| 1 | /* |
| 2 | * Copyright 1999-2005 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 | */ |
| 25 | |
| 26 | package com.sun.tools.javac.jvm; |
| 27 | |
| 28 | import java.util.*; |
| 29 | |
| 30 | import com.sun.tools.javac.util.*; |
| 31 | import com.sun.tools.javac.code.Symbol.*; |
| 32 | import com.sun.tools.javac.code.Type; |
| 33 | |
| 34 | /** An internal structure that corresponds to the constant pool of a classfile. |
| 35 | * |
| 36 | * <p><b>This is NOT part of any API supported by Sun Microsystems. If |
| 37 | * you write code that depends on this, you do so at your own risk. |
| 38 | * This code and its internal interfaces are subject to change or |
| 39 | * deletion without notice.</b> |
| 40 | */ |
| 41 | public class Pool { |
| 42 | |
| 43 | public static final int MAX_ENTRIES = 0xFFFF; |
| 44 | public static final int MAX_STRING_LENGTH = 0xFFFF; |
| 45 | |
| 46 | /** Index of next constant to be entered. |
| 47 | */ |
| 48 | int pp; |
| 49 | |
| 50 | /** The initial pool buffer. |
| 51 | */ |
| 52 | Object[] pool; |
| 53 | |
| 54 | /** A hashtable containing all constants in the pool. |
| 55 | */ |
| 56 | Map<Object,Integer> indices; |
| 57 | |
| 58 | /** Construct a pool with given number of elements and element array. |
| 59 | */ |
| 60 | public Pool(int pp, Object[] pool) { |
| 61 | this.pp = pp; |
| 62 | this.pool = pool; |
| 63 | this.indices = new HashMap<Object,Integer>(pool.length); |
| 64 | for (int i = 1; i < pp; i++) { |
| 65 | if (pool[i] != null) indices.put(pool[i], i); |
| 66 | } |
| 67 | } |
| 68 | |
| 69 | /** Construct an empty pool. |
| 70 | */ |
| 71 | public Pool() { |
| 72 | this(1, new Object[64]); |
| 73 | } |
| 74 | |
| 75 | /** Return the number of entries in the constant pool. |
| 76 | */ |
| 77 | public int numEntries() { |
| 78 | return pp; |
| 79 | } |
| 80 | |
| 81 | /** Remove everything from this pool. |
| 82 | */ |
| 83 | public void reset() { |
| 84 | pp = 1; |
| 85 | indices.clear(); |
| 86 | } |
| 87 | |
| 88 | /** Double pool buffer in size. |
| 89 | */ |
| 90 | private void doublePool() { |
| 91 | Object[] newpool = new Object[pool.length * 2]; |
| 92 | System.arraycopy(pool, 0, newpool, 0, pool.length); |
| 93 | pool = newpool; |
| 94 | } |
| 95 | |
| 96 | /** Place an object in the pool, unless it is already there. |
| 97 | * If object is a symbol also enter its owner unless the owner is a |
| 98 | * package. Return the object's index in the pool. |
| 99 | */ |
| 100 | public int put(Object value) { |
| 101 | if (value instanceof MethodSymbol) |
| 102 | value = new Method((MethodSymbol)value); |
| 103 | else if (value instanceof VarSymbol) |
| 104 | value = new Variable((VarSymbol)value); |
| 105 | // assert !(value instanceof Type.TypeVar); |
| 106 | Integer index = indices.get(value); |
| 107 | if (index == null) { |
| 108 | // System.err.println("put " + value + " " + value.getClass());//DEBUG |
| 109 | index = pp; |
| 110 | indices.put(value, index); |
| 111 | if (pp == pool.length) doublePool(); |
| 112 | pool[pp++] = value; |
| 113 | if (value instanceof Long || value instanceof Double) { |
| 114 | if (pp == pool.length) doublePool(); |
| 115 | pool[pp++] = null; |
| 116 | } |
| 117 | } |
| 118 | return index.intValue(); |
| 119 | } |
| 120 | |
| 121 | /** Return the given object's index in the pool, |
| 122 | * or -1 if object is not in there. |
| 123 | */ |
| 124 | public int get(Object o) { |
| 125 | Integer n = indices.get(o); |
| 126 | return n == null ? -1 : n.intValue(); |
| 127 | } |
| 128 | |
| 129 | static class Method extends DelegatedSymbol { |
| 130 | MethodSymbol m; |
| 131 | Method(MethodSymbol m) { |
| 132 | super(m); |
| 133 | this.m = m; |
| 134 | } |
| 135 | public boolean equals(Object other) { |
| 136 | if (!(other instanceof Method)) return false; |
| 137 | MethodSymbol o = ((Method)other).m; |
| 138 | return |
| 139 | o.name == m.name && |
| 140 | o.owner == m.owner && |
| 141 | o.type.equals(m.type); |
| 142 | } |
| 143 | public int hashCode() { |
| 144 | return |
| 145 | m.name.hashCode() * 33 + |
| 146 | m.owner.hashCode() * 9 + |
| 147 | m.type.hashCode(); |
| 148 | } |
| 149 | } |
| 150 | |
| 151 | static class Variable extends DelegatedSymbol { |
| 152 | VarSymbol v; |
| 153 | Variable(VarSymbol v) { |
| 154 | super(v); |
| 155 | this.v = v; |
| 156 | } |
| 157 | public boolean equals(Object other) { |
| 158 | if (!(other instanceof Variable)) return false; |
| 159 | VarSymbol o = ((Variable)other).v; |
| 160 | return |
| 161 | o.name == v.name && |
| 162 | o.owner == v.owner && |
| 163 | o.type.equals(v.type); |
| 164 | } |
| 165 | public int hashCode() { |
| 166 | return |
| 167 | v.name.hashCode() * 33 + |
| 168 | v.owner.hashCode() * 9 + |
| 169 | v.type.hashCode(); |
| 170 | } |
| 171 | } |
| 172 | } |