128 lines
2.7 KiB
Go
128 lines
2.7 KiB
Go
package null
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import (
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"database/sql/driver"
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"gopkg.in/nullbio/null.v4/convert"
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)
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// NullBytes is a nullable byte slice.
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type NullBytes struct {
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Bytes []byte
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Valid bool
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}
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// Bytes is a nullable []byte.
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// JSON marshals to zero if null.
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// Considered null to SQL if zero.
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type Bytes struct {
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NullBytes
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}
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// NewBytes creates a new Bytes
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func NewBytes(b []byte, valid bool) Bytes {
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return Bytes{
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NullBytes: NullBytes{
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Bytes: b,
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Valid: valid,
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},
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}
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}
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// BytesFrom creates a new Bytes that will be null if len zero.
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func BytesFrom(b []byte) Bytes {
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return NewBytes(b, len(b) != 0)
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}
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// BytesFromPtr creates a new Bytes that be null if len zero.
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func BytesFromPtr(b *[]byte) Bytes {
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if b == nil || len(*b) == 0 {
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return NewBytes(nil, false)
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}
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n := NewBytes(*b, true)
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return n
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}
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// UnmarshalJSON implements json.Unmarshaler.
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// If data is len 0 or nil, it will unmarshal to JSON null.
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// If not, it will copy your data slice into Bytes.
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func (b *Bytes) UnmarshalJSON(data []byte) error {
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if data == nil || len(data) == 0 {
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b.Bytes = []byte("null")
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} else {
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b.Bytes = append(b.Bytes[0:0], data...)
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}
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b.Valid = true
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return nil
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}
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// UnmarshalText implements encoding.TextUnmarshaler.
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// It will unmarshal to nil if the text is nil or len 0.
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func (b *Bytes) UnmarshalText(text []byte) error {
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if text == nil || len(text) == 0 {
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b.Bytes = nil
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b.Valid = false
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} else {
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b.Bytes = append(b.Bytes[0:0], text...)
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b.Valid = true
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}
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return nil
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}
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// MarshalJSON implements json.Marshaler.
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// It will encode null if the Bytes is nil.
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func (b Bytes) MarshalJSON() ([]byte, error) {
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if len(b.Bytes) == 0 || b.Bytes == nil {
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return []byte("null"), nil
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}
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return b.Bytes, nil
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}
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// MarshalText implements encoding.TextMarshaler.
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// It will encode nil if the Bytes is invalid.
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func (b Bytes) MarshalText() ([]byte, error) {
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if !b.Valid {
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return nil, nil
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}
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return b.Bytes, nil
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}
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// SetValid changes this Bytes's value and also sets it to be non-null.
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func (b *Bytes) SetValid(n []byte) {
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b.Bytes = n
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b.Valid = true
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}
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// Ptr returns a pointer to this Bytes's value, or a nil pointer if this Bytes is null.
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func (b Bytes) Ptr() *[]byte {
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if !b.Valid {
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return nil
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}
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return &b.Bytes
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}
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// IsZero returns true for null or zero Bytes's, for future omitempty support (Go 1.4?)
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func (b Bytes) IsZero() bool {
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return !b.Valid
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}
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// Scan implements the Scanner interface.
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func (n *NullBytes) Scan(value interface{}) error {
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if value == nil {
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n.Bytes, n.Valid = []byte{}, false
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return nil
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}
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n.Valid = true
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return convert.ConvertAssign(&n.Bytes, value)
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}
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// Value implements the driver Valuer interface.
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func (n NullBytes) Value() (driver.Value, error) {
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if !n.Valid {
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return nil, nil
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}
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return n.Bytes, nil
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}
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