| /* |
| * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package org.reactivestreams.tck; |
| |
| import org.reactivestreams.Publisher; |
| import org.reactivestreams.tck.flow.support.Function; |
| import org.reactivestreams.tck.flow.support.HelperPublisher; |
| import org.reactivestreams.tck.flow.support.InfiniteHelperPublisher; |
| |
| import java.util.concurrent.ExecutorService; |
| |
| /** |
| * Type which is able to create elements based on a seed {@code id} value. |
| * <p> |
| * Simplest implementations will simply return the incoming id as the element. |
| * |
| * @param <T> type of element to be delivered to the Subscriber |
| */ |
| public abstract class WithHelperPublisher<T> { |
| |
| /** ExecutorService to be used by the provided helper {@link org.reactivestreams.Publisher} */ |
| public abstract ExecutorService publisherExecutorService(); |
| |
| /** |
| * Implement this method to match your expected element type. |
| * In case of implementing a simple Subscriber which is able to consume any kind of element simply return the |
| * incoming {@code element} element. |
| * <p> |
| * Sometimes the Subscriber may be limited in what type of element it is able to consume, this you may have to implement |
| * this method such that the emitted element matches the Subscribers requirements. Simplest implementations would be |
| * to simply pass in the {@code element} as payload of your custom element, such as appending it to a String or other identifier. |
| * <p> |
| * <b>Warning:</b> This method may be called concurrently by the helper publisher, thus it should be implemented in a |
| * thread-safe manner. |
| * |
| * @return element of the matching type {@code T} that will be delivered to the tested Subscriber |
| */ |
| public abstract T createElement(int element); |
| |
| /** |
| * Helper method required for creating the Publisher to which the tested Subscriber will be subscribed and tested against. |
| * <p> |
| * By default an <b>asynchronously signalling Publisher</b> is provided, which will use {@link #createElement(int)} |
| * to generate elements type your Subscriber is able to consume. |
| * <p> |
| * Sometimes you may want to implement your own custom custom helper Publisher - to validate behaviour of a Subscriber |
| * when facing a synchronous Publisher for example. If you do, it MUST emit the exact number of elements asked for |
| * (via the {@code elements} parameter) and MUST also must treat the following numbers of elements in these specific ways: |
| * <ul> |
| * <li> |
| * If {@code elements} is {@code Long.MAX_VALUE} the produced stream must be infinite. |
| * </li> |
| * <li> |
| * If {@code elements} is {@code 0} the {@code Publisher} should signal {@code onComplete} immediatly. |
| * In other words, it should represent a "completed stream". |
| * </li> |
| * </ul> |
| */ |
| @SuppressWarnings("unchecked") |
| public Publisher<T> createHelperPublisher(long elements) { |
| final Function<Integer, T> mkElement = new Function<Integer, T>() { |
| @Override public T apply(Integer id) throws Throwable { |
| return createElement(id); |
| } |
| }; |
| |
| if (elements > Integer.MAX_VALUE) return new InfiniteHelperPublisher(mkElement, publisherExecutorService()); |
| else return new HelperPublisher(0, (int) elements, mkElement, publisherExecutorService()); |
| } |
| |
| } |