1/*
2 * Copyright (C) 2010 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
17#ifndef _UTILS_PROPERTY_MAP_H
18#define _UTILS_PROPERTY_MAP_H
19
20#include <utils/KeyedVector.h>
21#include <utils/String8.h>
22#include <utils/Errors.h>
23#include <utils/Tokenizer.h>
24
25namespace android {
26
27/*
28 * Provides a mechanism for passing around string-based property key / value pairs
29 * and loading them from property files.
30 *
31 * The property files have the following simple structure:
32 *
33 * # Comment
34 * key = value
35 *
36 * Keys and values are any sequence of printable ASCII characters.
37 * The '=' separates the key from the value.
38 * The key and value may not contain whitespace.
39 *
40 * The '\' character is reserved for escape sequences and is not currently supported.
41 * The '"" character is reserved for quoting and is not currently supported.
42 * Files that contain the '\' or '"' character will fail to parse.
43 *
44 * The file must not contain duplicate keys.
45 *
46 * TODO Support escape sequences and quoted values when needed.
47 */
48class PropertyMap {
49public:
50    /* Creates an empty property map. */
51    PropertyMap();
52    ~PropertyMap();
53
54    /* Clears the property map. */
55    void clear();
56
57    /* Adds a property.
58     * Replaces the property with the same key if it is already present.
59     */
60    void addProperty(const String8& key, const String8& value);
61
62    /* Returns true if the property map contains the specified key. */
63    bool hasProperty(const String8& key) const;
64
65    /* Gets the value of a property and parses it.
66     * Returns true and sets outValue if the key was found and its value was parsed successfully.
67     * Otherwise returns false and does not modify outValue.  (Also logs a warning.)
68     */
69    bool tryGetProperty(const String8& key, String8& outValue) const;
70    bool tryGetProperty(const String8& key, bool& outValue) const;
71    bool tryGetProperty(const String8& key, int32_t& outValue) const;
72    bool tryGetProperty(const String8& key, float& outValue) const;
73
74    /* Adds all values from the specified property map. */
75    void addAll(const PropertyMap* map);
76
77    /* Gets the underlying property map. */
78    inline const KeyedVector<String8, String8>& getProperties() const { return mProperties; }
79
80    /* Loads a property map from a file. */
81    static status_t load(const String8& filename, PropertyMap** outMap);
82
83private:
84    class Parser {
85        PropertyMap* mMap;
86        Tokenizer* mTokenizer;
87
88    public:
89        Parser(PropertyMap* map, Tokenizer* tokenizer);
90        ~Parser();
91        status_t parse();
92
93    private:
94        status_t parseType();
95        status_t parseKey();
96        status_t parseKeyProperty();
97        status_t parseModifier(const String8& token, int32_t* outMetaState);
98        status_t parseCharacterLiteral(char16_t* outCharacter);
99    };
100
101    KeyedVector<String8, String8> mProperties;
102};
103
104} // namespace android
105
106#endif // _UTILS_PROPERTY_MAP_H
107