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 <android-base/result.h> 21 #include <utils/Errors.h> 22 #include <utils/KeyedVector.h> 23 #include <utils/String8.h> 24 #include <utils/Tokenizer.h> 25 26 namespace android { 27 28 /* 29 * Provides a mechanism for passing around string-based property key / value pairs 30 * and loading them from property files. 31 * 32 * The property files have the following simple structure: 33 * 34 * # Comment 35 * key = value 36 * 37 * Keys and values are any sequence of printable ASCII characters. 38 * The '=' separates the key from the value. 39 * The key and value may not contain whitespace. 40 * 41 * The '\' character is reserved for escape sequences and is not currently supported. 42 * The '"" character is reserved for quoting and is not currently supported. 43 * Files that contain the '\' or '"' character will fail to parse. 44 * 45 * The file must not contain duplicate keys. 46 * 47 * TODO Support escape sequences and quoted values when needed. 48 */ 49 class PropertyMap { 50 public: 51 /* Creates an empty property map. */ 52 PropertyMap(); 53 ~PropertyMap(); 54 55 /* Clears the property map. */ 56 void clear(); 57 58 /* Adds a property. 59 * Replaces the property with the same key if it is already present. 60 */ 61 void addProperty(const String8& key, const String8& value); 62 63 /* Returns true if the property map contains the specified key. */ 64 bool hasProperty(const String8& key) const; 65 66 /* Gets the value of a property and parses it. 67 * Returns true and sets outValue if the key was found and its value was parsed successfully. 68 * Otherwise returns false and does not modify outValue. (Also logs a warning.) 69 */ 70 bool tryGetProperty(const String8& key, String8& outValue) const; 71 bool tryGetProperty(const String8& key, bool& outValue) const; 72 bool tryGetProperty(const String8& key, int32_t& outValue) const; 73 bool tryGetProperty(const String8& key, float& outValue) const; 74 75 /* Adds all values from the specified property map. */ 76 void addAll(const PropertyMap* map); 77 78 /* Gets the underlying property map. */ getProperties()79 inline const KeyedVector<String8, String8>& getProperties() const { return mProperties; } 80 81 /* Loads a property map from a file. */ 82 static android::base::Result<std::unique_ptr<PropertyMap>> load(const char* filename); 83 84 private: 85 class Parser { 86 PropertyMap* mMap; 87 Tokenizer* mTokenizer; 88 89 public: 90 Parser(PropertyMap* map, Tokenizer* tokenizer); 91 ~Parser(); 92 status_t parse(); 93 94 private: 95 status_t parseType(); 96 status_t parseKey(); 97 status_t parseKeyProperty(); 98 status_t parseModifier(const String8& token, int32_t* outMetaState); 99 status_t parseCharacterLiteral(char16_t* outCharacter); 100 }; 101 102 KeyedVector<String8, String8> mProperties; 103 }; 104 105 } // namespace android 106 107 #endif // _UTILS_PROPERTY_MAP_H 108