C++ LogMessage::getLineNumber方法代码示例

void LogCategory::admitMessage(const LogMessage& message) const {
  processMessage(message);

  // If this is a fatal message, flush the handlers to make sure the log
  // message was written out, then crash.
  if (isLogLevelFatal(message.getLevel())) {
    auto numHandlers = db_->flushAllHandlers();
    if (numHandlers == 0) {
      // No log handlers were configured.
      // Print the message to stderr, to make sure we always print the reason
      // we are crashing somewhere.
      auto msg = folly::to<std::string>(
          "FATAL:",
          message.getFileName(),
          ":",
          message.getLineNumber(),
          ": ",
          message.getMessage(),
          "\n");
      folly::writeFull(STDERR_FILENO, msg.data(), msg.size());
    }
    std::abort();
  }
}

std::string GlogStyleFormatter::formatMessage(
    const LogMessage& message,
    const LogCategory* /* handlerCategory */) {
  // Get the local time info
  struct tm ltime;
  auto timeSinceEpoch = message.getTimestamp().time_since_epoch();
  auto epochSeconds =
      std::chrono::duration_cast<std::chrono::seconds>(timeSinceEpoch);
  std::chrono::microseconds usecs =
      std::chrono::duration_cast<std::chrono::microseconds>(timeSinceEpoch) -
      epochSeconds;
  time_t unixTimestamp = epochSeconds.count();
  if (!localtime_r(&unixTimestamp, &ltime)) {
    memset(&ltime, 0, sizeof(ltime));
  }

  auto basename = message.getFileBaseName();
  auto headerFormatter = folly::format(
      "{}{:02d}{:02d} {:02d}:{:02d}:{:02d}.{:06d} {:5d} {}:{}] ",
      getGlogLevelName(message.getLevel())[0],
      ltime.tm_mon + 1,
      ltime.tm_mday,
      ltime.tm_hour,
      ltime.tm_min,
      ltime.tm_sec,
      usecs.count(),
      message.getThreadID(),
      basename,
      message.getLineNumber());

  // TODO: Support including thread names and thread context info.

  // The fixed portion of the header takes up 31 bytes.
  //
  // The variable portions that we can't account for here include the line
  // number and the thread ID (just in case it is larger than 6 digits long).
  // Here we guess that 40 bytes will be long enough to include room for this.
  //
  // If this still isn't long enough the string will grow as necessary, so the
  // code will still be correct, but just slightly less efficient than if we
  // had allocated a large enough buffer the first time around.
  size_t headerLengthGuess = 40 + basename.size();

  // Format the data into a buffer.
  std::string buffer;
  StringPiece msgData{message.getMessage()};
  if (message.containsNewlines()) {
    // If there are multiple lines in the log message, add a header
    // before each one.
    std::string header;
    header.reserve(headerLengthGuess);
    headerFormatter.appendTo(header);

    // Make a guess at how many lines will be in the message, just to make an
    // initial buffer allocation.  If the guess is too small then the string
    // will reallocate and grow as necessary, it will just be slightly less
    // efficient than if we had guessed enough space.
    size_t numLinesGuess = 4;
    buffer.reserve(((header.size() + 1) * numLinesGuess) + msgData.size());

    size_t idx = 0;
    while (true) {
      auto end = msgData.find('\n', idx);
      if (end == StringPiece::npos) {
        end = msgData.size();
      }

      buffer.append(header);
      auto line = msgData.subpiece(idx, end - idx);
      buffer.append(line.data(), line.size());
      buffer.push_back('\n');

      if (end == msgData.size()) {
        break;
      }
      idx = end + 1;
    }
  } else {
    buffer.reserve(headerLengthGuess + msgData.size());
    headerFormatter.appendTo(buffer);
    buffer.append(msgData.data(), msgData.size());
    buffer.push_back('\n');
  }

  return buffer;
}