cms/util/QueueMonitor.java

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

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

/**
 * 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  $Author$
 * @version $Id$
 */
class QueueMonitor extends Thread {

//---FINAL ATTRIBUTES---

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