EnqueuedMessageSender.java

package org.cowboycoders.ant.utils;

import org.cowboycoders.ant.Channel;
import org.cowboycoders.ant.events.MessageCondition;
import org.cowboycoders.ant.messages.ChannelMessage;

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;
import java.util.logging.Logger;

public class EnqueuedMessageSender implements ChannelMessageSender {

  private boolean send = true;
  private ExecutorService channelExecutorService = Executors.newSingleThreadExecutor();
  public final static Logger LOGGER = Logger.getLogger(AntUtils.class.getName());
  private Channel channel;
  private static final MessageCondition DEFAULT_CONDITION = AntUtils.CONDITION_CHANNEL_TX;
  private static final long DEFAULT_TIMEOUT_DURATION = 10L;
  private static final TimeUnit DEFAULT_TIMEOUT_TIMEUNIT = TimeUnit.SECONDS;

  /**
   * If locked should not send data packets;
   */
  private Lock sendLock = new ReentrantLock();

  public EnqueuedMessageSender(Channel channel) {
    this.channel = channel;
  }


  @Override
  public void sendMessage(final ChannelMessage msg, final Runnable callback) {
    channelExecutorService.execute(new Runnable() {

      @Override
      public void run() {

        try {
          sendLock.lock();
          if (!send) {
            if (callback != null) {
              callback.run();
            }
            return;
          }
        } finally {
          sendLock.unlock();
        }

        try {
          channel.sendAndWaitForMessage(msg, DEFAULT_CONDITION, DEFAULT_TIMEOUT_DURATION,
              DEFAULT_TIMEOUT_TIMEUNIT, null);
        } catch (Exception e) {
          LOGGER.severe("Message send failed");
        }

        if (callback != null) {
          callback.run();
        }

      }
    });

  }

  @Override
  public void sendMessage(ChannelMessage msg) {
    sendMessage(msg, null);

  }

  public void pause(boolean pause) {
    try {
      sendLock.lock();
      send = !pause;
    } finally {
      sendLock.unlock();
    }
  }

}