netty5/common/src/main/java/io/netty/util/concurrent/PromiseAggregator.java
田欧 9d62deeb6f Java 8 migration: Use diamond operator (#8749)
Motivation:

We can use the diamond operator these days.

Modification:

Use diamond operator whenever possible.

Result:

More modern code and less boiler-plate.
2019-01-22 16:07:26 +01:00

116 lines
3.7 KiB
Java

/*
* Copyright 2014 The Netty Project
*
* The Netty Project 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 io.netty.util.concurrent;
import java.util.LinkedHashSet;
import java.util.Set;
/**
* @deprecated Use {@link PromiseCombiner}
*
* {@link GenericFutureListener} implementation which consolidates multiple {@link Future}s
* into one, by listening to individual {@link Future}s and producing an aggregated result
* (success/failure) when all {@link Future}s have completed.
*
* @param <V> the type of value returned by the {@link Future}
* @param <F> the type of {@link Future}
*/
@Deprecated
public class PromiseAggregator<V, F extends Future<V>> implements GenericFutureListener<F> {
private final Promise<?> aggregatePromise;
private final boolean failPending;
private Set<Promise<V>> pendingPromises;
/**
* Creates a new instance.
*
* @param aggregatePromise the {@link Promise} to notify
* @param failPending {@code true} to fail pending promises, false to leave them unaffected
*/
public PromiseAggregator(Promise<Void> aggregatePromise, boolean failPending) {
if (aggregatePromise == null) {
throw new NullPointerException("aggregatePromise");
}
this.aggregatePromise = aggregatePromise;
this.failPending = failPending;
}
/**
* See {@link PromiseAggregator#PromiseAggregator(Promise, boolean)}.
* Defaults {@code failPending} to true.
*/
public PromiseAggregator(Promise<Void> aggregatePromise) {
this(aggregatePromise, true);
}
/**
* Add the given {@link Promise}s to the aggregator.
*/
@SafeVarargs
public final PromiseAggregator<V, F> add(Promise<V>... promises) {
if (promises == null) {
throw new NullPointerException("promises");
}
if (promises.length == 0) {
return this;
}
synchronized (this) {
if (pendingPromises == null) {
int size;
if (promises.length > 1) {
size = promises.length;
} else {
size = 2;
}
pendingPromises = new LinkedHashSet<>(size);
}
for (Promise<V> p : promises) {
if (p == null) {
continue;
}
pendingPromises.add(p);
p.addListener(this);
}
}
return this;
}
@Override
public synchronized void operationComplete(F future) throws Exception {
if (pendingPromises == null) {
aggregatePromise.setSuccess(null);
} else {
pendingPromises.remove(future);
if (!future.isSuccess()) {
Throwable cause = future.cause();
aggregatePromise.setFailure(cause);
if (failPending) {
for (Promise<V> pendingFuture : pendingPromises) {
pendingFuture.setFailure(cause);
}
}
} else {
if (pendingPromises.isEmpty()) {
aggregatePromise.setSuccess(null);
}
}
}
}
}