KickJava   Java API By Example, From Geeks To Geeks.

Java > Open Source Codes > org > apache > excalibur > instrument > manager > MeanValueInstrumentSample


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.manager;
51
52 import org.apache.avalon.framework.configuration.Configuration;
53 import org.apache.avalon.framework.configuration.ConfigurationException;
54 import org.apache.avalon.framework.configuration.DefaultConfiguration;
55 import org.apache.excalibur.instrument.manager.interfaces.InstrumentManagerClient;
56
57 /**
58  * A InstrumentSample which stores the mean value set during the sample
59  * period.
60  *
61  * @author <a HREF="mailto:leif@tanukisoftware.com">Leif Mortenson</a>
62  * @version CVS $Revision: 1.3 $ $Date: 2003/02/25 16:28:16 $
63  * @since 4.1
64  */
65 class MeanValueInstrumentSample
66     extends AbstractValueInstrumentSample
67 {
68     /** Total of all values seen during the sample period. */
69     private long m_valueTotal;
70     
71     /*---------------------------------------------------------------
72      * Constructors
73      *-------------------------------------------------------------*/
74     /**
75      * Creates a new MeanValueInstrumentSample
76      *
77      * @param instrumentProxy The InstrumentProxy which owns the
78      * InstrumentSample.
79      * @param name The name of the new InstrumentSample.
80      * @param interval The sample interval of the new InstrumentSample.
81      * @param size The number of samples to store as history. Assumes that size is at least 1.
82      * @param description The description of the new InstrumentSample.
83      * @param lease The length of the lease in milliseconds.
84      */
85     MeanValueInstrumentSample( InstrumentProxy instrumentProxy,
86                                String JavaDoc name,
87                                long interval,
88                                int size,
89                                String JavaDoc description,
90                                long lease )
91     {
92         super( instrumentProxy, name, interval, size, description, lease );
93     }
94     
95     /*---------------------------------------------------------------
96      * InstrumentSample Methods
97      *-------------------------------------------------------------*/
98     /**
99      * Returns the type of the Instrument Sample.
100      *
101      * @return The type of the Instrument Sample.
102      */
103     public int getType()
104     {
105         return InstrumentManagerClient.INSTRUMENT_SAMPLE_TYPE_MEAN;
106     }
107     
108     /*---------------------------------------------------------------
109      * AbstractInstrumentSample Methods
110      *-------------------------------------------------------------*/
111     /**
112      * The current sample has already been stored. Reset the current sample
113      * and move on to the next.
114      * <p>
115      * Should only be called when synchronized.
116      */
117     protected void advanceToNextSample()
118     {
119         // Leave the value as is so that it will propagate to the next sample
120 // if needed. But reset the value count so that new values will not
121 // be affected by the old.
122 m_valueCount = 0;
123     }
124     
125     /**
126      * Allow subclasses to add information into the saved state.
127      *
128      * @param state State configuration.
129      */
130     protected void saveState( DefaultConfiguration state )
131     {
132         super.saveState( state );
133         
134         state.setAttribute( "value-total", Long.toString( m_valueTotal ) );
135     }
136     
137     /**
138      * Used to load the state, called from AbstractInstrumentSample.loadState();
139      * <p>
140      * Should only be called when synchronized.
141      *
142      * @param value Current value loaded from the state.
143      * @param state Configuration object to load state from.
144      *
145      * @throws ConfigurationException If there were any problems loading the
146      * state.
147      */
148     protected void loadState( int value, Configuration state )
149         throws ConfigurationException
150     {
151         super.loadState( value, state );
152         
153         m_valueTotal = state.getAttributeAsLong( "value-total" );
154     }
155     
156     /**
157      * Called after a state is loaded if the sample period is not the same
158      * as the last period saved.
159      */
160     protected void postSaveNeedsReset()
161     {
162         super.postSaveNeedsReset();
163         
164         m_valueTotal = 0;
165     }
166     
167     /*---------------------------------------------------------------
168      * AbstractValueInstrumentSample Methods
169      *-------------------------------------------------------------*/
170     /**
171      * Sets the current value of the sample. The value will be set as the
172      * mean of the new value and other values seen during the sample period.
173      *
174      * @param value New sample value.
175      * @param time Time that the new sample arrives.
176      */
177     protected void setValueInner( int value, long time )
178     {
179         int sampleValue;
180         long sampleTime;
181         
182         synchronized(this)
183         {
184             update( time );
185             
186             if ( m_valueCount > 0 )
187             {
188                 // Additional sample
189 m_valueCount++;
190                 m_valueTotal += value;
191                 m_value = (int)(m_valueTotal / m_valueCount);
192             }
193             else
194             {
195                 // First value of this sample.
196 m_valueCount = 1;
197                 m_valueTotal = m_value = value;
198             }
199             sampleValue = m_value;
200             sampleTime = m_time;
201         }
202         
203         updateListeners( sampleValue, sampleTime );
204     }
205 }
206
Popular Tags