server: http log sent bytes

server.go

@@ -252,8 +252,10 @@ func (s *Server) proxy(host string, w io.Writer, r interface{}, msg *proto.Contr
 
 	localToRemote := func() {
 		if hr, ok := r.(*http.Request); ok {
-			hr.Write(pw)
+			cw := &countWriter{pw, 0}
+			hr.Write(cw)
 			pw.Close()
+			s.log.Debug("Coppied %d bytes from %s", cw.count, "local to remote")
 		} else {
 			transfer("local to remote", pw, r.(io.ReadCloser), s.log)
 		}

utils.go

@@ -46,6 +46,17 @@ func copyHeader(dst, src http.Header) {
 	}
 }
 
+type countWriter struct {
+	w io.Writer
+	count int64
+}
+
+func (cw *countWriter) Write(p []byte) (n int, err error) {
+	n, err = cw.w.Write(p)
+	cw.count += int64(n)
+	return
+}
+
 type flushWriter struct {
 	w io.Writer
 }