| /** |
| * 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 backtype.storm.windowing; |
| |
| import java.util.concurrent.atomic.AtomicInteger; |
| |
| /** |
| * A trigger that tracks event counts and calls back {@link TriggerHandler#onTrigger()} |
| * when the count threshold is hit. |
| * |
| * @param <T> the type of event tracked by this policy. |
| */ |
| public class CountTriggerPolicy<T> implements TriggerPolicy<T> { |
| private final int count; |
| private final AtomicInteger currentCount; |
| private final TriggerHandler handler; |
| |
| public CountTriggerPolicy(int count, TriggerHandler handler) { |
| this.count = count; |
| this.currentCount = new AtomicInteger(); |
| this.handler = handler; |
| } |
| |
| @Override |
| public void track(Event<T> event) { |
| if (currentCount.incrementAndGet() >= count) { |
| handler.onTrigger(); |
| } |
| } |
| |
| @Override |
| public void reset() { |
| currentCount.set(0); |
| } |
| |
| @Override |
| public void shutdown() { |
| // NOOP |
| } |
| |
| @Override |
| public String toString() { |
| return "CountTriggerPolicy{" + |
| "count=" + count + |
| ", currentCount=" + currentCount + |
| '}'; |
| } |
| } |