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

    public function replace($key, $value, $expire = 0)
    {
        $ttl = $this->ttl($expire);
        /*
         * 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) {
            return $this->delete($key);
        }
        /*
         * Redis supports passing set() an extended options array since >=2.6.12
         * which allows for an easy and 1-request way to replace a value.
         * That version already comes with Ubuntu 14.04. Ubuntu 12.04 (still
         * widely used and in LTS) comes with an older version, however, so I
         * want to support that too.
         * Supporting both versions comes at a cost.
         * I'll optimize for recent versions, which will get (in case of replace
         * failure) 1 additional network request (for version info). Older
         * versions will get 2 additional network requests: a failed replace
         * (because the options are unknown) & a version check.
         */
        if ($this->version === null || $this->supportsOptionsArray()) {
            $options = array('xx');
            if ($ttl > 0) {
                /*
                 * Not adding 0 TTL to options:
                 * * HHVM (used to) interpret(s) wrongly & throw an exception
                 * * it's not needed anyway, for 0...
                 * @see https://github.com/facebook/hhvm/pull/4833
                 */
                $options['ex'] = $ttl;
            }
            // either we support options array or we haven't yet checked, in
            // which case I'll assume a recent server is running
            $result = $this->client->set($key, $value, $options);
            if ($result !== false) {
                return $result;
            }
            if ($this->supportsOptionsArray()) {
                // failed execution, but not because our Redis version is too old
                return false;
            }
        }
        // workaround for old Redis versions
        $this->client->watch($key);
        $exists = $this->client->exists('key');
        if (!$exists) {
            /*
             * 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;
        }
        // since we're watching the key, this will fail should it change in the
        // meantime
        $this->client->multi();
        $this->client->set($key, $value, $ttl);
        /** @var bool[] $return */
        $return = (array) $this->client->exec();
        return !in_array(false, $return);
    }