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
   9 /**
  10  * Base code for files.
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation; either version 2 of the License, or
  15  * (at your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  20  * GNU General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU General Public License along
  23  * with this program; if not, write to the Free Software Foundation, Inc.,
  24  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  25  * http://www.gnu.org/copyleft/gpl.html
  26  *
  27  * @file
  28  * @ingroup FileAbstraction
  29  */
  30
  31 /**
  32  * Implements some public methods and some protected utility functions which
  33  * are required by multiple child classes. Contains stub functionality for
  34  * unimplemented public methods.
  35  *
  36  * Stub functions which should be overridden are marked with STUB. Some more
  37  * concrete functions are also typically overridden by child classes.
  38  *
  39  * Note that only the repo object knows what its file class is called. You should
  40  * never name a file class explictly outside of the repo class. Instead use the
  41  * repo's factory functions to generate file objects, for example:
  42  *
  43  * RepoGroup::singleton()->getLocalRepo()->newFile($title);
  44  *
  45  * The convenience functions wfLocalFile() and wfFindFile() should be sufficient
  46  * in most cases.
  47  *
  48  * @ingroup FileAbstraction
  49  */
  50 abstract class File {
  51         const DELETED_FILE = 1;
  52         const DELETED_COMMENT = 2;
  53         const DELETED_USER = 4;
  54         const DELETED_RESTRICTED = 8;
  55
  56         /** Force rendering in the current process */
  57         const RENDER_NOW   = 1;
  58         /**
  59          * Force rendering even if thumbnail already exist and using RENDER_NOW
  60          * I.e. you have to pass both flags: File::RENDER_NOW | File::RENDER_FORCE
  61          */
  62         const RENDER_FORCE = 2;
  63
  64         const DELETE_SOURCE = 1;
  65
  66         // Audience options for File::getDescription()
  67         const FOR_PUBLIC = 1;
  68         const FOR_THIS_USER = 2;
  69         const RAW = 3;
  70
  71         /**
  72          * Some member variables can be lazy-initialised using __get(). The
  73          * initialisation function for these variables is always a function named
  74          * like getVar(), where Var is the variable name with upper-case first
  75          * letter.
  76          *
  77          * The following variables are initialised in this way in this base class:
  78          *    name, extension, handler, path, canRender, isSafeFile,
  79          *    transformScript, hashPath, pageCount, url
  80          *
  81          * Code within this class should generally use the accessor function
  82          * directly, since __get() isn't re-entrant and therefore causes bugs that
  83          * depend on initialisation order.
  84          */
  85
  86         /**
  87          * The following member variables are not lazy-initialised
  88          */
  89
  90         /**
  91          * @var FileRepo|bool
  92          */
  93         var $repo;
  94
  95         /**
  96          * @var Title
  97          */
  98         var $title;
  99
 100         var $lastError, $redirected, $redirectedTitle;
 101
 102         /**
 103          * @var FSFile|bool False if undefined
 104          */
 105         protected $fsFile;
 106
 107         /**
 108          * @var MediaHandler
 109          */
 110         protected $handler;
 111
 112         /**
 113          * @var string
 114          */
 115         protected $url, $extension, $name, $path, $hashPath, $pageCount, $transformScript;
 116
 117         protected $redirectTitle;
 118
 119         /**
 120          * @var bool
 121          */
 122         protected $canRender, $isSafeFile;
 123
 124         /**
 125          * @var string Required Repository class type
 126          */
 127         protected $repoClass = 'FileRepo';
 128
 129         /**
 130          * Call this constructor from child classes.
 131          *
 132          * Both $title and $repo are optional, though some functions
 133          * may return false or throw exceptions if they are not set.
 134          * Most subclasses will want to call assertRepoDefined() here.
 135          *
 136          * @param $title Title|string|bool
 137          * @param $repo FileRepo|bool
 138          */
 139         function __construct( $title, $repo ) {
 140                 if ( $title !== false ) { // subclasses may not use MW titles
 141                         $title = self::normalizeTitle( $title, 'exception' );
 142                 }
 143                 $this->title = $title;
 144                 $this->repo = $repo;
 145         }
 146
 147         /**
 148          * Given a string or Title object return either a
 149          * valid Title object with namespace NS_FILE or null
 150          *
 151          * @param $title Title|string
 152          * @param $exception string|bool Use 'exception' to throw an error on bad titles
 153          * @throws MWException
 154          * @return Title|null
 155          */
 156         static function normalizeTitle( $title, $exception = false ) {
 157                 $ret = $title;
 158                 if ( $ret instanceof Title ) {
 159                         # Normalize NS_MEDIA -> NS_FILE
 160                         if ( $ret->getNamespace() == NS_MEDIA ) {
 161                                 $ret = Title::makeTitleSafe( NS_FILE, $ret->getDBkey() );
 162                         # Sanity check the title namespace
 163                         } elseif ( $ret->getNamespace() !== NS_FILE ) {
 164                                 $ret = null;
 165                         }
 166                 } else {
 167                         # Convert strings to Title objects
 168                         $ret = Title::makeTitleSafe( NS_FILE, (string)$ret );
 169                 }
 170                 if ( !$ret && $exception !== false ) {
 171                         throw new MWException( "`$title` is not a valid file title." );
 172                 }
 173                 return $ret;
 174         }
 175
 176         function __get( $name ) {
 177                 $function = array( $this, 'get' . ucfirst( $name ) );
 178                 if ( !is_callable( $function ) ) {
 179                         return null;
 180                 } else {
 181                         $this->$name = call_user_func( $function );
 182                         return $this->$name;
 183                 }
 184         }
 185
 186         /**
 187          * Normalize a file extension to the common form, and ensure it's clean.
 188          * Extensions with non-alphanumeric characters will be discarded.
 189          *
 190          * @param $ext string (without the .)
 191          * @return string
 192          */
 193         static function normalizeExtension( $ext ) {
 194                 $lower = strtolower( $ext );
 195                 $squish = array(
 196                         'htm' => 'html',
 197                         'jpeg' => 'jpg',
 198                         'mpeg' => 'mpg',
 199                         'tiff' => 'tif',
 200                         'ogv' => 'ogg' );
 201                 if( isset( $squish[$lower] ) ) {
 202                         return $squish[$lower];
 203                 } elseif( preg_match( '/^[0-9a-z]+$/', $lower ) ) {
 204                         return $lower;
 205                 } else {
 206                         return '';
 207                 }
 208         }
 209
 210         /**
 211          * Checks if file extensions are compatible
 212          *
 213          * @param $old File Old file
 214          * @param $new string New name
 215          *
 216          * @return bool|null
 217          */
 218         static function checkExtensionCompatibility( File $old, $new ) {
 219                 $oldMime = $old->getMimeType();
 220                 $n = strrpos( $new, '.' );
 221                 $newExt = self::normalizeExtension( $n ? substr( $new, $n + 1 ) : '' );
 222                 $mimeMagic = MimeMagic::singleton();
 223                 return $mimeMagic->isMatchingExtension( $newExt, $oldMime );
 224         }
 225
 226         /**
 227          * Upgrade the database row if there is one
 228          * Called by ImagePage
 229          * STUB
 230          */
 231         function upgradeRow() {}
 232
 233         /**
 234          * Split an internet media type into its two components; if not
 235          * a two-part name, set the minor type to 'unknown'.
 236          *
 237          * @param string $mime "text/html" etc
 238          * @return array ("text", "html") etc
 239          */
 240         public static function splitMime( $mime ) {
 241                 if( strpos( $mime, '/' ) !== false ) {
 242                         return explode( '/', $mime, 2 );
 243                 } else {
 244                         return array( $mime, 'unknown' );
 245                 }
 246         }
 247
 248         /**
 249          * Callback for usort() to do file sorts by name
 250          *
 251          * @param $a File
 252          * @param $b File
 253          *
 254          * @return Integer: result of name comparison
 255          */
 256         public static function compare( File $a, File $b ) {
 257                 return strcmp( $a->getName(), $b->getName() );
 258         }
 259
 260         /**
 261          * Return the name of this file
 262          *
 263          * @return string
 264          */
 265         public function getName() {
 266                 if ( !isset( $this->name ) ) {
 267                         $this->assertRepoDefined();
 268                         $this->name = $this->repo->getNameFromTitle( $this->title );
 269                 }
 270                 return $this->name;
 271         }
 272
 273         /**
 274          * Get the file extension, e.g. "svg"
 275          *
 276          * @return string
 277          */
 278         function getExtension() {
 279                 if ( !isset( $this->extension ) ) {
 280                         $n = strrpos( $this->getName(), '.' );
 281                         $this->extension = self::normalizeExtension(
 282                                 $n ? substr( $this->getName(), $n + 1 ) : '' );
 283                 }
 284                 return $this->extension;
 285         }
 286
 287         /**
 288          * Return the associated title object
 289          *
 290          * @return Title
 291          */
 292         public function getTitle() {
 293                 return $this->title;
 294         }
 295
 296         /**
 297          * Return the title used to find this file
 298          *
 299          * @return Title
 300          */
 301         public function getOriginalTitle() {
 302                 if ( $this->redirected ) {
 303                         return $this->getRedirectedTitle();
 304                 }
 305                 return $this->title;
 306         }
 307
 308         /**
 309          * Return the URL of the file
 310          *
 311          * @return string
 312          */
 313         public function getUrl() {
 314                 if ( !isset( $this->url ) ) {
 315                         $this->assertRepoDefined();
 316                         $this->url = $this->repo->getZoneUrl( 'public' ) . '/' . $this->getUrlRel();
 317                 }
 318                 return $this->url;
 319         }
 320
 321         /**
 322          * Return a fully-qualified URL to the file.
 323          * Upload URL paths _may or may not_ be fully qualified, so
 324          * we check. Local paths are assumed to belong on $wgServer.
 325          *
 326          * @return String
 327          */
 328         public function getFullUrl() {
 329                 return wfExpandUrl( $this->getUrl(), PROTO_RELATIVE );
 330         }
 331
 332         /**
 333          * @return string
 334          */
 335         public function getCanonicalUrl() {
 336                 return wfExpandUrl( $this->getUrl(), PROTO_CANONICAL );
 337         }
 338
 339         /**
 340          * @return string
 341          */
 342         function getViewURL() {
 343                 if ( $this->mustRender() ) {
 344                         if ( $this->canRender() ) {
 345                                 return $this->createThumb( $this->getWidth() );
 346                         } else {
 347                                 wfDebug( __METHOD__.': supposed to render ' . $this->getName() .
 348                                         ' (' . $this->getMimeType() . "), but can't!\n" );
 349                                 return $this->getURL(); #hm... return NULL?
 350                         }
 351                 } else {
 352                         return $this->getURL();
 353                 }
 354         }
 355
 356         /**
 357          * Return the storage path to the file. Note that this does
 358          * not mean that a file actually exists under that location.
 359          *
 360          * This path depends on whether directory hashing is active or not,
 361          * i.e. whether the files are all found in the same directory,
 362          * or in hashed paths like /images/3/3c.
 363          *
 364          * Most callers don't check the return value, but ForeignAPIFile::getPath
 365          * returns false.
 366          *
 367          * @return string|bool ForeignAPIFile::getPath can return false
 368         */
 369         public function getPath() {
 370                 if ( !isset( $this->path ) ) {
 371                         $this->assertRepoDefined();
 372                         $this->path = $this->repo->getZonePath( 'public' ) . '/' . $this->getRel();
 373                 }
 374                 return $this->path;
 375         }
 376
 377         /**
 378          * Get an FS copy or original of this file and return the path.
 379          * Returns false on failure. Callers must not alter the file.
 380          * Temporary files are cleared automatically.
 381          *
 382          * @return string|bool False on failure
 383          */
 384         public function getLocalRefPath() {
 385                 $this->assertRepoDefined();
 386                 if ( !isset( $this->fsFile ) ) {
 387                         $this->fsFile = $this->repo->getLocalReference( $this->getPath() );
 388                         if ( !$this->fsFile ) {
 389                                 $this->fsFile = false; // null => false; cache negative hits
 390                         }
 391                 }
 392                 return ( $this->fsFile )
 393                         ? $this->fsFile->getPath()
 394                         : false;
 395         }
 396
 397         /**
 398          * Return the width of the image. Returns false if the width is unknown
 399          * or undefined.
 400          *
 401          * STUB
 402          * Overridden by LocalFile, UnregisteredLocalFile
 403          *
 404          * @param $page int
 405          *
 406          * @return number
 407          */
 408         public function getWidth( $page = 1 ) {
 409                 return false;
 410         }
 411
 412         /**
 413          * Return the height of the image. Returns false if the height is unknown
 414          * or undefined
 415          *
 416          * STUB
 417          * Overridden by LocalFile, UnregisteredLocalFile
 418          *
 419          * @param $page int
 420          *
 421          * @return bool|number False on failure
 422          */
 423         public function getHeight( $page = 1 ) {
 424                 return false;
 425         }
 426
 427         /**
 428          * Returns ID or name of user who uploaded the file
 429          * STUB
 430          *
 431          * @param $type string 'text' or 'id'
 432          *
 433          * @return string|int
 434          */
 435         public function getUser( $type = 'text' ) {
 436                 return null;
 437         }
 438
 439         /**
 440          * Get the duration of a media file in seconds
 441          *
 442          * @return number
 443          */
 444         public function getLength() {
 445                 $handler = $this->getHandler();
 446                 if ( $handler ) {
 447                         return $handler->getLength( $this );
 448                 } else {
 449                         return 0;
 450                 }
 451         }
 452
 453         /**
 454          * Return true if the file is vectorized
 455          *
 456          * @return bool
 457          */
 458         public function isVectorized() {
 459                 $handler = $this->getHandler();
 460                 if ( $handler ) {
 461                         return $handler->isVectorized( $this );
 462                 } else {
 463                         return false;
 464                 }
 465         }
 466
 467         /**
 468          * Will the thumbnail be animated if one would expect it to be.
 469          *
 470          * Currently used to add a warning to the image description page
 471          *
 472          * @return bool false if the main image is both animated
 473          *   and the thumbnail is not. In all other cases must return
 474          *   true. If image is not renderable whatsoever, should
 475          *   return true.
 476          */
 477         public function canAnimateThumbIfAppropriate() {
 478                 $handler = $this->getHandler();
 479                 if ( !$handler ) {
 480                         // We cannot handle image whatsoever, thus
 481                         // one would not expect it to be animated
 482                         // so true.
 483                         return true;
 484                 } else {
 485                         if ( $this->allowInlineDisplay()
 486                                 && $handler->isAnimatedImage( $this )
 487                                 && !$handler->canAnimateThumbnail( $this )
 488                         ) {
 489                                 // Image is animated, but thumbnail isn't.
 490                                 // This is unexpected to the user.
 491                                 return false;
 492                         } else {
 493                                 // Image is not animated, so one would
 494                                 // not expect thumb to be
 495                                 return true;
 496                         }
 497                 }
 498         }
 499
 500         /**
 501          * Get handler-specific metadata
 502          * Overridden by LocalFile, UnregisteredLocalFile
 503          * STUB
 504          * @return bool
 505          */
 506         public function getMetadata() {
 507                 return false;
 508         }
 509
 510         /**
 511         * get versioned metadata
 512         *
 513         * @param $metadata Mixed Array or String of (serialized) metadata
 514         * @param $version integer version number.
 515         * @return Array containing metadata, or what was passed to it on fail (unserializing if not array)
 516         */
 517         public function convertMetadataVersion($metadata, $version) {
 518                 $handler = $this->getHandler();
 519                 if ( !is_array( $metadata ) ) {
 520                         // Just to make the return type consistent
 521                         $metadata = unserialize( $metadata );
 522                 }
 523                 if ( $handler ) {
 524                         return $handler->convertMetadataVersion( $metadata, $version );
 525                 } else {
 526                         return $metadata;
 527                 }
 528         }
 529
 530         /**
 531          * Return the bit depth of the file
 532          * Overridden by LocalFile
 533          * STUB
 534          * @return int
 535          */
 536         public function getBitDepth() {
 537                 return 0;
 538         }
 539
 540         /**
 541          * Return the size of the image file, in bytes
 542          * Overridden by LocalFile, UnregisteredLocalFile
 543          * STUB
 544          * @return bool
 545          */
 546         public function getSize() {
 547                 return false;
 548         }
 549
 550         /**
 551          * Returns the mime type of the file.
 552          * Overridden by LocalFile, UnregisteredLocalFile
 553          * STUB
 554          *
 555          * @return string
 556          */
 557         function getMimeType() {
 558                 return 'unknown/unknown';
 559         }
 560
 561         /**
 562          * Return the type of the media in the file.
 563          * Use the value returned by this function with the MEDIATYPE_xxx constants.
 564          * Overridden by LocalFile,
 565          * STUB
 566          * @return string
 567          */
 568         function getMediaType() {
 569                 return MEDIATYPE_UNKNOWN;
 570         }
 571
 572         /**
 573          * Checks if the output of transform() for this file is likely
 574          * to be valid. If this is false, various user elements will
 575          * display a placeholder instead.
 576          *
 577          * Currently, this checks if the file is an image format
 578          * that can be converted to a format
 579          * supported by all browsers (namely GIF, PNG and JPEG),
 580          * or if it is an SVG image and SVG conversion is enabled.
 581          *
 582          * @return bool
 583          */
 584         function canRender() {
 585                 if ( !isset( $this->canRender ) ) {
 586                         $this->canRender = $this->getHandler() && $this->handler->canRender( $this );
 587                 }
 588                 return $this->canRender;
 589         }
 590
 591         /**
 592          * Accessor for __get()
 593          * @return bool
 594          */
 595         protected function getCanRender() {
 596                 return $this->canRender();
 597         }
 598
 599         /**
 600          * Return true if the file is of a type that can't be directly
 601          * rendered by typical browsers and needs to be re-rasterized.
 602          *
 603          * This returns true for everything but the bitmap types
 604          * supported by all browsers, i.e. JPEG; GIF and PNG. It will
 605          * also return true for any non-image formats.
 606          *
 607          * @return bool
 608          */
 609         function mustRender() {
 610                 return $this->getHandler() && $this->handler->mustRender( $this );
 611         }
 612
 613         /**
 614          * Alias for canRender()
 615          *
 616          * @return bool
 617          */
 618         function allowInlineDisplay() {
 619                 return $this->canRender();
 620         }
 621
 622         /**
 623          * Determines if this media file is in a format that is unlikely to
 624          * contain viruses or malicious content. It uses the global
 625          * $wgTrustedMediaFormats list to determine if the file is safe.
 626          *
 627          * This is used to show a warning on the description page of non-safe files.
 628          * It may also be used to disallow direct [[media:...]] links to such files.
 629          *
 630          * Note that this function will always return true if allowInlineDisplay()
 631          * or isTrustedFile() is true for this file.
 632          *
 633          * @return bool
 634          */
 635         function isSafeFile() {
 636                 if ( !isset( $this->isSafeFile ) ) {
 637                         $this->isSafeFile = $this->_getIsSafeFile();
 638                 }
 639                 return $this->isSafeFile;
 640         }
 641
 642         /**
 643          * Accessor for __get()
 644          *
 645          * @return bool
 646          */
 647         protected function getIsSafeFile() {
 648                 return $this->isSafeFile();
 649         }
 650
 651         /**
 652          * Uncached accessor
 653          *
 654          * @return bool
 655          */
 656         protected function _getIsSafeFile() {
 657                 global $wgTrustedMediaFormats;
 658
 659                 if ( $this->allowInlineDisplay() ) {
 660                         return true;
 661                 }
 662                 if ($this->isTrustedFile()) {
 663                         return true;
 664                 }
 665
 666                 $type = $this->getMediaType();
 667                 $mime = $this->getMimeType();
 668                 #wfDebug("LocalFile::isSafeFile: type= $type, mime= $mime\n");
 669
 670                 if ( !$type || $type === MEDIATYPE_UNKNOWN ) {
 671                         return false; #unknown type, not trusted
 672                 }
 673                 if ( in_array( $type, $wgTrustedMediaFormats ) ) {
 674                         return true;
 675                 }
 676
 677                 if ( $mime === "unknown/unknown" ) {
 678                         return false; #unknown type, not trusted
 679                 }
 680                 if ( in_array( $mime, $wgTrustedMediaFormats) ) {
 681                         return true;
 682                 }
 683
 684                 return false;
 685         }
 686
 687         /**
 688          * Returns true if the file is flagged as trusted. Files flagged that way
 689          * can be linked to directly, even if that is not allowed for this type of
 690          * file normally.
 691          *
 692          * This is a dummy function right now and always returns false. It could be
 693          * implemented to extract a flag from the database. The trusted flag could be
 694          * set on upload, if the user has sufficient privileges, to bypass script-
 695          * and html-filters. It may even be coupled with cryptographics signatures
 696          * or such.
 697          *
 698          * @return bool
 699          */
 700         function isTrustedFile() {
 701                 #this could be implemented to check a flag in the database,
 702                 #look for signatures, etc
 703                 return false;
 704         }
 705
 706         /**
 707          * Returns true if file exists in the repository.
 708          *
 709          * Overridden by LocalFile to avoid unnecessary stat calls.
 710          *
 711          * @return boolean Whether file exists in the repository.
 712          */
 713         public function exists() {
 714                 return $this->getPath() && $this->repo->fileExists( $this->path );
 715         }
 716
 717         /**
 718          * Returns true if file exists in the repository and can be included in a page.
 719          * It would be unsafe to include private images, making public thumbnails inadvertently
 720          *
 721          * @return boolean Whether file exists in the repository and is includable.
 722          */
 723         public function isVisible() {
 724                 return $this->exists();
 725         }
 726
 727         /**
 728          * @return string
 729          */
 730         function getTransformScript() {
 731                 if ( !isset( $this->transformScript ) ) {
 732                         $this->transformScript = false;
 733                         if ( $this->repo ) {
 734                                 $script = $this->repo->getThumbScriptUrl();
 735                                 if ( $script ) {
 736                                         $this->transformScript = "$script?f=" . urlencode( $this->getName() );
 737                                 }
 738                         }
 739                 }
 740                 return $this->transformScript;
 741         }
 742
 743         /**
 744          * Get a ThumbnailImage which is the same size as the source
 745          *
 746          * @param $handlerParams array
 747          *
 748          * @return string
 749          */
 750         function getUnscaledThumb( $handlerParams = array() ) {
 751                 $hp =& $handlerParams;
 752                 $page = isset( $hp['page'] ) ? $hp['page'] : false;
 753                 $width = $this->getWidth( $page );
 754                 if ( !$width ) {
 755                         return $this->iconThumb();
 756                 }
 757                 $hp['width'] = $width;
 758                 return $this->transform( $hp );
 759         }
 760
 761         /**
 762          * Return the file name of a thumbnail with the specified parameters
 763          *
 764          * @param $params Array: handler-specific parameters
 765          * @private -ish
 766          *
 767          * @return string
 768          */
 769         function thumbName( $params ) {
 770                 $name = $this->repo ? $this->repo->nameForThumb( $this->getName() ) : $this->getName();
 771                 return $this->generateThumbName( $name, $params );
 772         }
 773
 774         /**
 775          * Generate a thumbnail file name from a name and specified parameters
 776          *
 777          * @param string $name
 778          * @param array $params Parameters which will be passed to MediaHandler::makeParamString
 779          *
 780          * @return string
 781          */
 782         function generateThumbName( $name, $params ) {
 783                 if ( !$this->getHandler() ) {
 784                         return null;
 785                 }
 786                 $extension = $this->getExtension();
 787                 list( $thumbExt, $thumbMime ) = $this->handler->getThumbType(
 788                         $extension, $this->getMimeType(), $params );
 789                 $thumbName = $this->handler->makeParamString( $params ) . '-' . $name;
 790                 if ( $thumbExt != $extension ) {
 791                         $thumbName .= ".$thumbExt";
 792                 }
 793                 return $thumbName;
 794         }
 795
 796         /**
 797          * Create a thumbnail of the image having the specified width/height.
 798          * The thumbnail will not be created if the width is larger than the
 799          * image's width. Let the browser do the scaling in this case.
 800          * The thumbnail is stored on disk and is only computed if the thumbnail
 801          * file does not exist OR if it is older than the image.
 802          * Returns the URL.
 803          *
 804          * Keeps aspect ratio of original image. If both width and height are
 805          * specified, the generated image will be no bigger than width x height,
 806          * and will also have correct aspect ratio.
 807          *
 808          * @param $width Integer: maximum width of the generated thumbnail
 809          * @param $height Integer: maximum height of the image (optional)
 810          *
 811          * @return string
 812          */
 813         public function createThumb( $width, $height = -1 ) {
 814                 $params = array( 'width' => $width );
 815                 if ( $height != -1 ) {
 816                         $params['height'] = $height;
 817                 }
 818                 $thumb = $this->transform( $params );
 819                 if ( is_null( $thumb ) || $thumb->isError() ) {
 820                         return '';
 821                 }
 822                 return $thumb->getUrl();
 823         }
 824
 825         /**
 826          * Return either a MediaTransformError or placeholder thumbnail (if $wgIgnoreImageErrors)
 827          *
 828          * @param $thumbPath string Thumbnail storage path
 829          * @param $thumbUrl string Thumbnail URL
 830          * @param $params Array
 831          * @param $flags integer
 832          * @return MediaTransformOutput
 833          */
 834         protected function transformErrorOutput( $thumbPath, $thumbUrl, $params, $flags ) {
 835                 global $wgIgnoreImageErrors;
 836
 837                 if ( $wgIgnoreImageErrors && !( $flags & self::RENDER_NOW ) ) {
 838                         return $this->handler->getTransform( $this, $thumbPath, $thumbUrl, $params );
 839                 } else {
 840                         return new MediaTransformError( 'thumbnail_error',
 841                                 $params['width'], 0, wfMessage( 'thumbnail-dest-create' )->text() );
 842                 }
 843         }
 844
 845         /**
 846          * Transform a media file
 847          *
 848          * @param $params Array: an associative array of handler-specific parameters.
 849          *                Typical keys are width, height and page.
 850          * @param $flags Integer: a bitfield, may contain self::RENDER_NOW to force rendering
 851          * @return MediaTransformOutput|bool False on failure
 852          */
 853         function transform( $params, $flags = 0 ) {
 854                 global $wgUseSquid, $wgIgnoreImageErrors, $wgThumbnailEpoch;
 855
 856                 wfProfileIn( __METHOD__ );
 857                 do {
 858                         if ( !$this->canRender() ) {
 859                                 $thumb = $this->iconThumb();
 860                                 break; // not a bitmap or renderable image, don't try
 861                         }
 862
 863                         // Get the descriptionUrl to embed it as comment into the thumbnail. Bug 19791.
 864                         $descriptionUrl = $this->getDescriptionUrl();
 865                         if ( $descriptionUrl ) {
 866                                 $params['descriptionUrl'] = wfExpandUrl( $descriptionUrl, PROTO_CANONICAL );
 867                         }
 868
 869                         $script = $this->getTransformScript();
 870                         if ( $script && !( $flags & self::RENDER_NOW ) ) {
 871                                 // Use a script to transform on client request, if possible
 872                                 $thumb = $this->handler->getScriptedTransform( $this, $script, $params );
 873                                 if ( $thumb ) {
 874                                         break;
 875                                 }
 876                         }
 877
 878                         $normalisedParams = $params;
 879                         $this->handler->normaliseParams( $this, $normalisedParams );
 880
 881                         $thumbName = $this->thumbName( $normalisedParams );
 882                         $thumbUrl = $this->getThumbUrl( $thumbName );
 883                         $thumbPath = $this->getThumbPath( $thumbName ); // final thumb path
 884
 885                         if ( $this->repo ) {
 886                                 // Defer rendering if a 404 handler is set up...
 887                                 if ( $this->repo->canTransformVia404() && !( $flags & self::RENDER_NOW ) ) {
 888                                         wfDebug( __METHOD__ . " transformation deferred." );
 889                                         // XXX: Pass in the storage path even though we are not rendering anything
 890                                         // and the path is supposed to be an FS path. This is due to getScalerType()
 891                                         // getting called on the path and clobbering $thumb->getUrl() if it's false.
 892                                         $thumb = $this->handler->getTransform( $this, $thumbPath, $thumbUrl, $params );
 893                                         break;
 894                                 }
 895                                 // Clean up broken thumbnails as needed
 896                                 $this->migrateThumbFile( $thumbName );
 897                                 // Check if an up-to-date thumbnail already exists...
 898                                 wfDebug( __METHOD__.": Doing stat for $thumbPath\n" );
 899                                 if ( $this->repo->fileExists( $thumbPath ) && !( $flags & self::RENDER_FORCE ) ) {
 900                                         $timestamp = $this->repo->getFileTimestamp( $thumbPath );
 901                                         if ( $timestamp !== false && $timestamp >= $wgThumbnailEpoch ) {
 902                                                 // XXX: Pass in the storage path even though we are not rendering anything
 903                                                 // and the path is supposed to be an FS path. This is due to getScalerType()
 904                                                 // getting called on the path and clobbering $thumb->getUrl() if it's false.
 905                                                 $thumb = $this->handler->getTransform( $this, $thumbPath, $thumbUrl, $params );
 906                                                 $thumb->setStoragePath( $thumbPath );
 907                                                 break;
 908                                         }
 909                                 } elseif ( $flags & self::RENDER_FORCE ) {
 910                                         wfDebug( __METHOD__ . " forcing rendering per flag File::RENDER_FORCE\n" );
 911                                 }
 912                         }
 913
 914                         // If the backend is ready-only, don't keep generating thumbnails
 915                         // only to return transformation errors, just return the error now.
 916                         if ( $this->repo->getReadOnlyReason() !== false ) {
 917                                 $thumb = $this->transformErrorOutput( $thumbPath, $thumbUrl, $params, $flags );
 918                                 break;
 919                         }
 920
 921                         // Create a temp FS file with the same extension and the thumbnail
 922                         $thumbExt = FileBackend::extensionFromPath( $thumbPath );
 923                         $tmpFile = TempFSFile::factory( 'transform_', $thumbExt );
 924                         if ( !$tmpFile ) {
 925                                 $thumb = $this->transformErrorOutput( $thumbPath, $thumbUrl, $params, $flags );
 926                                 break;
 927                         }
 928                         $tmpThumbPath = $tmpFile->getPath(); // path of 0-byte temp file
 929
 930                         // Actually render the thumbnail...
 931                         wfProfileIn( __METHOD__ . '-doTransform' );
 932                         $thumb = $this->handler->doTransform( $this, $tmpThumbPath, $thumbUrl, $params );
 933                         wfProfileOut( __METHOD__ . '-doTransform' );
 934                         $tmpFile->bind( $thumb ); // keep alive with $thumb
 935
 936                         if ( !$thumb ) { // bad params?
 937                                 $thumb = null;
 938                         } elseif ( $thumb->isError() ) { // transform error
 939                                 $this->lastError = $thumb->toText();
 940                                 // Ignore errors if requested
 941                                 if ( $wgIgnoreImageErrors && !( $flags & self::RENDER_NOW ) ) {
 942                                         $thumb = $this->handler->getTransform( $this, $tmpThumbPath, $thumbUrl, $params );
 943                                 }
 944                         } elseif ( $this->repo && $thumb->hasFile() && !$thumb->fileIsSource() ) {
 945                                 // Copy the thumbnail from the file system into storage...
 946                                 $disposition = FileBackend::makeContentDisposition( 'inline', $this->name );
 947                                 $status = $this->repo->quickImport( $tmpThumbPath, $thumbPath, $disposition );
 948                                 if ( $status->isOK() ) {
 949                                         $thumb->setStoragePath( $thumbPath );
 950                                 } else {
 951                                         $thumb = $this->transformErrorOutput( $thumbPath, $thumbUrl, $params, $flags );
 952                                 }
 953                                 // Give extensions a chance to do something with this thumbnail...
 954                                 wfRunHooks( 'FileTransformed', array( $this, $thumb, $tmpThumbPath, $thumbPath ) );
 955                         }
 956
 957                         // Purge. Useful in the event of Core -> Squid connection failure or squid
 958                         // purge collisions from elsewhere during failure. Don't keep triggering for
 959                         // "thumbs" which have the main image URL though (bug 13776)
 960                         if ( $wgUseSquid ) {
 961                                 if ( !$thumb || $thumb->isError() || $thumb->getUrl() != $this->getURL() ) {
 962                                         SquidUpdate::purge( array( $thumbUrl ) );
 963                                 }
 964                         }
 965                 } while ( false );
 966
 967                 wfProfileOut( __METHOD__ );
 968                 return is_object( $thumb ) ? $thumb : false;
 969         }
 970
 971         /**
 972          * Hook into transform() to allow migration of thumbnail files
 973          * STUB
 974          * Overridden by LocalFile
 975          */
 976         function migrateThumbFile( $thumbName ) {}
 977
 978         /**
 979          * Get a MediaHandler instance for this file
 980          *
 981          * @return MediaHandler
 982          */
 983         function getHandler() {
 984                 if ( !isset( $this->handler ) ) {
 985                         $this->handler = MediaHandler::getHandler( $this->getMimeType() );
 986                 }
 987                 return $this->handler;
 988         }
 989
 990         /**
 991          * Get a ThumbnailImage representing a file type icon
 992          *
 993          * @return ThumbnailImage
 994          */
 995         function iconThumb() {
 996                 global $wgStylePath, $wgStyleDirectory;
 997
 998                 $try = array( 'fileicon-' . $this->getExtension() . '.png', 'fileicon.png' );
 999                 foreach ( $try as $icon ) {
1000                         $path = '/common/images/icons/' . $icon;
1001                         $filepath = $wgStyleDirectory . $path;
1002                         if ( file_exists( $filepath ) ) { // always FS
1003                                 $params = array( 'width' => 120, 'height' => 120 );
1004                                 return new ThumbnailImage( $this, $wgStylePath . $path, false, $params );
1005                         }
1006                 }
1007                 return null;
1008         }
1009
1010         /**
1011          * Get last thumbnailing error.
1012          * Largely obsolete.
1013          */
1014         function getLastError() {
1015                 return $this->lastError;
1016         }
1017
1018         /**
1019          * Get all thumbnail names previously generated for this file
1020          * STUB
1021          * Overridden by LocalFile
1022          * @return array
1023          */
1024         function getThumbnails() {
1025                 return array();
1026         }
1027
1028         /**
1029          * Purge shared caches such as thumbnails and DB data caching
1030          * STUB
1031          * Overridden by LocalFile
1032          * @param $options Array Options, which include:
1033          *     'forThumbRefresh' : The purging is only to refresh thumbnails
1034          */
1035         function purgeCache( $options = array() ) {}
1036
1037         /**
1038          * Purge the file description page, but don't go after
1039          * pages using the file. Use when modifying file history
1040          * but not the current data.
1041          */
1042         function purgeDescription() {
1043                 $title = $this->getTitle();
1044                 if ( $title ) {
1045                         $title->invalidateCache();
1046                         $title->purgeSquid();
1047                 }
1048         }
1049
1050         /**
1051          * Purge metadata and all affected pages when the file is created,
1052          * deleted, or majorly updated.
1053          */
1054         function purgeEverything() {
1055                 // Delete thumbnails and refresh file metadata cache
1056                 $this->purgeCache();
1057                 $this->purgeDescription();
1058
1059                 // Purge cache of all pages using this file
1060                 $title = $this->getTitle();
1061                 if ( $title ) {
1062                         $update = new HTMLCacheUpdate( $title, 'imagelinks' );
1063                         $update->doUpdate();
1064                 }
1065         }
1066
1067         /**
1068          * Return a fragment of the history of file.
1069          *
1070          * STUB
1071          * @param $limit integer Limit of rows to return
1072          * @param $start string timestamp Only revisions older than $start will be returned
1073          * @param $end string timestamp Only revisions newer than $end will be returned
1074          * @param $inc bool Include the endpoints of the time range
1075          *
1076          * @return array
1077          */
1078         function getHistory( $limit = null, $start = null, $end = null, $inc=true ) {
1079                 return array();
1080         }
1081
1082         /**
1083          * Return the history of this file, line by line. Starts with current version,
1084          * then old versions. Should return an object similar to an image/oldimage
1085          * database row.
1086          *
1087          * STUB
1088          * Overridden in LocalFile
1089          * @return bool
1090          */
1091         public function nextHistoryLine() {
1092                 return false;
1093         }
1094
1095         /**
1096          * Reset the history pointer to the first element of the history.
1097          * Always call this function after using nextHistoryLine() to free db resources
1098          * STUB
1099          * Overridden in LocalFile.
1100          */
1101         public function resetHistory() {}
1102
1103         /**
1104          * Get the filename hash component of the directory including trailing slash,
1105          * e.g. f/fa/
1106          * If the repository is not hashed, returns an empty string.
1107          *
1108          * @return string
1109          */
1110         function getHashPath() {
1111                 if ( !isset( $this->hashPath ) ) {
1112                         $this->assertRepoDefined();
1113                         $this->hashPath = $this->repo->getHashPath( $this->getName() );
1114                 }
1115                 return $this->hashPath;
1116         }
1117
1118         /**
1119          * Get the path of the file relative to the public zone root.
1120          * This function is overriden in OldLocalFile to be like getArchiveRel().
1121          *
1122          * @return string
1123          */
1124         function getRel() {
1125                 return $this->getHashPath() . $this->getName();
1126         }
1127
1128         /**
1129          * Get the path of an archived file relative to the public zone root
1130          *
1131          * @param $suffix bool|string if not false, the name of an archived thumbnail file
1132          *
1133          * @return string
1134          */
1135         function getArchiveRel( $suffix = false ) {
1136                 $path = 'archive/' . $this->getHashPath();
1137                 if ( $suffix === false ) {
1138                         $path = substr( $path, 0, -1 );
1139                 } else {
1140                         $path .= $suffix;
1141                 }
1142                 return $path;
1143         }
1144
1145         /**
1146          * Get the path, relative to the thumbnail zone root, of the
1147          * thumbnail directory or a particular file if $suffix is specified
1148          *
1149          * @param $suffix bool|string if not false, the name of a thumbnail file
1150          *
1151          * @return string
1152          */
1153         function getThumbRel( $suffix = false ) {
1154                 $path = $this->getRel();
1155                 if ( $suffix !== false ) {
1156                         $path .= '/' . $suffix;
1157                 }
1158                 return $path;
1159         }
1160
1161         /**
1162          * Get urlencoded path of the file relative to the public zone root.
1163          * This function is overriden in OldLocalFile to be like getArchiveUrl().
1164          *
1165          * @return string
1166          */
1167         function getUrlRel() {
1168                 return $this->getHashPath() . rawurlencode( $this->getName() );
1169         }
1170
1171         /**
1172          * Get the path, relative to the thumbnail zone root, for an archived file's thumbs directory
1173          * or a specific thumb if the $suffix is given.
1174          *
1175          * @param $archiveName string the timestamped name of an archived image
1176          * @param $suffix bool|string if not false, the name of a thumbnail file
1177          *
1178          * @return string
1179          */
1180         function getArchiveThumbRel( $archiveName, $suffix = false ) {
1181                 $path = 'archive/' . $this->getHashPath() . $archiveName . "/";
1182                 if ( $suffix === false ) {
1183                         $path = substr( $path, 0, -1 );
1184                 } else {
1185                         $path .= $suffix;
1186                 }
1187                 return $path;
1188         }
1189
1190         /**
1191          * Get the path of the archived file.
1192          *
1193          * @param $suffix bool|string if not false, the name of an archived file.
1194          *
1195          * @return string
1196          */
1197         function getArchivePath( $suffix = false ) {
1198                 $this->assertRepoDefined();
1199                 return $this->repo->getZonePath( 'public' ) . '/' . $this->getArchiveRel( $suffix );
1200         }
1201
1202         /**
1203          * Get the path of an archived file's thumbs, or a particular thumb if $suffix is specified
1204          *
1205          * @param $archiveName string the timestamped name of an archived image
1206          * @param $suffix bool|string if not false, the name of a thumbnail file
1207          *
1208          * @return string
1209          */
1210         function getArchiveThumbPath( $archiveName, $suffix = false ) {
1211                 $this->assertRepoDefined();
1212                 return $this->repo->getZonePath( 'thumb' ) . '/' .
1213                         $this->getArchiveThumbRel( $archiveName, $suffix );
1214         }
1215
1216         /**
1217          * Get the path of the thumbnail directory, or a particular file if $suffix is specified
1218          *
1219          * @param $suffix bool|string if not false, the name of a thumbnail file
1220          *
1221          * @return string
1222          */
1223         function getThumbPath( $suffix = false ) {
1224                 $this->assertRepoDefined();
1225                 return $this->repo->getZonePath( 'thumb' ) . '/' . $this->getThumbRel( $suffix );
1226         }
1227
1228         /**
1229          * Get the URL of the archive directory, or a particular file if $suffix is specified
1230          *
1231          * @param $suffix bool|string if not false, the name of an archived file
1232          *
1233          * @return string
1234          */
1235         function getArchiveUrl( $suffix = false ) {
1236                 $this->assertRepoDefined();
1237                 $path = $this->repo->getZoneUrl( 'public' ) . '/archive/' . $this->getHashPath();
1238                 if ( $suffix === false ) {
1239                         $path = substr( $path, 0, -1 );
1240                 } else {
1241                         $path .= rawurlencode( $suffix );
1242                 }
1243                 return $path;
1244         }
1245
1246         /**
1247          * Get the URL of the archived file's thumbs, or a particular thumb if $suffix is specified
1248          *
1249          * @param $archiveName string the timestamped name of an archived image
1250          * @param $suffix bool|string if not false, the name of a thumbnail file
1251          *
1252          * @return string
1253          */
1254         function getArchiveThumbUrl( $archiveName, $suffix = false ) {
1255                 $this->assertRepoDefined();
1256                 $path = $this->repo->getZoneUrl( 'thumb' ) . '/archive/' .
1257                         $this->getHashPath() . rawurlencode( $archiveName ) . "/";
1258                 if ( $suffix === false ) {
1259                         $path = substr( $path, 0, -1 );
1260                 } else {
1261                         $path .= rawurlencode( $suffix );
1262                 }
1263                 return $path;
1264         }
1265
1266         /**
1267          * Get the URL of the thumbnail directory, or a particular file if $suffix is specified
1268          *
1269          * @param $suffix bool|string if not false, the name of a thumbnail file
1270          *
1271          * @return string path
1272          */
1273         function getThumbUrl( $suffix = false ) {
1274                 $this->assertRepoDefined();
1275                 $path = $this->repo->getZoneUrl( 'thumb' ) . '/' . $this->getUrlRel();
1276                 if ( $suffix !== false ) {
1277                         $path .= '/' . rawurlencode( $suffix );
1278                 }
1279                 return $path;
1280         }
1281
1282         /**
1283          * Get the public zone virtual URL for a current version source file
1284          *
1285          * @param $suffix bool|string if not false, the name of a thumbnail file
1286          *
1287          * @return string
1288          */
1289         function getVirtualUrl( $suffix = false ) {
1290                 $this->assertRepoDefined();
1291                 $path = $this->repo->getVirtualUrl() . '/public/' . $this->getUrlRel();
1292                 if ( $suffix !== false ) {
1293                         $path .= '/' . rawurlencode( $suffix );
1294                 }
1295                 return $path;
1296         }
1297
1298         /**
1299          * Get the public zone virtual URL for an archived version source file
1300          *
1301          * @param $suffix bool|string if not false, the name of a thumbnail file
1302          *
1303          * @return string
1304          */
1305         function getArchiveVirtualUrl( $suffix = false ) {
1306                 $this->assertRepoDefined();
1307                 $path = $this->repo->getVirtualUrl() . '/public/archive/' . $this->getHashPath();
1308                 if ( $suffix === false ) {
1309                         $path = substr( $path, 0, -1 );
1310                 } else {
1311                         $path .= rawurlencode( $suffix );
1312                 }
1313                 return $path;
1314         }
1315
1316         /**
1317          * Get the virtual URL for a thumbnail file or directory
1318          *
1319          * @param $suffix bool|string if not false, the name of a thumbnail file
1320          *
1321          * @return string
1322          */
1323         function getThumbVirtualUrl( $suffix = false ) {
1324                 $this->assertRepoDefined();
1325                 $path = $this->repo->getVirtualUrl() . '/thumb/' . $this->getUrlRel();
1326                 if ( $suffix !== false ) {
1327                         $path .= '/' . rawurlencode( $suffix );
1328                 }
1329                 return $path;
1330         }
1331
1332         /**
1333          * @return bool
1334          */
1335         function isHashed() {
1336                 $this->assertRepoDefined();
1337                 return (bool)$this->repo->getHashLevels();
1338         }
1339
1340         /**
1341          * @throws MWException
1342          */
1343         function readOnlyError() {
1344                 throw new MWException( get_class($this) . ': write operations are not supported' );
1345         }
1346
1347         /**
1348          * Record a file upload in the upload log and the image table
1349          * STUB
1350          * Overridden by LocalFile
1351          * @param $oldver
1352          * @param $desc
1353          * @param $license string
1354          * @param $copyStatus string
1355          * @param $source string
1356          * @param $watch bool
1357          */
1358         function recordUpload( $oldver, $desc, $license = '', $copyStatus = '', $source = '', $watch = false ) {
1359                 $this->readOnlyError();
1360         }
1361
1362         /**
1363          * Move or copy a file to its public location. If a file exists at the
1364          * destination, move it to an archive. Returns a FileRepoStatus object with
1365          * the archive name in the "value" member on success.
1366          *
1367          * The archive name should be passed through to recordUpload for database
1368          * registration.
1369          *
1370          * @param $srcPath String: local filesystem path to the source image
1371          * @param $flags Integer: a bitwise combination of:
1372          *     File::DELETE_SOURCE    Delete the source file, i.e. move
1373          *         rather than copy
1374          * @return FileRepoStatus object. On success, the value member contains the
1375          *     archive name, or an empty string if it was a new file.
1376          *
1377          * STUB
1378          * Overridden by LocalFile
1379          */
1380         function publish( $srcPath, $flags = 0 ) {
1381                 $this->readOnlyError();
1382         }
1383
1384         /**
1385          * @return bool
1386          */
1387         function formatMetadata() {
1388                 if ( !$this->getHandler() ) {
1389                         return false;
1390                 }
1391                 return $this->getHandler()->formatMetadata( $this, $this->getMetadata() );
1392         }
1393
1394         /**
1395          * Returns true if the file comes from the local file repository.
1396          *
1397          * @return bool
1398          */
1399         function isLocal() {
1400                 return $this->repo && $this->repo->isLocal();
1401         }
1402
1403         /**
1404          * Returns the name of the repository.
1405          *
1406          * @return string
1407          */
1408         function getRepoName() {
1409                 return $this->repo ? $this->repo->getName() : 'unknown';
1410         }
1411
1412         /**
1413          * Returns the repository
1414          *
1415          * @return FileRepo|bool
1416          */
1417         function getRepo() {
1418                 return $this->repo;
1419         }
1420
1421         /**
1422          * Returns true if the image is an old version
1423          * STUB
1424          *
1425          * @return bool
1426          */
1427         function isOld() {
1428                 return false;
1429         }
1430
1431         /**
1432          * Is this file a "deleted" file in a private archive?
1433          * STUB
1434          *
1435          * @param $field
1436          *
1437          * @return bool
1438          */
1439         function isDeleted( $field ) {
1440                 return false;
1441         }
1442
1443         /**
1444          * Return the deletion bitfield
1445          * STUB
1446          * @return int
1447          */
1448         function getVisibility() {
1449                 return 0;
1450         }
1451
1452         /**
1453          * Was this file ever deleted from the wiki?
1454          *
1455          * @return bool
1456          */
1457         function wasDeleted() {
1458                 $title = $this->getTitle();
1459                 return $title && $title->isDeletedQuick();
1460         }
1461
1462         /**
1463          * Move file to the new title
1464          *
1465          * Move current, old version and all thumbnails
1466          * to the new filename. Old file is deleted.
1467          *
1468          * Cache purging is done; checks for validity
1469          * and logging are caller's responsibility
1470          *
1471          * @param $target Title New file name
1472          * @return FileRepoStatus object.
1473          */
1474          function move( $target ) {
1475                 $this->readOnlyError();
1476          }
1477
1478         /**
1479          * Delete all versions of the file.
1480          *
1481          * Moves the files into an archive directory (or deletes them)
1482          * and removes the database rows.
1483          *
1484          * Cache purging is done; logging is caller's responsibility.
1485          *
1486          * @param $reason String
1487          * @param $suppress Boolean: hide content from sysops?
1488          * @return bool on success, false on some kind of failure
1489          * STUB
1490          * Overridden by LocalFile
1491          */
1492         function delete( $reason, $suppress = false ) {
1493                 $this->readOnlyError();
1494         }
1495
1496         /**
1497          * Restore all or specified deleted revisions to the given file.
1498          * Permissions and logging are left to the caller.
1499          *
1500          * May throw database exceptions on error.
1501          *
1502          * @param $versions array set of record ids of deleted items to restore,
1503          *                    or empty to restore all revisions.
1504          * @param $unsuppress bool remove restrictions on content upon restoration?
1505          * @return int|bool the number of file revisions restored if successful,
1506          *         or false on failure
1507          * STUB
1508          * Overridden by LocalFile
1509          */
1510         function restore( $versions = array(), $unsuppress = false ) {
1511                 $this->readOnlyError();
1512         }
1513
1514         /**
1515          * Returns 'true' if this file is a type which supports multiple pages,
1516          * e.g. DJVU or PDF. Note that this may be true even if the file in
1517          * question only has a single page.
1518          *
1519          * @return Bool
1520          */
1521         function isMultipage() {
1522                 return $this->getHandler() && $this->handler->isMultiPage( $this );
1523         }
1524
1525         /**
1526          * Returns the number of pages of a multipage document, or false for
1527          * documents which aren't multipage documents
1528          *
1529          * @return bool|int
1530          */
1531         function pageCount() {
1532                 if ( !isset( $this->pageCount ) ) {
1533                         if ( $this->getHandler() && $this->handler->isMultiPage( $this ) ) {
1534                                 $this->pageCount = $this->handler->pageCount( $this );
1535                         } else {
1536                                 $this->pageCount = false;
1537                         }
1538                 }
1539                 return $this->pageCount;
1540         }
1541
1542         /**
1543          * Calculate the height of a thumbnail using the source and destination width
1544          *
1545          * @param $srcWidth
1546          * @param $srcHeight
1547          * @param $dstWidth
1548          *
1549          * @return int
1550          */
1551         static function scaleHeight( $srcWidth, $srcHeight, $dstWidth ) {
1552                 // Exact integer multiply followed by division
1553                 if ( $srcWidth == 0 ) {
1554                         return 0;
1555                 } else {
1556                         return round( $srcHeight * $dstWidth / $srcWidth );
1557                 }
1558         }
1559
1560         /**
1561          * Get an image size array like that returned by getImageSize(), or false if it
1562          * can't be determined.
1563          *
1564          * @param $fileName String: The filename
1565          * @return Array
1566          */
1567         function getImageSize( $fileName ) {
1568                 if ( !$this->getHandler() ) {
1569                         return false;
1570                 }
1571                 return $this->handler->getImageSize( $this, $fileName );
1572         }
1573
1574         /**
1575          * Get the URL of the image description page. May return false if it is
1576          * unknown or not applicable.
1577          *
1578          * @return string
1579          */
1580         function getDescriptionUrl() {
1581                 if ( $this->repo ) {
1582                         return $this->repo->getDescriptionUrl( $this->getName() );
1583                 } else {
1584                         return false;
1585                 }
1586         }
1587
1588         /**
1589          * Get the HTML text of the description page, if available
1590          *
1591          * @return string
1592          */
1593         function getDescriptionText() {
1594                 global $wgMemc, $wgLang;
1595                 if ( !$this->repo || !$this->repo->fetchDescription ) {
1596                         return false;
1597                 }
1598                 $renderUrl = $this->repo->getDescriptionRenderUrl( $this->getName(), $wgLang->getCode() );
1599                 if ( $renderUrl ) {
1600                         if ( $this->repo->descriptionCacheExpiry > 0 ) {
1601                                 wfDebug("Attempting to get the description from cache...");
1602                                 $key = $this->repo->getLocalCacheKey( 'RemoteFileDescription', 'url', $wgLang->getCode(),
1603                                                                         $this->getName() );
1604                                 $obj = $wgMemc->get($key);
1605                                 if ($obj) {
1606                                         wfDebug("success!\n");
1607                                         return $obj;
1608                                 }
1609                                 wfDebug("miss\n");
1610                         }
1611                         wfDebug( "Fetching shared description from $renderUrl\n" );
1612                         $res = Http::get( $renderUrl );
1613                         if ( $res && $this->repo->descriptionCacheExpiry > 0 ) {
1614                                 $wgMemc->set( $key, $res, $this->repo->descriptionCacheExpiry );
1615                         }
1616                         return $res;
1617                 } else {
1618                         return false;
1619                 }
1620         }
1621
1622         /**
1623          * Get description of file revision
1624          * STUB
1625          *
1626          * @param $audience Integer: one of:
1627          *      File::FOR_PUBLIC       to be displayed to all users
1628          *      File::FOR_THIS_USER    to be displayed to the given user
1629          *      File::RAW              get the description regardless of permissions
1630          * @param $user User object to check for, only if FOR_THIS_USER is passed
1631          *              to the $audience parameter
1632          * @return string
1633          */
1634         function getDescription( $audience = self::FOR_PUBLIC, User $user = null ) {
1635                 return null;
1636         }
1637
1638         /**
1639          * Get the 14-character timestamp of the file upload
1640          *
1641          * @return string|bool TS_MW timestamp or false on failure
1642          */
1643         function getTimestamp() {
1644                 $this->assertRepoDefined();
1645                 return $this->repo->getFileTimestamp( $this->getPath() );
1646         }
1647
1648         /**
1649          * Get the SHA-1 base 36 hash of the file
1650          *
1651          * @return string
1652          */
1653         function getSha1() {
1654                 $this->assertRepoDefined();
1655                 return $this->repo->getFileSha1( $this->getPath() );
1656         }
1657
1658         /**
1659          * Get the deletion archive key, "<sha1>.<ext>"
1660          *
1661          * @return string
1662          */
1663         function getStorageKey() {
1664                 $hash = $this->getSha1();
1665                 if ( !$hash ) {
1666                         return false;
1667                 }
1668                 $ext = $this->getExtension();
1669                 $dotExt = $ext === '' ? '' : ".$ext";
1670                 return $hash . $dotExt;
1671         }
1672
1673         /**
1674          * Determine if the current user is allowed to view a particular
1675          * field of this file, if it's marked as deleted.
1676          * STUB
1677          * @param $field Integer
1678          * @param $user User object to check, or null to use $wgUser
1679          * @return Boolean
1680          */
1681         function userCan( $field, User $user = null ) {
1682                 return true;
1683         }
1684
1685         /**
1686          * Get an associative array containing information about a file in the local filesystem.
1687          *
1688          * @param $path String: absolute local filesystem path
1689          * @param $ext Mixed: the file extension, or true to extract it from the filename.
1690          *             Set it to false to ignore the extension.
1691          *
1692          * @return array
1693          */
1694         static function getPropsFromPath( $path, $ext = true ) {
1695                 wfDebug( __METHOD__.": Getting file info for $path\n" );
1696                 wfDeprecated( __METHOD__, '1.19' );
1697
1698                 $fsFile = new FSFile( $path );
1699                 return $fsFile->getProps();
1700         }
1701
1702         /**
1703          * Get a SHA-1 hash of a file in the local filesystem, in base-36 lower case
1704          * encoding, zero padded to 31 digits.
1705          *
1706          * 160 log 2 / log 36 = 30.95, so the 160-bit hash fills 31 digits in base 36
1707          * fairly neatly.
1708          *
1709          * @param $path string
1710          *
1711          * @return bool|string False on failure
1712          */
1713         static function sha1Base36( $path ) {
1714                 wfDeprecated( __METHOD__, '1.19' );
1715
1716                 $fsFile = new FSFile( $path );
1717                 return $fsFile->getSha1Base36();
1718         }
1719
1720         /**
1721          * @return string
1722          */
1723         function getLongDesc() {
1724                 $handler = $this->getHandler();
1725                 if ( $handler ) {
1726                         return $handler->getLongDesc( $this );
1727                 } else {
1728                         return MediaHandler::getGeneralLongDesc( $this );
1729                 }
1730         }
1731
1732         /**
1733          * @return string
1734          */
1735         function getShortDesc() {
1736                 $handler = $this->getHandler();
1737                 if ( $handler ) {
1738                         return $handler->getShortDesc( $this );
1739                 } else {
1740                         return MediaHandler::getGeneralShortDesc( $this );
1741                 }
1742         }
1743
1744         /**
1745          * @return string
1746          */
1747         function getDimensionsString() {
1748                 $handler = $this->getHandler();
1749                 if ( $handler ) {
1750                         return $handler->getDimensionsString( $this );
1751                 } else {
1752                         return '';
1753                 }
1754         }
1755
1756         /**
1757          * @return
1758          */
1759         function getRedirected() {
1760                 return $this->redirected;
1761         }
1762
1763         /**
1764          * @return Title
1765          */
1766         function getRedirectedTitle() {
1767                 if ( $this->redirected ) {
1768                         if ( !$this->redirectTitle ) {
1769                                 $this->redirectTitle = Title::makeTitle( NS_FILE, $this->redirected );
1770                         }
1771                         return $this->redirectTitle;
1772                 }
1773         }
1774
1775         /**
1776          * @param  $from
1777          * @return void
1778          */
1779         function redirectedFrom( $from ) {
1780                 $this->redirected = $from;
1781         }
1782
1783         /**
1784          * @return bool
1785          */
1786         function isMissing() {
1787                 return false;
1788         }
1789
1790         /**
1791          * Check if this file object is small and can be cached
1792          * @return boolean
1793          */
1794         public function isCacheable() {
1795                 return true;
1796         }
1797
1798         /**
1799          * Assert that $this->repo is set to a valid FileRepo instance
1800          * @throws MWException
1801          */
1802         protected function assertRepoDefined() {
1803                 if ( !( $this->repo instanceof $this->repoClass ) ) {
1804                         throw new MWException( "A {$this->repoClass} object is not set for this File.\n" );
1805                 }
1806         }
1807
1808         /**
1809          * Assert that $this->title is set to a Title
1810          * @throws MWException
1811          */
1812         protected function assertTitleDefined() {
1813                 if ( !( $this->title instanceof Title ) ) {
1814                         throw new MWException( "A Title object is not set for this File.\n" );
1815                 }
1816         }
1817 }