func (self *PointRange) UpdateRange(point *protocol.Point) {
	timestamp := *point.GetTimestampInMicroseconds()
	if timestamp < self.startTime {
		self.startTime = timestamp
	}
	if timestamp > self.endTime {
		self.endTime = timestamp
	}
}

// set the fields of the other time series to null making sure that
// the order of the null values match the order of the field
// definitions, i.e. left timeseries first followed by values from the
// right timeseries
func (self *mergeState) getPoint(fields []string, p *protocol.Point) *protocol.Point {
	if !self.modifyValues {
		return p
	}

	newValues := make([]*protocol.FieldValue, len(self.fields))
	oldValues := p.Values
	for idx, f := range fields {
		newIdx := self.fields[f]
		newValues[newIdx] = oldValues[idx]
	}
	p.Values = newValues
	return p
}

func filterColumns(columns map[string]struct{}, fields []string, point *protocol.Point) {
	if _, ok := columns["*"]; ok {
		return
	}

	newValues := []*protocol.FieldValue{}
	newFields := []string{}
	for idx, f := range fields {
		if _, ok := columns[f]; !ok {
			continue
		}

		newValues = append(newValues, point.Values[idx])
		newFields = append(newFields, f)
	}
	point.Values = newValues
}

func (self *AggregatorEngine) getTimestampFromPoint(point *protocol.Point) int64 {
	return self.getTimestampBucket(*point.GetTimestampInMicroseconds())
}

func (self *QueryEngine) getTimestampFromPoint(point *protocol.Point) int64 {
	return self.getTimestampBucket(uint64(*point.GetTimestampInMicroseconds()))
}