org.neo4j.bolt.v1.messaging.BoltMessageRouter Maven / Gradle / Ivy

/*
 * Copyright (c) 2002-2017 "Neo Technology,"
 * Network Engine for Objects in Lund AB [http://neotechnology.com]
 *
 * This file is part of Neo4j.
 *
 * Neo4j is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see .
 */
package org.neo4j.bolt.v1.messaging;

import java.io.IOException;
import java.util.Map;

import org.neo4j.bolt.v1.runtime.BoltWorker;
import org.neo4j.bolt.v1.runtime.Neo4jError;
import org.neo4j.bolt.v1.runtime.spi.BoltResult;
import org.neo4j.bolt.v1.runtime.spi.Record;
import org.neo4j.logging.Log;

/**
 * This class is responsible for routing incoming request messages to a worker
 * as well as handling outgoing response messages via appropriate handlers.
 */
public class BoltMessageRouter implements BoltRequestMessageHandler
{
    // Note that these callbacks can be used for multiple in-flight requests simultaneously, you cannot reset them
    // while there are in-flight requests.
    private final MessageProcessingHandler initHandler;
    private final MessageProcessingHandler runHandler;
    private final MessageProcessingHandler resultHandler;
    private final MessageProcessingHandler defaultHandler;

    private BoltWorker worker;

    public BoltMessageRouter( Log log, BoltWorker worker, BoltResponseMessageHandler output,
            Runnable onEachCompletedRequest )
    {
        this.initHandler = new InitHandler( output, onEachCompletedRequest, worker, log );
        this.runHandler = new RunHandler( output, onEachCompletedRequest, worker, log );
        this.resultHandler = new ResultHandler( output, onEachCompletedRequest, worker, log );
        this.defaultHandler = new MessageProcessingHandler( output, onEachCompletedRequest, worker, log );

        this.worker = worker;
    }

    @Override
    public void onInit( String userAgent, Map authToken ) throws RuntimeException
    {
        // TODO: make the client transmit the version for now it is hardcoded to -1 to ensure current behaviour
        worker.enqueue( session -> session.init( userAgent, authToken, initHandler ) );
    }

    @Override
    public void onAckFailure() throws RuntimeException
    {
        worker.enqueue( session -> session.ackFailure( defaultHandler ) );
    }

    @Override
    public void onReset() throws RuntimeException
    {
        worker.interrupt();
        worker.enqueue( session -> session.reset( defaultHandler ) );
    }

    @Override
    public void onRun( String statement, Map params )
    {
        worker.enqueue( session -> session.run( statement, params, runHandler ) );
    }

    @Override
    public void onExternalError( Neo4jError error)
    {
        worker.enqueue( session -> session.externalError( error, defaultHandler ) );
    }

    @Override
    public void onDiscardAll()
    {
        worker.enqueue( session -> session.discardAll( resultHandler ) );
    }

    @Override
    public void onPullAll()
    {
        worker.enqueue( session -> session.pullAll( resultHandler ) );
    }

    private static class InitHandler extends MessageProcessingHandler
    {
        InitHandler( BoltResponseMessageHandler handler, Runnable onCompleted, BoltWorker worker, Log log )
        {
            super( handler, onCompleted, worker, log );
        }

    }

    private static class RunHandler extends MessageProcessingHandler
    {
        RunHandler( BoltResponseMessageHandler handler, Runnable onCompleted, BoltWorker worker, Log log )
        {
            super( handler, onCompleted, worker, log );
        }

    }

    private static class ResultHandler extends MessageProcessingHandler
    {
        ResultHandler( BoltResponseMessageHandler handler, Runnable onCompleted, BoltWorker worker,
                Log log )
        {
            super( handler, onCompleted, worker, log );
        }

        @Override
        public void onRecords( final BoltResult result, final boolean pull ) throws Exception
        {
            result.accept( new BoltResult.Visitor()
            {
                @Override
                public void visit( Record record ) throws Exception
                {
                    if ( pull )
                    {
                        handler.onRecord( record );
                    }
                }

                @Override
                public void addMetadata( String key, Object value )
                {
                    metadata.put( key, value );
                }

            } );
        }

    }
}