egroupware_official/phpgwapi/inc/class.egw_vfs.inc.php

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<?php
/**
* eGroupWare API: VFS - static methods to use the new eGW virtual file system
*
* @link http://www.egroupware.org
* @license http://opensource.org/licenses/gpl-license.php GPL - GNU General Public License
* @package api
* @subpackage vfs
* @author Ralf Becker <RalfBecker-AT-outdoor-training.de>
* @copyright (c) 2008 by Ralf Becker <RalfBecker-AT-outdoor-training.de>
* @version $Id$
*/
/**
* Class containing static methods to use the new eGW virtual file system
*
* This extension of the vfs stream-wrapper allows to use the following static functions,
* which only allow access to the eGW VFS and need no 'vfs://default' prefix for filenames:
*
* - resource egw_vfs::fopen($path,$mode) like fopen, returned resource can be used with fwrite etc.
* - resource egw_vfs::opendir($path) like opendir, returned resource can be used with readdir etc.
* - boolean egw_vfs::copy($from,$to) like copy
* - boolean egw_vfs::rename($old,$new) renaming or moving a file in the vfs
* - boolean egw_vfs::mkdir($path) creating a new dir in the vfs
* - boolean egw_vfs::rmdir($path) removing (an empty) directory
* - boolean egw_vfs::unlink($path) removing a file
* - boolean egw_vfs::touch($path,$mtime=null) touch a file
* - boolean egw_vfs::stat($path) returning status of file like stat(), but only with string keys (no numerical indexes)!
*
* With the exception of egw_vfs::touch() (not yet part of the stream_wrapper interface)
* you can always use the standard php functions, if you add a 'vfs://default' prefix
* to every filename or path. Be sure to always add the prefix, as the user otherwise gains
* access to the real filesystem of the server!
*
* The two following methods can be used to persitently mount further filesystems (without editing the code):
*
* - boolean/array egw_vfs::mount($url,$path) to mount $ur on $path or to return the fstab when called without argument
* - boolean egw_vfs::umount($path) to unmount a path or url
*
* The stream wrapper interface allows to access hugh files in junks to not be limited by the
* memory_limit setting of php. To do you should path a resource to the opened file and not the content:
*
* $file = egw_vfs::fopen('/home/user/somefile','r');
* $content = fread($file,1024);
*
* You can also attach stream filters, to eg. base64 encode or compress it on the fly,
* without the need to hold the content of the whole file in memmory.
*
* If you want to copy a file, you can use stream_copy_to_stream to do a copy of a file far bigger then
* php's memory_limit:
*
* $from = egw_vfs::fopen('/home/user/fromfile','r');
* $to = egw_vfs::fopen('/home/user/tofile','w');
*
* stream_copy_to_stream($from,$to);
*
* The static egw_vfs::copy() method does exactly that, but you have to do it eg. on your own, if
* you want to copy eg. an uploaded file into the vfs.
*/
class egw_vfs extends vfs_stream_wrapper
{
/**
* fopen working on just the eGW VFS
*
* @param string $path filename with absolute path in the eGW VFS
* @param string $mode 'r', 'w', ... like fopen
* @return resource
*/
static function fopen($path,$mode)
{
if ($path[0] != '/')
{
throw new egw_exception_assertion_failed("Filename '$path' is not an absolute path!");
}
return fopen(self::SCHEME.'://default'.$path);
}
/**
* opendir working on just the eGW VFS
*
* @param string $path filename with absolute path in the eGW VFS
* @return resource
*/
static function opendir($path)
{
if ($path[0] != '/')
{
throw new egw_exception_assertion_failed("Directory '$path' is not an absolute path!");
}
return opendir(self::SCHEME.'://default'.$path);
}
/**
* copy working on just the eGW VFS
*
* @param string $from
* @param string $to
* @return boolean
*/
static function copy($from,$to)
{
$ret = false;
if (($from_fp = self::fopen($from,'r')) &&
($to_fp = self::fopen($to,'w')))
{
$ret = stream_copy_to_stream($from,$to) !== false;
}
if ($from_fp)
{
fclose($from_fp);
}
if ($to_fp)
{
fclose($to_fp);
}
return $ret;
}
/**
* stat working on just the eGW VFS (alias of url_stat)
*
* @param string $path filename with absolute path in the eGW VFS
* @return resource
*/
static function stat($path)
{
if ($path[0] != '/')
{
throw new egw_exception_assertion_failed("File '$path' is not an absolute path!");
}
return self::url_stat($path);
}
/**
* Mounts $url under $path in the vfs, called without parameter it returns the fstab
*
* The fstab is stored in the eGW configuration and used for all eGW users.
*
* @param string $url=null url of the filesystem to mount, eg. oldvfs://default/
* @param string $path=null path to mount the filesystem in the vfs, eg. /
* @return array/boolean array with fstab, if called without parameter or true on successful mount
*/
static function mount($url=null,$path=null)
{
if (is_null($url) || is_null($path))
{
return self::$fstab;
}
if (isset(self::$fstab[$path]))
{
return true; // already mounted
}
if (stat($url) === false && opendir($url) === false)
{
return false; // url does not exist
}
self::$fstab[$path] = $url;
uksort(self::$fstab,create_function('$a,$b','return strlen($a)-strlen($b);'));
config::save_value('vfs_fstab',self::$fstab,'phpgwapi');
$GLOBALS['egw_info']['server']['vfs_fstab'] = self::$fstab;
return true;
}
/**
* Unmounts a filesystem part of the vfs
*
* @param string $path url or path of the filesystem to unmount
*/
static function umount($path)
{
if (!isset(self::$fstab[$path]) && ($path = array_search($path,self::$fstab)) === false)
{
return false; // $path not mounted
}
unset(self::$fstab[$path]);
config::save_value('vfs_fstab',self::$fstab,'phpgwapi');
$GLOBALS['egw_info']['server']['vfs_fstab'] = self::$fstab;
return true;
}
/**
* Private constructor to prevent instanciating this class, only it's static methods should be used
*/
private function __construct()
{
}
}