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 }