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         public 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                 } elseif ( $params['physicalHeight'] > $wgSVGMaxSize ) {
 203                         $srcWidth = $image->getWidth( $params['page'] );
 204                         $srcHeight = $image->getHeight( $params['page'] );
 205                         $params['physicalWidth'] = File::scaleHeight( $srcHeight, $srcWidth, $wgSVGMaxSize );
 206                         $params['physicalHeight'] = $wgSVGMaxSize;
 207                 }
 208                 // To prevent the proliferation of thumbnails in languages not present in SVGs, unless
 209                 // explicitly forced by user.
 210                 if ( isset( $params['targetlang'] ) && !$image->getMatchedLanguage( $params['targetlang'] ) ) {
 211                         unset( $params['targetlang'] );
 212                 }
 213
 214                 return $params;
 215         }
 216
 217         /**
 218          * @param File $image
 219          * @param string $dstPath
 220          * @param string $dstUrl
 221          * @param array $params
 222          * @param int $flags
 223          * @return bool|MediaTransformError|ThumbnailImage|TransformParameterError
 224          */
 225         function doTransform( $image, $dstPath, $dstUrl, $params, $flags = 0 ) {
 226                 if ( !$this->normaliseParams( $image, $params ) ) {
 227                         return new TransformParameterError( $params );
 228                 }
 229                 $clientWidth = $params['width'];
 230                 $clientHeight = $params['height'];
 231                 $physicalWidth = $params['physicalWidth'];
 232                 $physicalHeight = $params['physicalHeight'];
 233                 $lang = $this->getLanguageFromParams( $params );
 234
 235                 if ( $flags & self::TRANSFORM_LATER ) {
 236                         return new ThumbnailImage( $image, $dstUrl, $dstPath, $params );
 237                 }
 238
 239                 $metadata = $this->unpackMetadata( $image->getMetadata() );
 240                 if ( isset( $metadata['error'] ) ) { // sanity check
 241                         $err = wfMessage( 'svg-long-error', $metadata['error']['message'] );
 242
 243                         return new MediaTransformError( 'thumbnail_error', $clientWidth, $clientHeight, $err );
 244                 }
 245
 246                 if ( !wfMkdirParents( dirname( $dstPath ), null, __METHOD__ ) ) {
 247                         return new MediaTransformError( 'thumbnail_error', $clientWidth, $clientHeight,
 248                                 wfMessage( 'thumbnail_dest_directory' ) );
 249                 }
 250
 251                 $srcPath = $image->getLocalRefPath();
 252                 if ( $srcPath === false ) { // Failed to get local copy
 253                         wfDebugLog( 'thumbnail',
 254                                 sprintf( 'Thumbnail failed on %s: could not get local copy of "%s"',
 255                                         wfHostname(), $image->getName() ) );
 256
 257                         return new MediaTransformError( 'thumbnail_error',
 258                                 $params['width'], $params['height'],
 259                                 wfMessage( 'filemissing' )
 260                         );
 261                 }
 262
 263                 // Make a temp dir with a symlink to the local copy in it.
 264                 // This plays well with rsvg-convert policy for external entities.
 265                 // https://git.gnome.org/browse/librsvg/commit/?id=f01aded72c38f0e18bc7ff67dee800e380251c8e
 266                 $tmpDir = wfTempDir() . '/svg_' . wfRandomString( 24 );
 267                 $lnPath = "$tmpDir/" . basename( $srcPath );
 268                 $ok = mkdir( $tmpDir, 0771 );
 269                 if ( !$ok ) {
 270                         wfDebugLog( 'thumbnail',
 271                                 sprintf( 'Thumbnail failed on %s: could not create temporary directory %s',
 272                                         wfHostname(), $tmpDir ) );
 273                         return new MediaTransformError( 'thumbnail_error',
 274                                 $params['width'], $params['height'],
 275                                 wfMessage( 'thumbnail-temp-create' )->text()
 276                         );
 277                 }
 278                 $ok = symlink( $srcPath, $lnPath );
 279                 /** @noinspection PhpUnusedLocalVariableInspection */
 280                 $cleaner = new ScopedCallback( function () use ( $tmpDir, $lnPath ) {
 281                         Wikimedia\suppressWarnings();
 282                         unlink( $lnPath );
 283                         rmdir( $tmpDir );
 284                         Wikimedia\restoreWarnings();
 285                 } );
 286                 if ( !$ok ) {
 287                         wfDebugLog( 'thumbnail',
 288                                 sprintf( 'Thumbnail failed on %s: could not link %s to %s',
 289                                         wfHostname(), $lnPath, $srcPath ) );
 290                         return new MediaTransformError( 'thumbnail_error',
 291                                 $params['width'], $params['height'],
 292                                 wfMessage( 'thumbnail-temp-create' )
 293                         );
 294                 }
 295
 296                 $status = $this->rasterize( $lnPath, $dstPath, $physicalWidth, $physicalHeight, $lang );
 297                 if ( $status === true ) {
 298                         return new ThumbnailImage( $image, $dstUrl, $dstPath, $params );
 299                 } else {
 300                         return $status; // MediaTransformError
 301                 }
 302         }
 303
 304         /**
 305          * Transform an SVG file to PNG
 306          * This function can be called outside of thumbnail contexts
 307          * @param string $srcPath
 308          * @param string $dstPath
 309          * @param string $width
 310          * @param string $height
 311          * @param bool|string $lang Language code of the language to render the SVG in
 312          * @throws MWException
 313          * @return bool|MediaTransformError
 314          */
 315         public function rasterize( $srcPath, $dstPath, $width, $height, $lang = false ) {
 316                 global $wgSVGConverters, $wgSVGConverter, $wgSVGConverterPath;
 317                 $err = false;
 318                 $retval = '';
 319                 if ( isset( $wgSVGConverters[$wgSVGConverter] ) ) {
 320                         if ( is_array( $wgSVGConverters[$wgSVGConverter] ) ) {
 321                                 // This is a PHP callable
 322                                 $func = $wgSVGConverters[$wgSVGConverter][0];
 323                                 if ( !is_callable( $func ) ) {
 324                                         throw new MWException( "$func is not callable" );
 325                                 }
 326                                 $err = $func( $srcPath,
 327                                         $dstPath,
 328                                         $width,
 329                                         $height,
 330                                         $lang,
 331                                         ...array_slice( $wgSVGConverters[$wgSVGConverter], 1 )
 332                                 );
 333                                 $retval = (bool)$err;
 334                         } else {
 335                                 // External command
 336                                 $cmd = str_replace(
 337                                         [ '$path/', '$width', '$height', '$input', '$output' ],
 338                                         [ $wgSVGConverterPath ? wfEscapeShellArg( "$wgSVGConverterPath/" ) : "",
 339                                                 intval( $width ),
 340                                                 intval( $height ),
 341                                                 wfEscapeShellArg( $srcPath ),
 342                                                 wfEscapeShellArg( $dstPath ) ],
 343                                         $wgSVGConverters[$wgSVGConverter]
 344                                 );
 345
 346                                 $env = [];
 347                                 if ( $lang !== false ) {
 348                                         $env['LANG'] = $lang;
 349                                 }
 350
 351                                 wfDebug( __METHOD__ . ": $cmd\n" );
 352                                 $err = wfShellExecWithStderr( $cmd, $retval, $env );
 353                         }
 354                 }
 355                 $removed = $this->removeBadFile( $dstPath, $retval );
 356                 if ( $retval != 0 || $removed ) {
 357                         $this->logErrorForExternalProcess( $retval, $err, $cmd );
 358                         return new MediaTransformError( 'thumbnail_error', $width, $height, $err );
 359                 }
 360
 361                 return true;
 362         }
 363
 364         public static function rasterizeImagickExt( $srcPath, $dstPath, $width, $height ) {
 365                 $im = new Imagick( $srcPath );
 366                 $im->setImageFormat( 'png' );
 367                 $im->setBackgroundColor( 'transparent' );
 368                 $im->setImageDepth( 8 );
 369
 370                 if ( !$im->thumbnailImage( intval( $width ), intval( $height ), /* fit */ false ) ) {
 371                         return 'Could not resize image';
 372                 }
 373                 if ( !$im->writeImage( $dstPath ) ) {
 374                         return "Could not write to $dstPath";
 375                 }
 376         }
 377
 378         /**
 379          * @param File|FSFile $file
 380          * @param string $path Unused
 381          * @param bool|array $metadata
 382          * @return array
 383          */
 384         function getImageSize( $file, $path, $metadata = false ) {
 385                 if ( $metadata === false && $file instanceof File ) {
 386                         $metadata = $file->getMetadata();
 387                 }
 388                 $metadata = $this->unpackMetadata( $metadata );
 389
 390                 if ( isset( $metadata['width'] ) && isset( $metadata['height'] ) ) {
 391                         return [ $metadata['width'], $metadata['height'], 'SVG',
 392                                 "width=\"{$metadata['width']}\" height=\"{$metadata['height']}\"" ];
 393                 } else { // error
 394                         return [ 0, 0, 'SVG', "width=\"0\" height=\"0\"" ];
 395                 }
 396         }
 397
 398         public function getThumbType( $ext, $mime, $params = null ) {
 399                 return [ 'png', 'image/png' ];
 400         }
 401
 402         /**
 403          * Subtitle for the image. Different from the base
 404          * class so it can be denoted that SVG's have
 405          * a "nominal" resolution, and not a fixed one,
 406          * as well as so animation can be denoted.
 407          *
 408          * @param File $file
 409          * @return string
 410          */
 411         public function getLongDesc( $file ) {
 412                 global $wgLang;
 413
 414                 $metadata = $this->unpackMetadata( $file->getMetadata() );
 415                 if ( isset( $metadata['error'] ) ) {
 416                         return wfMessage( 'svg-long-error', $metadata['error']['message'] )->text();
 417                 }
 418
 419                 $size = $wgLang->formatSize( $file->getSize() );
 420
 421                 if ( $this->isAnimatedImage( $file ) ) {
 422                         $msg = wfMessage( 'svg-long-desc-animated' );
 423                 } else {
 424                         $msg = wfMessage( 'svg-long-desc' );
 425                 }
 426
 427                 $msg->numParams( $file->getWidth(), $file->getHeight() )->params( $size );
 428
 429                 return $msg->parse();
 430         }
 431
 432         /**
 433          * @param File|FSFile $file
 434          * @param string $filename
 435          * @return string Serialised metadata
 436          */
 437         public function getMetadata( $file, $filename ) {
 438                 $metadata = [ 'version' => self::SVG_METADATA_VERSION ];
 439                 try {
 440                         $metadata += SVGMetadataExtractor::getMetadata( $filename );
 441                 } catch ( Exception $e ) { // @todo SVG specific exceptions
 442                         // File not found, broken, etc.
 443                         $metadata['error'] = [
 444                                 'message' => $e->getMessage(),
 445                                 'code' => $e->getCode()
 446                         ];
 447                         wfDebug( __METHOD__ . ': ' . $e->getMessage() . "\n" );
 448                 }
 449
 450                 return serialize( $metadata );
 451         }
 452
 453         function unpackMetadata( $metadata ) {
 454                 Wikimedia\suppressWarnings();
 455                 $unser = unserialize( $metadata );
 456                 Wikimedia\restoreWarnings();
 457                 if ( isset( $unser['version'] ) && $unser['version'] == self::SVG_METADATA_VERSION ) {
 458                         return $unser;
 459                 } else {
 460                         return false;
 461                 }
 462         }
 463
 464         function getMetadataType( $image ) {
 465                 return 'parsed-svg';
 466         }
 467
 468         public function isMetadataValid( $image, $metadata ) {
 469                 $meta = $this->unpackMetadata( $metadata );
 470                 if ( $meta === false ) {
 471                         return self::METADATA_BAD;
 472                 }
 473                 if ( !isset( $meta['originalWidth'] ) ) {
 474                         // Old but compatible
 475                         return self::METADATA_COMPATIBLE;
 476                 }
 477
 478                 return self::METADATA_GOOD;
 479         }
 480
 481         protected function visibleMetadataFields() {
 482                 $fields = [ 'objectname', 'imagedescription' ];
 483
 484                 return $fields;
 485         }
 486
 487         /**
 488          * @param File $file
 489          * @param bool|IContextSource $context Context to use (optional)
 490          * @return array|bool
 491          */
 492         public function formatMetadata( $file, $context = false ) {
 493                 $result = [
 494                         'visible' => [],
 495                         'collapsed' => []
 496                 ];
 497                 $metadata = $file->getMetadata();
 498                 if ( !$metadata ) {
 499                         return false;
 500                 }
 501                 $metadata = $this->unpackMetadata( $metadata );
 502                 if ( !$metadata || isset( $metadata['error'] ) ) {
 503                         return false;
 504                 }
 505
 506                 /* @todo Add a formatter
 507                 $format = new FormatSVG( $metadata );
 508                 $formatted = $format->getFormattedData();
 509                 */
 510
 511                 // Sort fields into visible and collapsed
 512                 $visibleFields = $this->visibleMetadataFields();
 513
 514                 $showMeta = false;
 515                 foreach ( $metadata as $name => $value ) {
 516                         $tag = strtolower( $name );
 517                         if ( isset( self::$metaConversion[$tag] ) ) {
 518                                 $tag = strtolower( self::$metaConversion[$tag] );
 519                         } else {
 520                                 // Do not output other metadata not in list
 521                                 continue;
 522                         }
 523                         $showMeta = true;
 524                         self::addMeta( $result,
 525                                 in_array( $tag, $visibleFields ) ? 'visible' : 'collapsed',
 526                                 'exif',
 527                                 $tag,
 528                                 $value
 529                         );
 530                 }
 531
 532                 return $showMeta ? $result : false;
 533         }
 534
 535         /**
 536          * @param string $name Parameter name
 537          * @param mixed $value Parameter value
 538          * @return bool Validity
 539          */
 540         public function validateParam( $name, $value ) {
 541                 if ( in_array( $name, [ 'width', 'height' ] ) ) {
 542                         // Reject negative heights, widths
 543                         return ( $value > 0 );
 544                 } elseif ( $name == 'lang' ) {
 545                         // Validate $code
 546                         if ( $value === '' || !Language::isValidCode( $value ) ) {
 547                                 return false;
 548                         }
 549
 550                         return true;
 551                 }
 552
 553                 // Only lang, width and height are acceptable keys
 554                 return false;
 555         }
 556
 557         /**
 558          * @param array $params Name=>value pairs of parameters
 559          * @return string Filename to use
 560          */
 561         public function makeParamString( $params ) {
 562                 $lang = '';
 563                 $code = $this->getLanguageFromParams( $params );
 564                 if ( $code !== 'en' ) {
 565                         $lang = 'lang' . strtolower( $code ) . '-';
 566                 }
 567                 if ( !isset( $params['width'] ) ) {
 568                         return false;
 569                 }
 570
 571                 return "$lang{$params['width']}px";
 572         }
 573
 574         public function parseParamString( $str ) {
 575                 $m = false;
 576                 if ( preg_match( '/^lang([a-z]+(?:-[a-z]+)*)-(\d+)px$/i', $str, $m ) ) {
 577                         return [ 'width' => array_pop( $m ), 'lang' => $m[1] ];
 578                 } elseif ( preg_match( '/^(\d+)px$/', $str, $m ) ) {
 579                         return [ 'width' => $m[1], 'lang' => 'en' ];
 580                 } else {
 581                         return false;
 582                 }
 583         }
 584
 585         public function getParamMap() {
 586                 return [ 'img_lang' => 'lang', 'img_width' => 'width' ];
 587         }
 588
 589         /**
 590          * @param array $params
 591          * @return array
 592          */
 593         protected function getScriptParams( $params ) {
 594                 $scriptParams = [ 'width' => $params['width'] ];
 595                 if ( isset( $params['lang'] ) ) {
 596                         $scriptParams['lang'] = $params['lang'];
 597                 }
 598
 599                 return $scriptParams;
 600         }
 601
 602         public function getCommonMetaArray( File $file ) {
 603                 $metadata = $file->getMetadata();
 604                 if ( !$metadata ) {
 605                         return [];
 606                 }
 607                 $metadata = $this->unpackMetadata( $metadata );
 608                 if ( !$metadata || isset( $metadata['error'] ) ) {
 609                         return [];
 610                 }
 611                 $stdMetadata = [];
 612                 foreach ( $metadata as $name => $value ) {
 613                         $tag = strtolower( $name );
 614                         if ( $tag === 'originalwidth' || $tag === 'originalheight' ) {
 615                                 // Skip these. In the exif metadata stuff, it is assumed these
 616                                 // are measured in px, which is not the case here.
 617                                 continue;
 618                         }
 619                         if ( isset( self::$metaConversion[$tag] ) ) {
 620                                 $tag = self::$metaConversion[$tag];
 621                                 $stdMetadata[$tag] = $value;
 622                         }
 623                 }
 624
 625                 return $stdMetadata;
 626         }
 627 }