includes/filerepo/File.php

   1 <?php
   2
   3 /**
   4  * Base file class. Do not instantiate.
   5  *
   6  * Implements some public methods and some protected utility functions which
   7  * are required by multiple child classes. Contains stub functionality for
   8  * unimplemented public methods.
   9  *
  10  * Stub functions which should be overridden are marked with STUB. Some more
  11  * concrete functions are also typically overridden by child classes.
  12  *
  13  * Note that only the repo object knows what its file class is called. You should
  14  * never name a file class explictly outside of the repo class. Instead use the
  15  * repo's factory functions to generate file objects, for example:
  16  *
  17  * RepoGroup::singleton()->getLocalRepo()->newFile($title);
  18  *
  19  * The convenience functions wfLocalFile() and wfFindFile() should be sufficient
  20  * in most cases.
  21  *
  22  * @addtogroup FileRepo
  23  */
  24 class File {
  25         const DELETED_FILE = 1;
  26         const DELETED_COMMENT = 2;
  27         const DELETED_USER = 4;
  28         const DELETED_RESTRICTED = 8;
  29         const RENDER_NOW = 1;
  30
  31         const DELETE_SOURCE = 1;
  32
  33         /**
  34          * Some member variables can be lazy-initialised using __get(). The
  35          * initialisation function for these variables is always a function named
  36          * like getVar(), where Var is the variable name with upper-case first
  37          * letter.
  38          *
  39          * The following variables are initialised in this way in this base class:
  40          *    name, extension, handler, path, canRender, isSafeFile,
  41          *    transformScript, hashPath, pageCount, url
  42          *
  43          * Code within this class should generally use the accessor function
  44          * directly, since __get() isn't re-entrant and therefore causes bugs that
  45          * depend on initialisation order.
  46          */
  47
  48         /**
  49          * The following member variables are not lazy-initialised
  50          */
  51         var $repo, $title, $lastError;
  52
  53         /**
  54          * Call this constructor from child classes
  55          */
  56         function __construct( $title, $repo ) {
  57                 $this->title = $title;
  58                 $this->repo = $repo;
  59         }
  60
  61         function __get( $name ) {
  62                 $function = array( $this, 'get' . ucfirst( $name ) );
  63                 if ( !is_callable( $function ) ) {
  64                         return null;
  65                 } else {
  66                         $this->$name = call_user_func( $function );
  67                         return $this->$name;
  68                 }
  69         }
  70
  71         /**
  72          * Normalize a file extension to the common form, and ensure it's clean.
  73          * Extensions with non-alphanumeric characters will be discarded.
  74          *
  75          * @param $ext string (without the .)
  76          * @return string
  77          */
  78         static function normalizeExtension( $ext ) {
  79                 $lower = strtolower( $ext );
  80                 $squish = array(
  81                         'htm' => 'html',
  82                         'jpeg' => 'jpg',
  83                         'mpeg' => 'mpg',
  84                         'tiff' => 'tif' );
  85                 if( isset( $squish[$lower] ) ) {
  86                         return $squish[$lower];
  87                 } elseif( preg_match( '/^[0-9a-z]+$/', $lower ) ) {
  88                         return $lower;
  89                 } else {
  90                         return '';
  91                 }
  92         }
  93
  94         /**
  95          * Upgrade the database row if there is one
  96          * Called by ImagePage
  97          * STUB
  98          */
  99         function upgradeRow() {}
 100
 101         /**
 102          * Split an internet media type into its two components; if not
 103          * a two-part name, set the minor type to 'unknown'.
 104          *
 105          * @param $mime "text/html" etc
 106          * @return array ("text", "html") etc
 107          */
 108         static function splitMime( $mime ) {
 109                 if( strpos( $mime, '/' ) !== false ) {
 110                         return explode( '/', $mime, 2 );
 111                 } else {
 112                         return array( $mime, 'unknown' );
 113                 }
 114         }
 115
 116         /**
 117          * Return the name of this file
 118          * @public
 119          */
 120         function getName() {
 121                 if ( !isset( $this->name ) ) {
 122                         $this->name = $this->repo->getNameFromTitle( $this->title );
 123                 }
 124                 return $this->name;
 125         }
 126
 127         /**
 128          * Get the file extension, e.g. "svg"
 129          */
 130         function getExtension() {
 131                 if ( !isset( $this->extension ) ) {
 132                         $n = strrpos( $this->getName(), '.' );
 133                         $this->extension = self::normalizeExtension(
 134                                 $n ? substr( $this->getName(), $n + 1 ) : '' );
 135                 }
 136                 return $this->extension;
 137         }
 138
 139         /**
 140          * Return the associated title object
 141          * @public
 142          */
 143         function getTitle() { return $this->title; }
 144
 145         /**
 146          * Return the URL of the file
 147          * @public
 148          */
 149         function getUrl() {
 150                 if ( !isset( $this->url ) ) {
 151                         $this->url = $this->repo->getZoneUrl( 'public' ) . '/' . $this->getUrlRel();
 152                 }
 153                 return $this->url;
 154         }
 155
 156         function getViewURL() {
 157                 if( $this->mustRender()) {
 158                         if( $this->canRender() ) {
 159                                 return $this->createThumb( $this->getWidth() );
 160                         }
 161                         else {
 162                                 wfDebug(__METHOD__.': supposed to render '.$this->getName().' ('.$this->getMimeType()."), but can't!\n");
 163                                 return $this->getURL(); #hm... return NULL?
 164                         }
 165                 } else {
 166                         return $this->getURL();
 167                 }
 168         }
 169
 170         /**
 171         * Return the full filesystem path to the file. Note that this does
 172         * not mean that a file actually exists under that location.
 173         *
 174         * This path depends on whether directory hashing is active or not,
 175         * i.e. whether the files are all found in the same directory,
 176         * or in hashed paths like /images/3/3c.
 177         *
 178         * May return false if the file is not locally accessible.
 179         *
 180         * @public
 181         */
 182         function getPath() {
 183                 if ( !isset( $this->path ) ) {
 184                         $this->path = $this->repo->getZonePath('public') . '/' . $this->getRel();
 185                 }
 186                 return $this->path;
 187         }
 188
 189         /**
 190         * Alias for getPath()
 191         * @public
 192         */
 193         function getFullPath() {
 194                 return $this->getPath();
 195         }
 196
 197         /**
 198          * Return the width of the image. Returns false if the width is unknown
 199          * or undefined.
 200          *
 201          * STUB
 202          * Overridden by LocalFile, UnregisteredLocalFile
 203          * @public
 204          */
 205         function getWidth( $page = 1 ) { return false; }
 206
 207         /**
 208          * Return the height of the image. Returns false if the height is unknown
 209          * or undefined
 210          *
 211          * STUB
 212          * Overridden by LocalFile, UnregisteredLocalFile
 213          * @public
 214          */
 215         function getHeight( $page = 1 ) { return false; }
 216
 217         /**
 218          * Get handler-specific metadata
 219          * Overridden by LocalFile, UnregisteredLocalFile
 220          * STUB
 221          */
 222         function getMetadata() { return false; }
 223
 224         /**
 225          * Return the size of the image file, in bytes
 226          * Overridden by LocalFile, UnregisteredLocalFile
 227          * STUB
 228          * @public
 229          */
 230         function getSize() { return false; }
 231
 232         /**
 233          * Returns the mime type of the file.
 234          * Overridden by LocalFile, UnregisteredLocalFile
 235          * STUB
 236          */
 237         function getMimeType() { return 'unknown/unknown'; }
 238
 239         /**
 240          * Return the type of the media in the file.
 241          * Use the value returned by this function with the MEDIATYPE_xxx constants.
 242          * Overridden by LocalFile,
 243          * STUB
 244          */
 245         function getMediaType() { return MEDIATYPE_UNKNOWN; }
 246
 247         /**
 248          * Checks if the file can be presented to the browser as a bitmap.
 249          *
 250          * Currently, this checks if the file is an image format
 251          * that can be converted to a format
 252          * supported by all browsers (namely GIF, PNG and JPEG),
 253          * or if it is an SVG image and SVG conversion is enabled.
 254          */
 255         function canRender() {
 256                 if ( !isset( $this->canRender ) ) {
 257                         $this->canRender = $this->getHandler() && $this->handler->canRender();
 258                 }
 259                 return $this->canRender;
 260         }
 261
 262         /**
 263          * Accessor for __get()
 264          */
 265         protected function getCanRender() {
 266                 return $this->canRender();
 267         }
 268
 269         /**
 270          * Return true if the file is of a type that can't be directly
 271          * rendered by typical browsers and needs to be re-rasterized.
 272          *
 273          * This returns true for everything but the bitmap types
 274          * supported by all browsers, i.e. JPEG; GIF and PNG. It will
 275          * also return true for any non-image formats.
 276          *
 277          * @return bool
 278          */
 279         function mustRender() {
 280                 return $this->getHandler() && $this->handler->mustRender();
 281         }
 282
 283         /**
 284          * Determines if this media file may be shown inline on a page.
 285          *
 286          * This is currently synonymous to canRender(), but this could be
 287          * extended to also allow inline display of other media,
 288          * like flash animations or videos. If you do so, please keep in mind that
 289          * that could be a security risk.
 290          */
 291         function allowInlineDisplay() {
 292                 return $this->canRender();
 293         }
 294
 295         /**
 296          * Determines if this media file is in a format that is unlikely to
 297          * contain viruses or malicious content. It uses the global
 298          * $wgTrustedMediaFormats list to determine if the file is safe.
 299          *
 300          * This is used to show a warning on the description page of non-safe files.
 301          * It may also be used to disallow direct [[media:...]] links to such files.
 302          *
 303          * Note that this function will always return true if allowInlineDisplay()
 304          * or isTrustedFile() is true for this file.
 305          */
 306         function isSafeFile() {
 307                 if ( !isset( $this->isSafeFile ) ) {
 308                         $this->isSafeFile = $this->_getIsSafeFile();
 309                 }
 310                 return $this->isSafeFile;
 311         }
 312
 313         /** Accessor for __get() */
 314         protected function getIsSafeFile() {
 315                 return $this->isSafeFile();
 316         }
 317
 318         /** Uncached accessor */
 319         protected function _getIsSafeFile() {
 320                 if ($this->allowInlineDisplay()) return true;
 321                 if ($this->isTrustedFile()) return true;
 322
 323                 global $wgTrustedMediaFormats;
 324
 325                 $type= $this->getMediaType();
 326                 $mime= $this->getMimeType();
 327                 #wfDebug("LocalFile::isSafeFile: type= $type, mime= $mime\n");
 328
 329                 if (!$type || $type===MEDIATYPE_UNKNOWN) return false; #unknown type, not trusted
 330                 if ( in_array( $type, $wgTrustedMediaFormats) ) return true;
 331
 332                 if ($mime==="unknown/unknown") return false; #unknown type, not trusted
 333                 if ( in_array( $mime, $wgTrustedMediaFormats) ) return true;
 334
 335                 return false;
 336         }
 337
 338         /** Returns true if the file is flagged as trusted. Files flagged that way
 339         * can be linked to directly, even if that is not allowed for this type of
 340         * file normally.
 341         *
 342         * This is a dummy function right now and always returns false. It could be
 343         * implemented to extract a flag from the database. The trusted flag could be
 344         * set on upload, if the user has sufficient privileges, to bypass script-
 345         * and html-filters. It may even be coupled with cryptographics signatures
 346         * or such.
 347         */
 348         function isTrustedFile() {
 349                 #this could be implemented to check a flag in the databas,
 350                 #look for signatures, etc
 351                 return false;
 352         }
 353
 354         /**
 355          * Returns true if file exists in the repository.
 356          *
 357          * Overridden by LocalFile to avoid unnecessary stat calls.
 358          *
 359          * @return boolean Whether file exists in the repository.
 360          * @public
 361          */
 362         function exists() {
 363                 return $this->getPath() && file_exists( $this->path );
 364         }
 365
 366         function getTransformScript() {
 367                 if ( !isset( $this->transformScript ) ) {
 368                         $this->transformScript = false;
 369                         if ( $this->repo ) {
 370                                 $script = $this->repo->getThumbScriptUrl();
 371                                 if ( $script ) {
 372                                         $this->transformScript = "$script?f=" . urlencode( $this->getName() );
 373                                 }
 374                         }
 375                 }
 376                 return $this->transformScript;
 377         }
 378
 379         /**
 380          * Get a ThumbnailImage which is the same size as the source
 381          */
 382         function getUnscaledThumb( $page = false ) {
 383                 $width = $this->getWidth( $page );
 384                 if ( !$width ) {
 385                         return $this->iconThumb();
 386                 }
 387                 if ( $page ) {
 388                         $params = array(
 389                                 'page' => $page,
 390                                 'width' => $this->getWidth( $page )
 391                         );
 392                 } else {
 393                         $params = array( 'width' => $this->getWidth() );
 394                 }
 395                 return $this->transform( $params );
 396         }
 397
 398         /**
 399          * Return the file name of a thumbnail with the specified parameters
 400          *
 401          * @param array $params Handler-specific parameters
 402          * @private
 403          */
 404         function thumbName( $params ) {
 405                 if ( !$this->getHandler() ) {
 406                         return null;
 407                 }
 408                 $extension = $this->getExtension();
 409                 list( $thumbExt, $thumbMime ) = $this->handler->getThumbType( $extension, $this->getMimeType() );
 410                 $thumbName = $this->handler->makeParamString( $params ) . '-' . $this->getName();
 411                 if ( $thumbExt != $extension ) {
 412                         $thumbName .= ".$thumbExt";
 413                 }
 414                 return $thumbName;
 415         }
 416
 417         /**
 418          * Create a thumbnail of the image having the specified width/height.
 419          * The thumbnail will not be created if the width is larger than the
 420          * image's width. Let the browser do the scaling in this case.
 421          * The thumbnail is stored on disk and is only computed if the thumbnail
 422          * file does not exist OR if it is older than the image.
 423          * Returns the URL.
 424          *
 425          * Keeps aspect ratio of original image. If both width and height are
 426          * specified, the generated image will be no bigger than width x height,
 427          * and will also have correct aspect ratio.
 428          *
 429          * @param integer $width        maximum width of the generated thumbnail
 430          * @param integer $height       maximum height of the image (optional)
 431          * @public
 432          */
 433         function createThumb( $width, $height = -1 ) {
 434                 $params = array( 'width' => $width );
 435                 if ( $height != -1 ) {
 436                         $params['height'] = $height;
 437                 }
 438                 $thumb = $this->transform( $params );
 439                 if( is_null( $thumb ) || $thumb->isError() ) return '';
 440                 return $thumb->getUrl();
 441         }
 442
 443         /**
 444          * As createThumb, but returns a ThumbnailImage object. This can
 445          * provide access to the actual file, the real size of the thumb,
 446          * and can produce a convenient <img> tag for you.
 447          *
 448          * For non-image formats, this may return a filetype-specific icon.
 449          *
 450          * @param integer $width        maximum width of the generated thumbnail
 451          * @param integer $height       maximum height of the image (optional)
 452          * @param boolean $render       True to render the thumbnail if it doesn't exist,
 453          *                              false to just return the URL
 454          *
 455          * @return ThumbnailImage or null on failure
 456          * @public
 457          *
 458          * @deprecated use transform()
 459          */
 460         function getThumbnail( $width, $height=-1, $render = true ) {
 461                 $params = array( 'width' => $width );
 462                 if ( $height != -1 ) {
 463                         $params['height'] = $height;
 464                 }
 465                 $flags = $render ? self::RENDER_NOW : 0;
 466                 return $this->transform( $params, $flags );
 467         }
 468
 469         /**
 470          * Transform a media file
 471          *
 472          * @param array $params An associative array of handler-specific parameters. Typical
 473          *                      keys are width, height and page.
 474          * @param integer $flags A bitfield, may contain self::RENDER_NOW to force rendering
 475          * @return MediaTransformOutput
 476          */
 477         function transform( $params, $flags = 0 ) {
 478                 global $wgUseSquid, $wgIgnoreImageErrors;
 479
 480                 wfProfileIn( __METHOD__ );
 481                 do {
 482                         if ( !$this->getHandler() || !$this->handler->canRender() ) {
 483                                 // not a bitmap or renderable image, don't try.
 484                                 $thumb = $this->iconThumb();
 485                                 break;
 486                         }
 487
 488                         $script = $this->getTransformScript();
 489                         if ( $script && !($flags & self::RENDER_NOW) ) {
 490                                 // Use a script to transform on client request
 491                                 $thumb = $this->handler->getScriptedTransform( $this, $script, $params );
 492                                 break;
 493                         }
 494
 495                         $normalisedParams = $params;
 496                         $this->handler->normaliseParams( $this, $normalisedParams );
 497                         $thumbName = $this->thumbName( $normalisedParams );
 498                         $thumbPath = $this->getThumbPath( $thumbName );
 499                         $thumbUrl = $this->getThumbUrl( $thumbName );
 500
 501                         if ( $this->repo->canTransformVia404() && !($flags & self::RENDER_NOW ) ) {
 502                                 $thumb = $this->handler->getTransform( $this, $thumbPath, $thumbUrl, $params );
 503                                 break;
 504                         }
 505
 506                         wfDebug( "Doing stat for $thumbPath\n" );
 507                         $this->migrateThumbFile( $thumbName );
 508                         if ( file_exists( $thumbPath ) ) {
 509                                 $thumb = $this->handler->getTransform( $this, $thumbPath, $thumbUrl, $params );
 510                                 break;
 511                         }
 512                         $thumb = $this->handler->doTransform( $this, $thumbPath, $thumbUrl, $params );
 513
 514                         // Ignore errors if requested
 515                         if ( !$thumb ) {
 516                                 $thumb = null;
 517                         } elseif ( $thumb->isError() ) {
 518                                 $this->lastError = $thumb->toText();
 519                                 if ( $wgIgnoreImageErrors && !($flags & self::RENDER_NOW) ) {
 520                                         $thumb = $this->handler->getTransform( $this, $thumbPath, $thumbUrl, $params );
 521                                 }
 522                         }
 523
 524                         if ( $wgUseSquid ) {
 525                                 wfPurgeSquidServers( array( $thumbUrl ) );
 526                         }
 527                 } while (false);
 528
 529                 wfProfileOut( __METHOD__ );
 530                 return $thumb;
 531         }
 532
 533         /**
 534          * Hook into transform() to allow migration of thumbnail files
 535          * STUB
 536          * Overridden by LocalFile
 537          */
 538         function migrateThumbFile() {}
 539
 540         /**
 541          * Get a MediaHandler instance for this file
 542          */
 543         function getHandler() {
 544                 if ( !isset( $this->handler ) ) {
 545                         $this->handler = MediaHandler::getHandler( $this->getMimeType() );
 546                 }
 547                 return $this->handler;
 548         }
 549
 550         /**
 551          * Get a ThumbnailImage representing a file type icon
 552          * @return ThumbnailImage
 553          */
 554         function iconThumb() {
 555                 global $wgStylePath, $wgStyleDirectory;
 556
 557                 $try = array( 'fileicon-' . $this->getExtension() . '.png', 'fileicon.png' );
 558                 foreach( $try as $icon ) {
 559                         $path = '/common/images/icons/' . $icon;
 560                         $filepath = $wgStyleDirectory . $path;
 561                         if( file_exists( $filepath ) ) {
 562                                 return new ThumbnailImage( $wgStylePath . $path, 120, 120 );
 563                         }
 564                 }
 565                 return null;
 566         }
 567
 568         /**
 569          * Get last thumbnailing error.
 570          * Largely obsolete.
 571          */
 572         function getLastError() {
 573                 return $this->lastError;
 574         }
 575
 576         /**
 577          * Get all thumbnail names previously generated for this file
 578          * STUB
 579          * Overridden by LocalFile
 580          */
 581         function getThumbnails() { return array(); }
 582
 583         /**
 584          * Purge shared caches such as thumbnails and DB data caching
 585          * STUB
 586          * Overridden by LocalFile
 587          */
 588         function purgeCache( $archiveFiles = array() ) {}
 589
 590         /**
 591          * Purge the file description page, but don't go after
 592          * pages using the file. Use when modifying file history
 593          * but not the current data.
 594          */
 595         function purgeDescription() {
 596                 $title = $this->getTitle();
 597                 if ( $title ) {
 598                         $title->invalidateCache();
 599                         $title->purgeSquid();
 600                 }
 601         }
 602
 603         /**
 604          * Purge metadata and all affected pages when the file is created,
 605          * deleted, or majorly updated. A set of additional URLs may be
 606          * passed to purge, such as specific file files which have changed.
 607          * @param $urlArray array
 608          */
 609         function purgeEverything( $urlArr=array() ) {
 610                 // Delete thumbnails and refresh file metadata cache
 611                 $this->purgeCache();
 612                 $this->purgeDescription();
 613
 614                 // Purge cache of all pages using this file
 615                 $title = $this->getTitle();
 616                 if ( $title ) {
 617                         $update = new HTMLCacheUpdate( $title, 'imagelinks' );
 618                         $update->doUpdate();
 619                 }
 620         }
 621
 622         /**
 623          * Return the history of this file, line by line. Starts with current version,
 624          * then old versions. Should return an object similar to an image/oldimage
 625          * database row.
 626          *
 627          * @public
 628          * STUB
 629          * Overridden in LocalFile
 630          */
 631         function nextHistoryLine() {
 632                 return false;
 633         }
 634
 635         /**
 636          * Reset the history pointer to the first element of the history
 637          * @public
 638          * STUB
 639          * Overridden in LocalFile.
 640          */
 641         function resetHistory() {}
 642
 643         /**
 644          * Get the filename hash component of the directory including trailing slash,
 645          * e.g. f/fa/
 646          * If the repository is not hashed, returns an empty string.
 647          */
 648         function getHashPath() {
 649                 if ( !isset( $this->hashPath ) ) {
 650                         $this->hashPath = $this->repo->getHashPath( $this->getName() );
 651                 }
 652                 return $this->hashPath;
 653         }
 654
 655         /**
 656          * Get the path of the file relative to the public zone root
 657          */
 658         function getRel() {
 659                 return $this->getHashPath() . $this->getName();
 660         }
 661
 662         /**
 663          * Get urlencoded relative path of the file
 664          */
 665         function getUrlRel() {
 666                 return $this->getHashPath() . urlencode( $this->getName() );
 667         }
 668
 669         /** Get the path of the archive directory, or a particular file if $suffix is specified */
 670         function getArchivePath( $suffix = false ) {
 671                 $path = $this->repo->getZonePath('public') . '/archive/' . $this->getHashPath();
 672                 if ( $suffix === false ) {
 673                         $path = substr( $path, 0, -1 );
 674                 } else {
 675                         $path .= $suffix;
 676                 }
 677                 return $path;
 678         }
 679
 680         /** Get the path of the thumbnail directory, or a particular file if $suffix is specified */
 681         function getThumbPath( $suffix = false ) {
 682                 $path = $this->repo->getZonePath('public') . '/thumb/' . $this->getRel();
 683                 if ( $suffix !== false ) {
 684                         $path .= '/' . $suffix;
 685                 }
 686                 return $path;
 687         }
 688
 689         /** Get the URL of the archive directory, or a particular file if $suffix is specified */
 690         function getArchiveUrl( $suffix = false ) {
 691                 $path = $this->repo->getZoneUrl('public') . '/archive/' . $this->getHashPath();
 692                 if ( $suffix === false ) {
 693                         $path = substr( $path, 0, -1 );
 694                 } else {
 695                         $path .= urlencode( $suffix );
 696                 }
 697                 return $path;
 698         }
 699
 700         /** Get the URL of the thumbnail directory, or a particular file if $suffix is specified */
 701         function getThumbUrl( $suffix = false ) {
 702                 $path = $this->repo->getZoneUrl('public') . '/thumb/' . $this->getUrlRel();
 703                 if ( $suffix !== false ) {
 704                         $path .= '/' . urlencode( $suffix );
 705                 }
 706                 return $path;
 707         }
 708
 709         /** Get the virtual URL for an archive file or directory */
 710         function getArchiveVirtualUrl( $suffix = false ) {
 711                 $path = $this->repo->getVirtualUrl() . '/public/archive/' . $this->getHashPath();
 712                 if ( $suffix === false ) {
 713                         $path = substr( $path, 0, -1 );
 714                 } else {
 715                         $path .= urlencode( $suffix );
 716                 }
 717                 return $path;
 718         }
 719
 720         /** Get the virtual URL for a thumbnail file or directory */
 721         function getThumbVirtualUrl( $suffix = false ) {
 722                 $path = $this->repo->getVirtualUrl() . '/public/thumb/' . $this->getUrlRel();
 723                 if ( $suffix !== false ) {
 724                         $path .= '/' . urlencode( $suffix );
 725                 }
 726                 return $path;
 727         }
 728
 729         /**
 730          * @return bool
 731          */
 732         function isHashed() {
 733                 return $this->repo->isHashed();
 734         }
 735
 736         function readOnlyError() {
 737                 throw new MWException( get_class($this) . ': write operations are not supported' );
 738         }
 739
 740         /**
 741          * Record a file upload in the upload log and the image table
 742          * STUB
 743          * Overridden by LocalFile
 744          */
 745         function recordUpload( $oldver, $desc, $license = '', $copyStatus = '', $source = '', $watch = false ) {
 746                 $this->readOnlyError();
 747         }
 748
 749         /**
 750          * Move or copy a file to its public location. If a file exists at the
 751          * destination, move it to an archive. Returns the archive name on success
 752          * or an empty string if it was a new file, and a wikitext-formatted
 753          * WikiError object on failure.
 754          *
 755          * The archive name should be passed through to recordUpload for database
 756          * registration.
 757          *
 758          * @param string $sourcePath Local filesystem path to the source image
 759          * @param integer $flags A bitwise combination of:
 760          *     File::DELETE_SOURCE    Delete the source file, i.e. move
 761          *         rather than copy
 762          * @return The archive name on success or an empty string if it was a new
 763          *     file, and a wikitext-formatted WikiError object on failure.
 764          *
 765          * STUB
 766          * Overridden by LocalFile
 767          */
 768         function publish( $srcPath, $flags = 0 ) {
 769                 $this->readOnlyError();
 770         }
 771
 772         /**
 773          * Get an array of Title objects which are articles which use this file
 774          * Also adds their IDs to the link cache
 775          *
 776          * This is mostly copied from Title::getLinksTo()
 777          *
 778          * @deprecated Use HTMLCacheUpdate, this function uses too much memory
 779          */
 780         function getLinksTo( $options = '' ) {
 781                 wfProfileIn( __METHOD__ );
 782
 783                 // Note: use local DB not repo DB, we want to know local links
 784                 if ( $options ) {
 785                         $db = wfGetDB( DB_MASTER );
 786                 } else {
 787                         $db = wfGetDB( DB_SLAVE );
 788                 }
 789                 $linkCache =& LinkCache::singleton();
 790
 791                 list( $page, $imagelinks ) = $db->tableNamesN( 'page', 'imagelinks' );
 792                 $encName = $db->addQuotes( $this->getName() );
 793                 $sql = "SELECT page_namespace,page_title,page_id FROM $page,$imagelinks WHERE page_id=il_from AND il_to=$encName $options";
 794                 $res = $db->query( $sql, __METHOD__ );
 795
 796                 $retVal = array();
 797                 if ( $db->numRows( $res ) ) {
 798                         while ( $row = $db->fetchObject( $res ) ) {
 799                                 if ( $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title ) ) {
 800                                         $linkCache->addGoodLinkObj( $row->page_id, $titleObj );
 801                                         $retVal[] = $titleObj;
 802                                 }
 803                         }
 804                 }
 805                 $db->freeResult( $res );
 806                 wfProfileOut( __METHOD__ );
 807                 return $retVal;
 808         }
 809
 810         function getExifData() {
 811                 if ( !$this->getHandler() || $this->handler->getMetadataType( $this ) != 'exif' ) {
 812                         return array();
 813                 }
 814                 $metadata = $this->getMetadata();
 815                 if ( !$metadata ) {
 816                         return array();
 817                 }
 818                 $exif = unserialize( $metadata );
 819                 if ( !$exif ) {
 820                         return array();
 821                 }
 822                 unset( $exif['MEDIAWIKI_EXIF_VERSION'] );
 823                 $format = new FormatExif( $exif );
 824
 825                 return $format->getFormattedData();
 826         }
 827
 828         /**
 829          * Returns true if the file comes from the local file repository.
 830          *
 831          * @return bool
 832          */
 833         function isLocal() {
 834                 return $this->repo && $this->repo->getName() == 'local';
 835         }
 836
 837         /**
 838          * Returns true if the image is an old version
 839          * STUB
 840          */
 841         function isOld() {
 842                 return false;
 843         }
 844
 845         /**
 846          * Is this file a "deleted" file in a private archive?
 847          * STUB
 848          */
 849         function isDeleted( $field ) {
 850                 return false;
 851         }
 852
 853         /**
 854          * Was this file ever deleted from the wiki?
 855          *
 856          * @return bool
 857          */
 858         function wasDeleted() {
 859                 $title = $this->getTitle();
 860                 return $title && $title->isDeleted() > 0;
 861         }
 862
 863         /**
 864          * Delete all versions of the file.
 865          *
 866          * Moves the files into an archive directory (or deletes them)
 867          * and removes the database rows.
 868          *
 869          * Cache purging is done; logging is caller's responsibility.
 870          *
 871          * @param $reason
 872          * @return true on success, false on some kind of failure
 873          * STUB
 874          * Overridden by LocalFile
 875          */
 876         function delete( $reason, $suppress=false ) {
 877                 $this->readOnlyError();
 878         }
 879
 880         /**
 881          * Restore all or specified deleted revisions to the given file.
 882          * Permissions and logging are left to the caller.
 883          *
 884          * May throw database exceptions on error.
 885          *
 886          * @param $versions set of record ids of deleted items to restore,
 887          *                    or empty to restore all revisions.
 888          * @return the number of file revisions restored if successful,
 889          *         or false on failure
 890          * STUB
 891          * Overridden by LocalFile
 892          */
 893         function restore( $versions=array(), $Unsuppress=false ) {
 894                 $this->readOnlyError();
 895         }
 896
 897         /**
 898          * Returns 'true' if this image is a multipage document, e.g. a DJVU
 899          * document.
 900          *
 901          * @return Bool
 902          */
 903         function isMultipage() {
 904                 return $this->getHandler() && $this->handler->isMultiPage();
 905         }
 906
 907         /**
 908          * Returns the number of pages of a multipage document, or NULL for
 909          * documents which aren't multipage documents
 910          */
 911         function pageCount() {
 912                 if ( !isset( $this->pageCount ) ) {
 913                         if ( $this->getHandler() && $this->handler->isMultiPage() ) {
 914                                 $this->pageCount = $this->handler->pageCount( $this );
 915                         } else {
 916                                 $this->pageCount = false;
 917                         }
 918                 }
 919                 return $this->pageCount;
 920         }
 921
 922         /**
 923          * Calculate the height of a thumbnail using the source and destination width
 924          */
 925         static function scaleHeight( $srcWidth, $srcHeight, $dstWidth ) {
 926                 // Exact integer multiply followed by division
 927                 if ( $srcWidth == 0 ) {
 928                         return 0;
 929                 } else {
 930                         return round( $srcHeight * $dstWidth / $srcWidth );
 931                 }
 932         }
 933
 934         /**
 935          * Get an image size array like that returned by getimagesize(), or false if it
 936          * can't be determined.
 937          *
 938          * @param string $fileName The filename
 939          * @return array
 940          */
 941         function getImageSize( $fileName ) {
 942                 if ( !$this->getHandler() ) {
 943                         return false;
 944                 }
 945                 return $this->handler->getImageSize( $this, $fileName );
 946         }
 947
 948         /**
 949          * Get the URL of the image description page. May return false if it is
 950          * unknown or not applicable.
 951          */
 952         function getDescriptionUrl() {
 953                 return $this->repo->getDescriptionUrl( $this->getName() );
 954         }
 955
 956         /**
 957          * Get the HTML text of the description page, if available
 958          */
 959         function getDescriptionText() {
 960                 if ( !$this->repo->fetchDescription ) {
 961                         return false;
 962                 }
 963                 $renderUrl = $this->repo->getDescriptionRenderUrl( $this->getName() );
 964                 if ( $renderUrl ) {
 965                         wfDebug( "Fetching shared description from $renderUrl\n" );
 966                         return Http::get( $renderUrl );
 967                 } else {
 968                         return false;
 969                 }
 970         }
 971
 972         /**
 973          * Get the 14-character timestamp of the file upload, or false if
 974          */
 975         function getTimestmap() {
 976                 $path = $this->getPath();
 977                 if ( !file_exists( $path ) ) {
 978                         return false;
 979                 }
 980                 return wfTimestamp( filemtime( $path ) );
 981         }
 982
 983         /**
 984          * Determine if the current user is allowed to view a particular
 985          * field of this file, if it's marked as deleted.
 986          * STUB
 987          * @param int $field
 988          * @return bool
 989          */
 990         function userCan( $field ) {
 991                 return true;
 992         }
 993 }
 994
 995 ?>