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