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 private static int attributeLength(int data) {
63 return (data & 0x7) + 1;
64 }
65
66 private static int attributeKind(int data) {
67 return data >>> 3;
68 }
69
70 static long[] decompress(ByteBuffer bytes) {
71 Objects.requireNonNull(bytes);
72 long[] attributes = new long[ATTRIBUTE_COUNT];
73
74 if (bytes != null) {
75 while (bytes.hasRemaining()) {
76 int data = bytes.get() & 0xFF;
77 int kind = attributeKind(data);
78
79 if (kind == ATTRIBUTE_END) {
80 break;
81 }
82
83 if (kind < ATTRIBUTE_END || ATTRIBUTE_COUNT <= kind) {
84 throw new InternalError(
85 "Invalid jimage attribute kind: " + kind);
86 }
87
88 int length = attributeLength(data);
89 long value = 0;
90
91 for (int j = 0; j < length; j++) {
92 value <<= 8;
93
94 if (!bytes.hasRemaining()) {
95 throw new InternalError("Missing jimage attribute data");
96 }
97
98 value |= bytes.get() & 0xFF;
99 }
100
101 attributes[kind] = value;
102 }
103 }
104
105 return attributes;
106 }
107
108 public static byte[] compress(long[] attributes) {
109 Objects.requireNonNull(attributes);
110 ImageStream stream = new ImageStream(16);
111
112 for (int kind = ATTRIBUTE_END + 1; kind < ATTRIBUTE_COUNT; kind++) {
113 long value = attributes[kind];
114
115 if (value != 0) {
116 int n = (63 - Long.numberOfLeadingZeros(value)) >> 3;
117 stream.put((kind << 3) | n);
118
119 for (int i = n; i >= 0; i--) {
120 stream.put((int)(value >> (i << 3)));
121 }
122 }
123 }
124
125 stream.put(ATTRIBUTE_END << 3);
126
127 return stream.toArray();
128 }
129
130 public boolean verify(String name) {
131 Objects.requireNonNull(name);
132
133 return name.equals(getFullName());
134 }
135
136 long getAttribute(int kind) {
137 if (kind < ATTRIBUTE_END || ATTRIBUTE_COUNT <= kind) {
138 throw new InternalError(
139 "Invalid jimage attribute kind: " + kind);
140 }
141
142 return attributes[kind];
143 }
144
145 String getAttributeString(int kind) {
146 if (kind < ATTRIBUTE_END || ATTRIBUTE_COUNT <= kind) {
147 throw new InternalError(
148 "Invalid jimage attribute kind: " + kind);
149 }
150
151 return getStrings().get((int)attributes[kind]);
152 }
153
154 public String getModule() {
155 return getAttributeString(ATTRIBUTE_MODULE);
156 }
157
158 public int getModuleOffset() {
159 return (int)getAttribute(ATTRIBUTE_MODULE);
160 }
161
162 public String getBase() {
163 return getAttributeString(ATTRIBUTE_BASE);
164 }
165
166 public int getBaseOffset() {
167 return (int)getAttribute(ATTRIBUTE_BASE);
168 }
169
170 public String getParent() {
171 return getAttributeString(ATTRIBUTE_PARENT);
172 }
173
174 public int getParentOffset() {
175 return (int)getAttribute(ATTRIBUTE_PARENT);
176 }
177
178 public String getExtension() {
179 return getAttributeString(ATTRIBUTE_EXTENSION);
180 }
181
182 public int getExtensionOffset() {
183 return (int)getAttribute(ATTRIBUTE_EXTENSION);
184 }
185
186 public String getFullName() {
187 return getFullName(false);
188 }
189
190 public String getFullName(boolean modulesPrefix) {
191 StringBuilder builder = new StringBuilder();
192
193 if (getModuleOffset() != 0) {
194 if (modulesPrefix) {
195 builder.append("/modules");
196 }
197
198 builder.append('/');
199 builder.append(getModule());
200 builder.append('/');
201 }
202
203 if (getParentOffset() != 0) {
204 builder.append(getParent());
205 builder.append('/');
206 }
207
208 builder.append(getBase());
209
210 if (getExtensionOffset() != 0) {
211 builder.append('.');
212 builder.append(getExtension());
213 }
214
215 return builder.toString();
216 }
217
218 String buildName(boolean includeModule, boolean includeParent,
219 boolean includeName) {
220 StringBuilder builder = new StringBuilder();
221
222 if (includeModule && getModuleOffset() != 0) {
223 builder.append("/modules/");
224 builder.append(getModule());
225 }
226
227 if (includeParent && getParentOffset() != 0) {
228 builder.append('/');
229 builder.append(getParent());
230 }
231
232 if (includeName) {
233 if (includeModule || includeParent) {
234 builder.append('/');
235 }
236
237 builder.append(getBase());
238
239 if (getExtensionOffset() != 0) {
240 builder.append('.');
241 builder.append(getExtension());
242 }
243 }
244
245 return builder.toString();
246 }
247
248 public long getContentOffset() {
249 return getAttribute(ATTRIBUTE_OFFSET);
250 }
251
252 public long getCompressedSize() {
253 return getAttribute(ATTRIBUTE_COMPRESSED);
254 }
255
256 public long getUncompressedSize() {
257 return getAttribute(ATTRIBUTE_UNCOMPRESSED);
258 }
259
260 static ImageLocation readFrom(BasicImageReader reader, int offset) {
261 Objects.requireNonNull(reader);
262 long[] attributes = reader.getAttributes(offset);
263 ImageStringsReader strings = reader.getStrings();
264
265 return new ImageLocation(attributes, strings);
266 }
267 }