inline std::pair get_timestamp()

in include/ylt/standalone/cinatra/time_util.hpp [104:255]

• 151 lines of code
• 64 McCabe index (conditional complexity)

inline std::pair<bool, std::time_t> get_timestamp(const String &gmt_time_str) {
  using namespace time_util;
  std::string_view sv(gmt_time_str);
  int year, month, day, hour, min, sec, day_of_week;
  int len_of_gmt_time_str = (int)gmt_time_str.length();
  int len_of_processed_part = 0;
  int len_of_ignored_part = 0;  // second_decimal_part is ignored
  char c;
  constexpr std::array<component_of_time_format, 32> real_format =
      time_util::get_format<Format>();
  if constexpr (Format == time_format::utc_format) {
    day_of_week = -1;
  }
  else if (Format == time_format::utc_without_punctuation_format) {
    day_of_week = -1;
  }

  for (auto &comp : real_format) {
    switch (comp) {
      case component_of_time_format::ending:
        goto travel_done;
        break;
      case component_of_time_format::colon:
      case component_of_time_format::comma:
      case component_of_time_format::SP:
      case component_of_time_format::hyphen:
      case component_of_time_format::dot:
      case component_of_time_format::T:
      case component_of_time_format::Z:
        if (len_of_gmt_time_str - len_of_processed_part < 1) {
          return {false, 0};
        }
        c = sv[len_of_processed_part];
        if ((comp == component_of_time_format::Z && c != 'Z') ||
            (comp == component_of_time_format::T && c != 'T') ||
            (comp == component_of_time_format::dot && c != '.') ||
            (comp == component_of_time_format::hyphen && c != '-') ||
            (comp == component_of_time_format::SP && c != ' ') ||
            (comp == component_of_time_format::colon && c != ':') ||
            (comp == component_of_time_format::comma && c != ',')) {
          return {false, 0};
        }
        len_of_processed_part += 1;
        break;
      case component_of_time_format::year:
        if (len_of_gmt_time_str - len_of_processed_part < 4) {
          return {false, 0};
        }
        if ((year = get_digit(sv.substr(len_of_processed_part, 4), 4)) == -1) {
          return {false, 0};
        }
        len_of_processed_part += 4;
        break;
      case component_of_time_format::month_name:
        if (len_of_gmt_time_str - len_of_processed_part < 3) {
          return {false, 0};
        }
        if ((month = get_month_index(sv.substr(len_of_processed_part, 3))) ==
            -1) {
          return {false, 0};
        }
        len_of_processed_part += 3;
        break;
      case component_of_time_format::hour:
      case component_of_time_format::minute:
      case component_of_time_format::second:
      case component_of_time_format::month:
      case component_of_time_format::day:
        if (len_of_gmt_time_str - len_of_processed_part < 2) {
          return {false, 0};
        }
        int digit;
        if ((digit = get_digit(sv.substr(len_of_processed_part, 2), 2)) == -1) {
          return {false, 0};
        }
        if (comp == component_of_time_format::hour) {
          hour = digit;
          if (hour < 0 || hour >= 24) {
            return {false, 0};
          }
        }
        else if (comp == component_of_time_format::minute) {
          min = digit;
          if (min < 0 || min >= 60) {
            return {false, 0};
          }
        }
        else if (comp == component_of_time_format::month) {
          month = digit;
          if (month < 1 || month > 12) {
            return {false, 0};
          }
          month--;
        }
        else if (comp == component_of_time_format::second) {
          sec = digit;
          if (sec < 0 || sec >= 60) {
            return {false, 0};
          }
        }
        else {
          day = digit;
        }
        len_of_processed_part += 2;
        break;
      case component_of_time_format::day_name:
        if (len_of_gmt_time_str - len_of_processed_part < 3) {
          return {false, 0};
        }
        if ((day_of_week = get_day_index(sv.substr(len_of_processed_part, 3))) <
            0) {
          return {false, 0};
        }
        len_of_processed_part += 3;
        break;
      case component_of_time_format::GMT:
        if (len_of_gmt_time_str - len_of_processed_part < 3) {
          return {false, 0};
        }
        if (sv.substr(len_of_processed_part, 3) != "GMT") {
          return {false, 0};
        }
        len_of_processed_part += 3;
        break;
      case component_of_time_format::second_decimal_part:
        int cur = len_of_processed_part;
        while (cur < len_of_gmt_time_str &&
               (sv[cur] >= '0' && sv[cur] <= '9')) {
          len_of_ignored_part++;
          cur++;
        }
        if (cur == len_of_processed_part) {
          return {false, 0};
        }
        len_of_processed_part = cur;
        break;
    }
  }
travel_done:
  if ((len_of_processed_part != len_of_gmt_time_str) ||
      (len_of_processed_part != len_of_http_time_format &&
       (len_of_processed_part - len_of_ignored_part) !=
           len_of_utc_time_format) &&
          (len_of_processed_part - len_of_ignored_part) !=
              len_of_utc_time_without_punctuation_format) {
    return {false, 0};
  }
  if (day < 1 || day > days_in(month, year)) {
    return {false, 0};
  }
  return faster_mktime(year, month, day, hour, min, sec, day_of_week);
}