com.lmax.disruptor.dsl.EventHandlerGroup Maven / Gradle / Ivy
/*
* Copyright 2011 LMAX Ltd.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.lmax.disruptor.dsl;
import com.lmax.disruptor.EventHandler;
import com.lmax.disruptor.EventProcessor;
import com.lmax.disruptor.Sequence;
import com.lmax.disruptor.SequenceBarrier;
import com.lmax.disruptor.WorkHandler;
import java.util.Arrays;
/**
* A group of {@link EventProcessor}s used as part of the {@link Disruptor}.
*
* @param the type of entry used by the event processors.
*/
public class EventHandlerGroup
{
private final Disruptor disruptor;
private final ConsumerRepository consumerRepository;
private final Sequence[] sequences;
EventHandlerGroup(
final Disruptor disruptor,
final ConsumerRepository consumerRepository,
final Sequence[] sequences)
{
this.disruptor = disruptor;
this.consumerRepository = consumerRepository;
this.sequences = Arrays.copyOf(sequences, sequences.length);
}
/**
* Create a new event handler group that combines the consumers in this group with otherHandlerGroup.
*
* @param otherHandlerGroup the event handler group to combine.
* @return a new EventHandlerGroup combining the existing and new consumers into a single dependency group.
*/
public EventHandlerGroup and(final EventHandlerGroup otherHandlerGroup)
{
final Sequence[] combinedSequences = new Sequence[this.sequences.length + otherHandlerGroup.sequences.length];
System.arraycopy(this.sequences, 0, combinedSequences, 0, this.sequences.length);
System.arraycopy(
otherHandlerGroup.sequences, 0,
combinedSequences, this.sequences.length, otherHandlerGroup.sequences.length);
return new EventHandlerGroup<>(disruptor, consumerRepository, combinedSequences);
}
/**
* Create a new event handler group that combines the handlers in this group with processors.
*
* @param processors the processors to combine.
* @return a new EventHandlerGroup combining the existing and new processors into a single dependency group.
*/
public EventHandlerGroup and(final EventProcessor... processors)
{
Sequence[] combinedSequences = new Sequence[sequences.length + processors.length];
for (int i = 0; i < processors.length; i++)
{
consumerRepository.add(processors[i]);
combinedSequences[i] = processors[i].getSequence();
}
System.arraycopy(sequences, 0, combinedSequences, processors.length, sequences.length);
return new EventHandlerGroup<>(disruptor, consumerRepository, combinedSequences);
}
/**
* Set up batch handlers to consume events from the ring buffer. These handlers will only process events
* after every {@link EventProcessor} in this group has processed the event.
*
* This method is generally used as part of a chain. For example if the handler A must
* process events before handler B:
*
* dw.handleEventsWith(A).then(B);
*
* @param handlers the batch handlers that will process events.
* @return a {@link EventHandlerGroup} that can be used to set up a event processor barrier over the created event processors.
*/
@SafeVarargs
public final EventHandlerGroup then(final EventHandler... handlers)
{
return handleEventsWith(handlers);
}
/**
* Set up custom event processors to handle events from the ring buffer. The Disruptor will
* automatically start these processors when {@link Disruptor#start()} is called.
*
* This method is generally used as part of a chain. For example if the handler A must
* process events before handler B:
*
* @param eventProcessorFactories the event processor factories to use to create the event processors that will process events.
* @return a {@link EventHandlerGroup} that can be used to chain dependencies.
*/
@SafeVarargs
public final EventHandlerGroup then(final EventProcessorFactory... eventProcessorFactories)
{
return handleEventsWith(eventProcessorFactories);
}
/**
* Set up a worker pool to handle events from the ring buffer. The worker pool will only process events
* after every {@link EventProcessor} in this group has processed the event. Each event will be processed
* by one of the work handler instances.
*
* This method is generally used as part of a chain. For example if the handler A must
* process events before the worker pool with handlers B, C:
*
* dw.handleEventsWith(A).thenHandleEventsWithWorkerPool(B, C);
*
* @param handlers the work handlers that will process events. Each work handler instance will provide an extra thread in the worker pool.
* @return a {@link EventHandlerGroup} that can be used to set up a event processor barrier over the created event processors.
*/
@SafeVarargs
public final EventHandlerGroup thenHandleEventsWithWorkerPool(final WorkHandler... handlers)
{
return handleEventsWithWorkerPool(handlers);
}
/**
* Set up batch handlers to handle events from the ring buffer. These handlers will only process events
* after every {@link EventProcessor} in this group has processed the event.
*
* This method is generally used as part of a chain. For example if A must
* process events before B:
*
* dw.after(A).handleEventsWith(B);
*
* @param handlers the batch handlers that will process events.
* @return a {@link EventHandlerGroup} that can be used to set up a event processor barrier over the created event processors.
*/
@SafeVarargs
public final EventHandlerGroup handleEventsWith(final EventHandler... handlers)
{
return disruptor.createEventProcessors(sequences, handlers);
}
/**
* Set up custom event processors to handle events from the ring buffer. The Disruptor will
* automatically start these processors when {@link Disruptor#start()} is called.
*
* This method is generally used as part of a chain. For example if A must
* process events before B:
*
* dw.after(A).handleEventsWith(B);
*
* @param eventProcessorFactories the event processor factories to use to create the event processors that will process events.
* @return a {@link EventHandlerGroup} that can be used to chain dependencies.
*/
@SafeVarargs
public final EventHandlerGroup handleEventsWith(final EventProcessorFactory... eventProcessorFactories)
{
return disruptor.createEventProcessors(sequences, eventProcessorFactories);
}
/**
* Set up a worker pool to handle events from the ring buffer. The worker pool will only process events
* after every {@link EventProcessor} in this group has processed the event. Each event will be processed
* by one of the work handler instances.
*
* This method is generally used as part of a chain. For example if the handler A must
* process events before the worker pool with handlers B, C:
*
* dw.after(A).handleEventsWithWorkerPool(B, C);
*
* @param handlers the work handlers that will process events. Each work handler instance will provide an extra thread in the worker pool.
* @return a {@link EventHandlerGroup} that can be used to set up a event processor barrier over the created event processors.
*/
@SafeVarargs
public final EventHandlerGroup handleEventsWithWorkerPool(final WorkHandler... handlers)
{
return disruptor.createWorkerPool(sequences, handlers);
}
/**
* Create a dependency barrier for the processors in this group.
* This allows custom event processors to have dependencies on
* {@link com.lmax.disruptor.BatchEventProcessor}s created by the disruptor.
*
* @return a {@link SequenceBarrier} including all the processors in this group.
*/
public SequenceBarrier asSequenceBarrier()
{
return disruptor.getRingBuffer().newBarrier(sequences);
}
}