1/*
2 * Copyright (C) 2007 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package com.android.dx.dex.file;
18
19import com.android.dx.rop.cst.Constant;
20import com.android.dx.rop.cst.CstNat;
21import com.android.dx.rop.cst.CstString;
22import com.android.dx.util.AnnotatedOutput;
23import com.android.dx.util.Hex;
24import java.util.Collection;
25import java.util.TreeMap;
26
27/**
28 * Strings list section of a {@code .dex} file.
29 */
30public final class StringIdsSection
31        extends UniformItemSection {
32    /**
33     * {@code non-null;} map from string constants to {@link
34     * StringIdItem} instances
35     */
36    private final TreeMap<CstString, StringIdItem> strings;
37
38    /**
39     * Constructs an instance. The file offset is initially unknown.
40     *
41     * @param file {@code non-null;} file that this instance is part of
42     */
43    public StringIdsSection(DexFile file) {
44        super("string_ids", file, 4);
45
46        strings = new TreeMap<CstString, StringIdItem>();
47    }
48
49    /** {@inheritDoc} */
50    @Override
51    public Collection<? extends Item> items() {
52        return strings.values();
53    }
54
55    /** {@inheritDoc} */
56    @Override
57    public IndexedItem get(Constant cst) {
58        if (cst == null) {
59            throw new NullPointerException("cst == null");
60        }
61
62        throwIfNotPrepared();
63
64        IndexedItem result = strings.get((CstString) cst);
65
66        if (result == null) {
67            throw new IllegalArgumentException("not found");
68        }
69
70        return result;
71    }
72
73    /**
74     * Writes the portion of the file header that refers to this instance.
75     *
76     * @param out {@code non-null;} where to write
77     */
78    public void writeHeaderPart(AnnotatedOutput out) {
79        throwIfNotPrepared();
80
81        int sz = strings.size();
82        int offset = (sz == 0) ? 0 : getFileOffset();
83
84        if (out.annotates()) {
85            out.annotate(4, "string_ids_size: " + Hex.u4(sz));
86            out.annotate(4, "string_ids_off:  " + Hex.u4(offset));
87        }
88
89        out.writeInt(sz);
90        out.writeInt(offset);
91    }
92
93    /**
94     * Interns an element into this instance.
95     *
96     * @param string {@code non-null;} the string to intern, as a regular Java
97     * {@code String}
98     * @return {@code non-null;} the interned string
99     */
100    public StringIdItem intern(String string) {
101        return intern(new StringIdItem(new CstString(string)));
102    }
103
104    /**
105     * Interns an element into this instance.
106     *
107     * @param string {@code non-null;} the string to intern, as a constant
108     * @return {@code non-null;} the interned string
109     */
110    public StringIdItem intern(CstString string) {
111        return intern(new StringIdItem(string));
112    }
113
114    /**
115     * Interns an element into this instance.
116     *
117     * @param string {@code non-null;} the string to intern
118     * @return {@code non-null;} the interned string
119     */
120    public synchronized StringIdItem intern(StringIdItem string) {
121        if (string == null) {
122            throw new NullPointerException("string == null");
123        }
124
125        throwIfPrepared();
126
127        CstString value = string.getValue();
128        StringIdItem already = strings.get(value);
129
130        if (already != null) {
131            return already;
132        }
133
134        strings.put(value, string);
135        return string;
136    }
137
138    /**
139     * Interns the components of a name-and-type into this instance.
140     *
141     * @param nat {@code non-null;} the name-and-type
142     */
143    public synchronized void intern(CstNat nat) {
144        intern(nat.getName());
145        intern(nat.getDescriptor());
146    }
147
148    /**
149     * Gets the index of the given string, which must have been added
150     * to this instance.
151     *
152     * @param string {@code non-null;} the string to look up
153     * @return {@code >= 0;} the string's index
154     */
155    public int indexOf(CstString string) {
156        if (string == null) {
157            throw new NullPointerException("string == null");
158        }
159
160        throwIfNotPrepared();
161
162        StringIdItem s = strings.get(string);
163
164        if (s == null) {
165            throw new IllegalArgumentException("not found");
166        }
167
168        return s.getIndex();
169    }
170
171    /** {@inheritDoc} */
172    @Override
173    protected void orderItems() {
174        int idx = 0;
175
176        for (StringIdItem s : strings.values()) {
177            s.setIndex(idx);
178            idx++;
179        }
180    }
181}
182