[concrete5][V8] Search all files from legacy database, then import files to modern concrete5

import_files.php

<?php
namespace Application\Job;

use Concrete\Core\File\Importer;
use Concrete\Core\Job\QueueableJob;
use ZendQueue\Message as ZendQueueMessage;
use ZendQueue\Queue as ZendQueue;

class ImportFiles extends QueueableJob
{
    protected static $basePath = '/var/www/vhost/www.example.com/files';

    public $jNotUninstallable=0;
    public $jSupportsQueue = true;

    public function getJobName() {
        return t("Import Files");
    }

    public function getJobDescription() {
        return t("Import all files from legacy site.");
    }

    public function start(ZendQueue $q)
    {
        /** @var \Doctrine\DBAL\Query\QueryBuilder $qb */
        $qb = \Database::connection('legacy')->createQueryBuilder();

        $query = $qb->select('f.fID')
            ->from('Files', 'f')
            ->innerJoin('f', 'FileVersions', 'fv', 'f.fID = fv.fID')
            ->where('fv.fvIsApproved = 1')
//            ->setMaxResults(5)
        ;
        $resp = $query->execute();

        $results = $resp->fetchAll();
        foreach ($results as $result) {
            $q->send($result['fID']);
        }
    }

    public function finish(ZendQueue $q)
    {
        return t('Done.');
    }

    public function processQueueItem(ZendQueueMessage $msg)
    {
        /** @var \Doctrine\DBAL\Query\QueryBuilder $qb */
        $qb = \Database::connection('legacy')->createQueryBuilder();

        $query = $qb->select('f.fID', 'fv.fvID', 'fv.fvFilename', 'fv.fvPrefix')
            ->from('Files', 'f')
            ->innerJoin('f', 'FileVersions', 'fv', 'f.fID = fv.fID')
            ->where('f.fID = :fID')
            ->setParameter('fID', $msg->body)
            ->andWhere('fv.fvIsApproved = 1')
            ->setMaxResults(1)
        ;
        $resp = $query->execute();

        $results = $resp->fetchAll();
        if (count($results)) {
            $result = $results[0];
            $cf = \Core::make('helper/concrete/file');
            $path = self::$basePath . $cf->prefix($result['fvPrefix'], $result['fvFilename']);
            $importer = new Importer();
            $fv = $importer->import($path);
            if (is_object($fv)) {
                \Log::info(sprintf('Import success: %s', $result['fvFilename']));
            } else {
                \Log::error(sprintf('Import failed: %s', $path));
            }

            unset($fv);
            unset($result);
            unset($cf);
            unset($path);
            unset($importer);
        }

        unset($results);
        unset($resp);
        unset($query);
        unset($qb);
    }
}