MatthiasMullie\Scrapbook\Adapters\Redis::cas PHP Метод

    public function cas($token, $key, $value, $expire = 0)
    {
        $this->client->watch($key);
        // check if the value still matches CAS token
        $comparison = $this->client->get($key);
        if (serialize($comparison) !== $token) {
            /*
             * HHVM Redis only got unwatch recently
             * @see https://github.com/asgrim/hhvm/commit/bf5a259cece5df8a7617133c85043608d1ad5316
             */
            if (method_exists($this->client, 'unwatch')) {
                $this->client->unwatch();
            } else {
                // this should also kill the watch...
                $this->client->multi()->discard();
            }
            return false;
        }
        $ttl = $this->ttl($expire);
        // since we're watching the key, this will fail should it change in the
        // meantime
        $this->client->multi();
        /*
         * Negative ttl behavior isn't properly documented & doesn't always
         * appear to treat the value as non-existing. Let's play safe and just
         * delete it right away!
         */
        if ($ttl < 0) {
            $this->client->del($key);
        } else {
            $this->client->set($key, $value, $ttl);
        }
        /** @var bool[] $return */
        $return = (array) $this->client->exec();
        return !in_array(false, $return);
    }