nl.topicus.jdbc.shaded.io.netty.util.concurrent.PromiseCombiner Maven / Gradle / Ivy
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/*
* Copyright 2016 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 nl.topicus.jdbc.shaded.com.liance
* with the License. You may obtain a copy of the License at:
*
* http://www.apache.nl.topicus.jdbc.shaded.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 nl.topicus.jdbc.shaded.io.nl.topicus.jdbc.shaded.net.y.util.concurrent;
import nl.topicus.jdbc.shaded.io.nl.topicus.jdbc.shaded.net.y.util.internal.ObjectUtil;
/**
* A promise nl.topicus.jdbc.shaded.com.iner monitors the outcome of a number of discrete futures, then notifies a final, aggregate promise
* when all of the nl.topicus.jdbc.shaded.com.ined futures are finished. The aggregate promise will succeed if and only if all of the nl.topicus.jdbc.shaded.com.ined
* futures succeed. If any of the nl.topicus.jdbc.shaded.com.ined futures fail, the aggregate promise will fail. The cause failure for the
* aggregate promise will be the failure for one of the failed nl.topicus.jdbc.shaded.com.ined futures; if more than one of the nl.topicus.jdbc.shaded.com.ined
* futures fails, exactly which cause of failure will be assigned to the aggregate promise is undefined.
*
* Callers may populate a promise nl.topicus.jdbc.shaded.com.iner with any number of futures to be nl.topicus.jdbc.shaded.com.ined via the
* {@link PromiseCombiner#add(Future)} and {@link PromiseCombiner#addAll(Future[])} methods. When all futures to be
* nl.topicus.jdbc.shaded.com.ined have been added, callers must provide an aggregate promise to be notified when all nl.topicus.jdbc.shaded.com.ined promises have
* finished via the {@link PromiseCombiner#finish(Promise)} method.
*/
public final class PromiseCombiner {
private int expectedCount;
private int doneCount;
private boolean doneAdding;
private Promise aggregatePromise;
private Throwable cause;
private final GenericFutureListener> listener = new GenericFutureListener>() {
@Override
public void operationComplete(Future future) throws Exception {
++doneCount;
if (!future.isSuccess() && cause == null) {
cause = future.cause();
}
if (doneCount == expectedCount && doneAdding) {
tryPromise();
}
}
};
/**
* Adds a new promise to be nl.topicus.jdbc.shaded.com.ined. New promises may be added until an aggregate promise is added via the
* {@link PromiseCombiner#finish(Promise)} method.
*
* @param promise the promise to add to this promise nl.topicus.jdbc.shaded.com.iner
*
* @deprecated Replaced by {@link PromiseCombiner#add(Future)}.
*/
@Deprecated
public void add(Promise promise) {
add((Future) promise);
}
/**
* Adds a new future to be nl.topicus.jdbc.shaded.com.ined. New futures may be added until an aggregate promise is added via the
* {@link PromiseCombiner#finish(Promise)} method.
*
* @param future the future to add to this promise nl.topicus.jdbc.shaded.com.iner
*/
@SuppressWarnings({ "unchecked", "rawtypes" })
public void add(Future future) {
checkAddAllowed();
++expectedCount;
future.addListener(listener);
}
/**
* Adds new promises to be nl.topicus.jdbc.shaded.com.ined. New promises may be added until an aggregate promise is added via the
* {@link PromiseCombiner#finish(Promise)} method.
*
* @param promises the promises to add to this promise nl.topicus.jdbc.shaded.com.iner
*
* @deprecated Replaced by {@link PromiseCombiner#addAll(Future[])}
*/
@Deprecated
public void addAll(Promise... promises) {
addAll((Future[]) promises);
}
/**
* Adds new futures to be nl.topicus.jdbc.shaded.com.ined. New futures may be added until an aggregate promise is added via the
* {@link PromiseCombiner#finish(Promise)} method.
*
* @param futures the futures to add to this promise nl.topicus.jdbc.shaded.com.iner
*/
@SuppressWarnings({ "unchecked", "rawtypes" })
public void addAll(Future... futures) {
for (Future future : futures) {
this.add(future);
}
}
/**
* Sets the promise to be notified when all nl.topicus.jdbc.shaded.com.ined futures have finished. If all nl.topicus.jdbc.shaded.com.ined futures succeed,
* then the aggregate promise will succeed. If one or more nl.topicus.jdbc.shaded.com.ined futures fails, then the aggregate promise will
* fail with the cause of one of the failed futures. If more than one nl.topicus.jdbc.shaded.com.ined future fails, then exactly which
* failure will be assigned to the aggregate promise is undefined.
*
* After this method is called, no more futures may be added via the {@link PromiseCombiner#add(Future)} or
* {@link PromiseCombiner#addAll(Future[])} methods.
*
* @param aggregatePromise the promise to notify when all nl.topicus.jdbc.shaded.com.ined futures have finished
*/
public void finish(Promise aggregatePromise) {
if (doneAdding) {
throw new IllegalStateException("Already finished");
}
doneAdding = true;
this.aggregatePromise = ObjectUtil.checkNotNull(aggregatePromise, "aggregatePromise");
if (doneCount == expectedCount) {
tryPromise();
}
}
private boolean tryPromise() {
return (cause == null) ? aggregatePromise.trySuccess(null) : aggregatePromise.tryFailure(cause);
}
private void checkAddAllowed() {
if (doneAdding) {
throw new IllegalStateException("Adding promises is not allowed after finished adding");
}
}
}