MatthiasMullie\Scrapbook\Adapters\Apc::add PHP Method

    public function add($key, $value, $expire = 0)
    {
        $ttl = $this->ttl($expire);
        // negative TTLs don't always seem to properly treat the key as deleted
        if ($ttl < 0) {
            // don't add - it's expired already; just check if it already
            // existed to return true/false as expected from add()
            return $this->get($key) === false;
        }
        // lock required for CAS
        if (!$this->lock($key)) {
            return false;
        }
        $success = $this->apcu_add($key, $value, $ttl);
        $this->expire($key, $ttl);
        $this->unlock($key);
        return $success;
    }