Module com.lmax.disruptor

Package com.lmax.disruptor

Class AggregateEventHandler<T>

java.lang.Object

com.lmax.disruptor.AggregateEventHandler<T>

Type Parameters:

T - event implementation storing the data for sharing during exchange or parallel coordination of an event.

All Implemented Interfaces:

EventHandler<T>, EventHandlerIdentity

public final class AggregateEventHandler<T>
extends java.lang.Object
implements EventHandler<T>

An aggregate collection of EventHandlers that get called in sequence for each event.

Constructor Summary

Constructors

Constructor	Description
AggregateEventHandler(EventHandler<T>... eventHandlers)	Construct an aggregate collection of EventHandlers to be called in sequence.

Method Summary

Modifier and Type	Method	Description
default void	onBatchStart(long batchSize, long queueDepth)	Invoked by BatchEventProcessor prior to processing a batch of events
void	onEvent(T event, long sequence, boolean endOfBatch)	Called when a publisher has published an event to the RingBuffer.
void	onShutdown()
void	onStart()
default void	onTimeout(long sequence)	Invoked when a BatchEventProcessor's WaitStrategy throws a TimeoutException.

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.lmax.disruptor.EventHandler

setSequenceCallback

Constructor Detail

AggregateEventHandler

@SafeVarargs
public AggregateEventHandler(EventHandler<T>... eventHandlers)

Construct an aggregate collection of EventHandlers to be called in sequence.

Parameters:

eventHandlers - to be called in sequence.

Method Detail

onEvent

public void onEvent(T event,
                    long sequence,
                    boolean endOfBatch)
             throws java.lang.Exception

Description copied from interface: EventHandler

Called when a publisher has published an event to the RingBuffer. The BatchEventProcessor will read messages from the RingBuffer in batches, where a batch is all of the events available to be processed without having to wait for any new event to arrive. This can be useful for event handlers that need to do slower operations like I/O as they can group together the data from multiple events into a single operation. Implementations should ensure that the operation is always performed when endOfBatch is true as the time between that message and the next one is indeterminate.

Specified by:

onEvent in interface EventHandler<T>

Parameters:

event - published to the RingBuffer

sequence - of the event being processed

endOfBatch - flag to indicate if this is the last event in a batch from the RingBuffer

Throws:

java.lang.Exception - if the EventHandler would like the exception handled further up the chain.

onStart

public void onStart()

onShutdown

public void onShutdown()

onBatchStart

public default void onBatchStart(long batchSize,
                                 long queueDepth)

Invoked by BatchEventProcessor prior to processing a batch of events

Parameters:

batchSize - the size of the batch that is starting

queueDepth - the total number of queued up events including the batch about to be processed

onTimeout

public default void onTimeout(long sequence)
                       throws java.lang.Exception

Invoked when a BatchEventProcessor's WaitStrategy throws a TimeoutException.

Parameters:

sequence - - the last processed sequence.

Throws:

java.lang.Exception - if the implementation is unable to handle this timeout.