pgx/pgtype/text.go

116 lines
2.2 KiB
Go

package pgtype
import (
"fmt"
"io"
"reflect"
"github.com/jackc/pgx/pgio"
)
type Text struct {
String string
Status Status
}
func (dst *Text) ConvertFrom(src interface{}) error {
switch value := src.(type) {
case Text:
*dst = value
case string:
*dst = Text{String: value, Status: Present}
case *string:
if value == nil {
*dst = Text{Status: Null}
} else {
*dst = Text{String: *value, Status: Present}
}
default:
if originalSrc, ok := underlyingStringType(src); ok {
return dst.ConvertFrom(originalSrc)
}
return fmt.Errorf("cannot convert %v to Text", value)
}
return nil
}
func (src *Text) AssignTo(dst interface{}) error {
switch v := dst.(type) {
case *string:
if src.Status != Present {
return fmt.Errorf("cannot assign %v to %T", src, dst)
}
*v = src.String
default:
if v := reflect.ValueOf(dst); v.Kind() == reflect.Ptr {
el := v.Elem()
switch el.Kind() {
// if dst is a pointer to pointer, strip the pointer and try again
case reflect.Ptr:
if src.Status == Null {
el.Set(reflect.Zero(el.Type()))
return nil
}
if el.IsNil() {
// allocate destination
el.Set(reflect.New(el.Type().Elem()))
}
return src.AssignTo(el.Interface())
case reflect.String:
if src.Status != Present {
return fmt.Errorf("cannot assign %v to %T", src, dst)
}
el.SetString(src.String)
return nil
}
}
return fmt.Errorf("cannot decode %v into %T", src, dst)
}
return nil
}
func (dst *Text) DecodeText(r io.Reader) error {
size, err := pgio.ReadInt32(r)
if err != nil {
return err
}
if size == -1 {
*dst = Text{Status: Null}
return nil
}
buf := make([]byte, int(size))
_, err = r.Read(buf)
if err != nil {
return err
}
*dst = Text{String: string(buf), Status: Present}
return nil
}
func (dst *Text) DecodeBinary(r io.Reader) error {
return dst.DecodeText(r)
}
func (src Text) EncodeText(w io.Writer) error {
if done, err := encodeNotPresent(w, src.Status); done {
return err
}
_, err := pgio.WriteInt32(w, int32(len(src.String)))
if err != nil {
return nil
}
_, err = io.WriteString(w, src.String)
return err
}
func (src Text) EncodeBinary(w io.Writer) error {
return src.EncodeText(w)
}