/*
* 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 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_voltpatches.util.concurrent;
import io.netty_voltpatches.util.internal.ObjectUtil;
import io.netty_voltpatches.util.internal.logging.InternalLogger;
import io.netty_voltpatches.util.internal.logging.InternalLoggerFactory;
public final class UnaryPromiseNotifier<T> implements FutureListener<T> {
private static final InternalLogger logger = InternalLoggerFactory.getInstance(UnaryPromiseNotifier.class);
private final Promise<? super T> promise;
public UnaryPromiseNotifier(Promise<? super T> promise) {
this.promise = ObjectUtil.checkNotNull(promise, "promise");
}
@Override
public void operationComplete(Future<T> future) throws Exception {
cascadeTo(future, promise);
}
public static <X> void cascadeTo(Future<X> completedFuture, Promise<? super X> promise) {
if (completedFuture.isSuccess()) {
if (!promise.trySuccess(completedFuture.getNow())) {
logger.warn("Failed to mark a promise as success because it is done already: {}", promise);
}
} else if (completedFuture.isCancelled()) {
if (!promise.cancel(false)) {
logger.warn("Failed to cancel a promise because it is done already: {}", promise);
}
} else {
if (!promise.tryFailure(completedFuture.cause())) {
logger.warn("Failed to mark a promise as failure because it's done already: {}", promise,
completedFuture.cause());
}
}
}
}