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 */
017 package org.apache.activemq.management;
018
019 import java.util.ArrayList;
020 import java.util.Iterator;
021 import java.util.List;
022
023 import javax.management.j2ee.statistics.CountStatistic;
024
025 /**
026 * A count statistic implementation
027 *
028 *
029 */
030 public 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 }