ch.epfl.dedis.byzcoin

Class Subscription

java.lang.Object

ch.epfl.dedis.byzcoin.Subscription

public class Subscription
extends Object

Subscription class for ByzCoin. A listener can subscribe to different events and then get notified whenever something happens via the streaming service. We only maintain one connection because we can replicate the events to all the subscribers.

- The connection is made if at least one receiver subscribes. - The connection stops once the last receiver has been unsubscribed. - The subscribers will only see events (blocks) that arrive after the subscription is made.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	Subscription.SkipBlockReceiver A SkipBlockReceiver will be informed on any new block arriving.

Constructor Summary

Constructors

Constructor and Description
Subscription(ByzCoinRPC bc) Starts a subscription service, but doesn't call the polling yet.

Method Summary

Modifier and Type	Method and Description
boolean	isClosed() Checks whether the connection is closed.
void	subscribeSkipBlock(Subscription.SkipBlockReceiver br) Subscribes the receiver to the service.
void	unsubscribeSkipBlock(Subscription.SkipBlockReceiver br) Unsubscribes an existing receiver from the system.

Methods inherited from class java.lang.Object

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

Constructor Detail

Subscription

public Subscription(ByzCoinRPC bc)

Starts a subscription service, but doesn't call the polling yet.

Parameters:

bc - a reference to the instantiated ByzCoinRPC

Method Detail

subscribeSkipBlock

public void subscribeSkipBlock(Subscription.SkipBlockReceiver br)
                        throws CothorityCommunicationException

Subscribes the receiver to the service. After the receiver has been subscribed, every new block will be sent to it. Previously received blocks will not be sent to the receiver.

Parameters:

br - the receiver that wants to be informed of new blocks.

Throws:

CothorityCommunicationException - is something went wrong

unsubscribeSkipBlock

public void unsubscribeSkipBlock(Subscription.SkipBlockReceiver br)

Unsubscribes an existing receiver from the system. If it was the last receiver, then the polling will stop.

Parameters:

br - the receiver to unsubscribe.

isClosed

public boolean isClosed()

Checks whether the connection is closed.

Returns:

true if closed