org.elasticsearch.action.support.AbstractListenableActionFuture Maven / Gradle / Ivy
/*
* Licensed to ElasticSearch and Shay Banon under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. ElasticSearch licenses this
* file to you 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.elasticsearch.action.support;
import com.google.common.collect.Lists;
import org.elasticsearch.ElasticSearchException;
import org.elasticsearch.action.ActionListener;
import org.elasticsearch.action.ListenableActionFuture;
import org.elasticsearch.threadpool.ThreadPool;
import java.util.List;
/**
*
*/
public abstract class AbstractListenableActionFuture extends AdapterActionFuture implements ListenableActionFuture {
final boolean listenerThreaded;
final ThreadPool threadPool;
volatile Object listeners;
boolean executedListeners = false;
protected AbstractListenableActionFuture(boolean listenerThreaded, ThreadPool threadPool) {
this.listenerThreaded = listenerThreaded;
this.threadPool = threadPool;
}
public boolean listenerThreaded() {
return false; // we control execution of the listener
}
public ThreadPool threadPool() {
return threadPool;
}
public void addListener(final ActionListener listener) {
internalAddListener(listener);
}
public void addListener(final Runnable listener) {
internalAddListener(listener);
}
public void internalAddListener(Object listener) {
boolean executeImmediate = false;
synchronized (this) {
if (executedListeners) {
executeImmediate = true;
} else {
Object listeners = this.listeners;
if (listeners == null) {
listeners = listener;
} else if (listeners instanceof List) {
((List) this.listeners).add(listener);
} else {
Object orig = listeners;
listeners = Lists.newArrayListWithCapacity(2);
((List) listeners).add(orig);
((List) listeners).add(listener);
}
this.listeners = listeners;
}
}
if (executeImmediate) {
executeListener(listener);
}
}
@Override
protected void done() {
super.done();
synchronized (this) {
executedListeners = true;
}
Object listeners = this.listeners;
if (listeners != null) {
if (listeners instanceof List) {
List list = (List) listeners;
for (Object listener : list) {
executeListener(listener);
}
} else {
executeListener(listeners);
}
}
}
private void executeListener(final Object listener) {
if (listenerThreaded) {
if (listener instanceof Runnable) {
threadPool.generic().execute((Runnable) listener);
} else {
threadPool.generic().execute(new Runnable() {
@Override
public void run() {
ActionListener lst = (ActionListener) listener;
try {
lst.onResponse(actionGet());
} catch (ElasticSearchException e) {
lst.onFailure(e);
}
}
});
}
} else {
if (listener instanceof Runnable) {
((Runnable) listener).run();
} else {
ActionListener lst = (ActionListener) listener;
try {
lst.onResponse(actionGet());
} catch (ElasticSearchException e) {
lst.onFailure(e);
}
}
}
}
}