mirror of
https://github.com/ecency/ecency-mobile.git
synced 2024-12-19 19:31:54 +03:00
326 lines
13 KiB
C++
326 lines
13 KiB
C++
/*
|
|
Copyright (c) Marshall Clow 2011-2012.
|
|
|
|
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)
|
|
|
|
Thanks to Nevin for his comments/help.
|
|
*/
|
|
|
|
/*
|
|
General problem - turn a sequence of integral types into a sequence of hexadecimal characters.
|
|
- and back.
|
|
*/
|
|
|
|
/// \file hex.hpp
|
|
/// \brief Convert sequence of integral types into a sequence of hexadecimal
|
|
/// characters and back. Based on the MySQL functions HEX and UNHEX
|
|
/// \author Marshall Clow
|
|
|
|
#ifndef BOOST_ALGORITHM_HEXHPP
|
|
#define BOOST_ALGORITHM_HEXHPP
|
|
|
|
#include <iterator> // for std::iterator_traits
|
|
#include <stdexcept>
|
|
|
|
#include <boost/range/begin.hpp>
|
|
#include <boost/range/end.hpp>
|
|
#include <boost/exception/exception.hpp>
|
|
#include <boost/exception/info.hpp>
|
|
#include <boost/throw_exception.hpp>
|
|
|
|
#include <boost/utility/enable_if.hpp>
|
|
#include <boost/type_traits/is_integral.hpp>
|
|
|
|
|
|
namespace boost { namespace algorithm {
|
|
|
|
/*!
|
|
\struct hex_decode_error
|
|
\brief Base exception class for all hex decoding errors
|
|
*/ /*!
|
|
\struct non_hex_input
|
|
\brief Thrown when a non-hex value (0-9, A-F) encountered when decoding.
|
|
Contains the offending character
|
|
*/ /*!
|
|
\struct not_enough_input
|
|
\brief Thrown when the input sequence unexpectedly ends
|
|
|
|
*/
|
|
struct hex_decode_error : virtual boost::exception, virtual std::exception {};
|
|
struct not_enough_input : virtual hex_decode_error {};
|
|
struct non_hex_input : virtual hex_decode_error {};
|
|
typedef boost::error_info<struct bad_char_,char> bad_char;
|
|
|
|
namespace detail {
|
|
/// \cond DOXYGEN_HIDE
|
|
|
|
template <typename T, typename OutputIterator>
|
|
OutputIterator encode_one ( T val, OutputIterator out, const char * hexDigits ) {
|
|
const std::size_t num_hex_digits = 2 * sizeof ( T );
|
|
char res [ num_hex_digits ];
|
|
char *p = res + num_hex_digits;
|
|
for ( std::size_t i = 0; i < num_hex_digits; ++i, val >>= 4 )
|
|
*--p = hexDigits [ val & 0x0F ];
|
|
return std::copy ( res, res + num_hex_digits, out );
|
|
}
|
|
|
|
template <typename T>
|
|
unsigned char hex_char_to_int ( T val ) {
|
|
char c = static_cast<char> ( val );
|
|
unsigned retval = 0;
|
|
if ( c >= '0' && c <= '9' ) retval = c - '0';
|
|
else if ( c >= 'A' && c <= 'F' ) retval = c - 'A' + 10;
|
|
else if ( c >= 'a' && c <= 'f' ) retval = c - 'a' + 10;
|
|
else BOOST_THROW_EXCEPTION (non_hex_input() << bad_char (c));
|
|
return retval;
|
|
}
|
|
|
|
// My own iterator_traits class.
|
|
// It is here so that I can "reach inside" some kinds of output iterators
|
|
// and get the type to write.
|
|
template <typename Iterator>
|
|
struct hex_iterator_traits {
|
|
typedef typename std::iterator_traits<Iterator>::value_type value_type;
|
|
};
|
|
|
|
template<typename Container>
|
|
struct hex_iterator_traits< std::back_insert_iterator<Container> > {
|
|
typedef typename Container::value_type value_type;
|
|
};
|
|
|
|
template<typename Container>
|
|
struct hex_iterator_traits< std::front_insert_iterator<Container> > {
|
|
typedef typename Container::value_type value_type;
|
|
};
|
|
|
|
template<typename Container>
|
|
struct hex_iterator_traits< std::insert_iterator<Container> > {
|
|
typedef typename Container::value_type value_type;
|
|
};
|
|
|
|
// ostream_iterators have three template parameters.
|
|
// The first one is the output type, the second one is the character type of
|
|
// the underlying stream, the third is the character traits.
|
|
// We only care about the first one.
|
|
template<typename T, typename charType, typename traits>
|
|
struct hex_iterator_traits< std::ostream_iterator<T, charType, traits> > {
|
|
typedef T value_type;
|
|
};
|
|
|
|
template <typename Iterator>
|
|
bool iter_end ( Iterator current, Iterator last ) { return current == last; }
|
|
|
|
template <typename T>
|
|
bool ptr_end ( const T* ptr, const T* /*end*/ ) { return *ptr == '\0'; }
|
|
|
|
// What can we assume here about the inputs?
|
|
// is std::iterator_traits<InputIterator>::value_type always 'char' ?
|
|
// Could it be wchar_t, say? Does it matter?
|
|
// We are assuming ASCII for the values - but what about the storage?
|
|
template <typename InputIterator, typename OutputIterator, typename EndPred>
|
|
typename boost::enable_if<boost::is_integral<typename hex_iterator_traits<OutputIterator>::value_type>, OutputIterator>::type
|
|
decode_one ( InputIterator &first, InputIterator last, OutputIterator out, EndPred pred ) {
|
|
typedef typename hex_iterator_traits<OutputIterator>::value_type T;
|
|
T res (0);
|
|
|
|
// Need to make sure that we get can read that many chars here.
|
|
for ( std::size_t i = 0; i < 2 * sizeof ( T ); ++i, ++first ) {
|
|
if ( pred ( first, last ))
|
|
BOOST_THROW_EXCEPTION (not_enough_input ());
|
|
res = ( 16 * res ) + hex_char_to_int (*first);
|
|
}
|
|
|
|
*out = res;
|
|
return ++out;
|
|
}
|
|
/// \endcond
|
|
}
|
|
|
|
|
|
/// \fn hex ( InputIterator first, InputIterator last, OutputIterator out )
|
|
/// \brief Converts a sequence of integral types into a hexadecimal sequence of characters.
|
|
///
|
|
/// \param first The start of the input sequence
|
|
/// \param last One past the end of the input sequence
|
|
/// \param out An output iterator to the results into
|
|
/// \return The updated output iterator
|
|
/// \note Based on the MySQL function of the same name
|
|
template <typename InputIterator, typename OutputIterator>
|
|
typename boost::enable_if<boost::is_integral<typename detail::hex_iterator_traits<InputIterator>::value_type>, OutputIterator>::type
|
|
hex ( InputIterator first, InputIterator last, OutputIterator out ) {
|
|
for ( ; first != last; ++first )
|
|
out = detail::encode_one ( *first, out, "0123456789ABCDEF" );
|
|
return out;
|
|
}
|
|
|
|
|
|
/// \fn hex_lower ( InputIterator first, InputIterator last, OutputIterator out )
|
|
/// \brief Converts a sequence of integral types into a lower case hexadecimal sequence of characters.
|
|
///
|
|
/// \param first The start of the input sequence
|
|
/// \param last One past the end of the input sequence
|
|
/// \param out An output iterator to the results into
|
|
/// \return The updated output iterator
|
|
/// \note Based on the MySQL function of the same name
|
|
template <typename InputIterator, typename OutputIterator>
|
|
typename boost::enable_if<boost::is_integral<typename detail::hex_iterator_traits<InputIterator>::value_type>, OutputIterator>::type
|
|
hex_lower ( InputIterator first, InputIterator last, OutputIterator out ) {
|
|
for ( ; first != last; ++first )
|
|
out = detail::encode_one ( *first, out, "0123456789abcdef" );
|
|
return out;
|
|
}
|
|
|
|
|
|
/// \fn hex ( const T *ptr, OutputIterator out )
|
|
/// \brief Converts a sequence of integral types into a hexadecimal sequence of characters.
|
|
///
|
|
/// \param ptr A pointer to a 0-terminated sequence of data.
|
|
/// \param out An output iterator to the results into
|
|
/// \return The updated output iterator
|
|
/// \note Based on the MySQL function of the same name
|
|
template <typename T, typename OutputIterator>
|
|
typename boost::enable_if<boost::is_integral<T>, OutputIterator>::type
|
|
hex ( const T *ptr, OutputIterator out ) {
|
|
while ( *ptr )
|
|
out = detail::encode_one ( *ptr++, out, "0123456789ABCDEF" );
|
|
return out;
|
|
}
|
|
|
|
|
|
/// \fn hex_lower ( const T *ptr, OutputIterator out )
|
|
/// \brief Converts a sequence of integral types into a lower case hexadecimal sequence of characters.
|
|
///
|
|
/// \param ptr A pointer to a 0-terminated sequence of data.
|
|
/// \param out An output iterator to the results into
|
|
/// \return The updated output iterator
|
|
/// \note Based on the MySQL function of the same name
|
|
template <typename T, typename OutputIterator>
|
|
typename boost::enable_if<boost::is_integral<T>, OutputIterator>::type
|
|
hex_lower ( const T *ptr, OutputIterator out ) {
|
|
while ( *ptr )
|
|
out = detail::encode_one ( *ptr++, out, "0123456789abcdef" );
|
|
return out;
|
|
}
|
|
|
|
|
|
/// \fn hex ( const Range &r, OutputIterator out )
|
|
/// \brief Converts a sequence of integral types into a hexadecimal sequence of characters.
|
|
///
|
|
/// \param r The input range
|
|
/// \param out An output iterator to the results into
|
|
/// \return The updated output iterator
|
|
/// \note Based on the MySQL function of the same name
|
|
template <typename Range, typename OutputIterator>
|
|
typename boost::enable_if<boost::is_integral<typename detail::hex_iterator_traits<typename Range::iterator>::value_type>, OutputIterator>::type
|
|
hex ( const Range &r, OutputIterator out ) {
|
|
return hex (boost::begin(r), boost::end(r), out);
|
|
}
|
|
|
|
|
|
/// \fn hex_lower ( const Range &r, OutputIterator out )
|
|
/// \brief Converts a sequence of integral types into a lower case hexadecimal sequence of characters.
|
|
///
|
|
/// \param r The input range
|
|
/// \param out An output iterator to the results into
|
|
/// \return The updated output iterator
|
|
/// \note Based on the MySQL function of the same name
|
|
template <typename Range, typename OutputIterator>
|
|
typename boost::enable_if<boost::is_integral<typename detail::hex_iterator_traits<typename Range::iterator>::value_type>, OutputIterator>::type
|
|
hex_lower ( const Range &r, OutputIterator out ) {
|
|
return hex_lower (boost::begin(r), boost::end(r), out);
|
|
}
|
|
|
|
|
|
/// \fn unhex ( InputIterator first, InputIterator last, OutputIterator out )
|
|
/// \brief Converts a sequence of hexadecimal characters into a sequence of integers.
|
|
///
|
|
/// \param first The start of the input sequence
|
|
/// \param last One past the end of the input sequence
|
|
/// \param out An output iterator to the results into
|
|
/// \return The updated output iterator
|
|
/// \note Based on the MySQL function of the same name
|
|
template <typename InputIterator, typename OutputIterator>
|
|
OutputIterator unhex ( InputIterator first, InputIterator last, OutputIterator out ) {
|
|
while ( first != last )
|
|
out = detail::decode_one ( first, last, out, detail::iter_end<InputIterator> );
|
|
return out;
|
|
}
|
|
|
|
|
|
/// \fn unhex ( const T *ptr, OutputIterator out )
|
|
/// \brief Converts a sequence of hexadecimal characters into a sequence of integers.
|
|
///
|
|
/// \param ptr A pointer to a null-terminated input sequence.
|
|
/// \param out An output iterator to the results into
|
|
/// \return The updated output iterator
|
|
/// \note Based on the MySQL function of the same name
|
|
template <typename T, typename OutputIterator>
|
|
OutputIterator unhex ( const T *ptr, OutputIterator out ) {
|
|
// If we run into the terminator while decoding, we will throw a
|
|
// malformed input exception. It would be nicer to throw a 'Not enough input'
|
|
// exception - but how much extra work would that require?
|
|
while ( *ptr )
|
|
out = detail::decode_one ( ptr, (const T *) NULL, out, detail::ptr_end<T> );
|
|
return out;
|
|
}
|
|
|
|
|
|
/// \fn OutputIterator unhex ( const Range &r, OutputIterator out )
|
|
/// \brief Converts a sequence of hexadecimal characters into a sequence of integers.
|
|
///
|
|
/// \param r The input range
|
|
/// \param out An output iterator to the results into
|
|
/// \return The updated output iterator
|
|
/// \note Based on the MySQL function of the same name
|
|
template <typename Range, typename OutputIterator>
|
|
OutputIterator unhex ( const Range &r, OutputIterator out ) {
|
|
return unhex (boost::begin(r), boost::end(r), out);
|
|
}
|
|
|
|
|
|
/// \fn String hex ( const String &input )
|
|
/// \brief Converts a sequence of integral types into a hexadecimal sequence of characters.
|
|
///
|
|
/// \param input A container to be converted
|
|
/// \return A container with the encoded text
|
|
template<typename String>
|
|
String hex ( const String &input ) {
|
|
String output;
|
|
output.reserve (input.size () * (2 * sizeof (typename String::value_type)));
|
|
(void) hex (input, std::back_inserter (output));
|
|
return output;
|
|
}
|
|
|
|
|
|
/// \fn String hex_lower ( const String &input )
|
|
/// \brief Converts a sequence of integral types into a lower case hexadecimal sequence of characters.
|
|
///
|
|
/// \param input A container to be converted
|
|
/// \return A container with the encoded text
|
|
template<typename String>
|
|
String hex_lower ( const String &input ) {
|
|
String output;
|
|
output.reserve (input.size () * (2 * sizeof (typename String::value_type)));
|
|
(void) hex_lower (input, std::back_inserter (output));
|
|
return output;
|
|
}
|
|
|
|
|
|
/// \fn String unhex ( const String &input )
|
|
/// \brief Converts a sequence of hexadecimal characters into a sequence of characters.
|
|
///
|
|
/// \param input A container to be converted
|
|
/// \return A container with the decoded text
|
|
template<typename String>
|
|
String unhex ( const String &input ) {
|
|
String output;
|
|
output.reserve (input.size () / (2 * sizeof (typename String::value_type)));
|
|
(void) unhex (input, std::back_inserter (output));
|
|
return output;
|
|
}
|
|
|
|
}}
|
|
|
|
#endif // BOOST_ALGORITHM_HEXHPP
|