can_message_frame.cpp

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//================================================================================================
//================================================================================================
#include "isobus/isobus/can_message_frame.hpp"
#include "isobus/isobus/can_constants.hpp"
#include "isobus/isobus/can_identifier.hpp"
 
namespace isobus
{
    std::uint32_t CANMessageFrame::get_number_bits_in_message() const
    {
        constexpr std::uint32_t MAX_CONSECUTIVE_SAME_BITS = 5; // After 5 consecutive bits, 6th will be opposite
        const std::uint32_t dataLengthBits = CAN_DATA_LENGTH * dataLength;
        std::uint32_t retVal = 0;
 
        if (isExtendedFrame)
        {
            constexpr std::uint32_t EXTENDED_ID_BEST_NON_DATA_LENGTH = 67; // SOF, ID, Control, CRC, ACK, EOF, and interframe space
            constexpr std::uint32_t EXTENDED_ID_WORST_NON_DATA_LENGTH = 78;
            retVal = ((dataLengthBits + EXTENDED_ID_BEST_NON_DATA_LENGTH) + (dataLengthBits + (dataLengthBits / MAX_CONSECUTIVE_SAME_BITS) + EXTENDED_ID_WORST_NON_DATA_LENGTH));
        }
        else
        {
            constexpr std::uint32_t STANDARD_ID_BEST_NON_DATA_LENGTH = 47; // SOF, ID, Control, CRC, ACK, EOF, and interframe space
            constexpr std::uint32_t STANDARD_ID_WORST_NON_DATA_LENGTH = 54;
            retVal = ((dataLengthBits + STANDARD_ID_BEST_NON_DATA_LENGTH) + (dataLengthBits + (dataLengthBits / MAX_CONSECUTIVE_SAME_BITS) + STANDARD_ID_WORST_NON_DATA_LENGTH));
        }
        return retVal / 2;
    }
} // namespace isobus