function getVisitIp() {
    $ipKeys = array(
        'HTTP_X_FORWARDED_FOR',
        'HTTP_CLIENT_IP',
        'HTTP_CF_CONNECTING_IP',
    );
    foreach($ipKeys as $ipKey) {
        if (isset($_SERVER[$ipKey]) && $_SERVER[$ipKey]!="")
            return $_SERVER[$ipKey];
    }
    return arrayValue($_SERVER, 'REMOTE_ADDR');
}