org.jboss.messaging.core.impl
Class RoundRobinDistributor

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

All Implemented Interfaces:

Distributor, Receiver

public class RoundRobinDistributor
extends java.lang.Object
implements Distributor

The distributor will always first try the next receiver in the list to the one it tried last time. This gives a more balanced distribution than the FirstReceiverDistributor and is better suited when batching messages to consumers since we will end up with messages interleaved amongst consumers rather than in contiguous blocks.

Version:

$Revision: 1 $ $Id: $

Author:

Tim Fox, Ovidiu Feodorov

Constructor Summary

RoundRobinDistributor()

Method Summary

boolean	add(Receiver r) Add a local receiver to this distributor.
void	clear() Remove all receivers.
boolean	contains(Receiver r) Does the distributor already contain the specified Receiver?
int	getNumberOfReceivers()
Delivery	handle(DeliveryObserver observer, MessageReference ref, Transaction tx) A receiver can return an active, "done" or null delivery.
java.util.Iterator	iterator()
boolean	remove(Receiver r) Remove a local receiver from this distributor.

Methods inherited from class java.lang.Object

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

Constructor Detail

RoundRobinDistributor

public RoundRobinDistributor()

Method Detail

handle

public Delivery handle(DeliveryObserver observer,
                       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:

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

See Also:

Delivery, DeliveryObserver

add

public boolean add(Receiver r)

Description copied from interface: Distributor

Add a local receiver to this distributor.

Specified by:

add in interface Distributor

Returns:

true if the distributor did not already contain the specified receiver and the receiver was added to the distributor, false otherwise.

remove

public boolean remove(Receiver r)

Description copied from interface: Distributor

Remove a local receiver from this distributor.

Specified by:

remove in interface Distributor

Returns:

true if this distributor contained the specified receiver.

clear

public void clear()

Description copied from interface: Distributor

Remove all receivers.

Specified by:

clear in interface Distributor

contains

public boolean contains(Receiver r)

Description copied from interface: Distributor

Does the distributor already contain the specified Receiver?

Specified by:

contains in interface Distributor

Returns:

iterator

public java.util.Iterator iterator()

Specified by:

iterator in interface Distributor

Returns:

an iterator of receivers

getNumberOfReceivers

public int getNumberOfReceivers()

Specified by:

getNumberOfReceivers in interface Distributor

Returns:

The number of receivers in the distributor