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
  27  *     the wiki.
  28  *      - Several parts of MediaWiki do this in similar ways: UploadBase,
  29  *        UploadWizard, and FirefoggChunkedExtension.
  30  *        And there are several that reimplement stashing from scratch, in
  31  *        idiosyncratic ways. The idea is to unify them all here.
  32  *        Mostly all of them are the same except for storing some custom fields,
  33  *        which we subsume into the data array.
  34  *   - Enable applications to find said files later, as long as the db table or
  35  *     temp files haven't been purged.
  36  *   - Enable the uploading user (and *ONLY* the uploading user) to access said
  37  *     files, and thumbnails of said files, via a URL. We accomplish this using
  38  *     a database table, with ownership checking as you might expect. See
  39  *     SpecialUploadStash, which implements a web interface to some files stored
  40  *     this way.
  41  *
  42  * UploadStash right now is *mostly* intended to show you one user's slice of
  43  * the entire stash. The user parameter is only optional because there are few
  44  * cases where we clean out the stash from an automated script. In the future we
  45  * might refactor this.
  46  *
  47  * UploadStash represents the entire stash of temporary files.
  48  * UploadStashFile is a filestore for the actual physical disk files.
  49  * UploadFromStash extends UploadBase, and represents a single stashed file as
  50  * it is moved from the stash to the regular file repository
  51  *
  52  * @ingroup Upload
  53  */
  54 class UploadStash {
  55         // Format of the key for files -- has to be suitable as a filename itself (e.g. ab12cd34ef.jpg)
  56         const KEY_FORMAT_REGEX = '/^[\w-\.]+\.\w*$/';
  57         const MAX_US_PROPS_SIZE = 65535;
  58
  59         /**
  60          * repository that this uses to store temp files
  61          * public because we sometimes need to get a LocalFile within the same repo.
  62          *
  63          * @var LocalRepo
  64          */
  65         public $repo;
  66
  67         // array of initialized repo objects
  68         protected $files = [];
  69
  70         // cache of the file metadata that's stored in the database
  71         protected $fileMetadata = [];
  72
  73         // fileprops cache
  74         protected $fileProps = [];
  75
  76         // current user
  77         protected $user, $userId, $isLoggedIn;
  78
  79         /**
  80          * Represents a temporary filestore, with metadata in the database.
  81          * Designed to be compatible with the session stashing code in UploadBase
  82          * (should replace it eventually).
  83          *
  84          * @param FileRepo $repo
  85          * @param User $user (default null)
  86          */
  87         public function __construct( FileRepo $repo, $user = null ) {
  88                 // this might change based on wiki's configuration.
  89                 $this->repo = $repo;
  90
  91                 // if a user was passed, use it. otherwise, attempt to use the global.
  92                 // this keeps FileRepo from breaking when it creates an UploadStash object
  93                 if ( $user ) {
  94                         $this->user = $user;
  95                 } else {
  96                         global $wgUser;
  97                         $this->user = $wgUser;
  98                 }
  99
 100                 if ( is_object( $this->user ) ) {
 101                         $this->userId = $this->user->getId();
 102                         $this->isLoggedIn = $this->user->isLoggedIn();
 103                 }
 104         }
 105
 106         /**
 107          * Get a file and its metadata from the stash.
 108          * The noAuth param is a bit janky but is required for automated scripts
 109          * which clean out the stash.
 110          *
 111          * @param string $key Key under which file information is stored
 112          * @param bool $noAuth (optional) Don't check authentication. Used by maintenance scripts.
 113          * @throws UploadStashFileNotFoundException
 114          * @throws UploadStashNotLoggedInException
 115          * @throws UploadStashWrongOwnerException
 116          * @throws UploadStashBadPathException
 117          * @return UploadStashFile
 118          */
 119         public function getFile( $key, $noAuth = false ) {
 120                 if ( !preg_match( self::KEY_FORMAT_REGEX, $key ) ) {
 121                         throw new UploadStashBadPathException( "key '$key' is not in a proper format" );
 122                 }
 123
 124                 if ( !$noAuth && !$this->isLoggedIn ) {
 125                         throw new UploadStashNotLoggedInException( __METHOD__ .
 126                                 ' No user is logged in, files must belong to users' );
 127                 }
 128
 129                 if ( !isset( $this->fileMetadata[$key] ) ) {
 130                         if ( !$this->fetchFileMetadata( $key ) ) {
 131                                 // If nothing was received, it's likely due to replication lag.
 132                                 // Check the master to see if the record is there.
 133                                 $this->fetchFileMetadata( $key, DB_MASTER );
 134                         }
 135
 136                         if ( !isset( $this->fileMetadata[$key] ) ) {
 137                                 throw new UploadStashFileNotFoundException( "key '$key' not found in stash" );
 138                         }
 139
 140                         // create $this->files[$key]
 141                         $this->initFile( $key );
 142
 143                         // fetch fileprops
 144                         if ( strlen( $this->fileMetadata[$key]['us_props'] ) ) {
 145                                 $this->fileProps[$key] = unserialize( $this->fileMetadata[$key]['us_props'] );
 146                         } else { // b/c for rows with no us_props
 147                                 wfDebug( __METHOD__ . " fetched props for $key from file\n" );
 148                                 $path = $this->fileMetadata[$key]['us_path'];
 149                                 $this->fileProps[$key] = $this->repo->getFileProps( $path );
 150                         }
 151                 }
 152
 153                 if ( !$this->files[$key]->exists() ) {
 154                         wfDebug( __METHOD__ . " tried to get file at $key, but it doesn't exist\n" );
 155                         // @todo Is this not an UploadStashFileNotFoundException case?
 156                         throw new UploadStashBadPathException( "path doesn't exist" );
 157                 }
 158
 159                 if ( !$noAuth ) {
 160                         if ( $this->fileMetadata[$key]['us_user'] != $this->userId ) {
 161                                 throw new UploadStashWrongOwnerException( "This file ($key) doesn't "
 162                                         . "belong to the current user." );
 163                         }
 164                 }
 165
 166                 return $this->files[$key];
 167         }
 168
 169         /**
 170          * Getter for file metadata.
 171          *
 172          * @param string $key Key under which file information is stored
 173          * @return array
 174          */
 175         public function getMetadata( $key ) {
 176                 $this->getFile( $key );
 177
 178                 return $this->fileMetadata[$key];
 179         }
 180
 181         /**
 182          * Getter for fileProps
 183          *
 184          * @param string $key Key under which file information is stored
 185          * @return array
 186          */
 187         public function getFileProps( $key ) {
 188                 $this->getFile( $key );
 189
 190                 return $this->fileProps[$key];
 191         }
 192
 193         /**
 194          * Stash a file in a temp directory and record that we did this in the
 195          * database, along with other metadata.
 196          *
 197          * @param string $path Path to file you want stashed
 198          * @param string $sourceType The type of upload that generated this file
 199          *   (currently, I believe, 'file' or null)
 200          * @throws UploadStashBadPathException
 201          * @throws UploadStashFileException
 202          * @throws UploadStashNotLoggedInException
 203          * @return UploadStashFile|null File, or null on failure
 204          */
 205         public function stashFile( $path, $sourceType = null ) {
 206                 if ( !is_file( $path ) ) {
 207                         wfDebug( __METHOD__ . " tried to stash file at '$path', but it doesn't exist\n" );
 208                         throw new UploadStashBadPathException( "path doesn't exist" );
 209                 }
 210
 211                 $mwProps = new MWFileProps( MimeMagic::singleton() );
 212                 $fileProps = $mwProps->getPropsFromPath( $path, true );
 213                 wfDebug( __METHOD__ . " stashing file at '$path'\n" );
 214
 215                 // we will be initializing from some tmpnam files that don't have extensions.
 216                 // most of MediaWiki assumes all uploaded files have good extensions. So, we fix this.
 217                 $extension = self::getExtensionForPath( $path );
 218                 if ( !preg_match( "/\\.\\Q$extension\\E$/", $path ) ) {
 219                         $pathWithGoodExtension = "$path.$extension";
 220                 } else {
 221                         $pathWithGoodExtension = $path;
 222                 }
 223
 224                 // If no key was supplied, make one.  a mysql insertid would be totally
 225                 // reasonable here, except that for historical reasons, the key is this
 226                 // random thing instead.  At least it's not guessable.
 227                 // Some things that when combined will make a suitably unique key.
 228                 // see: http://www.jwz.org/doc/mid.html
 229                 list( $usec, $sec ) = explode( ' ', microtime() );
 230                 $usec = substr( $usec, 2 );
 231                 $key = Wikimedia\base_convert( $sec . $usec, 10, 36 ) . '.' .
 232                         Wikimedia\base_convert( mt_rand(), 10, 36 ) . '.' .
 233                         $this->userId . '.' .
 234                         $extension;
 235
 236                 $this->fileProps[$key] = $fileProps;
 237
 238                 if ( !preg_match( self::KEY_FORMAT_REGEX, $key ) ) {
 239                         throw new UploadStashBadPathException( "key '$key' is not in a proper format" );
 240                 }
 241
 242                 wfDebug( __METHOD__ . " key for '$path': $key\n" );
 243
 244                 // if not already in a temporary area, put it there
 245                 $storeStatus = $this->repo->storeTemp( basename( $pathWithGoodExtension ), $path );
 246
 247                 if ( !$storeStatus->isOK() ) {
 248                         // It is a convention in MediaWiki to only return one error per API
 249                         // exception, even if multiple errors are available. We use reset()
 250                         // to pick the "first" thing that was wrong, preferring errors to
 251                         // warnings. This is a bit lame, as we may have more info in the
 252                         // $storeStatus and we're throwing it away, but to fix it means
 253                         // redesigning API errors significantly.
 254                         // $storeStatus->value just contains the virtual URL (if anything)
 255                         // which is probably useless to the caller.
 256                         $error = $storeStatus->getErrorsArray();
 257                         $error = reset( $error );
 258                         if ( !count( $error ) ) {
 259                                 $error = $storeStatus->getWarningsArray();
 260                                 $error = reset( $error );
 261                                 if ( !count( $error ) ) {
 262                                         $error = [ 'unknown', 'no error recorded' ];
 263                                 }
 264                         }
 265                         // At this point, $error should contain the single "most important"
 266                         // error, plus any parameters.
 267                         $errorMsg = array_shift( $error );
 268                         throw new UploadStashFileException( "Error storing file in '$path': "
 269                                 . wfMessage( $errorMsg, $error )->text() );
 270                 }
 271                 $stashPath = $storeStatus->value;
 272
 273                 // fetch the current user ID
 274                 if ( !$this->isLoggedIn ) {
 275                         throw new UploadStashNotLoggedInException( __METHOD__
 276                                 . ' No user is logged in, files must belong to users' );
 277                 }
 278
 279                 // insert the file metadata into the db.
 280                 wfDebug( __METHOD__ . " inserting $stashPath under $key\n" );
 281                 $dbw = $this->repo->getMasterDB();
 282
 283                 $serializedFileProps = serialize( $fileProps );
 284                 if ( strlen( $serializedFileProps ) > self::MAX_US_PROPS_SIZE ) {
 285                         // Database is going to truncate this and make the field invalid.
 286                         // Prioritize important metadata over file handler metadata.
 287                         // File handler should be prepared to regenerate invalid metadata if needed.
 288                         $fileProps['metadata'] = false;
 289                         $serializedFileProps = serialize( $fileProps );
 290                 }
 291
 292                 $this->fileMetadata[$key] = [
 293                         'us_id' => $dbw->nextSequenceValue( 'uploadstash_us_id_seq' ),
 294                         'us_user' => $this->userId,
 295                         'us_key' => $key,
 296                         'us_orig_path' => $path,
 297                         'us_path' => $stashPath, // virtual URL
 298                         'us_props' => $dbw->encodeBlob( $serializedFileProps ),
 299                         'us_size' => $fileProps['size'],
 300                         'us_sha1' => $fileProps['sha1'],
 301                         'us_mime' => $fileProps['mime'],
 302                         'us_media_type' => $fileProps['media_type'],
 303                         'us_image_width' => $fileProps['width'],
 304                         'us_image_height' => $fileProps['height'],
 305                         'us_image_bits' => $fileProps['bits'],
 306                         'us_source_type' => $sourceType,
 307                         'us_timestamp' => $dbw->timestamp(),
 308                         'us_status' => 'finished'
 309                 ];
 310
 311                 $dbw->insert(
 312                         'uploadstash',
 313                         $this->fileMetadata[$key],
 314                         __METHOD__
 315                 );
 316
 317                 // store the insertid in the class variable so immediate retrieval
 318                 // (possibly laggy) isn't necesary.
 319                 $this->fileMetadata[$key]['us_id'] = $dbw->insertId();
 320
 321                 # create the UploadStashFile object for this file.
 322                 $this->initFile( $key );
 323
 324                 return $this->getFile( $key );
 325         }
 326
 327         /**
 328          * Remove all files from the stash.
 329          * Does not clean up files in the repo, just the record of them.
 330          *
 331          * @throws UploadStashNotLoggedInException
 332          * @return bool Success
 333          */
 334         public function clear() {
 335                 if ( !$this->isLoggedIn ) {
 336                         throw new UploadStashNotLoggedInException( __METHOD__
 337                                 . ' No user is logged in, files must belong to users' );
 338                 }
 339
 340                 wfDebug( __METHOD__ . ' clearing all rows for user ' . $this->userId . "\n" );
 341                 $dbw = $this->repo->getMasterDB();
 342                 $dbw->delete(
 343                         'uploadstash',
 344                         [ 'us_user' => $this->userId ],
 345                         __METHOD__
 346                 );
 347
 348                 # destroy objects.
 349                 $this->files = [];
 350                 $this->fileMetadata = [];
 351
 352                 return true;
 353         }
 354
 355         /**
 356          * Remove a particular file from the stash.  Also removes it from the repo.
 357          *
 358          * @param string $key
 359          * @throws UploadStashNoSuchKeyException|UploadStashNotLoggedInException
 360          * @throws UploadStashWrongOwnerException
 361          * @return bool Success
 362          */
 363         public function removeFile( $key ) {
 364                 if ( !$this->isLoggedIn ) {
 365                         throw new UploadStashNotLoggedInException( __METHOD__
 366                                 . ' No user is logged in, files must belong to users' );
 367                 }
 368
 369                 $dbw = $this->repo->getMasterDB();
 370
 371                 // this is a cheap query. it runs on the master so that this function
 372                 // still works when there's lag. It won't be called all that often.
 373                 $row = $dbw->selectRow(
 374                         'uploadstash',
 375                         'us_user',
 376                         [ 'us_key' => $key ],
 377                         __METHOD__
 378                 );
 379
 380                 if ( !$row ) {
 381                         throw new UploadStashNoSuchKeyException( "No such key ($key), cannot remove" );
 382                 }
 383
 384                 if ( $row->us_user != $this->userId ) {
 385                         throw new UploadStashWrongOwnerException( "Can't delete: "
 386                                 . "the file ($key) doesn't belong to this user." );
 387                 }
 388
 389                 return $this->removeFileNoAuth( $key );
 390         }
 391
 392         /**
 393          * Remove a file (see removeFile), but doesn't check ownership first.
 394          *
 395          * @param string $key
 396          * @return bool Success
 397          */
 398         public function removeFileNoAuth( $key ) {
 399                 wfDebug( __METHOD__ . " clearing row $key\n" );
 400
 401                 // Ensure we have the UploadStashFile loaded for this key
 402                 $this->getFile( $key, true );
 403
 404                 $dbw = $this->repo->getMasterDB();
 405
 406                 $dbw->delete(
 407                         'uploadstash',
 408                         [ 'us_key' => $key ],
 409                         __METHOD__
 410                 );
 411
 412                 /** @todo Look into UnregisteredLocalFile and find out why the rv here is
 413                  *  sometimes wrong (false when file was removed). For now, ignore.
 414                  */
 415                 $this->files[$key]->remove();
 416
 417                 unset( $this->files[$key] );
 418                 unset( $this->fileMetadata[$key] );
 419
 420                 return true;
 421         }
 422
 423         /**
 424          * List all files in the stash.
 425          *
 426          * @throws UploadStashNotLoggedInException
 427          * @return array
 428          */
 429         public function listFiles() {
 430                 if ( !$this->isLoggedIn ) {
 431                         throw new UploadStashNotLoggedInException( __METHOD__
 432                                 . ' No user is logged in, files must belong to users' );
 433                 }
 434
 435                 $dbr = $this->repo->getSlaveDB();
 436                 $res = $dbr->select(
 437                         'uploadstash',
 438                         'us_key',
 439                         [ 'us_user' => $this->userId ],
 440                         __METHOD__
 441                 );
 442
 443                 if ( !is_object( $res ) || $res->numRows() == 0 ) {
 444                         // nothing to do.
 445                         return false;
 446                 }
 447
 448                 // finish the read before starting writes.
 449                 $keys = [];
 450                 foreach ( $res as $row ) {
 451                         array_push( $keys, $row->us_key );
 452                 }
 453
 454                 return $keys;
 455         }
 456
 457         /**
 458          * Find or guess extension -- ensuring that our extension matches our MIME type.
 459          * Since these files are constructed from php tempnames they may not start off
 460          * with an extension.
 461          * XXX this is somewhat redundant with the checks that ApiUpload.php does with incoming
 462          * uploads versus the desired filename. Maybe we can get that passed to us...
 463          * @param string $path
 464          * @throws UploadStashFileException
 465          * @return string
 466          */
 467         public static function getExtensionForPath( $path ) {
 468                 global $wgFileBlacklist;
 469                 // Does this have an extension?
 470                 $n = strrpos( $path, '.' );
 471                 $extension = null;
 472                 if ( $n !== false ) {
 473                         $extension = $n ? substr( $path, $n + 1 ) : '';
 474                 } else {
 475                         // If not, assume that it should be related to the MIME type of the original file.
 476                         $magic = MimeMagic::singleton();
 477                         $mimeType = $magic->guessMimeType( $path );
 478                         $extensions = explode( ' ', MimeMagic::singleton()->getExtensionsForType( $mimeType ) );
 479                         if ( count( $extensions ) ) {
 480                                 $extension = $extensions[0];
 481                         }
 482                 }
 483
 484                 if ( is_null( $extension ) ) {
 485                         throw new UploadStashFileException( "extension is null" );
 486                 }
 487
 488                 $extension = File::normalizeExtension( $extension );
 489                 if ( in_array( $extension, $wgFileBlacklist ) ) {
 490                         // The file should already be checked for being evil.
 491                         // However, if somehow we got here, we definitely
 492                         // don't want to give it an extension of .php and
 493                         // put it in a web accesible directory.
 494                         return '';
 495                 }
 496
 497                 return $extension;
 498         }
 499
 500         /**
 501          * Helper function: do the actual database query to fetch file metadata.
 502          *
 503          * @param string $key
 504          * @param int $readFromDB Constant (default: DB_REPLICA)
 505          * @return bool
 506          */
 507         protected function fetchFileMetadata( $key, $readFromDB = DB_REPLICA ) {
 508                 // populate $fileMetadata[$key]
 509                 $dbr = null;
 510                 if ( $readFromDB === DB_MASTER ) {
 511                         // sometimes reading from the master is necessary, if there's replication lag.
 512                         $dbr = $this->repo->getMasterDB();
 513                 } else {
 514                         $dbr = $this->repo->getSlaveDB();
 515                 }
 516
 517                 $row = $dbr->selectRow(
 518                         'uploadstash',
 519                         '*',
 520                         [ 'us_key' => $key ],
 521                         __METHOD__
 522                 );
 523
 524                 if ( !is_object( $row ) ) {
 525                         // key wasn't present in the database. this will happen sometimes.
 526                         return false;
 527                 }
 528
 529                 $this->fileMetadata[$key] = (array)$row;
 530                 $this->fileMetadata[$key]['us_props'] = $dbr->decodeBlob( $row->us_props );
 531
 532                 return true;
 533         }
 534
 535         /**
 536          * Helper function: Initialize the UploadStashFile for a given file.
 537          *
 538          * @param string $key Key under which to store the object
 539          * @throws UploadStashZeroLengthFileException
 540          * @return bool
 541          */
 542         protected function initFile( $key ) {
 543                 $file = new UploadStashFile( $this->repo, $this->fileMetadata[$key]['us_path'], $key );
 544                 if ( $file->getSize() === 0 ) {
 545                         throw new UploadStashZeroLengthFileException( "File is zero length" );
 546                 }
 547                 $this->files[$key] = $file;
 548
 549                 return true;
 550         }
 551 }
 552
 553 class UploadStashFile extends UnregisteredLocalFile {
 554         private $fileKey;
 555         private $urlName;
 556         protected $url;
 557
 558         /**
 559          * A LocalFile wrapper around a file that has been temporarily stashed,
 560          * so we can do things like create thumbnails for it. Arguably
 561          * UnregisteredLocalFile should be handling its own file repo but that
 562          * class is a bit retarded currently.
 563          *
 564          * @param FileRepo $repo Repository where we should find the path
 565          * @param string $path Path to file
 566          * @param string $key Key to store the path and any stashed data under
 567          * @throws UploadStashBadPathException
 568          * @throws UploadStashFileNotFoundException
 569          */
 570         public function __construct( $repo, $path, $key ) {
 571                 $this->fileKey = $key;
 572
 573                 // resolve mwrepo:// urls
 574                 if ( $repo->isVirtualUrl( $path ) ) {
 575                         $path = $repo->resolveVirtualUrl( $path );
 576                 } else {
 577                         // check if path appears to be sane, no parent traversals,
 578                         // and is in this repo's temp zone.
 579                         $repoTempPath = $repo->getZonePath( 'temp' );
 580                         if ( ( !$repo->validateFilename( $path ) ) ||
 581                                 ( strpos( $path, $repoTempPath ) !== 0 )
 582                         ) {
 583                                 wfDebug( "UploadStash: tried to construct an UploadStashFile "
 584                                         . "from a file that should already exist at '$path', but path is not valid\n" );
 585                                 throw new UploadStashBadPathException( 'path is not valid' );
 586                         }
 587
 588                         // check if path exists! and is a plain file.
 589                         if ( !$repo->fileExists( $path ) ) {
 590                                 wfDebug( "UploadStash: tried to construct an UploadStashFile from "
 591                                         . "a file that should already exist at '$path', but path is not found\n" );
 592                                 throw new UploadStashFileNotFoundException( 'cannot find path, or not a plain file' );
 593                         }
 594                 }
 595
 596                 parent::__construct( false, $repo, $path, false );
 597
 598                 $this->name = basename( $this->path );
 599         }
 600
 601         /**
 602          * A method needed by the file transforming and scaling routines in File.php
 603          * We do not necessarily care about doing the description at this point
 604          * However, we also can't return the empty string, as the rest of MediaWiki
 605          * demands this (and calls to imagemagick convert require it to be there)
 606          *
 607          * @return string Dummy value
 608          */
 609         public function getDescriptionUrl() {
 610                 return $this->getUrl();
 611         }
 612
 613         /**
 614          * Get the path for the thumbnail (actually any transformation of this file)
 615          * The actual argument is the result of thumbName although we seem to have
 616          * buggy code elsewhere that expects a boolean 'suffix'
 617          *
 618          * @param string $thumbName Name of thumbnail (e.g. "120px-123456.jpg" ),
 619          *   or false to just get the path
 620          * @return string Path thumbnail should take on filesystem, or containing
 621          *   directory if thumbname is false
 622          */
 623         public function getThumbPath( $thumbName = false ) {
 624                 $path = dirname( $this->path );
 625                 if ( $thumbName !== false ) {
 626                         $path .= "/$thumbName";
 627                 }
 628
 629                 return $path;
 630         }
 631
 632         /**
 633          * Return the file/url base name of a thumbnail with the specified parameters.
 634          * We override this because we want to use the pretty url name instead of the
 635          * ugly file name.
 636          *
 637          * @param array $params Handler-specific parameters
 638          * @param int $flags Bitfield that supports THUMB_* constants
 639          * @return string|null Base name for URL, like '120px-12345.jpg', or null if there is no handler
 640          */
 641         function thumbName( $params, $flags = 0 ) {
 642                 return $this->generateThumbName( $this->getUrlName(), $params );
 643         }
 644
 645         /**
 646          * Helper function -- given a 'subpage', return the local URL,
 647          * e.g. /wiki/Special:UploadStash/subpage
 648          * @param string $subPage
 649          * @return string Local URL for this subpage in the Special:UploadStash space.
 650          */
 651         private function getSpecialUrl( $subPage ) {
 652                 return SpecialPage::getTitleFor( 'UploadStash', $subPage )->getLocalURL();
 653         }
 654
 655         /**
 656          * Get a URL to access the thumbnail
 657          * This is required because the model of how files work requires that
 658          * the thumbnail urls be predictable. However, in our model the URL is
 659          * not based on the filename (that's hidden in the db)
 660          *
 661          * @param string $thumbName Basename of thumbnail file -- however, we don't
 662          *   want to use the file exactly
 663          * @return string URL to access thumbnail, or URL with partial path
 664          */
 665         public function getThumbUrl( $thumbName = false ) {
 666                 wfDebug( __METHOD__ . " getting for $thumbName \n" );
 667
 668                 return $this->getSpecialUrl( 'thumb/' . $this->getUrlName() . '/' . $thumbName );
 669         }
 670
 671         /**
 672          * The basename for the URL, which we want to not be related to the filename.
 673          * Will also be used as the lookup key for a thumbnail file.
 674          *
 675          * @return string Base url name, like '120px-123456.jpg'
 676          */
 677         public function getUrlName() {
 678                 if ( !$this->urlName ) {
 679                         $this->urlName = $this->fileKey;
 680                 }
 681
 682                 return $this->urlName;
 683         }
 684
 685         /**
 686          * Return the URL of the file, if for some reason we wanted to download it
 687          * We tend not to do this for the original file, but we do want thumb icons
 688          *
 689          * @return string Url
 690          */
 691         public function getUrl() {
 692                 if ( !isset( $this->url ) ) {
 693                         $this->url = $this->getSpecialUrl( 'file/' . $this->getUrlName() );
 694                 }
 695
 696                 return $this->url;
 697         }
 698
 699         /**
 700          * Parent classes use this method, for no obvious reason, to return the path
 701          * (relative to wiki root, I assume). But with this class, the URL is
 702          * unrelated to the path.
 703          *
 704          * @return string Url
 705          */
 706         public function getFullUrl() {
 707                 return $this->getUrl();
 708         }
 709
 710         /**
 711          * Getter for file key (the unique id by which this file's location &
 712          * metadata is stored in the db)
 713          *
 714          * @return string File key
 715          */
 716         public function getFileKey() {
 717                 return $this->fileKey;
 718         }
 719
 720         /**
 721          * Remove the associated temporary file
 722          * @return status Success
 723          */
 724         public function remove() {
 725                 if ( !$this->repo->fileExists( $this->path ) ) {
 726                         // Maybe the file's already been removed? This could totally happen in UploadBase.
 727                         return true;
 728                 }
 729
 730                 return $this->repo->freeTemp( $this->path );
 731         }
 732
 733         public function exists() {
 734                 return $this->repo->fileExists( $this->path );
 735         }
 736 }
 737
 738 class UploadStashException extends MWException {
 739 }
 740
 741 class UploadStashFileNotFoundException extends UploadStashException {
 742 }
 743
 744 class UploadStashBadPathException extends UploadStashException {
 745 }
 746
 747 class UploadStashFileException extends UploadStashException {
 748 }
 749
 750 class UploadStashZeroLengthFileException extends UploadStashException {
 751 }
 752
 753 class UploadStashNotLoggedInException extends UploadStashException {
 754 }
 755
 756 class UploadStashWrongOwnerException extends UploadStashException {
 757 }
 758
 759 class UploadStashNoSuchKeyException extends UploadStashException {
 760 }