style: put the loop into a separate file and add relevant comments

core/engine/engine.go

@@ -2,7 +2,6 @@ package engine
 
 import (
 	"context"
-	"fmt"
 	"io"
 	"net/netip"
 	"sync"
@@ -11,7 +10,6 @@ import (
 
 	"github.com/wlynxg/NetHive/core/config"
 	"github.com/wlynxg/NetHive/core/device"
-	"github.com/wlynxg/NetHive/core/protocol"
 	mlog "github.com/wlynxg/NetHive/pkgs/log"
 	"github.com/wlynxg/NetHive/pkgs/xsync"
 
@@ -168,86 +166,6 @@ func (e *Engine) Run() error {
 	return nil
 }
 
-func (e *Engine) RoutineTUNReader() {
-	var (
-		buff = make([]byte, BuffSize)
-		err  error
-		n    int
-	)
-	for {
-		n, err = e.device.Read(buff)
-		if err != nil {
-			e.errChan <- fmt.Errorf("[RoutineTUNReader]: %s", err)
-			return
-		}
-		ip, err := protocol.ParseIP(buff[:n])
-		if err != nil {
-			e.log.Warnf("[RoutineTUNReader] drop packet, because %s", err)
-			continue
-		}
-		payload := Payload{
-			Src:  ip.Src(),
-			Dst:  ip.Dst(),
-			Data: make([]byte, n),
-		}
-		copy(payload.Data, buff[:n])
-		select {
-		case e.devReader <- payload:
-		default:
-			e.log.Warnf("[RoutineTUNReader] drop packet: %s, because the sending queue is already full", payload.Dst)
-		}
-	}
-}
-
-func (e *Engine) RoutineTUNWriter() {
-	var (
-		payload Payload
-		err     error
-	)
-
-	for payload = range e.devWriter {
-		_, err = e.device.Write(payload.Data)
-		if err != nil {
-			e.log.Error(e.ctx, fmt.Errorf("[RoutineTUNWriter]: %s", err))
-			return
-		}
-	}
-}
-
-func (e *Engine) RoutineRouteTableWriter() {
-	var (
-		payload Payload
-	)
-
-	for payload = range e.devReader {
-		var conn PacketChan
-
-		e.log.Debugf("%s -> %s", payload.Src, payload.Dst)
-
-		c, ok := e.routeTable.addr.Load(payload.Dst)
-		if ok {
-			conn = c
-		} else {
-			c, err := e.addConnByDst(payload.Dst)
-			if err != nil {
-				e.log.Warnf("[RoutineRouteTableWriter] drop packet: %s, because %s", payload.Dst, err)
-				continue
-			}
-			conn = c
-		}
-
-		if conn == nil {
-			continue
-		}
-
-		select {
-		case conn <- payload:
-		default:
-			e.log.Warnf("[RoutineRouteTableWriter] drop packet: %s, because the sending queue is already full", payload.Dst)
-		}
-	}
-}
-
 func (e *Engine) VPNHandler(stream network.Stream) {
 	e.log.Debugf("%s connect", stream.Conn().RemotePeer())
 

core/engine/routine.go

@@ -0,0 +1,90 @@
+package engine
+
+import (
+	"fmt"
+
+	"github.com/wlynxg/NetHive/core/protocol"
+)
+
+// RoutineTUNReader loop to read packets from TUN
+func (e *Engine) RoutineTUNReader() {
+	var (
+		buff = make([]byte, BuffSize)
+		err  error
+		n    int
+	)
+	for {
+		n, err = e.device.Read(buff)
+		if err != nil {
+			e.errChan <- fmt.Errorf("[RoutineTUNReader]: %s", err)
+			return
+		}
+		ip, err := protocol.ParseIP(buff[:n])
+		if err != nil {
+			e.log.Warnf("[RoutineTUNReader] drop packet, because %s", err)
+			continue
+		}
+		payload := Payload{
+			Src:  ip.Src(),
+			Dst:  ip.Dst(),
+			Data: make([]byte, n),
+		}
+		copy(payload.Data, buff[:n])
+		select {
+		case e.devReader <- payload:
+		default:
+			e.log.Warnf("[RoutineTUNReader] drop packet: %s, because the sending queue is already full", payload.Dst)
+		}
+	}
+}
+
+// RoutineTUNWriter loop writing packets to TUN
+func (e *Engine) RoutineTUNWriter() {
+	var (
+		payload Payload
+		err     error
+	)
+
+	for payload = range e.devWriter {
+		_, err = e.device.Write(payload.Data)
+		if err != nil {
+			e.log.Error(e.ctx, fmt.Errorf("[RoutineTUNWriter]: %s", err))
+			return
+		}
+	}
+}
+
+// RoutineRouteTableWriter loop sending the data packet to the corresponding channel according to the routing table
+func (e *Engine) RoutineRouteTableWriter() {
+	var (
+		payload Payload
+	)
+
+	for payload = range e.devReader {
+		var conn PacketChan
+
+		e.log.Debugf("%s -> %s", payload.Src, payload.Dst)
+
+		c, ok := e.routeTable.addr.Load(payload.Dst)
+		if ok {
+			conn = c
+		} else {
+			c, err := e.addConnByDst(payload.Dst)
+			if err != nil {
+				e.log.Warnf("[RoutineRouteTableWriter] drop packet: %s, because %s", payload.Dst, err)
+				continue
+			}
+			conn = c
+		}
+
+		if conn == nil {
+			continue
+		}
+
+		select {
+		case conn <- payload:
+		default:
+			e.log.Warnf("[RoutineRouteTableWriter] drop packet: %s, because the sending queue is already full", payload.Dst)
+		}
+	}
+}