YugabyteDB (2.13.0.0-b42, bfc6a6643e7399ac8a0e81d06a3ee6d6571b33ab)

//--------------------------------------------------------------------------------------------------

// Copyright (c) YugaByte, Inc.

//

// Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except

// in compliance with the License.  You may obtain a copy of the License at

//

// http://www.apache.org/licenses/LICENSE-2.0

//

// Unless required by applicable law or agreed to in writing, software distributed under the License

// is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express

// or implied.  See the License for the specific language governing permissions and limitations

// under the License.

//

//

// DateTime parser and serializer

//--------------------------------------------------------------------------------------------------

#include "yb/util/date_time.h"

#include <unicode/gregocal.h>

#include <regex>

#include <boost/date_time/c_local_time_adjustor.hpp>

#include <boost/date_time/local_time/local_time.hpp>

#include <boost/smart_ptr/make_shared.hpp>

#include "yb/gutil/casts.h"

#include "yb/util/result.h"

#include "yb/util/status_format.h"

using std::locale;

using std::vector;

using std::string;

using std::regex;

using icu::GregorianCalendar;

using icu::TimeZone;

using icu::UnicodeString;

using boost::gregorian::date;

using boost::local_time::local_date_time;

using boost::local_time::local_time_facet;

using boost::local_time::local_microsec_clock;

using boost::local_time::posix_time_zone;

using boost::local_time::time_zone_ptr;

using boost::posix_time::ptime;

using boost::posix_time::microseconds;

using boost::posix_time::time_duration;

using boost::posix_time::microsec_clock;

using boost::posix_time::milliseconds;

DEFINE_bool(use_icu_timezones, true, "Use the new ICU library for timezones instead of boost");

namespace yb {

namespace {

// UTC timezone.

static const time_zone_ptr kUtcTimezone(new posix_time_zone("UTC"));

// Unix epoch (time_t 0) at UTC.

static const local_date_time kEpoch(boost::posix_time::from_time_t(0), kUtcTimezone);

// Date offset of Unix epoch (2^31).

static constexpr uint32_t kEpochDateOffset = 1<<31;

// Day in milli- and micro-seconds.

static constexpr int64_t kDayInMilliSeconds = 24 * 60 * 60 * 1000L;

static constexpr int64_t kDayInMicroSeconds = kDayInMilliSeconds * 1000L;

Timestamp ToTimestamp(const local_date_time& t) {

  return Timestamp((t - kEpoch).total_microseconds());

}

Result<uint32_t> ToDate(const int64_t days_since_epoch) {

  const int64_t date = days_since_epoch + kEpochDateOffset;

  if (date < std::numeric_limits<uint32_t>::min() || date > std::numeric_limits<uint32_t>::max()) {

    return STATUS(InvalidArgument, "Invalid date");

  }

  return narrow_cast<uint32_t>(date);

}

Result<GregorianCalendar> CreateCalendar() {

  UErrorCode status = U_ZERO_ERROR;

  GregorianCalendar cal(*TimeZone::getGMT(), status);

  if (U_FAILURE(status)) {

    return STATUS(InvalidArgument, "Failed to create Gregorian calendar", u_errorName(status));

  }

  cal.setGregorianChange(U_DATE_MIN, status);

  if (U_FAILURE(status)) {

    return STATUS(InvalidArgument, "Failed to set Gregorian change", u_errorName(status));

  }

  cal.setLenient(FALSE);

  cal.clear();

  return cal;

}

// Get system (local) time zone.

string GetSystemTimezone() {

  // Get system timezone by getting current UTC time, converting to local time and computing the

  // offset.

  const ptime utc_time = microsec_clock::universal_time();

  const ptime local_time = boost::date_time::c_local_adjustor<ptime>::utc_to_local(utc_time);

  const time_duration offset = local_time - utc_time;

  const int hours = narrow_cast<int>(offset.hours());

  const int minutes = narrow_cast<int>(offset.minutes());

  char buffer[7]; // "+HH:MM" or "-HH:MM"

  const size_t result = snprintf(buffer, sizeof(buffer), "%+2.2d:%2.2d", hours, minutes);

  CHECK(result > 0 && result < sizeof(buffer)) << "Unexpected snprintf result: " << result;

  return buffer;

}

/* Subset of supported Timezone formats https://docs.oracle.com/cd/E51711_01/DR/ICU_Time_Zones.html

 * Full database can be found at https://www.iana.org/time-zones

 * We support everything that Cassandra supports, like z/Z, +/-0800, +/-08:30 GMT+/-[0]7:00,

 * and we also support UTC+/-[0]9:30 which Cassandra does not support

 */

Result<string> GetTimezone(string timezoneID) {

  /* Parse timezone offset from string in most formats of timezones

   * Some formats are supported by ICU and some different ones by Boost::PosixTime

   * To capture both, return posix supported directly, and for ICU, create ICU Timezone and then

   * convert to a supported Posix format.

   */

  // [+/-]0830 is not supported by ICU TimeZone or Posixtime so need to do some extra work

  std::smatch m;

  std::regex rgx = regex("(?:\\+|-)(\\d{2})(\\d{2})");

  if (timezoneID.empty()) {

    return GetSystemTimezone();

  } else if (timezoneID == "z" || timezoneID == "Z") {

    timezoneID = "GMT";

  } else if (std::regex_match(timezoneID, m , rgx)) {

    return m.str(1) + ":" + m.str(2);

  } else if (timezoneID.at(0) == '+' || timezoneID.at(0) == '-' ||

             timezoneID.substr(0, 3) == "UTC") {

    return timezoneID;

  }

  std::unique_ptr<TimeZone> tzone(TimeZone::createTimeZone(timezoneID.c_str()));

  UnicodeString id;

  tzone->getID(id);

  string timezone;

  id.toUTF8String(timezone);

  if (*tzone == TimeZone::getUnknown()) {

    return STATUS(InvalidArgument, "Invalid Timezone: " + timezoneID +

        "\nUse standardized timezone such as \"America/New_York\" or offset such as UTC-07:00.");

  }

  time_duration td = milliseconds(tzone->getRawOffset());

  const int hours = narrow_cast<int>(td.hours());

  const int minutes = narrow_cast<int>(td.minutes());

  char buffer[7]; // "+HH:MM" or "-HH:MM"

  const size_t result = snprintf(buffer, sizeof(buffer), "%+2.2d:%2.2d", hours, abs(minutes));

  if (result <= 0 || result >= sizeof(buffer)) {

    return STATUS(Corruption, "Parsing timezone into timezone offset string failed");

  }

  return buffer;

}

Result<time_zone_ptr> StringToTimezone(const std::string& tz, bool use_utc) {

  if (tz.empty()) {

    return use_utc ? kUtcTimezone : boost::make_shared<posix_time_zone>(GetSystemTimezone());

  }

  if (FLAGS_use_icu_timezones) {

    return boost::make_shared<posix_time_zone>(VERIFY_RESULT(GetTimezone(tz)));

  }

  return boost::make_shared<posix_time_zone>(tz);

}

} // namespace

//------------------------------------------------------------------------------------------------

Result<Timestamp> DateTime::TimestampFromString(const string& str,

                                                const InputFormat& input_format) {

  std::smatch m;

  // trying first regex to match from the format

  for (const auto& reg : input_format.regexes) {

    if (std::regex_match(str, m, reg)) {

      // setting default values where missing

      const int year = stoi(m.str(1));

      const int month = stoi(m.str(2));

      const int day = stoi(m.str(3));

      const int hours = m.str(4).empty() ? 0 : stoi(m.str(4));

      const int minutes = m.str(5).empty() ? 0 : stoi(m.str(5));

      const int seconds = m.str(6).empty() ? 0 : stoi(m.str(6));

      int64_t frac = m.str(7).empty() ? 0 : stoi(m.str(7));

      frac = AdjustPrecision(frac, m.str(7).size(), time_duration::num_fractional_digits());

      // constructing date_time and getting difference from epoch to set as Timestamp value

      try {

        const date d(year, month, day);

        const time_duration t(hours, minutes, seconds, frac);

        time_zone_ptr tz = VERIFY_RESULT(StringToTimezone(m.str(8), input_format.use_utc));

        return ToTimestamp(local_date_time(d, t, tz, local_date_time::NOT_DATE_TIME_ON_ERROR));

      } catch (std::exception& e) {

        return STATUS(InvalidArgument, "Invalid timestamp", e.what());

      }

    }

  }

  return STATUS_FORMAT(InvalidArgument, "Invalid timestamp $0: Wrong format of input string", str);

}

Timestamp DateTime::TimestampFromInt(const int64_t val, const InputFormat& input_format) {

  return Timestamp(AdjustPrecision(val, input_format.input_precision, kInternalPrecision));

}

string DateTime::TimestampToString(const Timestamp timestamp, const OutputFormat& output_format) {

  std::ostringstream ss;

  ss.imbue(output_format.output_locale);

  static const local_date_time kSystemEpoch(

      boost::posix_time::from_time_t(0), boost::make_shared<posix_time_zone>(GetSystemTimezone()));

  try {

    auto epoch = output_format.use_utc ? kEpoch : kSystemEpoch;

    ss << epoch + microseconds(timestamp.value());

  } catch (...) {

    // If we cannot produce a valid date, default to showing the exact timestamp value.

    // This can happen if timestamp value is outside the standard year range (1400..10000).

    ss << timestamp.value();

  }

  return ss.str();

}

Timestamp DateTime::TimestampNow() {

  return ToTimestamp(local_microsec_clock::local_time(kUtcTimezone));

}

//------------------------------------------------------------------------------------------------

Result<uint32_t> DateTime::DateFromString(const std::string& str) {

  // Regex for date format "yyyy-mm-dd"

  static const regex date_format("(-?\\d{1,7})-(\\d{1,2})-(\\d{1,2})");

  std::smatch m;

  if (!std::regex_match(str, m, date_format)) {

    return STATUS(InvalidArgument, "Invalid date format");

  }

  const int year = stoi(m.str(1));

  const int month = stoi(m.str(2));

  const int day = stoi(m.str(3));

  if (month < 1 || month > 12) {

    return STATUS(InvalidArgument, "Invalid month");

  }

  if (day < 1 || day > 31) {

    return STATUS(InvalidArgument, "Invalid day of month");

  }

  const auto cal_era = (year <= 0) ? GregorianCalendar::EEras::BC : GregorianCalendar::EEras::AD;

  const int cal_year = (year <= 0) ? -year + 1 : year;

  GregorianCalendar cal = VERIFY_RESULT(CreateCalendar());

  cal.set(UCAL_ERA, cal_era);

  cal.set(cal_year, month - 1, day);

  UErrorCode status = U_ZERO_ERROR;

  const int64_t ms_since_epoch = cal.getTime(status);

  if (U_FAILURE(status)) {

    return STATUS(InvalidArgument, "Failed to get time", u_errorName(status));

  }

  return ToDate(ms_since_epoch / kDayInMilliSeconds);

}

Result<uint32_t> DateTime::DateFromTimestamp(const Timestamp timestamp) {

  return ToDate(timestamp.ToInt64() / kDayInMicroSeconds);

}

Result<uint32_t> DateTime::DateFromUnixTimestamp(const int64_t unix_timestamp) {

  return ToDate(unix_timestamp / kDayInMilliSeconds);

}

Result<string> DateTime::DateToString(const uint32_t date) {

  GregorianCalendar cal = VERIFY_RESULT(CreateCalendar());

  UErrorCode status = U_ZERO_ERROR;

  cal.setTime(DateToUnixTimestamp(date), status);

  if (U_FAILURE(status)) {

    return STATUS(InvalidArgument, "Failed to set time", u_errorName(status));

  }

  const int year  = cal.get(UCAL_ERA, status) == GregorianCalendar::EEras::BC ?

                    -(cal.get(UCAL_YEAR, status) - 1) : cal.get(UCAL_YEAR, status);

  const int month = cal.get(UCAL_MONTH, status) + 1;

  const int day   = cal.get(UCAL_DATE, status);

  if (U_FAILURE(status)) {

    return STATUS(InvalidArgument, "Failed to get date", u_errorName(status));

  }

  char buffer[15]; // Between "-5877641-06-23" and "5881580-07-11".

  const size_t result = snprintf(buffer, sizeof(buffer), "%d-%2.2d-%2.2d", year, month, day);

  CHECK(result > 0 && result < sizeof(buffer)) << "Unexpected snprintf result: " << result;

  return buffer;

}

Timestamp DateTime::DateToTimestamp(uint32_t date) {

  return Timestamp((static_cast<int64_t>(date) - kEpochDateOffset) * kDayInMicroSeconds);

}

int64_t DateTime::DateToUnixTimestamp(uint32_t date) {

  return (static_cast<int64_t>(date) - kEpochDateOffset) * kDayInMilliSeconds;

}

uint32_t DateTime::DateNow() {

  return narrow_cast<uint32_t>(TimestampNow().ToInt64() / kDayInMicroSeconds + kEpochDateOffset);

}

//------------------------------------------------------------------------------------------------

Result<int64_t> DateTime::TimeFromString(const std::string& str) {

  // Regex for time format "hh:mm:ss[.fffffffff]"

  static const regex time_format("(\\d{1,2}):(\\d{1,2}):(\\d{1,2})(\\.(\\d{0,9}))?");

  std::smatch m;

  if (!std::regex_match(str, m, time_format)) {

    return STATUS(InvalidArgument, "Invalid time format");

  }

  const int64_t hour = stoi(m.str(1));

  const int64_t minute = stoi(m.str(2));

  const int64_t second = stoi(m.str(3));

  const int64_t nano_sec = m.str(5).empty() ? 0 : (stoi(m.str(5)) * pow(10, 9 - m.str(5).size()));

  if (hour < 0 || hour > 23) {

    return STATUS(InvalidArgument, "Invalid hour");

  }

  if (minute < 0 || minute > 59) {

    return STATUS(InvalidArgument, "Invalid minute");

  }

  if (second < 0 || second > 59) {

    return STATUS(InvalidArgument, "Invalid second");

  }

  return ((hour * 60 + minute) * 60 + second) * 1000000000 + nano_sec;

}

Result<string> DateTime::TimeToString(int64_t time) {

  if (time < 0) {

    return STATUS(InvalidArgument, "Invalid time");

  }

  const int nano_sec = time % 1000000000; time /= 1000000000;

  const int second = time % 60; time /= 60;

  const int minute = time % 60; time /= 60;

  if (time > 23) {

    return STATUS(InvalidArgument, "Invalid hour");

  }

  const int hour = narrow_cast<int>(time);

  char buffer[19]; // "hh:mm:ss[.fffffffff]"

  const size_t result = snprintf(buffer, sizeof(buffer), "%2.2d:%2.2d:%2.2d.%9.9d",

                                 hour, minute, second, nano_sec);

  CHECK(result > 0 && result < sizeof(buffer)) << "Unexpected snprintf result: " << result;

  return buffer;

}

int64_t DateTime::TimeNow() {

  return (TimestampNow().ToInt64() % kDayInMicroSeconds) * 1000;

}

//------------------------------------------------------------------------------------------------

Result<MonoDelta> DateTime::IntervalFromString(const std::string& str) {

  /* See Postgres: DecodeInterval() in datetime.c */

  static const std::vector<std::regex> regexes {

      // ISO 8601: '3d 4h 5m 6s'

      // Abbreviated Postgres: '3 d 4 hrs 5 mins 6 secs'

      // Traditional Postgres: '3 days 4 hours 5 minutes 6 seconds'

      std::regex("(?:(\\d+) ?d(?:ay)?s?)? *(?:(\\d+) ?h(?:ou)?r?s?)? *"

                     "(?:(\\d+) ?m(?:in(?:ute)?s?)?)? *(?:(\\d+) ?s(?:ec(?:ond)?s?)?)?",

                 std::regex_constants::icase),

      // SQL Standard: 'D H:M:S'

      std::regex("(?:(\\d+) )?(\\d{1,2}):(\\d{1,2}):(\\d{1,2})", std::regex_constants::icase),

  };

  // Try each regex to see if one matches.

  for (const auto& reg : regexes) {

    std::smatch m;

    if (std::regex_match(str, m, reg)) {

      // All regex's have the name 4 capture groups, in order.

      const auto day = m.str(1).empty() ? 0 : stol(m.str(1));

      const auto hours = m.str(2).empty() ? 0 : stol(m.str(2));

      const auto minutes = m.str(3).empty() ? 0 : stol(m.str(3));

      const auto seconds = m.str(4).empty() ? 0 : stol(m.str(4));

      // Convert to microseconds.

      return MonoDelta::FromSeconds(seconds + (60 * (minutes + 60 * (hours + 24 * day))));

    }

  }

  return STATUS(InvalidArgument, "Invalid interval", "Wrong format of input string: " + str);

}

//------------------------------------------------------------------------------------------------

int64_t DateTime::AdjustPrecision(int64_t val,

                                  size_t input_precision,

                                  const size_t output_precision) {

  while (input_precision < output_precision) {

    // In case of overflow we just return max/min values -- this is needed for correctness of

    // comparison operations and is similar to Cassandra behaviour.

    if (val > (INT64_MAX / 10)) return INT64_MAX;

    if (val < (INT64_MIN / 10)) return INT64_MIN;

    val *= 10;

    input_precision += 1;

  }

  while (input_precision > output_precision) {

    val /= 10;

    input_precision -= 1;

  }

  return val;

}

namespace {

std::vector<std::regex> InputFormatRegexes() {

  // declaring format components used to construct regexes below

  string fmt_empty = "()";

  string date_fmt = "(\\d{4})-(\\d{1,2})-(\\d{1,2})";

  string time_fmt = "(\\d{1,2}):(\\d{1,2}):(\\d{1,2})";

  string time_fmt_no_sec = "(\\d{1,2}):(\\d{1,2})" + fmt_empty;

  string time_empty = fmt_empty + fmt_empty + fmt_empty;

  string frac_fmt = "\\.(\\d{6}|\\d{1,3})";

  // Offset, i.e. +/-xx:xx, +/-0000, timezone parser will do additional checking.

  string tzX_fmt = "((?:\\+|-)\\d{2}:?\\d{2})";

  // Zulu Timezone e.g allows user to just add z or Z at the end with no space in front to indicate

  // Zulu Time which is equivlent to GMT/UTC.

  string tzY_fmt = "([zZ])";

  // Timezone name, abbreviation, or offset (preceded by space), e.g. PDT, UDT+/-xx:xx, etc..

  // At this point this allows anything that starts with a letter or '+' (after space), and leaves

  // further processing to the timezone parser.

  string tzZ_fmt = " ([a-zA-Z\\+].+)";

  std::vector<std::regex> result;

  for (const auto& sep : { " ", "T" }) {

    for (const auto& time : { time_fmt_no_sec, time_fmt }) {

      for (const auto& frac : { fmt_empty, frac_fmt }) {

        for (const auto& tz : { fmt_empty, tzX_fmt, tzY_fmt, tzZ_fmt }) {

          result.emplace_back(date_fmt + sep + time + frac + tz);

        }

      }

    }

  }

  for (const auto& tz : { fmt_empty, tzX_fmt, tzY_fmt, tzZ_fmt }) {

    result.emplace_back(date_fmt + time_empty + fmt_empty + tz);

  }

  return result;

}

} // namespace

const DateTime::InputFormat DateTime::CqlInputFormat = {

  .regexes = InputFormatRegexes(),

  .input_precision = 3, // Cassandra current default

  .use_utc = false,

};

const DateTime::OutputFormat DateTime::CqlOutputFormat = OutputFormat {

  .output_locale = locale(locale::classic(), new local_time_facet("%Y-%m-%dT%H:%M:%S.%f%q")),

  .use_utc = true,

};

const DateTime::InputFormat DateTime::HumanReadableInputFormat = DateTime::InputFormat {

  .regexes = InputFormatRegexes(),

  .input_precision = 6,

  .use_utc = false,

};

const DateTime::OutputFormat DateTime::HumanReadableOutputFormat = OutputFormat {

  .output_locale = locale(locale::classic(), new local_time_facet("%Y-%m-%d %H:%M:%S.%f")),

  .use_utc = false,

};

} // namespace yb