requestmultiplexer.java

一个类似于openJMS分布在ObjectWeb之下的JMS消息中间件。

/*
 * JORAM: Java(TM) Open Reliable Asynchronous Messaging
 * Copyright (C) 2001 - 2006 ScalAgent Distributed Technologies
 * Copyright (C) 1996 - 2000 Dyade
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or any later version.
 * 
 * This library 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
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307
 * USA.
 *
 * Initial developer(s): ScalAgent Distributed Technologies
 */
package org.objectweb.joram.client.jms.connection;

import java.util.Enumeration;
import java.util.Hashtable;
import java.util.Timer;
import java.util.TimerTask;
import java.util.Vector;

import javax.jms.IllegalStateException;
import javax.jms.InvalidDestinationException;
import javax.jms.JMSException;
import javax.jms.JMSSecurityException;

import org.objectweb.joram.client.jms.Connection;
import org.objectweb.joram.client.jms.JoramTracing;
import org.objectweb.joram.shared.client.AbstractJmsReply;
import org.objectweb.joram.shared.client.AbstractJmsRequest;
import org.objectweb.joram.shared.client.ConsumerMessages;
import org.objectweb.joram.shared.client.JmsRequestGroup;
import org.objectweb.joram.shared.client.MomExceptionReply;
import org.objectweb.joram.shared.client.PingRequest;
import org.objectweb.joram.shared.client.SessDenyRequest;
import org.objectweb.joram.shared.excepts.AccessException;
import org.objectweb.joram.shared.excepts.DestinationException;
import org.objectweb.joram.shared.excepts.MomException;
import org.objectweb.util.monolog.api.BasicLevel;

public class RequestMultiplexer {

  private static class Status {
    public static final int OPEN = 0;
    public static final int CLOSE = 1;
    
    private static final String[] names = {
      "OPEN", "CLOSE"};

    public static String toString(int status) {
      return names[status];
    }
  }

  private Connection cnx;

  private volatile int status;

  private RequestChannel channel;

  public Hashtable requestsTable;

  private int requestCounter;

  private DemultiplexerDaemon demtpx;

  private Timer timer;
  
  /**
   * The task responsible for keeping
   * the connection alive.
   */
  private HeartBeatTask heartBeatTask;

  private javax.jms.ExceptionListener exceptionListener;

  /**
   * The date of the last request
   */
  private volatile long lastRequestDate;
  
  public RequestMultiplexer(Connection cnx,
                            RequestChannel channel,
                            long heartBeat) throws JMSException {
    this.channel = channel;
    this.cnx = cnx; 
    requestsTable = new Hashtable();
    requestCounter = 0;
    timer = new Timer();
    channel.setTimer(timer);
    try {
      channel.connect();
    } catch (Exception exc) {
      if (JoramTracing.dbgClient.isLoggable(BasicLevel.DEBUG))
        JoramTracing.dbgClient.log(BasicLevel.DEBUG, "", exc);
      throw new JMSException(exc.toString());
    }
    
    demtpx = new DemultiplexerDaemon();
    demtpx.start();
    setStatus(Status.OPEN);
    
    if (heartBeat > 0) {
      heartBeatTask = new HeartBeatTask(heartBeat);
      lastRequestDate = System.currentTimeMillis();
      try {
        heartBeatTask.start();
      } catch (Exception exc) {
        if (JoramTracing.dbgClient.isLoggable(BasicLevel.DEBUG))
          JoramTracing.dbgClient.log(BasicLevel.DEBUG, "", exc);
        throw new JMSException(exc.toString());
      }
    }
  }

  private void setStatus(int status) {
    if (JoramTracing.dbgClient.isLoggable(BasicLevel.DEBUG))
      JoramTracing.dbgClient.log(
        BasicLevel.DEBUG, 
        "RequestMultiplexer.setStatus(" + 
        Status.toString(status) + ')');
    this.status = status;
  }
  
  public boolean isClosed() {
    return status == Status.CLOSE;
  }

  public void setExceptionListener(
    javax.jms.ExceptionListener exceptionListener) {
    this.exceptionListener = exceptionListener;
  }

  public javax.jms.ExceptionListener getExceptionListener() {
    return exceptionListener;
  }

  public void sendRequest(
    AbstractJmsRequest request)
    throws JMSException {
    sendRequest(request, null);
  }
  
  public void sendRequest(AbstractJmsRequest request, ReplyListener listener)
      throws JMSException {

    synchronized (this) {
      if (status == Status.CLOSE)
        throw new IllegalStateException("Connection closed");

      if (requestCounter == Integer.MAX_VALUE) {
        requestCounter = 0;
      }

      request.setRequestId(requestCounter++);

      if (listener != null) {
        requestsTable.put(new Integer(request.getRequestId()), listener);
      }

      if (heartBeatTask != null) {
        lastRequestDate = System.currentTimeMillis();
      }
    }

    try {
      channel.send(request);
    } catch (Exception exc) {
      if (JoramTracing.dbgClient.isLoggable(BasicLevel.DEBUG))
        JoramTracing.dbgClient.log(BasicLevel.DEBUG, "", exc);
      JMSException jmsExc = new JMSException(exc.toString());
      jmsExc.setLinkedException(exc);
      throw jmsExc;
    }
  }
  
  public void setMultiThreadSync(int delay) {
    channel = new MultiThreadSyncChannel(channel, delay);
  }

  /**
   * Not synchronized because it would possibly
   * deadlock with some reply listeners 
   * (actually requestors).
   */
  public void close() {
    if (JoramTracing.dbgClient.isLoggable(BasicLevel.DEBUG))
      JoramTracing.dbgClient.log(
        BasicLevel.DEBUG, 
        "RequestMultiplexer.close()");
    
    synchronized (this) {
      if (status == Status.CLOSE)
        return;
      // Immediately set the status as no error
      // can be thrown. This enables to release
      // the lock and avoid any dead lock
      // with the demultiplexer thread that
      // calls close() when interrupted.
      setStatus(Status.CLOSE);
    }

    if (heartBeatTask != null)
      heartBeatTask.cancel();

    if (timer != null)
      timer.cancel();
    
    channel.close();

    demtpx.stop();

    if (JoramTracing.dbgClient.isLoggable(BasicLevel.DEBUG))
      JoramTracing.dbgClient.log(
        BasicLevel.DEBUG, " -> requestsTable=" + requestsTable);
    
    // The requests table can't be accessed
    // either by an external thread (status CLOSE)
    // or by the internal demultiplexer thread (stopped).
    Enumeration requestIds = requestsTable.keys();
    Enumeration listeners = requestsTable.elements();
    while (listeners.hasMoreElements()) {
      Integer requestId = (Integer)requestIds.nextElement();
      ReplyListener rl = (ReplyListener)listeners.nextElement();
      rl.replyAborted(requestId.intValue());
    }
    requestsTable.clear();
  }

  /**
   * Used by Connection clean up.
   * It's a very specific usage linked to
   * the connector layer.
   */
  public void cleanup() {
    Enumeration requestIds = requestsTable.keys();
    Enumeration listeners = requestsTable.elements();
    while (listeners.hasMoreElements()) {
      Integer requestId = (Integer)requestIds.nextElement();
      ReplyListener rl = (ReplyListener)listeners.nextElement();
      rl.replyAborted(requestId.intValue());
    }
    requestsTable.clear();
  }

  /**
   * Not synchronized because it would possibly
   * deadlock with some reply listeners 
   * (actually requestors).
   */
  public void abortRequest(int requestId) {
    if (JoramTracing.dbgClient.isLoggable(BasicLevel.DEBUG))
      JoramTracing.dbgClient.log(
        BasicLevel.DEBUG, 
        "RequestMultiplexer.abortRequest(" + requestId + ')');
    ReplyListener rl = doAbortRequest(requestId);    
    if (rl != null) {
      rl.replyAborted(requestId);
    }
  }
  
  private synchronized ReplyListener doAbortRequest(int requestId) {
    if (JoramTracing.dbgClient.isLoggable(BasicLevel.DEBUG))
      JoramTracing.dbgClient.log(
        BasicLevel.DEBUG, "RequestMultiplexer.doAbortRequest(" +