TimestampVal DoTrunc()

in be/src/exprs/udf-builtins.cc [283:385]
95 lines of code
42 McCabe index (conditional complexity)

TimestampVal DoTrunc(
    const TimestampValue& ts, TruncUnit trunc_unit, FunctionContext* ctx) {
  const date& orig_date = ts.date();
  const time_duration& orig_time = ts.time();
  TimestampValue ret;
  TimestampVal ret_val;

  // check for invalid or malformed timestamps
  switch (trunc_unit) {
    case TruncUnit::MILLENNIUM:
      // for millenium <= 2000 year value goes to 1001 (outside the supported range)
      if (orig_date.is_special()) return TimestampVal::null();
      if (orig_date.year() <= 2000) return TimestampVal::null();
      break;
    case TruncUnit::CENTURY:
      // for century <= 1400 year value goes to 1301 (outside the supported range)
      if (orig_date.is_special()) return TimestampVal::null();
      if (orig_date.year() <= 1400) return TimestampVal::null();
      break;
    case TruncUnit::WEEK:
      // anything less than 1400-1-6 we have to move to year 1399
      if (orig_date.is_special()) return TimestampVal::null();
      if (orig_date < date(1400, 1, 6)) return TimestampVal::null();
      break;
    case TruncUnit::YEAR:
    case TruncUnit::QUARTER:
    case TruncUnit::MONTH:
    case TruncUnit::WW:
    case TruncUnit::W:
    case TruncUnit::DAY:
    case TruncUnit::DAY_OF_WEEK:
    case TruncUnit::DECADE:
      if (orig_date.is_special()) return TimestampVal::null();
      break;
    case TruncUnit::HOUR:
    case TruncUnit::MINUTE:
    case TruncUnit::SECOND:
    case TruncUnit::MILLISECONDS:
    case TruncUnit::MICROSECONDS:
      if (orig_time.is_special()) return TimestampVal::null();
      break;
    case TruncUnit::UNIT_INVALID:
      DCHECK(false);
  }

  switch(trunc_unit) {
    case TruncUnit::YEAR:
      ret = TruncYear(orig_date);
      break;
    case TruncUnit::QUARTER:
      ret = TruncQuarter(orig_date);
      break;
    case TruncUnit::MONTH:
      ret = TruncMonth(orig_date);
      break;
    case TruncUnit::WW:
      ret = TruncWW(orig_date);
      break;
    case TruncUnit::W:
      ret = TruncW(orig_date);
      break;
    case TruncUnit::DAY:
      ret = TruncDay(orig_date);
      break;
    case TruncUnit::DAY_OF_WEEK:
      ret = TruncDayOfWeek(orig_date);
      break;
    case TruncUnit::HOUR:
      ret = TruncHour(orig_date, orig_time);
      break;
    case TruncUnit::MINUTE:
      ret = TruncMinute(orig_date, orig_time);
      break;
    case TruncUnit::MILLENNIUM:
      ret = TruncMillennium(orig_date);
      break;
    case TruncUnit::CENTURY:
      ret = TruncCentury(orig_date);
      break;
    case TruncUnit::DECADE:
      ret = TruncDecade(orig_date);
      break;
    case TruncUnit::WEEK:
      ret = TruncWeek(orig_date);
      break;
    case TruncUnit::SECOND:
      ret = TruncSecond(orig_date, orig_time);
      break;
    case TruncUnit::MILLISECONDS:
      ret = TruncMilliseconds(orig_date, orig_time);
      break;
    case TruncUnit::MICROSECONDS:
      ret = TruncMicroseconds(orig_date, orig_time);
      break;
    default:
      // internal error: implies StrToTruncUnit out of sync with this switch
      ctx->SetError("truncate unit not supported");
      return TimestampVal::null();
  }

  ret.ToTimestampVal(&ret_val);
  return ret_val;
}