| /** |
| * 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.storm.windowing; |
| |
| import java.util.concurrent.ExecutionException; |
| import java.util.concurrent.Executors; |
| import java.util.concurrent.ScheduledExecutorService; |
| import java.util.concurrent.ScheduledFuture; |
| import java.util.concurrent.ThreadFactory; |
| import java.util.concurrent.TimeUnit; |
| import org.apache.storm.shade.com.google.common.util.concurrent.ThreadFactoryBuilder; |
| import org.apache.storm.topology.FailedException; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| /** |
| * Invokes {@link TriggerHandler#onTrigger()} after the duration. |
| */ |
| public class TimeTriggerPolicy<T> implements TriggerPolicy<T, Void> { |
| private static final Logger LOG = LoggerFactory.getLogger(TimeTriggerPolicy.class); |
| private final TriggerHandler handler; |
| private final ScheduledExecutorService executor; |
| private final EvictionPolicy<T, ?> evictionPolicy; |
| private long duration; |
| private ScheduledFuture<?> executorFuture; |
| |
| public TimeTriggerPolicy(long millis, TriggerHandler handler) { |
| this(millis, handler, null); |
| } |
| |
| public TimeTriggerPolicy(long millis, TriggerHandler handler, EvictionPolicy<T, ?> evictionPolicy) { |
| this.duration = millis; |
| this.handler = handler; |
| ThreadFactory threadFactory = new ThreadFactoryBuilder() |
| .setNameFormat("time-trigger-policy-%d") |
| .setDaemon(true) |
| .build(); |
| this.executor = Executors.newSingleThreadScheduledExecutor(threadFactory); |
| this.evictionPolicy = evictionPolicy; |
| } |
| |
| @Override |
| public void track(Event<T> event) { |
| checkFailures(); |
| } |
| |
| @Override |
| public void reset() { |
| checkFailures(); |
| } |
| |
| @Override |
| public void start() { |
| executorFuture = executor.scheduleAtFixedRate(newTriggerTask(), duration, duration, TimeUnit.MILLISECONDS); |
| } |
| |
| @Override |
| public void shutdown() { |
| executor.shutdown(); |
| try { |
| if (!executor.awaitTermination(2, TimeUnit.SECONDS)) { |
| executor.shutdownNow(); |
| } |
| } catch (InterruptedException ie) { |
| executor.shutdownNow(); |
| Thread.currentThread().interrupt(); |
| } |
| } |
| |
| @Override |
| public String toString() { |
| return "TimeTriggerPolicy{" |
| + "duration=" + duration |
| + '}'; |
| } |
| |
| /* |
| * Check for uncaught exceptions during the execution |
| * of the trigger and fail fast. |
| * The uncaught exceptions will be wrapped in |
| * ExecutionException and thrown when future.get() is invoked. |
| */ |
| private void checkFailures() { |
| if (executorFuture != null && executorFuture.isDone()) { |
| try { |
| executorFuture.get(); |
| } catch (InterruptedException ex) { |
| LOG.error("Got exception ", ex); |
| throw new FailedException(ex); |
| } catch (ExecutionException ex) { |
| LOG.error("Got exception ", ex); |
| throw new FailedException(ex.getCause()); |
| } |
| } |
| } |
| |
| private Runnable newTriggerTask() { |
| return new Runnable() { |
| @Override |
| public void run() { |
| // do not process current timestamp since tuples might arrive while the trigger is executing |
| long now = System.currentTimeMillis() - 1; |
| try { |
| /* |
| * set the current timestamp as the reference time for the eviction policy |
| * to evict the events |
| */ |
| evictionPolicy.setContext(new DefaultEvictionContext(now, null, null, duration)); |
| handler.onTrigger(); |
| } catch (Throwable th) { |
| LOG.error("handler.onTrigger failed ", th); |
| /* |
| * propagate it so that task gets canceled and the exception |
| * can be retrieved from executorFuture.get() |
| */ |
| throw th; |
| } |
| } |
| }; |
| } |
| |
| @Override |
| public Void getState() { |
| return null; |
| } |
| |
| @Override |
| public void restoreState(Void state) { |
| |
| } |
| } |