nextcloud/lib/fileproxy.php

118 lines
3.4 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 returnes 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 calue 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, fileatime, filemtime, filectime, file_get_contents, getMimeType, hash, fopen, free_space and search
*/
class OC_FileProxy{
private static $proxies=array();
public static $enabled=true;
/**
* check if this proxy implments a specific proxy operation
* @param string #proxy name of the proxy operation
* @return bool
*/
public function provides($operation){
return method_exists($this,$operation);
}
/**
* fallback function when a proxy operation is not implement
* @param string $function the name of the proxy operation
* @param mixed
*
* this implements a dummy proxy for all operations
*/
public function __call($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;
}
public static function getProxies($operation,$post){
$operation=(($post)?'post':'pre').$operation;
$proxies=array();
foreach(self::$proxies as $proxy){
if($proxy->provides($operation)){
$proxies[]=$proxy;
}
}
return $proxies;
}
public static function runPreProxies($operation,&$filepath,&$filepath2=null){
if(!self::$enabled){
return true;
}
$proxies=self::getProxies($operation,false);
$operation='pre'.$operation;
foreach($proxies as $proxy){
if(!is_null($filepath2)){
if($proxy->$operation($filepath,$filepath2)===false){
return false;
}
}else{
if($proxy->$operation($filepath)===false){
return false;
}
}
}
return true;
}
public static function runPostProxies($operation,$path,$result){
if(!self::$enabled){
return $result;
}
$proxies=self::getProxies($operation,true);
$operation='post'.$operation;
foreach($proxies as $proxy){
$result=$proxy->$operation($path,$result);
}
return $result;
}
}