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Java > Open Source Codes > org > apache > excalibur > instrument > CounterInstrument


1 /*
2
3  ============================================================================
4                    The Apache Software License, Version 1.1
5  ============================================================================
6  
7  Copyright (C) 1999-2003 The Apache Software Foundation. All rights reserved.
8  
9  Redistribution and use in source and binary forms, with or without modifica-
10  tion, are permitted provided that the following conditions are met:
11  
12  1. Redistributions of source code must retain the above copyright notice,
13     this list of conditions and the following disclaimer.
14  
15  2. Redistributions in binary form must reproduce the above copyright notice,
16     this list of conditions and the following disclaimer in the documentation
17     and/or other materials provided with the distribution.
18  
19  3. The end-user documentation included with the redistribution, if any, must
20     include the following acknowledgment: "This product includes software
21     developed by the Apache Software Foundation (http://www.apache.org/)."
22     Alternately, this acknowledgment may appear in the software itself, if
23     and wherever such third-party acknowledgments normally appear.
24  
25  4. The names "Jakarta", "Avalon", "Excalibur" and "Apache Software Foundation"
26     must not be used to endorse or promote products derived from this software
27     without prior written permission. For written permission, please contact
28     apache@apache.org.
29  
30  5. Products derived from this software may not be called "Apache", nor may
31     "Apache" appear in their name, without prior written permission of the
32     Apache Software Foundation.
33  
34  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES,
35  INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
36  FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
37  APACHE SOFTWARE FOUNDATION OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
38  INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLU-
39  DING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
40  OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
41  ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
42  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
43  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
44  
45  This software consists of voluntary contributions made by many individuals
46  on behalf of the Apache Software Foundation. For more information on the
47  Apache Software Foundation, please see <http://www.apache.org/>.
48  
49 */
50 package org.apache.excalibur.instrument;
51
52 /**
53  * CounterInstruments can be used to profile the number of times that
54  * something happens. They are perfect for profiling things like the number
55  * of times a class instance is created or destroyed. Or the number of
56  * times that a method is accessed.
57  *
58  * @author <a HREF="mailto:leif@tanukisoftware.com">Leif Mortenson</a>
59  * @version CVS $Revision: 1.6 $ $Date: 2003/02/20 17:07:55 $
60  * @since 4.1
61  */
62 public class CounterInstrument
63     extends AbstractInstrument
64 {
65     /*---------------------------------------------------------------
66      * Constructors
67      *-------------------------------------------------------------*/
68     /**
69      * Creates a new CounterInstrument.
70      *
71      * @param name The name of the Instrument. The value should be a string
72      * which does not contain spaces or periods.
73      */
74     public CounterInstrument( String JavaDoc name )
75     {
76         super( name );
77     }
78
79     /*---------------------------------------------------------------
80      * Methods
81      *-------------------------------------------------------------*/
82     /**
83      * Increments the Instrument. This method is optimized to be extremely
84      * light weight when an InstrumentManager is not present and there are no
85      * registered CounterInstrumentListeners.
86      */
87     public void increment()
88     {
89         InstrumentProxy proxy = getInstrumentProxy();
90         if( proxy != null )
91         {
92             proxy.increment( 1 );
93         }
94     }
95
96     /**
97      * Increments the Instrument by a specified count. This method is
98      * optimized to be extremely light weight when an InstrumentManager is not
99      * present and there are no registered CounterInstrumentListeners.
100      *
101      * @param count A positive integer to increment the counter by.
102      *
103      * @throws IllegalArgumentException If the count is not positive.
104      */
105     public void increment( int count )
106     {
107         // Check the count
108 if( count <= 0 )
109         {
110             throw new IllegalArgumentException JavaDoc( "Count must be a positive value." );
111         }
112
113         InstrumentProxy proxy = getInstrumentProxy();
114         if( proxy != null )
115         {
116             proxy.increment( count );
117         }
118     }
119 }
120
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