/**
* Redistribution and use of this software and associated documentation
* ("Software"), with or without modification, are permitted provided
* that the following conditions are met:
*
* 1. Redistributions of source code must retain copyright
* statements and notices. Redistributions must also contain a
* copy of this document.
*
* 2. Redistributions in binary form must reproduce the
* above copyright notice, this list of conditions and the
* following disclaimer in the documentation and/or other
* materials provided with the distribution.
*
* 3. The name "Exolab" must not be used to endorse or promote
* products derived from this Software without prior written
* permission of Exoffice Technologies. For written permission,
* please contact info@exolab.org.
*
* 4. Products derived from this Software may not be called "Exolab"
* nor may "Exolab" appear in their names without prior written
* permission of Exoffice Technologies. Exolab is a registered
* trademark of Exoffice Technologies.
*
* 5. Due credit should be given to the Exolab Project
* (http://www.exolab.org/).
*
* THIS SOFTWARE IS PROVIDED BY EXOFFICE TECHNOLOGIES AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT
* NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
* EXOFFICE TECHNOLOGIES OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
*
* Copyright 2002-2004 (C) Exoffice Technologies Inc. All Rights Reserved.
*
* $Id: SentMessageCache.java,v 1.5 2005/12/20 20:31:59 tanderson Exp $
*/
package org.exolab.jms.server;
import java.util.Collections;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import javax.jms.JMSException;
import javax.jms.Session;
import org.exolab.jms.messagemgr.MessageHandle;
/**
* Helper class to cache all sent messages and unacked messages for a session.
* It also does some other processing like marking the message as sent to
* minimize the number of transactions.
* <p/>
* Messages will only be added to the cache, if the session is transacted or the
* ack mode for the session is set to CLIENT_ACKNOWLEDGE
*
* @author <a href="mailto:jima@exoffice.com">Jim Alateras</a>
* @author <a href="mailto:tma@netspace.net.au">Tim Anderson</a>
* @version $Revision: 1.5 $ $Date: 2005/12/20 20:31:59 $
* @see ServerSessionImpl
*/
class SentMessageCache {
/**
* The message acknowledgement mode, or <code>Session.TRANSACTED_SESSION</code>
* if the session is transactional.
*/
private final int _ackMode;
/**
* Holds a list of unacked messages in the order they were sent.
*/
private List _unackedMessages = Collections.synchronizedList(
new LinkedList());
/**
* Construct a new <code>SentMessageCache</code>.
*
* @param ackMode the message acknowledgement mode, or
* <code>Session.TRANSACTED_SESSION</code>
* if the session is transactional
*/
public SentMessageCache(int ackMode) {
_ackMode = ackMode;
}
/**
* Process a messge handle prior to it being sent to the client.
* Applicable to both synchronous and asynchronous delivery.
*
* @param handle the message handle
* @throws JMSException for any error
*/
public void preSend(MessageHandle handle) throws JMSException {
handle.setDelivered(true);
_unackedMessages.add(handle);
if (handle.isPersistent()) {
handle.update();
}
}
/**
* Process a message handle after it has been successfully sent to the
* client using asynchronous delivery.
*
* @param handle the message handle
* @throws JMSException for any error
*/
public void postSend(MessageHandle handle) throws JMSException {
if (_ackMode == Session.AUTO_ACKNOWLEDGE
|| _ackMode == Session.DUPS_OK_ACKNOWLEDGE) {
_unackedMessages.remove(handle);
handle.destroy();
}
}
/**
* Acknowledge the specified messages in the cache and all previously sent
* messages.
*
* @param messageId the id of the message to ack
* @param consumerId the consumer id that sent the ack.
* @throws JMSException if the acknowledge fails
*/
public void acknowledge(String messageId, long consumerId)
throws JMSException {
// first check that the message exists in the list of unacked
// messages
boolean exists = false;
Iterator iterator = _unackedMessages.iterator();
while (iterator.hasNext()) {
MessageHandle handle = (MessageHandle) iterator.next();
if (handle.getConsumerId() == consumerId
&& handle.getMessageId().equals(messageId)) {
exists = true;
break;
}
}
if (exists) {
// start from the top of the cache and remove each
// message and then call destroy on it.
while (!_unackedMessages.isEmpty()) {
MessageHandle handle
= (MessageHandle) _unackedMessages.remove(0);
handle.destroy();
// if the handle is equal to the source handle then
// break the loop
if (handle.getConsumerId() == consumerId
&& handle.getMessageId().equals(messageId)) {
break;
}
}
}
}
/**
* Acknowledge all the messages in the cache.
*
* @throws JMSException for any error
*/
public void acknowledgeAll() throws JMSException {
// start from the top of the cache and remove each
// message and then call destroy on it.
while (!_unackedMessages.isEmpty()) {
MessageHandle handle = (MessageHandle) _unackedMessages.remove(0);
handle.destroy();
}
}
/**
* Release all unacknowledged message handles.
*
* @throws JMSException for any error
*/
public void clear() throws JMSException {
if (!_unackedMessages.isEmpty()) {
MessageHandle[] handles
= (MessageHandle[]) _unackedMessages.toArray(
new MessageHandle[0]);
_unackedMessages.clear();
for (int i = 0; i < handles.length; ++i) {
MessageHandle handle = handles[i];
handle.release();
}
}
}
}