owncloud/core

<?php
/**
 * @author Arthur Schiwon <blizzz@arthur-schiwon.de>
 * @author Joas Schilling <coding@schilljs.com>
 * @author Vincent Petry <pvince81@owncloud.com>
 *
 * @copyright Copyright (c) 2018, ownCloud GmbH
 * @license AGPL-3.0
 *
 * This code is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License, version 3,
 * as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License, version 3,
 * along with this program.  If not, see <http://www.gnu.org/licenses/>
 *
 */

namespace OCA\Files\BackgroundJob;

use OC\BackgroundJob\TimedJob;
use OCP\DB\QueryBuilder\IQueryBuilder;

/**
 * Delete all share entries that have no matching entries in the file cache table.
 */
class DeleteOrphanedItems extends TimedJob {
    public const CHUNK_SIZE = 200;

    /** @var \OCP\IDBConnection */
    protected $connection;

    /** @var \OCP\ILogger */
    protected $logger;

    /**
     * Default interval in minutes
     *
     * @var int $defaultIntervalMin
     **/
    protected $defaultIntervalMin = 60;

    /**
     * sets the correct interval for this timed job
     */
    public function __construct() {
        $this->interval = $this->defaultIntervalMin * 60;
        $this->connection = \OC::$server->getDatabaseConnection();
        $this->logger = \OC::$server->getLogger();
    }

    /**
     * Makes the background job do its work
     *
     * @param array $argument unused argument
     */
    public function run($argument) {
        $this->cleanSystemTags();
        $this->cleanUserTags();
        $this->cleanComments();
        $this->cleanCommentMarkers();
    }

    /**
     * Deleting orphaned system tag mappings
     *
     * @param string $table
     * @param string $idCol
     * @param string $typeCol
     * @return int Number of deleted entries
     */
    protected function cleanUp($table, $idCol, $typeCol) {
        $deletedEntries = 0;

        $query = $this->connection->getQueryBuilder();
        $query->select('t1.' . $idCol)
            ->from($table, 't1')
            ->where($query->expr()->eq($typeCol, $query->expr()->literal('files')))
            ->andWhere($query->expr()->isNull('t2.fileid'))
            ->leftJoin('t1', 'filecache', 't2', $query->expr()->eq($query->expr()->castColumn('t1.' . $idCol, IQueryBuilder::PARAM_INT), 't2.fileid'))
            ->groupBy('t1.' . $idCol)
            ->setMaxResults(self::CHUNK_SIZE);

        $deleteQuery = $this->connection->getQueryBuilder();
        $deleteQuery->delete($table)
            ->where($deleteQuery->expr()->eq($idCol, $deleteQuery->createParameter('objectid')));

        $deletedInLastChunk = self::CHUNK_SIZE;
        while ($deletedInLastChunk === self::CHUNK_SIZE) {
            $result = $query->execute();
            $deletedInLastChunk = 0;
            while ($row = $result->fetch()) {
                $deletedInLastChunk++;
                $deletedEntries += $deleteQuery->setParameter('objectid', (int) $row[$idCol])
                    ->execute();
            }
            $result->closeCursor();
        }

        return $deletedEntries;
    }

    /**
     * Deleting orphaned system tag mappings
     *
     * @return int Number of deleted entries
     */
    protected function cleanSystemTags() {
        $deletedEntries = $this->cleanUp('systemtag_object_mapping', 'objectid', 'objecttype');
        $this->logger->debug("$deletedEntries orphaned system tag relations deleted", ['app' => 'DeleteOrphanedItems']);
        return $deletedEntries;
    }

    /**
     * Deleting orphaned user tag mappings
     *
     * @return int Number of deleted entries
     */
    protected function cleanUserTags() {
        $deletedEntries = $this->cleanUp('vcategory_to_object', 'objid', 'type');
        $this->logger->debug("$deletedEntries orphaned user tag relations deleted", ['app' => 'DeleteOrphanedItems']);
        return $deletedEntries;
    }

    /**
     * Deleting orphaned comments
     *
     * @return int Number of deleted entries
     */
    protected function cleanComments() {
        $deletedEntries = $this->cleanUp('comments', 'object_id', 'object_type');
        $this->logger->debug("$deletedEntries orphaned comments deleted", ['app' => 'DeleteOrphanedItems']);
        return $deletedEntries;
    }

    /**
     * Deleting orphaned comment read markers
     *
     * @return int Number of deleted entries
     */
    protected function cleanCommentMarkers() {
        $deletedEntries = $this->cleanUp('comments_read_markers', 'object_id', 'object_type');
        $this->logger->debug("$deletedEntries orphaned comment read marks deleted", ['app' => 'DeleteOrphanedItems']);
        return $deletedEntries;
    }
}