0cb4cc4e49
Motivation: We wish to separate these two into clearer write/read interfaces. In particular, we don't want to be able to add listeners to promises, because it makes it easy to add them out of order. We can't prevent it entirely, because any promise can be freely converted to a future where listeners can be added. We can, however, discourage this in the API. Modification: The Promise interface no longer extends the Future interface. Numerous changes to make the project compile and its tests run. Result: Clearer separation of concerns in the code.
53 lines
2.1 KiB
Java
53 lines
2.1 KiB
Java
/*
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* Copyright 2016 The Netty Project
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*
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* The Netty Project licenses this file to you under the Apache License,
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* version 2.0 (the "License"); you may not use this file except in compliance
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* with the License. You may obtain a copy of the License at:
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*
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* https://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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* License for the specific language governing permissions and limitations
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* under the License.
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*/
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package io.netty.util.concurrent;
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import static java.util.Objects.requireNonNull;
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import io.netty.util.internal.logging.InternalLogger;
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import io.netty.util.internal.logging.InternalLoggerFactory;
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public final class UnaryPromiseNotifier<T> implements FutureListener<T> {
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private static final InternalLogger logger = InternalLoggerFactory.getInstance(UnaryPromiseNotifier.class);
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private final Promise<? super T> promise;
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public UnaryPromiseNotifier(Promise<? super T> promise) {
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this.promise = requireNonNull(promise, "promise");
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}
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@Override
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public void operationComplete(Future<? extends T> future) throws Exception {
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cascadeTo(future, promise);
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}
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public static <X> void cascadeTo(Future<X> completedFuture, Promise<? super X> promise) {
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if (completedFuture.isSuccess()) {
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if (!promise.trySuccess(completedFuture.getNow())) {
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logger.warn("Failed to mark a promise as success because it is done already: {}", promise);
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}
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} else if (completedFuture.isCancelled()) {
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if (!promise.cancel()) {
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logger.warn("Failed to cancel a promise because it is done already: {}", promise);
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}
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} else {
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if (!promise.tryFailure(completedFuture.cause())) {
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logger.warn("Failed to mark a promise as failure because it's done already: {}", promise,
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completedFuture.cause());
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}
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}
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}
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}
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