140 lines
3.2 KiB
C++
140 lines
3.2 KiB
C++
|
/*
|
||
|
|
* Copyright (C) 2014 Jared Boone, ShareBrained Technology, Inc.
|
||
|
|
*
|
||
|
|
* This file is part of PortaPack.
|
||
|
|
*
|
||
|
|
* This program is free software; you can redistribute it and/or modify
|
||
|
|
* it under the terms of the GNU General Public License as published by
|
||
|
|
* the Free Software Foundation; either version 2, or (at your option)
|
||
|
|
* any later version.
|
||
|
|
*
|
||
|
|
* This program is distributed in the hope that it will be useful,
|
||
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||
|
|
* GNU General Public License for more details.
|
||
|
|
*
|
||
|
|
* You should have received a copy of the GNU General Public License
|
||
|
|
* along with this program; see the file COPYING. If not, write to
|
||
|
|
* the Free Software Foundation, Inc., 51 Franklin Street,
|
||
|
|
* Boston, MA 02110-1301, USA.
|
||
|
|
*/
|
||
|
|
|
||
|
|
#ifndef __PACKET_BUILDER_H__
|
||
|
|
#define __PACKET_BUILDER_H__
|
||
|
|
|
||
|
|
#include <cstdint>
|
||
|
|
#include <cstddef>
|
||
|
|
#include <bitset>
|
||
|
|
#include <functional>
|
||
|
|
|
||
|
|
#include "bit_pattern.hpp"
|
||
|
|
#include "baseband_packet.hpp"
|
||
|
|
|
||
|
|
struct NeverMatch {
|
||
|
|
bool operator()(const BitHistory&, const size_t) const {
|
||
|
|
return false;
|
||
|
|
}
|
||
|
|
};
|
||
|
|
|
||
|
|
struct FixedLength {
|
||
|
|
bool operator()(const BitHistory&, const size_t symbols_received) const {
|
||
|
|
return symbols_received >= length;
|
||
|
|
}
|
||
|
|
|
||
|
|
const size_t length;
|
||
|
|
};
|
||
|
|
|
||
|
|
template<typename PreambleMatcher, typename UnstuffMatcher, typename EndMatcher>
|
||
|
|
class PacketBuilder {
|
||
|
|
public:
|
||
|
|
using PayloadHandlerFunc = std::function<void(const baseband::Packet& packet)>;
|
||
|
|
|
||
|
|
PacketBuilder(
|
||
|
|
const PreambleMatcher preamble_matcher,
|
||
|
|
const UnstuffMatcher unstuff_matcher,
|
||
|
|
const EndMatcher end_matcher,
|
||
|
|
PayloadHandlerFunc payload_handler
|
||
|
|
) : payload_handler { std::move(payload_handler) },
|
||
|
|
preamble(preamble_matcher),
|
||
|
|
unstuff(unstuff_matcher),
|
||
|
|
end(end_matcher)
|
||
|
|
{
|
||
|
|
}
|
||
|
|
|
||
|
|
void configure(
|
||
|
|
const PreambleMatcher preamble_matcher,
|
||
|
|
const UnstuffMatcher unstuff_matcher
|
||
|
|
) {
|
||
|
|
preamble = preamble_matcher;
|
||
|
|
unstuff = unstuff_matcher;
|
||
|
|
|
||
|
|
reset_state();
|
||
|
|
}
|
||
|
|
|
||
|
|
void execute(
|
||
|
|
const uint_fast8_t symbol
|
||
|
|
) {
|
||
|
|
bit_history.add(symbol);
|
||
|
|
|
||
|
|
switch(state) {
|
||
|
|
case State::Preamble:
|
||
|
|
if( preamble(bit_history, packet.size()) ) {
|
||
|
|
state = State::Payload;
|
||
|
|
}
|
||
|
|
break;
|
||
|
|
|
||
|
|
case State::Payload:
|
||
|
|
if( !unstuff(bit_history, packet.size()) ) {
|
||
|
|
packet.add(symbol);
|
||
|
|
}
|
||
|
|
|
||
|
|
if( end(bit_history, packet.size()) ) {
|
||
|
|
// NOTE: This check is to avoid std::function nullptr check, which
|
||
|
|
// brings in "_ZSt25__throw_bad_function_callv" and a lot of extra code.
|
||
|
|
// TODO: Make payload_handler known at compile time.
|
||
|
|
if( payload_handler ) {
|
||
|
|
packet.set_timestamp(Timestamp::now());
|
||
|
|
payload_handler(packet);
|
||
|
|
}
|
||
|
|
reset_state();
|
||
|
|
} else {
|
||
|
|
if( packet_truncated() ) {
|
||
|
|
reset_state();
|
||
|
|
}
|
||
|
|
}
|
||
|
|
break;
|
||
|
|
|
||
|
|
default:
|
||
|
|
reset_state();
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
private:
|
||
|
|
enum State {
|
||
|
|
Preamble,
|
||
|
|
Payload,
|
||
|
|
};
|
||
|
|
|
||
|
|
bool packet_truncated() const {
|
||
|
|
return packet.size() >= packet.capacity();
|
||
|
|
}
|
||
|
|
|
||
|
|
const PayloadHandlerFunc payload_handler;
|
||
|
|
|
||
|
|
BitHistory bit_history { };
|
||
|
|
PreambleMatcher preamble { };
|
||
|
|
UnstuffMatcher unstuff { };
|
||
|
|
EndMatcher end { };
|
||
|
|
|
||
|
|
State state { State::Preamble };
|
||
|
|
baseband::Packet packet { };
|
||
|
|
|
||
|
|
void reset_state() {
|
||
|
|
packet.clear();
|
||
|
|
state = State::Preamble;
|
||
|
|
}
|
||
|
|
};
|
||
|
|
|
||
|
|
#endif/*__PACKET_BUILDER_H__*/
|