new vfs-stream-wrapper class, which uses a fstab (in a static class var at the moment) to mount different filesystems/stream-wrappers together in a single virtual file system for eGroupWare, can be tested with filemanager/ls.php and the default fstab of / => oldvfs:/

This commit is contained in:
Ralf Becker 2008-01-30 06:51:54 +00:00
parent 399e087f2c
commit e657227035

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<?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.
*
* @link http://www.php.net/manual/en/function.stream-wrapper-register.php
*/
class vfs_stream_wrapper implements iface_stream_wrapper
{
/**
* 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
*/
static $fstab = array(
'/' => 'oldvfs://$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;
/**
* 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];
}
$parts = parse_url($path);
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($path)))
{
return false;
}
return mkdir($path,$mode,$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($path)))
{
return false;
}
return rmdir($path,$options);
}
/**
* 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 $atime=null access time (unix timestamp), default null = current time, not implemented in the vfs!
*/
static function touch($path,$time=null,$atime=null)
{
if (!($url = self::resolve_url($path)))
{
return false;
}
if (($scheme = parse_url($url,PHP_URL_SCHEME)))
{
if (!class_exists($class = $scheme.'_stream_wrapper') || !method_exists($class,'touch'))
{
trigger_error("Can't touch for scheme $scheme!\n",E_USER_WARNING);
return false;
}
return call_user_func(array($scheme.'_stream_wrapper','touch'),$url,$time);
}
return touch($url,$time);
}
/**
* 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;
$this->extra_dir_ptr = 0;
if (!($url = self::resolve_url($path)))
{
return false;
}
if (!($this->opened_dir = opendir($url)))
{
return false;
}
// check our fstab if we need to add some of the mountpoints
$basepath = parse_url($url,PHP_URL_PATH);
foreach(self::$fstab as $mounted => $nul)
{
if (dirname($mounted) == $basepath)
{
$this->extra_dirs[] = basename($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($path)))
{
return false;
}
return stat($url);
}
/**
* This method is called in response to readdir().
*
* It should return a string representing the next filename in the location opened by dir_opendir().
*
* @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++];
}
return readdir($this->opened_dir);
}
/**
* 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::$wrappers[] = 'webdav';
break;
case 'oldvfs':
require_once(EGW_API_INC.'/class.oldvfs_stream_wrapper.inc.php');
self::$wrappers[] = 'oldvfs';
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;
}
}
stream_register_wrapper('vfs','vfs_stream_wrapper');