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