1 /*
2 * The contents of this file are subject to the BT "ZEUS" Open Source
3 * Licence (L77741), Version 1.0 (the "Licence"); you may not use this file
4 * except in compliance with the Licence. You may obtain a copy of the Licence
5 * from $ZEUS_INSTALL/licence.html or alternatively from
6 * http://www.labs.bt.com/projects/agents/zeus/licence.htm
7 *
8 * Except as stated in Clause 7 of the Licence, software distributed under the
9 * Licence is distributed WITHOUT WARRANTY OF ANY KIND, either express or
10 * implied. See the Licence for the specific language governing rights and
11 * limitations under the Licence.
12 *
13 * The Original Code is within the package zeus.*.
14 * The Initial Developer of the Original Code is British Telecommunications
15 * public limited company, whose registered office is at 81 Newgate Street,
16 * London, EC1A 7AJ, England. Portions created by British Telecommunications
17 * public limited company are Copyright 1996-9. All Rights Reserved.
18 *
19 * THIS NOTICE MUST BE INCLUDED ON ANY COPY OF THIS FILE
20 */
21
22
23
24 package zeus.actors;
25
26 import java.util.*;
27 import zeus.util.*;
28 import zeus.concepts.*;
29
30
31 public abstract class MsgNode {
32 Hashtable successors = new Hashtable();
33 MsgHandler engine = null;
34 int use_count = 0;
35
36 // meaningless init to allow rearch
37 // this one may be tricky...
38 public MsgNode () {
39 ;
40 }
41
42 MsgNode(MsgHandler engine) {
43 this.engine = engine;
44 }
45
46 void addSuccessor(String path, MsgNode node) {
47 //System.out.println("path = " + path + " node = " + node);
48 Assert.notFalse( successors.put(path,node) == null );
49 }
50
51 void propagate(String path, Performative input) {
52 StringBuffer err = new StringBuffer (40);
53 err.append ("\nMsgHandler Propagate: ");
54 err.append (path);
55 err.append (" MsgNode");
56 //err.append (this);
57 Core.DEBUG(5,err);
58 MsgNode node = (MsgNode)successors.get(path);
59 node.evaluate(path,input);
60 }
61
62 abstract void evaluate(String path, Performative input);
63
64 void remove(String path) {
65 Core.DEBUG(5,"\nMsgHandler Remove: " + path + " " + this);
66 MsgNode node = (MsgNode)successors.remove(path);
67 if ( node != null ) {
68 use_count--;
69 node.remove(path);
70 }
71 }
72 }