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.beans;

    85 

    86 import java.lang.invoke.MethodHandle;

    87 import jdk.internal.dynalink.linker.GuardedInvocation;

    88 

    89 /**

    90  * Represents one component for a GuardedInvocation of a potentially composite operation of an

    91  * {@link AbstractJavaLinker}. In addition to holding a guarded invocation, it holds semantic information about its

    92  * guard. All guards produced in the AbstractJavaLinker are either "Class.isInstance()" or "getClass() == clazz"

    93  * expressions. This allows choosing the most restrictive guard as the guard for the composition of two components.

    94  */

    95 class GuardedInvocationComponent {

    96     enum ValidationType {

    97         NONE, // No guard; the operation can be linked unconditionally (quite rare); least strict.

    98         INSTANCE_OF, // "validatorClass.isInstance(obj)" guard

    99         EXACT_CLASS, // "obj.getClass() == validatorClass" guard; most strict.

   100         IS_ARRAY, // "obj.getClass().isArray()"

   101     }

   102 

   103     private final GuardedInvocation guardedInvocation;

   104     private final Validator validator;

   105 

   106     GuardedInvocationComponent(final MethodHandle invocation) {

   107         this(invocation, null, ValidationType.NONE);

   108     }

   109 

   110     GuardedInvocationComponent(final MethodHandle invocation, final MethodHandle guard, final ValidationType validationType) {

   111         this(invocation, guard, null, validationType);

   112     }

   113 

   114     GuardedInvocationComponent(final MethodHandle invocation, final MethodHandle guard, final Class<?> validatorClass,

   115             final ValidationType validationType) {

   116         this(invocation, guard, new Validator(validatorClass, validationType));

   117     }

   118 

   119     GuardedInvocationComponent(final GuardedInvocation guardedInvocation, final Class<?> validatorClass,

   120             final ValidationType validationType) {

   121         this(guardedInvocation, new Validator(validatorClass, validationType));

   122     }

   123 

   124     GuardedInvocationComponent replaceInvocation(final MethodHandle newInvocation) {

   125         return replaceInvocation(newInvocation, guardedInvocation.getGuard());

   126     }

   127 

   128     GuardedInvocationComponent replaceInvocation(final MethodHandle newInvocation, final MethodHandle newGuard) {

   129         return new GuardedInvocationComponent(guardedInvocation.replaceMethods(newInvocation,

   130                 newGuard), validator);

   131     }

   132 

   133     private GuardedInvocationComponent(final MethodHandle invocation, final MethodHandle guard, final Validator validator) {

   134         this(new GuardedInvocation(invocation, guard), validator);

   135     }

   136 

   137     private GuardedInvocationComponent(final GuardedInvocation guardedInvocation, final Validator validator) {

   138         this.guardedInvocation = guardedInvocation;

   139         this.validator = validator;

   140     }

   141 

   142     GuardedInvocation getGuardedInvocation() {

   143         return guardedInvocation;

   144     }

   145 

   146     Class<?> getValidatorClass() {

   147         return validator.validatorClass;

   148     }

   149 

   150     ValidationType getValidationType() {

   151         return validator.validationType;

   152     }

   153 

   154     GuardedInvocationComponent compose(final MethodHandle compositeInvocation, final MethodHandle otherGuard,

   155             final Class<?> otherValidatorClass, final ValidationType otherValidationType) {

   156         final Validator compositeValidator = validator.compose(new Validator(otherValidatorClass, otherValidationType));

   157         final MethodHandle compositeGuard = compositeValidator == validator ? guardedInvocation.getGuard() : otherGuard;

   158         return new GuardedInvocationComponent(compositeInvocation, compositeGuard, compositeValidator);

   159     }

   160 

   161     private static class Validator {

   162         /*private*/ final Class<?> validatorClass;

   163         /*private*/ final ValidationType validationType;

   164 

   165         Validator(final Class<?> validatorClass, final ValidationType validationType) {

   166             this.validatorClass = validatorClass;

   167             this.validationType = validationType;

   168         }

   169 

   170         Validator compose(final Validator other) {

   171             if(other.validationType == ValidationType.NONE) {

   172                 return this;

   173             }

   174             switch(validationType) {

   175                 case NONE:

   176                     return other;

   177                 case INSTANCE_OF:

   178                     switch(other.validationType) {

   179                         case INSTANCE_OF:

   180                             if(isAssignableFrom(other)) {

   181                                 return other;

   182                             } else if(other.isAssignableFrom(this)) {

   183                                 return this;

   184                             }

   185                             break;

   186                         case EXACT_CLASS:

   187                             if(isAssignableFrom(other)) {

   188                                 return other;

   189                             }

   190                             break;

   191                         case IS_ARRAY:

   192                             if(validatorClass.isArray()) {

   193                                 return this;

   194                             }

   195                             break;

   196                         default:

   197                             throw new AssertionError();

   198                     }

   199                     break;

   200                 case EXACT_CLASS:

   201                     switch(other.validationType) {

   202                         case INSTANCE_OF:

   203                             if(other.isAssignableFrom(this)) {

   204                                 return this;

   205                             }

   206                             break;

   207                         case EXACT_CLASS:

   208                             if(validatorClass == other.validatorClass) {

   209                                 return this;

   210                             }

   211                             break;

   212                         case IS_ARRAY:

   213                             if(validatorClass.isArray()) {

   214                                 return this;

   215                             }

   216                             break;

   217                         default:

   218                             throw new AssertionError();

   219                     }

   220                     break;

   221                 case IS_ARRAY:

   222                     switch(other.validationType) {

   223                         case INSTANCE_OF:

   224                         case EXACT_CLASS:

   225                             if(other.validatorClass.isArray()) {

   226                                 return other;

   227                             }

   228                             break;

   229                         case IS_ARRAY:

   230                             return this;

   231                         default:

   232                             throw new AssertionError();

   233                     }

   234                     break;

   235                 default:

   236                     throw new AssertionError();

   237             }

   238             throw new AssertionError("Incompatible composition " + this + " vs " + other);

   239         }

   240 

   241         private boolean isAssignableFrom(final Validator other) {

   242             return validatorClass.isAssignableFrom(other.validatorClass);

   243         }

   244 

   245         @Override

   246         public String toString() {

   247             return "Validator[" + validationType + (validatorClass == null ? "" : (" " + validatorClass.getName())) + "]";

   248         }

   249     }

   250 }