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.nio.ByteBuffer;
29 import java.util.Objects;
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 ImageLocation {
39 public static final int ATTRIBUTE_END = 0;
40 public static final int ATTRIBUTE_MODULE = 1;
41 public static final int ATTRIBUTE_PARENT = 2;
42 public static final int ATTRIBUTE_BASE = 3;
43 public static final int ATTRIBUTE_EXTENSION = 4;
44 public static final int ATTRIBUTE_OFFSET = 5;
45 public static final int ATTRIBUTE_COMPRESSED = 6;
46 public static final int ATTRIBUTE_UNCOMPRESSED = 7;
47 public static final int ATTRIBUTE_COUNT = 8;
48
49 protected final long[] attributes;
50
51 protected final ImageStrings strings;
52
53 public ImageLocation(long[] attributes, ImageStrings strings) {
54 this.attributes = Objects.requireNonNull(attributes);
55 this.strings = Objects.requireNonNull(strings);
56 }
57
58 ImageStrings getStrings() {
59 return strings;
60 }
61
62 static long[] decompress(ByteBuffer bytes) {
63 Objects.requireNonNull(bytes);
64 long[] attributes = new long[ATTRIBUTE_COUNT];
65
66 if (bytes != null) {
67 while (bytes.hasRemaining()) {
68 int data = bytes.get() & 0xFF;
69 int kind = data >>> 3;
70
71 if (kind == ATTRIBUTE_END) {
72 break;
73 }
74
75 if (kind < ATTRIBUTE_END || ATTRIBUTE_COUNT <= kind) {
76 throw new InternalError(
77 "Invalid jimage attribute kind: " + kind);
78 }
79
80 int length = (data & 0x7) + 1;
81 long value = 0;
82
83 for (int j = 0; j < length; j++) {
84 value <<= 8;
85
86 if (!bytes.hasRemaining()) {
87 throw new InternalError("Missing jimage attribute data");
88 }
89
90 value |= bytes.get() & 0xFF;
91 }
92
93 attributes[kind] = value;
94 }
95 }
96
97 return attributes;
98 }
99
100 public static byte[] compress(long[] attributes) {
101 Objects.requireNonNull(attributes);
102 ImageStream stream = new ImageStream(16);
103
104 for (int kind = ATTRIBUTE_END + 1; kind < ATTRIBUTE_COUNT; kind++) {
105 long value = attributes[kind];
106
107 if (value != 0) {
108 int n = (63 - Long.numberOfLeadingZeros(value)) >> 3;
109 stream.put((kind << 3) | n);
110
111 for (int i = n; i >= 0; i--) {
112 stream.put((int)(value >> (i << 3)));
113 }
114 }
115 }
116
117 stream.put(ATTRIBUTE_END << 3);
118
119 return stream.toArray();
120 }
121
122 public boolean verify(String name) {
123 return verify(name, attributes, strings);
124 }
125
126 /**
127 * A simpler verification would be {@code name.equals(getFullName())}, but
128 * by not creating the full name and enabling early returns we allocate
129 * fewer objects. Could possibly be made allocation free by extending
130 * ImageStrings to test if strings at an offset match the name region.
131 */
132 static boolean verify(String name, final long[] attributes,
133 final ImageStrings strings) {
134 Objects.requireNonNull(name);
135 final int length = name.length();
136 int index = 0;
137 int moduleOffset = (int)attributes[ATTRIBUTE_MODULE];
138 if (moduleOffset != 0) {
139 String module = strings.get(moduleOffset);
140 final int moduleLen = module.length();
141 index = moduleLen + 1;
142 if (length <= index
143 || name.charAt(0) != '/'
144 || !name.regionMatches(1, module, 0, moduleLen)
145 || name.charAt(index++) != '/') {
146 return false;
147 }
148 }
149
150 return verifyName(name, index, length, attributes, strings);
151 }
152
153 static boolean verify(String module, String name,
154 final long[] attributes, final ImageStrings strings) {
155 Objects.requireNonNull(module);
156 Objects.requireNonNull(name);
157 int moduleOffset = (int)attributes[ATTRIBUTE_MODULE];
158 if (moduleOffset != 0) {
159 if (!module.equals(strings.get(moduleOffset))) {
160 return false;
161 }
162 }
163
164 return verifyName(name, 0, name.length(), attributes, strings);
165 }
166
167 private static boolean verifyName(String name, int index, final int length,
168 final long[] attributes, final ImageStrings strings) {
169
170 int parentOffset = (int) attributes[ATTRIBUTE_PARENT];
171 if (parentOffset != 0) {
172 String parent = strings.get(parentOffset);
173 final int parentLen = parent.length();
174 if (!name.regionMatches(index, parent, 0, parentLen)) {
175 return false;
176 }
177 index += parentLen;
178 if (length <= index || name.charAt(index++) != '/') {
179 return false;
180 }
181 }
182 String base = strings.get((int) attributes[ATTRIBUTE_BASE]);
183 final int baseLen = base.length();
184 if (!name.regionMatches(index, base, 0, baseLen)) {
185 return false;
186 }
187 index += baseLen;
188 int extOffset = (int) attributes[ATTRIBUTE_EXTENSION];
189 if (extOffset != 0) {
190 String extension = strings.get(extOffset);
191 int extLen = extension.length();
192 if (length <= index
193 || name.charAt(index++) != '.'
194 || !name.regionMatches(index, extension, 0, extLen)) {
195 return false;
196 }
197 index += extLen;
198 }
199 return length == index;
200 }
201
202 long getAttribute(int kind) {
203 if (kind < ATTRIBUTE_END || ATTRIBUTE_COUNT <= kind) {
204 throw new InternalError(
205 "Invalid jimage attribute kind: " + kind);
206 }
207
208 return attributes[kind];
209 }
210
211 String getAttributeString(int kind) {
212 if (kind < ATTRIBUTE_END || ATTRIBUTE_COUNT <= kind) {
213 throw new InternalError(
214 "Invalid jimage attribute kind: " + kind);
215 }
216
217 return getStrings().get((int)attributes[kind]);
218 }
219
220 public String getModule() {
221 return getAttributeString(ATTRIBUTE_MODULE);
222 }
223
224 public int getModuleOffset() {
225 return (int)getAttribute(ATTRIBUTE_MODULE);
226 }
227
228 public String getBase() {
229 return getAttributeString(ATTRIBUTE_BASE);
230 }
231
232 public int getBaseOffset() {
233 return (int)getAttribute(ATTRIBUTE_BASE);
234 }
235
236 public String getParent() {
237 return getAttributeString(ATTRIBUTE_PARENT);
238 }
239
240 public int getParentOffset() {
241 return (int)getAttribute(ATTRIBUTE_PARENT);
242 }
243
244 public String getExtension() {
245 return getAttributeString(ATTRIBUTE_EXTENSION);
246 }
247
248 public int getExtensionOffset() {
249 return (int)getAttribute(ATTRIBUTE_EXTENSION);
250 }
251
252 public String getFullName() {
253 return getFullName(false);
254 }
255
256 public String getFullName(boolean modulesPrefix) {
257 StringBuilder builder = new StringBuilder();
258
259 if (getModuleOffset() != 0) {
260 if (modulesPrefix) {
261 builder.append("/modules");
262 }
263
264 builder.append('/');
265 builder.append(getModule());
266 builder.append('/');
267 }
268
269 if (getParentOffset() != 0) {
270 builder.append(getParent());
271 builder.append('/');
272 }
273
274 builder.append(getBase());
275
276 if (getExtensionOffset() != 0) {
277 builder.append('.');
278 builder.append(getExtension());
279 }
280
281 return builder.toString();
282 }
283
284 String buildName(boolean includeModule, boolean includeParent,
285 boolean includeName) {
286 StringBuilder builder = new StringBuilder();
287
288 if (includeModule && getModuleOffset() != 0) {
289 builder.append("/modules/");
290 builder.append(getModule());
291 }
292
293 if (includeParent && getParentOffset() != 0) {
294 builder.append('/');
295 builder.append(getParent());
296 }
297
298 if (includeName) {
299 if (includeModule || includeParent) {
300 builder.append('/');
301 }
302
303 builder.append(getBase());
304
305 if (getExtensionOffset() != 0) {
306 builder.append('.');
307 builder.append(getExtension());
308 }
309 }
310
311 return builder.toString();
312 }
313
314 public long getContentOffset() {
315 return getAttribute(ATTRIBUTE_OFFSET);
316 }
317
318 public long getCompressedSize() {
319 return getAttribute(ATTRIBUTE_COMPRESSED);
320 }
321
322 public long getUncompressedSize() {
323 return getAttribute(ATTRIBUTE_UNCOMPRESSED);
324 }
325
326 static ImageLocation readFrom(BasicImageReader reader, int offset) {
327 Objects.requireNonNull(reader);
328 long[] attributes = reader.getAttributes(offset);
329 ImageStringsReader strings = reader.getStrings();
330
331 return new ImageLocation(attributes, strings);
332 }
333 }