lbry.go/uint32.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"
)
// Uint32 is an nullable uint32.
type Uint32 struct {
Uint32 uint32
Valid bool
}
// NewUint32 creates a new Uint32
func NewUint32(i uint32, valid bool) Uint32 {
return Uint32{
Uint32: i,
Valid: valid,
}
}
// Uint32From creates a new Uint32 that will always be valid.
func Uint32From(i uint32) Uint32 {
return NewUint32(i, true)
}
// Uint32FromPtr creates a new Uint32 that be null if i is nil.
func Uint32FromPtr(i *uint32) Uint32 {
if i == nil {
return NewUint32(0, false)
}
return NewUint32(*i, true)
}
// UnmarshalJSON implements json.Unmarshaler.
func (u *Uint32) UnmarshalJSON(data []byte) error {
if bytes.Equal(data, NullBytes) {
u.Valid = false
u.Uint32 = 0
return nil
}
var x uint64
if err := json.Unmarshal(data, &x); err != nil {
return err
}
if x > math.MaxUint32 {
return fmt.Errorf("json: %d overflows max uint32 value", x)
}
u.Uint32 = uint32(x)
u.Valid = true
return nil
}
// UnmarshalText implements encoding.TextUnmarshaler.
func (u *Uint32) 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, 32)
u.Valid = err == nil
if u.Valid {
u.Uint32 = uint32(res)
}
return err
}
// MarshalJSON implements json.Marshaler.
func (u Uint32) MarshalJSON() ([]byte, error) {
if !u.Valid {
return []byte("null"), nil
}
return []byte(strconv.FormatUint(uint64(u.Uint32), 10)), nil
}
// MarshalText implements encoding.TextMarshaler.
func (u Uint32) MarshalText() ([]byte, error) {
if !u.Valid {
return []byte{}, nil
}
return []byte(strconv.FormatUint(uint64(u.Uint32), 10)), nil
}
// SetValid changes this Uint32's value and also sets it to be non-null.
func (u *Uint32) SetValid(n uint32) {
u.Uint32 = n
u.Valid = true
}
// Ptr returns a pointer to this Uint32's value, or a nil pointer if this Uint32 is null.
func (u Uint32) Ptr() *uint32 {
if !u.Valid {
return nil
}
return &u.Uint32
}
// IsZero returns true for invalid Uint32's, for future omitempty support (Go 1.4?)
func (u Uint32) IsZero() bool {
return !u.Valid
}
// Scan implements the Scanner interface.
func (u *Uint32) Scan(value interface{}) error {
if value == nil {
u.Uint32, u.Valid = 0, false
return nil
}
u.Valid = true
return convert.ConvertAssign(&u.Uint32, value)
}
// Value implements the driver Valuer interface.
func (u Uint32) Value() (driver.Value, error) {
if !u.Valid {
return nil, nil
}
return uint64(u.Uint32), nil
}