function drupalwiki_privatefile_imagecache($preset,$prv_id) {
  if(is_numeric($prv_id)) {
    // Now actually check if we have access
    if(_drupalwiki_privatefile_access_api('view',$prv_id)) {
      $file = _drupalwiki_privatefile_load_file($prv_id);
      _imagecache_cache($preset, $file->orig_src);
    }
    else {
    return '';
    // well this url is not valid
    $accesspath = file_create_path('imagecache/'. $preset .'.403.png');
    if (is_file($accesspath)) {
      imagecache_transfer($accesspath);
      exit;
    }
    header('HTTP/1.0 403 Forbidden');
    exit;
    }
  }
  else {
    header('HTTP/1.0 404 Not found');
    exit;
  }
}

function drupalwiki_privatefile_imagecache_prefixpath_alter(&$path,$base,$filepath, $absolute) {
  $matches = array();
  if(preg_match("@privatefile/(\d)+@", $filepath, $matches)) {
    // override completely
    $path = 'privatefile';
  }
  // else this is no private file, dont change anything
}