001/** 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017package org.apache.activemq.management; 018 019import java.util.ArrayList; 020import java.util.Iterator; 021import java.util.List; 022 023import javax.management.j2ee.statistics.CountStatistic; 024 025/** 026 * A count statistic implementation 027 * 028 * 029 */ 030public class PollCountStatisticImpl extends StatisticImpl implements CountStatistic { 031 032 private PollCountStatisticImpl parent; 033 private List<PollCountStatisticImpl> children; 034 035 public PollCountStatisticImpl(PollCountStatisticImpl parent, String name, String description) { 036 this(name, description); 037 setParent(parent); 038 } 039 040 public PollCountStatisticImpl(String name, String description) { 041 this(name, "count", description); 042 } 043 044 public PollCountStatisticImpl(String name, String unit, String description) { 045 super(name, unit, description); 046 } 047 048 public PollCountStatisticImpl getParent() { 049 return parent; 050 } 051 052 public void setParent(PollCountStatisticImpl parent) { 053 if (this.parent != null) { 054 this.parent.removeChild(this); 055 } 056 this.parent = parent; 057 if (this.parent != null) { 058 this.parent.addChild(this); 059 } 060 } 061 062 private synchronized void removeChild(PollCountStatisticImpl child) { 063 if (children != null) { 064 children.remove(child); 065 } 066 } 067 068 private synchronized void addChild(PollCountStatisticImpl child) { 069 if (children == null) { 070 children = new ArrayList<PollCountStatisticImpl>(); 071 } 072 children.add(child); 073 } 074 075 public synchronized long getCount() { 076 if (children == null) { 077 return 0; 078 } 079 long count = 0; 080 for (Iterator<PollCountStatisticImpl> iter = children.iterator(); iter.hasNext();) { 081 PollCountStatisticImpl child = iter.next(); 082 count += child.getCount(); 083 } 084 return count; 085 } 086 087 protected void appendFieldDescription(StringBuffer buffer) { 088 buffer.append(" count: "); 089 buffer.append(Long.toString(getCount())); 090 super.appendFieldDescription(buffer); 091 } 092 093 /** 094 * @return the average time period that elapses between counter increments 095 * since the last reset. 096 */ 097 public double getPeriod() { 098 double count = getCount(); 099 if (count == 0) { 100 return 0; 101 } 102 double time = System.currentTimeMillis() - getStartTime(); 103 return time / (count * 1000.0); 104 } 105 106 /** 107 * @return the number of times per second that the counter is incrementing 108 * since the last reset. 109 */ 110 public double getFrequency() { 111 double count = getCount(); 112 double time = System.currentTimeMillis() - getStartTime(); 113 return count * 1000.0 / time; 114 } 115 116}