platform_system_core/include/utils/PropertyMap.h

107 lines
3.4 KiB
C++

/*
* Copyright (C) 2010 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef _UTILS_PROPERTY_MAP_H
#define _UTILS_PROPERTY_MAP_H
#include <utils/KeyedVector.h>
#include <utils/String8.h>
#include <utils/Errors.h>
#include <utils/Tokenizer.h>
namespace android {
/*
* Provides a mechanism for passing around string-based property key / value pairs
* and loading them from property files.
*
* The property files have the following simple structure:
*
* # Comment
* key = value
*
* Keys and values are any sequence of printable ASCII characters.
* The '=' separates the key from the value.
* The key and value may not contain whitespace.
*
* The '\' character is reserved for escape sequences and is not currently supported.
* The '"" character is reserved for quoting and is not currently supported.
* Files that contain the '\' or '"' character will fail to parse.
*
* The file must not contain duplicate keys.
*
* TODO Support escape sequences and quoted values when needed.
*/
class PropertyMap {
public:
/* Creates an empty property map. */
PropertyMap();
~PropertyMap();
/* Clears the property map. */
void clear();
/* Adds a property.
* Replaces the property with the same key if it is already present.
*/
void addProperty(const String8& key, const String8& value);
/* Returns true if the property map contains the specified key. */
bool hasProperty(const String8& key) const;
/* Gets the value of a property and parses it.
* Returns true and sets outValue if the key was found and its value was parsed successfully.
* Otherwise returns false and does not modify outValue. (Also logs a warning.)
*/
bool tryGetProperty(const String8& key, String8& outValue) const;
bool tryGetProperty(const String8& key, bool& outValue) const;
bool tryGetProperty(const String8& key, int32_t& outValue) const;
bool tryGetProperty(const String8& key, float& outValue) const;
/* Adds all values from the specified property map. */
void addAll(const PropertyMap* map);
/* Gets the underlying property map. */
inline const KeyedVector<String8, String8>& getProperties() const { return mProperties; }
/* Loads a property map from a file. */
static status_t load(const String8& filename, PropertyMap** outMap);
private:
class Parser {
PropertyMap* mMap;
Tokenizer* mTokenizer;
public:
Parser(PropertyMap* map, Tokenizer* tokenizer);
~Parser();
status_t parse();
private:
status_t parseType();
status_t parseKey();
status_t parseKeyProperty();
status_t parseModifier(const String8& token, int32_t* outMetaState);
status_t parseCharacterLiteral(char16_t* outCharacter);
};
KeyedVector<String8, String8> mProperties;
};
} // namespace android
#endif // _UTILS_PROPERTY_MAP_H