gnss-sim/3rdparty/boost/mysql/impl/escape_string.ipp

133 lines
3.6 KiB
C++

//
// Copyright (c) 2019-2024 Ruben Perez Hidalgo (rubenperez038 at gmail dot com)
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
#ifndef BOOST_MYSQL_IMPL_ESCAPE_STRING_IPP
#define BOOST_MYSQL_IMPL_ESCAPE_STRING_IPP
#pragma once
#include <boost/mysql/character_set.hpp>
#include <boost/mysql/client_errc.hpp>
#include <boost/mysql/error_code.hpp>
#include <boost/mysql/escape_string.hpp>
#include <boost/mysql/string_view.hpp>
#include <boost/mysql/detail/output_string.hpp>
#include <boost/mysql/impl/internal/call_next_char.hpp>
namespace boost {
namespace mysql {
namespace detail {
// A (possibly null) escape sequence of two characters. Used as the return value for escapers
class escape_sequence
{
char data_[2]{};
public:
escape_sequence() = default;
escape_sequence(char ch1, char ch2) noexcept : data_{ch1, ch2} {}
bool is_escape() const noexcept { return data_[0] != '\0'; }
string_view data() const noexcept { return string_view(data_, 2); }
};
// Escaper is a function object that takes a char and returns a
// escape_sequence determining whether we should escape the char or not
template <class Escaper>
BOOST_ATTRIBUTE_NODISCARD error_code
escape_impl(string_view input, character_set charset, Escaper escaper, output_string_ref output)
{
const char* it = input.data();
const char* end = it + input.size();
// The raw range is a range of contiguous characters that don't need escaping.
// We only append the raw range once we find a character that needs escaping
const char* raw_begin = it;
while (it != end)
{
escape_sequence seq = escaper(*it);
if (seq.is_escape())
{
// Dump what we already had
output.append({raw_begin, it});
// Output the escape sequence
output.append(seq.data());
// Advance
++it;
// Update the start of the range that doesn't need escaping
raw_begin = it;
}
else
{
// Advance with the charset function
std::size_t char_size = detail::call_next_char(charset, it, end);
if (char_size == 0u)
return client_errc::invalid_encoding;
it += char_size;
}
}
// Dump the remaining of the string, if any
output.append({raw_begin, end});
// Done
return error_code();
}
struct backslash_escaper
{
escape_sequence operator()(char input) const noexcept
{
switch (input)
{
case '\0': return {'\\', '0'};
case '\n': return {'\\', 'n'};
case '\r': return {'\\', 'r'};
case '\\': return {'\\', '\\'};
case '\'': return {'\\', '\''};
case '"': return {'\\', '"'};
case '\x1a': return {'\\', 'Z'}; // Ctrl+Z
default: return escape_sequence(); // No escape
}
};
};
struct quote_escaper
{
char quot;
quote_escaper(char q) noexcept : quot(q) {}
escape_sequence operator()(char input) const noexcept
{
return input == quot ? escape_sequence(quot, quot) : escape_sequence();
}
};
} // namespace detail
} // namespace mysql
} // namespace boost
boost::mysql::error_code boost::mysql::detail::escape_string(
string_view input,
const format_options& opts,
char escape_char,
output_string_ref output
)
{
return (escape_char == '`' || !opts.backslash_escapes)
? detail::escape_impl(input, opts.charset, quote_escaper(escape_char), output)
: detail::escape_impl(input, opts.charset, backslash_escaper(), output);
}
#endif