Add direct io option for clash api

experimental/trackerconn/conn.go

@@ -0,0 +1,82 @@
+package trackerconn
+
+import (
+	"io"
+	"net"
+
+	"github.com/sagernet/sing/common/buf"
+	"github.com/sagernet/sing/common/bufio"
+	N "github.com/sagernet/sing/common/network"
+
+	"go.uber.org/atomic"
+)
+
+func New(conn net.Conn, readCounter *atomic.Int64, writeCounter *atomic.Int64, direct bool) N.ExtendedConn {
+	trackerConn := &Conn{bufio.NewExtendedConn(conn), readCounter, writeCounter}
+	if direct {
+		return (*DirectConn)(trackerConn)
+	} else {
+		return trackerConn
+	}
+}
+
+type Conn struct {
+	N.ExtendedConn
+	readCounter  *atomic.Int64
+	writeCounter *atomic.Int64
+}
+
+func (c *Conn) Read(p []byte) (n int, err error) {
+	n, err = c.ExtendedConn.Read(p)
+	c.readCounter.Add(int64(n))
+	return n, err
+}
+
+func (c *Conn) ReadBuffer(buffer *buf.Buffer) error {
+	err := c.ExtendedConn.ReadBuffer(buffer)
+	if err != nil {
+		return err
+	}
+	c.readCounter.Add(int64(buffer.Len()))
+	return nil
+}
+
+func (c *Conn) Write(p []byte) (n int, err error) {
+	n, err = c.ExtendedConn.Write(p)
+	c.writeCounter.Add(int64(n))
+	return n, err
+}
+
+func (c *Conn) WriteBuffer(buffer *buf.Buffer) error {
+	dataLen := int64(buffer.Len())
+	err := c.ExtendedConn.WriteBuffer(buffer)
+	if err != nil {
+		return err
+	}
+	c.writeCounter.Add(dataLen)
+	return nil
+}
+
+type DirectConn Conn
+
+func (c *DirectConn) WriteTo(w io.Writer) (n int64, err error) {
+	reader := N.UnwrapReader(c.ExtendedConn)
+	if wt, ok := reader.(io.WriterTo); ok {
+		n, err = wt.WriteTo(w)
+		c.readCounter.Add(n)
+		return
+	} else {
+		return bufio.Copy(w, (*Conn)(c))
+	}
+}
+
+func (c *DirectConn) ReadFrom(r io.Reader) (n int64, err error) {
+	writer := N.UnwrapWriter(c.ExtendedConn)
+	if rt, ok := writer.(io.ReaderFrom); ok {
+		n, err = rt.ReadFrom(r)
+		c.writeCounter.Add(n)
+		return
+	} else {
+		return bufio.Copy((*Conn)(c), r)
+	}
+}