includes/filerepo/File.php

   1 <?php
   2 /**
   3  * Base code for files.
   4  *
   5  * @file
   6  * @ingroup FileRepo
   7  */
   8
   9 /**
  10  * Implements some public methods and some protected utility functions which
  11  * are required by multiple child classes. Contains stub functionality for
  12  * unimplemented public methods.
  13  *
  14  * Stub functions which should be overridden are marked with STUB. Some more
  15  * concrete functions are also typically overridden by child classes.
  16  *
  17  * Note that only the repo object knows what its file class is called. You should
  18  * never name a file class explictly outside of the repo class. Instead use the
  19  * repo's factory functions to generate file objects, for example:
  20  *
  21  * RepoGroup::singleton()->getLocalRepo()->newFile($title);
  22  *
  23  * The convenience functions wfLocalFile() and wfFindFile() should be sufficient
  24  * in most cases.
  25  *
  26  * @ingroup FileRepo
  27  */
  28 abstract class File {
  29         const DELETED_FILE = 1;
  30         const DELETED_COMMENT = 2;
  31         const DELETED_USER = 4;
  32         const DELETED_RESTRICTED = 8;
  33         const RENDER_NOW = 1;
  34
  35         const DELETE_SOURCE = 1;
  36
  37         /**
  38          * Some member variables can be lazy-initialised using __get(). The
  39          * initialisation function for these variables is always a function named
  40          * like getVar(), where Var is the variable name with upper-case first
  41          * letter.
  42          *
  43          * The following variables are initialised in this way in this base class:
  44          *    name, extension, handler, path, canRender, isSafeFile,
  45          *    transformScript, hashPath, pageCount, url
  46          *
  47          * Code within this class should generally use the accessor function
  48          * directly, since __get() isn't re-entrant and therefore causes bugs that
  49          * depend on initialisation order.
  50          */
  51
  52         /**
  53          * The following member variables are not lazy-initialised
  54          */
  55
  56         /**
  57          * @var LocalRepo
  58          */
  59         var $repo;
  60
  61         /**
  62          * @var Title
  63          */
  64         var $title;
  65
  66         var $lastError, $redirected, $redirectedTitle;
  67
  68         /**
  69          * @var MediaHandler
  70          */
  71         protected $handler;
  72
  73         /**
  74          * Call this constructor from child classes
  75          */
  76         function __construct( $title, $repo ) {
  77                 $this->title = $title;
  78                 $this->repo = $repo;
  79         }
  80
  81         function __get( $name ) {
  82                 $function = array( $this, 'get' . ucfirst( $name ) );
  83                 if ( !is_callable( $function ) ) {
  84                         return null;
  85                 } else {
  86                         $this->$name = call_user_func( $function );
  87                         return $this->$name;
  88                 }
  89         }
  90
  91         /**
  92          * Normalize a file extension to the common form, and ensure it's clean.
  93          * Extensions with non-alphanumeric characters will be discarded.
  94          *
  95          * @param $ext string (without the .)
  96          * @return string
  97          */
  98         static function normalizeExtension( $ext ) {
  99                 $lower = strtolower( $ext );
 100                 $squish = array(
 101                         'htm' => 'html',
 102                         'jpeg' => 'jpg',
 103                         'mpeg' => 'mpg',
 104                         'tiff' => 'tif',
 105                         'ogv' => 'ogg' );
 106                 if( isset( $squish[$lower] ) ) {
 107                         return $squish[$lower];
 108                 } elseif( preg_match( '/^[0-9a-z]+$/', $lower ) ) {
 109                         return $lower;
 110                 } else {
 111                         return '';
 112                 }
 113         }
 114
 115         /**
 116          * Checks if file extensions are compatible
 117          *
 118          * @param $old File Old file
 119          * @param $new string New name
 120          */
 121         static function checkExtensionCompatibility( File $old, $new ) {
 122                 $oldMime = $old->getMimeType();
 123                 $n = strrpos( $new, '.' );
 124                 $newExt = self::normalizeExtension(
 125                         $n ? substr( $new, $n + 1 ) : '' );
 126                 $mimeMagic = MimeMagic::singleton();
 127                 return $mimeMagic->isMatchingExtension( $newExt, $oldMime );
 128         }
 129
 130         /**
 131          * Upgrade the database row if there is one
 132          * Called by ImagePage
 133          * STUB
 134          */
 135         function upgradeRow() {}
 136
 137         /**
 138          * Split an internet media type into its two components; if not
 139          * a two-part name, set the minor type to 'unknown'.
 140          *
 141          * @param string $mime "text/html" etc
 142          * @return array ("text", "html") etc
 143          */
 144         public static function splitMime( $mime ) {
 145                 if( strpos( $mime, '/' ) !== false ) {
 146                         return explode( '/', $mime, 2 );
 147                 } else {
 148                         return array( $mime, 'unknown' );
 149                 }
 150         }
 151
 152         /**
 153          * Return the name of this file
 154          */
 155         public function getName() {
 156                 if ( !isset( $this->name ) ) {
 157                         $this->name = $this->repo->getNameFromTitle( $this->title );
 158                 }
 159                 return $this->name;
 160         }
 161
 162         /**
 163          * Get the file extension, e.g. "svg"
 164          */
 165         function getExtension() {
 166                 if ( !isset( $this->extension ) ) {
 167                         $n = strrpos( $this->getName(), '.' );
 168                         $this->extension = self::normalizeExtension(
 169                                 $n ? substr( $this->getName(), $n + 1 ) : '' );
 170                 }
 171                 return $this->extension;
 172         }
 173
 174         /**
 175          * Return the associated title object
 176          * @return Title
 177          */
 178         public function getTitle() { return $this->title; }
 179
 180         /**
 181          * Return the title used to find this file
 182          */
 183         public function getOriginalTitle() {
 184                 if ( $this->redirected )
 185                         return $this->getRedirectedTitle();
 186                 return $this->title;
 187         }
 188
 189         /**
 190          * Return the URL of the file
 191          */
 192         public function getUrl() {
 193                 if ( !isset( $this->url ) ) {
 194                         $this->url = $this->repo->getZoneUrl( 'public' ) . '/' . $this->getUrlRel();
 195                 }
 196                 return $this->url;
 197         }
 198
 199         /**
 200          * Return a fully-qualified URL to the file.
 201          * Upload URL paths _may or may not_ be fully qualified, so
 202          * we check. Local paths are assumed to belong on $wgServer.
 203          *
 204          * @return String
 205          */
 206         public function getFullUrl() {
 207                 return wfExpandUrl( $this->getUrl() );
 208         }
 209
 210         function getViewURL() {
 211                 if( $this->mustRender()) {
 212                         if( $this->canRender() ) {
 213                                 return $this->createThumb( $this->getWidth() );
 214                         }
 215                         else {
 216                                 wfDebug(__METHOD__.': supposed to render '.$this->getName().' ('.$this->getMimeType()."), but can't!\n");
 217                                 return $this->getURL(); #hm... return NULL?
 218                         }
 219                 } else {
 220                         return $this->getURL();
 221                 }
 222         }
 223
 224         /**
 225         * Return the full filesystem path to the file. Note that this does
 226         * not mean that a file actually exists under that location.
 227         *
 228         * This path depends on whether directory hashing is active or not,
 229         * i.e. whether the files are all found in the same directory,
 230         * or in hashed paths like /images/3/3c.
 231         *
 232         * May return false if the file is not locally accessible.
 233         */
 234         public function getPath() {
 235                 if ( !isset( $this->path ) ) {
 236                         $this->path = $this->repo->getZonePath('public') . '/' . $this->getRel();
 237                 }
 238                 return $this->path;
 239         }
 240
 241         /**
 242         * Alias for getPath()
 243         *
 244         * @deprecated Use getPath().
 245         */
 246         public function getFullPath() {
 247                 wfDeprecated( __METHOD__ );
 248                 return $this->getPath();
 249         }
 250
 251         /**
 252          * Return the width of the image. Returns false if the width is unknown
 253          * or undefined.
 254          *
 255          * STUB
 256          * Overridden by LocalFile, UnregisteredLocalFile
 257          */
 258         public function getWidth( $page = 1 ) { return false; }
 259
 260         /**
 261          * Return the height of the image. Returns false if the height is unknown
 262          * or undefined
 263          *
 264          * STUB
 265          * Overridden by LocalFile, UnregisteredLocalFile
 266          */
 267         public function getHeight( $page = 1 ) { return false; }
 268
 269         /**
 270          * Returns ID or name of user who uploaded the file
 271          * STUB
 272          *
 273          * @param $type string 'text' or 'id'
 274          */
 275         public function getUser( $type='text' ) { return null; }
 276
 277         /**
 278          * Get the duration of a media file in seconds
 279          */
 280         public function getLength() {
 281                 $handler = $this->getHandler();
 282                 if ( $handler ) {
 283                         return $handler->getLength( $this );
 284                 } else {
 285                         return 0;
 286                 }
 287         }
 288
 289         /**
 290          *  Return true if the file is vectorized
 291          */
 292         public function isVectorized() {
 293                 $handler = $this->getHandler();
 294                 if ( $handler ) {
 295                         return $handler->isVectorized( $this );
 296                 } else {
 297                         return false;
 298                 }
 299         }
 300
 301
 302         /**
 303          * Get handler-specific metadata
 304          * Overridden by LocalFile, UnregisteredLocalFile
 305          * STUB
 306          */
 307         public function getMetadata() { return false; }
 308
 309         /**
 310         * get versioned metadata
 311         *
 312         * @param $metadata Mixed Array or String of (serialized) metadata
 313         * @param $version integer version number.
 314         * @return Array containing metadata, or what was passed to it on fail (unserializing if not array)
 315         */
 316         public function convertMetadataVersion($metadata, $version) {
 317                 $handler = $this->getHandler();
 318                 if ( !is_array( $metadata ) ) {
 319                         //just to make the return type consistant
 320                         $metadata = unserialize( $metadata );
 321                 }
 322                 if ( $handler ) {
 323                         return $handler->convertMetadataVersion( $metadata, $version );
 324                 } else {
 325                         return $metadata;
 326                 }
 327         }
 328
 329         /**
 330          * Return the bit depth of the file
 331          * Overridden by LocalFile
 332          * STUB
 333          */
 334         public function getBitDepth() { return 0; }
 335
 336         /**
 337          * Return the size of the image file, in bytes
 338          * Overridden by LocalFile, UnregisteredLocalFile
 339          * STUB
 340          */
 341         public function getSize() { return false; }
 342
 343         /**
 344          * Returns the mime type of the file.
 345          * Overridden by LocalFile, UnregisteredLocalFile
 346          * STUB
 347          */
 348         function getMimeType() { return 'unknown/unknown'; }
 349
 350         /**
 351          * Return the type of the media in the file.
 352          * Use the value returned by this function with the MEDIATYPE_xxx constants.
 353          * Overridden by LocalFile,
 354          * STUB
 355          */
 356         function getMediaType() { return MEDIATYPE_UNKNOWN; }
 357
 358         /**
 359          * Checks if the output of transform() for this file is likely
 360          * to be valid. If this is false, various user elements will
 361          * display a placeholder instead.
 362          *
 363          * Currently, this checks if the file is an image format
 364          * that can be converted to a format
 365          * supported by all browsers (namely GIF, PNG and JPEG),
 366          * or if it is an SVG image and SVG conversion is enabled.
 367          */
 368         function canRender() {
 369                 if ( !isset( $this->canRender ) ) {
 370                         $this->canRender = $this->getHandler() && $this->handler->canRender( $this );
 371                 }
 372                 return $this->canRender;
 373         }
 374
 375         /**
 376          * Accessor for __get()
 377          */
 378         protected function getCanRender() {
 379                 return $this->canRender();
 380         }
 381
 382         /**
 383          * Return true if the file is of a type that can't be directly
 384          * rendered by typical browsers and needs to be re-rasterized.
 385          *
 386          * This returns true for everything but the bitmap types
 387          * supported by all browsers, i.e. JPEG; GIF and PNG. It will
 388          * also return true for any non-image formats.
 389          *
 390          * @return bool
 391          */
 392         function mustRender() {
 393                 return $this->getHandler() && $this->handler->mustRender( $this );
 394         }
 395
 396         /**
 397          * Alias for canRender()
 398          */
 399         function allowInlineDisplay() {
 400                 return $this->canRender();
 401         }
 402
 403         /**
 404          * Determines if this media file is in a format that is unlikely to
 405          * contain viruses or malicious content. It uses the global
 406          * $wgTrustedMediaFormats list to determine if the file is safe.
 407          *
 408          * This is used to show a warning on the description page of non-safe files.
 409          * It may also be used to disallow direct [[media:...]] links to such files.
 410          *
 411          * Note that this function will always return true if allowInlineDisplay()
 412          * or isTrustedFile() is true for this file.
 413          */
 414         function isSafeFile() {
 415                 if ( !isset( $this->isSafeFile ) ) {
 416                         $this->isSafeFile = $this->_getIsSafeFile();
 417                 }
 418                 return $this->isSafeFile;
 419         }
 420
 421         /** Accessor for __get() */
 422         protected function getIsSafeFile() {
 423                 return $this->isSafeFile();
 424         }
 425
 426         /** Uncached accessor */
 427         protected function _getIsSafeFile() {
 428                 if ($this->allowInlineDisplay()) return true;
 429                 if ($this->isTrustedFile()) return true;
 430
 431                 global $wgTrustedMediaFormats;
 432
 433                 $type= $this->getMediaType();
 434                 $mime= $this->getMimeType();
 435                 #wfDebug("LocalFile::isSafeFile: type= $type, mime= $mime\n");
 436
 437                 if (!$type || $type===MEDIATYPE_UNKNOWN) return false; #unknown type, not trusted
 438                 if ( in_array( $type, $wgTrustedMediaFormats) ) return true;
 439
 440                 if ($mime==="unknown/unknown") return false; #unknown type, not trusted
 441                 if ( in_array( $mime, $wgTrustedMediaFormats) ) return true;
 442
 443                 return false;
 444         }
 445
 446         /** Returns true if the file is flagged as trusted. Files flagged that way
 447         * can be linked to directly, even if that is not allowed for this type of
 448         * file normally.
 449         *
 450         * This is a dummy function right now and always returns false. It could be
 451         * implemented to extract a flag from the database. The trusted flag could be
 452         * set on upload, if the user has sufficient privileges, to bypass script-
 453         * and html-filters. It may even be coupled with cryptographics signatures
 454         * or such.
 455         */
 456         function isTrustedFile() {
 457                 #this could be implemented to check a flag in the databas,
 458                 #look for signatures, etc
 459                 return false;
 460         }
 461
 462         /**
 463          * Returns true if file exists in the repository.
 464          *
 465          * Overridden by LocalFile to avoid unnecessary stat calls.
 466          *
 467          * @return boolean Whether file exists in the repository.
 468          */
 469         public function exists() {
 470                 return $this->getPath() && file_exists( $this->path );
 471         }
 472
 473         /**
 474          * Returns true if file exists in the repository and can be included in a page.
 475          * It would be unsafe to include private images, making public thumbnails inadvertently
 476          *
 477          * @return boolean Whether file exists in the repository and is includable.
 478          */
 479         public function isVisible() {
 480                 return $this->exists();
 481         }
 482
 483         function getTransformScript() {
 484                 if ( !isset( $this->transformScript ) ) {
 485                         $this->transformScript = false;
 486                         if ( $this->repo ) {
 487                                 $script = $this->repo->getThumbScriptUrl();
 488                                 if ( $script ) {
 489                                         $this->transformScript = "$script?f=" . urlencode( $this->getName() );
 490                                 }
 491                         }
 492                 }
 493                 return $this->transformScript;
 494         }
 495
 496         /**
 497          * Get a ThumbnailImage which is the same size as the source
 498          */
 499         function getUnscaledThumb( $handlerParams = array() ) {
 500                 $hp =& $handlerParams;
 501                 $page = isset( $hp['page'] ) ? $hp['page'] : false;
 502                 $width = $this->getWidth( $page );
 503                 if ( !$width ) {
 504                         return $this->iconThumb();
 505                 }
 506                 $hp['width'] = $width;
 507                 return $this->transform( $hp );
 508         }
 509
 510         /**
 511          * Return the file name of a thumbnail with the specified parameters
 512          *
 513          * @param $params Array: handler-specific parameters
 514          * @private -ish
 515          */
 516         function thumbName( $params ) {
 517                 return $this->generateThumbName( $this->getName(), $params );
 518         }
 519
 520         /**
 521          * Generate a thumbnail file name from a name and specified parameters
 522          *
 523          * @param string $name
 524          * @param array $params Parameters which will be passed to MediaHandler::makeParamString
 525          */
 526         function generateThumbName( $name, $params ) {
 527                 if ( !$this->getHandler() ) {
 528                         return null;
 529                 }
 530                 $extension = $this->getExtension();
 531                 list( $thumbExt, $thumbMime ) = $this->handler->getThumbType( $extension, $this->getMimeType(), $params );
 532                 $thumbName = $this->handler->makeParamString( $params ) . '-' . $name;
 533                 if ( $thumbExt != $extension ) {
 534                         $thumbName .= ".$thumbExt";
 535                 }
 536                 return $thumbName;
 537         }
 538
 539         /**
 540          * Create a thumbnail of the image having the specified width/height.
 541          * The thumbnail will not be created if the width is larger than the
 542          * image's width. Let the browser do the scaling in this case.
 543          * The thumbnail is stored on disk and is only computed if the thumbnail
 544          * file does not exist OR if it is older than the image.
 545          * Returns the URL.
 546          *
 547          * Keeps aspect ratio of original image. If both width and height are
 548          * specified, the generated image will be no bigger than width x height,
 549          * and will also have correct aspect ratio.
 550          *
 551          * @param $width Integer: maximum width of the generated thumbnail
 552          * @param $height Integer: maximum height of the image (optional)
 553          */
 554         public function createThumb( $width, $height = -1 ) {
 555                 $params = array( 'width' => $width );
 556                 if ( $height != -1 ) {
 557                         $params['height'] = $height;
 558                 }
 559                 $thumb = $this->transform( $params );
 560                 if( is_null( $thumb ) || $thumb->isError() ) return '';
 561                 return $thumb->getUrl();
 562         }
 563
 564         /**
 565          * Transform a media file
 566          *
 567          * @param $params Array: an associative array of handler-specific parameters.
 568          *                Typical keys are width, height and page.
 569          * @param $flags Integer: a bitfield, may contain self::RENDER_NOW to force rendering
 570          * @return MediaTransformOutput | false
 571          */
 572         function transform( $params, $flags = 0 ) {
 573                 global $wgUseSquid, $wgIgnoreImageErrors, $wgThumbnailEpoch, $wgServer;
 574
 575                 wfProfileIn( __METHOD__ );
 576                 do {
 577                         if ( !$this->canRender() ) {
 578                                 // not a bitmap or renderable image, don't try.
 579                                 $thumb = $this->iconThumb();
 580                                 break;
 581                         }
 582
 583                         // Get the descriptionUrl to embed it as comment into the thumbnail. Bug 19791.
 584                         $descriptionUrl =  $this->getDescriptionUrl();
 585                         if ( $descriptionUrl ) {
 586                                 $params['descriptionUrl'] = $wgServer . $descriptionUrl;
 587                         }
 588
 589                         $script = $this->getTransformScript();
 590                         if ( $script && !($flags & self::RENDER_NOW) ) {
 591                                 // Use a script to transform on client request, if possible
 592                                 $thumb = $this->handler->getScriptedTransform( $this, $script, $params );
 593                                 if( $thumb ) {
 594                                         break;
 595                                 }
 596                         }
 597
 598                         $normalisedParams = $params;
 599                         $this->handler->normaliseParams( $this, $normalisedParams );
 600                         $thumbName = $this->thumbName( $normalisedParams );
 601                         $thumbPath = $this->getThumbPath( $thumbName );
 602                         $thumbUrl = $this->getThumbUrl( $thumbName );
 603
 604                         if ( $this->repo && $this->repo->canTransformVia404() && !($flags & self::RENDER_NOW ) ) {
 605                                 $thumb = $this->handler->getTransform( $this, $thumbPath, $thumbUrl, $params );
 606                                 break;
 607                         }
 608
 609                         wfDebug( __METHOD__.": Doing stat for $thumbPath\n" );
 610                         $this->migrateThumbFile( $thumbName );
 611                         if ( file_exists( $thumbPath )) {
 612                                 $thumbTime = filemtime( $thumbPath );
 613                                 if ( $thumbTime !== FALSE &&
 614                                      gmdate( 'YmdHis', $thumbTime ) >= $wgThumbnailEpoch ) {
 615
 616                                         $thumb = $this->handler->getTransform( $this, $thumbPath, $thumbUrl, $params );
 617                                         break;
 618                                 }
 619                         }
 620                         $thumb = $this->handler->doTransform( $this, $thumbPath, $thumbUrl, $params );
 621
 622                         // Ignore errors if requested
 623                         if ( !$thumb ) {
 624                                 $thumb = null;
 625                         } elseif ( $thumb->isError() ) {
 626                                 $this->lastError = $thumb->toText();
 627                                 if ( $wgIgnoreImageErrors && !($flags & self::RENDER_NOW) ) {
 628                                         $thumb = $this->handler->getTransform( $this, $thumbPath, $thumbUrl, $params );
 629                                 }
 630                         }
 631
 632                         // Purge. Useful in the event of Core -> Squid connection failure or squid
 633                         // purge collisions from elsewhere during failure. Don't keep triggering for
 634                         // "thumbs" which have the main image URL though (bug 13776)
 635                         if ( $wgUseSquid && ( !$thumb || $thumb->isError() || $thumb->getUrl() != $this->getURL()) ) {
 636                                 SquidUpdate::purge( array( $thumbUrl ) );
 637                         }
 638                 } while (false);
 639
 640                 wfProfileOut( __METHOD__ );
 641                 return is_object( $thumb ) ? $thumb : false;
 642         }
 643
 644         /**
 645          * Hook into transform() to allow migration of thumbnail files
 646          * STUB
 647          * Overridden by LocalFile
 648          */
 649         function migrateThumbFile( $thumbName ) {}
 650
 651         /**
 652          * Get a MediaHandler instance for this file
 653          * @return MediaHandler
 654          */
 655         function getHandler() {
 656                 if ( !isset( $this->handler ) ) {
 657                         $this->handler = MediaHandler::getHandler( $this->getMimeType() );
 658                 }
 659                 return $this->handler;
 660         }
 661
 662         /**
 663          * Get a ThumbnailImage representing a file type icon
 664          * @return ThumbnailImage
 665          */
 666         function iconThumb() {
 667                 global $wgStylePath, $wgStyleDirectory;
 668
 669                 $try = array( 'fileicon-' . $this->getExtension() . '.png', 'fileicon.png' );
 670                 foreach( $try as $icon ) {
 671                         $path = '/common/images/icons/' . $icon;
 672                         $filepath = $wgStyleDirectory . $path;
 673                         if( file_exists( $filepath ) ) {
 674                                 return new ThumbnailImage( $this, $wgStylePath . $path, 120, 120 );
 675                         }
 676                 }
 677                 return null;
 678         }
 679
 680         /**
 681          * Get last thumbnailing error.
 682          * Largely obsolete.
 683          */
 684         function getLastError() {
 685                 return $this->lastError;
 686         }
 687
 688         /**
 689          * Get all thumbnail names previously generated for this file
 690          * STUB
 691          * Overridden by LocalFile
 692          */
 693         function getThumbnails() { return array(); }
 694
 695         /**
 696          * Purge shared caches such as thumbnails and DB data caching
 697          * STUB
 698          * Overridden by LocalFile
 699          */
 700         function purgeCache() {}
 701
 702         /**
 703          * Purge the file description page, but don't go after
 704          * pages using the file. Use when modifying file history
 705          * but not the current data.
 706          */
 707         function purgeDescription() {
 708                 $title = $this->getTitle();
 709                 if ( $title ) {
 710                         $title->invalidateCache();
 711                         $title->purgeSquid();
 712                 }
 713         }
 714
 715         /**
 716          * Purge metadata and all affected pages when the file is created,
 717          * deleted, or majorly updated.
 718          */
 719         function purgeEverything() {
 720                 // Delete thumbnails and refresh file metadata cache
 721                 $this->purgeCache();
 722                 $this->purgeDescription();
 723
 724                 // Purge cache of all pages using this file
 725                 $title = $this->getTitle();
 726                 if ( $title ) {
 727                         $update = new HTMLCacheUpdate( $title, 'imagelinks' );
 728                         $update->doUpdate();
 729                 }
 730         }
 731
 732         /**
 733          * Return a fragment of the history of file.
 734          *
 735          * STUB
 736          * @param $limit integer Limit of rows to return
 737          * @param $start timestamp Only revisions older than $start will be returned
 738          * @param $end timestamp Only revisions newer than $end will be returned
 739          * @param $inc bool Include the endpoints of the time range
 740          */
 741         function getHistory($limit = null, $start = null, $end = null, $inc=true) {
 742                 return array();
 743         }
 744
 745         /**
 746          * Return the history of this file, line by line. Starts with current version,
 747          * then old versions. Should return an object similar to an image/oldimage
 748          * database row.
 749          *
 750          * STUB
 751          * Overridden in LocalFile
 752          */
 753         public function nextHistoryLine() {
 754                 return false;
 755         }
 756
 757         /**
 758          * Reset the history pointer to the first element of the history.
 759          * Always call this function after using nextHistoryLine() to free db resources
 760          * STUB
 761          * Overridden in LocalFile.
 762          */
 763         public function resetHistory() {}
 764
 765         /**
 766          * Get the filename hash component of the directory including trailing slash,
 767          * e.g. f/fa/
 768          * If the repository is not hashed, returns an empty string.
 769          */
 770         function getHashPath() {
 771                 if ( !isset( $this->hashPath ) ) {
 772                         $this->hashPath = $this->repo->getHashPath( $this->getName() );
 773                 }
 774                 return $this->hashPath;
 775         }
 776
 777         /**
 778          * Get the path of the file relative to the public zone root
 779          */
 780         function getRel() {
 781                 return $this->getHashPath() . $this->getName();
 782         }
 783
 784         /**
 785          * Get urlencoded relative path of the file
 786          */
 787         function getUrlRel() {
 788                 return $this->getHashPath() . rawurlencode( $this->getName() );
 789         }
 790
 791         /** Get the relative path for an archive file */
 792         function getArchiveRel( $suffix = false ) {
 793                 $path = 'archive/' . $this->getHashPath();
 794                 if ( $suffix === false ) {
 795                         $path = substr( $path, 0, -1 );
 796                 } else {
 797                         $path .= $suffix;
 798                 }
 799                 return $path;
 800         }
 801
 802         /** Get the path of the archive directory, or a particular file if $suffix is specified */
 803         function getArchivePath( $suffix = false ) {
 804                 return $this->repo->getZonePath('public') . '/' . $this->getArchiveRel( $suffix );
 805         }
 806
 807         /** Get the path of the thumbnail directory, or a particular file if $suffix is specified */
 808         function getThumbPath( $suffix = false ) {
 809                 $path = $this->repo->getZonePath('thumb') . '/' . $this->getRel();
 810                 if ( $suffix !== false ) {
 811                         $path .= '/' . $suffix;
 812                 }
 813                 return $path;
 814         }
 815
 816         /** Get the URL of the archive directory, or a particular file if $suffix is specified */
 817         function getArchiveUrl( $suffix = false ) {
 818                 $path = $this->repo->getZoneUrl('public') . '/archive/' . $this->getHashPath();
 819                 if ( $suffix === false ) {
 820                         $path = substr( $path, 0, -1 );
 821                 } else {
 822                         $path .= rawurlencode( $suffix );
 823                 }
 824                 return $path;
 825         }
 826
 827         /** Get the URL of the thumbnail directory, or a particular file if $suffix is specified */
 828         function getThumbUrl( $suffix = false ) {
 829                 $path = $this->repo->getZoneUrl('thumb') . '/' . $this->getUrlRel();
 830                 if ( $suffix !== false ) {
 831                         $path .= '/' . rawurlencode( $suffix );
 832                 }
 833                 return $path;
 834         }
 835
 836         /** Get the virtual URL for an archive file or directory */
 837         function getArchiveVirtualUrl( $suffix = false ) {
 838                 $path = $this->repo->getVirtualUrl() . '/public/archive/' . $this->getHashPath();
 839                 if ( $suffix === false ) {
 840                         $path = substr( $path, 0, -1 );
 841                 } else {
 842                         $path .= rawurlencode( $suffix );
 843                 }
 844                 return $path;
 845         }
 846
 847         /** Get the virtual URL for a thumbnail file or directory */
 848         function getThumbVirtualUrl( $suffix = false ) {
 849                 $path = $this->repo->getVirtualUrl() . '/thumb/' . $this->getUrlRel();
 850                 if ( $suffix !== false ) {
 851                         $path .= '/' . rawurlencode( $suffix );
 852                 }
 853                 return $path;
 854         }
 855
 856         /** Get the virtual URL for the file itself */
 857         function getVirtualUrl( $suffix = false ) {
 858                 $path = $this->repo->getVirtualUrl() . '/public/' . $this->getUrlRel();
 859                 if ( $suffix !== false ) {
 860                         $path .= '/' . rawurlencode( $suffix );
 861                 }
 862                 return $path;
 863         }
 864
 865         /**
 866          * @return bool
 867          */
 868         function isHashed() {
 869                 return $this->repo->isHashed();
 870         }
 871
 872         function readOnlyError() {
 873                 throw new MWException( get_class($this) . ': write operations are not supported' );
 874         }
 875
 876         /**
 877          * Record a file upload in the upload log and the image table
 878          * STUB
 879          * Overridden by LocalFile
 880          */
 881         function recordUpload( $oldver, $desc, $license = '', $copyStatus = '', $source = '', $watch = false ) {
 882                 $this->readOnlyError();
 883         }
 884
 885         /**
 886          * Move or copy a file to its public location. If a file exists at the
 887          * destination, move it to an archive. Returns a FileRepoStatus object with
 888          * the archive name in the "value" member on success.
 889          *
 890          * The archive name should be passed through to recordUpload for database
 891          * registration.
 892          *
 893          * @param $srcPath String: local filesystem path to the source image
 894          * @param $flags Integer: a bitwise combination of:
 895          *     File::DELETE_SOURCE    Delete the source file, i.e. move
 896          *         rather than copy
 897          * @return FileRepoStatus object. On success, the value member contains the
 898          *     archive name, or an empty string if it was a new file.
 899          *
 900          * STUB
 901          * Overridden by LocalFile
 902          */
 903         function publish( $srcPath, $flags = 0 ) {
 904                 $this->readOnlyError();
 905         }
 906
 907         /**
 908          * Get an array of Title objects which are articles which use this file
 909          * Also adds their IDs to the link cache
 910          *
 911          * This is mostly copied from Title::getLinksTo()
 912          *
 913          * @deprecated Use HTMLCacheUpdate, this function uses too much memory
 914          */
 915         function getLinksTo( $options = array() ) {
 916                 wfDeprecated( __METHOD__ );
 917                 wfProfileIn( __METHOD__ );
 918
 919                 // Note: use local DB not repo DB, we want to know local links
 920                 if ( count( $options ) > 0 ) {
 921                         $db = wfGetDB( DB_MASTER );
 922                 } else {
 923                         $db = wfGetDB( DB_SLAVE );
 924                 }
 925                 $linkCache = LinkCache::singleton();
 926
 927                 $encName = $db->addQuotes( $this->getName() );
 928                 $res = $db->select( array( 'page', 'imagelinks'),
 929                                                         array( 'page_namespace', 'page_title', 'page_id', 'page_len', 'page_is_redirect', 'page_latest' ),
 930                                                         array( 'page_id=il_from', 'il_to' => $encName ),
 931                                                         __METHOD__,
 932                                                         $options );
 933
 934                 $retVal = array();
 935                 if ( $db->numRows( $res ) ) {
 936                         foreach ( $res as $row ) {
 937                                 $titleObj = Title::newFromRow( $row );
 938                                 if ( $titleObj ) {
 939                                         $linkCache->addGoodLinkObj( $row->page_id, $titleObj, $row->page_len, $row->page_is_redirect, $row->page_latest );
 940                                         $retVal[] = $titleObj;
 941                                 }
 942                         }
 943                 }
 944                 wfProfileOut( __METHOD__ );
 945                 return $retVal;
 946         }
 947
 948         function formatMetadata() {
 949                 if ( !$this->getHandler() ) {
 950                         return false;
 951                 }
 952                 return $this->getHandler()->formatMetadata( $this, $this->getMetadata() );
 953         }
 954
 955         /**
 956          * Returns true if the file comes from the local file repository.
 957          *
 958          * @return bool
 959          */
 960         function isLocal() {
 961                 $repo = $this->getRepo();
 962                 return $repo && $repo->isLocal();
 963         }
 964
 965         /**
 966          * Returns the name of the repository.
 967          *
 968          * @return string
 969          */
 970         function getRepoName() {
 971                 return $this->repo ? $this->repo->getName() : 'unknown';
 972         }
 973         /*
 974          * Returns the repository
 975          */
 976         function getRepo() {
 977                 return $this->repo;
 978         }
 979
 980         /**
 981          * Returns true if the image is an old version
 982          * STUB
 983          */
 984         function isOld() {
 985                 return false;
 986         }
 987
 988         /**
 989          * Is this file a "deleted" file in a private archive?
 990          * STUB
 991          */
 992         function isDeleted( $field ) {
 993                 return false;
 994         }
 995
 996         /**
 997          * Return the deletion bitfield
 998          * STUB
 999          */
1000         function getVisibility() {
1001                 return 0;
1002         }
1003
1004         /**
1005          * Was this file ever deleted from the wiki?
1006          *
1007          * @return bool
1008          */
1009         function wasDeleted() {
1010                 $title = $this->getTitle();
1011                 return $title && $title->isDeletedQuick();
1012         }
1013
1014         /**
1015          * Move file to the new title
1016          *
1017          * Move current, old version and all thumbnails
1018          * to the new filename. Old file is deleted.
1019          *
1020          * Cache purging is done; checks for validity
1021          * and logging are caller's responsibility
1022          *
1023          * @param $target Title New file name
1024          * @return FileRepoStatus object.
1025          */
1026          function move( $target ) {
1027                 $this->readOnlyError();
1028          }
1029
1030         /**
1031          * Delete all versions of the file.
1032          *
1033          * Moves the files into an archive directory (or deletes them)
1034          * and removes the database rows.
1035          *
1036          * Cache purging is done; logging is caller's responsibility.
1037          *
1038          * @param $reason String
1039          * @param $suppress Boolean: hide content from sysops?
1040          * @return true on success, false on some kind of failure
1041          * STUB
1042          * Overridden by LocalFile
1043          */
1044         function delete( $reason, $suppress = false ) {
1045                 $this->readOnlyError();
1046         }
1047
1048         /**
1049          * Restore all or specified deleted revisions to the given file.
1050          * Permissions and logging are left to the caller.
1051          *
1052          * May throw database exceptions on error.
1053          *
1054          * @param $versions set of record ids of deleted items to restore,
1055          *                    or empty to restore all revisions.
1056          * @param $unsuppress remove restrictions on content upon restoration?
1057          * @return the number of file revisions restored if successful,
1058          *         or false on failure
1059          * STUB
1060          * Overridden by LocalFile
1061          */
1062         function restore( $versions=array(), $unsuppress=false ) {
1063                 $this->readOnlyError();
1064         }
1065
1066         /**
1067          * Returns 'true' if this file is a type which supports multiple pages,
1068          * e.g. DJVU or PDF. Note that this may be true even if the file in
1069          * question only has a single page.
1070          *
1071          * @return Bool
1072          */
1073         function isMultipage() {
1074                 return $this->getHandler() && $this->handler->isMultiPage( $this );
1075         }
1076
1077         /**
1078          * Returns the number of pages of a multipage document, or false for
1079          * documents which aren't multipage documents
1080          */
1081         function pageCount() {
1082                 if ( !isset( $this->pageCount ) ) {
1083                         if ( $this->getHandler() && $this->handler->isMultiPage( $this ) ) {
1084                                 $this->pageCount = $this->handler->pageCount( $this );
1085                         } else {
1086                                 $this->pageCount = false;
1087                         }
1088                 }
1089                 return $this->pageCount;
1090         }
1091
1092         /**
1093          * Calculate the height of a thumbnail using the source and destination width
1094          */
1095         static function scaleHeight( $srcWidth, $srcHeight, $dstWidth ) {
1096                 // Exact integer multiply followed by division
1097                 if ( $srcWidth == 0 ) {
1098                         return 0;
1099                 } else {
1100                         return round( $srcHeight * $dstWidth / $srcWidth );
1101                 }
1102         }
1103
1104         /**
1105          * Get an image size array like that returned by getImageSize(), or false if it
1106          * can't be determined.
1107          *
1108          * @param $fileName String: The filename
1109          * @return Array
1110          */
1111         function getImageSize( $fileName ) {
1112                 if ( !$this->getHandler() ) {
1113                         return false;
1114                 }
1115                 return $this->handler->getImageSize( $this, $fileName );
1116         }
1117
1118         /**
1119          * Get the URL of the image description page. May return false if it is
1120          * unknown or not applicable.
1121          */
1122         function getDescriptionUrl() {
1123                 return $this->repo->getDescriptionUrl( $this->getName() );
1124         }
1125
1126         /**
1127          * Get the HTML text of the description page, if available
1128          */
1129         function getDescriptionText() {
1130                 global $wgMemc, $wgLang;
1131                 if ( !$this->repo->fetchDescription ) {
1132                         return false;
1133                 }
1134                 $renderUrl = $this->repo->getDescriptionRenderUrl( $this->getName(), $wgLang->getCode() );
1135                 if ( $renderUrl ) {
1136                         if ( $this->repo->descriptionCacheExpiry > 0 ) {
1137                                 wfDebug("Attempting to get the description from cache...");
1138                                 $key = $this->repo->getLocalCacheKey( 'RemoteFileDescription', 'url', $wgLang->getCode(),
1139                                                                         $this->getName() );
1140                                 $obj = $wgMemc->get($key);
1141                                 if ($obj) {
1142                                         wfDebug("success!\n");
1143                                         return $obj;
1144                                 }
1145                                 wfDebug("miss\n");
1146                         }
1147                         wfDebug( "Fetching shared description from $renderUrl\n" );
1148                         $res = Http::get( $renderUrl );
1149                         if ( $res && $this->repo->descriptionCacheExpiry > 0 ) {
1150                                 $wgMemc->set( $key, $res, $this->repo->descriptionCacheExpiry );
1151                         }
1152                         return $res;
1153                 } else {
1154                         return false;
1155                 }
1156         }
1157
1158         /**
1159          * Get discription of file revision
1160          * STUB
1161          */
1162         function getDescription() {
1163                 return null;
1164         }
1165
1166         /**
1167          * Get the 14-character timestamp of the file upload, or false if
1168          * it doesn't exist
1169          */
1170         function getTimestamp() {
1171                 $path = $this->getPath();
1172                 if ( !file_exists( $path ) ) {
1173                         return false;
1174                 }
1175                 return wfTimestamp( TS_MW, filemtime( $path ) );
1176         }
1177
1178         /**
1179          * Get the SHA-1 base 36 hash of the file
1180          */
1181         function getSha1() {
1182                 return self::sha1Base36( $this->getPath() );
1183         }
1184
1185         /**
1186          * Get the deletion archive key, <sha1>.<ext>
1187          */
1188         function getStorageKey() {
1189                 $hash = $this->getSha1();
1190                 if ( !$hash ) {
1191                         return false;
1192                 }
1193                 $ext = $this->getExtension();
1194                 $dotExt = $ext === '' ? '' : ".$ext";
1195                 return $hash . $dotExt;
1196         }
1197
1198         /**
1199          * Determine if the current user is allowed to view a particular
1200          * field of this file, if it's marked as deleted.
1201          * STUB
1202          * @param $field Integer
1203          * @return Boolean
1204          */
1205         function userCan( $field ) {
1206                 return true;
1207         }
1208
1209         /**
1210          * Get an associative array containing information about a file in the local filesystem.
1211          *
1212          * @param $path String: absolute local filesystem path
1213          * @param $ext Mixed: the file extension, or true to extract it from the filename.
1214          *             Set it to false to ignore the extension.
1215          */
1216         static function getPropsFromPath( $path, $ext = true ) {
1217                 wfProfileIn( __METHOD__ );
1218                 wfDebug( __METHOD__.": Getting file info for $path\n" );
1219                 $info = array(
1220                         'fileExists' => file_exists( $path ) && !is_dir( $path )
1221                 );
1222                 $gis = false;
1223                 if ( $info['fileExists'] ) {
1224                         $magic = MimeMagic::singleton();
1225
1226                         if ( $ext === true ) {
1227                                 $i = strrpos( $path, '.' );
1228                                 $ext = strtolower( $i ? substr( $path, $i + 1 ) : '' );
1229                         }
1230
1231                         # mime type according to file contents
1232                         $info['file-mime'] = $magic->guessMimeType( $path, false );
1233                         # logical mime type
1234                         $info['mime'] = $magic->improveTypeFromExtension( $info['file-mime'], $ext );
1235
1236                         list( $info['major_mime'], $info['minor_mime'] ) = self::splitMime( $info['mime'] );
1237                         $info['media_type'] = $magic->getMediaType( $path, $info['mime'] );
1238
1239                         # Get size in bytes
1240                         $info['size'] = filesize( $path );
1241
1242                         # Height, width and metadata
1243                         $handler = MediaHandler::getHandler( $info['mime'] );
1244                         if ( $handler ) {
1245                                 $tempImage = (object)array();
1246                                 $info['metadata'] = $handler->getMetadata( $tempImage, $path );
1247                                 $gis = $handler->getImageSize( $tempImage, $path, $info['metadata'] );
1248                         } else {
1249                                 $gis = false;
1250                                 $info['metadata'] = '';
1251                         }
1252                         $info['sha1'] = self::sha1Base36( $path );
1253
1254                         wfDebug(__METHOD__.": $path loaded, {$info['size']} bytes, {$info['mime']}.\n");
1255                 } else {
1256                         $info['mime'] = null;
1257                         $info['media_type'] = MEDIATYPE_UNKNOWN;
1258                         $info['metadata'] = '';
1259                         $info['sha1'] = '';
1260                         wfDebug(__METHOD__.": $path NOT FOUND!\n");
1261                 }
1262                 if( $gis ) {
1263                         # NOTE: $gis[2] contains a code for the image type. This is no longer used.
1264                         $info['width'] = $gis[0];
1265                         $info['height'] = $gis[1];
1266                         if ( isset( $gis['bits'] ) ) {
1267                                 $info['bits'] = $gis['bits'];
1268                         } else {
1269                                 $info['bits'] = 0;
1270                         }
1271                 } else {
1272                         $info['width'] = 0;
1273                         $info['height'] = 0;
1274                         $info['bits'] = 0;
1275                 }
1276                 wfProfileOut( __METHOD__ );
1277                 return $info;
1278         }
1279
1280         /**
1281          * Get a SHA-1 hash of a file in the local filesystem, in base-36 lower case
1282          * encoding, zero padded to 31 digits.
1283          *
1284          * 160 log 2 / log 36 = 30.95, so the 160-bit hash fills 31 digits in base 36
1285          * fairly neatly.
1286          *
1287          * Returns false on failure
1288          */
1289         static function sha1Base36( $path ) {
1290                 wfSuppressWarnings();
1291                 $hash = sha1_file( $path );
1292                 wfRestoreWarnings();
1293                 if ( $hash === false ) {
1294                         return false;
1295                 } else {
1296                         return wfBaseConvert( $hash, 16, 36, 31 );
1297                 }
1298         }
1299
1300         function getLongDesc() {
1301                 $handler = $this->getHandler();
1302                 if ( $handler ) {
1303                         return $handler->getLongDesc( $this );
1304                 } else {
1305                         return MediaHandler::getGeneralLongDesc( $this );
1306                 }
1307         }
1308
1309         function getShortDesc() {
1310                 $handler = $this->getHandler();
1311                 if ( $handler ) {
1312                         return $handler->getShortDesc( $this );
1313                 } else {
1314                         return MediaHandler::getGeneralShortDesc( $this );
1315                 }
1316         }
1317
1318         function getDimensionsString() {
1319                 $handler = $this->getHandler();
1320                 if ( $handler ) {
1321                         return $handler->getDimensionsString( $this );
1322                 } else {
1323                         return '';
1324                 }
1325         }
1326
1327         function getRedirected() {
1328                 return $this->redirected;
1329         }
1330
1331         function getRedirectedTitle() {
1332                 if ( $this->redirected ) {
1333                         if ( !$this->redirectTitle ) {
1334                                 $this->redirectTitle = Title::makeTitle( NS_FILE, $this->redirected );
1335                         }
1336                         return $this->redirectTitle;
1337                 }
1338         }
1339
1340         function redirectedFrom( $from ) {
1341                 $this->redirected = $from;
1342         }
1343
1344         function isMissing() {
1345                 return false;
1346         }
1347 }
1348 /**
1349  * Aliases for backwards compatibility with 1.6
1350  */
1351 define( 'MW_IMG_DELETED_FILE', File::DELETED_FILE );
1352 define( 'MW_IMG_DELETED_COMMENT', File::DELETED_COMMENT );
1353 define( 'MW_IMG_DELETED_USER', File::DELETED_USER );
1354 define( 'MW_IMG_DELETED_RESTRICTED', File::DELETED_RESTRICTED );