1 /*
2 * Copyright (c) 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.module;
27
28 import java.io.IOException;
29 import java.io.UncheckedIOException;
30 import java.lang.module.ModuleDescriptor;
31 import java.lang.module.ModuleReader;
32 import java.lang.module.ModuleReference;
33 import java.net.URI;
34 import java.util.Objects;
35 import java.util.function.Supplier;
36
37 /**
38 * A ModuleReference implementation that supports referencing a module that
39 * is patched and/or can be tied to other modules by means of hashes.
40 */
41
42 public class ModuleReferenceImpl extends ModuleReference {
43
44 private final Supplier<ModuleReader> readerSupplier;
45
46 // non-null if the module is patched
47 private final ModulePatcher patcher;
48
49 // ModuleTarget if the module is OS/architecture specific
50 private final ModuleTarget target;
51
52 // the hashes of other modules recorded in this module
53 private final ModuleHashes recordedHashes;
54
55 // the function that computes the hash of this module
56 private final ModuleHashes.HashSupplier hasher;
57
58 // ModuleResolution flags
59 private final ModuleResolution moduleResolution;
60
61 // cached hash of this module to avoid needing to compute it many times
62 private byte[] cachedHash;
63
64 /**
65 * Constructs a new instance of this class.
66 */
67 ModuleReferenceImpl(ModuleDescriptor descriptor,
68 URI location,
69 Supplier<ModuleReader> readerSupplier,
70 ModulePatcher patcher,
71 ModuleTarget target,
72 ModuleHashes recordedHashes,
73 ModuleHashes.HashSupplier hasher,
74 ModuleResolution moduleResolution)
75 {
76 super(descriptor, Objects.requireNonNull(location));
77 this.readerSupplier = readerSupplier;
78 this.patcher = patcher;
79 this.target = target;
80 this.recordedHashes = recordedHashes;
81 this.hasher = hasher;
82 this.moduleResolution = moduleResolution;
83 }
84
85 @Override
86 public ModuleReader open() throws IOException {
87 try {
88 return readerSupplier.get();
89 } catch (UncheckedIOException e) {
90 throw e.getCause();
91 }
92 }
93
94 /**
95 * Returns {@code true} if this module has been patched via --patch-module.
96 */
97 public boolean isPatched() {
98 return (patcher != null);
99 }
100
101 /**
102 * Returns the ModuleTarget or {@code null} if the no target platform.
103 */
104 public ModuleTarget moduleTarget() {
105 return target;
106 }
107
108 /**
109 * Returns the hashes recorded in this module or {@code null} if there
110 * are no hashes recorded.
111 */
112 public ModuleHashes recordedHashes() {
113 return recordedHashes;
114 }
115
116 /**
117 * Returns the supplier that computes the hash of this module.
118 */
119 ModuleHashes.HashSupplier hasher() {
120 return hasher;
121 }
122
123 /**
124 * Returns the ModuleResolution flags.
125 */
126 public ModuleResolution moduleResolution() {
127 return moduleResolution;
128 }
129
130 /**
131 * Computes the hash of this module. Returns {@code null} if the hash
132 * cannot be computed.
133 *
134 * @throws java.io.UncheckedIOException if an I/O error occurs
135 */
136 public byte[] computeHash(String algorithm) {
137 byte[] result = cachedHash;
138 if (result != null)
139 return result;
140 if (hasher == null)
141 return null;
142 cachedHash = result = hasher.generate(algorithm);
143 return result;
144 }
145
146 @Override
147 public int hashCode() {
148 int hc = hash;
149 if (hc == 0) {
150 hc = descriptor().hashCode();
151 hc = 43 * hc + Objects.hashCode(location());
152 hc = 43 * hc + Objects.hashCode(patcher);
153 if (hc == 0)
154 hc = -1;
155 hash = hc;
156 }
157 return hc;
158 }
159
160 private int hash;
161
162 @Override
163 public boolean equals(Object ob) {
164 if (!(ob instanceof ModuleReferenceImpl))
165 return false;
166 ModuleReferenceImpl that = (ModuleReferenceImpl)ob;
167
168 // assume module content, recorded hashes, etc. are the same
169 // when the modules have equal module descriptors, are at the
170 // same location, and are patched by the same patcher.
171 return Objects.equals(this.descriptor(), that.descriptor())
172 && Objects.equals(this.location(), that.location())
173 && Objects.equals(this.patcher, that.patcher);
174 }
175
176 @Override
177 public String toString() {
178 StringBuilder sb = new StringBuilder();
179 sb.append("[module ");
180 sb.append(descriptor().name());
181 sb.append(", location=");
182 sb.append(location().orElseThrow(() -> new InternalError()));
183 if (isPatched()) sb.append(" (patched)");
184 sb.append("]");
185 return sb.toString();
186 }
187
188 }