includes/Revision.php

   1 <?php
   2 /**
   3  * @todo document
   4  * @file
   5  */
   6
   7 /**
   8  * @todo document
   9  */
  10 class Revision {
  11         const DELETED_TEXT = 1;
  12         const DELETED_COMMENT = 2;
  13         const DELETED_USER = 4;
  14         const DELETED_RESTRICTED = 8;
  15
  16         /**
  17          * Load a page revision from a given revision ID number.
  18          * Returns null if no such revision can be found.
  19          *
  20          * @param int $id
  21          * @access public
  22          * @static
  23          */
  24         public static function newFromId( $id ) {
  25                 return Revision::newFromConds(
  26                         array( 'page_id=rev_page',
  27                                'rev_id' => intval( $id ) ) );
  28         }
  29
  30         /**
  31          * Load either the current, or a specified, revision
  32          * that's attached to a given title. If not attached
  33          * to that title, will return null.
  34          *
  35          * @param Title $title
  36          * @param int $id
  37          * @return Revision
  38          * @access public
  39          * @static
  40          */
  41         public static function newFromTitle( &$title, $id = 0 ) {
  42                 if( $id ) {
  43                         $matchId = intval( $id );
  44                 } else {
  45                         $matchId = 'page_latest';
  46                 }
  47                 return Revision::newFromConds(
  48                         array( "rev_id=$matchId",
  49                                'page_id=rev_page',
  50                                'page_namespace' => $title->getNamespace(),
  51                                'page_title'     => $title->getDBkey() ) );
  52         }
  53
  54         /**
  55          * Load a page revision from a given revision ID number.
  56          * Returns null if no such revision can be found.
  57          *
  58          * @param Database $db
  59          * @param int $id
  60          * @access public
  61          * @static
  62          */
  63         public static function loadFromId( &$db, $id ) {
  64                 return Revision::loadFromConds( $db,
  65                         array( 'page_id=rev_page',
  66                                'rev_id' => intval( $id ) ) );
  67         }
  68
  69         /**
  70          * Load either the current, or a specified, revision
  71          * that's attached to a given page. If not attached
  72          * to that page, will return null.
  73          *
  74          * @param Database $db
  75          * @param int $pageid
  76          * @param int $id
  77          * @return Revision
  78          * @access public
  79          * @static
  80          */
  81         public static function loadFromPageId( $db, $pageid, $id = 0 ) {
  82                 $conds=array('page_id=rev_page','rev_page'=>intval( $pageid ), 'page_id'=>intval( $pageid ));
  83                 if( $id ) {
  84                         $conds['rev_id']=intval($id);
  85                 } else {
  86                         $conds[]='rev_id=page_latest';
  87                 }
  88                 return Revision::loadFromConds( $db, $conds );
  89         }
  90
  91         /**
  92          * Load either the current, or a specified, revision
  93          * that's attached to a given page. If not attached
  94          * to that page, will return null.
  95          *
  96          * @param Database $db
  97          * @param Title $title
  98          * @param int $id
  99          * @return Revision
 100          * @access public
 101          * @static
 102          */
 103         public static function loadFromTitle( &$db, $title, $id = 0 ) {
 104                 if( $id ) {
 105                         $matchId = intval( $id );
 106                 } else {
 107                         $matchId = 'page_latest';
 108                 }
 109                 return Revision::loadFromConds(
 110                         $db,
 111                         array( "rev_id=$matchId",
 112                                'page_id=rev_page',
 113                                'page_namespace' => $title->getNamespace(),
 114                                'page_title'     => $title->getDBkey() ) );
 115         }
 116
 117         /**
 118          * Load the revision for the given title with the given timestamp.
 119          * WARNING: Timestamps may in some circumstances not be unique,
 120          * so this isn't the best key to use.
 121          *
 122          * @param Database $db
 123          * @param Title $title
 124          * @param string $timestamp
 125          * @return Revision
 126          * @access public
 127          * @static
 128          */
 129         public static function loadFromTimestamp( &$db, &$title, $timestamp ) {
 130                 return Revision::loadFromConds(
 131                         $db,
 132                         array( 'rev_timestamp'  => $db->timestamp( $timestamp ),
 133                                'page_id=rev_page',
 134                                'page_namespace' => $title->getNamespace(),
 135                                'page_title'     => $title->getDBkey() ) );
 136         }
 137
 138         /**
 139          * Given a set of conditions, fetch a revision.
 140          *
 141          * @param array $conditions
 142          * @return Revision
 143          * @access private
 144          * @static
 145          */
 146         private static function newFromConds( $conditions ) {
 147                 $db = wfGetDB( DB_SLAVE );
 148                 $row = Revision::loadFromConds( $db, $conditions );
 149                 if( is_null( $row ) ) {
 150                         $dbw = wfGetDB( DB_MASTER );
 151                         $row = Revision::loadFromConds( $dbw, $conditions );
 152                 }
 153                 return $row;
 154         }
 155
 156         /**
 157          * Given a set of conditions, fetch a revision from
 158          * the given database connection.
 159          *
 160          * @param Database $db
 161          * @param array $conditions
 162          * @return Revision
 163          * @access private
 164          * @static
 165          */
 166         private static function loadFromConds( $db, $conditions ) {
 167                 $res = Revision::fetchFromConds( $db, $conditions );
 168                 if( $res ) {
 169                         $row = $res->fetchObject();
 170                         $res->free();
 171                         if( $row ) {
 172                                 $ret = new Revision( $row );
 173                                 return $ret;
 174                         }
 175                 }
 176                 $ret = null;
 177                 return $ret;
 178         }
 179
 180         /**
 181          * Return a wrapper for a series of database rows to
 182          * fetch all of a given page's revisions in turn.
 183          * Each row can be fed to the constructor to get objects.
 184          *
 185          * @param Title $title
 186          * @return ResultWrapper
 187          * @access public
 188          * @static
 189          */
 190         public static function fetchAllRevisions( &$title ) {
 191                 return Revision::fetchFromConds(
 192                         wfGetDB( DB_SLAVE ),
 193                         array( 'page_namespace' => $title->getNamespace(),
 194                                'page_title'     => $title->getDBkey(),
 195                                'page_id=rev_page' ) );
 196         }
 197
 198         /**
 199          * Return a wrapper for a series of database rows to
 200          * fetch all of a given page's revisions in turn.
 201          * Each row can be fed to the constructor to get objects.
 202          *
 203          * @param Title $title
 204          * @return ResultWrapper
 205          * @access public
 206          * @static
 207          */
 208         public static function fetchRevision( &$title ) {
 209                 return Revision::fetchFromConds(
 210                         wfGetDB( DB_SLAVE ),
 211                         array( 'rev_id=page_latest',
 212                                'page_namespace' => $title->getNamespace(),
 213                                'page_title'     => $title->getDBkey(),
 214                                'page_id=rev_page' ) );
 215         }
 216
 217         /**
 218          * Given a set of conditions, return a ResultWrapper
 219          * which will return matching database rows with the
 220          * fields necessary to build Revision objects.
 221          *
 222          * @param Database $db
 223          * @param array $conditions
 224          * @return ResultWrapper
 225          * @access private
 226          * @static
 227          */
 228         private static function fetchFromConds( $db, $conditions ) {
 229                 $fields = self::selectFields();
 230                 $fields[] = 'page_namespace';
 231                 $fields[] = 'page_title';
 232                 $fields[] = 'page_latest';
 233                 $res = $db->select(
 234                         array( 'page', 'revision' ),
 235                         $fields,
 236                         $conditions,
 237                         'Revision::fetchRow',
 238                         array( 'LIMIT' => 1 ) );
 239                 $ret = $db->resultObject( $res );
 240                 return $ret;
 241         }
 242
 243         /**
 244          * Return the list of revision fields that should be selected to create
 245          * a new revision.
 246          */
 247         static function selectFields() {
 248                 return array(
 249                         'rev_id',
 250                         'rev_page',
 251                         'rev_text_id',
 252                         'rev_timestamp',
 253                         'rev_comment',
 254                         'rev_user_text,'.
 255                         'rev_user',
 256                         'rev_minor_edit',
 257                         'rev_deleted',
 258                         'rev_len',
 259                         'rev_parent_id'
 260                 );
 261         }
 262
 263         /**
 264          * Return the list of text fields that should be selected to read the
 265          * revision text
 266          */
 267         static function selectTextFields() {
 268                 return array(
 269                         'old_text',
 270                         'old_flags'
 271                 );
 272         }
 273         /**
 274          * Return the list of page fields that should be selected from page table
 275          */
 276         static function selectPageFields() {
 277                 return array(
 278                         'page_namespace',
 279                         'page_title',
 280                         'page_latest'
 281                 );
 282         }
 283
 284         /**
 285          * @param object $row
 286          * @access private
 287          */
 288         function Revision( $row ) {
 289                 if( is_object( $row ) ) {
 290                         $this->mId        = intval( $row->rev_id );
 291                         $this->mPage      = intval( $row->rev_page );
 292                         $this->mTextId    = intval( $row->rev_text_id );
 293                         $this->mComment   =         $row->rev_comment;
 294                         $this->mUserText  =         $row->rev_user_text;
 295                         $this->mUser      = intval( $row->rev_user );
 296                         $this->mMinorEdit = intval( $row->rev_minor_edit );
 297                         $this->mTimestamp =         $row->rev_timestamp;
 298                         $this->mDeleted   = intval( $row->rev_deleted );
 299
 300                         if( !isset( $row->rev_parent_id ) )
 301                                 $this->mParentId = is_null($row->rev_parent_id) ? null : 0;
 302                         else
 303                                 $this->mParentId  = intval( $row->rev_parent_id );
 304
 305                         if( !isset( $row->rev_len ) || is_null( $row->rev_len ) )
 306                                 $this->mSize = null;
 307                         else
 308                                 $this->mSize = intval( $row->rev_len );
 309
 310                         if( isset( $row->page_latest ) ) {
 311                                 $this->mCurrent   = ( $row->rev_id == $row->page_latest );
 312                                 $this->mTitle     = Title::makeTitle( $row->page_namespace,
 313                                                                       $row->page_title );
 314                         } else {
 315                                 $this->mCurrent = false;
 316                                 $this->mTitle = null;
 317                         }
 318
 319                         // Lazy extraction...
 320                         $this->mText      = null;
 321                         if( isset( $row->old_text ) ) {
 322                                 $this->mTextRow = $row;
 323                         } else {
 324                                 // 'text' table row entry will be lazy-loaded
 325                                 $this->mTextRow = null;
 326                         }
 327                 } elseif( is_array( $row ) ) {
 328                         // Build a new revision to be saved...
 329                         global $wgUser;
 330
 331                         $this->mId        = isset( $row['id']         ) ? intval( $row['id']         ) : null;
 332                         $this->mPage      = isset( $row['page']       ) ? intval( $row['page']       ) : null;
 333                         $this->mTextId    = isset( $row['text_id']    ) ? intval( $row['text_id']    ) : null;
 334                         $this->mUserText  = isset( $row['user_text']  ) ? strval( $row['user_text']  ) : $wgUser->getName();
 335                         $this->mUser      = isset( $row['user']       ) ? intval( $row['user']       ) : $wgUser->getId();
 336                         $this->mMinorEdit = isset( $row['minor_edit'] ) ? intval( $row['minor_edit'] ) : 0;
 337                         $this->mTimestamp = isset( $row['timestamp']  ) ? strval( $row['timestamp']  ) : wfTimestamp( TS_MW );
 338                         $this->mDeleted   = isset( $row['deleted']    ) ? intval( $row['deleted']    ) : 0;
 339                         $this->mSize      = isset( $row['len']        ) ? intval( $row['len']        ) : null;
 340                         $this->mParentId  = isset( $row['parent_id']  ) ? intval( $row['parent_id']  ) : null;
 341
 342                         // Enforce spacing trimming on supplied text
 343                         $this->mComment   = isset( $row['comment']    ) ?  trim( strval( $row['comment'] ) ) : null;
 344                         $this->mText      = isset( $row['text']       ) ? rtrim( strval( $row['text']    ) ) : null;
 345                         $this->mTextRow   = null;
 346
 347                         $this->mTitle     = null; # Load on demand if needed
 348                         $this->mCurrent   = false;
 349                         # If we still have no len_size, see it we have the text to figure it out
 350                         if ( !$this->mSize )
 351                                 $this->mSize      = is_null($this->mText) ? null : strlen($this->mText);
 352                 } else {
 353                         throw new MWException( 'Revision constructor passed invalid row format.' );
 354                 }
 355         }
 356
 357         /**#@+
 358          * @access public
 359          */
 360
 361         /**
 362          * Get revision ID
 363          * @return int
 364          */
 365         public function getId() {
 366                 return $this->mId;
 367         }
 368
 369         /**
 370          * Get text row ID
 371          * @return int
 372          */
 373         public function getTextId() {
 374                 return $this->mTextId;
 375         }
 376
 377         /**
 378          * Get parent revision ID (the original previous page revision)
 379          * @return int
 380          */
 381         public function getParentId() {
 382                 return $this->mParentId;
 383         }
 384
 385         /**
 386          * Returns the length of the text in this revision, or null if unknown.
 387          * @return int
 388          */
 389         public function getSize() {
 390                 return $this->mSize;
 391         }
 392
 393         /**
 394          * Returns the title of the page associated with this entry.
 395          * @return Title
 396          */
 397         public function getTitle() {
 398                 if( isset( $this->mTitle ) ) {
 399                         return $this->mTitle;
 400                 }
 401                 $dbr = wfGetDB( DB_SLAVE );
 402                 $row = $dbr->selectRow(
 403                         array( 'page', 'revision' ),
 404                         array( 'page_namespace', 'page_title' ),
 405                         array( 'page_id=rev_page',
 406                                'rev_id' => $this->mId ),
 407                         'Revision::getTitle' );
 408                 if( $row ) {
 409                         $this->mTitle = Title::makeTitle( $row->page_namespace,
 410                                                           $row->page_title );
 411                 }
 412                 return $this->mTitle;
 413         }
 414
 415         /**
 416          * Set the title of the revision
 417          * @param Title $title
 418          */
 419         public function setTitle( $title ) {
 420                 $this->mTitle = $title;
 421         }
 422
 423         /**
 424          * Get the page ID
 425          * @return int
 426          */
 427         public function getPage() {
 428                 return $this->mPage;
 429         }
 430
 431         /**
 432          * Fetch revision's user id if it's available to all users
 433          * @return int
 434          */
 435         public function getUser() {
 436                 if( $this->isDeleted( self::DELETED_USER ) ) {
 437                         return 0;
 438                 } else {
 439                         return $this->mUser;
 440                 }
 441         }
 442
 443         /**
 444          * Fetch revision's user id without regard for the current user's permissions
 445          * @return string
 446          */
 447         public function getRawUser() {
 448                 return $this->mUser;
 449         }
 450
 451         /**
 452          * Fetch revision's username if it's available to all users
 453          * @return string
 454          */
 455         public function getUserText() {
 456                 if( $this->isDeleted( self::DELETED_USER ) ) {
 457                         return "";
 458                 } else {
 459                         return $this->mUserText;
 460                 }
 461         }
 462
 463         /**
 464          * Fetch revision's username without regard for view restrictions
 465          * @return string
 466          */
 467         public function getRawUserText() {
 468                 return $this->mUserText;
 469         }
 470
 471         /**
 472          * Fetch revision comment if it's available to all users
 473          * @return string
 474          */
 475         function getComment() {
 476                 if( $this->isDeleted( self::DELETED_COMMENT ) ) {
 477                         return "";
 478                 } else {
 479                         return $this->mComment;
 480                 }
 481         }
 482
 483         /**
 484          * Fetch revision comment without regard for the current user's permissions
 485          * @return string
 486          */
 487         public function getRawComment() {
 488                 return $this->mComment;
 489         }
 490
 491         /**
 492          * @return bool
 493          */
 494         public function isMinor() {
 495                 return (bool)$this->mMinorEdit;
 496         }
 497
 498         /**
 499          * int $field one of DELETED_* bitfield constants
 500          * @return bool
 501          */
 502         public function isDeleted( $field ) {
 503                 return ($this->mDeleted & $field) == $field;
 504         }
 505
 506         /**
 507          * Fetch revision text if it's available to all users
 508          * @return string
 509          */
 510         public function getText() {
 511                 if( $this->isDeleted( self::DELETED_TEXT ) ) {
 512                         return "";
 513                 } else {
 514                         return $this->getRawText();
 515                 }
 516         }
 517
 518         /**
 519          * Fetch revision text without regard for view restrictions
 520          * @return string
 521          */
 522         public function getRawText() {
 523                 if( is_null( $this->mText ) ) {
 524                         // Revision text is immutable. Load on demand:
 525                         $this->mText = $this->loadText();
 526                 }
 527                 return $this->mText;
 528         }
 529
 530         /**
 531          * Fetch revision text if it's available to THIS user
 532          * @return string
 533          */
 534         public function revText() {
 535                 if( !$this->userCan( self::DELETED_TEXT ) ) {
 536                         return "";
 537                 } else {
 538                         return $this->getRawText();
 539                 }
 540         }
 541
 542         /**
 543          * @return string
 544          */
 545         public function getTimestamp() {
 546                 return wfTimestamp(TS_MW, $this->mTimestamp);
 547         }
 548
 549         /**
 550          * @return bool
 551          */
 552         public function isCurrent() {
 553                 return $this->mCurrent;
 554         }
 555
 556         /**
 557          * Get previous revision for this title
 558          * @return Revision
 559          */
 560         public function getPrevious() {
 561                 if( $this->getTitle() ) {
 562                         $prev = $this->getTitle()->getPreviousRevisionID( $this->getId() );
 563                         if( $prev ) {
 564                                 return Revision::newFromTitle( $this->getTitle(), $prev );
 565                         }
 566                 }
 567                 return null;
 568         }
 569
 570         /**
 571          * @return Revision
 572          */
 573         public function getNext() {
 574                 if( $this->getTitle() ) {
 575                         $next = $this->getTitle()->getNextRevisionID( $this->getId() );
 576                         if ( $next ) {
 577                                 return Revision::newFromTitle( $this->getTitle(), $next );
 578                         }
 579                 }
 580                 return null;
 581         }
 582
 583         /**
 584          * Get previous revision Id for this page_id
 585          * This is used to populate rev_parent_id on save
 586          * @param Database $db
 587          * @return int
 588          */
 589         private function getPreviousRevisionId( $db ) {
 590                 if( is_null($this->mPage) ) {
 591                         return 0;
 592                 }
 593                 # Use page_latest if ID is not given
 594                 if( !$this->mId ) {
 595                         $prevId = $db->selectField( 'page', 'page_latest',
 596                                 array( 'page_id' => $this->mPage ),
 597                                 __METHOD__ );
 598                 } else {
 599                         $prevId = $db->selectField( 'revision', 'rev_id',
 600                                 array( 'rev_page' => $this->mPage, 'rev_id < ' . $this->mId ),
 601                                 __METHOD__,
 602                                 array( 'ORDER BY' => 'rev_id DESC' ) );
 603                 }
 604                 return intval($prevId);
 605         }
 606
 607         /**
 608           * Get revision text associated with an old or archive row
 609           * $row is usually an object from wfFetchRow(), both the flags and the text
 610           * field must be included
 611           *
 612           * @param integer $row Id of a row
 613           * @param string $prefix table prefix (default 'old_')
 614           * @return string $text|false the text requested
 615           */
 616         public static function getRevisionText( $row, $prefix = 'old_' ) {
 617                 wfProfileIn( __METHOD__ );
 618
 619                 # Get data
 620                 $textField = $prefix . 'text';
 621                 $flagsField = $prefix . 'flags';
 622
 623                 if( isset( $row->$flagsField ) ) {
 624                         $flags = explode( ',', $row->$flagsField );
 625                 } else {
 626                         $flags = array();
 627                 }
 628
 629                 if( isset( $row->$textField ) ) {
 630                         $text = $row->$textField;
 631                 } else {
 632                         wfProfileOut( __METHOD__ );
 633                         return false;
 634                 }
 635
 636                 # Use external methods for external objects, text in table is URL-only then
 637                 if ( in_array( 'external', $flags ) ) {
 638                         $url=$text;
 639                         @list(/* $proto */,$path)=explode('://',$url,2);
 640                         if ($path=="") {
 641                                 wfProfileOut( __METHOD__ );
 642                                 return false;
 643                         }
 644                         $text=ExternalStore::fetchFromURL($url);
 645                 }
 646
 647                 // If the text was fetched without an error, convert it
 648                 if ( $text !== false ) {
 649                         if( in_array( 'gzip', $flags ) ) {
 650                                 # Deal with optional compression of archived pages.
 651                                 # This can be done periodically via maintenance/compressOld.php, and
 652                                 # as pages are saved if $wgCompressRevisions is set.
 653                                 $text = gzinflate( $text );
 654                         }
 655
 656                         if( in_array( 'object', $flags ) ) {
 657                                 # Generic compressed storage
 658                                 $obj = unserialize( $text );
 659                                 if ( !is_object( $obj ) ) {
 660                                         // Invalid object
 661                                         wfProfileOut( __METHOD__ );
 662                                         return false;
 663                                 }
 664                                 $text = $obj->getText();
 665                         }
 666
 667                         global $wgLegacyEncoding;
 668                         if( $wgLegacyEncoding && !in_array( 'utf-8', $flags ) ) {
 669                                 # Old revisions kept around in a legacy encoding?
 670                                 # Upconvert on demand.
 671                                 global $wgInputEncoding, $wgContLang;
 672                                 $text = $wgContLang->iconv( $wgLegacyEncoding, $wgInputEncoding, $text );
 673                         }
 674                 }
 675                 wfProfileOut( __METHOD__ );
 676                 return $text;
 677         }
 678
 679         /**
 680          * If $wgCompressRevisions is enabled, we will compress data.
 681          * The input string is modified in place.
 682          * Return value is the flags field: contains 'gzip' if the
 683          * data is compressed, and 'utf-8' if we're saving in UTF-8
 684          * mode.
 685          *
 686          * @param mixed $text reference to a text
 687          * @return string
 688          */
 689         public static function compressRevisionText( &$text ) {
 690                 global $wgCompressRevisions;
 691                 $flags = array();
 692
 693                 # Revisions not marked this way will be converted
 694                 # on load if $wgLegacyCharset is set in the future.
 695                 $flags[] = 'utf-8';
 696
 697                 if( $wgCompressRevisions ) {
 698                         if( function_exists( 'gzdeflate' ) ) {
 699                                 $text = gzdeflate( $text );
 700                                 $flags[] = 'gzip';
 701                         } else {
 702                                 wfDebug( "Revision::compressRevisionText() -- no zlib support, not compressing\n" );
 703                         }
 704                 }
 705                 return implode( ',', $flags );
 706         }
 707
 708         /**
 709          * Insert a new revision into the database, returning the new revision ID
 710          * number on success and dies horribly on failure.
 711          *
 712          * @param Database $dbw
 713          * @return int
 714          */
 715         public function insertOn( &$dbw ) {
 716                 global $wgDefaultExternalStore;
 717
 718                 wfProfileIn( __METHOD__ );
 719
 720                 $data = $this->mText;
 721                 $flags = Revision::compressRevisionText( $data );
 722
 723                 # Write to external storage if required
 724                 if ( $wgDefaultExternalStore ) {
 725                         if ( is_array( $wgDefaultExternalStore ) ) {
 726                                 // Distribute storage across multiple clusters
 727                                 $store = $wgDefaultExternalStore[mt_rand(0, count( $wgDefaultExternalStore ) - 1)];
 728                         } else {
 729                                 $store = $wgDefaultExternalStore;
 730                         }
 731                         // Store and get the URL
 732                         $data = ExternalStore::insert( $store, $data );
 733                         if ( !$data ) {
 734                                 # This should only happen in the case of a configuration error, where the external store is not valid
 735                                 throw new MWException( "Unable to store text to external storage $store" );
 736                         }
 737                         if ( $flags ) {
 738                                 $flags .= ',';
 739                         }
 740                         $flags .= 'external';
 741                 }
 742
 743                 # Record the text (or external storage URL) to the text table
 744                 if( !isset( $this->mTextId ) ) {
 745                         $old_id = $dbw->nextSequenceValue( 'text_old_id_val' );
 746                         $dbw->insert( 'text',
 747                                 array(
 748                                         'old_id'    => $old_id,
 749                                         'old_text'  => $data,
 750                                         'old_flags' => $flags,
 751                                 ), __METHOD__
 752                         );
 753                         $this->mTextId = $dbw->insertId();
 754                 }
 755
 756                 # Record the edit in revisions
 757                 $rev_id = isset( $this->mId )
 758                         ? $this->mId
 759                         : $dbw->nextSequenceValue( 'rev_rev_id_val' );
 760                 $dbw->insert( 'revision',
 761                         array(
 762                                 'rev_id'         => $rev_id,
 763                                 'rev_page'       => $this->mPage,
 764                                 'rev_text_id'    => $this->mTextId,
 765                                 'rev_comment'    => $this->mComment,
 766                                 'rev_minor_edit' => $this->mMinorEdit ? 1 : 0,
 767                                 'rev_user'       => $this->mUser,
 768                                 'rev_user_text'  => $this->mUserText,
 769                                 'rev_timestamp'  => $dbw->timestamp( $this->mTimestamp ),
 770                                 'rev_deleted'    => $this->mDeleted,
 771                                 'rev_len'            => $this->mSize,
 772                                 'rev_parent_id'  => $this->mParentId ? $this->mParentId : $this->getPreviousRevisionId( $dbw )
 773                         ), __METHOD__
 774                 );
 775
 776                 $this->mId = !is_null($rev_id) ? $rev_id : $dbw->insertId();
 777
 778                 wfRunHooks( 'RevisionInsertComplete', array( &$this ) );
 779
 780                 wfProfileOut( __METHOD__ );
 781                 return $this->mId;
 782         }
 783
 784         /**
 785          * Lazy-load the revision's text.
 786          * Currently hardcoded to the 'text' table storage engine.
 787          *
 788          * @return string
 789          */
 790         private function loadText() {
 791                 wfProfileIn( __METHOD__ );
 792
 793                 // Caching may be beneficial for massive use of external storage
 794                 global $wgRevisionCacheExpiry, $wgMemc;
 795                 $key = wfMemcKey( 'revisiontext', 'textid', $this->getTextId() );
 796                 if( $wgRevisionCacheExpiry ) {
 797                         $text = $wgMemc->get( $key );
 798                         if( is_string( $text ) ) {
 799                                 wfProfileOut( __METHOD__ );
 800                                 return $text;
 801                         }
 802                 }
 803
 804                 // If we kept data for lazy extraction, use it now...
 805                 if ( isset( $this->mTextRow ) ) {
 806                         $row = $this->mTextRow;
 807                         $this->mTextRow = null;
 808                 } else {
 809                         $row = null;
 810                 }
 811
 812                 if( !$row ) {
 813                         // Text data is immutable; check slaves first.
 814                         $dbr = wfGetDB( DB_SLAVE );
 815                         $row = $dbr->selectRow( 'text',
 816                                 array( 'old_text', 'old_flags' ),
 817                                 array( 'old_id' => $this->getTextId() ),
 818                                 __METHOD__ );
 819                 }
 820
 821                 if( !$row ) {
 822                         // Possible slave lag!
 823                         $dbw = wfGetDB( DB_MASTER );
 824                         $row = $dbw->selectRow( 'text',
 825                                 array( 'old_text', 'old_flags' ),
 826                                 array( 'old_id' => $this->getTextId() ),
 827                                 __METHOD__ );
 828                 }
 829
 830                 $text = self::getRevisionText( $row );
 831
 832                 if( $wgRevisionCacheExpiry ) {
 833                         $wgMemc->set( $key, $text, $wgRevisionCacheExpiry );
 834                 }
 835
 836                 wfProfileOut( __METHOD__ );
 837
 838                 return $text;
 839         }
 840
 841         /**
 842          * Create a new null-revision for insertion into a page's
 843          * history. This will not re-save the text, but simply refer
 844          * to the text from the previous version.
 845          *
 846          * Such revisions can for instance identify page rename
 847          * operations and other such meta-modifications.
 848          *
 849          * @param Database $dbw
 850          * @param int      $pageId ID number of the page to read from
 851          * @param string   $summary
 852          * @param bool     $minor
 853          * @return Revision
 854          */
 855         public static function newNullRevision( &$dbw, $pageId, $summary, $minor ) {
 856                 wfProfileIn( __METHOD__ );
 857
 858                 $current = $dbw->selectRow(
 859                         array( 'page', 'revision' ),
 860                         array( 'page_latest', 'rev_text_id' ),
 861                         array(
 862                                 'page_id' => $pageId,
 863                                 'page_latest=rev_id',
 864                                 ),
 865                         __METHOD__ );
 866
 867                 if( $current ) {
 868                         $revision = new Revision( array(
 869                                 'page'       => $pageId,
 870                                 'comment'    => $summary,
 871                                 'minor_edit' => $minor,
 872                                 'text_id'    => $current->rev_text_id,
 873                                 'parent_id'  => $current->page_latest
 874                                 ) );
 875                 } else {
 876                         $revision = null;
 877                 }
 878
 879                 wfProfileOut( __METHOD__ );
 880                 return $revision;
 881         }
 882
 883         /**
 884          * Determine if the current user is allowed to view a particular
 885          * field of this revision, if it's marked as deleted.
 886          * @param int $field one of self::DELETED_TEXT,
 887          *                          self::DELETED_COMMENT,
 888          *                          self::DELETED_USER
 889          * @return bool
 890          */
 891         public function userCan( $field ) {
 892                 if( ( $this->mDeleted & $field ) == $field ) {
 893                         global $wgUser;
 894                         $permission = ( $this->mDeleted & self::DELETED_RESTRICTED ) == self::DELETED_RESTRICTED
 895                                 ? 'hiderevision'
 896                                 : 'deleterevision';
 897                         wfDebug( "Checking for $permission due to $field match on $this->mDeleted\n" );
 898                         return $wgUser->isAllowed( $permission );
 899                 } else {
 900                         return true;
 901                 }
 902         }
 903
 904
 905         /**
 906          * Get rev_timestamp from rev_id, without loading the rest of the row
 907          * @param integer $id
 908          * @param integer $pageid, optional
 909          */
 910         static function getTimestampFromId( $id, $pageId = 0 ) {
 911                 $dbr = wfGetDB( DB_SLAVE );
 912                 $conds = array( 'rev_id' => $id );
 913                 if( $pageId ) {
 914                         $conds['rev_page'] = $pageId;
 915                 }
 916                 $timestamp = $dbr->selectField( 'revision', 'rev_timestamp', $conds, __METHOD__ );
 917                 if ( $timestamp === false ) {
 918                         # Not in slave, try master
 919                         $dbw = wfGetDB( DB_MASTER );
 920                         $timestamp = $dbw->selectField( 'revision', 'rev_timestamp', $conds, __METHOD__ );
 921                 }
 922                 return $timestamp;
 923         }
 924
 925         /**
 926          * Get count of revisions per page...not very efficient
 927          * @param Database $db
 928          * @param int $id, page id
 929          */
 930         static function countByPageId( $db, $id ) {
 931                 $row = $db->selectRow( 'revision', 'COUNT(*) AS revCount',
 932                         array( 'rev_page' => $id ), __METHOD__ );
 933                 if( $row ) {
 934                         return $row->revCount;
 935                 }
 936                 return 0;
 937         }
 938
 939         /**
 940          * Get count of revisions per page...not very efficient
 941          * @param Database $db
 942          * @param Title $title
 943          */
 944         static function countByTitle( $db, $title ) {
 945                 $id = $title->getArticleId();
 946                 if( $id ) {
 947                         return Revision::countByPageId( $db, $id );
 948                 }
 949                 return 0;
 950         }
 951 }
 952
 953 /**
 954  * Aliases for backwards compatibility with 1.6
 955  */
 956 define( 'MW_REV_DELETED_TEXT', Revision::DELETED_TEXT );
 957 define( 'MW_REV_DELETED_COMMENT', Revision::DELETED_COMMENT );
 958 define( 'MW_REV_DELETED_USER', Revision::DELETED_USER );
 959 define( 'MW_REV_DELETED_RESTRICTED', Revision::DELETED_RESTRICTED );