src/jdk/internal/dynalink/support/AbstractCallSiteDescriptor.java

Thu, 14 Feb 2013 13:22:26 +0100

author
attila
date
Thu, 14 Feb 2013 13:22:26 +0100
changeset 90
5a820fb11814
child 101
f8221ce53c2e
permissions
-rw-r--r--

8008085: Integrate Dynalink source code into Nashorn codebase
Reviewed-by: jlaskey, lagergren, sundar

     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  */
    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
    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.
    40    You may not use this file except in compliance with either the Apache
    41    License or the BSD License.
    43    If you choose to use this file in compliance with the Apache License, the
    44    following notice applies to you:
    46        You may obtain a copy of the Apache License at
    48            http://www.apache.org/licenses/LICENSE-2.0
    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.
    56    If you choose to use this file in compliance with the BSD License, the
    57    following notice applies to you:
    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.
    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 */
    84 package jdk.internal.dynalink.support;
    86 import java.lang.invoke.MethodHandles;
    87 import java.lang.invoke.MethodHandles.Lookup;
    88 import java.util.Objects;
    89 import jdk.internal.dynalink.CallSiteDescriptor;
    92 /**
    93  * A base class for call site descriptor implementations. Provides reconstruction of the name from the tokens, as well
    94  * as a generally useful {@code equals} and {@code hashCode} methods.
    95  * @author Attila Szegedi
    96  */
    97 public abstract class AbstractCallSiteDescriptor implements CallSiteDescriptor {
    99     @Override
   100     public String getName() {
   101         return appendName(new StringBuilder(getNameLength())).toString();
   102     }
   104    @Override
   105    public Lookup getLookup() {
   106        return MethodHandles.publicLookup();
   107    }
   109     @Override
   110     public boolean equals(Object obj) {
   111         return obj instanceof CallSiteDescriptor && equals((CallSiteDescriptor)obj);
   112     }
   114     /**
   115      * Returns true if this call site descriptor is equal to the passed call site descriptor.
   116      * @param csd the other call site descriptor.
   117      * @return true if they are equal.
   118      */
   119     public boolean equals(CallSiteDescriptor csd) {
   120         if(csd == null) {
   121             return false;
   122         }
   123         if(csd == this) {
   124             return true;
   125         }
   126         final int ntc = getNameTokenCount();
   127         if(ntc != csd.getNameTokenCount()) {
   128             return false;
   129         }
   130         for(int i = ntc; i-- > 0;) { // Reverse order as variability is higher at the end
   131             if(!Objects.equals(getNameToken(i), csd.getNameToken(i))) {
   132                 return false;
   133             }
   134         }
   135         if(!getMethodType().equals(csd.getMethodType())) {
   136             return false;
   137         }
   138         return lookupsEqual(getLookup(), csd.getLookup());
   139     }
   141     @Override
   142     public int hashCode() {
   143         final int c = getNameTokenCount();
   144         int h = 0;
   145         for(int i = 0; i < c; ++i) {
   146             h = h * 31 + getNameToken(i).hashCode();
   147         }
   148         return h * 31 + getMethodType().hashCode();
   149     }
   151     @Override
   152     public String toString() {
   153         final String mt = getMethodType().toString();
   154         final String l = getLookup().toString();
   155         final StringBuilder b = new StringBuilder(l.length() + 1 + mt.length() + getNameLength());
   156         return appendName(b).append(mt).append("@").append(l).toString();
   157     }
   159     private int getNameLength() {
   160         final int c = getNameTokenCount();
   161         int l = 0;
   162         for(int i = 0; i < c; ++i) {
   163             l += getNameToken(i).length();
   164         }
   165         return l +  c - 1;
   166     }
   168     private StringBuilder appendName(StringBuilder b) {
   169         b.append(getNameToken(0));
   170         final int c = getNameTokenCount();
   171         for(int i = 1; i < c; ++i) {
   172             b.append(':').append(getNameToken(i));
   173         }
   174         return b;
   175     }
   177     private static boolean lookupsEqual(Lookup l1, Lookup l2) {
   178         if(l1 == l2) {
   179             return true;
   180         }
   181         if(l1.lookupClass() != l2.lookupClass()) {
   182             return false;
   183         }
   184         return l1.lookupModes() == l2.lookupModes();
   185     }
   186 }

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