UnreliableCommandDatagramChannel.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 org.apache.activemq.transport.reliable;

import java.io.IOException;
import java.net.SocketAddress;
import java.nio.ByteBuffer;
import java.nio.channels.DatagramChannel;

import org.apache.activemq.openwire.OpenWireFormat;
import org.apache.activemq.transport.udp.ByteBufferPool;
import org.apache.activemq.transport.udp.CommandDatagramChannel;
import org.apache.activemq.transport.udp.DatagramHeaderMarshaller;
import org.apache.activemq.transport.udp.UdpTransport;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 *
 */
public class UnreliableCommandDatagramChannel extends CommandDatagramChannel {

   private static final Logger LOG = LoggerFactory.getLogger(UnreliableCommandDatagramChannel.class);

   private DropCommandStrategy dropCommandStrategy;

   public UnreliableCommandDatagramChannel(UdpTransport transport,
                                           OpenWireFormat wireFormat,
                                           int datagramSize,
                                           SocketAddress targetAddress,
                                           DatagramHeaderMarshaller headerMarshaller,
                                           ReplayBuffer replayBuffer,
                                           DatagramChannel channel,
                                           ByteBufferPool bufferPool,
                                           DropCommandStrategy strategy) {
      super(transport, wireFormat, datagramSize, targetAddress, headerMarshaller, channel, bufferPool);
      this.dropCommandStrategy = strategy;
   }

   @Override
   protected void sendWriteBuffer(int commandId,
                                  SocketAddress address,
                                  ByteBuffer writeBuffer,
                                  boolean redelivery) throws IOException {
      if (dropCommandStrategy.shouldDropCommand(commandId, address, redelivery)) {
         writeBuffer.flip();
         LOG.info("Dropping datagram with command: " + commandId);

         // lets still add it to the replay buffer though!
         getReplayBuffer().addBuffer(commandId, writeBuffer);
      } else {
         super.sendWriteBuffer(commandId, address, writeBuffer, redelivery);
      }
   }
}