Imbo\Database\Mongo::getNumBytes PHP Method

    public function getNumBytes($user = null)
    {
        try {
            $pipeline = [['$group' => ['_id' => null, 'numBytes' => ['$sum' => '$size']]]];
            if ($user) {
                array_unshift($pipeline, ['$match' => ['user' => $user]]);
            }
            $result = $this->getImageCollection()->aggregate($pipeline, ['useCursor' => false]);
            if (!count($result)) {
                return 0;
            }
            return (int) $result[0]->numBytes;
        } catch (MongoException $e) {
            throw new DatabaseException('Unable to fetch information from the database', 500, $e);
        }
    }