lbry.go/zero/int64.go
Patrick O'brien 4f91fe41ce Add all additional types to zero package
* Add all additional float, int and uint types to zero package
* Moved convert to its own package

* Updated README to reflect changes
2016-05-18 17:00:15 +10:00

120 lines
2.8 KiB
Go

package zero
import (
"database/sql"
"encoding/json"
"fmt"
"reflect"
"strconv"
)
// Int64 is a nullable int64.
// JSON marshals to zero if null.
// Considered null to SQL if zero.
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 be null if zero.
func Int64From(i int64) Int64 {
return NewInt64(i, i != 0)
}
// Int64FromPtr creates a new Int64 that be null if i is nil.
func Int64FromPtr(i *int64) Int64 {
if i == nil {
return NewInt64(0, false)
}
n := NewInt64(*i, true)
return n
}
// UnmarshalJSON implements json.Unmarshaler.
// It supports number and null input.
// 0 will 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 zero.Int64", reflect.TypeOf(v).Name())
}
i.Valid = (err == nil) && (i.Int64 != 0)
return err
}
// UnmarshalText implements encoding.TextUnmarshaler.
// It will unmarshal to a null Int64 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 *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) && (i.Int64 != 0)
return err
}
// MarshalJSON implements json.Marshaler.
// It will encode 0 if this Int64 is null.
func (i Int64) MarshalJSON() ([]byte, error) {
n := i.Int64
if !i.Valid {
n = 0
}
return []byte(strconv.FormatInt(n, 10)), nil
}
// MarshalText implements encoding.TextMarshaler.
// It will encode a zero if this Int64 is null.
func (i Int64) MarshalText() ([]byte, error) {
n := i.Int64
if !i.Valid {
n = 0
}
return []byte(strconv.FormatInt(n, 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 null or zero Int64s, for future omitempty support (Go 1.4?)
func (i Int64) IsZero() bool {
return !i.Valid || i.Int64 == 0
}