70 lines
1.6 KiB
C++
70 lines
1.6 KiB
C++
#pragma once
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#include "file_deserialising.h"
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#include <unistd.h>
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class file_reader
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{
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public:
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file_reader(int file_fd)
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:fd(file_fd)
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{
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buf.size = 0;
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buf.allocated = 0;
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buf.data = nullptr;
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file_size = lseek(fd, 0, SEEK_END);
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lseek(fd, 0, SEEK_SET);
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file_size_remaining = file_size;
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}
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template<typename ...T>
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void read_from_tuple(std::tuple<T...> &in)
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{
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constexpr std::size_t size_tuple = sizeof...(T);
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int size = 0;
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std::array<size_t, size_tuple> sizes;
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const_for_<size_tuple>([&](auto i)
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{
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if constexpr (typeid(std::get<i.value>(in)) == typeid(buffer))
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{
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size += std::get<i.value>(in).size;
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sizes[i.value] = std::get<i.value>(in).size;
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}
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else
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{
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size += sizeof(std::get<i.value>(in));
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sizes[i.value] = sizeof(std::get<i.value>(in));
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}
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});
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if (size > buf.size)
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{
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int extra_size = 0;
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if (size + BUFFER_SIZE <= file_size_remaining)
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{
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extra_size = BUFFER_SIZE;
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}
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else if (size > file_size_remaining)
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{
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extra_size = file_size_remaining - size;
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}
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char *new_read = (char *)calloc(size + extra_size, sizeof(char));
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size_t res = read(fd, new_read, size + extra_size);
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if (res != size + extra_size)
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{
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free(new_read);
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throw std::runtime_error("Read failed!");
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}
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buf.write(new_read, size + extra_size);
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file_size_remaining -= size + extra_size;
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free(new_read);
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}
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parsing_buffer par_buf(buf);
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par_buf.point = buf.data;
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par_buf.consumed_size = 0;
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read_comp(size_tuple, par_buf, in, sizes);
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buf.remove(0, size);
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}
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buffer buf;
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int fd;
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off_t file_size;
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off_t file_size_remaining;
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};
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