plugin_can_flush (struct backend *b, struct connection *conn)
{
  struct backend_plugin *p = container_of (b, struct backend_plugin, backend);

  assert (connection_get_handle (conn, 0));

  if (p->plugin.can_flush)
    return p->plugin.can_flush (connection_get_handle (conn, 0));
  else
    return p->plugin.flush || p->plugin._flush_old;
}
plugin_can_flush (struct backend *b, struct connection *conn)
{
  struct backend_plugin *p = container_of (b, struct backend_plugin, backend);

  assert (connection_get_handle (conn, 0));

  if (p->plugin.can_flush)
    return p->plugin.can_flush (connection_get_handle (conn, 0));
  else
    return p->plugin.flush || p->plugin._flush_old;
}