Method AddSub

be/src/exprs/timestamp-functions-ir.cc:784–822

template <bool is_add, typename AnyIntVal, typename Interval,
    bool is_add_months_keep_last_day>
TimestampVal TimestampFunctions::AddSub(FunctionContext* context,
    const TimestampVal& timestamp, const AnyIntVal& num_interval_units) {
  DCHECK_EQ(Date(max_date_time).year(), MAX_YEAR);
  DCHECK_EQ(Date(min_date_time).year(), MIN_YEAR);
  if (timestamp.is_null || num_interval_units.is_null) return TimestampVal::null();
  const TimestampValue& value = TimestampValue::FromTimestampVal(timestamp);
  if (!value.HasDate()) return TimestampVal::null();
  // Adding/subtracting boost::gregorian::dates can throw if the result exceeds the
  // min/max supported dates. (Sometimes the exception is thrown lazily and calling an
  // accessor functions is needed to trigger validation.)
  if (UNLIKELY(IsOverMaxInterval<Interval>(num_interval_units.val))) {
    context->AddWarning(Substitute("Cannot $0 interval $1: Interval value too large",
        is_add ? "add" : "subtract", num_interval_units.val).c_str());
    return TimestampVal::null();
  }
  try {
    ptime datetime;
    value.ToPtime(&datetime);
    if (is_add_months_keep_last_day) {
      AddMonths(context, is_add ? num_interval_units.val : -num_interval_units.val, true,
          &datetime);
    } else {
      AddInterval<Interval>(context,
          is_add ? num_interval_units.val : -num_interval_units.val, &datetime);
    }
    // Validate that the ptime is not "special" (ie not_a_date_time) and has a valid year.
    // If validation fails, an exception is thrown.
    datetime.date().year();
    const TimestampValue result_value(datetime);
    TimestampVal result_val;
    result_value.ToTimestampVal(&result_val);
    DcheckAddSubResult(timestamp, result_val, is_add, num_interval_units.val);
    return result_val;
  } catch (const std::exception& e) {
    context->AddWarning(Substitute("Cannot $0 interval $1: $2",
        is_add ? "add" : "subtract", num_interval_units.val, e.what()).c_str());
    return TimestampVal::null();
  }
}

IntVal TimestampFunctions::DateDiff(FunctionContext* context,
    const TimestampVal& ts_val1,