lbry.go/zero/uint32.go
Patrick O'brien 67ba4e0272 Fix README, fix Valuer methods
* Fix import paths
2016-06-08 13:53:02 +10:00

146 lines
3.4 KiB
Go

package zero
import (
"database/sql/driver"
"encoding/json"
"fmt"
"reflect"
"strconv"
"gopkg.in/nullbio/null.v4/convert"
)
type NullUint32 struct {
Uint32 uint32
Valid bool
}
// Uint32 is a nullable uint32.
// JSON marshals to zero if null.
// Considered null to SQL if zero.
type Uint32 struct {
NullUint32
}
// NewUint32 creates a new Uint32
func NewUint32(i uint32, valid bool) Uint32 {
return Uint32{
NullUint32: NullUint32{
Uint32: i,
Valid: valid,
},
}
}
// Uint32From creates a new Uint32 that will be null if zero.
func Uint32From(i uint32) Uint32 {
return NewUint32(i, i != 0)
}
// Uint32FromPtr creates a new Uint32 that be null if i is nil.
func Uint32FromPtr(i *uint32) Uint32 {
if i == nil {
return NewUint32(0, false)
}
n := NewUint32(*i, true)
return n
}
// UnmarshalJSON implements json.Unmarshaler.
// It supports number and null input.
// 0 will be considered a null Uint32.
// It also supports unmarshalling a sql.NullUint32.
func (i *Uint32) 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 uint32, to avoid intermediate float64
err = json.Unmarshal(data, &i.Uint32)
case map[string]interface{}:
err = json.Unmarshal(data, &i.NullUint32)
case nil:
i.Valid = false
return nil
default:
err = fmt.Errorf("json: cannot unmarshal %v into Go value of type zero.Uint32", reflect.TypeOf(v).Name())
}
i.Valid = (err == nil) && (i.Uint32 != 0)
return err
}
// UnmarshalText implements encoding.TextUnmarshaler.
// It will unmarshal to a null Uint32 if the input is a blank, zero, or not an integer.
// It will return an error if the input is not an integer, blank, or "null".
func (i *Uint32) 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, 32)
i.Uint32 = uint32(res)
i.Valid = (err == nil) && (i.Uint32 != 0)
return err
}
// MarshalJSON implements json.Marshaler.
// It will encode 0 if this Uint32 is null.
func (i Uint32) MarshalJSON() ([]byte, error) {
n := i.Uint32
if !i.Valid {
n = 0
}
return []byte(strconv.FormatUint(uint64(n), 10)), nil
}
// MarshalText implements encoding.TextMarshaler.
// It will encode a zero if this Uint32 is null.
func (i Uint32) MarshalText() ([]byte, error) {
n := i.Uint32
if !i.Valid {
n = 0
}
return []byte(strconv.FormatUint(uint64(n), 10)), nil
}
// SetValid changes this Uint32's value and also sets it to be non-null.
func (i *Uint32) SetValid(n uint32) {
i.Uint32 = n
i.Valid = true
}
// Ptr returns a pointer to this Uint32's value, or a nil pointer if this Uint32 is null.
func (i Uint32) Ptr() *uint32 {
if !i.Valid {
return nil
}
return &i.Uint32
}
// IsZero returns true for null or zero Uint32s, for future omitempty support (Go 1.4?)
func (i Uint32) IsZero() bool {
return !i.Valid || i.Uint32 == 0
}
// Scan implements the Scanner interface.
func (n *NullUint32) Scan(value interface{}) error {
if value == nil {
n.Uint32, n.Valid = 0, false
return nil
}
n.Valid = true
return convert.ConvertAssign(&n.Uint32, value)
}
// Value implements the driver Valuer interface.
func (n NullUint32) Value() (driver.Value, error) {
if !n.Valid {
return nil, nil
}
return int64(n.Uint32), nil
}