AdController.php

<?php

class AdController extends Controller
{
    /**
     * @Route("/ad", name="ad")
     */
    public function indexAction(Request $request)
    {
        $criterias     = $this->get('advertisement.criterias')->resolveRequest($request);
        $advertisement = $this->get('advertisement.manager')->getByCriterias($criterias);

        //There the problem with performance might occur
        $this->getDoctrine()->getRepository('XsolveAdverisementBundle:Advertisement')->saveStatistics($request, $advertisement);

        return new Response(
            $advertisement->getImage(),
            200
        );
    }
}