1 /*
2 * Copyright (c) 1999, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25 /*
26 * COMPONENT_NAME: idl.parser
27 *
28 * ORIGINS: 27
29 *
30 * Licensed Materials - Property of IBM
31 * 5639-D57 (C) COPYRIGHT International Business Machines Corp. 1997, 1999
32 * RMI-IIOP v1.0
33 *
34 */
35
36 package com.sun.tools.corba.se.idl;
37
38 // NOTES:
39
40 import java.security.MessageDigest;
41 import java.util.Hashtable;
42
43 /**
44 *
45 **/
46 public class ValueRepositoryId
47 {
48 private MessageDigest sha; // Message digest used to compute SHA-1
49 private int index; // Current index in the 'logical' sequence
50 private Hashtable types; // Already processed types
51 private String hashcode; // The computed hashcode
52
53 public ValueRepositoryId ()
54 {
55 try
56 {
57 sha = MessageDigest.getInstance ("SHA-1");
58 }
59 catch (Exception exception)
60 {}
61 index = 0;
62 types = new Hashtable ();
63 hashcode = null;
64 } // ctor
65
66 /**Add a value to the hashcode being computed.
67 @param value the value to be added to the value RepositoryID. */
68 public void addValue (int value)
69 {
70 sha.update ((byte)((value >> 24) & 0x0F));
71 sha.update ((byte)((value >> 16) & 0x0F));
72 sha.update ((byte)((value >> 8) & 0x0F));
73 sha.update ((byte)(value & 0x0F));
74 index++;
75 } // addValue
76
77 /** Add a type to the list of types which have already been included.
78 Note that the type should be added prior to its value.
79 @param entry the type to be added to the value RepositoryID. */
80 public void addType (SymtabEntry entry)
81 {
82 types.put (entry, new Integer (index));
83 }
84
85 /** Check to see if a specified type has already been processed. If so,
86 add the appropriate 'previously processed' code (0xFFFFFFFF) and
87 sequence offset, and return false; otherwise add the symbol table entry
88 and current offset to the hashtable and return false.
89 @param entry the type to be checked
90 @return true if the symbol table entry has not been previously added;
91 and false otherwise. */
92 public boolean isNewType (SymtabEntry entry)
93 {
94 Object index = types.get (entry);
95 if (index == null)
96 {
97 addType (entry);
98 return true;
99 }
100 addValue (0xFFFFFFFF);
101 addValue (((Integer)index).intValue ());
102 return false;
103 } // isNewType
104
105 /** Get the hashcode computed for the value type. This method MUST not be
106 called until all fields have been added, since it computes the hash
107 code from the values entered for each field.
108 @return the 64 bit hashcode for the value type represented as a
109 16 character hexadecimal string. */
110 public String getHashcode ()
111 {
112 if (hashcode == null)
113 {
114 byte [] digest = sha.digest ();
115 hashcode = hexOf (digest[0]) + hexOf (digest[1]) +
116 hexOf (digest[2]) + hexOf (digest[3]) +
117 hexOf (digest[4]) + hexOf (digest[5]) +
118 hexOf (digest[6]) + hexOf (digest[7]);
119 }
120 return hashcode;
121 } // getHashCode
122
123 // Convert a byte to a two character hex string:
124 private static String hexOf (byte value)
125 {
126 int d1 = (value >> 4) & 0x0F;
127 int d2 = value & 0x0F;
128 return "0123456789ABCDEF".substring (d1, d1 + 1) +
129 "0123456789ABCDEF".substring (d2, d2 + 1);
130 } // hexOf
131 } // class ValueRepositoryId