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<?php
/**
* @copyright Copyright (c) 2016, ownCloud, Inc.
*
* @author Christoph Wurst <christoph@winzerhof-wurst.at>
* @author Jörn Friedrich Dreyer <jfd@butonic.de>
* @author Morris Jobke <hey@morrisjobke.de>
* @author Robin Appelman <robin@icewind.nl>
* @author Vincent Petry <vincent@nextcloud.com>
*
* @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\Stream;
use Icewind\Streams\Wrapper;
/**
* stream wrapper limits the amount of data that can be written to a stream
*
* usage: resource \OC\Files\Stream\Quota::wrap($stream, $limit)
*/
class Quota extends Wrapper {
/**
* @var int $limit
*/
private $limit;
/**
* @param resource $stream
* @param int $limit
* @return bool|resource
*/
public static function wrap($stream, $limit) {
$context = stream_context_create([
'quota' => [
'source' => $stream,
'limit' => $limit
]
]);
return Wrapper::wrapSource($stream, $context, 'quota', self::class);
}
public function stream_open($path, $mode, $options, &$opened_path) {
$context = $this->loadContext('quota');
$this->source = $context['source'];
$this->limit = $context['limit'];
return true;
}
public function dir_opendir($path, $options) {
return false;
}
public function stream_seek($offset, $whence = SEEK_SET) {
if ($whence === SEEK_END) {
// go to the end to find out last position's offset
$oldOffset = $this->stream_tell();
if (fseek($this->source, 0, $whence) !== 0) {
return false;
}
$whence = SEEK_SET;
$offset = $this->stream_tell() + $offset;
$this->limit += $oldOffset - $offset;
} elseif ($whence === SEEK_SET) {
$this->limit += $this->stream_tell() - $offset;
} else {
$this->limit -= $offset;
}
// this wrapper needs to return "true" for success.
// the fseek call itself returns 0 on succeess
return fseek($this->source, $offset, $whence) === 0;
}
public function stream_read($count) {
$this->limit -= $count;
return fread($this->source, $count);
}
public function stream_write($data) {
$size = strlen($data);
if ($size > $this->limit) {
$data = substr($data, 0, $this->limit);
$size = $this->limit;
}
$this->limit -= $size;
return fwrite($this->source, $data);
}
}
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