nextcloud/lib/private/fileproxy.php

133 lines
3.5 KiB
PHP

<?php
/**
* ownCloud
*
* @author Robin Appelman
* @copyright 2011 Robin Appelman icewind1991@gmail.com
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU AFFERO GENERAL PUBLIC LICENSE
* License as published by the Free Software Foundation; either
* version 3 of the License, or any later version.
*
* This library 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 along with this library. If not, see <http://www.gnu.org/licenses/>.
*
*/
/**
* Class for manipulating filesystem requests
*
* Manipulation happens by using 2 kind of proxy operations, pre and post proxies
* that manipulate the filesystem call and the result of the call respectively
*
* A pre-proxy recieves the filepath as arugments (or 2 filespaths in case of
* operations like copy or move) and return a boolean
* If a pre-proxy returns false the file operation will be canceled
* All filesystem operations have a pre-proxy
*
* A post-proxy recieves 2 arguments, the filepath and the result of the operation.
* The return value of the post-proxy will be used as the new result of the operation
* The operations that have a post-proxy are:
* file_get_contents, is_file, is_dir, file_exists, stat, is_readable,
* is_writable, filemtime, filectime, file_get_contents,
* getMimeType, hash, fopen, free_space and search
*/
class OC_FileProxy{
private static $proxies=array();
public static $enabled=true;
/**
* fallback function when a proxy operation is not implemented
* @param string $function the name of the proxy operation
* @param mixed $arguments
*
* this implements a dummy proxy for all operations
*/
public function __call($function, $arguments) {
if(substr($function, 0, 3)=='pre') {
return true;
}else{
return $arguments[1];
}
}
/**
* register a proxy to be used
* @param OC_FileProxy $proxy
*/
public static function register($proxy) {
self::$proxies[]=$proxy;
}
/**
* @param string $operation
*/
public static function getProxies($operation = null) {
if ($operation === null) {
// return all
return self::$proxies;
}
$proxies=array();
foreach(self::$proxies as $proxy) {
if(method_exists($proxy, $operation)) {
$proxies[]=$proxy;
}
}
return $proxies;
}
/**
* @param string $operation
* @param string|boolean $filepath
*/
public static function runPreProxies($operation,&$filepath,&$filepath2=null) {
if(!self::$enabled) {
return true;
}
$operation='pre'.$operation;
$proxies=self::getProxies($operation);
foreach($proxies as $proxy) {
if(!is_null($filepath2)) {
if($proxy->$operation($filepath, $filepath2)===false) {
return false;
}
}else{
if($proxy->$operation($filepath)===false) {
return false;
}
}
}
return true;
}
/**
* @param string $operation
* @param string|boolean $path
*
* @return string
*/
public static function runPostProxies($operation, $path, $result) {
if(!self::$enabled) {
return $result;
}
$operation='post'.$operation;
$proxies=self::getProxies($operation);
foreach($proxies as $proxy) {
$result=$proxy->$operation($path, $result);
}
return $result;
}
public static function clearProxies() {
self::$proxies=array();
}
}