| Index: base/json_reader.h
|
| ===================================================================
|
| --- base/json_reader.h (revision 29830)
|
| +++ base/json_reader.h (working copy)
|
| @@ -1,186 +0,0 @@
|
| -// Copyright (c) 2006-2008 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.
|
| -//
|
| -// A JSON parser. Converts strings of JSON into a Value object (see
|
| -// base/values.h).
|
| -// http://www.ietf.org/rfc/rfc4627.txt?number=4627
|
| -//
|
| -// Known limitations/deviations from the RFC:
|
| -// - Only knows how to parse ints within the range of a signed 32 bit int and
|
| -// decimal numbers within a double.
|
| -// - Assumes input is encoded as UTF8. The spec says we should allow UTF-16
|
| -// (BE or LE) and UTF-32 (BE or LE) as well.
|
| -// - We limit nesting to 100 levels to prevent stack overflow (this is allowed
|
| -// by the RFC).
|
| -// - A Unicode FAQ ("http://unicode.org/faq/utf_bom.html") writes a data
|
| -// stream may start with a Unicode Byte-Order-Mark (U+FEFF), i.e. the input
|
| -// UTF-8 string for the JSONReader::JsonToValue() function may start with a
|
| -// UTF-8 BOM (0xEF, 0xBB, 0xBF).
|
| -// To avoid the function from mis-treating a UTF-8 BOM as an invalid
|
| -// character, the function skips a Unicode BOM at the beginning of the
|
| -// Unicode string (converted from the input UTF-8 string) before parsing it.
|
| -//
|
| -// TODO(tc): Add a parsing option to to relax object keys being wrapped in
|
| -// double quotes
|
| -// TODO(tc): Add an option to disable comment stripping
|
| -// TODO(aa): Consider making the constructor public and the static Read() method
|
| -// only a convenience for the common uses with more complex configuration going
|
| -// on the instance.
|
| -
|
| -#ifndef BASE_JSON_READER_H_
|
| -#define BASE_JSON_READER_H_
|
| -
|
| -#include <string>
|
| -
|
| -#include "base/basictypes.h"
|
| -#include "testing/gtest/include/gtest/gtest_prod.h"
|
| -
|
| -class Value;
|
| -
|
| -class JSONReader {
|
| - public:
|
| - // A struct to hold a JS token.
|
| - class Token {
|
| - public:
|
| - enum Type {
|
| - OBJECT_BEGIN, // {
|
| - OBJECT_END, // }
|
| - ARRAY_BEGIN, // [
|
| - ARRAY_END, // ]
|
| - STRING,
|
| - NUMBER,
|
| - BOOL_TRUE, // true
|
| - BOOL_FALSE, // false
|
| - NULL_TOKEN, // null
|
| - LIST_SEPARATOR, // ,
|
| - OBJECT_PAIR_SEPARATOR, // :
|
| - END_OF_INPUT,
|
| - INVALID_TOKEN,
|
| - };
|
| - Token(Type t, const wchar_t* b, int len)
|
| - : type(t), begin(b), length(len) {}
|
| -
|
| - Type type;
|
| -
|
| - // A pointer into JSONReader::json_pos_ that's the beginning of this token.
|
| - const wchar_t* begin;
|
| -
|
| - // End should be one char past the end of the token.
|
| - int length;
|
| -
|
| - // Get the character that's one past the end of this token.
|
| - wchar_t NextChar() {
|
| - return *(begin + length);
|
| - }
|
| - };
|
| -
|
| - // Error messages that can be returned.
|
| - static const char* kBadRootElementType;
|
| - static const char* kInvalidEscape;
|
| - static const char* kSyntaxError;
|
| - static const char* kTrailingComma;
|
| - static const char* kTooMuchNesting;
|
| - static const char* kUnexpectedDataAfterRoot;
|
| - static const char* kUnsupportedEncoding;
|
| - static const char* kUnquotedDictionaryKey;
|
| -
|
| - JSONReader();
|
| -
|
| - // Reads and parses |json|, returning a Value. The caller owns the returned
|
| - // instance. If |json| is not a properly formed JSON string, returns NULL.
|
| - // If |allow_trailing_comma| is true, we will ignore trailing commas in
|
| - // objects and arrays even though this goes against the RFC.
|
| - static Value* Read(const std::string& json, bool allow_trailing_comma);
|
| -
|
| - // Reads and parses |json| like Read(). |error_message_out| is optional. If
|
| - // specified and NULL is returned, |error_message_out| will be populated with
|
| - // a string describing the error. Otherwise, |error_message_out| is
|
| - // unmodified.
|
| - static Value* ReadAndReturnError(const std::string& json,
|
| - bool allow_trailing_comma,
|
| - std::string* error_message_out);
|
| -
|
| - // Returns the error message if the last call to JsonToValue() failed. If the
|
| - // last call did not fail, returns a valid empty string.
|
| - std::string error_message() { return error_message_; }
|
| -
|
| - // Reads and parses |json|, returning a Value. The caller owns the returned
|
| - // instance. If |json| is not a properly formed JSON string, returns NULL and
|
| - // a detailed error can be retrieved from |error_message()|.
|
| - // If |check_root| is true, we require that the root object be an object or
|
| - // array. Otherwise, it can be any valid JSON type.
|
| - // If |allow_trailing_comma| is true, we will ignore trailing commas in
|
| - // objects and arrays even though this goes against the RFC.
|
| - Value* JsonToValue(const std::string& json, bool check_root,
|
| - bool allow_trailing_comma);
|
| -
|
| - private:
|
| - static std::string FormatErrorMessage(int line, int column,
|
| - const char* description);
|
| -
|
| - DISALLOW_EVIL_CONSTRUCTORS(JSONReader);
|
| -
|
| - FRIEND_TEST(JSONReaderTest, Reading);
|
| - FRIEND_TEST(JSONReaderTest, ErrorMessages);
|
| -
|
| - // Recursively build Value. Returns NULL if we don't have a valid JSON
|
| - // string. If |is_root| is true, we verify that the root element is either
|
| - // an object or an array.
|
| - Value* BuildValue(bool is_root);
|
| -
|
| - // Parses a sequence of characters into a Token::NUMBER. If the sequence of
|
| - // characters is not a valid number, returns a Token::INVALID_TOKEN. Note
|
| - // that DecodeNumber is used to actually convert from a string to an
|
| - // int/double.
|
| - Token ParseNumberToken();
|
| -
|
| - // Try and convert the substring that token holds into an int or a double. If
|
| - // we can (ie., no overflow), return the value, else return NULL.
|
| - Value* DecodeNumber(const Token& token);
|
| -
|
| - // Parses a sequence of characters into a Token::STRING. If the sequence of
|
| - // characters is not a valid string, returns a Token::INVALID_TOKEN. Note
|
| - // that DecodeString is used to actually decode the escaped string into an
|
| - // actual wstring.
|
| - Token ParseStringToken();
|
| -
|
| - // Convert the substring into a value string. This should always succeed
|
| - // (otherwise ParseStringToken would have failed).
|
| - Value* DecodeString(const Token& token);
|
| -
|
| - // Grabs the next token in the JSON stream. This does not increment the
|
| - // stream so it can be used to look ahead at the next token.
|
| - Token ParseToken();
|
| -
|
| - // Increments |json_pos_| past leading whitespace and comments.
|
| - void EatWhitespaceAndComments();
|
| -
|
| - // If |json_pos_| is at the start of a comment, eat it, otherwise, returns
|
| - // false.
|
| - bool EatComment();
|
| -
|
| - // Checks if |json_pos_| matches str.
|
| - bool NextStringMatch(const std::wstring& str);
|
| -
|
| - // Creates the error message that will be returned to the caller. The current
|
| - // line and column are determined and added into the final message.
|
| - void SetErrorMessage(const char* description, const wchar_t* error_pos);
|
| -
|
| - // Pointer to the starting position in the input string.
|
| - const wchar_t* start_pos_;
|
| -
|
| - // Pointer to the current position in the input string.
|
| - const wchar_t* json_pos_;
|
| -
|
| - // Used to keep track of how many nested lists/dicts there are.
|
| - int stack_depth_;
|
| -
|
| - // A parser flag that allows trailing commas in objects and arrays.
|
| - bool allow_trailing_comma_;
|
| -
|
| - // Contains the error message for the last call to JsonToValue(), if any.
|
| - std::string error_message_;
|
| -};
|
| -
|
| -#endif // BASE_JSON_READER_H_
|
|
|