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cpp-thirdparty/linx64/include/boost/mysql/impl/internal/channel/message_parser.ipp
2023-11-24 12:56:13 -06:00

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3.7 KiB
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//
// Copyright (c) 2019-2023 Ruben Perez Hidalgo (rubenperez038 at gmail dot com)
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
#ifndef BOOST_MYSQL_IMPL_INTERNAL_CHANNEL_MESSAGE_PARSER_IPP
#define BOOST_MYSQL_IMPL_INTERNAL_CHANNEL_MESSAGE_PARSER_IPP
#pragma once
#include <boost/mysql/impl/internal/channel/message_parser.hpp>
#include <boost/mysql/impl/internal/protocol/protocol.hpp>
void boost::mysql::detail::message_parser::parse_message(read_buffer& buff, result& res) noexcept
{
while (true)
{
if (state_.reading_header)
{
// If there are not enough bytes to process a header, request more
if (buff.pending_size() < HEADER_SIZE)
{
res.set_required_size(HEADER_SIZE - buff.pending_size());
return;
}
// Mark the header as belonging to the current message
buff.move_to_current_message(HEADER_SIZE);
// Deserialize the header
auto header = deserialize_frame_header(
span<const std::uint8_t, frame_header_size>(buff.pending_first() - HEADER_SIZE, HEADER_SIZE)
);
// Process the sequence number
if (state_.is_first_frame)
{
state_.seqnum_first = header.sequence_number;
state_.seqnum_last = header.sequence_number;
}
else
{
std::uint8_t expected_seqnum = state_.seqnum_last + 1;
if (header.sequence_number != expected_seqnum)
{
state_.has_seqnum_mismatch = true;
}
state_.seqnum_last = expected_seqnum;
}
// Process the packet size
state_.remaining_bytes = header.size;
state_.more_frames_follow = (state_.remaining_bytes == max_frame_size_);
// We are done with the header
if (state_.is_first_frame)
{
// If it's the 1st frame, we can just move the header bytes to the reserved
// area, avoiding a big memmove
buff.move_to_reserved(HEADER_SIZE);
}
else
{
buff.remove_current_message_last(HEADER_SIZE);
}
state_.is_first_frame = false;
state_.reading_header = false;
}
if (!state_.reading_header)
{
// Get the number of bytes belonging to this message
std::size_t new_bytes = (std::min)(buff.pending_size(), state_.remaining_bytes);
// Mark them as belonging to the current message in the buffer
buff.move_to_current_message(new_bytes);
// Update remaining bytes
state_.remaining_bytes -= new_bytes;
if (state_.remaining_bytes == 0)
{
state_.reading_header = true;
}
else
{
res.set_required_size(state_.remaining_bytes);
return;
}
// If we've fully read a message, we're done
if (!state_.remaining_bytes && !state_.more_frames_follow)
{
std::size_t message_size = buff.current_message_size();
buff.move_to_reserved(message_size);
res.set_message({
state_.seqnum_first,
state_.seqnum_last,
message_size,
state_.has_seqnum_mismatch,
});
state_ = state_t();
return;
}
}
}
}
#endif