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|bool
  72          */
  73         var $repo;
  74
  75         /**
  76          * @var Title
  77          */
  78         var $title;
  79
  80         var $lastError, $redirected, $redirectedTitle;
  81
  82         /**
  83          * @var FSFile|bool False if undefined
  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|bool
 115          * @param $repo FileRepo|bool
 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|bool 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
 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|bool ForeignAPIFile::getPath can return 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|bool False on failure
 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 bool|number False on failure
 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          * @return bool
 437          */
 438         public function getMetadata() {
 439                 return false;
 440         }
 441
 442         /**
 443         * get versioned metadata
 444         *
 445         * @param $metadata Mixed Array or String of (serialized) metadata
 446         * @param $version integer version number.
 447         * @return Array containing metadata, or what was passed to it on fail (unserializing if not array)
 448         */
 449         public function convertMetadataVersion($metadata, $version) {
 450                 $handler = $this->getHandler();
 451                 if ( !is_array( $metadata ) ) {
 452                         // Just to make the return type consistent
 453                         $metadata = unserialize( $metadata );
 454                 }
 455                 if ( $handler ) {
 456                         return $handler->convertMetadataVersion( $metadata, $version );
 457                 } else {
 458                         return $metadata;
 459                 }
 460         }
 461
 462         /**
 463          * Return the bit depth of the file
 464          * Overridden by LocalFile
 465          * STUB
 466          * @return int
 467          */
 468         public function getBitDepth() {
 469                 return 0;
 470         }
 471
 472         /**
 473          * Return the size of the image file, in bytes
 474          * Overridden by LocalFile, UnregisteredLocalFile
 475          * STUB
 476          * @return bool
 477          */
 478         public function getSize() {
 479                 return false;
 480         }
 481
 482         /**
 483          * Returns the mime type of the file.
 484          * Overridden by LocalFile, UnregisteredLocalFile
 485          * STUB
 486          *
 487          * @return string
 488          */
 489         function getMimeType() {
 490                 return 'unknown/unknown';
 491         }
 492
 493         /**
 494          * Return the type of the media in the file.
 495          * Use the value returned by this function with the MEDIATYPE_xxx constants.
 496          * Overridden by LocalFile,
 497          * STUB
 498          * @return string
 499          */
 500         function getMediaType() {
 501                 return MEDIATYPE_UNKNOWN;
 502         }
 503
 504         /**
 505          * Checks if the output of transform() for this file is likely
 506          * to be valid. If this is false, various user elements will
 507          * display a placeholder instead.
 508          *
 509          * Currently, this checks if the file is an image format
 510          * that can be converted to a format
 511          * supported by all browsers (namely GIF, PNG and JPEG),
 512          * or if it is an SVG image and SVG conversion is enabled.
 513          *
 514          * @return bool
 515          */
 516         function canRender() {
 517                 if ( !isset( $this->canRender ) ) {
 518                         $this->canRender = $this->getHandler() && $this->handler->canRender( $this );
 519                 }
 520                 return $this->canRender;
 521         }
 522
 523         /**
 524          * Accessor for __get()
 525          * @return bool
 526          */
 527         protected function getCanRender() {
 528                 return $this->canRender();
 529         }
 530
 531         /**
 532          * Return true if the file is of a type that can't be directly
 533          * rendered by typical browsers and needs to be re-rasterized.
 534          *
 535          * This returns true for everything but the bitmap types
 536          * supported by all browsers, i.e. JPEG; GIF and PNG. It will
 537          * also return true for any non-image formats.
 538          *
 539          * @return bool
 540          */
 541         function mustRender() {
 542                 return $this->getHandler() && $this->handler->mustRender( $this );
 543         }
 544
 545         /**
 546          * Alias for canRender()
 547          *
 548          * @return bool
 549          */
 550         function allowInlineDisplay() {
 551                 return $this->canRender();
 552         }
 553
 554         /**
 555          * Determines if this media file is in a format that is unlikely to
 556          * contain viruses or malicious content. It uses the global
 557          * $wgTrustedMediaFormats list to determine if the file is safe.
 558          *
 559          * This is used to show a warning on the description page of non-safe files.
 560          * It may also be used to disallow direct [[media:...]] links to such files.
 561          *
 562          * Note that this function will always return true if allowInlineDisplay()
 563          * or isTrustedFile() is true for this file.
 564          *
 565          * @return bool
 566          */
 567         function isSafeFile() {
 568                 if ( !isset( $this->isSafeFile ) ) {
 569                         $this->isSafeFile = $this->_getIsSafeFile();
 570                 }
 571                 return $this->isSafeFile;
 572         }
 573
 574         /**
 575          * Accessor for __get()
 576          *
 577          * @return bool
 578          */
 579         protected function getIsSafeFile() {
 580                 return $this->isSafeFile();
 581         }
 582
 583         /**
 584          * Uncached accessor
 585          *
 586          * @return bool
 587          */
 588         protected function _getIsSafeFile() {
 589                 global $wgTrustedMediaFormats;
 590
 591                 if ( $this->allowInlineDisplay() ) {
 592                         return true;
 593                 }
 594                 if ($this->isTrustedFile()) {
 595                         return true;
 596                 }
 597
 598                 $type = $this->getMediaType();
 599                 $mime = $this->getMimeType();
 600                 #wfDebug("LocalFile::isSafeFile: type= $type, mime= $mime\n");
 601
 602                 if ( !$type || $type === MEDIATYPE_UNKNOWN ) {
 603                         return false; #unknown type, not trusted
 604                 }
 605                 if ( in_array( $type, $wgTrustedMediaFormats ) ) {
 606                         return true;
 607                 }
 608
 609                 if ( $mime === "unknown/unknown" ) {
 610                         return false; #unknown type, not trusted
 611                 }
 612                 if ( in_array( $mime, $wgTrustedMediaFormats) ) {
 613                         return true;
 614                 }
 615
 616                 return false;
 617         }
 618
 619         /**
 620          * Returns true if the file is flagged as trusted. Files flagged that way
 621          * can be linked to directly, even if that is not allowed for this type of
 622          * file normally.
 623          *
 624          * This is a dummy function right now and always returns false. It could be
 625          * implemented to extract a flag from the database. The trusted flag could be
 626          * set on upload, if the user has sufficient privileges, to bypass script-
 627          * and html-filters. It may even be coupled with cryptographics signatures
 628          * or such.
 629          *
 630          * @return bool
 631          */
 632         function isTrustedFile() {
 633                 #this could be implemented to check a flag in the database,
 634                 #look for signatures, etc
 635                 return false;
 636         }
 637
 638         /**
 639          * Returns true if file exists in the repository.
 640          *
 641          * Overridden by LocalFile to avoid unnecessary stat calls.
 642          *
 643          * @return boolean Whether file exists in the repository.
 644          */
 645         public function exists() {
 646                 return $this->getPath() && $this->repo->fileExists( $this->path );
 647         }
 648
 649         /**
 650          * Returns true if file exists in the repository and can be included in a page.
 651          * It would be unsafe to include private images, making public thumbnails inadvertently
 652          *
 653          * @return boolean Whether file exists in the repository and is includable.
 654          */
 655         public function isVisible() {
 656                 return $this->exists();
 657         }
 658
 659         /**
 660          * @return string
 661          */
 662         function getTransformScript() {
 663                 if ( !isset( $this->transformScript ) ) {
 664                         $this->transformScript = false;
 665                         if ( $this->repo ) {
 666                                 $script = $this->repo->getThumbScriptUrl();
 667                                 if ( $script ) {
 668                                         $this->transformScript = "$script?f=" . urlencode( $this->getName() );
 669                                 }
 670                         }
 671                 }
 672                 return $this->transformScript;
 673         }
 674
 675         /**
 676          * Get a ThumbnailImage which is the same size as the source
 677          *
 678          * @param $handlerParams array
 679          *
 680          * @return string
 681          */
 682         function getUnscaledThumb( $handlerParams = array() ) {
 683                 $hp =& $handlerParams;
 684                 $page = isset( $hp['page'] ) ? $hp['page'] : false;
 685                 $width = $this->getWidth( $page );
 686                 if ( !$width ) {
 687                         return $this->iconThumb();
 688                 }
 689                 $hp['width'] = $width;
 690                 return $this->transform( $hp );
 691         }
 692
 693         /**
 694          * Return the file name of a thumbnail with the specified parameters
 695          *
 696          * @param $params Array: handler-specific parameters
 697          * @private -ish
 698          *
 699          * @return string
 700          */
 701         function thumbName( $params ) {
 702                 return $this->generateThumbName( $this->getName(), $params );
 703         }
 704
 705         /**
 706          * Generate a thumbnail file name from a name and specified parameters
 707          *
 708          * @param string $name
 709          * @param array $params Parameters which will be passed to MediaHandler::makeParamString
 710          *
 711          * @return string
 712          */
 713         function generateThumbName( $name, $params ) {
 714                 if ( !$this->getHandler() ) {
 715                         return null;
 716                 }
 717                 $extension = $this->getExtension();
 718                 list( $thumbExt, $thumbMime ) = $this->handler->getThumbType(
 719                         $extension, $this->getMimeType(), $params );
 720                 $thumbName = $this->handler->makeParamString( $params ) . '-' . $name;
 721                 if ( $thumbExt != $extension ) {
 722                         $thumbName .= ".$thumbExt";
 723                 }
 724                 return $thumbName;
 725         }
 726
 727         /**
 728          * Create a thumbnail of the image having the specified width/height.
 729          * The thumbnail will not be created if the width is larger than the
 730          * image's width. Let the browser do the scaling in this case.
 731          * The thumbnail is stored on disk and is only computed if the thumbnail
 732          * file does not exist OR if it is older than the image.
 733          * Returns the URL.
 734          *
 735          * Keeps aspect ratio of original image. If both width and height are
 736          * specified, the generated image will be no bigger than width x height,
 737          * and will also have correct aspect ratio.
 738          *
 739          * @param $width Integer: maximum width of the generated thumbnail
 740          * @param $height Integer: maximum height of the image (optional)
 741          *
 742          * @return string
 743          */
 744         public function createThumb( $width, $height = -1 ) {
 745                 $params = array( 'width' => $width );
 746                 if ( $height != -1 ) {
 747                         $params['height'] = $height;
 748                 }
 749                 $thumb = $this->transform( $params );
 750                 if ( is_null( $thumb ) || $thumb->isError() ) {
 751                         return '';
 752                 }
 753                 return $thumb->getUrl();
 754         }
 755
 756         /**
 757          * Return either a MediaTransformError or placeholder thumbnail (if $wgIgnoreImageErrors)
 758          *
 759          * @param $thumbPath string Thumbnail storage path
 760          * @param $thumbUrl string Thumbnail URL
 761          * @param $params Array
 762          * @param $flags integer
 763          * @return MediaTransformOutput
 764          */
 765         protected function transformErrorOutput( $thumbPath, $thumbUrl, $params, $flags ) {
 766                 global $wgIgnoreImageErrors;
 767
 768                 if ( $wgIgnoreImageErrors && !( $flags & self::RENDER_NOW ) ) {
 769                         return $this->handler->getTransform( $this, $thumbPath, $thumbUrl, $params );
 770                 } else {
 771                         return new MediaTransformError( 'thumbnail_error',
 772                                 $params['width'], 0, wfMsg( 'thumbnail-dest-create' ) );
 773                 }
 774         }
 775
 776         /**
 777          * Transform a media file
 778          *
 779          * @param $params Array: an associative array of handler-specific parameters.
 780          *                Typical keys are width, height and page.
 781          * @param $flags Integer: a bitfield, may contain self::RENDER_NOW to force rendering
 782          * @return MediaTransformOutput|bool False on failure
 783          */
 784         function transform( $params, $flags = 0 ) {
 785                 global $wgUseSquid, $wgIgnoreImageErrors, $wgThumbnailEpoch;
 786
 787                 wfProfileIn( __METHOD__ );
 788                 do {
 789                         if ( !$this->canRender() ) {
 790                                 $thumb = $this->iconThumb();
 791                                 break; // not a bitmap or renderable image, don't try
 792                         }
 793
 794                         // Get the descriptionUrl to embed it as comment into the thumbnail. Bug 19791.
 795                         $descriptionUrl = $this->getDescriptionUrl();
 796                         if ( $descriptionUrl ) {
 797                                 $params['descriptionUrl'] = wfExpandUrl( $descriptionUrl, PROTO_CANONICAL );
 798                         }
 799
 800                         $script = $this->getTransformScript();
 801                         if ( $script && !( $flags & self::RENDER_NOW ) ) {
 802                                 // Use a script to transform on client request, if possible
 803                                 $thumb = $this->handler->getScriptedTransform( $this, $script, $params );
 804                                 if ( $thumb ) {
 805                                         break;
 806                                 }
 807                         }
 808
 809                         $normalisedParams = $params;
 810                         $this->handler->normaliseParams( $this, $normalisedParams );
 811
 812                         $thumbName = $this->thumbName( $normalisedParams );
 813                         $thumbUrl = $this->getThumbUrl( $thumbName );
 814                         $thumbPath = $this->getThumbPath( $thumbName ); // final thumb path
 815
 816                         if ( $this->repo ) {
 817                                 // Defer rendering if a 404 handler is set up...
 818                                 if ( $this->repo->canTransformVia404() && !( $flags & self::RENDER_NOW ) ) {
 819                                         wfDebug( __METHOD__ . " transformation deferred." );
 820                                         // XXX: Pass in the storage path even though we are not rendering anything
 821                                         // and the path is supposed to be an FS path. This is due to getScalerType()
 822                                         // getting called on the path and clobbering $thumb->getUrl() if it's false.
 823                                         $thumb = $this->handler->getTransform( $this, $thumbPath, $thumbUrl, $params );
 824                                         break;
 825                                 }
 826                                 // Clean up broken thumbnails as needed
 827                                 $this->migrateThumbFile( $thumbName );
 828                                 // Check if an up-to-date thumbnail already exists...
 829                                 wfDebug( __METHOD__.": Doing stat for $thumbPath\n" );
 830                                 if ( $this->repo->fileExists( $thumbPath ) && !( $flags & self::RENDER_FORCE ) ) {
 831                                         $timestamp = $this->repo->getFileTimestamp( $thumbPath );
 832                                         if ( $timestamp !== false && $timestamp >= $wgThumbnailEpoch ) {
 833                                                 // XXX: Pass in the storage path even though we are not rendering anything
 834                                                 // and the path is supposed to be an FS path. This is due to getScalerType()
 835                                                 // getting called on the path and clobbering $thumb->getUrl() if it's false.
 836                                                 $thumb = $this->handler->getTransform( $this, $thumbPath, $thumbUrl, $params );
 837                                                 $thumb->setStoragePath( $thumbPath );
 838                                                 break;
 839                                         }
 840                                 } elseif ( $flags & self::RENDER_FORCE ) {
 841                                         wfDebug( __METHOD__ . " forcing rendering per flag File::RENDER_FORCE\n" );
 842                                 }
 843                         }
 844
 845                         // If the backend is ready-only, don't keep generating thumbnails
 846                         // only to return transformation errors, just return the error now.
 847                         if ( $this->repo->getReadOnlyReason() !== false ) {
 848                                 $thumb = $this->transformErrorOutput( $thumbPath, $thumbUrl, $params, $flags );
 849                                 break;
 850                         }
 851
 852                         // Create a temp FS file with the same extension and the thumbnail
 853                         $thumbExt = FileBackend::extensionFromPath( $thumbPath );
 854                         $tmpFile = TempFSFile::factory( 'transform_', $thumbExt );
 855                         if ( !$tmpFile ) {
 856                                 $thumb = $this->transformErrorOutput( $thumbPath, $thumbUrl, $params, $flags );
 857                                 break;
 858                         }
 859                         $tmpThumbPath = $tmpFile->getPath(); // path of 0-byte temp file
 860
 861                         // Actually render the thumbnail...
 862                         $thumb = $this->handler->doTransform( $this, $tmpThumbPath, $thumbUrl, $params );
 863                         $tmpFile->bind( $thumb ); // keep alive with $thumb
 864
 865                         if ( !$thumb ) { // bad params?
 866                                 $thumb = null;
 867                         } elseif ( $thumb->isError() ) { // transform error
 868                                 $this->lastError = $thumb->toText();
 869                                 // Ignore errors if requested
 870                                 if ( $wgIgnoreImageErrors && !( $flags & self::RENDER_NOW ) ) {
 871                                         $thumb = $this->handler->getTransform( $this, $tmpThumbPath, $thumbUrl, $params );
 872                                 }
 873                         } elseif ( $this->repo && $thumb->hasFile() && !$thumb->fileIsSource() ) {
 874                                 // Copy the thumbnail from the file system into storage...
 875                                 $status = $this->repo->quickImport( $tmpThumbPath, $thumbPath );
 876                                 if ( $status->isOK() ) {
 877                                         $thumb->setStoragePath( $thumbPath );
 878                                 } else {
 879                                         $thumb = $this->transformErrorOutput( $thumbPath, $thumbUrl, $params, $flags );
 880                                 }
 881                                 // Give extensions a chance to do something with this thumbnail...
 882                                 wfRunHooks( 'FileTransformed', array( $this, $thumb, $tmpThumbPath, $thumbPath ) );
 883                         }
 884
 885                         // Purge. Useful in the event of Core -> Squid connection failure or squid
 886                         // purge collisions from elsewhere during failure. Don't keep triggering for
 887                         // "thumbs" which have the main image URL though (bug 13776)
 888                         if ( $wgUseSquid ) {
 889                                 if ( !$thumb || $thumb->isError() || $thumb->getUrl() != $this->getURL() ) {
 890                                         SquidUpdate::purge( array( $thumbUrl ) );
 891                                 }
 892                         }
 893                 } while ( false );
 894
 895                 wfProfileOut( __METHOD__ );
 896                 return is_object( $thumb ) ? $thumb : false;
 897         }
 898
 899         /**
 900          * Hook into transform() to allow migration of thumbnail files
 901          * STUB
 902          * Overridden by LocalFile
 903          */
 904         function migrateThumbFile( $thumbName ) {}
 905
 906         /**
 907          * Get a MediaHandler instance for this file
 908          *
 909          * @return MediaHandler
 910          */
 911         function getHandler() {
 912                 if ( !isset( $this->handler ) ) {
 913                         $this->handler = MediaHandler::getHandler( $this->getMimeType() );
 914                 }
 915                 return $this->handler;
 916         }
 917
 918         /**
 919          * Get a ThumbnailImage representing a file type icon
 920          *
 921          * @return ThumbnailImage
 922          */
 923         function iconThumb() {
 924                 global $wgStylePath, $wgStyleDirectory;
 925
 926                 $try = array( 'fileicon-' . $this->getExtension() . '.png', 'fileicon.png' );
 927                 foreach ( $try as $icon ) {
 928                         $path = '/common/images/icons/' . $icon;
 929                         $filepath = $wgStyleDirectory . $path;
 930                         if ( file_exists( $filepath ) ) { // always FS
 931                                 return new ThumbnailImage( $this, $wgStylePath . $path, 120, 120 );
 932                         }
 933                 }
 934                 return null;
 935         }
 936
 937         /**
 938          * Get last thumbnailing error.
 939          * Largely obsolete.
 940          */
 941         function getLastError() {
 942                 return $this->lastError;
 943         }
 944
 945         /**
 946          * Get all thumbnail names previously generated for this file
 947          * STUB
 948          * Overridden by LocalFile
 949          * @return array
 950          */
 951         function getThumbnails() {
 952                 return array();
 953         }
 954
 955         /**
 956          * Purge shared caches such as thumbnails and DB data caching
 957          * STUB
 958          * Overridden by LocalFile
 959          * @param $options Array Options, which include:
 960          *     'forThumbRefresh' : The purging is only to refresh thumbnails
 961          */
 962         function purgeCache( $options = array() ) {}
 963
 964         /**
 965          * Purge the file description page, but don't go after
 966          * pages using the file. Use when modifying file history
 967          * but not the current data.
 968          */
 969         function purgeDescription() {
 970                 $title = $this->getTitle();
 971                 if ( $title ) {
 972                         $title->invalidateCache();
 973                         $title->purgeSquid();
 974                 }
 975         }
 976
 977         /**
 978          * Purge metadata and all affected pages when the file is created,
 979          * deleted, or majorly updated.
 980          */
 981         function purgeEverything() {
 982                 // Delete thumbnails and refresh file metadata cache
 983                 $this->purgeCache();
 984                 $this->purgeDescription();
 985
 986                 // Purge cache of all pages using this file
 987                 $title = $this->getTitle();
 988                 if ( $title ) {
 989                         $update = new HTMLCacheUpdate( $title, 'imagelinks' );
 990                         $update->doUpdate();
 991                 }
 992         }
 993
 994         /**
 995          * Return a fragment of the history of file.
 996          *
 997          * STUB
 998          * @param $limit integer Limit of rows to return
 999          * @param $start string timestamp Only revisions older than $start will be returned
1000          * @param $end string timestamp Only revisions newer than $end will be returned
1001          * @param $inc bool Include the endpoints of the time range
1002          *
1003          * @return array
1004          */
1005         function getHistory($limit = null, $start = null, $end = null, $inc=true) {
1006                 return array();
1007         }
1008
1009         /**
1010          * Return the history of this file, line by line. Starts with current version,
1011          * then old versions. Should return an object similar to an image/oldimage
1012          * database row.
1013          *
1014          * STUB
1015          * Overridden in LocalFile
1016          * @return bool
1017          */
1018         public function nextHistoryLine() {
1019                 return false;
1020         }
1021
1022         /**
1023          * Reset the history pointer to the first element of the history.
1024          * Always call this function after using nextHistoryLine() to free db resources
1025          * STUB
1026          * Overridden in LocalFile.
1027          */
1028         public function resetHistory() {}
1029
1030         /**
1031          * Get the filename hash component of the directory including trailing slash,
1032          * e.g. f/fa/
1033          * If the repository is not hashed, returns an empty string.
1034          *
1035          * @return string
1036          */
1037         function getHashPath() {
1038                 if ( !isset( $this->hashPath ) ) {
1039                         $this->assertRepoDefined();
1040                         $this->hashPath = $this->repo->getHashPath( $this->getName() );
1041                 }
1042                 return $this->hashPath;
1043         }
1044
1045         /**
1046          * Get the path of the file relative to the public zone root.
1047          * This function is overriden in OldLocalFile to be like getArchiveRel().
1048          *
1049          * @return string
1050          */
1051         function getRel() {
1052                 return $this->getHashPath() . $this->getName();
1053         }
1054
1055         /**
1056          * Get the path of an archived file relative to the public zone root
1057          *
1058          * @param $suffix bool|string if not false, the name of an archived thumbnail file
1059          *
1060          * @return string
1061          */
1062         function getArchiveRel( $suffix = false ) {
1063                 $path = 'archive/' . $this->getHashPath();
1064                 if ( $suffix === false ) {
1065                         $path = substr( $path, 0, -1 );
1066                 } else {
1067                         $path .= $suffix;
1068                 }
1069                 return $path;
1070         }
1071
1072         /**
1073          * Get the path, relative to the thumbnail zone root, of the
1074          * thumbnail directory or a particular file if $suffix is specified
1075          *
1076          * @param $suffix bool|string if not false, the name of a thumbnail file
1077          *
1078          * @return string
1079          */
1080         function getThumbRel( $suffix = false ) {
1081                 $path = $this->getRel();
1082                 if ( $suffix !== false ) {
1083                         $path .= '/' . $suffix;
1084                 }
1085                 return $path;
1086         }
1087
1088         /**
1089          * Get urlencoded path of the file relative to the public zone root.
1090          * This function is overriden in OldLocalFile to be like getArchiveUrl().
1091          *
1092          * @return string
1093          */
1094         function getUrlRel() {
1095                 return $this->getHashPath() . rawurlencode( $this->getName() );
1096         }
1097
1098         /**
1099          * Get the path, relative to the thumbnail zone root, for an archived file's thumbs directory
1100          * or a specific thumb if the $suffix is given.
1101          *
1102          * @param $archiveName string the timestamped name of an archived image
1103          * @param $suffix bool|string if not false, the name of a thumbnail file
1104          *
1105          * @return string
1106          */
1107         function getArchiveThumbRel( $archiveName, $suffix = false ) {
1108                 $path = 'archive/' . $this->getHashPath() . $archiveName . "/";
1109                 if ( $suffix === false ) {
1110                         $path = substr( $path, 0, -1 );
1111                 } else {
1112                         $path .= $suffix;
1113                 }
1114                 return $path;
1115         }
1116
1117         /**
1118          * Get the path of the archived file.
1119          *
1120          * @param $suffix bool|string if not false, the name of an archived file.
1121          *
1122          * @return string
1123          */
1124         function getArchivePath( $suffix = false ) {
1125                 $this->assertRepoDefined();
1126                 return $this->repo->getZonePath( 'public' ) . '/' . $this->getArchiveRel( $suffix );
1127         }
1128
1129         /**
1130          * Get the path of an archived file's thumbs, or a particular thumb if $suffix is specified
1131          *
1132          * @param $archiveName string the timestamped name of an archived image
1133          * @param $suffix bool|string if not false, the name of a thumbnail file
1134          *
1135          * @return string
1136          */
1137         function getArchiveThumbPath( $archiveName, $suffix = false ) {
1138                 $this->assertRepoDefined();
1139                 return $this->repo->getZonePath( 'thumb' ) . '/' .
1140                         $this->getArchiveThumbRel( $archiveName, $suffix );
1141         }
1142
1143         /**
1144          * Get the path of the thumbnail directory, or a particular file if $suffix is specified
1145          *
1146          * @param $suffix bool|string if not false, the name of a thumbnail file
1147          *
1148          * @return string
1149          */
1150         function getThumbPath( $suffix = false ) {
1151                 $this->assertRepoDefined();
1152                 return $this->repo->getZonePath( 'thumb' ) . '/' . $this->getThumbRel( $suffix );
1153         }
1154
1155         /**
1156          * Get the URL of the archive directory, or a particular file if $suffix is specified
1157          *
1158          * @param $suffix bool|string if not false, the name of an archived file
1159          *
1160          * @return string
1161          */
1162         function getArchiveUrl( $suffix = false ) {
1163                 $this->assertRepoDefined();
1164                 $path = $this->repo->getZoneUrl( 'public' ) . '/archive/' . $this->getHashPath();
1165                 if ( $suffix === false ) {
1166                         $path = substr( $path, 0, -1 );
1167                 } else {
1168                         $path .= rawurlencode( $suffix );
1169                 }
1170                 return $path;
1171         }
1172
1173         /**
1174          * Get the URL of the archived file's thumbs, or a particular thumb if $suffix is specified
1175          *
1176          * @param $archiveName string the timestamped name of an archived image
1177          * @param $suffix bool|string if not false, the name of a thumbnail file
1178          *
1179          * @return string
1180          */
1181         function getArchiveThumbUrl( $archiveName, $suffix = false ) {
1182                 $this->assertRepoDefined();
1183                 $path = $this->repo->getZoneUrl( 'thumb' ) . '/archive/' .
1184                         $this->getHashPath() . rawurlencode( $archiveName ) . "/";
1185                 if ( $suffix === false ) {
1186                         $path = substr( $path, 0, -1 );
1187                 } else {
1188                         $path .= rawurlencode( $suffix );
1189                 }
1190                 return $path;
1191         }
1192
1193         /**
1194          * Get the URL of the thumbnail directory, or a particular file if $suffix is specified
1195          *
1196          * @param $suffix bool|string if not false, the name of a thumbnail file
1197          *
1198          * @return string path
1199          */
1200         function getThumbUrl( $suffix = false ) {
1201                 $this->assertRepoDefined();
1202                 $path = $this->repo->getZoneUrl( 'thumb' ) . '/' . $this->getUrlRel();
1203                 if ( $suffix !== false ) {
1204                         $path .= '/' . rawurlencode( $suffix );
1205                 }
1206                 return $path;
1207         }
1208
1209         /**
1210          * Get the public zone virtual URL for a current version source file
1211          *
1212          * @param $suffix bool|string if not false, the name of a thumbnail file
1213          *
1214          * @return string
1215          */
1216         function getVirtualUrl( $suffix = false ) {
1217                 $this->assertRepoDefined();
1218                 $path = $this->repo->getVirtualUrl() . '/public/' . $this->getUrlRel();
1219                 if ( $suffix !== false ) {
1220                         $path .= '/' . rawurlencode( $suffix );
1221                 }
1222                 return $path;
1223         }
1224
1225         /**
1226          * Get the public zone virtual URL for an archived version source file
1227          *
1228          * @param $suffix bool|string if not false, the name of a thumbnail file
1229          *
1230          * @return string
1231          */
1232         function getArchiveVirtualUrl( $suffix = false ) {
1233                 $this->assertRepoDefined();
1234                 $path = $this->repo->getVirtualUrl() . '/public/archive/' . $this->getHashPath();
1235                 if ( $suffix === false ) {
1236                         $path = substr( $path, 0, -1 );
1237                 } else {
1238                         $path .= rawurlencode( $suffix );
1239                 }
1240                 return $path;
1241         }
1242
1243         /**
1244          * Get the virtual URL for a thumbnail file or directory
1245          *
1246          * @param $suffix bool|string if not false, the name of a thumbnail file
1247          *
1248          * @return string
1249          */
1250         function getThumbVirtualUrl( $suffix = false ) {
1251                 $this->assertRepoDefined();
1252                 $path = $this->repo->getVirtualUrl() . '/thumb/' . $this->getUrlRel();
1253                 if ( $suffix !== false ) {
1254                         $path .= '/' . rawurlencode( $suffix );
1255                 }
1256                 return $path;
1257         }
1258
1259         /**
1260          * @return bool
1261          */
1262         function isHashed() {
1263                 $this->assertRepoDefined();
1264                 return (bool)$this->repo->getHashLevels();
1265         }
1266
1267         /**
1268          * @throws MWException
1269          */
1270         function readOnlyError() {
1271                 throw new MWException( get_class($this) . ': write operations are not supported' );
1272         }
1273
1274         /**
1275          * Record a file upload in the upload log and the image table
1276          * STUB
1277          * Overridden by LocalFile
1278          * @param $oldver
1279          * @param $desc
1280          * @param $license string
1281          * @param $copyStatus string
1282          * @param $source string
1283          * @param $watch bool
1284          */
1285         function recordUpload( $oldver, $desc, $license = '', $copyStatus = '', $source = '', $watch = false ) {
1286                 $this->readOnlyError();
1287         }
1288
1289         /**
1290          * Move or copy a file to its public location. If a file exists at the
1291          * destination, move it to an archive. Returns a FileRepoStatus object with
1292          * the archive name in the "value" member on success.
1293          *
1294          * The archive name should be passed through to recordUpload for database
1295          * registration.
1296          *
1297          * @param $srcPath String: local filesystem path to the source image
1298          * @param $flags Integer: a bitwise combination of:
1299          *     File::DELETE_SOURCE    Delete the source file, i.e. move
1300          *         rather than copy
1301          * @return FileRepoStatus object. On success, the value member contains the
1302          *     archive name, or an empty string if it was a new file.
1303          *
1304          * STUB
1305          * Overridden by LocalFile
1306          */
1307         function publish( $srcPath, $flags = 0 ) {
1308                 $this->readOnlyError();
1309         }
1310
1311         /**
1312          * @return bool
1313          */
1314         function formatMetadata() {
1315                 if ( !$this->getHandler() ) {
1316                         return false;
1317                 }
1318                 return $this->getHandler()->formatMetadata( $this, $this->getMetadata() );
1319         }
1320
1321         /**
1322          * Returns true if the file comes from the local file repository.
1323          *
1324          * @return bool
1325          */
1326         function isLocal() {
1327                 return $this->repo && $this->repo->isLocal();
1328         }
1329
1330         /**
1331          * Returns the name of the repository.
1332          *
1333          * @return string
1334          */
1335         function getRepoName() {
1336                 return $this->repo ? $this->repo->getName() : 'unknown';
1337         }
1338
1339         /**
1340          * Returns the repository
1341          *
1342          * @return FileRepo|bool
1343          */
1344         function getRepo() {
1345                 return $this->repo;
1346         }
1347
1348         /**
1349          * Returns true if the image is an old version
1350          * STUB
1351          *
1352          * @return bool
1353          */
1354         function isOld() {
1355                 return false;
1356         }
1357
1358         /**
1359          * Is this file a "deleted" file in a private archive?
1360          * STUB
1361          *
1362          * @param $field
1363          *
1364          * @return bool
1365          */
1366         function isDeleted( $field ) {
1367                 return false;
1368         }
1369
1370         /**
1371          * Return the deletion bitfield
1372          * STUB
1373          * @return int
1374          */
1375         function getVisibility() {
1376                 return 0;
1377         }
1378
1379         /**
1380          * Was this file ever deleted from the wiki?
1381          *
1382          * @return bool
1383          */
1384         function wasDeleted() {
1385                 $title = $this->getTitle();
1386                 return $title && $title->isDeletedQuick();
1387         }
1388
1389         /**
1390          * Move file to the new title
1391          *
1392          * Move current, old version and all thumbnails
1393          * to the new filename. Old file is deleted.
1394          *
1395          * Cache purging is done; checks for validity
1396          * and logging are caller's responsibility
1397          *
1398          * @param $target Title New file name
1399          * @return FileRepoStatus object.
1400          */
1401          function move( $target ) {
1402                 $this->readOnlyError();
1403          }
1404
1405         /**
1406          * Delete all versions of the file.
1407          *
1408          * Moves the files into an archive directory (or deletes them)
1409          * and removes the database rows.
1410          *
1411          * Cache purging is done; logging is caller's responsibility.
1412          *
1413          * @param $reason String
1414          * @param $suppress Boolean: hide content from sysops?
1415          * @return bool on success, false on some kind of failure
1416          * STUB
1417          * Overridden by LocalFile
1418          */
1419         function delete( $reason, $suppress = false ) {
1420                 $this->readOnlyError();
1421         }
1422
1423         /**
1424          * Restore all or specified deleted revisions to the given file.
1425          * Permissions and logging are left to the caller.
1426          *
1427          * May throw database exceptions on error.
1428          *
1429          * @param $versions array set of record ids of deleted items to restore,
1430          *                    or empty to restore all revisions.
1431          * @param $unsuppress bool remove restrictions on content upon restoration?
1432          * @return int|bool the number of file revisions restored if successful,
1433          *         or false on failure
1434          * STUB
1435          * Overridden by LocalFile
1436          */
1437         function restore( $versions = array(), $unsuppress = false ) {
1438                 $this->readOnlyError();
1439         }
1440
1441         /**
1442          * Returns 'true' if this file is a type which supports multiple pages,
1443          * e.g. DJVU or PDF. Note that this may be true even if the file in
1444          * question only has a single page.
1445          *
1446          * @return Bool
1447          */
1448         function isMultipage() {
1449                 return $this->getHandler() && $this->handler->isMultiPage( $this );
1450         }
1451
1452         /**
1453          * Returns the number of pages of a multipage document, or false for
1454          * documents which aren't multipage documents
1455          *
1456          * @return bool|int
1457          */
1458         function pageCount() {
1459                 if ( !isset( $this->pageCount ) ) {
1460                         if ( $this->getHandler() && $this->handler->isMultiPage( $this ) ) {
1461                                 $this->pageCount = $this->handler->pageCount( $this );
1462                         } else {
1463                                 $this->pageCount = false;
1464                         }
1465                 }
1466                 return $this->pageCount;
1467         }
1468
1469         /**
1470          * Calculate the height of a thumbnail using the source and destination width
1471          *
1472          * @param $srcWidth
1473          * @param $srcHeight
1474          * @param $dstWidth
1475          *
1476          * @return int
1477          */
1478         static function scaleHeight( $srcWidth, $srcHeight, $dstWidth ) {
1479                 // Exact integer multiply followed by division
1480                 if ( $srcWidth == 0 ) {
1481                         return 0;
1482                 } else {
1483                         return round( $srcHeight * $dstWidth / $srcWidth );
1484                 }
1485         }
1486
1487         /**
1488          * Get an image size array like that returned by getImageSize(), or false if it
1489          * can't be determined.
1490          *
1491          * @param $fileName String: The filename
1492          * @return Array
1493          */
1494         function getImageSize( $fileName ) {
1495                 if ( !$this->getHandler() ) {
1496                         return false;
1497                 }
1498                 return $this->handler->getImageSize( $this, $fileName );
1499         }
1500
1501         /**
1502          * Get the URL of the image description page. May return false if it is
1503          * unknown or not applicable.
1504          *
1505          * @return string
1506          */
1507         function getDescriptionUrl() {
1508                 if ( $this->repo ) {
1509                         return $this->repo->getDescriptionUrl( $this->getName() );
1510                 } else {
1511                         return false;
1512                 }
1513         }
1514
1515         /**
1516          * Get the HTML text of the description page, if available
1517          *
1518          * @return string
1519          */
1520         function getDescriptionText() {
1521                 global $wgMemc, $wgLang;
1522                 if ( !$this->repo || !$this->repo->fetchDescription ) {
1523                         return false;
1524                 }
1525                 $renderUrl = $this->repo->getDescriptionRenderUrl( $this->getName(), $wgLang->getCode() );
1526                 if ( $renderUrl ) {
1527                         if ( $this->repo->descriptionCacheExpiry > 0 ) {
1528                                 wfDebug("Attempting to get the description from cache...");
1529                                 $key = $this->repo->getLocalCacheKey( 'RemoteFileDescription', 'url', $wgLang->getCode(),
1530                                                                         $this->getName() );
1531                                 $obj = $wgMemc->get($key);
1532                                 if ($obj) {
1533                                         wfDebug("success!\n");
1534                                         return $obj;
1535                                 }
1536                                 wfDebug("miss\n");
1537                         }
1538                         wfDebug( "Fetching shared description from $renderUrl\n" );
1539                         $res = Http::get( $renderUrl );
1540                         if ( $res && $this->repo->descriptionCacheExpiry > 0 ) {
1541                                 $wgMemc->set( $key, $res, $this->repo->descriptionCacheExpiry );
1542                         }
1543                         return $res;
1544                 } else {
1545                         return false;
1546                 }
1547         }
1548
1549         /**
1550          * Get discription of file revision
1551          * STUB
1552          *
1553          * @return string
1554          */
1555         function getDescription() {
1556                 return null;
1557         }
1558
1559         /**
1560          * Get the 14-character timestamp of the file upload
1561          *
1562          * @return string|bool TS_MW timestamp or false on failure
1563          */
1564         function getTimestamp() {
1565                 $this->assertRepoDefined();
1566                 return $this->repo->getFileTimestamp( $this->getPath() );
1567         }
1568
1569         /**
1570          * Get the SHA-1 base 36 hash of the file
1571          *
1572          * @return string
1573          */
1574         function getSha1() {
1575                 $this->assertRepoDefined();
1576                 return $this->repo->getFileSha1( $this->getPath() );
1577         }
1578
1579         /**
1580          * Get the deletion archive key, <sha1>.<ext>
1581          *
1582          * @return string
1583          */
1584         function getStorageKey() {
1585                 $hash = $this->getSha1();
1586                 if ( !$hash ) {
1587                         return false;
1588                 }
1589                 $ext = $this->getExtension();
1590                 $dotExt = $ext === '' ? '' : ".$ext";
1591                 return $hash . $dotExt;
1592         }
1593
1594         /**
1595          * Determine if the current user is allowed to view a particular
1596          * field of this file, if it's marked as deleted.
1597          * STUB
1598          * @param $field Integer
1599          * @param $user User object to check, or null to use $wgUser
1600          * @return Boolean
1601          */
1602         function userCan( $field, User $user = null ) {
1603                 return true;
1604         }
1605
1606         /**
1607          * Get an associative array containing information about a file in the local filesystem.
1608          *
1609          * @param $path String: absolute local filesystem path
1610          * @param $ext Mixed: the file extension, or true to extract it from the filename.
1611          *             Set it to false to ignore the extension.
1612          *
1613          * @return array
1614          */
1615         static function getPropsFromPath( $path, $ext = true ) {
1616                 wfDebug( __METHOD__.": Getting file info for $path\n" );
1617                 wfDeprecated( __METHOD__, '1.19' );
1618
1619                 $fsFile = new FSFile( $path );
1620                 return $fsFile->getProps();
1621         }
1622
1623         /**
1624          * Get a SHA-1 hash of a file in the local filesystem, in base-36 lower case
1625          * encoding, zero padded to 31 digits.
1626          *
1627          * 160 log 2 / log 36 = 30.95, so the 160-bit hash fills 31 digits in base 36
1628          * fairly neatly.
1629          *
1630          * @param $path string
1631          *
1632          * @return bool|string False on failure
1633          */
1634         static function sha1Base36( $path ) {
1635                 wfDeprecated( __METHOD__, '1.19' );
1636
1637                 $fsFile = new FSFile( $path );
1638                 return $fsFile->getSha1Base36();
1639         }
1640
1641         /**
1642          * @return string
1643          */
1644         function getLongDesc() {
1645                 $handler = $this->getHandler();
1646                 if ( $handler ) {
1647                         return $handler->getLongDesc( $this );
1648                 } else {
1649                         return MediaHandler::getGeneralLongDesc( $this );
1650                 }
1651         }
1652
1653         /**
1654          * @return string
1655          */
1656         function getShortDesc() {
1657                 $handler = $this->getHandler();
1658                 if ( $handler ) {
1659                         return $handler->getShortDesc( $this );
1660                 } else {
1661                         return MediaHandler::getGeneralShortDesc( $this );
1662                 }
1663         }
1664
1665         /**
1666          * @return string
1667          */
1668         function getDimensionsString() {
1669                 $handler = $this->getHandler();
1670                 if ( $handler ) {
1671                         return $handler->getDimensionsString( $this );
1672                 } else {
1673                         return '';
1674                 }
1675         }
1676
1677         /**
1678          * @return
1679          */
1680         function getRedirected() {
1681                 return $this->redirected;
1682         }
1683
1684         /**
1685          * @return Title
1686          */
1687         function getRedirectedTitle() {
1688                 if ( $this->redirected ) {
1689                         if ( !$this->redirectTitle ) {
1690                                 $this->redirectTitle = Title::makeTitle( NS_FILE, $this->redirected );
1691                         }
1692                         return $this->redirectTitle;
1693                 }
1694         }
1695
1696         /**
1697          * @param  $from
1698          * @return void
1699          */
1700         function redirectedFrom( $from ) {
1701                 $this->redirected = $from;
1702         }
1703
1704         /**
1705          * @return bool
1706          */
1707         function isMissing() {
1708                 return false;
1709         }
1710
1711         /**
1712          * Check if this file object is small and can be cached
1713          * @return boolean
1714          */
1715         public function isCacheable() {
1716                 return true;
1717         }
1718
1719         /**
1720          * Assert that $this->repo is set to a valid FileRepo instance
1721          * @throws MWException
1722          */
1723         protected function assertRepoDefined() {
1724                 if ( !( $this->repo instanceof $this->repoClass ) ) {
1725                         throw new MWException( "A {$this->repoClass} object is not set for this File.\n" );
1726                 }
1727         }
1728
1729         /**
1730          * Assert that $this->title is set to a Title
1731          * @throws MWException
1732          */
1733         protected function assertTitleDefined() {
1734                 if ( !( $this->title instanceof Title ) ) {
1735                         throw new MWException( "A Title object is not set for this File.\n" );
1736                 }
1737         }
1738 }