TcpMessagePipelineFactory.java

/*
 * Galaxy
 * Copyright (c) 2012-2014, Parallel Universe Software Co. All rights reserved.
 * 
 * This program and the accompanying materials are dual-licensed under
 * either the terms of the Eclipse Public License v1.0 as published by
 * the Eclipse Foundation
 *  
 *   or (per the licensee's choosing)
 *  
 * under the terms of the GNU Lesser General Public License version 3.0
 * as published by the Free Software Foundation.
 */
package co.paralleluniverse.galaxy.netty;

import java.util.concurrent.Executor;
import org.jboss.netty.channel.ChannelHandlerContext;
import org.jboss.netty.channel.ChannelPipeline;
import org.jboss.netty.channel.ChannelPipelineFactory;
import org.jboss.netty.channel.ChannelStateEvent;
import org.jboss.netty.channel.Channels;
import org.jboss.netty.channel.ExceptionEvent;
import org.jboss.netty.channel.SimpleChannelUpstreamHandler;
import org.jboss.netty.channel.group.DefaultChannelGroup;
import org.jboss.netty.handler.codec.frame.LengthFieldBasedFrameDecoder;
import org.jboss.netty.handler.codec.frame.LengthFieldPrepender;
import org.jboss.netty.handler.execution.ExecutionHandler;
import org.slf4j.Logger;

/**
 *
 * @author pron
 */
public class TcpMessagePipelineFactory implements ChannelPipelineFactory {

    private final Logger logger;
    private final DefaultChannelGroup channelGroup;
    private final ChannelMessageNodeResolver nodeResolver;
    private final int lengthFieldSize;
    private final Executor executor;

    public TcpMessagePipelineFactory(Logger logger, DefaultChannelGroup channelGroup, Executor executor) {
        this.logger = logger;
        this.channelGroup = channelGroup;
        this.nodeResolver = new ChannelAttachedNodeResolver();
        this.lengthFieldSize = 4;
        this.executor = executor;
    }

    @Override
    public ChannelPipeline getPipeline() throws Exception {
        final ChannelPipeline pipeline = Channels.pipeline();
        pipeline.addLast("frameDecoder", new LengthFieldBasedFrameDecoder((int) ((1L << (lengthFieldSize * 8)) - 1) & (-1 >>> 1), 0, lengthFieldSize, 0, lengthFieldSize));
        pipeline.addLast("frameEncoder", new LengthFieldPrepender(lengthFieldSize, false));
        if (executor != null)
            pipeline.addLast("executor", new ExecutionHandler(executor));
        pipeline.addLast("logging", new LoggingHandler(logger));
        // a node resolver must be added before the mesage codec
        pipeline.addLast("messageCodec", new MessageCodec());
        pipeline.addLast("nodeResolver", nodeResolver);
        pipeline.addLast("common", new SimpleChannelUpstreamHandler() {

            @Override
            public void channelConnected(ChannelHandlerContext ctx, ChannelStateEvent e) throws Exception {
                if (channelGroup != null)
                    channelGroup.add(e.getChannel());
                super.channelConnected(ctx, e);
            }

            @Override
            public void channelDisconnected(ChannelHandlerContext ctx, ChannelStateEvent e) throws Exception {
                if (channelGroup != null)
                    channelGroup.remove(e.getChannel());
                super.channelDisconnected(ctx, e);
                e.getChannel().close();
            }

            @Override
            public void exceptionCaught(ChannelHandlerContext ctx, ExceptionEvent e) throws Exception {
                e.getChannel().close();
                super.exceptionCaught(ctx, e);
            }

        });
        return pipeline;
    }

}