1 /***
2  * ASM: a very small and fast Java bytecode manipulation framework
3  * Copyright (c) 2000-2007 INRIA, France Telecom
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 3. Neither the name of the copyright holders nor the names of its
15  *    contributors may be used to endorse or promote products derived from
16  *    this software without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
19  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
22  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
28  * THE POSSIBILITY OF SUCH DAMAGE.
29  */
30 package org.mockito.asm;
31 
32 /**
33  * A constant pool item. Constant pool items can be created with the 'newXXX'
34  * methods in the {@link ClassWriter} class.
35  *
36  * @author Eric Bruneton
37  */
38 final class Item {
39 
40     /**
41      * Index of this item in the constant pool.
42      */
43     int index;
44 
45     /**
46      * Type of this constant pool item. A single class is used to represent all
47      * constant pool item types, in order to minimize the bytecode size of this
48      * package. The value of this field is one of {@link ClassWriter#INT},
49      * {@link ClassWriter#LONG}, {@link ClassWriter#FLOAT},
50      * {@link ClassWriter#DOUBLE}, {@link ClassWriter#UTF8},
51      * {@link ClassWriter#STR}, {@link ClassWriter#CLASS},
52      * {@link ClassWriter#NAME_TYPE}, {@link ClassWriter#FIELD},
53      * {@link ClassWriter#METH}, {@link ClassWriter#IMETH}.
54      *
55      * Special Item types are used for Items that are stored in the ClassWriter
56      * {@link ClassWriter#typeTable}, instead of the constant pool, in order to
57      * avoid clashes with normal constant pool items in the ClassWriter constant
58      * pool's hash table. These special item types are
59      * {@link ClassWriter#TYPE_NORMAL}, {@link ClassWriter#TYPE_UNINIT} and
60      * {@link ClassWriter#TYPE_MERGED}.
61      */
62     int type;
63 
64     /**
65      * Value of this item, for an integer item.
66      */
67     int intVal;
68 
69     /**
70      * Value of this item, for a long item.
71      */
72     long longVal;
73 
74     /**
75      * First part of the value of this item, for items that do not hold a
76      * primitive value.
77      */
78     String strVal1;
79 
80     /**
81      * Second part of the value of this item, for items that do not hold a
82      * primitive value.
83      */
84     String strVal2;
85 
86     /**
87      * Third part of the value of this item, for items that do not hold a
88      * primitive value.
89      */
90     String strVal3;
91 
92     /**
93      * The hash code value of this constant pool item.
94      */
95     int hashCode;
96 
97     /**
98      * Link to another constant pool item, used for collision lists in the
99      * constant pool's hash table.
100      */
101     Item next;
102 
103     /**
104      * Constructs an uninitialized {@link Item}.
105      */
Item()106     Item() {
107     }
108 
109     /**
110      * Constructs an uninitialized {@link Item} for constant pool element at
111      * given position.
112      *
113      * @param index index of the item to be constructed.
114      */
Item(final int index)115     Item(final int index) {
116         this.index = index;
117     }
118 
119     /**
120      * Constructs a copy of the given item.
121      *
122      * @param index index of the item to be constructed.
123      * @param i the item that must be copied into the item to be constructed.
124      */
Item(final int index, final Item i)125     Item(final int index, final Item i) {
126         this.index = index;
127         type = i.type;
128         intVal = i.intVal;
129         longVal = i.longVal;
130         strVal1 = i.strVal1;
131         strVal2 = i.strVal2;
132         strVal3 = i.strVal3;
133         hashCode = i.hashCode;
134     }
135 
136     /**
137      * Sets this item to an integer item.
138      *
139      * @param intVal the value of this item.
140      */
set(final int intVal)141     void set(final int intVal) {
142         this.type = ClassWriter.INT;
143         this.intVal = intVal;
144         this.hashCode = 0x7FFFFFFF & (type + intVal);
145     }
146 
147     /**
148      * Sets this item to a long item.
149      *
150      * @param longVal the value of this item.
151      */
set(final long longVal)152     void set(final long longVal) {
153         this.type = ClassWriter.LONG;
154         this.longVal = longVal;
155         this.hashCode = 0x7FFFFFFF & (type + (int) longVal);
156     }
157 
158     /**
159      * Sets this item to a float item.
160      *
161      * @param floatVal the value of this item.
162      */
set(final float floatVal)163     void set(final float floatVal) {
164         this.type = ClassWriter.FLOAT;
165         this.intVal = Float.floatToRawIntBits(floatVal);
166         this.hashCode = 0x7FFFFFFF & (type + (int) floatVal);
167     }
168 
169     /**
170      * Sets this item to a double item.
171      *
172      * @param doubleVal the value of this item.
173      */
set(final double doubleVal)174     void set(final double doubleVal) {
175         this.type = ClassWriter.DOUBLE;
176         this.longVal = Double.doubleToRawLongBits(doubleVal);
177         this.hashCode = 0x7FFFFFFF & (type + (int) doubleVal);
178     }
179 
180     /**
181      * Sets this item to an item that do not hold a primitive value.
182      *
183      * @param type the type of this item.
184      * @param strVal1 first part of the value of this item.
185      * @param strVal2 second part of the value of this item.
186      * @param strVal3 third part of the value of this item.
187      */
set( final int type, final String strVal1, final String strVal2, final String strVal3)188     void set(
189         final int type,
190         final String strVal1,
191         final String strVal2,
192         final String strVal3)
193     {
194         this.type = type;
195         this.strVal1 = strVal1;
196         this.strVal2 = strVal2;
197         this.strVal3 = strVal3;
198         switch (type) {
199             case ClassWriter.UTF8:
200             case ClassWriter.STR:
201             case ClassWriter.CLASS:
202             case ClassWriter.TYPE_NORMAL:
203                 hashCode = 0x7FFFFFFF & (type + strVal1.hashCode());
204                 return;
205             case ClassWriter.NAME_TYPE:
206                 hashCode = 0x7FFFFFFF & (type + strVal1.hashCode()
207                         * strVal2.hashCode());
208                 return;
209                 // ClassWriter.FIELD:
210                 // ClassWriter.METH:
211                 // ClassWriter.IMETH:
212             default:
213                 hashCode = 0x7FFFFFFF & (type + strVal1.hashCode()
214                         * strVal2.hashCode() * strVal3.hashCode());
215         }
216     }
217 
218     /**
219      * Indicates if the given item is equal to this one.
220      *
221      * @param i the item to be compared to this one.
222      * @return <tt>true</tt> if the given item if equal to this one,
223      *         <tt>false</tt> otherwise.
224      */
isEqualTo(final Item i)225     boolean isEqualTo(final Item i) {
226         if (i.type == type) {
227             switch (type) {
228                 case ClassWriter.INT:
229                 case ClassWriter.FLOAT:
230                     return i.intVal == intVal;
231                 case ClassWriter.TYPE_MERGED:
232                 case ClassWriter.LONG:
233                 case ClassWriter.DOUBLE:
234                     return i.longVal == longVal;
235                 case ClassWriter.UTF8:
236                 case ClassWriter.STR:
237                 case ClassWriter.CLASS:
238                 case ClassWriter.TYPE_NORMAL:
239                     return i.strVal1.equals(strVal1);
240                 case ClassWriter.TYPE_UNINIT:
241                     return i.intVal == intVal && i.strVal1.equals(strVal1);
242                 case ClassWriter.NAME_TYPE:
243                     return i.strVal1.equals(strVal1)
244                             && i.strVal2.equals(strVal2);
245                     // ClassWriter.FIELD:
246                     // ClassWriter.METH:
247                     // ClassWriter.IMETH:
248                 default:
249                     return i.strVal1.equals(strVal1)
250                             && i.strVal2.equals(strVal2)
251                             && i.strVal3.equals(strVal3);
252             }
253         }
254         return false;
255     }
256 }
257