1 files changed, 464 insertions, 0 deletions
diff --git a/www/wiki/includes/media/DjVu.php b/www/wiki/includes/media/DjVu.php
new file mode 100644
index 00000000..2541e35b
--- /dev/null
+++ b/www/wiki/includes/media/DjVu.php
@@ -0,0 +1,464 @@
+<?php
+/**
+ * Handler for DjVu images.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * @file
+ * @ingroup Media
+ */
+
+/**
+ * Handler for DjVu images
+ *
+ * @ingroup Media
+ */
+class DjVuHandler extends ImageHandler {
+	const EXPENSIVE_SIZE_LIMIT = 10485760; // 10MiB
+
+	/**
+	 * @return bool
+	 */
+	function isEnabled() {
+		global $wgDjvuRenderer, $wgDjvuDump, $wgDjvuToXML;
+		if ( !$wgDjvuRenderer || ( !$wgDjvuDump && !$wgDjvuToXML ) ) {
+			wfDebug( "DjVu is disabled, please set \$wgDjvuRenderer and \$wgDjvuDump\n" );
+
+			return false;
+		} else {
+			return true;
+		}
+	}
+
+	/**
+	 * @param File $file
+	 * @return bool
+	 */
+	public function mustRender( $file ) {
+		return true;
+	}
+
+	/**
+	 * True if creating thumbnails from the file is large or otherwise resource-intensive.
+	 * @param File $file
+	 * @return bool
+	 */
+	public function isExpensiveToThumbnail( $file ) {
+		return $file->getSize() > static::EXPENSIVE_SIZE_LIMIT;
+	}
+
+	/**
+	 * @param File $file
+	 * @return bool
+	 */
+	public function isMultiPage( $file ) {
+		return true;
+	}
+
+	/**
+	 * @return array
+	 */
+	public function getParamMap() {
+		return [
+			'img_width' => 'width',
+			'img_page' => 'page',
+		];
+	}
+
+	/**
+	 * @param string $name
+	 * @param mixed $value
+	 * @return bool
+	 */
+	public function validateParam( $name, $value ) {
+		if ( $name === 'page' && trim( $value ) !== (string)intval( $value ) ) {
+			// Extra junk on the end of page, probably actually a caption
+			// e.g. [[File:Foo.djvu|thumb|Page 3 of the document shows foo]]
+			return false;
+		}
+		if ( in_array( $name, [ 'width', 'height', 'page' ] ) ) {
+			if ( $value <= 0 ) {
+				return false;
+			} else {
+				return true;
+			}
+		} else {
+			return false;
+		}
+	}
+
+	/**
+	 * @param array $params
+	 * @return bool|string
+	 */
+	public function makeParamString( $params ) {
+		$page = isset( $params['page'] ) ? $params['page'] : 1;
+		if ( !isset( $params['width'] ) ) {
+			return false;
+		}
+
+		return "page{$page}-{$params['width']}px";
+	}
+
+	/**
+	 * @param string $str
+	 * @return array|bool
+	 */
+	public function parseParamString( $str ) {
+		$m = false;
+		if ( preg_match( '/^page(\d+)-(\d+)px$/', $str, $m ) ) {
+			return [ 'width' => $m[2], 'page' => $m[1] ];
+		} else {
+			return false;
+		}
+	}
+
+	/**
+	 * @param array $params
+	 * @return array
+	 */
+	function getScriptParams( $params ) {
+		return [
+			'width' => $params['width'],
+			'page' => $params['page'],
+		];
+	}
+
+	/**
+	 * @param File $image
+	 * @param string $dstPath
+	 * @param string $dstUrl
+	 * @param array $params
+	 * @param int $flags
+	 * @return MediaTransformError|ThumbnailImage|TransformParameterError
+	 */
+	function doTransform( $image, $dstPath, $dstUrl, $params, $flags = 0 ) {
+		global $wgDjvuRenderer, $wgDjvuPostProcessor;
+
+		if ( !$this->normaliseParams( $image, $params ) ) {
+			return new TransformParameterError( $params );
+		}
+		$width = $params['width'];
+		$height = $params['height'];
+		$page = $params['page'];
+
+		if ( $flags & self::TRANSFORM_LATER ) {
+			$params = [
+				'width' => $width,
+				'height' => $height,
+				'page' => $page
+			];
+
+			return new ThumbnailImage( $image, $dstUrl, $dstPath, $params );
+		}
+
+		if ( !wfMkdirParents( dirname( $dstPath ), null, __METHOD__ ) ) {
+			return new MediaTransformError(
+				'thumbnail_error',
+				$width,
+				$height,
+				wfMessage( 'thumbnail_dest_directory' )
+			);
+		}
+
+		// Get local copy source for shell scripts
+		// Thumbnail extraction is very inefficient for large files.
+		// Provide a way to pool count limit the number of downloaders.
+		if ( $image->getSize() >= 1e7 ) { // 10MB
+			$work = new PoolCounterWorkViaCallback( 'GetLocalFileCopy', sha1( $image->getName() ),
+				[
+					'doWork' => function () use ( $image ) {
+						return $image->getLocalRefPath();
+					}
+				]
+			);
+			$srcPath = $work->execute();
+		} else {
+			$srcPath = $image->getLocalRefPath();
+		}
+
+		if ( $srcPath === false ) { // Failed to get local copy
+			wfDebugLog( 'thumbnail',
+				sprintf( 'Thumbnail failed on %s: could not get local copy of "%s"',
+					wfHostname(), $image->getName() ) );
+
+			return new MediaTransformError( 'thumbnail_error',
+				$params['width'], $params['height'],
+				wfMessage( 'filemissing' )
+			);
+		}
+
+		# Use a subshell (brackets) to aggregate stderr from both pipeline commands
+		# before redirecting it to the overall stdout. This works in both Linux and Windows XP.
+		$cmd = '(' . wfEscapeShellArg(
+			$wgDjvuRenderer,
+			"-format=ppm",
+			"-page={$page}",
+			"-size={$params['physicalWidth']}x{$params['physicalHeight']}",
+			$srcPath );
+		if ( $wgDjvuPostProcessor ) {
+			$cmd .= " | {$wgDjvuPostProcessor}";
+		}
+		$cmd .= ' > ' . wfEscapeShellArg( $dstPath ) . ') 2>&1';
+		wfDebug( __METHOD__ . ": $cmd\n" );
+		$retval = '';
+		$err = wfShellExec( $cmd, $retval );
+
+		$removed = $this->removeBadFile( $dstPath, $retval );
+		if ( $retval != 0 || $removed ) {
+			$this->logErrorForExternalProcess( $retval, $err, $cmd );
+			return new MediaTransformError( 'thumbnail_error', $width, $height, $err );
+		} else {
+			$params = [
+				'width' => $width,
+				'height' => $height,
+				'page' => $page
+			];
+
+			return new ThumbnailImage( $image, $dstUrl, $dstPath, $params );
+		}
+	}
+
+	/**
+	 * Cache an instance of DjVuImage in an Image object, return that instance
+	 *
+	 * @param File|FSFile $image
+	 * @param string $path
+	 * @return DjVuImage
+	 */
+	function getDjVuImage( $image, $path ) {
+		if ( !$image ) {
+			$deja = new DjVuImage( $path );
+		} elseif ( !isset( $image->dejaImage ) ) {
+			$deja = $image->dejaImage = new DjVuImage( $path );
+		} else {
+			$deja = $image->dejaImage;
+		}
+
+		return $deja;
+	}
+
+	/**
+	 * Get metadata, unserializing it if neccessary.
+	 *
+	 * @param File $file The DjVu file in question
+	 * @return string XML metadata as a string.
+	 * @throws MWException
+	 */
+	private function getUnserializedMetadata( File $file ) {
+		$metadata = $file->getMetadata();
+		if ( substr( $metadata, 0, 3 ) === '<?xml' ) {
+			// Old style. Not serialized but instead just a raw string of XML.
+			return $metadata;
+		}
+
+		Wikimedia\suppressWarnings();
+		$unser = unserialize( $metadata );
+		Wikimedia\restoreWarnings();
+		if ( is_array( $unser ) ) {
+			if ( isset( $unser['error'] ) ) {
+				return false;
+			} elseif ( isset( $unser['xml'] ) ) {
+				return $unser['xml'];
+			} else {
+				// Should never ever reach here.
+				throw new MWException( "Error unserializing DjVu metadata." );
+			}
+		}
+
+		// unserialize failed. Guess it wasn't really serialized after all,
+		return $metadata;
+	}
+
+	/**
+	 * Cache a document tree for the DjVu XML metadata
+	 * @param File $image
+	 * @param bool $gettext DOCUMENT (Default: false)
+	 * @return bool|SimpleXMLElement
+	 */
+	public function getMetaTree( $image, $gettext = false ) {
+		if ( $gettext && isset( $image->djvuTextTree ) ) {
+			return $image->djvuTextTree;
+		}
+		if ( !$gettext && isset( $image->dejaMetaTree ) ) {
+			return $image->dejaMetaTree;
+		}
+
+		$metadata = $this->getUnserializedMetadata( $image );
+		if ( !$this->isMetadataValid( $image, $metadata ) ) {
+			wfDebug( "DjVu XML metadata is invalid or missing, should have been fixed in upgradeRow\n" );
+
+			return false;
+		}
+
+		$trees = $this->extractTreesFromMetadata( $metadata );
+		$image->djvuTextTree = $trees['TextTree'];
+		$image->dejaMetaTree = $trees['MetaTree'];
+
+		if ( $gettext ) {
+			return $image->djvuTextTree;
+		} else {
+			return $image->dejaMetaTree;
+		}
+	}
+
+	/**
+	 * Extracts metadata and text trees from metadata XML in string form
+	 * @param string $metadata XML metadata as a string
+	 * @return array
+	 */
+	protected function extractTreesFromMetadata( $metadata ) {
+		Wikimedia\suppressWarnings();
+		try {
+			// Set to false rather than null to avoid further attempts
+			$metaTree = false;
+			$textTree = false;
+			$tree = new SimpleXMLElement( $metadata, LIBXML_PARSEHUGE );
+			if ( $tree->getName() == 'mw-djvu' ) {
+				/** @var SimpleXMLElement $b */
+				foreach ( $tree->children() as $b ) {
+					if ( $b->getName() == 'DjVuTxt' ) {
+						// @todo File::djvuTextTree and File::dejaMetaTree are declared
+						// dynamically. Add a public File::$data to facilitate this?
+						$textTree = $b;
+					} elseif ( $b->getName() == 'DjVuXML' ) {
+						$metaTree = $b;
+					}
+				}
+			} else {
+				$metaTree = $tree;
+			}
+		} catch ( Exception $e ) {
+			wfDebug( "Bogus multipage XML metadata\n" );
+		}
+		Wikimedia\restoreWarnings();
+
+		return [ 'MetaTree' => $metaTree, 'TextTree' => $textTree ];
+	}
+
+	function getImageSize( $image, $path ) {
+		return $this->getDjVuImage( $image, $path )->getImageSize();
+	}
+
+	function getThumbType( $ext, $mime, $params = null ) {
+		global $wgDjvuOutputExtension;
+		static $mime;
+		if ( !isset( $mime ) ) {
+			$magic = MediaWiki\MediaWikiServices::getInstance()->getMimeAnalyzer();
+			$mime = $magic->guessTypesForExtension( $wgDjvuOutputExtension );
+		}
+
+		return [ $wgDjvuOutputExtension, $mime ];
+	}
+
+	function getMetadata( $image, $path ) {
+		wfDebug( "Getting DjVu metadata for $path\n" );
+
+		$xml = $this->getDjVuImage( $image, $path )->retrieveMetaData();
+		if ( $xml === false ) {
+			// Special value so that we don't repetitively try and decode a broken file.
+			return serialize( [ 'error' => 'Error extracting metadata' ] );
+		} else {
+			return serialize( [ 'xml' => $xml ] );
+		}
+	}
+
+	function getMetadataType( $image ) {
+		return 'djvuxml';
+	}
+
+	function isMetadataValid( $image, $metadata ) {
+		return !empty( $metadata ) && $metadata != serialize( [] );
+	}
+
+	function pageCount( File $image ) {
+		$info = $this->getDimensionInfo( $image );
+
+		return $info ? $info['pageCount'] : false;
+	}
+
+	function getPageDimensions( File $image, $page ) {
+		$index = $page - 1; // MW starts pages at 1
+
+		$info = $this->getDimensionInfo( $image );
+		if ( $info && isset( $info['dimensionsByPage'][$index] ) ) {
+			return $info['dimensionsByPage'][$index];
+		}
+
+		return false;
+	}
+
+	protected function getDimensionInfo( File $file ) {
+		$cache = ObjectCache::getMainWANInstance();
+		return $cache->getWithSetCallback(
+			$cache->makeKey( 'file-djvu', 'dimensions', $file->getSha1() ),
+			$cache::TTL_INDEFINITE,
+			function () use ( $file ) {
+				$tree = $this->getMetaTree( $file );
+				return $this->getDimensionInfoFromMetaTree( $tree );
+			},
+			[ 'pcTTL' => $cache::TTL_INDEFINITE ]
+		);
+	}
+
+	/**
+	 * Given an XML metadata tree, returns dimension information about the document
+	 * @param bool|SimpleXMLElement $metatree The file's XML metadata tree
+	 * @return bool|array
+	 */
+	protected function getDimensionInfoFromMetaTree( $metatree ) {
+		if ( !$metatree ) {
+			return false;
+		}
+
+		$dimsByPage = [];
+		$count = count( $metatree->xpath( '//OBJECT' ) );
+		for ( $i = 0; $i < $count; $i++ ) {
+			$o = $metatree->BODY[0]->OBJECT[$i];
+			if ( $o ) {
+				$dimsByPage[$i] = [
+					'width' => (int)$o['width'],
+					'height' => (int)$o['height'],
+				];
+			} else {
+				$dimsByPage[$i] = false;
+			}
+		}
+
+		return [ 'pageCount' => $count, 'dimensionsByPage' => $dimsByPage ];
+	}
+
+	/**
+	 * @param File $image
+	 * @param int $page Page number to get information for
+	 * @return bool|string Page text or false when no text found.
+	 */
+	function getPageText( File $image, $page ) {
+		$tree = $this->getMetaTree( $image, true );
+		if ( !$tree ) {
+			return false;
+		}
+
+		$o = $tree->BODY[0]->PAGE[$page - 1];
+		if ( $o ) {
+			$txt = $o['value'];
+
+			return $txt;
+		} else {
+			return false;
+		}
+	}
+}