PHP统计页面浏览次数，带文本缓存

//@统计点击
private function visit($id)
{
    if (isset($GLOBALS['cfg_safe']['visit-article']) && $GLOBALS['cfg_safe']['visit-article'])
    {
        $file = SYS_PATH . 'cache/visit-article.txt';

        if (!file_exists($file))
        {
            file_put_contents($file, ',' . $id);    
        }
        else if ((time() - filectime($file)) < $GLOBALS['cfg_safe']['visit-article'])
        {
            file_put_contents($file, ',' . $id, FILE_APPEND);      
        }
        else
        {
            $string = file_get_contents($file);
            if ($string != '')
            {
                $temp = explode(',', $string);
                foreach ($temp as $row)
                {
                    if (empty($row))
                        continue;
                    $this->mysql->update('UPDATE `pcb_article` SET `visit` = `visit` + 1 WHERE `id` = ' . $row . ' LIMIT 1');
                }    
            }
            unlink($file);
        } 
    }    
}
//该片段来自于http://outofmemory.cn