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<?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\Stream;
/**
* stream wrapper limits the amount of data that can be written to a stream
*
* usage: void \OC\Files\Stream\Quota::register($id, $stream, $limit)
* or: resource \OC\Files\Stream\Quota::wrap($stream, $limit)
*/
class Quota {
private static $streams = array();
/**
* @var resource $source
*/
private $source;
/**
* @var int $limit
*/
private $limit;
/**
* @param string $id
* @param resource $stream
* @param int $limit
*/
public static function register($id, $stream, $limit) {
self::$streams[$id] = array($stream, $limit);
}
/**
* remove all registered streams
*/
public static function clear() {
self::$streams = array();
}
/**
* @param resource $stream
* @param int $limit
* @return resource
*/
static public function wrap($stream, $limit) {
$id = uniqid();
self::register($id, $stream, $limit);
$meta = stream_get_meta_data($stream);
return fopen('quota://' . $id, $meta['mode']);
}
public function stream_open($path, $mode, $options, &$opened_path) {
$id = substr($path, strlen('quota://'));
if (isset(self::$streams[$id])) {
list($this->source, $this->limit) = self::$streams[$id];
return true;
} else {
return false;
}
}
public function stream_seek($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 - $offset;
}
else if ($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, $whence) === 0;
}
public function stream_tell() {
return ftell($this->source);
}
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, $data);
}
public function stream_set_option($option, $arg1, $arg2) {
switch ($option) {
case STREAM_OPTION_BLOCKING:
stream_set_blocking($this->source, $arg1);
break;
case STREAM_OPTION_READ_TIMEOUT:
stream_set_timeout($this->source, $arg1, $arg2);
break;
case STREAM_OPTION_WRITE_BUFFER:
stream_set_write_buffer($this->source, $arg1, $arg2);
}
}
public function stream_stat() {
return fstat($this->source);
}
public function stream_lock($mode) {
return flock($this->source, $mode);
}
public function stream_flush() {
return fflush($this->source);
}
public function stream_eof() {
return feof($this->source);
}
public function stream_close() {
fclose($this->source);
}
}
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