lbry.go/uint16.go
2016-09-07 21:33:21 +10:00

147 lines
3.5 KiB
Go

package null
import (
"database/sql/driver"
"encoding/json"
"fmt"
"reflect"
"strconv"
"gopkg.in/nullbio/null.v5/convert"
)
// NullUint16 is a replica of sql.NullInt64 for uint16 types.
type NullUint16 struct {
Uint16 uint16
Valid bool
}
// Uint16 is an nullable uint16.
// It does not consider zero values to be null.
// It will decode to null, not zero, if null.
type Uint16 struct {
NullUint16
}
// NewUint16 creates a new Uint16
func NewUint16(i uint16, valid bool) Uint16 {
return Uint16{
NullUint16: NullUint16{
Uint16: i,
Valid: valid,
},
}
}
// Uint16From creates a new Uint16 that will always be valid.
func Uint16From(i uint16) Uint16 {
return NewUint16(i, true)
}
// Uint16FromPtr creates a new Uint16 that be null if i is nil.
func Uint16FromPtr(i *uint16) Uint16 {
if i == nil {
return NewUint16(0, false)
}
return NewUint16(*i, true)
}
// UnmarshalJSON implements json.Unmarshaler.
// It supports number and null input.
// 0 will not be considered a null Uint16.
// It also supports unmarshalling a sql.NullUint16.
func (i *Uint16) UnmarshalJSON(data []byte) error {
var err error
var v interface{}
if err = json.Unmarshal(data, &v); err != nil {
return err
}
switch v.(type) {
case float64:
// Unmarshal again, directly to uint16, to avoid intermediate float64
err = json.Unmarshal(data, &i.Uint16)
case map[string]interface{}:
err = json.Unmarshal(data, &i.NullUint16)
case nil:
i.Valid = false
return nil
default:
err = fmt.Errorf("json: cannot unmarshal %v into Go value of type null.Uint16", reflect.TypeOf(v).Name())
}
i.Valid = err == nil
return err
}
// UnmarshalText implements encoding.TextUnmarshaler.
// It will unmarshal to a null Uint16 if the input is a blank or not an integer.
// It will return an error if the input is not an integer, blank, or "null".
func (i *Uint16) UnmarshalText(text []byte) error {
str := string(text)
if str == "" || str == "null" {
i.Valid = false
return nil
}
var err error
res, err := strconv.ParseUint(string(text), 10, 16)
i.Valid = err == nil
if i.Valid {
i.Uint16 = uint16(res)
}
return err
}
// MarshalJSON implements json.Marshaler.
// It will encode null if this Uint16 is null.
func (i Uint16) MarshalJSON() ([]byte, error) {
if !i.Valid {
return []byte("null"), nil
}
return []byte(strconv.FormatUint(uint64(i.Uint16), 10)), nil
}
// MarshalText implements encoding.TextMarshaler.
// It will encode a blank string if this Uint16 is null.
func (i Uint16) MarshalText() ([]byte, error) {
if !i.Valid {
return []byte{}, nil
}
return []byte(strconv.FormatUint(uint64(i.Uint16), 10)), nil
}
// SetValid changes this Uint16's value and also sets it to be non-null.
func (i *Uint16) SetValid(n uint16) {
i.Uint16 = n
i.Valid = true
}
// Ptr returns a pointer to this Uint16's value, or a nil pointer if this Uint16 is null.
func (i Uint16) Ptr() *uint16 {
if !i.Valid {
return nil
}
return &i.Uint16
}
// IsZero returns true for invalid Uint16's, for future omitempty support (Go 1.4?)
// A non-null Uint16 with a 0 value will not be considered zero.
func (i Uint16) IsZero() bool {
return !i.Valid
}
// Scan implements the Scanner interface.
func (n *NullUint16) Scan(value interface{}) error {
if value == nil {
n.Uint16, n.Valid = 0, false
return nil
}
n.Valid = true
return convert.ConvertAssign(&n.Uint16, value)
}
// Value implements the driver Valuer interface.
func (n NullUint16) Value() (driver.Value, error) {
if !n.Valid {
return nil, nil
}
return int64(n.Uint16), nil
}