Improve smux write

common/mux/client.go

@@ -146,7 +146,12 @@ func (c *Client) offerNew() (abstractSession, error) {
 	if err != nil {
 		return nil, err
 	}
-	session, err := c.protocol.newClient(&protocolConn{Conn: conn, protocol: c.protocol})
+	if vectorisedWriter, isVectorised := bufio.CreateVectorisedWriter(conn); isVectorised {
+		conn = &vectorisedProtocolConn{protocolConn{Conn: conn, protocol: c.protocol}, vectorisedWriter}
+	} else {
+		conn = &protocolConn{Conn: conn, protocol: c.protocol}
+	}
+	session, err := c.protocol.newClient(conn)
 	if err != nil {
 		return nil, err
 	}

common/mux/protocol.go

@@ -43,7 +43,7 @@ func ParseProtocol(name string) (Protocol, error) {
 func (p Protocol) newServer(conn net.Conn) (abstractSession, error) {
 	switch p {
 	case ProtocolSMux:
-		session, err := smux.Server(wrapSMuxConn(conn), nil)
+		session, err := smux.Server(conn, nil)
 		if err != nil {
 			return nil, err
 		}
@@ -58,7 +58,7 @@ func (p Protocol) newServer(conn net.Conn) (abstractSession, error) {
 func (p Protocol) newClient(conn net.Conn) (abstractSession, error) {
 	switch p {
 	case ProtocolSMux:
-		session, err := smux.Client(wrapSMuxConn(conn), nil)
+		session, err := smux.Client(conn, nil)
 		if err != nil {
 			return nil, err
 		}
@@ -201,31 +201,6 @@ func ReadStreamResponse(reader io.Reader) (*StreamResponse, error) {
 	return &response, nil
 }
 
-type smuxTCPConn struct {
-	*net.TCPConn
-}
-
-func wrapSMuxConn(originConn net.Conn) net.Conn {
-	switch conn := originConn.(type) {
-	case *net.TCPConn:
-		return &smuxTCPConn{conn}
-	}
-	return originConn
-}
-
-func (w *smuxTCPConn) WriteBuffers(v [][]byte) (n int, err error) {
-	buffers := net.Buffers(v)
-	writeN, err := buffers.WriteTo(w.TCPConn)
-	if err != nil {
-		return
-	}
-	return int(writeN), nil
-}
-
-func (w *smuxTCPConn) Upstream() any {
-	return w.TCPConn
-}
-
 type wrapStream struct {
 	net.Conn
 }

common/mux/session.go

@@ -7,6 +7,7 @@ import (
 	"github.com/sagernet/sing/common"
 	"github.com/sagernet/sing/common/buf"
 	"github.com/sagernet/sing/common/bufio"
+	N "github.com/sagernet/sing/common/network"
 	"github.com/sagernet/smux"
 )
 
@@ -68,3 +69,23 @@ func (c *protocolConn) ReadFrom(r io.Reader) (n int64, err error) {
 func (c *protocolConn) Upstream() any {
 	return c.Conn
 }
+
+type vectorisedProtocolConn struct {
+	protocolConn
+	N.VectorisedWriter
+}
+
+func (c *vectorisedProtocolConn) WriteVectorised(buffers []*buf.Buffer) error {
+	if c.protocolWritten {
+		return c.VectorisedWriter.WriteVectorised(buffers)
+	}
+	c.protocolWritten = true
+	_buffer := buf.StackNewSize(2)
+	defer common.KeepAlive(_buffer)
+	buffer := common.Dup(_buffer)
+	defer buffer.Release()
+	EncodeRequest(buffer, Request{
+		Protocol: c.protocol,
+	})
+	return c.VectorisedWriter.WriteVectorised(append([]*buf.Buffer{buffer}, buffers...))
+}