MediaWiki  REL1_31
DjVuImage.php
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1 <?php
36 class DjVuImage {
40  const DJVUTXT_MEMORY_LIMIT = 300000;
41 
45  function __construct( $filename ) {
46  $this->mFilename = $filename;
47  }
48 
53  public function isValid() {
54  $info = $this->getInfo();
55 
56  return $info !== false;
57  }
58 
63  public function getImageSize() {
64  $data = $this->getInfo();
65 
66  if ( $data !== false ) {
67  $width = $data['width'];
68  $height = $data['height'];
69 
70  return [ $width, $height, 'DjVu',
71  "width=\"$width\" height=\"$height\"" ];
72  }
73 
74  return false;
75  }
76 
77  // ---------
78 
82  function dump() {
83  $file = fopen( $this->mFilename, 'rb' );
84  $header = fread( $file, 12 );
85  $arr = unpack( 'a4magic/a4chunk/NchunkLength', $header );
86  $chunk = $arr['chunk'];
87  $chunkLength = $arr['chunkLength'];
88  echo "$chunk $chunkLength\n";
89  $this->dumpForm( $file, $chunkLength, 1 );
90  fclose( $file );
91  }
92 
93  private function dumpForm( $file, $length, $indent ) {
94  $start = ftell( $file );
95  $secondary = fread( $file, 4 );
96  echo str_repeat( ' ', $indent * 4 ) . "($secondary)\n";
97  while ( ftell( $file ) - $start < $length ) {
98  $chunkHeader = fread( $file, 8 );
99  if ( $chunkHeader == '' ) {
100  break;
101  }
102  $arr = unpack( 'a4chunk/NchunkLength', $chunkHeader );
103  $chunk = $arr['chunk'];
104  $chunkLength = $arr['chunkLength'];
105  echo str_repeat( ' ', $indent * 4 ) . "$chunk $chunkLength\n";
106 
107  if ( $chunk == 'FORM' ) {
108  $this->dumpForm( $file, $chunkLength, $indent + 1 );
109  } else {
110  fseek( $file, $chunkLength, SEEK_CUR );
111  if ( $chunkLength & 1 == 1 ) {
112  // Padding byte between chunks
113  fseek( $file, 1, SEEK_CUR );
114  }
115  }
116  }
117  }
118 
119  function getInfo() {
120  Wikimedia\suppressWarnings();
121  $file = fopen( $this->mFilename, 'rb' );
122  Wikimedia\restoreWarnings();
123  if ( $file === false ) {
124  wfDebug( __METHOD__ . ": missing or failed file read\n" );
125 
126  return false;
127  }
128 
129  $header = fread( $file, 16 );
130  $info = false;
131 
132  if ( strlen( $header ) < 16 ) {
133  wfDebug( __METHOD__ . ": too short file header\n" );
134  } else {
135  $arr = unpack( 'a4magic/a4form/NformLength/a4subtype', $header );
136 
137  $subtype = $arr['subtype'];
138  if ( $arr['magic'] != 'AT&T' ) {
139  wfDebug( __METHOD__ . ": not a DjVu file\n" );
140  } elseif ( $subtype == 'DJVU' ) {
141  // Single-page document
142  $info = $this->getPageInfo( $file );
143  } elseif ( $subtype == 'DJVM' ) {
144  // Multi-page document
145  $info = $this->getMultiPageInfo( $file, $arr['formLength'] );
146  } else {
147  wfDebug( __METHOD__ . ": unrecognized DJVU file type '{$arr['subtype']}'\n" );
148  }
149  }
150  fclose( $file );
151 
152  return $info;
153  }
154 
155  private function readChunk( $file ) {
156  $header = fread( $file, 8 );
157  if ( strlen( $header ) < 8 ) {
158  return [ false, 0 ];
159  } else {
160  $arr = unpack( 'a4chunk/Nlength', $header );
161 
162  return [ $arr['chunk'], $arr['length'] ];
163  }
164  }
165 
166  private function skipChunk( $file, $chunkLength ) {
167  fseek( $file, $chunkLength, SEEK_CUR );
168 
169  if ( $chunkLength & 0x01 == 1 && !feof( $file ) ) {
170  // padding byte
171  fseek( $file, 1, SEEK_CUR );
172  }
173  }
174 
175  private function getMultiPageInfo( $file, $formLength ) {
176  // For now, we'll just look for the first page in the file
177  // and report its information, hoping others are the same size.
178  $start = ftell( $file );
179  do {
180  list( $chunk, $length ) = $this->readChunk( $file );
181  if ( !$chunk ) {
182  break;
183  }
184 
185  if ( $chunk == 'FORM' ) {
186  $subtype = fread( $file, 4 );
187  if ( $subtype == 'DJVU' ) {
188  wfDebug( __METHOD__ . ": found first subpage\n" );
189 
190  return $this->getPageInfo( $file );
191  }
192  $this->skipChunk( $file, $length - 4 );
193  } else {
194  wfDebug( __METHOD__ . ": skipping '$chunk' chunk\n" );
195  $this->skipChunk( $file, $length );
196  }
197  } while ( $length != 0 && !feof( $file ) && ftell( $file ) - $start < $formLength );
198 
199  wfDebug( __METHOD__ . ": multi-page DJVU file contained no pages\n" );
200 
201  return false;
202  }
203 
204  private function getPageInfo( $file ) {
205  list( $chunk, $length ) = $this->readChunk( $file );
206  if ( $chunk != 'INFO' ) {
207  wfDebug( __METHOD__ . ": expected INFO chunk, got '$chunk'\n" );
208 
209  return false;
210  }
211 
212  if ( $length < 9 ) {
213  wfDebug( __METHOD__ . ": INFO should be 9 or 10 bytes, found $length\n" );
214 
215  return false;
216  }
217  $data = fread( $file, $length );
218  if ( strlen( $data ) < $length ) {
219  wfDebug( __METHOD__ . ": INFO chunk cut off\n" );
220 
221  return false;
222  }
223 
224  $arr = unpack(
225  'nwidth/' .
226  'nheight/' .
227  'Cminor/' .
228  'Cmajor/' .
229  'vresolution/' .
230  'Cgamma', $data );
231 
232  # Newer files have rotation info in byte 10, but we don't use it yet.
233 
234  return [
235  'width' => $arr['width'],
236  'height' => $arr['height'],
237  'version' => "{$arr['major']}.{$arr['minor']}",
238  'resolution' => $arr['resolution'],
239  'gamma' => $arr['gamma'] / 10.0 ];
240  }
241 
246  function retrieveMetaData() {
248 
249  if ( !$this->isValid() ) {
250  return false;
251  }
252 
253  if ( isset( $wgDjvuDump ) ) {
254  # djvudump is faster as of version 3.5
255  # https://sourceforge.net/p/djvu/bugs/71/
256  $cmd = wfEscapeShellArg( $wgDjvuDump ) . ' ' . wfEscapeShellArg( $this->mFilename );
257  $dump = wfShellExec( $cmd );
258  $xml = $this->convertDumpToXML( $dump );
259  } elseif ( isset( $wgDjvuToXML ) ) {
260  $cmd = wfEscapeShellArg( $wgDjvuToXML ) . ' --without-anno --without-text ' .
261  wfEscapeShellArg( $this->mFilename );
262  $xml = wfShellExec( $cmd );
263  } else {
264  $xml = null;
265  }
266  # Text layer
267  if ( isset( $wgDjvuTxt ) ) {
268  $cmd = wfEscapeShellArg( $wgDjvuTxt ) . ' --detail=page ' . wfEscapeShellArg( $this->mFilename );
269  wfDebug( __METHOD__ . ": $cmd\n" );
270  $retval = '';
271  $txt = wfShellExec( $cmd, $retval, [], [ 'memory' => self::DJVUTXT_MEMORY_LIMIT ] );
272  if ( $retval == 0 ) {
273  # Strip some control characters
274  $txt = preg_replace( "/[\013\035\037]/", "", $txt );
275  $reg = <<<EOR
276  /\‍(page\s[\d-]*\s[\d-]*\s[\d-]*\s[\d-]*\s*"
277  ((?> # Text to match is composed of atoms of either:
278  \\\\. # - any escaped character
279  | # - any character different from " and \
280  [^"\\\\]+
281  )*?)
282  "\s*\‍)
283  | # Or page can be empty ; in this case, djvutxt dumps ()
284  \‍(\s*()\)/sx
285 EOR;
286  $txt = preg_replace_callback( $reg, [ $this, 'pageTextCallback' ], $txt );
287  $txt = "<DjVuTxt>\n<HEAD></HEAD>\n<BODY>\n" . $txt . "</BODY>\n</DjVuTxt>\n";
288  $xml = preg_replace( "/<DjVuXML>/", "<mw-djvu><DjVuXML>", $xml, 1 );
289  $xml = $xml . $txt . '</mw-djvu>';
290  }
291  }
292 
293  return $xml;
294  }
295 
297  # Get rid of invalid UTF-8, strip control characters
298  $val = htmlspecialchars( UtfNormal\Validator::cleanUp( stripcslashes( $matches[1] ) ) );
299  $val = str_replace( [ "\n", '�' ], [ '&#10;', '' ], $val );
300  return '<PAGE value="' . $val . '" />';
301  }
302 
308  function convertDumpToXML( $dump ) {
309  if ( strval( $dump ) == '' ) {
310  return false;
311  }
312 
313  $xml = <<<EOT
314 <?xml version="1.0" ?>
315 <!DOCTYPE DjVuXML PUBLIC "-//W3C//DTD DjVuXML 1.1//EN" "pubtext/DjVuXML-s.dtd">
316 <DjVuXML>
317 <HEAD></HEAD>
318 <BODY>
319 EOT;
320 
321  $dump = str_replace( "\r", '', $dump );
322  $line = strtok( $dump, "\n" );
323  $m = false;
324  $good = false;
325  if ( preg_match( '/^( *)FORM:DJVU/', $line, $m ) ) {
326  # Single-page
327  if ( $this->parseFormDjvu( $line, $xml ) ) {
328  $good = true;
329  } else {
330  return false;
331  }
332  } elseif ( preg_match( '/^( *)FORM:DJVM/', $line, $m ) ) {
333  # Multi-page
334  $parentLevel = strlen( $m[1] );
335  # Find DIRM
336  $line = strtok( "\n" );
337  while ( $line !== false ) {
338  $childLevel = strspn( $line, ' ' );
339  if ( $childLevel <= $parentLevel ) {
340  # End of chunk
341  break;
342  }
343 
344  if ( preg_match( '/^ *DIRM.*indirect/', $line ) ) {
345  wfDebug( "Indirect multi-page DjVu document, bad for server!\n" );
346 
347  return false;
348  }
349  if ( preg_match( '/^ *FORM:DJVU/', $line ) ) {
350  # Found page
351  if ( $this->parseFormDjvu( $line, $xml ) ) {
352  $good = true;
353  } else {
354  return false;
355  }
356  }
357  $line = strtok( "\n" );
358  }
359  }
360  if ( !$good ) {
361  return false;
362  }
363 
364  $xml .= "</BODY>\n</DjVuXML>\n";
365 
366  return $xml;
367  }
368 
369  function parseFormDjvu( $line, &$xml ) {
370  $parentLevel = strspn( $line, ' ' );
371  $line = strtok( "\n" );
372 
373  # Find INFO
374  while ( $line !== false ) {
375  $childLevel = strspn( $line, ' ' );
376  if ( $childLevel <= $parentLevel ) {
377  # End of chunk
378  break;
379  }
380 
381  if ( preg_match(
382  '/^ *INFO *\[\d*\] *DjVu *(\d+)x(\d+), *\w*, *(\d+) *dpi, *gamma=([0-9.-]+)/',
383  $line,
384  $m
385  ) ) {
386  $xml .= Xml::tags(
387  'OBJECT',
388  [
389  # 'data' => '',
390  # 'type' => 'image/x.djvu',
391  'height' => $m[2],
392  'width' => $m[1],
393  # 'usemap' => '',
394  ],
395  "\n" .
396  Xml::element( 'PARAM', [ 'name' => 'DPI', 'value' => $m[3] ] ) . "\n" .
397  Xml::element( 'PARAM', [ 'name' => 'GAMMA', 'value' => $m[4] ] ) . "\n"
398  ) . "\n";
399 
400  return true;
401  }
402  $line = strtok( "\n" );
403  }
404 
405  # Not found
406  return false;
407  }
408 }
$wgDjvuTxt
$wgDjvuTxt
Path of the djvutxt DJVU text extraction utility Enable this and $wgDjvuDump to enable text layer ext...
Definition: DefaultSettings.php:1546
Xml\tags
static tags( $element, $attribs=null, $contents)
Same as Xml::element(), but does not escape contents.
Definition: Xml.php:131
DjVuImage\skipChunk
skipChunk( $file, $chunkLength)
Definition: DjVuImage.php:166
DjVuImage
Support for detecting/validating DjVu image files and getting some basic file metadata (resolution et...
Definition: DjVuImage.php:36
DjVuImage\parseFormDjvu
parseFormDjvu( $line, &$xml)
Definition: DjVuImage.php:369
page
target page
Definition: All_system_messages.txt:1267
php
injection txt This is an overview of how MediaWiki makes use of dependency injection The design described here grew from the discussion of RFC T384 The term dependency this means that anything an object needs to operate should be injected from the the object itself should only know narrow no concrete implementation of the logic it relies on The requirement to inject everything typically results in an architecture that based on two main types of and essentially stateless service objects that use other service objects to operate on the value objects As of the beginning MediaWiki is only starting to use the DI approach Much of the code still relies on global state or direct resulting in a highly cyclical dependency which acts as the top level factory for services in MediaWiki which can be used to gain access to default instances of various services MediaWikiServices however also allows new services to be defined and default services to be redefined Services are defined or redefined by providing a callback the instantiator that will return a new instance of the service When it will create an instance of MediaWikiServices and populate it with the services defined in the files listed by thereby bootstrapping the DI framework Per $wgServiceWiringFiles lists includes ServiceWiring php
Definition: injection.txt:37
DjVuImage\getPageInfo
getPageInfo( $file)
Definition: DjVuImage.php:204
DjVuImage\pageTextCallback
pageTextCallback( $matches)
Definition: DjVuImage.php:296
DjVuImage\DJVUTXT_MEMORY_LIMIT
const DJVUTXT_MEMORY_LIMIT
@const DJVUTXT_MEMORY_LIMIT Memory limit for the DjVu description software
Definition: DjVuImage.php:40
UtfNormal
Unicode normalization routines for working with UTF-8 strings.
Definition: UtfNormal.php:48
$matches
$matches
Definition: NoLocalSettings.php:24
$wgDjvuToXML
$wgDjvuToXML
Path of the djvutoxml executable This works like djvudump except much, much slower as of version 3....
Definition: DefaultSettings.php:1562
Xml\element
static element( $element, $attribs=null, $contents='', $allowShortTag=true)
Format an XML element with given attributes and, optionally, text content.
Definition: Xml.php:39
version
Prior to version
Definition: maintenance.txt:1
global
when a variable name is used in a it is silently declared as a new masking the global
Definition: design.txt:95
DjVuImage\dumpForm
dumpForm( $file, $length, $indent)
Definition: DjVuImage.php:93
wfDebug
wfDebug( $text, $dest='all', array $context=[])
Sends a line to the debug log if enabled or, optionally, to a comment in output.
Definition: GlobalFunctions.php:994
list
deferred txt A few of the database updates required by various functions here can be deferred until after the result page is displayed to the user For updating the view updating the linked to tables after a etc PHP does not yet have any way to tell the server to actually return and disconnect while still running these but it might have such a feature in the future We handle these by creating a deferred update object and putting those objects on a global list
Definition: deferred.txt:11
DjVuImage\readChunk
readChunk( $file)
Definition: DjVuImage.php:155
$line
$line
Definition: cdb.php:59
$header
$header
Definition: updateCredits.php:35
wfEscapeShellArg
wfEscapeShellArg()
Version of escapeshellarg() that works better on Windows.
Definition: GlobalFunctions.php:2209
and
and(b) You must cause any modified files to carry prominent notices stating that You changed the files
DjVuImage\isValid
isValid()
Check if the given file is indeed a valid DjVu image file.
Definition: DjVuImage.php:53
DjVuImage\getInfo
getInfo()
Definition: DjVuImage.php:119
DjVuImage\retrieveMetaData
retrieveMetaData()
Return an XML string describing the DjVu image.
Definition: DjVuImage.php:246
DjVuImage\dump
dump()
For debugging; dump the IFF chunk structure.
Definition: DjVuImage.php:82
in
null for the wiki Added in
Definition: hooks.txt:1591
$wgDjvuDump
$wgDjvuDump
Path of the djvudump executable Enable this and $wgDjvuRenderer to enable djvu rendering example: $wg...
Definition: DefaultSettings.php:1532
DjVuImage\getMultiPageInfo
getMultiPageInfo( $file, $formLength)
Definition: DjVuImage.php:175
DjVuImage\convertDumpToXML
convertDumpToXML( $dump)
Hack to temporarily work around djvutoxml bug.
Definition: DjVuImage.php:308
$retval
please add to it if you re going to add events to the MediaWiki code where normally authentication against an external auth plugin would be creating a account incomplete not yet checked for validity & $retval
Definition: hooks.txt:266
DjVuImage\__construct
__construct( $filename)
Definition: DjVuImage.php:45
DjVuImage\getImageSize
getImageSize()
Return data in the style of getimagesize()
Definition: DjVuImage.php:63
wfShellExec
wfShellExec( $cmd, &$retval=null, $environ=[], $limits=[], $options=[])
Execute a shell command, with time and memory limits mirrored from the PHP configuration if supported...
Definition: GlobalFunctions.php:2250