AnnotationItem.java revision 928790f2939e0eec7ab2e4653a19c6c27a113634 
1/*
2 * [The "BSD licence"]
3 * Copyright (c) 2009 Ben Gruver
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. The name of the author may not be used to endorse or promote products
15 *    derived from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29package org.jf.dexlib;
30
31import org.jf.dexlib.EncodedValue.AnnotationEncodedSubValue;
32import org.jf.dexlib.Util.Input;
33import org.jf.dexlib.Util.AnnotatedOutput;
34
35public class AnnotationItem extends Item<AnnotationItem> {
36    private int hashCode = 0;
37
38    private AnnotationVisibility visibility;
39    private AnnotationEncodedSubValue annotationValue;
40
41    /**
42     * Creates a new uninitialized <code>AnnotationItem</code>
43     * @param dexFile The <code>DexFile</code> that this item belongs to
44     */
45    protected AnnotationItem(DexFile dexFile) {
46        super(dexFile);
47    }
48
49    /**
50     * Creates a new <code>AnnotationItem</code> with the given values
51     * @param dexFile The <code>DexFile</code> that this item belongs to
52     * @param visibility The visibility of this annotation
53     * @param annotationValue The value of this annotation
54     */
55    private AnnotationItem(DexFile dexFile, AnnotationVisibility visibility,
56                           AnnotationEncodedSubValue annotationValue) {
57        super(dexFile);
58        this.visibility = visibility;
59        this.annotationValue = annotationValue;
60    }
61
62    /**
63     * Returns an <code>AnnotationItem</code> for the given values, and that has been interned into the given
64     * <code>DexFile</code>
65     * @param dexFile The <code>DexFile</code> that this item belongs to
66     * @param visibility The visibility of this annotation
67     * @param annotationValue The value of this annotation
68     * @return an <code>AnnotationItem</code> for the given values, and that has been interned into the given
69     * <code>DexFile</code>
70     */
71    public static AnnotationItem internAnnotationItem(DexFile dexFile, AnnotationVisibility visibility,
72                           AnnotationEncodedSubValue annotationValue) {
73        AnnotationItem annotationItem = new AnnotationItem(dexFile, visibility, annotationValue);
74        return dexFile.AnnotationsSection.intern(annotationItem);
75    }
76
77    /** {@inheritDoc} */
78    protected void readItem(Input in, ReadContext readContext) {
79        visibility = AnnotationVisibility.fromByte(in.readByte());
80        annotationValue = new AnnotationEncodedSubValue(dexFile, in);
81    }
82
83    /** {@inheritDoc} */
84    protected int placeItem(int offset) {
85        return annotationValue.placeValue(offset + 1);
86    }
87
88    /** {@inheritDoc} */
89    protected void writeItem(AnnotatedOutput out) {
90        if (out.annotates()) {
91            out.annotate("visibility: " + visibility.name());
92            out.writeByte(visibility.value);
93            annotationValue.writeValue(out);
94        }else {
95            out.writeByte(visibility.value);
96            annotationValue.writeValue(out);
97        }
98    }
99
100    /** {@inheritDoc} */
101    public ItemType getItemType() {
102        return ItemType.TYPE_ANNOTATION_ITEM;
103    }
104
105    /** {@inheritDoc} */
106    public String getConciseIdentity() {
107        return "annotation_item @0x" + Integer.toHexString(getOffset());
108    }
109
110    /** {@inheritDoc} */
111    public int compareTo(AnnotationItem o) {
112        int comp = visibility.value - o.visibility.value;
113        if (comp == 0) {
114            comp = annotationValue.compareTo(o.annotationValue);
115        }
116        return comp;
117    }
118
119    /**
120     * @return The visibility of this annotation
121     */
122    public AnnotationVisibility getVisibility() {
123        return visibility;
124    }
125
126    /**
127     * @return The encoded annotation value of this annotation
128     */
129    public AnnotationEncodedSubValue getEncodedAnnotation() {
130        return annotationValue;
131    }
132
133    /**
134     * calculate and cache the hashcode
135     */
136    private void calcHashCode() {
137        hashCode = visibility.value;
138        hashCode = hashCode * 31 + annotationValue.hashCode();
139    }
140
141    @Override
142    public int hashCode() {
143        //there's a small possibility that the actual hash code will be 0. If so, we'll
144        //just end up recalculating it each time
145        if (hashCode == 0)
146            calcHashCode();
147        return hashCode;
148    }
149
150    @Override
151    public boolean equals(Object o) {
152        if (this==o) {
153            return true;
154        }
155        if (o==null || !this.getClass().equals(o.getClass())) {
156            return false;
157        }
158
159        AnnotationItem other = (AnnotationItem)o;
160        return visibility == other.visibility && annotationValue.equals(other.annotationValue);
161    }
162}
163