// Copyright (c) 2012 The Chromium Authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. #ifndef BASE_JSON_JSON_FILE_VALUE_SERIALIZER_H_ #define BASE_JSON_JSON_FILE_VALUE_SERIALIZER_H_ #include #include "base/base_export.h" #include "base/basictypes.h" #include "base/files/file_path.h" #include "base/values.h" class BASE_EXPORT JSONFileValueSerializer : public base::ValueSerializer { public: // json_file_patch is the path of a file that will be source of the // deserialization or the destination of the serialization. // When deserializing, the file should exist, but when serializing, the // serializer will attempt to create the file at the specified location. explicit JSONFileValueSerializer(const base::FilePath& json_file_path) : json_file_path_(json_file_path), allow_trailing_comma_(false) {} virtual ~JSONFileValueSerializer() {} // DO NOT USE except in unit tests to verify the file was written properly. // We should never serialize directly to a file since this will block the // thread. Instead, serialize to a string and write to the file you want on // the file thread. // // Attempt to serialize the data structure represented by Value into // JSON. If the return value is true, the result will have been written // into the file whose name was passed into the constructor. virtual bool Serialize(const base::Value& root) OVERRIDE; // Equivalent to Serialize(root) except binary values are omitted from the // output. bool SerializeAndOmitBinaryValues(const base::Value& root); // Attempt to deserialize the data structure encoded in the file passed // in to the constructor into a structure of Value objects. If the return // value is NULL, and if |error_code| is non-null, |error_code| will // contain an integer error code (either JsonFileError or JsonParseError). // If |error_message| is non-null, it will be filled in with a formatted // error message including the location of the error if appropriate. // The caller takes ownership of the returned value. virtual base::Value* Deserialize(int* error_code, std::string* error_message) OVERRIDE; // This enum is designed to safely overlap with JSONReader::JsonParseError. enum JsonFileError { JSON_NO_ERROR = 0, JSON_ACCESS_DENIED = 1000, JSON_CANNOT_READ_FILE, JSON_FILE_LOCKED, JSON_NO_SUCH_FILE }; // File-specific error messages that can be returned. static const char* kAccessDenied; static const char* kCannotReadFile; static const char* kFileLocked; static const char* kNoSuchFile; // Convert an error code into an error message. |error_code| is assumed to // be a JsonFileError. static const char* GetErrorMessageForCode(int error_code); void set_allow_trailing_comma(bool new_value) { allow_trailing_comma_ = new_value; } private: bool SerializeInternal(const base::Value& root, bool omit_binary_values); base::FilePath json_file_path_; bool allow_trailing_comma_; // A wrapper for file_util::ReadFileToString which returns a non-zero // JsonFileError if there were file errors. int ReadFileToString(std::string* json_string); DISALLOW_IMPLICIT_CONSTRUCTORS(JSONFileValueSerializer); }; #endif // BASE_JSON_JSON_FILE_VALUE_SERIALIZER_H_