WC_Download_Handler::download_file_xsendfile PHP Method

    public static function download_file_xsendfile($file_path, $filename)
    {
        $parsed_file_path = self::parse_file_path($file_path);
        if (function_exists('apache_get_modules') && in_array('mod_xsendfile', apache_get_modules())) {
            self::download_headers($parsed_file_path['file_path'], $filename);
            header("X-Sendfile: " . $parsed_file_path['file_path']);
            exit;
        } elseif (stristr(getenv('SERVER_SOFTWARE'), 'lighttpd')) {
            self::download_headers($parsed_file_path['file_path'], $filename);
            header("X-Lighttpd-Sendfile: " . $parsed_file_path['file_path']);
            exit;
        } elseif (stristr(getenv('SERVER_SOFTWARE'), 'nginx') || stristr(getenv('SERVER_SOFTWARE'), 'cherokee')) {
            self::download_headers($parsed_file_path['file_path'], $filename);
            $xsendfile_path = trim(preg_replace('`^' . str_replace('\\', '/', getcwd()) . '`', '', $parsed_file_path['file_path']), '/');
            header("X-Accel-Redirect: /{$xsendfile_path}");
            exit;
        }
        // Fallback
        self::download_file_force($file_path, $filename);
    }