KickJava   Java API By Example, From Geeks To Geeks.

Java > Open Source Codes > org > apache > bsf > debug > util > StubTable


1 /*
2  * The Apache Software License, Version 1.1
3  *
4  * Copyright (c) 2002 The Apache Software Foundation. All rights
5  * reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  *
11  * 1. Redistributions of source code must retain the above copyright
12  * notice, this list of conditions and the following disclaimer.
13  *
14  * 2. Redistributions in binary form must reproduce the above copyright
15  * notice, this list of conditions and the following disclaimer in
16  * the documentation and/or other materials provided with the
17  * distribution.
18  *
19  * 3. The end-user documentation included with the redistribution, if
20  * any, must include the following acknowlegement:
21  * "This product includes software developed by the
22  * Apache Software Foundation (http://www.apache.org/)."
23  * Alternately, this acknowlegement may appear in the software itself,
24  * if and wherever such third-party acknowlegements normally appear.
25  *
26  * 4. The names "Apache BSF", "Apache", and "Apache Software Foundation"
27  * must not be used to endorse or promote products derived from
28  * this software without prior written permission. For written
29  * permission, please contact apache@apache.org.
30  *
31  * 5. Products derived from this software may not be called "Apache"
32  * nor may "Apache" appear in their names without prior written
33  * permission of the Apache Group.
34  *
35  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
36  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
37  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
38  * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
39  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
40  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
41  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
42  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
43  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
44  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
45  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
46  * SUCH DAMAGE.
47  * ====================================================================
48  *
49  * This software consists of voluntary contributions made by many individuals
50  * on behalf of the Apache Software Foundation and was originally created by
51  * Sanjiva Weerawarana and others at International Business Machines
52  * Corporation. For more information on the Apache Software Foundation,
53  * please see <http://www.apache.org/>.
54  */
55
56 package org.apache.bsf.debug.util;
57
58 import java.util.*;
59 import org.apache.bsf.debug.jsdi.*;
60 import org.apache.bsf.debug.util.*;
61
62 /**
63  * This class provides the resident object table for the
64  * mirrors. A Stub represents a remote JavaScript object
65  * or any remote concept that needs to be identified such
66  * engines or contexts which are not JavaScript objects.
67  *
68  * A Stub has a unique identifier allocated on the
69  * server. This is called its oid, for object identifier.
70  * The oid is not only carrying the identity but also the
71  * type of the remote object. Knowing the type is essential
72  * when a Stub has to be created. For instance, it is important
73  * to know if a remote object is just an object or a reified
74  * code as a script or a function.
75  *
76  * The oid is a long, the high word is the type (tid), the low word
77  * is the unique identifier (uid). The unique identifier is globally
78  * unique across all types.
79  *
80  * This class also acts as the factory for Stub objects.
81  * When a Stub is created, it is remembered in the resident
82  * object table for later rebinding from its uid.
83  *
84  */
85 public abstract class StubTable {
86
87     protected IntHashtable m_stubs;
88     protected SocketConnection m_con;
89         
90     public StubTable(SocketConnection con) {
91         m_con = con;
92         m_stubs = new IntHashtable();
93     }
94
95     //------------------------------------------------------------
96 public void disconnectNotify() {
97         Enumeration e;
98         Stub s;
99         DebugLog.stdoutPrintln("Revoking stubs...",
100                                        DebugLog.BSF_LOG_L3);
101
102         e = m_stubs.elements();
103         while (e.hasMoreElements()) {
104             s = (Stub)e.nextElement();
105             s.revoked();
106         }
107         m_stubs = new IntHashtable();
108     }
109         
110     //------------------------------------------------------------
111 protected abstract Stub factory(int tid, int uid);
112
113     //------------------------------------------------------------
114 public synchronized Stub swizzle(int tid, int uid) {
115         Stub Stub=null;
116              
117         if (uid== DebugConstants.NOT_FOUND_UID)
118             return Stub.NOT_FOUND;
119         if (uid== DebugConstants.UNDEFINED_UID)
120             return Stub.UNDEFINED;
121         
122         Stub = (Stub)m_stubs.get(uid);
123         if (Stub==null) {
124             Stub = factory(tid,uid);
125             m_stubs.put(uid,Stub);
126         }
127         return Stub;
128     }
129 }
130
131
Popular Tags