AnnotationSetItem.java revision 83b80f81d311b233188c281059aad4a9f5e8b4e6 
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.Util.Input;
32import org.jf.dexlib.Util.AnnotatedOutput;
33
34public class AnnotationSetItem extends Item<AnnotationSetItem> {
35    private int hashCode = 0;
36
37    private AnnotationItem[] annotations;
38
39    /**
40     * Creates a new uninitialized <code>AnnotationSetItem</code>
41     * @param dexFile The <code>DexFile</code> that this item belongs to
42     */
43    protected AnnotationSetItem(DexFile dexFile) {
44        super(dexFile);
45    }
46
47    /**
48     * Creates a new <code>AnnotationSetItem</code> for the given annotations
49     * @param dexFile The <code>DexFile</code> that this item belongs to
50     * @param annotations The annotations for this <code>AnnotationSetItem</code>
51     */
52    private AnnotationSetItem(DexFile dexFile, AnnotationItem[] annotations) {
53        super(dexFile);
54        this.annotations = annotations;
55    }
56
57    /**
58     * Returns an <code>AnnotationSetItem</code> for the given annotations, and that has been interned into the given
59     * <code>DexFile</code>
60     * @param dexFile The <code>DexFile</code> that this item belongs to
61     * @param annotations The annotations for this <code>AnnotationSetItem</code>
62     * @return an <code>AnnotationSetItem</code> for the given annotations
63     */
64    public static AnnotationSetItem getInternedAnnotationSetItem(DexFile dexFile, AnnotationItem[] annotations) {
65        AnnotationSetItem annotationSetItem = new AnnotationSetItem(dexFile, annotations);
66        return dexFile.AnnotationSetsSection.intern(annotationSetItem);
67    }
68
69    /** {@inheritDoc} */
70    protected void readItem(Input in, ReadContext readContext) {
71        annotations = new AnnotationItem[in.readInt()];
72
73        for (int i=0; i<annotations.length; i++) {
74            annotations[i] = (AnnotationItem)readContext.getOffsettedItemByOffset(ItemType.TYPE_ANNOTATION_ITEM,
75                    in.readInt());
76        }
77    }
78
79    /** {@inheritDoc} */
80    protected int placeItem(int offset) {
81        return offset + 4 + annotations.length * 4;
82    }
83
84    /** {@inheritDoc} */
85    protected void writeItem(AnnotatedOutput out) {
86        if (out.annotates()) {
87            out.annotate(4, "size");
88            for (int i=0; i<annotations.length; i++) {
89                out.annotate(4, "annotation_off");
90            }
91        }
92        out.writeInt(annotations.length);
93        for (AnnotationItem annotationItem: annotations) {
94            out.writeInt(annotationItem.getOffset());
95        }
96    }
97
98    /** {@inheritDoc} */
99    public ItemType getItemType() {
100        return ItemType.TYPE_ANNOTATION_SET_ITEM;
101    }
102
103    /** {@inheritDoc} */
104    public String getConciseIdentity() {
105        return "annotation_set_item @0x" + Integer.toHexString(getOffset());
106    }
107
108/** {@inheritDoc} */
109    public int compareTo(AnnotationSetItem o) {
110        if (o == null) {
111            return 1;
112        }
113
114        int comp = annotations.length - o.annotations.length;
115        if (comp == 0) {
116            for (int i=0; i<annotations.length; i++) {
117                comp = annotations[i].compareTo(o.annotations[i]);
118                if (comp != 0) {
119                    return comp;
120                }
121            }
122        }
123        return comp;
124    }
125
126    /**
127     * @return An array of the <code>AnnotationItem</code> objects in this <code>AnnotationSetItem</code>
128     */
129    public AnnotationItem[] getAnnotations() {
130        return annotations;
131    }
132
133    /**
134     * calculate and cache the hashcode
135     */
136    private void calcHashCode() {
137        hashCode = 0;
138        for (AnnotationItem annotationItem: annotations) {
139            hashCode = hashCode * 31 + annotationItem.hashCode();
140        }
141    }
142
143    @Override
144    public int hashCode() {
145        //there's a small possibility that the actual hash code will be 0. If so, we'll
146        //just end up recalculating it each time
147        if (hashCode == 0)
148            calcHashCode();
149        return hashCode;
150    }
151
152    @Override
153    public boolean equals(Object o) {
154        if (this==o) {
155            return true;
156        }
157        if (o==null || !this.getClass().equals(o.getClass())) {
158            return false;
159        }
160
161        AnnotationSetItem other = (AnnotationSetItem)o;
162        return (this.compareTo(other) == 0);
163    }
164}
165