includes/filerepo/FileRepo.php

   1 <?php
   2 /**
   3  * Base code for file repositories.
   4  *
   5  * @file
   6  * @ingroup FileRepo
   7  */
   8
   9 /**
  10  * Base class for file repositories.
  11  * Do not instantiate, use a derived class.
  12  *
  13  * @ingroup FileRepo
  14  */
  15 abstract class FileRepo {
  16         const FILES_ONLY = 1;
  17         const DELETE_SOURCE = 1;
  18         const OVERWRITE = 2;
  19         const OVERWRITE_SAME = 4;
  20         const SKIP_VALIDATION = 8;
  21
  22         var $thumbScriptUrl, $transformVia404;
  23         var $descBaseUrl, $scriptDirUrl, $scriptExtension, $articleUrl;
  24         var $fetchDescription, $initialCapital;
  25         var $pathDisclosureProtection = 'paranoid';
  26         var $descriptionCacheExpiry, $hashLevels, $url, $thumbUrl;
  27
  28         /**
  29          * Factory functions for creating new files
  30          * Override these in the base class
  31          */
  32         var $fileFactory = false, $oldFileFactory = false;
  33         var $fileFactoryKey = false, $oldFileFactoryKey = false;
  34
  35         function __construct( $info ) {
  36                 // Required settings
  37                 $this->name = $info['name'];
  38
  39                 // Optional settings
  40                 $this->initialCapital = MWNamespace::isCapitalized( NS_FILE );
  41                 foreach ( array( 'descBaseUrl', 'scriptDirUrl', 'articleUrl', 'fetchDescription',
  42                         'thumbScriptUrl', 'initialCapital', 'pathDisclosureProtection',
  43                         'descriptionCacheExpiry', 'hashLevels', 'url', 'thumbUrl', 'scriptExtension' )
  44                         as $var )
  45                 {
  46                         if ( isset( $info[$var] ) ) {
  47                                 $this->$var = $info[$var];
  48                         }
  49                 }
  50                 $this->transformVia404 = !empty( $info['transformVia404'] );
  51         }
  52
  53         /**
  54          * Determine if a string is an mwrepo:// URL
  55          */
  56         static function isVirtualUrl( $url ) {
  57                 return substr( $url, 0, 9 ) == 'mwrepo://';
  58         }
  59
  60         /**
  61          * Create a new File object from the local repository
  62          *
  63          * @param $title Mixed: Title object or string
  64          * @param $time Mixed: Time at which the image was uploaded.
  65          *              If this is specified, the returned object will be an
  66          *              instance of the repository's old file class instead of a
  67          *              current file. Repositories not supporting version control
  68          *              should return false if this parameter is set.
  69          *
  70          * @return File
  71          */
  72         function newFile( $title, $time = false ) {
  73                 if ( !($title instanceof Title) ) {
  74                         $title = Title::makeTitleSafe( NS_FILE, $title );
  75                         if ( !is_object( $title ) ) {
  76                                 return null;
  77                         }
  78                 }
  79                 if ( $time ) {
  80                         if ( $this->oldFileFactory ) {
  81                                 return call_user_func( $this->oldFileFactory, $title, $this, $time );
  82                         } else {
  83                                 return false;
  84                         }
  85                 } else {
  86                         return call_user_func( $this->fileFactory, $title, $this );
  87                 }
  88         }
  89
  90         /**
  91          * Find an instance of the named file created at the specified time
  92          * Returns false if the file does not exist. Repositories not supporting
  93          * version control should return false if the time is specified.
  94          *
  95          * @param $title Mixed: Title object or string
  96          * @param $options Associative array of options:
  97          *     time:           requested time for an archived image, or false for the
  98          *                     current version. An image object will be returned which was
  99          *                     created at the specified time.
 100          *
 101          *     ignoreRedirect: If true, do not follow file redirects
 102          *
 103          *     private:        If true, return restricted (deleted) files if the current
 104          *                     user is allowed to view them. Otherwise, such files will not
 105          *                     be found.
 106          */
 107         function findFile( $title, $options = array() ) {
 108                 $time = isset( $options['time'] ) ? $options['time'] : false;
 109                 if ( !($title instanceof Title) ) {
 110                         $title = Title::makeTitleSafe( NS_FILE, $title );
 111                         if ( !is_object( $title ) ) {
 112                                 return false;
 113                         }
 114                 }
 115                 # First try the current version of the file to see if it precedes the timestamp
 116                 $img = $this->newFile( $title );
 117                 if ( !$img ) {
 118                         return false;
 119                 }
 120                 if ( $img->exists() && ( !$time || $img->getTimestamp() == $time ) ) {
 121                         return $img;
 122                 }
 123                 # Now try an old version of the file
 124                 if ( $time !== false ) {
 125                         $img = $this->newFile( $title, $time );
 126                         if ( $img && $img->exists() ) {
 127                                 if ( !$img->isDeleted(File::DELETED_FILE) ) {
 128                                         return $img;
 129                                 } else if ( !empty( $options['private'] )  && $img->userCan(File::DELETED_FILE) ) {
 130                                         return $img;
 131                                 }
 132                         }
 133                 }
 134
 135                 # Now try redirects
 136                 if ( !empty( $options['ignoreRedirect'] ) ) {
 137                         return false;
 138                 }
 139                 $redir = $this->checkRedirect( $title );
 140                 if( $redir && $title->getNamespace() == NS_FILE) {
 141                         $img = $this->newFile( $redir );
 142                         if( !$img ) {
 143                                 return false;
 144                         }
 145                         if( $img->exists() ) {
 146                                 $img->redirectedFrom( $title->getDBkey() );
 147                                 return $img;
 148                         }
 149                 }
 150                 return false;
 151         }
 152
 153         /**
 154          * Find many files at once.
 155          * @param $items An array of titles, or an array of findFile() options with
 156          *    the "title" option giving the title. Example:
 157          *
 158          *     $findItem = array( 'title' => $title, 'private' => true );
 159          *     $findBatch = array( $findItem );
 160          *     $repo->findFiles( $findBatch );
 161          */
 162         function findFiles( $items ) {
 163                 $result = array();
 164                 foreach ( $items as $item ) {
 165                         if ( is_array( $item ) ) {
 166                                 $title = $item['title'];
 167                                 $options = $item;
 168                                 unset( $options['title'] );
 169                         } else {
 170                                 $title = $item;
 171                                 $options = array();
 172                         }
 173                         $file = $this->findFile( $title, $options );
 174                         if ( $file ) {
 175                                 $result[$file->getTitle()->getDBkey()] = $file;
 176                         }
 177                 }
 178                 return $result;
 179         }
 180
 181         /**
 182          * Create a new File object from the local repository
 183          * @param $sha1 Mixed: base 36 SHA-1 hash
 184          * @param $time Mixed: time at which the image was uploaded.
 185          *              If this is specified, the returned object will be an
 186          *              of the repository's old file class instead of a current
 187          *              file. Repositories not supporting version control should
 188          *              return false if this parameter is set.
 189          *
 190          * @return File
 191          */
 192         function newFileFromKey( $sha1, $time = false ) {
 193                 if ( $time ) {
 194                         if ( $this->oldFileFactoryKey ) {
 195                                 return call_user_func( $this->oldFileFactoryKey, $sha1, $this, $time );
 196                         }
 197                 } else {
 198                         if ( $this->fileFactoryKey ) {
 199                                 return call_user_func( $this->fileFactoryKey, $sha1, $this );
 200                         }
 201                 }
 202                 return false;
 203         }
 204
 205         /**
 206          * Find an instance of the file with this key, created at the specified time
 207          * Returns false if the file does not exist. Repositories not supporting
 208          * version control should return false if the time is specified.
 209          *
 210          * @param $sha1 String base 36 SHA-1 hash
 211          * @param $options Option array, same as findFile().
 212          */
 213         function findFileFromKey( $sha1, $options = array() ) {
 214                 $time = isset( $options['time'] ) ? $options['time'] : false;
 215
 216                 # First try the current version of the file to see if it precedes the timestamp
 217                 $img = $this->newFileFromKey( $sha1 );
 218                 if ( !$img ) {
 219                         return false;
 220                 }
 221                 if ( $img->exists() && ( !$time || $img->getTimestamp() == $time ) ) {
 222                         return $img;
 223                 }
 224                 # Now try an old version of the file
 225                 if ( $time !== false ) {
 226                         $img = $this->newFileFromKey( $sha1, $time );
 227                         if ( $img && $img->exists() ) {
 228                                 if ( !$img->isDeleted(File::DELETED_FILE) ) {
 229                                         return $img;
 230                                 } else if ( !empty( $options['private'] ) && $img->userCan(File::DELETED_FILE) ) {
 231                                         return $img;
 232                                 }
 233                         }
 234                 }
 235                 return false;
 236         }
 237
 238         /**
 239          * Get the URL of thumb.php
 240          */
 241         function getThumbScriptUrl() {
 242                 return $this->thumbScriptUrl;
 243         }
 244
 245         /**
 246          * Get the URL corresponding to one of the four basic zones
 247          * @param $zone String: one of: public, deleted, temp, thumb
 248          * @return String or false
 249          */
 250         function getZoneUrl( $zone ) {
 251                 return false;
 252         }
 253
 254         /**
 255          * Returns true if the repository can transform files via a 404 handler
 256          */
 257         function canTransformVia404() {
 258                 return $this->transformVia404;
 259         }
 260
 261         /**
 262          * Get the name of an image from its title object
 263          * @param $title Title
 264          */
 265         function getNameFromTitle( $title ) {
 266                 if ( $this->initialCapital != MWNamespace::isCapitalized( NS_FILE ) ) {
 267                         global $wgContLang;
 268                         $name = $title->getUserCaseDBKey();
 269                         if ( $this->initialCapital ) {
 270                                 $name = $wgContLang->ucfirst( $name );
 271                         }
 272                 } else {
 273                         $name = $title->getDBkey();
 274                 }
 275                 return $name;
 276         }
 277
 278         static function getHashPathForLevel( $name, $levels ) {
 279                 if ( $levels == 0 ) {
 280                         return '';
 281                 } else {
 282                         $hash = md5( $name );
 283                         $path = '';
 284                         for ( $i = 1; $i <= $levels; $i++ ) {
 285                                 $path .= substr( $hash, 0, $i ) . '/';
 286                         }
 287                         return $path;
 288                 }
 289         }
 290
 291         /**
 292          * Get a relative path including trailing slash, e.g. f/fa/
 293          * If the repo is not hashed, returns an empty string
 294          */
 295         function getHashPath( $name ) {
 296                 return self::getHashPathForLevel( $name, $this->hashLevels );
 297         }
 298
 299         /**
 300          * Get the name of this repository, as specified by $info['name]' to the constructor
 301          */
 302         function getName() {
 303                 return $this->name;
 304         }
 305
 306         /**
 307          * Make an url to this repo
 308          *
 309          * @param $query mixed Query string to append
 310          * @param $entry string Entry point; defaults to index
 311          * @return string
 312          */
 313         function makeUrl( $query = '', $entry = 'index' ) {
 314                 $ext = isset( $this->scriptExtension ) ? $this->scriptExtension : '.php';
 315                 return wfAppendQuery( "{$this->scriptDirUrl}/{$entry}{$ext}", $query );
 316         }
 317
 318         /**
 319          * Get the URL of an image description page. May return false if it is
 320          * unknown or not applicable. In general this should only be called by the
 321          * File class, since it may return invalid results for certain kinds of
 322          * repositories. Use File::getDescriptionUrl() in user code.
 323          *
 324          * In particular, it uses the article paths as specified to the repository
 325          * constructor, whereas local repositories use the local Title functions.
 326          */
 327         function getDescriptionUrl( $name ) {
 328                 $encName = wfUrlencode( $name );
 329                 if ( !is_null( $this->descBaseUrl ) ) {
 330                         # "http://example.com/wiki/Image:"
 331                         return $this->descBaseUrl . $encName;
 332                 }
 333                 if ( !is_null( $this->articleUrl ) ) {
 334                         # "http://example.com/wiki/$1"
 335                         #
 336                         # We use "Image:" as the canonical namespace for
 337                         # compatibility across all MediaWiki versions.
 338                         return str_replace( '$1',
 339                                 "Image:$encName", $this->articleUrl );
 340                 }
 341                 if ( !is_null( $this->scriptDirUrl ) ) {
 342                         # "http://example.com/w"
 343                         #
 344                         # We use "Image:" as the canonical namespace for
 345                         # compatibility across all MediaWiki versions,
 346                         # and just sort of hope index.php is right. ;)
 347                         return $this->makeUrl( "title=Image:$encName" );
 348                 }
 349                 return false;
 350         }
 351
 352         /**
 353          * Get the URL of the content-only fragment of the description page. For
 354          * MediaWiki this means action=render. This should only be called by the
 355          * repository's file class, since it may return invalid results. User code
 356          * should use File::getDescriptionText().
 357          * @param $name String: name of image to fetch
 358          * @param $lang String: language to fetch it in, if any.
 359          */
 360         function getDescriptionRenderUrl( $name, $lang = null ) {
 361                 $query = 'action=render';
 362                 if ( !is_null( $lang ) ) {
 363                         $query .= '&uselang=' . $lang;
 364                 }
 365                 if ( isset( $this->scriptDirUrl ) ) {
 366                         return $this->makeUrl(
 367                                 'title=' .
 368                                 wfUrlencode( 'Image:' . $name ) .
 369                                 "&$query" );
 370                 } else {
 371                         $descUrl = $this->getDescriptionUrl( $name );
 372                         if ( $descUrl ) {
 373                                 return wfAppendQuery( $descUrl, $query );
 374                         } else {
 375                                 return false;
 376                         }
 377                 }
 378         }
 379
 380         /**
 381          * Get the URL of the stylesheet to apply to description pages
 382          * @return string
 383          */
 384         function getDescriptionStylesheetUrl() {
 385                 if ( $this->scriptDirUrl ) {
 386                         return $this->makeUrl( 'title=MediaWiki:Filepage.css&' .
 387                                 wfArrayToCGI( Skin::getDynamicStylesheetQuery() ) );
 388                 }
 389         }
 390
 391         /**
 392          * Store a file to a given destination.
 393          *
 394          * @param $srcPath String: source path or virtual URL
 395          * @param $dstZone String: destination zone
 396          * @param $dstRel String: destination relative path
 397          * @param $flags Integer: bitwise combination of the following flags:
 398          *     self::DELETE_SOURCE     Delete the source file after upload
 399          *     self::OVERWRITE         Overwrite an existing destination file instead of failing
 400          *     self::OVERWRITE_SAME    Overwrite the file if the destination exists and has the
 401          *                             same contents as the source
 402          * @return FileRepoStatus
 403          */
 404         function store( $srcPath, $dstZone, $dstRel, $flags = 0 ) {
 405                 $status = $this->storeBatch( array( array( $srcPath, $dstZone, $dstRel ) ), $flags );
 406                 if ( $status->successCount == 0 ) {
 407                         $status->ok = false;
 408                 }
 409                 return $status;
 410         }
 411
 412         /**
 413          * Store a batch of files
 414          *
 415          * @param $triplets Array: (src,zone,dest) triplets as per store()
 416          * @param $flags Integer: flags as per store
 417          */
 418         abstract function storeBatch( $triplets, $flags = 0 );
 419
 420         /**
 421          * Pick a random name in the temp zone and store a file to it.
 422          * Returns a FileRepoStatus object with the URL in the value.
 423          *
 424          * @param $originalName String: the base name of the file as specified
 425          *     by the user. The file extension will be maintained.
 426          * @param $srcPath String: the current location of the file.
 427          */
 428         abstract function storeTemp( $originalName, $srcPath );
 429
 430
 431         /**
 432          * Append the contents of the source path to the given file.
 433          * @param $srcPath String: location of the source file
 434          * @param $toAppendPath String: path to append to.
 435          * @param $flags Integer: bitfield, may be FileRepo::DELETE_SOURCE to indicate
 436          *        that the source file should be deleted if possible
 437          * @return mixed Status or false
 438          */
 439         abstract function append( $srcPath, $toAppendPath, $flags = 0 );
 440
 441         /**
 442          * Remove a temporary file or mark it for garbage collection
 443          * @param $virtualUrl String: the virtual URL returned by storeTemp
 444          * @return Boolean: true on success, false on failure
 445          * STUB
 446          */
 447         function freeTemp( $virtualUrl ) {
 448                 return true;
 449         }
 450
 451         /**
 452          * Copy or move a file either from the local filesystem or from an mwrepo://
 453          * virtual URL, into this repository at the specified destination location.
 454          *
 455          * Returns a FileRepoStatus object. On success, the value contains "new" or
 456          * "archived", to indicate whether the file was new with that name.
 457          *
 458          * @param $srcPath String: the source path or URL
 459          * @param $dstRel String: the destination relative path
 460          * @param $archiveRel String: rhe relative path where the existing file is to
 461          *        be archived, if there is one. Relative to the public zone root.
 462          * @param $flags Integer: bitfield, may be FileRepo::DELETE_SOURCE to indicate
 463          *        that the source file should be deleted if possible
 464          */
 465         function publish( $srcPath, $dstRel, $archiveRel, $flags = 0 ) {
 466                 $status = $this->publishBatch( array( array( $srcPath, $dstRel, $archiveRel ) ), $flags );
 467                 if ( $status->successCount == 0 ) {
 468                         $status->ok = false;
 469                 }
 470                 if ( isset( $status->value[0] ) ) {
 471                         $status->value = $status->value[0];
 472                 } else {
 473                         $status->value = false;
 474                 }
 475                 return $status;
 476         }
 477
 478         /**
 479          * Publish a batch of files
 480          * @param $triplets Array: (source,dest,archive) triplets as per publish()
 481          * @param $flags Integer: bitfield, may be FileRepo::DELETE_SOURCE to indicate
 482          *        that the source files should be deleted if possible
 483          */
 484         abstract function publishBatch( $triplets, $flags = 0 );
 485
 486         function fileExists( $file, $flags = 0 ) {
 487                 $result = $this->fileExistsBatch( array( $file ), $flags );
 488                 return $result[0];
 489         }
 490
 491         /**
 492          * Checks existence of an array of files.
 493          *
 494          * @param $files Array: URLs (or paths) of files to check
 495          * @param $flags Integer: bitwise combination of the following flags:
 496          *     self::FILES_ONLY     Mark file as existing only if it is a file (not directory)
 497          * @return Either array of files and existence flags, or false
 498          */
 499         abstract function fileExistsBatch( $files, $flags = 0 );
 500
 501         /**
 502          * Move a group of files to the deletion archive.
 503          *
 504          * If no valid deletion archive is configured, this may either delete the
 505          * file or throw an exception, depending on the preference of the repository.
 506          *
 507          * The overwrite policy is determined by the repository -- currently FSRepo
 508          * assumes a naming scheme in the deleted zone based on content hash, as
 509          * opposed to the public zone which is assumed to be unique.
 510          *
 511          * @param $sourceDestPairs Array of source/destination pairs. Each element
 512          *        is a two-element array containing the source file path relative to the
 513          *        public root in the first element, and the archive file path relative
 514          *        to the deleted zone root in the second element.
 515          * @return FileRepoStatus
 516          */
 517         abstract function deleteBatch( $sourceDestPairs );
 518
 519         /**
 520          * Move a file to the deletion archive.
 521          * If no valid deletion archive exists, this may either delete the file
 522          * or throw an exception, depending on the preference of the repository
 523          * @param $srcRel Mixed: relative path for the file to be deleted
 524          * @param $archiveRel Mixed: relative path for the archive location.
 525          *        Relative to a private archive directory.
 526          * @return FileRepoStatus object
 527          */
 528         function delete( $srcRel, $archiveRel ) {
 529                 return $this->deleteBatch( array( array( $srcRel, $archiveRel ) ) );
 530         }
 531
 532         /**
 533          * Get properties of a file with a given virtual URL
 534          * The virtual URL must refer to this repo
 535          * Properties should ultimately be obtained via File::getPropsFromPath()
 536          */
 537         abstract function getFileProps( $virtualUrl );
 538
 539         /**
 540          * Call a callback function for every file in the repository
 541          * May use either the database or the filesystem
 542          * STUB
 543          */
 544         function enumFiles( $callback ) {
 545                 throw new MWException( 'enumFiles is not supported by ' . get_class( $this ) );
 546         }
 547
 548         /**
 549          * Determine if a relative path is valid, i.e. not blank or involving directory traveral
 550          */
 551         function validateFilename( $filename ) {
 552                 if ( strval( $filename ) == '' ) {
 553                         return false;
 554                 }
 555                 if ( wfIsWindows() ) {
 556                         $filename = strtr( $filename, '\\', '/' );
 557                 }
 558                 /**
 559                  * Use the same traversal protection as Title::secureAndSplit()
 560                  */
 561                 if ( strpos( $filename, '.' ) !== false &&
 562                      ( $filename === '.' || $filename === '..' ||
 563                        strpos( $filename, './' ) === 0  ||
 564                        strpos( $filename, '../' ) === 0 ||
 565                        strpos( $filename, '/./' ) !== false ||
 566                        strpos( $filename, '/../' ) !== false ) )
 567                 {
 568                         return false;
 569                 } else {
 570                         return true;
 571                 }
 572         }
 573
 574         /**#@+
 575          * Path disclosure protection functions
 576          */
 577         function paranoidClean( $param ) { return '[hidden]'; }
 578         function passThrough( $param ) { return $param; }
 579
 580         /**
 581          * Get a callback function to use for cleaning error message parameters
 582          */
 583         function getErrorCleanupFunction() {
 584                 switch ( $this->pathDisclosureProtection ) {
 585                         case 'none':
 586                                 $callback = array( $this, 'passThrough' );
 587                                 break;
 588                         default: // 'paranoid'
 589                                 $callback = array( $this, 'paranoidClean' );
 590                 }
 591                 return $callback;
 592         }
 593         /**#@-*/
 594
 595         /**
 596          * Create a new fatal error
 597          */
 598         function newFatal( $message /*, parameters...*/ ) {
 599                 $params = func_get_args();
 600                 array_unshift( $params, $this );
 601                 return call_user_func_array( array( 'FileRepoStatus', 'newFatal' ), $params );
 602         }
 603
 604         /**
 605          * Create a new good result
 606          */
 607         function newGood( $value = null ) {
 608                 return FileRepoStatus::newGood( $this, $value );
 609         }
 610
 611         /**
 612          * Delete files in the deleted directory if they are not referenced in the filearchive table
 613          * STUB
 614          */
 615         function cleanupDeletedBatch( $storageKeys ) {}
 616
 617         /**
 618          * Checks if there is a redirect named as $title. If there is, return the
 619          * title object. If not, return false.
 620          * STUB
 621          *
 622          * @param $title Title of image
 623          * @return Bool
 624          */
 625         function checkRedirect( $title ) {
 626                 return false;
 627         }
 628
 629         /**
 630          * Invalidates image redirect cache related to that image
 631          * Doesn't do anything for repositories that don't support image redirects.
 632          *
 633          * STUB
 634          * @param $title Title of image
 635          */
 636         function invalidateImageRedirect( $title ) {}
 637
 638         /**
 639          * Get an array or iterator of file objects for files that have a given
 640          * SHA-1 content hash.
 641          *
 642          * STUB
 643          */
 644         function findBySha1( $hash ) {
 645                 return array();
 646         }
 647
 648         /**
 649          * Get the human-readable name of the repo.
 650          * @return string
 651          */
 652         public function getDisplayName() {
 653                 // We don't name our own repo, return nothing
 654                 if ( $this->isLocal() ) {
 655                         return null;
 656                 }
 657                 // 'shared-repo-name-wikimediacommons' is used when $wgUseInstantCommons = true
 658                 return wfMessageFallback( 'shared-repo-name-' . $this->name, 'shared-repo' )->text();
 659         }
 660
 661         /**
 662          * Returns true if this the local file repository.
 663          *
 664          * @return bool
 665          */
 666         function isLocal() {
 667                 return $this->getName() == 'local';
 668         }
 669
 670
 671         /**
 672          * Get a key on the primary cache for this repository.
 673          * Returns false if the repository's cache is not accessible at this site.
 674          * The parameters are the parts of the key, as for wfMemcKey().
 675          *
 676          * STUB
 677          */
 678         function getSharedCacheKey( /*...*/ ) {
 679                 return false;
 680         }
 681
 682         /**
 683          * Get a key for this repo in the local cache domain. These cache keys are
 684          * not shared with remote instances of the repo.
 685          * The parameters are the parts of the key, as for wfMemcKey().
 686          */
 687         function getLocalCacheKey( /*...*/ ) {
 688                 $args = func_get_args();
 689                 array_unshift( $args, 'filerepo', $this->getName() );
 690                 return call_user_func_array( 'wfMemcKey', $args );
 691         }
 692
 693         /**
 694          * Get an UploadStash associated with this repo.
 695          *
 696          * @return UploadStash
 697          */
 698         function getUploadStash() {
 699                 return new UploadStash( $this );
 700         }
 701 }