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