org.jboss.messaging.core.impl
Class ChannelSupport

java.lang.Object
  org.jboss.messaging.core.impl.ChannelSupport

All Implemented Interfaces:

Channel, DeliveryObserver, Receiver

Direct Known Subclasses:

PagingChannelSupport

public abstract class ChannelSupport
extends java.lang.Object
implements Channel

This class provides much of the functionality needed to implement a channel. This partial implementation supports atomicity, isolation and recoverability for reliable messages.

Version:

$Revision: 3020 $ $Id: ChannelSupport.java,v 1.65 2006/06/27 19:44:39 timfox Exp $

Author:

Ovidiu Feodorov, Tim Fox

Field Summary

protected boolean	active
protected long	channelID
protected SynchronizedInt	deliveringCount
protected Distributor	distributor
protected java.lang.Object	lock
protected int	maxSize
protected PriorityLinkedList	messageRefs
protected SynchronizedInt	messagesAdded
protected PersistenceManager	pm
protected boolean	receiversReady
protected boolean	recoverable
protected java.util.Set	scheduledDeliveries

Constructor Summary

protected

ChannelSupport(long channelID, PersistenceManager pm, boolean recoverable, int maxSize)

Method Summary

void	acknowledge(Delivery d, Transaction tx)
protected void	acknowledgeInternal(Delivery d, Transaction tx, boolean persist)
void	activate() Activate the channel.
protected void	addReferenceInMemory(MessageReference ref)
java.util.List	browse(Filter filter)
void	cancel(Delivery del)
protected void	cancelInternal(MessageReference ref)
protected boolean	checkAndSchedule(MessageReference ref)
protected void	checkClosed()
protected void	clearAllScheduledDeliveries()
void	close() Close the channel
void	deactivate() Deactivate the channel
void	deliver() Delivers as many references as possible to its router until receivers will accept no more
protected void	deliverInternal() This methods delivers as many messages as possible to the distributor until no more deliveries are returned.
protected boolean	deliverScheduled(MessageReference ref)
protected org.jboss.messaging.core.impl.ChannelSupport.InMemoryCallback	getCallback(Transaction tx)
long	getChannelID()
int	getDeliveringCount()
int	getMaxSize()
int	getMessageCount() Returns the count of messages stored AND being delivered AND scheduled
int	getMessagesAdded() Get the total number of messages added since this channel was started
protected boolean	getReceiversReady()
int	getScheduledCount() Count scheduled for delivery
Delivery	handle(DeliveryObserver sender, MessageReference ref, Transaction tx) A receiver can return an active, "done" or null delivery.
protected Delivery	handleInternal(DeliveryObserver sender, MessageReference ref, Transaction tx, boolean persist)
boolean	isActive()
boolean	isRecoverable()
int	memoryRefCount()
protected void	processMessageBeforeStorage(MessageReference reference) Give subclass a chance to process the message before storing it internally.
void	removeAllReferences() Remove all the references in the channel
protected MessageReference	removeFirstInMemory()
void	setMaxSize(int newSize) Set the maximum number of references this channel can store
protected void	setReceiversReady(boolean receiversReady)
java.util.List	undelivered(Filter filter)

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.jboss.messaging.core.contract.Channel

load, unload

Field Detail

channelID

protected long channelID

distributor

protected Distributor distributor

receiversReady

protected boolean receiversReady

messageRefs

protected PriorityLinkedList messageRefs

recoverable

protected boolean recoverable

pm

protected PersistenceManager pm

lock

protected java.lang.Object lock

active

protected volatile boolean active

deliveringCount

protected SynchronizedInt deliveringCount

scheduledDeliveries

protected java.util.Set scheduledDeliveries

maxSize

protected int maxSize

messagesAdded

protected SynchronizedInt messagesAdded

Constructor Detail

ChannelSupport

protected ChannelSupport(long channelID,
                         PersistenceManager pm,
                         boolean recoverable,
                         int maxSize)

Method Detail

handle

public Delivery handle(DeliveryObserver sender,
                       MessageReference ref,
                       Transaction tx)

Description copied from interface: Receiver

A receiver can return an active, "done" or null delivery. The method returns null in case the receiver doesn't accept the message. The return value is unspecified when the message is submitted in the context of a transaction (tx not null).

Specified by:

handle in interface Receiver

Parameters:

sender - - the component the delivery should be acknowledged to.

See Also:

Delivery, DeliveryObserver

acknowledge

public void acknowledge(Delivery d,
                        Transaction tx)
                 throws java.lang.Throwable

Specified by:

acknowledge in interface DeliveryObserver

Throws:

java.lang.Throwable

cancel

public void cancel(Delivery del)
            throws java.lang.Throwable

Specified by:

cancel in interface DeliveryObserver

Throws:

java.lang.Throwable

getChannelID

public long getChannelID()

Specified by:

getChannelID in interface Channel

Returns:

the unique ID of the channel

isRecoverable

public boolean isRecoverable()

Specified by:

isRecoverable in interface Channel

Returns:

true if the channel can guarantee recoverability for reliable messages. Recoverability is not guaranteed for non-reliable messages even if the channel is recoverable.

browse

public java.util.List browse(Filter filter)

Specified by:

browse in interface Channel

Parameters:

filter - - may be null, in which case no filter is applied.

Returns:

a List containing message references of messages whose state is maintained by this State instance.

deliver

public void deliver()

Description copied from interface: Channel

Delivers as many references as possible to its router until receivers will accept no more

Specified by:

deliver in interface Channel

close

public void close()

Description copied from interface: Channel

Close the channel

Specified by:

close in interface Channel

removeAllReferences

public void removeAllReferences()
                         throws java.lang.Throwable

Description copied from interface: Channel

Remove all the references in the channel

Specified by:

removeAllReferences in interface Channel

Throws:

java.lang.Throwable

undelivered

public java.util.List undelivered(Filter filter)

getMessageCount

public int getMessageCount()

Returns the count of messages stored AND being delivered AND scheduled

Specified by:

getMessageCount in interface Channel

Returns:

Total message count = undelivered + delivering + scheduled

getDeliveringCount

public int getDeliveringCount()

Specified by:

getDeliveringCount in interface Channel

Returns:

Count being delivered

getScheduledCount

public int getScheduledCount()

Description copied from interface: Channel

Count scheduled for delivery

Specified by:

getScheduledCount in interface Channel

activate

public void activate()

Description copied from interface: Channel

Activate the channel.

Specified by:

activate in interface Channel

deactivate

public void deactivate()

Description copied from interface: Channel

Deactivate the channel

Specified by:

deactivate in interface Channel

isActive

public boolean isActive()

Specified by:

isActive in interface Channel

Returns:

true if the channel is active

getMaxSize

public int getMaxSize()

Specified by:

getMaxSize in interface Channel

Returns:

The maxiumum number of references this channel can store

setMaxSize

public void setMaxSize(int newSize)

Description copied from interface: Channel

Set the maximum number of references this channel can store

Specified by:

setMaxSize in interface Channel

getMessagesAdded

public int getMessagesAdded()

Description copied from interface: Channel

Get the total number of messages added since this channel was started

Specified by:

getMessagesAdded in interface Channel

Returns:

memoryRefCount

public int memoryRefCount()

clearAllScheduledDeliveries

protected void clearAllScheduledDeliveries()

cancelInternal

protected void cancelInternal(MessageReference ref)
                       throws java.lang.Exception

Throws:

java.lang.Exception

deliverInternal

protected void deliverInternal()

This methods delivers as many messages as possible to the distributor until no more deliveries are returned. This method should never be called at the same time as handle.

See Also:

Channel.deliver()

deliverScheduled

protected boolean deliverScheduled(MessageReference ref)

handleInternal

protected Delivery handleInternal(DeliveryObserver sender,
                                  MessageReference ref,
                                  Transaction tx,
                                  boolean persist)

checkAndSchedule

protected boolean checkAndSchedule(MessageReference ref)

acknowledgeInternal

protected void acknowledgeInternal(Delivery d,
                                   Transaction tx,
                                   boolean persist)
                            throws java.lang.Exception

Throws:

java.lang.Exception

getCallback

protected org.jboss.messaging.core.impl.ChannelSupport.InMemoryCallback getCallback(Transaction tx)

removeFirstInMemory

protected MessageReference removeFirstInMemory()
                                        throws java.lang.Exception

Throws:

java.lang.Exception

addReferenceInMemory

protected void addReferenceInMemory(MessageReference ref)
                             throws java.lang.Exception

Throws:

java.lang.Exception

getReceiversReady

protected boolean getReceiversReady()

setReceiversReady

protected void setReceiversReady(boolean receiversReady)

processMessageBeforeStorage

protected void processMessageBeforeStorage(MessageReference reference)

Give subclass a chance to process the message before storing it internally. TODO - Do we really need this?

checkClosed

protected void checkClosed()