includes/Revision.php

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