org.apache.activemq.broker.region
Class QueueSubscription

java.lang.Object
  org.apache.activemq.broker.region.AbstractSubscription
      org.apache.activemq.broker.region.PrefetchSubscription
          org.apache.activemq.broker.region.QueueSubscription

All Implemented Interfaces:

LockOwner, Subscription

Direct Known Subclasses:

QueueBrowserSubscription

public class QueueSubscription
extends PrefetchSubscription
implements LockOwner

Field Summary

Fields inherited from class org.apache.activemq.broker.region.PrefetchSubscription

dispatched, pending, prefetchExtension

Fields inherited from class org.apache.activemq.broker.region.AbstractSubscription

broker, context, destinationFilter, destinations, info

Fields inherited from interface org.apache.activemq.broker.region.LockOwner

HIGH_PRIORITY_LOCK_OWNER

Constructor Summary

QueueSubscription(Broker broker, ConnectionContext context, ConsumerInfo info)

Method Summary

protected void	acknowledge(ConnectionContext context, MessageAck ack, MessageReference n) In the queue case, mark the node as dropped and then a gc cycle will remove it from the queue.
protected void	assignGroupToMe(MessageGroupMap messageGroupOwners, MessageReference n, java.lang.String groupId) Assigns the message group to this subscription and set the flag on the message that it is the first message to be dispatched.
protected boolean	canDispatch(MessageReference n) Use when a matched message is about to be dispatched to the client.
void	destroy() Called when the subscription is destroyed.
protected boolean	dispatch(MessageReference node) Override so that the message ref count is > 0 only when the message is being dispatched to a client.
int	getLockPriority()
boolean	isLockExclusive()
protected void	onDispatch(MessageReference node, Message message) OK Message was transmitted, we can now drop the reference count.
protected void	sendToDLQ(ConnectionContext context, MessageReference node) Sending a message to the DQL will require us to increment the ref count so we can get at the content.
java.lang.String	toString()

Methods inherited from class org.apache.activemq.broker.region.PrefetchSubscription

acknowledge, add, add, createMessageDispatch, dispatchMatched, getDequeueCounter, getDispatchedCounter, getDispatchedQueueSize, getEnqueueCounter, getPendingQueueSize, isFull, isHighWaterMark, isLowWaterMark, isRecoveryRequired, optimizePrefetch, processMessageDispatchNotification, pullMessage, remove, updateConsumerPrefetch

Methods inherited from class org.apache.activemq.broker.region.AbstractSubscription

gc, getConsumerInfo, getContext, getInfo, getObjectName, getPrefetchSize, getSelector, getSelectorExpression, isSlaveBroker, matches, matches, setObjectName, setSelector

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

QueueSubscription

public QueueSubscription(Broker broker,
                         ConnectionContext context,
                         ConsumerInfo info)
                  throws javax.jms.InvalidSelectorException

Throws:

javax.jms.InvalidSelectorException

Method Detail

acknowledge

protected void acknowledge(ConnectionContext context,
                           MessageAck ack,
                           MessageReference n)
                    throws java.io.IOException

In the queue case, mark the node as dropped and then a gc cycle will remove it from the queue.

Overrides:

acknowledge in class PrefetchSubscription

Throws:

java.io.IOException

canDispatch

protected boolean canDispatch(MessageReference n)
                       throws java.io.IOException

Description copied from class: PrefetchSubscription

Use when a matched message is about to be dispatched to the client.

Specified by:

canDispatch in class PrefetchSubscription

Returns:

false if the message should not be dispatched to the client (another sub may have already dispatched it for example).

Throws:

java.io.IOException

assignGroupToMe

protected void assignGroupToMe(MessageGroupMap messageGroupOwners,
                               MessageReference n,
                               java.lang.String groupId)
                        throws java.io.IOException

Assigns the message group to this subscription and set the flag on the message that it is the first message to be dispatched.

Throws:

java.io.IOException

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

getLockPriority

public int getLockPriority()

Specified by:

getLockPriority in interface LockOwner

isLockExclusive

public boolean isLockExclusive()

Specified by:

isLockExclusive in interface LockOwner

dispatch

protected boolean dispatch(MessageReference node)
                    throws java.io.IOException

Override so that the message ref count is > 0 only when the message is being dispatched to a client. Keeping it at 0 when it is in the pending list allows the message to be swapped out to disk.

Overrides:

dispatch in class PrefetchSubscription

Returns:

true if the message was dispatched.

Throws:

java.io.IOException

onDispatch

protected void onDispatch(MessageReference node,
                          Message message)

OK Message was transmitted, we can now drop the reference count.

Overrides:

onDispatch in class PrefetchSubscription

See Also:

PrefetchSubscription.onDispatch(org.apache.activemq.broker.region.MessageReference, org.apache.activemq.command.Message)

sendToDLQ

protected void sendToDLQ(ConnectionContext context,
                         MessageReference node)
                  throws java.io.IOException,
                         java.lang.Exception

Sending a message to the DQL will require us to increment the ref count so we can get at the content.

Overrides:

sendToDLQ in class PrefetchSubscription

Throws:

java.io.IOException

java.lang.Exception

destroy

public void destroy()

Description copied from interface: Subscription

Called when the subscription is destroyed.

Specified by:

destroy in interface Subscription