includes/filerepo/file/File.php

   1 <?php
   2 /**
   3  * @defgroup FileAbstraction File abstraction
   4  * @ingroup FileRepo
   5  *
   6  * Represents files in a repository.
   7  */
   8
   9 /**
  10  * Base code for files.
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation; either version 2 of the License, or
  15  * (at your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  20  * GNU General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU General Public License along
  23  * with this program; if not, write to the Free Software Foundation, Inc.,
  24  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  25  * http://www.gnu.org/copyleft/gpl.html
  26  *
  27  * @file
  28  * @ingroup FileAbstraction
  29  */
  30
  31 /**
  32  * Implements some public methods and some protected utility functions which
  33  * are required by multiple child classes. Contains stub functionality for
  34  * unimplemented public methods.
  35  *
  36  * Stub functions which should be overridden are marked with STUB. Some more
  37  * concrete functions are also typically overridden by child classes.
  38  *
  39  * Note that only the repo object knows what its file class is called. You should
  40  * never name a file class explictly outside of the repo class. Instead use the
  41  * repo's factory functions to generate file objects, for example:
  42  *
  43  * RepoGroup::singleton()->getLocalRepo()->newFile($title);
  44  *
  45  * The convenience functions wfLocalFile() and wfFindFile() should be sufficient
  46  * in most cases.
  47  *
  48  * @ingroup FileAbstraction
  49  */
  50 abstract class File {
  51         const DELETED_FILE = 1;
  52         const DELETED_COMMENT = 2;
  53         const DELETED_USER = 4;
  54         const DELETED_RESTRICTED = 8;
  55
  56         /** Force rendering in the current process */
  57         const RENDER_NOW   = 1;
  58         /**
  59          * Force rendering even if thumbnail already exist and using RENDER_NOW
  60          * I.e. you have to pass both flags: File::RENDER_NOW | File::RENDER_FORCE
  61          */
  62         const RENDER_FORCE = 2;
  63
  64         const DELETE_SOURCE = 1;
  65
  66         /**
  67          * Some member variables can be lazy-initialised using __get(). The
  68          * initialisation function for these variables is always a function named
  69          * like getVar(), where Var is the variable name with upper-case first
  70          * letter.
  71          *
  72          * The following variables are initialised in this way in this base class:
  73          *    name, extension, handler, path, canRender, isSafeFile,
  74          *    transformScript, hashPath, pageCount, url
  75          *
  76          * Code within this class should generally use the accessor function
  77          * directly, since __get() isn't re-entrant and therefore causes bugs that
  78          * depend on initialisation order.
  79          */
  80
  81         /**
  82          * The following member variables are not lazy-initialised
  83          */
  84
  85         /**
  86          * @var FileRepo|bool
  87          */
  88         var $repo;
  89
  90         /**
  91          * @var Title
  92          */
  93         var $title;
  94
  95         var $lastError, $redirected, $redirectedTitle;
  96
  97         /**
  98          * @var FSFile|bool False if undefined
  99          */
 100         protected $fsFile;
 101
 102         /**
 103          * @var MediaHandler
 104          */
 105         protected $handler;
 106
 107         /**
 108          * @var string
 109          */
 110         protected $url, $extension, $name, $path, $hashPath, $pageCount, $transformScript;
 111
 112         /**
 113          * @var bool
 114          */
 115         protected $canRender, $isSafeFile;
 116
 117         /**
 118          * @var string Required Repository class type
 119          */
 120         protected $repoClass = 'FileRepo';
 121
 122         /**
 123          * Call this constructor from child classes.
 124          *
 125          * Both $title and $repo are optional, though some functions
 126          * may return false or throw exceptions if they are not set.
 127          * Most subclasses will want to call assertRepoDefined() here.
 128          *
 129          * @param $title Title|string|bool
 130          * @param $repo FileRepo|bool
 131          */
 132         function __construct( $title, $repo ) {
 133                 if ( $title !== false ) { // subclasses may not use MW titles
 134                         $title = self::normalizeTitle( $title, 'exception' );
 135                 }
 136                 $this->title = $title;
 137                 $this->repo = $repo;
 138         }
 139
 140         /**
 141          * Given a string or Title object return either a
 142          * valid Title object with namespace NS_FILE or null
 143          *
 144          * @param $title Title|string
 145          * @param $exception string|bool Use 'exception' to throw an error on bad titles
 146          * @return Title|null
 147          */
 148         static function normalizeTitle( $title, $exception = false ) {
 149                 $ret = $title;
 150                 if ( $ret instanceof Title ) {
 151                         # Normalize NS_MEDIA -> NS_FILE
 152                         if ( $ret->getNamespace() == NS_MEDIA ) {
 153                                 $ret = Title::makeTitleSafe( NS_FILE, $ret->getDBkey() );
 154                         # Sanity check the title namespace
 155                         } elseif ( $ret->getNamespace() !== NS_FILE ) {
 156                                 $ret = null;
 157                         }
 158                 } else {
 159                         # Convert strings to Title objects
 160                         $ret = Title::makeTitleSafe( NS_FILE, (string)$ret );
 161                 }
 162                 if ( !$ret && $exception !== false ) {
 163                         throw new MWException( "`$title` is not a valid file title." );
 164                 }
 165                 return $ret;
 166         }
 167
 168         function __get( $name ) {
 169                 $function = array( $this, 'get' . ucfirst( $name ) );
 170                 if ( !is_callable( $function ) ) {
 171                         return null;
 172                 } else {
 173                         $this->$name = call_user_func( $function );
 174                         return $this->$name;
 175                 }
 176         }
 177
 178         /**
 179          * Normalize a file extension to the common form, and ensure it's clean.
 180          * Extensions with non-alphanumeric characters will be discarded.
 181          *
 182          * @param $ext string (without the .)
 183          * @return string
 184          */
 185         static function normalizeExtension( $ext ) {
 186                 $lower = strtolower( $ext );
 187                 $squish = array(
 188                         'htm' => 'html',
 189                         'jpeg' => 'jpg',
 190                         'mpeg' => 'mpg',
 191                         'tiff' => 'tif',
 192                         'ogv' => 'ogg' );
 193                 if( isset( $squish[$lower] ) ) {
 194                         return $squish[$lower];
 195                 } elseif( preg_match( '/^[0-9a-z]+$/', $lower ) ) {
 196                         return $lower;
 197                 } else {
 198                         return '';
 199                 }
 200         }
 201
 202         /**
 203          * Checks if file extensions are compatible
 204          *
 205          * @param $old File Old file
 206          * @param $new string New name
 207          *
 208          * @return bool|null
 209          */
 210         static function checkExtensionCompatibility( File $old, $new ) {
 211                 $oldMime = $old->getMimeType();
 212                 $n = strrpos( $new, '.' );
 213                 $newExt = self::normalizeExtension( $n ? substr( $new, $n + 1 ) : '' );
 214                 $mimeMagic = MimeMagic::singleton();
 215                 return $mimeMagic->isMatchingExtension( $newExt, $oldMime );
 216         }
 217
 218         /**
 219          * Upgrade the database row if there is one
 220          * Called by ImagePage
 221          * STUB
 222          */
 223         function upgradeRow() {}
 224
 225         /**
 226          * Split an internet media type into its two components; if not
 227          * a two-part name, set the minor type to 'unknown'.
 228          *
 229          * @param string $mime "text/html" etc
 230          * @return array ("text", "html") etc
 231          */
 232         public static function splitMime( $mime ) {
 233                 if( strpos( $mime, '/' ) !== false ) {
 234                         return explode( '/', $mime, 2 );
 235                 } else {
 236                         return array( $mime, 'unknown' );
 237                 }
 238         }
 239
 240         /**
 241          * Return the name of this file
 242          *
 243          * @return string
 244          */
 245         public function getName() {
 246                 if ( !isset( $this->name ) ) {
 247                         $this->assertRepoDefined();
 248                         $this->name = $this->repo->getNameFromTitle( $this->title );
 249                 }
 250                 return $this->name;
 251         }
 252
 253         /**
 254          * Get the file extension, e.g. "svg"
 255          *
 256          * @return string
 257          */
 258         function getExtension() {
 259                 if ( !isset( $this->extension ) ) {
 260                         $n = strrpos( $this->getName(), '.' );
 261                         $this->extension = self::normalizeExtension(
 262                                 $n ? substr( $this->getName(), $n + 1 ) : '' );
 263                 }
 264                 return $this->extension;
 265         }
 266
 267         /**
 268          * Return the associated title object
 269          *
 270          * @return Title
 271          */
 272         public function getTitle() {
 273                 return $this->title;
 274         }
 275
 276         /**
 277          * Return the title used to find this file
 278          *
 279          * @return Title
 280          */
 281         public function getOriginalTitle() {
 282                 if ( $this->redirected ) {
 283                         return $this->getRedirectedTitle();
 284                 }
 285                 return $this->title;
 286         }
 287
 288         /**
 289          * Return the URL of the file
 290          *
 291          * @return string
 292          */
 293         public function getUrl() {
 294                 if ( !isset( $this->url ) ) {
 295                         $this->assertRepoDefined();
 296                         $this->url = $this->repo->getZoneUrl( 'public' ) . '/' . $this->getUrlRel();
 297                 }
 298                 return $this->url;
 299         }
 300
 301         /**
 302          * Return a fully-qualified URL to the file.
 303          * Upload URL paths _may or may not_ be fully qualified, so
 304          * we check. Local paths are assumed to belong on $wgServer.
 305          *
 306          * @return String
 307          */
 308         public function getFullUrl() {
 309                 return wfExpandUrl( $this->getUrl(), PROTO_RELATIVE );
 310         }
 311
 312         /**
 313          * @return string
 314          */
 315         public function getCanonicalUrl() {
 316                 return wfExpandUrl( $this->getUrl(), PROTO_CANONICAL );
 317         }
 318
 319         /**
 320          * @return string
 321          */
 322         function getViewURL() {
 323                 if ( $this->mustRender() ) {
 324                         if ( $this->canRender() ) {
 325                                 return $this->createThumb( $this->getWidth() );
 326                         } else {
 327                                 wfDebug( __METHOD__.': supposed to render ' . $this->getName() .
 328                                         ' (' . $this->getMimeType() . "), but can't!\n" );
 329                                 return $this->getURL(); #hm... return NULL?
 330                         }
 331                 } else {
 332                         return $this->getURL();
 333                 }
 334         }
 335
 336         /**
 337          * Return the storage path to the file. Note that this does
 338          * not mean that a file actually exists under that location.
 339          *
 340          * This path depends on whether directory hashing is active or not,
 341          * i.e. whether the files are all found in the same directory,
 342          * or in hashed paths like /images/3/3c.
 343          *
 344          * Most callers don't check the return value, but ForeignAPIFile::getPath
 345          * returns false.
 346          *
 347          * @return string|bool ForeignAPIFile::getPath can return false
 348         */
 349         public function getPath() {
 350                 if ( !isset( $this->path ) ) {
 351                         $this->assertRepoDefined();
 352                         $this->path = $this->repo->getZonePath( 'public' ) . '/' . $this->getRel();
 353                 }
 354                 return $this->path;
 355         }
 356
 357         /**
 358          * Get an FS copy or original of this file and return the path.
 359          * Returns false on failure. Callers must not alter the file.
 360          * Temporary files are cleared automatically.
 361          *
 362          * @return string|bool False on failure
 363          */
 364         public function getLocalRefPath() {
 365                 $this->assertRepoDefined();
 366                 if ( !isset( $this->fsFile ) ) {
 367                         $this->fsFile = $this->repo->getLocalReference( $this->getPath() );
 368                         if ( !$this->fsFile ) {
 369                                 $this->fsFile = false; // null => false; cache negative hits
 370                         }
 371                 }
 372                 return ( $this->fsFile )
 373                         ? $this->fsFile->getPath()
 374                         : false;
 375         }
 376
 377         /**
 378          * Return the width of the image. Returns false if the width is unknown
 379          * or undefined.
 380          *
 381          * STUB
 382          * Overridden by LocalFile, UnregisteredLocalFile
 383          *
 384          * @param $page int
 385          *
 386          * @return number
 387          */
 388         public function getWidth( $page = 1 ) {
 389                 return false;
 390         }
 391
 392         /**
 393          * Return the height of the image. Returns false if the height is unknown
 394          * or undefined
 395          *
 396          * STUB
 397          * Overridden by LocalFile, UnregisteredLocalFile
 398          *
 399          * @param $page int
 400          *
 401          * @return bool|number False on failure
 402          */
 403         public function getHeight( $page = 1 ) {
 404                 return false;
 405         }
 406
 407         /**
 408          * Returns ID or name of user who uploaded the file
 409          * STUB
 410          *
 411          * @param $type string 'text' or 'id'
 412          *
 413          * @return string|int
 414          */
 415         public function getUser( $type = 'text' ) {
 416                 return null;
 417         }
 418
 419         /**
 420          * Get the duration of a media file in seconds
 421          *
 422          * @return number
 423          */
 424         public function getLength() {
 425                 $handler = $this->getHandler();
 426                 if ( $handler ) {
 427                         return $handler->getLength( $this );
 428                 } else {
 429                         return 0;
 430                 }
 431         }
 432
 433         /**
 434          * Return true if the file is vectorized
 435          *
 436          * @return bool
 437          */
 438         public function isVectorized() {
 439                 $handler = $this->getHandler();
 440                 if ( $handler ) {
 441                         return $handler->isVectorized( $this );
 442                 } else {
 443                         return false;
 444                 }
 445         }
 446
 447         /**
 448          * Get handler-specific metadata
 449          * Overridden by LocalFile, UnregisteredLocalFile
 450          * STUB
 451          * @return bool
 452          */
 453         public function getMetadata() {
 454                 return false;
 455         }
 456
 457         /**
 458         * get versioned metadata
 459         *
 460         * @param $metadata Mixed Array or String of (serialized) metadata
 461         * @param $version integer version number.
 462         * @return Array containing metadata, or what was passed to it on fail (unserializing if not array)
 463         */
 464         public function convertMetadataVersion($metadata, $version) {
 465                 $handler = $this->getHandler();
 466                 if ( !is_array( $metadata ) ) {
 467                         // Just to make the return type consistent
 468                         $metadata = unserialize( $metadata );
 469                 }
 470                 if ( $handler ) {
 471                         return $handler->convertMetadataVersion( $metadata, $version );
 472                 } else {
 473                         return $metadata;
 474                 }
 475         }
 476
 477         /**
 478          * Return the bit depth of the file
 479          * Overridden by LocalFile
 480          * STUB
 481          * @return int
 482          */
 483         public function getBitDepth() {
 484                 return 0;
 485         }
 486
 487         /**
 488          * Return the size of the image file, in bytes
 489          * Overridden by LocalFile, UnregisteredLocalFile
 490          * STUB
 491          * @return bool
 492          */
 493         public function getSize() {
 494                 return false;
 495         }
 496
 497         /**
 498          * Returns the mime type of the file.
 499          * Overridden by LocalFile, UnregisteredLocalFile
 500          * STUB
 501          *
 502          * @return string
 503          */
 504         function getMimeType() {
 505                 return 'unknown/unknown';
 506         }
 507
 508         /**
 509          * Return the type of the media in the file.
 510          * Use the value returned by this function with the MEDIATYPE_xxx constants.
 511          * Overridden by LocalFile,
 512          * STUB
 513          * @return string
 514          */
 515         function getMediaType() {
 516                 return MEDIATYPE_UNKNOWN;
 517         }
 518
 519         /**
 520          * Checks if the output of transform() for this file is likely
 521          * to be valid. If this is false, various user elements will
 522          * display a placeholder instead.
 523          *
 524          * Currently, this checks if the file is an image format
 525          * that can be converted to a format
 526          * supported by all browsers (namely GIF, PNG and JPEG),
 527          * or if it is an SVG image and SVG conversion is enabled.
 528          *
 529          * @return bool
 530          */
 531         function canRender() {
 532                 if ( !isset( $this->canRender ) ) {
 533                         $this->canRender = $this->getHandler() && $this->handler->canRender( $this );
 534                 }
 535                 return $this->canRender;
 536         }
 537
 538         /**
 539          * Accessor for __get()
 540          * @return bool
 541          */
 542         protected function getCanRender() {
 543                 return $this->canRender();
 544         }
 545
 546         /**
 547          * Return true if the file is of a type that can't be directly
 548          * rendered by typical browsers and needs to be re-rasterized.
 549          *
 550          * This returns true for everything but the bitmap types
 551          * supported by all browsers, i.e. JPEG; GIF and PNG. It will
 552          * also return true for any non-image formats.
 553          *
 554          * @return bool
 555          */
 556         function mustRender() {
 557                 return $this->getHandler() && $this->handler->mustRender( $this );
 558         }
 559
 560         /**
 561          * Alias for canRender()
 562          *
 563          * @return bool
 564          */
 565         function allowInlineDisplay() {
 566                 return $this->canRender();
 567         }
 568
 569         /**
 570          * Determines if this media file is in a format that is unlikely to
 571          * contain viruses or malicious content. It uses the global
 572          * $wgTrustedMediaFormats list to determine if the file is safe.
 573          *
 574          * This is used to show a warning on the description page of non-safe files.
 575          * It may also be used to disallow direct [[media:...]] links to such files.
 576          *
 577          * Note that this function will always return true if allowInlineDisplay()
 578          * or isTrustedFile() is true for this file.
 579          *
 580          * @return bool
 581          */
 582         function isSafeFile() {
 583                 if ( !isset( $this->isSafeFile ) ) {
 584                         $this->isSafeFile = $this->_getIsSafeFile();
 585                 }
 586                 return $this->isSafeFile;
 587         }
 588
 589         /**
 590          * Accessor for __get()
 591          *
 592          * @return bool
 593          */
 594         protected function getIsSafeFile() {
 595                 return $this->isSafeFile();
 596         }
 597
 598         /**
 599          * Uncached accessor
 600          *
 601          * @return bool
 602          */
 603         protected function _getIsSafeFile() {
 604                 global $wgTrustedMediaFormats;
 605
 606                 if ( $this->allowInlineDisplay() ) {
 607                         return true;
 608                 }
 609                 if ($this->isTrustedFile()) {
 610                         return true;
 611                 }
 612
 613                 $type = $this->getMediaType();
 614                 $mime = $this->getMimeType();
 615                 #wfDebug("LocalFile::isSafeFile: type= $type, mime= $mime\n");
 616
 617                 if ( !$type || $type === MEDIATYPE_UNKNOWN ) {
 618                         return false; #unknown type, not trusted
 619                 }
 620                 if ( in_array( $type, $wgTrustedMediaFormats ) ) {
 621                         return true;
 622                 }
 623
 624                 if ( $mime === "unknown/unknown" ) {
 625                         return false; #unknown type, not trusted
 626                 }
 627                 if ( in_array( $mime, $wgTrustedMediaFormats) ) {
 628                         return true;
 629                 }
 630
 631                 return false;
 632         }
 633
 634         /**
 635          * Returns true if the file is flagged as trusted. Files flagged that way
 636          * can be linked to directly, even if that is not allowed for this type of
 637          * file normally.
 638          *
 639          * This is a dummy function right now and always returns false. It could be
 640          * implemented to extract a flag from the database. The trusted flag could be
 641          * set on upload, if the user has sufficient privileges, to bypass script-
 642          * and html-filters. It may even be coupled with cryptographics signatures
 643          * or such.
 644          *
 645          * @return bool
 646          */
 647         function isTrustedFile() {
 648                 #this could be implemented to check a flag in the database,
 649                 #look for signatures, etc
 650                 return false;
 651         }
 652
 653         /**
 654          * Returns true if file exists in the repository.
 655          *
 656          * Overridden by LocalFile to avoid unnecessary stat calls.
 657          *
 658          * @return boolean Whether file exists in the repository.
 659          */
 660         public function exists() {
 661                 return $this->getPath() && $this->repo->fileExists( $this->path );
 662         }
 663
 664         /**
 665          * Returns true if file exists in the repository and can be included in a page.
 666          * It would be unsafe to include private images, making public thumbnails inadvertently
 667          *
 668          * @return boolean Whether file exists in the repository and is includable.
 669          */
 670         public function isVisible() {
 671                 return $this->exists();
 672         }
 673
 674         /**
 675          * @return string
 676          */
 677         function getTransformScript() {
 678                 if ( !isset( $this->transformScript ) ) {
 679                         $this->transformScript = false;
 680                         if ( $this->repo ) {
 681                                 $script = $this->repo->getThumbScriptUrl();
 682                                 if ( $script ) {
 683                                         $this->transformScript = "$script?f=" . urlencode( $this->getName() );
 684                                 }
 685                         }
 686                 }
 687                 return $this->transformScript;
 688         }
 689
 690         /**
 691          * Get a ThumbnailImage which is the same size as the source
 692          *
 693          * @param $handlerParams array
 694          *
 695          * @return string
 696          */
 697         function getUnscaledThumb( $handlerParams = array() ) {
 698                 $hp =& $handlerParams;
 699                 $page = isset( $hp['page'] ) ? $hp['page'] : false;
 700                 $width = $this->getWidth( $page );
 701                 if ( !$width ) {
 702                         return $this->iconThumb();
 703                 }
 704                 $hp['width'] = $width;
 705                 return $this->transform( $hp );
 706         }
 707
 708         /**
 709          * Return the file name of a thumbnail with the specified parameters
 710          *
 711          * @param $params Array: handler-specific parameters
 712          * @private -ish
 713          *
 714          * @return string
 715          */
 716         function thumbName( $params ) {
 717                 return $this->generateThumbName( $this->getName(), $params );
 718         }
 719
 720         /**
 721          * Generate a thumbnail file name from a name and specified parameters
 722          *
 723          * @param string $name
 724          * @param array $params Parameters which will be passed to MediaHandler::makeParamString
 725          *
 726          * @return string
 727          */
 728         function generateThumbName( $name, $params ) {
 729                 if ( !$this->getHandler() ) {
 730                         return null;
 731                 }
 732                 $extension = $this->getExtension();
 733                 list( $thumbExt, $thumbMime ) = $this->handler->getThumbType(
 734                         $extension, $this->getMimeType(), $params );
 735                 $thumbName = $this->handler->makeParamString( $params ) . '-' . $name;
 736                 if ( $thumbExt != $extension ) {
 737                         $thumbName .= ".$thumbExt";
 738                 }
 739                 return $thumbName;
 740         }
 741
 742         /**
 743          * Create a thumbnail of the image having the specified width/height.
 744          * The thumbnail will not be created if the width is larger than the
 745          * image's width. Let the browser do the scaling in this case.
 746          * The thumbnail is stored on disk and is only computed if the thumbnail
 747          * file does not exist OR if it is older than the image.
 748          * Returns the URL.
 749          *
 750          * Keeps aspect ratio of original image. If both width and height are
 751          * specified, the generated image will be no bigger than width x height,
 752          * and will also have correct aspect ratio.
 753          *
 754          * @param $width Integer: maximum width of the generated thumbnail
 755          * @param $height Integer: maximum height of the image (optional)
 756          *
 757          * @return string
 758          */
 759         public function createThumb( $width, $height = -1 ) {
 760                 $params = array( 'width' => $width );
 761                 if ( $height != -1 ) {
 762                         $params['height'] = $height;
 763                 }
 764                 $thumb = $this->transform( $params );
 765                 if ( is_null( $thumb ) || $thumb->isError() ) {
 766                         return '';
 767                 }
 768                 return $thumb->getUrl();
 769         }
 770
 771         /**
 772          * Return either a MediaTransformError or placeholder thumbnail (if $wgIgnoreImageErrors)
 773          *
 774          * @param $thumbPath string Thumbnail storage path
 775          * @param $thumbUrl string Thumbnail URL
 776          * @param $params Array
 777          * @param $flags integer
 778          * @return MediaTransformOutput
 779          */
 780         protected function transformErrorOutput( $thumbPath, $thumbUrl, $params, $flags ) {
 781                 global $wgIgnoreImageErrors;
 782
 783                 if ( $wgIgnoreImageErrors && !( $flags & self::RENDER_NOW ) ) {
 784                         return $this->handler->getTransform( $this, $thumbPath, $thumbUrl, $params );
 785                 } else {
 786                         return new MediaTransformError( 'thumbnail_error',
 787                                 $params['width'], 0, wfMsg( 'thumbnail-dest-create' ) );
 788                 }
 789         }
 790
 791         /**
 792          * Transform a media file
 793          *
 794          * @param $params Array: an associative array of handler-specific parameters.
 795          *                Typical keys are width, height and page.
 796          * @param $flags Integer: a bitfield, may contain self::RENDER_NOW to force rendering
 797          * @return MediaTransformOutput|bool False on failure
 798          */
 799         function transform( $params, $flags = 0 ) {
 800                 global $wgUseSquid, $wgIgnoreImageErrors, $wgThumbnailEpoch;
 801
 802                 wfProfileIn( __METHOD__ );
 803                 do {
 804                         if ( !$this->canRender() ) {
 805                                 $thumb = $this->iconThumb();
 806                                 break; // not a bitmap or renderable image, don't try
 807                         }
 808
 809                         // Get the descriptionUrl to embed it as comment into the thumbnail. Bug 19791.
 810                         $descriptionUrl = $this->getDescriptionUrl();
 811                         if ( $descriptionUrl ) {
 812                                 $params['descriptionUrl'] = wfExpandUrl( $descriptionUrl, PROTO_CANONICAL );
 813                         }
 814
 815                         $script = $this->getTransformScript();
 816                         if ( $script && !( $flags & self::RENDER_NOW ) ) {
 817                                 // Use a script to transform on client request, if possible
 818                                 $thumb = $this->handler->getScriptedTransform( $this, $script, $params );
 819                                 if ( $thumb ) {
 820                                         break;
 821                                 }
 822                         }
 823
 824                         $normalisedParams = $params;
 825                         $this->handler->normaliseParams( $this, $normalisedParams );
 826
 827                         $thumbName = $this->thumbName( $normalisedParams );
 828                         $thumbUrl = $this->getThumbUrl( $thumbName );
 829                         $thumbPath = $this->getThumbPath( $thumbName ); // final thumb path
 830
 831                         if ( $this->repo ) {
 832                                 // Defer rendering if a 404 handler is set up...
 833                                 if ( $this->repo->canTransformVia404() && !( $flags & self::RENDER_NOW ) ) {
 834                                         wfDebug( __METHOD__ . " transformation deferred." );
 835                                         // XXX: Pass in the storage path even though we are not rendering anything
 836                                         // and the path is supposed to be an FS path. This is due to getScalerType()
 837                                         // getting called on the path and clobbering $thumb->getUrl() if it's false.
 838                                         $thumb = $this->handler->getTransform( $this, $thumbPath, $thumbUrl, $params );
 839                                         break;
 840                                 }
 841                                 // Clean up broken thumbnails as needed
 842                                 $this->migrateThumbFile( $thumbName );
 843                                 // Check if an up-to-date thumbnail already exists...
 844                                 wfDebug( __METHOD__.": Doing stat for $thumbPath\n" );
 845                                 if ( $this->repo->fileExists( $thumbPath ) && !( $flags & self::RENDER_FORCE ) ) {
 846                                         $timestamp = $this->repo->getFileTimestamp( $thumbPath );
 847                                         if ( $timestamp !== false && $timestamp >= $wgThumbnailEpoch ) {
 848                                                 // XXX: Pass in the storage path even though we are not rendering anything
 849                                                 // and the path is supposed to be an FS path. This is due to getScalerType()
 850                                                 // getting called on the path and clobbering $thumb->getUrl() if it's false.
 851                                                 $thumb = $this->handler->getTransform( $this, $thumbPath, $thumbUrl, $params );
 852                                                 $thumb->setStoragePath( $thumbPath );
 853                                                 break;
 854                                         }
 855                                 } elseif ( $flags & self::RENDER_FORCE ) {
 856                                         wfDebug( __METHOD__ . " forcing rendering per flag File::RENDER_FORCE\n" );
 857                                 }
 858                         }
 859
 860                         // If the backend is ready-only, don't keep generating thumbnails
 861                         // only to return transformation errors, just return the error now.
 862                         if ( $this->repo->getReadOnlyReason() !== false ) {
 863                                 $thumb = $this->transformErrorOutput( $thumbPath, $thumbUrl, $params, $flags );
 864                                 break;
 865                         }
 866
 867                         // Create a temp FS file with the same extension and the thumbnail
 868                         $thumbExt = FileBackend::extensionFromPath( $thumbPath );
 869                         $tmpFile = TempFSFile::factory( 'transform_', $thumbExt );
 870                         if ( !$tmpFile ) {
 871                                 $thumb = $this->transformErrorOutput( $thumbPath, $thumbUrl, $params, $flags );
 872                                 break;
 873                         }
 874                         $tmpThumbPath = $tmpFile->getPath(); // path of 0-byte temp file
 875
 876                         // Actually render the thumbnail...
 877                         $thumb = $this->handler->doTransform( $this, $tmpThumbPath, $thumbUrl, $params );
 878                         $tmpFile->bind( $thumb ); // keep alive with $thumb
 879
 880                         if ( !$thumb ) { // bad params?
 881                                 $thumb = null;
 882                         } elseif ( $thumb->isError() ) { // transform error
 883                                 $this->lastError = $thumb->toText();
 884                                 // Ignore errors if requested
 885                                 if ( $wgIgnoreImageErrors && !( $flags & self::RENDER_NOW ) ) {
 886                                         $thumb = $this->handler->getTransform( $this, $tmpThumbPath, $thumbUrl, $params );
 887                                 }
 888                         } elseif ( $this->repo && $thumb->hasFile() && !$thumb->fileIsSource() ) {
 889                                 // Copy the thumbnail from the file system into storage...
 890                                 $status = $this->repo->quickImport( $tmpThumbPath, $thumbPath );
 891                                 if ( $status->isOK() ) {
 892                                         $thumb->setStoragePath( $thumbPath );
 893                                 } else {
 894                                         $thumb = $this->transformErrorOutput( $thumbPath, $thumbUrl, $params, $flags );
 895                                 }
 896                                 // Give extensions a chance to do something with this thumbnail...
 897                                 wfRunHooks( 'FileTransformed', array( $this, $thumb, $tmpThumbPath, $thumbPath ) );
 898                         }
 899
 900                         // Purge. Useful in the event of Core -> Squid connection failure or squid
 901                         // purge collisions from elsewhere during failure. Don't keep triggering for
 902                         // "thumbs" which have the main image URL though (bug 13776)
 903                         if ( $wgUseSquid ) {
 904                                 if ( !$thumb || $thumb->isError() || $thumb->getUrl() != $this->getURL() ) {
 905                                         SquidUpdate::purge( array( $thumbUrl ) );
 906                                 }
 907                         }
 908                 } while ( false );
 909
 910                 wfProfileOut( __METHOD__ );
 911                 return is_object( $thumb ) ? $thumb : false;
 912         }
 913
 914         /**
 915          * Hook into transform() to allow migration of thumbnail files
 916          * STUB
 917          * Overridden by LocalFile
 918          */
 919         function migrateThumbFile( $thumbName ) {}
 920
 921         /**
 922          * Get a MediaHandler instance for this file
 923          *
 924          * @return MediaHandler
 925          */
 926         function getHandler() {
 927                 if ( !isset( $this->handler ) ) {
 928                         $this->handler = MediaHandler::getHandler( $this->getMimeType() );
 929                 }
 930                 return $this->handler;
 931         }
 932
 933         /**
 934          * Get a ThumbnailImage representing a file type icon
 935          *
 936          * @return ThumbnailImage
 937          */
 938         function iconThumb() {
 939                 global $wgStylePath, $wgStyleDirectory;
 940
 941                 $try = array( 'fileicon-' . $this->getExtension() . '.png', 'fileicon.png' );
 942                 foreach ( $try as $icon ) {
 943                         $path = '/common/images/icons/' . $icon;
 944                         $filepath = $wgStyleDirectory . $path;
 945                         if ( file_exists( $filepath ) ) { // always FS
 946                                 return new ThumbnailImage( $this, $wgStylePath . $path, 120, 120 );
 947                         }
 948                 }
 949                 return null;
 950         }
 951
 952         /**
 953          * Get last thumbnailing error.
 954          * Largely obsolete.
 955          */
 956         function getLastError() {
 957                 return $this->lastError;
 958         }
 959
 960         /**
 961          * Get all thumbnail names previously generated for this file
 962          * STUB
 963          * Overridden by LocalFile
 964          * @return array
 965          */
 966         function getThumbnails() {
 967                 return array();
 968         }
 969
 970         /**
 971          * Purge shared caches such as thumbnails and DB data caching
 972          * STUB
 973          * Overridden by LocalFile
 974          * @param $options Array Options, which include:
 975          *     'forThumbRefresh' : The purging is only to refresh thumbnails
 976          */
 977         function purgeCache( $options = array() ) {}
 978
 979         /**
 980          * Purge the file description page, but don't go after
 981          * pages using the file. Use when modifying file history
 982          * but not the current data.
 983          */
 984         function purgeDescription() {
 985                 $title = $this->getTitle();
 986                 if ( $title ) {
 987                         $title->invalidateCache();
 988                         $title->purgeSquid();
 989                 }
 990         }
 991
 992         /**
 993          * Purge metadata and all affected pages when the file is created,
 994          * deleted, or majorly updated.
 995          */
 996         function purgeEverything() {
 997                 // Delete thumbnails and refresh file metadata cache
 998                 $this->purgeCache();
 999                 $this->purgeDescription();
1000
1001                 // Purge cache of all pages using this file
1002                 $title = $this->getTitle();
1003                 if ( $title ) {
1004                         $update = new HTMLCacheUpdate( $title, 'imagelinks' );
1005                         $update->doUpdate();
1006                 }
1007         }
1008
1009         /**
1010          * Return a fragment of the history of file.
1011          *
1012          * STUB
1013          * @param $limit integer Limit of rows to return
1014          * @param $start string timestamp Only revisions older than $start will be returned
1015          * @param $end string timestamp Only revisions newer than $end will be returned
1016          * @param $inc bool Include the endpoints of the time range
1017          *
1018          * @return array
1019          */
1020         function getHistory($limit = null, $start = null, $end = null, $inc=true) {
1021                 return array();
1022         }
1023
1024         /**
1025          * Return the history of this file, line by line. Starts with current version,
1026          * then old versions. Should return an object similar to an image/oldimage
1027          * database row.
1028          *
1029          * STUB
1030          * Overridden in LocalFile
1031          * @return bool
1032          */
1033         public function nextHistoryLine() {
1034                 return false;
1035         }
1036
1037         /**
1038          * Reset the history pointer to the first element of the history.
1039          * Always call this function after using nextHistoryLine() to free db resources
1040          * STUB
1041          * Overridden in LocalFile.
1042          */
1043         public function resetHistory() {}
1044
1045         /**
1046          * Get the filename hash component of the directory including trailing slash,
1047          * e.g. f/fa/
1048          * If the repository is not hashed, returns an empty string.
1049          *
1050          * @return string
1051          */
1052         function getHashPath() {
1053                 if ( !isset( $this->hashPath ) ) {
1054                         $this->assertRepoDefined();
1055                         $this->hashPath = $this->repo->getHashPath( $this->getName() );
1056                 }
1057                 return $this->hashPath;
1058         }
1059
1060         /**
1061          * Get the path of the file relative to the public zone root.
1062          * This function is overriden in OldLocalFile to be like getArchiveRel().
1063          *
1064          * @return string
1065          */
1066         function getRel() {
1067                 return $this->getHashPath() . $this->getName();
1068         }
1069
1070         /**
1071          * Get the path of an archived file relative to the public zone root
1072          *
1073          * @param $suffix bool|string if not false, the name of an archived thumbnail file
1074          *
1075          * @return string
1076          */
1077         function getArchiveRel( $suffix = false ) {
1078                 $path = 'archive/' . $this->getHashPath();
1079                 if ( $suffix === false ) {
1080                         $path = substr( $path, 0, -1 );
1081                 } else {
1082                         $path .= $suffix;
1083                 }
1084                 return $path;
1085         }
1086
1087         /**
1088          * Get the path, relative to the thumbnail zone root, of the
1089          * thumbnail directory or a particular file if $suffix is specified
1090          *
1091          * @param $suffix bool|string if not false, the name of a thumbnail file
1092          *
1093          * @return string
1094          */
1095         function getThumbRel( $suffix = false ) {
1096                 $path = $this->getRel();
1097                 if ( $suffix !== false ) {
1098                         $path .= '/' . $suffix;
1099                 }
1100                 return $path;
1101         }
1102
1103         /**
1104          * Get urlencoded path of the file relative to the public zone root.
1105          * This function is overriden in OldLocalFile to be like getArchiveUrl().
1106          *
1107          * @return string
1108          */
1109         function getUrlRel() {
1110                 return $this->getHashPath() . rawurlencode( $this->getName() );
1111         }
1112
1113         /**
1114          * Get the path, relative to the thumbnail zone root, for an archived file's thumbs directory
1115          * or a specific thumb if the $suffix is given.
1116          *
1117          * @param $archiveName string the timestamped name of an archived image
1118          * @param $suffix bool|string if not false, the name of a thumbnail file
1119          *
1120          * @return string
1121          */
1122         function getArchiveThumbRel( $archiveName, $suffix = false ) {
1123                 $path = 'archive/' . $this->getHashPath() . $archiveName . "/";
1124                 if ( $suffix === false ) {
1125                         $path = substr( $path, 0, -1 );
1126                 } else {
1127                         $path .= $suffix;
1128                 }
1129                 return $path;
1130         }
1131
1132         /**
1133          * Get the path of the archived file.
1134          *
1135          * @param $suffix bool|string if not false, the name of an archived file.
1136          *
1137          * @return string
1138          */
1139         function getArchivePath( $suffix = false ) {
1140                 $this->assertRepoDefined();
1141                 return $this->repo->getZonePath( 'public' ) . '/' . $this->getArchiveRel( $suffix );
1142         }
1143
1144         /**
1145          * Get the path of an archived file's thumbs, or a particular thumb if $suffix is specified
1146          *
1147          * @param $archiveName string the timestamped name of an archived image
1148          * @param $suffix bool|string if not false, the name of a thumbnail file
1149          *
1150          * @return string
1151          */
1152         function getArchiveThumbPath( $archiveName, $suffix = false ) {
1153                 $this->assertRepoDefined();
1154                 return $this->repo->getZonePath( 'thumb' ) . '/' .
1155                         $this->getArchiveThumbRel( $archiveName, $suffix );
1156         }
1157
1158         /**
1159          * Get the path of the thumbnail directory, or a particular file if $suffix is specified
1160          *
1161          * @param $suffix bool|string if not false, the name of a thumbnail file
1162          *
1163          * @return string
1164          */
1165         function getThumbPath( $suffix = false ) {
1166                 $this->assertRepoDefined();
1167                 return $this->repo->getZonePath( 'thumb' ) . '/' . $this->getThumbRel( $suffix );
1168         }
1169
1170         /**
1171          * Get the URL of the archive directory, or a particular file if $suffix is specified
1172          *
1173          * @param $suffix bool|string if not false, the name of an archived file
1174          *
1175          * @return string
1176          */
1177         function getArchiveUrl( $suffix = false ) {
1178                 $this->assertRepoDefined();
1179                 $path = $this->repo->getZoneUrl( 'public' ) . '/archive/' . $this->getHashPath();
1180                 if ( $suffix === false ) {
1181                         $path = substr( $path, 0, -1 );
1182                 } else {
1183                         $path .= rawurlencode( $suffix );
1184                 }
1185                 return $path;
1186         }
1187
1188         /**
1189          * Get the URL of the archived file's thumbs, or a particular thumb if $suffix is specified
1190          *
1191          * @param $archiveName string the timestamped name of an archived image
1192          * @param $suffix bool|string if not false, the name of a thumbnail file
1193          *
1194          * @return string
1195          */
1196         function getArchiveThumbUrl( $archiveName, $suffix = false ) {
1197                 $this->assertRepoDefined();
1198                 $path = $this->repo->getZoneUrl( 'thumb' ) . '/archive/' .
1199                         $this->getHashPath() . rawurlencode( $archiveName ) . "/";
1200                 if ( $suffix === false ) {
1201                         $path = substr( $path, 0, -1 );
1202                 } else {
1203                         $path .= rawurlencode( $suffix );
1204                 }
1205                 return $path;
1206         }
1207
1208         /**
1209          * Get the URL of the thumbnail directory, or a particular file if $suffix is specified
1210          *
1211          * @param $suffix bool|string if not false, the name of a thumbnail file
1212          *
1213          * @return string path
1214          */
1215         function getThumbUrl( $suffix = false ) {
1216                 $this->assertRepoDefined();
1217                 $path = $this->repo->getZoneUrl( 'thumb' ) . '/' . $this->getUrlRel();
1218                 if ( $suffix !== false ) {
1219                         $path .= '/' . rawurlencode( $suffix );
1220                 }
1221                 return $path;
1222         }
1223
1224         /**
1225          * Get the public zone virtual URL for a current version source file
1226          *
1227          * @param $suffix bool|string if not false, the name of a thumbnail file
1228          *
1229          * @return string
1230          */
1231         function getVirtualUrl( $suffix = false ) {
1232                 $this->assertRepoDefined();
1233                 $path = $this->repo->getVirtualUrl() . '/public/' . $this->getUrlRel();
1234                 if ( $suffix !== false ) {
1235                         $path .= '/' . rawurlencode( $suffix );
1236                 }
1237                 return $path;
1238         }
1239
1240         /**
1241          * Get the public zone virtual URL for an archived version source file
1242          *
1243          * @param $suffix bool|string if not false, the name of a thumbnail file
1244          *
1245          * @return string
1246          */
1247         function getArchiveVirtualUrl( $suffix = false ) {
1248                 $this->assertRepoDefined();
1249                 $path = $this->repo->getVirtualUrl() . '/public/archive/' . $this->getHashPath();
1250                 if ( $suffix === false ) {
1251                         $path = substr( $path, 0, -1 );
1252                 } else {
1253                         $path .= rawurlencode( $suffix );
1254                 }
1255                 return $path;
1256         }
1257
1258         /**
1259          * Get the virtual URL for a thumbnail file or directory
1260          *
1261          * @param $suffix bool|string if not false, the name of a thumbnail file
1262          *
1263          * @return string
1264          */
1265         function getThumbVirtualUrl( $suffix = false ) {
1266                 $this->assertRepoDefined();
1267                 $path = $this->repo->getVirtualUrl() . '/thumb/' . $this->getUrlRel();
1268                 if ( $suffix !== false ) {
1269                         $path .= '/' . rawurlencode( $suffix );
1270                 }
1271                 return $path;
1272         }
1273
1274         /**
1275          * @return bool
1276          */
1277         function isHashed() {
1278                 $this->assertRepoDefined();
1279                 return (bool)$this->repo->getHashLevels();
1280         }
1281
1282         /**
1283          * @throws MWException
1284          */
1285         function readOnlyError() {
1286                 throw new MWException( get_class($this) . ': write operations are not supported' );
1287         }
1288
1289         /**
1290          * Record a file upload in the upload log and the image table
1291          * STUB
1292          * Overridden by LocalFile
1293          * @param $oldver
1294          * @param $desc
1295          * @param $license string
1296          * @param $copyStatus string
1297          * @param $source string
1298          * @param $watch bool
1299          */
1300         function recordUpload( $oldver, $desc, $license = '', $copyStatus = '', $source = '', $watch = false ) {
1301                 $this->readOnlyError();
1302         }
1303
1304         /**
1305          * Move or copy a file to its public location. If a file exists at the
1306          * destination, move it to an archive. Returns a FileRepoStatus object with
1307          * the archive name in the "value" member on success.
1308          *
1309          * The archive name should be passed through to recordUpload for database
1310          * registration.
1311          *
1312          * @param $srcPath String: local filesystem path to the source image
1313          * @param $flags Integer: a bitwise combination of:
1314          *     File::DELETE_SOURCE    Delete the source file, i.e. move
1315          *         rather than copy
1316          * @return FileRepoStatus object. On success, the value member contains the
1317          *     archive name, or an empty string if it was a new file.
1318          *
1319          * STUB
1320          * Overridden by LocalFile
1321          */
1322         function publish( $srcPath, $flags = 0 ) {
1323                 $this->readOnlyError();
1324         }
1325
1326         /**
1327          * @return bool
1328          */
1329         function formatMetadata() {
1330                 if ( !$this->getHandler() ) {
1331                         return false;
1332                 }
1333                 return $this->getHandler()->formatMetadata( $this, $this->getMetadata() );
1334         }
1335
1336         /**
1337          * Returns true if the file comes from the local file repository.
1338          *
1339          * @return bool
1340          */
1341         function isLocal() {
1342                 return $this->repo && $this->repo->isLocal();
1343         }
1344
1345         /**
1346          * Returns the name of the repository.
1347          *
1348          * @return string
1349          */
1350         function getRepoName() {
1351                 return $this->repo ? $this->repo->getName() : 'unknown';
1352         }
1353
1354         /**
1355          * Returns the repository
1356          *
1357          * @return FileRepo|bool
1358          */
1359         function getRepo() {
1360                 return $this->repo;
1361         }
1362
1363         /**
1364          * Returns true if the image is an old version
1365          * STUB
1366          *
1367          * @return bool
1368          */
1369         function isOld() {
1370                 return false;
1371         }
1372
1373         /**
1374          * Is this file a "deleted" file in a private archive?
1375          * STUB
1376          *
1377          * @param $field
1378          *
1379          * @return bool
1380          */
1381         function isDeleted( $field ) {
1382                 return false;
1383         }
1384
1385         /**
1386          * Return the deletion bitfield
1387          * STUB
1388          * @return int
1389          */
1390         function getVisibility() {
1391                 return 0;
1392         }
1393
1394         /**
1395          * Was this file ever deleted from the wiki?
1396          *
1397          * @return bool
1398          */
1399         function wasDeleted() {
1400                 $title = $this->getTitle();
1401                 return $title && $title->isDeletedQuick();
1402         }
1403
1404         /**
1405          * Move file to the new title
1406          *
1407          * Move current, old version and all thumbnails
1408          * to the new filename. Old file is deleted.
1409          *
1410          * Cache purging is done; checks for validity
1411          * and logging are caller's responsibility
1412          *
1413          * @param $target Title New file name
1414          * @return FileRepoStatus object.
1415          */
1416          function move( $target ) {
1417                 $this->readOnlyError();
1418          }
1419
1420         /**
1421          * Delete all versions of the file.
1422          *
1423          * Moves the files into an archive directory (or deletes them)
1424          * and removes the database rows.
1425          *
1426          * Cache purging is done; logging is caller's responsibility.
1427          *
1428          * @param $reason String
1429          * @param $suppress Boolean: hide content from sysops?
1430          * @return bool on success, false on some kind of failure
1431          * STUB
1432          * Overridden by LocalFile
1433          */
1434         function delete( $reason, $suppress = false ) {
1435                 $this->readOnlyError();
1436         }
1437
1438         /**
1439          * Restore all or specified deleted revisions to the given file.
1440          * Permissions and logging are left to the caller.
1441          *
1442          * May throw database exceptions on error.
1443          *
1444          * @param $versions array set of record ids of deleted items to restore,
1445          *                    or empty to restore all revisions.
1446          * @param $unsuppress bool remove restrictions on content upon restoration?
1447          * @return int|bool the number of file revisions restored if successful,
1448          *         or false on failure
1449          * STUB
1450          * Overridden by LocalFile
1451          */
1452         function restore( $versions = array(), $unsuppress = false ) {
1453                 $this->readOnlyError();
1454         }
1455
1456         /**
1457          * Returns 'true' if this file is a type which supports multiple pages,
1458          * e.g. DJVU or PDF. Note that this may be true even if the file in
1459          * question only has a single page.
1460          *
1461          * @return Bool
1462          */
1463         function isMultipage() {
1464                 return $this->getHandler() && $this->handler->isMultiPage( $this );
1465         }
1466
1467         /**
1468          * Returns the number of pages of a multipage document, or false for
1469          * documents which aren't multipage documents
1470          *
1471          * @return bool|int
1472          */
1473         function pageCount() {
1474                 if ( !isset( $this->pageCount ) ) {
1475                         if ( $this->getHandler() && $this->handler->isMultiPage( $this ) ) {
1476                                 $this->pageCount = $this->handler->pageCount( $this );
1477                         } else {
1478                                 $this->pageCount = false;
1479                         }
1480                 }
1481                 return $this->pageCount;
1482         }
1483
1484         /**
1485          * Calculate the height of a thumbnail using the source and destination width
1486          *
1487          * @param $srcWidth
1488          * @param $srcHeight
1489          * @param $dstWidth
1490          *
1491          * @return int
1492          */
1493         static function scaleHeight( $srcWidth, $srcHeight, $dstWidth ) {
1494                 // Exact integer multiply followed by division
1495                 if ( $srcWidth == 0 ) {
1496                         return 0;
1497                 } else {
1498                         return round( $srcHeight * $dstWidth / $srcWidth );
1499                 }
1500         }
1501
1502         /**
1503          * Get an image size array like that returned by getImageSize(), or false if it
1504          * can't be determined.
1505          *
1506          * @param $fileName String: The filename
1507          * @return Array
1508          */
1509         function getImageSize( $fileName ) {
1510                 if ( !$this->getHandler() ) {
1511                         return false;
1512                 }
1513                 return $this->handler->getImageSize( $this, $fileName );
1514         }
1515
1516         /**
1517          * Get the URL of the image description page. May return false if it is
1518          * unknown or not applicable.
1519          *
1520          * @return string
1521          */
1522         function getDescriptionUrl() {
1523                 if ( $this->repo ) {
1524                         return $this->repo->getDescriptionUrl( $this->getName() );
1525                 } else {
1526                         return false;
1527                 }
1528         }
1529
1530         /**
1531          * Get the HTML text of the description page, if available
1532          *
1533          * @return string
1534          */
1535         function getDescriptionText() {
1536                 global $wgMemc, $wgLang;
1537                 if ( !$this->repo || !$this->repo->fetchDescription ) {
1538                         return false;
1539                 }
1540                 $renderUrl = $this->repo->getDescriptionRenderUrl( $this->getName(), $wgLang->getCode() );
1541                 if ( $renderUrl ) {
1542                         if ( $this->repo->descriptionCacheExpiry > 0 ) {
1543                                 wfDebug("Attempting to get the description from cache...");
1544                                 $key = $this->repo->getLocalCacheKey( 'RemoteFileDescription', 'url', $wgLang->getCode(),
1545                                                                         $this->getName() );
1546                                 $obj = $wgMemc->get($key);
1547                                 if ($obj) {
1548                                         wfDebug("success!\n");
1549                                         return $obj;
1550                                 }
1551                                 wfDebug("miss\n");
1552                         }
1553                         wfDebug( "Fetching shared description from $renderUrl\n" );
1554                         $res = Http::get( $renderUrl );
1555                         if ( $res && $this->repo->descriptionCacheExpiry > 0 ) {
1556                                 $wgMemc->set( $key, $res, $this->repo->descriptionCacheExpiry );
1557                         }
1558                         return $res;
1559                 } else {
1560                         return false;
1561                 }
1562         }
1563
1564         /**
1565          * Get discription of file revision
1566          * STUB
1567          *
1568          * @return string
1569          */
1570         function getDescription() {
1571                 return null;
1572         }
1573
1574         /**
1575          * Get the 14-character timestamp of the file upload
1576          *
1577          * @return string|bool TS_MW timestamp or false on failure
1578          */
1579         function getTimestamp() {
1580                 $this->assertRepoDefined();
1581                 return $this->repo->getFileTimestamp( $this->getPath() );
1582         }
1583
1584         /**
1585          * Get the SHA-1 base 36 hash of the file
1586          *
1587          * @return string
1588          */
1589         function getSha1() {
1590                 $this->assertRepoDefined();
1591                 return $this->repo->getFileSha1( $this->getPath() );
1592         }
1593
1594         /**
1595          * Get the deletion archive key, <sha1>.<ext>
1596          *
1597          * @return string
1598          */
1599         function getStorageKey() {
1600                 $hash = $this->getSha1();
1601                 if ( !$hash ) {
1602                         return false;
1603                 }
1604                 $ext = $this->getExtension();
1605                 $dotExt = $ext === '' ? '' : ".$ext";
1606                 return $hash . $dotExt;
1607         }
1608
1609         /**
1610          * Determine if the current user is allowed to view a particular
1611          * field of this file, if it's marked as deleted.
1612          * STUB
1613          * @param $field Integer
1614          * @param $user User object to check, or null to use $wgUser
1615          * @return Boolean
1616          */
1617         function userCan( $field, User $user = null ) {
1618                 return true;
1619         }
1620
1621         /**
1622          * Get an associative array containing information about a file in the local filesystem.
1623          *
1624          * @param $path String: absolute local filesystem path
1625          * @param $ext Mixed: the file extension, or true to extract it from the filename.
1626          *             Set it to false to ignore the extension.
1627          *
1628          * @return array
1629          */
1630         static function getPropsFromPath( $path, $ext = true ) {
1631                 wfDebug( __METHOD__.": Getting file info for $path\n" );
1632                 wfDeprecated( __METHOD__, '1.19' );
1633
1634                 $fsFile = new FSFile( $path );
1635                 return $fsFile->getProps();
1636         }
1637
1638         /**
1639          * Get a SHA-1 hash of a file in the local filesystem, in base-36 lower case
1640          * encoding, zero padded to 31 digits.
1641          *
1642          * 160 log 2 / log 36 = 30.95, so the 160-bit hash fills 31 digits in base 36
1643          * fairly neatly.
1644          *
1645          * @param $path string
1646          *
1647          * @return bool|string False on failure
1648          */
1649         static function sha1Base36( $path ) {
1650                 wfDeprecated( __METHOD__, '1.19' );
1651
1652                 $fsFile = new FSFile( $path );
1653                 return $fsFile->getSha1Base36();
1654         }
1655
1656         /**
1657          * @return string
1658          */
1659         function getLongDesc() {
1660                 $handler = $this->getHandler();
1661                 if ( $handler ) {
1662                         return $handler->getLongDesc( $this );
1663                 } else {
1664                         return MediaHandler::getGeneralLongDesc( $this );
1665                 }
1666         }
1667
1668         /**
1669          * @return string
1670          */
1671         function getShortDesc() {
1672                 $handler = $this->getHandler();
1673                 if ( $handler ) {
1674                         return $handler->getShortDesc( $this );
1675                 } else {
1676                         return MediaHandler::getGeneralShortDesc( $this );
1677                 }
1678         }
1679
1680         /**
1681          * @return string
1682          */
1683         function getDimensionsString() {
1684                 $handler = $this->getHandler();
1685                 if ( $handler ) {
1686                         return $handler->getDimensionsString( $this );
1687                 } else {
1688                         return '';
1689                 }
1690         }
1691
1692         /**
1693          * @return
1694          */
1695         function getRedirected() {
1696                 return $this->redirected;
1697         }
1698
1699         /**
1700          * @return Title
1701          */
1702         function getRedirectedTitle() {
1703                 if ( $this->redirected ) {
1704                         if ( !$this->redirectTitle ) {
1705                                 $this->redirectTitle = Title::makeTitle( NS_FILE, $this->redirected );
1706                         }
1707                         return $this->redirectTitle;
1708                 }
1709         }
1710
1711         /**
1712          * @param  $from
1713          * @return void
1714          */
1715         function redirectedFrom( $from ) {
1716                 $this->redirected = $from;
1717         }
1718
1719         /**
1720          * @return bool
1721          */
1722         function isMissing() {
1723                 return false;
1724         }
1725
1726         /**
1727          * Check if this file object is small and can be cached
1728          * @return boolean
1729          */
1730         public function isCacheable() {
1731                 return true;
1732         }
1733
1734         /**
1735          * Assert that $this->repo is set to a valid FileRepo instance
1736          * @throws MWException
1737          */
1738         protected function assertRepoDefined() {
1739                 if ( !( $this->repo instanceof $this->repoClass ) ) {
1740                         throw new MWException( "A {$this->repoClass} object is not set for this File.\n" );
1741                 }
1742         }
1743
1744         /**
1745          * Assert that $this->title is set to a Title
1746          * @throws MWException
1747          */
1748         protected function assertTitleDefined() {
1749                 if ( !( $this->title instanceof Title ) ) {
1750                         throw new MWException( "A Title object is not set for this File.\n" );
1751                 }
1752         }
1753 }