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 com.alibaba.jstorm.common.metric;
  
  import com.codahale.metrics.Metered;
  import java.util.concurrent.atomic.AtomicLong;
  
  /**
   * @author wange
   * @since 2.1.1
   */
  public class MeanMeter implements Metered {
  
      private final AtomicLong count = new AtomicLong(0L);
      private final long startTime;
  
      /**
       * Creates a new {@link MeanMeter}.
       */
      public MeanMeter() {
          this.startTime = System.currentTimeMillis();
      }
  
      /**
       * Mark the occurrence of an event.
       */
      public void mark() {
          mark(1);
      }
  
      /**
       * Mark the occurrence of a given number of events.
       *
       * @param n the number of events
       */
      public void mark(long n) {
          count.addAndGet(n);
      }
  
      @Override
      public long getCount() {
          return count.get();
      }
  
      @Override
      public double getFifteenMinuteRate() {
          return 0d;
      }
  
      @Override
      public double getFiveMinuteRate() {
          return 0d;
      }
  
      @Override
      public double getMeanRate() {
          return calcMean();
      }
  
      @Override
      public double getOneMinuteRate() {
          return calcMean();
      }
  
      private double calcMean() {
          double elapsedSec = (System.currentTimeMillis() - startTime) / 1000d;
          if (elapsedSec > 0) {
              return count.get() / elapsedSec;
          }
          return 0;
      }
  }
  