server/rootfilter/CorbaControlHandlerServant.java

/* 
 * i-scream central monitoring system
 * http://www.i-scream.org.uk
 * Copyright (C) 2000-2002 i-scream
 * 
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */

//---PACKAGE DECLARATION---
package uk.org.iscream.cms.server.rootfilter;

//---IMPORTS---
import uk.org.iscream.cms.util.*;
import uk.org.iscream.cms.server.componentmanager.*;
import uk.org.iscream.cms.server.core.*;
import uk.org.iscream.cms.server.clientinterface.*;


/**
 * Acts as a Control Handler to a CORBA based client.
 *
 * @author  $Author: tdb $
 * @version $Id: CorbaControlHandlerServant.java,v 1.17 2003/02/05 16:43:46 tdb Exp $
 */
class CorbaControlHandlerServant extends CorbaControlHandlerPOA {

//---FINAL ATTRIBUTES---

    /**
     * The current CVS revision of this class
     */
    public final String REVISION = "$Revision: 1.1 $";
    
//---STATIC METHODS---

//---CONSTRUCTORS---
    
    /**
     * Construct a new CorbaControlHandlerServant.
     *
     * @param queue A reference to the Queue we're using
     * @param client A reference to the "servant" part of the connecting client.
     * @param clientname A name to identify the client.
     */
    public CorbaControlHandlerServant(Queue queue, Client client, String clientname) {
        _queue = queue;
        _client = client;
        _clientname = clientname;
        _dataHandler = null;
        _logger.write(toString(), Logger.SYSINIT, "created");
    }
    
//---PUBLIC METHODS---
    
    /**
     * Start sending data to the client.
     *
     * @return a boolean stating whether the attempt to start succeeded
     */
    public boolean startData() {
        if(_dataHandler == null) {
            // create a new DataHandler
            CorbaDataHandler dh = new CorbaDataHandler(_client, this, _queue);
            // start the DataHandler running
            dh.start();
            // keep a reference
            _dataHandler = dh;
            return true;
        }
        else {
            return false;
        }
    }
    
    /**
     * Stop sending data to the client.
     *
     * @return a boolean stating whether the attempt to stop succeeded
     */
    public boolean stopData() {
        if(_dataHandler != null) {
            // stop the DataHandler
            _dataHandler.shutdown();
            // destroy the reference
            _dataHandler = null;
            return true;
        }
        else {
            return false;
        }
    }
    
    /**
     * Sets the host list for the Client to the requested semi-colon separated
     * list of hostnames. This will only succeed if we are not sending data.
     *
     * @param hostList A semi-colon separated list of hostnames to use.
     * @return Whether the request succeeded.
     */
    public boolean setHostList(String hostList) {
        return false;
    }
    
    /**
     * Disconnect, this will shutdown the data and unhook from
     * the CORBA ORB.
     */
    public void disconnect() {
        // close the data handler
        stopData();
        // disconnect from the ORB
        try {
            byte[] oid = _refman.getRootPOA().servant_to_id(this);
            _refman.getRootPOA().deactivate_object(oid);
        } catch(Exception e) {
            _logger.write(this.toString(), Logger.ERROR, "disconnect failed: "+e);
        }
    }
    
    /**
     * Overrides the {@link java.lang.Object#toString() Object.toString()}
     * method to provide clean logging (every class should have this).
     *
     * This uses the uk.org.iscream.cms.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---

    /**
     * Overridden for debugging purposes
     * to see when an instance of this class
     * is destroyed
     */
    protected void finalize() throws Throwable {
        _logger.write(this.toString(), Logger.DEBUG, "finalized by GC");
    }

//---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 = RootFilter.NAME;
    
    /**
     * This holds a reference to the
     * system logger that is being used.
     */
    private Logger _logger = ReferenceManager.getInstance().getLogger();

    /**
     * A reference to the reference manager in use
     */
    private ReferenceManager _refman = ReferenceManager.getInstance();
    
    /**
     * A reference to our Queue.
     */
    private Queue _queue;
    
    /**
     * The "servant" part of the client we're connected to.
     */
    private Client _client;
    
    /**
     * A reference to our DataHandler, if we have one
     */
    private CorbaDataHandler _dataHandler;
    
    /**
     * A name to identify the client
     */
    private String _clientname;
    
//---STATIC ATTRIBUTES---

}
Revision:	1.1
Committed:	Mon May 5 22:05:14 2003 UTC (21 years ago) by tdb
Branch:	MAIN
Log Message:	Tidy up of the client interface code - more commonly known as the "right hand side of the server". Right since the start the filter side of the server has been nice and tree like - every Filter sent data to another Filter. At the top of the tree there was a "special" Filter known as the RootFilter, which to the other Filters just looked like a normal Filter. This was nice, and simple, and expandable. The Client Interface on the other hand was messy. The root filter had some hacky wrapper threads which pulled from a queue and pushed to the relevant client interfaces (one for real time stuff, and the other for databases). There was no simple room for expandability - it was all hardwired to do just what was needed at the time. This commit changes that. A Client Interface now connects to another Client Interface, with a special one being found in the RootFilter (yes, maybe that needs a name change now :-). So we can chain client interfaces, and move other bits and bobs around in the server - for example, alerting no longer needs to be connected to the Client Interface, it can connect straight to the RootFilter (or, wherever the config tells it ;). Hopefully this sanitizes the underlying layout of the server a bit. As a final note, I dropped the DBInterface. This used to insert data in to a MySQL database. We've long since stopped using that, and it's fallen behind and is way out of date. For now, it's gone in to the attic.
#	Content
1	/*
2	* i-scream central monitoring system
3	* http://www.i-scream.org.uk
4	* Copyright (C) 2000-2002 i-scream
5	*
6	* This program is free software; you can redistribute it and/or
7	* modify it under the terms of the GNU General Public License
8	* as published by the Free Software Foundation; either version 2
9	* of the License, or (at your option) any later version.
10	*
11	* This program is distributed in the hope that it will be useful,
12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14	* GNU General Public License for more details.
15	*
16	* You should have received a copy of the GNU General Public License
17	* along with this program; if not, write to the Free Software
18	* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
19	*/
20
21	//---PACKAGE DECLARATION---
22	package uk.org.iscream.cms.server.rootfilter;
23
24	//---IMPORTS---
25	import uk.org.iscream.cms.util.*;
26	import uk.org.iscream.cms.server.componentmanager.*;
27	import uk.org.iscream.cms.server.core.*;
28	import uk.org.iscream.cms.server.clientinterface.*;
29
30
31	/**
32	* Acts as a Control Handler to a CORBA based client.
33	*
34	* @author $Author: tdb $
35	* @version $Id: CorbaControlHandlerServant.java,v 1.17 2003/02/05 16:43:46 tdb Exp $
36	*/
37	class CorbaControlHandlerServant extends CorbaControlHandlerPOA {
38
39	//---FINAL ATTRIBUTES---
40
41	/**
42	* The current CVS revision of this class
43	*/
44	public final String REVISION = "$Revision: 1.1 $";
45
46	//---STATIC METHODS---
47
48	//---CONSTRUCTORS---
49
50	/**
51	* Construct a new CorbaControlHandlerServant.
52	*
53	* @param queue A reference to the Queue we're using
54	* @param client A reference to the "servant" part of the connecting client.
55	* @param clientname A name to identify the client.
56	*/
57	public CorbaControlHandlerServant(Queue queue, Client client, String clientname) {
58	_queue = queue;
59	_client = client;
60	_clientname = clientname;
61	_dataHandler = null;
62	_logger.write(toString(), Logger.SYSINIT, "created");
63	}
64
65	//---PUBLIC METHODS---
66
67	/**
68	* Start sending data to the client.
69	*
70	* @return a boolean stating whether the attempt to start succeeded
71	*/
72	public boolean startData() {
73	if(_dataHandler == null) {
74	// create a new DataHandler
75	CorbaDataHandler dh = new CorbaDataHandler(_client, this, _queue);
76	// start the DataHandler running
77	dh.start();
78	// keep a reference
79	_dataHandler = dh;
80	return true;
81	}
82	else {
83	return false;
84	}
85	}
86
87	/**
88	* Stop sending data to the client.
89	*
90	* @return a boolean stating whether the attempt to stop succeeded
91	*/
92	public boolean stopData() {
93	if(_dataHandler != null) {
94	// stop the DataHandler
95	_dataHandler.shutdown();
96	// destroy the reference
97	_dataHandler = null;
98	return true;
99	}
100	else {
101	return false;
102	}
103	}
104
105	/**
106	* Sets the host list for the Client to the requested semi-colon separated
107	* list of hostnames. This will only succeed if we are not sending data.
108	*
109	* @param hostList A semi-colon separated list of hostnames to use.
110	* @return Whether the request succeeded.
111	*/
112	public boolean setHostList(String hostList) {
113	return false;
114	}
115
116	/**
117	* Disconnect, this will shutdown the data and unhook from
118	* the CORBA ORB.
119	*/
120	public void disconnect() {
121	// close the data handler
122	stopData();
123	// disconnect from the ORB
124	try {
125	byte[] oid = _refman.getRootPOA().servant_to_id(this);
126	_refman.getRootPOA().deactivate_object(oid);
127	} catch(Exception e) {
128	_logger.write(this.toString(), Logger.ERROR, "disconnect failed: "+e);
129	}
130	}
131
132	/**
133	* Overrides the {@link java.lang.Object#toString() Object.toString()}
134	* method to provide clean logging (every class should have this).
135	*
136	* This uses the uk.org.iscream.cms.util.NameFormat class
137	* to format the toString()
138	*
139	* @return the name of this class and its CVS revision
140	*/
141	public String toString() {
142	return FormatName.getName(
143	_name,
144	getClass().getName(),
145	REVISION);
146	}
147
148	//---PRIVATE METHODS---
149
150	/**
151	* Overridden for debugging purposes
152	* to see when an instance of this class
153	* is destroyed
154	*/
155	protected void finalize() throws Throwable {
156	_logger.write(this.toString(), Logger.DEBUG, "finalized by GC");
157	}
158
159	//---ACCESSOR/MUTATOR METHODS---
160
161	//---ATTRIBUTES---
162
163	/**
164	* This is the friendly identifier of the
165	* component this class is running in.
166	* eg, a Filter may be called "filter1",
167	* If this class does not have an owning
168	* component, a name from the configuration
169	* can be placed here. This name could also
170	* be changed to null for utility classes.
171	*/
172	private String _name = RootFilter.NAME;
173
174	/**
175	* This holds a reference to the
176	* system logger that is being used.
177	*/
178	private Logger _logger = ReferenceManager.getInstance().getLogger();
179
180	/**
181	* A reference to the reference manager in use
182	*/
183	private ReferenceManager _refman = ReferenceManager.getInstance();
184
185	/**
186	* A reference to our Queue.
187	*/
188	private Queue _queue;
189
190	/**
191	* The "servant" part of the client we're connected to.
192	*/
193	private Client _client;
194
195	/**
196	* A reference to our DataHandler, if we have one
197	*/
198	private CorbaDataHandler _dataHandler;
199
200	/**
201	* A name to identify the client
202	*/
203	private String _clientname;
204
205	//---STATIC ATTRIBUTES---
206
207	}