| /** |
| * 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.Gauge; |
| |
| /** |
| * |
| * @author zhongyan.feng |
| * @version $Id: |
| */ |
| public class TimerRatio implements Gauge<Double> { |
| |
| private long lastUpdateTime = 0; |
| private long sum = 0; |
| private long lastGaugeTime = 0; |
| |
| public synchronized void start() { |
| if (lastUpdateTime == 0) { |
| lastUpdateTime = System.nanoTime(); |
| } |
| } |
| |
| public synchronized void stop() { |
| if (lastUpdateTime != 0) { |
| long now = System.nanoTime(); |
| long cost = now - lastUpdateTime; |
| lastUpdateTime = 0; |
| sum += cost; |
| } |
| |
| } |
| |
| @Override |
| public Double getValue() { |
| synchronized (this) { |
| stop(); |
| |
| long now = System.nanoTime(); |
| long cost = now - lastGaugeTime; |
| if (cost == 0) { |
| return 1.0; |
| } |
| |
| lastGaugeTime = now; |
| double ratio = ((double) sum) / cost; |
| sum = 0; |
| return ratio; |
| |
| } |
| |
| } |
| |
| } |