lbry.go/uint16.go
2016-11-11 01:00:05 +10:00

130 lines
2.6 KiB
Go

package null
import (
"bytes"
"database/sql/driver"
"encoding/json"
"fmt"
"math"
"strconv"
"gopkg.in/nullbio/null.v5/convert"
)
// Uint16 is an nullable uint16.
type Uint16 struct {
Uint16 uint16
Valid bool
}
// NewUint16 creates a new Uint16
func NewUint16(i uint16, valid bool) Uint16 {
return Uint16{
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.
func (u *Uint16) UnmarshalJSON(data []byte) error {
if bytes.Equal(data, NullBytes) {
u.Valid = false
u.Uint16 = 0
return nil
}
var x uint64
if err := json.Unmarshal(data, &x); err != nil {
return err
}
if x > math.MaxUint16 {
return fmt.Errorf("json: %d overflows max uint8 value", x)
}
u.Uint16 = uint16(x)
u.Valid = true
return nil
}
// UnmarshalText implements encoding.TextUnmarshaler.
func (u *Uint16) UnmarshalText(text []byte) error {
str := string(text)
if str == "" || str == "null" {
u.Valid = false
return nil
}
var err error
res, err := strconv.ParseUint(string(text), 10, 16)
u.Valid = err == nil
if u.Valid {
u.Uint16 = uint16(res)
}
return err
}
// MarshalJSON implements json.Marshaler.
func (u Uint16) MarshalJSON() ([]byte, error) {
if !u.Valid {
return []byte("null"), nil
}
return []byte(strconv.FormatUint(uint64(u.Uint16), 10)), nil
}
// MarshalText implements encoding.TextMarshaler.
func (u Uint16) MarshalText() ([]byte, error) {
if !u.Valid {
return []byte{}, nil
}
return []byte(strconv.FormatUint(uint64(u.Uint16), 10)), nil
}
// SetValid changes this Uint16's value and also sets it to be non-null.
func (u *Uint16) SetValid(n uint16) {
u.Uint16 = n
u.Valid = true
}
// Ptr returns a pointer to this Uint16's value, or a nil pointer if this Uint16 is null.
func (u Uint16) Ptr() *uint16 {
if !u.Valid {
return nil
}
return &u.Uint16
}
// IsZero returns true for invalid Uint16's, for future omitempty support (Go 1.4?)
func (u Uint16) IsZero() bool {
return !u.Valid
}
// Scan implements the Scanner interface.
func (u *Uint16) Scan(value interface{}) error {
if value == nil {
u.Uint16, u.Valid = 0, false
return nil
}
u.Valid = true
return convert.ConvertAssign(&u.Uint16, value)
}
// Value implements the driver Valuer interface.
func (u Uint16) Value() (driver.Value, error) {
if !u.Valid {
return nil, nil
}
return int64(u.Uint16), nil
}