82 lines
1.8 KiB
Go
82 lines
1.8 KiB
Go
package column
|
|
|
|
import (
|
|
"fmt"
|
|
"reflect"
|
|
"time"
|
|
|
|
"github.com/kshvakov/clickhouse/lib/binary"
|
|
)
|
|
|
|
type Nullable struct {
|
|
base
|
|
column Column
|
|
}
|
|
|
|
func (null *Nullable) ScanType() reflect.Type {
|
|
return null.column.ScanType()
|
|
}
|
|
|
|
func (null *Nullable) Read(decoder *binary.Decoder) (interface{}, error) {
|
|
return null.column.Read(decoder)
|
|
}
|
|
|
|
func (null *Nullable) Write(encoder *binary.Encoder, v interface{}) error {
|
|
return nil
|
|
}
|
|
|
|
func (null *Nullable) ReadNull(decoder *binary.Decoder, rows int) (_ []interface{}, err error) {
|
|
var (
|
|
isNull byte
|
|
value interface{}
|
|
nulls = make([]byte, rows)
|
|
values = make([]interface{}, rows)
|
|
)
|
|
for i := 0; i < rows; i++ {
|
|
if isNull, err = decoder.ReadByte(); err != nil {
|
|
return nil, err
|
|
}
|
|
nulls[i] = isNull
|
|
}
|
|
for i, isNull := range nulls {
|
|
switch value, err = null.column.Read(decoder); true {
|
|
case err != nil:
|
|
return nil, err
|
|
case isNull == 0:
|
|
values[i] = value
|
|
default:
|
|
values[i] = nil
|
|
}
|
|
}
|
|
return values, nil
|
|
}
|
|
func (null *Nullable) WriteNull(nulls, encoder *binary.Encoder, v interface{}) error {
|
|
if value := reflect.ValueOf(v); v == nil || (value.Kind() == reflect.Ptr && value.IsNil()) {
|
|
if _, err := nulls.Write([]byte{1}); err != nil {
|
|
return err
|
|
}
|
|
return null.column.Write(encoder, null.column.defaultValue())
|
|
}
|
|
if _, err := nulls.Write([]byte{0}); err != nil {
|
|
return err
|
|
}
|
|
return null.column.Write(encoder, v)
|
|
}
|
|
|
|
func parseNullable(name, chType string, timezone *time.Location) (*Nullable, error) {
|
|
if len(chType) < 14 {
|
|
return nil, fmt.Errorf("invalid Nullable column type: %s", chType)
|
|
}
|
|
column, err := Factory(name, chType[9:][:len(chType)-10], timezone)
|
|
if err != nil {
|
|
return nil, fmt.Errorf("Nullable(T): %v", err)
|
|
}
|
|
return &Nullable{
|
|
base: base{
|
|
name: name,
|
|
chType: chType,
|
|
},
|
|
column: column,
|
|
}, nil
|
|
}
|