owncloud/core

<?php
/**
 * @author Björn Schießle <bjoern@schiessle.org>
 * @author Morris Jobke <hey@morrisjobke.de>
 * @author Roeland Jago Douma <rullzer@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_Sharing;

use Doctrine\DBAL\Connection;
use OC\Cache\CappedMemoryCache;
use OCP\IDBConnection;

/**
 * Class Migration
 *
 * @package OCA\Files_Sharing
 * @group DB
 */
class Migration {
    /** @var IDBConnection */
    private $connection;

    /** @var  array with all shares we already saw */
    private $shareCache;

    /** @var string */
    private $table = 'share';

    public function __construct(IDBConnection $connection) {
        $this->connection = $connection;

        // We cache up to 10k share items (~20MB)
        $this->shareCache = new CappedMemoryCache(10000);
    }

    /**
     * move all re-shares to the owner in order to have a flat list of shares
     * upgrade from oC 8.2 to 9.0 with the new sharing
     */
    public function removeReShares() {
        $stmt = $this->getReShares();

        $owners = [];
        while ($share = $stmt->fetch()) {
            $this->shareCache[$share['id']] = $share;

            $owners[$share['id']] = [
                    'owner' => $this->findOwner($share),
                    'initiator' => $share['uid_owner'],
                    'type' => $share['share_type'],
            ];

            if (\count($owners) === 1000) {
                $this->updateOwners($owners);
                $owners = [];
            }
        }

        $stmt->closeCursor();

        if (\count($owners)) {
            $this->updateOwners($owners);
        }
    }

    /**
     * update all owner information so that all shares have an owner
     * and an initiator for the upgrade from oC 8.2 to 9.0 with the new sharing
     */
    public function updateInitiatorInfo() {
        while (true) {
            $shares = $this->getMissingInitiator(1000);

            if (empty($shares)) {
                break;
            }

            $owners = [];
            foreach ($shares as $share) {
                $owners[$share['id']] = [
                    'owner' => $share['uid_owner'],
                    'initiator' => $share['uid_owner'],
                    'type' => $share['share_type'],
                ];
            }
            $this->updateOwners($owners);
        }
    }

    /**
     * find the owner of a re-shared file/folder
     *
     * @param array $share
     * @return array
     */
    private function findOwner($share) {
        $currentShare = $share;
        while ($currentShare['parent'] !== null) {
            if (isset($this->shareCache[$currentShare['parent']])) {
                $currentShare = $this->shareCache[$currentShare['parent']];
            } else {
                $currentShare = $this->getShare((int)$currentShare['parent']);
                $this->shareCache[$currentShare['id']] = $currentShare;
            }
        }

        return $currentShare['uid_owner'];
    }

    /**
     * Get $n re-shares from the database
     *
     * @param int $n The max number of shares to fetch
     * @return \Doctrine\DBAL\Driver\Statement
     */
    private function getReShares() {
        $query = $this->connection->getQueryBuilder();
        $query->select(['id', 'parent', 'uid_owner', 'share_type'])
            ->from($this->table)
            ->where($query->expr()->in(
                'share_type',
                $query->createNamedParameter(
                    [
                        \OCP\Share::SHARE_TYPE_USER,
                        \OCP\Share::SHARE_TYPE_GROUP,
                        \OCP\Share::SHARE_TYPE_LINK,
                        \OCP\Share::SHARE_TYPE_REMOTE,
                    ],
                    Connection::PARAM_INT_ARRAY
                )
            ))
            ->andWhere($query->expr()->in(
                'item_type',
                $query->createNamedParameter(
                    ['file', 'folder'],
                    Connection::PARAM_STR_ARRAY
                )
            ))
            ->andWhere($query->expr()->isNotNull('parent'))
            ->orderBy('id', 'asc');
        return $query->execute();
    }

    /**
     * Get $n re-shares from the database
     *
     * @param int $n The max number of shares to fetch
     * @return array
     */
    private function getMissingInitiator($n = 1000) {
        $query = $this->connection->getQueryBuilder();
        $query->select(['id', 'uid_owner', 'share_type'])
            ->from($this->table)
            ->where($query->expr()->in(
                'share_type',
                $query->createNamedParameter(
                    [
                        \OCP\Share::SHARE_TYPE_USER,
                        \OCP\Share::SHARE_TYPE_GROUP,
                        \OCP\Share::SHARE_TYPE_LINK,
                        \OCP\Share::SHARE_TYPE_REMOTE,
                    ],
                    Connection::PARAM_INT_ARRAY
                )
            ))
            ->andWhere($query->expr()->in(
                'item_type',
                $query->createNamedParameter(
                    ['file', 'folder'],
                    Connection::PARAM_STR_ARRAY
                )
            ))
            ->andWhere($query->expr()->isNull('uid_initiator'))
            ->orderBy('id', 'asc')
            ->setMaxResults($n);
        $result = $query->execute();
        $shares = $result->fetchAll();
        $result->closeCursor();

        $ordered = [];
        foreach ($shares as $share) {
            $ordered[(int)$share['id']] = $share;
        }

        return $ordered;
    }

    /**
     * get a specific share
     *
     * @param int $id
     * @return array
     */
    private function getShare($id) {
        $query = $this->connection->getQueryBuilder();
        $query->select(['id', 'parent', 'uid_owner'])
            ->from($this->table)
            ->where($query->expr()->eq('id', $query->createNamedParameter($id)));
        $result = $query->execute();
        $share = $result->fetchAll();
        $result->closeCursor();

        return $share[0];
    }

    /**
     * update database with the new owners
     *
     * @param array $owners
     * @throws \Exception
     */
    private function updateOwners($owners) {
        $this->connection->beginTransaction();

        try {
            foreach ($owners as $id => $owner) {
                $query = $this->connection->getQueryBuilder();
                $query->update($this->table)
                    ->set('uid_owner', $query->createNamedParameter($owner['owner']))
                    ->set('uid_initiator', $query->createNamedParameter($owner['initiator']));

                if ((int)$owner['type'] !== \OCP\Share::SHARE_TYPE_LINK) {
                    $query->set('parent', $query->createNamedParameter(null));
                }

                $query->where($query->expr()->eq('id', $query->createNamedParameter($id)));

                $query->execute();
            }

            $this->connection->commit();
        } catch (\Exception $e) {
            $this->connection->rollBack();
            throw $e;
        }
    }
}