Fix stream decoding

decode.go

@@ -60,7 +60,7 @@ const (
 // The decoder introduces its own buffering and may
 // read data from r beyond the JSON values requested.
 func NewDecoder(r io.Reader) *Decoder {
-	s := &stream{r: r}
+	s := newStream(r)
 	s.read()
 	return &Decoder{
 		s: s,

decode_bytes.go

@@ -19,12 +19,17 @@ func (d *bytesDecoder) decodeStream(s *stream, p unsafe.Pointer) error {
 	if err != nil {
 		return err
 	}
+	if bytes == nil {
+		s.reset()
+		return nil
+	}
 	decodedLen := base64.StdEncoding.DecodedLen(len(bytes))
 	buf := make([]byte, decodedLen)
 	if _, err := base64.StdEncoding.Decode(buf, bytes); err != nil {
 		return err
 	}
 	*(*[]byte)(p) = buf
+	s.reset()
 	return nil
 }
 
@@ -51,7 +56,6 @@ func binaryBytes(s *stream) ([]byte, error) {
 		case '"':
 			literal := s.buf[start:s.cursor]
 			s.cursor++
-			s.reset()
 			return literal, nil
 		case nul:
 			if s.read() {
@@ -77,7 +81,7 @@ func (d *bytesDecoder) decodeStreamBinary(s *stream) ([]byte, error) {
 			if err := nullBytes(s); err != nil {
 				return nil, err
 			}
-			return []byte{}, nil
+			return nil, nil
 		case nul:
 			if s.read() {
 				continue

decode_int.go

@@ -1,6 +1,8 @@
 package json
 
-import "unsafe"
+import (
+	"unsafe"
+)
 
 type intDecoder struct {
 	op         func(unsafe.Pointer, int64)
@@ -74,7 +76,6 @@ func (d *intDecoder) decodeStreamByte(s *stream) ([]byte, error) {
 				break
 			}
 			num := s.buf[start:s.cursor]
-			s.reset()
 			if len(num) < 2 {
 				goto ERROR
 			}
@@ -94,7 +95,6 @@ func (d *intDecoder) decodeStreamByte(s *stream) ([]byte, error) {
 				break
 			}
 			num := s.buf[start:s.cursor]
-			s.reset()
 			return num, nil
 		case nul:
 			if s.read() {
@@ -138,6 +138,7 @@ func (d *intDecoder) decodeStream(s *stream, p unsafe.Pointer) error {
 		return err
 	}
 	d.op(p, d.parseInt(bytes))
+	s.reset()
 	return nil
 }
 

decode_interface.go

@@ -52,7 +52,7 @@ func (d *interfaceDecoder) decodeStream(s *stream, p unsafe.Pointer) error {
 			).decodeStream(s, ptr); err != nil {
 				return err
 			}
-			**(**interface{})(unsafe.Pointer(&p)) = v
+			*(*interface{})(p) = v
 			return nil
 		case '[':
 			var v []interface{}
@@ -66,7 +66,7 @@ func (d *interfaceDecoder) decodeStream(s *stream, p unsafe.Pointer) error {
 			).decodeStream(s, ptr); err != nil {
 				return err
 			}
-			**(**interface{})(unsafe.Pointer(&p)) = v
+			*(*interface{})(p) = v
 			return nil
 		case '-', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9':
 			return d.numDecoder(s).decodeStream(s, p)
@@ -82,7 +82,7 @@ func (d *interfaceDecoder) decodeStream(s *stream, p unsafe.Pointer) error {
 				case '"':
 					literal := s.buf[start:s.cursor]
 					s.cursor++
-					**(**interface{})(unsafe.Pointer(&p)) = *(*string)(unsafe.Pointer(&literal))
+					*(*interface{})(p) = string(literal)
 					return nil
 				case nul:
 					if s.read() {
@@ -109,7 +109,7 @@ func (d *interfaceDecoder) decodeStream(s *stream, p unsafe.Pointer) error {
 			if err := nullBytes(s); err != nil {
 				return err
 			}
-			**(**interface{})(unsafe.Pointer(&p)) = nil
+			*(*interface{})(p) = nil
 			return nil
 		case nul:
 			if s.read() {

decode_map.go

@@ -64,8 +64,8 @@ func (d *mapDecoder) decodeStream(s *stream, p unsafe.Pointer) error {
 	s.skipWhiteSpace()
 	mapValue := makemap(d.mapType, 0)
 	if s.buf[s.cursor+1] == '}' {
-		**(**unsafe.Pointer)(unsafe.Pointer(&p)) = mapValue
-		s.cursor++
+		*(*unsafe.Pointer)(p) = mapValue
+		s.cursor += 2
 		return nil
 	}
 	for {
@@ -82,9 +82,6 @@ func (d *mapDecoder) decodeStream(s *stream, p unsafe.Pointer) error {
 			return errExpected("colon after object key", s.totalOffset())
 		}
 		s.cursor++
-		if s.end() {
-			return errUnexpectedEndOfJSON("map", s.totalOffset())
-		}
 		var value interface{}
 		if err := d.setValueStream(s, &value); err != nil {
 			return err

decode_number.go

@@ -25,8 +25,8 @@ func (d *numberDecoder) decodeStream(s *stream, p unsafe.Pointer) error {
 	if err != nil {
 		return err
 	}
-	str := *(*string)(unsafe.Pointer(&bytes))
-	d.op(p, Number(str))
+	d.op(p, Number(string(bytes)))
+	s.reset()
 	return nil
 }
 

decode_slice.go

@@ -74,7 +74,7 @@ func (d *sliceDecoder) decodeStream(s *stream, p unsafe.Pointer) error {
 			s.cursor++
 			s.skipWhiteSpace()
 			if s.char() == ']' {
-				**(**sliceHeader)(unsafe.Pointer(&p)) = sliceHeader{
+				*(*sliceHeader)(p) = sliceHeader{
 					data: newArray(d.elemType, 0),
 					len:  0,
 					cap:  0,
@@ -116,7 +116,7 @@ func (d *sliceDecoder) decodeStream(s *stream, p unsafe.Pointer) error {
 						len:  slice.len,
 						cap:  slice.cap,
 					})
-					**(**sliceHeader)(unsafe.Pointer(&p)) = dst
+					*(*sliceHeader)(p) = dst
 					d.releaseSlice(slice)
 					s.cursor++
 					return nil

decode_stream.go

@@ -6,20 +6,29 @@ import (
 )
 
 const (
-	readChunkSize = 512
+	initBufSize = 512
 )
 
 type stream struct {
 	buf                   []byte
+	bufSize               int64
 	length                int64
 	r                     io.Reader
 	offset                int64
 	cursor                int64
+	readPos               int64
 	allRead               bool
 	useNumber             bool
 	disallowUnknownFields bool
 }
 
+func newStream(r io.Reader) *stream {
+	return &stream{
+		r:       r,
+		bufSize: initBufSize,
+	}
+}
+
 func (s *stream) buffered() io.Reader {
 	return bytes.NewReader(s.buf[s.cursor:])
 }
@@ -36,59 +45,33 @@ func (s *stream) char() byte {
 	return s.buf[s.cursor]
 }
 
-func (s *stream) end() bool {
-	return s.allRead && s.length <= s.cursor
-}
-
-func (s *stream) progressN(n int64) bool {
-	if s.cursor+n < s.length-1 || s.read() {
-		s.cursor += n
-		return true
-	}
-	s.cursor = s.length
-	return false
-}
-
 func (s *stream) reset() {
+	s.offset += s.cursor
 	s.buf = s.buf[s.cursor:]
-	s.length -= s.cursor
 	s.cursor = 0
+	s.length = int64(len(s.buf))
+}
+
+func (s *stream) readBuf() []byte {
+	s.bufSize *= 2
+	remainBuf := s.buf
+	s.buf = make([]byte, s.bufSize)
+	copy(s.buf, remainBuf)
+	return s.buf[s.cursor:]
 }
 
 func (s *stream) read() bool {
 	if s.allRead {
 		return false
 	}
-	buf := make([]byte, readChunkSize)
-	n, err := s.r.Read(buf)
-	if err != nil && err != io.EOF {
-		return false
-	}
-	if n < readChunkSize || err == io.EOF {
+	buf := s.readBuf()
+	last := len(buf) - 1
+	buf[last] = nul
+	n, err := s.r.Read(buf[:last])
+	s.length = s.cursor + int64(n)
+	if n < last || err == io.EOF {
 		s.allRead = true
-	}
-	// extend buffer (2) is protect ( s.cursor++ x2 )
-	// e.g.) decodeEscapeString
-	const extendBufLength = int64(2)
-
-	totalSize := s.length + int64(n) + extendBufLength
-	if totalSize > readChunkSize {
-		newBuf := make([]byte, totalSize)
-		copy(newBuf, s.buf)
-		copy(newBuf[s.length:], buf)
-		s.buf = newBuf
-		s.length = totalSize - extendBufLength
-	} else if s.length > 0 {
-		copy(buf[s.length:], buf)
-		copy(buf, s.buf[:s.length])
-		s.buf = buf
-		s.length = totalSize - extendBufLength
-	} else {
-		s.buf = buf
-		s.length = totalSize - extendBufLength
-	}
-	s.offset += s.cursor
-	if n == 0 {
+	} else if err != nil {
 		return false
 	}
 	return true

decode_string.go

@@ -34,7 +34,8 @@ func (d *stringDecoder) decodeStream(s *stream, p unsafe.Pointer) error {
 	if err != nil {
 		return err
 	}
-	**(**string)(unsafe.Pointer(&p)) = *(*string)(unsafe.Pointer(&bytes))
+	*(*string)(p) = string(bytes)
+	s.reset()
 	return nil
 }
 
@@ -160,7 +161,6 @@ func stringBytes(s *stream) ([]byte, error) {
 		case '"':
 			literal := s.buf[start:s.cursor]
 			s.cursor++
-			s.reset()
 			return literal, nil
 		case nul:
 			if s.read() {

decode_struct.go

@@ -53,10 +53,9 @@ func (d *structDecoder) decodeStream(s *stream, p unsafe.Pointer) error {
 		}
 		s.cursor++
 		if s.char() == nul {
-			s.read()
-		}
-		if s.end() {
-			return errExpected("object value after colon", s.totalOffset())
+			if !s.read() {
+				return errExpected("object value after colon", s.totalOffset())
+			}
 		}
 		k := *(*string)(unsafe.Pointer(&key))
 		field, exists := d.fieldMap[k]

decode_unmarshal_json.go

@@ -36,13 +36,15 @@ func (d *unmarshalJSONDecoder) decodeStream(s *stream, p unsafe.Pointer) error {
 		return err
 	}
 	src := s.buf[start:s.cursor]
+	dst := make([]byte, len(src))
+	copy(dst, src)
 	if d.isDoublePointer {
 		newptr := unsafe_New(d.typ.Elem())
 		v := *(*interface{})(unsafe.Pointer(&interfaceHeader{
 			typ: d.typ,
 			ptr: newptr,
 		}))
-		if err := v.(Unmarshaler).UnmarshalJSON(src); err != nil {
+		if err := v.(Unmarshaler).UnmarshalJSON(dst); err != nil {
 			d.annotateError(s.cursor, err)
 			return err
 		}
@@ -52,7 +54,7 @@ func (d *unmarshalJSONDecoder) decodeStream(s *stream, p unsafe.Pointer) error {
 			typ: d.typ,
 			ptr: p,
 		}))
-		if err := v.(Unmarshaler).UnmarshalJSON(src); err != nil {
+		if err := v.(Unmarshaler).UnmarshalJSON(dst); err != nil {
 			d.annotateError(s.cursor, err)
 			return err
 		}

decode_unmarshal_text.go

@@ -39,15 +39,18 @@ func (d *unmarshalTextDecoder) decodeStream(s *stream, p unsafe.Pointer) error {
 		return err
 	}
 	src := s.buf[start:s.cursor]
-	if s, ok := unquoteBytes(src); ok {
-		src = s
+	dst := make([]byte, len(src))
+	copy(dst, src)
+
+	if b, ok := unquoteBytes(dst); ok {
+		dst = b
 	}
 	newptr := unsafe_New(d.typ.Elem())
 	v := *(*interface{})(unsafe.Pointer(&interfaceHeader{
 		typ: d.typ,
 		ptr: newptr,
 	}))
-	if err := v.(encoding.TextUnmarshaler).UnmarshalText(src); err != nil {
+	if err := v.(encoding.TextUnmarshaler).UnmarshalText(dst); err != nil {
 		d.annotateError(s.cursor, err)
 		return err
 	}

decode_wrapped_string.go

@@ -23,25 +23,11 @@ func (d *wrappedStringDecoder) decodeStream(s *stream, p unsafe.Pointer) error {
 	if err != nil {
 		return err
 	}
-
-	// save current state
-	buf := s.buf
-	length := s.length
-	cursor := s.cursor
-
-	// set content in string to stream
-	bytes = append(bytes, nul)
-	s.buf = bytes
-	s.cursor = 0
-	s.length = int64(len(bytes))
-	if err := d.dec.decodeStream(s, p); err != nil {
-		return nil
+	b := make([]byte, len(bytes)+1)
+	copy(b, bytes)
+	if _, err := d.dec.decode(b, 0, p); err != nil {
+		return err
 	}
-
-	// restore state
-	s.buf = buf
-	s.length = length
-	s.cursor = cursor
 	return nil
 }