DefaultLogger.h

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#ifndef Default_Logger_h
#define Default_Logger_h
 
// Local includes.
#include "Helper.h"
 
 
// Log messages.
char constexpr FAILED_MESSAGE[] = "Invalid arguments passed to format specifiers (%) in Logger::printfln";
char constexpr LOG_MESSAGE_FORMAT[] = "[TB] %s\n";
 
 
class DefaultLogger {
  public:
    template<typename ...Args>
    static int printfln(char const * format, Args const &... args) {
        // Check if variadic template contains any actual additional arguments that should be inserted into format message.
        // If it does, use constexpr if statement for C++20 supported devices to optimize away the branch instruction at compile time
        // or alternatively runtime for devices that do not support C++20
#if THINGSBOARD_ENABLE_CXX20
        if constexpr (sizeof...(Args) == 0U) {
#else
        if (sizeof...(Args) == 0U) {
#endif // THINGSBOARD_ENABLE_CXX20
            return printf(LOG_MESSAGE_FORMAT, format);
        }
        else {
            auto const size = static_cast<int>(Helper::Calculate_Print_Size(format, args...));
            char arguments[size] = {};
            auto const written_characters = snprintf(arguments, size, format, args...);
            // Written characters is expected to be one less, because of the null termination character
            bool const result = (written_characters == size - 1U);
            return printf(LOG_MESSAGE_FORMAT, result ? arguments : FAILED_MESSAGE);
        }
    }
};
 
#endif // Default_Logger_h