C++ BSONObj::findElement方法代码示例

    bool dbEval(const char *ns, BSONObj& cmd, BSONObjBuilder& result, string& errmsg) {
        BSONElement e = cmd.firstElement();
        uassert( "eval needs Code" , e.type() == Code || e.type() == CodeWScope || e.type() == String );

        const char *code = 0;
        switch ( e.type() ) {
        case String:
        case Code:
            code = e.valuestr();
            break;
        case CodeWScope:
            code = e.codeWScopeCode();
            break;
        default:
            assert(0);
        }
        assert( code );

        if ( ! globalScriptEngine ) {
            errmsg = "db side execution is disabled";
            return false;
        }

        auto_ptr<Scope> s = globalScriptEngine->getPooledScope( ns );
        ScriptingFunction f = s->createFunction(code);
        if ( f == 0 ) {
            errmsg = (string)"compile failed: " + s->getError();
            return false;
        }
        
        if ( e.type() == CodeWScope )
            s->init( e.codeWScopeScopeData() );
        s->localConnect( database->name.c_str() );

        BSONObj args;
        {
            BSONElement argsElement = cmd.findElement("args");
            if ( argsElement.type() == Array ) {
                args = argsElement.embeddedObject();
                if ( edebug ) {
                    out() << "args:" << args.toString() << endl;
                    out() << "code:\n" << code << endl;
                }
            }
        }

        int res;
        {
            Timer t;
            res = s->invoke(f,args, 10 * 60 * 1000);
            int m = t.millis();
            if ( m > 100 ) {
                out() << "dbeval slow, time: " << dec << m << "ms " << ns << endl;
                if ( m >= 1000 ) log() << code << endl;
                else OCCASIONALLY log() << code << endl;
            }
        }
        if ( res ) {
            result.append("errno", (double) res);
            errmsg = "invoke failed: ";
            errmsg += s->getError();
            return false;
        }
        
        s->append( result , "retval" , "return" );

        return true;
    }

    bool Cloner::go(const char *masterHost, string& errmsg, const string& fromdb, bool logForRepl, bool slaveOk, bool useReplAuth, bool snapshot) {

		massert( "useReplAuth is not written to replication log", !useReplAuth || !logForRepl );

        string todb = cc().database()->name;
        stringstream a,b;
        a << "localhost:" << cmdLine.port;
        b << "127.0.0.1:" << cmdLine.port;
        bool masterSameProcess = ( a.str() == masterHost || b.str() == masterHost );
        if ( masterSameProcess ) {
            if ( fromdb == todb && cc().database()->path == dbpath ) {
                // guard against an "infinite" loop
                /* if you are replicating, the local.sources config may be wrong if you get this */
                errmsg = "can't clone from self (localhost).";
                return false;
            }
        }
        /* todo: we can put these releases inside dbclient or a dbclient specialization.
           or just wait until we get rid of global lock anyway.
           */
        string ns = fromdb + ".system.namespaces";
        list<BSONObj> toClone;
        {  
            dbtemprelease r;
		
            auto_ptr<DBClientCursor> c;
            {
                if ( !masterSameProcess ) {
                    auto_ptr< DBClientConnection > c( new DBClientConnection() );
                    if ( !c->connect( masterHost, errmsg ) )
                        return false;
                    if( !replAuthenticate(c.get()) )
                        return false;
                    
                    conn = c;
                } else {
                    conn.reset( new DBDirectClient() );
                }
                c = conn->query( ns.c_str(), BSONObj(), 0, 0, 0, slaveOk ? Option_SlaveOk : 0 );
            }

            if ( c.get() == 0 ) {
                errmsg = "query failed " + ns;
                return false;
            }
            
            while ( c->more() ){
                BSONObj collection = c->next();

                log(2) << "\t cloner got " << collection << endl;

                BSONElement e = collection.findElement("name");
                if ( e.eoo() ) {
                    string s = "bad system.namespaces object " + collection.toString();
                    massert(s.c_str(), false);
                }
                assert( !e.eoo() );
                assert( e.type() == String );
                const char *from_name = e.valuestr();

                if( strstr(from_name, ".system.") ) { 
                    /* system.users is cloned -- but nothing else from system. */
                    if( legalClientSystemNS( from_name , true ) == 0 ){
                        log(2) << "\t\t not cloning because system collection" << endl;
                        continue;
                    }
                }
                else if( strchr(from_name, '$') ) {
                    // don't clone index namespaces -- we take care of those separately below.
                    log(2) << "\t\t not cloning because has $ " << endl;
                    continue;
                }            
                
                toClone.push_back( collection.getOwned() );
            }
        }

        for ( list<BSONObj>::iterator i=toClone.begin(); i != toClone.end(); i++ ){
            {
                dbtemprelease r;
            }
            BSONObj collection = *i;
            log(2) << "  really will clone: " << collection << endl;
            const char * from_name = collection["name"].valuestr();
            BSONObj options = collection.getObjectField("options");
            
            /* change name "<fromdb>.collection" -> <todb>.collection */
            const char *p = strchr(from_name, '.');
            assert(p);
            string to_name = todb + p;

            {
                string err;
                const char *toname = to_name.c_str();
                userCreateNS(toname, options, err, logForRepl);
            }
            log(1) << "\t\t cloning " << from_name << " -> " << to_name << endl;
            Query q;
            if( snapshot ) 
                q.snapshot();
//.........这里部分代码省略.........

    bool Cloner::go(const char *masterHost, string& errmsg, const string& fromdb, bool logForRepl, bool slaveOk, bool useReplAuth) {

		massert( "useReplAuth is not written to replication log", !useReplAuth || !logForRepl );

        string todb = database->name;
        stringstream a,b;
        a << "localhost:" << port;
        b << "127.0.0.1:" << port;
        bool masterSameProcess = ( a.str() == masterHost || b.str() == masterHost );
        if ( masterSameProcess ) {
            if ( fromdb == todb && database->path == dbpath ) {
                // guard against an "infinite" loop
                /* if you are replicating, the local.sources config may be wrong if you get this */
                errmsg = "can't clone from self (localhost).";
                return false;
            }
        }
        /* todo: we can put thesee releases inside dbclient or a dbclient specialization.
           or just wait until we get rid of global lock anyway.
           */
        string ns = fromdb + ".system.namespaces";
        auto_ptr<DBClientCursor> c;
        {
            dbtemprelease r;
            if ( !masterSameProcess ) {
                auto_ptr< DBClientConnection > c( new DBClientConnection() );
                if ( !c->connect( masterHost, errmsg ) )
                    return false;
				if( !replAuthenticate(c.get()) )
					return false;

                conn = c;
            } else {
                conn.reset( new DBDirectClient() );
            }
            c = conn->query( ns.c_str(), BSONObj(), 0, 0, 0, slaveOk ? Option_SlaveOk : 0 );
        }
        if ( c.get() == 0 ) {
            errmsg = "query failed " + ns;
            return false;
        }

        while ( 1 ) {
            {
                dbtemprelease r;
                if ( !c->more() )
                    break;
            }
            BSONObj collection = c->next();
            BSONElement e = collection.findElement("name");
            if ( e.eoo() ) {
                string s = "bad system.namespaces object " + collection.toString();

                /* temp
                out() << masterHost << endl;
                out() << ns << endl;
                out() << e.toString() << endl;
                exit(1);*/

                massert(s.c_str(), false);
            }
            assert( !e.eoo() );
            assert( e.type() == String );
            const char *from_name = e.valuestr();

            if( strstr(from_name, ".system.") ) { 
				/* system.users is cloned -- but nothing else from system. */
				if( strstr(from_name, ".system.users") == 0 ) 
					continue;
			}
			else if( strchr(from_name, '$') ) {
                // don't clone index namespaces -- we take care of those separately below.
                continue;
            }
            BSONObj options = collection.getObjectField("options");

            /* change name "<fromdb>.collection" -> <todb>.collection */
            const char *p = strchr(from_name, '.');
            assert(p);
            string to_name = todb + p;

            //if( !options.isEmpty() )
            {
                string err;
                const char *toname = to_name.c_str();
                userCreateNS(toname, options, err, logForRepl);

                /* chunks are big enough that we should create the _id index up front, that should
                   be faster. perhaps we should do that for everything?  Not doing that yet -- not sure
                   how we want to handle _id-less collections, and we might not want to create the index
                   there.
                   */
                if ( strstr(toname, "._chunks") )
                    ensureHaveIdIndex(toname);
            }
            copy(from_name, to_name.c_str(), false, logForRepl, masterSameProcess, slaveOk);
        }

        // now build the indexes
        string system_indexes_from = fromdb + ".system.indexes";
//.........这里部分代码省略.........