ladybird/AK/Endian.h
2023-02-08 19:18:26 +00:00

147 lines
4.3 KiB
C++

/*
* Copyright (c) 2020, the SerenityOS developers.
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/Format.h>
#include <AK/Forward.h>
#include <AK/Platform.h>
#if defined(AK_OS_MACOS)
# include <libkern/OSByteOrder.h>
# include <machine/endian.h>
# define htobe16(x) OSSwapHostToBigInt16(x)
# define htole16(x) OSSwapHostToLittleInt16(x)
# define be16toh(x) OSSwapBigToHostInt16(x)
# define le16toh(x) OSSwapLittleToHostInt16(x)
# define htobe32(x) OSSwapHostToBigInt32(x)
# define htole32(x) OSSwapHostToLittleInt32(x)
# define be32toh(x) OSSwapBigToHostInt32(x)
# define le32toh(x) OSSwapLittleToHostInt32(x)
# define htobe64(x) OSSwapHostToBigInt64(x)
# define htole64(x) OSSwapHostToLittleInt64(x)
# define be64toh(x) OSSwapBigToHostInt64(x)
# define le64toh(x) OSSwapLittleToHostInt64(x)
# define __BIG_ENDIAN BIG_ENDIAN
# define __LITTLE_ENDIAN LITTLE_ENDIAN
# define __BYTE_ORDER BYTE_ORDER
#endif
namespace AK {
template<typename T>
ALWAYS_INLINE constexpr T convert_between_host_and_little_endian(T value)
{
#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
return value;
#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
if constexpr (sizeof(T) == 8)
return static_cast<T>(__builtin_bswap64(static_cast<u64>(value)));
if constexpr (sizeof(T) == 4)
return static_cast<T>(__builtin_bswap32(static_cast<u32>(value)));
if constexpr (sizeof(T) == 2)
return static_cast<T>(__builtin_bswap16(static_cast<u16>(value)));
if constexpr (sizeof(T) == 1)
return value;
#endif
}
template<typename T>
ALWAYS_INLINE constexpr T convert_between_host_and_big_endian(T value)
{
#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
if constexpr (sizeof(T) == 8)
return static_cast<T>(__builtin_bswap64(static_cast<u64>(value)));
if constexpr (sizeof(T) == 4)
return static_cast<T>(__builtin_bswap32(static_cast<u32>(value)));
if constexpr (sizeof(T) == 2)
return static_cast<T>(__builtin_bswap16(static_cast<u16>(value)));
if constexpr (sizeof(T) == 1)
return value;
#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
return value;
#endif
}
template<typename T>
ALWAYS_INLINE T convert_between_host_and_network_endian(T value)
{
return convert_between_host_and_big_endian(value);
}
template<typename T>
class [[gnu::packed]] LittleEndian {
public:
constexpr LittleEndian() = default;
constexpr LittleEndian(T value)
: m_value(convert_between_host_and_little_endian(value))
{
}
constexpr operator T() const { return convert_between_host_and_little_endian(m_value); }
// This returns the internal representation. In this case, that is the value stored in little endian format.
constexpr Bytes bytes() { return Bytes { &m_value, sizeof(m_value) }; }
constexpr ReadonlyBytes bytes() const { return ReadonlyBytes { &m_value, sizeof(m_value) }; }
private:
T m_value { 0 };
};
template<typename T>
class [[gnu::packed]] BigEndian {
public:
constexpr BigEndian() = default;
constexpr BigEndian(T value)
: m_value(convert_between_host_and_big_endian(value))
{
}
constexpr operator T() const { return convert_between_host_and_big_endian(m_value); }
// This returns the internal representation. In this case, that is the value stored in big endian format.
constexpr Bytes bytes() { return Bytes { &m_value, sizeof(m_value) }; }
constexpr ReadonlyBytes bytes() const { return ReadonlyBytes { &m_value, sizeof(m_value) }; }
private:
T m_value { 0 };
};
template<typename T>
using NetworkOrdered = BigEndian<T>;
template<typename T>
requires(HasFormatter<T>) struct Formatter<LittleEndian<T>> : Formatter<T> {
};
template<typename T>
requires(HasFormatter<T>) struct Formatter<BigEndian<T>> : Formatter<T> {
};
template<typename T>
struct Traits<LittleEndian<T>> : public GenericTraits<LittleEndian<T>> {
static constexpr bool is_trivially_serializable() { return Traits<T>::is_trivially_serializable(); }
};
template<typename T>
struct Traits<BigEndian<T>> : public GenericTraits<BigEndian<T>> {
static constexpr bool is_trivially_serializable() { return Traits<T>::is_trivially_serializable(); }
};
}
#if USING_AK_GLOBALLY
using AK::BigEndian;
using AK::LittleEndian;
using AK::NetworkOrdered;
#endif