Reuse the buffer in encoder and decoder (#29)

src/msg/protocol/proto/common.go

@@ -27,7 +27,7 @@ import (
 )
 
 const (
-	sizeBufferSize = 4
+	sizeEncodingLength = 4
 )
 
 var sizeEncodeDecoder = binary.BigEndian

src/msg/protocol/proto/decoder.go

@@ -29,8 +29,7 @@ import (
 
 type decoder struct {
 	r              io.Reader
-	sizeBuffer     []byte
-	dataBuffer     []byte
+	buffer         []byte
 	bytesPool      pool.BytesPool
 	maxMessageSize int
 }
@@ -47,7 +46,7 @@ func newDecoder(r io.Reader, opts BaseOptions) *decoder {
 	pool := opts.BytesPool()
 	return &decoder{
 		r:              r,
-		sizeBuffer:     getByteSliceWithLength(sizeBufferSize, pool),
+		buffer:         getByteSliceWithLength(sizeEncodingLength, pool),
 		bytesPool:      pool,
 		maxMessageSize: opts.MaxMessageSize(),
 	}
@@ -65,19 +64,19 @@ func (d *decoder) Decode(m Unmarshaler) error {
 }
 
 func (d *decoder) decodeSize() (int, error) {
-	if _, err := io.ReadFull(d.r, d.sizeBuffer); err != nil {
+	if _, err := io.ReadFull(d.r, d.buffer[:sizeEncodingLength]); err != nil {
 		return 0, err
 	}
-	size := sizeEncodeDecoder.Uint32(d.sizeBuffer)
+	size := sizeEncodeDecoder.Uint32(d.buffer[:sizeEncodingLength])
 	return int(size), nil
 }
 
 func (d *decoder) decodeData(m Unmarshaler, size int) error {
-	d.dataBuffer = growDataBufferIfNeeded(d.dataBuffer, size, d.bytesPool)
-	if _, err := io.ReadFull(d.r, d.dataBuffer[:size]); err != nil {
+	d.buffer = growDataBufferIfNeeded(d.buffer, size, d.bytesPool)
+	if _, err := io.ReadFull(d.r, d.buffer[:size]); err != nil {
 		return err
 	}
-	return m.Unmarshal(d.dataBuffer[:size])
+	return m.Unmarshal(d.buffer[:size])
 }
 
 func (d *decoder) resetReader(r io.Reader) {

src/msg/protocol/proto/encoder.go

@@ -29,8 +29,7 @@ import (
 
 type encoder struct {
 	w              io.Writer
-	sizeBuffer     []byte
-	dataBuffer     []byte
+	buffer         []byte
 	bytesPool      pool.BytesPool
 	maxMessageSize int
 }
@@ -47,7 +46,7 @@ func newEncoder(w io.Writer, opts BaseOptions) *encoder {
 	pool := opts.BytesPool()
 	return &encoder{
 		w:              w,
-		sizeBuffer:     getByteSliceWithLength(sizeBufferSize, pool),
+		buffer:         getByteSliceWithLength(sizeEncodingLength, pool),
 		bytesPool:      pool,
 		maxMessageSize: opts.MaxMessageSize(),
 	}
@@ -65,18 +64,18 @@ func (e *encoder) Encode(m Marshaler) error {
 }
 
 func (e *encoder) encodeSize(size int) error {
-	sizeEncodeDecoder.PutUint32(e.sizeBuffer, uint32(size))
-	_, err := e.w.Write(e.sizeBuffer)
+	sizeEncodeDecoder.PutUint32(e.buffer, uint32(size))
+	_, err := e.w.Write(e.buffer[:sizeEncodingLength])
 	return err
 }
 
 func (e *encoder) encodeData(m Marshaler, size int) error {
-	e.dataBuffer = growDataBufferIfNeeded(e.dataBuffer, size, e.bytesPool)
-	size, err := m.MarshalTo(e.dataBuffer)
+	e.buffer = growDataBufferIfNeeded(e.buffer, size, e.bytesPool)
+	size, err := m.MarshalTo(e.buffer)
 	if err != nil {
 		return err
 	}
-	_, err = e.w.Write(e.dataBuffer[:size])
+	_, err = e.w.Write(e.buffer[:size])
 	return err
 }
 

src/msg/protocol/proto/roundtrip_test.go

@@ -33,11 +33,11 @@ import (
 func TestBaseEncodeDecodeRoundTripWithoutPool(t *testing.T) {
 	mimicTCP := bytes.NewBuffer(nil)
 	enc := newEncoder(mimicTCP, NewBaseOptions().SetBytesPool(nil))
-	require.Equal(t, 4, len(enc.sizeBuffer))
-	require.Equal(t, 4, cap(enc.sizeBuffer))
+	require.Equal(t, 4, len(enc.buffer))
+	require.Equal(t, 4, cap(enc.buffer))
 	dec := newDecoder(mimicTCP, NewBaseOptions().SetBytesPool(nil))
-	require.Equal(t, 4, len(dec.sizeBuffer))
-	require.Equal(t, 4, cap(dec.sizeBuffer))
+	require.Equal(t, 4, len(dec.buffer))
+	require.Equal(t, 4, cap(dec.buffer))
 	encodeMsg := msgpb.Message{
 		Metadata: msgpb.Metadata{
 			Shard: 1,
@@ -48,23 +48,23 @@ func TestBaseEncodeDecodeRoundTripWithoutPool(t *testing.T) {
 	decodeMsg := msgpb.Message{}
 
 	require.NoError(t, enc.Encode(&encodeMsg))
-	require.Equal(t, encodeMsg.Size(), len(enc.dataBuffer))
-	require.Equal(t, encodeMsg.Size(), cap(enc.dataBuffer))
+	require.Equal(t, encodeMsg.Size(), len(enc.buffer))
+	require.Equal(t, encodeMsg.Size(), cap(enc.buffer))
 	require.NoError(t, dec.Decode(&decodeMsg))
-	require.Equal(t, decodeMsg.Size(), len(dec.dataBuffer))
-	require.Equal(t, encodeMsg.Size(), cap(dec.dataBuffer))
+	require.Equal(t, decodeMsg.Size(), len(dec.buffer))
+	require.Equal(t, encodeMsg.Size(), cap(dec.buffer))
 }
 
 func TestBaseEncodeDecodeRoundTripWithPool(t *testing.T) {
 	p := getBytesPool(2, []int{2, 8, 100})
 	p.Init()
 	mimicTCP := bytes.NewBuffer(nil)
 	enc := newEncoder(mimicTCP, NewBaseOptions().SetBytesPool(p))
-	require.Equal(t, 8, len(enc.sizeBuffer))
-	require.Equal(t, 8, cap(enc.sizeBuffer))
+	require.Equal(t, 8, len(enc.buffer))
+	require.Equal(t, 8, cap(enc.buffer))
 	dec := newDecoder(mimicTCP, NewBaseOptions().SetBytesPool(p))
-	require.Equal(t, 8, len(dec.sizeBuffer))
-	require.Equal(t, 8, cap(dec.sizeBuffer))
+	require.Equal(t, 8, len(dec.buffer))
+	require.Equal(t, 8, cap(dec.buffer))
 	encodeMsg := msgpb.Message{
 		Metadata: msgpb.Metadata{
 			Shard: 1,
@@ -75,11 +75,11 @@ func TestBaseEncodeDecodeRoundTripWithPool(t *testing.T) {
 	decodeMsg := msgpb.Message{}
 
 	require.NoError(t, enc.Encode(&encodeMsg))
-	require.Equal(t, 100, len(enc.dataBuffer))
-	require.Equal(t, 100, cap(enc.dataBuffer))
+	require.Equal(t, 100, len(enc.buffer))
+	require.Equal(t, 100, cap(enc.buffer))
 	require.NoError(t, dec.Decode(&decodeMsg))
-	require.Equal(t, 100, len(dec.dataBuffer))
-	require.Equal(t, 100, cap(dec.dataBuffer))
+	require.Equal(t, 100, len(dec.buffer))
+	require.Equal(t, 100, cap(dec.buffer))
 }
 
 func TestResetReader(t *testing.T) {