SammyVimes commented on code in PR #1626: URL: https://github.com/apache/ignite-3/pull/1626#discussion_r1097405723
########## modules/core/src/testFixtures/java/org/apache/ignite/internal/testframework/flow/FlowUtils.java: ########## @@ -0,0 +1,158 @@ +/* + * 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.ignite.internal.testframework.flow; + +import java.util.ArrayList; +import java.util.List; +import java.util.NoSuchElementException; +import java.util.concurrent.CompletableFuture; +import java.util.concurrent.Flow.Publisher; +import java.util.concurrent.Flow.Subscriber; +import java.util.concurrent.Flow.Subscription; +import java.util.concurrent.ForkJoinPool; +import org.apache.ignite.internal.util.Cursor; + +/** + * Utility methods for extracting data from {@link Publisher}s. + */ +public class FlowUtils { + /** + * Subscribes to the given publisher, collecting all values into a list. + */ + public static <T> CompletableFuture<List<T>> subscribeToList(Publisher<T> publisher) { + var resultFuture = new CompletableFuture<List<T>>(); + + publisher.subscribe(new Subscriber<>() { + private final List<T> items = new ArrayList<>(); + + @Override + public void onSubscribe(Subscription subscription) { + subscription.request(Long.MAX_VALUE); + } + + @Override + public void onNext(T item) { + items.add(item); + } + + @Override + public void onError(Throwable throwable) { + resultFuture.completeExceptionally(throwable); + } + + @Override + public void onComplete() { + resultFuture.complete(items); + } + }); + + return resultFuture; + } + + /** + * Subscribes to the given publisher, extracting a single value from it. + */ + public static <T> CompletableFuture<T> subscribeToValue(Publisher<T> publisher) { + var resultFuture = new CompletableFuture<T>(); + + publisher.subscribe(new Subscriber<>() { + private Subscription subscription; + + @Override + public void onSubscribe(Subscription subscription) { + this.subscription = subscription; + + subscription.request(1); + } + + @Override + public void onNext(T item) { + resultFuture.complete(item); + + subscription.cancel(); + } + + @Override + public void onError(Throwable throwable) { + resultFuture.completeExceptionally(throwable); + } + + @Override + public void onComplete() { + resultFuture.completeExceptionally(new NoSuchElementException()); + } + }); + + return resultFuture; + } + + /** + * Creates a Publisher that provides data form a given cursor. Review Comment: ```suggestion * Creates a Publisher that provides data from a given cursor. ``` -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
