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.metric;
  
  import com.codahale.metrics.Gauge;
  import java.util.concurrent.atomic.AtomicLong;
  
  /**
   * @author JohnFang (xiaojian.fxj@alibaba-inc.com).
   */
  public class CallIntervalGauge implements Gauge<Double> {
      private AtomicLong times = new AtomicLong(0);
      private long lastTime = System.currentTimeMillis();
      private Double value = 0.0;
  
      public long incrementAndGet(){
          return times.incrementAndGet();
      }
      public long addAndGet(long delta){
          return times.addAndGet(delta);
      }
  
  
      @Override
      public Double getValue() {
          long totalTimes = times.getAndSet(0);
          long now = System.currentTimeMillis();
          long timeInterval = now - lastTime;
          lastTime = now;
          if (timeInterval > 0 && totalTimes > 0){
              //convert us
              value = timeInterval/(double)totalTimes * 1000;
          }else {
              value = 0.0;
          }
          return value;
      }
  }
  