content: /*
   * 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.distributedlog.common.rate;
  
  import java.util.concurrent.CopyOnWriteArrayList;
  import java.util.concurrent.ScheduledExecutorService;
  import java.util.concurrent.ScheduledFuture;
  import java.util.concurrent.TimeUnit;
  
  /**
   * Factory to create {@link MovingAverageRate} instances.
   */
  public class MovingAverageRateFactory implements Runnable {
  
      private static final int DEFAULT_INTERVAL_SECS = 1;
  
      private final ScheduledExecutorService scheduler;
      private final ScheduledFuture<?> scheduledFuture;
      private final CopyOnWriteArrayList<SampledMovingAverageRate> avgs;
  
      public MovingAverageRateFactory(ScheduledExecutorService scheduler) {
          this.avgs = new CopyOnWriteArrayList<SampledMovingAverageRate>();
          this.scheduler = scheduler;
          this.scheduledFuture = this.scheduler.scheduleAtFixedRate(
              this, DEFAULT_INTERVAL_SECS, DEFAULT_INTERVAL_SECS, TimeUnit.SECONDS);
      }
  
      public MovingAverageRate create(int intervalSecs) {
          SampledMovingAverageRate avg = new SampledMovingAverageRate(intervalSecs);
          avgs.add(avg);
          return avg;
      }
  
      public void close() {
          scheduledFuture.cancel(true);
          avgs.clear();
      }
  
      @Override
      public void run() {
          sampleAll();
      }
  
      private void sampleAll() {
          avgs.forEach(SampledMovingAverageRate::sample);
      }
  }
  