created mirror

Java/net/ReliableUDPMessage.java

@@ -0,0 +1,71 @@
+/*   
+ReliableUDPMessage.java
+ *    
+ *    You may use and distribute under the terms of either the GNU Lesser
+ *    General Public License, either version 2 of the license or,
+ *    at your choice, any later version. Alternatively, you may use and
+ *    distribute under the terms of the XPL.
+ *
+ *    See the LICENSE.lgpl and LICENSE.xpl files for the specific terms of 
+ *    the licenses.
+ *
+ *    This software is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the README
+ *    file for more details.
+ *
+ */
+/* Written by Antti-Juhani Kaijanaho */
+
+package org.gzigzag.net;
+import java.text.*;
+import java.util.*;
+
+/** An abstract superclass of all message classes for the Reliable UDP
+ * scheme.  
+ * The message contains enough metainformation so that delivery 
+ * can be guaranteed using an acknowledgment scheme.
+ * <p>
+ * This superclass contains almost all functionality that
+ * ReliableUDPSocket needs from subclasses of this class; all
+ * subclasses need to do is implementing their own payload
+ * functionality.  The only exception is that the subclass must take
+ * care of including the values from getSeq() and getAck() in the UDP
+ * payload.  
+ */
+public abstract class ReliableUDPMessage {
+    private long seq = 0;
+    private long ack = 0;
+    private long timestamp = 0;
+    private Peer peer = null;
+
+    static private DateFormat df = DateFormat.getDateInstance();
+
+    public final synchronized long getSeq() { return seq; }
+    public final synchronized long getAck() { return ack; }
+    public final synchronized long getTimestamp() { return timestamp; }
+
+    public final synchronized void setSeq(long seq) { this.seq = seq; }
+    public final synchronized void setAck(long ack) { this.ack = ack; }
+    public final synchronized void setTimestamp(long timestamp) {
+        this.timestamp = timestamp;
+    }
+
+    public final synchronized Peer getPeer() { return peer; }
+    public final synchronized void setPeer(Peer p) { peer = p; }
+
+    /** Return a fresh byte array usable as UDP packet payload.  Note
+     * that the return value must encode seq and ack to work with a
+     * ReliableUDPSocket; timestamp is optional.  */
+    public abstract byte[] toByteArray();
+
+    /** Make a fresh copy of this message. */
+    public abstract ReliableUDPMessage copy();
+
+    public synchronized String toString() {
+        return "[" + df.format(new Date(timestamp))
+            + "] " + peer;
+    }
+
+}
+