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#pragma once
#include <array>
#include <cassert>
#include <cstddef>
#include <cstdint>
#include <cstdio>
#include <cstring>
#include <format>
#include <stdexcept>
#include <vector>
#include <sys/socket.h>
#include <sys/types.h>
#include <boost/pfr/core.hpp>
#include <zlib.h>
#include "types.hpp"
namespace net {
namespace packet {
using packet_header = std::tuple<uint8_t, uint16_t>;
template <packet T>
void decode_packet(std::span<uint8_t> payload, T& t)
{
std::size_t offset = 0;
boost::pfr::for_each_field(t, [&payload, &offset](auto& field, int i) {
if (offset >= payload.size()) {
throw std::runtime_error("Received invalid packet");
}
offset += decode_field(payload.subspan(offset), field);
});
if (offset < payload.size()) {
throw std::runtime_error(std::format("{}: {}", offset, payload.size()));
}
}
template <packet T>
std::vector<uint8_t> encode_raw_packet(T& t)
{
std::vector<uint8_t> payload;
boost::pfr::for_each_field(t, [&payload](auto& field) {
encode_field(payload, field);
});
return payload;
}
template <packet T>
std::vector<uint8_t> encode_packet(T& t)
{
return encode_raw_packet(t);
}
template <compressed_packet T>
std::vector<uint8_t> encode_packet(T& t)
{
static constexpr auto chunk_size = 1024;
std::array<uint8_t, chunk_size> buffer;
std::vector<uint8_t> payload;
int ret, flush;
z_stream strm;
auto raw_payload = encode_raw_packet(t);
strm.zalloc = Z_NULL;
strm.zfree = Z_NULL;
strm.opaque = Z_NULL;
ret = deflateInit(&strm, 15);
if (ret != Z_OK)
throw std::runtime_error("deflate init error");
strm.avail_in = raw_payload.size();
strm.next_in = raw_payload.data();
do {
strm.avail_out = chunk_size;
strm.next_out = reinterpret_cast<Bytef *>(buffer.data());
ret = deflate(&strm, flush);
assert(ret != Z_STREAM_ERROR);
payload.insert(payload.end(), buffer.begin(), buffer.end()-strm.avail_out);
} while (strm.avail_out == 0);
assert(strm.avail_in == 0); /* all input will be used */
deflateEnd(&strm);
return payload;
}
}
}
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