includes/media/DjVu.php

   1 <?php
   2 /**
   3  * Handler for DjVu 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
  24 /**
  25  * Handler for DjVu images
  26  *
  27  * @ingroup Media
  28  */
  29 class DjVuHandler extends ImageHandler {
  30
  31         /**
  32          * @return bool
  33          */
  34         function isEnabled() {
  35                 global $wgDjvuRenderer, $wgDjvuDump, $wgDjvuToXML;
  36                 if ( !$wgDjvuRenderer || ( !$wgDjvuDump && !$wgDjvuToXML ) ) {
  37                         wfDebug( "DjVu is disabled, please set \$wgDjvuRenderer and \$wgDjvuDump\n" );
  38                         return false;
  39                 } else {
  40                         return true;
  41                 }
  42         }
  43
  44         /**
  45          * @param $file
  46          * @return bool
  47          */
  48         function mustRender( $file ) {
  49                 return true;
  50         }
  51
  52         /**
  53          * @param $file
  54          * @return bool
  55          */
  56         function isMultiPage( $file ) {
  57                 return true;
  58         }
  59
  60         /**
  61          * @return array
  62          */
  63         function getParamMap() {
  64                 return array(
  65                         'img_width' => 'width',
  66                         'img_page' => 'page',
  67                 );
  68         }
  69
  70         /**
  71          * @param $name
  72          * @param $value
  73          * @return bool
  74          */
  75         function validateParam( $name, $value ) {
  76                 if ( in_array( $name, array( 'width', 'height', 'page' ) ) ) {
  77                         if ( $value <= 0 ) {
  78                                 return false;
  79                         } else {
  80                                 return true;
  81                         }
  82                 } else {
  83                         return false;
  84                 }
  85         }
  86
  87         /**
  88          * @param $params
  89          * @return bool|string
  90          */
  91         function makeParamString( $params ) {
  92                 $page = isset( $params['page'] ) ? $params['page'] : 1;
  93                 if ( !isset( $params['width'] ) ) {
  94                         return false;
  95                 }
  96                 return "page{$page}-{$params['width']}px";
  97         }
  98
  99         /**
 100          * @param $str
 101          * @return array|bool
 102          */
 103         function parseParamString( $str ) {
 104                 $m = false;
 105                 if ( preg_match( '/^page(\d+)-(\d+)px$/', $str, $m ) ) {
 106                         return array( 'width' => $m[2], 'page' => $m[1] );
 107                 } else {
 108                         return false;
 109                 }
 110         }
 111
 112         /**
 113          * @param $params
 114          * @return array
 115          */
 116         function getScriptParams( $params ) {
 117                 return array(
 118                         'width' => $params['width'],
 119                         'page' => $params['page'],
 120                 );
 121         }
 122
 123         /**
 124          * @param $image File
 125          * @param  $dstPath
 126          * @param  $dstUrl
 127          * @param  $params
 128          * @param int $flags
 129          * @return MediaTransformError|ThumbnailImage|TransformParameterError
 130          */
 131         function doTransform( $image, $dstPath, $dstUrl, $params, $flags = 0 ) {
 132                 global $wgDjvuRenderer, $wgDjvuPostProcessor;
 133
 134                 // Fetch XML and check it, to give a more informative error message than the one which
 135                 // normaliseParams will inevitably give.
 136                 $xml = $image->getMetadata();
 137                 if ( !$xml ) {
 138                         $width = isset( $params['width'] ) ? $params['width'] : 0;
 139                         $height = isset( $params['height'] ) ? $params['height'] : 0;
 140                         return new MediaTransformError( 'thumbnail_error', $width, $height,
 141                                 wfMessage( 'djvu_no_xml' )->text() );
 142                 }
 143
 144                 if ( !$this->normaliseParams( $image, $params ) ) {
 145                         return new TransformParameterError( $params );
 146                 }
 147                 $width = $params['width'];
 148                 $height = $params['height'];
 149                 $page = $params['page'];
 150                 if ( $page > $this->pageCount( $image ) ) {
 151                         return new MediaTransformError(
 152                                 'thumbnail_error',
 153                                 $width,
 154                                 $height,
 155                                 wfMessage( 'djvu_page_error' )->text()
 156                         );
 157                 }
 158
 159                 if ( $flags & self::TRANSFORM_LATER ) {
 160                         $params = array(
 161                                 'width' => $width,
 162                                 'height' => $height,
 163                                 'page' => $page
 164                         );
 165                         return new ThumbnailImage( $image, $dstUrl, $dstPath, $params );
 166                 }
 167
 168                 if ( !wfMkdirParents( dirname( $dstPath ), null, __METHOD__ ) ) {
 169                         return new MediaTransformError(
 170                                 'thumbnail_error',
 171                                 $width,
 172                                 $height,
 173                                 wfMessage( 'thumbnail_dest_directory' )->text()
 174                         );
 175                 }
 176
 177                 $srcPath = $image->getLocalRefPath();
 178                 # Use a subshell (brackets) to aggregate stderr from both pipeline commands
 179                 # before redirecting it to the overall stdout. This works in both Linux and Windows XP.
 180                 $cmd = '(' . wfEscapeShellArg( $wgDjvuRenderer ) . " -format=ppm -page={$page}" .
 181                         " -size={$params['physicalWidth']}x{$params['physicalHeight']} " .
 182                         wfEscapeShellArg( $srcPath );
 183                 if ( $wgDjvuPostProcessor ) {
 184                         $cmd .= " | {$wgDjvuPostProcessor}";
 185                 }
 186                 $cmd .= ' > ' . wfEscapeShellArg( $dstPath ) . ') 2>&1';
 187                 wfProfileIn( 'ddjvu' );
 188                 wfDebug( __METHOD__ . ": $cmd\n" );
 189                 $retval = '';
 190                 $err = wfShellExec( $cmd, $retval );
 191                 wfProfileOut( 'ddjvu' );
 192
 193                 $removed = $this->removeBadFile( $dstPath, $retval );
 194                 if ( $retval != 0 || $removed ) {
 195                         wfDebugLog( 'thumbnail',
 196                                 sprintf( 'thumbnail failed on %s: error %d "%s" from "%s"',
 197                                         wfHostname(), $retval, trim( $err ), $cmd ) );
 198                         return new MediaTransformError( 'thumbnail_error', $width, $height, $err );
 199                 } else {
 200                         $params = array(
 201                                 'width' => $width,
 202                                 'height' => $height,
 203                                 'page' => $page
 204                         );
 205                         return new ThumbnailImage( $image, $dstUrl, $dstPath, $params );
 206                 }
 207         }
 208
 209         /**
 210          * Cache an instance of DjVuImage in an Image object, return that instance
 211          *
 212          * @return DjVuImage
 213          */
 214         function getDjVuImage( $image, $path ) {
 215                 if ( !$image ) {
 216                         $deja = new DjVuImage( $path );
 217                 } elseif ( !isset( $image->dejaImage ) ) {
 218                         $deja = $image->dejaImage = new DjVuImage( $path );
 219                 } else {
 220                         $deja = $image->dejaImage;
 221                 }
 222                 return $deja;
 223         }
 224
 225         /**
 226          * Cache a document tree for the DjVu XML metadata
 227          * @param $image File
 228          * @param $gettext Boolean: DOCUMENT (Default: false)
 229          * @return bool
 230          */
 231         function getMetaTree( $image, $gettext = false ) {
 232                 if ( isset( $image->dejaMetaTree ) ) {
 233                         return $image->dejaMetaTree;
 234                 }
 235
 236                 $metadata = $image->getMetadata();
 237                 if ( !$this->isMetadataValid( $image, $metadata ) ) {
 238                         wfDebug( "DjVu XML metadata is invalid or missing, should have been fixed in upgradeRow\n" );
 239                         return false;
 240                 }
 241                 wfProfileIn( __METHOD__ );
 242
 243                 wfSuppressWarnings();
 244                 try {
 245                         // Set to false rather than null to avoid further attempts
 246                         $image->dejaMetaTree = false;
 247                         $image->djvuTextTree = false;
 248                         $tree = new SimpleXMLElement( $metadata );
 249                         if( $tree->getName() == 'mw-djvu' ) {
 250                                 foreach( $tree->children() as $b ) {
 251                                         if( $b->getName() == 'DjVuTxt' ) {
 252                                                 $image->djvuTextTree = $b;
 253                                         }
 254                                         elseif ( $b->getName() == 'DjVuXML' ) {
 255                                                 $image->dejaMetaTree = $b;
 256                                         }
 257                                 }
 258                         } else {
 259                                 $image->dejaMetaTree = $tree;
 260                         }
 261                 } catch( Exception $e ) {
 262                         wfDebug( "Bogus multipage XML metadata on '{$image->getName()}'\n" );
 263                 }
 264                 wfRestoreWarnings();
 265                 wfProfileOut( __METHOD__ );
 266                 if( $gettext ) {
 267                         return $image->djvuTextTree;
 268                 } else {
 269                         return $image->dejaMetaTree;
 270                 }
 271         }
 272
 273         function getImageSize( $image, $path ) {
 274                 return $this->getDjVuImage( $image, $path )->getImageSize();
 275         }
 276
 277         function getThumbType( $ext, $mime, $params = null ) {
 278                 global $wgDjvuOutputExtension;
 279                 static $mime;
 280                 if ( !isset( $mime ) ) {
 281                         $magic = MimeMagic::singleton();
 282                         $mime = $magic->guessTypesForExtension( $wgDjvuOutputExtension );
 283                 }
 284                 return array( $wgDjvuOutputExtension, $mime );
 285         }
 286
 287         function getMetadata( $image, $path ) {
 288                 wfDebug( "Getting DjVu metadata for $path\n" );
 289                 return $this->getDjVuImage( $image, $path )->retrieveMetaData();
 290         }
 291
 292         function getMetadataType( $image ) {
 293                 return 'djvuxml';
 294         }
 295
 296         function isMetadataValid( $image, $metadata ) {
 297                 return !empty( $metadata ) && $metadata != serialize( array() );
 298         }
 299
 300         function pageCount( $image ) {
 301                 $tree = $this->getMetaTree( $image );
 302                 if ( !$tree ) {
 303                         return false;
 304                 }
 305                 return count( $tree->xpath( '//OBJECT' ) );
 306         }
 307
 308         function getPageDimensions( $image, $page ) {
 309                 $tree = $this->getMetaTree( $image );
 310                 if ( !$tree ) {
 311                         return false;
 312                 }
 313
 314                 $o = $tree->BODY[0]->OBJECT[$page - 1];
 315                 if ( $o ) {
 316                         return array(
 317                                 'width' => intval( $o['width'] ),
 318                                 'height' => intval( $o['height'] )
 319                         );
 320                 } else {
 321                         return false;
 322                 }
 323         }
 324
 325         function getPageText( $image, $page ) {
 326                 $tree = $this->getMetaTree( $image, true );
 327                 if ( !$tree ) {
 328                         return false;
 329                 }
 330
 331                 $o = $tree->BODY[0]->PAGE[$page - 1];
 332                 if ( $o ) {
 333                         $txt = $o['value'];
 334                         return $txt;
 335                 } else {
 336                         return false;
 337                 }
 338
 339         }
 340
 341 }