includes/Revision.php

   1 <?php
   2 /**
   3  * @package MediaWiki
   4  * @todo document
   5  */
   6
   7 /** */
   8 require_once( 'Database.php' );
   9 require_once( 'Article.php' );
  10
  11 /** @+ */
  12 define( 'MW_REV_DELETED_TEXT',       1 );
  13 define( 'MW_REV_DELETED_COMMENT',    2 );
  14 define( 'MW_REV_DELETED_USER',       4 );
  15 define( 'MW_REV_DELETED_RESTRICTED', 8 );
  16 /** @- */
  17
  18 /**
  19  * @package MediaWiki
  20  * @todo document
  21  */
  22 class Revision {
  23         /**
  24          * Load a page revision from a given revision ID number.
  25          * Returns null if no such revision can be found.
  26          *
  27          * @param int $id
  28          * @static
  29          * @access public
  30          */
  31         function newFromId( $id ) {
  32                 return Revision::newFromConds(
  33                         array( 'page_id=rev_page',
  34                                'rev_id' => intval( $id ) ) );
  35         }
  36
  37         /**
  38          * Load either the current, or a specified, revision
  39          * that's attached to a given title. If not attached
  40          * to that title, will return null.
  41          *
  42          * @param Title $title
  43          * @param int $id
  44          * @return Revision
  45          * @access public
  46          * @static
  47          */
  48         function newFromTitle( &$title, $id = 0 ) {
  49                 if( $id ) {
  50                         $matchId = intval( $id );
  51                 } else {
  52                         $matchId = 'page_latest';
  53                 }
  54                 return Revision::newFromConds(
  55                         array( "rev_id=$matchId",
  56                                'page_id=rev_page',
  57                                'page_namespace' => $title->getNamespace(),
  58                                'page_title'     => $title->getDbkey() ) );
  59         }
  60
  61         /**
  62          * Load either the current, or a specified, revision
  63          * that's attached to a given page. If not attached
  64          * to that page, will return null.
  65          *
  66          * @param Database $db
  67          * @param int $pageid
  68          * @param int $id
  69          * @return Revision
  70          * @access public
  71          */
  72         function loadFromPageId( &$db, $pageid, $id = 0 ) {
  73                 $conds=array('page_id=rev_page','rev_page'=>intval( $pageid ), 'page_id'=>intval( $pageid ));
  74                 if( $id ) {
  75                         $conds['rev_id']=intval($id);
  76                 } else {
  77                         $conds[]='rev_id=page_latest';
  78                 }
  79                 return Revision::loadFromConds( $db, $conds );
  80         }
  81
  82         /**
  83          * Load either the current, or a specified, revision
  84          * that's attached to a given page. If not attached
  85          * to that page, will return null.
  86          *
  87          * @param Database $db
  88          * @param Title $title
  89          * @param int $id
  90          * @return Revision
  91          * @access public
  92          */
  93         function loadFromTitle( &$db, $title, $id = 0 ) {
  94                 if( $id ) {
  95                         $matchId = intval( $id );
  96                 } else {
  97                         $matchId = 'page_latest';
  98                 }
  99                 return Revision::loadFromConds(
 100                         $db,
 101                         array( "rev_id=$matchId",
 102                                'page_id=rev_page',
 103                                'page_namespace' => $title->getNamespace(),
 104                                'page_title'     => $title->getDbkey() ) );
 105         }
 106
 107         /**
 108          * Load the revision for the given title with the given timestamp.
 109          * WARNING: Timestamps may in some circumstances not be unique,
 110          * so this isn't the best key to use.
 111          *
 112          * @param Database $db
 113          * @param Title $title
 114          * @param string $timestamp
 115          * @return Revision
 116          * @access public
 117          * @static
 118          */
 119         function loadFromTimestamp( &$db, &$title, $timestamp ) {
 120                 return Revision::loadFromConds(
 121                         $db,
 122                         array( 'rev_timestamp'  => $db->timestamp( $timestamp ),
 123                                'page_id=rev_page',
 124                                'page_namespace' => $title->getNamespace(),
 125                                'page_title'     => $title->getDbkey() ) );
 126         }
 127
 128         /**
 129          * Given a set of conditions, fetch a revision.
 130          *
 131          * @param array $conditions
 132          * @return Revision
 133          * @static
 134          * @access private
 135          */
 136         function newFromConds( $conditions ) {
 137                 $db =& wfGetDB( DB_SLAVE );
 138                 $row = Revision::loadFromConds( $db, $conditions );
 139                 if( is_null( $row ) ) {
 140                         $dbw =& wfGetDB( DB_MASTER );
 141                         $row = Revision::loadFromConds( $dbw, $conditions );
 142                 }
 143                 return $row;
 144         }
 145
 146         /**
 147          * Given a set of conditions, fetch a revision from
 148          * the given database connection.
 149          *
 150          * @param Database $db
 151          * @param array $conditions
 152          * @return Revision
 153          * @static
 154          * @access private
 155          */
 156         function loadFromConds( &$db, $conditions ) {
 157                 $res = Revision::fetchFromConds( $db, $conditions );
 158                 if( $res ) {
 159                         $row = $res->fetchObject();
 160                         $res->free();
 161                         if( $row ) {
 162                                 $ret = new Revision( $row );
 163                                 return $ret;
 164                         }
 165                 }
 166                 $ret = null;
 167                 return $ret;
 168         }
 169
 170         /**
 171          * Return a wrapper for a series of database rows to
 172          * fetch all of a given page's revisions in turn.
 173          * Each row can be fed to the constructor to get objects.
 174          *
 175          * @param Title $title
 176          * @return ResultWrapper
 177          * @static
 178          * @access public
 179          */
 180         function fetchAllRevisions( &$title ) {
 181                 return Revision::fetchFromConds(
 182                         wfGetDB( DB_SLAVE ),
 183                         array( 'page_namespace' => $title->getNamespace(),
 184                                'page_title'     => $title->getDbkey(),
 185                                'page_id=rev_page' ) );
 186         }
 187
 188         /**
 189          * Return a wrapper for a series of database rows to
 190          * fetch all of a given page's revisions in turn.
 191          * Each row can be fed to the constructor to get objects.
 192          *
 193          * @param Title $title
 194          * @return ResultWrapper
 195          * @static
 196          * @access public
 197          */
 198         function fetchRevision( &$title ) {
 199                 return Revision::fetchFromConds(
 200                         wfGetDB( DB_SLAVE ),
 201                         array( 'rev_id=page_latest',
 202                                'page_namespace' => $title->getNamespace(),
 203                                'page_title'     => $title->getDbkey(),
 204                                'page_id=rev_page' ) );
 205         }
 206
 207         /**
 208          * Given a set of conditions, return a ResultWrapper
 209          * which will return matching database rows with the
 210          * fields necessary to build Revision objects.
 211          *
 212          * @param Database $db
 213          * @param array $conditions
 214          * @return ResultWrapper
 215          * @static
 216          * @access private
 217          */
 218         function fetchFromConds( &$db, $conditions ) {
 219                 $res = $db->select(
 220                         array( 'page', 'revision' ),
 221                         array( 'page_namespace',
 222                                'page_title',
 223                                'page_latest',
 224                                'rev_id',
 225                                'rev_page',
 226                                'rev_text_id',
 227                                'rev_comment',
 228                                'rev_user_text',
 229                                'rev_user',
 230                                'rev_minor_edit',
 231                                'rev_timestamp',
 232                                'rev_deleted' ),
 233                         $conditions,
 234                         'Revision::fetchRow',
 235                         array( 'LIMIT' => 1 ) );
 236                 $ret = $db->resultObject( $res );
 237                 return $ret;
 238         }
 239
 240         /**
 241          * @param object $row
 242          * @access private
 243          */
 244         function Revision( $row ) {
 245                 if( is_object( $row ) ) {
 246                         $this->mId        = intval( $row->rev_id );
 247                         $this->mPage      = intval( $row->rev_page );
 248                         $this->mTextId    = intval( $row->rev_text_id );
 249                         $this->mComment   =         $row->rev_comment;
 250                         $this->mUserText  =         $row->rev_user_text;
 251                         $this->mUser      = intval( $row->rev_user );
 252                         $this->mMinorEdit = intval( $row->rev_minor_edit );
 253                         $this->mTimestamp =         $row->rev_timestamp;
 254                         $this->mDeleted   = intval( $row->rev_deleted );
 255
 256                         if( isset( $row->page_latest ) ) {
 257                                 $this->mCurrent   = ( $row->rev_id == $row->page_latest );
 258                                 $this->mTitle     = Title::makeTitle( $row->page_namespace,
 259                                                                       $row->page_title );
 260                         } else {
 261                                 $this->mCurrent = false;
 262                                 $this->mTitle = null;
 263                         }
 264
 265                         if( isset( $row->old_text ) ) {
 266                                 $this->mText  = $this->getRevisionText( $row );
 267                         } else {
 268                                 $this->mText  = null;
 269                         }
 270                 } elseif( is_array( $row ) ) {
 271                         // Build a new revision to be saved...
 272                         global $wgUser;
 273
 274                         $this->mId        = isset( $row['id']         ) ? intval( $row['id']         ) : null;
 275                         $this->mPage      = isset( $row['page']       ) ? intval( $row['page']       ) : null;
 276                         $this->mTextId    = isset( $row['text_id']    ) ? intval( $row['text_id']    ) : null;
 277                         $this->mUserText  = isset( $row['user_text']  ) ? strval( $row['user_text']  ) : $wgUser->getName();
 278                         $this->mUser      = isset( $row['user']       ) ? intval( $row['user']       ) : $wgUser->getId();
 279                         $this->mMinorEdit = isset( $row['minor_edit'] ) ? intval( $row['minor_edit'] ) : 0;
 280                         $this->mTimestamp = isset( $row['timestamp']  ) ? strval( $row['timestamp']  ) : wfTimestamp( TS_MW );
 281                         $this->mDeleted   = isset( $row['deleted']    ) ? intval( $row['deleted']    ) : 0;
 282
 283                         // Enforce spacing trimming on supplied text
 284                         $this->mComment   = isset( $row['comment']    ) ?  trim( strval( $row['comment'] ) ) : null;
 285                         $this->mText      = isset( $row['text']       ) ? rtrim( strval( $row['text']    ) ) : null;
 286
 287                         $this->mTitle     = null; # Load on demand if needed
 288                         $this->mCurrent   = false;
 289                 } else {
 290                         wfDebugDieBacktrace( 'Revision constructor passed invalid row format.' );
 291                 }
 292         }
 293
 294         /**#@+
 295          * @access public
 296          */
 297
 298         /**
 299          * @return int
 300          */
 301         function getId() {
 302                 return $this->mId;
 303         }
 304
 305         /**
 306          * @return int
 307          */
 308         function getTextId() {
 309                 return $this->mTextId;
 310         }
 311
 312         /**
 313          * Returns the title of the page associated with this entry.
 314          * @return Title
 315          */
 316         function getTitle() {
 317                 if( isset( $this->mTitle ) ) {
 318                         return $this->mTitle;
 319                 }
 320                 $dbr =& wfGetDB( DB_SLAVE );
 321                 $row = $dbr->selectRow(
 322                         array( 'page', 'revision' ),
 323                         array( 'page_namespace', 'page_title' ),
 324                         array( 'page_id=rev_page',
 325                                'rev_id' => $this->mId ),
 326                         'Revision::getTItle' );
 327                 if( $row ) {
 328                         $this->mTitle = Title::makeTitle( $row->page_namespace,
 329                                                            $row->page_title );
 330                 }
 331                 return $this->mTitle;
 332         }
 333
 334         /**
 335          * @return int
 336          */
 337         function getPage() {
 338                 return $this->mPage;
 339         }
 340
 341         /**
 342          * Fetch revision's user id if it's available to all users
 343          * @return int
 344          */
 345         function getUser() {
 346                 if( $this->isDeleted( MW_REV_DELETED_USER ) ) {
 347                         return 0;
 348                 } else {
 349                         return $this->mUser;
 350                 }
 351         }
 352
 353         /**
 354          * Fetch revision's user id without regard for the current user's permissions
 355          * @return string
 356          */
 357         function getRawUser() {
 358                 return $this->mUser;
 359         }
 360
 361         /**
 362          * Fetch revision's username if it's available to all users
 363          * @return string
 364          */
 365         function getUserText() {
 366                 if( $this->isDeleted( MW_REV_DELETED_USER ) ) {
 367                         return "";
 368                 } else {
 369                         return $this->mUserText;
 370                 }
 371         }
 372
 373         /**
 374          * Fetch revision's username without regard for view restrictions
 375          * @return string
 376          */
 377         function getRawUserText() {
 378                 return $this->mUserText;
 379         }
 380
 381         /**
 382          * Fetch revision comment if it's available to all users
 383          * @return string
 384          */
 385         function getComment() {
 386                 if( $this->isDeleted( MW_REV_DELETED_COMMENT ) ) {
 387                         return "";
 388                 } else {
 389                         return $this->mComment;
 390                 }
 391         }
 392
 393         /**
 394          * Fetch revision comment without regard for the current user's permissions
 395          * @return string
 396          */
 397         function getRawComment() {
 398                 return $this->mComment;
 399         }
 400
 401         /**
 402          * @return bool
 403          */
 404         function isMinor() {
 405                 return (bool)$this->mMinorEdit;
 406         }
 407
 408         /**
 409          * int $field one of MW_REV_DELETED_* bitfield constants
 410          * @return bool
 411          */
 412         function isDeleted( $field ) {
 413                 return ($this->mDeleted & $field) == $field;
 414         }
 415
 416         /**
 417          * Fetch revision text if it's available to all users
 418          * @return string
 419          */
 420         function getText() {
 421                 if( $this->isDeleted( MW_REV_DELETED_TEXT ) ) {
 422                         return "";
 423                 } else {
 424                         return $this->getRawText();
 425                 }
 426         }
 427
 428         /**
 429          * Fetch revision text without regard for view restrictions
 430          * @return string
 431          */
 432         function getRawText() {
 433                 if( is_null( $this->mText ) ) {
 434                         // Revision text is immutable. Load on demand:
 435                         $this->mText = $this->loadText();
 436                 }
 437                 return $this->mText;
 438         }
 439
 440         /**
 441          * @return string
 442          */
 443         function getTimestamp() {
 444                 return wfTimestamp(TS_MW, $this->mTimestamp);
 445         }
 446
 447         /**
 448          * @return bool
 449          */
 450         function isCurrent() {
 451                 return $this->mCurrent;
 452         }
 453
 454         /**
 455          * @return Revision
 456          */
 457         function getPrevious() {
 458                 $prev = $this->mTitle->getPreviousRevisionID( $this->mId );
 459                 if ( $prev ) {
 460                         return Revision::newFromTitle( $this->mTitle, $prev );
 461                 } else {
 462                         return null;
 463                 }
 464         }
 465
 466         /**
 467          * @return Revision
 468          */
 469         function getNext() {
 470                 $next = $this->mTitle->getNextRevisionID( $this->mId );
 471                 if ( $next ) {
 472                         return Revision::newFromTitle( $this->mTitle, $next );
 473                 } else {
 474                         return null;
 475                 }
 476         }
 477         /**#@-*/
 478
 479         /**
 480           * Get revision text associated with an old or archive row
 481           * $row is usually an object from wfFetchRow(), both the flags and the text
 482           * field must be included
 483           * @static
 484           * @param integer $row Id of a row
 485           * @param string $prefix table prefix (default 'old_')
 486           * @return string $text|false the text requested
 487           */
 488         function getRevisionText( $row, $prefix = 'old_' ) {
 489                 $fname = 'Revision::getRevisionText';
 490                 wfProfileIn( $fname );
 491
 492                 # Get data
 493                 $textField = $prefix . 'text';
 494                 $flagsField = $prefix . 'flags';
 495
 496                 if( isset( $row->$flagsField ) ) {
 497                         $flags = explode( ',', $row->$flagsField );
 498                 } else {
 499                         $flags = array();
 500                 }
 501
 502                 if( isset( $row->$textField ) ) {
 503                         $text = $row->$textField;
 504                 } else {
 505                         wfProfileOut( $fname );
 506                         return false;
 507                 }
 508
 509                 # Use external methods for external objects, text in table is URL-only then
 510                 if ( in_array( 'external', $flags ) ) {
 511                         $url=$text;
 512                         @list($proto,$path)=explode('://',$url,2);
 513                         if ($path=="") {
 514                                 wfProfileOut( $fname );
 515                                 return false;
 516                         }
 517                         require_once('ExternalStore.php');
 518                         $text=ExternalStore::fetchFromURL($url);
 519                 }
 520
 521                 // If the text was fetched without an error, convert it
 522                 if ( $text !== false ) {
 523                         if( in_array( 'gzip', $flags ) ) {
 524                                 # Deal with optional compression of archived pages.
 525                                 # This can be done periodically via maintenance/compressOld.php, and
 526                                 # as pages are saved if $wgCompressRevisions is set.
 527                                 $text = gzinflate( $text );
 528                         }
 529
 530                         if( in_array( 'object', $flags ) ) {
 531                                 # Generic compressed storage
 532                                 $obj = unserialize( $text );
 533                                 $text = $obj->getText();
 534                         }
 535
 536                         global $wgLegacyEncoding;
 537                         if( $wgLegacyEncoding && !in_array( 'utf-8', $flags ) ) {
 538                                 # Old revisions kept around in a legacy encoding?
 539                                 # Upconvert on demand.
 540                                 global $wgInputEncoding, $wgContLang;
 541                                 $text = $wgContLang->iconv( $wgLegacyEncoding, $wgInputEncoding . '//IGNORE', $text );
 542                         }
 543                 }
 544                 wfProfileOut( $fname );
 545                 return $text;
 546         }
 547
 548         /**
 549          * If $wgCompressRevisions is enabled, we will compress data.
 550          * The input string is modified in place.
 551          * Return value is the flags field: contains 'gzip' if the
 552          * data is compressed, and 'utf-8' if we're saving in UTF-8
 553          * mode.
 554          *
 555          * @static
 556          * @param mixed $text reference to a text
 557          * @return string
 558          */
 559         function compressRevisionText( &$text ) {
 560                 global $wgCompressRevisions;
 561                 $flags = array();
 562
 563                 # Revisions not marked this way will be converted
 564                 # on load if $wgLegacyCharset is set in the future.
 565                 $flags[] = 'utf-8';
 566
 567                 if( $wgCompressRevisions ) {
 568                         if( function_exists( 'gzdeflate' ) ) {
 569                                 $text = gzdeflate( $text );
 570                                 $flags[] = 'gzip';
 571                         } else {
 572                                 wfDebug( "Revision::compressRevisionText() -- no zlib support, not compressing\n" );
 573                         }
 574                 }
 575                 return implode( ',', $flags );
 576         }
 577
 578         /**
 579          * Insert a new revision into the database, returning the new revision ID
 580          * number on success and dies horribly on failure.
 581          *
 582          * @param Database $dbw
 583          * @return int
 584          */
 585         function insertOn( &$dbw ) {
 586                 global $wgDefaultExternalStore;
 587
 588                 $fname = 'Revision::insertOn';
 589                 wfProfileIn( $fname );
 590
 591                 $data = $this->mText;
 592                 $flags = Revision::compressRevisionText( $data );
 593
 594                 # Write to external storage if required
 595                 if ( $wgDefaultExternalStore ) {
 596                         if ( is_array( $wgDefaultExternalStore ) ) {
 597                                 // Distribute storage across multiple clusters
 598                                 $store = $wgDefaultExternalStore[mt_rand(0, count( $wgDefaultExternalStore ) - 1)];
 599                         } else {
 600                                 $store = $wgDefaultExternalStore;
 601                         }
 602                         require_once('ExternalStore.php');
 603                         // Store and get the URL
 604                         $data = ExternalStore::insert( $store, $data );
 605                         if ( !$data ) {
 606                                 # This should only happen in the case of a configuration error, where the external store is not valid
 607                                 wfDebugDieBacktrace( "Unable to store text to external storage $store" );
 608                         }
 609                         if ( $flags ) {
 610                                 $flags .= ',';
 611                         }
 612                         $flags .= 'external';
 613                 }
 614
 615                 # Record the text (or external storage URL) to the text table
 616                 if( !isset( $this->mTextId ) ) {
 617                         $old_id = $dbw->nextSequenceValue( 'text_old_id_val' );
 618                         $dbw->insert( 'text',
 619                                 array(
 620                                         'old_id'    => $old_id,
 621                                         'old_text'  => $data,
 622                                         'old_flags' => $flags,
 623                                 ), $fname
 624                         );
 625                         $this->mTextId = $dbw->insertId();
 626                 }
 627
 628                 # Record the edit in revisions
 629                 $rev_id = isset( $this->mId )
 630                         ? $this->mId
 631                         : $dbw->nextSequenceValue( 'rev_rev_id_val' );
 632                 $dbw->insert( 'revision',
 633                         array(
 634                                 'rev_id'         => $rev_id,
 635                                 'rev_page'       => $this->mPage,
 636                                 'rev_text_id'    => $this->mTextId,
 637                                 'rev_comment'    => $this->mComment,
 638                                 'rev_minor_edit' => $this->mMinorEdit ? 1 : 0,
 639                                 'rev_user'       => $this->mUser,
 640                                 'rev_user_text'  => $this->mUserText,
 641                                 'rev_timestamp'  => $dbw->timestamp( $this->mTimestamp ),
 642                                 'rev_deleted'    => $this->mDeleted,
 643                         ), $fname
 644                 );
 645
 646                 $this->mId = !is_null($rev_id) ? $rev_id : $dbw->insertId();
 647
 648                 wfProfileOut( $fname );
 649                 return $this->mId;
 650         }
 651
 652         /**
 653          * Lazy-load the revision's text.
 654          * Currently hardcoded to the 'text' table storage engine.
 655          *
 656          * @return string
 657          * @access private
 658          */
 659         function loadText() {
 660                 $fname = 'Revision::loadText';
 661                 wfProfileIn( $fname );
 662
 663                 $dbr =& wfGetDB( DB_SLAVE );
 664                 $row = $dbr->selectRow( 'text',
 665                         array( 'old_text', 'old_flags' ),
 666                         array( 'old_id' => $this->getTextId() ),
 667                         $fname);
 668
 669                 if( !$row ) {
 670                         $dbw =& wfGetDB( DB_MASTER );
 671                         $row = $dbw->selectRow( 'text',
 672                                 array( 'old_text', 'old_flags' ),
 673                                 array( 'old_id' => $this->getTextId() ),
 674                                 $fname);
 675                 }
 676
 677                 $text = Revision::getRevisionText( $row );
 678                 wfProfileOut( $fname );
 679
 680                 return $text;
 681         }
 682
 683         /**
 684          * Create a new null-revision for insertion into a page's
 685          * history. This will not re-save the text, but simply refer
 686          * to the text from the previous version.
 687          *
 688          * Such revisions can for instance identify page rename
 689          * operations and other such meta-modifications.
 690          *
 691          * @param Database $dbw
 692          * @param int      $pageId ID number of the page to read from
 693          * @param string   $summary
 694          * @param bool     $minor
 695          * @return Revision
 696          */
 697         function newNullRevision( &$dbw, $pageId, $summary, $minor ) {
 698                 $fname = 'Revision::newNullRevision';
 699                 wfProfileIn( $fname );
 700
 701                 $current = $dbw->selectRow(
 702                         array( 'page', 'revision' ),
 703                         array( 'page_latest', 'rev_text_id' ),
 704                         array(
 705                                 'page_id' => $pageId,
 706                                 'page_latest=rev_id',
 707                                 ),
 708                         $fname );
 709
 710                 if( $current ) {
 711                         $revision = new Revision( array(
 712                                 'page'       => $pageId,
 713                                 'comment'    => $summary,
 714                                 'minor_edit' => $minor,
 715                                 'text_id'    => $current->rev_text_id,
 716                                 ) );
 717                 } else {
 718                         $revision = null;
 719                 }
 720
 721                 wfProfileOut( $fname );
 722                 return $revision;
 723         }
 724
 725         /**
 726          * Determine if the current user is allowed to view a particular
 727          * field of this revision, if it's marked as deleted.
 728          * @param int $field one of MW_REV_DELETED_TEXT,
 729          *                          MW_REV_DELETED_COMMENT,
 730          *                          MW_REV_DELETED_USER
 731          * @return bool
 732          */
 733         function userCan( $field ) {
 734                 if( ( $this->mDeleted & $field ) == $field ) {
 735                         global $wgUser;
 736                         $permission = ( $this->mDeleted & MW_REV_DELETED_RESTRICTED ) == MW_REV_DELETED_RESTRICTED
 737                                 ? 'hiderevision'
 738                                 : 'deleterevision';
 739                         wfDebug( "Checking for $permission due to $field match on $this->mDeleted\n" );
 740                         return $wgUser->isAllowed( $permission );
 741                 } else {
 742                         return true;
 743                 }
 744         }
 745
 746 }
 747
 748 ?>