/*
* Copyright 2014 Netflix, Inc.
*
* 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 io.reactivex.netty.util;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelFutureListener;
import io.netty.channel.ChannelPromise;
import rx.Observable;
import rx.Subscriber;
import java.util.Iterator;
import java.util.concurrent.ConcurrentLinkedQueue;
import java.util.concurrent.atomic.AtomicInteger;
/**
* @author Nitesh Kant
*/
public class MultipleFutureListener implements ChannelFutureListener {
private final ChannelPromise completionPromise;
private final Observable<Void> completionObservable;
private final AtomicInteger listeningToCount = new AtomicInteger();
private final ConcurrentLinkedQueue<ChannelFuture> pendingFutures = new ConcurrentLinkedQueue<ChannelFuture>();
public MultipleFutureListener(final ChannelPromise completionPromise) {
if (null == completionPromise) {
throw new NullPointerException("Promise can not be null.");
}
this.completionPromise = completionPromise;
completionObservable = Observable.create(new Observable.OnSubscribe<Void>() {
@Override
public void call(final Subscriber<? super Void> subscriber) {
if (listeningToCount.get() == 0) {
MultipleFutureListener.this.completionPromise.trySuccess();
}
MultipleFutureListener.this.completionPromise.addListener(new ChannelFutureListener() {
@Override
public void operationComplete(ChannelFuture future) throws Exception {
if (future.isSuccess()) {
subscriber.onCompleted();
} else {
subscriber.onError(future.cause());
}
}
});
}
});
}
public void listen(ChannelFuture future) {
pendingFutures.add(future);
listeningToCount.incrementAndGet();
future.addListener(this);
}
public Observable<Void> asObservable() {
return completionObservable;
}
public void cancelPendingFutures(boolean mayInterruptIfRunning) {
for (Iterator<ChannelFuture> iterator = pendingFutures.iterator(); iterator.hasNext(); ) {
ChannelFuture pendingFuture = iterator.next();
iterator.remove();
pendingFuture.cancel(mayInterruptIfRunning);
}
}
@Override
public void operationComplete(ChannelFuture future) throws Exception {
pendingFutures.remove(future);
int nowListeningTo = listeningToCount.decrementAndGet();
/**
* If any one of the future fails, we fail the subscribers.
* If all complete (listen count == 0) we complete the subscribers.
*/
if (!future.isSuccess()) {
completionPromise.tryFailure(future.cause());
} else if (nowListeningTo == 0) {
completionPromise.trySuccess(null);
}
}
}