C++ ShardingState::getVersion方法代码示例

        bool run(const string& , BSONObj& cmdObj, int, string& errmsg, BSONObjBuilder& result, bool) {
            string ns = cmdObj["getShardVersion"].valuestrsafe();
            if ( ns.size() == 0 ) {
                errmsg = "need to specify full namespace";
                return false;
            }

            result.append( "configServer" , shardingState.getConfigServer() );

            result.appendTimestamp( "global" , shardingState.getVersion(ns).toLong() );

            ShardedConnectionInfo* info = ShardedConnectionInfo::get( false );
            result.appendBool( "inShardedMode" , info != 0 );
            if ( info )
                result.appendTimestamp( "mine" , info->getVersion(ns).toLong() );
            else
                result.appendTimestamp( "mine" , 0 );

            if ( cmdObj["fullMetadata"].trueValue() ) {
                CollectionMetadataPtr metadata = shardingState.getCollectionMetadata( ns );
                if ( metadata ) result.append( "metadata", metadata->toBSON() );
                else result.append( "metadata", BSONObj() );
            }

            return true;
        }

        bool run(const string& , BSONObj& cmdObj, string& errmsg, BSONObjBuilder& result, bool) {
            string ns = cmdObj["getShardVersion"].valuestrsafe();
            if ( ns.size() == 0 ) {
                errmsg = "need to speciy fully namespace";
                return false;
            }

            result.append( "configServer" , shardingState.getConfigServer() );

            result.appendTimestamp( "global" , shardingState.getVersion(ns) );

            ShardedConnectionInfo* info = ShardedConnectionInfo::get( false );
            if ( info )
                result.appendTimestamp( "mine" , info->getVersion(ns) );
            else
                result.appendTimestamp( "mine" , 0 );

            return true;
        }

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

        // Steps
        // 1. check basic config
        // 2. extract params from command
        // 3. fast check
        // 4. slow check (LOCKS)

        // step 1

        lastError.disableForCommand();
        ShardedConnectionInfo* info = ShardedConnectionInfo::get( true );

        // make sure we have the mongos id for writebacks
        if ( ! checkMongosID( info , cmdObj["serverID"] , errmsg ) )
            return false;

        bool authoritative = cmdObj.getBoolField( "authoritative" );

        // check config server is ok or enable sharding
        if ( ! checkConfigOrInit( cmdObj["configdb"].valuestrsafe() , authoritative , errmsg , result ) )
            return false;

        // check shard name/hosts are correct
        if ( cmdObj["shard"].type() == String ) {
            shardingState.gotShardName( cmdObj["shard"].String() );
            shardingState.gotShardHost( cmdObj["shardHost"].String() );
        }


        // Handle initial shard connection
        if( cmdObj["version"].eoo() && cmdObj["init"].trueValue() ) {
            result.append( "initialized", true );
            return true;
        }

        // we can run on a slave up to here
        if ( ! isMaster( "admin" ) ) {
            result.append( "errmsg" , "not master" );
            result.append( "note" , "from post init in setShardVersion" );
            return false;
        }

        // step 2

        string ns = cmdObj["setShardVersion"].valuestrsafe();
        if ( ns.size() == 0 ) {
            errmsg = "need to specify namespace";
            return false;
        }

        const ConfigVersion version = ConfigVersion( extractVersion( cmdObj["version"] , errmsg ), OID() );
        if ( errmsg.size() )
            return false;

        // step 3

        const ConfigVersion oldVersion = info->getVersion(ns);
        const ConfigVersion globalVersion = shardingState.getVersion(ns);

        oldVersion.addToBSON( result, "oldVersion" );

        if ( globalVersion.isSet() && version.isSet() ) {
            // this means there is no reset going on an either side
            // so its safe to make some assumptions

            if ( version.isEquivalentTo( globalVersion ) ) {
                // mongos and mongod agree!
                if ( ! oldVersion.isEquivalentTo( version ) ) {
                    if ( oldVersion < globalVersion ) {
                        info->setVersion( ns , version );
                    }
                    else if ( authoritative ) {
                        // this means there was a drop and our version is reset
                        info->setVersion( ns , version );
                    }
                    else {
                        result.append( "ns" , ns );
                        result.appendBool( "need_authoritative" , true );
                        errmsg = "verifying drop on '" + ns + "'";
                        return false;
                    }
                }
                return true;
            }

        }

        // step 4

        // this is because of a weird segfault I saw and I can't see why this should ever be set
        massert( 13647 , str::stream() << "context should be empty here, is: " << cc().getContext()->ns() , cc().getContext() == 0 );

        Lock::GlobalWrite setShardVersionLock; // TODO: can we get rid of this??

        if ( oldVersion.isSet() && ! globalVersion.isSet() ) {
            // this had been reset
            info->setVersion( ns , ShardChunkVersion( 0, OID() ) );
        }

//.........这里部分代码省略.........

    /**
     * @ return true if not in sharded mode
                     or if version for this client is ok
     */
    bool shardVersionOk( const string& ns , string& errmsg, ChunkVersion& received, ChunkVersion& wanted ) {

        if ( ! shardingState.enabled() )
            return true;

        if ( ! isMasterNs( ns.c_str() ) )  {
            // right now connections to secondaries aren't versioned at all
            return true;
        }

        ShardedConnectionInfo* info = ShardedConnectionInfo::get( false );

        if ( ! info ) {
            // this means the client has nothing sharded
            // so this allows direct connections to do whatever they want
            // which i think is the correct behavior
            return true;
        }

        if ( info->inForceVersionOkMode() ) {
            return true;
        }

        // TODO : all collections at some point, be sharded or not, will have a version
        //  (and a CollectionMetadata)
        received = info->getVersion( ns );
        wanted = shardingState.getVersion( ns );

        if( received.isWriteCompatibleWith( wanted ) ) return true;

        //
        // Figure out exactly why not compatible, send appropriate error message
        // The versions themselves are returned in the error, so not needed in messages here
        //

        // Check epoch first, to send more meaningful message, since other parameters probably
        // won't match either
        if( ! wanted.hasCompatibleEpoch( received ) ){
            errmsg = str::stream() << "version epoch mismatch detected for " << ns << ", "
                                   << "the collection may have been dropped and recreated";
            return false;
        }

        if( ! wanted.isSet() && received.isSet() ){
            errmsg = str::stream() << "this shard no longer contains chunks for " << ns << ", "
                                   << "the collection may have been dropped";
            return false;
        }

        if( wanted.isSet() && ! received.isSet() ){
            errmsg = str::stream() << "this shard contains versioned chunks for " << ns << ", "
                                   << "but no version set in request";
            return false;
        }

        if( wanted.majorVersion() != received.majorVersion() ){

            //
            // Could be > or < - wanted is > if this is the source of a migration,
            // wanted < if this is the target of a migration
            //

            errmsg = str::stream() << "version mismatch detected for " << ns << ", "
                                   << "stored major version " << wanted.majorVersion()
                                   << " does not match received " << received.majorVersion();
            return false;
        }

        // Those are all the reasons the versions can mismatch
        verify( false );

        return false;

    }

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

            // Debugging code for SERVER-1633. Commands have already a coarser timer for
            // normal operation.
            Timer timer;
            vector<int> laps;

            lastError.disableForCommand();
            ShardedConnectionInfo* info = ShardedConnectionInfo::get( true );

            bool authoritative = cmdObj.getBoolField( "authoritative" );

            string configdb = cmdObj["configdb"].valuestrsafe();
            { // configdb checking
                if ( configdb.size() == 0 ){
                    errmsg = "no configdb";
                    return false;
                }
                
                if ( shardingState.enabled() ){
                    if ( configdb != shardingState.getConfigServer() ){
                        errmsg = "specified a different configdb!";
                        return false;
                    }
                }
                else {
                    if ( ! authoritative ){
                        result.appendBool( "need_authoritative" , true );
                        errmsg = "first setShardVersion";
                        return false;
                    }
                    shardingState.enable( configdb );
                    configServer.init( configdb );
                }
            }

            // SERVER-1633
            laps.push_back( timer.millis() );
            
            if ( cmdObj["shard"].type() == String ){
                shardingState.gotShardName( cmdObj["shard"].String() );
                shardingState.gotShardHost( cmdObj["shardHost"].String() );
            }

            { // setting up ids
                if ( cmdObj["serverID"].type() != jstOID ){
                    // TODO: fix this
                    //errmsg = "need serverID to be an OID";
                    //return 0;
                }
                else {
                    OID clientId = cmdObj["serverID"].__oid();
                    if ( ! info->hasID() ){
                        info->setID( clientId );
                    }
                    else if ( clientId != info->getID() ){
                        errmsg = "server id has changed!";
                        return 0;
                    }
                }
            }

            // SERVER-1633
            laps.push_back( timer.millis() );
            
            unsigned long long version = extractVersion( cmdObj["version"] , errmsg );

            if ( errmsg.size() ){
                return false;
            }
            
            string ns = cmdObj["setShardVersion"].valuestrsafe();
            if ( ns.size() == 0 ){
                errmsg = "need to speciy fully namespace";
                return false;
            }
            
            ConfigVersion& oldVersion = info->getVersion(ns);
            ConfigVersion& globalVersion = shardingState.getVersion(ns);
            
            if ( oldVersion > 0 && globalVersion == 0 ){
                // this had been reset
                oldVersion = 0;
            }

            if ( version == 0 && globalVersion == 0 ){
                // this connection is cleaning itself
                oldVersion = 0;
                return 1;
            }

            // SERVER-1633
            laps.push_back( timer.millis() );

            if ( version == 0 && globalVersion > 0 ){
                if ( ! authoritative ){
                    result.appendBool( "need_authoritative" , true );
                    result.appendTimestamp( "globalVersion" , globalVersion );
                    result.appendTimestamp( "oldVersion" , oldVersion );
                    errmsg = "dropping needs to be authoritative";
//.........这里部分代码省略.........

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

            // Steps
            // 1. check basic config
            // 2. extract params from command
            // 3. fast check
            // 4. slow check (LOCKS)
            
            // step 1

            lastError.disableForCommand();
            ShardedConnectionInfo* info = ShardedConnectionInfo::get( true );

            bool authoritative = cmdObj.getBoolField( "authoritative" );
            
            // check config server is ok or enable sharding
            if ( ! checkConfigOrInit( cmdObj["configdb"].valuestrsafe() , authoritative , errmsg , result ) )
                return false;

            // check shard name/hosts are correct
            if ( cmdObj["shard"].type() == String ) {
                shardingState.gotShardName( cmdObj["shard"].String() );
                shardingState.gotShardHost( cmdObj["shardHost"].String() );
            }
            
            // make sure we have the mongos id for writebacks
            if ( ! checkMongosID( info , cmdObj["serverID"] , errmsg ) )
                return false;

            // step 2
            
            string ns = cmdObj["setShardVersion"].valuestrsafe();
            if ( ns.size() == 0 ) {
                errmsg = "need to speciy namespace";
                return false;
            }

            const ConfigVersion version = extractVersion( cmdObj["version"] , errmsg );
            if ( errmsg.size() )
                return false;
            
            // step 3

            const ConfigVersion oldVersion = info->getVersion(ns);
            const ConfigVersion globalVersion = shardingState.getVersion(ns);

            result.appendTimestamp( "oldVersion" , oldVersion );
            
            if ( globalVersion > 0 && version > 0 ) {
                // this means there is no reset going on an either side
                // so its safe to make some assuptions

                if ( version == globalVersion ) {
                    // mongos and mongod agree!
                    if ( oldVersion != version ) {
                        assert( oldVersion < globalVersion );
                        info->setVersion( ns , version );
                    }
                    return true;
                }
                
            }

            // step 4
            
            // this is because of a weird segfault I saw and I can't see why this should ever be set
            massert( 13647 , str::stream() << "context should be empty here, is: " << cc().getContext()->ns() , cc().getContext() == 0 ); 
        
            dblock setShardVersionLock; // TODO: can we get rid of this??
            
            if ( oldVersion > 0 && globalVersion == 0 ) {
                // this had been reset
                info->setVersion( ns , 0 );
            }

            if ( version == 0 && globalVersion == 0 ) {
                // this connection is cleaning itself
                info->setVersion( ns , 0 );
                return true;
            }

            if ( version == 0 && globalVersion > 0 ) {
                if ( ! authoritative ) {
                    result.appendBool( "need_authoritative" , true );
                    result.append( "ns" , ns );
                    result.appendTimestamp( "globalVersion" , globalVersion );
                    errmsg = "dropping needs to be authoritative";
                    return false;
                }
                log() << "wiping data for: " << ns << endl;
                result.appendTimestamp( "beforeDrop" , globalVersion );
                // only setting global version on purpose
                // need clients to re-find meta-data
                shardingState.resetVersion( ns );
                info->setVersion( ns , 0 );
                return true;
            }

            if ( version < oldVersion ) {
                errmsg = "this connection already had a newer version of collection '" + ns + "'";
//.........这里部分代码省略.........