094289d4cf
Repo: github.com/lbryio/null.go git-subtree-dir: null git-subtree-mainline:75e2abdeacgit-subtree-split:109a79fb20
135 lines
2.5 KiB
Go
135 lines
2.5 KiB
Go
package null
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import (
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"bytes"
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"database/sql/driver"
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"encoding/json"
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"errors"
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)
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// Byte is an nullable int.
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type Byte struct {
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Byte byte
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Valid bool
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}
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// NewByte creates a new Byte
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func NewByte(b byte, valid bool) Byte {
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return Byte{
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Byte: b,
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Valid: valid,
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}
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}
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// ByteFrom creates a new Byte that will always be valid.
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func ByteFrom(b byte) Byte {
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return NewByte(b, true)
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}
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// ByteFromPtr creates a new Byte that be null if i is nil.
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func ByteFromPtr(b *byte) Byte {
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if b == nil {
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return NewByte(0, false)
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}
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return NewByte(*b, true)
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}
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// UnmarshalJSON implements json.Unmarshaler.
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func (b *Byte) UnmarshalJSON(data []byte) error {
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if len(data) == 0 || bytes.Equal(data, NullBytes) {
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b.Valid = false
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b.Byte = 0
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return nil
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}
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var x string
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if err := json.Unmarshal(data, &x); err != nil {
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return err
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}
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if len(x) > 1 {
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return errors.New("json: cannot convert to byte, text len is greater than one")
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}
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b.Byte = x[0]
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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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func (b *Byte) UnmarshalText(text []byte) error {
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if text == nil || len(text) == 0 {
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b.Valid = false
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return nil
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}
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if len(text) > 1 {
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return errors.New("text: cannot convert to byte, text len is greater than one")
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}
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b.Valid = true
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b.Byte = text[0]
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return nil
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}
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// MarshalJSON implements json.Marshaler.
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func (b Byte) MarshalJSON() ([]byte, error) {
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if !b.Valid {
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return NullBytes, nil
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}
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return []byte{'"', b.Byte, '"'}, nil
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}
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// MarshalText implements encoding.TextMarshaler.
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func (b Byte) MarshalText() ([]byte, error) {
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if !b.Valid {
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return []byte{}, nil
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}
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return []byte{b.Byte}, nil
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}
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// SetValid changes this Byte's value and also sets it to be non-null.
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func (b *Byte) SetValid(n byte) {
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b.Byte = n
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b.Valid = true
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}
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// Ptr returns a pointer to this Byte's value, or a nil pointer if this Byte is null.
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func (b Byte) 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.Byte
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}
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// IsNull returns true for invalid Bytes, for future omitempty support (Go 1.4?)
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func (b Byte) IsNull() 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 (b *Byte) Scan(value interface{}) error {
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if value == nil {
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b.Byte, b.Valid = 0, false
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return nil
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}
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val := value.(string)
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if len(val) == 0 {
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b.Valid = false
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b.Byte = 0
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return nil
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}
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b.Valid = true
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b.Byte = byte(val[0])
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return nil
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}
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// Value implements the driver Valuer interface.
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func (b Byte) Value() (driver.Value, error) {
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if !b.Valid {
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return nil, nil
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}
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return []byte{b.Byte}, nil
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}
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