std::chrono::microseconds parseTimeOnly()

in squangle/mysql_client/Row.cpp [193:221]

• 28 lines of code
• 4 McCabe index (conditional complexity)

std::chrono::microseconds parseTimeOnly(
    folly::StringPiece mysql_time,
    enum_field_types field_type) {
  static re2::RE2 time_pattern(
      "([-]?\\d{1,3}):(\\d{2}):(\\d{2})(?:\\.(\\d{1,6}))?");
  int hours = 0, minutes = 0, seconds = 0, microseconds = 0;
  std::string microseconds_str;
  if (field_type != MYSQL_TYPE_TIME) {
    throw std::range_error("No conversion available");
  }

  re2::StringPiece re2_mysql_time(mysql_time.data(), mysql_time.size());
  if (!re2::RE2::FullMatch(
          re2_mysql_time.data(),
          time_pattern,
          &hours,
          &minutes,
          &seconds,
          &microseconds_str)) {
    throw std::range_error("Can't parse time");
  }
  if (!microseconds_str.empty()) {
    microseconds_str.resize(6, '0');
    microseconds = folly::to<int>(microseconds_str.c_str());
  }
  auto result = std::chrono::hours(hours) + std::chrono::minutes(minutes) +
      std::chrono::seconds(seconds) + std::chrono::microseconds(microseconds);
  return result;
}