package org.jgroups.stack;
import org.jgroups.logging.Log;
import org.jgroups.logging.LogFactory;
import org.jgroups.Address;
import java.util.Enumeration;
import java.util.Hashtable;
import java.util.Vector;
import java.net.UnknownHostException;
/**
* Keeps track of messages received from various senders. Acks each message received and checks whether
* it was already delivered. If yes, the message is discarded, otherwise it is delivered (passed up).
* The messages contain sequence numbers of old messages to be deleted, those are removed from the
* message table.
*
* @author Bela Ban June 17 1999
*/
public class AckMcastReceiverWindow {
final Hashtable msgs=new Hashtable(); // sender -- Vector (of seqnos)
protected static final Log log=LogFactory.getLog(AckMcastReceiverWindow.class);
/**
Records the sender/seqno pair in the message table
@param sender The sender of the message
@param seqno The sequence number associated with the message
@return boolean If false, message is already present. Otherwise true.
*/
public boolean add(Object sender, long seqno) {
Vector seqnos=(Vector)msgs.get(sender);
Long val=new Long(seqno);
if(seqnos == null) {
seqnos=new Vector();
seqnos.addElement(val);
msgs.put(sender, seqnos);
return true;
}
if(seqnos.contains(val))
return false;
seqnos.addElement(val);
return true;
}
public void remove(Object sender, Vector seqnos) {
Vector v=(Vector)msgs.get(sender);
Long seqno;
if(v != null && seqnos != null) {
for(int i=0; i < seqnos.size(); i++) {
seqno=(Long)seqnos.elementAt(i);
v.removeElement(seqno);
}
}
}
public long size() {
long ret=0;
for(Enumeration e=msgs.elements(); e.hasMoreElements();) {
ret+=((Vector)e.nextElement()).size();
}
return ret;
}
public void reset() {
removeAll();
}
public void removeAll() {msgs.clear();}
public void suspect(Object sender) {
if(log.isInfoEnabled()) log.info("suspect is " + sender);
msgs.remove(sender);
}
public String toString() {
StringBuilder ret=new StringBuilder();
Object sender;
for(Enumeration e=msgs.keys(); e.hasMoreElements();) {
sender=e.nextElement();
ret.append(sender).append(" --> ").append(msgs.get(sender)).append('\n');
}
return ret.toString();
}
public static void main(String[] args) throws UnknownHostException {
AckMcastReceiverWindow win=new AckMcastReceiverWindow();
Address sender1=new IpAddress("janet", 1111);
Address sender2=new IpAddress("janet", 4444);
Address sender3=new IpAddress("janet", 6767);
Address sender4=new IpAddress("janet", 3333);
win.add(sender1, 1);
win.add(sender1, 2);
win.add(sender3, 2);
win.add(sender2, 2);
win.add(sender4, 2);
win.add(sender1, 3);
win.add(sender1, 2);
System.out.println(win);
win.suspect(sender1);
System.out.println(win);
win.add(sender1, 1);
win.add(sender1, 2);
win.add(sender1, 3);
win.add(sender1, 4);
win.add(sender1, 5);
win.add(sender1, 6);
win.add(sender1, 7);
win.add(sender1, 8);
System.out.println(win);
Vector seqnos=new Vector();
seqnos.addElement(new Long(4));
seqnos.addElement(new Long(6));
seqnos.addElement(new Long(8));
win.remove(sender2, seqnos);
System.out.println(win);
win.remove(sender1, seqnos);
System.out.println(win);
}
}