prometheus/vendor/github.com/json-iterator/go/feature_reflect_optional.go

125 lines
3.3 KiB
Go

package jsoniter
import (
"reflect"
"unsafe"
)
func decoderOfOptional(cfg *frozenConfig, prefix string, typ reflect.Type) ValDecoder {
elemType := typ.Elem()
decoder := decoderOfType(cfg, prefix, elemType)
return &OptionalDecoder{elemType, decoder}
}
func encoderOfOptional(cfg *frozenConfig, prefix string, typ reflect.Type) ValEncoder {
elemType := typ.Elem()
elemEncoder := encoderOfType(cfg, prefix, elemType)
encoder := &OptionalEncoder{elemEncoder}
if elemType.Kind() == reflect.Map {
encoder = &OptionalEncoder{encoder}
}
return encoder
}
type OptionalDecoder struct {
ValueType reflect.Type
ValueDecoder ValDecoder
}
func (decoder *OptionalDecoder) Decode(ptr unsafe.Pointer, iter *Iterator) {
if iter.ReadNil() {
*((*unsafe.Pointer)(ptr)) = nil
} else {
if *((*unsafe.Pointer)(ptr)) == nil {
//pointer to null, we have to allocate memory to hold the value
value := reflect.New(decoder.ValueType)
newPtr := extractInterface(value.Interface()).word
decoder.ValueDecoder.Decode(newPtr, iter)
*((*uintptr)(ptr)) = uintptr(newPtr)
} else {
//reuse existing instance
decoder.ValueDecoder.Decode(*((*unsafe.Pointer)(ptr)), iter)
}
}
}
type dereferenceDecoder struct {
// only to deference a pointer
valueType reflect.Type
valueDecoder ValDecoder
}
func (decoder *dereferenceDecoder) Decode(ptr unsafe.Pointer, iter *Iterator) {
if *((*unsafe.Pointer)(ptr)) == nil {
//pointer to null, we have to allocate memory to hold the value
value := reflect.New(decoder.valueType)
newPtr := extractInterface(value.Interface()).word
decoder.valueDecoder.Decode(newPtr, iter)
*((*uintptr)(ptr)) = uintptr(newPtr)
} else {
//reuse existing instance
decoder.valueDecoder.Decode(*((*unsafe.Pointer)(ptr)), iter)
}
}
type OptionalEncoder struct {
ValueEncoder ValEncoder
}
func (encoder *OptionalEncoder) Encode(ptr unsafe.Pointer, stream *Stream) {
if *((*unsafe.Pointer)(ptr)) == nil {
stream.WriteNil()
} else {
encoder.ValueEncoder.Encode(*((*unsafe.Pointer)(ptr)), stream)
}
}
func (encoder *OptionalEncoder) EncodeInterface(val interface{}, stream *Stream) {
WriteToStream(val, stream, encoder)
}
func (encoder *OptionalEncoder) IsEmpty(ptr unsafe.Pointer) bool {
return *((*unsafe.Pointer)(ptr)) == nil
}
type dereferenceEncoder struct {
ValueEncoder ValEncoder
}
func (encoder *dereferenceEncoder) Encode(ptr unsafe.Pointer, stream *Stream) {
if *((*unsafe.Pointer)(ptr)) == nil {
stream.WriteNil()
} else {
encoder.ValueEncoder.Encode(*((*unsafe.Pointer)(ptr)), stream)
}
}
func (encoder *dereferenceEncoder) EncodeInterface(val interface{}, stream *Stream) {
WriteToStream(val, stream, encoder)
}
func (encoder *dereferenceEncoder) IsEmpty(ptr unsafe.Pointer) bool {
return encoder.ValueEncoder.IsEmpty(*((*unsafe.Pointer)(ptr)))
}
type optionalMapEncoder struct {
valueEncoder ValEncoder
}
func (encoder *optionalMapEncoder) Encode(ptr unsafe.Pointer, stream *Stream) {
if *((*unsafe.Pointer)(ptr)) == nil {
stream.WriteNil()
} else {
encoder.valueEncoder.Encode(*((*unsafe.Pointer)(ptr)), stream)
}
}
func (encoder *optionalMapEncoder) EncodeInterface(val interface{}, stream *Stream) {
WriteToStream(val, stream, encoder)
}
func (encoder *optionalMapEncoder) IsEmpty(ptr unsafe.Pointer) bool {
p := *((*unsafe.Pointer)(ptr))
return p == nil || encoder.valueEncoder.IsEmpty(p)
}