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