lbry.go/int64.go
Patrick O'brien bbb7b84bb6 Add all int and float null types
* Add Scan and Value methods for non sql.Int64 and sql.Float64 types
* Change NullInt to use int in the code opposed to int64
* Rename Float to Float64
* Add support for all missing key int and float types:
  float32, int8, int16, int32, int64, uint8, uint16, uint32, uint64

* Update README to include new additions/changes
2016-05-17 22:02:36 +10:00

118 lines
2.8 KiB
Go

package null
import (
"database/sql"
"encoding/json"
"fmt"
"reflect"
"strconv"
)
// Int64 is an nullable int64.
// It does not consider zero values to be null.
// It will decode to null, not zero, if null.
type Int64 struct {
sql.NullInt64
}
// NewInt64 creates a new Int64
func NewInt64(i int64, valid bool) Int64 {
return Int64{
NullInt64: sql.NullInt64{
Int64: i,
Valid: valid,
},
}
}
// Int64From creates a new Int64 that will always be valid.
func Int64From(i int64) Int64 {
return NewInt64(i, true)
}
// Int64FromPtr creates a new Int64 that be null if i is nil.
func Int64FromPtr(i *int64) Int64 {
if i == nil {
return NewInt64(0, false)
}
return NewInt64(*i, true)
}
// UnmarshalJSON implements json.Unmarshaler.
// It supports number and null input.
// 0 will not be considered a null Int64.
// It also supports unmarshalling a sql.NullInt64.
func (i *Int64) 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 int64, to avoid intermediate float64
err = json.Unmarshal(data, &i.Int64)
case map[string]interface{}:
err = json.Unmarshal(data, &i.NullInt64)
case nil:
i.Valid = false
return nil
default:
err = fmt.Errorf("json: cannot unmarshal %v into Go value of type null.Int64", reflect.TypeOf(v).Name())
}
i.Valid = err == nil
return err
}
// UnmarshalText implements encoding.TextUnmarshaler.
// It will unmarshal to a null Int64 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 *Int64) UnmarshalText(text []byte) error {
str := string(text)
if str == "" || str == "null" {
i.Valid = false
return nil
}
var err error
i.Int64, err = strconv.ParseInt(string(text), 10, 64)
i.Valid = err == nil
return err
}
// MarshalJSON implements json.Marshaler.
// It will encode null if this Int64 is null.
func (i Int64) MarshalJSON() ([]byte, error) {
if !i.Valid {
return []byte("null"), nil
}
return []byte(strconv.FormatInt(i.Int64, 10)), nil
}
// MarshalText implements encoding.TextMarshaler.
// It will encode a blank string if this Int64 is null.
func (i Int64) MarshalText() ([]byte, error) {
if !i.Valid {
return []byte{}, nil
}
return []byte(strconv.FormatInt(i.Int64, 10)), nil
}
// SetValid changes this Int64's value and also sets it to be non-null.
func (i *Int64) SetValid(n int64) {
i.Int64 = n
i.Valid = true
}
// Ptr returns a pointer to this Int64's value, or a nil pointer if this Int64 is null.
func (i Int64) Ptr() *int64 {
if !i.Valid {
return nil
}
return &i.Int64
}
// IsZero returns true for invalid Int64's, for future omitempty support (Go 1.4?)
// A non-null Int64 with a 0 value will not be considered zero.
func (i Int64) IsZero() bool {
return !i.Valid
}