includes/upload/UploadStash.php

   1 <?php
   2 /**
   3  * Temporary storage for uploaded files.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @ingroup Upload
  22  */
  23
  24 /**
  25  * UploadStash is intended to accomplish a few things:
  26  *   - enable applications to temporarily stash files without publishing them to the wiki.
  27  *      - Several parts of MediaWiki do this in similar ways: UploadBase, UploadWizard, and FirefoggChunkedExtension
  28  *        And there are several that reimplement stashing from scratch, in idiosyncratic ways. The idea is to unify them all here.
  29  *        Mostly all of them are the same except for storing some custom fields, which we subsume into the data array.
  30  *   - enable applications to find said files later, as long as the db table or temp files haven't been purged.
  31  *   - enable the uploading user (and *ONLY* the uploading user) to access said files, and thumbnails of said files, via a URL.
  32  *     We accomplish this using a database table, with ownership checking as you might expect. See SpecialUploadStash, which
  33  *     implements a web interface to some files stored this way.
  34  *
  35  * UploadStash right now is *mostly* intended to show you one user's slice of the entire stash. The user parameter is only optional
  36  * because there are few cases where we clean out the stash from an automated script. In the future we might refactor this.
  37  *
  38  * UploadStash represents the entire stash of temporary files.
  39  * UploadStashFile is a filestore for the actual physical disk files.
  40  * UploadFromStash extends UploadBase, and represents a single stashed file as it is moved from the stash to the regular file repository
  41  *
  42  * @ingroup Upload
  43  */
  44 class UploadStash {
  45
  46         // Format of the key for files -- has to be suitable as a filename itself (e.g. ab12cd34ef.jpg)
  47         const KEY_FORMAT_REGEX = '/^[\w-\.]+\.\w*$/';
  48
  49         /**
  50          * repository that this uses to store temp files
  51          * public because we sometimes need to get a LocalFile within the same repo.
  52          *
  53          * @var LocalRepo
  54          */
  55         public $repo;
  56
  57         // array of initialized repo objects
  58         protected $files = array();
  59
  60         // cache of the file metadata that's stored in the database
  61         protected $fileMetadata = array();
  62
  63         // fileprops cache
  64         protected $fileProps = array();
  65
  66         // current user
  67         protected $user, $userId, $isLoggedIn;
  68
  69         /**
  70          * Represents a temporary filestore, with metadata in the database.
  71          * Designed to be compatible with the session stashing code in UploadBase
  72          * (should replace it eventually).
  73          *
  74          * @param $repo FileRepo
  75          * @param $user User (default null)
  76          */
  77         public function __construct( FileRepo $repo, $user = null ) {
  78                 // this might change based on wiki's configuration.
  79                 $this->repo = $repo;
  80
  81                 // if a user was passed, use it. otherwise, attempt to use the global.
  82                 // this keeps FileRepo from breaking when it creates an UploadStash object
  83                 if ( $user ) {
  84                         $this->user = $user;
  85                 } else {
  86                         global $wgUser;
  87                         $this->user = $wgUser;
  88                 }
  89
  90                 if ( is_object( $this->user ) ) {
  91                         $this->userId = $this->user->getId();
  92                         $this->isLoggedIn = $this->user->isLoggedIn();
  93                 }
  94         }
  95
  96         /**
  97          * Get a file and its metadata from the stash.
  98          * The noAuth param is a bit janky but is required for automated scripts which clean out the stash.
  99          *
 100          * @param $key String: key under which file information is stored
 101          * @param $noAuth Boolean (optional) Don't check authentication. Used by maintenance scripts.
 102          * @throws UploadStashFileNotFoundException
 103          * @throws UploadStashNotLoggedInException
 104          * @throws UploadStashWrongOwnerException
 105          * @throws UploadStashBadPathException
 106          * @return UploadStashFile
 107          */
 108         public function getFile( $key, $noAuth = false ) {
 109                 if ( ! preg_match( self::KEY_FORMAT_REGEX, $key ) ) {
 110                         throw new UploadStashBadPathException( "key '$key' is not in a proper format" );
 111                 }
 112
 113                 if ( !$noAuth && !$this->isLoggedIn ) {
 114                         throw new UploadStashNotLoggedInException( __METHOD__ .
 115                                 ' No user is logged in, files must belong to users' );
 116                 }
 117
 118                 if ( !isset( $this->fileMetadata[$key] ) ) {
 119                         if ( !$this->fetchFileMetadata( $key ) ) {
 120                                 // If nothing was received, it's likely due to replication lag.  Check the master to see if the record is there.
 121                                 $this->fetchFileMetadata( $key, DB_MASTER );
 122                         }
 123
 124                         if ( !isset( $this->fileMetadata[$key] ) ) {
 125                                 throw new UploadStashFileNotFoundException( "key '$key' not found in stash" );
 126                         }
 127
 128                         // create $this->files[$key]
 129                         $this->initFile( $key );
 130
 131                         // fetch fileprops
 132                         if ( strlen( $this->fileMetadata[$key]['us_props'] ) ) {
 133                                 $this->fileProps[$key] = unserialize( $this->fileMetadata[$key]['us_props'] );
 134                         } else { // b/c for rows with no us_props
 135                                 wfDebug( __METHOD__ . " fetched props for $key from file\n" );
 136                                 $path = $this->fileMetadata[$key]['us_path'];
 137                                 $this->fileProps[$key] = $this->repo->getFileProps( $path );
 138                         }
 139                 }
 140
 141                 if ( ! $this->files[$key]->exists() ) {
 142                         wfDebug( __METHOD__ . " tried to get file at $key, but it doesn't exist\n" );
 143                         throw new UploadStashBadPathException( "path doesn't exist" );
 144                 }
 145
 146                 if ( !$noAuth ) {
 147                         if ( $this->fileMetadata[$key]['us_user'] != $this->userId ) {
 148                                 throw new UploadStashWrongOwnerException( "This file ($key) doesn't belong to the current user." );
 149                         }
 150                 }
 151
 152                 return $this->files[$key];
 153         }
 154
 155         /**
 156          * Getter for file metadata.
 157          *
 158          * @param $key String: key under which file information is stored
 159          * @return Array
 160          */
 161         public function getMetadata ( $key ) {
 162                 $this->getFile( $key );
 163                 return $this->fileMetadata[$key];
 164         }
 165
 166         /**
 167          * Getter for fileProps
 168          *
 169          * @param $key String: key under which file information is stored
 170          * @return Array
 171          */
 172         public function getFileProps ( $key ) {
 173                 $this->getFile( $key );
 174                 return $this->fileProps[$key];
 175         }
 176
 177         /**
 178          * Stash a file in a temp directory and record that we did this in the database, along with other metadata.
 179          *
 180          * @param $path String: path to file you want stashed
 181          * @param $sourceType String: the type of upload that generated this file (currently, I believe, 'file' or null)
 182          * @throws UploadStashBadPathException
 183          * @throws UploadStashFileException
 184          * @throws UploadStashNotLoggedInException
 185          * @return UploadStashFile: file, or null on failure
 186          */
 187         public function stashFile( $path, $sourceType = null ) {
 188                 if ( !is_file( $path ) ) {
 189                         wfDebug( __METHOD__ . " tried to stash file at '$path', but it doesn't exist\n" );
 190                         throw new UploadStashBadPathException( "path doesn't exist" );
 191                 }
 192                 $fileProps = FSFile::getPropsFromPath( $path );
 193                 wfDebug( __METHOD__ . " stashing file at '$path'\n" );
 194
 195                 // we will be initializing from some tmpnam files that don't have extensions.
 196                 // most of MediaWiki assumes all uploaded files have good extensions. So, we fix this.
 197                 $extension = self::getExtensionForPath( $path );
 198                 if ( !preg_match( "/\\.\\Q$extension\\E$/", $path ) ) {
 199                         $pathWithGoodExtension = "$path.$extension";
 200                 } else {
 201                         $pathWithGoodExtension = $path;
 202                 }
 203
 204                 // If no key was supplied, make one.  a mysql insertid would be totally reasonable here, except
 205                 // that for historical reasons, the key is this random thing instead.  At least it's not guessable.
 206                 //
 207                 // some things that when combined will make a suitably unique key.
 208                 // see: http://www.jwz.org/doc/mid.html
 209                 list( $usec, $sec ) = explode( ' ', microtime() );
 210                 $usec = substr( $usec, 2 );
 211                 $key = wfBaseConvert( $sec . $usec, 10, 36 ) . '.' .
 212                         wfBaseConvert( mt_rand(), 10, 36 ) . '.'.
 213                         $this->userId . '.' .
 214                         $extension;
 215
 216                 $this->fileProps[$key] = $fileProps;
 217
 218                 if ( ! preg_match( self::KEY_FORMAT_REGEX, $key ) ) {
 219                         throw new UploadStashBadPathException( "key '$key' is not in a proper format" );
 220                 }
 221
 222                 wfDebug( __METHOD__ . " key for '$path': $key\n" );
 223
 224                 // if not already in a temporary area, put it there
 225                 $storeStatus = $this->repo->storeTemp( basename( $pathWithGoodExtension ), $path );
 226
 227                 if ( ! $storeStatus->isOK() ) {
 228                         // It is a convention in MediaWiki to only return one error per API exception, even if multiple errors
 229                         // are available. We use reset() to pick the "first" thing that was wrong, preferring errors to warnings.
 230                         // This is a bit lame, as we may have more info in the $storeStatus and we're throwing it away, but to fix it means
 231                         // redesigning API errors significantly.
 232                         // $storeStatus->value just contains the virtual URL (if anything) which is probably useless to the caller
 233                         $error = $storeStatus->getErrorsArray();
 234                         $error = reset( $error );
 235                         if ( ! count( $error ) ) {
 236                                 $error = $storeStatus->getWarningsArray();
 237                                 $error = reset( $error );
 238                                 if ( ! count( $error ) ) {
 239                                         $error = array( 'unknown', 'no error recorded' );
 240                                 }
 241                         }
 242                         // at this point, $error should contain the single "most important" error, plus any parameters.
 243                         $errorMsg = array_shift( $error );
 244                         throw new UploadStashFileException( "Error storing file in '$path': " . wfMessage( $errorMsg, $error )->text() );
 245                 }
 246                 $stashPath = $storeStatus->value;
 247
 248                 // fetch the current user ID
 249                 if ( !$this->isLoggedIn ) {
 250                         throw new UploadStashNotLoggedInException( __METHOD__ . ' No user is logged in, files must belong to users' );
 251                 }
 252
 253                 // insert the file metadata into the db.
 254                 wfDebug( __METHOD__ . " inserting $stashPath under $key\n" );
 255                 $dbw = $this->repo->getMasterDb();
 256
 257                 $this->fileMetadata[$key] = array(
 258                         'us_id' => $dbw->nextSequenceValue( 'uploadstash_us_id_seq' ),
 259                         'us_user' => $this->userId,
 260                         'us_key' => $key,
 261                         'us_orig_path' => $path,
 262                         'us_path' => $stashPath, // virtual URL
 263                         'us_props' => serialize( $fileProps ),
 264                         'us_size' => $fileProps['size'],
 265                         'us_sha1' => $fileProps['sha1'],
 266                         'us_mime' => $fileProps['mime'],
 267                         'us_media_type' => $fileProps['media_type'],
 268                         'us_image_width' => $fileProps['width'],
 269                         'us_image_height' => $fileProps['height'],
 270                         'us_image_bits' => $fileProps['bits'],
 271                         'us_source_type' => $sourceType,
 272                         'us_timestamp' => $dbw->timestamp(),
 273                         'us_status' => 'finished'
 274                 );
 275
 276                 $dbw->insert(
 277                         'uploadstash',
 278                         $this->fileMetadata[$key],
 279                         __METHOD__
 280                 );
 281
 282                 // store the insertid in the class variable so immediate retrieval (possibly laggy) isn't necesary.
 283                 $this->fileMetadata[$key]['us_id'] = $dbw->insertId();
 284
 285                 # create the UploadStashFile object for this file.
 286                 $this->initFile( $key );
 287
 288                 return $this->getFile( $key );
 289         }
 290
 291         /**
 292          * Remove all files from the stash.
 293          * Does not clean up files in the repo, just the record of them.
 294          *
 295          * @throws UploadStashNotLoggedInException
 296          * @return boolean: success
 297          */
 298         public function clear() {
 299                 if ( !$this->isLoggedIn ) {
 300                         throw new UploadStashNotLoggedInException( __METHOD__ . ' No user is logged in, files must belong to users' );
 301                 }
 302
 303                 wfDebug( __METHOD__ . ' clearing all rows for user ' . $this->userId . "\n" );
 304                 $dbw = $this->repo->getMasterDb();
 305                 $dbw->delete(
 306                         'uploadstash',
 307                         array( 'us_user' => $this->userId ),
 308                         __METHOD__
 309                 );
 310
 311                 # destroy objects.
 312                 $this->files = array();
 313                 $this->fileMetadata = array();
 314
 315                 return true;
 316         }
 317
 318         /**
 319          * Remove a particular file from the stash.  Also removes it from the repo.
 320          *
 321          * @param $key
 322          * @throws UploadStashNoSuchKeyException|UploadStashNotLoggedInException|UploadStashWrongOwnerException
 323          * @return boolean: success
 324          */
 325         public function removeFile( $key ) {
 326                 if ( !$this->isLoggedIn ) {
 327                         throw new UploadStashNotLoggedInException( __METHOD__ . ' No user is logged in, files must belong to users' );
 328                 }
 329
 330                 $dbw = $this->repo->getMasterDb();
 331
 332                 // this is a cheap query. it runs on the master so that this function still works when there's lag.
 333                 // it won't be called all that often.
 334                 $row = $dbw->selectRow(
 335                         'uploadstash',
 336                         'us_user',
 337                         array( 'us_key' => $key ),
 338                         __METHOD__
 339                 );
 340
 341                 if( !$row ) {
 342                         throw new UploadStashNoSuchKeyException( "No such key ($key), cannot remove" );
 343                 }
 344
 345                 if ( $row->us_user != $this->userId ) {
 346                         throw new UploadStashWrongOwnerException( "Can't delete: the file ($key) doesn't belong to this user." );
 347                 }
 348
 349                 return $this->removeFileNoAuth( $key );
 350         }
 351
 352
 353         /**
 354          * Remove a file (see removeFile), but doesn't check ownership first.
 355          *
 356          * @return boolean: success
 357          */
 358         public function removeFileNoAuth( $key ) {
 359                 wfDebug( __METHOD__ . " clearing row $key\n" );
 360
 361                 $dbw = $this->repo->getMasterDb();
 362
 363                 $dbw->delete(
 364                         'uploadstash',
 365                         array( 'us_key' => $key ),
 366                         __METHOD__
 367                 );
 368
 369                 // TODO: look into UnregisteredLocalFile and find out why the rv here is sometimes wrong (false when file was removed)
 370                 // for now, ignore.
 371                 $this->files[$key]->remove();
 372
 373                 unset( $this->files[$key] );
 374                 unset( $this->fileMetadata[$key] );
 375
 376                 return true;
 377         }
 378
 379         /**
 380          * List all files in the stash.
 381          *
 382          * @throws UploadStashNotLoggedInException
 383          * @return Array
 384          */
 385         public function listFiles() {
 386                 if ( !$this->isLoggedIn ) {
 387                         throw new UploadStashNotLoggedInException( __METHOD__ . ' No user is logged in, files must belong to users' );
 388                 }
 389
 390                 $dbr = $this->repo->getSlaveDb();
 391                 $res = $dbr->select(
 392                         'uploadstash',
 393                         'us_key',
 394                         array( 'us_user' => $this->userId ),
 395                         __METHOD__
 396                 );
 397
 398                 if ( !is_object( $res ) || $res->numRows() == 0 ) {
 399                         // nothing to do.
 400                         return false;
 401                 }
 402
 403                 // finish the read before starting writes.
 404                 $keys = array();
 405                 foreach ( $res as $row ) {
 406                         array_push( $keys, $row->us_key );
 407                 }
 408
 409                 return $keys;
 410         }
 411
 412         /**
 413          * Find or guess extension -- ensuring that our extension matches our mime type.
 414          * Since these files are constructed from php tempnames they may not start off
 415          * with an extension.
 416          * XXX this is somewhat redundant with the checks that ApiUpload.php does with incoming
 417          * uploads versus the desired filename. Maybe we can get that passed to us...
 418          * @param $path
 419          * @throws UploadStashFileException
 420          * @return string
 421          */
 422         public static function getExtensionForPath( $path ) {
 423                 // Does this have an extension?
 424                 $n = strrpos( $path, '.' );
 425                 $extension = null;
 426                 if ( $n !== false ) {
 427                         $extension = $n ? substr( $path, $n + 1 ) : '';
 428                 } else {
 429                         // If not, assume that it should be related to the mime type of the original file.
 430                         $magic = MimeMagic::singleton();
 431                         $mimeType = $magic->guessMimeType( $path );
 432                         $extensions = explode( ' ', MimeMagic::singleton()->getExtensionsForType( $mimeType ) );
 433                         if ( count( $extensions ) ) {
 434                                 $extension = $extensions[0];
 435                         }
 436                 }
 437
 438                 if ( is_null( $extension ) ) {
 439                         throw new UploadStashFileException( "extension is null" );
 440                 }
 441
 442                 return File::normalizeExtension( $extension );
 443         }
 444
 445         /**
 446          * Helper function: do the actual database query to fetch file metadata.
 447          *
 448          * @param $key String: key
 449          * @param $readFromDB: constant (default: DB_SLAVE)
 450          * @return boolean
 451          */
 452         protected function fetchFileMetadata( $key, $readFromDB = DB_SLAVE ) {
 453                 // populate $fileMetadata[$key]
 454                 $dbr = null;
 455                 if( $readFromDB === DB_MASTER ) {
 456                         // sometimes reading from the master is necessary, if there's replication lag.
 457                         $dbr = $this->repo->getMasterDb();
 458                 } else {
 459                         $dbr = $this->repo->getSlaveDb();
 460                 }
 461
 462                 $row = $dbr->selectRow(
 463                         'uploadstash',
 464                         '*',
 465                         array( 'us_key' => $key ),
 466                         __METHOD__
 467                 );
 468
 469                 if ( !is_object( $row ) ) {
 470                         // key wasn't present in the database. this will happen sometimes.
 471                         return false;
 472                 }
 473
 474                 $this->fileMetadata[$key] = (array)$row;
 475
 476                 return true;
 477         }
 478
 479         /**
 480          * Helper function: Initialize the UploadStashFile for a given file.
 481          *
 482          * @param $key String: key under which to store the object
 483          * @throws UploadStashZeroLengthFileException
 484          * @return bool
 485          */
 486         protected function initFile( $key ) {
 487                 $file = new UploadStashFile( $this->repo, $this->fileMetadata[$key]['us_path'], $key );
 488                 if ( $file->getSize() === 0 ) {
 489                         throw new UploadStashZeroLengthFileException( "File is zero length" );
 490                 }
 491                 $this->files[$key] = $file;
 492                 return true;
 493         }
 494 }
 495
 496 class UploadStashFile extends UnregisteredLocalFile {
 497         private $fileKey;
 498         private $urlName;
 499         protected $url;
 500
 501         /**
 502          * A LocalFile wrapper around a file that has been temporarily stashed, so we can do things like create thumbnails for it
 503          * Arguably UnregisteredLocalFile should be handling its own file repo but that class is a bit retarded currently
 504          *
 505          * @param $repo FileRepo: repository where we should find the path
 506          * @param $path String: path to file
 507          * @param $key String: key to store the path and any stashed data under
 508          * @throws UploadStashBadPathException
 509          * @throws UploadStashFileNotFoundException
 510          */
 511         public function __construct( $repo, $path, $key ) {
 512                 $this->fileKey = $key;
 513
 514                 // resolve mwrepo:// urls
 515                 if ( $repo->isVirtualUrl( $path ) ) {
 516                         $path = $repo->resolveVirtualUrl( $path );
 517                 } else {
 518
 519                         // check if path appears to be sane, no parent traversals, and is in this repo's temp zone.
 520                         $repoTempPath = $repo->getZonePath( 'temp' );
 521                         if ( ( ! $repo->validateFilename( $path ) ) ||
 522                                         ( strpos( $path, $repoTempPath ) !== 0 ) ) {
 523                                 wfDebug( "UploadStash: tried to construct an UploadStashFile from a file that should already exist at '$path', but path is not valid\n" );
 524                                 throw new UploadStashBadPathException( 'path is not valid' );
 525                         }
 526
 527                         // check if path exists! and is a plain file.
 528                         if ( ! $repo->fileExists( $path ) ) {
 529                                 wfDebug( "UploadStash: tried to construct an UploadStashFile from a file that should already exist at '$path', but path is not found\n" );
 530                                 throw new UploadStashFileNotFoundException( 'cannot find path, or not a plain file' );
 531                         }
 532                 }
 533
 534                 parent::__construct( false, $repo, $path, false );
 535
 536                 $this->name = basename( $this->path );
 537         }
 538
 539         /**
 540          * A method needed by the file transforming and scaling routines in File.php
 541          * We do not necessarily care about doing the description at this point
 542          * However, we also can't return the empty string, as the rest of MediaWiki demands this (and calls to imagemagick
 543          * convert require it to be there)
 544          *
 545          * @return String: dummy value
 546          */
 547         public function getDescriptionUrl() {
 548                 return $this->getUrl();
 549         }
 550
 551         /**
 552          * Get the path for the thumbnail (actually any transformation of this file)
 553          * The actual argument is the result of thumbName although we seem to have
 554          * buggy code elsewhere that expects a boolean 'suffix'
 555          *
 556          * @param $thumbName String: name of thumbnail (e.g. "120px-123456.jpg" ), or false to just get the path
 557          * @return String: path thumbnail should take on filesystem, or containing directory if thumbname is false
 558          */
 559         public function getThumbPath( $thumbName = false ) {
 560                 $path = dirname( $this->path );
 561                 if ( $thumbName !== false ) {
 562                         $path .= "/$thumbName";
 563                 }
 564                 return $path;
 565         }
 566
 567         /**
 568          * Return the file/url base name of a thumbnail with the specified parameters.
 569          * We override this because we want to use the pretty url name instead of the
 570          * ugly file name.
 571          *
 572          * @param $params Array: handler-specific parameters
 573          * @param $flags integer Bitfield that supports THUMB_* constants
 574          * @return String: base name for URL, like '120px-12345.jpg', or null if there is no handler
 575          */
 576         function thumbName( $params, $flags = 0 ) {
 577                 return $this->generateThumbName( $this->getUrlName(), $params );
 578         }
 579
 580         /**
 581          * Helper function -- given a 'subpage', return the local URL e.g. /wiki/Special:UploadStash/subpage
 582          * @param $subPage String
 583          * @return String: local URL for this subpage in the Special:UploadStash space.
 584          */
 585         private function getSpecialUrl( $subPage ) {
 586                 return SpecialPage::getTitleFor( 'UploadStash', $subPage )->getLocalURL();
 587         }
 588
 589         /**
 590          * Get a URL to access the thumbnail
 591          * This is required because the model of how files work requires that
 592          * the thumbnail urls be predictable. However, in our model the URL is not based on the filename
 593          * (that's hidden in the db)
 594          *
 595          * @param $thumbName String: basename of thumbnail file -- however, we don't want to use the file exactly
 596          * @return String: URL to access thumbnail, or URL with partial path
 597          */
 598         public function getThumbUrl( $thumbName = false ) {
 599                 wfDebug( __METHOD__ . " getting for $thumbName \n" );
 600                 return $this->getSpecialUrl( 'thumb/' . $this->getUrlName() . '/' . $thumbName );
 601         }
 602
 603         /**
 604          * The basename for the URL, which we want to not be related to the filename.
 605          * Will also be used as the lookup key for a thumbnail file.
 606          *
 607          * @return String: base url name, like '120px-123456.jpg'
 608          */
 609         public function getUrlName() {
 610                 if ( ! $this->urlName ) {
 611                         $this->urlName = $this->fileKey;
 612                 }
 613                 return $this->urlName;
 614         }
 615
 616         /**
 617          * Return the URL of the file, if for some reason we wanted to download it
 618          * We tend not to do this for the original file, but we do want thumb icons
 619          *
 620          * @return String: url
 621          */
 622         public function getUrl() {
 623                 if ( !isset( $this->url ) ) {
 624                         $this->url = $this->getSpecialUrl( 'file/' . $this->getUrlName() );
 625                 }
 626                 return $this->url;
 627         }
 628
 629         /**
 630          * Parent classes use this method, for no obvious reason, to return the path (relative to wiki root, I assume).
 631          * But with this class, the URL is unrelated to the path.
 632          *
 633          * @return String: url
 634          */
 635         public function getFullUrl() {
 636                 return $this->getUrl();
 637         }
 638
 639         /**
 640          * Getter for file key (the unique id by which this file's location & metadata is stored in the db)
 641          *
 642          * @return String: file key
 643          */
 644         public function getFileKey() {
 645                 return $this->fileKey;
 646         }
 647
 648         /**
 649          * Remove the associated temporary file
 650          * @return Status: success
 651          */
 652         public function remove() {
 653                 if ( !$this->repo->fileExists( $this->path ) ) {
 654                         // Maybe the file's already been removed? This could totally happen in UploadBase.
 655                         return true;
 656                 }
 657
 658                 return $this->repo->freeTemp( $this->path );
 659         }
 660
 661         public function exists() {
 662                 return $this->repo->fileExists( $this->path );
 663         }
 664
 665 }
 666
 667 class UploadStashNotAvailableException extends MWException {};
 668 class UploadStashFileNotFoundException extends MWException {};
 669 class UploadStashBadPathException extends MWException {};
 670 class UploadStashFileException extends MWException {};
 671 class UploadStashZeroLengthFileException extends MWException {};
 672 class UploadStashNotLoggedInException extends MWException {};
 673 class UploadStashWrongOwnerException extends MWException {};
 674 class UploadStashNoSuchKeyException extends MWException {};