org.apache.hudi.common.util.FutureUtils Maven / Gradle / Ivy
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* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF 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 org.apache.hudi.common.util;
import java.util.List;
import java.util.concurrent.CompletableFuture;
import java.util.stream.Collectors;
/**
* A utility class for future operation.
*/
public class FutureUtils {
/**
* Similar to {@link CompletableFuture#allOf(CompletableFuture[])} with a few important
* differences:
*
*
* - Completes successfully as soon as *all* of the futures complete successfully
* - Completes exceptionally as soon as *any* of the futures complete exceptionally
* - In case it's completed exceptionally all the other futures not completed yet, will be
* cancelled
*
*
* @param futures list of {@link CompletableFuture}s
*/
public static CompletableFuture> allOf(List> futures) {
CompletableFuture union = CompletableFuture.allOf(futures.toArray(new CompletableFuture[0]));
futures.forEach(future -> {
// NOTE: We add a callback to every future, to cancel all the other not yet completed futures,
// which will be providing for an early termination semantic: whenever any of the futures
// fail other futures will be cancelled and the exception will be returned as a result
future.whenComplete((ignored, throwable) -> {
if (throwable != null) {
futures.forEach(f -> f.cancel(true));
union.completeExceptionally(throwable);
}
});
});
return union.thenApply(aVoid ->
futures.stream()
// NOTE: This join wouldn't block, since all the
// futures are completed at this point.
.map(CompletableFuture::join)
.collect(Collectors.toList()));
}
}