/*
* JBoss, Home of Professional Open Source
* Copyright 2005, JBoss Inc., and individual contributors as indicated
* by the @authors tag. See the copyright.txt in the distribution for a
* full listing of individual contributors.
*
* This 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 (at your option) any later version.
*
* This software 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 software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.jboss.jms.server.endpoint;
import javax.jms.IllegalStateException;
import javax.jms.InvalidSelectorException;
import javax.jms.JMSException;
import org.jboss.jms.delegate.ConsumerEndpoint;
import org.jboss.jms.destination.JBossDestination;
import org.jboss.jms.message.JBossMessage;
import org.jboss.jms.server.ServerPeer;
import org.jboss.jms.server.destination.ManagedDestination;
import org.jboss.jms.server.destination.TopicService;
import org.jboss.jms.server.messagecounter.MessageCounter;
import org.jboss.jms.server.selector.Selector;
import org.jboss.jms.wireformat.Dispatcher;
import org.jboss.logging.Logger;
import org.jboss.messaging.core.contract.Delivery;
import org.jboss.messaging.core.contract.DeliveryObserver;
import org.jboss.messaging.core.contract.Message;
import org.jboss.messaging.core.contract.MessageReference;
import org.jboss.messaging.core.contract.PostOffice;
import org.jboss.messaging.core.contract.Queue;
import org.jboss.messaging.core.contract.Receiver;
import org.jboss.messaging.core.contract.Replicator;
import org.jboss.messaging.core.impl.SimpleDelivery;
import org.jboss.messaging.core.impl.tx.Transaction;
import org.jboss.messaging.util.ExceptionUtil;
/**
* Concrete implementation of ConsumerEndpoint. Lives on the boundary between Messaging Core and the
* JMS Facade. Handles delivery of messages from the server to the client side consumer.
*
* @author <a href="mailto:ovidiu@feodorov.com">Ovidiu Feodorov</a>
* @author <a href="mailto:tim.fox@jboss.com">Tim Fox</a>
* @version <tt>$Revision: 3268 $</tt> $Id: ServerConsumerEndpoint.java 3268 2007-10-31 14:35:03Z timfox $
*/
public class ServerConsumerEndpoint implements Receiver, ConsumerEndpoint
{
// Constants ------------------------------------------------------------------------------------
private static final Logger log = Logger.getLogger(ServerConsumerEndpoint.class);
// Static ---------------------------------------------------------------------------------------
// Attributes -----------------------------------------------------------------------------------
private boolean trace = log.isTraceEnabled();
private String id;
private Queue messageQueue;
private String queueName;
private ServerSessionEndpoint sessionEndpoint;
private boolean noLocal;
private Selector messageSelector;
private JBossDestination destination;
private Queue dlq;
private Queue expiryQueue;
private long redeliveryDelay;
private int maxDeliveryAttempts;
private boolean started;
// This lock protects starting and stopping
private Object startStopLock;
// Must be volatile
private volatile boolean clientAccepting;
private boolean retainDeliveries;
private long lastDeliveryID = -1;
private boolean remote;
private boolean preserveOrdering;
private boolean replicating;
private boolean slow;
private volatile boolean dead;
// Constructors ---------------------------------------------------------------------------------
ServerConsumerEndpoint(String id, Queue messageQueue, String queueName,
ServerSessionEndpoint sessionEndpoint, String selector,
boolean noLocal, JBossDestination dest, Queue dlq,
Queue expiryQueue, long redeliveryDelay, int maxDeliveryAttempts,
boolean remote, boolean replicating) throws InvalidSelectorException
{
if (trace)
{
log.trace("constructing consumer endpoint " + id);
}
this.id = id;
this.messageQueue = messageQueue;
this.queueName = queueName;
this.sessionEndpoint = sessionEndpoint;
this.noLocal = noLocal;
this.destination = dest;
this.dlq = dlq;
this.redeliveryDelay = redeliveryDelay;
this.expiryQueue = expiryQueue;
this.maxDeliveryAttempts = maxDeliveryAttempts;
// Always start as false - wait for consumer to initiate.
this.clientAccepting = false;
this.remote = remote;
this.startStopLock = new Object();
this.preserveOrdering = sessionEndpoint.getConnectionEndpoint().getServerPeer().isDefaultPreserveOrdering();
this.replicating = replicating;
this.slow = sessionEndpoint.getConnectionEndpoint().getConnectionFactoryEndpoint().isSlowConsumers();
if (dest.isTopic() && !messageQueue.isRecoverable())
{
// This is a consumer of a non durable topic subscription. We don't need to store
// deliveries since if the consumer is closed or dies the refs go too.
this.retainDeliveries = false;
}
else
{
this.retainDeliveries = true;
}
if (selector != null)
{
if (trace) { log.trace("creating selector:" + selector); }
this.messageSelector = new Selector(selector);
if (trace) { log.trace("created selector"); }
}
this.started = this.sessionEndpoint.getConnectionEndpoint().isStarted();
// adding the consumer to the queue
if (remote)
{
this.messageQueue.getRemoteDistributor().add(this);
}
else
{
this.messageQueue.getLocalDistributor().add(this);
}
// We don't need to prompt delivery - this will come from the client in a changeRate request
log.trace(this + " constructed");
}
// Receiver implementation ----------------------------------------------------------------------
/*
* The queue ensures that handle is never called concurrently by more than
* one thread.
*/
public Delivery handle(DeliveryObserver observer, MessageReference ref, Transaction tx)
{
if (trace)
{
log.trace(this + " receives " + ref + " for delivery");
}
// This is ok to have outside lock - is volatile
if (!clientAccepting)
{
if (trace) { log.trace(this + "'s client is NOT accepting messages!"); }
return null;
}
if (ref.getMessage().isExpired())
{
SimpleDelivery delivery = new SimpleDelivery(observer, ref, true, false);
try
{
sessionEndpoint.expireDelivery(delivery, expiryQueue);
}
catch (Throwable t)
{
log.error("Failed to expire delivery: " + delivery, t);
}
return delivery;
}
if (preserveOrdering && remote)
{
//If the header exists it means the message has already been sucked once - so reject.
if (ref.getMessage().getHeader(Message.CLUSTER_SUCKED) != null)
{
if (trace) { log.trace("Message has already been sucked once - not sucking again"); }
return null;
}
}
synchronized (startStopLock)
{
// If the consumer is stopped then we don't accept the message, it should go back into the
// queue for delivery later.
if (!started)
{
if (trace) { log.trace(this + " NOT started!"); }
return null;
}
if (trace) { log.trace(this + " has startStopLock lock, preparing the message for delivery"); }
Message message = ref.getMessage();
boolean selectorRejected = !this.accept(message);
SimpleDelivery delivery = new SimpleDelivery(observer, ref, !selectorRejected, false);
if (selectorRejected)
{
return delivery;
}
if (noLocal)
{
String conId = ((JBossMessage) message).getConnectionID();
if (trace) { log.trace("message connection id: " + conId + " current connection connection id: " + sessionEndpoint.getConnectionEndpoint().getConnectionID()); }
if (sessionEndpoint.getConnectionEndpoint().getConnectionID().equals(conId))
{
if (trace) { log.trace("Message from local connection so rejecting"); }
try
{
delivery.acknowledge(null);
}
catch (Throwable t)
{
log.error("Failed to acknowledge delivery", t);
return null;
}
return delivery;
}
}
if (slow)
{
//If this is a slow consumer, we do not want to do any message buffering, so we immediately
//set clientAccepting to false
//When the client has consumed the message it will send a changeRate + message which will set
//clientAccepting to true again
//We cannot just rely on setting the prefetchSize to 1, since this is not a hard guarantee that only one message
//will be buffered at once due to the asynchronous nature of sending changeRate
this.clientAccepting = false;
}
try
{
sessionEndpoint.handleDelivery(delivery, this);
}
catch (Exception e)
{
log.error("Failed to handle delivery", e);
this.started = false; // DO NOT return null or the message might get delivered more than once
}
return delivery;
}
}
// Filter implementation ------------------------------------------------------------------------
public boolean accept(Message msg)
{
boolean accept = true;
if (destination.isQueue())
{
// For subscriptions message selection is handled in the Subscription itself we do not want
// to do the check twice
if (messageSelector != null)
{
accept = messageSelector.accept(msg);
if (trace) { log.trace("message selector " + (accept ? "accepts " : "DOES NOT accept ") + "the message"); }
}
}
return accept;
}
// Closeable implementation ---------------------------------------------------------------------
public long closing(long sequence) throws JMSException
{
try
{
if (trace) { log.trace(this + " closing");}
stop();
return lastDeliveryID;
}
catch (Throwable t)
{
throw ExceptionUtil.handleJMSInvocation(t, this + " closing");
}
}
public void close() throws JMSException
{
try
{
if (trace)
{
log.trace(this + " close");
}
localClose();
sessionEndpoint.removeConsumer(id);
}
catch (Throwable t)
{
throw ExceptionUtil.handleJMSInvocation(t, this + " close");
}
}
// ConsumerEndpoint implementation --------------------------------------------------------------
public void changeRate(float newRate) throws JMSException
{
if (trace)
{
log.trace(this + " changing rate to " + newRate);
}
try
{
// For now we just support a binary on/off.
// The client will send newRate = 0, to say it does not want any more messages when its
// client side buffer gets full or it will send an arbitrary non zero number to say it
// does want more messages, when its client side buffer empties to half its full size.
// Note the client does not wait until the client side buffer is empty before sending a
// newRate(+ve) message since this would add extra latency.
// In the future we can fine tune this by allowing the client to specify an actual rate in
// the newRate value so this is basically a placeholder for the future so we don't have to
// change the wire format when we support it.
// No need to synchronize - clientAccepting is volatile.
if (newRate > 0)
{
clientAccepting = true;
}
else
{
clientAccepting = false;
}
if (clientAccepting)
{
promptDelivery();
}
}
catch (Throwable t)
{
throw ExceptionUtil.handleJMSInvocation(t, this + " changeRate");
}
}
// Public ---------------------------------------------------------------------------------------
public String toString()
{
return "ConsumerEndpoint[" + id + "]";
}
public JBossDestination getDestination()
{
return destination;
}
public ServerSessionEndpoint getSessionEndpoint()
{
return sessionEndpoint;
}
// Package protected ----------------------------------------------------------------------------
boolean isReplicating()
{
return replicating;
}
String getID()
{
return this.id;
}
boolean isRetainDeliveries()
{
return this.retainDeliveries;
}
void setLastDeliveryID(long id)
{
this.lastDeliveryID = id;
}
void setStarted(boolean started)
{
//No need to lock since caller already has the lock
this.started = started;
}
void setDead()
{
dead = true;
}
boolean isDead()
{
return dead;
}
Queue getDLQ()
{
return dlq;
}
Queue getExpiryQueue()
{
return expiryQueue;
}
long getRedliveryDelay()
{
return redeliveryDelay;
}
int getMaxDeliveryAttempts()
{
return maxDeliveryAttempts;
}
String getQueueName()
{
return queueName;
}
void localClose() throws Throwable
{
if (trace) { log.trace(this + " grabbed the main lock in close() " + this); }
if (remote)
{
messageQueue.getRemoteDistributor().remove(this);
}
else
{
messageQueue.getLocalDistributor().remove(this);
}
Dispatcher.instance.unregisterTarget(id, this);
// If this is a consumer of a non durable subscription then we want to unbind the
// subscription and delete all its data.
if (destination.isTopic())
{
PostOffice postOffice = sessionEndpoint.getConnectionEndpoint().getServerPeer().getPostOfficeInstance();
ServerPeer sp = sessionEndpoint.getConnectionEndpoint().getServerPeer();
Queue queue = postOffice.getBindingForQueueName(queueName).queue;
ManagedDestination mDest = sp.getDestinationManager().getDestination(destination.getName(), false);
if (!queue.isRecoverable())
{
postOffice.removeBinding(queueName, false);
if (!mDest.isTemporary())
{
String counterName = TopicService.SUBSCRIPTION_MESSAGECOUNTER_PREFIX + queueName;
MessageCounter counter = sp.getMessageCounterManager().unregisterMessageCounter(counterName);
if (counter == null)
{
throw new IllegalStateException("Cannot find counter to remove " + counterName);
}
}
}
else
{
//Durable sub consumer
if (queue.isClustered() && postOffice.isClustered())
{
//Clustered durable sub consumer created - we need to remove this info from the replicator
Replicator rep = (Replicator)postOffice;
rep.remove(queue.getName());
}
}
}
}
void start()
{
synchronized (startStopLock)
{
if (started)
{
return;
}
started = true;
}
// Prompt delivery
promptDelivery();
}
void stop() throws Throwable
{
synchronized (startStopLock)
{
if (!started)
{
return;
}
started = false;
// Any message deliveries already transit to the consumer, will just be ignored by the
// ClientConsumer since it will be closed.
//
// To clarify, the close protocol (from connection) is as follows:
//
// 1) ClientConsumer::close() - any messages in buffer are cancelled to the server
// session, and any subsequent receive messages will be ignored.
//
// 2) ServerConsumerEndpoint::closing() causes stop() this flushes any deliveries yet to
// deliver to the client callback handler.
//
// 3) ClientConsumer waits for all deliveries to arrive at client side
//
// 4) ServerConsumerEndpoint:close() - endpoint is deregistered.
//
// 5) Session.close() - acks or cancels any remaining deliveries in the SessionState as
// appropriate.
//
// 6) ServerSessionEndpoint::close() - cancels any remaining deliveries and deregisters
// session.
//
// 7) Client side session executor is shutdown.
//
// 8) ServerConnectionEndpoint::close() - connection is deregistered.
//
// 9) Remoting connection listener is removed and remoting connection stopped.
}
if (replicating)
{
sessionEndpoint.waitForDeliveriesFromConsumer(id);
}
}
// Protected ------------------------------------------------------------------------------------
// Private --------------------------------------------------------------------------------------
private void promptDelivery()
{
sessionEndpoint.promptDelivery(messageQueue);
}
// Inner classes --------------------------------------------------------------------------------
}