server/clientinterface/PacketSorter.java

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

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

/**
 * Receives data from the incoming CORBA servant, places
 * it in a Queue, and then arranges distribution to the
 * DataHandlers.
 * Has extra functionality to send data to DataHandlers
 * on a per-host basis - ie. the Client can request which
 * hosts it would like to listen for.
 *
 * @author  $Author: tdb1 $
 * @version $Id: PacketSorter.java,v 1.4 2001/01/27 23:30:40 tdb1 Exp $
 */
class PacketSorter extends Thread {

//---FINAL ATTRIBUTES---

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

//---CONSTRUCTORS---

    /**
     * Creates a new PacketSorter.
     */
    public PacketSorter() {
        _queue = new Queue();
        // startup a monitor on this queue, every minute
        _queue.startMonitor(60*1000, _name);
        _hostMap = new HashMap();
        _allHostsList = new LinkedList();
        _logger.write(toString(), Logger.SYSINIT, "created");
    }
    
//---PUBLIC METHODS---

    /**
     * Method to start the PacketSorter running. This method will
     * loop forever processing and sending data.
     */
    public void run() {
        int qID = _queue.getQueue();
        while(true) {
            // attempt to get some data from the Queue
            String xml = "";
            try {
                xml = (String) _queue.get(qID);
            }
            catch(InvalidQueueException e) {
                _logger.write(toString(), Logger.ERROR, "Queue failure: "+e);
            }
            
            // find out which host this packet is actually for
            XMLPacketMaker xmlPacketMaker = new XMLPacketMaker(xml);
            XMLPacket packet = xmlPacketMaker.createXMLPacket();
            String host = packet.getParam("packet.attributes.machine_name");
            
            // look in the hostMap to see if anyone wants this data
            if(_hostMap.containsKey(host)) {
                LinkedList list = (LinkedList) _hostMap.get(host);
                Iterator i = list.iterator();
                // push the data to the listening Handler's queue
                while(i.hasNext()) {
                    ((Queue) i.next()).add(xml);
                }
            }
            
            // any handler in this list wants all packets, so send
            // it on to them regardless
            Iterator j = _allHostsList.iterator();
            while(j.hasNext()) {
                ((Queue) j.next()).add(xml);
            }
        }
    }
    
    /**
     * Register a DataHandler in the system. This method
     * actually takes a reference to a Queue, which should be
     * a Queue that the DataHandler is making use of.
     * It also takes a hostList, this being a semi-colon
     * seperated list of hosts that the Client the DataHandler
     * is serving has requested. If this list is simply an empty
     * String, it is assumed the Client wants to listen to all
     * host information.
     *
     * @param dhQueue a Queue being used by the DataHandler that is registering
     * @param hostList a semi-colon seperated list of hosts
     */
    public void register(Queue dhQueue, String hostList) {
        // check to see if we want all hosts
        if(hostList.equals("")) {
            _allHostsList.add(dhQueue);
            _logger.write(toString(), Logger.SYSMSG, "registered DataHandler for all hosts");
        }
        else {
            // go through the list of hosts
            StringTokenizer st = new StringTokenizer(hostList, ";");
            while(st.hasMoreTokens()) {
                String host = st.nextToken();
                // see if we already have a list in the map for this host
                if(_hostMap.containsKey(host)) {
                    // we do, so add to it
                    LinkedList list = (LinkedList) _hostMap.get(host);
                    list.add(dhQueue);
                }
                else {
                    // we don't, so create a list and put it in the map
                    LinkedList list = new LinkedList();
                    list.add(dhQueue);
                    _hostMap.put(host, list);
                }
            }
            _logger.write(toString(), Logger.SYSMSG, "registered DataHandler for hosts: "+hostList);
        }
    }
    
    /**
     * Deregister a DataHandler. The DataHandler should give a reference
     * to the Queue it's using, and the *same* hostList it gave when it
     * register. It is imperative that the hostList is the same, otherwise
     * there will be all sorts of problems with lists getting out of sync.
     *
     * NB: Possible future addition would be recording of hostList's.
     *
     * @param dhQueue a Queue being used by the DataHandler that is deregistering
     * @param hostList a semi-colon seperated list of hosts
     */
    public void deregister(Queue dhQueue, String hostList) {
        // go through the list of hosts
        if(hostList.equals("")) {
            _allHostsList.remove(dhQueue);
            _logger.write(toString(), Logger.SYSMSG, "deregistered DataHandler for all hosts");
        }
        else {
            StringTokenizer st = new StringTokenizer(hostList, ";");
            while(st.hasMoreTokens()) {
                String host = st.nextToken();
                // this should in reality always be true, but best check
                if(_hostMap.containsKey(host)) {
                    // get the list and remove the host in question
                    LinkedList list = (LinkedList) _hostMap.get(host);
                    list.remove(dhQueue);
                    // if the list is now empty, we might as well remove it
                    if(list.size()==0) {
                        _hostMap.remove(host);
                    }
                }
            }
            _logger.write(toString(), Logger.SYSMSG, "deregistered DataHandler for hosts: "+hostList);
        }
    }
    
    /**
     * 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---
    
    /**
     * Accessor to return a reference to the Queue object. This
     * is needed so the ClientInterfaceServant can get add data
     * easily.
     *
     * @return a reference to our Queue object.
     */
    public Queue getQueue() {
        return _queue;
    }

//---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 = ClientInterfaceMain.NAME;

    /**
     * This holds a reference to the
     * system logger that is being used.
     */
    private Logger _logger = ReferenceManager.getInstance().getLogger();
    
    /**
     * A reference to the Queue we're using.
     */
    private Queue _queue;
    
    /**
     * A HashMap to store lists of Queue's (in the DataHandlers)
     * in a way that can be easily accessed when data comes in.
     */
    private HashMap _hostMap;
    
    /**
     * A list specifically for a Queue's associated with DataHandlers
     * that want all host information.
     */
    private LinkedList _allHostsList;
    
//---STATIC ATTRIBUTES---

}
Revision:	1.5
Committed:	Mon Feb 12 02:23:52 2001 UTC (23 years, 3 months ago) by tdb
Branch:	MAIN
Changes since 1.4:	+4 -2 lines
Log Message:	Now monitor the Queue here every 60 seconds, reporting back to the Queue in the PacketSorter class.
#	User	Rev	Content
1	tdb	1.1	//---PACKAGE DECLARATION---
2			package uk.ac.ukc.iscream.clientinterface;
3
4			//---IMPORTS---
5			import uk.ac.ukc.iscream.util.*;
6			import uk.ac.ukc.iscream.componentmanager.*;
7			import uk.ac.ukc.iscream.core.*;
8			import java.util.*;
9
10			/**
11			* Receives data from the incoming CORBA servant, places
12			* it in a Queue, and then arranges distribution to the
13	tdb	1.4	* DataHandlers.
14			* Has extra functionality to send data to DataHandlers
15			* on a per-host basis - ie. the Client can request which
16			* hosts it would like to listen for.
17	tdb	1.1	*
18	tdb	1.2	* @author $Author: tdb1 $
19	tdb	1.5	* @version $Id: PacketSorter.java,v 1.4 2001/01/27 23:30:40 tdb1 Exp $
20	tdb	1.1	*/
21			class PacketSorter extends Thread {
22
23			//---FINAL ATTRIBUTES---
24
25			/**
26			* The current CVS revision of this class
27			*/
28	tdb	1.5	public final String REVISION = "$Revision: 1.4 $";
29	tdb	1.1
30			//---STATIC METHODS---
31
32			//---CONSTRUCTORS---
33
34			/**
35			* Creates a new PacketSorter.
36			*/
37			public PacketSorter() {
38			_queue = new Queue();
39	tdb	1.5	// startup a monitor on this queue, every minute
40			_queue.startMonitor(60*1000, _name);
41	tdb	1.1	_hostMap = new HashMap();
42	tdb	1.2	_allHostsList = new LinkedList();
43	tdb	1.1	_logger.write(toString(), Logger.SYSINIT, "created");
44			}
45
46			//---PUBLIC METHODS---
47
48	tdb	1.4	/**
49			* Method to start the PacketSorter running. This method will
50			* loop forever processing and sending data.
51			*/
52	tdb	1.1	public void run() {
53			int qID = _queue.getQueue();
54			while(true) {
55	tdb	1.4	// attempt to get some data from the Queue
56	tdb	1.1	String xml = "";
57			try {
58			xml = (String) _queue.get(qID);
59			}
60			catch(InvalidQueueException e) {
61			_logger.write(toString(), Logger.ERROR, "Queue failure: "+e);
62			}
63
64	tdb	1.4	// find out which host this packet is actually for
65	tdb	1.3	XMLPacketMaker xmlPacketMaker = new XMLPacketMaker(xml);
66			XMLPacket packet = xmlPacketMaker.createXMLPacket();
67	tdb	1.1	String host = packet.getParam("packet.attributes.machine_name");
68
69	tdb	1.4	// look in the hostMap to see if anyone wants this data
70	tdb	1.3	if(_hostMap.containsKey(host)) {
71			LinkedList list = (LinkedList) _hostMap.get(host);
72			Iterator i = list.iterator();
73	tdb	1.4	// push the data to the listening Handler's queue
74	tdb	1.3	while(i.hasNext()) {
75			((Queue) i.next()).add(xml);
76			}
77	tdb	1.1	}
78	tdb	1.2
79	tdb	1.4	// any handler in this list wants all packets, so send
80			// it on to them regardless
81	tdb	1.2	Iterator j = _allHostsList.iterator();
82			while(j.hasNext()) {
83			((Queue) j.next()).add(xml);
84			}
85	tdb	1.1	}
86			}
87
88	tdb	1.4	/**
89			* Register a DataHandler in the system. This method
90			* actually takes a reference to a Queue, which should be
91			* a Queue that the DataHandler is making use of.
92			* It also takes a hostList, this being a semi-colon
93			* seperated list of hosts that the Client the DataHandler
94			* is serving has requested. If this list is simply an empty
95			* String, it is assumed the Client wants to listen to all
96			* host information.
97			*
98			* @param dhQueue a Queue being used by the DataHandler that is registering
99			* @param hostList a semi-colon seperated list of hosts
100			*/
101	tdb	1.1	public void register(Queue dhQueue, String hostList) {
102	tdb	1.4	// check to see if we want all hosts
103	tdb	1.2	if(hostList.equals("")) {
104			_allHostsList.add(dhQueue);
105			_logger.write(toString(), Logger.SYSMSG, "registered DataHandler for all hosts");
106			}
107			else {
108	tdb	1.4	// go through the list of hosts
109	tdb	1.2	StringTokenizer st = new StringTokenizer(hostList, ";");
110			while(st.hasMoreTokens()) {
111			String host = st.nextToken();
112	tdb	1.4	// see if we already have a list in the map for this host
113	tdb	1.2	if(_hostMap.containsKey(host)) {
114	tdb	1.4	// we do, so add to it
115	tdb	1.2	LinkedList list = (LinkedList) _hostMap.get(host);
116			list.add(dhQueue);
117			}
118			else {
119	tdb	1.4	// we don't, so create a list and put it in the map
120	tdb	1.2	LinkedList list = new LinkedList();
121			list.add(dhQueue);
122			_hostMap.put(host, list);
123			}
124	tdb	1.1	}
125	tdb	1.2	_logger.write(toString(), Logger.SYSMSG, "registered DataHandler for hosts: "+hostList);
126	tdb	1.1	}
127			}
128
129	tdb	1.4	/**
130			* Deregister a DataHandler. The DataHandler should give a reference
131			* to the Queue it's using, and the same hostList it gave when it
132			* register. It is imperative that the hostList is the same, otherwise
133			* there will be all sorts of problems with lists getting out of sync.
134			*
135			* NB: Possible future addition would be recording of hostList's.
136			*
137			* @param dhQueue a Queue being used by the DataHandler that is deregistering
138			* @param hostList a semi-colon seperated list of hosts
139			*/
140	tdb	1.1	public void deregister(Queue dhQueue, String hostList) {
141	tdb	1.4	// go through the list of hosts
142	tdb	1.2	if(hostList.equals("")) {
143			_allHostsList.remove(dhQueue);
144			_logger.write(toString(), Logger.SYSMSG, "deregistered DataHandler for all hosts");
145			}
146			else {
147			StringTokenizer st = new StringTokenizer(hostList, ";");
148			while(st.hasMoreTokens()) {
149			String host = st.nextToken();
150	tdb	1.4	// this should in reality always be true, but best check
151	tdb	1.2	if(_hostMap.containsKey(host)) {
152	tdb	1.4	// get the list and remove the host in question
153	tdb	1.2	LinkedList list = (LinkedList) _hostMap.get(host);
154			list.remove(dhQueue);
155	tdb	1.4	// if the list is now empty, we might as well remove it
156	tdb	1.2	if(list.size()==0) {
157			_hostMap.remove(host);
158			}
159	tdb	1.1	}
160			}
161	tdb	1.2	_logger.write(toString(), Logger.SYSMSG, "deregistered DataHandler for hosts: "+hostList);
162	tdb	1.1	}
163			}
164
165			/**
166			* Overrides the {@link java.lang.Object#toString() Object.toString()}
167			* method to provide clean logging (every class should have this).
168			*
169			* This uses the uk.ac.ukc.iscream.util.NameFormat class
170			* to format the toString()
171			*
172			* @return the name of this class and its CVS revision
173			*/
174			public String toString() {
175			return FormatName.getName(
176			_name,
177			getClass().getName(),
178			REVISION);
179			}
180
181			//---PRIVATE METHODS---
182
183			//---ACCESSOR/MUTATOR METHODS---
184	tdb	1.4
185			/**
186			* Accessor to return a reference to the Queue object. This
187			* is needed so the ClientInterfaceServant can get add data
188			* easily.
189			*
190			* @return a reference to our Queue object.
191			*/
192	tdb	1.1	public Queue getQueue() {
193			return _queue;
194			}
195
196			//---ATTRIBUTES---
197
198			/**
199			* This is the friendly identifier of the
200			* component this class is running in.
201			* eg, a Filter may be called "filter1",
202			* If this class does not have an owning
203			* component, a name from the configuration
204			* can be placed here. This name could also
205			* be changed to null for utility classes.
206			*/
207			private String _name = ClientInterfaceMain.NAME;
208
209			/**
210			* This holds a reference to the
211			* system logger that is being used.
212			*/
213			private Logger _logger = ReferenceManager.getInstance().getLogger();
214
215	tdb	1.4	/**
216			* A reference to the Queue we're using.
217			*/
218	tdb	1.1	private Queue _queue;
219
220	tdb	1.4	/**
221			* A HashMap to store lists of Queue's (in the DataHandlers)
222			* in a way that can be easily accessed when data comes in.
223			*/
224	tdb	1.1	private HashMap _hostMap;
225	tdb	1.4
226			/**
227			* A list specifically for a Queue's associated with DataHandlers
228			* that want all host information.
229			*/
230	tdb	1.2	private LinkedList _allHostsList;
231	tdb	1.1
232			//---STATIC ATTRIBUTES---
233
234			}