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 1.5 2001/02/12 02:23:52 tdb1 Exp $
 */
class PacketSorter extends Thread {

//---FINAL ATTRIBUTES---

    /**
     * The current CVS revision of this class
     */
    public final String REVISION = "$Revision: 1.5 $";
    
//---STATIC METHODS---

//---CONSTRUCTORS---

    /**
     * Creates a new PacketSorter.
     *
     * @param queueMonitorInterval The interval at which to monitor the Queue
     */
    public PacketSorter(int queueMonitorInterval) {
        _queue = new Queue();
        // startup a monitor on this queue, every minute
        String queueName = _name + " PacketSorterQueue";
        _queue.startMonitor(queueMonitorInterval*1000, queueName);
        _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:	1.6
Committed:	Wed Feb 21 19:11:28 2001 UTC (23 years, 2 months ago) by tdb
Branch:	MAIN
Changes since 1.5:	+7 -4 lines
Log Message:	Modification to the Queue system; - interval of monitor is now configurable. - attempt to identify each Queue better, although this is still hard.
#	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	1.6	* @version $Id: PacketSorter.java,v 1.5 2001/02/12 02:23:52 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	1.6	public final String REVISION = "$Revision: 1.5 $";
29	tdb	1.1
30			//---STATIC METHODS---
31
32			//---CONSTRUCTORS---
33
34			/**
35			* Creates a new PacketSorter.
36	tdb	1.6	*
37			* @param queueMonitorInterval The interval at which to monitor the Queue
38	tdb	1.1	*/
39	tdb	1.6	public PacketSorter(int queueMonitorInterval) {
40	tdb	1.1	_queue = new Queue();
41	tdb	1.5	// startup a monitor on this queue, every minute
42	tdb	1.6	String queueName = _name + " PacketSorterQueue";
43			_queue.startMonitor(queueMonitorInterval*1000, queueName);
44	tdb	1.1	_hostMap = new HashMap();
45	tdb	1.2	_allHostsList = new LinkedList();
46	tdb	1.1	_logger.write(toString(), Logger.SYSINIT, "created");
47			}
48
49			//---PUBLIC METHODS---
50
51	tdb	1.4	/**
52			* Method to start the PacketSorter running. This method will
53			* loop forever processing and sending data.
54			*/
55	tdb	1.1	public void run() {
56			int qID = _queue.getQueue();
57			while(true) {
58	tdb	1.4	// attempt to get some data from the Queue
59	tdb	1.1	String xml = "";
60			try {
61			xml = (String) _queue.get(qID);
62			}
63			catch(InvalidQueueException e) {
64			_logger.write(toString(), Logger.ERROR, "Queue failure: "+e);
65			}
66
67	tdb	1.4	// find out which host this packet is actually for
68	tdb	1.3	XMLPacketMaker xmlPacketMaker = new XMLPacketMaker(xml);
69			XMLPacket packet = xmlPacketMaker.createXMLPacket();
70	tdb	1.1	String host = packet.getParam("packet.attributes.machine_name");
71
72	tdb	1.4	// look in the hostMap to see if anyone wants this data
73	tdb	1.3	if(_hostMap.containsKey(host)) {
74			LinkedList list = (LinkedList) _hostMap.get(host);
75			Iterator i = list.iterator();
76	tdb	1.4	// push the data to the listening Handler's queue
77	tdb	1.3	while(i.hasNext()) {
78			((Queue) i.next()).add(xml);
79			}
80	tdb	1.1	}
81	tdb	1.2
82	tdb	1.4	// any handler in this list wants all packets, so send
83			// it on to them regardless
84	tdb	1.2	Iterator j = _allHostsList.iterator();
85			while(j.hasNext()) {
86			((Queue) j.next()).add(xml);
87			}
88	tdb	1.1	}
89			}
90
91	tdb	1.4	/**
92			* Register a DataHandler in the system. This method
93			* actually takes a reference to a Queue, which should be
94			* a Queue that the DataHandler is making use of.
95			* It also takes a hostList, this being a semi-colon
96			* seperated list of hosts that the Client the DataHandler
97			* is serving has requested. If this list is simply an empty
98			* String, it is assumed the Client wants to listen to all
99			* host information.
100			*
101			* @param dhQueue a Queue being used by the DataHandler that is registering
102			* @param hostList a semi-colon seperated list of hosts
103			*/
104	tdb	1.1	public void register(Queue dhQueue, String hostList) {
105	tdb	1.4	// check to see if we want all hosts
106	tdb	1.2	if(hostList.equals("")) {
107			_allHostsList.add(dhQueue);
108			_logger.write(toString(), Logger.SYSMSG, "registered DataHandler for all hosts");
109			}
110			else {
111	tdb	1.4	// go through the list of hosts
112	tdb	1.2	StringTokenizer st = new StringTokenizer(hostList, ";");
113			while(st.hasMoreTokens()) {
114			String host = st.nextToken();
115	tdb	1.4	// see if we already have a list in the map for this host
116	tdb	1.2	if(_hostMap.containsKey(host)) {
117	tdb	1.4	// we do, so add to it
118	tdb	1.2	LinkedList list = (LinkedList) _hostMap.get(host);
119			list.add(dhQueue);
120			}
121			else {
122	tdb	1.4	// we don't, so create a list and put it in the map
123	tdb	1.2	LinkedList list = new LinkedList();
124			list.add(dhQueue);
125			_hostMap.put(host, list);
126			}
127	tdb	1.1	}
128	tdb	1.2	_logger.write(toString(), Logger.SYSMSG, "registered DataHandler for hosts: "+hostList);
129	tdb	1.1	}
130			}
131
132	tdb	1.4	/**
133			* Deregister a DataHandler. The DataHandler should give a reference
134			* to the Queue it's using, and the same hostList it gave when it
135			* register. It is imperative that the hostList is the same, otherwise
136			* there will be all sorts of problems with lists getting out of sync.
137			*
138			* NB: Possible future addition would be recording of hostList's.
139			*
140			* @param dhQueue a Queue being used by the DataHandler that is deregistering
141			* @param hostList a semi-colon seperated list of hosts
142			*/
143	tdb	1.1	public void deregister(Queue dhQueue, String hostList) {
144	tdb	1.4	// go through the list of hosts
145	tdb	1.2	if(hostList.equals("")) {
146			_allHostsList.remove(dhQueue);
147			_logger.write(toString(), Logger.SYSMSG, "deregistered DataHandler for all hosts");
148			}
149			else {
150			StringTokenizer st = new StringTokenizer(hostList, ";");
151			while(st.hasMoreTokens()) {
152			String host = st.nextToken();
153	tdb	1.4	// this should in reality always be true, but best check
154	tdb	1.2	if(_hostMap.containsKey(host)) {
155	tdb	1.4	// get the list and remove the host in question
156	tdb	1.2	LinkedList list = (LinkedList) _hostMap.get(host);
157			list.remove(dhQueue);
158	tdb	1.4	// if the list is now empty, we might as well remove it
159	tdb	1.2	if(list.size()==0) {
160			_hostMap.remove(host);
161			}
162	tdb	1.1	}
163			}
164	tdb	1.2	_logger.write(toString(), Logger.SYSMSG, "deregistered DataHandler for hosts: "+hostList);
165	tdb	1.1	}
166			}
167
168			/**
169			* Overrides the {@link java.lang.Object#toString() Object.toString()}
170			* method to provide clean logging (every class should have this).
171			*
172			* This uses the uk.ac.ukc.iscream.util.NameFormat class
173			* to format the toString()
174			*
175			* @return the name of this class and its CVS revision
176			*/
177			public String toString() {
178			return FormatName.getName(
179			_name,
180			getClass().getName(),
181			REVISION);
182			}
183
184			//---PRIVATE METHODS---
185
186			//---ACCESSOR/MUTATOR METHODS---
187	tdb	1.4
188			/**
189			* Accessor to return a reference to the Queue object. This
190			* is needed so the ClientInterfaceServant can get add data
191			* easily.
192			*
193			* @return a reference to our Queue object.
194			*/
195	tdb	1.1	public Queue getQueue() {
196			return _queue;
197			}
198
199			//---ATTRIBUTES---
200
201			/**
202			* This is the friendly identifier of the
203			* component this class is running in.
204			* eg, a Filter may be called "filter1",
205			* If this class does not have an owning
206			* component, a name from the configuration
207			* can be placed here. This name could also
208			* be changed to null for utility classes.
209			*/
210			private String _name = ClientInterfaceMain.NAME;
211
212			/**
213			* This holds a reference to the
214			* system logger that is being used.
215			*/
216			private Logger _logger = ReferenceManager.getInstance().getLogger();
217
218	tdb	1.4	/**
219			* A reference to the Queue we're using.
220			*/
221	tdb	1.1	private Queue _queue;
222
223	tdb	1.4	/**
224			* A HashMap to store lists of Queue's (in the DataHandlers)
225			* in a way that can be easily accessed when data comes in.
226			*/
227	tdb	1.1	private HashMap _hostMap;
228	tdb	1.4
229			/**
230			* A list specifically for a Queue's associated with DataHandlers
231			* that want all host information.
232			*/
233	tdb	1.2	private LinkedList _allHostsList;
234	tdb	1.1
235			//---STATIC ATTRIBUTES---
236
237			}