file_reader/src/file_deserialising.h

124 lines
2.7 KiB
C++

#pragma once
#include <tuple>
#include <cstring>
#include <print>
#include <type_traits>
#include "buffer.h"
#define read_comp(size, ptr, t) const_for_<size>([&](auto i){read_var<std::tuple_element_t<i.value, std::remove_cvref_t<decltype(t)>>>::call(std::get<i.value>(t), &ptr);});
#ifdef __APPLE__
#include <libkern/OSByteOrder.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)
#endif
struct parsing_buffer
{
parsing_buffer(buffer &b)
:buf(b)
{}
buffer &buf;
char *point;
int consumed_size;
};
template <typename T>
static void read_type(T& val, char *data)
{
std::memcpy(&val, data, sizeof(T));
switch (sizeof(T))
{
case 1:
break;
case 2:
val = be16toh(val);
break;
case 4:
val = be32toh(val);
break;
case 8:
val = be64toh(val);
break;
default:
std::println("This integer is not supported!");
}
}
template <>
inline void read_type<float>(float &val, char *data)
{
uint32_t num_as_uint32;
memcpy(&num_as_uint32, data, sizeof(float));
num_as_uint32 = be32toh(num_as_uint32);
memcpy(&val, &num_as_uint32, sizeof(float));
}
template <>
inline void read_type<double>(double &val, char *data)
{
uint64_t num_as_uint64;
memcpy(&num_as_uint64, data, sizeof(double));
num_as_uint64 = be64toh(num_as_uint64);
memcpy(&val, &num_as_uint64, sizeof(double));
}
template<>
inline void read_type<buffer>(buffer &val, char *data)
{
val.allocated = val.size + 1;
val.data = (char *)calloc(val.size + 1,sizeof(char));
std::memcpy(val.data, data, val.size);
}
template<typename T>
struct read_var
{
static void call(T& val, parsing_buffer* v)
{
int size = 0;
if constexpr (typeid(T) == typeid(buffer))
size = val.size;
else
size = sizeof(T);
if (size + v->consumed_size > v->buf.size)
{
if constexpr (typeid(T) == typeid(buffer))
{
val.size = v->buf.size;
}
else
return ;
}
read_type<T>(val, v->point);
v->point += size;
v->consumed_size += size;
}
};
template <typename Integer, Integer ...I, typename F> constexpr void const_for_each_(std::integer_sequence<Integer, I...>, F&& func)
{
(func(std::integral_constant<Integer, I>{}), ...);
}
template <auto N, typename F> constexpr void const_for_(F&& func)
{
if constexpr (N > 0)
const_for_each_(std::make_integer_sequence<decltype(N), N>{}, std::forward<F>(func));
}