternOrig;

                if ( logop ) {
                    BSONObjBuilder idPattern;
                    BSONElement id;
                    // NOTE: If the matching object lacks an id, we'll log
                    // with the original pattern.  This isn't replay-safe.
                    // It might make sense to suppress the log instead
                    // if there's no id.
                    if ( js.getObjectID( id ) ) {
                        idPattern.append( id );
                        pattern = idPattern.obj();
                    }
                    else {
                        uassert( 10157 ,  "multi-update requires all modified objects to have an _id" , ! multi );
                    }
                }

                /* look for $inc etc.  note as listed here, all fields to inc must be this type, you can't set some
                    regular ones at the moment. */
                if ( isOperatorUpdate ) {

                    if ( multi ) {
                        // go to next record in case this one moves
                        c->advance();

                        // Update operations are deduped for cursors that implement their own
                        // deduplication.  In particular, some geo cursors are excluded.
                        if ( autoDedup ) {

                            if ( seenObjects.count( loc ) ) {
                                continue;
                            }

                            // SERVER-5198 Advance past the document to be modified, provided
                            // deduplication is enabled, but see SERVER-5725.
                            while( c->ok() && loc == c->currLoc() ) {
                                c->advance();
                            }
                        }
                    }

                    const BSONObj& onDisk = loc.obj();

    Status MMAPV1DatabaseCatalogEntry::_renameSingleNamespace( OperationContext* txn,
                                                              const StringData& fromNS,
                                                              const StringData& toNS,
                                                              bool stayTemp ) {
        // some sanity checking
        NamespaceDetails* fromDetails = _namespaceIndex.details( fromNS );
        if ( !fromDetails )
            return Status( ErrorCodes::BadValue, "from namespace doesn't exist" );

        if ( _namespaceIndex.details( toNS ) )
            return Status( ErrorCodes::BadValue, "to namespace already exists" );

        _removeFromCache( fromNS );

        // at this point, we haven't done anything destructive yet

        // ----
        // actually start moving
        // ----

        // this could throw, but if it does we're ok
        _namespaceIndex.add_ns( txn, toNS, fromDetails );
        NamespaceDetails* toDetails = _namespaceIndex.details( toNS );

        try {
            toDetails->copyingFrom(txn,
                                   toNS,
                                   _namespaceIndex,
                                   fromDetails); // fixes extraOffset
        }
        catch( DBException& ) {
            // could end up here if .ns is full - if so try to clean up / roll back a little
            _namespaceIndex.kill_ns( txn, toNS );
            throw;
        }

        // at this point, code .ns stuff moved

        _namespaceIndex.kill_ns( txn, fromNS );
        fromDetails = NULL;

        // fix system.namespaces
        BSONObj newSpec;
        DiskLoc oldSpecLocation;
        {

            BSONObj oldSpec;
            {
                RecordStoreV1Base* rs = _getNamespaceRecordStore();
                scoped_ptr<RecordIterator> it( rs->getIterator(txn) );
                while ( !it->isEOF() ) {
                    DiskLoc loc = it->getNext();
                    BSONObj entry = it->dataFor( loc ).toBson();
                    if ( fromNS == entry["name"].String() ) {
                        oldSpecLocation = loc;
                        oldSpec = entry.getOwned();
                        break;
                    }
                }
            }
            invariant( !oldSpec.isEmpty() );
            invariant( !oldSpecLocation.isNull() );

            BSONObjBuilder b;
            BSONObjIterator i( oldSpec.getObjectField( "options" ) );
            while( i.more() ) {
                BSONElement e = i.next();
                if ( strcmp( e.fieldName(), "create" ) != 0 ) {
                    if (stayTemp || (strcmp(e.fieldName(), "temp") != 0))
                        b.append( e );
                }
                else {
                    b << "create" << toNS;
                }
            }
            newSpec = b.obj();
        }

        _addNamespaceToNamespaceCollection( txn, toNS, newSpec.isEmpty() ? 0 : &newSpec );

        _getNamespaceRecordStore()->deleteRecord( txn, oldSpecLocation );

        boost::mutex::scoped_lock lk( _collectionsLock );
        Entry*& entry = _collections[toNS.toString()];
        invariant( entry == NULL );
        entry = new Entry();
        _fillInEntry_inlock( txn, toNS, entry );

        return Status::OK();
    }

    Status MMAPV1DatabaseCatalogEntry::renameCollection( OperationContext* txn,
                                                        const StringData& fromNS,
                                                        const StringData& toNS,
                                                        bool stayTemp ) {
        Status s = _renameSingleNamespace( txn, fromNS, toNS, stayTemp );
        if ( !s.isOK() )
            return s;

        NamespaceDetails* details = _namespaceIndex.details( toNS );
        invariant( details );

        RecordStoreV1Base* systemIndexRecordStore = _getIndexRecordStore();
        scoped_ptr<RecordIterator> it( systemIndexRecordStore->getIterator(txn) );

        while ( !it->isEOF() ) {
            DiskLoc loc = it->getNext();
            BSONObj oldIndexSpec = it->dataFor( loc ).toBson();
            if ( fromNS != oldIndexSpec["ns"].valuestrsafe() )
                continue;

            BSONObj newIndexSpec;
            {
                BSONObjBuilder b;
                BSONObjIterator i( oldIndexSpec );
                while( i.more() ) {
                    BSONElement e = i.next();
                    if ( strcmp( e.fieldName(), "ns" ) != 0 )
                        b.append( e );
                    else
                        b << "ns" << toNS;
                }
                newIndexSpec = b.obj();
            }

            StatusWith<DiskLoc> newIndexSpecLoc =
                systemIndexRecordStore->insertRecord( txn,
                                                      newIndexSpec.objdata(),
                                                      newIndexSpec.objsize(),
                                                      -1 );
            if ( !newIndexSpecLoc.isOK() )
                return newIndexSpecLoc.getStatus();

            const string& indexName = oldIndexSpec.getStringField( "name" );

            {
                // fix IndexDetails pointer
                NamespaceDetailsCollectionCatalogEntry ce( toNS,
                                                           details,
                                                           systemIndexRecordStore,
                                                           this );
                int indexI = ce._findIndexNumber( indexName );

                IndexDetails& indexDetails = details->idx(indexI);
                *txn->recoveryUnit()->writing(&indexDetails.info) = newIndexSpecLoc.getValue(); // XXX: dur
            }

            {
                // move underlying namespac
                string oldIndexNs = IndexDescriptor::makeIndexNamespace( fromNS, indexName );
                string newIndexNs = IndexDescriptor::makeIndexNamespace( toNS, indexName );

                Status s = _renameSingleNamespace( txn, oldIndexNs, newIndexNs, false );
                if ( !s.isOK() )
                    return s;
            }

            systemIndexRecordStore->deleteRecord( txn, loc );
        }

        return Status::OK();
    }

        bool handleSpecialNamespaces( Request& r , QueryMessage& q ) {
            const char * ns = r.getns();
            ns = strstr( r.getns() , ".$cmd.sys." );
            if ( ! ns )
                return false;
            ns += 10;

            BSONObjBuilder b;
            vector<Shard> shards;

            if ( strcmp( ns , "inprog" ) == 0 ) {
                Shard::getAllShards( shards );

                BSONArrayBuilder arr( b.subarrayStart( "inprog" ) );

                for ( unsigned i=0; i<shards.size(); i++ ) {
                    Shard shard = shards[i];
                    ScopedDbConnection conn( shard );
                    BSONObj temp = conn->findOne( r.getns() , BSONObj() );
                    if ( temp["inprog"].isABSONObj() ) {
                        BSONObjIterator i( temp["inprog"].Obj() );
                        while ( i.more() ) {
                            BSONObjBuilder x;

                            BSONObjIterator j( i.next().Obj() );
                            while( j.more() ) {
                                BSONElement e = j.next();
                                if ( str::equals( e.fieldName() , "opid" ) ) {
                                    stringstream ss;
                                    ss << shard.getName() << ':' << e.numberInt();
                                    x.append( "opid" , ss.str() );
                                }
                                else if ( str::equals( e.fieldName() , "client" ) ) {
                                    x.appendAs( e , "client_s" );
                                }
                                else {
                                    x.append( e );
                                }
                            }
                            arr.append( x.obj() );
                        }
                    }
                    conn.done();
                }

                arr.done();
            }
            else if ( strcmp( ns , "killop" ) == 0 ) {
                BSONElement e = q.query["op"];
                if ( strstr( r.getns() , "admin." ) != 0 ) {
                    b.append( "err" , "unauthorized" );
                }
                else if ( e.type() != String ) {
                    b.append( "err" , "bad op" );
                    b.append( e );
                }
                else {
                    b.append( e );
                    string s = e.String();
                    string::size_type i = s.find( ':' );
                    if ( i == string::npos ) {
                        b.append( "err" , "bad opid" );
                    }
                    else {
                        string shard = s.substr( 0 , i );
                        int opid = atoi( s.substr( i + 1 ).c_str() );
                        b.append( "shard" , shard );
                        b.append( "shardid" , opid );

                        log() << "want to kill op: " << e << endl;
                        Shard s(shard);

                        ScopedDbConnection conn( s );
                        conn->findOne( r.getns() , BSON( "op" << opid ) );
                        conn.done();
                    }
                }
            }
            else if ( strcmp( ns , "unlock" ) == 0 ) {
                b.append( "err" , "can't do unlock through mongos" );
            }
            else {
                log( LL_WARNING ) << "unknown sys command [" << ns << "]" << endl;
                return false;
            }

            BSONObj x = b.done();
            replyToQuery(0, r.p(), r.m(), x);
            return true;
        }

    bool OpDebug::append(const CurOp& curop, BSONObjBuilder& b, size_t maxSize) const {
        b.append( "op" , iscommand ? "command" : opToString( op ) );
        b.append( "ns" , ns.toString() );
        
        int queryUpdateObjSize = 0;
        if (!query.isEmpty()) {
            queryUpdateObjSize += query.objsize();
        }
        else if (!iscommand && curop.haveQuery()) {
            queryUpdateObjSize += curop.query()["query"].size();
        }

        if (!updateobj.isEmpty()) {
            queryUpdateObjSize += updateobj.objsize();
        }

        if (static_cast<size_t>(queryUpdateObjSize) > maxSize) {
            if (!query.isEmpty()) {
                // Use 60 since BSONObj::toString can truncate strings into 150 chars
                // and we want to have enough room for both query and updateobj when
                // the entire document is going to be serialized into a string
                const string abbreviated(query.toString(false, false), 0, 60);
                b.append(iscommand ? "command" : "query", abbreviated + "...");
            }
            else if (!iscommand && curop.haveQuery()) {
                const string abbreviated(curop.query()["query"].toString(false, false), 0, 60);
                b.append("query", abbreviated + "...");
            }

            if (!updateobj.isEmpty()) {
                const string abbreviated(updateobj.toString(false, false), 0, 60);
                b.append("updateobj", abbreviated + "...");
            }

            return false;
        }

        if (!query.isEmpty()) {
            b.append(iscommand ? "command" : "query", query);
        }
        else if (!iscommand && curop.haveQuery()) {
            curop.appendQuery(b, "query");
        }

        if (!updateobj.isEmpty()) {
            b.append("updateobj", updateobj);
        }

        const bool moved = (nmoved >= 1);

        OPDEBUG_APPEND_NUMBER( cursorid );
        OPDEBUG_APPEND_NUMBER( ntoreturn );
        OPDEBUG_APPEND_NUMBER( ntoskip );
        OPDEBUG_APPEND_BOOL( exhaust );

        OPDEBUG_APPEND_NUMBER( nscanned );
        OPDEBUG_APPEND_BOOL( idhack );
        OPDEBUG_APPEND_BOOL( scanAndOrder );
        OPDEBUG_APPEND_BOOL( moved );
        OPDEBUG_APPEND_NUMBER( nmoved );
        OPDEBUG_APPEND_NUMBER( nupdated );
        OPDEBUG_APPEND_NUMBER( ninserted );
        OPDEBUG_APPEND_NUMBER( ndeleted );
        OPDEBUG_APPEND_BOOL( fastmod );
        OPDEBUG_APPEND_BOOL( fastmodinsert );
        OPDEBUG_APPEND_BOOL( upsert );
        OPDEBUG_APPEND_NUMBER( keyUpdates );

        b.appendNumber( "numYield" , curop.numYields() );
        b.append( "lockStats" , curop.lockStat().report() );

        if ( ! exceptionInfo.empty() )
            exceptionInfo.append( b , "exception" , "exceptionCode" );

        OPDEBUG_APPEND_NUMBER( nreturned );
        OPDEBUG_APPEND_NUMBER( responseLength );
        b.append( "millis" , executionTime );

        return true;
    }