diff --git a/feature_reflect_native.go b/feature_reflect_native.go
index 464a8f7a..e4e956aa 100644
--- a/feature_reflect_native.go
+++ b/feature_reflect_native.go
@@ -599,10 +599,10 @@ func (codec *base64Codec) Encode(ptr unsafe.Pointer, stream *Stream) {
 	}
 	encoding := base64.StdEncoding
 	stream.writeByte('"')
-	toGrow := encoding.EncodedLen(len(src))
-	stream.ensure(toGrow)
-	encoding.Encode(stream.buf[stream.n:], src)
-	stream.n += toGrow
+	size := encoding.EncodedLen(len(src))
+	buf := make([]byte, size)
+	encoding.Encode(buf, src)
+	stream.buf = append(stream.buf, buf...)
 	stream.writeByte('"')
 }
 
@@ -615,10 +615,10 @@ func (codec *base64Codec) EncodeInterface(val interface{}, stream *Stream) {
 	}
 	encoding := base64.StdEncoding
 	stream.writeByte('"')
-	toGrow := encoding.EncodedLen(len(src))
-	stream.ensure(toGrow)
-	encoding.Encode(stream.buf[stream.n:], src)
-	stream.n += toGrow
+	size := encoding.EncodedLen(len(src))
+	buf := make([]byte, size)
+	encoding.Encode(buf, src)
+	stream.buf = append(stream.buf, buf...)
 	stream.writeByte('"')
 }
 
diff --git a/feature_stream.go b/feature_stream.go
index db78ec6f..d6e52980 100644
--- a/feature_stream.go
+++ b/feature_stream.go
@@ -10,11 +10,9 @@ type Stream struct {
 	cfg        *frozenConfig
 	out        io.Writer
 	buf        []byte
-	n          int
 	Error      error
 	indention  int
 	Attachment interface{} // open for customized encoder
-	floatBuf   []byte
 }
 
 // NewStream create new stream instance.
@@ -25,11 +23,9 @@ func NewStream(cfg API, out io.Writer, bufSize int) *Stream {
 	return &Stream{
 		cfg:       cfg.(*frozenConfig),
 		out:       out,
-		buf:       make([]byte, bufSize),
-		n:         0,
+		buf:       make([]byte, 0, bufSize),
 		Error:     nil,
 		indention: 0,
-		floatBuf:  make([]byte, 0, 32),
 	}
 }
 
@@ -41,22 +37,22 @@ func (stream *Stream) Pool() StreamPool {
 // Reset reuse this stream instance by assign a new writer
 func (stream *Stream) Reset(out io.Writer) {
 	stream.out = out
-	stream.n = 0
+	stream.buf = stream.buf[:0]
 }
 
 // Available returns how many bytes are unused in the buffer.
 func (stream *Stream) Available() int {
-	return len(stream.buf) - stream.n
+	return cap(stream.buf) - len(stream.buf)
 }
 
 // Buffered returns the number of bytes that have been written into the current buffer.
 func (stream *Stream) Buffered() int {
-	return stream.n
+	return len(stream.buf)
 }
 
 // Buffer if writer is nil, use this method to take the result
 func (stream *Stream) Buffer() []byte {
-	return stream.buf[:stream.n]
+	return stream.buf
 }
 
 // Write writes the contents of p into the buffer.
@@ -64,97 +60,34 @@ func (stream *Stream) Buffer() []byte {
 // If nn < len(p), it also returns an error explaining
 // why the write is short.
 func (stream *Stream) Write(p []byte) (nn int, err error) {
-	for len(p) > stream.Available() && stream.Error == nil {
-		if stream.out == nil {
-			stream.growAtLeast(len(p))
-		} else {
-			var n int
-			if stream.Buffered() == 0 {
-				// Large write, empty buffer.
-				// Write directly from p to avoid copy.
-				n, stream.Error = stream.out.Write(p)
-			} else {
-				n = copy(stream.buf[stream.n:], p)
-				stream.n += n
-				stream.Flush()
-			}
-			nn += n
-			p = p[n:]
-		}
-	}
-	if stream.Error != nil {
-		return nn, stream.Error
+	stream.buf = append(stream.buf, p...)
+	if stream.out != nil {
+		nn, err = stream.out.Write(stream.buf)
+		stream.buf = stream.buf[nn:]
+		return
 	}
-	n := copy(stream.buf[stream.n:], p)
-	stream.n += n
-	nn += n
-	return nn, nil
+	return len(p), nil
 }
 
 // WriteByte writes a single byte.
 func (stream *Stream) writeByte(c byte) {
-	if stream.Error != nil {
-		return
-	}
-	if stream.Available() < 1 {
-		stream.growAtLeast(1)
-	}
-	stream.buf[stream.n] = c
-	stream.n++
+	stream.buf = append(stream.buf, c)
 }
 
 func (stream *Stream) writeTwoBytes(c1 byte, c2 byte) {
-	if stream.Error != nil {
-		return
-	}
-	if stream.Available() < 2 {
-		stream.growAtLeast(2)
-	}
-	stream.buf[stream.n] = c1
-	stream.buf[stream.n+1] = c2
-	stream.n += 2
+	stream.buf = append(stream.buf, c1, c2)
 }
 
 func (stream *Stream) writeThreeBytes(c1 byte, c2 byte, c3 byte) {
-	if stream.Error != nil {
-		return
-	}
-	if stream.Available() < 3 {
-		stream.growAtLeast(3)
-	}
-	stream.buf[stream.n] = c1
-	stream.buf[stream.n+1] = c2
-	stream.buf[stream.n+2] = c3
-	stream.n += 3
+	stream.buf = append(stream.buf, c1, c2, c3)
 }
 
 func (stream *Stream) writeFourBytes(c1 byte, c2 byte, c3 byte, c4 byte) {
-	if stream.Error != nil {
-		return
-	}
-	if stream.Available() < 4 {
-		stream.growAtLeast(4)
-	}
-	stream.buf[stream.n] = c1
-	stream.buf[stream.n+1] = c2
-	stream.buf[stream.n+2] = c3
-	stream.buf[stream.n+3] = c4
-	stream.n += 4
+	stream.buf = append(stream.buf, c1, c2, c3, c4)
 }
 
 func (stream *Stream) writeFiveBytes(c1 byte, c2 byte, c3 byte, c4 byte, c5 byte) {
-	if stream.Error != nil {
-		return
-	}
-	if stream.Available() < 5 {
-		stream.growAtLeast(5)
-	}
-	stream.buf[stream.n] = c1
-	stream.buf[stream.n+1] = c2
-	stream.buf[stream.n+2] = c3
-	stream.buf[stream.n+3] = c4
-	stream.buf[stream.n+4] = c5
-	stream.n += 5
+	stream.buf = append(stream.buf, c1, c2, c3, c4, c5)
 }
 
 // Flush writes any buffered data to the underlying io.Writer.
@@ -165,56 +98,20 @@ func (stream *Stream) Flush() error {
 	if stream.Error != nil {
 		return stream.Error
 	}
-	if stream.n == 0 {
-		return nil
-	}
-	n, err := stream.out.Write(stream.buf[0:stream.n])
-	if n < stream.n && err == nil {
-		err = io.ErrShortWrite
-	}
+	n, err := stream.out.Write(stream.buf)
 	if err != nil {
-		if n > 0 && n < stream.n {
-			copy(stream.buf[0:stream.n-n], stream.buf[n:stream.n])
+		if stream.Error == nil {
+			stream.Error = err
 		}
-		stream.n -= n
-		stream.Error = err
 		return err
 	}
-	stream.n = 0
+	stream.buf = stream.buf[n:]
 	return nil
 }
 
-func (stream *Stream) ensure(minimal int) {
-	available := stream.Available()
-	if available < minimal {
-		stream.growAtLeast(minimal)
-	}
-}
-
-func (stream *Stream) growAtLeast(minimal int) {
-	if stream.out != nil {
-		stream.Flush()
-		if stream.Available() >= minimal {
-			return
-		}
-	}
-	toGrow := len(stream.buf)
-	if toGrow < minimal {
-		toGrow = minimal
-	}
-	newBuf := make([]byte, len(stream.buf)+toGrow)
-	copy(newBuf, stream.Buffer())
-	stream.buf = newBuf
-}
-
 // WriteRaw write string out without quotes, just like []byte
 func (stream *Stream) WriteRaw(s string) {
-	stream.ensure(len(s))
-	if stream.Error != nil {
-		return
-	}
-	n := copy(stream.buf[stream.n:], s)
-	stream.n += n
+	stream.buf = append(stream.buf, s...)
 }
 
 // WriteNil write null to stream
@@ -275,6 +172,7 @@ func (stream *Stream) WriteEmptyObject() {
 func (stream *Stream) WriteMore() {
 	stream.writeByte(',')
 	stream.writeIndention(0)
+	stream.Flush()
 }
 
 // WriteArrayStart write [ with possible indention
@@ -302,9 +200,7 @@ func (stream *Stream) writeIndention(delta int) {
 	}
 	stream.writeByte('\n')
 	toWrite := stream.indention - delta
-	stream.ensure(toWrite)
-	for i := 0; i < toWrite && stream.n < len(stream.buf); i++ {
-		stream.buf[stream.n] = ' '
-		stream.n++
+	for i := 0; i < toWrite; i++ {
+		stream.buf = append(stream.buf, ' ')
 	}
 }
diff --git a/feature_stream_float.go b/feature_stream_float.go
index 2838713f..f318d2c5 100644
--- a/feature_stream_float.go
+++ b/feature_stream_float.go
@@ -21,9 +21,7 @@ func (stream *Stream) WriteFloat32(val float32) {
 			fmt = 'e'
 		}
 	}
-	stream.floatBuf = strconv.AppendFloat(stream.floatBuf, float64(val), fmt, -1, 32)
-	stream.Write(stream.floatBuf)
-	stream.floatBuf = stream.floatBuf[:0]
+	stream.buf = strconv.AppendFloat(stream.buf, float64(val), fmt, -1, 32)
 }
 
 // WriteFloat32Lossy write float32 to stream with ONLY 6 digits precision although much much faster
@@ -45,13 +43,12 @@ func (stream *Stream) WriteFloat32Lossy(val float32) {
 		return
 	}
 	stream.writeByte('.')
-	stream.ensure(10)
 	for p := precision - 1; p > 0 && fval < pow10[p]; p-- {
 		stream.writeByte('0')
 	}
 	stream.WriteUint64(fval)
-	for stream.buf[stream.n-1] == '0' {
-		stream.n--
+	for stream.buf[len(stream.buf)-1] == '0' {
+		stream.buf = stream.buf[:len(stream.buf)-1]
 	}
 }
 
@@ -65,9 +62,7 @@ func (stream *Stream) WriteFloat64(val float64) {
 			fmt = 'e'
 		}
 	}
-	stream.floatBuf = strconv.AppendFloat(stream.floatBuf, float64(val), fmt, -1, 64)
-	stream.Write(stream.floatBuf)
-	stream.floatBuf = stream.floatBuf[:0]
+	stream.buf = strconv.AppendFloat(stream.buf, float64(val), fmt, -1, 64)
 }
 
 // WriteFloat64Lossy write float64 to stream with ONLY 6 digits precision although much much faster
@@ -89,12 +84,11 @@ func (stream *Stream) WriteFloat64Lossy(val float64) {
 		return
 	}
 	stream.writeByte('.')
-	stream.ensure(10)
 	for p := precision - 1; p > 0 && fval < pow10[p]; p-- {
 		stream.writeByte('0')
 	}
 	stream.WriteUint64(fval)
-	for stream.buf[stream.n-1] == '0' {
-		stream.n--
+	for stream.buf[len(stream.buf)-1] == '0' {
+		stream.buf = stream.buf[:len(stream.buf)-1]
 	}
 }
diff --git a/feature_stream_int.go b/feature_stream_int.go
index 7cfd522c..0f742486 100644
--- a/feature_stream_int.go
+++ b/feature_stream_int.go
@@ -14,299 +14,169 @@ func init() {
 	}
 }
 
-func writeFirstBuf(buf []byte, v uint32, n int) int {
+func writeFirstBuf(space []byte, v uint32) []byte {
 	start := v >> 24
 	if start == 0 {
-		buf[n] = byte(v >> 16)
-		n++
-		buf[n] = byte(v >> 8)
-		n++
+		space = append(space, byte(v >> 16), byte(v >> 8))
 	} else if start == 1 {
-		buf[n] = byte(v >> 8)
-		n++
+		space = append(space, byte(v >> 8))
 	}
-	buf[n] = byte(v)
-	n++
-	return n
+	space = append(space, byte(v))
+	return space
 }
 
-func writeBuf(buf []byte, v uint32, n int) {
-	buf[n] = byte(v >> 16)
-	buf[n+1] = byte(v >> 8)
-	buf[n+2] = byte(v)
+func writeBuf(buf []byte, v uint32) []byte {
+	return append(buf, byte(v >> 16), byte(v >> 8), byte(v))
 }
 
 // WriteUint8 write uint8 to stream
 func (stream *Stream) WriteUint8(val uint8) {
-	stream.ensure(3)
-	stream.n = writeFirstBuf(stream.buf, digits[val], stream.n)
+	stream.buf = writeFirstBuf(stream.buf, digits[val])
 }
 
 // WriteInt8 write int8 to stream
 func (stream *Stream) WriteInt8(nval int8) {
-	stream.ensure(4)
-	n := stream.n
 	var val uint8
 	if nval < 0 {
 		val = uint8(-nval)
-		stream.buf[n] = '-'
-		n++
+		stream.buf = append(stream.buf, '-')
 	} else {
 		val = uint8(nval)
 	}
-	stream.n = writeFirstBuf(stream.buf, digits[val], n)
+	stream.buf = writeFirstBuf(stream.buf, digits[val])
 }
 
 // WriteUint16 write uint16 to stream
 func (stream *Stream) WriteUint16(val uint16) {
-	stream.ensure(5)
 	q1 := val / 1000
 	if q1 == 0 {
-		stream.n = writeFirstBuf(stream.buf, digits[val], stream.n)
+		stream.buf = writeFirstBuf(stream.buf, digits[val])
 		return
 	}
 	r1 := val - q1*1000
-	n := writeFirstBuf(stream.buf, digits[q1], stream.n)
-	writeBuf(stream.buf, digits[r1], n)
-	stream.n = n + 3
+	stream.buf = writeFirstBuf(stream.buf, digits[q1])
+	stream.buf = writeBuf(stream.buf, digits[r1])
 	return
 }
 
 // WriteInt16 write int16 to stream
 func (stream *Stream) WriteInt16(nval int16) {
-	stream.ensure(6)
-	n := stream.n
 	var val uint16
 	if nval < 0 {
 		val = uint16(-nval)
-		stream.buf[n] = '-'
-		n++
+		stream.buf = append(stream.buf, '-')
 	} else {
 		val = uint16(nval)
 	}
-	q1 := val / 1000
-	if q1 == 0 {
-		stream.n = writeFirstBuf(stream.buf, digits[val], n)
-		return
-	}
-	r1 := val - q1*1000
-	n = writeFirstBuf(stream.buf, digits[q1], n)
-	writeBuf(stream.buf, digits[r1], n)
-	stream.n = n + 3
-	return
+	stream.WriteUint16(val)
 }
 
 // WriteUint32 write uint32 to stream
 func (stream *Stream) WriteUint32(val uint32) {
-	stream.ensure(10)
-	n := stream.n
 	q1 := val / 1000
 	if q1 == 0 {
-		stream.n = writeFirstBuf(stream.buf, digits[val], n)
+		stream.buf = writeFirstBuf(stream.buf, digits[val])
 		return
 	}
 	r1 := val - q1*1000
 	q2 := q1 / 1000
 	if q2 == 0 {
-		n := writeFirstBuf(stream.buf, digits[q1], n)
-		writeBuf(stream.buf, digits[r1], n)
-		stream.n = n + 3
+		stream.buf = writeFirstBuf(stream.buf, digits[q1])
+		stream.buf = writeBuf(stream.buf, digits[r1])
 		return
 	}
 	r2 := q1 - q2*1000
 	q3 := q2 / 1000
 	if q3 == 0 {
-		n = writeFirstBuf(stream.buf, digits[q2], n)
+		stream.buf = writeFirstBuf(stream.buf, digits[q2])
 	} else {
 		r3 := q2 - q3*1000
-		stream.buf[n] = byte(q3 + '0')
-		n++
-		writeBuf(stream.buf, digits[r3], n)
-		n += 3
+		stream.buf = append(stream.buf, byte(q3 + '0'))
+		stream.buf = writeBuf(stream.buf, digits[r3])
 	}
-	writeBuf(stream.buf, digits[r2], n)
-	writeBuf(stream.buf, digits[r1], n+3)
-	stream.n = n + 6
+	stream.buf = writeBuf(stream.buf, digits[r2])
+	stream.buf = writeBuf(stream.buf, digits[r1])
 }
 
 // WriteInt32 write int32 to stream
 func (stream *Stream) WriteInt32(nval int32) {
-	stream.ensure(11)
-	n := stream.n
 	var val uint32
 	if nval < 0 {
 		val = uint32(-nval)
-		stream.buf[n] = '-'
-		n++
+		stream.buf = append(stream.buf, '-')
 	} else {
 		val = uint32(nval)
 	}
-	q1 := val / 1000
-	if q1 == 0 {
-		stream.n = writeFirstBuf(stream.buf, digits[val], n)
-		return
-	}
-	r1 := val - q1*1000
-	q2 := q1 / 1000
-	if q2 == 0 {
-		n := writeFirstBuf(stream.buf, digits[q1], n)
-		writeBuf(stream.buf, digits[r1], n)
-		stream.n = n + 3
-		return
-	}
-	r2 := q1 - q2*1000
-	q3 := q2 / 1000
-	if q3 == 0 {
-		n = writeFirstBuf(stream.buf, digits[q2], n)
-	} else {
-		r3 := q2 - q3*1000
-		stream.buf[n] = byte(q3 + '0')
-		n++
-		writeBuf(stream.buf, digits[r3], n)
-		n += 3
-	}
-	writeBuf(stream.buf, digits[r2], n)
-	writeBuf(stream.buf, digits[r1], n+3)
-	stream.n = n + 6
+	stream.WriteUint32(val)
 }
 
 // WriteUint64 write uint64 to stream
 func (stream *Stream) WriteUint64(val uint64) {
-	stream.ensure(20)
-	n := stream.n
 	q1 := val / 1000
 	if q1 == 0 {
-		stream.n = writeFirstBuf(stream.buf, digits[val], n)
+		stream.buf = writeFirstBuf(stream.buf, digits[val])
 		return
 	}
 	r1 := val - q1*1000
 	q2 := q1 / 1000
 	if q2 == 0 {
-		n := writeFirstBuf(stream.buf, digits[q1], n)
-		writeBuf(stream.buf, digits[r1], n)
-		stream.n = n + 3
+		stream.buf = writeFirstBuf(stream.buf, digits[q1])
+		stream.buf = writeBuf(stream.buf, digits[r1])
 		return
 	}
 	r2 := q1 - q2*1000
 	q3 := q2 / 1000
 	if q3 == 0 {
-		n = writeFirstBuf(stream.buf, digits[q2], n)
-		writeBuf(stream.buf, digits[r2], n)
-		writeBuf(stream.buf, digits[r1], n+3)
-		stream.n = n + 6
+		stream.buf = writeFirstBuf(stream.buf, digits[q2])
+		stream.buf = writeBuf(stream.buf, digits[r2])
+		stream.buf = writeBuf(stream.buf, digits[r1])
 		return
 	}
 	r3 := q2 - q3*1000
 	q4 := q3 / 1000
 	if q4 == 0 {
-		n = writeFirstBuf(stream.buf, digits[q3], n)
-		writeBuf(stream.buf, digits[r3], n)
-		writeBuf(stream.buf, digits[r2], n+3)
-		writeBuf(stream.buf, digits[r1], n+6)
-		stream.n = n + 9
+		stream.buf = writeFirstBuf(stream.buf, digits[q3])
+		stream.buf = writeBuf(stream.buf, digits[r3])
+		stream.buf = writeBuf(stream.buf, digits[r2])
+		stream.buf = writeBuf(stream.buf, digits[r1])
 		return
 	}
 	r4 := q3 - q4*1000
 	q5 := q4 / 1000
 	if q5 == 0 {
-		n = writeFirstBuf(stream.buf, digits[q4], n)
-		writeBuf(stream.buf, digits[r4], n)
-		writeBuf(stream.buf, digits[r3], n+3)
-		writeBuf(stream.buf, digits[r2], n+6)
-		writeBuf(stream.buf, digits[r1], n+9)
-		stream.n = n + 12
+		stream.buf = writeFirstBuf(stream.buf, digits[q4])
+		stream.buf = writeBuf(stream.buf, digits[r4])
+		stream.buf = writeBuf(stream.buf, digits[r3])
+		stream.buf = writeBuf(stream.buf, digits[r2])
+		stream.buf = writeBuf(stream.buf, digits[r1])
 		return
 	}
 	r5 := q4 - q5*1000
 	q6 := q5 / 1000
 	if q6 == 0 {
-		n = writeFirstBuf(stream.buf, digits[q5], n)
+		stream.buf = writeFirstBuf(stream.buf, digits[q5])
 	} else {
-		n = writeFirstBuf(stream.buf, digits[q6], n)
+		stream.buf = writeFirstBuf(stream.buf, digits[q6])
 		r6 := q5 - q6*1000
-		writeBuf(stream.buf, digits[r6], n)
-		n += 3
+		stream.buf = writeBuf(stream.buf, digits[r6])
 	}
-	writeBuf(stream.buf, digits[r5], n)
-	writeBuf(stream.buf, digits[r4], n+3)
-	writeBuf(stream.buf, digits[r3], n+6)
-	writeBuf(stream.buf, digits[r2], n+9)
-	writeBuf(stream.buf, digits[r1], n+12)
-	stream.n = n + 15
+	stream.buf = writeBuf(stream.buf, digits[r5])
+	stream.buf = writeBuf(stream.buf, digits[r4])
+	stream.buf = writeBuf(stream.buf, digits[r3])
+	stream.buf = writeBuf(stream.buf, digits[r2])
+	stream.buf = writeBuf(stream.buf, digits[r1])
 }
 
 // WriteInt64 write int64 to stream
 func (stream *Stream) WriteInt64(nval int64) {
-	stream.ensure(20)
-	n := stream.n
 	var val uint64
 	if nval < 0 {
 		val = uint64(-nval)
-		stream.buf[n] = '-'
-		n++
+		stream.buf = append(stream.buf, '-')
 	} else {
 		val = uint64(nval)
 	}
-	q1 := val / 1000
-	if q1 == 0 {
-		stream.n = writeFirstBuf(stream.buf, digits[val], n)
-		return
-	}
-	r1 := val - q1*1000
-	q2 := q1 / 1000
-	if q2 == 0 {
-		n := writeFirstBuf(stream.buf, digits[q1], n)
-		writeBuf(stream.buf, digits[r1], n)
-		stream.n = n + 3
-		return
-	}
-	r2 := q1 - q2*1000
-	q3 := q2 / 1000
-	if q3 == 0 {
-		n = writeFirstBuf(stream.buf, digits[q2], n)
-		writeBuf(stream.buf, digits[r2], n)
-		writeBuf(stream.buf, digits[r1], n+3)
-		stream.n = n + 6
-		return
-	}
-	r3 := q2 - q3*1000
-	q4 := q3 / 1000
-	if q4 == 0 {
-		n = writeFirstBuf(stream.buf, digits[q3], n)
-		writeBuf(stream.buf, digits[r3], n)
-		writeBuf(stream.buf, digits[r2], n+3)
-		writeBuf(stream.buf, digits[r1], n+6)
-		stream.n = n + 9
-		return
-	}
-	r4 := q3 - q4*1000
-	q5 := q4 / 1000
-	if q5 == 0 {
-		n = writeFirstBuf(stream.buf, digits[q4], n)
-		writeBuf(stream.buf, digits[r4], n)
-		writeBuf(stream.buf, digits[r3], n+3)
-		writeBuf(stream.buf, digits[r2], n+6)
-		writeBuf(stream.buf, digits[r1], n+9)
-		stream.n = n + 12
-		return
-	}
-	r5 := q4 - q5*1000
-	q6 := q5 / 1000
-	if q6 == 0 {
-		n = writeFirstBuf(stream.buf, digits[q5], n)
-	} else {
-		stream.buf[n] = byte(q6 + '0')
-		n++
-		r6 := q5 - q6*1000
-		writeBuf(stream.buf, digits[r6], n)
-		n += 3
-	}
-	writeBuf(stream.buf, digits[r5], n)
-	writeBuf(stream.buf, digits[r4], n+3)
-	writeBuf(stream.buf, digits[r3], n+6)
-	writeBuf(stream.buf, digits[r2], n+9)
-	writeBuf(stream.buf, digits[r1], n+12)
-	stream.n = n + 15
+	stream.WriteUint64(val)
 }
 
 // WriteInt write int to stream
diff --git a/feature_stream_string.go b/feature_stream_string.go
index 334282f0..54c2ba0b 100644
--- a/feature_stream_string.go
+++ b/feature_stream_string.go
@@ -219,34 +219,22 @@ var hex = "0123456789abcdef"
 
 // WriteStringWithHTMLEscaped write string to stream with html special characters escaped
 func (stream *Stream) WriteStringWithHTMLEscaped(s string) {
-	stream.ensure(32)
 	valLen := len(s)
-	toWriteLen := valLen
-	bufLengthMinusTwo := len(stream.buf) - 2 // make room for the quotes
-	if stream.n+toWriteLen > bufLengthMinusTwo {
-		toWriteLen = bufLengthMinusTwo - stream.n
-	}
-	n := stream.n
-	stream.buf[n] = '"'
-	n++
+	stream.buf = append(stream.buf, '"')
 	// write string, the fast path, without utf8 and escape support
 	i := 0
-	for ; i < toWriteLen; i++ {
+	for ; i < valLen; i++ {
 		c := s[i]
 		if c < utf8.RuneSelf && htmlSafeSet[c] {
-			stream.buf[n] = c
-			n++
+			stream.buf = append(stream.buf, c)
 		} else {
 			break
 		}
 	}
 	if i == valLen {
-		stream.buf[n] = '"'
-		n++
-		stream.n = n
+		stream.buf = append(stream.buf, '"')
 		return
 	}
-	stream.n = n
 	writeStringSlowPathWithHTMLEscaped(stream, i, s, valLen)
 }
 
@@ -321,34 +309,22 @@ func writeStringSlowPathWithHTMLEscaped(stream *Stream, i int, s string, valLen
 
 // WriteString write string to stream without html escape
 func (stream *Stream) WriteString(s string) {
-	stream.ensure(32)
 	valLen := len(s)
-	toWriteLen := valLen
-	bufLengthMinusTwo := len(stream.buf) - 2 // make room for the quotes
-	if stream.n+toWriteLen > bufLengthMinusTwo {
-		toWriteLen = bufLengthMinusTwo - stream.n
-	}
-	n := stream.n
-	stream.buf[n] = '"'
-	n++
+	stream.buf = append(stream.buf, '"')
 	// write string, the fast path, without utf8 and escape support
 	i := 0
-	for ; i < toWriteLen; i++ {
+	for ; i < valLen; i++ {
 		c := s[i]
 		if c > 31 && c != '"' && c != '\\' {
-			stream.buf[n] = c
-			n++
+			stream.buf = append(stream.buf, c)
 		} else {
 			break
 		}
 	}
 	if i == valLen {
-		stream.buf[n] = '"'
-		n++
-		stream.n = n
+		stream.buf = append(stream.buf, '"')
 		return
 	}
-	stream.n = n
 	writeStringSlowPath(stream, i, s, valLen)
 }
 
diff --git a/feature_stream_test.go b/feature_stream_test.go
index 8df96b9f..d407c7ab 100644
--- a/feature_stream_test.go
+++ b/feature_stream_test.go
@@ -23,10 +23,10 @@ func Test_writeBytes_should_grow_buffer(t *testing.T) {
 	stream := NewStream(ConfigDefault, nil, 1)
 	stream.Write([]byte{'1', '2'})
 	should.Equal("12", string(stream.Buffer()))
-	should.Equal(3, len(stream.buf))
+	should.Equal(2, len(stream.buf))
 	stream.Write([]byte{'3', '4', '5', '6', '7'})
 	should.Equal("1234567", string(stream.Buffer()))
-	should.Equal(8, len(stream.buf))
+	should.Equal(7, len(stream.buf))
 }
 
 func Test_writeIndention_should_grow_buffer(t *testing.T) {
@@ -65,5 +65,5 @@ func Test_flush_buffer_should_stop_grow_buffer(t *testing.T) {
 	writer := new(NopWriter)
 	NewEncoder(writer).Encode(make([]int, 10000000))
 	should := require.New(t)
-	should.Equal(512, writer.bufferSize)
+	should.Equal(8, writer.bufferSize)
 }