server/Queue/QueueMonitor.java

//---PACKAGE DECLARATION---
//package uk.ac.ukc.iscream.util;

//---IMPORTS---
//import uk.ac.ukc.iscream.util.*;

/**
 * This class monitors a given Queue at regular intervals,
 * reporting back to a Queue with XML - this could be the
 * same Queue being monitored.
 *
 * @author  $Author: tdb1 $
 * @version $Id: QueueMonitor.java,v 1.4 2001/02/28 19:02:22 tdb1 Exp $
 */
class QueueMonitor extends Thread {

//---FINAL ATTRIBUTES---

    /**
     * The current CVS revision of this class
     */
    public static final String REVISION = "$Revision: 1.4 $";
    
//---STATIC METHODS---

//---CONSTRUCTORS---
    
    /**
     * Construct a new QueueMonitor.
     *
     * @param sourceQueue The Queue to monitor
     * @param destQueue The Queue to monitor to
     * @param interval The interval, in milliseconds, at which to sample
     * @param name A name to identify the source Queue with
     */
    public QueueMonitor (Queue sourceQueue, Queue destQueue, long interval, String name) {
        _sourceQueue = sourceQueue;
        _destQueue = destQueue;
        _interval = interval;
        _srcName = name;
    }

//---PUBLIC METHODS---
    
    /**
     * Loops continuosly polling our source Queue at
     * the given interval, and then logging the results
     * in the destination Queue.
     */
    public void run() {
        _run = true;
        // so we can stop this thread...
        while(_run) {
            // first sleep for our interval
            try { Thread.sleep(_interval); } catch(Exception e) {}
            // check the Queue
            String status = _sourceQueue.xmlStatus();
            // get a hash of our Queue (for identification)
            String hashCode = String.valueOf(_sourceQueue.hashCode());
            // create some XML
            String date = new Long(System.currentTimeMillis()/((long) 1000)).toString();
            String xml = "<packet type=\"queueStat\" date=\""+date+"\" name=\""+_srcName+"\" hashCode=\""+hashCode+"\">" + status + "</packet>";
            // write XML to destination Queue
            _destQueue.add(xml);
        }
    }
    
    /**
     * Shuts down this QueueMonitor
     */
    public void shutdown() {
        // this will stop the main loop
        _run = false;
        // create some XML
        String date = new Long(System.currentTimeMillis()/((long) 1000)).toString();
        String xml = "<packet type=\"queueStat\" date=\""+date+"\" name=\""+_srcName+"\" shutdown=\"true\"></packet>";
        // write XML to destination Queue
        _destQueue.add(xml);
    }
    
    /**
     * Overrides the {@link java.lang.Object#toString() Object.toString()}
     * method to provide clean logging (every class should have this).
     *
     * This uses the uk.ac.ukc.iscream.util.FormatName class
     * to format the toString()
     *
     * @return the name of this class and its CVS revision
     */
    public String toString() {
        return FormatName.getName(
            _name,
            getClass().getName(),
            REVISION);
    }

//---PRIVATE METHODS---

//---ACCESSOR/MUTATOR METHODS---

//---ATTRIBUTES---

    /**
     * This is the friendly identifier of the
     * component this class is running in.
     * eg, a Filter may be called "filter1",
     * If this class does not have an owning
     * component,  a name from the configuration
     * can be placed here.  This name could also
     * be changed to null for utility classes.
     */
    private String _name = null;
    
    /**
     * The Queue we're monitoring.
     */
    private Queue _sourceQueue;
    
    /**
     * The Queue we'll output results to.
     */
    private Queue _destQueue;
    
    /**
     * The interval at which we'll check the
     * sourceQueue status.
     */
    private long _interval;
    
    /**
     * The name to identify the source Queue
     */
    private String _srcName;
    
    /**
     * Allows us to stop the main loop cleanly.
     */
    private boolean _run;
    
//---STATIC ATTRIBUTES---

}
Revision:	1.3
Committed:	Thu Mar 1 03:04:28 2001 UTC (23 years, 9 months ago) by tdb
Branch:	MAIN
CVS Tags:	PROJECT_COMPLETION, HEAD
Changes since 1.2:	+5 -3 lines
Log Message:	Brought inline with main source tree.
#	User	Rev	Content
1	tdb	1.1	//---PACKAGE DECLARATION---
2			//package uk.ac.ukc.iscream.util;
3
4			//---IMPORTS---
5			//import uk.ac.ukc.iscream.util.*;
6
7			/**
8			* This class monitors a given Queue at regular intervals,
9			* reporting back to a Queue with XML - this could be the
10			* same Queue being monitored.
11			*
12			* @author $Author: tdb1 $
13	tdb	1.3	* @version $Id: QueueMonitor.java,v 1.4 2001/02/28 19:02:22 tdb1 Exp $
14	tdb	1.1	*/
15			class QueueMonitor extends Thread {
16
17			//---FINAL ATTRIBUTES---
18
19			/**
20			* The current CVS revision of this class
21			*/
22	tdb	1.3	public static final String REVISION = "$Revision: 1.4 $";
23	tdb	1.1
24			//---STATIC METHODS---
25
26			//---CONSTRUCTORS---
27
28			/**
29			* Construct a new QueueMonitor.
30			*
31			* @param sourceQueue The Queue to monitor
32			* @param destQueue The Queue to monitor to
33			* @param interval The interval, in milliseconds, at which to sample
34			* @param name A name to identify the source Queue with
35			*/
36			public QueueMonitor (Queue sourceQueue, Queue destQueue, long interval, String name) {
37			_sourceQueue = sourceQueue;
38			_destQueue = destQueue;
39			_interval = interval;
40			_srcName = name;
41			}
42
43			//---PUBLIC METHODS---
44
45			/**
46			* Loops continuosly polling our source Queue at
47			* the given interval, and then logging the results
48			* in the destination Queue.
49			*/
50			public void run() {
51			_run = true;
52			// so we can stop this thread...
53			while(_run) {
54			// first sleep for our interval
55			try { Thread.sleep(_interval); } catch(Exception e) {}
56			// check the Queue
57			String status = _sourceQueue.xmlStatus();
58	tdb	1.3	// get a hash of our Queue (for identification)
59			String hashCode = String.valueOf(_sourceQueue.hashCode());
60	tdb	1.1	// create some XML
61			String date = new Long(System.currentTimeMillis()/((long) 1000)).toString();
62	tdb	1.3	String xml = "<packet type=\"queueStat\" date=\""+date+"\" name=\""+_srcName+"\" hashCode=\""+hashCode+"\">" + status + "</packet>";
63	tdb	1.1	// write XML to destination Queue
64			_destQueue.add(xml);
65			}
66			}
67
68			/**
69			* Shuts down this QueueMonitor
70			*/
71			public void shutdown() {
72			// this will stop the main loop
73			_run = false;
74	tdb	1.2	// create some XML
75			String date = new Long(System.currentTimeMillis()/((long) 1000)).toString();
76			String xml = "<packet type=\"queueStat\" date=\""+date+"\" name=\""+_srcName+"\" shutdown=\"true\"></packet>";
77			// write XML to destination Queue
78			_destQueue.add(xml);
79	tdb	1.1	}
80
81			/**
82			* Overrides the {@link java.lang.Object#toString() Object.toString()}
83			* method to provide clean logging (every class should have this).
84			*
85			* This uses the uk.ac.ukc.iscream.util.FormatName class
86			* to format the toString()
87			*
88			* @return the name of this class and its CVS revision
89			*/
90			public String toString() {
91			return FormatName.getName(
92			_name,
93			getClass().getName(),
94			REVISION);
95			}
96
97			//---PRIVATE METHODS---
98
99			//---ACCESSOR/MUTATOR METHODS---
100
101			//---ATTRIBUTES---
102
103			/**
104			* This is the friendly identifier of the
105			* component this class is running in.
106			* eg, a Filter may be called "filter1",
107			* If this class does not have an owning
108			* component, a name from the configuration
109			* can be placed here. This name could also
110			* be changed to null for utility classes.
111			*/
112			private String _name = null;
113
114			/**
115			* The Queue we're monitoring.
116			*/
117			private Queue _sourceQueue;
118
119			/**
120			* The Queue we'll output results to.
121			*/
122			private Queue _destQueue;
123
124			/**
125			* The interval at which we'll check the
126			* sourceQueue status.
127			*/
128			private long _interval;
129
130			/**
131			* The name to identify the source Queue
132			*/
133			private String _srcName;
134
135			/**
136			* Allows us to stop the main loop cleanly.
137			*/
138			private boolean _run;
139
140			//---STATIC ATTRIBUTES---
141
142			}