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 1.7 2001/02/26 23:41:35 tdb1 Exp $
 */
class PacketSorter extends Thread {

//---FINAL ATTRIBUTES---

    /**
     * The current CVS revision of this class
     */
    public final String REVISION = "$Revision: 1.7 $";
    
//---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)) {
                    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 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
                    LinkedList list = (LinkedList) _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
                    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 Map _hostMap;
    
    /**
     * A list specifically for a Queue's associated with DataHandlers
     * that want all host information.
     */
    private List _allHostsList;
    
//---STATIC ATTRIBUTES---

}
Revision:	1.8
Committed:	Wed Feb 28 10:26:47 2001 UTC (23 years, 3 months ago) by tdb
Branch:	MAIN
Changes since 1.7:	+27 -15 lines
Log Message:	Changes to fix a bug where the server wouldn't send queueStat packets if the client had set a hostlist.
#	Content
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	* 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	*
18	* @author $Author: tdb1 $
19	* @version $Id: PacketSorter.java,v 1.7 2001/02/26 23:41:35 tdb1 Exp $
20	*/
21	class PacketSorter extends Thread {
22
23	//---FINAL ATTRIBUTES---
24
25	/**
26	* The current CVS revision of this class
27	*/
28	public final String REVISION = "$Revision: 1.7 $";
29
30	//---STATIC METHODS---
31
32	//---CONSTRUCTORS---
33
34	/**
35	* Creates a new PacketSorter.
36	*
37	* @param queueMonitorInterval The interval at which to monitor the Queue
38	*/
39	public PacketSorter(int queueMonitorInterval) {
40	_queue = new Queue();
41	// startup a monitor on this queue, every minute
42	String queueName = _name + " PacketSorterQueue";
43	_queue.startMonitor(queueMonitorInterval*1000, queueName);
44	_hostMap = Collections.synchronizedMap(new HashMap());
45	_allHostsList = Collections.synchronizedList(new LinkedList());
46	_logger.write(toString(), Logger.SYSINIT, "created");
47	}
48
49	//---PUBLIC METHODS---
50
51	/**
52	* Method to start the PacketSorter running. This method will
53	* loop forever processing and sending data.
54	*/
55	public void run() {
56	int qID = _queue.getQueue();
57	while(true) {
58	// attempt to get some data from the Queue
59	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	// find out which host this packet is actually for
68	XMLPacketMaker xmlPacketMaker = new XMLPacketMaker(xml);
69	XMLPacket packet = xmlPacketMaker.createXMLPacket();
70
71	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	LinkedList list = (LinkedList) _hostMap.get(host);
79	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	while(i.hasNext()) {
90	((Queue) i.next()).add(xml);
91	}
92	}
93	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	}
100	}
101	}
102
103	/**
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	public void register(Queue dhQueue, String hostList) {
117	// check to see if we want all hosts
118	if(hostList.equals("")) {
119	_allHostsList.add(dhQueue);
120	_logger.write(toString(), Logger.SYSMSG, "registered DataHandler for all hosts");
121	}
122	else {
123	// go through the list of hosts
124	StringTokenizer st = new StringTokenizer(hostList, ";");
125	while(st.hasMoreTokens()) {
126	String host = st.nextToken();
127	// see if we already have a list in the map for this host
128	if(_hostMap.containsKey(host)) {
129	// we do, so add to it
130	LinkedList list = (LinkedList) _hostMap.get(host);
131	list.add(dhQueue);
132	}
133	else {
134	// we don't, so create a list and put it in the map
135	List list = Collections.synchronizedList(new LinkedList());
136	list.add(dhQueue);
137	_hostMap.put(host, list);
138	}
139	}
140	_logger.write(toString(), Logger.SYSMSG, "registered DataHandler for hosts: "+hostList);
141	}
142	}
143
144	/**
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	public void deregister(Queue dhQueue, String hostList) {
156	// go through the list of hosts
157	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	// this should in reality always be true, but best check
166	if(_hostMap.containsKey(host)) {
167	// get the list and remove the host in question
168	LinkedList list = (LinkedList) _hostMap.get(host);
169	list.remove(dhQueue);
170	// if the list is now empty, we might as well remove it
171	if(list.size()==0) {
172	_hostMap.remove(host);
173	}
174	}
175	}
176	_logger.write(toString(), Logger.SYSMSG, "deregistered DataHandler for hosts: "+hostList);
177	}
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
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	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	/**
231	* A reference to the Queue we're using.
232	*/
233	private Queue _queue;
234
235	/**
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	private Map _hostMap;
240
241	/**
242	* A list specifically for a Queue's associated with DataHandlers
243	* that want all host information.
244	*/
245	private List _allHostsList;
246
247	//---STATIC ATTRIBUTES---
248
249	}