includes/media/SvgHandler.php

   1 <?php
   2 /**
   3  * Handler for SVG images.
   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
  24 use MediaWiki\Shell\Shell;
  25 use Wikimedia\ScopedCallback;
  26
  27 /**
  28  * Handler for SVG images.
  29  *
  30  * @ingroup Media
  31  */
  32 class SvgHandler extends ImageHandler {
  33         const SVG_METADATA_VERSION = 2;
  34
  35         /** @var array A list of metadata tags that can be converted
  36          *  to the commonly used exif tags. This allows messages
  37          *  to be reused, and consistent tag names for {{#formatmetadata:..}}
  38          */
  39         private static $metaConversion = [
  40                 'originalwidth' => 'ImageWidth',
  41                 'originalheight' => 'ImageLength',
  42                 'description' => 'ImageDescription',
  43                 'title' => 'ObjectName',
  44         ];
  45
  46         public function isEnabled() {
  47                 global $wgSVGConverters, $wgSVGConverter;
  48                 if ( !isset( $wgSVGConverters[$wgSVGConverter] ) ) {
  49                         wfDebug( "\$wgSVGConverter is invalid, disabling SVG rendering.\n" );
  50
  51                         return false;
  52                 } else {
  53                         return true;
  54                 }
  55         }
  56
  57         public function mustRender( $file ) {
  58                 return true;
  59         }
  60
  61         function isVectorized( $file ) {
  62                 return true;
  63         }
  64
  65         /**
  66          * @param File $file
  67          * @return bool
  68          */
  69         function isAnimatedImage( $file ) {
  70                 # @todo Detect animated SVGs
  71                 $metadata = $file->getMetadata();
  72                 if ( $metadata ) {
  73                         $metadata = $this->unpackMetadata( $metadata );
  74                         if ( isset( $metadata['animated'] ) ) {
  75                                 return $metadata['animated'];
  76                         }
  77                 }
  78
  79                 return false;
  80         }
  81
  82         /**
  83          * Which languages (systemLanguage attribute) is supported.
  84          *
  85          * @note This list is not guaranteed to be exhaustive.
  86          * To avoid OOM errors, we only look at first bit of a file.
  87          * Thus all languages on this list are present in the file,
  88          * but its possible for the file to have a language not on
  89          * this list.
  90          *
  91          * @param File $file
  92          * @return array Array of language codes, or empty if no language switching supported.
  93          */
  94         public function getAvailableLanguages( File $file ) {
  95                 $metadata = $file->getMetadata();
  96                 $langList = [];
  97                 if ( $metadata ) {
  98                         $metadata = $this->unpackMetadata( $metadata );
  99                         if ( isset( $metadata['translations'] ) ) {
 100                                 foreach ( $metadata['translations'] as $lang => $langType ) {
 101                                         if ( $langType === SVGReader::LANG_FULL_MATCH ) {
 102                                                 $langList[] = strtolower( $lang );
 103                                         }
 104                                 }
 105                         }
 106                 }
 107                 return array_unique( $langList );
 108         }
 109
 110         /**
 111          * SVG's systemLanguage matching rules state:
 112          * 'The `systemLanguage` attribute ... [e]valuates to "true" if one of the languages indicated
 113          * by user preferences exactly equals one of the languages given in the value of this parameter,
 114          * or if one of the languages indicated by user preferences exactly equals a prefix of one of
 115          * the languages given in the value of this parameter such that the first tag character
 116          * following the prefix is "-".'
 117          *
 118          * Return the first element of $svgLanguages that matches $userPreferredLanguage
 119          *
 120          * @see https://www.w3.org/TR/SVG/struct.html#SystemLanguageAttribute
 121          * @param string $userPreferredLanguage
 122          * @param array $svgLanguages
 123          * @return string|null
 124          */
 125         public function getMatchedLanguage( $userPreferredLanguage, array $svgLanguages ) {
 126                 foreach ( $svgLanguages as $svgLang ) {
 127                         if ( strcasecmp( $svgLang, $userPreferredLanguage ) === 0 ) {
 128                                 return $svgLang;
 129                         }
 130                         $trimmedSvgLang = $svgLang;
 131                         while ( strpos( $trimmedSvgLang, '-' ) !== false ) {
 132                                 $trimmedSvgLang = substr( $trimmedSvgLang, 0, strrpos( $trimmedSvgLang, '-' ) );
 133                                 if ( strcasecmp( $trimmedSvgLang, $userPreferredLanguage ) === 0 ) {
 134                                         return $svgLang;
 135                                 }
 136                         }
 137                 }
 138                 return null;
 139         }
 140
 141         /**
 142          * Determines render language from image parameters
 143          *
 144          * @param array $params
 145          * @return string
 146          */
 147         protected function getLanguageFromParams( array $params ) {
 148                 return $params['lang'] ?? $params['targetlang'] ?? 'en';
 149         }
 150
 151         /**
 152          * What language to render file in if none selected
 153          *
 154          * @param File $file Language code
 155          * @return string
 156          */
 157         public function getDefaultRenderLanguage( File $file ) {
 158                 return 'en';
 159         }
 160
 161         /**
 162          * We do not support making animated svg thumbnails
 163          * @param File $file
 164          * @return bool
 165          */
 166         function canAnimateThumbnail( $file ) {
 167                 return false;
 168         }
 169
 170         /**
 171          * @param File $image
 172          * @param array &$params
 173          * @return bool
 174          */
 175         public function normaliseParams( $image, &$params ) {
 176                 if ( parent::normaliseParams( $image, $params ) ) {
 177                         $params = $this->normaliseParamsInternal( $image, $params );
 178                         return true;
 179                 }
 180
 181                 return false;
 182         }
 183
 184         /**
 185          * Code taken out of normaliseParams() for testability
 186          *
 187          * @since 1.33
 188          *
 189          * @param File $image
 190          * @param array $params
 191          * @return array Modified $params
 192          */
 193         protected function normaliseParamsInternal( $image, $params ) {
 194                 global $wgSVGMaxSize;
 195
 196                 # Don't make an image bigger than wgMaxSVGSize on the smaller side
 197                 if ( $params['physicalWidth'] <= $params['physicalHeight'] ) {
 198                         if ( $params['physicalWidth'] > $wgSVGMaxSize ) {
 199                                 $srcWidth = $image->getWidth( $params['page'] );
 200                                 $srcHeight = $image->getHeight( $params['page'] );
 201                                 $params['physicalWidth'] = $wgSVGMaxSize;
 202                                 $params['physicalHeight'] = File::scaleHeight( $srcWidth, $srcHeight, $wgSVGMaxSize );
 203                         }
 204                 } elseif ( $params['physicalHeight'] > $wgSVGMaxSize ) {
 205                         $srcWidth = $image->getWidth( $params['page'] );
 206                         $srcHeight = $image->getHeight( $params['page'] );
 207                         $params['physicalWidth'] = File::scaleHeight( $srcHeight, $srcWidth, $wgSVGMaxSize );
 208                         $params['physicalHeight'] = $wgSVGMaxSize;
 209                 }
 210                 // To prevent the proliferation of thumbnails in languages not present in SVGs, unless
 211                 // explicitly forced by user.
 212                 if ( isset( $params['targetlang'] ) && !$image->getMatchedLanguage( $params['targetlang'] ) ) {
 213                         unset( $params['targetlang'] );
 214                 }
 215
 216                 return $params;
 217         }
 218
 219         /**
 220          * @param File $image
 221          * @param string $dstPath
 222          * @param string $dstUrl
 223          * @param array $params
 224          * @param int $flags
 225          * @return bool|MediaTransformError|ThumbnailImage|TransformParameterError
 226          */
 227         function doTransform( $image, $dstPath, $dstUrl, $params, $flags = 0 ) {
 228                 if ( !$this->normaliseParams( $image, $params ) ) {
 229                         return new TransformParameterError( $params );
 230                 }
 231                 $clientWidth = $params['width'];
 232                 $clientHeight = $params['height'];
 233                 $physicalWidth = $params['physicalWidth'];
 234                 $physicalHeight = $params['physicalHeight'];
 235                 $lang = $this->getLanguageFromParams( $params );
 236
 237                 if ( $flags & self::TRANSFORM_LATER ) {
 238                         return new ThumbnailImage( $image, $dstUrl, $dstPath, $params );
 239                 }
 240
 241                 $metadata = $this->unpackMetadata( $image->getMetadata() );
 242                 if ( isset( $metadata['error'] ) ) { // sanity check
 243                         $err = wfMessage( 'svg-long-error', $metadata['error']['message'] );
 244
 245                         return new MediaTransformError( 'thumbnail_error', $clientWidth, $clientHeight, $err );
 246                 }
 247
 248                 if ( !wfMkdirParents( dirname( $dstPath ), null, __METHOD__ ) ) {
 249                         return new MediaTransformError( 'thumbnail_error', $clientWidth, $clientHeight,
 250                                 wfMessage( 'thumbnail_dest_directory' ) );
 251                 }
 252
 253                 $srcPath = $image->getLocalRefPath();
 254                 if ( $srcPath === false ) { // Failed to get local copy
 255                         wfDebugLog( 'thumbnail',
 256                                 sprintf( 'Thumbnail failed on %s: could not get local copy of "%s"',
 257                                         wfHostname(), $image->getName() ) );
 258
 259                         return new MediaTransformError( 'thumbnail_error',
 260                                 $params['width'], $params['height'],
 261                                 wfMessage( 'filemissing' )
 262                         );
 263                 }
 264
 265                 // Make a temp dir with a symlink to the local copy in it.
 266                 // This plays well with rsvg-convert policy for external entities.
 267                 // https://git.gnome.org/browse/librsvg/commit/?id=f01aded72c38f0e18bc7ff67dee800e380251c8e
 268                 $tmpDir = wfTempDir() . '/svg_' . wfRandomString( 24 );
 269                 $lnPath = "$tmpDir/" . basename( $srcPath );
 270                 $ok = mkdir( $tmpDir, 0771 );
 271                 if ( !$ok ) {
 272                         wfDebugLog( 'thumbnail',
 273                                 sprintf( 'Thumbnail failed on %s: could not create temporary directory %s',
 274                                         wfHostname(), $tmpDir ) );
 275                         return new MediaTransformError( 'thumbnail_error',
 276                                 $params['width'], $params['height'],
 277                                 wfMessage( 'thumbnail-temp-create' )->text()
 278                         );
 279                 }
 280                 $ok = symlink( $srcPath, $lnPath );
 281                 /** @noinspection PhpUnusedLocalVariableInspection */
 282                 $cleaner = new ScopedCallback( function () use ( $tmpDir, $lnPath ) {
 283                         Wikimedia\suppressWarnings();
 284                         unlink( $lnPath );
 285                         rmdir( $tmpDir );
 286                         Wikimedia\restoreWarnings();
 287                 } );
 288                 if ( !$ok ) {
 289                         wfDebugLog( 'thumbnail',
 290                                 sprintf( 'Thumbnail failed on %s: could not link %s to %s',
 291                                         wfHostname(), $lnPath, $srcPath ) );
 292                         return new MediaTransformError( 'thumbnail_error',
 293                                 $params['width'], $params['height'],
 294                                 wfMessage( 'thumbnail-temp-create' )
 295                         );
 296                 }
 297
 298                 $status = $this->rasterize( $lnPath, $dstPath, $physicalWidth, $physicalHeight, $lang );
 299                 if ( $status === true ) {
 300                         return new ThumbnailImage( $image, $dstUrl, $dstPath, $params );
 301                 } else {
 302                         return $status; // MediaTransformError
 303                 }
 304         }
 305
 306         /**
 307          * Transform an SVG file to PNG
 308          * This function can be called outside of thumbnail contexts
 309          * @param string $srcPath
 310          * @param string $dstPath
 311          * @param string $width
 312          * @param string $height
 313          * @param bool|string $lang Language code of the language to render the SVG in
 314          * @throws MWException
 315          * @return bool|MediaTransformError
 316          */
 317         public function rasterize( $srcPath, $dstPath, $width, $height, $lang = false ) {
 318                 global $wgSVGConverters, $wgSVGConverter, $wgSVGConverterPath;
 319                 $err = false;
 320                 $retval = '';
 321                 if ( isset( $wgSVGConverters[$wgSVGConverter] ) ) {
 322                         if ( is_array( $wgSVGConverters[$wgSVGConverter] ) ) {
 323                                 // This is a PHP callable
 324                                 $func = $wgSVGConverters[$wgSVGConverter][0];
 325                                 if ( !is_callable( $func ) ) {
 326                                         throw new MWException( "$func is not callable" );
 327                                 }
 328                                 $err = $func( $srcPath,
 329                                         $dstPath,
 330                                         $width,
 331                                         $height,
 332                                         $lang,
 333                                         ...array_slice( $wgSVGConverters[$wgSVGConverter], 1 )
 334                                 );
 335                                 $retval = (bool)$err;
 336                         } else {
 337                                 // External command
 338                                 $cmd = str_replace(
 339                                         [ '$path/', '$width', '$height', '$input', '$output' ],
 340                                         [ $wgSVGConverterPath ? Shell::escape( "$wgSVGConverterPath/" ) : "",
 341                                                 intval( $width ),
 342                                                 intval( $height ),
 343                                                 Shell::escape( $srcPath ),
 344                                                 Shell::escape( $dstPath ) ],
 345                                         $wgSVGConverters[$wgSVGConverter]
 346                                 );
 347
 348                                 $env = [];
 349                                 if ( $lang !== false ) {
 350                                         $env['LANG'] = $lang;
 351                                 }
 352
 353                                 wfDebug( __METHOD__ . ": $cmd\n" );
 354                                 $err = wfShellExecWithStderr( $cmd, $retval, $env );
 355                         }
 356                 }
 357                 $removed = $this->removeBadFile( $dstPath, $retval );
 358                 if ( $retval != 0 || $removed ) {
 359                         $this->logErrorForExternalProcess( $retval, $err, $cmd );
 360                         return new MediaTransformError( 'thumbnail_error', $width, $height, $err );
 361                 }
 362
 363                 return true;
 364         }
 365
 366         public static function rasterizeImagickExt( $srcPath, $dstPath, $width, $height ) {
 367                 $im = new Imagick( $srcPath );
 368                 $im->setImageFormat( 'png' );
 369                 $im->setBackgroundColor( 'transparent' );
 370                 $im->setImageDepth( 8 );
 371
 372                 if ( !$im->thumbnailImage( intval( $width ), intval( $height ), /* fit */ false ) ) {
 373                         return 'Could not resize image';
 374                 }
 375                 if ( !$im->writeImage( $dstPath ) ) {
 376                         return "Could not write to $dstPath";
 377                 }
 378         }
 379
 380         /**
 381          * @param File|FSFile $file
 382          * @param string $path Unused
 383          * @param bool|array $metadata
 384          * @return array
 385          */
 386         function getImageSize( $file, $path, $metadata = false ) {
 387                 if ( $metadata === false && $file instanceof File ) {
 388                         $metadata = $file->getMetadata();
 389                 }
 390                 $metadata = $this->unpackMetadata( $metadata );
 391
 392                 if ( isset( $metadata['width'] ) && isset( $metadata['height'] ) ) {
 393                         return [ $metadata['width'], $metadata['height'], 'SVG',
 394                                 "width=\"{$metadata['width']}\" height=\"{$metadata['height']}\"" ];
 395                 } else { // error
 396                         return [ 0, 0, 'SVG', "width=\"0\" height=\"0\"" ];
 397                 }
 398         }
 399
 400         public function getThumbType( $ext, $mime, $params = null ) {
 401                 return [ 'png', 'image/png' ];
 402         }
 403
 404         /**
 405          * Subtitle for the image. Different from the base
 406          * class so it can be denoted that SVG's have
 407          * a "nominal" resolution, and not a fixed one,
 408          * as well as so animation can be denoted.
 409          *
 410          * @param File $file
 411          * @return string
 412          */
 413         public function getLongDesc( $file ) {
 414                 global $wgLang;
 415
 416                 $metadata = $this->unpackMetadata( $file->getMetadata() );
 417                 if ( isset( $metadata['error'] ) ) {
 418                         return wfMessage( 'svg-long-error', $metadata['error']['message'] )->text();
 419                 }
 420
 421                 $size = $wgLang->formatSize( $file->getSize() );
 422
 423                 if ( $this->isAnimatedImage( $file ) ) {
 424                         $msg = wfMessage( 'svg-long-desc-animated' );
 425                 } else {
 426                         $msg = wfMessage( 'svg-long-desc' );
 427                 }
 428
 429                 $msg->numParams( $file->getWidth(), $file->getHeight() )->params( $size );
 430
 431                 return $msg->parse();
 432         }
 433
 434         /**
 435          * @param File|FSFile $file
 436          * @param string $filename
 437          * @return string Serialised metadata
 438          */
 439         public function getMetadata( $file, $filename ) {
 440                 $metadata = [ 'version' => self::SVG_METADATA_VERSION ];
 441                 try {
 442                         $metadata += SVGMetadataExtractor::getMetadata( $filename );
 443                 } catch ( Exception $e ) { // @todo SVG specific exceptions
 444                         // File not found, broken, etc.
 445                         $metadata['error'] = [
 446                                 'message' => $e->getMessage(),
 447                                 'code' => $e->getCode()
 448                         ];
 449                         wfDebug( __METHOD__ . ': ' . $e->getMessage() . "\n" );
 450                 }
 451
 452                 return serialize( $metadata );
 453         }
 454
 455         function unpackMetadata( $metadata ) {
 456                 Wikimedia\suppressWarnings();
 457                 $unser = unserialize( $metadata );
 458                 Wikimedia\restoreWarnings();
 459                 if ( isset( $unser['version'] ) && $unser['version'] == self::SVG_METADATA_VERSION ) {
 460                         return $unser;
 461                 } else {
 462                         return false;
 463                 }
 464         }
 465
 466         function getMetadataType( $image ) {
 467                 return 'parsed-svg';
 468         }
 469
 470         public function isMetadataValid( $image, $metadata ) {
 471                 $meta = $this->unpackMetadata( $metadata );
 472                 if ( $meta === false ) {
 473                         return self::METADATA_BAD;
 474                 }
 475                 if ( !isset( $meta['originalWidth'] ) ) {
 476                         // Old but compatible
 477                         return self::METADATA_COMPATIBLE;
 478                 }
 479
 480                 return self::METADATA_GOOD;
 481         }
 482
 483         protected function visibleMetadataFields() {
 484                 $fields = [ 'objectname', 'imagedescription' ];
 485
 486                 return $fields;
 487         }
 488
 489         /**
 490          * @param File $file
 491          * @param bool|IContextSource $context Context to use (optional)
 492          * @return array|bool
 493          */
 494         public function formatMetadata( $file, $context = false ) {
 495                 $result = [
 496                         'visible' => [],
 497                         'collapsed' => []
 498                 ];
 499                 $metadata = $file->getMetadata();
 500                 if ( !$metadata ) {
 501                         return false;
 502                 }
 503                 $metadata = $this->unpackMetadata( $metadata );
 504                 if ( !$metadata || isset( $metadata['error'] ) ) {
 505                         return false;
 506                 }
 507
 508                 /* @todo Add a formatter
 509                 $format = new FormatSVG( $metadata );
 510                 $formatted = $format->getFormattedData();
 511                 */
 512
 513                 // Sort fields into visible and collapsed
 514                 $visibleFields = $this->visibleMetadataFields();
 515
 516                 $showMeta = false;
 517                 foreach ( $metadata as $name => $value ) {
 518                         $tag = strtolower( $name );
 519                         if ( isset( self::$metaConversion[$tag] ) ) {
 520                                 $tag = strtolower( self::$metaConversion[$tag] );
 521                         } else {
 522                                 // Do not output other metadata not in list
 523                                 continue;
 524                         }
 525                         $showMeta = true;
 526                         self::addMeta( $result,
 527                                 in_array( $tag, $visibleFields ) ? 'visible' : 'collapsed',
 528                                 'exif',
 529                                 $tag,
 530                                 $value
 531                         );
 532                 }
 533
 534                 return $showMeta ? $result : false;
 535         }
 536
 537         /**
 538          * @param string $name Parameter name
 539          * @param mixed $value Parameter value
 540          * @return bool Validity
 541          */
 542         public function validateParam( $name, $value ) {
 543                 if ( in_array( $name, [ 'width', 'height' ] ) ) {
 544                         // Reject negative heights, widths
 545                         return ( $value > 0 );
 546                 } elseif ( $name == 'lang' ) {
 547                         // Validate $code
 548                         if ( $value === '' || !Language::isValidCode( $value ) ) {
 549                                 return false;
 550                         }
 551
 552                         return true;
 553                 }
 554
 555                 // Only lang, width and height are acceptable keys
 556                 return false;
 557         }
 558
 559         /**
 560          * @param array $params Name=>value pairs of parameters
 561          * @return string Filename to use
 562          */
 563         public function makeParamString( $params ) {
 564                 $lang = '';
 565                 $code = $this->getLanguageFromParams( $params );
 566                 if ( $code !== 'en' ) {
 567                         $lang = 'lang' . strtolower( $code ) . '-';
 568                 }
 569                 if ( !isset( $params['width'] ) ) {
 570                         return false;
 571                 }
 572
 573                 return "$lang{$params['width']}px";
 574         }
 575
 576         public function parseParamString( $str ) {
 577                 $m = false;
 578                 if ( preg_match( '/^lang([a-z]+(?:-[a-z]+)*)-(\d+)px$/i', $str, $m ) ) {
 579                         return [ 'width' => array_pop( $m ), 'lang' => $m[1] ];
 580                 } elseif ( preg_match( '/^(\d+)px$/', $str, $m ) ) {
 581                         return [ 'width' => $m[1], 'lang' => 'en' ];
 582                 } else {
 583                         return false;
 584                 }
 585         }
 586
 587         public function getParamMap() {
 588                 return [ 'img_lang' => 'lang', 'img_width' => 'width' ];
 589         }
 590
 591         /**
 592          * @param array $params
 593          * @return array
 594          */
 595         protected function getScriptParams( $params ) {
 596                 $scriptParams = [ 'width' => $params['width'] ];
 597                 if ( isset( $params['lang'] ) ) {
 598                         $scriptParams['lang'] = $params['lang'];
 599                 }
 600
 601                 return $scriptParams;
 602         }
 603
 604         public function getCommonMetaArray( File $file ) {
 605                 $metadata = $file->getMetadata();
 606                 if ( !$metadata ) {
 607                         return [];
 608                 }
 609                 $metadata = $this->unpackMetadata( $metadata );
 610                 if ( !$metadata || isset( $metadata['error'] ) ) {
 611                         return [];
 612                 }
 613                 $stdMetadata = [];
 614                 foreach ( $metadata as $name => $value ) {
 615                         $tag = strtolower( $name );
 616                         if ( $tag === 'originalwidth' || $tag === 'originalheight' ) {
 617                                 // Skip these. In the exif metadata stuff, it is assumed these
 618                                 // are measured in px, which is not the case here.
 619                                 continue;
 620                         }
 621                         if ( isset( self::$metaConversion[$tag] ) ) {
 622                                 $tag = self::$metaConversion[$tag];
 623                                 $stdMetadata[$tag] = $value;
 624                         }
 625                 }
 626
 627                 return $stdMetadata;
 628         }
 629 }