includes/filerepo/file/File.php

   1 <?php
   2 /**
   3  * @defgroup FileAbstraction File abstraction
   4  * @ingroup FileRepo
   5  *
   6  * Represents files in a repository.
   7  */
   8
   9 /**
  10  * Base code for files.
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation; either version 2 of the License, or
  15  * (at your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  20  * GNU General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU General Public License along
  23  * with this program; if not, write to the Free Software Foundation, Inc.,
  24  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  25  * http://www.gnu.org/copyleft/gpl.html
  26  *
  27  * @file
  28  * @ingroup FileAbstraction
  29  */
  30
  31 /**
  32  * Implements some public methods and some protected utility functions which
  33  * are required by multiple child classes. Contains stub functionality for
  34  * unimplemented public methods.
  35  *
  36  * Stub functions which should be overridden are marked with STUB. Some more
  37  * concrete functions are also typically overridden by child classes.
  38  *
  39  * Note that only the repo object knows what its file class is called. You should
  40  * never name a file class explictly outside of the repo class. Instead use the
  41  * repo's factory functions to generate file objects, for example:
  42  *
  43  * RepoGroup::singleton()->getLocalRepo()->newFile($title);
  44  *
  45  * The convenience functions wfLocalFile() and wfFindFile() should be sufficient
  46  * in most cases.
  47  *
  48  * @ingroup FileAbstraction
  49  */
  50 abstract class File {
  51         const DELETED_FILE = 1;
  52         const DELETED_COMMENT = 2;
  53         const DELETED_USER = 4;
  54         const DELETED_RESTRICTED = 8;
  55
  56         /** Force rendering in the current process */
  57         const RENDER_NOW   = 1;
  58         /**
  59          * Force rendering even if thumbnail already exist and using RENDER_NOW
  60          * I.e. you have to pass both flags: File::RENDER_NOW | File::RENDER_FORCE
  61          */
  62         const RENDER_FORCE = 2;
  63
  64         const DELETE_SOURCE = 1;
  65
  66         // Audience options for File::getDescription()
  67         const FOR_PUBLIC = 1;
  68         const FOR_THIS_USER = 2;
  69         const RAW = 3;
  70
  71         /**
  72          * Some member variables can be lazy-initialised using __get(). The
  73          * initialisation function for these variables is always a function named
  74          * like getVar(), where Var is the variable name with upper-case first
  75          * letter.
  76          *
  77          * The following variables are initialised in this way in this base class:
  78          *    name, extension, handler, path, canRender, isSafeFile,
  79          *    transformScript, hashPath, pageCount, url
  80          *
  81          * Code within this class should generally use the accessor function
  82          * directly, since __get() isn't re-entrant and therefore causes bugs that
  83          * depend on initialisation order.
  84          */
  85
  86         /**
  87          * The following member variables are not lazy-initialised
  88          */
  89
  90         /**
  91          * @var FileRepo|bool
  92          */
  93         var $repo;
  94
  95         /**
  96          * @var Title
  97          */
  98         var $title;
  99
 100         var $lastError, $redirected, $redirectedTitle;
 101
 102         /**
 103          * @var FSFile|bool False if undefined
 104          */
 105         protected $fsFile;
 106
 107         /**
 108          * @var MediaHandler
 109          */
 110         protected $handler;
 111
 112         /**
 113          * @var string
 114          */
 115         protected $url, $extension, $name, $path, $hashPath, $pageCount, $transformScript;
 116
 117         protected $redirectTitle;
 118
 119         /**
 120          * @var bool
 121          */
 122         protected $canRender, $isSafeFile;
 123
 124         /**
 125          * @var string Required Repository class type
 126          */
 127         protected $repoClass = 'FileRepo';
 128
 129         /**
 130          * Call this constructor from child classes.
 131          *
 132          * Both $title and $repo are optional, though some functions
 133          * may return false or throw exceptions if they are not set.
 134          * Most subclasses will want to call assertRepoDefined() here.
 135          *
 136          * @param $title Title|string|bool
 137          * @param $repo FileRepo|bool
 138          */
 139         function __construct( $title, $repo ) {
 140                 if ( $title !== false ) { // subclasses may not use MW titles
 141                         $title = self::normalizeTitle( $title, 'exception' );
 142                 }
 143                 $this->title = $title;
 144                 $this->repo = $repo;
 145         }
 146
 147         /**
 148          * Given a string or Title object return either a
 149          * valid Title object with namespace NS_FILE or null
 150          *
 151          * @param $title Title|string
 152          * @param $exception string|bool Use 'exception' to throw an error on bad titles
 153          * @throws MWException
 154          * @return Title|null
 155          */
 156         static function normalizeTitle( $title, $exception = false ) {
 157                 $ret = $title;
 158                 if ( $ret instanceof Title ) {
 159                         # Normalize NS_MEDIA -> NS_FILE
 160                         if ( $ret->getNamespace() == NS_MEDIA ) {
 161                                 $ret = Title::makeTitleSafe( NS_FILE, $ret->getDBkey() );
 162                         # Sanity check the title namespace
 163                         } elseif ( $ret->getNamespace() !== NS_FILE ) {
 164                                 $ret = null;
 165                         }
 166                 } else {
 167                         # Convert strings to Title objects
 168                         $ret = Title::makeTitleSafe( NS_FILE, (string)$ret );
 169                 }
 170                 if ( !$ret && $exception !== false ) {
 171                         throw new MWException( "`$title` is not a valid file title." );
 172                 }
 173                 return $ret;
 174         }
 175
 176         function __get( $name ) {
 177                 $function = array( $this, 'get' . ucfirst( $name ) );
 178                 if ( !is_callable( $function ) ) {
 179                         return null;
 180                 } else {
 181                         $this->$name = call_user_func( $function );
 182                         return $this->$name;
 183                 }
 184         }
 185
 186         /**
 187          * Normalize a file extension to the common form, and ensure it's clean.
 188          * Extensions with non-alphanumeric characters will be discarded.
 189          *
 190          * @param $ext string (without the .)
 191          * @return string
 192          */
 193         static function normalizeExtension( $ext ) {
 194                 $lower = strtolower( $ext );
 195                 $squish = array(
 196                         'htm' => 'html',
 197                         'jpeg' => 'jpg',
 198                         'mpeg' => 'mpg',
 199                         'tiff' => 'tif',
 200                         'ogv' => 'ogg' );
 201                 if( isset( $squish[$lower] ) ) {
 202                         return $squish[$lower];
 203                 } elseif( preg_match( '/^[0-9a-z]+$/', $lower ) ) {
 204                         return $lower;
 205                 } else {
 206                         return '';
 207                 }
 208         }
 209
 210         /**
 211          * Checks if file extensions are compatible
 212          *
 213          * @param $old File Old file
 214          * @param $new string New name
 215          *
 216          * @return bool|null
 217          */
 218         static function checkExtensionCompatibility( File $old, $new ) {
 219                 $oldMime = $old->getMimeType();
 220                 $n = strrpos( $new, '.' );
 221                 $newExt = self::normalizeExtension( $n ? substr( $new, $n + 1 ) : '' );
 222                 $mimeMagic = MimeMagic::singleton();
 223                 return $mimeMagic->isMatchingExtension( $newExt, $oldMime );
 224         }
 225
 226         /**
 227          * Upgrade the database row if there is one
 228          * Called by ImagePage
 229          * STUB
 230          */
 231         function upgradeRow() {}
 232
 233         /**
 234          * Split an internet media type into its two components; if not
 235          * a two-part name, set the minor type to 'unknown'.
 236          *
 237          * @param string $mime "text/html" etc
 238          * @return array ("text", "html") etc
 239          */
 240         public static function splitMime( $mime ) {
 241                 if( strpos( $mime, '/' ) !== false ) {
 242                         return explode( '/', $mime, 2 );
 243                 } else {
 244                         return array( $mime, 'unknown' );
 245                 }
 246         }
 247
 248         /**
 249          * Callback for usort() to do file sorts by name
 250          *
 251          * @param $a File
 252          * @param $b File
 253          *
 254          * @return Integer: result of name comparison
 255          */
 256         public static function compare( File $a, File $b ) {
 257                 return strcmp( $a->getName(), $b->getName() );
 258         }
 259
 260         /**
 261          * Return the name of this file
 262          *
 263          * @return string
 264          */
 265         public function getName() {
 266                 if ( !isset( $this->name ) ) {
 267                         $this->assertRepoDefined();
 268                         $this->name = $this->repo->getNameFromTitle( $this->title );
 269                 }
 270                 return $this->name;
 271         }
 272
 273         /**
 274          * Get the file extension, e.g. "svg"
 275          *
 276          * @return string
 277          */
 278         function getExtension() {
 279                 if ( !isset( $this->extension ) ) {
 280                         $n = strrpos( $this->getName(), '.' );
 281                         $this->extension = self::normalizeExtension(
 282                                 $n ? substr( $this->getName(), $n + 1 ) : '' );
 283                 }
 284                 return $this->extension;
 285         }
 286
 287         /**
 288          * Return the associated title object
 289          *
 290          * @return Title
 291          */
 292         public function getTitle() {
 293                 return $this->title;
 294         }
 295
 296         /**
 297          * Return the title used to find this file
 298          *
 299          * @return Title
 300          */
 301         public function getOriginalTitle() {
 302                 if ( $this->redirected ) {
 303                         return $this->getRedirectedTitle();
 304                 }
 305                 return $this->title;
 306         }
 307
 308         /**
 309          * Return the URL of the file
 310          *
 311          * @return string
 312          */
 313         public function getUrl() {
 314                 if ( !isset( $this->url ) ) {
 315                         $this->assertRepoDefined();
 316                         $this->url = $this->repo->getZoneUrl( 'public' ) . '/' . $this->getUrlRel();
 317                 }
 318                 return $this->url;
 319         }
 320
 321         /**
 322          * Return a fully-qualified URL to the file.
 323          * Upload URL paths _may or may not_ be fully qualified, so
 324          * we check. Local paths are assumed to belong on $wgServer.
 325          *
 326          * @return String
 327          */
 328         public function getFullUrl() {
 329                 return wfExpandUrl( $this->getUrl(), PROTO_RELATIVE );
 330         }
 331
 332         /**
 333          * @return string
 334          */
 335         public function getCanonicalUrl() {
 336                 return wfExpandUrl( $this->getUrl(), PROTO_CANONICAL );
 337         }
 338
 339         /**
 340          * @return string
 341          */
 342         function getViewURL() {
 343                 if ( $this->mustRender() ) {
 344                         if ( $this->canRender() ) {
 345                                 return $this->createThumb( $this->getWidth() );
 346                         } else {
 347                                 wfDebug( __METHOD__.': supposed to render ' . $this->getName() .
 348                                         ' (' . $this->getMimeType() . "), but can't!\n" );
 349                                 return $this->getURL(); #hm... return NULL?
 350                         }
 351                 } else {
 352                         return $this->getURL();
 353                 }
 354         }
 355
 356         /**
 357          * Return the storage path to the file. Note that this does
 358          * not mean that a file actually exists under that location.
 359          *
 360          * This path depends on whether directory hashing is active or not,
 361          * i.e. whether the files are all found in the same directory,
 362          * or in hashed paths like /images/3/3c.
 363          *
 364          * Most callers don't check the return value, but ForeignAPIFile::getPath
 365          * returns false.
 366          *
 367          * @return string|bool ForeignAPIFile::getPath can return false
 368         */
 369         public function getPath() {
 370                 if ( !isset( $this->path ) ) {
 371                         $this->assertRepoDefined();
 372                         $this->path = $this->repo->getZonePath( 'public' ) . '/' . $this->getRel();
 373                 }
 374                 return $this->path;
 375         }
 376
 377         /**
 378          * Get an FS copy or original of this file and return the path.
 379          * Returns false on failure. Callers must not alter the file.
 380          * Temporary files are cleared automatically.
 381          *
 382          * @return string|bool False on failure
 383          */
 384         public function getLocalRefPath() {
 385                 $this->assertRepoDefined();
 386                 if ( !isset( $this->fsFile ) ) {
 387                         $this->fsFile = $this->repo->getLocalReference( $this->getPath() );
 388                         if ( !$this->fsFile ) {
 389                                 $this->fsFile = false; // null => false; cache negative hits
 390                         }
 391                 }
 392                 return ( $this->fsFile )
 393                         ? $this->fsFile->getPath()
 394                         : false;
 395         }
 396
 397         /**
 398          * Return the width of the image. Returns false if the width is unknown
 399          * or undefined.
 400          *
 401          * STUB
 402          * Overridden by LocalFile, UnregisteredLocalFile
 403          *
 404          * @param $page int
 405          *
 406          * @return number
 407          */
 408         public function getWidth( $page = 1 ) {
 409                 return false;
 410         }
 411
 412         /**
 413          * Return the height of the image. Returns false if the height is unknown
 414          * or undefined
 415          *
 416          * STUB
 417          * Overridden by LocalFile, UnregisteredLocalFile
 418          *
 419          * @param $page int
 420          *
 421          * @return bool|number False on failure
 422          */
 423         public function getHeight( $page = 1 ) {
 424                 return false;
 425         }
 426
 427         /**
 428          * Returns ID or name of user who uploaded the file
 429          * STUB
 430          *
 431          * @param $type string 'text' or 'id'
 432          *
 433          * @return string|int
 434          */
 435         public function getUser( $type = 'text' ) {
 436                 return null;
 437         }
 438
 439         /**
 440          * Get the duration of a media file in seconds
 441          *
 442          * @return number
 443          */
 444         public function getLength() {
 445                 $handler = $this->getHandler();
 446                 if ( $handler ) {
 447                         return $handler->getLength( $this );
 448                 } else {
 449                         return 0;
 450                 }
 451         }
 452
 453         /**
 454          * Return true if the file is vectorized
 455          *
 456          * @return bool
 457          */
 458         public function isVectorized() {
 459                 $handler = $this->getHandler();
 460                 if ( $handler ) {
 461                         return $handler->isVectorized( $this );
 462                 } else {
 463                         return false;
 464                 }
 465         }
 466
 467         /**
 468          * Get handler-specific metadata
 469          * Overridden by LocalFile, UnregisteredLocalFile
 470          * STUB
 471          * @return bool
 472          */
 473         public function getMetadata() {
 474                 return false;
 475         }
 476
 477         /**
 478         * get versioned metadata
 479         *
 480         * @param $metadata Mixed Array or String of (serialized) metadata
 481         * @param $version integer version number.
 482         * @return Array containing metadata, or what was passed to it on fail (unserializing if not array)
 483         */
 484         public function convertMetadataVersion($metadata, $version) {
 485                 $handler = $this->getHandler();
 486                 if ( !is_array( $metadata ) ) {
 487                         // Just to make the return type consistent
 488                         $metadata = unserialize( $metadata );
 489                 }
 490                 if ( $handler ) {
 491                         return $handler->convertMetadataVersion( $metadata, $version );
 492                 } else {
 493                         return $metadata;
 494                 }
 495         }
 496
 497         /**
 498          * Return the bit depth of the file
 499          * Overridden by LocalFile
 500          * STUB
 501          * @return int
 502          */
 503         public function getBitDepth() {
 504                 return 0;
 505         }
 506
 507         /**
 508          * Return the size of the image file, in bytes
 509          * Overridden by LocalFile, UnregisteredLocalFile
 510          * STUB
 511          * @return bool
 512          */
 513         public function getSize() {
 514                 return false;
 515         }
 516
 517         /**
 518          * Returns the mime type of the file.
 519          * Overridden by LocalFile, UnregisteredLocalFile
 520          * STUB
 521          *
 522          * @return string
 523          */
 524         function getMimeType() {
 525                 return 'unknown/unknown';
 526         }
 527
 528         /**
 529          * Return the type of the media in the file.
 530          * Use the value returned by this function with the MEDIATYPE_xxx constants.
 531          * Overridden by LocalFile,
 532          * STUB
 533          * @return string
 534          */
 535         function getMediaType() {
 536                 return MEDIATYPE_UNKNOWN;
 537         }
 538
 539         /**
 540          * Checks if the output of transform() for this file is likely
 541          * to be valid. If this is false, various user elements will
 542          * display a placeholder instead.
 543          *
 544          * Currently, this checks if the file is an image format
 545          * that can be converted to a format
 546          * supported by all browsers (namely GIF, PNG and JPEG),
 547          * or if it is an SVG image and SVG conversion is enabled.
 548          *
 549          * @return bool
 550          */
 551         function canRender() {
 552                 if ( !isset( $this->canRender ) ) {
 553                         $this->canRender = $this->getHandler() && $this->handler->canRender( $this );
 554                 }
 555                 return $this->canRender;
 556         }
 557
 558         /**
 559          * Accessor for __get()
 560          * @return bool
 561          */
 562         protected function getCanRender() {
 563                 return $this->canRender();
 564         }
 565
 566         /**
 567          * Return true if the file is of a type that can't be directly
 568          * rendered by typical browsers and needs to be re-rasterized.
 569          *
 570          * This returns true for everything but the bitmap types
 571          * supported by all browsers, i.e. JPEG; GIF and PNG. It will
 572          * also return true for any non-image formats.
 573          *
 574          * @return bool
 575          */
 576         function mustRender() {
 577                 return $this->getHandler() && $this->handler->mustRender( $this );
 578         }
 579
 580         /**
 581          * Alias for canRender()
 582          *
 583          * @return bool
 584          */
 585         function allowInlineDisplay() {
 586                 return $this->canRender();
 587         }
 588
 589         /**
 590          * Determines if this media file is in a format that is unlikely to
 591          * contain viruses or malicious content. It uses the global
 592          * $wgTrustedMediaFormats list to determine if the file is safe.
 593          *
 594          * This is used to show a warning on the description page of non-safe files.
 595          * It may also be used to disallow direct [[media:...]] links to such files.
 596          *
 597          * Note that this function will always return true if allowInlineDisplay()
 598          * or isTrustedFile() is true for this file.
 599          *
 600          * @return bool
 601          */
 602         function isSafeFile() {
 603                 if ( !isset( $this->isSafeFile ) ) {
 604                         $this->isSafeFile = $this->_getIsSafeFile();
 605                 }
 606                 return $this->isSafeFile;
 607         }
 608
 609         /**
 610          * Accessor for __get()
 611          *
 612          * @return bool
 613          */
 614         protected function getIsSafeFile() {
 615                 return $this->isSafeFile();
 616         }
 617
 618         /**
 619          * Uncached accessor
 620          *
 621          * @return bool
 622          */
 623         protected function _getIsSafeFile() {
 624                 global $wgTrustedMediaFormats;
 625
 626                 if ( $this->allowInlineDisplay() ) {
 627                         return true;
 628                 }
 629                 if ($this->isTrustedFile()) {
 630                         return true;
 631                 }
 632
 633                 $type = $this->getMediaType();
 634                 $mime = $this->getMimeType();
 635                 #wfDebug("LocalFile::isSafeFile: type= $type, mime= $mime\n");
 636
 637                 if ( !$type || $type === MEDIATYPE_UNKNOWN ) {
 638                         return false; #unknown type, not trusted
 639                 }
 640                 if ( in_array( $type, $wgTrustedMediaFormats ) ) {
 641                         return true;
 642                 }
 643
 644                 if ( $mime === "unknown/unknown" ) {
 645                         return false; #unknown type, not trusted
 646                 }
 647                 if ( in_array( $mime, $wgTrustedMediaFormats) ) {
 648                         return true;
 649                 }
 650
 651                 return false;
 652         }
 653
 654         /**
 655          * Returns true if the file is flagged as trusted. Files flagged that way
 656          * can be linked to directly, even if that is not allowed for this type of
 657          * file normally.
 658          *
 659          * This is a dummy function right now and always returns false. It could be
 660          * implemented to extract a flag from the database. The trusted flag could be
 661          * set on upload, if the user has sufficient privileges, to bypass script-
 662          * and html-filters. It may even be coupled with cryptographics signatures
 663          * or such.
 664          *
 665          * @return bool
 666          */
 667         function isTrustedFile() {
 668                 #this could be implemented to check a flag in the database,
 669                 #look for signatures, etc
 670                 return false;
 671         }
 672
 673         /**
 674          * Returns true if file exists in the repository.
 675          *
 676          * Overridden by LocalFile to avoid unnecessary stat calls.
 677          *
 678          * @return boolean Whether file exists in the repository.
 679          */
 680         public function exists() {
 681                 return $this->getPath() && $this->repo->fileExists( $this->path );
 682         }
 683
 684         /**
 685          * Returns true if file exists in the repository and can be included in a page.
 686          * It would be unsafe to include private images, making public thumbnails inadvertently
 687          *
 688          * @return boolean Whether file exists in the repository and is includable.
 689          */
 690         public function isVisible() {
 691                 return $this->exists();
 692         }
 693
 694         /**
 695          * @return string
 696          */
 697         function getTransformScript() {
 698                 if ( !isset( $this->transformScript ) ) {
 699                         $this->transformScript = false;
 700                         if ( $this->repo ) {
 701                                 $script = $this->repo->getThumbScriptUrl();
 702                                 if ( $script ) {
 703                                         $this->transformScript = "$script?f=" . urlencode( $this->getName() );
 704                                 }
 705                         }
 706                 }
 707                 return $this->transformScript;
 708         }
 709
 710         /**
 711          * Get a ThumbnailImage which is the same size as the source
 712          *
 713          * @param $handlerParams array
 714          *
 715          * @return string
 716          */
 717         function getUnscaledThumb( $handlerParams = array() ) {
 718                 $hp =& $handlerParams;
 719                 $page = isset( $hp['page'] ) ? $hp['page'] : false;
 720                 $width = $this->getWidth( $page );
 721                 if ( !$width ) {
 722                         return $this->iconThumb();
 723                 }
 724                 $hp['width'] = $width;
 725                 return $this->transform( $hp );
 726         }
 727
 728         /**
 729          * Return the file name of a thumbnail with the specified parameters
 730          *
 731          * @param $params Array: handler-specific parameters
 732          * @private -ish
 733          *
 734          * @return string
 735          */
 736         function thumbName( $params ) {
 737                 return $this->generateThumbName( $this->getName(), $params );
 738         }
 739
 740         /**
 741          * Generate a thumbnail file name from a name and specified parameters
 742          *
 743          * @param string $name
 744          * @param array $params Parameters which will be passed to MediaHandler::makeParamString
 745          *
 746          * @return string
 747          */
 748         function generateThumbName( $name, $params ) {
 749                 if ( !$this->getHandler() ) {
 750                         return null;
 751                 }
 752                 $extension = $this->getExtension();
 753                 list( $thumbExt, $thumbMime ) = $this->handler->getThumbType(
 754                         $extension, $this->getMimeType(), $params );
 755                 $thumbName = $this->handler->makeParamString( $params ) . '-' . $name;
 756                 if ( $thumbExt != $extension ) {
 757                         $thumbName .= ".$thumbExt";
 758                 }
 759                 return $thumbName;
 760         }
 761
 762         /**
 763          * Create a thumbnail of the image having the specified width/height.
 764          * The thumbnail will not be created if the width is larger than the
 765          * image's width. Let the browser do the scaling in this case.
 766          * The thumbnail is stored on disk and is only computed if the thumbnail
 767          * file does not exist OR if it is older than the image.
 768          * Returns the URL.
 769          *
 770          * Keeps aspect ratio of original image. If both width and height are
 771          * specified, the generated image will be no bigger than width x height,
 772          * and will also have correct aspect ratio.
 773          *
 774          * @param $width Integer: maximum width of the generated thumbnail
 775          * @param $height Integer: maximum height of the image (optional)
 776          *
 777          * @return string
 778          */
 779         public function createThumb( $width, $height = -1 ) {
 780                 $params = array( 'width' => $width );
 781                 if ( $height != -1 ) {
 782                         $params['height'] = $height;
 783                 }
 784                 $thumb = $this->transform( $params );
 785                 if ( is_null( $thumb ) || $thumb->isError() ) {
 786                         return '';
 787                 }
 788                 return $thumb->getUrl();
 789         }
 790
 791         /**
 792          * Return either a MediaTransformError or placeholder thumbnail (if $wgIgnoreImageErrors)
 793          *
 794          * @param $thumbPath string Thumbnail storage path
 795          * @param $thumbUrl string Thumbnail URL
 796          * @param $params Array
 797          * @param $flags integer
 798          * @return MediaTransformOutput
 799          */
 800         protected function transformErrorOutput( $thumbPath, $thumbUrl, $params, $flags ) {
 801                 global $wgIgnoreImageErrors;
 802
 803                 if ( $wgIgnoreImageErrors && !( $flags & self::RENDER_NOW ) ) {
 804                         return $this->handler->getTransform( $this, $thumbPath, $thumbUrl, $params );
 805                 } else {
 806                         return new MediaTransformError( 'thumbnail_error',
 807                                 $params['width'], 0, wfMsg( 'thumbnail-dest-create' ) );
 808                 }
 809         }
 810
 811         /**
 812          * Transform a media file
 813          *
 814          * @param $params Array: an associative array of handler-specific parameters.
 815          *                Typical keys are width, height and page.
 816          * @param $flags Integer: a bitfield, may contain self::RENDER_NOW to force rendering
 817          * @return MediaTransformOutput|bool False on failure
 818          */
 819         function transform( $params, $flags = 0 ) {
 820                 global $wgUseSquid, $wgIgnoreImageErrors, $wgThumbnailEpoch;
 821
 822                 wfProfileIn( __METHOD__ );
 823                 do {
 824                         if ( !$this->canRender() ) {
 825                                 $thumb = $this->iconThumb();
 826                                 break; // not a bitmap or renderable image, don't try
 827                         }
 828
 829                         // Get the descriptionUrl to embed it as comment into the thumbnail. Bug 19791.
 830                         $descriptionUrl = $this->getDescriptionUrl();
 831                         if ( $descriptionUrl ) {
 832                                 $params['descriptionUrl'] = wfExpandUrl( $descriptionUrl, PROTO_CANONICAL );
 833                         }
 834
 835                         $script = $this->getTransformScript();
 836                         if ( $script && !( $flags & self::RENDER_NOW ) ) {
 837                                 // Use a script to transform on client request, if possible
 838                                 $thumb = $this->handler->getScriptedTransform( $this, $script, $params );
 839                                 if ( $thumb ) {
 840                                         break;
 841                                 }
 842                         }
 843
 844                         $normalisedParams = $params;
 845                         $this->handler->normaliseParams( $this, $normalisedParams );
 846
 847                         $thumbName = $this->thumbName( $normalisedParams );
 848                         $thumbUrl = $this->getThumbUrl( $thumbName );
 849                         $thumbPath = $this->getThumbPath( $thumbName ); // final thumb path
 850
 851                         if ( $this->repo ) {
 852                                 // Defer rendering if a 404 handler is set up...
 853                                 if ( $this->repo->canTransformVia404() && !( $flags & self::RENDER_NOW ) ) {
 854                                         wfDebug( __METHOD__ . " transformation deferred." );
 855                                         // XXX: Pass in the storage path even though we are not rendering anything
 856                                         // and the path is supposed to be an FS path. This is due to getScalerType()
 857                                         // getting called on the path and clobbering $thumb->getUrl() if it's false.
 858                                         $thumb = $this->handler->getTransform( $this, $thumbPath, $thumbUrl, $params );
 859                                         break;
 860                                 }
 861                                 // Clean up broken thumbnails as needed
 862                                 $this->migrateThumbFile( $thumbName );
 863                                 // Check if an up-to-date thumbnail already exists...
 864                                 wfDebug( __METHOD__.": Doing stat for $thumbPath\n" );
 865                                 if ( $this->repo->fileExists( $thumbPath ) && !( $flags & self::RENDER_FORCE ) ) {
 866                                         $timestamp = $this->repo->getFileTimestamp( $thumbPath );
 867                                         if ( $timestamp !== false && $timestamp >= $wgThumbnailEpoch ) {
 868                                                 // XXX: Pass in the storage path even though we are not rendering anything
 869                                                 // and the path is supposed to be an FS path. This is due to getScalerType()
 870                                                 // getting called on the path and clobbering $thumb->getUrl() if it's false.
 871                                                 $thumb = $this->handler->getTransform( $this, $thumbPath, $thumbUrl, $params );
 872                                                 $thumb->setStoragePath( $thumbPath );
 873                                                 break;
 874                                         }
 875                                 } elseif ( $flags & self::RENDER_FORCE ) {
 876                                         wfDebug( __METHOD__ . " forcing rendering per flag File::RENDER_FORCE\n" );
 877                                 }
 878                         }
 879
 880                         // If the backend is ready-only, don't keep generating thumbnails
 881                         // only to return transformation errors, just return the error now.
 882                         if ( $this->repo->getReadOnlyReason() !== false ) {
 883                                 $thumb = $this->transformErrorOutput( $thumbPath, $thumbUrl, $params, $flags );
 884                                 break;
 885                         }
 886
 887                         // Create a temp FS file with the same extension and the thumbnail
 888                         $thumbExt = FileBackend::extensionFromPath( $thumbPath );
 889                         $tmpFile = TempFSFile::factory( 'transform_', $thumbExt );
 890                         if ( !$tmpFile ) {
 891                                 $thumb = $this->transformErrorOutput( $thumbPath, $thumbUrl, $params, $flags );
 892                                 break;
 893                         }
 894                         $tmpThumbPath = $tmpFile->getPath(); // path of 0-byte temp file
 895
 896                         // Actually render the thumbnail...
 897                         wfProfileIn( __METHOD__ . '-doTransform' );
 898                         $thumb = $this->handler->doTransform( $this, $tmpThumbPath, $thumbUrl, $params );
 899                         wfProfileOut( __METHOD__ . '-doTransform' );
 900                         $tmpFile->bind( $thumb ); // keep alive with $thumb
 901
 902                         if ( !$thumb ) { // bad params?
 903                                 $thumb = null;
 904                         } elseif ( $thumb->isError() ) { // transform error
 905                                 $this->lastError = $thumb->toText();
 906                                 // Ignore errors if requested
 907                                 if ( $wgIgnoreImageErrors && !( $flags & self::RENDER_NOW ) ) {
 908                                         $thumb = $this->handler->getTransform( $this, $tmpThumbPath, $thumbUrl, $params );
 909                                 }
 910                         } elseif ( $this->repo && $thumb->hasFile() && !$thumb->fileIsSource() ) {
 911                                 // Copy the thumbnail from the file system into storage...
 912                                 $status = $this->repo->quickImport( $tmpThumbPath, $thumbPath );
 913                                 if ( $status->isOK() ) {
 914                                         $thumb->setStoragePath( $thumbPath );
 915                                 } else {
 916                                         $thumb = $this->transformErrorOutput( $thumbPath, $thumbUrl, $params, $flags );
 917                                 }
 918                                 // Give extensions a chance to do something with this thumbnail...
 919                                 wfRunHooks( 'FileTransformed', array( $this, $thumb, $tmpThumbPath, $thumbPath ) );
 920                         }
 921
 922                         // Purge. Useful in the event of Core -> Squid connection failure or squid
 923                         // purge collisions from elsewhere during failure. Don't keep triggering for
 924                         // "thumbs" which have the main image URL though (bug 13776)
 925                         if ( $wgUseSquid ) {
 926                                 if ( !$thumb || $thumb->isError() || $thumb->getUrl() != $this->getURL() ) {
 927                                         SquidUpdate::purge( array( $thumbUrl ) );
 928                                 }
 929                         }
 930                 } while ( false );
 931
 932                 wfProfileOut( __METHOD__ );
 933                 return is_object( $thumb ) ? $thumb : false;
 934         }
 935
 936         /**
 937          * Hook into transform() to allow migration of thumbnail files
 938          * STUB
 939          * Overridden by LocalFile
 940          */
 941         function migrateThumbFile( $thumbName ) {}
 942
 943         /**
 944          * Get a MediaHandler instance for this file
 945          *
 946          * @return MediaHandler
 947          */
 948         function getHandler() {
 949                 if ( !isset( $this->handler ) ) {
 950                         $this->handler = MediaHandler::getHandler( $this->getMimeType() );
 951                 }
 952                 return $this->handler;
 953         }
 954
 955         /**
 956          * Get a ThumbnailImage representing a file type icon
 957          *
 958          * @return ThumbnailImage
 959          */
 960         function iconThumb() {
 961                 global $wgStylePath, $wgStyleDirectory;
 962
 963                 $try = array( 'fileicon-' . $this->getExtension() . '.png', 'fileicon.png' );
 964                 foreach ( $try as $icon ) {
 965                         $path = '/common/images/icons/' . $icon;
 966                         $filepath = $wgStyleDirectory . $path;
 967                         if ( file_exists( $filepath ) ) { // always FS
 968                                 return new ThumbnailImage( $this, $wgStylePath . $path, 120, 120 );
 969                         }
 970                 }
 971                 return null;
 972         }
 973
 974         /**
 975          * Get last thumbnailing error.
 976          * Largely obsolete.
 977          */
 978         function getLastError() {
 979                 return $this->lastError;
 980         }
 981
 982         /**
 983          * Get all thumbnail names previously generated for this file
 984          * STUB
 985          * Overridden by LocalFile
 986          * @return array
 987          */
 988         function getThumbnails() {
 989                 return array();
 990         }
 991
 992         /**
 993          * Purge shared caches such as thumbnails and DB data caching
 994          * STUB
 995          * Overridden by LocalFile
 996          * @param $options Array Options, which include:
 997          *     'forThumbRefresh' : The purging is only to refresh thumbnails
 998          */
 999         function purgeCache( $options = array() ) {}
1000
1001         /**
1002          * Purge the file description page, but don't go after
1003          * pages using the file. Use when modifying file history
1004          * but not the current data.
1005          */
1006         function purgeDescription() {
1007                 $title = $this->getTitle();
1008                 if ( $title ) {
1009                         $title->invalidateCache();
1010                         $title->purgeSquid();
1011                 }
1012         }
1013
1014         /**
1015          * Purge metadata and all affected pages when the file is created,
1016          * deleted, or majorly updated.
1017          */
1018         function purgeEverything() {
1019                 // Delete thumbnails and refresh file metadata cache
1020                 $this->purgeCache();
1021                 $this->purgeDescription();
1022
1023                 // Purge cache of all pages using this file
1024                 $title = $this->getTitle();
1025                 if ( $title ) {
1026                         $update = new HTMLCacheUpdate( $title, 'imagelinks' );
1027                         $update->doUpdate();
1028                 }
1029         }
1030
1031         /**
1032          * Return a fragment of the history of file.
1033          *
1034          * STUB
1035          * @param $limit integer Limit of rows to return
1036          * @param $start string timestamp Only revisions older than $start will be returned
1037          * @param $end string timestamp Only revisions newer than $end will be returned
1038          * @param $inc bool Include the endpoints of the time range
1039          *
1040          * @return array
1041          */
1042         function getHistory( $limit = null, $start = null, $end = null, $inc=true ) {
1043                 return array();
1044         }
1045
1046         /**
1047          * Return the history of this file, line by line. Starts with current version,
1048          * then old versions. Should return an object similar to an image/oldimage
1049          * database row.
1050          *
1051          * STUB
1052          * Overridden in LocalFile
1053          * @return bool
1054          */
1055         public function nextHistoryLine() {
1056                 return false;
1057         }
1058
1059         /**
1060          * Reset the history pointer to the first element of the history.
1061          * Always call this function after using nextHistoryLine() to free db resources
1062          * STUB
1063          * Overridden in LocalFile.
1064          */
1065         public function resetHistory() {}
1066
1067         /**
1068          * Get the filename hash component of the directory including trailing slash,
1069          * e.g. f/fa/
1070          * If the repository is not hashed, returns an empty string.
1071          *
1072          * @return string
1073          */
1074         function getHashPath() {
1075                 if ( !isset( $this->hashPath ) ) {
1076                         $this->assertRepoDefined();
1077                         $this->hashPath = $this->repo->getHashPath( $this->getName() );
1078                 }
1079                 return $this->hashPath;
1080         }
1081
1082         /**
1083          * Get the path of the file relative to the public zone root.
1084          * This function is overriden in OldLocalFile to be like getArchiveRel().
1085          *
1086          * @return string
1087          */
1088         function getRel() {
1089                 return $this->getHashPath() . $this->getName();
1090         }
1091
1092         /**
1093          * Get the path of an archived file relative to the public zone root
1094          *
1095          * @param $suffix bool|string if not false, the name of an archived thumbnail file
1096          *
1097          * @return string
1098          */
1099         function getArchiveRel( $suffix = false ) {
1100                 $path = 'archive/' . $this->getHashPath();
1101                 if ( $suffix === false ) {
1102                         $path = substr( $path, 0, -1 );
1103                 } else {
1104                         $path .= $suffix;
1105                 }
1106                 return $path;
1107         }
1108
1109         /**
1110          * Get the path, relative to the thumbnail zone root, of the
1111          * thumbnail directory or a particular file if $suffix is specified
1112          *
1113          * @param $suffix bool|string if not false, the name of a thumbnail file
1114          *
1115          * @return string
1116          */
1117         function getThumbRel( $suffix = false ) {
1118                 $path = $this->getRel();
1119                 if ( $suffix !== false ) {
1120                         $path .= '/' . $suffix;
1121                 }
1122                 return $path;
1123         }
1124
1125         /**
1126          * Get urlencoded path of the file relative to the public zone root.
1127          * This function is overriden in OldLocalFile to be like getArchiveUrl().
1128          *
1129          * @return string
1130          */
1131         function getUrlRel() {
1132                 return $this->getHashPath() . rawurlencode( $this->getName() );
1133         }
1134
1135         /**
1136          * Get the path, relative to the thumbnail zone root, for an archived file's thumbs directory
1137          * or a specific thumb if the $suffix is given.
1138          *
1139          * @param $archiveName string the timestamped name of an archived image
1140          * @param $suffix bool|string if not false, the name of a thumbnail file
1141          *
1142          * @return string
1143          */
1144         function getArchiveThumbRel( $archiveName, $suffix = false ) {
1145                 $path = 'archive/' . $this->getHashPath() . $archiveName . "/";
1146                 if ( $suffix === false ) {
1147                         $path = substr( $path, 0, -1 );
1148                 } else {
1149                         $path .= $suffix;
1150                 }
1151                 return $path;
1152         }
1153
1154         /**
1155          * Get the path of the archived file.
1156          *
1157          * @param $suffix bool|string if not false, the name of an archived file.
1158          *
1159          * @return string
1160          */
1161         function getArchivePath( $suffix = false ) {
1162                 $this->assertRepoDefined();
1163                 return $this->repo->getZonePath( 'public' ) . '/' . $this->getArchiveRel( $suffix );
1164         }
1165
1166         /**
1167          * Get the path of an archived file's thumbs, or a particular thumb if $suffix is specified
1168          *
1169          * @param $archiveName string the timestamped name of an archived image
1170          * @param $suffix bool|string if not false, the name of a thumbnail file
1171          *
1172          * @return string
1173          */
1174         function getArchiveThumbPath( $archiveName, $suffix = false ) {
1175                 $this->assertRepoDefined();
1176                 return $this->repo->getZonePath( 'thumb' ) . '/' .
1177                         $this->getArchiveThumbRel( $archiveName, $suffix );
1178         }
1179
1180         /**
1181          * Get the path of the thumbnail directory, or a particular file if $suffix is specified
1182          *
1183          * @param $suffix bool|string if not false, the name of a thumbnail file
1184          *
1185          * @return string
1186          */
1187         function getThumbPath( $suffix = false ) {
1188                 $this->assertRepoDefined();
1189                 return $this->repo->getZonePath( 'thumb' ) . '/' . $this->getThumbRel( $suffix );
1190         }
1191
1192         /**
1193          * Get the URL of the archive directory, or a particular file if $suffix is specified
1194          *
1195          * @param $suffix bool|string if not false, the name of an archived file
1196          *
1197          * @return string
1198          */
1199         function getArchiveUrl( $suffix = false ) {
1200                 $this->assertRepoDefined();
1201                 $path = $this->repo->getZoneUrl( 'public' ) . '/archive/' . $this->getHashPath();
1202                 if ( $suffix === false ) {
1203                         $path = substr( $path, 0, -1 );
1204                 } else {
1205                         $path .= rawurlencode( $suffix );
1206                 }
1207                 return $path;
1208         }
1209
1210         /**
1211          * Get the URL of the archived file's thumbs, or a particular thumb if $suffix is specified
1212          *
1213          * @param $archiveName string the timestamped name of an archived image
1214          * @param $suffix bool|string if not false, the name of a thumbnail file
1215          *
1216          * @return string
1217          */
1218         function getArchiveThumbUrl( $archiveName, $suffix = false ) {
1219                 $this->assertRepoDefined();
1220                 $path = $this->repo->getZoneUrl( 'thumb' ) . '/archive/' .
1221                         $this->getHashPath() . rawurlencode( $archiveName ) . "/";
1222                 if ( $suffix === false ) {
1223                         $path = substr( $path, 0, -1 );
1224                 } else {
1225                         $path .= rawurlencode( $suffix );
1226                 }
1227                 return $path;
1228         }
1229
1230         /**
1231          * Get the URL of the thumbnail directory, or a particular file if $suffix is specified
1232          *
1233          * @param $suffix bool|string if not false, the name of a thumbnail file
1234          *
1235          * @return string path
1236          */
1237         function getThumbUrl( $suffix = false ) {
1238                 $this->assertRepoDefined();
1239                 $path = $this->repo->getZoneUrl( 'thumb' ) . '/' . $this->getUrlRel();
1240                 if ( $suffix !== false ) {
1241                         $path .= '/' . rawurlencode( $suffix );
1242                 }
1243                 return $path;
1244         }
1245
1246         /**
1247          * Get the public zone virtual URL for a current version source file
1248          *
1249          * @param $suffix bool|string if not false, the name of a thumbnail file
1250          *
1251          * @return string
1252          */
1253         function getVirtualUrl( $suffix = false ) {
1254                 $this->assertRepoDefined();
1255                 $path = $this->repo->getVirtualUrl() . '/public/' . $this->getUrlRel();
1256                 if ( $suffix !== false ) {
1257                         $path .= '/' . rawurlencode( $suffix );
1258                 }
1259                 return $path;
1260         }
1261
1262         /**
1263          * Get the public zone virtual URL for an archived version source file
1264          *
1265          * @param $suffix bool|string if not false, the name of a thumbnail file
1266          *
1267          * @return string
1268          */
1269         function getArchiveVirtualUrl( $suffix = false ) {
1270                 $this->assertRepoDefined();
1271                 $path = $this->repo->getVirtualUrl() . '/public/archive/' . $this->getHashPath();
1272                 if ( $suffix === false ) {
1273                         $path = substr( $path, 0, -1 );
1274                 } else {
1275                         $path .= rawurlencode( $suffix );
1276                 }
1277                 return $path;
1278         }
1279
1280         /**
1281          * Get the virtual URL for a thumbnail file or directory
1282          *
1283          * @param $suffix bool|string if not false, the name of a thumbnail file
1284          *
1285          * @return string
1286          */
1287         function getThumbVirtualUrl( $suffix = false ) {
1288                 $this->assertRepoDefined();
1289                 $path = $this->repo->getVirtualUrl() . '/thumb/' . $this->getUrlRel();
1290                 if ( $suffix !== false ) {
1291                         $path .= '/' . rawurlencode( $suffix );
1292                 }
1293                 return $path;
1294         }
1295
1296         /**
1297          * @return bool
1298          */
1299         function isHashed() {
1300                 $this->assertRepoDefined();
1301                 return (bool)$this->repo->getHashLevels();
1302         }
1303
1304         /**
1305          * @throws MWException
1306          */
1307         function readOnlyError() {
1308                 throw new MWException( get_class($this) . ': write operations are not supported' );
1309         }
1310
1311         /**
1312          * Record a file upload in the upload log and the image table
1313          * STUB
1314          * Overridden by LocalFile
1315          * @param $oldver
1316          * @param $desc
1317          * @param $license string
1318          * @param $copyStatus string
1319          * @param $source string
1320          * @param $watch bool
1321          */
1322         function recordUpload( $oldver, $desc, $license = '', $copyStatus = '', $source = '', $watch = false ) {
1323                 $this->readOnlyError();
1324         }
1325
1326         /**
1327          * Move or copy a file to its public location. If a file exists at the
1328          * destination, move it to an archive. Returns a FileRepoStatus object with
1329          * the archive name in the "value" member on success.
1330          *
1331          * The archive name should be passed through to recordUpload for database
1332          * registration.
1333          *
1334          * @param $srcPath String: local filesystem path to the source image
1335          * @param $flags Integer: a bitwise combination of:
1336          *     File::DELETE_SOURCE    Delete the source file, i.e. move
1337          *         rather than copy
1338          * @return FileRepoStatus object. On success, the value member contains the
1339          *     archive name, or an empty string if it was a new file.
1340          *
1341          * STUB
1342          * Overridden by LocalFile
1343          */
1344         function publish( $srcPath, $flags = 0 ) {
1345                 $this->readOnlyError();
1346         }
1347
1348         /**
1349          * @return bool
1350          */
1351         function formatMetadata() {
1352                 if ( !$this->getHandler() ) {
1353                         return false;
1354                 }
1355                 return $this->getHandler()->formatMetadata( $this, $this->getMetadata() );
1356         }
1357
1358         /**
1359          * Returns true if the file comes from the local file repository.
1360          *
1361          * @return bool
1362          */
1363         function isLocal() {
1364                 return $this->repo && $this->repo->isLocal();
1365         }
1366
1367         /**
1368          * Returns the name of the repository.
1369          *
1370          * @return string
1371          */
1372         function getRepoName() {
1373                 return $this->repo ? $this->repo->getName() : 'unknown';
1374         }
1375
1376         /**
1377          * Returns the repository
1378          *
1379          * @return FileRepo|bool
1380          */
1381         function getRepo() {
1382                 return $this->repo;
1383         }
1384
1385         /**
1386          * Returns true if the image is an old version
1387          * STUB
1388          *
1389          * @return bool
1390          */
1391         function isOld() {
1392                 return false;
1393         }
1394
1395         /**
1396          * Is this file a "deleted" file in a private archive?
1397          * STUB
1398          *
1399          * @param $field
1400          *
1401          * @return bool
1402          */
1403         function isDeleted( $field ) {
1404                 return false;
1405         }
1406
1407         /**
1408          * Return the deletion bitfield
1409          * STUB
1410          * @return int
1411          */
1412         function getVisibility() {
1413                 return 0;
1414         }
1415
1416         /**
1417          * Was this file ever deleted from the wiki?
1418          *
1419          * @return bool
1420          */
1421         function wasDeleted() {
1422                 $title = $this->getTitle();
1423                 return $title && $title->isDeletedQuick();
1424         }
1425
1426         /**
1427          * Move file to the new title
1428          *
1429          * Move current, old version and all thumbnails
1430          * to the new filename. Old file is deleted.
1431          *
1432          * Cache purging is done; checks for validity
1433          * and logging are caller's responsibility
1434          *
1435          * @param $target Title New file name
1436          * @return FileRepoStatus object.
1437          */
1438          function move( $target ) {
1439                 $this->readOnlyError();
1440          }
1441
1442         /**
1443          * Delete all versions of the file.
1444          *
1445          * Moves the files into an archive directory (or deletes them)
1446          * and removes the database rows.
1447          *
1448          * Cache purging is done; logging is caller's responsibility.
1449          *
1450          * @param $reason String
1451          * @param $suppress Boolean: hide content from sysops?
1452          * @return bool on success, false on some kind of failure
1453          * STUB
1454          * Overridden by LocalFile
1455          */
1456         function delete( $reason, $suppress = false ) {
1457                 $this->readOnlyError();
1458         }
1459
1460         /**
1461          * Restore all or specified deleted revisions to the given file.
1462          * Permissions and logging are left to the caller.
1463          *
1464          * May throw database exceptions on error.
1465          *
1466          * @param $versions array set of record ids of deleted items to restore,
1467          *                    or empty to restore all revisions.
1468          * @param $unsuppress bool remove restrictions on content upon restoration?
1469          * @return int|bool the number of file revisions restored if successful,
1470          *         or false on failure
1471          * STUB
1472          * Overridden by LocalFile
1473          */
1474         function restore( $versions = array(), $unsuppress = false ) {
1475                 $this->readOnlyError();
1476         }
1477
1478         /**
1479          * Returns 'true' if this file is a type which supports multiple pages,
1480          * e.g. DJVU or PDF. Note that this may be true even if the file in
1481          * question only has a single page.
1482          *
1483          * @return Bool
1484          */
1485         function isMultipage() {
1486                 return $this->getHandler() && $this->handler->isMultiPage( $this );
1487         }
1488
1489         /**
1490          * Returns the number of pages of a multipage document, or false for
1491          * documents which aren't multipage documents
1492          *
1493          * @return bool|int
1494          */
1495         function pageCount() {
1496                 if ( !isset( $this->pageCount ) ) {
1497                         if ( $this->getHandler() && $this->handler->isMultiPage( $this ) ) {
1498                                 $this->pageCount = $this->handler->pageCount( $this );
1499                         } else {
1500                                 $this->pageCount = false;
1501                         }
1502                 }
1503                 return $this->pageCount;
1504         }
1505
1506         /**
1507          * Calculate the height of a thumbnail using the source and destination width
1508          *
1509          * @param $srcWidth
1510          * @param $srcHeight
1511          * @param $dstWidth
1512          *
1513          * @return int
1514          */
1515         static function scaleHeight( $srcWidth, $srcHeight, $dstWidth ) {
1516                 // Exact integer multiply followed by division
1517                 if ( $srcWidth == 0 ) {
1518                         return 0;
1519                 } else {
1520                         return round( $srcHeight * $dstWidth / $srcWidth );
1521                 }
1522         }
1523
1524         /**
1525          * Get an image size array like that returned by getImageSize(), or false if it
1526          * can't be determined.
1527          *
1528          * @param $fileName String: The filename
1529          * @return Array
1530          */
1531         function getImageSize( $fileName ) {
1532                 if ( !$this->getHandler() ) {
1533                         return false;
1534                 }
1535                 return $this->handler->getImageSize( $this, $fileName );
1536         }
1537
1538         /**
1539          * Get the URL of the image description page. May return false if it is
1540          * unknown or not applicable.
1541          *
1542          * @return string
1543          */
1544         function getDescriptionUrl() {
1545                 if ( $this->repo ) {
1546                         return $this->repo->getDescriptionUrl( $this->getName() );
1547                 } else {
1548                         return false;
1549                 }
1550         }
1551
1552         /**
1553          * Get the HTML text of the description page, if available
1554          *
1555          * @return string
1556          */
1557         function getDescriptionText() {
1558                 global $wgMemc, $wgLang;
1559                 if ( !$this->repo || !$this->repo->fetchDescription ) {
1560                         return false;
1561                 }
1562                 $renderUrl = $this->repo->getDescriptionRenderUrl( $this->getName(), $wgLang->getCode() );
1563                 if ( $renderUrl ) {
1564                         if ( $this->repo->descriptionCacheExpiry > 0 ) {
1565                                 wfDebug("Attempting to get the description from cache...");
1566                                 $key = $this->repo->getLocalCacheKey( 'RemoteFileDescription', 'url', $wgLang->getCode(),
1567                                                                         $this->getName() );
1568                                 $obj = $wgMemc->get($key);
1569                                 if ($obj) {
1570                                         wfDebug("success!\n");
1571                                         return $obj;
1572                                 }
1573                                 wfDebug("miss\n");
1574                         }
1575                         wfDebug( "Fetching shared description from $renderUrl\n" );
1576                         $res = Http::get( $renderUrl );
1577                         if ( $res && $this->repo->descriptionCacheExpiry > 0 ) {
1578                                 $wgMemc->set( $key, $res, $this->repo->descriptionCacheExpiry );
1579                         }
1580                         return $res;
1581                 } else {
1582                         return false;
1583                 }
1584         }
1585
1586         /**
1587          * Get description of file revision
1588          * STUB
1589          *
1590          * @param $audience Integer: one of:
1591          *      File::FOR_PUBLIC       to be displayed to all users
1592          *      File::FOR_THIS_USER    to be displayed to the given user
1593          *      File::RAW              get the description regardless of permissions
1594          * @param $user User object to check for, only if FOR_THIS_USER is passed
1595          *              to the $audience parameter
1596          * @return string
1597          */
1598         function getDescription( $audience = self::FOR_PUBLIC, User $user = null ) {
1599                 return null;
1600         }
1601
1602         /**
1603          * Get the 14-character timestamp of the file upload
1604          *
1605          * @return string|bool TS_MW timestamp or false on failure
1606          */
1607         function getTimestamp() {
1608                 $this->assertRepoDefined();
1609                 return $this->repo->getFileTimestamp( $this->getPath() );
1610         }
1611
1612         /**
1613          * Get the SHA-1 base 36 hash of the file
1614          *
1615          * @return string
1616          */
1617         function getSha1() {
1618                 $this->assertRepoDefined();
1619                 return $this->repo->getFileSha1( $this->getPath() );
1620         }
1621
1622         /**
1623          * Get the deletion archive key, "<sha1>.<ext>"
1624          *
1625          * @return string
1626          */
1627         function getStorageKey() {
1628                 $hash = $this->getSha1();
1629                 if ( !$hash ) {
1630                         return false;
1631                 }
1632                 $ext = $this->getExtension();
1633                 $dotExt = $ext === '' ? '' : ".$ext";
1634                 return $hash . $dotExt;
1635         }
1636
1637         /**
1638          * Determine if the current user is allowed to view a particular
1639          * field of this file, if it's marked as deleted.
1640          * STUB
1641          * @param $field Integer
1642          * @param $user User object to check, or null to use $wgUser
1643          * @return Boolean
1644          */
1645         function userCan( $field, User $user = null ) {
1646                 return true;
1647         }
1648
1649         /**
1650          * Get an associative array containing information about a file in the local filesystem.
1651          *
1652          * @param $path String: absolute local filesystem path
1653          * @param $ext Mixed: the file extension, or true to extract it from the filename.
1654          *             Set it to false to ignore the extension.
1655          *
1656          * @return array
1657          */
1658         static function getPropsFromPath( $path, $ext = true ) {
1659                 wfDebug( __METHOD__.": Getting file info for $path\n" );
1660                 wfDeprecated( __METHOD__, '1.19' );
1661
1662                 $fsFile = new FSFile( $path );
1663                 return $fsFile->getProps();
1664         }
1665
1666         /**
1667          * Get a SHA-1 hash of a file in the local filesystem, in base-36 lower case
1668          * encoding, zero padded to 31 digits.
1669          *
1670          * 160 log 2 / log 36 = 30.95, so the 160-bit hash fills 31 digits in base 36
1671          * fairly neatly.
1672          *
1673          * @param $path string
1674          *
1675          * @return bool|string False on failure
1676          */
1677         static function sha1Base36( $path ) {
1678                 wfDeprecated( __METHOD__, '1.19' );
1679
1680                 $fsFile = new FSFile( $path );
1681                 return $fsFile->getSha1Base36();
1682         }
1683
1684         /**
1685          * @return string
1686          */
1687         function getLongDesc() {
1688                 $handler = $this->getHandler();
1689                 if ( $handler ) {
1690                         return $handler->getLongDesc( $this );
1691                 } else {
1692                         return MediaHandler::getGeneralLongDesc( $this );
1693                 }
1694         }
1695
1696         /**
1697          * @return string
1698          */
1699         function getShortDesc() {
1700                 $handler = $this->getHandler();
1701                 if ( $handler ) {
1702                         return $handler->getShortDesc( $this );
1703                 } else {
1704                         return MediaHandler::getGeneralShortDesc( $this );
1705                 }
1706         }
1707
1708         /**
1709          * @return string
1710          */
1711         function getDimensionsString() {
1712                 $handler = $this->getHandler();
1713                 if ( $handler ) {
1714                         return $handler->getDimensionsString( $this );
1715                 } else {
1716                         return '';
1717                 }
1718         }
1719
1720         /**
1721          * @return
1722          */
1723         function getRedirected() {
1724                 return $this->redirected;
1725         }
1726
1727         /**
1728          * @return Title
1729          */
1730         function getRedirectedTitle() {
1731                 if ( $this->redirected ) {
1732                         if ( !$this->redirectTitle ) {
1733                                 $this->redirectTitle = Title::makeTitle( NS_FILE, $this->redirected );
1734                         }
1735                         return $this->redirectTitle;
1736                 }
1737         }
1738
1739         /**
1740          * @param  $from
1741          * @return void
1742          */
1743         function redirectedFrom( $from ) {
1744                 $this->redirected = $from;
1745         }
1746
1747         /**
1748          * @return bool
1749          */
1750         function isMissing() {
1751                 return false;
1752         }
1753
1754         /**
1755          * Check if this file object is small and can be cached
1756          * @return boolean
1757          */
1758         public function isCacheable() {
1759                 return true;
1760         }
1761
1762         /**
1763          * Assert that $this->repo is set to a valid FileRepo instance
1764          * @throws MWException
1765          */
1766         protected function assertRepoDefined() {
1767                 if ( !( $this->repo instanceof $this->repoClass ) ) {
1768                         throw new MWException( "A {$this->repoClass} object is not set for this File.\n" );
1769                 }
1770         }
1771
1772         /**
1773          * Assert that $this->title is set to a Title
1774          * @throws MWException
1775          */
1776         protected function assertTitleDefined() {
1777                 if ( !( $this->title instanceof Title ) ) {
1778                         throw new MWException( "A Title object is not set for this File.\n" );
1779                 }
1780         }
1781 }