Package com.lmax.disruptor

Class 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>, LifecycleAware
    public final class AggregateEventHandler<T>
extends java.lang.Object
implements EventHandler<T>, LifecycleAware
    An aggregate collection of EventHandlers that get called in sequence for each event.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void onEvent​(T event, long sequence, boolean endOfBatch)
      Called when a publisher has published an event to the RingBuffer.
      void onShutdown()
      Called once just before the thread is shutdown.
      void onStart()
      Called once on thread start before first event is available.

      • Methods inherited from class java.lang.Object

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

    • Field Detail

    • 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 an the next one is inderminate.
        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()
        Description copied from interface: LifecycleAware
        Called once on thread start before first event is available.
        Specified by:
        onStart in interface LifecycleAware

      • onShutdown

        public void onShutdown()
        Description copied from interface: LifecycleAware

        Called once just before the thread is shutdown.

        Sequence event processing will already have stopped before this method is called. No events will be processed after this message.

        Specified by:
        onShutdown in interface LifecycleAware