Chore: use protobytes replace most of bytes.Buffer

transport/gun/gun.go

@@ -126,11 +126,11 @@ func (g *Conn) Write(b []byte) (n int, err error) {
 	grpcPayloadLen := uint32(varuintSize + 1 + len(b))
 	binary.BigEndian.PutUint32(grpcHeader[1:5], grpcPayloadLen)
 
-	buf := pool.GetBuffer()
-	defer pool.PutBuffer(buf)
-	buf.Write(grpcHeader)
-	buf.Write(protobufHeader[:varuintSize+1])
-	buf.Write(b)
+	buf := pool.GetBytesBuffer()
+	defer pool.PutBytesBuffer(buf)
+	buf.PutSlice(grpcHeader)
+	buf.PutSlice(protobufHeader[:varuintSize+1])
+	buf.PutSlice(b)
 
 	_, err = g.writer.Write(buf.Bytes())
 	if err == io.ErrClosedPipe && g.err != nil {