| /* |
| * 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.flink.statefun.examples.async.service; |
| |
| import java.util.concurrent.CompletableFuture; |
| import java.util.concurrent.Executors; |
| import java.util.concurrent.ScheduledExecutorService; |
| import java.util.concurrent.ThreadLocalRandom; |
| import java.util.concurrent.TimeUnit; |
| |
| /** |
| * A dummy implementation that simulates a service that might take a while to compute it's result. |
| */ |
| public final class DummyTaskQueryService implements TaskQueryService { |
| |
| /** |
| * used to complete the futures after an artificial random delay, that simulates network latency, |
| * service busyness etc' |
| */ |
| private final ScheduledExecutorService executor = newScheduledExecutorService(); |
| |
| public CompletableFuture<TaskStatus> getTaskStatusAsync(String taskId) { |
| CompletableFuture<TaskStatus> result = new CompletableFuture<>(); |
| |
| final long randomCompletionDelay = ThreadLocalRandom.current().nextLong(5_000); |
| executor.schedule( |
| completeRandomly(taskId, result), randomCompletionDelay, TimeUnit.MILLISECONDS); |
| |
| return result; |
| } |
| |
| /** |
| * returns a {@link Runnable}, that when runs, it completes the supplied future {@code result} |
| * with a {@link TaskStatus} that might be either done or still running. If done, then the task |
| * status would have a completion time. |
| */ |
| private static Runnable completeRandomly(String taskId, CompletableFuture<TaskStatus> result) { |
| return () -> { |
| boolean taskStatus = ThreadLocalRandom.current().nextBoolean(); |
| |
| if (taskStatus) { |
| final long now = System.currentTimeMillis(); |
| result.complete(new TaskStatus(taskId, true, now)); |
| } else { |
| result.complete(new TaskStatus(taskId, false, null)); |
| } |
| }; |
| } |
| |
| /** A scheduled executor service with daemon threads. */ |
| private static ScheduledExecutorService newScheduledExecutorService() { |
| return Executors.newSingleThreadScheduledExecutor( |
| r -> { |
| Thread t = new Thread(r); |
| t.setDaemon(true); |
| return t; |
| }); |
| } |
| } |