includes/filerepo/file/File.php

   1 <?php
   2 /**
   3  * @defgroup FileAbstraction File abstraction
   4  * @ingroup FileRepo
   5  *
   6  * Represents files in a repository.
   7  */
   8 use Wikimedia\AtEase\AtEase;
   9 use MediaWiki\MediaWikiServices;
  10
  11 /**
  12  * Base code for files.
  13  *
  14  * This program is free software; you can redistribute it and/or modify
  15  * it under the terms of the GNU General Public License as published by
  16  * the Free Software Foundation; either version 2 of the License, or
  17  * (at your option) any later version.
  18  *
  19  * This program is distributed in the hope that it will be useful,
  20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  22  * GNU General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU General Public License along
  25  * with this program; if not, write to the Free Software Foundation, Inc.,
  26  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  27  * http://www.gnu.org/copyleft/gpl.html
  28  *
  29  * @file
  30  * @ingroup FileAbstraction
  31  */
  32
  33 // @phan-file-suppress PhanTypeMissingReturn false positives
  34 /**
  35  * Implements some public methods and some protected utility functions which
  36  * are required by multiple child classes. Contains stub functionality for
  37  * unimplemented public methods.
  38  *
  39  * Stub functions which should be overridden are marked with STUB. Some more
  40  * concrete functions are also typically overridden by child classes.
  41  *
  42  * Note that only the repo object knows what its file class is called. You should
  43  * never name a file class explictly outside of the repo class. Instead use the
  44  * repo's factory functions to generate file objects, for example:
  45  *
  46  * RepoGroup::singleton()->getLocalRepo()->newFile( $title );
  47  *
  48  * Consider the services container below;
  49  *
  50  * $services = MediaWikiServices::getInstance();
  51  *
  52  * The convenience services $services->getRepoGroup()->getLocalRepo()->newFile()
  53  * and $services->getRepoGroup()->findFile() should be sufficient in most cases.
  54  *
  55  * @TODO: DI - Instead of using MediaWikiServices::getInstance(), a service should
  56  * ideally accept a RepoGroup in its constructor and then, use $this->repoGroup->findFile()
  57  * and $this->repoGroup->getLocalRepo()->newFile().
  58  *
  59  * @ingroup FileAbstraction
  60  */
  61 abstract class File implements IDBAccessObject {
  62         // Bitfield values akin to the Revision deletion constants
  63         const DELETED_FILE = 1;
  64         const DELETED_COMMENT = 2;
  65         const DELETED_USER = 4;
  66         const DELETED_RESTRICTED = 8;
  67
  68         /** Force rendering in the current process */
  69         const RENDER_NOW = 1;
  70         /**
  71          * Force rendering even if thumbnail already exist and using RENDER_NOW
  72          * I.e. you have to pass both flags: File::RENDER_NOW | File::RENDER_FORCE
  73          */
  74         const RENDER_FORCE = 2;
  75
  76         const DELETE_SOURCE = 1;
  77
  78         // Audience options for File::getDescription()
  79         const FOR_PUBLIC = 1;
  80         const FOR_THIS_USER = 2;
  81         const RAW = 3;
  82
  83         // Options for File::thumbName()
  84         const THUMB_FULL_NAME = 1;
  85
  86         /**
  87          * Some member variables can be lazy-initialised using __get(). The
  88          * initialisation function for these variables is always a function named
  89          * like getVar(), where Var is the variable name with upper-case first
  90          * letter.
  91          *
  92          * The following variables are initialised in this way in this base class:
  93          *    name, extension, handler, path, canRender, isSafeFile,
  94          *    transformScript, hashPath, pageCount, url
  95          *
  96          * Code within this class should generally use the accessor function
  97          * directly, since __get() isn't re-entrant and therefore causes bugs that
  98          * depend on initialisation order.
  99          */
 100
 101         /**
 102          * The following member variables are not lazy-initialised
 103          */
 104
 105         /** @var FileRepo|LocalRepo|ForeignAPIRepo|bool */
 106         public $repo;
 107
 108         /** @var Title|string|bool */
 109         protected $title;
 110
 111         /** @var string Text of last error */
 112         protected $lastError;
 113
 114         /** @var string Main part of the title, with underscores (Title::getDBkey) */
 115         protected $redirected;
 116
 117         /** @var Title */
 118         protected $redirectedTitle;
 119
 120         /** @var FSFile|bool False if undefined */
 121         protected $fsFile;
 122
 123         /** @var MediaHandler */
 124         protected $handler;
 125
 126         /** @var string The URL corresponding to one of the four basic zones */
 127         protected $url;
 128
 129         /** @var string File extension */
 130         protected $extension;
 131
 132         /** @var string The name of a file from its title object */
 133         protected $name;
 134
 135         /** @var string The storage path corresponding to one of the zones */
 136         protected $path;
 137
 138         /** @var string Relative path including trailing slash */
 139         protected $hashPath;
 140
 141         /** @var string|false Number of pages of a multipage document, or false for
 142          *    documents which aren't multipage documents
 143          */
 144         protected $pageCount;
 145
 146         /** @var string URL of transformscript (for example thumb.php) */
 147         protected $transformScript;
 148
 149         /** @var Title */
 150         protected $redirectTitle;
 151
 152         /** @var bool Whether the output of transform() for this file is likely to be valid. */
 153         protected $canRender;
 154
 155         /** @var bool Whether this media file is in a format that is unlikely to
 156          *    contain viruses or malicious content
 157          */
 158         protected $isSafeFile;
 159
 160         /** @var string Required Repository class type */
 161         protected $repoClass = FileRepo::class;
 162
 163         /** @var array Cache of tmp filepaths pointing to generated bucket thumbnails, keyed by width */
 164         protected $tmpBucketedThumbCache = [];
 165
 166         /**
 167          * Call this constructor from child classes.
 168          *
 169          * Both $title and $repo are optional, though some functions
 170          * may return false or throw exceptions if they are not set.
 171          * Most subclasses will want to call assertRepoDefined() here.
 172          *
 173          * @param Title|string|bool $title
 174          * @param FileRepo|bool $repo
 175          */
 176         function __construct( $title, $repo ) {
 177                 // Some subclasses do not use $title, but set name/title some other way
 178                 if ( $title !== false ) {
 179                         $title = self::normalizeTitle( $title, 'exception' );
 180                 }
 181                 $this->title = $title;
 182                 $this->repo = $repo;
 183         }
 184
 185         /**
 186          * Given a string or Title object return either a
 187          * valid Title object with namespace NS_FILE or null
 188          *
 189          * @param Title|string $title
 190          * @param string|bool $exception Use 'exception' to throw an error on bad titles
 191          * @throws MWException
 192          * @return Title|null
 193          */
 194         static function normalizeTitle( $title, $exception = false ) {
 195                 $ret = $title;
 196                 if ( $ret instanceof Title ) {
 197                         # Normalize NS_MEDIA -> NS_FILE
 198                         if ( $ret->getNamespace() == NS_MEDIA ) {
 199                                 $ret = Title::makeTitleSafe( NS_FILE, $ret->getDBkey() );
 200                         # Sanity check the title namespace
 201                         } elseif ( $ret->getNamespace() !== NS_FILE ) {
 202                                 $ret = null;
 203                         }
 204                 } else {
 205                         # Convert strings to Title objects
 206                         $ret = Title::makeTitleSafe( NS_FILE, (string)$ret );
 207                 }
 208                 if ( !$ret && $exception !== false ) {
 209                         throw new MWException( "`$title` is not a valid file title." );
 210                 }
 211
 212                 return $ret;
 213         }
 214
 215         function __get( $name ) {
 216                 $function = [ $this, 'get' . ucfirst( $name ) ];
 217                 if ( !is_callable( $function ) ) {
 218                         return null;
 219                 } else {
 220                         $this->$name = $function();
 221
 222                         return $this->$name;
 223                 }
 224         }
 225
 226         /**
 227          * Normalize a file extension to the common form, making it lowercase and checking some synonyms,
 228          * and ensure it's clean. Extensions with non-alphanumeric characters will be discarded.
 229          * Keep in sync with mw.Title.normalizeExtension() in JS.
 230          *
 231          * @param string $extension File extension (without the leading dot)
 232          * @return string File extension in canonical form
 233          */
 234         static function normalizeExtension( $extension ) {
 235                 $lower = strtolower( $extension );
 236                 $squish = [
 237                         'htm' => 'html',
 238                         'jpeg' => 'jpg',
 239                         'mpeg' => 'mpg',
 240                         'tiff' => 'tif',
 241                         'ogv' => 'ogg' ];
 242                 if ( isset( $squish[$lower] ) ) {
 243                         return $squish[$lower];
 244                 } elseif ( preg_match( '/^[0-9a-z]+$/', $lower ) ) {
 245                         return $lower;
 246                 } else {
 247                         return '';
 248                 }
 249         }
 250
 251         /**
 252          * Checks if file extensions are compatible
 253          *
 254          * @param File $old Old file
 255          * @param string $new New name
 256          *
 257          * @return bool|null
 258          */
 259         static function checkExtensionCompatibility( File $old, $new ) {
 260                 $oldMime = $old->getMimeType();
 261                 $n = strrpos( $new, '.' );
 262                 $newExt = self::normalizeExtension( $n ? substr( $new, $n + 1 ) : '' );
 263                 $mimeMagic = MediaWiki\MediaWikiServices::getInstance()->getMimeAnalyzer();
 264
 265                 return $mimeMagic->isMatchingExtension( $newExt, $oldMime );
 266         }
 267
 268         /**
 269          * Upgrade the database row if there is one
 270          * Called by ImagePage
 271          * STUB
 272          */
 273         function upgradeRow() {
 274         }
 275
 276         /**
 277          * Split an internet media type into its two components; if not
 278          * a two-part name, set the minor type to 'unknown'.
 279          *
 280          * @param string $mime "text/html" etc
 281          * @return string[] ("text", "html") etc
 282          */
 283         public static function splitMime( $mime ) {
 284                 if ( strpos( $mime, '/' ) !== false ) {
 285                         return explode( '/', $mime, 2 );
 286                 } else {
 287                         return [ $mime, 'unknown' ];
 288                 }
 289         }
 290
 291         /**
 292          * Callback for usort() to do file sorts by name
 293          *
 294          * @param File $a
 295          * @param File $b
 296          * @return int Result of name comparison
 297          */
 298         public static function compare( File $a, File $b ) {
 299                 return strcmp( $a->getName(), $b->getName() );
 300         }
 301
 302         /**
 303          * Return the name of this file
 304          *
 305          * @return string
 306          */
 307         public function getName() {
 308                 if ( $this->name === null ) {
 309                         $this->assertRepoDefined();
 310                         $this->name = $this->repo->getNameFromTitle( $this->title );
 311                 }
 312
 313                 return $this->name;
 314         }
 315
 316         /**
 317          * Get the file extension, e.g. "svg"
 318          *
 319          * @return string
 320          */
 321         function getExtension() {
 322                 if ( !isset( $this->extension ) ) {
 323                         $n = strrpos( $this->getName(), '.' );
 324                         $this->extension = self::normalizeExtension(
 325                                 $n ? substr( $this->getName(), $n + 1 ) : '' );
 326                 }
 327
 328                 return $this->extension;
 329         }
 330
 331         /**
 332          * Return the associated title object
 333          *
 334          * @return Title
 335          */
 336         public function getTitle() {
 337                 return $this->title;
 338         }
 339
 340         /**
 341          * Return the title used to find this file
 342          *
 343          * @return Title
 344          */
 345         public function getOriginalTitle() {
 346                 if ( $this->redirected ) {
 347                         return $this->getRedirectedTitle();
 348                 }
 349
 350                 return $this->title;
 351         }
 352
 353         /**
 354          * Return the URL of the file
 355          *
 356          * @return string
 357          */
 358         public function getUrl() {
 359                 if ( !isset( $this->url ) ) {
 360                         $this->assertRepoDefined();
 361                         $ext = $this->getExtension();
 362                         $this->url = $this->repo->getZoneUrl( 'public', $ext ) . '/' . $this->getUrlRel();
 363                 }
 364
 365                 return $this->url;
 366         }
 367
 368         /**
 369          * Get short description URL for a files based on the page ID
 370          *
 371          * @return string|null
 372          * @since 1.27
 373          */
 374         public function getDescriptionShortUrl() {
 375                 return null;
 376         }
 377
 378         /**
 379          * Return a fully-qualified URL to the file.
 380          * Upload URL paths _may or may not_ be fully qualified, so
 381          * we check. Local paths are assumed to belong on $wgServer.
 382          *
 383          * @return string
 384          */
 385         public function getFullUrl() {
 386                 return wfExpandUrl( $this->getUrl(), PROTO_RELATIVE );
 387         }
 388
 389         /**
 390          * @return string
 391          */
 392         public function getCanonicalUrl() {
 393                 return wfExpandUrl( $this->getUrl(), PROTO_CANONICAL );
 394         }
 395
 396         /**
 397          * @return string
 398          */
 399         function getViewURL() {
 400                 if ( $this->mustRender() ) {
 401                         if ( $this->canRender() ) {
 402                                 return $this->createThumb( $this->getWidth() );
 403                         } else {
 404                                 wfDebug( __METHOD__ . ': supposed to render ' . $this->getName() .
 405                                         ' (' . $this->getMimeType() . "), but can't!\n" );
 406
 407                                 return $this->getUrl(); # hm... return NULL?
 408                         }
 409                 } else {
 410                         return $this->getUrl();
 411                 }
 412         }
 413
 414         /**
 415          * Return the storage path to the file. Note that this does
 416          * not mean that a file actually exists under that location.
 417          *
 418          * This path depends on whether directory hashing is active or not,
 419          * i.e. whether the files are all found in the same directory,
 420          * or in hashed paths like /images/3/3c.
 421          *
 422          * Most callers don't check the return value, but ForeignAPIFile::getPath
 423          * returns false.
 424          *
 425          * @return string|bool ForeignAPIFile::getPath can return false
 426          */
 427         public function getPath() {
 428                 if ( !isset( $this->path ) ) {
 429                         $this->assertRepoDefined();
 430                         $this->path = $this->repo->getZonePath( 'public' ) . '/' . $this->getRel();
 431                 }
 432
 433                 return $this->path;
 434         }
 435
 436         /**
 437          * Get an FS copy or original of this file and return the path.
 438          * Returns false on failure. Callers must not alter the file.
 439          * Temporary files are cleared automatically.
 440          *
 441          * @return string|bool False on failure
 442          */
 443         public function getLocalRefPath() {
 444                 $this->assertRepoDefined();
 445                 if ( !isset( $this->fsFile ) ) {
 446                         $starttime = microtime( true );
 447                         $this->fsFile = $this->repo->getLocalReference( $this->getPath() );
 448
 449                         $statTiming = microtime( true ) - $starttime;
 450                         MediaWikiServices::getInstance()->getStatsdDataFactory()->timing(
 451                                 'media.thumbnail.generate.fetchoriginal', 1000 * $statTiming );
 452
 453                         if ( !$this->fsFile ) {
 454                                 $this->fsFile = false; // null => false; cache negative hits
 455                         }
 456                 }
 457
 458                 return ( $this->fsFile )
 459                         ? $this->fsFile->getPath()
 460                         : false;
 461         }
 462
 463         /**
 464          * Return the width of the image. Returns false if the width is unknown
 465          * or undefined.
 466          *
 467          * STUB
 468          * Overridden by LocalFile, UnregisteredLocalFile
 469          *
 470          * @param int $page
 471          * @return int|bool
 472          */
 473         public function getWidth( $page = 1 ) {
 474                 return false;
 475         }
 476
 477         /**
 478          * Return the height of the image. Returns false if the height is unknown
 479          * or undefined
 480          *
 481          * STUB
 482          * Overridden by LocalFile, UnregisteredLocalFile
 483          *
 484          * @param int $page
 485          * @return bool|int False on failure
 486          */
 487         public function getHeight( $page = 1 ) {
 488                 return false;
 489         }
 490
 491         /**
 492          * Return the smallest bucket from $wgThumbnailBuckets which is at least
 493          * $wgThumbnailMinimumBucketDistance larger than $desiredWidth. The returned bucket, if any,
 494          * will always be bigger than $desiredWidth.
 495          *
 496          * @param int $desiredWidth
 497          * @param int $page
 498          * @return bool|int
 499          */
 500         public function getThumbnailBucket( $desiredWidth, $page = 1 ) {
 501                 global $wgThumbnailBuckets, $wgThumbnailMinimumBucketDistance;
 502
 503                 $imageWidth = $this->getWidth( $page );
 504
 505                 if ( $imageWidth === false ) {
 506                         return false;
 507                 }
 508
 509                 if ( $desiredWidth > $imageWidth ) {
 510                         return false;
 511                 }
 512
 513                 if ( !$wgThumbnailBuckets ) {
 514                         return false;
 515                 }
 516
 517                 $sortedBuckets = $wgThumbnailBuckets;
 518
 519                 sort( $sortedBuckets );
 520
 521                 foreach ( $sortedBuckets as $bucket ) {
 522                         if ( $bucket >= $imageWidth ) {
 523                                 return false;
 524                         }
 525
 526                         if ( $bucket - $wgThumbnailMinimumBucketDistance > $desiredWidth ) {
 527                                 return $bucket;
 528                         }
 529                 }
 530
 531                 // Image is bigger than any available bucket
 532                 return false;
 533         }
 534
 535         /**
 536          * Returns ID or name of user who uploaded the file
 537          * STUB
 538          *
 539          * @param string $type 'text' or 'id'
 540          * @return string|int
 541          */
 542         public function getUser( $type = 'text' ) {
 543                 return null;
 544         }
 545
 546         /**
 547          * Get the duration of a media file in seconds
 548          *
 549          * @return float|int
 550          */
 551         public function getLength() {
 552                 $handler = $this->getHandler();
 553                 if ( $handler ) {
 554                         return $handler->getLength( $this );
 555                 } else {
 556                         return 0;
 557                 }
 558         }
 559
 560         /**
 561          * Return true if the file is vectorized
 562          *
 563          * @return bool
 564          */
 565         public function isVectorized() {
 566                 $handler = $this->getHandler();
 567                 if ( $handler ) {
 568                         return $handler->isVectorized( $this );
 569                 } else {
 570                         return false;
 571                 }
 572         }
 573
 574         /**
 575          * Gives a (possibly empty) list of languages to render
 576          * the file in.
 577          *
 578          * If the file doesn't have translations, or if the file
 579          * format does not support that sort of thing, returns
 580          * an empty array.
 581          *
 582          * @return string[]
 583          * @since 1.23
 584          */
 585         public function getAvailableLanguages() {
 586                 $handler = $this->getHandler();
 587                 if ( $handler ) {
 588                         return $handler->getAvailableLanguages( $this );
 589                 } else {
 590                         return [];
 591                 }
 592         }
 593
 594         /**
 595          * Get the language code from the available languages for this file that matches the language
 596          * requested by the user
 597          *
 598          * @param string $userPreferredLanguage
 599          * @return string|null
 600          */
 601         public function getMatchedLanguage( $userPreferredLanguage ) {
 602                 $handler = $this->getHandler();
 603                 if ( $handler ) {
 604                         return $handler->getMatchedLanguage(
 605                                 $userPreferredLanguage,
 606                                 $handler->getAvailableLanguages( $this )
 607                         );
 608                 }
 609
 610                 return null;
 611         }
 612
 613         /**
 614          * In files that support multiple language, what is the default language
 615          * to use if none specified.
 616          *
 617          * @return string|null Lang code, or null if filetype doesn't support multiple languages.
 618          * @since 1.23
 619          */
 620         public function getDefaultRenderLanguage() {
 621                 $handler = $this->getHandler();
 622                 if ( $handler ) {
 623                         return $handler->getDefaultRenderLanguage( $this );
 624                 } else {
 625                         return null;
 626                 }
 627         }
 628
 629         /**
 630          * Will the thumbnail be animated if one would expect it to be.
 631          *
 632          * Currently used to add a warning to the image description page
 633          *
 634          * @return bool False if the main image is both animated
 635          *   and the thumbnail is not. In all other cases must return
 636          *   true. If image is not renderable whatsoever, should
 637          *   return true.
 638          */
 639         public function canAnimateThumbIfAppropriate() {
 640                 $handler = $this->getHandler();
 641                 if ( !$handler ) {
 642                         // We cannot handle image whatsoever, thus
 643                         // one would not expect it to be animated
 644                         // so true.
 645                         return true;
 646                 }
 647
 648                 return !$this->allowInlineDisplay()
 649                         // Image is not animated, so one would
 650                         // not expect thumb to be
 651                         || !$handler->isAnimatedImage( $this )
 652                         // Image is animated, but thumbnail isn't.
 653                         // This is unexpected to the user.
 654                         || $handler->canAnimateThumbnail( $this );
 655         }
 656
 657         /**
 658          * Get handler-specific metadata
 659          * Overridden by LocalFile, UnregisteredLocalFile
 660          * STUB
 661          * @return bool|array
 662          */
 663         public function getMetadata() {
 664                 return false;
 665         }
 666
 667         /**
 668          * Like getMetadata but returns a handler independent array of common values.
 669          * @see MediaHandler::getCommonMetaArray()
 670          * @return array|bool Array or false if not supported
 671          * @since 1.23
 672          */
 673         public function getCommonMetaArray() {
 674                 $handler = $this->getHandler();
 675
 676                 if ( !$handler ) {
 677                         return false;
 678                 }
 679
 680                 return $handler->getCommonMetaArray( $this );
 681         }
 682
 683         /**
 684          * get versioned metadata
 685          *
 686          * @param array|string $metadata Array or string of (serialized) metadata
 687          * @param int $version Version number.
 688          * @return array Array containing metadata, or what was passed to it on fail
 689          *   (unserializing if not array)
 690          */
 691         public function convertMetadataVersion( $metadata, $version ) {
 692                 $handler = $this->getHandler();
 693                 if ( !is_array( $metadata ) ) {
 694                         // Just to make the return type consistent
 695                         $metadata = unserialize( $metadata );
 696                 }
 697                 if ( $handler ) {
 698                         return $handler->convertMetadataVersion( $metadata, $version );
 699                 } else {
 700                         return $metadata;
 701                 }
 702         }
 703
 704         /**
 705          * Return the bit depth of the file
 706          * Overridden by LocalFile
 707          * STUB
 708          * @return int
 709          */
 710         public function getBitDepth() {
 711                 return 0;
 712         }
 713
 714         /**
 715          * Return the size of the image file, in bytes
 716          * Overridden by LocalFile, UnregisteredLocalFile
 717          * STUB
 718          * @return bool
 719          */
 720         public function getSize() {
 721                 return false;
 722         }
 723
 724         /**
 725          * Returns the MIME type of the file.
 726          * Overridden by LocalFile, UnregisteredLocalFile
 727          * STUB
 728          *
 729          * @return string
 730          */
 731         function getMimeType() {
 732                 return 'unknown/unknown';
 733         }
 734
 735         /**
 736          * Return the type of the media in the file.
 737          * Use the value returned by this function with the MEDIATYPE_xxx constants.
 738          * Overridden by LocalFile,
 739          * STUB
 740          * @return string
 741          */
 742         function getMediaType() {
 743                 return MEDIATYPE_UNKNOWN;
 744         }
 745
 746         /**
 747          * Checks if the output of transform() for this file is likely
 748          * to be valid. If this is false, various user elements will
 749          * display a placeholder instead.
 750          *
 751          * Currently, this checks if the file is an image format
 752          * that can be converted to a format
 753          * supported by all browsers (namely GIF, PNG and JPEG),
 754          * or if it is an SVG image and SVG conversion is enabled.
 755          *
 756          * @return bool
 757          */
 758         function canRender() {
 759                 if ( !isset( $this->canRender ) ) {
 760                         $this->canRender = $this->getHandler() && $this->handler->canRender( $this ) && $this->exists();
 761                 }
 762
 763                 return $this->canRender;
 764         }
 765
 766         /**
 767          * Accessor for __get()
 768          * @return bool
 769          */
 770         protected function getCanRender() {
 771                 return $this->canRender();
 772         }
 773
 774         /**
 775          * Return true if the file is of a type that can't be directly
 776          * rendered by typical browsers and needs to be re-rasterized.
 777          *
 778          * This returns true for everything but the bitmap types
 779          * supported by all browsers, i.e. JPEG; GIF and PNG. It will
 780          * also return true for any non-image formats.
 781          *
 782          * @return bool
 783          */
 784         function mustRender() {
 785                 return $this->getHandler() && $this->handler->mustRender( $this );
 786         }
 787
 788         /**
 789          * Alias for canRender()
 790          *
 791          * @return bool
 792          */
 793         function allowInlineDisplay() {
 794                 return $this->canRender();
 795         }
 796
 797         /**
 798          * Determines if this media file is in a format that is unlikely to
 799          * contain viruses or malicious content. It uses the global
 800          * $wgTrustedMediaFormats list to determine if the file is safe.
 801          *
 802          * This is used to show a warning on the description page of non-safe files.
 803          * It may also be used to disallow direct [[media:...]] links to such files.
 804          *
 805          * Note that this function will always return true if allowInlineDisplay()
 806          * or isTrustedFile() is true for this file.
 807          *
 808          * @return bool
 809          */
 810         function isSafeFile() {
 811                 if ( !isset( $this->isSafeFile ) ) {
 812                         $this->isSafeFile = $this->getIsSafeFileUncached();
 813                 }
 814
 815                 return $this->isSafeFile;
 816         }
 817
 818         /**
 819          * Accessor for __get()
 820          *
 821          * @return bool
 822          */
 823         protected function getIsSafeFile() {
 824                 return $this->isSafeFile();
 825         }
 826
 827         /**
 828          * Uncached accessor
 829          *
 830          * @return bool
 831          */
 832         protected function getIsSafeFileUncached() {
 833                 global $wgTrustedMediaFormats;
 834
 835                 if ( $this->allowInlineDisplay() ) {
 836                         return true;
 837                 }
 838                 if ( $this->isTrustedFile() ) {
 839                         return true;
 840                 }
 841
 842                 $type = $this->getMediaType();
 843                 $mime = $this->getMimeType();
 844                 # wfDebug( "LocalFile::isSafeFile: type= $type, mime= $mime\n" );
 845
 846                 if ( !$type || $type === MEDIATYPE_UNKNOWN ) {
 847                         return false; # unknown type, not trusted
 848                 }
 849                 if ( in_array( $type, $wgTrustedMediaFormats ) ) {
 850                         return true;
 851                 }
 852
 853                 if ( $mime === "unknown/unknown" ) {
 854                         return false; # unknown type, not trusted
 855                 }
 856                 if ( in_array( $mime, $wgTrustedMediaFormats ) ) {
 857                         return true;
 858                 }
 859
 860                 return false;
 861         }
 862
 863         /**
 864          * Returns true if the file is flagged as trusted. Files flagged that way
 865          * can be linked to directly, even if that is not allowed for this type of
 866          * file normally.
 867          *
 868          * This is a dummy function right now and always returns false. It could be
 869          * implemented to extract a flag from the database. The trusted flag could be
 870          * set on upload, if the user has sufficient privileges, to bypass script-
 871          * and html-filters. It may even be coupled with cryptographics signatures
 872          * or such.
 873          *
 874          * @return bool
 875          */
 876         function isTrustedFile() {
 877                 # this could be implemented to check a flag in the database,
 878                 # look for signatures, etc
 879                 return false;
 880         }
 881
 882         /**
 883          * Load any lazy-loaded file object fields from source
 884          *
 885          * This is only useful when setting $flags
 886          *
 887          * Overridden by LocalFile to actually query the DB
 888          *
 889          * @param int $flags Bitfield of File::READ_* constants
 890          */
 891         public function load( $flags = 0 ) {
 892         }
 893
 894         /**
 895          * Returns true if file exists in the repository.
 896          *
 897          * Overridden by LocalFile to avoid unnecessary stat calls.
 898          *
 899          * @return bool Whether file exists in the repository.
 900          */
 901         public function exists() {
 902                 return $this->getPath() && $this->repo->fileExists( $this->path );
 903         }
 904
 905         /**
 906          * Returns true if file exists in the repository and can be included in a page.
 907          * It would be unsafe to include private images, making public thumbnails inadvertently
 908          *
 909          * @return bool Whether file exists in the repository and is includable.
 910          */
 911         public function isVisible() {
 912                 return $this->exists();
 913         }
 914
 915         /**
 916          * @return string
 917          */
 918         function getTransformScript() {
 919                 if ( !isset( $this->transformScript ) ) {
 920                         $this->transformScript = false;
 921                         if ( $this->repo ) {
 922                                 $script = $this->repo->getThumbScriptUrl();
 923                                 if ( $script ) {
 924                                         $this->transformScript = wfAppendQuery( $script, [ 'f' => $this->getName() ] );
 925                                 }
 926                         }
 927                 }
 928
 929                 return $this->transformScript;
 930         }
 931
 932         /**
 933          * Get a ThumbnailImage which is the same size as the source
 934          *
 935          * @param array $handlerParams
 936          *
 937          * @return ThumbnailImage|MediaTransformOutput|bool False on failure
 938          */
 939         function getUnscaledThumb( $handlerParams = [] ) {
 940                 $hp =& $handlerParams;
 941                 $page = $hp['page'] ?? false;
 942                 $width = $this->getWidth( $page );
 943                 if ( !$width ) {
 944                         return $this->iconThumb();
 945                 }
 946                 $hp['width'] = $width;
 947                 // be sure to ignore any height specification as well (T64258)
 948                 unset( $hp['height'] );
 949
 950                 return $this->transform( $hp );
 951         }
 952
 953         /**
 954          * Return the file name of a thumbnail with the specified parameters.
 955          * Use File::THUMB_FULL_NAME to always get a name like "<params>-<source>".
 956          * Otherwise, the format may be "<params>-<source>" or "<params>-thumbnail.<ext>".
 957          *
 958          * @param array $params Handler-specific parameters
 959          * @param int $flags Bitfield that supports THUMB_* constants
 960          * @return string|null
 961          */
 962         public function thumbName( $params, $flags = 0 ) {
 963                 $name = ( $this->repo && !( $flags & self::THUMB_FULL_NAME ) )
 964                         ? $this->repo->nameForThumb( $this->getName() )
 965                         : $this->getName();
 966
 967                 return $this->generateThumbName( $name, $params );
 968         }
 969
 970         /**
 971          * Generate a thumbnail file name from a name and specified parameters
 972          *
 973          * @param string $name
 974          * @param array $params Parameters which will be passed to MediaHandler::makeParamString
 975          * @return string|null
 976          */
 977         public function generateThumbName( $name, $params ) {
 978                 if ( !$this->getHandler() ) {
 979                         return null;
 980                 }
 981                 $extension = $this->getExtension();
 982                 list( $thumbExt, ) = $this->getHandler()->getThumbType(
 983                         $extension, $this->getMimeType(), $params );
 984                 $thumbName = $this->getHandler()->makeParamString( $params );
 985
 986                 if ( $this->repo->supportsSha1URLs() ) {
 987                         $thumbName .= '-' . $this->getSha1() . '.' . $thumbExt;
 988                 } else {
 989                         $thumbName .= '-' . $name;
 990
 991                         if ( $thumbExt != $extension ) {
 992                                 $thumbName .= ".$thumbExt";
 993                         }
 994                 }
 995
 996                 return $thumbName;
 997         }
 998
 999         /**
1000          * Create a thumbnail of the image having the specified width/height.
1001          * The thumbnail will not be created if the width is larger than the
1002          * image's width. Let the browser do the scaling in this case.
1003          * The thumbnail is stored on disk and is only computed if the thumbnail
1004          * file does not exist OR if it is older than the image.
1005          * Returns the URL.
1006          *
1007          * Keeps aspect ratio of original image. If both width and height are
1008          * specified, the generated image will be no bigger than width x height,
1009          * and will also have correct aspect ratio.
1010          *
1011          * @param int $width Maximum width of the generated thumbnail
1012          * @param int $height Maximum height of the image (optional)
1013          *
1014          * @return string
1015          */
1016         public function createThumb( $width, $height = -1 ) {
1017                 $params = [ 'width' => $width ];
1018                 if ( $height != -1 ) {
1019                         $params['height'] = $height;
1020                 }
1021                 $thumb = $this->transform( $params );
1022                 if ( !$thumb || $thumb->isError() ) {
1023                         return '';
1024                 }
1025
1026                 return $thumb->getUrl();
1027         }
1028
1029         /**
1030          * Return either a MediaTransformError or placeholder thumbnail (if $wgIgnoreImageErrors)
1031          *
1032          * @param string $thumbPath Thumbnail storage path
1033          * @param string $thumbUrl Thumbnail URL
1034          * @param array $params
1035          * @param int $flags
1036          * @return MediaTransformOutput
1037          */
1038         protected function transformErrorOutput( $thumbPath, $thumbUrl, $params, $flags ) {
1039                 global $wgIgnoreImageErrors;
1040
1041                 $handler = $this->getHandler();
1042                 if ( $handler && $wgIgnoreImageErrors && !( $flags & self::RENDER_NOW ) ) {
1043                         return $handler->getTransform( $this, $thumbPath, $thumbUrl, $params );
1044                 } else {
1045                         return new MediaTransformError( 'thumbnail_error',
1046                                 $params['width'], 0, wfMessage( 'thumbnail-dest-create' ) );
1047                 }
1048         }
1049
1050         /**
1051          * Transform a media file
1052          *
1053          * @param array $params An associative array of handler-specific parameters.
1054          *   Typical keys are width, height and page.
1055          * @param int $flags A bitfield, may contain self::RENDER_NOW to force rendering
1056          * @return ThumbnailImage|MediaTransformOutput|bool False on failure
1057          */
1058         function transform( $params, $flags = 0 ) {
1059                 global $wgThumbnailEpoch;
1060
1061                 do {
1062                         if ( !$this->canRender() ) {
1063                                 $thumb = $this->iconThumb();
1064                                 break; // not a bitmap or renderable image, don't try
1065                         }
1066
1067                         // Get the descriptionUrl to embed it as comment into the thumbnail. T21791.
1068                         $descriptionUrl = $this->getDescriptionUrl();
1069                         if ( $descriptionUrl ) {
1070                                 $params['descriptionUrl'] = wfExpandUrl( $descriptionUrl, PROTO_CANONICAL );
1071                         }
1072
1073                         $handler = $this->getHandler();
1074                         $script = $this->getTransformScript();
1075                         if ( $script && !( $flags & self::RENDER_NOW ) ) {
1076                                 // Use a script to transform on client request, if possible
1077                                 $thumb = $handler->getScriptedTransform( $this, $script, $params );
1078                                 if ( $thumb ) {
1079                                         break;
1080                                 }
1081                         }
1082
1083                         $normalisedParams = $params;
1084                         $handler->normaliseParams( $this, $normalisedParams );
1085
1086                         $thumbName = $this->thumbName( $normalisedParams );
1087                         $thumbUrl = $this->getThumbUrl( $thumbName );
1088                         $thumbPath = $this->getThumbPath( $thumbName ); // final thumb path
1089
1090                         if ( $this->repo ) {
1091                                 // Defer rendering if a 404 handler is set up...
1092                                 if ( $this->repo->canTransformVia404() && !( $flags & self::RENDER_NOW ) ) {
1093                                         // XXX: Pass in the storage path even though we are not rendering anything
1094                                         // and the path is supposed to be an FS path. This is due to getScalerType()
1095                                         // getting called on the path and clobbering $thumb->getUrl() if it's false.
1096                                         $thumb = $handler->getTransform( $this, $thumbPath, $thumbUrl, $params );
1097                                         break;
1098                                 }
1099                                 // Check if an up-to-date thumbnail already exists...
1100                                 wfDebug( __METHOD__ . ": Doing stat for $thumbPath\n" );
1101                                 if ( !( $flags & self::RENDER_FORCE ) && $this->repo->fileExists( $thumbPath ) ) {
1102                                         $timestamp = $this->repo->getFileTimestamp( $thumbPath );
1103                                         if ( $timestamp !== false && $timestamp >= $wgThumbnailEpoch ) {
1104                                                 // XXX: Pass in the storage path even though we are not rendering anything
1105                                                 // and the path is supposed to be an FS path. This is due to getScalerType()
1106                                                 // getting called on the path and clobbering $thumb->getUrl() if it's false.
1107                                                 $thumb = $handler->getTransform( $this, $thumbPath, $thumbUrl, $params );
1108                                                 $thumb->setStoragePath( $thumbPath );
1109                                                 break;
1110                                         }
1111                                 } elseif ( $flags & self::RENDER_FORCE ) {
1112                                         wfDebug( __METHOD__ . " forcing rendering per flag File::RENDER_FORCE\n" );
1113                                 }
1114
1115                                 // If the backend is ready-only, don't keep generating thumbnails
1116                                 // only to return transformation errors, just return the error now.
1117                                 if ( $this->repo->getReadOnlyReason() !== false ) {
1118                                         $thumb = $this->transformErrorOutput( $thumbPath, $thumbUrl, $params, $flags );
1119                                         break;
1120                                 }
1121                         }
1122
1123                         $tmpFile = $this->makeTransformTmpFile( $thumbPath );
1124
1125                         if ( !$tmpFile ) {
1126                                 $thumb = $this->transformErrorOutput( $thumbPath, $thumbUrl, $params, $flags );
1127                         } else {
1128                                 $thumb = $this->generateAndSaveThumb( $tmpFile, $params, $flags );
1129                         }
1130                 } while ( false );
1131
1132                 return is_object( $thumb ) ? $thumb : false;
1133         }
1134
1135         /**
1136          * Generates a thumbnail according to the given parameters and saves it to storage
1137          * @param TempFSFile $tmpFile Temporary file where the rendered thumbnail will be saved
1138          * @param array $transformParams
1139          * @param int $flags
1140          * @return bool|MediaTransformOutput
1141          */
1142         public function generateAndSaveThumb( $tmpFile, $transformParams, $flags ) {
1143                 global $wgIgnoreImageErrors;
1144
1145                 $stats = MediaWikiServices::getInstance()->getStatsdDataFactory();
1146
1147                 $handler = $this->getHandler();
1148
1149                 $normalisedParams = $transformParams;
1150                 $handler->normaliseParams( $this, $normalisedParams );
1151
1152                 $thumbName = $this->thumbName( $normalisedParams );
1153                 $thumbUrl = $this->getThumbUrl( $thumbName );
1154                 $thumbPath = $this->getThumbPath( $thumbName ); // final thumb path
1155
1156                 $tmpThumbPath = $tmpFile->getPath();
1157
1158                 if ( $handler->supportsBucketing() ) {
1159                         $this->generateBucketsIfNeeded( $normalisedParams, $flags );
1160                 }
1161
1162                 $starttime = microtime( true );
1163
1164                 // Actually render the thumbnail...
1165                 $thumb = $handler->doTransform( $this, $tmpThumbPath, $thumbUrl, $transformParams );
1166                 $tmpFile->bind( $thumb ); // keep alive with $thumb
1167
1168                 $statTiming = microtime( true ) - $starttime;
1169                 $stats->timing( 'media.thumbnail.generate.transform', 1000 * $statTiming );
1170
1171                 if ( !$thumb ) { // bad params?
1172                         $thumb = false;
1173                 } elseif ( $thumb->isError() ) { // transform error
1174                         /** @var MediaTransformError $thumb */
1175                         '@phan-var MediaTransformError $thumb';
1176                         $this->lastError = $thumb->toText();
1177                         // Ignore errors if requested
1178                         if ( $wgIgnoreImageErrors && !( $flags & self::RENDER_NOW ) ) {
1179                                 $thumb = $handler->getTransform( $this, $tmpThumbPath, $thumbUrl, $transformParams );
1180                         }
1181                 } elseif ( $this->repo && $thumb->hasFile() && !$thumb->fileIsSource() ) {
1182                         // Copy the thumbnail from the file system into storage...
1183
1184                         $starttime = microtime( true );
1185
1186                         $disposition = $this->getThumbDisposition( $thumbName );
1187                         $status = $this->repo->quickImport( $tmpThumbPath, $thumbPath, $disposition );
1188                         if ( $status->isOK() ) {
1189                                 $thumb->setStoragePath( $thumbPath );
1190                         } else {
1191                                 $thumb = $this->transformErrorOutput( $thumbPath, $thumbUrl, $transformParams, $flags );
1192                         }
1193
1194                         $statTiming = microtime( true ) - $starttime;
1195                         $stats->timing( 'media.thumbnail.generate.store', 1000 * $statTiming );
1196
1197                         // Give extensions a chance to do something with this thumbnail...
1198                         Hooks::run( 'FileTransformed', [ $this, $thumb, $tmpThumbPath, $thumbPath ] );
1199                 }
1200
1201                 return $thumb;
1202         }
1203
1204         /**
1205          * Generates chained bucketed thumbnails if needed
1206          * @param array $params
1207          * @param int $flags
1208          * @return bool Whether at least one bucket was generated
1209          */
1210         protected function generateBucketsIfNeeded( $params, $flags = 0 ) {
1211                 if ( !$this->repo
1212                         || !isset( $params['physicalWidth'] )
1213                         || !isset( $params['physicalHeight'] )
1214                 ) {
1215                         return false;
1216                 }
1217
1218                 $bucket = $this->getThumbnailBucket( $params['physicalWidth'] );
1219
1220                 if ( !$bucket || $bucket == $params['physicalWidth'] ) {
1221                         return false;
1222                 }
1223
1224                 $bucketPath = $this->getBucketThumbPath( $bucket );
1225
1226                 if ( $this->repo->fileExists( $bucketPath ) ) {
1227                         return false;
1228                 }
1229
1230                 $starttime = microtime( true );
1231
1232                 $params['physicalWidth'] = $bucket;
1233                 $params['width'] = $bucket;
1234
1235                 $params = $this->getHandler()->sanitizeParamsForBucketing( $params );
1236
1237                 $tmpFile = $this->makeTransformTmpFile( $bucketPath );
1238
1239                 if ( !$tmpFile ) {
1240                         return false;
1241                 }
1242
1243                 $thumb = $this->generateAndSaveThumb( $tmpFile, $params, $flags );
1244
1245                 $buckettime = microtime( true ) - $starttime;
1246
1247                 if ( !$thumb || $thumb->isError() ) {
1248                         return false;
1249                 }
1250
1251                 $this->tmpBucketedThumbCache[$bucket] = $tmpFile->getPath();
1252                 // For the caching to work, we need to make the tmp file survive as long as
1253                 // this object exists
1254                 $tmpFile->bind( $this );
1255
1256                 MediaWikiServices::getInstance()->getStatsdDataFactory()->timing(
1257                         'media.thumbnail.generate.bucket', 1000 * $buckettime );
1258
1259                 return true;
1260         }
1261
1262         /**
1263          * Returns the most appropriate source image for the thumbnail, given a target thumbnail size
1264          * @param array $params
1265          * @return array Source path and width/height of the source
1266          */
1267         public function getThumbnailSource( $params ) {
1268                 if ( $this->repo
1269                         && $this->getHandler()->supportsBucketing()
1270                         && isset( $params['physicalWidth'] )
1271                         && $bucket = $this->getThumbnailBucket( $params['physicalWidth'] )
1272                 ) {
1273                         if ( $this->getWidth() != 0 ) {
1274                                 $bucketHeight = round( $this->getHeight() * ( $bucket / $this->getWidth() ) );
1275                         } else {
1276                                 $bucketHeight = 0;
1277                         }
1278
1279                         // Try to avoid reading from storage if the file was generated by this script
1280                         if ( isset( $this->tmpBucketedThumbCache[$bucket] ) ) {
1281                                 $tmpPath = $this->tmpBucketedThumbCache[$bucket];
1282
1283                                 if ( file_exists( $tmpPath ) ) {
1284                                         return [
1285                                                 'path' => $tmpPath,
1286                                                 'width' => $bucket,
1287                                                 'height' => $bucketHeight
1288                                         ];
1289                                 }
1290                         }
1291
1292                         $bucketPath = $this->getBucketThumbPath( $bucket );
1293
1294                         if ( $this->repo->fileExists( $bucketPath ) ) {
1295                                 $fsFile = $this->repo->getLocalReference( $bucketPath );
1296
1297                                 if ( $fsFile ) {
1298                                         return [
1299                                                 'path' => $fsFile->getPath(),
1300                                                 'width' => $bucket,
1301                                                 'height' => $bucketHeight
1302                                         ];
1303                                 }
1304                         }
1305                 }
1306
1307                 // Thumbnailing a very large file could result in network saturation if
1308                 // everyone does it at once.
1309                 if ( $this->getSize() >= 1e7 ) { // 10MB
1310                         $work = new PoolCounterWorkViaCallback( 'GetLocalFileCopy', sha1( $this->getName() ),
1311                                 [
1312                                         'doWork' => function () {
1313                                                 return $this->getLocalRefPath();
1314                                         }
1315                                 ]
1316                         );
1317                         $srcPath = $work->execute();
1318                 } else {
1319                         $srcPath = $this->getLocalRefPath();
1320                 }
1321
1322                 // Original file
1323                 return [
1324                         'path' => $srcPath,
1325                         'width' => $this->getWidth(),
1326                         'height' => $this->getHeight()
1327                 ];
1328         }
1329
1330         /**
1331          * Returns the repo path of the thumb for a given bucket
1332          * @param int $bucket
1333          * @return string
1334          */
1335         protected function getBucketThumbPath( $bucket ) {
1336                 $thumbName = $this->getBucketThumbName( $bucket );
1337                 return $this->getThumbPath( $thumbName );
1338         }
1339
1340         /**
1341          * Returns the name of the thumb for a given bucket
1342          * @param int $bucket
1343          * @return string
1344          */
1345         protected function getBucketThumbName( $bucket ) {
1346                 return $this->thumbName( [ 'physicalWidth' => $bucket ] );
1347         }
1348
1349         /**
1350          * Creates a temp FS file with the same extension and the thumbnail
1351          * @param string $thumbPath Thumbnail path
1352          * @return TempFSFile|null
1353          */
1354         protected function makeTransformTmpFile( $thumbPath ) {
1355                 $thumbExt = FileBackend::extensionFromPath( $thumbPath );
1356                 return MediaWikiServices::getInstance()->getTempFSFileFactory()
1357                         ->newTempFSFile( 'transform_', $thumbExt );
1358         }
1359
1360         /**
1361          * @param string $thumbName Thumbnail name
1362          * @param string $dispositionType Type of disposition (either "attachment" or "inline")
1363          * @return string Content-Disposition header value
1364          */
1365         function getThumbDisposition( $thumbName, $dispositionType = 'inline' ) {
1366                 $fileName = $this->name; // file name to suggest
1367                 $thumbExt = FileBackend::extensionFromPath( $thumbName );
1368                 if ( $thumbExt != '' && $thumbExt !== $this->getExtension() ) {
1369                         $fileName .= ".$thumbExt";
1370                 }
1371
1372                 return FileBackend::makeContentDisposition( $dispositionType, $fileName );
1373         }
1374
1375         /**
1376          * Hook into transform() to allow migration of thumbnail files
1377          * STUB
1378          * Overridden by LocalFile
1379          * @param string $thumbName
1380          */
1381         function migrateThumbFile( $thumbName ) {
1382         }
1383
1384         /**
1385          * Get a MediaHandler instance for this file
1386          *
1387          * @return MediaHandler|bool Registered MediaHandler for file's MIME type
1388          *   or false if none found
1389          */
1390         function getHandler() {
1391                 if ( !isset( $this->handler ) ) {
1392                         $this->handler = MediaHandler::getHandler( $this->getMimeType() );
1393                 }
1394
1395                 return $this->handler;
1396         }
1397
1398         /**
1399          * Get a ThumbnailImage representing a file type icon
1400          *
1401          * @return ThumbnailImage
1402          */
1403         function iconThumb() {
1404                 global $wgResourceBasePath, $IP;
1405                 $assetsPath = "$wgResourceBasePath/resources/assets/file-type-icons/";
1406                 $assetsDirectory = "$IP/resources/assets/file-type-icons/";
1407
1408                 $try = [ 'fileicon-' . $this->getExtension() . '.png', 'fileicon.png' ];
1409                 foreach ( $try as $icon ) {
1410                         if ( file_exists( $assetsDirectory . $icon ) ) { // always FS
1411                                 $params = [ 'width' => 120, 'height' => 120 ];
1412
1413                                 return new ThumbnailImage( $this, $assetsPath . $icon, false, $params );
1414                         }
1415                 }
1416
1417                 return null;
1418         }
1419
1420         /**
1421          * Get last thumbnailing error.
1422          * Largely obsolete.
1423          * @return string
1424          */
1425         function getLastError() {
1426                 return $this->lastError;
1427         }
1428
1429         /**
1430          * Get all thumbnail names previously generated for this file
1431          * STUB
1432          * Overridden by LocalFile
1433          * @return string[]
1434          */
1435         function getThumbnails() {
1436                 return [];
1437         }
1438
1439         /**
1440          * Purge shared caches such as thumbnails and DB data caching
1441          * STUB
1442          * Overridden by LocalFile
1443          * @param array $options Options, which include:
1444          *   'forThumbRefresh' : The purging is only to refresh thumbnails
1445          */
1446         function purgeCache( $options = [] ) {
1447         }
1448
1449         /**
1450          * Purge the file description page, but don't go after
1451          * pages using the file. Use when modifying file history
1452          * but not the current data.
1453          */
1454         function purgeDescription() {
1455                 $title = $this->getTitle();
1456                 if ( $title ) {
1457                         $title->invalidateCache();
1458                         $title->purgeSquid();
1459                 }
1460         }
1461
1462         /**
1463          * Purge metadata and all affected pages when the file is created,
1464          * deleted, or majorly updated.
1465          */
1466         function purgeEverything() {
1467                 // Delete thumbnails and refresh file metadata cache
1468                 $this->purgeCache();
1469                 $this->purgeDescription();
1470                 // Purge cache of all pages using this file
1471                 $title = $this->getTitle();
1472                 if ( $title ) {
1473                         $job = HTMLCacheUpdateJob::newForBacklinks(
1474                                 $title,
1475                                 'imagelinks',
1476                                 [ 'causeAction' => 'file-purge' ]
1477                         );
1478                         JobQueueGroup::singleton()->lazyPush( $job );
1479                 }
1480         }
1481
1482         /**
1483          * Return a fragment of the history of file.
1484          *
1485          * STUB
1486          * @param int|null $limit Limit of rows to return
1487          * @param string|int|null $start Only revisions older than $start will be returned
1488          * @param string|int|null $end Only revisions newer than $end will be returned
1489          * @param bool $inc Include the endpoints of the time range
1490          *
1491          * @return File[]
1492          */
1493         function getHistory( $limit = null, $start = null, $end = null, $inc = true ) {
1494                 return [];
1495         }
1496
1497         /**
1498          * Return the history of this file, line by line. Starts with current version,
1499          * then old versions. Should return an object similar to an image/oldimage
1500          * database row.
1501          *
1502          * STUB
1503          * Overridden in LocalFile
1504          * @return bool
1505          */
1506         public function nextHistoryLine() {
1507                 return false;
1508         }
1509
1510         /**
1511          * Reset the history pointer to the first element of the history.
1512          * Always call this function after using nextHistoryLine() to free db resources
1513          * STUB
1514          * Overridden in LocalFile.
1515          */
1516         public function resetHistory() {
1517         }
1518
1519         /**
1520          * Get the filename hash component of the directory including trailing slash,
1521          * e.g. f/fa/
1522          * If the repository is not hashed, returns an empty string.
1523          *
1524          * @return string
1525          */
1526         function getHashPath() {
1527                 if ( $this->hashPath === null ) {
1528                         $this->assertRepoDefined();
1529                         $this->hashPath = $this->repo->getHashPath( $this->getName() );
1530                 }
1531
1532                 return $this->hashPath;
1533         }
1534
1535         /**
1536          * Get the path of the file relative to the public zone root.
1537          * This function is overridden in OldLocalFile to be like getArchiveRel().
1538          *
1539          * @return string
1540          */
1541         function getRel() {
1542                 return $this->getHashPath() . $this->getName();
1543         }
1544
1545         /**
1546          * Get the path of an archived file relative to the public zone root
1547          *
1548          * @param bool|string $suffix If not false, the name of an archived thumbnail file
1549          *
1550          * @return string
1551          */
1552         function getArchiveRel( $suffix = false ) {
1553                 $path = 'archive/' . $this->getHashPath();
1554                 if ( $suffix === false ) {
1555                         $path = rtrim( $path, '/' );
1556                 } else {
1557                         $path .= $suffix;
1558                 }
1559
1560                 return $path;
1561         }
1562
1563         /**
1564          * Get the path, relative to the thumbnail zone root, of the
1565          * thumbnail directory or a particular file if $suffix is specified
1566          *
1567          * @param bool|string $suffix If not false, the name of a thumbnail file
1568          * @return string
1569          */
1570         function getThumbRel( $suffix = false ) {
1571                 $path = $this->getRel();
1572                 if ( $suffix !== false ) {
1573                         $path .= '/' . $suffix;
1574                 }
1575
1576                 return $path;
1577         }
1578
1579         /**
1580          * Get urlencoded path of the file relative to the public zone root.
1581          * This function is overridden in OldLocalFile to be like getArchiveUrl().
1582          *
1583          * @return string
1584          */
1585         function getUrlRel() {
1586                 return $this->getHashPath() . rawurlencode( $this->getName() );
1587         }
1588
1589         /**
1590          * Get the path, relative to the thumbnail zone root, for an archived file's thumbs directory
1591          * or a specific thumb if the $suffix is given.
1592          *
1593          * @param string $archiveName The timestamped name of an archived image
1594          * @param bool|string $suffix If not false, the name of a thumbnail file
1595          * @return string
1596          */
1597         function getArchiveThumbRel( $archiveName, $suffix = false ) {
1598                 $path = $this->getArchiveRel( $archiveName );
1599                 if ( $suffix !== false ) {
1600                         $path .= '/' . $suffix;
1601                 }
1602
1603                 return $path;
1604         }
1605
1606         /**
1607          * Get the path of the archived file.
1608          *
1609          * @param bool|string $suffix If not false, the name of an archived file.
1610          * @return string
1611          */
1612         function getArchivePath( $suffix = false ) {
1613                 $this->assertRepoDefined();
1614
1615                 return $this->repo->getZonePath( 'public' ) . '/' . $this->getArchiveRel( $suffix );
1616         }
1617
1618         /**
1619          * Get the path of an archived file's thumbs, or a particular thumb if $suffix is specified
1620          *
1621          * @param string $archiveName The timestamped name of an archived image
1622          * @param bool|string $suffix If not false, the name of a thumbnail file
1623          * @return string
1624          */
1625         function getArchiveThumbPath( $archiveName, $suffix = false ) {
1626                 $this->assertRepoDefined();
1627
1628                 return $this->repo->getZonePath( 'thumb' ) . '/' .
1629                 $this->getArchiveThumbRel( $archiveName, $suffix );
1630         }
1631
1632         /**
1633          * Get the path of the thumbnail directory, or a particular file if $suffix is specified
1634          *
1635          * @param bool|string $suffix If not false, the name of a thumbnail file
1636          * @return string
1637          */
1638         function getThumbPath( $suffix = false ) {
1639                 $this->assertRepoDefined();
1640
1641                 return $this->repo->getZonePath( 'thumb' ) . '/' . $this->getThumbRel( $suffix );
1642         }
1643
1644         /**
1645          * Get the path of the transcoded directory, or a particular file if $suffix is specified
1646          *
1647          * @param bool|string $suffix If not false, the name of a media file
1648          * @return string
1649          */
1650         function getTranscodedPath( $suffix = false ) {
1651                 $this->assertRepoDefined();
1652
1653                 return $this->repo->getZonePath( 'transcoded' ) . '/' . $this->getThumbRel( $suffix );
1654         }
1655
1656         /**
1657          * Get the URL of the archive directory, or a particular file if $suffix is specified
1658          *
1659          * @param bool|string $suffix If not false, the name of an archived file
1660          * @return string
1661          */
1662         function getArchiveUrl( $suffix = false ) {
1663                 $this->assertRepoDefined();
1664                 $ext = $this->getExtension();
1665                 $path = $this->repo->getZoneUrl( 'public', $ext ) . '/archive/' . $this->getHashPath();
1666                 if ( $suffix === false ) {
1667                         $path = rtrim( $path, '/' );
1668                 } else {
1669                         $path .= rawurlencode( $suffix );
1670                 }
1671
1672                 return $path;
1673         }
1674
1675         /**
1676          * Get the URL of the archived file's thumbs, or a particular thumb if $suffix is specified
1677          *
1678          * @param string $archiveName The timestamped name of an archived image
1679          * @param bool|string $suffix If not false, the name of a thumbnail file
1680          * @return string
1681          */
1682         function getArchiveThumbUrl( $archiveName, $suffix = false ) {
1683                 $this->assertRepoDefined();
1684                 $ext = $this->getExtension();
1685                 $path = $this->repo->getZoneUrl( 'thumb', $ext ) . '/archive/' .
1686                         $this->getHashPath() . rawurlencode( $archiveName );
1687                 if ( $suffix !== false ) {
1688                         $path .= '/' . rawurlencode( $suffix );
1689                 }
1690
1691                 return $path;
1692         }
1693
1694         /**
1695          * Get the URL of the zone directory, or a particular file if $suffix is specified
1696          *
1697          * @param string $zone Name of requested zone
1698          * @param bool|string $suffix If not false, the name of a file in zone
1699          * @return string Path
1700          */
1701         function getZoneUrl( $zone, $suffix = false ) {
1702                 $this->assertRepoDefined();
1703                 $ext = $this->getExtension();
1704                 $path = $this->repo->getZoneUrl( $zone, $ext ) . '/' . $this->getUrlRel();
1705                 if ( $suffix !== false ) {
1706                         $path .= '/' . rawurlencode( $suffix );
1707                 }
1708
1709                 return $path;
1710         }
1711
1712         /**
1713          * Get the URL of the thumbnail directory, or a particular file if $suffix is specified
1714          *
1715          * @param bool|string $suffix If not false, the name of a thumbnail file
1716          * @return string Path
1717          */
1718         function getThumbUrl( $suffix = false ) {
1719                 return $this->getZoneUrl( 'thumb', $suffix );
1720         }
1721
1722         /**
1723          * Get the URL of the transcoded directory, or a particular file if $suffix is specified
1724          *
1725          * @param bool|string $suffix If not false, the name of a media file
1726          * @return string Path
1727          */
1728         function getTranscodedUrl( $suffix = false ) {
1729                 return $this->getZoneUrl( 'transcoded', $suffix );
1730         }
1731
1732         /**
1733          * Get the public zone virtual URL for a current version source file
1734          *
1735          * @param bool|string $suffix If not false, the name of a thumbnail file
1736          * @return string
1737          */
1738         function getVirtualUrl( $suffix = false ) {
1739                 $this->assertRepoDefined();
1740                 $path = $this->repo->getVirtualUrl() . '/public/' . $this->getUrlRel();
1741                 if ( $suffix !== false ) {
1742                         $path .= '/' . rawurlencode( $suffix );
1743                 }
1744
1745                 return $path;
1746         }
1747
1748         /**
1749          * Get the public zone virtual URL for an archived version source file
1750          *
1751          * @param bool|string $suffix If not false, the name of a thumbnail file
1752          * @return string
1753          */
1754         function getArchiveVirtualUrl( $suffix = false ) {
1755                 $this->assertRepoDefined();
1756                 $path = $this->repo->getVirtualUrl() . '/public/archive/' . $this->getHashPath();
1757                 if ( $suffix === false ) {
1758                         $path = rtrim( $path, '/' );
1759                 } else {
1760                         $path .= rawurlencode( $suffix );
1761                 }
1762
1763                 return $path;
1764         }
1765
1766         /**
1767          * Get the virtual URL for a thumbnail file or directory
1768          *
1769          * @param bool|string $suffix If not false, the name of a thumbnail file
1770          * @return string
1771          */
1772         function getThumbVirtualUrl( $suffix = false ) {
1773                 $this->assertRepoDefined();
1774                 $path = $this->repo->getVirtualUrl() . '/thumb/' . $this->getUrlRel();
1775                 if ( $suffix !== false ) {
1776                         $path .= '/' . rawurlencode( $suffix );
1777                 }
1778
1779                 return $path;
1780         }
1781
1782         /**
1783          * @return bool
1784          */
1785         function isHashed() {
1786                 $this->assertRepoDefined();
1787
1788                 return (bool)$this->repo->getHashLevels();
1789         }
1790
1791         /**
1792          * @throws MWException
1793          */
1794         function readOnlyError() {
1795                 throw new MWException( static::class . ': write operations are not supported' );
1796         }
1797
1798         /**
1799          * Record a file upload in the upload log and the image table
1800          * STUB
1801          * Overridden by LocalFile
1802          * @param string $oldver
1803          * @param string $desc
1804          * @param string $license
1805          * @param string $copyStatus
1806          * @param string $source
1807          * @param bool $watch
1808          * @param string|bool $timestamp
1809          * @param null|User $user User object or null to use $wgUser
1810          * @return bool
1811          * @throws MWException
1812          */
1813         function recordUpload( $oldver, $desc, $license = '', $copyStatus = '', $source = '',
1814                 $watch = false, $timestamp = false, User $user = null
1815         ) {
1816                 $this->readOnlyError();
1817         }
1818
1819         /**
1820          * Move or copy a file to its public location. If a file exists at the
1821          * destination, move it to an archive. Returns a Status object with
1822          * the archive name in the "value" member on success.
1823          *
1824          * The archive name should be passed through to recordUpload for database
1825          * registration.
1826          *
1827          * Options to $options include:
1828          *   - headers : name/value map of HTTP headers to use in response to GET/HEAD requests
1829          *
1830          * @param string|FSFile $src Local filesystem path to the source image
1831          * @param int $flags A bitwise combination of:
1832          *   File::DELETE_SOURCE    Delete the source file, i.e. move rather than copy
1833          * @param array $options Optional additional parameters
1834          * @return Status On success, the value member contains the
1835          *   archive name, or an empty string if it was a new file.
1836          *
1837          * STUB
1838          * Overridden by LocalFile
1839          */
1840         function publish( $src, $flags = 0, array $options = [] ) {
1841                 $this->readOnlyError();
1842         }
1843
1844         /**
1845          * @param bool|IContextSource $context Context to use (optional)
1846          * @return bool
1847          */
1848         function formatMetadata( $context = false ) {
1849                 if ( !$this->getHandler() ) {
1850                         return false;
1851                 }
1852
1853                 return $this->getHandler()->formatMetadata( $this, $context );
1854         }
1855
1856         /**
1857          * Returns true if the file comes from the local file repository.
1858          *
1859          * @return bool
1860          */
1861         function isLocal() {
1862                 return $this->repo && $this->repo->isLocal();
1863         }
1864
1865         /**
1866          * Returns the name of the repository.
1867          *
1868          * @return string
1869          */
1870         function getRepoName() {
1871                 return $this->repo ? $this->repo->getName() : 'unknown';
1872         }
1873
1874         /**
1875          * Returns the repository
1876          *
1877          * @return FileRepo|LocalRepo|bool
1878          */
1879         function getRepo() {
1880                 return $this->repo;
1881         }
1882
1883         /**
1884          * Returns true if the image is an old version
1885          * STUB
1886          *
1887          * @return bool
1888          */
1889         function isOld() {
1890                 return false;
1891         }
1892
1893         /**
1894          * Is this file a "deleted" file in a private archive?
1895          * STUB
1896          *
1897          * @param int $field One of DELETED_* bitfield constants
1898          * @return bool
1899          */
1900         function isDeleted( $field ) {
1901                 return false;
1902         }
1903
1904         /**
1905          * Return the deletion bitfield
1906          * STUB
1907          * @return int
1908          */
1909         function getVisibility() {
1910                 return 0;
1911         }
1912
1913         /**
1914          * Was this file ever deleted from the wiki?
1915          *
1916          * @return bool
1917          */
1918         function wasDeleted() {
1919                 $title = $this->getTitle();
1920
1921                 return $title && $title->isDeletedQuick();
1922         }
1923
1924         /**
1925          * Move file to the new title
1926          *
1927          * Move current, old version and all thumbnails
1928          * to the new filename. Old file is deleted.
1929          *
1930          * Cache purging is done; checks for validity
1931          * and logging are caller's responsibility
1932          *
1933          * @param Title $target New file name
1934          * @return Status
1935          */
1936         function move( $target ) {
1937                 $this->readOnlyError();
1938         }
1939
1940         /**
1941          * Delete all versions of the file.
1942          *
1943          * Moves the files into an archive directory (or deletes them)
1944          * and removes the database rows.
1945          *
1946          * Cache purging is done; logging is caller's responsibility.
1947          *
1948          * @param string $reason
1949          * @param bool $suppress Hide content from sysops?
1950          * @param User|null $user
1951          * @return Status
1952          * STUB
1953          * Overridden by LocalFile
1954          */
1955         function delete( $reason, $suppress = false, $user = null ) {
1956                 $this->readOnlyError();
1957         }
1958
1959         /**
1960          * Restore all or specified deleted revisions to the given file.
1961          * Permissions and logging are left to the caller.
1962          *
1963          * May throw database exceptions on error.
1964          *
1965          * @param array $versions Set of record ids of deleted items to restore,
1966          *   or empty to restore all revisions.
1967          * @param bool $unsuppress Remove restrictions on content upon restoration?
1968          * @return Status
1969          * STUB
1970          * Overridden by LocalFile
1971          */
1972         function restore( $versions = [], $unsuppress = false ) {
1973                 $this->readOnlyError();
1974         }
1975
1976         /**
1977          * Returns 'true' if this file is a type which supports multiple pages,
1978          * e.g. DJVU or PDF. Note that this may be true even if the file in
1979          * question only has a single page.
1980          *
1981          * @return bool
1982          */
1983         function isMultipage() {
1984                 return $this->getHandler() && $this->handler->isMultiPage( $this );
1985         }
1986
1987         /**
1988          * Returns the number of pages of a multipage document, or false for
1989          * documents which aren't multipage documents
1990          *
1991          * @return string|bool|int
1992          */
1993         function pageCount() {
1994                 if ( !isset( $this->pageCount ) ) {
1995                         if ( $this->getHandler() && $this->handler->isMultiPage( $this ) ) {
1996                                 $this->pageCount = $this->handler->pageCount( $this );
1997                         } else {
1998                                 $this->pageCount = false;
1999                         }
2000                 }
2001
2002                 return $this->pageCount;
2003         }
2004
2005         /**
2006          * Calculate the height of a thumbnail using the source and destination width
2007          *
2008          * @param int $srcWidth
2009          * @param int $srcHeight
2010          * @param int $dstWidth
2011          *
2012          * @return int
2013          */
2014         static function scaleHeight( $srcWidth, $srcHeight, $dstWidth ) {
2015                 // Exact integer multiply followed by division
2016                 if ( $srcWidth == 0 ) {
2017                         return 0;
2018                 } else {
2019                         return (int)round( $srcHeight * $dstWidth / $srcWidth );
2020                 }
2021         }
2022
2023         /**
2024          * Get an image size array like that returned by getImageSize(), or false if it
2025          * can't be determined. Loads the image size directly from the file ignoring caches.
2026          *
2027          * @note Use getWidth()/getHeight() instead of this method unless you have a
2028          *  a good reason. This method skips all caches.
2029          *
2030          * @param string $filePath The path to the file (e.g. From getLocalRefPath() )
2031          * @return array|false The width, followed by height, with optionally more things after
2032          */
2033         function getImageSize( $filePath ) {
2034                 if ( !$this->getHandler() ) {
2035                         return false;
2036                 }
2037
2038                 return $this->getHandler()->getImageSize( $this, $filePath );
2039         }
2040
2041         /**
2042          * Get the URL of the image description page. May return false if it is
2043          * unknown or not applicable.
2044          *
2045          * @return string|bool
2046          */
2047         function getDescriptionUrl() {
2048                 if ( $this->repo ) {
2049                         return $this->repo->getDescriptionUrl( $this->getName() );
2050                 } else {
2051                         return false;
2052                 }
2053         }
2054
2055         /**
2056          * Get the HTML text of the description page, if available
2057          *
2058          * @param Language|null $lang Optional language to fetch description in
2059          * @return string|false
2060          */
2061         function getDescriptionText( Language $lang = null ) {
2062                 global $wgLang;
2063
2064                 if ( !$this->repo || !$this->repo->fetchDescription ) {
2065                         return false;
2066                 }
2067
2068                 $lang = $lang ?? $wgLang;
2069
2070                 $renderUrl = $this->repo->getDescriptionRenderUrl( $this->getName(), $lang->getCode() );
2071                 if ( $renderUrl ) {
2072                         $cache = MediaWikiServices::getInstance()->getMainWANObjectCache();
2073                         $key = $this->repo->getLocalCacheKey(
2074                                 'RemoteFileDescription',
2075                                 $lang->getCode(),
2076                                 md5( $this->getName() )
2077                         );
2078                         $fname = __METHOD__;
2079
2080                         return $cache->getWithSetCallback(
2081                                 $key,
2082                                 $this->repo->descriptionCacheExpiry ?: $cache::TTL_UNCACHEABLE,
2083                                 function ( $oldValue, &$ttl, array &$setOpts ) use ( $renderUrl, $fname ) {
2084                                         wfDebug( "Fetching shared description from $renderUrl\n" );
2085                                         $res = MediaWikiServices::getInstance()->getHttpRequestFactory()->
2086                                                 get( $renderUrl, [], $fname );
2087                                         if ( !$res ) {
2088                                                 $ttl = WANObjectCache::TTL_UNCACHEABLE;
2089                                         }
2090
2091                                         return $res;
2092                                 }
2093                         );
2094                 }
2095
2096                 return false;
2097         }
2098
2099         /**
2100          * Get description of file revision
2101          * STUB
2102          *
2103          * @param int $audience One of:
2104          *   File::FOR_PUBLIC       to be displayed to all users
2105          *   File::FOR_THIS_USER    to be displayed to the given user
2106          *   File::RAW              get the description regardless of permissions
2107          * @param User|null $user User object to check for, only if FOR_THIS_USER is
2108          *   passed to the $audience parameter
2109          * @return null|string
2110          */
2111         function getDescription( $audience = self::FOR_PUBLIC, User $user = null ) {
2112                 return null;
2113         }
2114
2115         /**
2116          * Get the 14-character timestamp of the file upload
2117          *
2118          * @return string|bool TS_MW timestamp or false on failure
2119          */
2120         function getTimestamp() {
2121                 $this->assertRepoDefined();
2122
2123                 return $this->repo->getFileTimestamp( $this->getPath() );
2124         }
2125
2126         /**
2127          * Returns the timestamp (in TS_MW format) of the last change of the description page.
2128          * Returns false if the file does not have a description page, or retrieving the timestamp
2129          * would be expensive.
2130          * @since 1.25
2131          * @return string|bool
2132          */
2133         public function getDescriptionTouched() {
2134                 return false;
2135         }
2136
2137         /**
2138          * Get the SHA-1 base 36 hash of the file
2139          *
2140          * @return string
2141          */
2142         function getSha1() {
2143                 $this->assertRepoDefined();
2144
2145                 return $this->repo->getFileSha1( $this->getPath() );
2146         }
2147
2148         /**
2149          * Get the deletion archive key, "<sha1>.<ext>"
2150          *
2151          * @return string|false
2152          */
2153         function getStorageKey() {
2154                 $hash = $this->getSha1();
2155                 if ( !$hash ) {
2156                         return false;
2157                 }
2158                 $ext = $this->getExtension();
2159                 $dotExt = $ext === '' ? '' : ".$ext";
2160
2161                 return $hash . $dotExt;
2162         }
2163
2164         /**
2165          * Determine if the current user is allowed to view a particular
2166          * field of this file, if it's marked as deleted.
2167          * STUB
2168          * @param int $field
2169          * @param User|null $user User object to check, or null to use $wgUser
2170          * @return bool
2171          */
2172         function userCan( $field, User $user = null ) {
2173                 return true;
2174         }
2175
2176         /**
2177          * @return string[] HTTP header name/value map to use for HEAD/GET request responses
2178          * @since 1.30
2179          */
2180         function getContentHeaders() {
2181                 $handler = $this->getHandler();
2182                 if ( $handler ) {
2183                         $metadata = $this->getMetadata();
2184
2185                         if ( is_string( $metadata ) ) {
2186                                 $metadata = AtEase::quietCall( 'unserialize', $metadata );
2187                         }
2188
2189                         if ( !is_array( $metadata ) ) {
2190                                 $metadata = [];
2191                         }
2192
2193                         return $handler->getContentHeaders( $metadata );
2194                 }
2195
2196                 return [];
2197         }
2198
2199         /**
2200          * @return string
2201          */
2202         function getLongDesc() {
2203                 $handler = $this->getHandler();
2204                 if ( $handler ) {
2205                         return $handler->getLongDesc( $this );
2206                 } else {
2207                         return MediaHandler::getGeneralLongDesc( $this );
2208                 }
2209         }
2210
2211         /**
2212          * @return string
2213          */
2214         function getShortDesc() {
2215                 $handler = $this->getHandler();
2216                 if ( $handler ) {
2217                         return $handler->getShortDesc( $this );
2218                 } else {
2219                         return MediaHandler::getGeneralShortDesc( $this );
2220                 }
2221         }
2222
2223         /**
2224          * @return string
2225          */
2226         function getDimensionsString() {
2227                 $handler = $this->getHandler();
2228                 if ( $handler ) {
2229                         return $handler->getDimensionsString( $this );
2230                 } else {
2231                         return '';
2232                 }
2233         }
2234
2235         /**
2236          * @return string
2237          */
2238         function getRedirected() {
2239                 return $this->redirected;
2240         }
2241
2242         /**
2243          * @return Title|null
2244          */
2245         function getRedirectedTitle() {
2246                 if ( $this->redirected ) {
2247                         if ( !$this->redirectTitle ) {
2248                                 $this->redirectTitle = Title::makeTitle( NS_FILE, $this->redirected );
2249                         }
2250
2251                         return $this->redirectTitle;
2252                 }
2253
2254                 return null;
2255         }
2256
2257         /**
2258          * @param string $from
2259          * @return void
2260          */
2261         function redirectedFrom( $from ) {
2262                 $this->redirected = $from;
2263         }
2264
2265         /**
2266          * @return bool
2267          */
2268         function isMissing() {
2269                 return false;
2270         }
2271
2272         /**
2273          * Check if this file object is small and can be cached
2274          * @return bool
2275          */
2276         public function isCacheable() {
2277                 return true;
2278         }
2279
2280         /**
2281          * Assert that $this->repo is set to a valid FileRepo instance
2282          * @throws MWException
2283          */
2284         protected function assertRepoDefined() {
2285                 if ( !( $this->repo instanceof $this->repoClass ) ) {
2286                         throw new MWException( "A {$this->repoClass} object is not set for this File.\n" );
2287                 }
2288         }
2289
2290         /**
2291          * Assert that $this->title is set to a Title
2292          * @throws MWException
2293          */
2294         protected function assertTitleDefined() {
2295                 if ( !( $this->title instanceof Title ) ) {
2296                         throw new MWException( "A Title object is not set for this File.\n" );
2297                 }
2298         }
2299
2300         /**
2301          * True if creating thumbnails from the file is large or otherwise resource-intensive.
2302          * @return bool
2303          */
2304         public function isExpensiveToThumbnail() {
2305                 $handler = $this->getHandler();
2306                 return $handler ? $handler->isExpensiveToThumbnail( $this ) : false;
2307         }
2308
2309         /**
2310          * Whether the thumbnails created on the same server as this code is running.
2311          * @since 1.25
2312          * @return bool
2313          */
2314         public function isTransformedLocally() {
2315                 return true;
2316         }
2317 }