chore: decrease direct depend on the sing package

common/net/sing.go

@@ -0,0 +1,24 @@
+package net
+
+import (
+	"context"
+	"net"
+
+	"github.com/sagernet/sing/common/bufio"
+	"github.com/sagernet/sing/common/network"
+)
+
+type ExtendedConnWrapper = bufio.ExtendedConnWrapper
+
+var NewExtendedConn = bufio.NewExtendedConn
+var NewExtendedWriter = bufio.NewExtendedWriter
+var NewExtendedReader = bufio.NewExtendedReader
+
+type ExtendedConn = network.ExtendedConn
+type ExtendedWriter = network.ExtendedWriter
+type ExtendedReader = network.ExtendedReader
+
+// Relay copies between left and right bidirectionally.
+func Relay(leftConn, rightConn net.Conn) {
+	_ = bufio.CopyConn(context.TODO(), leftConn, rightConn)
+}