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.dynalink.beans;
85
86 import java.lang.invoke.MethodHandle;
87 import java.lang.invoke.MethodType;
88 import java.security.AccessControlContext;
89 import java.security.AccessController;
90 import java.security.PrivilegedAction;
91 import java.util.LinkedList;
92 import java.util.List;
93 import jdk.dynalink.internal.AccessControlContextFactory;
94 import jdk.dynalink.internal.InternalTypeUtilities;
95 import jdk.dynalink.linker.LinkerServices;
96 import jdk.dynalink.linker.support.TypeUtilities;
97
98 /**
99 * Represents a sequence of {@link Class} objects, useful for representing method signatures. Provides value
100 * semantics for using them as map keys, as well as specificity calculations and applicability checks as per
101 * JLS.
102 */
103 final class ClassString {
104 private static final AccessControlContext GET_CLASS_LOADER_CONTEXT =
105 AccessControlContextFactory.createAccessControlContext("getClassLoader");
106
107 /**
108 * An anonymous inner class used solely to represent the "type" of null values for method applicability checking.
109 */
110 static final Class<?> NULL_CLASS = (new Object() { /* Intentionally empty */ }).getClass();
111
112 private final Class<?>[] classes;
113 private int hashCode;
114
115 ClassString(final Class<?>[] classes) {
116 this.classes = classes;
117 }
118
119 ClassString(final MethodType type) {
120 this(type.parameterArray());
121 }
122
123 @Override
124 public boolean equals(final Object other) {
125 if(!(other instanceof ClassString)) {
126 return false;
127 }
128 final Class<?>[] otherClasses = ((ClassString)other).classes;
129 if(otherClasses.length != classes.length) {
130 return false;
131 }
132 for(int i = 0; i < otherClasses.length; ++i) {
133 if(otherClasses[i] != classes[i]) {
134 return false;
135 }
136 }
137 return true;
138 }
139
140 @Override
141 public int hashCode() {
142 if(hashCode == 0) {
143 int h = 0;
144 for(int i = 0; i < classes.length; ++i) {
145 h ^= classes[i].hashCode();
146 }
147 hashCode = h;
148 }
149 return hashCode;
150 }
151
152 boolean isVisibleFrom(final ClassLoader classLoader) {
153 return AccessController.doPrivileged(new PrivilegedAction<Boolean>() {
154 @Override
155 public Boolean run() {
156 for(final Class<?> clazz: classes) {
157 if(!InternalTypeUtilities.canReferenceDirectly(classLoader, clazz.getClassLoader())) {
158 return false;
159 }
160 }
161 return true;
162 }
163 }, GET_CLASS_LOADER_CONTEXT);
164 }
165
166 List<MethodHandle> getMaximallySpecifics(final List<MethodHandle> methods, final LinkerServices linkerServices, final boolean varArg) {
167 return MaximallySpecific.getMaximallySpecificMethodHandles(getApplicables(methods, linkerServices, varArg),
168 varArg, classes, linkerServices);
169 }
170
171 /**
172 * Returns all methods that are applicable to actual parameter classes represented by this ClassString object.
173 */
174 LinkedList<MethodHandle> getApplicables(final List<MethodHandle> methods, final LinkerServices linkerServices, final boolean varArg) {
175 final LinkedList<MethodHandle> list = new LinkedList<>();
176 for(final MethodHandle member: methods) {
177 if(isApplicable(member, linkerServices, varArg)) {
178 list.add(member);
179 }
180 }
181 return list;
182 }
183
184 /**
185 * Returns true if the supplied method is applicable to actual parameter classes represented by this ClassString
186 * object.
187 *
188 */
189 private boolean isApplicable(final MethodHandle method, final LinkerServices linkerServices, final boolean varArg) {
190 final Class<?>[] formalTypes = method.type().parameterArray();
191 final int cl = classes.length;
192 final int fl = formalTypes.length - (varArg ? 1 : 0);
193 if(varArg) {
194 if(cl < fl) {
195 return false;
196 }
197 } else {
198 if(cl != fl) {
199 return false;
200 }
201 }
202 // Starting from 1 as we ignore the receiver type
203 for(int i = 1; i < fl; ++i) {
204 if(!canConvert(linkerServices, classes[i], formalTypes[i])) {
205 return false;
206 }
207 }
208 if(varArg) {
209 final Class<?> varArgType = formalTypes[fl].getComponentType();
210 for(int i = fl; i < cl; ++i) {
211 if(!canConvert(linkerServices, classes[i], varArgType)) {
212 return false;
213 }
214 }
215 }
216 return true;
217 }
218
219 private static boolean canConvert(final LinkerServices ls, final Class<?> from, final Class<?> to) {
220 if(from == NULL_CLASS) {
221 return !to.isPrimitive();
222 }
223 return ls == null ? TypeUtilities.isMethodInvocationConvertible(from, to) : ls.canConvert(from, to);
224 }
225 }