|
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 } |