org.dizitart.no2.event.NitriteEventBus Maven / Gradle / Ivy
/*
*
* Copyright 2017-2018 Nitrite author or authors.
*
* 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 org.dizitart.no2.event;
import org.dizitart.no2.NitriteContext;
import java.util.Collections;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ExecutorService;
/**
* An abstract implementation of {@link EventBus}.
*
* @param the event information type parameter
* @param the event listener type parameter
*
* @since 1.0
* @author Anindya Chatterjee.
*/
public abstract class NitriteEventBus
implements EventBus {
private Set listeners;
private ExecutorService eventExecutor;
/**
* Instantiates a new Nitrite event bus.
*
* @param context the context
*/
public NitriteEventBus(NitriteContext context) {
this.listeners = Collections.newSetFromMap(new ConcurrentHashMap());
this.eventExecutor = context.getWorkerPool();
}
@Override
public void register(EventListener eventListener) {
if (eventListener != null) {
listeners.add(eventListener);
}
}
@Override
public void deregister(EventListener eventListener) {
if (eventListener != null) {
listeners.remove(eventListener);
}
}
@Override
public void close() {
listeners.clear();
}
/**
* Gets the {@link ExecutorService} that executes listeners' code.
*
* @return the {@link ExecutorService}.
*/
protected ExecutorService getEventExecutor() {
return eventExecutor;
}
/**
* Gets a set of all event listeners.
*
* @return the event listeners
*/
protected Set getListeners() {
return listeners;
}
}