connection.hpp

// Modbus for c++ <https://github.com/Mazurel/Modbus>
// Copyright (c) 2020 Mateusz Mazur aka Mazurel
// Licensed under: MIT License <http://opensource.org/licenses/MIT>
 
#pragma once
 
#include <sstream>
#include <stdexcept>
#include <string>
#include <tuple>
#include <vector>
 
#include <cerrno>
#include <fcntl.h>
#include <poll.h>
#include <termios.h>
#include <unistd.h>
 
#include "MB/modbusException.hpp"
#include "MB/modbusRequest.hpp"
#include "MB/modbusResponse.hpp"
#include "MB/modbusUtils.hpp"
 
namespace MB::Serial {
class Connection {
  public:
    // Pretty high timeout
    static const unsigned int DefaultSerialTimeout = 100;
 
  private:
    struct termios _termios;
    int _fd;
 
    int _timeout = Connection::DefaultSerialTimeout;
 
  public:
    constexpr explicit Connection() : _termios(), _fd(-1) {}
    explicit Connection(const std::string &path);
    explicit Connection(const Connection &) = delete;
    explicit Connection(Connection &&) noexcept;
    Connection &operator=(Connection &&);
    ~Connection();
 
    void connect();
 
    std::vector<uint8_t> sendRequest(const MB::ModbusRequest &request);
    std::vector<uint8_t> sendResponse(const MB::ModbusResponse &response);
    std::vector<uint8_t> sendException(const MB::ModbusException &exception);
 
    std::vector<uint8_t> send(std::vector<uint8_t> data);
 
    void clearInput();
 
    [[nodiscard]] std::tuple<MB::ModbusResponse, std::vector<uint8_t>> awaitResponse();
    [[nodiscard]] std::tuple<MB::ModbusRequest, std::vector<uint8_t>> awaitRequest();
 
    [[nodiscard]] std::vector<uint8_t> awaitRawMessage();
 
    void enableParity(const bool parity) {
        if (parity)
            getTTY().c_cflag |= PARENB;
        else
            getTTY().c_cflag &= ~PARENB;
    }
 
    void setEvenParity() {
        enableParity(true);
        getTTY().c_cflag &= ~PARODD;
    }
 
    void setOddParity() {
        enableParity(true);
        getTTY().c_cflag |= PARODD;
    }
 
    void setTwoStopBits(const bool two) {
        if (two) {
            getTTY().c_cflag |= CSTOPB;
        } else {
            getTTY().c_cflag &= ~CSTOPB;
        }
    }
 
#define setBaud(s)                                                                       \
    case s:                                                                              \
        speed = B##s;                                                                    \
        break;
    void setBaudRate(speed_t speed) {
        switch (speed) {
            setBaud(0);
            setBaud(50);
            setBaud(75);
            setBaud(110);
            setBaud(134);
            setBaud(150);
            setBaud(200);
            setBaud(300);
            setBaud(600);
            setBaud(1200);
            setBaud(1800);
            setBaud(2400);
            setBaud(4800);
            setBaud(9600);
            setBaud(19200);
            setBaud(38400);
            setBaud(57600);
            setBaud(115200);
            setBaud(230400);
        default:
            throw std::runtime_error("Invalid baud rate");
        }
        cfsetospeed(&_termios, speed);
        cfsetispeed(&_termios, speed);
    }
#undef setBaud
 
    termios &getTTY() { return _termios; }
 
    int getTimeout() const { return _timeout; }
 
    void setTimeout(int timeout) { _timeout = timeout; }
};
} // namespace MB::Serial