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 }