Method FileLogger2

src/loggers/bt_file_logger_v2.cpp:43–93

};

FileLogger2::FileLogger2(const BT::Tree& tree, std::filesystem::path const& filepath)
  : StatusChangeLogger()  // Deferred subscription
  , _p(std::make_unique<Pimpl>())
{
  if(filepath.filename().extension() != ".btlog")
  {
    throw RuntimeError("FileLogger2: the file extension must be [.btlog]");
  }

  enableTransitionToIdle(true);

  //-------------------------------------
  _p->file_stream.open(filepath, std::ofstream::binary | std::ofstream::out);

  if(!_p->file_stream.is_open())
  {
    throw RuntimeError("problem opening file in FileLogger2");
  }

  _p->file_stream << "BTCPP4-FileLogger2";

  const uint8_t protocol = 1;

  _p->file_stream << protocol;

  std::string const xml = WriteTreeToXML(tree, true, true);

  // serialize the length of the buffer in the first 4 bytes
  std::array<char, 8> write_buffer{};
  flatbuffers::WriteScalar(write_buffer.data(), static_cast<int32_t>(xml.size()));
  _p->file_stream.write(write_buffer.data(), 4);

  // write the XML definition
  _p->file_stream.write(xml.data(), static_cast<std::streamsize>(xml.size()));

  _p->first_timestamp = std::chrono::system_clock::now().time_since_epoch();

  // save the first timestamp in the next 8 bytes (microseconds)
  const int64_t timestamp_usec = ToUsec(_p->first_timestamp);
  flatbuffers::WriteScalar(write_buffer.data(), timestamp_usec);
  _p->file_stream.write(write_buffer.data(), 8);

  _p->writer_thread = std::thread(&FileLogger2::writerLoop, this);

  // Wait for writer thread to signal readiness (under mutex for proper synchronization)
  {
    std::unique_lock lock(_p->queue_mutex);
    _p->queue_cv.wait(lock, [this]() { return _p->writer_ready.load(); });
  }
  subscribeToTreeChanges(tree.rootNode());
}

FileLogger2::~FileLogger2()
{