1 /*
2 * Copyright (c) 2014, 2016, 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 package jdk.internal.jimage;
27
28 import java.io.UTFDataFormatException;
29 import java.nio.ByteBuffer;
30
31 /**
32 * @implNote This class needs to maintain JDK 8 source compatibility.
33 *
34 * It is used internally in the JDK to implement jimage/jrtfs access,
35 * but also compiled and delivered as part of the jrtfs.jar to support access
36 * to the jimage file provided by the shipped JDK by tools running on JDK 8.
37 */
38 public class ImageStringsReader implements ImageStrings {
39 public static final int HASH_MULTIPLIER = 0x01000193;
40 private final BasicImageReader reader;
41
42 ImageStringsReader(BasicImageReader reader) {
43 this.reader = reader;
44 }
45
46 @Override
47 public String get(int offset) {
48 return reader.getString(offset);
49 }
50
51 @Override
52 public int add(final String string) {
53 throw new InternalError("Can not add strings at runtime");
54 }
55
56 private static int hashCode(byte[] bytes, int offset, int count, int seed) {
57 for (int i = offset, limit = offset + count; i < limit; i++) {
58 seed = (seed * HASH_MULTIPLIER) ^ (bytes[i] & 0xFF);
59 }
60
61 return seed & 0x7FFFFFFF;
62 }
63
64 public static int hashCode(byte[] bytes, int seed) {
65 return hashCode(bytes, 0, bytes.length, seed);
66 }
67
68 public static int hashCode(byte[] bytes) {
69 return hashCode(bytes, 0, bytes.length, HASH_MULTIPLIER);
70 }
71
72 public static int hashCode(String string, int seed) {
73 return hashCode(mutf8FromString(string), seed);
74 }
75
76 public static int hashCode(String string) {
77 return hashCode(mutf8FromString(string), HASH_MULTIPLIER);
78 }
79
80 static int charsFromMUTF8Length(byte[] bytes, int offset, int count) {
81 int length = 0;
82
83 for (int i = offset; i < offset + count; i++) {
84 byte ch = bytes[i];
85
86 if (ch == 0) {
87 break;
88 }
89
90 if ((ch & 0xC0) != 0x80) {
91 length++;
92 }
93 }
94
95 return length;
96 }
97
98 static void charsFromMUTF8(char[] chars, byte[] bytes, int offset, int count) throws UTFDataFormatException {
99 int j = 0;
100
101 for (int i = offset; i < offset + count; i++) {
102 byte ch = bytes[i];
103
104 if (ch == 0) {
105 break;
106 }
107
108 boolean is_unicode = (ch & 0x80) != 0;
109 int uch = ch & 0x7F;
110
111 if (is_unicode) {
112 int mask = 0x40;
113
114 while ((uch & mask) != 0) {
115 ch = bytes[++i];
116
117 if ((ch & 0xC0) != 0x80) {
118 throw new UTFDataFormatException("bad continuation 0x" + Integer.toHexString(ch));
119 }
120
121 uch = ((uch & ~mask) << 6) | (ch & 0x3F);
122 mask <<= 6 - 1;
123 }
124
125 if ((uch & 0xFFFF) != uch) {
126 throw new UTFDataFormatException("character out of range \\u" + Integer.toHexString(uch));
127 }
128 }
129
130 chars[j++] = (char)uch;
131 }
132 }
133
134 public static String stringFromMUTF8(byte[] bytes, int offset, int count) {
135 int length = charsFromMUTF8Length(bytes, offset, count);
136 char[] chars = new char[length];
137
138 try {
139 charsFromMUTF8(chars, bytes, offset, count);
140 } catch (UTFDataFormatException ex) {
141 throw new InternalError("Attempt to convert non modified UTF-8 byte sequence");
142 }
143
144 return new String(chars);
145 }
146
147 public static String stringFromMUTF8(byte[] bytes) {
148 return stringFromMUTF8(bytes, 0, bytes.length);
149 }
150
151 static int charsFromByteBufferLength(ByteBuffer buffer) {
152 int length = 0;
153
154 while(buffer.hasRemaining()) {
155 byte ch = buffer.get();
156
157 if (ch == 0) {
158 return length;
159 }
160
161 if ((ch & 0xC0) != 0x80) {
162 length++;
163 }
164 }
165
166 throw new InternalError("No terminating zero byte for modified UTF-8 byte sequence");
167 }
168
169 static void charsFromByteBuffer(char chars[], ByteBuffer buffer) {
170 int j = 0;
171
172 while(buffer.hasRemaining()) {
173 byte ch = buffer.get();
174
175 if (ch == 0) {
176 return;
177 }
178
179 boolean is_unicode = (ch & 0x80) != 0;
180 int uch = ch & 0x7F;
181
182 if (is_unicode) {
183 int mask = 0x40;
184
185 while ((uch & mask) != 0) {
186 ch = buffer.get();
187
188 if ((ch & 0xC0) != 0x80) {
189 throw new InternalError("Bad continuation in modified UTF-8 byte sequence");
190 }
191
192 uch = ((uch & ~mask) << 6) | (ch & 0x3F);
193 mask <<= 6 - 1;
194 }
195 }
196
197 if ((uch & 0xFFFF) != uch) {
198 throw new InternalError("UTF-32 char in modified UTF-8 byte sequence");
199 }
200
201 chars[j++] = (char)uch;
202 }
203
204 throw new InternalError("No terminating zero byte for modified UTF-8 byte sequence");
205 }
206
207 public static String stringFromByteBuffer(ByteBuffer buffer) {
208 int length = charsFromByteBufferLength(buffer);
209 buffer.rewind();
210 char[] chars = new char[length];
211 charsFromByteBuffer(chars, buffer);
212
213 return new String(chars);
214 }
215
216 static int mutf8FromCharsLength(char chars[]) {
217 int length = 0;
218
219 for (char ch : chars) {
220 int uch = ch & 0xFFFF;
221
222 if ((uch & ~0x7F) != 0) {
223 int mask = ~0x3F;
224 int n = 0;
225
226 do {
227 n++;
228 uch >>= 6;
229 mask >>= 1;
230 } while ((uch & mask) != 0);
231
232 length += n + 1;
233 } else if (uch == 0) {
234 length += 2;
235 } else {
236 length++;
237 }
238 }
239
240 return length;
241 }
242
243 static void mutf8FromChars(byte[] bytes, int offset, char chars[]) {
244 int j = offset;
245 byte[] buffer = new byte[8];
246
247 for (char ch : chars) {
248 int uch = ch & 0xFFFF;
249
250 if ((uch & ~0x7F) != 0) {
251 int mask = ~0x3F;
252 int n = 0;
253
254 do {
255 buffer[n++] = (byte)(0x80 | (uch & 0x3F));
256 uch >>= 6;
257 mask >>= 1;
258 } while ((uch & mask) != 0);
259
260 buffer[n] = (byte)((mask << 1) | uch);
261
262 do {
263 bytes[j++] = buffer[n--];
264 } while (0 <= n);
265 } else if (uch == 0) {
266 bytes[j++] = (byte)0xC0;
267 bytes[j++] = (byte)0x80;
268 } else {
269 bytes[j++] = (byte)uch;
270 }
271 }
272 }
273
274 public static byte[] mutf8FromString(String string) {
275 char[] chars = string.toCharArray();
276 int length = mutf8FromCharsLength(chars);
277 byte[] bytes = new byte[length];
278 mutf8FromChars(bytes, 0, chars);
279
280 return bytes;
281 }
282 }