go-json/internal/decoder/ptr.go

88 lines
1.8 KiB
Go

package decoder
import (
"unsafe"
"github.com/goccy/go-json/internal/runtime"
)
type ptrDecoder struct {
dec Decoder
typ *runtime.Type
structName string
fieldName string
}
func newPtrDecoder(dec Decoder, typ *runtime.Type, structName, fieldName string) *ptrDecoder {
return &ptrDecoder{
dec: dec,
typ: typ,
structName: structName,
fieldName: fieldName,
}
}
func (d *ptrDecoder) contentDecoder() Decoder {
dec, ok := d.dec.(*ptrDecoder)
if !ok {
return d.dec
}
return dec.contentDecoder()
}
//nolint:golint
//go:linkname unsafe_New reflect.unsafe_New
func unsafe_New(*runtime.Type) unsafe.Pointer
func (d *ptrDecoder) DecodeStream(s *Stream, depth int64, p unsafe.Pointer) error {
s.skipWhiteSpace()
if s.char() == nul {
s.read()
}
if s.char() == 'n' {
if err := nullBytes(s); err != nil {
return err
}
*(*unsafe.Pointer)(p) = nil
return nil
}
var newptr unsafe.Pointer
if *(*unsafe.Pointer)(p) == nil {
newptr = unsafe_New(d.typ)
*(*unsafe.Pointer)(p) = newptr
} else {
newptr = *(*unsafe.Pointer)(p)
}
if err := d.dec.DecodeStream(s, depth, newptr); err != nil {
return err
}
return nil
}
func (d *ptrDecoder) Decode(buf []byte, cursor, depth int64, p unsafe.Pointer) (int64, error) {
cursor = skipWhiteSpace(buf, cursor)
if buf[cursor] == 'n' {
if err := validateNull(buf, cursor); err != nil {
return 0, err
}
if p != nil {
*(*unsafe.Pointer)(p) = nil
}
cursor += 4
return cursor, nil
}
var newptr unsafe.Pointer
if *(*unsafe.Pointer)(p) == nil {
newptr = unsafe_New(d.typ)
*(*unsafe.Pointer)(p) = newptr
} else {
newptr = *(*unsafe.Pointer)(p)
}
c, err := d.dec.Decode(buf, cursor, depth, newptr)
if err != nil {
return 0, err
}
cursor = c
return cursor, nil
}