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  * @package MediaWiki
  13  * @todo document
  14  */
  15 class Revision {
  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          * @static
  22          * @access public
  23          */
  24         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 $id
  37          * @return Revision
  38          * @access public
  39          * @static
  40          */
  41         function &newFromTitle( &$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 either the current, or a specified, revision
  56          * that's attached to a given page. If not attached
  57          * to that page, will return null.
  58          *
  59          * @param Database $db
  60          * @param int $pageid
  61          * @param int $id
  62          * @return Revision
  63          * @access public
  64          */
  65         function &loadFromPageId( &$db, $pageid, $id = 0 ) {
  66                 if( $id ) {
  67                         $matchId = IntVal( $id );
  68                 } else {
  69                         $matchId = 'page_latest';
  70                 }
  71                 return Revision::loadFromConds(
  72                         $db,
  73                         array( "rev_id=$matchId",
  74                                'rev_page' => IntVal( $pageid ),
  75                                'page_id=rev_page' ) );
  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                                 return new Revision( $row );
 159                         }
 160                 }
 161                 return null;
 162         }
 163
 164         /**
 165          * Return a wrapper for a series of database rows to
 166          * fetch all of a given page's revisions in turn.
 167          * Each row can be fed to the constructor to get objects.
 168          *
 169          * @param Title $title
 170          * @return ResultWrapper
 171          * @static
 172          * @access public
 173          */
 174         function &fetchAllRevisions( &$title ) {
 175                 return Revision::fetchFromConds(
 176                         wfGetDB( DB_SLAVE ),
 177                         array( 'page_namespace' => $title->getNamespace(),
 178                                'page_title'     => $title->getDbkey(),
 179                                'page_id=rev_page' ) );
 180         }
 181
 182         /**
 183          * Return a wrapper for a series of database rows to
 184          * fetch all of a given page's revisions in turn.
 185          * Each row can be fed to the constructor to get objects.
 186          *
 187          * @param Title $title
 188          * @return ResultWrapper
 189          * @static
 190          * @access public
 191          */
 192         function &fetchRevision( &$title ) {
 193                 return Revision::fetchFromConds(
 194                         wfGetDB( DB_SLAVE ),
 195                         array( 'rev_id=page_latest',
 196                                'page_namespace' => $title->getNamespace(),
 197                                'page_title'     => $title->getDbkey(),
 198                                'page_id=rev_page' ) );
 199         }
 200
 201         /**
 202          * Given a set of conditions, return a ResultWrapper
 203          * which will return matching database rows with the
 204          * fields necessary to build Revision objects.
 205          *
 206          * @param Database $db
 207          * @param array $conditions
 208          * @return ResultWrapper
 209          * @static
 210          * @access private
 211          */
 212         function &fetchFromConds( &$db, $conditions ) {
 213                 $res = $db->select(
 214                         array( 'page', 'revision' ),
 215                         array( 'page_namespace',
 216                                'page_title',
 217                                'page_latest',
 218                                'rev_id',
 219                                'rev_page',
 220                                'rev_text_id',
 221                                'rev_comment',
 222                                'rev_user_text',
 223                                'rev_user',
 224                                'rev_minor_edit',
 225                                'rev_timestamp',
 226                                'rev_deleted' ),
 227                         $conditions,
 228                         'Revision::fetchRow',
 229                         array( 'LIMIT' => 1 ) );
 230                 return $db->resultObject( $res );
 231         }
 232
 233         /**
 234          * @param object $row
 235          * @access private
 236          */
 237         function Revision( $row ) {
 238                 if( is_object( $row ) ) {
 239                         $this->mId        = IntVal( $row->rev_id );
 240                         $this->mPage      = IntVal( $row->rev_page );
 241                         $this->mTextId    = IntVal( $row->rev_text_id );
 242                         $this->mComment   =         $row->rev_comment;
 243                         $this->mUserText  =         $row->rev_user_text;
 244                         $this->mUser      = IntVal( $row->rev_user );
 245                         $this->mMinorEdit = IntVal( $row->rev_minor_edit );
 246                         $this->mTimestamp =         $row->rev_timestamp;
 247                         $this->mDeleted   = IntVal( $row->rev_deleted );
 248
 249                         $this->mCurrent   = ( $row->rev_id == $row->page_latest );
 250                         $this->mTitle     = Title::makeTitle( $row->page_namespace,
 251                                                               $row->page_title );
 252
 253                         if( isset( $row->old_text ) ) {
 254                                 $this->mText  = $this->getRevisionText( $row );
 255                         } else {
 256                                 $this->mText  = null;
 257                         }
 258                 } elseif( is_array( $row ) ) {
 259                         // Build a new revision to be saved...
 260                         global $wgUser;
 261
 262                         $this->mId        = isset( $row['id']         ) ? IntVal( $row['id']         ) : null;
 263                         $this->mPage      = isset( $row['page']       ) ? IntVal( $row['page']       ) : null;
 264                         $this->mTextId    = isset( $row['text_id']    ) ? IntVal( $row['text_id']    ) : null;
 265                         $this->mUserText  = isset( $row['user_text']  ) ? StrVal( $row['user_text']  ) : $wgUser->getName();
 266                         $this->mUser      = isset( $row['user']       ) ? IntVal( $row['user']       ) : $wgUser->getId();
 267                         $this->mMinorEdit = isset( $row['minor_edit'] ) ? IntVal( $row['minor_edit'] ) : 0;
 268                         $this->mTimestamp = isset( $row['timestamp']  ) ? StrVal( $row['timestamp']  ) : wfTimestamp( TS_MW );
 269                         $this->mDeleted   = isset( $row['deleted']    ) ? IntVal( $row['deleted']    ) : 0;
 270
 271                         // Enforce spacing trimming on supplied text
 272                         $this->mComment   = isset( $row['comment']    ) ?  trim( StrVal( $row['comment'] ) ) : null;
 273                         $this->mText      = isset( $row['text']       ) ? rtrim( StrVal( $row['text']    ) ) : null;
 274
 275                         $this->mTitle     = null; # Load on demand if needed
 276                         $this->mCurrent   = false;
 277                 } else {
 278                         wfDebugDieBacktrace( 'Revision constructor passed invalid row format.' );
 279                 }
 280         }
 281
 282         /**#@+
 283          * @access public
 284          */
 285
 286         /**
 287          * @return int
 288          */
 289         function getId() {
 290                 return $this->mId;
 291         }
 292
 293         /**
 294          * @return int
 295          */
 296         function getTextId() {
 297                 return $this->mTextId;
 298         }
 299
 300         /**
 301          * Returns the title of the page associated with this entry.
 302          * @return Title
 303          */
 304         function &getTitle() {
 305                 if( isset( $this->mTitle ) ) {
 306                         return $this->mTitle;
 307                 }
 308                 $dbr =& wfGetDB( DB_SLAVE );
 309                 $row = $dbr->selectRow(
 310                         array( 'page', 'revision' ),
 311                         array( 'page_namespace', 'page_title' ),
 312                         array( 'page_id=rev_page',
 313                                'rev_id' => $this->mId ),
 314                         'Revision::getTItle' );
 315                 if( $row ) {
 316                         $this->mTitle =& Title::makeTitle( $row->page_namespace,
 317                                                            $row->page_title );
 318                 }
 319                 return $this->mTitle;
 320         }
 321
 322         /**
 323          * @return int
 324          */
 325         function getPage() {
 326                 return $this->mPage;
 327         }
 328
 329         /**
 330          * @return int
 331          */
 332         function getUser() {
 333                 return $this->mUser;
 334         }
 335
 336         /**
 337          * @return string
 338          */
 339         function getUserText() {
 340                 return $this->mUserText;
 341         }
 342
 343         /**
 344          * @return string
 345          */
 346         function getComment() {
 347                 return $this->mComment;
 348         }
 349
 350         /**
 351          * @return bool
 352          */
 353         function isMinor() {
 354                 return (bool)$this->mMinorEdit;
 355         }
 356
 357         /**
 358          * @return bool
 359          */
 360         function isDeleted() {
 361                 return (bool)$this->mDeleted;
 362         }
 363
 364         /**
 365          * @return string
 366          */
 367         function getText() {
 368                 if( is_null( $this->mText ) ) {
 369                         // Revision text is immutable. Load on demand:
 370                         $this->mText = $this->loadText();
 371                 }
 372                 return $this->mText;
 373         }
 374
 375         /**
 376          * @return string
 377          */
 378         function getTimestamp() {
 379                 return $this->mTimestamp;
 380         }
 381
 382         /**
 383          * @return bool
 384          */
 385         function isCurrent() {
 386                 return $this->mCurrent;
 387         }
 388
 389         /**
 390          * @return Revision
 391          */
 392         function &getPrevious() {
 393                 $prev = $this->mTitle->getPreviousRevisionID( $this->mId );
 394                 return Revision::newFromTitle( $this->mTitle, $prev );
 395         }
 396
 397         /**
 398          * @return Revision
 399          */
 400         function &getNext() {
 401                 $next = $this->mTitle->getNextRevisionID( $this->mId );
 402                 return Revision::newFromTitle( $this->mTitle, $next );
 403         }
 404         /**#@-*/
 405
 406         /**
 407           * Get revision text associated with an old or archive row
 408           * $row is usually an object from wfFetchRow(), both the flags and the text
 409           * field must be included
 410           * @static
 411           * @param integer $row Id of a row
 412           * @param string $prefix table prefix (default 'old_')
 413           * @return string $text|false the text requested
 414           */
 415         function getRevisionText( $row, $prefix = 'old_' ) {
 416                 $fname = 'Revision::getRevisionText';
 417                 wfProfileIn( $fname );
 418
 419                 # Get data
 420                 $textField = $prefix . 'text';
 421                 $flagsField = $prefix . 'flags';
 422
 423                 if( isset( $row->$flagsField ) ) {
 424                         $flags = explode( ',', $row->$flagsField );
 425                 } else {
 426                         $flags = array();
 427                 }
 428
 429                 if( isset( $row->$textField ) ) {
 430                         $text = $row->$textField;
 431                 } else {
 432                         wfProfileOut( $fname );
 433                         return false;
 434                 }
 435
 436                 # Use external methods for external objects, text in table is URL-only then
 437                 if ( in_array( 'external', $flags ) ) {
 438                         $url=$text;
 439                         @list($proto,$path)=explode('://',$url,2);
 440                         if ($path=="") {
 441                                 wfProfileOut( $fname );
 442                                 return false;
 443                         }
 444                         require_once('ExternalStore.php');
 445                         $text=ExternalStore::fetchFromURL($url);
 446                 }
 447
 448                 if( in_array( 'gzip', $flags ) ) {
 449                         # Deal with optional compression of archived pages.
 450                         # This can be done periodically via maintenance/compressOld.php, and
 451                         # as pages are saved if $wgCompressRevisions is set.
 452                         $text = gzinflate( $text );
 453                 }
 454
 455                 if( in_array( 'object', $flags ) ) {
 456                         # Generic compressed storage
 457                         $obj = unserialize( $text );
 458
 459                         # Bugger, corrupted my test database by double-serializing
 460                         if ( !is_object( $obj ) ) {
 461                                 $obj = unserialize( $obj );
 462                         }
 463
 464                         $text = $obj->getText();
 465                 }
 466
 467                 global $wgLegacyEncoding;
 468                 if( $wgLegacyEncoding && !in_array( 'utf-8', $flags ) ) {
 469                         # Old revisions kept around in a legacy encoding?
 470                         # Upconvert on demand.
 471                         global $wgInputEncoding, $wgContLang;
 472                         $text = $wgContLang->iconv( $wgLegacyEncoding, $wgInputEncoding, $text );
 473                 }
 474                 wfProfileOut( $fname );
 475                 return $text;
 476         }
 477
 478         /**
 479          * If $wgCompressRevisions is enabled, we will compress data.
 480          * The input string is modified in place.
 481          * Return value is the flags field: contains 'gzip' if the
 482          * data is compressed, and 'utf-8' if we're saving in UTF-8
 483          * mode.
 484          *
 485          * @static
 486          * @param mixed $text reference to a text
 487          * @return string
 488          */
 489         function compressRevisionText( &$text ) {
 490                 global $wgCompressRevisions;
 491                 $flags = array();
 492
 493                 # Revisions not marked this way will be converted
 494                 # on load if $wgLegacyCharset is set in the future.
 495                 $flags[] = 'utf-8';
 496
 497                 if( $wgCompressRevisions ) {
 498                         if( function_exists( 'gzdeflate' ) ) {
 499                                 $text = gzdeflate( $text );
 500                                 $flags[] = 'gzip';
 501                         } else {
 502                                 wfDebug( "Revision::compressRevisionText() -- no zlib support, not compressing\n" );
 503                         }
 504                 }
 505                 return implode( ',', $flags );
 506         }
 507
 508         /**
 509          * Insert a new revision into the database, returning the new revision ID
 510          * number on success and dies horribly on failure.
 511          *
 512          * @param Database $dbw
 513          * @return int
 514          */
 515         function insertOn( &$dbw ) {
 516                 $fname = 'Revision::insertOn';
 517                 wfProfileIn( $fname );
 518
 519                 $mungedText = $this->mText;
 520                 $flags = Revision::compressRevisionText( $mungedText );
 521
 522                 # Record the text to the text table
 523                 if( !isset( $this->mTextId ) ) {
 524                         $old_id = $dbw->nextSequenceValue( 'text_old_id_val' );
 525                         $dbw->insert( 'text',
 526                                 array(
 527                                         'old_id'    => $old_id,
 528                                         'old_text'  => $mungedText,
 529                                         'old_flags' => $flags,
 530                                 ), $fname
 531                         );
 532                         $this->mTextId = $dbw->insertId();
 533                 }
 534
 535                 # Record the edit in revisions
 536                 $rev_id = isset( $this->mId )
 537                         ? $this->mId
 538                         : $dbw->nextSequenceValue( 'rev_rev_id_val' );
 539                 $dbw->insert( 'revision',
 540                         array(
 541                                 'rev_id'         => $rev_id,
 542                                 'rev_page'       => $this->mPage,
 543                                 'rev_text_id'    => $this->mTextId,
 544                                 'rev_comment'    => $this->mComment,
 545                                 'rev_minor_edit' => $this->mMinorEdit ? 1 : 0,
 546                                 'rev_user'       => $this->mUser,
 547                                 'rev_user_text'  => $this->mUserText,
 548                                 'rev_timestamp'  => $dbw->timestamp( $this->mTimestamp ),
 549                                 'rev_deleted'    => $this->mDeleted,
 550                         ), $fname
 551                 );
 552
 553                 $this->mId = $dbw->insertId();
 554
 555                 wfProfileOut( $fname );
 556                 return $this->mId;
 557         }
 558
 559         /**
 560          * Lazy-load the revision's text.
 561          * Currently hardcoded to the 'text' table storage engine.
 562          *
 563          * @return string
 564          * @access private
 565          */
 566         function loadText() {
 567                 $fname = 'Revision::loadText';
 568                 wfProfileIn( $fname );
 569
 570                 $dbr =& wfGetDB( DB_SLAVE );
 571                 $row = $dbr->selectRow( 'text',
 572                         array( 'old_text', 'old_flags' ),
 573                         array( 'old_id' => $this->getTextId() ),
 574                         $fname);
 575
 576                 if( !$row ) {
 577                         $dbw =& wfGetDB( DB_MASTER );
 578                         $row = $dbw->selectRow( 'text',
 579                                 array( 'old_text', 'old_flags' ),
 580                                 array( 'old_id' => $this->getTextId() ),
 581                                 $fname);
 582                 }
 583
 584                 $text = Revision::getRevisionText( $row );
 585                 wfProfileOut( $fname );
 586
 587                 return $text;
 588         }
 589
 590         /**
 591          * Create a new null-revision for insertion into a page's
 592          * history. This will not re-save the text, but simply refer
 593          * to the text from the previous version.
 594          *
 595          * Such revisions can for instance identify page rename
 596          * operations and other such meta-modifications.
 597          *
 598          * @param Database $dbw
 599          * @param int      $pageId ID number of the page to read from
 600          * @param string   $summary
 601          * @param bool     $minor
 602          * @return Revision
 603          */
 604         function &newNullRevision( &$dbw, $pageId, $summary, $minor ) {
 605                 $fname = 'Revision::newNullRevision';
 606                 wfProfileIn( $fname );
 607
 608                 $current = $dbw->selectRow(
 609                         array( 'page', 'revision' ),
 610                         array( 'page_latest', 'rev_text_id' ),
 611                         array(
 612                                 'page_id' => $pageId,
 613                                 'page_latest=rev_id',
 614                                 ),
 615                         $fname );
 616
 617                 if( $current ) {
 618                         $revision = new Revision( array(
 619                                 'page'       => $pageId,
 620                                 'comment'    => $summary,
 621                                 'minor_edit' => $minor,
 622                                 'text_id'    => $current->rev_text_id,
 623                                 ) );
 624                 } else {
 625                         $revision = null;
 626                 }
 627
 628                 wfProfileOut( $fname );
 629                 return $revision;
 630         }
 631
 632 }
 633 ?>