* Some enhancements to live preview
[lhc/web/wiklou.git] / includes / Image.php
index e5b1216..9145a0d 100644 (file)
@@ -1,6 +1,5 @@
 <?php
 /**
- * @package MediaWiki
  */
 
 /**
@@ -22,7 +21,6 @@ define( 'MW_IMAGE_VERSION', 1 );
  *
  * Provides methods to retrieve paths (physical, logical, URL),
  * to generate thumbnails or for uploading.
- * @package MediaWiki
  */
 class Image
 {
@@ -46,6 +44,7 @@ class Image
                $size,          # Size in bytes (loadFromXxx)
                $metadata,      # Metadata
                $dataLoaded,    # Whether or not all this has been loaded from the database (loadFromXxx)
+               $page,          # Page to render when creating thumbnails
                $lastError;     # Error string associated with a thumbnail display error
 
 
@@ -57,7 +56,7 @@ class Image
         * @param string $name name of the image, used to create a title object using Title::makeTitleSafe
         * @public
         */
-       function newFromName( $name ) {
+       public static function newFromName( $name ) {
                $title = Title::makeTitleSafe( NS_IMAGE, $name );
                if ( is_object( $title ) ) {
                        return new Image( $title );
@@ -86,11 +85,12 @@ class Image
                $this->extension = Image::normalizeExtension( $n ?
                        substr( $this->name, $n + 1 ) : '' );
                $this->historyLine = 0;
+               $this->page = 1;
 
                $this->dataLoaded = false;
        }
 
-       
+
        /**
         * Normalize a file extension to the common form, and ensure it's clean.
         * Extensions with non-alphanumeric characters will be discarded.
@@ -113,18 +113,18 @@ class Image
                        return '';
                }
        }
-       
+
        /**
         * Get the memcached keys
         * Returns an array, first element is the local cache key, second is the shared cache key, if there is one
         */
        function getCacheKeys( ) {
-               global $wgDBname, $wgUseSharedUploads, $wgSharedUploadDBname, $wgCacheSharedUploads;
+               global $wgUseSharedUploads, $wgSharedUploadDBname, $wgCacheSharedUploads;
 
                $hashedName = md5($this->name);
-               $keys = array( "$wgDBname:Image:$hashedName" );
+               $keys = array( wfMemcKey( 'Image', $hashedName ) );
                if ( $wgUseSharedUploads && $wgSharedUploadDBname && $wgCacheSharedUploads ) {
-                       $keys[] = "$wgSharedUploadDBname:Image:$hashedName";
+                       $keys[] = wfForeignMemcKey( $wgSharedUploadDBname, false, 'Image', $hashedName );
                }
                return $keys;
        }
@@ -142,7 +142,7 @@ class Image
                // Check if the key existed and belongs to this version of MediaWiki
                if (!empty($cachedValues) && is_array($cachedValues)
                  && isset($cachedValues['version']) && ( $cachedValues['version'] == MW_IMAGE_VERSION )
-                 && $cachedValues['fileExists'] && isset( $cachedValues['mime'] ) && isset( $cachedValues['metadata'] ) )
+                 && isset( $cachedValues['mime'] ) && isset( $cachedValues['metadata'] ) )
                {
                        if ( $wgUseSharedUploads && $cachedValues['fromShared']) {
                                # if this is shared file, we need to check if image
@@ -200,13 +200,13 @@ class Image
         * Save the image metadata to memcached
         */
        function saveToCache() {
-               global $wgMemc;
+               global $wgMemc, $wgUseSharedUploads;
                $this->load();
                $keys = $this->getCacheKeys();
-               if ( $this->fileExists ) {
-                       // We can't cache negative metadata for non-existent files,
-                       // because if the file later appears in commons, the local
-                       // keys won't be purged.
+               // We can't cache negative metadata for non-existent files,
+               // because if the file later appears in commons, the local
+               // keys won't be purged.
+               if ( $this->fileExists || !$wgUseSharedUploads ) {
                        $cachedValues = array(
                                'version'    => MW_IMAGE_VERSION,
                                'name'       => $this->name,
@@ -233,7 +233,7 @@ class Image
         * Load metadata from the file itself
         */
        function loadFromFile() {
-               global $wgUseSharedUploads, $wgSharedUploadDirectory, $wgContLang, $wgShowEXIF;
+               global $wgUseSharedUploads, $wgSharedUploadDirectory, $wgContLang;
                wfProfileIn( __METHOD__ );
                $this->imagePath = $this->getFullPath();
                $this->fileExists = file_exists( $this->imagePath );
@@ -258,7 +258,7 @@ class Image
 
 
                if ( $this->fileExists ) {
-                       $magic=& wfGetMimeMagic();
+                       $magic=& MimeMagic::singleton();
 
                        $this->mime = $magic->guessMimeType($this->imagePath,true);
                        $this->type = $magic->getMediaType($this->imagePath,$this->mime);
@@ -266,7 +266,7 @@ class Image
                        # Get size in bytes
                        $this->size = filesize( $this->imagePath );
 
-                       $magic=& wfGetMimeMagic();
+                       $magic=& MimeMagic::singleton();
 
                        # Height and width
                        wfSuppressWarnings();
@@ -307,7 +307,11 @@ class Image
                $this->dataLoaded = true;
 
 
-               $this->metadata = serialize( $this->retrieveExifData( $this->imagePath ) );
+               if ( $this->mime == 'image/vnd.djvu' ) {
+                       $this->metadata = $deja->retrieveMetaData();
+               } else {
+                       $this->metadata = serialize( $this->retrieveExifData( $this->imagePath ) );
+               }
 
                if ( isset( $gis['bits'] ) )  $this->bits = $gis['bits'];
                else $this->bits = 0;
@@ -322,8 +326,7 @@ class Image
                global $wgUseSharedUploads, $wgSharedUploadDBname, $wgSharedUploadDBprefix, $wgContLang;
                wfProfileIn( __METHOD__ );
 
-               $dbr =& wfGetDB( DB_SLAVE );
-
+               $dbr = wfGetDB( DB_SLAVE );
                $this->checkDBSchema($dbr);
 
                $row = $dbr->selectRow( 'image',
@@ -344,7 +347,7 @@ class Image
                        # capitalize the first letter of the filename before
                        # looking it up in the shared repository.
                        $name = $wgContLang->ucfirst($this->name);
-                       $dbc =& wfGetDB( DB_SLAVE, 'commons' );
+                       $dbc = wfGetDB( DB_SLAVE, 'commons' );
 
                        $row = $dbc->selectRow( "`$wgSharedUploadDBname`.{$wgSharedUploadDBprefix}image",
                                array(
@@ -374,6 +377,7 @@ class Image
                        $this->fileExists = false;
                        $this->fromSharedDirectory = false;
                        $this->metadata = serialize ( array() ) ;
+                       $this->mime = false;
                }
 
                # Unconditionally set loaded=true, we don't want the accessors constantly rechecking
@@ -416,9 +420,12 @@ class Image
                                $this->loadFromDB();
                                if ( !$wgSharedUploadDBname && $wgUseSharedUploads ) {
                                        $this->loadFromFile();
-                               } elseif ( $this->fileExists ) {
+                               } elseif ( $this->fileExists || !$wgUseSharedUploads ) {
+                                       // We can do negative caching for local images, because the cache
+                                       // will be purged on upload. But we can't do it when shared images
+                                       // are enabled, since updates to that won't purge foreign caches.
                                        $this->saveToCache();
-                               }
+                               } 
                        }
                        $this->dataLoaded = true;
                }
@@ -442,10 +449,10 @@ class Image
 
                        // Write to the other DB using selectDB, not database selectors
                        // This avoids breaking replication in MySQL
-                       $dbw =& wfGetDB( DB_MASTER, 'commons' );
+                       $dbw = wfGetDB( DB_MASTER, 'commons' );
                        $dbw->selectDB( $wgSharedUploadDBname );
                } else {
-                       $dbw =& wfGetDB( DB_MASTER );
+                       $dbw = wfGetDB( DB_MASTER );
                }
 
                $this->checkDBSchema($dbw);
@@ -470,7 +477,7 @@ class Image
                }
                wfProfileOut( __METHOD__ );
        }
-       
+
        /**
         * Split an internet media type into its two components; if not
         * a two-part name, set the minor type to 'unknown'.
@@ -601,7 +608,7 @@ class Image
         * @todo remember the result of this check.
         */
        function canRender() {
-               global $wgUseImageMagick;
+               global $wgUseImageMagick, $wgDjvuRenderer;
 
                if( $this->getWidth()<=0 || $this->getHeight()<=0 ) return false;
 
@@ -647,6 +654,7 @@ class Image
                        if ( $mime === 'image/vnd.wap.wbmp'
                          || $mime === 'image/x-xbitmap' ) return true;
                }
+               if ( $mime === 'image/vnd.djvu' && isset( $wgDjvuRenderer ) && $wgDjvuRenderer ) return true;
 
                return false;
        }
@@ -734,9 +742,16 @@ class Image
         * Return the escapeLocalURL of this image
         * @public
         */
-       function getEscapeLocalURL() {
+       function getEscapeLocalURL( $query=false) {
                $this->getTitle();
-               return $this->title->escapeLocalURL();
+               if ( $query === false ) {
+                       if ( $this->page != 1 ) {
+                               $query = 'page=' . $this->page;
+                       } else {
+                               $query = '';
+                       }
+               }
+               return $this->title->escapeLocalURL( $query );
        }
 
        /**
@@ -836,6 +851,9 @@ class Image
         */
        function thumbName( $width ) {
                $thumb = $width."px-".$this->name;
+               if ( $this->page != 1 ) {
+                       $thumb = "page{$this->page}-$thumb";
+               }
 
                if( $this->mustRender() ) {
                        if( $this->canRender() ) {
@@ -902,10 +920,10 @@ class Image
                        } else {
                                // Don't render, just return the URL
                                if ( $this->validateThumbParams( $width, $height ) ) {
-                                       if ( $width == $this->width && $height == $this->height ) {
+                                       if ( !$this->mustRender() && $width == $this->width && $height == $this->height ) {
                                                $url = $this->getURL();
                                        } else {
-                                               list( $isScriptUrl, $url ) = $this->thumbUrl( $width );
+                                               list( /* $isScriptUrl */, $url ) = $this->thumbUrl( $width );
                                        }
                                        $thumb = new ThumbnailImage( $url, $width, $height );
                                } else {
@@ -946,7 +964,7 @@ class Image
         */
        function validateThumbParams( &$width, &$height ) {
                global $wgSVGMaxSize, $wgMaxImageArea;
-               
+
                $this->load();
 
                if ( ! $this->exists() )
@@ -954,9 +972,9 @@ class Image
                        # If there is no image, there will be no thumbnail
                        return false;
                }
-               
+
                $width = intval( $width );
-               
+
                # Sanity check $width
                if( $width <= 0 || $this->width <= 0) {
                        # BZZZT
@@ -985,7 +1003,7 @@ class Image
                $height = round( $this->height * $width / $this->width );
                return true;
        }
-       
+
        /**
         * Create a thumbnail of the image having the specified width.
         * The thumbnail will not be created if the width is larger than the
@@ -1011,13 +1029,13 @@ class Image
                        return null;
                }
 
-               if ( $width == $this->width && $height == $this->height ) {
+               if ( !$this->mustRender() && $width == $this->width && $height == $this->height ) {
                        # validateThumbParams (or the user) wants us to return the unscaled image
                        $thumb = new ThumbnailImage( $this->getURL(), $width, $height );
                        wfProfileOut( __METHOD__ );
                        return $thumb;
                }
-               
+
                list( $isScriptUrl, $url ) = $this->thumbUrl( $width );
                if ( $isScriptUrl && $useScript ) {
                        // Use thumb.php to render the image
@@ -1056,7 +1074,7 @@ class Image
                                @unlink( $thumbDir );
                        }
                        wfMkdirParents( $thumbDir );
-                       
+
                        $oldThumbPath = wfDeprecatedThumbDir( $thumbName, 'thumb', $this->fromSharedDirectory ).
                                '/'.$thumbName;
                        $done = false;
@@ -1123,13 +1141,14 @@ class Image
                global $wgSVGConverters, $wgSVGConverter;
                global $wgUseImageMagick, $wgImageMagickConvertCommand;
                global $wgCustomConvertCommand;
+               global $wgDjvuRenderer, $wgDjvuPostProcessor;
 
                $this->load();
 
                $err = false;
                $cmd = "";
                $retval = 0;
-               
+
                if( $this->mime === "image/svg" ) {
                        #Right now we have only SVG
 
@@ -1149,96 +1168,112 @@ class Image
                                $err = wfShellExec( $cmd, $retval );
                                wfProfileOut( 'rsvg' );
                        }
-               } elseif ( $wgUseImageMagick ) {
-                       # use ImageMagick
-                       
-                       if ( $this->mime == 'image/jpeg' ) {
-                               $quality = "-quality 80"; // 80%
-                       } elseif ( $this->mime == 'image/png' ) {
-                               $quality = "-quality 95"; // zlib 9, adaptive filtering
-                       } else {
-                               $quality = ''; // default
-                       }
-
-                       # Specify white background color, will be used for transparent images
-                       # in Internet Explorer/Windows instead of default black.
-
-                       # Note, we specify "-size {$width}" and NOT "-size {$width}x{$height}".
-                       # It seems that ImageMagick has a bug wherein it produces thumbnails of
-                       # the wrong size in the second case.
-                       
-                       $cmd  =  wfEscapeShellArg($wgImageMagickConvertCommand) .
-                               " {$quality} -background white -size {$width} ".
-                               wfEscapeShellArg($this->imagePath) .
-                               // Coalesce is needed to scale animated GIFs properly (bug 1017).
-                               ' -coalesce ' .
-                               // For the -resize option a "!" is needed to force exact size,
-                               // or ImageMagick may decide your ratio is wrong and slice off
-                               // a pixel.
-                               " -resize " . wfEscapeShellArg( "{$width}x{$height}!" ) .
-                               " -depth 8 " .
-                               wfEscapeShellArg($thumbPath) . " 2>&1";
-                       wfDebug("reallyRenderThumb: running ImageMagick: $cmd\n");
-                       wfProfileIn( 'convert' );
-                       $err = wfShellExec( $cmd, $retval );
-                       wfProfileOut( 'convert' );
-               } elseif( $wgCustomConvertCommand ) {
-                       # Use a custom convert command
-                       # Variables: %s %d %w %h
-                       $src = wfEscapeShellArg( $this->imagePath );
-                       $dst = wfEscapeShellArg( $thumbPath );
-                       $cmd = $wgCustomConvertCommand;
-                       $cmd = str_replace( '%s', $src, str_replace( '%d', $dst, $cmd ) ); # Filenames
-                       $cmd = str_replace( '%h', $height, str_replace( '%w', $width, $cmd ) ); # Size
-                       wfDebug( "reallyRenderThumb: Running custom convert command $cmd\n" );
-                       wfProfileIn( 'convert' );
-                       $err = wfShellExec( $cmd, $retval );
-                       wfProfileOut( 'convert' );
                } else {
-                       # Use PHP's builtin GD library functions.
-                       #
-                       # First find out what kind of file this is, and select the correct
-                       # input routine for this.
-
-                       $typemap = array(
-                               'image/gif'          => array( 'imagecreatefromgif',  'palette',   'imagegif'  ),
-                               'image/jpeg'         => array( 'imagecreatefromjpeg', 'truecolor', array( &$this, 'imageJpegWrapper' ) ),
-                               'image/png'          => array( 'imagecreatefrompng',  'bits',      'imagepng'  ),
-                               'image/vnd.wap.wmbp' => array( 'imagecreatefromwbmp', 'palette',   'imagewbmp'  ),
-                               'image/xbm'          => array( 'imagecreatefromxbm',  'palette',   'imagexbm'  ),
-                       );
-                       if( !isset( $typemap[$this->mime] ) ) {
-                               $err = 'Image type not supported';
-                               wfDebug( "$err\n" );
-                               return $err;
-                       }
-                       list( $loader, $colorStyle, $saveType ) = $typemap[$this->mime];
+                       if ( $this->mime === "image/vnd.djvu" && $wgDjvuRenderer ) {
+                               // DJVU image
+                               // The file contains several images. First, extract the
+                               // page in hi-res, if it doesn't yet exist. Then, thumbnail
+                               // it.
+
+                               $cmd = "{$wgDjvuRenderer} -page={$this->page} -size=${width}x${height} " .
+                                       wfEscapeShellArg( $this->imagePath ) . 
+                                       " | {$wgDjvuPostProcessor} > " . wfEscapeShellArg($thumbPath);
+                               wfProfileIn( 'ddjvu' );
+                               wfDebug( "reallyRenderThumb DJVU: $cmd\n" );
+                               $err = wfShellExec( $cmd, $retval );
+                               wfProfileOut( 'ddjvu' );
 
-                       if( !function_exists( $loader ) ) {
-                               $err = "Incomplete GD library configuration: missing function $loader";
-                               wfDebug( "$err\n" );
-                               return $err;
-                       }
-                       if( $colorStyle == 'palette' ) {
-                               $truecolor = false;
-                       } elseif( $colorStyle == 'truecolor' ) {
-                               $truecolor = true;
-                       } elseif( $colorStyle == 'bits' ) {
-                               $truecolor = ( $this->bits > 8 );
-                       }
+                       } elseif ( $wgUseImageMagick ) {
+                               # use ImageMagick
 
-                       $src_image = call_user_func( $loader, $this->imagePath );
-                       if ( $truecolor ) {
-                               $dst_image = imagecreatetruecolor( $width, $height );
+                               if ( $this->mime == 'image/jpeg' ) {
+                                       $quality = "-quality 80"; // 80%
+                               } elseif ( $this->mime == 'image/png' ) {
+                                       $quality = "-quality 95"; // zlib 9, adaptive filtering
+                               } else {
+                                       $quality = ''; // default
+                               }
+
+                               # Specify white background color, will be used for transparent images
+                               # in Internet Explorer/Windows instead of default black.
+
+                               # Note, we specify "-size {$width}" and NOT "-size {$width}x{$height}".
+                               # It seems that ImageMagick has a bug wherein it produces thumbnails of
+                               # the wrong size in the second case.
+
+                               $cmd  =  wfEscapeShellArg($wgImageMagickConvertCommand) .
+                                       " {$quality} -background white -size {$width} ".
+                                       wfEscapeShellArg($this->imagePath) .
+                                       // Coalesce is needed to scale animated GIFs properly (bug 1017).
+                                       ' -coalesce ' .
+                                       // For the -resize option a "!" is needed to force exact size,
+                                       // or ImageMagick may decide your ratio is wrong and slice off
+                                       // a pixel.
+                                       " -thumbnail " . wfEscapeShellArg( "{$width}x{$height}!" ) .
+                                       " -depth 8 " .
+                                       wfEscapeShellArg($thumbPath) . " 2>&1";
+                               wfDebug("reallyRenderThumb: running ImageMagick: $cmd\n");
+                               wfProfileIn( 'convert' );
+                               $err = wfShellExec( $cmd, $retval );
+                               wfProfileOut( 'convert' );
+                       } elseif( $wgCustomConvertCommand ) {
+                               # Use a custom convert command
+                               # Variables: %s %d %w %h
+                               $src = wfEscapeShellArg( $this->imagePath );
+                               $dst = wfEscapeShellArg( $thumbPath );
+                               $cmd = $wgCustomConvertCommand;
+                               $cmd = str_replace( '%s', $src, str_replace( '%d', $dst, $cmd ) ); # Filenames
+                               $cmd = str_replace( '%h', $height, str_replace( '%w', $width, $cmd ) ); # Size
+                               wfDebug( "reallyRenderThumb: Running custom convert command $cmd\n" );
+                               wfProfileIn( 'convert' );
+                               $err = wfShellExec( $cmd, $retval );
+                               wfProfileOut( 'convert' );
                        } else {
-                               $dst_image = imagecreate( $width, $height );
+                               # Use PHP's builtin GD library functions.
+                               #
+                               # First find out what kind of file this is, and select the correct
+                               # input routine for this.
+
+                               $typemap = array(
+                                       'image/gif'          => array( 'imagecreatefromgif',  'palette',   'imagegif'  ),
+                                       'image/jpeg'         => array( 'imagecreatefromjpeg', 'truecolor', array( &$this, 'imageJpegWrapper' ) ),
+                                       'image/png'          => array( 'imagecreatefrompng',  'bits',      'imagepng'  ),
+                                       'image/vnd.wap.wmbp' => array( 'imagecreatefromwbmp', 'palette',   'imagewbmp'  ),
+                                       'image/xbm'          => array( 'imagecreatefromxbm',  'palette',   'imagexbm'  ),
+                               );
+                               if( !isset( $typemap[$this->mime] ) ) {
+                                       $err = 'Image type not supported';
+                                       wfDebug( "$err\n" );
+                                       return $err;
+                               }
+                               list( $loader, $colorStyle, $saveType ) = $typemap[$this->mime];
+
+                               if( !function_exists( $loader ) ) {
+                                       $err = "Incomplete GD library configuration: missing function $loader";
+                                       wfDebug( "$err\n" );
+                                       return $err;
+                               }
+                               if( $colorStyle == 'palette' ) {
+                                       $truecolor = false;
+                               } elseif( $colorStyle == 'truecolor' ) {
+                                       $truecolor = true;
+                               } elseif( $colorStyle == 'bits' ) {
+                                       $truecolor = ( $this->bits > 8 );
+                               }
+
+                               $src_image = call_user_func( $loader, $this->imagePath );
+                               if ( $truecolor ) {
+                                       $dst_image = imagecreatetruecolor( $width, $height );
+                               } else {
+                                       $dst_image = imagecreate( $width, $height );
+                               }
+                               imagecopyresampled( $dst_image, $src_image,
+                                                       0,0,0,0,
+                                                       $width, $height, $this->width, $this->height );
+                               call_user_func( $saveType, $dst_image, $thumbPath );
+                               imagedestroy( $dst_image );
+                               imagedestroy( $src_image );
                        }
-                       imagecopyresampled( $dst_image, $src_image,
-                                               0,0,0,0,
-                                               $width, $height, $this->width, $this->height );
-                       call_user_func( $saveType, $dst_image, $thumbPath );
-                       imagedestroy( $dst_image );
-                       imagedestroy( $src_image );
                }
 
                #
@@ -1282,16 +1317,17 @@ class Image
                        $files = array();
                        $dir = wfImageThumbDir( $this->name, $shared );
 
-                       // This generates an error on failure, hence the @
-                       $handle = @opendir( $dir );
+                       if ( is_dir( $dir ) ) {
+                               $handle = opendir( $dir );
 
-                       if ( $handle ) {
-                               while ( false !== ( $file = readdir($handle) ) ) {
-                                       if ( $file{0} != '.' ) {
-                                               $files[] = $file;
+                               if ( $handle ) {
+                                       while ( false !== ( $file = readdir($handle) ) ) {
+                                               if ( $file{0} != '.' ) {
+                                                       $files[] = $file;
+                                               }
                                        }
+                                       closedir( $handle );
                                }
-                               closedir( $handle );
                        }
                } else {
                        $files = array();
@@ -1323,22 +1359,24 @@ class Image
                $dir = wfImageThumbDir( $this->name, $shared );
                $urls = array();
                foreach ( $files as $file ) {
+                       $m = array();
                        if ( preg_match( '/^(\d+)px/', $file, $m ) ) {
-                               $urls[] = $this->thumbUrl( $m[1], $this->fromSharedDirectory );
+                               list( /* $isScriptUrl */, $url ) = $this->thumbUrl( $m[1] );
+                               $urls[] = $url;
                                @unlink( "$dir/$file" );
                        }
                }
 
                // Purge the squid
                if ( $wgUseSquid ) {
-                       $urls[] = $this->getViewURL();
+                       $urls[] = $this->getURL();
                        foreach ( $archiveFiles as $file ) {
                                $urls[] = wfImageArchiveUrl( $file );
                        }
                        wfPurgeSquidServers( $urls );
                }
        }
-       
+
        /**
         * Purge the image description page, but don't go after
         * pages using the image. Use when modifying file history
@@ -1349,7 +1387,7 @@ class Image
                $page->invalidateCache();
                $page->purgeSquid();
        }
-       
+
        /**
         * Purge metadata and all affected pages when the image is created,
         * deleted, or majorly updated. A set of additional URLs may be
@@ -1360,21 +1398,23 @@ class Image
                // Delete thumbnails and refresh image metadata cache
                $this->purgeCache();
                $this->purgeDescription();
-               
+
                // Purge cache of all pages using this image
                $update = new HTMLCacheUpdate( $this->getTitle(), 'imagelinks' );
                $update->doUpdate();
        }
 
        function checkDBSchema(&$db) {
+               static $checkDone = false;
                global $wgCheckDBSchema;
-               if (!$wgCheckDBSchema) {
+               if (!$wgCheckDBSchema || $checkDone) {
                        return;
                }
                # img_name must be unique
                if ( !$db->indexUnique( 'image', 'img_name' ) && !$db->indexExists('image','PRIMARY') ) {
                        throw new MWException( 'Database schema not up to date, please run maintenance/archives/patch-image_name_unique.sql' );
                }
+               $checkDone = true;
 
                # new fields must exist
                # 
@@ -1404,7 +1444,7 @@ class Image
         * @public
         */
        function nextHistoryLine() {
-               $dbr =& wfGetDB( DB_SLAVE );
+               $dbr = wfGetDB( DB_SLAVE );
 
                $this->checkDBSchema($dbr);
 
@@ -1422,7 +1462,7 @@ class Image
                                array( 'img_name' => $this->title->getDBkey() ),
                                __METHOD__
                        );
-                       if ( 0 == wfNumRows( $this->historyRes ) ) {
+                       if ( 0 == $dbr->numRows( $this->historyRes ) ) {
                                return FALSE;
                        }
                } else if ( $this->historyLine == 1 ) {
@@ -1489,7 +1529,7 @@ class Image
         * @return bool
         * @static
         */
-       function isHashed( $shared ) {
+       public static function isHashed( $shared ) {
                global $wgHashedUploadDirectory, $wgHashedSharedUploadDirectory;
                return $shared ? $wgHashedSharedUploadDirectory : $wgHashedUploadDirectory;
        }
@@ -1500,7 +1540,7 @@ class Image
        function recordUpload( $oldver, $desc, $license = '', $copyStatus = '', $source = '', $watch = false ) {
                global $wgUser, $wgUseCopyrightUpload;
 
-               $dbw =& wfGetDB( DB_MASTER );
+               $dbw = wfGetDB( DB_MASTER );
 
                $this->checkDBSchema($dbw);
 
@@ -1656,13 +1696,13 @@ class Image
                wfProfileIn( __METHOD__ );
 
                if ( $options ) {
-                       $db =& wfGetDB( DB_MASTER );
+                       $db = wfGetDB( DB_MASTER );
                } else {
-                       $db =& wfGetDB( DB_SLAVE );
+                       $db = wfGetDB( DB_SLAVE );
                }
                $linkCache =& LinkCache::singleton();
 
-               extract( $db->tableNames( 'page', 'imagelinks' ) );
+               list( $page, $imagelinks ) = $db->tableNamesN( 'page', 'imagelinks' );
                $encName = $db->addQuotes( $this->name );
                $sql = "SELECT page_namespace,page_title,page_id FROM $page,$imagelinks WHERE page_id=il_from AND il_to=$encName $options";
                $res = $db->query( $sql, __METHOD__ );
@@ -1680,7 +1720,7 @@ class Image
                wfProfileOut( __METHOD__ );
                return $retVal;
        }
-       
+
        /**
         * Retrive Exif data from the file and prune unrecognized tags
         * and/or tags with invalid contents
@@ -1690,7 +1730,7 @@ class Image
         */
        private function retrieveExifData( $filename ) {
                global $wgShowEXIF;
-               
+
                /*
                if ( $this->getMimeType() !== "image/jpeg" )
                        return array();
@@ -1700,13 +1740,13 @@ class Image
                        $exif = new Exif( $filename );
                        return $exif->getFilteredData();
                }
-               
+
                return array();
        }
 
        function getExifData() {
                global $wgRequest;
-               if ( $this->metadata === '0' )
+               if ( $this->metadata === '0' || $this->mime == 'image/vnd.djvu' )
                        return array();
 
                $purge = $wgRequest->getVal( 'action' ) == 'purge';
@@ -1740,7 +1780,7 @@ class Image
                }
 
                # Update EXIF data in database
-               $dbw =& wfGetDB( DB_MASTER );
+               $dbw = wfGetDB( DB_MASTER );
 
                $this->checkDBSchema($dbw);
 
@@ -1760,7 +1800,7 @@ class Image
        function isLocal() {
                return !$this->fromSharedDirectory;
        }
-       
+
        /**
         * Was this image ever deleted from the wiki?
         *
@@ -1770,7 +1810,7 @@ class Image
                $title = Title::makeTitle( NS_IMAGE, $this->name );
                return ( $title->isDeleted() > 0 );
        }
-       
+
        /**
         * Delete all versions of the image.
         *
@@ -1785,34 +1825,34 @@ class Image
        function delete( $reason ) {
                $transaction = new FSTransaction();
                $urlArr = array( $this->getURL() );
-               
+
                if( !FileStore::lock() ) {
                        wfDebug( __METHOD__.": failed to acquire file store lock, aborting\n" );
                        return false;
                }
-               
+
                try {
                        $dbw = wfGetDB( DB_MASTER );
                        $dbw->begin();
-                       
+
                        // Delete old versions
                        $result = $dbw->select( 'oldimage',
                                array( 'oi_archive_name' ),
                                array( 'oi_name' => $this->name ) );
-                       
+
                        while( $row = $dbw->fetchObject( $result ) ) {
                                $oldName = $row->oi_archive_name;
-                               
+
                                $transaction->add( $this->prepareDeleteOld( $oldName, $reason ) );
-                               
+
                                // We'll need to purge this URL from caches...
                                $urlArr[] = wfImageArchiveUrl( $oldName );
                        }
                        $dbw->freeResult( $result );
-                       
+
                        // And the current version...
                        $transaction->add( $this->prepareDeleteCurrent( $reason ) );
-                       
+
                        $dbw->immediateCommit();
                } catch( MWException $e ) {
                        wfDebug( __METHOD__.": db error, rolling back file transactions\n" );
@@ -1820,22 +1860,22 @@ class Image
                        FileStore::unlock();
                        throw $e;
                }
-               
+
                wfDebug( __METHOD__.": deleted db items, applying file transactions\n" );
                $transaction->commit();
                FileStore::unlock();
 
-               
+
                // Update site_stats
                $site_stats = $dbw->tableName( 'site_stats' );
                $dbw->query( "UPDATE $site_stats SET ss_images=ss_images-1", __METHOD__ );
-               
+
                $this->purgeEverything( $urlArr );
-               
+
                return true;
        }
-       
-       
+
+
        /**
         * Delete an old version of the image.
         *
@@ -1851,12 +1891,12 @@ class Image
        function deleteOld( $archiveName, $reason ) {
                $transaction = new FSTransaction();
                $urlArr = array();
-               
+
                if( !FileStore::lock() ) {
                        wfDebug( __METHOD__.": failed to acquire file store lock, aborting\n" );
                        return false;
                }
-               
+
                $transaction = new FSTransaction();
                try {
                        $dbw = wfGetDB( DB_MASTER );
@@ -1869,11 +1909,11 @@ class Image
                        FileStore::unlock();
                        throw $e;
                }
-               
+
                wfDebug( __METHOD__.": deleted db items, applying file transaction\n" );
                $transaction->commit();
                FileStore::unlock();
-               
+
                $this->purgeDescription();
 
                // Squid purging
@@ -1886,7 +1926,7 @@ class Image
                }
                return true;
        }
-       
+
        /**
         * Delete the current version of a file.
         * May throw a database error.
@@ -1960,12 +2000,12 @@ class Image
         */
        private function prepareDeleteVersion( $path, $reason, $table, $fieldMap, $where, $fname ) {
                global $wgUser, $wgSaveDeletedFiles;
-               
+
                // Dupe the file into the file store
                if( file_exists( $path ) ) {
                        if( $wgSaveDeletedFiles ) {
                                $group = 'deleted';
-                               
+
                                $store = FileStore::get( $group );
                                $key = FileStore::calculateKey( $path, $this->extension );
                                $transaction = $store->insert( $key, $path,
@@ -1981,24 +2021,24 @@ class Image
                        $key = null;
                        $transaction = new FSTransaction(); // empty
                }
-               
+
                if( $transaction === false ) {
                        // Fail to restore?
                        wfDebug( __METHOD__.": import to file store failed, aborting\n" );
                        throw new MWException( "Could not archive and delete file $path" );
                        return false;
                }
-               
+
                $dbw = wfGetDB( DB_MASTER );
                $storageMap = array(
                        'fa_storage_group' => $dbw->addQuotes( $group ),
                        'fa_storage_key'   => $dbw->addQuotes( $key ),
-                       
+
                        'fa_deleted_user'      => $dbw->addQuotes( $wgUser->getId() ),
                        'fa_deleted_timestamp' => $dbw->timestamp(),
                        'fa_deleted_reason'    => $dbw->addQuotes( $reason ) );
                $allFields = array_merge( $storageMap, $fieldMap );
-               
+
                try {
                        if( $wgSaveDeletedFiles ) {
                                $dbw->insertSelect( 'filearchive', $table, $allFields, $where, $fname );
@@ -2011,10 +2051,10 @@ class Image
                        $transaction->rollback();
                        throw $e;
                }
-               
+
                return $transaction;
        }
-       
+
        /**
         * Restore all or specified deleted revisions to the given file.
         * Permissions and logging are left to the caller.
@@ -2031,31 +2071,31 @@ class Image
                        wfDebug( __METHOD__." could not acquire filestore lock\n" );
                        return false;
                }
-               
+
                $transaction = new FSTransaction();
                try {
                        $dbw = wfGetDB( DB_MASTER );
                        $dbw->begin();
-                       
+
                        // Re-confirm whether this image presently exists;
                        // if no we'll need to create an image record for the
                        // first item we restore.
                        $exists = $dbw->selectField( 'image', '1',
                                array( 'img_name' => $this->name ),
                                __METHOD__ );
-                       
+
                        // Fetch all or selected archived revisions for the file,
                        // sorted from the most recent to the oldest.
                        $conditions = array( 'fa_name' => $this->name );
                        if( $versions ) {
                                $conditions['fa_id'] = $versions;
                        }
-                       
+
                        $result = $dbw->select( 'filearchive', '*',
                                $conditions,
                                __METHOD__,
                                array( 'ORDER BY' => 'fa_timestamp DESC' ) );
-                       
+
                        if( $dbw->numRows( $result ) < count( $versions ) ) {
                                // There's some kind of conflict or confusion;
                                // we can't restore everything we were asked to.
@@ -2072,7 +2112,7 @@ class Image
                                FileStore::unlock();
                                return true;
                        }
-                       
+
                        $revisions = 0;
                        while( $row = $dbw->fetchObject( $result ) ) {
                                $revisions++;
@@ -2081,21 +2121,21 @@ class Image
                                        wfDebug( __METHOD__.": skipping row with no file.\n" );
                                        continue;
                                }
-                               
+
                                if( $revisions == 1 && !$exists ) {
                                        $destDir = wfImageDir( $row->fa_name );
                                        if ( !is_dir( $destDir ) ) {
                                                wfMkdirParents( $destDir );
                                        }
                                        $destPath = $destDir . DIRECTORY_SEPARATOR . $row->fa_name;
-                                       
+
                                        // We may have to fill in data if this was originally
                                        // an archived file revision.
                                        if( is_null( $row->fa_metadata ) ) {
                                                $tempFile = $store->filePath( $row->fa_storage_key );
                                                $metadata = serialize( $this->retrieveExifData( $tempFile ) );
-                                               
-                                               $magic = wfGetMimeMagic();
+
+                                               $magic = MimeMagic::singleton();
                                                $mime = $magic->guessMimeType( $tempFile, true );
                                                $media_type = $magic->getMediaType( $tempFile, $mime );
                                                list( $major_mime, $minor_mime ) = self::splitMime( $mime );
@@ -2105,7 +2145,7 @@ class Image
                                                $minor_mime = $row->fa_minor_mime;
                                                $media_type = $row->fa_media_type;
                                        }
-                                       
+
                                        $table = 'image';
                                        $fields = array(
                                                'img_name'        => $row->fa_name,
@@ -2136,7 +2176,7 @@ class Image
                                                wfMkdirParents( $destDir );
                                        }
                                        $destPath = $destDir . DIRECTORY_SEPARATOR . $archiveName;
-                                       
+
                                        $table = 'oldimage';
                                        $fields = array(
                                                'oi_name'         => $row->fa_name,
@@ -2150,13 +2190,13 @@ class Image
                                                'oi_user_text'    => $row->fa_user_text,
                                                'oi_timestamp'    => $row->fa_timestamp );
                                }
-                               
+
                                $dbw->insert( $table, $fields, __METHOD__ );
                                /// @fixme this delete is not totally safe, potentially
                                $dbw->delete( 'filearchive',
                                        array( 'fa_id' => $row->fa_id ),
                                        __METHOD__ );
-                               
+
                                // Check if any other stored revisions use this file;
                                // if so, we shouldn't remove the file from the deletion
                                // archives so they will still work.
@@ -2172,44 +2212,127 @@ class Image
                                } else {
                                        $flags = 0;
                                }
-                               
+
                                $transaction->add( $store->export( $row->fa_storage_key,
                                        $destPath, $flags ) );
                        }
-                       
+
                        $dbw->immediateCommit();
                } catch( MWException $e ) {
                        wfDebug( __METHOD__." caught error, aborting\n" );
                        $transaction->rollback();
                        throw $e;
                }
-               
+
                $transaction->commit();
                FileStore::unlock();
-               
+
                if( $revisions > 0 ) {
                        if( !$exists ) {
                                wfDebug( __METHOD__." restored $revisions items, creating a new current\n" );
-                               
+
                                // Update site_stats
                                $site_stats = $dbw->tableName( 'site_stats' );
                                $dbw->query( "UPDATE $site_stats SET ss_images=ss_images+1", __METHOD__ );
-                               
+
                                $this->purgeEverything();
                        } else {
                                wfDebug( __METHOD__." restored $revisions as archived versions\n" );
                                $this->purgeDescription();
                        }
                }
-               
+
                return $revisions;
        }
-       
+
+       /**
+        * Select a page from a multipage document. Determines the page used for
+        * rendering thumbnails.
+        *
+        * @param $page Integer: page number, starting with 1
+        */
+       function selectPage( $page ) {
+               if( $this->initializeMultiPageXML() ) {
+                       wfDebug( __METHOD__." selecting page $page \n" );
+                       $this->page = $page;
+                       $o = $this->multiPageXML->BODY[0]->OBJECT[$page-1];
+                       $this->height = intval( $o['height'] );
+                       $this->width = intval( $o['width'] );
+               } else {
+                       wfDebug( __METHOD__." selectPage($page) for bogus multipage xml on '$this->name'\n" );
+                       return;
+               }
+       }
+
+       /**
+        * Lazy-initialize multipage XML metadata for DjVu files.
+        * @return bool true if $this->multiPageXML is set up and ready;
+        *              false if corrupt or otherwise failing
+        */
+       function initializeMultiPageXML() {
+               $this->load();
+               if ( isset( $this->multiPageXML ) ) {
+                       return true;
+               }
+
+               #
+               # Check for files uploaded prior to DJVU support activation,
+               # or damaged.
+               #
+               if( empty( $this->metadata ) || $this->metadata == serialize( array() ) ) {
+                       $deja = new DjVuImage( $this->imagePath );
+                       $this->metadata = $deja->retrieveMetaData();
+                       $this->purgeMetadataCache();
+
+                       # Update metadata in the database
+                       $dbw = wfGetDB( DB_MASTER );
+                       $dbw->update( 'image',
+                               array( 'img_metadata' => $this->metadata ),
+                               array( 'img_name' => $this->name ),
+                               __METHOD__
+                       );
+               }
+               wfSuppressWarnings();
+               try {
+                       $this->multiPageXML = new SimpleXMLElement( $this->metadata );
+               } catch( Exception $e ) {
+                       wfDebug( "Bogus multipage XML metadata on '$this->name'\n" );
+                       $this->multiPageXML = null;
+               }
+               wfRestoreWarnings();
+               return isset( $this->multiPageXML );
+       }
+
+       /**
+        * Returns 'true' if this image is a multipage document, e.g. a DJVU
+        * document.
+        *
+        * @return Bool
+        */
+       function isMultipage() {
+               return ( $this->mime == 'image/vnd.djvu' );
+       }
+
+       /**
+        * Returns the number of pages of a multipage document, or NULL for
+        * documents which aren't multipage documents
+        */
+       function pageCount() {
+               if ( ! $this->isMultipage() ) {
+                       return null;
+               }
+               if( $this->initializeMultiPageXML() ) {
+                       return count( $this->multiPageXML->xpath( '//OBJECT' ) );
+               } else {
+                       wfDebug( "Requested pageCount() for bogus multi-page metadata for '$this->name'\n" );
+                       return null;
+               }
+       }
+
 } //class
 
 /**
  * Wrapper class for thumbnail images
- * @package MediaWiki
  */
 class ThumbnailImage {
        /**