GoToSocial/vendor/github.com/goccy/go-json/internal/decoder/map.go

281 lines
6.9 KiB
Go

package decoder
import (
"reflect"
"unsafe"
"github.com/goccy/go-json/internal/errors"
"github.com/goccy/go-json/internal/runtime"
)
type mapDecoder struct {
mapType *runtime.Type
keyType *runtime.Type
valueType *runtime.Type
canUseAssignFaststrType bool
keyDecoder Decoder
valueDecoder Decoder
structName string
fieldName string
}
func newMapDecoder(mapType *runtime.Type, keyType *runtime.Type, keyDec Decoder, valueType *runtime.Type, valueDec Decoder, structName, fieldName string) *mapDecoder {
return &mapDecoder{
mapType: mapType,
keyDecoder: keyDec,
keyType: keyType,
canUseAssignFaststrType: canUseAssignFaststrType(keyType, valueType),
valueType: valueType,
valueDecoder: valueDec,
structName: structName,
fieldName: fieldName,
}
}
const (
mapMaxElemSize = 128
)
// See detail: https://github.com/goccy/go-json/pull/283
func canUseAssignFaststrType(key *runtime.Type, value *runtime.Type) bool {
indirectElem := value.Size() > mapMaxElemSize
if indirectElem {
return false
}
return key.Kind() == reflect.String
}
//go:linkname makemap reflect.makemap
func makemap(*runtime.Type, int) unsafe.Pointer
//nolint:golint
//go:linkname mapassign_faststr runtime.mapassign_faststr
//go:noescape
func mapassign_faststr(t *runtime.Type, m unsafe.Pointer, s string) unsafe.Pointer
//go:linkname mapassign reflect.mapassign
//go:noescape
func mapassign(t *runtime.Type, m unsafe.Pointer, k, v unsafe.Pointer)
func (d *mapDecoder) mapassign(t *runtime.Type, m, k, v unsafe.Pointer) {
if d.canUseAssignFaststrType {
mapV := mapassign_faststr(t, m, *(*string)(k))
typedmemmove(d.valueType, mapV, v)
} else {
mapassign(t, m, k, v)
}
}
func (d *mapDecoder) DecodeStream(s *Stream, depth int64, p unsafe.Pointer) error {
depth++
if depth > maxDecodeNestingDepth {
return errors.ErrExceededMaxDepth(s.char(), s.cursor)
}
switch s.skipWhiteSpace() {
case 'n':
if err := nullBytes(s); err != nil {
return err
}
**(**unsafe.Pointer)(unsafe.Pointer(&p)) = nil
return nil
case '{':
default:
return errors.ErrExpected("{ character for map value", s.totalOffset())
}
mapValue := *(*unsafe.Pointer)(p)
if mapValue == nil {
mapValue = makemap(d.mapType, 0)
}
s.cursor++
if s.skipWhiteSpace() == '}' {
*(*unsafe.Pointer)(p) = mapValue
s.cursor++
return nil
}
for {
k := unsafe_New(d.keyType)
if err := d.keyDecoder.DecodeStream(s, depth, k); err != nil {
return err
}
s.skipWhiteSpace()
if !s.equalChar(':') {
return errors.ErrExpected("colon after object key", s.totalOffset())
}
s.cursor++
v := unsafe_New(d.valueType)
if err := d.valueDecoder.DecodeStream(s, depth, v); err != nil {
return err
}
d.mapassign(d.mapType, mapValue, k, v)
s.skipWhiteSpace()
if s.equalChar('}') {
**(**unsafe.Pointer)(unsafe.Pointer(&p)) = mapValue
s.cursor++
return nil
}
if !s.equalChar(',') {
return errors.ErrExpected("comma after object value", s.totalOffset())
}
s.cursor++
}
}
func (d *mapDecoder) Decode(ctx *RuntimeContext, cursor, depth int64, p unsafe.Pointer) (int64, error) {
buf := ctx.Buf
depth++
if depth > maxDecodeNestingDepth {
return 0, errors.ErrExceededMaxDepth(buf[cursor], cursor)
}
cursor = skipWhiteSpace(buf, cursor)
buflen := int64(len(buf))
if buflen < 2 {
return 0, errors.ErrExpected("{} for map", cursor)
}
switch buf[cursor] {
case 'n':
if err := validateNull(buf, cursor); err != nil {
return 0, err
}
cursor += 4
**(**unsafe.Pointer)(unsafe.Pointer(&p)) = nil
return cursor, nil
case '{':
default:
return 0, errors.ErrExpected("{ character for map value", cursor)
}
cursor++
cursor = skipWhiteSpace(buf, cursor)
mapValue := *(*unsafe.Pointer)(p)
if mapValue == nil {
mapValue = makemap(d.mapType, 0)
}
if buf[cursor] == '}' {
**(**unsafe.Pointer)(unsafe.Pointer(&p)) = mapValue
cursor++
return cursor, nil
}
for {
k := unsafe_New(d.keyType)
keyCursor, err := d.keyDecoder.Decode(ctx, cursor, depth, k)
if err != nil {
return 0, err
}
cursor = skipWhiteSpace(buf, keyCursor)
if buf[cursor] != ':' {
return 0, errors.ErrExpected("colon after object key", cursor)
}
cursor++
v := unsafe_New(d.valueType)
valueCursor, err := d.valueDecoder.Decode(ctx, cursor, depth, v)
if err != nil {
return 0, err
}
d.mapassign(d.mapType, mapValue, k, v)
cursor = skipWhiteSpace(buf, valueCursor)
if buf[cursor] == '}' {
**(**unsafe.Pointer)(unsafe.Pointer(&p)) = mapValue
cursor++
return cursor, nil
}
if buf[cursor] != ',' {
return 0, errors.ErrExpected("comma after object value", cursor)
}
cursor++
}
}
func (d *mapDecoder) DecodePath(ctx *RuntimeContext, cursor, depth int64) ([][]byte, int64, error) {
buf := ctx.Buf
depth++
if depth > maxDecodeNestingDepth {
return nil, 0, errors.ErrExceededMaxDepth(buf[cursor], cursor)
}
cursor = skipWhiteSpace(buf, cursor)
buflen := int64(len(buf))
if buflen < 2 {
return nil, 0, errors.ErrExpected("{} for map", cursor)
}
switch buf[cursor] {
case 'n':
if err := validateNull(buf, cursor); err != nil {
return nil, 0, err
}
cursor += 4
return [][]byte{nullbytes}, cursor, nil
case '{':
default:
return nil, 0, errors.ErrExpected("{ character for map value", cursor)
}
cursor++
cursor = skipWhiteSpace(buf, cursor)
if buf[cursor] == '}' {
cursor++
return nil, cursor, nil
}
keyDecoder, ok := d.keyDecoder.(*stringDecoder)
if !ok {
return nil, 0, &errors.UnmarshalTypeError{
Value: "string",
Type: reflect.TypeOf(""),
Offset: cursor,
Struct: d.structName,
Field: d.fieldName,
}
}
ret := [][]byte{}
for {
key, keyCursor, err := keyDecoder.decodeByte(buf, cursor)
if err != nil {
return nil, 0, err
}
cursor = skipWhiteSpace(buf, keyCursor)
if buf[cursor] != ':' {
return nil, 0, errors.ErrExpected("colon after object key", cursor)
}
cursor++
child, found, err := ctx.Option.Path.Field(string(key))
if err != nil {
return nil, 0, err
}
if found {
if child != nil {
oldPath := ctx.Option.Path.node
ctx.Option.Path.node = child
paths, c, err := d.valueDecoder.DecodePath(ctx, cursor, depth)
if err != nil {
return nil, 0, err
}
ctx.Option.Path.node = oldPath
ret = append(ret, paths...)
cursor = c
} else {
start := cursor
end, err := skipValue(buf, cursor, depth)
if err != nil {
return nil, 0, err
}
ret = append(ret, buf[start:end])
cursor = end
}
} else {
c, err := skipValue(buf, cursor, depth)
if err != nil {
return nil, 0, err
}
cursor = c
}
cursor = skipWhiteSpace(buf, cursor)
if buf[cursor] == '}' {
cursor++
return ret, cursor, nil
}
if buf[cursor] != ',' {
return nil, 0, errors.ErrExpected("comma after object value", cursor)
}
cursor++
}
}