src/share/classes/com/sun/tools/javac/jvm/Pool.java

Thu, 02 Oct 2008 19:58:40 -0700

author
xdono
date
Thu, 02 Oct 2008 19:58:40 -0700
changeset 117
24a47c3062fe
parent 104
5e89c4ca637c
child 554
9d9f26857129
permissions
-rw-r--r--

6754988: Update copyright year
Summary: Update for files that have been modified starting July 2008
Reviewed-by: ohair, tbell

     1 /*
     2  * Copyright 1999-2008 Sun Microsystems, Inc.  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.  Sun designates this
     8  * particular file as subject to the "Classpath" exception as provided
     9  * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
    22  * CA 95054 USA or visit www.sun.com if you need additional information or
    23  * have any questions.
    24  */
    26 package com.sun.tools.javac.jvm;
    28 import java.util.*;
    30 import com.sun.tools.javac.code.Symbol.*;
    32 /** An internal structure that corresponds to the constant pool of a classfile.
    33  *
    34  *  <p><b>This is NOT part of any API supported by Sun Microsystems.  If
    35  *  you write code that depends on this, you do so at your own risk.
    36  *  This code and its internal interfaces are subject to change or
    37  *  deletion without notice.</b>
    38  */
    39 public class Pool {
    41     public static final int MAX_ENTRIES = 0xFFFF;
    42     public static final int MAX_STRING_LENGTH = 0xFFFF;
    44     /** Index of next constant to be entered.
    45      */
    46     int pp;
    48     /** The initial pool buffer.
    49      */
    50     Object[] pool;
    52     /** A hashtable containing all constants in the pool.
    53      */
    54     Map<Object,Integer> indices;
    56     /** Construct a pool with given number of elements and element array.
    57      */
    58     public Pool(int pp, Object[] pool) {
    59         this.pp = pp;
    60         this.pool = pool;
    61         this.indices = new HashMap<Object,Integer>(pool.length);
    62         for (int i = 1; i < pp; i++) {
    63             if (pool[i] != null) indices.put(pool[i], i);
    64         }
    65     }
    67     /** Construct an empty pool.
    68      */
    69     public Pool() {
    70         this(1, new Object[64]);
    71     }
    73     /** Return the number of entries in the constant pool.
    74      */
    75     public int numEntries() {
    76         return pp;
    77     }
    79     /** Remove everything from this pool.
    80      */
    81     public void reset() {
    82         pp = 1;
    83         indices.clear();
    84     }
    86     /** Double pool buffer in size.
    87      */
    88     private void doublePool() {
    89         Object[] newpool = new Object[pool.length * 2];
    90         System.arraycopy(pool, 0, newpool, 0, pool.length);
    91         pool = newpool;
    92     }
    94     /** Place an object in the pool, unless it is already there.
    95      *  If object is a symbol also enter its owner unless the owner is a
    96      *  package.  Return the object's index in the pool.
    97      */
    98     public int put(Object value) {
    99         if (value instanceof MethodSymbol)
   100             value = new Method((MethodSymbol)value);
   101         else if (value instanceof VarSymbol)
   102             value = new Variable((VarSymbol)value);
   103 //      assert !(value instanceof Type.TypeVar);
   104         Integer index = indices.get(value);
   105         if (index == null) {
   106 //          System.err.println("put " + value + " " + value.getClass());//DEBUG
   107             index = pp;
   108             indices.put(value, index);
   109             if (pp == pool.length) doublePool();
   110             pool[pp++] = value;
   111             if (value instanceof Long || value instanceof Double) {
   112                 if (pp == pool.length) doublePool();
   113                 pool[pp++] = null;
   114             }
   115         }
   116         return index.intValue();
   117     }
   119     /** Return the given object's index in the pool,
   120      *  or -1 if object is not in there.
   121      */
   122     public int get(Object o) {
   123         Integer n = indices.get(o);
   124         return n == null ? -1 : n.intValue();
   125     }
   127     static class Method extends DelegatedSymbol {
   128         MethodSymbol m;
   129         Method(MethodSymbol m) {
   130             super(m);
   131             this.m = m;
   132         }
   133         public boolean equals(Object other) {
   134             if (!(other instanceof Method)) return false;
   135             MethodSymbol o = ((Method)other).m;
   136             return
   137                 o.name == m.name &&
   138                 o.owner == m.owner &&
   139                 o.type.equals(m.type);
   140         }
   141         public int hashCode() {
   142             return
   143                 m.name.hashCode() * 33 +
   144                 m.owner.hashCode() * 9 +
   145                 m.type.hashCode();
   146         }
   147     }
   149     static class Variable extends DelegatedSymbol {
   150         VarSymbol v;
   151         Variable(VarSymbol v) {
   152             super(v);
   153             this.v = v;
   154         }
   155         public boolean equals(Object other) {
   156             if (!(other instanceof Variable)) return false;
   157             VarSymbol o = ((Variable)other).v;
   158             return
   159                 o.name == v.name &&
   160                 o.owner == v.owner &&
   161                 o.type.equals(v.type);
   162         }
   163         public int hashCode() {
   164             return
   165                 v.name.hashCode() * 33 +
   166                 v.owner.hashCode() * 9 +
   167                 v.type.hashCode();
   168         }
   169     }
   170 }

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