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 1.9 2001/03/01 02:14:37 tdb1 Exp $
 */
class PacketSorter extends Thread {

//---FINAL ATTRIBUTES---

    /**
     * The current CVS revision of this class
     */
    public final String REVISION = "$Revision: 1.9 $";
    
//---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());
        _allHostDataList = Collections.synchronizedList(new LinkedList());
        _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);
            }
            
            XMLPacket packet = null;
            
            try {
                XMLPacketMaker xmlPacketMaker = new XMLPacketMaker(xml);
                packet = xmlPacketMaker.createXMLPacket();
            } catch(InvalidXMLException e) {
                _logger.write(toString(), Logger.ERROR, "Invalid XML: "+e);
                // skip the rest of this loop iteration
                continue;
            }
            
            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 = _allHostDataList.iterator();
                while(i.hasNext()) {
                    ((Queue) i.next()).add(xml);
                } 
            }
            else {
                // always send this packet to all hosts, because it's
                // "extra" data, not host data
                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 synchronized void register(Queue dhQueue, String hostList) {
        // check to see if we want all hosts
        if(hostList.equals("")) {
            _allHostDataList.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);
        }
        // always add host to our complete host list
        _allHostsList.add(dhQueue);
    }
    
    /**
     * 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 synchronized void deregister(Queue dhQueue, String hostList) {
        // go through the list of hosts
        if(hostList.equals("")) {
            _allHostDataList.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);
        }
        // always remove host from our complete host list
        _allHostsList.remove(dhQueue);
    }
    
    /**
     * 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 _allHostDataList;
    
    /**
     * A list of all hosts.
     */
    private List _allHostsList;
    
//---STATIC ATTRIBUTES---

}
Revision:	1.10
Committed:	Thu Mar 1 16:53:16 2001 UTC (23 years, 3 months ago) by tdb
Branch:	MAIN
Changes since 1.9:	+29 -11 lines
Log Message:	Added a try catch section for creating the XMLPacket. Hopefully fixed the JVM deadlock/crash thing. Fixed the problem with clients not receiving Queue data if they've called the SETHOSTLIST command on a Handler.
#	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 1.9 2001/03/01 02:14:37 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: 1.9 $";
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	_allHostDataList = Collections.synchronizedList(new LinkedList());
46	_allHostsList = Collections.synchronizedList(new LinkedList());
47	_logger.write(toString(), Logger.SYSINIT, "created");
48	}
49
50	//---PUBLIC METHODS---
51
52	/**
53	* Method to start the PacketSorter running. This method will
54	* loop forever processing and sending data.
55	*/
56	public void run() {
57	int qID = _queue.getQueue();
58	while(true) {
59	// attempt to get some data from the Queue
60	String xml = "";
61	try {
62	xml = (String) _queue.get(qID);
63	}
64	catch(InvalidQueueException e) {
65	_logger.write(toString(), Logger.ERROR, "Queue failure: "+e);
66	}
67
68	XMLPacket packet = null;
69
70	try {
71	XMLPacketMaker xmlPacketMaker = new XMLPacketMaker(xml);
72	packet = xmlPacketMaker.createXMLPacket();
73	} catch(InvalidXMLException e) {
74	_logger.write(toString(), Logger.ERROR, "Invalid XML: "+e);
75	// skip the rest of this loop iteration
76	continue;
77	}
78
79	String packetType = packet.getParam("packet.attributes.type");
80	// check if we need to send it regardless
81	if(packetType.equals("data") \|\| packetType.equals("heartbeat")) {
82	String host = packet.getParam("packet.attributes.machine_name");
83
84	// look in the hostMap to see if anyone wants this data
85	if(_hostMap.containsKey(host)) {
86	List list = (List) _hostMap.get(host);
87	Iterator i = list.iterator();
88	// push the data to the listening Handler's queue
89	while(i.hasNext()) {
90	((Queue) i.next()).add(xml);
91	}
92	}
93
94	// any handler in this list wants all packets, so send
95	// it on to them regardless
96	Iterator i = _allHostDataList.iterator();
97	while(i.hasNext()) {
98	((Queue) i.next()).add(xml);
99	}
100	}
101	else {
102	// always send this packet to all hosts, because it's
103	// "extra" data, not host data
104	Iterator i = _allHostsList.iterator();
105	while(i.hasNext()) {
106	((Queue) i.next()).add(xml);
107	}
108	}
109	}
110	}
111
112	/**
113	* Register a DataHandler in the system. This method
114	* actually takes a reference to a Queue, which should be
115	* a Queue that the DataHandler is making use of.
116	* It also takes a hostList, this being a semi-colon
117	* seperated list of hosts that the Client the DataHandler
118	* is serving has requested. If this list is simply an empty
119	* String, it is assumed the Client wants to listen to all
120	* host information.
121	*
122	* @param dhQueue a Queue being used by the DataHandler that is registering
123	* @param hostList a semi-colon seperated list of hosts
124	*/
125	public synchronized void register(Queue dhQueue, String hostList) {
126	// check to see if we want all hosts
127	if(hostList.equals("")) {
128	_allHostDataList.add(dhQueue);
129	_logger.write(toString(), Logger.SYSMSG, "registered DataHandler for all hosts");
130	}
131	else {
132	// go through the list of hosts
133	StringTokenizer st = new StringTokenizer(hostList, ";");
134	while(st.hasMoreTokens()) {
135	String host = st.nextToken();
136	// see if we already have a list in the map for this host
137	if(_hostMap.containsKey(host)) {
138	// we do, so add to it
139	List list = (List) _hostMap.get(host);
140	list.add(dhQueue);
141	}
142	else {
143	// we don't, so create a list and put it in the map
144	List list = Collections.synchronizedList(new LinkedList());
145	list.add(dhQueue);
146	_hostMap.put(host, list);
147	}
148	}
149	_logger.write(toString(), Logger.SYSMSG, "registered DataHandler for hosts: "+hostList);
150	}
151	// always add host to our complete host list
152	_allHostsList.add(dhQueue);
153	}
154
155	/**
156	* Deregister a DataHandler. The DataHandler should give a reference
157	* to the Queue it's using, and the same hostList it gave when it
158	* register. It is imperative that the hostList is the same, otherwise
159	* there will be all sorts of problems with lists getting out of sync.
160	*
161	* NB: Possible future addition would be recording of hostList's.
162	*
163	* @param dhQueue a Queue being used by the DataHandler that is deregistering
164	* @param hostList a semi-colon seperated list of hosts
165	*/
166	public synchronized void deregister(Queue dhQueue, String hostList) {
167	// go through the list of hosts
168	if(hostList.equals("")) {
169	_allHostDataList.remove(dhQueue);
170	_logger.write(toString(), Logger.SYSMSG, "deregistered DataHandler for all hosts");
171	}
172	else {
173	StringTokenizer st = new StringTokenizer(hostList, ";");
174	while(st.hasMoreTokens()) {
175	String host = st.nextToken();
176	// this should in reality always be true, but best check
177	if(_hostMap.containsKey(host)) {
178	// get the list and remove the host in question
179	List list = (List) _hostMap.get(host);
180	list.remove(dhQueue);
181	// if the list is now empty, we might as well remove it
182	if(list.size()==0) {
183	_hostMap.remove(host);
184	}
185	}
186	}
187	_logger.write(toString(), Logger.SYSMSG, "deregistered DataHandler for hosts: "+hostList);
188	}
189	// always remove host from our complete host list
190	_allHostsList.remove(dhQueue);
191	}
192
193	/**
194	* Overrides the {@link java.lang.Object#toString() Object.toString()}
195	* method to provide clean logging (every class should have this).
196	*
197	* This uses the uk.ac.ukc.iscream.util.NameFormat class
198	* to format the toString()
199	*
200	* @return the name of this class and its CVS revision
201	*/
202	public String toString() {
203	return FormatName.getName(
204	_name,
205	getClass().getName(),
206	REVISION);
207	}
208
209	//---PRIVATE METHODS---
210
211	//---ACCESSOR/MUTATOR METHODS---
212
213	/**
214	* Accessor to return a reference to the Queue object. This
215	* is needed so the ClientInterfaceServant can get add data
216	* easily.
217	*
218	* @return a reference to our Queue object.
219	*/
220	public Queue getQueue() {
221	return _queue;
222	}
223
224	//---ATTRIBUTES---
225
226	/**
227	* This is the friendly identifier of the
228	* component this class is running in.
229	* eg, a Filter may be called "filter1",
230	* If this class does not have an owning
231	* component, a name from the configuration
232	* can be placed here. This name could also
233	* be changed to null for utility classes.
234	*/
235	private String _name = ClientInterfaceMain.NAME;
236
237	/**
238	* This holds a reference to the
239	* system logger that is being used.
240	*/
241	private Logger _logger = ReferenceManager.getInstance().getLogger();
242
243	/**
244	* A reference to the Queue we're using.
245	*/
246	private Queue _queue;
247
248	/**
249	* A HashMap to store lists of Queue's (in the DataHandlers)
250	* in a way that can be easily accessed when data comes in.
251	*/
252	private Map _hostMap;
253
254	/**
255	* A list specifically for a Queue's associated with DataHandlers
256	* that want all host information.
257	*/
258	private List _allHostDataList;
259
260	/**
261	* A list of all hosts.
262	*/
263	private List _allHostsList;
264
265	//---STATIC ATTRIBUTES---
266
267	}