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

124 lines
2.4 KiB
Go

package null
import (
"bytes"
"database/sql/driver"
"encoding/json"
"strconv"
"gopkg.in/nullbio/null.v5/convert"
)
// Uint is an nullable uint.
type Uint struct {
Uint uint
Valid bool
}
// NewUint creates a new Uint
func NewUint(i uint, valid bool) Uint {
return Uint{
Uint: i,
Valid: valid,
}
}
// UintFrom creates a new Uint that will always be valid.
func UintFrom(i uint) Uint {
return NewUint(i, true)
}
// UintFromPtr creates a new Uint that be null if i is nil.
func UintFromPtr(i *uint) Uint {
if i == nil {
return NewUint(0, false)
}
return NewUint(*i, true)
}
// UnmarshalJSON implements json.Unmarshaler.
func (u *Uint) UnmarshalJSON(data []byte) error {
if bytes.Equal(data, NullBytes) {
u.Valid = false
u.Uint = 0
return nil
}
var x uint64
if err := json.Unmarshal(data, &x); err != nil {
return err
}
u.Uint = uint(x)
u.Valid = true
return nil
}
// UnmarshalText implements encoding.TextUnmarshaler.
func (u *Uint) 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, 0)
u.Valid = err == nil
if u.Valid {
u.Uint = uint(res)
}
return err
}
// MarshalJSON implements json.Marshaler.
func (u Uint) MarshalJSON() ([]byte, error) {
if !u.Valid {
return []byte("null"), nil
}
return []byte(strconv.FormatUint(uint64(u.Uint), 10)), nil
}
// MarshalText implements encoding.TextMarshaler.
func (u Uint) MarshalText() ([]byte, error) {
if !u.Valid {
return []byte{}, nil
}
return []byte(strconv.FormatUint(uint64(u.Uint), 10)), nil
}
// SetValid changes this Uint's value and also sets it to be non-null.
func (u *Uint) SetValid(n uint) {
u.Uint = n
u.Valid = true
}
// Ptr returns a pointer to this Uint's value, or a nil pointer if this Uint is null.
func (u Uint) Ptr() *uint {
if !u.Valid {
return nil
}
return &u.Uint
}
// IsZero returns true for invalid Uints, for future omitempty support (Go 1.4?)
func (u Uint) IsZero() bool {
return !u.Valid
}
// Scan implements the Scanner interface.
func (u *Uint) Scan(value interface{}) error {
if value == nil {
u.Uint, u.Valid = 0, false
return nil
}
u.Valid = true
return convert.ConvertAssign(&u.Uint, value)
}
// Value implements the driver Valuer interface.
func (u Uint) Value() (driver.Value, error) {
if !u.Valid {
return nil, nil
}
return int64(u.Uint), nil
}