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 use Wikimedia\ScopedCallback;
  24
  25 /**
  26  * Handler for SVG images.
  27  *
  28  * @ingroup Media
  29  */
  30 class SvgHandler extends ImageHandler {
  31         const SVG_METADATA_VERSION = 2;
  32
  33         /** @var array A list of metadata tags that can be converted
  34          *  to the commonly used exif tags. This allows messages
  35          *  to be reused, and consistent tag names for {{#formatmetadata:..}}
  36          */
  37         private static $metaConversion = [
  38                 'originalwidth' => 'ImageWidth',
  39                 'originalheight' => 'ImageLength',
  40                 'description' => 'ImageDescription',
  41                 'title' => 'ObjectName',
  42         ];
  43
  44         function isEnabled() {
  45                 global $wgSVGConverters, $wgSVGConverter;
  46                 if ( !isset( $wgSVGConverters[$wgSVGConverter] ) ) {
  47                         wfDebug( "\$wgSVGConverter is invalid, disabling SVG rendering.\n" );
  48
  49                         return false;
  50                 } else {
  51                         return true;
  52                 }
  53         }
  54
  55         public function mustRender( $file ) {
  56                 return true;
  57         }
  58
  59         function isVectorized( $file ) {
  60                 return true;
  61         }
  62
  63         /**
  64          * @param File $file
  65          * @return bool
  66          */
  67         function isAnimatedImage( $file ) {
  68                 # @todo Detect animated SVGs
  69                 $metadata = $file->getMetadata();
  70                 if ( $metadata ) {
  71                         $metadata = $this->unpackMetadata( $metadata );
  72                         if ( isset( $metadata['animated'] ) ) {
  73                                 return $metadata['animated'];
  74                         }
  75                 }
  76
  77                 return false;
  78         }
  79
  80         /**
  81          * Which languages (systemLanguage attribute) is supported.
  82          *
  83          * @note This list is not guaranteed to be exhaustive.
  84          * To avoid OOM errors, we only look at first bit of a file.
  85          * Thus all languages on this list are present in the file,
  86          * but its possible for the file to have a language not on
  87          * this list.
  88          *
  89          * @param File $file
  90          * @return array Array of language codes, or empty if no language switching supported.
  91          */
  92         public function getAvailableLanguages( File $file ) {
  93                 $metadata = $file->getMetadata();
  94                 $langList = [];
  95                 if ( $metadata ) {
  96                         $metadata = $this->unpackMetadata( $metadata );
  97                         if ( isset( $metadata['translations'] ) ) {
  98                                 foreach ( $metadata['translations'] as $lang => $langType ) {
  99                                         if ( $langType === SVGReader::LANG_FULL_MATCH ) {
 100                                                 $langList[] = strtolower( $lang );
 101                                         }
 102                                 }
 103                         }
 104                 }
 105                 return array_unique( $langList );
 106         }
 107
 108         /**
 109          * SVG's systemLanguage matching rules state:
 110          * 'The `systemLanguage` attribute ... [e]valuates to "true" if one of the languages indicated
 111          * by user preferences exactly equals one of the languages given in the value of this parameter,
 112          * or if one of the languages indicated by user preferences exactly equals a prefix of one of
 113          * the languages given in the value of this parameter such that the first tag character
 114          * following the prefix is "-".'
 115          *
 116          * Return the first element of $svgLanguages that matches $userPreferredLanguage
 117          *
 118          * @see https://www.w3.org/TR/SVG/struct.html#SystemLanguageAttribute
 119          * @param string $userPreferredLanguage
 120          * @param array $svgLanguages
 121          * @return string|null
 122          */
 123         public function getMatchedLanguage( $userPreferredLanguage, array $svgLanguages ) {
 124                 foreach ( $svgLanguages as $svgLang ) {
 125                         if ( strcasecmp( $svgLang, $userPreferredLanguage ) === 0 ) {
 126                                 return $svgLang;
 127                         }
 128                         $trimmedSvgLang = $svgLang;
 129                         while ( strpos( $trimmedSvgLang, '-' ) !== false ) {
 130                                 $trimmedSvgLang = substr( $trimmedSvgLang, 0, strrpos( $trimmedSvgLang, '-' ) );
 131                                 if ( strcasecmp( $trimmedSvgLang, $userPreferredLanguage ) === 0 ) {
 132                                         return $svgLang;
 133                                 }
 134                         }
 135                 }
 136                 return null;
 137         }
 138
 139         /**
 140          * Determines render language from image parameters
 141          *
 142          * @param array $params
 143          * @return string
 144          */
 145         protected function getLanguageFromParams( array $params ) {
 146                 return $params['lang'] ?? $params['targetlang'] ?? 'en';
 147         }
 148
 149         /**
 150          * What language to render file in if none selected
 151          *
 152          * @param File $file Language code
 153          * @return string
 154          */
 155         public function getDefaultRenderLanguage( File $file ) {
 156                 return 'en';
 157         }
 158
 159         /**
 160          * We do not support making animated svg thumbnails
 161          * @param File $file
 162          * @return bool
 163          */
 164         function canAnimateThumbnail( $file ) {
 165                 return false;
 166         }
 167
 168         /**
 169          * @param File $image
 170          * @param array &$params
 171          * @return bool
 172          */
 173         public function normaliseParams( $image, &$params ) {
 174                 if ( parent::normaliseParams( $image, $params ) ) {
 175                         $params = $this->normaliseParamsInternal( $image, $params );
 176                         return true;
 177                 }
 178
 179                 return false;
 180         }
 181
 182         /**
 183          * Code taken out of normaliseParams() for testability
 184          *
 185          * @since 1.33
 186          *
 187          * @param File $image
 188          * @param array $params
 189          * @return array Modified $params
 190          */
 191         protected function normaliseParamsInternal( $image, $params ) {
 192                 global $wgSVGMaxSize;
 193
 194                 # Don't make an image bigger than wgMaxSVGSize on the smaller side
 195                 if ( $params['physicalWidth'] <= $params['physicalHeight'] ) {
 196                         if ( $params['physicalWidth'] > $wgSVGMaxSize ) {
 197                                 $srcWidth = $image->getWidth( $params['page'] );
 198                                 $srcHeight = $image->getHeight( $params['page'] );
 199                                 $params['physicalWidth'] = $wgSVGMaxSize;
 200                                 $params['physicalHeight'] = File::scaleHeight( $srcWidth, $srcHeight, $wgSVGMaxSize );
 201                         }
 202                 } else {
 203                         if ( $params['physicalHeight'] > $wgSVGMaxSize ) {
 204                                 $srcWidth = $image->getWidth( $params['page'] );
 205                                 $srcHeight = $image->getHeight( $params['page'] );
 206                                 $params['physicalWidth'] = File::scaleHeight( $srcHeight, $srcWidth, $wgSVGMaxSize );
 207                                 $params['physicalHeight'] = $wgSVGMaxSize;
 208                         }
 209                 }
 210                 // To prevent the proliferation of thumbnails in languages not present in SVGs, unless
 211                 // explicitly forced by user.
 212                 if ( isset( $params['targetlang'] ) ) {
 213                         if ( !$image->getMatchedLanguage( $params['targetlang'] ) ) {
 214                                 unset( $params['targetlang'] );
 215                         }
 216                 }
 217
 218                 return $params;
 219         }
 220
 221         /**
 222          * @param File $image
 223          * @param string $dstPath
 224          * @param string $dstUrl
 225          * @param array $params
 226          * @param int $flags
 227          * @return bool|MediaTransformError|ThumbnailImage|TransformParameterError
 228          */
 229         function doTransform( $image, $dstPath, $dstUrl, $params, $flags = 0 ) {
 230                 if ( !$this->normaliseParams( $image, $params ) ) {
 231                         return new TransformParameterError( $params );
 232                 }
 233                 $clientWidth = $params['width'];
 234                 $clientHeight = $params['height'];
 235                 $physicalWidth = $params['physicalWidth'];
 236                 $physicalHeight = $params['physicalHeight'];
 237                 $lang = $this->getLanguageFromParams( $params );
 238
 239                 if ( $flags & self::TRANSFORM_LATER ) {
 240                         return new ThumbnailImage( $image, $dstUrl, $dstPath, $params );
 241                 }
 242
 243                 $metadata = $this->unpackMetadata( $image->getMetadata() );
 244                 if ( isset( $metadata['error'] ) ) { // sanity check
 245                         $err = wfMessage( 'svg-long-error', $metadata['error']['message'] );
 246
 247                         return new MediaTransformError( 'thumbnail_error', $clientWidth, $clientHeight, $err );
 248                 }
 249
 250                 if ( !wfMkdirParents( dirname( $dstPath ), null, __METHOD__ ) ) {
 251                         return new MediaTransformError( 'thumbnail_error', $clientWidth, $clientHeight,
 252                                 wfMessage( 'thumbnail_dest_directory' ) );
 253                 }
 254
 255                 $srcPath = $image->getLocalRefPath();
 256                 if ( $srcPath === false ) { // Failed to get local copy
 257                         wfDebugLog( 'thumbnail',
 258                                 sprintf( 'Thumbnail failed on %s: could not get local copy of "%s"',
 259                                         wfHostname(), $image->getName() ) );
 260
 261                         return new MediaTransformError( 'thumbnail_error',
 262                                 $params['width'], $params['height'],
 263                                 wfMessage( 'filemissing' )
 264                         );
 265                 }
 266
 267                 // Make a temp dir with a symlink to the local copy in it.
 268                 // This plays well with rsvg-convert policy for external entities.
 269                 // https://git.gnome.org/browse/librsvg/commit/?id=f01aded72c38f0e18bc7ff67dee800e380251c8e
 270                 $tmpDir = wfTempDir() . '/svg_' . wfRandomString( 24 );
 271                 $lnPath = "$tmpDir/" . basename( $srcPath );
 272                 $ok = mkdir( $tmpDir, 0771 );
 273                 if ( !$ok ) {
 274                         wfDebugLog( 'thumbnail',
 275                                 sprintf( 'Thumbnail failed on %s: could not create temporary directory %s',
 276                                         wfHostname(), $tmpDir ) );
 277                         return new MediaTransformError( 'thumbnail_error',
 278                                 $params['width'], $params['height'],
 279                                 wfMessage( 'thumbnail-temp-create' )->text()
 280                         );
 281                 }
 282                 $ok = symlink( $srcPath, $lnPath );
 283                 /** @noinspection PhpUnusedLocalVariableInspection */
 284                 $cleaner = new ScopedCallback( function () use ( $tmpDir, $lnPath ) {
 285                         Wikimedia\suppressWarnings();
 286                         unlink( $lnPath );
 287                         rmdir( $tmpDir );
 288                         Wikimedia\restoreWarnings();
 289                 } );
 290                 if ( !$ok ) {
 291                         wfDebugLog( 'thumbnail',
 292                                 sprintf( 'Thumbnail failed on %s: could not link %s to %s',
 293                                         wfHostname(), $lnPath, $srcPath ) );
 294                         return new MediaTransformError( 'thumbnail_error',
 295                                 $params['width'], $params['height'],
 296                                 wfMessage( 'thumbnail-temp-create' )
 297                         );
 298                 }
 299
 300                 $status = $this->rasterize( $lnPath, $dstPath, $physicalWidth, $physicalHeight, $lang );
 301                 if ( $status === true ) {
 302                         return new ThumbnailImage( $image, $dstUrl, $dstPath, $params );
 303                 } else {
 304                         return $status; // MediaTransformError
 305                 }
 306         }
 307
 308         /**
 309          * Transform an SVG file to PNG
 310          * This function can be called outside of thumbnail contexts
 311          * @param string $srcPath
 312          * @param string $dstPath
 313          * @param string $width
 314          * @param string $height
 315          * @param bool|string $lang Language code of the language to render the SVG in
 316          * @throws MWException
 317          * @return bool|MediaTransformError
 318          */
 319         public function rasterize( $srcPath, $dstPath, $width, $height, $lang = false ) {
 320                 global $wgSVGConverters, $wgSVGConverter, $wgSVGConverterPath;
 321                 $err = false;
 322                 $retval = '';
 323                 if ( isset( $wgSVGConverters[$wgSVGConverter] ) ) {
 324                         if ( is_array( $wgSVGConverters[$wgSVGConverter] ) ) {
 325                                 // This is a PHP callable
 326                                 $func = $wgSVGConverters[$wgSVGConverter][0];
 327                                 if ( !is_callable( $func ) ) {
 328                                         throw new MWException( "$func is not callable" );
 329                                 }
 330                                 $err = $func( $srcPath,
 331                                         $dstPath,
 332                                         $width,
 333                                         $height,
 334                                         $lang,
 335                                         ...array_slice( $wgSVGConverters[$wgSVGConverter], 1 )
 336                                 );
 337                                 $retval = (bool)$err;
 338                         } else {
 339                                 // External command
 340                                 $cmd = str_replace(
 341                                         [ '$path/', '$width', '$height', '$input', '$output' ],
 342                                         [ $wgSVGConverterPath ? wfEscapeShellArg( "$wgSVGConverterPath/" ) : "",
 343                                                 intval( $width ),
 344                                                 intval( $height ),
 345                                                 wfEscapeShellArg( $srcPath ),
 346                                                 wfEscapeShellArg( $dstPath ) ],
 347                                         $wgSVGConverters[$wgSVGConverter]
 348                                 );
 349
 350                                 $env = [];
 351                                 if ( $lang !== false ) {
 352                                         $env['LANG'] = $lang;
 353                                 }
 354
 355                                 wfDebug( __METHOD__ . ": $cmd\n" );
 356                                 $err = wfShellExecWithStderr( $cmd, $retval, $env );
 357                         }
 358                 }
 359                 $removed = $this->removeBadFile( $dstPath, $retval );
 360                 if ( $retval != 0 || $removed ) {
 361                         $this->logErrorForExternalProcess( $retval, $err, $cmd );
 362                         return new MediaTransformError( 'thumbnail_error', $width, $height, $err );
 363                 }
 364
 365                 return true;
 366         }
 367
 368         public static function rasterizeImagickExt( $srcPath, $dstPath, $width, $height ) {
 369                 $im = new Imagick( $srcPath );
 370                 $im->setImageFormat( 'png' );
 371                 $im->setBackgroundColor( 'transparent' );
 372                 $im->setImageDepth( 8 );
 373
 374                 if ( !$im->thumbnailImage( intval( $width ), intval( $height ), /* fit */ false ) ) {
 375                         return 'Could not resize image';
 376                 }
 377                 if ( !$im->writeImage( $dstPath ) ) {
 378                         return "Could not write to $dstPath";
 379                 }
 380         }
 381
 382         /**
 383          * @param File|FSFile $file
 384          * @param string $path Unused
 385          * @param bool|array $metadata
 386          * @return array
 387          */
 388         function getImageSize( $file, $path, $metadata = false ) {
 389                 if ( $metadata === false && $file instanceof File ) {
 390                         $metadata = $file->getMetadata();
 391                 }
 392                 $metadata = $this->unpackMetadata( $metadata );
 393
 394                 if ( isset( $metadata['width'] ) && isset( $metadata['height'] ) ) {
 395                         return [ $metadata['width'], $metadata['height'], 'SVG',
 396                                 "width=\"{$metadata['width']}\" height=\"{$metadata['height']}\"" ];
 397                 } else { // error
 398                         return [ 0, 0, 'SVG', "width=\"0\" height=\"0\"" ];
 399                 }
 400         }
 401
 402         function getThumbType( $ext, $mime, $params = null ) {
 403                 return [ 'png', 'image/png' ];
 404         }
 405
 406         /**
 407          * Subtitle for the image. Different from the base
 408          * class so it can be denoted that SVG's have
 409          * a "nominal" resolution, and not a fixed one,
 410          * as well as so animation can be denoted.
 411          *
 412          * @param File $file
 413          * @return string
 414          */
 415         function getLongDesc( $file ) {
 416                 global $wgLang;
 417
 418                 $metadata = $this->unpackMetadata( $file->getMetadata() );
 419                 if ( isset( $metadata['error'] ) ) {
 420                         return wfMessage( 'svg-long-error', $metadata['error']['message'] )->text();
 421                 }
 422
 423                 $size = $wgLang->formatSize( $file->getSize() );
 424
 425                 if ( $this->isAnimatedImage( $file ) ) {
 426                         $msg = wfMessage( 'svg-long-desc-animated' );
 427                 } else {
 428                         $msg = wfMessage( 'svg-long-desc' );
 429                 }
 430
 431                 $msg->numParams( $file->getWidth(), $file->getHeight() )->params( $size );
 432
 433                 return $msg->parse();
 434         }
 435
 436         /**
 437          * @param File|FSFile $file
 438          * @param string $filename
 439          * @return string Serialised metadata
 440          */
 441         function getMetadata( $file, $filename ) {
 442                 $metadata = [ 'version' => self::SVG_METADATA_VERSION ];
 443                 try {
 444                         $metadata += SVGMetadataExtractor::getMetadata( $filename );
 445                 } catch ( Exception $e ) { // @todo SVG specific exceptions
 446                         // File not found, broken, etc.
 447                         $metadata['error'] = [
 448                                 'message' => $e->getMessage(),
 449                                 'code' => $e->getCode()
 450                         ];
 451                         wfDebug( __METHOD__ . ': ' . $e->getMessage() . "\n" );
 452                 }
 453
 454                 return serialize( $metadata );
 455         }
 456
 457         function unpackMetadata( $metadata ) {
 458                 Wikimedia\suppressWarnings();
 459                 $unser = unserialize( $metadata );
 460                 Wikimedia\restoreWarnings();
 461                 if ( isset( $unser['version'] ) && $unser['version'] == self::SVG_METADATA_VERSION ) {
 462                         return $unser;
 463                 } else {
 464                         return false;
 465                 }
 466         }
 467
 468         function getMetadataType( $image ) {
 469                 return 'parsed-svg';
 470         }
 471
 472         function isMetadataValid( $image, $metadata ) {
 473                 $meta = $this->unpackMetadata( $metadata );
 474                 if ( $meta === false ) {
 475                         return self::METADATA_BAD;
 476                 }
 477                 if ( !isset( $meta['originalWidth'] ) ) {
 478                         // Old but compatible
 479                         return self::METADATA_COMPATIBLE;
 480                 }
 481
 482                 return self::METADATA_GOOD;
 483         }
 484
 485         protected function visibleMetadataFields() {
 486                 $fields = [ 'objectname', 'imagedescription' ];
 487
 488                 return $fields;
 489         }
 490
 491         /**
 492          * @param File $file
 493          * @param bool|IContextSource $context Context to use (optional)
 494          * @return array|bool
 495          */
 496         function formatMetadata( $file, $context = false ) {
 497                 $result = [
 498                         'visible' => [],
 499                         'collapsed' => []
 500                 ];
 501                 $metadata = $file->getMetadata();
 502                 if ( !$metadata ) {
 503                         return false;
 504                 }
 505                 $metadata = $this->unpackMetadata( $metadata );
 506                 if ( !$metadata || isset( $metadata['error'] ) ) {
 507                         return false;
 508                 }
 509
 510                 /* @todo Add a formatter
 511                 $format = new FormatSVG( $metadata );
 512                 $formatted = $format->getFormattedData();
 513                 */
 514
 515                 // Sort fields into visible and collapsed
 516                 $visibleFields = $this->visibleMetadataFields();
 517
 518                 $showMeta = false;
 519                 foreach ( $metadata as $name => $value ) {
 520                         $tag = strtolower( $name );
 521                         if ( isset( self::$metaConversion[$tag] ) ) {
 522                                 $tag = strtolower( self::$metaConversion[$tag] );
 523                         } else {
 524                                 // Do not output other metadata not in list
 525                                 continue;
 526                         }
 527                         $showMeta = true;
 528                         self::addMeta( $result,
 529                                 in_array( $tag, $visibleFields ) ? 'visible' : 'collapsed',
 530                                 'exif',
 531                                 $tag,
 532                                 $value
 533                         );
 534                 }
 535
 536                 return $showMeta ? $result : false;
 537         }
 538
 539         /**
 540          * @param string $name Parameter name
 541          * @param mixed $value Parameter value
 542          * @return bool Validity
 543          */
 544         public function validateParam( $name, $value ) {
 545                 if ( in_array( $name, [ 'width', 'height' ] ) ) {
 546                         // Reject negative heights, widths
 547                         return ( $value > 0 );
 548                 } elseif ( $name == 'lang' ) {
 549                         // Validate $code
 550                         if ( $value === '' || !Language::isValidCode( $value ) ) {
 551                                 return false;
 552                         }
 553
 554                         return true;
 555                 }
 556
 557                 // Only lang, width and height are acceptable keys
 558                 return false;
 559         }
 560
 561         /**
 562          * @param array $params Name=>value pairs of parameters
 563          * @return string Filename to use
 564          */
 565         public function makeParamString( $params ) {
 566                 $lang = '';
 567                 $code = $this->getLanguageFromParams( $params );
 568                 if ( $code !== 'en' ) {
 569                         $lang = 'lang' . strtolower( $code ) . '-';
 570                 }
 571                 if ( !isset( $params['width'] ) ) {
 572                         return false;
 573                 }
 574
 575                 return "$lang{$params['width']}px";
 576         }
 577
 578         public function parseParamString( $str ) {
 579                 $m = false;
 580                 if ( preg_match( '/^lang([a-z]+(?:-[a-z]+)*)-(\d+)px$/i', $str, $m ) ) {
 581                         return [ 'width' => array_pop( $m ), 'lang' => $m[1] ];
 582                 } elseif ( preg_match( '/^(\d+)px$/', $str, $m ) ) {
 583                         return [ 'width' => $m[1], 'lang' => 'en' ];
 584                 } else {
 585                         return false;
 586                 }
 587         }
 588
 589         public function getParamMap() {
 590                 return [ 'img_lang' => 'lang', 'img_width' => 'width' ];
 591         }
 592
 593         /**
 594          * @param array $params
 595          * @return array
 596          */
 597         function getScriptParams( $params ) {
 598                 $scriptParams = [ 'width' => $params['width'] ];
 599                 if ( isset( $params['lang'] ) ) {
 600                         $scriptParams['lang'] = $params['lang'];
 601                 }
 602
 603                 return $scriptParams;
 604         }
 605
 606         public function getCommonMetaArray( File $file ) {
 607                 $metadata = $file->getMetadata();
 608                 if ( !$metadata ) {
 609                         return [];
 610                 }
 611                 $metadata = $this->unpackMetadata( $metadata );
 612                 if ( !$metadata || isset( $metadata['error'] ) ) {
 613                         return [];
 614                 }
 615                 $stdMetadata = [];
 616                 foreach ( $metadata as $name => $value ) {
 617                         $tag = strtolower( $name );
 618                         if ( $tag === 'originalwidth' || $tag === 'originalheight' ) {
 619                                 // Skip these. In the exif metadata stuff, it is assumed these
 620                                 // are measured in px, which is not the case here.
 621                                 continue;
 622                         }
 623                         if ( isset( self::$metaConversion[$tag] ) ) {
 624                                 $tag = self::$metaConversion[$tag];
 625                                 $stdMetadata[$tag] = $value;
 626                         }
 627                 }
 628
 629                 return $stdMetadata;
 630         }
 631 }