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 MediaWiki\MediaWikiServices;
   9
  10 /**
  11  * Base code for files.
  12  *
  13  * This program is free software; you can redistribute it and/or modify
  14  * it under the terms of the GNU General Public License as published by
  15  * the Free Software Foundation; either version 2 of the License, or
  16  * (at your option) any later version.
  17  *
  18  * This program is distributed in the hope that it will be useful,
  19  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  20  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  21  * GNU General Public License for more details.
  22  *
  23  * You should have received a copy of the GNU General Public License along
  24  * with this program; if not, write to the Free Software Foundation, Inc.,
  25  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  26  * http://www.gnu.org/copyleft/gpl.html
  27  *
  28  * @file
  29  * @ingroup FileAbstraction
  30  */
  31
  32 /**
  33  * Implements some public methods and some protected utility functions which
  34  * are required by multiple child classes. Contains stub functionality for
  35  * unimplemented public methods.
  36  *
  37  * Stub functions which should be overridden are marked with STUB. Some more
  38  * concrete functions are also typically overridden by child classes.
  39  *
  40  * Note that only the repo object knows what its file class is called. You should
  41  * never name a file class explictly outside of the repo class. Instead use the
  42  * repo's factory functions to generate file objects, for example:
  43  *
  44  * RepoGroup::singleton()->getLocalRepo()->newFile( $title );
  45  *
  46  * The convenience functions wfLocalFile() and wfFindFile() should be sufficient
  47  * in most cases.
  48  *
  49  * @ingroup FileAbstraction
  50  */
  51 abstract class File implements IDBAccessObject {
  52         // Bitfield values akin to the Revision deletion constants
  53         const DELETED_FILE = 1;
  54         const DELETED_COMMENT = 2;
  55         const DELETED_USER = 4;
  56         const DELETED_RESTRICTED = 8;
  57
  58         /** Force rendering in the current process */
  59         const RENDER_NOW = 1;
  60         /**
  61          * Force rendering even if thumbnail already exist and using RENDER_NOW
  62          * I.e. you have to pass both flags: File::RENDER_NOW | File::RENDER_FORCE
  63          */
  64         const RENDER_FORCE = 2;
  65
  66         const DELETE_SOURCE = 1;
  67
  68         // Audience options for File::getDescription()
  69         const FOR_PUBLIC = 1;
  70         const FOR_THIS_USER = 2;
  71         const RAW = 3;
  72
  73         // Options for File::thumbName()
  74         const THUMB_FULL_NAME = 1;
  75
  76         /**
  77          * Some member variables can be lazy-initialised using __get(). The
  78          * initialisation function for these variables is always a function named
  79          * like getVar(), where Var is the variable name with upper-case first
  80          * letter.
  81          *
  82          * The following variables are initialised in this way in this base class:
  83          *    name, extension, handler, path, canRender, isSafeFile,
  84          *    transformScript, hashPath, pageCount, url
  85          *
  86          * Code within this class should generally use the accessor function
  87          * directly, since __get() isn't re-entrant and therefore causes bugs that
  88          * depend on initialisation order.
  89          */
  90
  91         /**
  92          * The following member variables are not lazy-initialised
  93          */
  94
  95         /** @var FileRepo|LocalRepo|ForeignAPIRepo|bool */
  96         public $repo;
  97
  98         /** @var Title|string|bool */
  99         protected $title;
 100
 101         /** @var string Text of last error */
 102         protected $lastError;
 103
 104         /** @var string Main part of the title, with underscores (Title::getDBkey) */
 105         protected $redirected;
 106
 107         /** @var Title */
 108         protected $redirectedTitle;
 109
 110         /** @var FSFile|bool False if undefined */
 111         protected $fsFile;
 112
 113         /** @var MediaHandler */
 114         protected $handler;
 115
 116         /** @var string The URL corresponding to one of the four basic zones */
 117         protected $url;
 118
 119         /** @var string File extension */
 120         protected $extension;
 121
 122         /** @var string The name of a file from its title object */
 123         protected $name;
 124
 125         /** @var string The storage path corresponding to one of the zones */
 126         protected $path;
 127
 128         /** @var string Relative path including trailing slash */
 129         protected $hashPath;
 130
 131         /** @var string|false Number of pages of a multipage document, or false for
 132          *    documents which aren't multipage documents
 133          */
 134         protected $pageCount;
 135
 136         /** @var string URL of transformscript (for example thumb.php) */
 137         protected $transformScript;
 138
 139         /** @var Title */
 140         protected $redirectTitle;
 141
 142         /** @var bool Whether the output of transform() for this file is likely to be valid. */
 143         protected $canRender;
 144
 145         /** @var bool Whether this media file is in a format that is unlikely to
 146          *    contain viruses or malicious content
 147          */
 148         protected $isSafeFile;
 149
 150         /** @var string Required Repository class type */
 151         protected $repoClass = FileRepo::class;
 152
 153         /** @var array Cache of tmp filepaths pointing to generated bucket thumbnails, keyed by width */
 154         protected $tmpBucketedThumbCache = [];
 155
 156         /**
 157          * Call this constructor from child classes.
 158          *
 159          * Both $title and $repo are optional, though some functions
 160          * may return false or throw exceptions if they are not set.
 161          * Most subclasses will want to call assertRepoDefined() here.
 162          *
 163          * @param Title|string|bool $title
 164          * @param FileRepo|bool $repo
 165          */
 166         function __construct( $title, $repo ) {
 167                 // Some subclasses do not use $title, but set name/title some other way
 168                 if ( $title !== false ) {
 169                         $title = self::normalizeTitle( $title, 'exception' );
 170                 }
 171                 $this->title = $title;
 172                 $this->repo = $repo;
 173         }
 174
 175         /**
 176          * Given a string or Title object return either a
 177          * valid Title object with namespace NS_FILE or null
 178          *
 179          * @param Title|string $title
 180          * @param string|bool $exception Use 'exception' to throw an error on bad titles
 181          * @throws MWException
 182          * @return Title|null
 183          */
 184         static function normalizeTitle( $title, $exception = false ) {
 185                 $ret = $title;
 186                 if ( $ret instanceof Title ) {
 187                         # Normalize NS_MEDIA -> NS_FILE
 188                         if ( $ret->getNamespace() == NS_MEDIA ) {
 189                                 $ret = Title::makeTitleSafe( NS_FILE, $ret->getDBkey() );
 190                         # Sanity check the title namespace
 191                         } elseif ( $ret->getNamespace() !== NS_FILE ) {
 192                                 $ret = null;
 193                         }
 194                 } else {
 195                         # Convert strings to Title objects
 196                         $ret = Title::makeTitleSafe( NS_FILE, (string)$ret );
 197                 }
 198                 if ( !$ret && $exception !== false ) {
 199                         throw new MWException( "`$title` is not a valid file title." );
 200                 }
 201
 202                 return $ret;
 203         }
 204
 205         function __get( $name ) {
 206                 $function = [ $this, 'get' . ucfirst( $name ) ];
 207                 if ( !is_callable( $function ) ) {
 208                         return null;
 209                 } else {
 210                         $this->$name = call_user_func( $function );
 211
 212                         return $this->$name;
 213                 }
 214         }
 215
 216         /**
 217          * Normalize a file extension to the common form, making it lowercase and checking some synonyms,
 218          * and ensure it's clean. Extensions with non-alphanumeric characters will be discarded.
 219          * Keep in sync with mw.Title.normalizeExtension() in JS.
 220          *
 221          * @param string $extension File extension (without the leading dot)
 222          * @return string File extension in canonical form
 223          */
 224         static function normalizeExtension( $extension ) {
 225                 $lower = strtolower( $extension );
 226                 $squish = [
 227                         'htm' => 'html',
 228                         'jpeg' => 'jpg',
 229                         'mpeg' => 'mpg',
 230                         'tiff' => 'tif',
 231                         'ogv' => 'ogg' ];
 232                 if ( isset( $squish[$lower] ) ) {
 233                         return $squish[$lower];
 234                 } elseif ( preg_match( '/^[0-9a-z]+$/', $lower ) ) {
 235                         return $lower;
 236                 } else {
 237                         return '';
 238                 }
 239         }
 240
 241         /**
 242          * Checks if file extensions are compatible
 243          *
 244          * @param File $old Old file
 245          * @param string $new New name
 246          *
 247          * @return bool|null
 248          */
 249         static function checkExtensionCompatibility( File $old, $new ) {
 250                 $oldMime = $old->getMimeType();
 251                 $n = strrpos( $new, '.' );
 252                 $newExt = self::normalizeExtension( $n ? substr( $new, $n + 1 ) : '' );
 253                 $mimeMagic = MediaWiki\MediaWikiServices::getInstance()->getMimeAnalyzer();
 254
 255                 return $mimeMagic->isMatchingExtension( $newExt, $oldMime );
 256         }
 257
 258         /**
 259          * Upgrade the database row if there is one
 260          * Called by ImagePage
 261          * STUB
 262          */
 263         function upgradeRow() {
 264         }
 265
 266         /**
 267          * Split an internet media type into its two components; if not
 268          * a two-part name, set the minor type to 'unknown'.
 269          *
 270          * @param string $mime "text/html" etc
 271          * @return array ("text", "html") etc
 272          */
 273         public static function splitMime( $mime ) {
 274                 if ( strpos( $mime, '/' ) !== false ) {
 275                         return explode( '/', $mime, 2 );
 276                 } else {
 277                         return [ $mime, 'unknown' ];
 278                 }
 279         }
 280
 281         /**
 282          * Callback for usort() to do file sorts by name
 283          *
 284          * @param File $a
 285          * @param File $b
 286          * @return int Result of name comparison
 287          */
 288         public static function compare( File $a, File $b ) {
 289                 return strcmp( $a->getName(), $b->getName() );
 290         }
 291
 292         /**
 293          * Return the name of this file
 294          *
 295          * @return string
 296          */
 297         public function getName() {
 298                 if ( !isset( $this->name ) ) {
 299                         $this->assertRepoDefined();
 300                         $this->name = $this->repo->getNameFromTitle( $this->title );
 301                 }
 302
 303                 return $this->name;
 304         }
 305
 306         /**
 307          * Get the file extension, e.g. "svg"
 308          *
 309          * @return string
 310          */
 311         function getExtension() {
 312                 if ( !isset( $this->extension ) ) {
 313                         $n = strrpos( $this->getName(), '.' );
 314                         $this->extension = self::normalizeExtension(
 315                                 $n ? substr( $this->getName(), $n + 1 ) : '' );
 316                 }
 317
 318                 return $this->extension;
 319         }
 320
 321         /**
 322          * Return the associated title object
 323          *
 324          * @return Title
 325          */
 326         public function getTitle() {
 327                 return $this->title;
 328         }
 329
 330         /**
 331          * Return the title used to find this file
 332          *
 333          * @return Title
 334          */
 335         public function getOriginalTitle() {
 336                 if ( $this->redirected ) {
 337                         return $this->getRedirectedTitle();
 338                 }
 339
 340                 return $this->title;
 341         }
 342
 343         /**
 344          * Return the URL of the file
 345          *
 346          * @return string
 347          */
 348         public function getUrl() {
 349                 if ( !isset( $this->url ) ) {
 350                         $this->assertRepoDefined();
 351                         $ext = $this->getExtension();
 352                         $this->url = $this->repo->getZoneUrl( 'public', $ext ) . '/' . $this->getUrlRel();
 353                 }
 354
 355                 return $this->url;
 356         }
 357
 358         /**
 359          * Get short description URL for a files based on the page ID
 360          *
 361          * @return string|null
 362          * @since 1.27
 363          */
 364         public function getDescriptionShortUrl() {
 365                 return null;
 366         }
 367
 368         /**
 369          * Return a fully-qualified URL to the file.
 370          * Upload URL paths _may or may not_ be fully qualified, so
 371          * we check. Local paths are assumed to belong on $wgServer.
 372          *
 373          * @return string
 374          */
 375         public function getFullUrl() {
 376                 return wfExpandUrl( $this->getUrl(), PROTO_RELATIVE );
 377         }
 378
 379         /**
 380          * @return string
 381          */
 382         public function getCanonicalUrl() {
 383                 return wfExpandUrl( $this->getUrl(), PROTO_CANONICAL );
 384         }
 385
 386         /**
 387          * @return string
 388          */
 389         function getViewURL() {
 390                 if ( $this->mustRender() ) {
 391                         if ( $this->canRender() ) {
 392                                 return $this->createThumb( $this->getWidth() );
 393                         } else {
 394                                 wfDebug( __METHOD__ . ': supposed to render ' . $this->getName() .
 395                                         ' (' . $this->getMimeType() . "), but can't!\n" );
 396
 397                                 return $this->getUrl(); # hm... return NULL?
 398                         }
 399                 } else {
 400                         return $this->getUrl();
 401                 }
 402         }
 403
 404         /**
 405          * Return the storage path to the file. Note that this does
 406          * not mean that a file actually exists under that location.
 407          *
 408          * This path depends on whether directory hashing is active or not,
 409          * i.e. whether the files are all found in the same directory,
 410          * or in hashed paths like /images/3/3c.
 411          *
 412          * Most callers don't check the return value, but ForeignAPIFile::getPath
 413          * returns false.
 414          *
 415          * @return string|bool ForeignAPIFile::getPath can return false
 416          */
 417         public function getPath() {
 418                 if ( !isset( $this->path ) ) {
 419                         $this->assertRepoDefined();
 420                         $this->path = $this->repo->getZonePath( 'public' ) . '/' . $this->getRel();
 421                 }
 422
 423                 return $this->path;
 424         }
 425
 426         /**
 427          * Get an FS copy or original of this file and return the path.
 428          * Returns false on failure. Callers must not alter the file.
 429          * Temporary files are cleared automatically.
 430          *
 431          * @return string|bool False on failure
 432          */
 433         public function getLocalRefPath() {
 434                 $this->assertRepoDefined();
 435                 if ( !isset( $this->fsFile ) ) {
 436                         $starttime = microtime( true );
 437                         $this->fsFile = $this->repo->getLocalReference( $this->getPath() );
 438
 439                         $statTiming = microtime( true ) - $starttime;
 440                         MediaWikiServices::getInstance()->getStatsdDataFactory()->timing(
 441                                 'media.thumbnail.generate.fetchoriginal', 1000 * $statTiming );
 442
 443                         if ( !$this->fsFile ) {
 444                                 $this->fsFile = false; // null => false; cache negative hits
 445                         }
 446                 }
 447
 448                 return ( $this->fsFile )
 449                         ? $this->fsFile->getPath()
 450                         : false;
 451         }
 452
 453         /**
 454          * Return the width of the image. Returns false if the width is unknown
 455          * or undefined.
 456          *
 457          * STUB
 458          * Overridden by LocalFile, UnregisteredLocalFile
 459          *
 460          * @param int $page
 461          * @return int|bool
 462          */
 463         public function getWidth( $page = 1 ) {
 464                 return false;
 465         }
 466
 467         /**
 468          * Return the height of the image. Returns false if the height is unknown
 469          * or undefined
 470          *
 471          * STUB
 472          * Overridden by LocalFile, UnregisteredLocalFile
 473          *
 474          * @param int $page
 475          * @return bool|int False on failure
 476          */
 477         public function getHeight( $page = 1 ) {
 478                 return false;
 479         }
 480
 481         /**
 482          * Return the smallest bucket from $wgThumbnailBuckets which is at least
 483          * $wgThumbnailMinimumBucketDistance larger than $desiredWidth. The returned bucket, if any,
 484          * will always be bigger than $desiredWidth.
 485          *
 486          * @param int $desiredWidth
 487          * @param int $page
 488          * @return bool|int
 489          */
 490         public function getThumbnailBucket( $desiredWidth, $page = 1 ) {
 491                 global $wgThumbnailBuckets, $wgThumbnailMinimumBucketDistance;
 492
 493                 $imageWidth = $this->getWidth( $page );
 494
 495                 if ( $imageWidth === false ) {
 496                         return false;
 497                 }
 498
 499                 if ( $desiredWidth > $imageWidth ) {
 500                         return false;
 501                 }
 502
 503                 if ( !$wgThumbnailBuckets ) {
 504                         return false;
 505                 }
 506
 507                 $sortedBuckets = $wgThumbnailBuckets;
 508
 509                 sort( $sortedBuckets );
 510
 511                 foreach ( $sortedBuckets as $bucket ) {
 512                         if ( $bucket >= $imageWidth ) {
 513                                 return false;
 514                         }
 515
 516                         if ( $bucket - $wgThumbnailMinimumBucketDistance > $desiredWidth ) {
 517                                 return $bucket;
 518                         }
 519                 }
 520
 521                 // Image is bigger than any available bucket
 522                 return false;
 523         }
 524
 525         /**
 526          * Returns ID or name of user who uploaded the file
 527          * STUB
 528          *
 529          * @param string $type 'text' or 'id'
 530          * @return string|int
 531          */
 532         public function getUser( $type = 'text' ) {
 533                 return null;
 534         }
 535
 536         /**
 537          * Get the duration of a media file in seconds
 538          *
 539          * @return float|int
 540          */
 541         public function getLength() {
 542                 $handler = $this->getHandler();
 543                 if ( $handler ) {
 544                         return $handler->getLength( $this );
 545                 } else {
 546                         return 0;
 547                 }
 548         }
 549
 550         /**
 551          * Return true if the file is vectorized
 552          *
 553          * @return bool
 554          */
 555         public function isVectorized() {
 556                 $handler = $this->getHandler();
 557                 if ( $handler ) {
 558                         return $handler->isVectorized( $this );
 559                 } else {
 560                         return false;
 561                 }
 562         }
 563
 564         /**
 565          * Gives a (possibly empty) list of languages to render
 566          * the file in.
 567          *
 568          * If the file doesn't have translations, or if the file
 569          * format does not support that sort of thing, returns
 570          * an empty array.
 571          *
 572          * @return array
 573          * @since 1.23
 574          */
 575         public function getAvailableLanguages() {
 576                 $handler = $this->getHandler();
 577                 if ( $handler ) {
 578                         return $handler->getAvailableLanguages( $this );
 579                 } else {
 580                         return [];
 581                 }
 582         }
 583
 584         /**
 585          * Get the language code from the available languages for this file that matches the language
 586          * requested by the user
 587          *
 588          * @param string $userPreferredLanguage
 589          * @return string|null
 590          */
 591         public function getMatchedLanguage( $userPreferredLanguage ) {
 592                 $handler = $this->getHandler();
 593                 if ( $handler && method_exists( $handler, 'getMatchedLanguage' ) ) {
 594                         return $handler->getMatchedLanguage(
 595                                 $userPreferredLanguage,
 596                                 $handler->getAvailableLanguages( $this )
 597                         );
 598                 } else {
 599                         return null;
 600                 }
 601         }
 602
 603         /**
 604          * In files that support multiple language, what is the default language
 605          * to use if none specified.
 606          *
 607          * @return string|null Lang code, or null if filetype doesn't support multiple languages.
 608          * @since 1.23
 609          */
 610         public function getDefaultRenderLanguage() {
 611                 $handler = $this->getHandler();
 612                 if ( $handler ) {
 613                         return $handler->getDefaultRenderLanguage( $this );
 614                 } else {
 615                         return null;
 616                 }
 617         }
 618
 619         /**
 620          * Will the thumbnail be animated if one would expect it to be.
 621          *
 622          * Currently used to add a warning to the image description page
 623          *
 624          * @return bool False if the main image is both animated
 625          *   and the thumbnail is not. In all other cases must return
 626          *   true. If image is not renderable whatsoever, should
 627          *   return true.
 628          */
 629         public function canAnimateThumbIfAppropriate() {
 630                 $handler = $this->getHandler();
 631                 if ( !$handler ) {
 632                         // We cannot handle image whatsoever, thus
 633                         // one would not expect it to be animated
 634                         // so true.
 635                         return true;
 636                 } else {
 637                         if ( $this->allowInlineDisplay()
 638                                 && $handler->isAnimatedImage( $this )
 639                                 && !$handler->canAnimateThumbnail( $this )
 640                         ) {
 641                                 // Image is animated, but thumbnail isn't.
 642                                 // This is unexpected to the user.
 643                                 return false;
 644                         } else {
 645                                 // Image is not animated, so one would
 646                                 // not expect thumb to be
 647                                 return true;
 648                         }
 649                 }
 650         }
 651
 652         /**
 653          * Get handler-specific metadata
 654          * Overridden by LocalFile, UnregisteredLocalFile
 655          * STUB
 656          * @return bool|array
 657          */
 658         public function getMetadata() {
 659                 return false;
 660         }
 661
 662         /**
 663          * Like getMetadata but returns a handler independent array of common values.
 664          * @see MediaHandler::getCommonMetaArray()
 665          * @return array|bool Array or false if not supported
 666          * @since 1.23
 667          */
 668         public function getCommonMetaArray() {
 669                 $handler = $this->getHandler();
 670
 671                 if ( !$handler ) {
 672                         return false;
 673                 }
 674
 675                 return $handler->getCommonMetaArray( $this );
 676         }
 677
 678         /**
 679          * get versioned metadata
 680          *
 681          * @param array|string $metadata Array or string of (serialized) metadata
 682          * @param int $version Version number.
 683          * @return array Array containing metadata, or what was passed to it on fail
 684          *   (unserializing if not array)
 685          */
 686         public function convertMetadataVersion( $metadata, $version ) {
 687                 $handler = $this->getHandler();
 688                 if ( !is_array( $metadata ) ) {
 689                         // Just to make the return type consistent
 690                         $metadata = unserialize( $metadata );
 691                 }
 692                 if ( $handler ) {
 693                         return $handler->convertMetadataVersion( $metadata, $version );
 694                 } else {
 695                         return $metadata;
 696                 }
 697         }
 698
 699         /**
 700          * Return the bit depth of the file
 701          * Overridden by LocalFile
 702          * STUB
 703          * @return int
 704          */
 705         public function getBitDepth() {
 706                 return 0;
 707         }
 708
 709         /**
 710          * Return the size of the image file, in bytes
 711          * Overridden by LocalFile, UnregisteredLocalFile
 712          * STUB
 713          * @return bool
 714          */
 715         public function getSize() {
 716                 return false;
 717         }
 718
 719         /**
 720          * Returns the MIME type of the file.
 721          * Overridden by LocalFile, UnregisteredLocalFile
 722          * STUB
 723          *
 724          * @return string
 725          */
 726         function getMimeType() {
 727                 return 'unknown/unknown';
 728         }
 729
 730         /**
 731          * Return the type of the media in the file.
 732          * Use the value returned by this function with the MEDIATYPE_xxx constants.
 733          * Overridden by LocalFile,
 734          * STUB
 735          * @return string
 736          */
 737         function getMediaType() {
 738                 return MEDIATYPE_UNKNOWN;
 739         }
 740
 741         /**
 742          * Checks if the output of transform() for this file is likely
 743          * to be valid. If this is false, various user elements will
 744          * display a placeholder instead.
 745          *
 746          * Currently, this checks if the file is an image format
 747          * that can be converted to a format
 748          * supported by all browsers (namely GIF, PNG and JPEG),
 749          * or if it is an SVG image and SVG conversion is enabled.
 750          *
 751          * @return bool
 752          */
 753         function canRender() {
 754                 if ( !isset( $this->canRender ) ) {
 755                         $this->canRender = $this->getHandler() && $this->handler->canRender( $this ) && $this->exists();
 756                 }
 757
 758                 return $this->canRender;
 759         }
 760
 761         /**
 762          * Accessor for __get()
 763          * @return bool
 764          */
 765         protected function getCanRender() {
 766                 return $this->canRender();
 767         }
 768
 769         /**
 770          * Return true if the file is of a type that can't be directly
 771          * rendered by typical browsers and needs to be re-rasterized.
 772          *
 773          * This returns true for everything but the bitmap types
 774          * supported by all browsers, i.e. JPEG; GIF and PNG. It will
 775          * also return true for any non-image formats.
 776          *
 777          * @return bool
 778          */
 779         function mustRender() {
 780                 return $this->getHandler() && $this->handler->mustRender( $this );
 781         }
 782
 783         /**
 784          * Alias for canRender()
 785          *
 786          * @return bool
 787          */
 788         function allowInlineDisplay() {
 789                 return $this->canRender();
 790         }
 791
 792         /**
 793          * Determines if this media file is in a format that is unlikely to
 794          * contain viruses or malicious content. It uses the global
 795          * $wgTrustedMediaFormats list to determine if the file is safe.
 796          *
 797          * This is used to show a warning on the description page of non-safe files.
 798          * It may also be used to disallow direct [[media:...]] links to such files.
 799          *
 800          * Note that this function will always return true if allowInlineDisplay()
 801          * or isTrustedFile() is true for this file.
 802          *
 803          * @return bool
 804          */
 805         function isSafeFile() {
 806                 if ( !isset( $this->isSafeFile ) ) {
 807                         $this->isSafeFile = $this->getIsSafeFileUncached();
 808                 }
 809
 810                 return $this->isSafeFile;
 811         }
 812
 813         /**
 814          * Accessor for __get()
 815          *
 816          * @return bool
 817          */
 818         protected function getIsSafeFile() {
 819                 return $this->isSafeFile();
 820         }
 821
 822         /**
 823          * Uncached accessor
 824          *
 825          * @return bool
 826          */
 827         protected function getIsSafeFileUncached() {
 828                 global $wgTrustedMediaFormats;
 829
 830                 if ( $this->allowInlineDisplay() ) {
 831                         return true;
 832                 }
 833                 if ( $this->isTrustedFile() ) {
 834                         return true;
 835                 }
 836
 837                 $type = $this->getMediaType();
 838                 $mime = $this->getMimeType();
 839                 # wfDebug( "LocalFile::isSafeFile: type= $type, mime= $mime\n" );
 840
 841                 if ( !$type || $type === MEDIATYPE_UNKNOWN ) {
 842                         return false; # unknown type, not trusted
 843                 }
 844                 if ( in_array( $type, $wgTrustedMediaFormats ) ) {
 845                         return true;
 846                 }
 847
 848                 if ( $mime === "unknown/unknown" ) {
 849                         return false; # unknown type, not trusted
 850                 }
 851                 if ( in_array( $mime, $wgTrustedMediaFormats ) ) {
 852                         return true;
 853                 }
 854
 855                 return false;
 856         }
 857
 858         /**
 859          * Returns true if the file is flagged as trusted. Files flagged that way
 860          * can be linked to directly, even if that is not allowed for this type of
 861          * file normally.
 862          *
 863          * This is a dummy function right now and always returns false. It could be
 864          * implemented to extract a flag from the database. The trusted flag could be
 865          * set on upload, if the user has sufficient privileges, to bypass script-
 866          * and html-filters. It may even be coupled with cryptographics signatures
 867          * or such.
 868          *
 869          * @return bool
 870          */
 871         function isTrustedFile() {
 872                 # this could be implemented to check a flag in the database,
 873                 # look for signatures, etc
 874                 return false;
 875         }
 876
 877         /**
 878          * Load any lazy-loaded file object fields from source
 879          *
 880          * This is only useful when setting $flags
 881          *
 882          * Overridden by LocalFile to actually query the DB
 883          *
 884          * @param int $flags Bitfield of File::READ_* constants
 885          */
 886         public function load( $flags = 0 ) {
 887         }
 888
 889         /**
 890          * Returns true if file exists in the repository.
 891          *
 892          * Overridden by LocalFile to avoid unnecessary stat calls.
 893          *
 894          * @return bool Whether file exists in the repository.
 895          */
 896         public function exists() {
 897                 return $this->getPath() && $this->repo->fileExists( $this->path );
 898         }
 899
 900         /**
 901          * Returns true if file exists in the repository and can be included in a page.
 902          * It would be unsafe to include private images, making public thumbnails inadvertently
 903          *
 904          * @return bool Whether file exists in the repository and is includable.
 905          */
 906         public function isVisible() {
 907                 return $this->exists();
 908         }
 909
 910         /**
 911          * @return string
 912          */
 913         function getTransformScript() {
 914                 if ( !isset( $this->transformScript ) ) {
 915                         $this->transformScript = false;
 916                         if ( $this->repo ) {
 917                                 $script = $this->repo->getThumbScriptUrl();
 918                                 if ( $script ) {
 919                                         $this->transformScript = wfAppendQuery( $script, [ 'f' => $this->getName() ] );
 920                                 }
 921                         }
 922                 }
 923
 924                 return $this->transformScript;
 925         }
 926
 927         /**
 928          * Get a ThumbnailImage which is the same size as the source
 929          *
 930          * @param array $handlerParams
 931          *
 932          * @return ThumbnailImage|MediaTransformOutput|bool False on failure
 933          */
 934         function getUnscaledThumb( $handlerParams = [] ) {
 935                 $hp =& $handlerParams;
 936                 $page = isset( $hp['page'] ) ? $hp['page'] : false;
 937                 $width = $this->getWidth( $page );
 938                 if ( !$width ) {
 939                         return $this->iconThumb();
 940                 }
 941                 $hp['width'] = $width;
 942                 // be sure to ignore any height specification as well (T64258)
 943                 unset( $hp['height'] );
 944
 945                 return $this->transform( $hp );
 946         }
 947
 948         /**
 949          * Return the file name of a thumbnail with the specified parameters.
 950          * Use File::THUMB_FULL_NAME to always get a name like "<params>-<source>".
 951          * Otherwise, the format may be "<params>-<source>" or "<params>-thumbnail.<ext>".
 952          *
 953          * @param array $params Handler-specific parameters
 954          * @param int $flags Bitfield that supports THUMB_* constants
 955          * @return string|null
 956          */
 957         public function thumbName( $params, $flags = 0 ) {
 958                 $name = ( $this->repo && !( $flags & self::THUMB_FULL_NAME ) )
 959                         ? $this->repo->nameForThumb( $this->getName() )
 960                         : $this->getName();
 961
 962                 return $this->generateThumbName( $name, $params );
 963         }
 964
 965         /**
 966          * Generate a thumbnail file name from a name and specified parameters
 967          *
 968          * @param string $name
 969          * @param array $params Parameters which will be passed to MediaHandler::makeParamString
 970          * @return string|null
 971          */
 972         public function generateThumbName( $name, $params ) {
 973                 if ( !$this->getHandler() ) {
 974                         return null;
 975                 }
 976                 $extension = $this->getExtension();
 977                 list( $thumbExt, ) = $this->getHandler()->getThumbType(
 978                         $extension, $this->getMimeType(), $params );
 979                 $thumbName = $this->getHandler()->makeParamString( $params );
 980
 981                 if ( $this->repo->supportsSha1URLs() ) {
 982                         $thumbName .= '-' . $this->getSha1() . '.' . $thumbExt;
 983                 } else {
 984                         $thumbName .= '-' . $name;
 985
 986                         if ( $thumbExt != $extension ) {
 987                                 $thumbName .= ".$thumbExt";
 988                         }
 989                 }
 990
 991                 return $thumbName;
 992         }
 993
 994         /**
 995          * Create a thumbnail of the image having the specified width/height.
 996          * The thumbnail will not be created if the width is larger than the
 997          * image's width. Let the browser do the scaling in this case.
 998          * The thumbnail is stored on disk and is only computed if the thumbnail
 999          * file does not exist OR if it is older than the image.
1000          * Returns the URL.
1001          *
1002          * Keeps aspect ratio of original image. If both width and height are
1003          * specified, the generated image will be no bigger than width x height,
1004          * and will also have correct aspect ratio.
1005          *
1006          * @param int $width Maximum width of the generated thumbnail
1007          * @param int $height Maximum height of the image (optional)
1008          *
1009          * @return string
1010          */
1011         public function createThumb( $width, $height = -1 ) {
1012                 $params = [ 'width' => $width ];
1013                 if ( $height != -1 ) {
1014                         $params['height'] = $height;
1015                 }
1016                 $thumb = $this->transform( $params );
1017                 if ( !$thumb || $thumb->isError() ) {
1018                         return '';
1019                 }
1020
1021                 return $thumb->getUrl();
1022         }
1023
1024         /**
1025          * Return either a MediaTransformError or placeholder thumbnail (if $wgIgnoreImageErrors)
1026          *
1027          * @param string $thumbPath Thumbnail storage path
1028          * @param string $thumbUrl Thumbnail URL
1029          * @param array $params
1030          * @param int $flags
1031          * @return MediaTransformOutput
1032          */
1033         protected function transformErrorOutput( $thumbPath, $thumbUrl, $params, $flags ) {
1034                 global $wgIgnoreImageErrors;
1035
1036                 $handler = $this->getHandler();
1037                 if ( $handler && $wgIgnoreImageErrors && !( $flags & self::RENDER_NOW ) ) {
1038                         return $handler->getTransform( $this, $thumbPath, $thumbUrl, $params );
1039                 } else {
1040                         return new MediaTransformError( 'thumbnail_error',
1041                                 $params['width'], 0, wfMessage( 'thumbnail-dest-create' ) );
1042                 }
1043         }
1044
1045         /**
1046          * Transform a media file
1047          *
1048          * @param array $params An associative array of handler-specific parameters.
1049          *   Typical keys are width, height and page.
1050          * @param int $flags A bitfield, may contain self::RENDER_NOW to force rendering
1051          * @return ThumbnailImage|MediaTransformOutput|bool False on failure
1052          */
1053         function transform( $params, $flags = 0 ) {
1054                 global $wgThumbnailEpoch;
1055
1056                 do {
1057                         if ( !$this->canRender() ) {
1058                                 $thumb = $this->iconThumb();
1059                                 break; // not a bitmap or renderable image, don't try
1060                         }
1061
1062                         // Get the descriptionUrl to embed it as comment into the thumbnail. T21791.
1063                         $descriptionUrl = $this->getDescriptionUrl();
1064                         if ( $descriptionUrl ) {
1065                                 $params['descriptionUrl'] = wfExpandUrl( $descriptionUrl, PROTO_CANONICAL );
1066                         }
1067
1068                         $handler = $this->getHandler();
1069                         $script = $this->getTransformScript();
1070                         if ( $script && !( $flags & self::RENDER_NOW ) ) {
1071                                 // Use a script to transform on client request, if possible
1072                                 $thumb = $handler->getScriptedTransform( $this, $script, $params );
1073                                 if ( $thumb ) {
1074                                         break;
1075                                 }
1076                         }
1077
1078                         $normalisedParams = $params;
1079                         $handler->normaliseParams( $this, $normalisedParams );
1080
1081                         $thumbName = $this->thumbName( $normalisedParams );
1082                         $thumbUrl = $this->getThumbUrl( $thumbName );
1083                         $thumbPath = $this->getThumbPath( $thumbName ); // final thumb path
1084
1085                         if ( $this->repo ) {
1086                                 // Defer rendering if a 404 handler is set up...
1087                                 if ( $this->repo->canTransformVia404() && !( $flags & self::RENDER_NOW ) ) {
1088                                         // XXX: Pass in the storage path even though we are not rendering anything
1089                                         // and the path is supposed to be an FS path. This is due to getScalerType()
1090                                         // getting called on the path and clobbering $thumb->getUrl() if it's false.
1091                                         $thumb = $handler->getTransform( $this, $thumbPath, $thumbUrl, $params );
1092                                         break;
1093                                 }
1094                                 // Check if an up-to-date thumbnail already exists...
1095                                 wfDebug( __METHOD__ . ": Doing stat for $thumbPath\n" );
1096                                 if ( !( $flags & self::RENDER_FORCE ) && $this->repo->fileExists( $thumbPath ) ) {
1097                                         $timestamp = $this->repo->getFileTimestamp( $thumbPath );
1098                                         if ( $timestamp !== false && $timestamp >= $wgThumbnailEpoch ) {
1099                                                 // XXX: Pass in the storage path even though we are not rendering anything
1100                                                 // and the path is supposed to be an FS path. This is due to getScalerType()
1101                                                 // getting called on the path and clobbering $thumb->getUrl() if it's false.
1102                                                 $thumb = $handler->getTransform( $this, $thumbPath, $thumbUrl, $params );
1103                                                 $thumb->setStoragePath( $thumbPath );
1104                                                 break;
1105                                         }
1106                                 } elseif ( $flags & self::RENDER_FORCE ) {
1107                                         wfDebug( __METHOD__ . " forcing rendering per flag File::RENDER_FORCE\n" );
1108                                 }
1109
1110                                 // If the backend is ready-only, don't keep generating thumbnails
1111                                 // only to return transformation errors, just return the error now.
1112                                 if ( $this->repo->getReadOnlyReason() !== false ) {
1113                                         $thumb = $this->transformErrorOutput( $thumbPath, $thumbUrl, $params, $flags );
1114                                         break;
1115                                 }
1116                         }
1117
1118                         $tmpFile = $this->makeTransformTmpFile( $thumbPath );
1119
1120                         if ( !$tmpFile ) {
1121                                 $thumb = $this->transformErrorOutput( $thumbPath, $thumbUrl, $params, $flags );
1122                         } else {
1123                                 $thumb = $this->generateAndSaveThumb( $tmpFile, $params, $flags );
1124                         }
1125                 } while ( false );
1126
1127                 return is_object( $thumb ) ? $thumb : false;
1128         }
1129
1130         /**
1131          * Generates a thumbnail according to the given parameters and saves it to storage
1132          * @param TempFSFile $tmpFile Temporary file where the rendered thumbnail will be saved
1133          * @param array $transformParams
1134          * @param int $flags
1135          * @return bool|MediaTransformOutput
1136          */
1137         public function generateAndSaveThumb( $tmpFile, $transformParams, $flags ) {
1138                 global $wgIgnoreImageErrors;
1139
1140                 $stats = MediaWikiServices::getInstance()->getStatsdDataFactory();
1141
1142                 $handler = $this->getHandler();
1143
1144                 $normalisedParams = $transformParams;
1145                 $handler->normaliseParams( $this, $normalisedParams );
1146
1147                 $thumbName = $this->thumbName( $normalisedParams );
1148                 $thumbUrl = $this->getThumbUrl( $thumbName );
1149                 $thumbPath = $this->getThumbPath( $thumbName ); // final thumb path
1150
1151                 $tmpThumbPath = $tmpFile->getPath();
1152
1153                 if ( $handler->supportsBucketing() ) {
1154                         $this->generateBucketsIfNeeded( $normalisedParams, $flags );
1155                 }
1156
1157                 $starttime = microtime( true );
1158
1159                 // Actually render the thumbnail...
1160                 $thumb = $handler->doTransform( $this, $tmpThumbPath, $thumbUrl, $transformParams );
1161                 $tmpFile->bind( $thumb ); // keep alive with $thumb
1162
1163                 $statTiming = microtime( true ) - $starttime;
1164                 $stats->timing( 'media.thumbnail.generate.transform', 1000 * $statTiming );
1165
1166                 if ( !$thumb ) { // bad params?
1167                         $thumb = false;
1168                 } elseif ( $thumb->isError() ) { // transform error
1169                         /** @var MediaTransformError $thumb */
1170                         $this->lastError = $thumb->toText();
1171                         // Ignore errors if requested
1172                         if ( $wgIgnoreImageErrors && !( $flags & self::RENDER_NOW ) ) {
1173                                 $thumb = $handler->getTransform( $this, $tmpThumbPath, $thumbUrl, $transformParams );
1174                         }
1175                 } elseif ( $this->repo && $thumb->hasFile() && !$thumb->fileIsSource() ) {
1176                         // Copy the thumbnail from the file system into storage...
1177
1178                         $starttime = microtime( true );
1179
1180                         $disposition = $this->getThumbDisposition( $thumbName );
1181                         $status = $this->repo->quickImport( $tmpThumbPath, $thumbPath, $disposition );
1182                         if ( $status->isOK() ) {
1183                                 $thumb->setStoragePath( $thumbPath );
1184                         } else {
1185                                 $thumb = $this->transformErrorOutput( $thumbPath, $thumbUrl, $transformParams, $flags );
1186                         }
1187
1188                         $statTiming = microtime( true ) - $starttime;
1189                         $stats->timing( 'media.thumbnail.generate.store', 1000 * $statTiming );
1190
1191                         // Give extensions a chance to do something with this thumbnail...
1192                         Hooks::run( 'FileTransformed', [ $this, $thumb, $tmpThumbPath, $thumbPath ] );
1193                 }
1194
1195                 return $thumb;
1196         }
1197
1198         /**
1199          * Generates chained bucketed thumbnails if needed
1200          * @param array $params
1201          * @param int $flags
1202          * @return bool Whether at least one bucket was generated
1203          */
1204         protected function generateBucketsIfNeeded( $params, $flags = 0 ) {
1205                 if ( !$this->repo
1206                         || !isset( $params['physicalWidth'] )
1207                         || !isset( $params['physicalHeight'] )
1208                 ) {
1209                         return false;
1210                 }
1211
1212                 $bucket = $this->getThumbnailBucket( $params['physicalWidth'] );
1213
1214                 if ( !$bucket || $bucket == $params['physicalWidth'] ) {
1215                         return false;
1216                 }
1217
1218                 $bucketPath = $this->getBucketThumbPath( $bucket );
1219
1220                 if ( $this->repo->fileExists( $bucketPath ) ) {
1221                         return false;
1222                 }
1223
1224                 $starttime = microtime( true );
1225
1226                 $params['physicalWidth'] = $bucket;
1227                 $params['width'] = $bucket;
1228
1229                 $params = $this->getHandler()->sanitizeParamsForBucketing( $params );
1230
1231                 $tmpFile = $this->makeTransformTmpFile( $bucketPath );
1232
1233                 if ( !$tmpFile ) {
1234                         return false;
1235                 }
1236
1237                 $thumb = $this->generateAndSaveThumb( $tmpFile, $params, $flags );
1238
1239                 $buckettime = microtime( true ) - $starttime;
1240
1241                 if ( !$thumb || $thumb->isError() ) {
1242                         return false;
1243                 }
1244
1245                 $this->tmpBucketedThumbCache[$bucket] = $tmpFile->getPath();
1246                 // For the caching to work, we need to make the tmp file survive as long as
1247                 // this object exists
1248                 $tmpFile->bind( $this );
1249
1250                 MediaWikiServices::getInstance()->getStatsdDataFactory()->timing(
1251                         'media.thumbnail.generate.bucket', 1000 * $buckettime );
1252
1253                 return true;
1254         }
1255
1256         /**
1257          * Returns the most appropriate source image for the thumbnail, given a target thumbnail size
1258          * @param array $params
1259          * @return array Source path and width/height of the source
1260          */
1261         public function getThumbnailSource( $params ) {
1262                 if ( $this->repo
1263                         && $this->getHandler()->supportsBucketing()
1264                         && isset( $params['physicalWidth'] )
1265                         && $bucket = $this->getThumbnailBucket( $params['physicalWidth'] )
1266                 ) {
1267                         if ( $this->getWidth() != 0 ) {
1268                                 $bucketHeight = round( $this->getHeight() * ( $bucket / $this->getWidth() ) );
1269                         } else {
1270                                 $bucketHeight = 0;
1271                         }
1272
1273                         // Try to avoid reading from storage if the file was generated by this script
1274                         if ( isset( $this->tmpBucketedThumbCache[$bucket] ) ) {
1275                                 $tmpPath = $this->tmpBucketedThumbCache[$bucket];
1276
1277                                 if ( file_exists( $tmpPath ) ) {
1278                                         return [
1279                                                 'path' => $tmpPath,
1280                                                 'width' => $bucket,
1281                                                 'height' => $bucketHeight
1282                                         ];
1283                                 }
1284                         }
1285
1286                         $bucketPath = $this->getBucketThumbPath( $bucket );
1287
1288                         if ( $this->repo->fileExists( $bucketPath ) ) {
1289                                 $fsFile = $this->repo->getLocalReference( $bucketPath );
1290
1291                                 if ( $fsFile ) {
1292                                         return [
1293                                                 'path' => $fsFile->getPath(),
1294                                                 'width' => $bucket,
1295                                                 'height' => $bucketHeight
1296                                         ];
1297                                 }
1298                         }
1299                 }
1300
1301                 // Thumbnailing a very large file could result in network saturation if
1302                 // everyone does it at once.
1303                 if ( $this->getSize() >= 1e7 ) { // 10MB
1304                         $work = new PoolCounterWorkViaCallback( 'GetLocalFileCopy', sha1( $this->getName() ),
1305                                 [
1306                                         'doWork' => function () {
1307                                                 return $this->getLocalRefPath();
1308                                         }
1309                                 ]
1310                         );
1311                         $srcPath = $work->execute();
1312                 } else {
1313                         $srcPath = $this->getLocalRefPath();
1314                 }
1315
1316                 // Original file
1317                 return [
1318                         'path' => $srcPath,
1319                         'width' => $this->getWidth(),
1320                         'height' => $this->getHeight()
1321                 ];
1322         }
1323
1324         /**
1325          * Returns the repo path of the thumb for a given bucket
1326          * @param int $bucket
1327          * @return string
1328          */
1329         protected function getBucketThumbPath( $bucket ) {
1330                 $thumbName = $this->getBucketThumbName( $bucket );
1331                 return $this->getThumbPath( $thumbName );
1332         }
1333
1334         /**
1335          * Returns the name of the thumb for a given bucket
1336          * @param int $bucket
1337          * @return string
1338          */
1339         protected function getBucketThumbName( $bucket ) {
1340                 return $this->thumbName( [ 'physicalWidth' => $bucket ] );
1341         }
1342
1343         /**
1344          * Creates a temp FS file with the same extension and the thumbnail
1345          * @param string $thumbPath Thumbnail path
1346          * @return TempFSFile|null
1347          */
1348         protected function makeTransformTmpFile( $thumbPath ) {
1349                 $thumbExt = FileBackend::extensionFromPath( $thumbPath );
1350                 return TempFSFile::factory( 'transform_', $thumbExt, wfTempDir() );
1351         }
1352
1353         /**
1354          * @param string $thumbName Thumbnail name
1355          * @param string $dispositionType Type of disposition (either "attachment" or "inline")
1356          * @return string Content-Disposition header value
1357          */
1358         function getThumbDisposition( $thumbName, $dispositionType = 'inline' ) {
1359                 $fileName = $this->name; // file name to suggest
1360                 $thumbExt = FileBackend::extensionFromPath( $thumbName );
1361                 if ( $thumbExt != '' && $thumbExt !== $this->getExtension() ) {
1362                         $fileName .= ".$thumbExt";
1363                 }
1364
1365                 return FileBackend::makeContentDisposition( $dispositionType, $fileName );
1366         }
1367
1368         /**
1369          * Hook into transform() to allow migration of thumbnail files
1370          * STUB
1371          * Overridden by LocalFile
1372          * @param string $thumbName
1373          */
1374         function migrateThumbFile( $thumbName ) {
1375         }
1376
1377         /**
1378          * Get a MediaHandler instance for this file
1379          *
1380          * @return MediaHandler|bool Registered MediaHandler for file's MIME type
1381          *   or false if none found
1382          */
1383         function getHandler() {
1384                 if ( !isset( $this->handler ) ) {
1385                         $this->handler = MediaHandler::getHandler( $this->getMimeType() );
1386                 }
1387
1388                 return $this->handler;
1389         }
1390
1391         /**
1392          * Get a ThumbnailImage representing a file type icon
1393          *
1394          * @return ThumbnailImage
1395          */
1396         function iconThumb() {
1397                 global $wgResourceBasePath, $IP;
1398                 $assetsPath = "$wgResourceBasePath/resources/assets/file-type-icons/";
1399                 $assetsDirectory = "$IP/resources/assets/file-type-icons/";
1400
1401                 $try = [ 'fileicon-' . $this->getExtension() . '.png', 'fileicon.png' ];
1402                 foreach ( $try as $icon ) {
1403                         if ( file_exists( $assetsDirectory . $icon ) ) { // always FS
1404                                 $params = [ 'width' => 120, 'height' => 120 ];
1405
1406                                 return new ThumbnailImage( $this, $assetsPath . $icon, false, $params );
1407                         }
1408                 }
1409
1410                 return null;
1411         }
1412
1413         /**
1414          * Get last thumbnailing error.
1415          * Largely obsolete.
1416          * @return string
1417          */
1418         function getLastError() {
1419                 return $this->lastError;
1420         }
1421
1422         /**
1423          * Get all thumbnail names previously generated for this file
1424          * STUB
1425          * Overridden by LocalFile
1426          * @return array
1427          */
1428         function getThumbnails() {
1429                 return [];
1430         }
1431
1432         /**
1433          * Purge shared caches such as thumbnails and DB data caching
1434          * STUB
1435          * Overridden by LocalFile
1436          * @param array $options Options, which include:
1437          *   'forThumbRefresh' : The purging is only to refresh thumbnails
1438          */
1439         function purgeCache( $options = [] ) {
1440         }
1441
1442         /**
1443          * Purge the file description page, but don't go after
1444          * pages using the file. Use when modifying file history
1445          * but not the current data.
1446          */
1447         function purgeDescription() {
1448                 $title = $this->getTitle();
1449                 if ( $title ) {
1450                         $title->invalidateCache();
1451                         $title->purgeSquid();
1452                 }
1453         }
1454
1455         /**
1456          * Purge metadata and all affected pages when the file is created,
1457          * deleted, or majorly updated.
1458          */
1459         function purgeEverything() {
1460                 // Delete thumbnails and refresh file metadata cache
1461                 $this->purgeCache();
1462                 $this->purgeDescription();
1463
1464                 // Purge cache of all pages using this file
1465                 $title = $this->getTitle();
1466                 if ( $title ) {
1467                         DeferredUpdates::addUpdate(
1468                                 new HTMLCacheUpdate( $title, 'imagelinks', 'file-purge' )
1469                         );
1470                 }
1471         }
1472
1473         /**
1474          * Return a fragment of the history of file.
1475          *
1476          * STUB
1477          * @param int $limit Limit of rows to return
1478          * @param string $start Only revisions older than $start will be returned
1479          * @param string $end Only revisions newer than $end will be returned
1480          * @param bool $inc Include the endpoints of the time range
1481          *
1482          * @return File[]
1483          */
1484         function getHistory( $limit = null, $start = null, $end = null, $inc = true ) {
1485                 return [];
1486         }
1487
1488         /**
1489          * Return the history of this file, line by line. Starts with current version,
1490          * then old versions. Should return an object similar to an image/oldimage
1491          * database row.
1492          *
1493          * STUB
1494          * Overridden in LocalFile
1495          * @return bool
1496          */
1497         public function nextHistoryLine() {
1498                 return false;
1499         }
1500
1501         /**
1502          * Reset the history pointer to the first element of the history.
1503          * Always call this function after using nextHistoryLine() to free db resources
1504          * STUB
1505          * Overridden in LocalFile.
1506          */
1507         public function resetHistory() {
1508         }
1509
1510         /**
1511          * Get the filename hash component of the directory including trailing slash,
1512          * e.g. f/fa/
1513          * If the repository is not hashed, returns an empty string.
1514          *
1515          * @return string
1516          */
1517         function getHashPath() {
1518                 if ( !isset( $this->hashPath ) ) {
1519                         $this->assertRepoDefined();
1520                         $this->hashPath = $this->repo->getHashPath( $this->getName() );
1521                 }
1522
1523                 return $this->hashPath;
1524         }
1525
1526         /**
1527          * Get the path of the file relative to the public zone root.
1528          * This function is overridden in OldLocalFile to be like getArchiveRel().
1529          *
1530          * @return string
1531          */
1532         function getRel() {
1533                 return $this->getHashPath() . $this->getName();
1534         }
1535
1536         /**
1537          * Get the path of an archived file relative to the public zone root
1538          *
1539          * @param bool|string $suffix If not false, the name of an archived thumbnail file
1540          *
1541          * @return string
1542          */
1543         function getArchiveRel( $suffix = false ) {
1544                 $path = 'archive/' . $this->getHashPath();
1545                 if ( $suffix === false ) {
1546                         $path = substr( $path, 0, -1 );
1547                 } else {
1548                         $path .= $suffix;
1549                 }
1550
1551                 return $path;
1552         }
1553
1554         /**
1555          * Get the path, relative to the thumbnail zone root, of the
1556          * thumbnail directory or a particular file if $suffix is specified
1557          *
1558          * @param bool|string $suffix If not false, the name of a thumbnail file
1559          * @return string
1560          */
1561         function getThumbRel( $suffix = false ) {
1562                 $path = $this->getRel();
1563                 if ( $suffix !== false ) {
1564                         $path .= '/' . $suffix;
1565                 }
1566
1567                 return $path;
1568         }
1569
1570         /**
1571          * Get urlencoded path of the file relative to the public zone root.
1572          * This function is overridden in OldLocalFile to be like getArchiveUrl().
1573          *
1574          * @return string
1575          */
1576         function getUrlRel() {
1577                 return $this->getHashPath() . rawurlencode( $this->getName() );
1578         }
1579
1580         /**
1581          * Get the path, relative to the thumbnail zone root, for an archived file's thumbs directory
1582          * or a specific thumb if the $suffix is given.
1583          *
1584          * @param string $archiveName The timestamped name of an archived image
1585          * @param bool|string $suffix If not false, the name of a thumbnail file
1586          * @return string
1587          */
1588         function getArchiveThumbRel( $archiveName, $suffix = false ) {
1589                 $path = 'archive/' . $this->getHashPath() . $archiveName . "/";
1590                 if ( $suffix === false ) {
1591                         $path = substr( $path, 0, -1 );
1592                 } else {
1593                         $path .= $suffix;
1594                 }
1595
1596                 return $path;
1597         }
1598
1599         /**
1600          * Get the path of the archived file.
1601          *
1602          * @param bool|string $suffix If not false, the name of an archived file.
1603          * @return string
1604          */
1605         function getArchivePath( $suffix = false ) {
1606                 $this->assertRepoDefined();
1607
1608                 return $this->repo->getZonePath( 'public' ) . '/' . $this->getArchiveRel( $suffix );
1609         }
1610
1611         /**
1612          * Get the path of an archived file's thumbs, or a particular thumb if $suffix is specified
1613          *
1614          * @param string $archiveName The timestamped name of an archived image
1615          * @param bool|string $suffix If not false, the name of a thumbnail file
1616          * @return string
1617          */
1618         function getArchiveThumbPath( $archiveName, $suffix = false ) {
1619                 $this->assertRepoDefined();
1620
1621                 return $this->repo->getZonePath( 'thumb' ) . '/' .
1622                 $this->getArchiveThumbRel( $archiveName, $suffix );
1623         }
1624
1625         /**
1626          * Get the path of the thumbnail directory, or a particular file if $suffix is specified
1627          *
1628          * @param bool|string $suffix If not false, the name of a thumbnail file
1629          * @return string
1630          */
1631         function getThumbPath( $suffix = false ) {
1632                 $this->assertRepoDefined();
1633
1634                 return $this->repo->getZonePath( 'thumb' ) . '/' . $this->getThumbRel( $suffix );
1635         }
1636
1637         /**
1638          * Get the path of the transcoded directory, or a particular file if $suffix is specified
1639          *
1640          * @param bool|string $suffix If not false, the name of a media file
1641          * @return string
1642          */
1643         function getTranscodedPath( $suffix = false ) {
1644                 $this->assertRepoDefined();
1645
1646                 return $this->repo->getZonePath( 'transcoded' ) . '/' . $this->getThumbRel( $suffix );
1647         }
1648
1649         /**
1650          * Get the URL of the archive directory, or a particular file if $suffix is specified
1651          *
1652          * @param bool|string $suffix If not false, the name of an archived file
1653          * @return string
1654          */
1655         function getArchiveUrl( $suffix = false ) {
1656                 $this->assertRepoDefined();
1657                 $ext = $this->getExtension();
1658                 $path = $this->repo->getZoneUrl( 'public', $ext ) . '/archive/' . $this->getHashPath();
1659                 if ( $suffix === false ) {
1660                         $path = substr( $path, 0, -1 );
1661                 } else {
1662                         $path .= rawurlencode( $suffix );
1663                 }
1664
1665                 return $path;
1666         }
1667
1668         /**
1669          * Get the URL of the archived file's thumbs, or a particular thumb if $suffix is specified
1670          *
1671          * @param string $archiveName The timestamped name of an archived image
1672          * @param bool|string $suffix If not false, the name of a thumbnail file
1673          * @return string
1674          */
1675         function getArchiveThumbUrl( $archiveName, $suffix = false ) {
1676                 $this->assertRepoDefined();
1677                 $ext = $this->getExtension();
1678                 $path = $this->repo->getZoneUrl( 'thumb', $ext ) . '/archive/' .
1679                         $this->getHashPath() . rawurlencode( $archiveName ) . "/";
1680                 if ( $suffix === false ) {
1681                         $path = substr( $path, 0, -1 );
1682                 } else {
1683                         $path .= rawurlencode( $suffix );
1684                 }
1685
1686                 return $path;
1687         }
1688
1689         /**
1690          * Get the URL of the zone directory, or a particular file if $suffix is specified
1691          *
1692          * @param string $zone Name of requested zone
1693          * @param bool|string $suffix If not false, the name of a file in zone
1694          * @return string Path
1695          */
1696         function getZoneUrl( $zone, $suffix = false ) {
1697                 $this->assertRepoDefined();
1698                 $ext = $this->getExtension();
1699                 $path = $this->repo->getZoneUrl( $zone, $ext ) . '/' . $this->getUrlRel();
1700                 if ( $suffix !== false ) {
1701                         $path .= '/' . rawurlencode( $suffix );
1702                 }
1703
1704                 return $path;
1705         }
1706
1707         /**
1708          * Get the URL of the thumbnail directory, or a particular file if $suffix is specified
1709          *
1710          * @param bool|string $suffix If not false, the name of a thumbnail file
1711          * @return string Path
1712          */
1713         function getThumbUrl( $suffix = false ) {
1714                 return $this->getZoneUrl( 'thumb', $suffix );
1715         }
1716
1717         /**
1718          * Get the URL of the transcoded directory, or a particular file if $suffix is specified
1719          *
1720          * @param bool|string $suffix If not false, the name of a media file
1721          * @return string Path
1722          */
1723         function getTranscodedUrl( $suffix = false ) {
1724                 return $this->getZoneUrl( 'transcoded', $suffix );
1725         }
1726
1727         /**
1728          * Get the public zone virtual URL for a current version source file
1729          *
1730          * @param bool|string $suffix If not false, the name of a thumbnail file
1731          * @return string
1732          */
1733         function getVirtualUrl( $suffix = false ) {
1734                 $this->assertRepoDefined();
1735                 $path = $this->repo->getVirtualUrl() . '/public/' . $this->getUrlRel();
1736                 if ( $suffix !== false ) {
1737                         $path .= '/' . rawurlencode( $suffix );
1738                 }
1739
1740                 return $path;
1741         }
1742
1743         /**
1744          * Get the public zone virtual URL for an archived version source file
1745          *
1746          * @param bool|string $suffix If not false, the name of a thumbnail file
1747          * @return string
1748          */
1749         function getArchiveVirtualUrl( $suffix = false ) {
1750                 $this->assertRepoDefined();
1751                 $path = $this->repo->getVirtualUrl() . '/public/archive/' . $this->getHashPath();
1752                 if ( $suffix === false ) {
1753                         $path = substr( $path, 0, -1 );
1754                 } else {
1755                         $path .= rawurlencode( $suffix );
1756                 }
1757
1758                 return $path;
1759         }
1760
1761         /**
1762          * Get the virtual URL for a thumbnail file or directory
1763          *
1764          * @param bool|string $suffix If not false, the name of a thumbnail file
1765          * @return string
1766          */
1767         function getThumbVirtualUrl( $suffix = false ) {
1768                 $this->assertRepoDefined();
1769                 $path = $this->repo->getVirtualUrl() . '/thumb/' . $this->getUrlRel();
1770                 if ( $suffix !== false ) {
1771                         $path .= '/' . rawurlencode( $suffix );
1772                 }
1773
1774                 return $path;
1775         }
1776
1777         /**
1778          * @return bool
1779          */
1780         function isHashed() {
1781                 $this->assertRepoDefined();
1782
1783                 return (bool)$this->repo->getHashLevels();
1784         }
1785
1786         /**
1787          * @throws MWException
1788          */
1789         function readOnlyError() {
1790                 throw new MWException( static::class . ': write operations are not supported' );
1791         }
1792
1793         /**
1794          * Record a file upload in the upload log and the image table
1795          * STUB
1796          * Overridden by LocalFile
1797          * @param string $oldver
1798          * @param string $desc
1799          * @param string $license
1800          * @param string $copyStatus
1801          * @param string $source
1802          * @param bool $watch
1803          * @param string|bool $timestamp
1804          * @param null|User $user User object or null to use $wgUser
1805          * @return bool
1806          * @throws MWException
1807          */
1808         function recordUpload( $oldver, $desc, $license = '', $copyStatus = '', $source = '',
1809                 $watch = false, $timestamp = false, User $user = null
1810         ) {
1811                 $this->readOnlyError();
1812         }
1813
1814         /**
1815          * Move or copy a file to its public location. If a file exists at the
1816          * destination, move it to an archive. Returns a Status object with
1817          * the archive name in the "value" member on success.
1818          *
1819          * The archive name should be passed through to recordUpload for database
1820          * registration.
1821          *
1822          * Options to $options include:
1823          *   - headers : name/value map of HTTP headers to use in response to GET/HEAD requests
1824          *
1825          * @param string|FSFile $src Local filesystem path to the source image
1826          * @param int $flags A bitwise combination of:
1827          *   File::DELETE_SOURCE    Delete the source file, i.e. move rather than copy
1828          * @param array $options Optional additional parameters
1829          * @return Status On success, the value member contains the
1830          *   archive name, or an empty string if it was a new file.
1831          *
1832          * STUB
1833          * Overridden by LocalFile
1834          */
1835         function publish( $src, $flags = 0, array $options = [] ) {
1836                 $this->readOnlyError();
1837         }
1838
1839         /**
1840          * @param bool|IContextSource $context Context to use (optional)
1841          * @return bool
1842          */
1843         function formatMetadata( $context = false ) {
1844                 if ( !$this->getHandler() ) {
1845                         return false;
1846                 }
1847
1848                 return $this->getHandler()->formatMetadata( $this, $context );
1849         }
1850
1851         /**
1852          * Returns true if the file comes from the local file repository.
1853          *
1854          * @return bool
1855          */
1856         function isLocal() {
1857                 return $this->repo && $this->repo->isLocal();
1858         }
1859
1860         /**
1861          * Returns the name of the repository.
1862          *
1863          * @return string
1864          */
1865         function getRepoName() {
1866                 return $this->repo ? $this->repo->getName() : 'unknown';
1867         }
1868
1869         /**
1870          * Returns the repository
1871          *
1872          * @return FileRepo|LocalRepo|bool
1873          */
1874         function getRepo() {
1875                 return $this->repo;
1876         }
1877
1878         /**
1879          * Returns true if the image is an old version
1880          * STUB
1881          *
1882          * @return bool
1883          */
1884         function isOld() {
1885                 return false;
1886         }
1887
1888         /**
1889          * Is this file a "deleted" file in a private archive?
1890          * STUB
1891          *
1892          * @param int $field One of DELETED_* bitfield constants
1893          * @return bool
1894          */
1895         function isDeleted( $field ) {
1896                 return false;
1897         }
1898
1899         /**
1900          * Return the deletion bitfield
1901          * STUB
1902          * @return int
1903          */
1904         function getVisibility() {
1905                 return 0;
1906         }
1907
1908         /**
1909          * Was this file ever deleted from the wiki?
1910          *
1911          * @return bool
1912          */
1913         function wasDeleted() {
1914                 $title = $this->getTitle();
1915
1916                 return $title && $title->isDeletedQuick();
1917         }
1918
1919         /**
1920          * Move file to the new title
1921          *
1922          * Move current, old version and all thumbnails
1923          * to the new filename. Old file is deleted.
1924          *
1925          * Cache purging is done; checks for validity
1926          * and logging are caller's responsibility
1927          *
1928          * @param Title $target New file name
1929          * @return Status
1930          */
1931         function move( $target ) {
1932                 $this->readOnlyError();
1933         }
1934
1935         /**
1936          * Delete all versions of the file.
1937          *
1938          * Moves the files into an archive directory (or deletes them)
1939          * and removes the database rows.
1940          *
1941          * Cache purging is done; logging is caller's responsibility.
1942          *
1943          * @param string $reason
1944          * @param bool $suppress Hide content from sysops?
1945          * @param User|null $user
1946          * @return Status
1947          * STUB
1948          * Overridden by LocalFile
1949          */
1950         function delete( $reason, $suppress = false, $user = null ) {
1951                 $this->readOnlyError();
1952         }
1953
1954         /**
1955          * Restore all or specified deleted revisions to the given file.
1956          * Permissions and logging are left to the caller.
1957          *
1958          * May throw database exceptions on error.
1959          *
1960          * @param array $versions Set of record ids of deleted items to restore,
1961          *   or empty to restore all revisions.
1962          * @param bool $unsuppress Remove restrictions on content upon restoration?
1963          * @return int|bool The number of file revisions restored if successful,
1964          *   or false on failure
1965          * STUB
1966          * Overridden by LocalFile
1967          */
1968         function restore( $versions = [], $unsuppress = false ) {
1969                 $this->readOnlyError();
1970         }
1971
1972         /**
1973          * Returns 'true' if this file is a type which supports multiple pages,
1974          * e.g. DJVU or PDF. Note that this may be true even if the file in
1975          * question only has a single page.
1976          *
1977          * @return bool
1978          */
1979         function isMultipage() {
1980                 return $this->getHandler() && $this->handler->isMultiPage( $this );
1981         }
1982
1983         /**
1984          * Returns the number of pages of a multipage document, or false for
1985          * documents which aren't multipage documents
1986          *
1987          * @return string|bool|int
1988          */
1989         function pageCount() {
1990                 if ( !isset( $this->pageCount ) ) {
1991                         if ( $this->getHandler() && $this->handler->isMultiPage( $this ) ) {
1992                                 $this->pageCount = $this->handler->pageCount( $this );
1993                         } else {
1994                                 $this->pageCount = false;
1995                         }
1996                 }
1997
1998                 return $this->pageCount;
1999         }
2000
2001         /**
2002          * Calculate the height of a thumbnail using the source and destination width
2003          *
2004          * @param int $srcWidth
2005          * @param int $srcHeight
2006          * @param int $dstWidth
2007          *
2008          * @return int
2009          */
2010         static function scaleHeight( $srcWidth, $srcHeight, $dstWidth ) {
2011                 // Exact integer multiply followed by division
2012                 if ( $srcWidth == 0 ) {
2013                         return 0;
2014                 } else {
2015                         return (int)round( $srcHeight * $dstWidth / $srcWidth );
2016                 }
2017         }
2018
2019         /**
2020          * Get an image size array like that returned by getImageSize(), or false if it
2021          * can't be determined. Loads the image size directly from the file ignoring caches.
2022          *
2023          * @note Use getWidth()/getHeight() instead of this method unless you have a
2024          *  a good reason. This method skips all caches.
2025          *
2026          * @param string $filePath The path to the file (e.g. From getLocalPathRef() )
2027          * @return array|false The width, followed by height, with optionally more things after
2028          */
2029         function getImageSize( $filePath ) {
2030                 if ( !$this->getHandler() ) {
2031                         return false;
2032                 }
2033
2034                 return $this->getHandler()->getImageSize( $this, $filePath );
2035         }
2036
2037         /**
2038          * Get the URL of the image description page. May return false if it is
2039          * unknown or not applicable.
2040          *
2041          * @return string
2042          */
2043         function getDescriptionUrl() {
2044                 if ( $this->repo ) {
2045                         return $this->repo->getDescriptionUrl( $this->getName() );
2046                 } else {
2047                         return false;
2048                 }
2049         }
2050
2051         /**
2052          * Get the HTML text of the description page, if available
2053          *
2054          * @param bool|Language $lang Optional language to fetch description in
2055          * @return string|false
2056          */
2057         function getDescriptionText( $lang = false ) {
2058                 global $wgLang;
2059
2060                 if ( !$this->repo || !$this->repo->fetchDescription ) {
2061                         return false;
2062                 }
2063
2064                 $lang = $lang ?: $wgLang;
2065
2066                 $renderUrl = $this->repo->getDescriptionRenderUrl( $this->getName(), $lang->getCode() );
2067                 if ( $renderUrl ) {
2068                         $cache = ObjectCache::getMainWANInstance();
2069                         $key = $this->repo->getLocalCacheKey(
2070                                 'RemoteFileDescription',
2071                                 'url',
2072                                 $lang->getCode(),
2073                                 $this->getName()
2074                         );
2075
2076                         return $cache->getWithSetCallback(
2077                                 $key,
2078                                 $this->repo->descriptionCacheExpiry ?: $cache::TTL_UNCACHEABLE,
2079                                 function ( $oldValue, &$ttl, array &$setOpts ) use ( $renderUrl ) {
2080                                         wfDebug( "Fetching shared description from $renderUrl\n" );
2081                                         $res = Http::get( $renderUrl, [], __METHOD__ );
2082                                         if ( !$res ) {
2083                                                 $ttl = WANObjectCache::TTL_UNCACHEABLE;
2084                                         }
2085
2086                                         return $res;
2087                                 }
2088                         );
2089                 }
2090
2091                 return false;
2092         }
2093
2094         /**
2095          * Get description of file revision
2096          * STUB
2097          *
2098          * @param int $audience One of:
2099          *   File::FOR_PUBLIC       to be displayed to all users
2100          *   File::FOR_THIS_USER    to be displayed to the given user
2101          *   File::RAW              get the description regardless of permissions
2102          * @param User $user User object to check for, only if FOR_THIS_USER is
2103          *   passed to the $audience parameter
2104          * @return string
2105          */
2106         function getDescription( $audience = self::FOR_PUBLIC, User $user = null ) {
2107                 return null;
2108         }
2109
2110         /**
2111          * Get the 14-character timestamp of the file upload
2112          *
2113          * @return string|bool TS_MW timestamp or false on failure
2114          */
2115         function getTimestamp() {
2116                 $this->assertRepoDefined();
2117
2118                 return $this->repo->getFileTimestamp( $this->getPath() );
2119         }
2120
2121         /**
2122          * Returns the timestamp (in TS_MW format) of the last change of the description page.
2123          * Returns false if the file does not have a description page, or retrieving the timestamp
2124          * would be expensive.
2125          * @since 1.25
2126          * @return string|bool
2127          */
2128         public function getDescriptionTouched() {
2129                 return false;
2130         }
2131
2132         /**
2133          * Get the SHA-1 base 36 hash of the file
2134          *
2135          * @return string
2136          */
2137         function getSha1() {
2138                 $this->assertRepoDefined();
2139
2140                 return $this->repo->getFileSha1( $this->getPath() );
2141         }
2142
2143         /**
2144          * Get the deletion archive key, "<sha1>.<ext>"
2145          *
2146          * @return string|false
2147          */
2148         function getStorageKey() {
2149                 $hash = $this->getSha1();
2150                 if ( !$hash ) {
2151                         return false;
2152                 }
2153                 $ext = $this->getExtension();
2154                 $dotExt = $ext === '' ? '' : ".$ext";
2155
2156                 return $hash . $dotExt;
2157         }
2158
2159         /**
2160          * Determine if the current user is allowed to view a particular
2161          * field of this file, if it's marked as deleted.
2162          * STUB
2163          * @param int $field
2164          * @param User $user User object to check, or null to use $wgUser
2165          * @return bool
2166          */
2167         function userCan( $field, User $user = null ) {
2168                 return true;
2169         }
2170
2171         /**
2172          * @deprecated since 1.30, use File::getContentHeaders instead
2173          */
2174         function getStreamHeaders() {
2175                 wfDeprecated( __METHOD__, '1.30' );
2176                 return $this->getContentHeaders();
2177         }
2178
2179         /**
2180          * @return array HTTP header name/value map to use for HEAD/GET request responses
2181          * @since 1.30
2182          */
2183         function getContentHeaders() {
2184                 $handler = $this->getHandler();
2185                 if ( $handler ) {
2186                         $metadata = $this->getMetadata();
2187
2188                         if ( is_string( $metadata ) ) {
2189                                 $metadata = MediaWiki\quietCall( 'unserialize', $metadata );
2190                         }
2191
2192                         if ( !is_array( $metadata ) ) {
2193                                 $metadata = [];
2194                         }
2195
2196                         return $handler->getContentHeaders( $metadata );
2197                 }
2198
2199                 return [];
2200         }
2201
2202         /**
2203          * @return string
2204          */
2205         function getLongDesc() {
2206                 $handler = $this->getHandler();
2207                 if ( $handler ) {
2208                         return $handler->getLongDesc( $this );
2209                 } else {
2210                         return MediaHandler::getGeneralLongDesc( $this );
2211                 }
2212         }
2213
2214         /**
2215          * @return string
2216          */
2217         function getShortDesc() {
2218                 $handler = $this->getHandler();
2219                 if ( $handler ) {
2220                         return $handler->getShortDesc( $this );
2221                 } else {
2222                         return MediaHandler::getGeneralShortDesc( $this );
2223                 }
2224         }
2225
2226         /**
2227          * @return string
2228          */
2229         function getDimensionsString() {
2230                 $handler = $this->getHandler();
2231                 if ( $handler ) {
2232                         return $handler->getDimensionsString( $this );
2233                 } else {
2234                         return '';
2235                 }
2236         }
2237
2238         /**
2239          * @return string
2240          */
2241         function getRedirected() {
2242                 return $this->redirected;
2243         }
2244
2245         /**
2246          * @return Title|null
2247          */
2248         function getRedirectedTitle() {
2249                 if ( $this->redirected ) {
2250                         if ( !$this->redirectTitle ) {
2251                                 $this->redirectTitle = Title::makeTitle( NS_FILE, $this->redirected );
2252                         }
2253
2254                         return $this->redirectTitle;
2255                 }
2256
2257                 return null;
2258         }
2259
2260         /**
2261          * @param string $from
2262          * @return void
2263          */
2264         function redirectedFrom( $from ) {
2265                 $this->redirected = $from;
2266         }
2267
2268         /**
2269          * @return bool
2270          */
2271         function isMissing() {
2272                 return false;
2273         }
2274
2275         /**
2276          * Check if this file object is small and can be cached
2277          * @return bool
2278          */
2279         public function isCacheable() {
2280                 return true;
2281         }
2282
2283         /**
2284          * Assert that $this->repo is set to a valid FileRepo instance
2285          * @throws MWException
2286          */
2287         protected function assertRepoDefined() {
2288                 if ( !( $this->repo instanceof $this->repoClass ) ) {
2289                         throw new MWException( "A {$this->repoClass} object is not set for this File.\n" );
2290                 }
2291         }
2292
2293         /**
2294          * Assert that $this->title is set to a Title
2295          * @throws MWException
2296          */
2297         protected function assertTitleDefined() {
2298                 if ( !( $this->title instanceof Title ) ) {
2299                         throw new MWException( "A Title object is not set for this File.\n" );
2300                 }
2301         }
2302
2303         /**
2304          * True if creating thumbnails from the file is large or otherwise resource-intensive.
2305          * @return bool
2306          */
2307         public function isExpensiveToThumbnail() {
2308                 $handler = $this->getHandler();
2309                 return $handler ? $handler->isExpensiveToThumbnail( $this ) : false;
2310         }
2311
2312         /**
2313          * Whether the thumbnails created on the same server as this code is running.
2314          * @since 1.25
2315          * @return bool
2316          */
2317         public function isTransformedLocally() {
2318                 return true;
2319         }
2320 }