egroupware_official/phpgwapi/inc/class.vfs_stream_wrapper.inc.php

713 lines
23 KiB
PHP

<?php
/**
* eGroupWare API: VFS - stream wrapper interface
*
* @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 $Id$
*/
/**
* eGroupWare API: VFS - stream wrapper interface
*
* The new vfs stream wrapper uses a kind of fstab to mount different filesystems / stream wrapper types
* together for eGW's virtual file system.
*
* @ToDo extended ACL with inheritance and specific rights for users or groups
* Backends can implement them, in which case they get stored independent of the current mount-points.
* If the backend does not implement them, they get stored by the VFS under the final URL of the backend,
* to also allow mounts to change. The URL's to these extended attributes need to be renamed, when the
* file or an underlaying directory get's renamed. That's the task of the backend, if it chooses to
* implement extended ACL itself.
* @ToDo storage for WebDAV properties
* @ToDo implement the necessary function of WebDAV locks
*
* @link http://www.php.net/manual/en/function.stream-wrapper-register.php
*/
class vfs_stream_wrapper implements iface_stream_wrapper
{
/**
* Scheme / protocol used for this stream-wrapper
*/
const SCHEME = 'vfs';
/**
* Mime type of directories, the old vfs used 'Directory', while eg. WebDAV uses 'httpd/unix-directory'
*/
const DIR_MIME_TYPE = 'httpd/unix-directory';
/**
* optional context param when opening the stream, null if no context passed
*
* @var mixed
*/
var $context;
/**
* Our fstab in the form mount-point => url
*
* The entry for root has to be the first, or more general if you mount into subdirs the parent has to be before!
*
* @var array
*/
protected static $fstab = array(
// '/' => 'sqlfs://$user:$pass@$host/',
'/' => 'oldvfs://$user:$pass@$host/',
// '/files' => 'oldvfs://$user:$pass@$host/home/Default',
// '/images' => 'http://localhost/egroupware/phpgwapi/templates/idots/images',
// '/home/ralf/linux' => '/home/ralf', // we probably need to forbid direct filesystem access for security reasons!
);
/**
* stream / ressouce this class is opened for by stream_open
*
* @var ressource
*/
private $opened_stream;
/**
* directory-ressouce this class is opened for by dir_open
*
* @var ressource
*/
private $opened_dir;
/**
* URL of the opened dir, used to build the complete URL of files in the dir
*
* @var string
*/
private $opened_dir_url;
/**
* Flag if opened dir is writable, in which case we return un-readable entries too
*
* @var boolean
*/
private $opened_dir_writable;
/**
* Extra dirs from our fstab in the current opened dir
*
* @var array
*/
private $extra_dirs;
/**
* Pointer in the extra dirs
*
* @var int
*/
private $extra_dir_ptr;
private static $wrappers;
/**
* Resolve the given path according to our fstab
*
* @param string $path
* @return string/boolean false if the url cant be relsolved, should not happen if fstab has a root entry
*/
static function resolve_url($path)
{
static $cache = array();
// we do some caching here
if (isset($cache[$path]))
{
return $cache[$path];
}
// setting default user, passwd and domain, if it's not contained int the url
static $defaults;
if (is_null($defaults))
{
$defaults = array(
'user' => $GLOBALS['egw_info']['user']['account_lid'],
'pass' => $GLOBALS['egw_info']['user']['passwd'],
'host' => $GLOBALS['egw_info']['user']['domain'],
);
}
$parts = array_merge(parse_url($path),$defaults);
if (empty($parts['path'])) $parts['path'] = '/';
foreach(array_reverse(self::$fstab) as $mounted => $url)
{
if ($mounted == substr($parts['path'],0,strlen($mounted)))
{
$scheme = parse_url($url,PHP_URL_SCHEME);
if (is_null(self::$wrappers) || !in_array($scheme,self::$wrappers))
{
self::load_wrapper($scheme);
}
$url .= substr($parts['path'],strlen($mounted));
$url = str_replace(array('$user','$pass','$host'),array($parts['user'],$parts['pass'],$parts['host']),$url);
//error_log(__METHOD__."($path) = $url");
return $cache[$path] = $url;
}
}
//error_log(__METHOD__."($path) can't resolve path!\n");
trigger_error(__METHOD__."($path) can't resolve path!\n",E_USER_WARNING);
return false;
}
/**
* This method is called immediately after your stream object is created.
*
* @param string $path URL that was passed to fopen() and that this object is expected to retrieve
* @param string $mode mode used to open the file, as detailed for fopen()
* @param int $options additional flags set by the streams API (or'ed together):
* - STREAM_USE_PATH If path is relative, search for the resource using the include_path.
* - STREAM_REPORT_ERRORS If this flag is set, you are responsible for raising errors using trigger_error() during opening of the stream.
* If this flag is not set, you should not raise any errors.
* @param string $opened_path full path of the file/resource, if the open was successfull and STREAM_USE_PATH was set
* @return boolean true if the ressource was opened successful, otherwise false
*/
function stream_open ( $path, $mode, $options, &$opened_path )
{
$this->opened_stream = null;
if (!($url = self::resolve_url($path)))
{
return false;
}
if (!($this->opened_stream = fopen($url,$mode,$options)))
{
return false;
}
return true;
}
/**
* This method is called when the stream is closed, using fclose().
*
* You must release any resources that were locked or allocated by the stream.
*/
function stream_close ( )
{
$ret = fclose($this->opened_stream);
$this->opened_stream = null;
return $ret;
}
/**
* This method is called in response to fread() and fgets() calls on the stream.
*
* You must return up-to count bytes of data from the current read/write position as a string.
* If there are less than count bytes available, return as many as are available.
* If no more data is available, return either FALSE or an empty string.
* You must also update the read/write position of the stream by the number of bytes that were successfully read.
*
* @param int $count
* @return string/false up to count bytes read or false on EOF
*/
function stream_read ( $count )
{
return fread($this->opened_stream,$count);
}
/**
* This method is called in response to fwrite() calls on the stream.
*
* You should store data into the underlying storage used by your stream.
* If there is not enough room, try to store as many bytes as possible.
* You should return the number of bytes that were successfully stored in the stream, or 0 if none could be stored.
* You must also update the read/write position of the stream by the number of bytes that were successfully written.
*
* @param string $data
* @return integer
*/
function stream_write ( $data )
{
return fwrite($this->opened_stream,$data);
}
/**
* This method is called in response to feof() calls on the stream.
*
* Important: PHP 5.0 introduced a bug that wasn't fixed until 5.1: the return value has to be the oposite!
*
* if(version_compare(PHP_VERSION,'5.0','>=') && version_compare(PHP_VERSION,'5.1','<'))
* {
* $eof = !$eof;
* }
*
* @return boolean true if the read/write position is at the end of the stream and no more data availible, false otherwise
*/
function stream_eof ( )
{
return feof($this->opened_stream);
}
/**
* This method is called in response to ftell() calls on the stream.
*
* @return integer current read/write position of the stream
*/
function stream_tell ( )
{
return ftell($this->opened_stream);
}
/**
* This method is called in response to fseek() calls on the stream.
*
* You should update the read/write position of the stream according to offset and whence.
* See fseek() for more information about these parameters.
*
* @param integer $offset
* @param integer $whence SEEK_SET - Set position equal to offset bytes
* SEEK_CUR - Set position to current location plus offset.
* SEEK_END - Set position to end-of-file plus offset. (To move to a position before the end-of-file, you need to pass a negative value in offset.)
* @return boolean TRUE if the position was updated, FALSE otherwise.
*/
function stream_seek ( $offset, $whence )
{
return fseek($this->opened_stream,$offset,$whence);
}
/**
* This method is called in response to fflush() calls on the stream.
*
* If you have cached data in your stream but not yet stored it into the underlying storage, you should do so now.
*
* @return booelan TRUE if the cached data was successfully stored (or if there was no data to store), or FALSE if the data could not be stored.
*/
function stream_flush ( )
{
return fflush($this->opened_stream);
}
/**
* This method is called in response to fstat() calls on the stream.
*
* If you plan to use your wrapper in a require_once you need to define stream_stat().
* If you plan to allow any other tests like is_file()/is_dir(), you have to define url_stat().
* stream_stat() must define the size of the file, or it will never be included.
* url_stat() must define mode, or is_file()/is_dir()/is_executable(), and any of those functions affected by clearstatcache() simply won't work.
* It's not documented, but directories must be a mode like 040777 (octal), and files a mode like 0100666.
* If you wish the file to be executable, use 7s instead of 6s.
* The last 3 digits are exactly the same thing as what you pass to chmod.
* 040000 defines a directory, and 0100000 defines a file.
*
* @return array containing the same values as appropriate for the stream.
*/
function stream_stat ( )
{
return fstat($this->opened_stream);
}
/**
* This method is called in response to unlink() calls on URL paths associated with the wrapper.
*
* It should attempt to delete the item specified by path.
* In order for the appropriate error message to be returned, do not define this method if your wrapper does not support unlinking!
*
* @param string $path
* @return boolean TRUE on success or FALSE on failure
*/
static function unlink ( $path )
{
if (!($url = self::resolve_url($path)))
{
return false;
}
return unlink($url);
}
/**
* This method is called in response to rename() calls on URL paths associated with the wrapper.
*
* It should attempt to rename the item specified by path_from to the specification given by path_to.
* In order for the appropriate error message to be returned, do not define this method if your wrapper does not support renaming.
*
* The regular filesystem stream-wrapper returns an error, if $url_from and $url_to are not either both files or both dirs!
*
* @param string $path_from
* @param string $path_to
* @return boolean TRUE on success or FALSE on failure
*/
static function rename ( $path_from, $path_to )
{
if (!($url_from = self::resolve_url($path_from)) ||
!($url_to = self::resolve_url($path_to)))
{
return false;
}
return rename($url_from,$url_to);
}
/**
* This method is called in response to mkdir() calls on URL paths associated with the wrapper.
*
* It should attempt to create the directory specified by path.
* In order for the appropriate error message to be returned, do not define this method if your wrapper does not support creating directories.
*
* @param string $path
* @param int $mode
* @param int $options Posible values include STREAM_REPORT_ERRORS and STREAM_MKDIR_RECURSIVE
* @return boolean TRUE on success or FALSE on failure
*/
static function mkdir ( $path, $mode, $options )
{
if (!($url = self::resolve_url($path)))
{
return false;
}
return mkdir($url,$mode,$options);
}
/**
* This method is called in response to rmdir() calls on URL paths associated with the wrapper.
*
* It should attempt to remove the directory specified by path.
* In order for the appropriate error message to be returned, do not define this method if your wrapper does not support removing directories.
*
* @param string $path
* @param int $options Possible values include STREAM_REPORT_ERRORS.
* @return boolean TRUE on success or FALSE on failure.
*/
static function rmdir ( $path, $options )
{
if (!($url = self::resolve_url($path)))
{
return false;
}
return rmdir($url);
}
/**
* Allow to call methods of the underlying stream wrapper: touch, chmod, chgrp, chown, ...
*
* We cant use a magic __call() method, as it does not work for static methods!
*
* @param string $name
* @param array $params first param has to be the path, otherwise we can not determine the correct wrapper
*/
static private function _call_on_backend($name,$params)
{
$path = $params[0];
if (!($url = self::resolve_url($params[0])))
{
return false;
}
if (($scheme = parse_url($url,PHP_URL_SCHEME)))
{
if (!class_exists($class = $scheme.'_stream_wrapper') || !method_exists($class,$name))
{
trigger_error("Can't $name for scheme $scheme!\n",E_USER_WARNING);
return false;
}
$params[0] = $url;
return call_user_func_array(array($scheme.'_stream_wrapper',$name),$params);
}
// call the filesystem specific function
if (!function_exists($name))
{
return false;
}
return $name($url,$time);
}
/**
* This is not (yet) a stream-wrapper function, but it's necessary and can be used static
*
* @param string $path
* @param int $time=null modification time (unix timestamp), default null = current time
* @param int $atime=null access time (unix timestamp), default null = current time, not implemented in the vfs!
* @return boolean true on success, false otherwise
*/
static function touch($path,$time=null,$atime=null)
{
return self::_call_on_backend('touch',array($path,$time,$atime));
}
/**
* This is not (yet) a stream-wrapper function, but it's necessary and can be used static
*
* Requires owner or root rights!
*
* @param string $path
* @param string $mode mode string see egw_vfs::mode2int
* @return boolean true on success, false otherwise
*/
static function chmod($path,$mode)
{
return self::_call_on_backend('chmod',array($path,$mode));
}
/**
* This is not (yet) a stream-wrapper function, but it's necessary and can be used static
*
* Requires root rights!
*
* @param string $path
* @param int $owner numeric user id
* @return boolean true on success, false otherwise
*/
static function chown($path,$owner)
{
return self::_call_on_backend('chown',array($path,$owner));
}
/**
* This is not (yet) a stream-wrapper function, but it's necessary and can be used static
*
* Requires owner or root rights!
*
* @param string $path
* @param int $group numeric group id
* @return boolean true on success, false otherwise
*/
static function chgrp($path,$group)
{
return self::_call_on_backend('chgrp',array($path,$group));
}
/**
* This is not (yet) a stream-wrapper function, but it's necessary and can be used static
*
* The methods use the following ways to get the mime type (in that order)
* - directories (is_dir()) --> self::DIR_MIME_TYPE
* - stream implemented by class defining the STAT_RETURN_MIME_TYPE constant --> use mime-type returned by url_stat
* - for regular filesystem use mime_content_type function if available
* - use eGW's mime-magic class
*
* @param string $path
* @return string mime-type (self::DIR_MIME_TYPE for directories)
*/
static function mime_content_type($path)
{
if (!($url = self::resolve_url($path)))
{
return false;
}
if (is_dir($url))
{
$mime = self::DIR_MIME_TYPE;
}
if (!$mime && ($scheme = parse_url($url,PHP_URL_SCHEME)))
{
// check it it's an eGW stream wrapper returning mime-type via url_stat
if (class_exists($class = $scheme.'_stream_wrapper') && ($mime_attr = constant($class.'::STAT_RETURN_MIME_TYPE')))
{
$stat = call_user_func(array($scheme.'_stream_wrapper','url_stat'),parse_url($url,PHP_URL_PATH),0);
if ($stat[$mime_attr])
{
$mime = $stat[$mime_attr];
}
}
}
// if we operate on the regular filesystem and the mime_content_type function is available --> use it
if (!$mime && !$scheme && function_exists('mime_content_type'))
{
$mime = mime_content_type($path);
}
// using eGW's own mime magic
// ToDo: rework mime_magic as all methods cound be static!
if (!$mime)
{
static $mime_magic;
if (is_null($mime_magic))
{
$mime_magic = new mime_magic();
}
$mime = $mime_magic->filename2mime(parse_url($url,PHP_URL_PATH));
}
//error_log(__METHOD__."($path) mime=$mime");
return $mime;
}
/**
* This method is called immediately when your stream object is created for examining directory contents with opendir().
*
* @param string $path URL that was passed to opendir() and that this object is expected to explore.
* @return booelan
*/
function dir_opendir ( $path, $options )
{
$this->opened_dir = $this->extra_dirs = null;
$this->extra_dir_ptr = 0;
if (!($this->opened_dir_url = self::resolve_url($path)))
{
return false;
}
if (!($this->opened_dir = opendir($this->opened_dir_url)))
{
return false;
}
$this->opened_dir_writable = ($stat = @stat($this->opened_dir_url)) && egw_vfs::check_access($stat,egw_vfs::WRITABLE);
// check our fstab if we need to add some of the mountpoints
$basepath = parse_url($this->opened_dir_url,PHP_URL_PATH);
foreach(self::$fstab as $mounted => $nul)
{
if (dirname($mounted) == $basepath && $mounted != '/')
{
$this->extra_dirs[] = basename($mounted);
}
}
return true;
}
/**
* This method is called in response to stat() calls on the URL paths associated with the wrapper.
*
* It should return as many elements in common with the system function as possible.
* Unknown or unavailable values should be set to a rational value (usually 0).
*
* If you plan to use your wrapper in a require_once you need to define stream_stat().
* If you plan to allow any other tests like is_file()/is_dir(), you have to define url_stat().
* stream_stat() must define the size of the file, or it will never be included.
* url_stat() must define mode, or is_file()/is_dir()/is_executable(), and any of those functions affected by clearstatcache() simply won't work.
* It's not documented, but directories must be a mode like 040777 (octal), and files a mode like 0100666.
* If you wish the file to be executable, use 7s instead of 6s.
* The last 3 digits are exactly the same thing as what you pass to chmod.
* 040000 defines a directory, and 0100000 defines a file.
*
* @param string $path
* @param int $flags holds additional flags set by the streams API. It can hold one or more of the following values OR'd together:
* - STREAM_URL_STAT_LINK For resources with the ability to link to other resource (such as an HTTP Location: forward,
* or a filesystem symlink). This flag specified that only information about the link itself should be returned,
* not the resource pointed to by the link.
* This flag is set in response to calls to lstat(), is_link(), or filetype().
* - STREAM_URL_STAT_QUIET If this flag is set, your wrapper should not raise any errors. If this flag is not set,
* you are responsible for reporting errors using the trigger_error() function during stating of the path.
* stat triggers it's own warning anyway, so it makes no sense to trigger one by our stream-wrapper!
* @return array
*/
static function url_stat ( $path, $flags )
{
//error_log(__METHOD__."('$path',$flags)");
if (!($url = self::resolve_url($path)))
{
return false;
}
//error_log(__METHOD__."('$path',$flags) calling stat($url)");
return @stat($url); // suppressed the stat failed warnings
}
/**
* This method is called in response to readdir().
*
* It should return a string representing the next filename in the location opened by dir_opendir().
*
* Unless other filesystem, we only return files readable by the user, if the dir is not writable for him.
* This is done to hide files and dirs not accessible by the user (eg. other peoples home-dirs in /home).
*
* @return string
*/
function dir_readdir ( )
{
if ($this->extra_dirs && count($this->extra_dirs) > $this->extra_dir_ptr)
{
return $this->extra_dirs[$this->extra_dir_ptr++];
}
// only return children readable by the user, if dir is not writable
do {
if (($file = readdir($this->opened_dir)) !== false && !$this->opened_dir_writable)
{
$stat = stat($this->opened_dir_url.'/'.$file);
}
//echo __METHOD__."() opened_dir_writable=$this->opened_dir_writable, file=$file, readable=".(int)egw_vfs::check_access($stat,egw_vfs::READABLE).", loop=".
// (int)($file !== false && $stat && !egw_vfs::check_access($stat,egw_vfs::READABLE))."\n";
}
while($file !== false && $stat && !egw_vfs::check_access($stat,egw_vfs::READABLE));
return $file;
}
/**
* This method is called in response to rewinddir().
*
* It should reset the output generated by dir_readdir(). i.e.:
* The next call to dir_readdir() should return the first entry in the location returned by dir_opendir().
*
* @return boolean
*/
function dir_rewinddir ( )
{
$this->extra_dir_ptr = 0;
return rewinddir($this->opened_dir);
}
/**
* This method is called in response to closedir().
*
* You should release any resources which were locked or allocated during the opening and use of the directory stream.
*
* @return boolean
*/
function dir_closedir ( )
{
$ret = closedir($this->opened_dir);
$this->opened_dir = $this->extra_dirs = null;
return $ret;
}
/**
* Load stream wrapper for a given schema
*
* @param string $scheme
* @return boolean
*/
static function load_wrapper($scheme)
{
if (!in_array($scheme,self::get_wrappers()))
{
switch($scheme)
{
case 'webdav':
require_once('HTTP/WebDAV/Client.php');
self::$wrappers[] = 'webdav';
break;
case 'oldvfs':
case 'sqlfs':
require_once(EGW_API_INC.'/class.'.$scheme.'_stream_wrapper.inc.php');
self::$wrappers[] = $scheme;
break;
case '':
return true; // default file, always loaded
default:
trigger_error("Can't load stream-wrapper for scheme '$scheme'!",E_USER_WARNING);
return false;
}
}
return true;
}
/**
* Return already loaded stream wrappers
*
* @return array
*/
static function get_wrappers()
{
if (is_null(self::$wrappers))
{
self::$wrappers = stream_get_wrappers();
}
return self::$wrappers;
}
static function init_static()
{
stream_register_wrapper(self::SCHEME,__CLASS__);
if ($GLOBALS['egw_info']['server']['vfs_fstab'] &&
is_array($fstab = unserialize($GLOBALS['egw_info']['server']['vfs_fstab'])))
{
self::$fstab = $fstab;
}
}
}
vfs_stream_wrapper::init_static();