server/filter/FilterMain.java

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

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

/**
 * A Filter Startup Class
 * A filter is an iscream component.
 *
 * @author  $Author: tdb1 $
 * @version $Id: FilterMain.java,v 1.25 2001/03/13 16:25:57 tdb1 Exp $
 */
public class FilterMain implements Component {

//---FINAL ATTRIBUTES---

    /**
     * The current CVS revision of this class
     */
    public static final String REVISION = "$Revision: 1.25 $";
    
//---STATIC METHODS---

//---CONSTRUCTORS---
    
    /**
     * Constructs a Filter with the name given
     *
     * @param givenName the name
     */
    public FilterMain(String givenName) {
        NAME = givenName;
    }

//---PUBLIC METHODS---

    /**
     * Starts the Filter component
     */
    public void start() throws ComponentStartException {
        // get references to key objects
        _refman = ReferenceManager.getInstance();
        _logger = ReferenceManager.getInstance().getLogger();
        
        _logger.write(toString(), Logger.SYSINIT, "coming up");
        
        ConfigurationProxy cp = ConfigurationProxy.getInstance();
        
        int UDPListenPort, TCPListenPort;
        try {
            UDPListenPort = Integer.parseInt(cp.getProperty(FilterMain.NAME, "Filter.UDPListenPort"));
            TCPListenPort = Integer.parseInt(cp.getProperty(FilterMain.NAME, "Filter.TCPListenPort"));
        } catch (PropertyNotFoundException e) {
            throw new ComponentStartException("Unable to obtain requried configuration property for component: " + e);
        }
        
        // setup a queue
        Queue queue = new Queue();
        
        // startup a monitor on this queue
        try {
            // try to get the interval, if this fails, we won't start up the monitor
            int queueMonitorInterval = Integer.parseInt(cp.getProperty(FilterMain.NAME, "Queue.MonitorInterval"));
            String queueName = NAME + " Filter";
            queue.startMonitor(queueMonitorInterval*1000, queueName);
        } catch (PropertyNotFoundException e) {
            _logger.write(toString(), Logger.WARNING, "failed to find queue monitor config, disabling. " + e);
        }
        
        // Start a filter thread
        _logger.write(toString(), Logger.SYSINIT, "starting Filter Thread / Queue consumer");
        FilterThread filterThread = new FilterThread(queue);
        filterThread.start();
        
        // FilterServant start (for inbound child filter data)
        _logger.write(toString(), Logger.DEBUG, "starting Servant to listen for downstream filters");
        FilterServant filterServant = new FilterServant(TCPListenPort, UDPListenPort, queue);
        _refman.bindToOrb(filterServant, "iscream.Filter." + FilterMain.NAME);

        // UDL Reader start (for inbound host data)
        _logger.write(toString(), Logger.SYSINIT, "starting Filter UDP listener");
        UDPReader udpReader = new UDPReader(UDPListenPort, queue);
        udpReader.start();

        // TCP Reader start (for heartbeats)
        _logger.write(toString(), Logger.SYSINIT, "starting Filter TCP listener");
        TCPReader tcpReader = new TCPReader(TCPListenPort, queue);
        tcpReader.start();
        
        _logger.write(toString(), Logger.SYSINIT, "started");
    }
    
    /**
     * Does a dependency check. Used mainly at startup to
     * see if the required dependencies (components) are up
     * and running.
     *
     * @return a boolean value, true if the depdencies are satisfied
     */
    public boolean depCheck() {
        try {
            org.omg.CORBA.Object obj;
            // first check the ConfigurationManager is alive
            obj = _refman.getCORBARef("iscream.ConfigurationManager");
            // then suss out our parent filter
            ConfigurationProxy cp = ConfigurationProxy.getInstance();
            String parentFilterName = cp.getProperty(NAME, "Filter.parentFilter");
            // finally check the parent filter is alive
            obj = _refman.getCORBARef("iscream.Filter." + parentFilterName);
        } catch(ComponentCORBAException e) {
            _logger.write(toString(), Logger.WARNING, "Dependency Failure: "+e);
            return false;
        } catch(PropertyNotFoundException e) {
            _logger.write(toString(), Logger.WARNING, "Unable to obtain configuration: "+e);
            return false;
        }
        // dependency check suceeded
        return true;
    }
    
    /**
     * 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.NameFormat 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 holds a reference to the
     * system logger that is being used.
     */
    private Logger _logger;

    /**
     * A reference to the reference manager in use
     */
    private ReferenceManager _refman;

//---STATIC ATTRIBUTES---

    /**
     * The friendly name for this component, used by
     * all related classes.
     * This is set from the configuration.
     */
    public static String NAME;

}
Revision:	1.26
Committed:	Wed Mar 14 01:34:28 2001 UTC (23 years, 2 months ago) by tdb
Branch:	MAIN
Changes since 1.25:	+32 -4 lines
Log Message:	New dependency checking. The old method was to attempt to start a Component, and if it failed, it probably had a depdency problem. The approach now is to ask the Component to perform a dependency check first, then if this suceeds, have a go at actually starting it up. The actual dependency check is a bit neater and more precise than before, and should be much more fool proof. The order the components are specified in the default.properties file is now irrelevant, although the "correct" order would certainly increase booting time.
#	User	Rev	Content
1	tdb	1.1	//---PACKAGE DECLARATION---
2	tdb	1.11	package uk.ac.ukc.iscream.filter;
3	tdb	1.1
4			//---IMPORTS---
5	ajm	1.14	import uk.ac.ukc.iscream.util.*;
6	tdb	1.1	import uk.ac.ukc.iscream.core.*;
7	tdb	1.19	import uk.ac.ukc.iscream.componentmanager.*;
8	tdb	1.1	import uk.ac.ukc.iscream.filter.*;
9
10			/**
11			* A Filter Startup Class
12	ajm	1.16	* A filter is an iscream component.
13	tdb	1.1	*
14	tdb	1.26	* @author $Author: tdb1 $
15			* @version $Id: FilterMain.java,v 1.25 2001/03/13 16:25:57 tdb1 Exp $
16	tdb	1.1	*/
17	tdb	1.19	public class FilterMain implements Component {
18	tdb	1.1
19			//---FINAL ATTRIBUTES---
20
21			/**
22			* The current CVS revision of this class
23			*/
24	tdb	1.26	public static final String REVISION = "$Revision: 1.25 $";
25	tdb	1.1
26			//---STATIC METHODS---
27
28	ajm	1.16	//---CONSTRUCTORS---
29
30			/**
31			* Constructs a Filter with the name given
32			*
33			* @param givenName the name
34			*/
35			public FilterMain(String givenName) {
36			NAME = givenName;
37			}
38
39			//---PUBLIC METHODS---
40
41			/**
42			* Starts the Filter component
43			*/
44			public void start() throws ComponentStartException {
45	ajm	1.24	// get references to key objects
46			_refman = ReferenceManager.getInstance();
47			_logger = ReferenceManager.getInstance().getLogger();
48
49	ajm	1.16	_logger.write(toString(), Logger.SYSINIT, "coming up");
50	tdb	1.20
51	tdb	1.25	ConfigurationProxy cp = ConfigurationProxy.getInstance();
52	ajm	1.16
53	tdb	1.25	int UDPListenPort, TCPListenPort;
54			try {
55			UDPListenPort = Integer.parseInt(cp.getProperty(FilterMain.NAME, "Filter.UDPListenPort"));
56			TCPListenPort = Integer.parseInt(cp.getProperty(FilterMain.NAME, "Filter.TCPListenPort"));
57			} catch (PropertyNotFoundException e) {
58			throw new ComponentStartException("Unable to obtain requried configuration property for component: " + e);
59			}
60	ajm	1.13
61	tdb	1.18	// setup a queue
62			Queue queue = new Queue();
63	tdb	1.25
64			// startup a monitor on this queue
65			try {
66			// try to get the interval, if this fails, we won't start up the monitor
67			int queueMonitorInterval = Integer.parseInt(cp.getProperty(FilterMain.NAME, "Queue.MonitorInterval"));
68			String queueName = NAME + " Filter";
69			queue.startMonitor(queueMonitorInterval*1000, queueName);
70			} catch (PropertyNotFoundException e) {
71			_logger.write(toString(), Logger.WARNING, "failed to find queue monitor config, disabling. " + e);
72			}
73	tdb	1.18
74			// Start a filter thread
75			_logger.write(toString(), Logger.SYSINIT, "starting Filter Thread / Queue consumer");
76	tdb	1.25	FilterThread filterThread = new FilterThread(queue);
77	tdb	1.18	filterThread.start();
78
79	ajm	1.13	// FilterServant start (for inbound child filter data)
80	tdb	1.25	_logger.write(toString(), Logger.DEBUG, "starting Servant to listen for downstream filters");
81	tdb	1.18	FilterServant filterServant = new FilterServant(TCPListenPort, UDPListenPort, queue);
82	ajm	1.16	_refman.bindToOrb(filterServant, "iscream.Filter." + FilterMain.NAME);
83	ajm	1.13
84			// UDL Reader start (for inbound host data)
85	ajm	1.16	_logger.write(toString(), Logger.SYSINIT, "starting Filter UDP listener");
86	tdb	1.18	UDPReader udpReader = new UDPReader(UDPListenPort, queue);
87	ajm	1.13	udpReader.start();
88
89			// TCP Reader start (for heartbeats)
90	ajm	1.16	_logger.write(toString(), Logger.SYSINIT, "starting Filter TCP listener");
91	tdb	1.18	TCPReader tcpReader = new TCPReader(TCPListenPort, queue);
92	ajm	1.13	tcpReader.start();
93
94	ajm	1.16	_logger.write(toString(), Logger.SYSINIT, "started");
95	tdb	1.1	}
96	tdb	1.26
97			/**
98			* Does a dependency check. Used mainly at startup to
99			* see if the required dependencies (components) are up
100			* and running.
101			*
102			* @return a boolean value, true if the depdencies are satisfied
103			*/
104			public boolean depCheck() {
105			try {
106			org.omg.CORBA.Object obj;
107			// first check the ConfigurationManager is alive
108			obj = _refman.getCORBARef("iscream.ConfigurationManager");
109			// then suss out our parent filter
110			ConfigurationProxy cp = ConfigurationProxy.getInstance();
111			String parentFilterName = cp.getProperty(NAME, "Filter.parentFilter");
112			// finally check the parent filter is alive
113			obj = _refman.getCORBARef("iscream.Filter." + parentFilterName);
114			} catch(ComponentCORBAException e) {
115			_logger.write(toString(), Logger.WARNING, "Dependency Failure: "+e);
116			return false;
117			} catch(PropertyNotFoundException e) {
118			_logger.write(toString(), Logger.WARNING, "Unable to obtain configuration: "+e);
119			return false;
120			}
121			// dependency check suceeded
122			return true;
123			}
124
125	ajm	1.16	/**
126			* Overrides the {@link java.lang.Object#toString() Object.toString()}
127			* method to provide clean logging (every class should have this).
128			*
129			* This uses the uk.ac.ukc.iscream.util.NameFormat class
130			* to format the toString()
131			*
132			* @return the name of this class and its CVS revision
133			*/
134			public String toString() {
135			return FormatName.getName(
136	ajm	1.17	NAME,
137	ajm	1.16	getClass().getName(),
138			REVISION);
139	tdb	1.1	}
140
141			//---PRIVATE METHODS---
142
143			//---ACCESSOR/MUTATOR METHODS---
144
145			//---ATTRIBUTES---
146	ajm	1.16
147			/**
148			* This holds a reference to the
149			* system logger that is being used.
150			*/
151	ajm	1.24	private Logger _logger;
152	ajm	1.16
153			/**
154			* A reference to the reference manager in use
155			*/
156	ajm	1.24	private ReferenceManager _refman;
157	ajm	1.16
158	tdb	1.1	//---STATIC ATTRIBUTES---
159	ajm	1.16
160			/**
161			* The friendly name for this component, used by
162			* all related classes.
163			* This is set from the configuration.
164			*/
165			public static String NAME;
166	tdb	1.1
167	tdb	1.21	}