perf: route packet by each tcp conn (#548)

pkg/core/bufferedtcp.go

@@ -0,0 +1,55 @@
+package core
+
+import (
+	"context"
+	"errors"
+	"net"
+
+	"github.com/wencaiwulue/kubevpn/v2/pkg/config"
+	plog "github.com/wencaiwulue/kubevpn/v2/pkg/log"
+)
+
+type bufferedTCP struct {
+	net.Conn
+	Chan   chan *DatagramPacket
+	closed bool
+}
+
+func NewBufferedTCP(conn net.Conn) net.Conn {
+	c := &bufferedTCP{
+		Conn: conn,
+		Chan: make(chan *DatagramPacket, MaxSize),
+	}
+	go c.Run()
+	return c
+}
+
+func (c *bufferedTCP) Write(b []byte) (n int, err error) {
+	if c.closed {
+		return 0, errors.New("tcp channel is closed")
+	}
+	if len(b) == 0 {
+		return 0, nil
+	}
+
+	buf := config.LPool.Get().([]byte)[:]
+	n = copy(buf, b)
+	c.Chan <- &DatagramPacket{
+		DataLength: uint16(n),
+		Data:       buf,
+	}
+	return n, nil
+}
+
+func (c *bufferedTCP) Run() {
+	for buf := range c.Chan {
+		_, err := c.Conn.Write(buf.Data[:buf.DataLength])
+		config.LPool.Put(buf.Data[:])
+		if err != nil {
+			plog.G(context.Background()).Errorf("[TCP] Write packet failed: %v", err)
+			_ = c.Conn.Close()
+			c.closed = true
+			return
+		}
+	}
+}