server/lib/private/Files/Storage/StorageFactory.php
2016-04-24 21:37:35 +02:00

107 lines
3.5 KiB
PHP

<?php
/**
* @author Jörn Friedrich Dreyer <jfd@butonic.de>
* @author Morris Jobke <hey@morrisjobke.de>
* @author Robin Appelman <icewind@owncloud.com>
* @author Vincent Petry <pvince81@owncloud.com>
*
* @copyright Copyright (c) 2016, ownCloud, Inc.
* @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\Files\Storage;
use OCP\Files\Mount\IMountPoint;
use OCP\Files\Storage\IStorageFactory;
class StorageFactory implements IStorageFactory {
/**
* @var array[] [$name=>['priority'=>$priority, 'wrapper'=>$callable] $storageWrappers
*/
private $storageWrappers = [];
/**
* allow modifier storage behaviour by adding wrappers around storages
*
* $callback should be a function of type (string $mountPoint, Storage $storage) => Storage
*
* @param string $wrapperName name of the wrapper
* @param callable $callback callback
* @param int $priority wrappers with the lower priority are applied last (meaning they get called first)
* @param \OCP\Files\Mount\IMountPoint[] $existingMounts existing mount points to apply the wrapper to
* @return bool true if the wrapper was added, false if there was already a wrapper with this
* name registered
*/
public function addStorageWrapper($wrapperName, $callback, $priority = 50, $existingMounts = []) {
if (isset($this->storageWrappers[$wrapperName])) {
return false;
}
// apply to existing mounts before registering it to prevent applying it double in MountPoint::createStorage
foreach ($existingMounts as $mount) {
$mount->wrapStorage($callback);
}
$this->storageWrappers[$wrapperName] = ['wrapper' => $callback, 'priority' => $priority];
return true;
}
/**
* Remove a storage wrapper by name.
* Note: internal method only to be used for cleanup
*
* @param string $wrapperName name of the wrapper
* @internal
*/
public function removeStorageWrapper($wrapperName) {
unset($this->storageWrappers[$wrapperName]);
}
/**
* Create an instance of a storage and apply the registered storage wrappers
*
* @param \OCP\Files\Mount\IMountPoint $mountPoint
* @param string $class
* @param array $arguments
* @return \OCP\Files\Storage
*/
public function getInstance(IMountPoint $mountPoint, $class, $arguments) {
return $this->wrap($mountPoint, new $class($arguments));
}
/**
* @param \OCP\Files\Mount\IMountPoint $mountPoint
* @param \OCP\Files\Storage $storage
* @return \OCP\Files\Storage
*/
public function wrap(IMountPoint $mountPoint, $storage) {
$wrappers = array_values($this->storageWrappers);
usort($wrappers, function ($a, $b) {
return $b['priority'] - $a['priority'];
});
/** @var callable[] $wrappers */
$wrappers = array_map(function ($wrapper) {
return $wrapper['wrapper'];
}, $wrappers);
foreach ($wrappers as $wrapper) {
$storage = $wrapper($mountPoint->getMountPoint(), $storage, $mountPoint);
if (!($storage instanceof \OCP\Files\Storage)) {
throw new \Exception('Invalid result from storage wrapper');
}
}
return $storage;
}
}