Merge pull request #220 from goccy/feature/fix-217

Fix calculating of length for stream decoder

decode_map.go

@@ -68,10 +68,7 @@ func (d *mapDecoder) decodeStream(s *stream, depth int64, p unsafe.Pointer) erro
 			return err
 		}
 		s.skipWhiteSpace()
-		if s.char() == nul {
-			s.read()
-		}
-		if s.char() != ':' {
+		if !s.equalChar(':') {
 			return errExpected("colon after object key", s.totalOffset())
 		}
 		s.cursor++
@@ -81,15 +78,12 @@ func (d *mapDecoder) decodeStream(s *stream, depth int64, p unsafe.Pointer) erro
 		}
 		mapassign(d.mapType, mapValue, k, v)
 		s.skipWhiteSpace()
-		if s.char() == nul {
-			s.read()
-		}
-		if s.char() == '}' {
+		if s.equalChar('}') {
 			**(**unsafe.Pointer)(unsafe.Pointer(&p)) = mapValue
 			s.cursor++
 			return nil
 		}
-		if s.char() != ',' {
+		if !s.equalChar(',') {
 			return errExpected("comma after object value", s.totalOffset())
 		}
 	}

decode_stream.go

@@ -49,6 +49,15 @@ func (s *stream) char() byte {
 	return s.buf[s.cursor]
 }
 
+func (s *stream) equalChar(c byte) bool {
+	cur := s.buf[s.cursor]
+	if cur == nul {
+		s.read()
+		cur = s.buf[s.cursor]
+	}
+	return cur == c
+}
+
 func (s *stream) stat() ([]byte, int64, unsafe.Pointer) {
 	return s.buf, s.cursor, (*sliceHeader)(unsafe.Pointer(&s.buf)).data
 }
@@ -73,10 +82,14 @@ func (s *stream) readBuf() []byte {
 		copy(s.buf, remainBuf)
 	}
 	remainLen := s.length - s.cursor
-	if remainLen > 0 {
-		remainLen-- // last char is nul
+	remainNotNulCharNum := int64(0)
+	for i := int64(0); i < remainLen; i++ {
+		if s.buf[s.cursor+i] == nul {
+			break
+		}
+		remainNotNulCharNum++
 	}
-	return s.buf[s.cursor+remainLen:]
+	return s.buf[s.cursor+remainNotNulCharNum:]
 }
 
 func (s *stream) read() bool {

decode_string.go

@@ -127,7 +127,8 @@ func decodeUnicode(s *stream) error {
 	unicode := []byte(string(r))
 	unicodeLen := int64(len(unicode))
 	s.buf = append(append(s.buf[:s.cursor-1], unicode...), s.buf[s.cursor+offset:]...)
-	s.length = int64(len(s.buf))
+	unicodeOrgLen := offset - 1
+	s.length = s.length - (backSlashAndULen + (unicodeOrgLen - unicodeLen))
 	s.cursor = s.cursor - backSlashAndULen + unicodeLen
 	return nil
 }
@@ -163,6 +164,7 @@ RETRY:
 		return errUnexpectedEndOfJSON("string", s.totalOffset())
 	}
 	s.buf = append(s.buf[:s.cursor-1], s.buf[s.cursor:]...)
+	s.length--
 	s.cursor--
 	return nil
 }
@@ -211,6 +213,7 @@ func stringBytes(s *stream) ([]byte, error) {
 			s.buf = append(append(append([]byte{}, s.buf[:cursor]...), runeErrBytes...), s.buf[cursor+1:]...)
 			_, _, p = s.stat()
 			cursor += runeErrBytesLen
+			s.length += runeErrBytesLen
 			continue
 		case nul:
 			s.cursor = cursor
@@ -236,6 +239,7 @@ func stringBytes(s *stream) ([]byte, error) {
 				_, _, p = s.stat()
 			}
 			cursor += int64(len(b))
+			s.length += int64(len(b))
 			continue
 		}
 		cursor++