includes/filerepo/file/File.php

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