winamp/Src/external_dependencies/openmpt-trunk/src/mpt/binary/hex.hpp

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2024-09-24 12:54:57 +00:00
/* SPDX-License-Identifier: BSL-1.0 OR BSD-3-Clause */
#ifndef MPT_BINARY_HEX_HPP
#define MPT_BINARY_HEX_HPP
#include "mpt/base/integer.hpp"
#include "mpt/base/memory.hpp"
#include "mpt/base/namespace.hpp"
#include "mpt/string/types.hpp"
#include <array>
#include <vector>
#include <cstddef>
namespace mpt {
inline namespace MPT_INLINE_NS {
inline constexpr std::array<mpt::uchar, 16> encode_nibble = {
{MPT_UCHAR('0'), MPT_UCHAR('1'), MPT_UCHAR('2'), MPT_UCHAR('3'),
MPT_UCHAR('4'), MPT_UCHAR('5'), MPT_UCHAR('6'), MPT_UCHAR('7'),
MPT_UCHAR('8'), MPT_UCHAR('9'), MPT_UCHAR('A'), MPT_UCHAR('B'),
MPT_UCHAR('C'), MPT_UCHAR('D'), MPT_UCHAR('E'), MPT_UCHAR('F')}
};
inline bool decode_byte(uint8 & byte, mpt::uchar c1, mpt::uchar c2) {
byte = 0;
if (MPT_UCHAR('0') <= c1 && c1 <= MPT_UCHAR('9')) {
byte += static_cast<uint8>((c1 - MPT_UCHAR('0')) << 4);
} else if (MPT_UCHAR('A') <= c1 && c1 <= MPT_UCHAR('F')) {
byte += static_cast<uint8>((c1 - MPT_UCHAR('A') + 10) << 4);
} else if (MPT_UCHAR('a') <= c1 && c1 <= MPT_UCHAR('f')) {
byte += static_cast<uint8>((c1 - MPT_UCHAR('a') + 10) << 4);
} else {
return false;
}
if (MPT_UCHAR('0') <= c2 && c2 <= MPT_UCHAR('9')) {
byte += static_cast<uint8>(c2 - MPT_UCHAR('0'));
} else if (MPT_UCHAR('A') <= c2 && c2 <= MPT_UCHAR('F')) {
byte += static_cast<uint8>(c2 - MPT_UCHAR('A') + 10);
} else if (MPT_UCHAR('a') <= c2 && c2 <= MPT_UCHAR('f')) {
byte += static_cast<uint8>(c2 - MPT_UCHAR('a') + 10);
} else {
return false;
}
return true;
}
template <typename Tbyte>
inline mpt::ustring encode_hex(mpt::span<Tbyte> src_) {
mpt::const_byte_span src = mpt::byte_cast<mpt::const_byte_span>(src_);
mpt::ustring result;
result.reserve(src.size() * 2);
for (std::byte byte : src) {
result.push_back(encode_nibble[(mpt::byte_cast<uint8>(byte) & 0xf0) >> 4]);
result.push_back(encode_nibble[mpt::byte_cast<uint8>(byte) & 0x0f]);
}
return result;
}
inline std::vector<std::byte> decode_hex(const mpt::ustring & src) {
std::vector<std::byte> result;
result.reserve(src.size() / 2);
for (std::size_t i = 0; (i + 1) < src.size(); i += 2) {
uint8 byte = 0;
if (!decode_byte(byte, src[i], src[i + 1])) {
return result;
}
result.push_back(mpt::byte_cast<std::byte>(byte));
}
return result;
}
} // namespace MPT_INLINE_NS
} // namespace mpt
#endif // MPT_BINARY_HEX_HPP