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 1.8 2001/02/28 10:26:47 tdb1 Exp $
 */
class PacketSorter extends Thread {

//---FINAL ATTRIBUTES---

    /**
     * The current CVS revision of this class
     */
    public final String REVISION = "$Revision: 1.8 $";
    
//---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 = Collections.synchronizedMap(new HashMap());
        _allHostsList = Collections.synchronizedList(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 packetType = packet.getParam("packet.attributes.type");
            // check if we need to send it regardless
            if(packetType.equals("data") || packetType.equals("heartbeat")) {
                String host = packet.getParam("packet.attributes.machine_name");
                
                // look in the hostMap to see if anyone wants this data
                if(_hostMap.containsKey(host)) {
                    List list = (List) _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 i = _allHostsList.iterator();
                while(i.hasNext()) {
                    ((Queue) i.next()).add(xml);
                } 
            }
            else {
                // send to all hosts because it's a special packet
                Iterator i = _allHostsList.iterator();
                while(i.hasNext()) {
                    ((Queue) i.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
                    List list = (List) _hostMap.get(host);
                    list.add(dhQueue);
                }
                else {
                    // we don't, so create a list and put it in the map
                    List list = Collections.synchronizedList(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
                    List list = (List) _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 Map _hostMap;
    
    /**
     * A list specifically for a Queue's associated with DataHandlers
     * that want all host information.
     */
    private List _allHostsList;
    
//---STATIC ATTRIBUTES---

}
Revision:	1.9
Committed:	Thu Mar 1 02:14:37 2001 UTC (23 years, 3 months ago) by tdb
Branch:	MAIN
Changes since 1.8:	+5 -5 lines
Log Message:	Some ClassCastExceptions going on that only just came up when the client got to 1.1 protocol :)
#	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	1.9	* @version $Id: PacketSorter.java,v 1.8 2001/02/28 10:26:47 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	1.9	public final String REVISION = "$Revision: 1.8 $";
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	1.7	_hostMap = Collections.synchronizedMap(new HashMap());
45			_allHostsList = Collections.synchronizedList(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
71	tdb	1.8	String packetType = packet.getParam("packet.attributes.type");
72			// check if we need to send it regardless
73			if(packetType.equals("data") \|\| packetType.equals("heartbeat")) {
74			String host = packet.getParam("packet.attributes.machine_name");
75
76			// look in the hostMap to see if anyone wants this data
77			if(_hostMap.containsKey(host)) {
78	tdb	1.9	List list = (List) _hostMap.get(host);
79	tdb	1.8	Iterator i = list.iterator();
80			// push the data to the listening Handler's queue
81			while(i.hasNext()) {
82			((Queue) i.next()).add(xml);
83			}
84			}
85
86			// any handler in this list wants all packets, so send
87			// it on to them regardless
88			Iterator i = _allHostsList.iterator();
89	tdb	1.3	while(i.hasNext()) {
90			((Queue) i.next()).add(xml);
91	tdb	1.8	}
92	tdb	1.1	}
93	tdb	1.8	else {
94			// send to all hosts because it's a special packet
95			Iterator i = _allHostsList.iterator();
96			while(i.hasNext()) {
97			((Queue) i.next()).add(xml);
98			}
99	tdb	1.2	}
100	tdb	1.1	}
101			}
102
103	tdb	1.4	/**
104			* Register a DataHandler in the system. This method
105			* actually takes a reference to a Queue, which should be
106			* a Queue that the DataHandler is making use of.
107			* It also takes a hostList, this being a semi-colon
108			* seperated list of hosts that the Client the DataHandler
109			* is serving has requested. If this list is simply an empty
110			* String, it is assumed the Client wants to listen to all
111			* host information.
112			*
113			* @param dhQueue a Queue being used by the DataHandler that is registering
114			* @param hostList a semi-colon seperated list of hosts
115			*/
116	tdb	1.1	public void register(Queue dhQueue, String hostList) {
117	tdb	1.4	// check to see if we want all hosts
118	tdb	1.2	if(hostList.equals("")) {
119			_allHostsList.add(dhQueue);
120			_logger.write(toString(), Logger.SYSMSG, "registered DataHandler for all hosts");
121			}
122			else {
123	tdb	1.4	// go through the list of hosts
124	tdb	1.2	StringTokenizer st = new StringTokenizer(hostList, ";");
125			while(st.hasMoreTokens()) {
126			String host = st.nextToken();
127	tdb	1.4	// see if we already have a list in the map for this host
128	tdb	1.2	if(_hostMap.containsKey(host)) {
129	tdb	1.4	// we do, so add to it
130	tdb	1.9	List list = (List) _hostMap.get(host);
131	tdb	1.2	list.add(dhQueue);
132			}
133			else {
134	tdb	1.4	// we don't, so create a list and put it in the map
135	tdb	1.7	List list = Collections.synchronizedList(new LinkedList());
136	tdb	1.2	list.add(dhQueue);
137			_hostMap.put(host, list);
138			}
139	tdb	1.1	}
140	tdb	1.2	_logger.write(toString(), Logger.SYSMSG, "registered DataHandler for hosts: "+hostList);
141	tdb	1.1	}
142			}
143
144	tdb	1.4	/**
145			* Deregister a DataHandler. The DataHandler should give a reference
146			* to the Queue it's using, and the same hostList it gave when it
147			* register. It is imperative that the hostList is the same, otherwise
148			* there will be all sorts of problems with lists getting out of sync.
149			*
150			* NB: Possible future addition would be recording of hostList's.
151			*
152			* @param dhQueue a Queue being used by the DataHandler that is deregistering
153			* @param hostList a semi-colon seperated list of hosts
154			*/
155	tdb	1.1	public void deregister(Queue dhQueue, String hostList) {
156	tdb	1.4	// go through the list of hosts
157	tdb	1.2	if(hostList.equals("")) {
158			_allHostsList.remove(dhQueue);
159			_logger.write(toString(), Logger.SYSMSG, "deregistered DataHandler for all hosts");
160			}
161			else {
162			StringTokenizer st = new StringTokenizer(hostList, ";");
163			while(st.hasMoreTokens()) {
164			String host = st.nextToken();
165	tdb	1.4	// this should in reality always be true, but best check
166	tdb	1.2	if(_hostMap.containsKey(host)) {
167	tdb	1.4	// get the list and remove the host in question
168	tdb	1.9	List list = (List) _hostMap.get(host);
169	tdb	1.2	list.remove(dhQueue);
170	tdb	1.4	// if the list is now empty, we might as well remove it
171	tdb	1.2	if(list.size()==0) {
172			_hostMap.remove(host);
173			}
174	tdb	1.1	}
175			}
176	tdb	1.2	_logger.write(toString(), Logger.SYSMSG, "deregistered DataHandler for hosts: "+hostList);
177	tdb	1.1	}
178			}
179
180			/**
181			* Overrides the {@link java.lang.Object#toString() Object.toString()}
182			* method to provide clean logging (every class should have this).
183			*
184			* This uses the uk.ac.ukc.iscream.util.NameFormat class
185			* to format the toString()
186			*
187			* @return the name of this class and its CVS revision
188			*/
189			public String toString() {
190			return FormatName.getName(
191			_name,
192			getClass().getName(),
193			REVISION);
194			}
195
196			//---PRIVATE METHODS---
197
198			//---ACCESSOR/MUTATOR METHODS---
199	tdb	1.4
200			/**
201			* Accessor to return a reference to the Queue object. This
202			* is needed so the ClientInterfaceServant can get add data
203			* easily.
204			*
205			* @return a reference to our Queue object.
206			*/
207	tdb	1.1	public Queue getQueue() {
208			return _queue;
209			}
210
211			//---ATTRIBUTES---
212
213			/**
214			* This is the friendly identifier of the
215			* component this class is running in.
216			* eg, a Filter may be called "filter1",
217			* If this class does not have an owning
218			* component, a name from the configuration
219			* can be placed here. This name could also
220			* be changed to null for utility classes.
221			*/
222			private String _name = ClientInterfaceMain.NAME;
223
224			/**
225			* This holds a reference to the
226			* system logger that is being used.
227			*/
228			private Logger _logger = ReferenceManager.getInstance().getLogger();
229
230	tdb	1.4	/**
231			* A reference to the Queue we're using.
232			*/
233	tdb	1.1	private Queue _queue;
234
235	tdb	1.4	/**
236			* A HashMap to store lists of Queue's (in the DataHandlers)
237			* in a way that can be easily accessed when data comes in.
238			*/
239	tdb	1.7	private Map _hostMap;
240	tdb	1.4
241			/**
242			* A list specifically for a Queue's associated with DataHandlers
243			* that want all host information.
244			*/
245	tdb	1.7	private List _allHostsList;
246	tdb	1.1
247			//---STATIC ATTRIBUTES---
248
249			}