owncloud/core

<?php
/**
 * @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 OCA\DAV\Upload;

use Sabre\DAV\Exception\BadRequest;
use Sabre\DAV\Server;
use Sabre\DAV\ServerPlugin;

class ChunkingPlugin extends ServerPlugin {
    /** @var Server */
    private $server;
    /** @var FutureFile */
    private $sourceNode;

    /**
     * @inheritdoc
     */
    public function initialize(Server $server) {
        $server->on('beforeMove', [$this, 'beforeMove']);
        $this->server = $server;
    }

    /**
     * @param string $sourcePath source path
     * @param string $destination destination path
     * @return bool|void
     * @throws BadRequest
     * @throws \Sabre\DAV\Exception\NotFound
     */
    public function beforeMove($sourcePath, $destination) {
        $this->sourceNode = $this->server->tree->getNodeForPath($sourcePath);
        if (!$this->sourceNode instanceof FutureFile) {
            // skip handling as the source is not a chunked FutureFile
            return;
        }

        $this->verifySize();
        return $this->performMove($sourcePath, $destination);
    }

    /**
     * Move handler for future file.
     *
     * This overrides the default move behavior to prevent Sabre
     * to delete the target file before moving. Because deleting would
     * lose the file id and metadata.
     *
     * @param string $path source path
     * @param string $destination destination path
     * @return bool|void false to stop handling, void to skip this handler
     */
    public function performMove($path, $destination) {
        if (!$this->server->tree->nodeExists($destination)) {
            // skip and let the default handler do its work
            return;
        }

        // do a move manually, skipping Sabre's default "delete" for existing nodes
        $this->server->tree->move($path, $destination);

        // trigger all default events (copied from CorePlugin::move)
        $this->server->emit('afterMove', [$path, $destination]);
        $this->server->emit('afterUnbind', [$path]);
        $this->server->emit('afterBind', [$destination]);

        $response = $this->server->httpResponse;
        $response->setHeader('Content-Length', '0');
        $response->setStatus(204);

        return false;
    }

    /**
     * @throws BadRequest
     */
    private function verifySize() {
        $expectedSize = $this->server->httpRequest->getHeader('OC-Total-Length');
        if ($expectedSize === null) {
            return;
        }
        $actualSize = $this->sourceNode->getSize();
        // $actualSize could be either an int or a float
        if ($expectedSize != $actualSize) {
            throw new BadRequest("Chunks on server do not sum up to $expectedSize but to $actualSize");
        }
    }
}