public function getUrlIdMap(array $urls)
    {
        $map = array();

        if (!empty($urls)) {
            $q = $this->getConnection()->createSelectQuery();
            $q
                ->select('id', 'url')
                ->from(self::URL_TABLE)
                ->where($q->expr->in('url', $urls));

            $statement = $q->prepare();
            $statement->execute();
            foreach ($statement->fetchAll(PDO::FETCH_ASSOC) as $row) {
                $map[$row['url']] = $row['id'];
            }
        }

        return $map;
    }