includes/media/MediaHandler.php

   1 <?php
   2 /**
   3  * Media-handling base classes and generic functionality.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @ingroup Media
  22  */
  23 use MediaWiki\MediaWikiServices;
  24
  25 /**
  26  * Base media handler class
  27  *
  28  * @ingroup Media
  29  */
  30 abstract class MediaHandler {
  31         const TRANSFORM_LATER = 1;
  32         const METADATA_GOOD = true;
  33         const METADATA_BAD = false;
  34         const METADATA_COMPATIBLE = 2; // for old but backwards compatible.
  35         /**
  36          * Max length of error logged by logErrorForExternalProcess()
  37          */
  38         const MAX_ERR_LOG_SIZE = 65535;
  39
  40         /**
  41          * Get a MediaHandler for a given MIME type from the instance cache
  42          *
  43          * @param string $type
  44          * @return MediaHandler|bool
  45          */
  46         static function getHandler( $type ) {
  47                 return MediaWikiServices::getInstance()
  48                         ->getMediaHandlerFactory()->getHandler( $type );
  49         }
  50
  51         /**
  52          * Get an associative array mapping magic word IDs to parameter names.
  53          * Will be used by the parser to identify parameters.
  54          */
  55         abstract public function getParamMap();
  56
  57         /**
  58          * Validate a thumbnail parameter at parse time.
  59          * Return true to accept the parameter, and false to reject it.
  60          * If you return false, the parser will do something quiet and forgiving.
  61          *
  62          * @param string $name
  63          * @param mixed $value
  64          */
  65         abstract public function validateParam( $name, $value );
  66
  67         /**
  68          * Merge a parameter array into a string appropriate for inclusion in filenames
  69          *
  70          * @param array $params Array of parameters that have been through normaliseParams.
  71          * @return string
  72          */
  73         abstract public function makeParamString( $params );
  74
  75         /**
  76          * Parse a param string made with makeParamString back into an array
  77          *
  78          * @param string $str The parameter string without file name (e.g. 122px)
  79          * @return array|bool Array of parameters or false on failure.
  80          */
  81         abstract public function parseParamString( $str );
  82
  83         /**
  84          * Changes the parameter array as necessary, ready for transformation.
  85          * Should be idempotent.
  86          * Returns false if the parameters are unacceptable and the transform should fail
  87          * @param File $image
  88          * @param array $params
  89          */
  90         abstract function normaliseParams( $image, &$params );
  91
  92         /**
  93          * Get an image size array like that returned by getimagesize(), or false if it
  94          * can't be determined.
  95          *
  96          * This function is used for determining the width, height and bitdepth directly
  97          * from an image. The results are stored in the database in the img_width,
  98          * img_height, img_bits fields.
  99          *
 100          * @note If this is a multipage file, return the width and height of the
 101          *  first page.
 102          *
 103          * @param File|FSFile $image The image object, or false if there isn't one.
 104          *   Warning, FSFile::getPropsFromPath might pass an FSFile instead of File (!)
 105          * @param string $path The filename
 106          * @return array|bool Follow the format of PHP getimagesize() internal function.
 107          *   See https://secure.php.net/getimagesize. MediaWiki will only ever use the
 108          *   first two array keys (the width and height), and the 'bits' associative
 109          *   key. All other array keys are ignored. Returning a 'bits' key is optional
 110          *   as not all formats have a notion of "bitdepth". Returns false on failure.
 111          */
 112         abstract function getImageSize( $image, $path );
 113
 114         /**
 115          * Get handler-specific metadata which will be saved in the img_metadata field.
 116          *
 117          * @param File|FSFile $image The image object, or false if there isn't one.
 118          *   Warning, FSFile::getPropsFromPath might pass an FSFile instead of File (!)
 119          * @param string $path The filename
 120          * @return string A string of metadata in php serialized form (Run through serialize())
 121          */
 122         function getMetadata( $image, $path ) {
 123                 return '';
 124         }
 125
 126         /**
 127          * Get metadata version.
 128          *
 129          * This is not used for validating metadata, this is used for the api when returning
 130          * metadata, since api content formats should stay the same over time, and so things
 131          * using ForeignApiRepo can keep backwards compatibility
 132          *
 133          * All core media handlers share a common version number, and extensions can
 134          * use the GetMetadataVersion hook to append to the array (they should append a unique
 135          * string so not to get confusing). If there was a media handler named 'foo' with metadata
 136          * version 3 it might add to the end of the array the element 'foo=3'. if the core metadata
 137          * version is 2, the end version string would look like '2;foo=3'.
 138          *
 139          * @return string Version string
 140          */
 141         static function getMetadataVersion() {
 142                 $version = [ '2' ]; // core metadata version
 143                 Hooks::run( 'GetMetadataVersion', [ &$version ] );
 144
 145                 return implode( ';', $version );
 146         }
 147
 148         /**
 149          * Convert metadata version.
 150          *
 151          * By default just returns $metadata, but can be used to allow
 152          * media handlers to convert between metadata versions.
 153          *
 154          * @param string|array $metadata Metadata array (serialized if string)
 155          * @param int $version Target version
 156          * @return array Serialized metadata in specified version, or $metadata on fail.
 157          */
 158         function convertMetadataVersion( $metadata, $version = 1 ) {
 159                 if ( !is_array( $metadata ) ) {
 160
 161                         // unserialize to keep return parameter consistent.
 162                         MediaWiki\suppressWarnings();
 163                         $ret = unserialize( $metadata );
 164                         MediaWiki\restoreWarnings();
 165
 166                         return $ret;
 167                 }
 168
 169                 return $metadata;
 170         }
 171
 172         /**
 173          * Get a string describing the type of metadata, for display purposes.
 174          *
 175          * @note This method is currently unused.
 176          * @param File $image
 177          * @return string
 178          */
 179         function getMetadataType( $image ) {
 180                 return false;
 181         }
 182
 183         /**
 184          * Check if the metadata string is valid for this handler.
 185          * If it returns MediaHandler::METADATA_BAD (or false), Image
 186          * will reload the metadata from the file and update the database.
 187          * MediaHandler::METADATA_GOOD for if the metadata is a-ok,
 188          * MediaHandler::METADATA_COMPATIBLE if metadata is old but backwards
 189          * compatible (which may or may not trigger a metadata reload).
 190          *
 191          * @note Returning self::METADATA_BAD will trigger a metadata reload from
 192          *  file on page view. Always returning this from a broken file, or suddenly
 193          *  triggering as bad metadata for a large number of files can cause
 194          *  performance problems.
 195          * @param File $image
 196          * @param string $metadata The metadata in serialized form
 197          * @return bool
 198          */
 199         function isMetadataValid( $image, $metadata ) {
 200                 return self::METADATA_GOOD;
 201         }
 202
 203         /**
 204          * Get an array of standard (FormatMetadata type) metadata values.
 205          *
 206          * The returned data is largely the same as that from getMetadata(),
 207          * but formatted in a standard, stable, handler-independent way.
 208          * The idea being that some values like ImageDescription or Artist
 209          * are universal and should be retrievable in a handler generic way.
 210          *
 211          * The specific properties are the type of properties that can be
 212          * handled by the FormatMetadata class. These values are exposed to the
 213          * user via the filemetadata parser function.
 214          *
 215          * Details of the response format of this function can be found at
 216          * https://www.mediawiki.org/wiki/Manual:File_metadata_handling
 217          * tl/dr: the response is an associative array of
 218          * properties keyed by name, but the value can be complex. You probably
 219          * want to call one of the FormatMetadata::flatten* functions on the
 220          * property values before using them, or call
 221          * FormatMetadata::getFormattedData() on the full response array, which
 222          * transforms all values into prettified, human-readable text.
 223          *
 224          * Subclasses overriding this function must return a value which is a
 225          * valid API response fragment (all associative array keys are valid
 226          * XML tagnames).
 227          *
 228          * Note, if the file simply has no metadata, but the handler supports
 229          * this interface, it should return an empty array, not false.
 230          *
 231          * @param File $file
 232          * @return array|bool False if interface not supported
 233          * @since 1.23
 234          */
 235         public function getCommonMetaArray( File $file ) {
 236                 return false;
 237         }
 238
 239         /**
 240          * Get a MediaTransformOutput object representing an alternate of the transformed
 241          * output which will call an intermediary thumbnail assist script.
 242          *
 243          * Used when the repository has a thumbnailScriptUrl option configured.
 244          *
 245          * Return false to fall back to the regular getTransform().
 246          * @param File $image
 247          * @param string $script
 248          * @param array $params
 249          * @return bool|ThumbnailImage
 250          */
 251         function getScriptedTransform( $image, $script, $params ) {
 252                 return false;
 253         }
 254
 255         /**
 256          * Get a MediaTransformOutput object representing the transformed output. Does not
 257          * actually do the transform.
 258          *
 259          * @param File $image The image object
 260          * @param string $dstPath Filesystem destination path
 261          * @param string $dstUrl Destination URL to use in output HTML
 262          * @param array $params Arbitrary set of parameters validated by $this->validateParam()
 263          * @return MediaTransformOutput
 264          */
 265         final function getTransform( $image, $dstPath, $dstUrl, $params ) {
 266                 return $this->doTransform( $image, $dstPath, $dstUrl, $params, self::TRANSFORM_LATER );
 267         }
 268
 269         /**
 270          * Get a MediaTransformOutput object representing the transformed output. Does the
 271          * transform unless $flags contains self::TRANSFORM_LATER.
 272          *
 273          * @param File $image The image object
 274          * @param string $dstPath Filesystem destination path
 275          * @param string $dstUrl Destination URL to use in output HTML
 276          * @param array $params Arbitrary set of parameters validated by $this->validateParam()
 277          *   Note: These parameters have *not* gone through $this->normaliseParams()
 278          * @param int $flags A bitfield, may contain self::TRANSFORM_LATER
 279          * @return MediaTransformOutput
 280          */
 281         abstract function doTransform( $image, $dstPath, $dstUrl, $params, $flags = 0 );
 282
 283         /**
 284          * Get the thumbnail extension and MIME type for a given source MIME type
 285          *
 286          * @param string $ext Extension of original file
 287          * @param string $mime MIME type of original file
 288          * @param array $params Handler specific rendering parameters
 289          * @return array Thumbnail extension and MIME type
 290          */
 291         function getThumbType( $ext, $mime, $params = null ) {
 292                 $magic = MimeMagic::singleton();
 293                 if ( !$ext || $magic->isMatchingExtension( $ext, $mime ) === false ) {
 294                         // The extension is not valid for this MIME type and we do
 295                         // recognize the MIME type
 296                         $extensions = $magic->getExtensionsForType( $mime );
 297                         if ( $extensions ) {
 298                                 return [ strtok( $extensions, ' ' ), $mime ];
 299                         }
 300                 }
 301
 302                 // The extension is correct (true) or the MIME type is unknown to
 303                 // MediaWiki (null)
 304                 return [ $ext, $mime ];
 305         }
 306
 307         /**
 308         * @deprecated since 1.30, use MediaHandler::getContentHeaders instead
 309         */
 310         public function getStreamHeaders( $metadata ) {
 311                 wfDeprecated( __METHOD__, '1.30' );
 312                 return $this->getContentHeaders( $metadata );
 313         }
 314
 315         /**
 316          * True if the handled types can be transformed
 317          *
 318          * @param File $file
 319          * @return bool
 320          */
 321         public function canRender( $file ) {
 322                 return true;
 323         }
 324
 325         /**
 326          * True if handled types cannot be displayed directly in a browser
 327          * but can be rendered
 328          *
 329          * @param File $file
 330          * @return bool
 331          */
 332         public function mustRender( $file ) {
 333                 return false;
 334         }
 335
 336         /**
 337          * True if the type has multi-page capabilities
 338          *
 339          * @param File $file
 340          * @return bool
 341          */
 342         public function isMultiPage( $file ) {
 343                 return false;
 344         }
 345
 346         /**
 347          * Page count for a multi-page document, false if unsupported or unknown
 348          *
 349          * @param File $file
 350          * @return bool
 351          */
 352         function pageCount( File $file ) {
 353                 return false;
 354         }
 355
 356         /**
 357          * The material is vectorized and thus scaling is lossless
 358          *
 359          * @param File $file
 360          * @return bool
 361          */
 362         function isVectorized( $file ) {
 363                 return false;
 364         }
 365
 366         /**
 367          * The material is an image, and is animated.
 368          * In particular, video material need not return true.
 369          * @note Before 1.20, this was a method of ImageHandler only
 370          *
 371          * @param File $file
 372          * @return bool
 373          */
 374         function isAnimatedImage( $file ) {
 375                 return false;
 376         }
 377
 378         /**
 379          * If the material is animated, we can animate the thumbnail
 380          * @since 1.20
 381          *
 382          * @param File $file
 383          * @return bool If material is not animated, handler may return any value.
 384          */
 385         function canAnimateThumbnail( $file ) {
 386                 return true;
 387         }
 388
 389         /**
 390          * False if the handler is disabled for all files
 391          * @return bool
 392          */
 393         function isEnabled() {
 394                 return true;
 395         }
 396
 397         /**
 398          * Get an associative array of page dimensions
 399          * Currently "width" and "height" are understood, but this might be
 400          * expanded in the future.
 401          * Returns false if unknown.
 402          *
 403          * It is expected that handlers for paged media (e.g. DjVuHandler)
 404          * will override this method so that it gives the correct results
 405          * for each specific page of the file, using the $page argument.
 406          *
 407          * @note For non-paged media, use getImageSize.
 408          *
 409          * @param File $image
 410          * @param int $page What page to get dimensions of
 411          * @return array|bool
 412          */
 413         function getPageDimensions( File $image, $page ) {
 414                 $gis = $this->getImageSize( $image, $image->getLocalRefPath() );
 415                 if ( $gis ) {
 416                         return [
 417                                 'width' => $gis[0],
 418                                 'height' => $gis[1]
 419                         ];
 420                 } else {
 421                         return false;
 422                 }
 423         }
 424
 425         /**
 426          * Generic getter for text layer.
 427          * Currently overloaded by PDF and DjVu handlers
 428          * @param File $image
 429          * @param int $page Page number to get information for
 430          * @return bool|string Page text or false when no text found or if
 431          *   unsupported.
 432          */
 433         function getPageText( File $image, $page ) {
 434                 return false;
 435         }
 436
 437         /**
 438          * Get the text of the entire document.
 439          * @param File $file
 440          * @return bool|string The text of the document or false if unsupported.
 441          */
 442         public function getEntireText( File $file ) {
 443                 $numPages = $file->pageCount();
 444                 if ( !$numPages ) {
 445                         // Not a multipage document
 446                         return $this->getPageText( $file, 1 );
 447                 }
 448                 $document = '';
 449                 for ( $i = 1; $i <= $numPages; $i++ ) {
 450                         $curPage = $this->getPageText( $file, $i );
 451                         if ( is_string( $curPage ) ) {
 452                                 $document .= $curPage . "\n";
 453                         }
 454                 }
 455                 if ( $document !== '' ) {
 456                         return $document;
 457                 }
 458                 return false;
 459         }
 460
 461         /**
 462          * Get an array structure that looks like this:
 463          *
 464          * [
 465          *    'visible' => [
 466          *       'Human-readable name' => 'Human readable value',
 467          *       ...
 468          *    ],
 469          *    'collapsed' => [
 470          *       'Human-readable name' => 'Human readable value',
 471          *       ...
 472          *    ]
 473          * ]
 474          * The UI will format this into a table where the visible fields are always
 475          * visible, and the collapsed fields are optionally visible.
 476          *
 477          * The function should return false if there is no metadata to display.
 478          */
 479
 480         /**
 481          * @todo FIXME: This interface is not very flexible. The media handler
 482          * should generate HTML instead. It can do all the formatting according
 483          * to some standard. That makes it possible to do things like visual
 484          * indication of grouped and chained streams in ogg container files.
 485          * @param File $image
 486          * @param bool|IContextSource $context Context to use (optional)
 487          * @return array|bool
 488          */
 489         function formatMetadata( $image, $context = false ) {
 490                 return false;
 491         }
 492
 493         /** sorts the visible/invisible field.
 494          * Split off from ImageHandler::formatMetadata, as used by more than
 495          * one type of handler.
 496          *
 497          * This is used by the media handlers that use the FormatMetadata class
 498          *
 499          * @param array $metadataArray Metadata array
 500          * @param bool|IContextSource $context Context to use (optional)
 501          * @return array Array for use displaying metadata.
 502          */
 503         function formatMetadataHelper( $metadataArray, $context = false ) {
 504                 $result = [
 505                         'visible' => [],
 506                         'collapsed' => []
 507                 ];
 508
 509                 $formatted = FormatMetadata::getFormattedData( $metadataArray, $context );
 510                 // Sort fields into visible and collapsed
 511                 $visibleFields = $this->visibleMetadataFields();
 512                 foreach ( $formatted as $name => $value ) {
 513                         $tag = strtolower( $name );
 514                         self::addMeta( $result,
 515                                 in_array( $tag, $visibleFields ) ? 'visible' : 'collapsed',
 516                                 'exif',
 517                                 $tag,
 518                                 $value
 519                         );
 520                 }
 521
 522                 return $result;
 523         }
 524
 525         /**
 526          * Get a list of metadata items which should be displayed when
 527          * the metadata table is collapsed.
 528          *
 529          * @return array Array of strings
 530          */
 531         protected function visibleMetadataFields() {
 532                 return FormatMetadata::getVisibleFields();
 533         }
 534
 535         /**
 536          * This is used to generate an array element for each metadata value
 537          * That array is then used to generate the table of metadata values
 538          * on the image page
 539          *
 540          * @param array &$array An array containing elements for each type of visibility
 541          *   and each of those elements being an array of metadata items. This function adds
 542          *   a value to that array.
 543          * @param string $visibility ('visible' or 'collapsed') if this value is hidden
 544          *   by default.
 545          * @param string $type Type of metadata tag (currently always 'exif')
 546          * @param string $id The name of the metadata tag (like 'artist' for example).
 547          *   its name in the table displayed is the message "$type-$id" (Ex exif-artist ).
 548          * @param string $value Thingy goes into a wikitext table; it used to be escaped but
 549          *   that was incompatible with previous practise of customized display
 550          *   with wikitext formatting via messages such as 'exif-model-value'.
 551          *   So the escaping is taken back out, but generally this seems a confusing
 552          *   interface.
 553          * @param bool|string $param Value to pass to the message for the name of the field
 554          *   as $1. Currently this parameter doesn't seem to ever be used.
 555          *
 556          * Note, everything here is passed through the parser later on (!)
 557          */
 558         protected static function addMeta( &$array, $visibility, $type, $id, $value, $param = false ) {
 559                 $msg = wfMessage( "$type-$id", $param );
 560                 if ( $msg->exists() ) {
 561                         $name = $msg->text();
 562                 } else {
 563                         // This is for future compatibility when using instant commons.
 564                         // So as to not display as ugly a name if a new metadata
 565                         // property is defined that we don't know about
 566                         // (not a major issue since such a property would be collapsed
 567                         // by default).
 568                         wfDebug( __METHOD__ . ' Unknown metadata name: ' . $id . "\n" );
 569                         $name = wfEscapeWikiText( $id );
 570                 }
 571                 $array[$visibility][] = [
 572                         'id' => "$type-$id",
 573                         'name' => $name,
 574                         'value' => $value
 575                 ];
 576         }
 577
 578         /**
 579          * Short description. Shown on Special:Search results.
 580          *
 581          * @param File $file
 582          * @return string
 583          */
 584         function getShortDesc( $file ) {
 585                 return self::getGeneralShortDesc( $file );
 586         }
 587
 588         /**
 589          * Long description. Shown under image on image description page surounded by ().
 590          *
 591          * @param File $file
 592          * @return string
 593          */
 594         function getLongDesc( $file ) {
 595                 return self::getGeneralLongDesc( $file );
 596         }
 597
 598         /**
 599          * Used instead of getShortDesc if there is no handler registered for file.
 600          *
 601          * @param File $file
 602          * @return string
 603          */
 604         static function getGeneralShortDesc( $file ) {
 605                 global $wgLang;
 606
 607                 return htmlspecialchars( $wgLang->formatSize( $file->getSize() ) );
 608         }
 609
 610         /**
 611          * Used instead of getLongDesc if there is no handler registered for file.
 612          *
 613          * @param File $file
 614          * @return string
 615          */
 616         static function getGeneralLongDesc( $file ) {
 617                 return wfMessage( 'file-info' )->sizeParams( $file->getSize() )
 618                         ->params( '<span class="mime-type">' . $file->getMimeType() . '</span>' )->parse();
 619         }
 620
 621         /**
 622          * Calculate the largest thumbnail width for a given original file size
 623          * such that the thumbnail's height is at most $maxHeight.
 624          * @param int $boxWidth Width of the thumbnail box.
 625          * @param int $boxHeight Height of the thumbnail box.
 626          * @param int $maxHeight Maximum height expected for the thumbnail.
 627          * @return int
 628          */
 629         public static function fitBoxWidth( $boxWidth, $boxHeight, $maxHeight ) {
 630                 $idealWidth = $boxWidth * $maxHeight / $boxHeight;
 631                 $roundedUp = ceil( $idealWidth );
 632                 if ( round( $roundedUp * $boxHeight / $boxWidth ) > $maxHeight ) {
 633                         return floor( $idealWidth );
 634                 } else {
 635                         return $roundedUp;
 636                 }
 637         }
 638
 639         /**
 640          * Shown in file history box on image description page.
 641          *
 642          * @param File $file
 643          * @return string Dimensions
 644          */
 645         function getDimensionsString( $file ) {
 646                 return '';
 647         }
 648
 649         /**
 650          * Modify the parser object post-transform.
 651          *
 652          * This is often used to do $parser->addOutputHook(),
 653          * in order to add some javascript to render a viewer.
 654          * See TimedMediaHandler or OggHandler for an example.
 655          *
 656          * @param Parser $parser
 657          * @param File $file
 658          */
 659         function parserTransformHook( $parser, $file ) {
 660         }
 661
 662         /**
 663          * File validation hook called on upload.
 664          *
 665          * If the file at the given local path is not valid, or its MIME type does not
 666          * match the handler class, a Status object should be returned containing
 667          * relevant errors.
 668          *
 669          * @param string $fileName The local path to the file.
 670          * @return Status
 671          */
 672         function verifyUpload( $fileName ) {
 673                 return Status::newGood();
 674         }
 675
 676         /**
 677          * Check for zero-sized thumbnails. These can be generated when
 678          * no disk space is available or some other error occurs
 679          *
 680          * @param string $dstPath The location of the suspect file
 681          * @param int $retval Return value of some shell process, file will be deleted if this is non-zero
 682          * @return bool True if removed, false otherwise
 683          */
 684         function removeBadFile( $dstPath, $retval = 0 ) {
 685                 if ( file_exists( $dstPath ) ) {
 686                         $thumbstat = stat( $dstPath );
 687                         if ( $thumbstat['size'] == 0 || $retval != 0 ) {
 688                                 $result = unlink( $dstPath );
 689
 690                                 if ( $result ) {
 691                                         wfDebugLog( 'thumbnail',
 692                                                 sprintf( 'Removing bad %d-byte thumbnail "%s". unlink() succeeded',
 693                                                         $thumbstat['size'], $dstPath ) );
 694                                 } else {
 695                                         wfDebugLog( 'thumbnail',
 696                                                 sprintf( 'Removing bad %d-byte thumbnail "%s". unlink() failed',
 697                                                         $thumbstat['size'], $dstPath ) );
 698                                 }
 699
 700                                 return true;
 701                         }
 702                 }
 703
 704                 return false;
 705         }
 706
 707         /**
 708          * Remove files from the purge list.
 709          *
 710          * This is used by some video handlers to prevent ?action=purge
 711          * from removing a transcoded video, which is expensive to
 712          * regenerate.
 713          *
 714          * @see LocalFile::purgeThumbnails
 715          *
 716          * @param array $files
 717          * @param array $options Purge options. Currently will always be
 718          *  an array with a single key 'forThumbRefresh' set to true.
 719          */
 720         public function filterThumbnailPurgeList( &$files, $options ) {
 721                 // Do nothing
 722         }
 723
 724         /**
 725          * True if the handler can rotate the media
 726          * @since 1.24 non-static. From 1.21-1.23 was static
 727          * @return bool
 728          */
 729         public function canRotate() {
 730                 return false;
 731         }
 732
 733         /**
 734          * On supporting image formats, try to read out the low-level orientation
 735          * of the file and return the angle that the file needs to be rotated to
 736          * be viewed.
 737          *
 738          * This information is only useful when manipulating the original file;
 739          * the width and height we normally work with is logical, and will match
 740          * any produced output views.
 741          *
 742          * For files we don't know, we return 0.
 743          *
 744          * @param File $file
 745          * @return int 0, 90, 180 or 270
 746          */
 747         public function getRotation( $file ) {
 748                 return 0;
 749         }
 750
 751         /**
 752          * Log an error that occurred in an external process
 753          *
 754          * Moved from BitmapHandler to MediaHandler with MediaWiki 1.23
 755          *
 756          * @since 1.23
 757          * @param int $retval
 758          * @param string $err Error reported by command. Anything longer than
 759          * MediaHandler::MAX_ERR_LOG_SIZE is stripped off.
 760          * @param string $cmd
 761          */
 762         protected function logErrorForExternalProcess( $retval, $err, $cmd ) {
 763                 # Keep error output limited (T59985)
 764                 $errMessage = trim( substr( $err, 0, self::MAX_ERR_LOG_SIZE ) );
 765
 766                 wfDebugLog( 'thumbnail',
 767                         sprintf( 'thumbnail failed on %s: error %d "%s" from "%s"',
 768                                         wfHostname(), $retval, $errMessage, $cmd ) );
 769         }
 770
 771         /**
 772          * Get list of languages file can be viewed in.
 773          *
 774          * @param File $file
 775          * @return string[] Array of language codes, or empty array if unsupported.
 776          * @since 1.23
 777          */
 778         public function getAvailableLanguages( File $file ) {
 779                 return [];
 780         }
 781
 782         /**
 783          * On file types that support renderings in multiple languages,
 784          * which language is used by default if unspecified.
 785          *
 786          * If getAvailableLanguages returns a non-empty array, this must return
 787          * a valid language code. Otherwise can return null if files of this
 788          * type do not support alternative language renderings.
 789          *
 790          * @param File $file
 791          * @return string|null Language code or null if multi-language not supported for filetype.
 792          * @since 1.23
 793          */
 794         public function getDefaultRenderLanguage( File $file ) {
 795                 return null;
 796         }
 797
 798         /**
 799          * If its an audio file, return the length of the file. Otherwise 0.
 800          *
 801          * File::getLength() existed for a long time, but was calling a method
 802          * that only existed in some subclasses of this class (The TMH ones).
 803          *
 804          * @param File $file
 805          * @return float Length in seconds
 806          * @since 1.23
 807          */
 808         public function getLength( $file ) {
 809                 return 0.0;
 810         }
 811
 812         /**
 813          * True if creating thumbnails from the file is large or otherwise resource-intensive.
 814          * @param File $file
 815          * @return bool
 816          */
 817         public function isExpensiveToThumbnail( $file ) {
 818                 return false;
 819         }
 820
 821         /**
 822          * Returns whether or not this handler supports the chained generation of thumbnails according
 823          * to buckets
 824          * @return bool
 825          * @since 1.24
 826          */
 827         public function supportsBucketing() {
 828                 return false;
 829         }
 830
 831         /**
 832          * Returns a normalised params array for which parameters have been cleaned up for bucketing
 833          * purposes
 834          * @param array $params
 835          * @return array
 836          */
 837         public function sanitizeParamsForBucketing( $params ) {
 838                 return $params;
 839         }
 840
 841         /**
 842          * Gets configuration for the file warning message. Return value of
 843          * the following structure:
 844          *   [
 845          *     // Required, module with messages loaded for the client
 846          *     'module' => 'example.filewarning.messages',
 847          *     // Required, array of names of messages
 848          *     'messages' => [
 849          *       // Required, main warning message
 850          *       'main' => 'example-filewarning-main',
 851          *       // Optional, header for warning dialog
 852          *       'header' => 'example-filewarning-header',
 853          *       // Optional, footer for warning dialog
 854          *       'footer' => 'example-filewarning-footer',
 855          *       // Optional, text for more-information link (see below)
 856          *       'info' => 'example-filewarning-info',
 857          *     ],
 858          *     // Optional, link for more information
 859          *     'link' => 'http://example.com',
 860          *   ]
 861          *
 862          * Returns null if no warning is necessary.
 863          * @param File $file
 864          * @return array|null
 865          */
 866         public function getWarningConfig( $file ) {
 867                 return null;
 868         }
 869
 870         /**
 871          * Converts a dimensions array about a potentially multipage document from an
 872          * exhaustive list of ordered page numbers to a list of page ranges
 873          * @param Array $pagesByDimensions
 874          * @return String
 875          * @since 1.30
 876         */
 877         public static function getPageRangesByDimensions( $pagesByDimensions ) {
 878                 $pageRangesByDimensions = [];
 879
 880                 foreach ( $pagesByDimensions as $dimensions => $pageList ) {
 881                         $ranges = [];
 882                         $firstPage = $pageList[0];
 883                         $lastPage = $firstPage - 1;
 884
 885                         foreach ( $pageList as $page ) {
 886                                 if ( $page > $lastPage + 1 ) {
 887                                         if ( $firstPage != $lastPage ) {
 888                                                 $ranges[] = "$firstPage-$lastPage";
 889                                         } else {
 890                                                 $ranges[] = "$firstPage";
 891                                         }
 892
 893                                         $firstPage = $page;
 894                                 }
 895
 896                                 $lastPage = $page;
 897                         }
 898
 899                         if ( $firstPage != $lastPage ) {
 900                                 $ranges[] = "$firstPage-$lastPage";
 901                         } else {
 902                                 $ranges[] = "$firstPage";
 903                         }
 904
 905                         $pageRangesByDimensions[ $dimensions ] = $ranges;
 906                 }
 907
 908                 $dimensionsString = [];
 909                 foreach ( $pageRangesByDimensions as $dimensions => $pageRanges ) {
 910                         $dimensionsString[] = "$dimensions:" . implode( ',', $pageRanges );
 911                 }
 912
 913                 return implode( '/', $dimensionsString );
 914         }
 915
 916         /**
 917         * Get useful response headers for GET/HEAD requests for a file with the given metadata
 918         * @param $metadata Array Contains this handler's unserialized getMetadata() for a file
 919         * @return Array
 920         * @since 1.30
 921         */
 922         public function getContentHeaders( $metadata ) {
 923                 return [];
 924         }
 925 }