chore: better packet deadline

common/net/deadline/packet_sing.go

@@ -0,0 +1,96 @@
+package deadline
+
+import (
+	"os"
+
+	"github.com/Dreamacro/clash/common/net/packet"
+	"github.com/sagernet/sing/common/buf"
+	M "github.com/sagernet/sing/common/metadata"
+)
+
+type SingPacketConn struct {
+	*NetPacketConn
+	singPacketConn
+}
+
+var _ packet.SingPacketConn = (*SingPacketConn)(nil)
+
+func NewSingPacketConn(pc packet.SingPacketConn) packet.SingPacketConn {
+	return NewNetPacketConn(pc).(packet.SingPacketConn)
+}
+
+type EnhanceSingPacketConn struct {
+	*EnhancePacketConn
+	singPacketConn
+}
+
+func NewEnhanceSingPacketConn(pc packet.EnhanceSingPacketConn) packet.EnhanceSingPacketConn {
+	return NewNetPacketConn(pc).(packet.EnhanceSingPacketConn)
+}
+
+var _ packet.EnhanceSingPacketConn = (*EnhanceSingPacketConn)(nil)
+
+type singReadResult struct {
+	buffer      *buf.Buffer
+	destination M.Socksaddr
+}
+
+type singPacketConn struct {
+	netPacketConn  *NetPacketConn
+	singPacketConn packet.SingPacketConn
+}
+
+func (c *singPacketConn) ReadPacket(buffer *buf.Buffer) (destination M.Socksaddr, err error) {
+	select {
+	case result := <-c.netPacketConn.resultCh:
+		if result != nil {
+			destination = result.destination
+			err = result.err
+			buffer.Resize(result.buffer.Start(), 0)
+			n := copy(buffer.FreeBytes(), result.buffer.Bytes())
+			buffer.Truncate(n)
+			result.buffer.Advance(n)
+			if result.buffer.IsEmpty() {
+				result.buffer.Release()
+			}
+			c.netPacketConn.resultCh <- nil // finish cache read
+			return
+		} else {
+			c.netPacketConn.resultCh <- nil
+			break
+		}
+	case <-c.netPacketConn.pipeDeadline.wait():
+		return M.Socksaddr{}, os.ErrDeadlineExceeded
+	}
+
+	if c.netPacketConn.disablePipe.Load() {
+		return c.singPacketConn.ReadPacket(buffer)
+	} else if c.netPacketConn.deadline.Load().IsZero() {
+		c.netPacketConn.inRead.Store(true)
+		defer c.netPacketConn.inRead.Store(false)
+		destination, err = c.singPacketConn.ReadPacket(buffer)
+		return
+	}
+
+	<-c.netPacketConn.resultCh
+	go c.pipeReadPacket(buffer.Cap(), buffer.Start())
+
+	return c.ReadPacket(buffer)
+}
+
+func (c *singPacketConn) pipeReadPacket(bufLen int, bufStart int) {
+	buffer := buf.NewSize(bufLen)
+	buffer.Advance(bufStart)
+	destination, err := c.singPacketConn.ReadPacket(buffer)
+	c.netPacketConn.resultCh <- &readResult{
+		singReadResult: singReadResult{
+			buffer:      buffer,
+			destination: destination,
+		},
+		err: err,
+	}
+}
+
+func (c *singPacketConn) WritePacket(buffer *buf.Buffer, destination M.Socksaddr) error {
+	return c.singPacketConn.WritePacket(buffer, destination)
+}