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.concurrent.atomic.AtomicLong; 020 021import javax.management.j2ee.statistics.CountStatistic; 022 023/** 024 * A count statistic implementation 025 * 026 * 027 */ 028public class CountStatisticImpl extends StatisticImpl implements CountStatistic { 029 030 private final AtomicLong counter = new AtomicLong(0); 031 private CountStatisticImpl parent; 032 033 public CountStatisticImpl(CountStatisticImpl parent, String name, String description) { 034 this(name, description); 035 this.parent = parent; 036 } 037 038 public CountStatisticImpl(String name, String description) { 039 this(name, "count", description); 040 } 041 042 public CountStatisticImpl(String name, String unit, String description) { 043 super(name, unit, description); 044 } 045 046 public void reset() { 047 if (isDoReset()) { 048 super.reset(); 049 counter.set(0); 050 } 051 } 052 053 public long getCount() { 054 return counter.get(); 055 } 056 057 public void setCount(long count) { 058 if (isEnabled()) { 059 counter.set(count); 060 } 061 } 062 063 public void add(long amount) { 064 if (isEnabled()) { 065 counter.addAndGet(amount); 066 updateSampleTime(); 067 if (parent != null) { 068 parent.add(amount); 069 } 070 } 071 } 072 073 public void increment() { 074 if (isEnabled()) { 075 counter.incrementAndGet(); 076 updateSampleTime(); 077 if (parent != null) { 078 parent.increment(); 079 } 080 } 081 } 082 083 public void subtract(long amount) { 084 if (isEnabled()) { 085 counter.addAndGet(-amount); 086 updateSampleTime(); 087 if (parent != null) { 088 parent.subtract(amount); 089 } 090 } 091 } 092 093 public void decrement() { 094 if (isEnabled()) { 095 counter.decrementAndGet(); 096 updateSampleTime(); 097 if (parent != null) { 098 parent.decrement(); 099 } 100 } 101 } 102 103 public CountStatisticImpl getParent() { 104 return parent; 105 } 106 107 public void setParent(CountStatisticImpl parent) { 108 if (this.parent != null) { 109 this.parent.subtract(this.getCount()); 110 } 111 this.parent = parent; 112 } 113 114 protected void appendFieldDescription(StringBuffer buffer) { 115 buffer.append(" count: "); 116 buffer.append(Long.toString(counter.get())); 117 super.appendFieldDescription(buffer); 118 } 119 120 /** 121 * @return the average time period that elapses between counter increments 122 * since the last reset. 123 */ 124 public double getPeriod() { 125 double count = counter.get(); 126 if (count == 0) { 127 return 0; 128 } 129 double time = System.currentTimeMillis() - getStartTime(); 130 return time / (count * 1000.0); 131 } 132 133 /** 134 * @return the number of times per second that the counter is incrementing 135 * since the last reset. 136 */ 137 public double getFrequency() { 138 double count = counter.get(); 139 double time = System.currentTimeMillis() - getStartTime(); 140 return count * 1000.0 / time; 141 } 142 143}