rice.pastry.messaging
Class MessageDispatch

java.lang.Object
  rice.pastry.messaging.MessageDispatch

public class MessageDispatch

extends java.lang.Object

An object which remembers the mapping from names to MessageReceivers and dispatches messages by request. For consistent routing, modified to only deliver messages to applications if the PastryNode.isReady(). It will still deliver messages to any non-PastryAppl because these "services" may be needed to boot the node into the ring. Any messages to a PastryAppl will be buffered until the node goes ready. TODO: We need to make it explicit which apps can receive messages before PastryNode.isReady().

Version:

$Id: MessageDispatch.java,v 1.15 2005/05/13 21:02:18 jeffh Exp $

Author:

Jeff Hoye, Andrew Ladd

Field Summary

static boolean	BUFFER_IF_NOT_READY If the node is not ready, we do not deliver messages to applications.
static int	BUFFER_SIZE DESCRIBE THE FIELD
protected PastryNode	localNode DESCRIBE THE FIELD

Constructor Summary

MessageDispatch(PastryNode pn)
Constructor.

Method Summary

void	deliverAllBufferedMessages() Called when PastryNode.isReady() becomes true.
protected void	deliverBuffered(Address address) Deliveres all buffered messages for the address.
boolean	dispatchMessage(Message msg) Dispatches a message to the appropriate receiver.
MessageReceiver	getDestination(Message msg) Gets the Destination attribute of the MessageDispatch object
MessageReceiver	getDestinationByAddress(Address addr) Gets the DestinationByAddress attribute of the MessageDispatch object
void	registerReceiver(Address address, MessageReceiver receiver) Registers a receiver with the mail service.

Methods inherited from class java.lang.Object

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

Field Detail

localNode

protected PastryNode localNode

DESCRIBE THE FIELD

BUFFER_SIZE

public static int BUFFER_SIZE

DESCRIBE THE FIELD

BUFFER_IF_NOT_READY

public static final boolean BUFFER_IF_NOT_READY

If the node is not ready, we do not deliver messages to applications. What should we do with these messages? Buffer or Drop? true will buffer the messages that should be delivered false will drop them and print a message

See Also:

Constant Field Values

Constructor Detail

MessageDispatch

public MessageDispatch(PastryNode pn)

Constructor.

Parameters:

pn - DESCRIBE THE PARAMETER

Method Detail

getDestination

public MessageReceiver getDestination(Message msg)

Gets the Destination attribute of the MessageDispatch object

Parameters:

msg - DESCRIBE THE PARAMETER

Returns:

The Destination value

getDestinationByAddress

public MessageReceiver getDestinationByAddress(Address addr)

Gets the DestinationByAddress attribute of the MessageDispatch object

Parameters:

addr - DESCRIBE THE PARAMETER

Returns:

The DestinationByAddress value

registerReceiver

public void registerReceiver(Address address,
                             MessageReceiver receiver)

Registers a receiver with the mail service.

Parameters:

receiver - the receiver.

address - DESCRIBE THE PARAMETER

dispatchMessage

public boolean dispatchMessage(Message msg)

Dispatches a message to the appropriate receiver. It will buffer the message under the following conditions: 1) The MessageReceiver is not yet registered. 2) The MessageReceiver is a PastryAppl, and localNode.isReady() == false

Parameters:

msg - the message.

Returns:

true if message could be dispatched, false otherwise.

deliverBuffered

protected void deliverBuffered(Address address)

Deliveres all buffered messages for the address. Unless: 1) The MR for the address is still null. 2) The MR is a PastryAppl and localNode.isReady() == false

Parameters:

address -

deliverAllBufferedMessages

public void deliverAllBufferedMessages()

Called when PastryNode.isReady() becomes true. Delivers all buffered messages.