1   /***
2    * 
3    * Copyright 2004 Protique Ltd
4    * 
5    * Licensed under the Apache License, Version 2.0 (the "License"); 
6    * you may not use this file except in compliance with the License. 
7    * You may obtain a copy of the License at 
8    * 
9    * http://www.apache.org/licenses/LICENSE-2.0
10   * 
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS, 
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 
14   * See the License for the specific language governing permissions and 
15   * limitations under the License. 
16   * 
17   **/
18  package org.activeio.stats;
19  
20  import EDU.oswego.cs.dl.util.concurrent.SynchronizedLong;
21  
22  import javax.management.j2ee.statistics.CountStatistic;
23  
24  /***
25   * Shamelessly taken from the ActiveMQ project ( http://activemq.com )
26   * A count statistic implementation
27   *
28   * @version $Revision: 1.1 $
29   */
30  public class CountStatisticImpl extends StatisticImpl implements CountStatistic {
31  
32      private final SynchronizedLong counter = new SynchronizedLong(0);
33      private CountStatisticImpl parent;
34  
35      public CountStatisticImpl(CountStatisticImpl parent, String name, String description) {
36          this(name, description);
37          this.parent = parent;
38      }
39  
40      public CountStatisticImpl(String name, String description) {
41          this(name, "count", description);
42      }
43  
44      public CountStatisticImpl(String name, String unit, String description) {
45          super(name, unit, description);
46      }
47  
48      public void reset() {
49          super.reset();
50          counter.set(0);
51      }
52  
53      public long getCount() {
54          return counter.get();
55      }
56  
57      public void setCount(long count) {
58          counter.set(count);
59      }
60  
61      public void add(long amount) {
62          counter.add(amount);
63          updateSampleTime();
64          if (parent != null) {
65              parent.add(amount);
66          }
67      }
68  
69      public void increment() {
70          counter.increment();
71          updateSampleTime();
72          if (parent != null) {
73              parent.increment();
74          }
75      }
76  
77      public void subtract(long amount) {
78          counter.subtract(amount);
79          updateSampleTime();
80          if (parent != null) {
81              parent.subtract(amount);
82          }
83      }
84      
85      public void decrement() {
86          counter.decrement();
87          updateSampleTime();
88          if (parent != null) {
89              parent.decrement();
90          }
91      }
92  
93      public CountStatisticImpl getParent() {
94          return parent;
95      }
96  
97      public void setParent(CountStatisticImpl parent) {
98          this.parent = parent;
99      }
100 
101     protected void appendFieldDescription(StringBuffer buffer) {
102         buffer.append(" count: ");
103         buffer.append(Long.toString(counter.get()));
104         super.appendFieldDescription(buffer);
105     }
106 }