software.amazon.jdbc.util.events

Class BatchingEventPublisher

java.lang.Object

software.amazon.jdbc.util.events.BatchingEventPublisher

All Implemented Interfaces:

EventPublisher

public class BatchingEventPublisher
extends java.lang.Object
implements EventPublisher

An event publisher that periodically publishes a batch of all unique events encountered during the latest time interval. Batches do not contain duplicate events; if the current batch receives a duplicate, it will not be added to the batch and the original event will only be published once, when the entire batch is published.

Field Summary

Fields

Modifier and Type	Field and Description
protected static long	DEFAULT_MESSAGE_INTERVAL_NANOS
protected java.util.Set<Event>	eventMessages
protected static java.util.concurrent.ScheduledExecutorService	publishingExecutor
protected java.util.Map<java.lang.Class<? extends Event>,java.util.Set<EventSubscriber>>	subscribersMap

Constructor Summary

Constructors

Constructor and Description
BatchingEventPublisher()
BatchingEventPublisher(long messageIntervalNanos) Constructs a PeriodicEventPublisher instance and submits a thread to periodically send message batches.

Method Summary

Modifier and Type	Method and Description
protected void	initPublishingThread(long messageIntervalNanos)
void	publish(Event event) Publishes an event.
protected void	sendMessages()
void	subscribe(EventSubscriber subscriber, java.util.Set<java.lang.Class<? extends Event>> eventClasses) Registers the given subscriber for the given event classes.
void	unsubscribe(EventSubscriber subscriber, java.util.Set<java.lang.Class<? extends Event>> eventClasses) Unsubscribes the given subscriber from the given event classes.

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_MESSAGE_INTERVAL_NANOS

protected static final long DEFAULT_MESSAGE_INTERVAL_NANOS

subscribersMap

protected final java.util.Map<java.lang.Class<? extends Event>,java.util.Set<EventSubscriber>> subscribersMap

eventMessages

protected final java.util.Set<Event> eventMessages

publishingExecutor

protected static final java.util.concurrent.ScheduledExecutorService publishingExecutor

Constructor Detail

BatchingEventPublisher

public BatchingEventPublisher()

BatchingEventPublisher

public BatchingEventPublisher(long messageIntervalNanos)

Constructs a PeriodicEventPublisher instance and submits a thread to periodically send message batches.

Parameters:

messageIntervalNanos - the rate at which messages batches should be sent, in nanoseconds.

Method Detail

initPublishingThread

protected void initPublishingThread(long messageIntervalNanos)

sendMessages

protected void sendMessages()

subscribe

public void subscribe(EventSubscriber subscriber,
                      java.util.Set<java.lang.Class<? extends Event>> eventClasses)

Description copied from interface: EventPublisher

Registers the given subscriber for the given event classes.

Specified by:

subscribe in interface EventPublisher

Parameters:

subscriber - the subscriber to be notified when the given event classes occur.

eventClasses - the classes of events that the subscriber should be notified of.

unsubscribe

public void unsubscribe(EventSubscriber subscriber,
                        java.util.Set<java.lang.Class<? extends Event>> eventClasses)

Description copied from interface: EventPublisher

Unsubscribes the given subscriber from the given event classes.

Specified by:

unsubscribe in interface EventPublisher

Parameters:

subscriber - the subscriber to unsubscribe from the given event classes.

eventClasses - the classes of events that the subscriber wants to unsubscribe from.

publish

public void publish(Event event)

Description copied from interface: EventPublisher

Publishes an event. All subscribers to the given event class will be notified of the event.

Specified by:

publish in interface EventPublisher

Parameters:

event - the event to publish.