StormServerHandler.java

/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package backtype.storm.messaging.netty;

import backtype.storm.messaging.TaskMessage;
import org.jboss.netty.channel.*;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.concurrent.atomic.AtomicInteger;

class StormServerHandler extends SimpleChannelUpstreamHandler  {
    private static final Logger LOG = LoggerFactory.getLogger(StormServerHandler.class);
    Server server;
    private AtomicInteger failure_count; 
    
    StormServerHandler(Server server) {
        this.server = server;
        failure_count = new AtomicInteger(0);
    }
    
    @Override
    public void channelConnected(ChannelHandlerContext ctx, ChannelStateEvent e) {
        server.addChannel(e.getChannel());
    }
    
    @Override
    public void messageReceived(ChannelHandlerContext ctx, MessageEvent e) {
        Object msg = e.getMessage();  
        if (msg == null) return;

        //end of batch?
        if (msg==ControlMessage.EOB_MESSAGE) {
            Channel channel = ctx.getChannel();
            LOG.debug("Send back response ...");
            if (failure_count.get()==0)
                channel.write(ControlMessage.OK_RESPONSE);
            else channel.write(ControlMessage.FAILURE_RESPONSE);
            return;
        }
        
        //enqueue the received message for processing
        try {
            server.enqueue((TaskMessage)msg);
        } catch (InterruptedException e1) {
            LOG.info("failed to enqueue a request message", e);
            failure_count.incrementAndGet();
        }
    }

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, ExceptionEvent e) {
        server.closeChannel(e.getChannel());
    }
}