owncloud/core

<?php
/**
 * @author Jörn Friedrich Dreyer <jfd@butonic.de>
 * @author Morris Jobke <hey@morrisjobke.de>
 * @author Thomas Müller <thomas.mueller@tmit.eu>
 *
 * @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 OC\Repair;

use OCP\Migration\IOutput;
use OCP\Migration\IRepairStep;

class SearchLuceneTables implements IRepairStep {
    public function getName() {
        return 'Repair duplicate entries in oc_lucene_status';
    }

    /**
     * Fix duplicate entries in oc_lucene_status
     *
     * search_lucene prior to v0.5.0 did not have a primary key on the lucene_status table. Newer versions do, which
     * causes the migration check to fail because it tries to insert duplicate rows into the new schema.
     *
     * FIXME Currently, apps don't have a way of repairing anything before the migration check:
     * @link https://github.com/owncloud/core/issues/10980
     *
     * As a result this repair step needs to live in the core repo, although it belongs into search_lucene:
     * @link https://github.com/owncloud/core/issues/10205#issuecomment-54957557
     *
     * It will completely remove any rows that make a file id have more than one status:
     *  fileid | status                       fileid | status
     * --------+--------     will become     --------+--------
     *     2   |   E                             3   |   E
     *     2   |   I
     *     3   |   E
     *
     * search_lucene will then reindex the fileids without a status when the next indexing job is executed
     */
    public function run(IOutput $out) {
        $connection = \OC::$server->getDatabaseConnection();
        if ($connection->tableExists('lucene_status')) {
            $out->info('removing duplicate entries from lucene_status');

            $query = $connection->prepare('
                DELETE FROM `*PREFIX*lucene_status`
                WHERE `fileid` IN (
                    SELECT `fileid`
                    FROM (
                        SELECT `fileid`
                        FROM `*PREFIX*lucene_status`
                        GROUP BY `fileid`
                        HAVING count(`fileid`) > 1
                    ) AS `mysqlerr1093hack`
                )');
            $query->execute();
        } else {
            $out->info('lucene_status table does not exist -> nothing to do');
        }
    }
}