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 int parentOffset = (int)attributes[ATTRIBUTE_PARENT];
151 if (parentOffset != 0) {
152 String parent = strings.get(parentOffset);
153 final int parentLen = parent.length();
154 if (!name.regionMatches(index, parent, 0, parentLen)) {
155 return false;
156 }
157 index += parentLen;
158 if (length <= index || name.charAt(index++) != '/') {
159 return false;
160 }
161 }
162
163 String base = strings.get((int)attributes[ATTRIBUTE_BASE]);
164 final int baseLen = base.length();
165 if (!name.regionMatches(index, base, 0, baseLen)) {
166 return false;
167 }
168 index += baseLen;
169
170 int extOffset = (int)attributes[ATTRIBUTE_EXTENSION];
171 if (extOffset != 0) {
172 String extension = strings.get(extOffset);
173 int extLen = extension.length();
174 if (length <= index
175 || name.charAt(index++) != '.'
176 || !name.regionMatches(index, extension, 0, extLen)) {
177 return false;
178 }
179 index += extLen;
180 }
181 return length == index;
182 }
183
184 long getAttribute(int kind) {
185 if (kind < ATTRIBUTE_END || ATTRIBUTE_COUNT <= kind) {
186 throw new InternalError(
187 "Invalid jimage attribute kind: " + kind);
188 }
189
190 return attributes[kind];
191 }
192
193 String getAttributeString(int kind) {
194 if (kind < ATTRIBUTE_END || ATTRIBUTE_COUNT <= kind) {
195 throw new InternalError(
196 "Invalid jimage attribute kind: " + kind);
197 }
198
199 return getStrings().get((int)attributes[kind]);
200 }
201
202 public String getModule() {
203 return getAttributeString(ATTRIBUTE_MODULE);
204 }
205
206 public int getModuleOffset() {
207 return (int)getAttribute(ATTRIBUTE_MODULE);
208 }
209
210 public String getBase() {
211 return getAttributeString(ATTRIBUTE_BASE);
212 }
213
214 public int getBaseOffset() {
215 return (int)getAttribute(ATTRIBUTE_BASE);
216 }
217
218 public String getParent() {
219 return getAttributeString(ATTRIBUTE_PARENT);
220 }
221
222 public int getParentOffset() {
223 return (int)getAttribute(ATTRIBUTE_PARENT);
224 }
225
226 public String getExtension() {
227 return getAttributeString(ATTRIBUTE_EXTENSION);
228 }
229
230 public int getExtensionOffset() {
231 return (int)getAttribute(ATTRIBUTE_EXTENSION);
232 }
233
234 public String getFullName() {
235 return getFullName(false);
236 }
237
238 public String getFullName(boolean modulesPrefix) {
239 StringBuilder builder = new StringBuilder();
240
241 if (getModuleOffset() != 0) {
242 if (modulesPrefix) {
243 builder.append("/modules");
244 }
245
246 builder.append('/');
247 builder.append(getModule());
248 builder.append('/');
249 }
250
251 if (getParentOffset() != 0) {
252 builder.append(getParent());
253 builder.append('/');
254 }
255
256 builder.append(getBase());
257
258 if (getExtensionOffset() != 0) {
259 builder.append('.');
260 builder.append(getExtension());
261 }
262
263 return builder.toString();
264 }
265
266 String buildName(boolean includeModule, boolean includeParent,
267 boolean includeName) {
268 StringBuilder builder = new StringBuilder();
269
270 if (includeModule && getModuleOffset() != 0) {
271 builder.append("/modules/");
272 builder.append(getModule());
273 }
274
275 if (includeParent && getParentOffset() != 0) {
276 builder.append('/');
277 builder.append(getParent());
278 }
279
280 if (includeName) {
281 if (includeModule || includeParent) {
282 builder.append('/');
283 }
284
285 builder.append(getBase());
286
287 if (getExtensionOffset() != 0) {
288 builder.append('.');
289 builder.append(getExtension());
290 }
291 }
292
293 return builder.toString();
294 }
295
296 public long getContentOffset() {
297 return getAttribute(ATTRIBUTE_OFFSET);
298 }
299
300 public long getCompressedSize() {
301 return getAttribute(ATTRIBUTE_COMPRESSED);
302 }
303
304 public long getUncompressedSize() {
305 return getAttribute(ATTRIBUTE_UNCOMPRESSED);
306 }
307
308 static ImageLocation readFrom(BasicImageReader reader, int offset) {
309 Objects.requireNonNull(reader);
310 long[] attributes = reader.getAttributes(offset);
311 ImageStringsReader strings = reader.getStrings();
312
313 return new ImageLocation(attributes, strings);
314 }
315 }