class UploadInstance

class UploadInstance extends DrupalSqlBase {
    use DummyQueryTrait;
    
    /**
     * {@inheritdoc}
     */
    protected function initializeIterator() {
        $node_types = $this->select('node_type', 'nt')
            ->fields('nt', [
            'type',
        ])
            ->execute()
            ->fetchCol();
        $variables = array_map(function ($type) {
            return 'upload_' . $type;
        }, $node_types);
        $max_filesize = $this->variableGet('upload_uploadsize_default', 1);
        $max_filesize = $max_filesize ? $max_filesize . 'MB' : '';
        $file_extensions = $this->variableGet('upload_extensions_default', 'jpg jpeg gif png txt doc xls pdf ppt pps odt ods odp');
        $return = [];
        $values = $this->select('variable', 'v')
            ->fields('v', [
            'name',
            'value',
        ])
            ->condition('v.name', $variables, 'IN')
            ->execute()
            ->fetchAllKeyed();
        foreach ($node_types as $node_type) {
            $name = 'upload_' . $node_type;
            // By default, file attachments in D6 are enabled unless upload_<type> is
            // false, so include types where the upload-variable is not set.
            $enabled = !isset($values[$name]) || unserialize($values[$name]);
            if ($enabled) {
                $return[$node_type]['node_type'] = $node_type;
                $return[$node_type]['max_filesize'] = $max_filesize;
                $return[$node_type]['file_extensions'] = $file_extensions;
            }
        }
        return new \ArrayIterator($return);
    }
    
    /**
     * {@inheritdoc}
     */
    public function getIds() {
        return [
            'node_type' => [
                'type' => 'string',
            ],
        ];
    }
    
    /**
     * {@inheritdoc}
     */
    public function fields() {
        return [
            'node_type' => $this->t('Node type'),
            'max_filesize' => $this->t('Max filesize'),
            'file_extensions' => $this->t('File extensions'),
        ];
    }
    
    /**
     * {@inheritdoc}
     */
    protected function doCount() {
        return count($this->initializeIterator());
    }

}