DjVu.php

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<?php
class DjVuHandler extends ImageHandler {

        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;
                }
        }

        function mustRender( $file ) {
                return true;
        }

        function isMultiPage( $file ) {
                return true;
        }

        function getParamMap() {
                return array(
                        'img_width' => 'width',
                        'img_page' => 'page',
                );
        }

        function validateParam( $name, $value ) {
                if ( in_array( $name, array( 'width', 'height', 'page' ) ) ) {
                        if ( $value <= 0 ) {
                                return false;
                        } else {
                                return true;
                        }
                } else {
                        return false;
                }
        }

        function makeParamString( $params ) {
                $page = isset( $params['page'] ) ? $params['page'] : 1;
                if ( !isset( $params['width'] ) ) {
                        return false;
                }
                return "page{$page}-{$params['width']}px";
        }

        function parseParamString( $str ) {
                $m = false;
                if ( preg_match( '/^page(\d+)-(\d+)px$/', $str, $m ) ) {
                        return array( 'width' => $m[2], 'page' => $m[1] );
                } else {
                        return false;
                }
        }

        function getScriptParams( $params ) {
                return array(
                        'width' => $params['width'],
                        'page' => $params['page'],
                );
        }

        function doTransform( $image, $dstPath, $dstUrl, $params, $flags = 0 ) {
                global $wgDjvuRenderer, $wgDjvuPostProcessor;

                // Fetch XML and check it, to give a more informative error message than the one which
                // normaliseParams will inevitably give.
                $xml = $image->getMetadata();
                if ( !$xml ) {
                        $width = isset( $params['width'] ) ? $params['width'] : 0;
                        $height = isset( $params['height'] ) ? $params['height'] : 0;
                        return new MediaTransformError( 'thumbnail_error', $width, $height,
                                wfMessage( 'djvu_no_xml' )->text() );
                }

                if ( !$this->normaliseParams( $image, $params ) ) {
                        return new TransformParameterError( $params );
                }
                $width = $params['width'];
                $height = $params['height'];
                $page = $params['page'];
                if ( $page > $this->pageCount( $image ) ) {
                        return new MediaTransformError(
                                'thumbnail_error',
                                $width,
                                $height,
                                wfMessage( 'djvu_page_error' )->text()
                        );
                }

                if ( $flags & self::TRANSFORM_LATER ) {
                        $params = array(
                                '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' )->text()
                        );
                }

                $srcPath = $image->getLocalRefPath();
                # 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';
                wfProfileIn( 'ddjvu' );
                wfDebug( __METHOD__.": $cmd\n" );
                $retval = '';
                $err = wfShellExec( $cmd, $retval );
                wfProfileOut( 'ddjvu' );

                $removed = $this->removeBadFile( $dstPath, $retval );
                if ( $retval != 0 || $removed ) {
                        wfDebugLog( 'thumbnail',
                                sprintf( 'thumbnail failed on %s: error %d "%s" from "%s"',
                                        wfHostname(), $retval, trim( $err ), $cmd ) );
                        return new MediaTransformError( 'thumbnail_error', $width, $height, $err );
                } else {
                        $params = array(
                                'width' => $width,
                                'height' => $height,
                                'page' => $page
                        );
                        return new ThumbnailImage( $image, $dstUrl, $dstPath, $params );
                }
        }

        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;
        }

        function getMetaTree( $image, $gettext = false ) {
                if ( isset( $image->dejaMetaTree ) ) {
                        return $image->dejaMetaTree;
                }

                $metadata = $image->getMetadata();
                if ( !$this->isMetadataValid( $image, $metadata ) ) {
                        wfDebug( "DjVu XML metadata is invalid or missing, should have been fixed in upgradeRow\n" );
                        return false;
                }
                wfProfileIn( __METHOD__ );

                wfSuppressWarnings();
                try {
                        // Set to false rather than null to avoid further attempts
                        $image->dejaMetaTree = false;
                        $image->djvuTextTree = false;
                        $tree = new SimpleXMLElement( $metadata );
                        if( $tree->getName() == 'mw-djvu' ) {
                                foreach( $tree->children() as $b ) {
                                        if( $b->getName() == 'DjVuTxt' ) {
                                                $image->djvuTextTree = $b;
                                        }
                                        elseif ( $b->getName() == 'DjVuXML' ) {
                                                $image->dejaMetaTree = $b;
                                        }
                                }
                        } else {
                                $image->dejaMetaTree = $tree;
                        }
                } catch( Exception $e ) {
                        wfDebug( "Bogus multipage XML metadata on '{$image->getName()}'\n" );
                }
                wfRestoreWarnings();
                wfProfileOut( __METHOD__ );
                if( $gettext ) {
                        return $image->djvuTextTree;
                } else {
                        return $image->dejaMetaTree;
                }
        }

        function getImageSize( $image, $path ) {
                return $this->getDjVuImage( $image, $path )->getImageSize();
        }

        function getThumbType( $ext, $mime, $params = null ) {
                global $wgDjvuOutputExtension;
                static $mime;
                if ( !isset( $mime ) ) {
                        $magic = MimeMagic::singleton();
                        $mime = $magic->guessTypesForExtension( $wgDjvuOutputExtension );
                }
                return array( $wgDjvuOutputExtension, $mime );
        }

        function getMetadata( $image, $path ) {
                wfDebug( "Getting DjVu metadata for $path\n" );
                return $this->getDjVuImage( $image, $path )->retrieveMetaData();
        }

        function getMetadataType( $image ) {
                return 'djvuxml';
        }

        function isMetadataValid( $image, $metadata ) {
                return !empty( $metadata ) && $metadata != serialize(array());
        }

        function pageCount( $image ) {
                $tree = $this->getMetaTree( $image );
                if ( !$tree ) {
                        return false;
                }
                return count( $tree->xpath( '//OBJECT' ) );
        }

        function getPageDimensions( $image, $page ) {
                $tree = $this->getMetaTree( $image );
                if ( !$tree ) {
                        return false;
                }

                $o = $tree->BODY[0]->OBJECT[$page-1];
                if ( $o ) {
                        return array(
                                'width' => intval( $o['width'] ),
                                'height' => intval( $o['height'] )
                        );
                } else {
                        return false;
                }
        }

        function getPageText( $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;
                }

        }

}