1 /* 2 * Copyright (c) 2010, 2013, 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 /* 27 * This file is available under and governed by the GNU General Public 28 * License version 2 only, as published by the Free Software Foundation. 29 * However, the following notice accompanied the original version of this 30 * file, and Oracle licenses the original version of this file under the BSD 31 * license: 32 */ 33 /* 34 Copyright 2009-2013 Attila Szegedi 35 36 Licensed under both the Apache License, Version 2.0 (the "Apache License") 37 and the BSD License (the "BSD License"), with licensee being free to 38 choose either of the two at their discretion. 39 40 You may not use this file except in compliance with either the Apache 41 License or the BSD License. 42 43 If you choose to use this file in compliance with the Apache License, the 44 following notice applies to you: 45 46 You may obtain a copy of the Apache License at 47 48 http://www.apache.org/licenses/LICENSE-2.0 49 50 Unless required by applicable law or agreed to in writing, software 51 distributed under the License is distributed on an "AS IS" BASIS, 52 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or 53 implied. See the License for the specific language governing 54 permissions and limitations under the License. 55 56 If you choose to use this file in compliance with the BSD License, the 57 following notice applies to you: 58 59 Redistribution and use in source and binary forms, with or without 60 modification, are permitted provided that the following conditions are 61 met: 62 * Redistributions of source code must retain the above copyright 63 notice, this list of conditions and the following disclaimer. 64 * Redistributions in binary form must reproduce the above copyright 65 notice, this list of conditions and the following disclaimer in the 66 documentation and/or other materials provided with the distribution. 67 * Neither the name of the copyright holder nor the names of 68 contributors may be used to endorse or promote products derived from 69 this software without specific prior written permission. 70 71 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS 72 IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 73 TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A 74 PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL COPYRIGHT HOLDER 75 BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 76 CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 77 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR 78 BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 79 WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 80 OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 81 ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 82 */ 83 84 package jdk.internal.dynalink.support; 85 86 import java.lang.invoke.MethodHandles; 87 import java.lang.invoke.MethodHandles.Lookup; 88 import java.lang.invoke.MethodType; 89 import java.lang.ref.Reference; 90 import java.lang.ref.WeakReference; 91 import java.util.Arrays; 92 import java.util.Collections; 93 import java.util.List; 94 import java.util.Objects; 95 import java.util.StringTokenizer; 96 import java.util.WeakHashMap; 97 import jdk.internal.dynalink.CallSiteDescriptor; 98 99 /** 100 * Usable as a default factory for call site descriptor implementations. It is weakly canonicalizing, meaning it will 101 * return the same immutable call site descriptor for identical inputs, i.e. repeated requests for a descriptor 102 * signifying public lookup for "dyn:getProp:color" of type "Object(Object)" will return the same object as long as 103 * a previously created, at least softly reachable one exists. It also uses several different implementations of the 104 * {@link CallSiteDescriptor} internally, and chooses the most space-efficient one based on the input. 105 * @author Attila Szegedi 106 */ 107 public class CallSiteDescriptorFactory { 108 private static final WeakHashMap<CallSiteDescriptor, Reference<CallSiteDescriptor>> publicDescs = 109 new WeakHashMap<>(); 110 111 112 private CallSiteDescriptorFactory() { 113 } 114 115 /** 116 * Creates a new call site descriptor instance. The actual underlying class of the instance is dependent on the 117 * passed arguments to be space efficient; i.e. if you only use the public lookup, you'll get back an 118 * implementation that doesn't waste space on storing the lookup object. 119 * @param lookup the lookup that determines access rights at the call site. If your language runtime doesn't have 120 * equivalents of Java access concepts, just use {@link MethodHandles#publicLookup()}. Must not be null. 121 * @param name the name of the method at the call site. Must not be null. 122 * @param methodType the type of the method at the call site. Must not be null. 123 * @return a call site descriptor representing the input. Note that although the method name is "create", it will 124 * in fact return a weakly-referenced canonical instance. 125 */ 126 public static CallSiteDescriptor create(final Lookup lookup, final String name, final MethodType methodType) { 127 Objects.requireNonNull(name); 128 Objects.requireNonNull(methodType); 129 Objects.requireNonNull(lookup); 130 final String[] tokenizedName = tokenizeName(name); 131 if(isPublicLookup(lookup)) { 132 return getCanonicalPublicDescriptor(createPublicCallSiteDescriptor(tokenizedName, methodType)); 133 } 134 return new LookupCallSiteDescriptor(tokenizedName, methodType, lookup); 135 } 136 137 static CallSiteDescriptor getCanonicalPublicDescriptor(final CallSiteDescriptor desc) { 138 synchronized(publicDescs) { 139 final Reference<CallSiteDescriptor> ref = publicDescs.get(desc); 140 if(ref != null) { 141 final CallSiteDescriptor canonical = ref.get(); 142 if(canonical != null) { 143 return canonical; 144 } 145 } 146 publicDescs.put(desc, createReference(desc)); 147 } 148 return desc; 149 } 150 151 /** 152 * Override this to use a different kind of references for the cache 153 * @param desc desc 154 * @return reference 155 */ 156 protected static Reference<CallSiteDescriptor> createReference(final CallSiteDescriptor desc) { 157 return new WeakReference<>(desc); 158 } 159 160 private static CallSiteDescriptor createPublicCallSiteDescriptor(final String[] tokenizedName, final MethodType methodType) { 161 final int l = tokenizedName.length; 162 if(l > 0 && tokenizedName[0] == "dyn") { 163 if(l == 2) { 164 return new UnnamedDynCallSiteDescriptor(tokenizedName[1], methodType); 165 } if (l == 3) { 166 return new NamedDynCallSiteDescriptor(tokenizedName[1], tokenizedName[2], methodType); 167 } 168 } 169 return new DefaultCallSiteDescriptor(tokenizedName, methodType); 170 } 171 172 private static boolean isPublicLookup(final Lookup lookup) { 173 return lookup == MethodHandles.publicLookup(); 174 } 175 176 /** 177 * Tokenizes the composite name along colons, as well as {@link NameCodec#decode(String) demangles} and interns 178 * the tokens. The first two tokens are not demangled as they are supposed to be the naming scheme and the name of 179 * the operation which can be expected to consist of just alphabetical characters. 180 * @param name the composite name consisting of colon-separated, possibly mangled tokens. 181 * @return an array of tokens 182 */ 183 public static String[] tokenizeName(final String name) { 184 final StringTokenizer tok = new StringTokenizer(name, CallSiteDescriptor.TOKEN_DELIMITER); 185 final String[] tokens = new String[tok.countTokens()]; 186 for(int i = 0; i < tokens.length; ++i) { 187 String token = tok.nextToken(); 188 if(i > 1) { 189 token = NameCodec.decode(token); 190 } 191 tokens[i] = token.intern(); 192 } 193 return tokens; 194 } 195 196 /** 197 * Tokenizes a composite operation name along pipe characters. I.e. if you have a "dyn:getElem|getProp|getMethod" 198 * operation, returns a list of ["getElem", "getProp", "getMethod"]. The tokens are not interned. 199 * @param desc the call site descriptor with the operation 200 * @return a list of tokens 201 */ 202 public static List<String> tokenizeOperators(final CallSiteDescriptor desc) { 203 final String ops = desc.getNameToken(CallSiteDescriptor.OPERATOR); 204 final StringTokenizer tok = new StringTokenizer(ops, CallSiteDescriptor.OPERATOR_DELIMITER); 205 final int count = tok.countTokens(); 206 if(count == 1) { 207 return Collections.singletonList(ops); 208 } 209 final String[] tokens = new String[count]; 210 for(int i = 0; i < count; ++i) { 211 tokens[i] = tok.nextToken(); 212 } 213 return Arrays.asList(tokens); 214 } 215 216 /** 217 * Returns a new call site descriptor that is identical to the passed one, except that it has some parameter types 218 * removed from its method type. 219 * @param desc the original call site descriptor 220 * @param start index of the first parameter to remove 221 * @param end index of the first parameter to not remove 222 * @return a new call site descriptor with modified method type 223 */ 224 public static CallSiteDescriptor dropParameterTypes(final CallSiteDescriptor desc, final int start, final int end) { 225 return desc.changeMethodType(desc.getMethodType().dropParameterTypes(start, end)); 226 } 227 228 /** 229 * Returns a new call site descriptor that is identical to the passed one, except that it has a single parameter 230 * type changed in its method type. 231 * @param desc the original call site descriptor 232 * @param num index of the parameter to change 233 * @param nptype the new parameter type 234 * @return a new call site descriptor with modified method type 235 */ 236 public static CallSiteDescriptor changeParameterType(final CallSiteDescriptor desc, final int num, final Class<?> nptype) { 237 return desc.changeMethodType(desc.getMethodType().changeParameterType(num, nptype)); 238 } 239 240 /** 241 * Returns a new call site descriptor that is identical to the passed one, except that it has the return type 242 * changed in its method type. 243 * @param desc the original call site descriptor 244 * @param nrtype the new return type 245 * @return a new call site descriptor with modified method type 246 */ 247 public static CallSiteDescriptor changeReturnType(final CallSiteDescriptor desc, final Class<?> nrtype) { 248 return desc.changeMethodType(desc.getMethodType().changeReturnType(nrtype)); 249 } 250 251 /** 252 * Returns a new call site descriptor that is identical to the passed one, except that it has additional parameter 253 * types inserted into its method type. 254 * @param desc the original call site descriptor 255 * @param num index at which the new parameters are inserted 256 * @param ptypesToInsert the new types to insert 257 * @return a new call site descriptor with modified method type 258 */ 259 public static CallSiteDescriptor insertParameterTypes(final CallSiteDescriptor desc, final int num, final Class<?>... ptypesToInsert) { 260 return desc.changeMethodType(desc.getMethodType().insertParameterTypes(num, ptypesToInsert)); 261 } 262 263 /** 264 * Returns a new call site descriptor that is identical to the passed one, except that it has additional parameter 265 * types inserted into its method type. 266 * @param desc the original call site descriptor 267 * @param num index at which the new parameters are inserted 268 * @param ptypesToInsert the new types to insert 269 * @return a new call site descriptor with modified method type 270 */ 271 public static CallSiteDescriptor insertParameterTypes(final CallSiteDescriptor desc, final int num, final List<Class<?>> ptypesToInsert) { 272 return desc.changeMethodType(desc.getMethodType().insertParameterTypes(num, ptypesToInsert)); 273 } 274 }