Redesign flexible buffer

core/port.go

@@ -47,8 +47,10 @@ func (self *NetPort) Pack(b *iovec.IoVec) error {
 }
 
 type RawNetPort struct {
-	C       net.Conn
-	timeout time.Duration
+	C        net.Conn
+	timeout  time.Duration
+	lastRead int
+	buf      []byte
 }
 
 func (self *RawNetPort) Pack(b *iovec.IoVec) error {
@@ -63,12 +65,23 @@ func (self *RawNetPort) Unpack(b *iovec.IoVec) error {
 	if err := self.C.SetReadDeadline(time.Now().Add(self.timeout)); err != nil {
 		return err
 	}
-	buf := make([]byte, DEFAULT_BUFFER_SIZE)
-	nr, err := self.C.Read(buf)
+	if len(self.buf) <= self.lastRead {
+		l := self.lastRead
+		if l < DEFAULT_UDP_BUFFER_SIZE || l < DEFAULT_BUFFER_SIZE {
+			l = DEFAULT_BUFFER_SIZE
+		} else {
+			l = self.lastRead * 2
+		}
+		self.buf = make([]byte, l)
+	}
+	nr, err := self.C.Read(self.buf)
 	if err != nil {
+		self.lastRead = 0
 		return err
 	}
-	b.Take(buf[:nr])
+	b.Take(self.buf[:nr])
+	self.buf = self.buf[nr:]
+	self.lastRead = nr
 	return nil
 }