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 // location of module 45 private final URI location; 46 47 // the module reader 48 private final Supplier<ModuleReader> readerSupplier; 49 50 // non-null if the module is patched 51 private final ModulePatcher patcher; 52 53 // ModuleTarget if the module is OS/architecture specific 54 private final ModuleTarget target; 55 56 // the hashes of other modules recorded in this module 57 private final ModuleHashes recordedHashes; 58 59 // the function that computes the hash of this module 60 private final ModuleHashes.HashSupplier hasher; 61 62 // ModuleResolution flags 63 private final ModuleResolution moduleResolution; 64 65 // cached hash of this module to avoid needing to compute it many times 66 private byte[] cachedHash; 67 68 /** 69 * Constructs a new instance of this class. 70 */ ModuleReferenceImpl(ModuleDescriptor descriptor, URI location, Supplier<ModuleReader> readerSupplier, ModulePatcher patcher, ModuleTarget target, ModuleHashes recordedHashes, ModuleHashes.HashSupplier hasher, ModuleResolution moduleResolution)71 public ModuleReferenceImpl(ModuleDescriptor descriptor, 72 URI location, 73 Supplier<ModuleReader> readerSupplier, 74 ModulePatcher patcher, 75 ModuleTarget target, 76 ModuleHashes recordedHashes, 77 ModuleHashes.HashSupplier hasher, 78 ModuleResolution moduleResolution) 79 { 80 super(descriptor, Objects.requireNonNull(location)); 81 this.location = location; 82 this.readerSupplier = readerSupplier; 83 this.patcher = patcher; 84 this.target = target; 85 this.recordedHashes = recordedHashes; 86 this.hasher = hasher; 87 this.moduleResolution = moduleResolution; 88 } 89 90 @Override open()91 public ModuleReader open() throws IOException { 92 try { 93 return readerSupplier.get(); 94 } catch (UncheckedIOException e) { 95 throw e.getCause(); 96 } 97 } 98 99 /** 100 * Returns {@code true} if this module has been patched via --patch-module. 101 */ isPatched()102 public boolean isPatched() { 103 return (patcher != null); 104 } 105 106 /** 107 * Returns the ModuleTarget or {@code null} if the no target platform. 108 */ moduleTarget()109 public ModuleTarget moduleTarget() { 110 return target; 111 } 112 113 /** 114 * Returns the hashes recorded in this module or {@code null} if there 115 * are no hashes recorded. 116 */ recordedHashes()117 public ModuleHashes recordedHashes() { 118 return recordedHashes; 119 } 120 121 /** 122 * Returns the supplier that computes the hash of this module. 123 */ hasher()124 ModuleHashes.HashSupplier hasher() { 125 return hasher; 126 } 127 128 /** 129 * Returns the ModuleResolution flags. 130 */ moduleResolution()131 public ModuleResolution moduleResolution() { 132 return moduleResolution; 133 } 134 135 /** 136 * Computes the hash of this module. Returns {@code null} if the hash 137 * cannot be computed. 138 * 139 * @throws java.io.UncheckedIOException if an I/O error occurs 140 */ computeHash(String algorithm)141 public byte[] computeHash(String algorithm) { 142 byte[] result = cachedHash; 143 if (result != null) 144 return result; 145 if (hasher == null) 146 return null; 147 cachedHash = result = hasher.generate(algorithm); 148 return result; 149 } 150 151 @Override hashCode()152 public int hashCode() { 153 int hc = hash; 154 if (hc == 0) { 155 hc = descriptor().hashCode(); 156 hc = 43 * hc + Objects.hashCode(location); 157 hc = 43 * hc + Objects.hashCode(patcher); 158 if (hc == 0) 159 hc = -1; 160 hash = hc; 161 } 162 return hc; 163 } 164 165 private int hash; 166 167 @Override equals(Object ob)168 public boolean equals(Object ob) { 169 if (!(ob instanceof ModuleReferenceImpl)) 170 return false; 171 ModuleReferenceImpl that = (ModuleReferenceImpl)ob; 172 173 // assume module content, recorded hashes, etc. are the same 174 // when the modules have equal module descriptors, are at the 175 // same location, and are patched by the same patcher. 176 return Objects.equals(this.descriptor(), that.descriptor()) 177 && Objects.equals(this.location, that.location) 178 && Objects.equals(this.patcher, that.patcher); 179 } 180 181 @Override toString()182 public String toString() { 183 StringBuilder sb = new StringBuilder(); 184 sb.append("[module "); 185 sb.append(descriptor().name()); 186 sb.append(", location="); 187 sb.append(location); 188 if (isPatched()) sb.append(" (patched)"); 189 sb.append("]"); 190 return sb.toString(); 191 } 192 193 } 194