MatthiasMullie\Scrapbook\Adapters\Memcached::encodeKey PHP Method

    protected function encodeKey($key)
    {
        $regex = '/[^\\x21\\x22\\x24\\x26-\\x39\\x3b-\\x7e]+/';
        $key = preg_replace_callback($regex, function ($match) {
            return rawurlencode($match[0]);
        }, $key);
        if (strlen($key) > 255) {
            throw new InvalidKey("Invalid key: {$key}. Encoded Memcached keys can not exceed 255 chars.");
        }
        return $key;
    }