FeedStorage.php

<?php

namespace Drupal\aggregator;

use Drupal\Core\Entity\Sql\SqlContentEntityStorage;

/**
 * Defines the storage handler class for feed entities.
 *
 * This extends the base storage class, adding required special handling for
 * feed entities.
 */
class FeedStorage extends SqlContentEntityStorage implements FeedStorageInterface {
    
    /**
     * {@inheritdoc}
     */
    public function getFeedIdsToRefresh() {
        return $this->database
            ->query('SELECT [fid] FROM {' . $this->getBaseTable() . '} WHERE [queued] = 0 AND [checked] + [refresh] < :time AND [refresh] <> :never', [
            ':time' => REQUEST_TIME,
            ':never' => static::CLEAR_NEVER,
        ])
            ->fetchCol();
    }

}