public function readAssetFile(AssetFileModel $asset)
{
$url = $asset->getUrl();
if (!UrlHelper::isAbsoluteUrl($url)) {
$protocol = craft()->request->isSecureConnection() ? 'https' : 'http';
$url = UrlHelper::getUrlWithProtocol($url, $protocol);
}
return $this->_readExternalFile($url);
}