rsb.transport.spread

Class SpreadMultiReceiver

java.lang.Object

rsb.transport.spread.SpreadMultiReceiver

public class SpreadMultiReceiver
extends Object

A class that encapsulates the logic to correctly handle multiple parallel clients of a SpreadReceiver by synchronizing the required access and calculating the effective scopes to join. The underlying SpreadReceiver is activated and deactivated depending on the currently active subscriptions to ensure proper termination in case the last client left. Users of this class call subscribe(Subscription) once they want to start receiving events via this class and use unsubscribe(Subscription) to stop this by reusing the same SpreadMultiReceiver.Subscription instance. TODO the whole scope logic in here currently does not calculate the effective root scopes and therefore possibly joins too many scopes. Spread ensures that events are still received only once, but I don't know what the performance impact is.

Author:

jwienke

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	SpreadMultiReceiver.Subscription Subscription information for a single client of this class.

Constructor Summary

Constructors

Constructor and Description
SpreadMultiReceiver(SpreadReceiver spread) Constructor.

Method Summary

Methods

Modifier and Type	Method and Description
URI	getTransportUri() Returns a URI representing the RSB transport encapsulated by this instance.
boolean	subscribe(SpreadMultiReceiver.Subscription subscription) Register a new client.
boolean	unsubscribe(SpreadMultiReceiver.Subscription subscription) Unregister an existing client.

Methods inherited from class java.lang.Object

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

Constructor Detail

SpreadMultiReceiver

public SpreadMultiReceiver(SpreadReceiver spread)

Constructor.

Parameters:

spread - the spread receiver to use. Must not be active when passed into this class, not null

Method Detail

subscribe

public boolean subscribe(SpreadMultiReceiver.Subscription subscription)
                  throws RSBException

Register a new client.

Parameters:

subscription - the subscription specifying the client needs, not null

Returns:

true if the client was successfully subscribed and did not exist before

Throws:

RSBException - error

unsubscribe

public boolean unsubscribe(SpreadMultiReceiver.Subscription subscription)
                    throws RSBException,
                           InterruptedException

Unregister an existing client.

Parameters:

subscription - existing subscription to remove, not null

Returns:

true if the subscription existed and was removed successfully

Throws:

RSBException - error

InterruptedException - interrupted while waiting for the subscription to become effectively unregistered

getTransportUri

public URI getTransportUri()

Returns a URI representing the RSB transport encapsulated by this instance.

Returns:

URI describing the transport