chore: use early conn to support real ws 0-rtt

common/callback/callback.go

@@ -0,0 +1,25 @@
+package callback
+
+import (
+	C "github.com/Dreamacro/clash/constant"
+)
+
+type FirstWriteCallBackConn struct {
+	C.Conn
+	Callback func(error)
+	written  bool
+}
+
+func (c *FirstWriteCallBackConn) Write(b []byte) (n int, err error) {
+	defer func() {
+		if !c.written {
+			c.written = true
+			c.Callback(err)
+		}
+	}()
+	return c.Conn.Write(b)
+}
+
+func (c *FirstWriteCallBackConn) Upstream() any {
+	return c.Conn
+}

common/net/bufconn.go

@@ -12,13 +12,14 @@ var _ ExtendedConn = (*BufferedConn)(nil)
 type BufferedConn struct {
 	r *bufio.Reader
 	ExtendedConn
+	peeked bool
 }
 
 func NewBufferedConn(c net.Conn) *BufferedConn {
 	if bc, ok := c.(*BufferedConn); ok {
 		return bc
 	}
-	return &BufferedConn{bufio.NewReader(c), NewExtendedConn(c)}
+	return &BufferedConn{bufio.NewReader(c), NewExtendedConn(c), false}
 }
 
 // Reader returns the internal bufio.Reader.
@@ -26,11 +27,20 @@ func (c *BufferedConn) Reader() *bufio.Reader {
 	return c.r
 }
 
+func (c *BufferedConn) Peeked() bool {
+	return c.peeked
+}
+
 // Peek returns the next n bytes without advancing the reader.
 func (c *BufferedConn) Peek(n int) ([]byte, error) {
+	c.peeked = true
 	return c.r.Peek(n)
 }
 
+func (c *BufferedConn) Discard(n int) (discarded int, err error) {
+	return c.r.Discard(n)
+}
+
 func (c *BufferedConn) Read(p []byte) (int, error) {
 	return c.r.Read(p)
 }