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                 $ret = Revision::loadFromConds(
  72                         $db,
  73                         array( "rev_id=$matchId",
  74                                'rev_page' => intval( $pageid ),
  75                                'page_id=rev_page' ) );
  76                 return $ret;
  77         }
  78
  79         /**
  80          * Load either the current, or a specified, revision
  81          * that's attached to a given page. If not attached
  82          * to that page, will return null.
  83          *
  84          * @param Database $db
  85          * @param Title $title
  86          * @param int $id
  87          * @return Revision
  88          * @access public
  89          */
  90         function loadFromTitle( &$db, $title, $id = 0 ) {
  91                 if( $id ) {
  92                         $matchId = intval( $id );
  93                 } else {
  94                         $matchId = 'page_latest';
  95                 }
  96                 return Revision::loadFromConds(
  97                         $db,
  98                         array( "rev_id=$matchId",
  99                                'page_id=rev_page',
 100                                'page_namespace' => $title->getNamespace(),
 101                                'page_title'     => $title->getDbkey() ) );
 102         }
 103
 104         /**
 105          * Load the revision for the given title with the given timestamp.
 106          * WARNING: Timestamps may in some circumstances not be unique,
 107          * so this isn't the best key to use.
 108          *
 109          * @param Database $db
 110          * @param Title $title
 111          * @param string $timestamp
 112          * @return Revision
 113          * @access public
 114          * @static
 115          */
 116         function loadFromTimestamp( &$db, &$title, $timestamp ) {
 117                 return Revision::loadFromConds(
 118                         $db,
 119                         array( 'rev_timestamp'  => $db->timestamp( $timestamp ),
 120                                'page_id=rev_page',
 121                                'page_namespace' => $title->getNamespace(),
 122                                'page_title'     => $title->getDbkey() ) );
 123         }
 124
 125         /**
 126          * Given a set of conditions, fetch a revision.
 127          *
 128          * @param array $conditions
 129          * @return Revision
 130          * @static
 131          * @access private
 132          */
 133         function newFromConds( $conditions ) {
 134                 $db =& wfGetDB( DB_SLAVE );
 135                 $row = Revision::loadFromConds( $db, $conditions );
 136                 if( is_null( $row ) ) {
 137                         $dbw =& wfGetDB( DB_MASTER );
 138                         $row = Revision::loadFromConds( $dbw, $conditions );
 139                 }
 140                 return $row;
 141         }
 142
 143         /**
 144          * Given a set of conditions, fetch a revision from
 145          * the given database connection.
 146          *
 147          * @param Database $db
 148          * @param array $conditions
 149          * @return Revision
 150          * @static
 151          * @access private
 152          */
 153         function loadFromConds( &$db, $conditions ) {
 154                 $res = Revision::fetchFromConds( $db, $conditions );
 155                 if( $res ) {
 156                         $row = $res->fetchObject();
 157                         $res->free();
 158                         if( $row ) {
 159                                 $ret = new Revision( $row );
 160                                 return $ret;
 161                         }
 162                 }
 163                 $ret = null;
 164                 return $ret;
 165         }
 166
 167         /**
 168          * Return a wrapper for a series of database rows to
 169          * fetch all of a given page's revisions in turn.
 170          * Each row can be fed to the constructor to get objects.
 171          *
 172          * @param Title $title
 173          * @return ResultWrapper
 174          * @static
 175          * @access public
 176          */
 177         function fetchAllRevisions( &$title ) {
 178                 return Revision::fetchFromConds(
 179                         wfGetDB( DB_SLAVE ),
 180                         array( 'page_namespace' => $title->getNamespace(),
 181                                'page_title'     => $title->getDbkey(),
 182                                'page_id=rev_page' ) );
 183         }
 184
 185         /**
 186          * Return a wrapper for a series of database rows to
 187          * fetch all of a given page's revisions in turn.
 188          * Each row can be fed to the constructor to get objects.
 189          *
 190          * @param Title $title
 191          * @return ResultWrapper
 192          * @static
 193          * @access public
 194          */
 195         function fetchRevision( &$title ) {
 196                 return Revision::fetchFromConds(
 197                         wfGetDB( DB_SLAVE ),
 198                         array( 'rev_id=page_latest',
 199                                'page_namespace' => $title->getNamespace(),
 200                                'page_title'     => $title->getDbkey(),
 201                                'page_id=rev_page' ) );
 202         }
 203
 204         /**
 205          * Given a set of conditions, return a ResultWrapper
 206          * which will return matching database rows with the
 207          * fields necessary to build Revision objects.
 208          *
 209          * @param Database $db
 210          * @param array $conditions
 211          * @return ResultWrapper
 212          * @static
 213          * @access private
 214          */
 215         function fetchFromConds( &$db, $conditions ) {
 216                 $res = $db->select(
 217                         array( 'page', 'revision' ),
 218                         array( 'page_namespace',
 219                                'page_title',
 220                                'page_latest',
 221                                'rev_id',
 222                                'rev_page',
 223                                'rev_text_id',
 224                                'rev_comment',
 225                                'rev_user_text',
 226                                'rev_user',
 227                                'rev_minor_edit',
 228                                'rev_timestamp',
 229                                'rev_deleted' ),
 230                         $conditions,
 231                         'Revision::fetchRow',
 232                         array( 'LIMIT' => 1 ) );
 233                 $ret = $db->resultObject( $res );
 234                 return $ret;
 235         }
 236
 237         /**
 238          * @param object $row
 239          * @access private
 240          */
 241         function Revision( $row ) {
 242                 if( is_object( $row ) ) {
 243                         $this->mId        = intval( $row->rev_id );
 244                         $this->mPage      = intval( $row->rev_page );
 245                         $this->mTextId    = intval( $row->rev_text_id );
 246                         $this->mComment   =         $row->rev_comment;
 247                         $this->mUserText  =         $row->rev_user_text;
 248                         $this->mUser      = intval( $row->rev_user );
 249                         $this->mMinorEdit = intval( $row->rev_minor_edit );
 250                         $this->mTimestamp =         $row->rev_timestamp;
 251                         $this->mDeleted   = intval( $row->rev_deleted );
 252
 253                         $this->mCurrent   = ( $row->rev_id == $row->page_latest );
 254                         $this->mTitle     = Title::makeTitle( $row->page_namespace,
 255                                                               $row->page_title );
 256
 257                         if( isset( $row->old_text ) ) {
 258                                 $this->mText  = $this->getRevisionText( $row );
 259                         } else {
 260                                 $this->mText  = null;
 261                         }
 262                 } elseif( is_array( $row ) ) {
 263                         // Build a new revision to be saved...
 264                         global $wgUser;
 265
 266                         $this->mId        = isset( $row['id']         ) ? intval( $row['id']         ) : null;
 267                         $this->mPage      = isset( $row['page']       ) ? intval( $row['page']       ) : null;
 268                         $this->mTextId    = isset( $row['text_id']    ) ? intval( $row['text_id']    ) : null;
 269                         $this->mUserText  = isset( $row['user_text']  ) ? strval( $row['user_text']  ) : $wgUser->getName();
 270                         $this->mUser      = isset( $row['user']       ) ? intval( $row['user']       ) : $wgUser->getId();
 271                         $this->mMinorEdit = isset( $row['minor_edit'] ) ? intval( $row['minor_edit'] ) : 0;
 272                         $this->mTimestamp = isset( $row['timestamp']  ) ? strval( $row['timestamp']  ) : wfTimestamp( TS_MW );
 273                         $this->mDeleted   = isset( $row['deleted']    ) ? intval( $row['deleted']    ) : 0;
 274
 275                         // Enforce spacing trimming on supplied text
 276                         $this->mComment   = isset( $row['comment']    ) ?  trim( strval( $row['comment'] ) ) : null;
 277                         $this->mText      = isset( $row['text']       ) ? rtrim( strval( $row['text']    ) ) : null;
 278
 279                         $this->mTitle     = null; # Load on demand if needed
 280                         $this->mCurrent   = false;
 281                 } else {
 282                         wfDebugDieBacktrace( 'Revision constructor passed invalid row format.' );
 283                 }
 284         }
 285
 286         /**#@+
 287          * @access public
 288          */
 289
 290         /**
 291          * @return int
 292          */
 293         function getId() {
 294                 return $this->mId;
 295         }
 296
 297         /**
 298          * @return int
 299          */
 300         function getTextId() {
 301                 return $this->mTextId;
 302         }
 303
 304         /**
 305          * Returns the title of the page associated with this entry.
 306          * @return Title
 307          */
 308         function getTitle() {
 309                 if( isset( $this->mTitle ) ) {
 310                         return $this->mTitle;
 311                 }
 312                 $dbr =& wfGetDB( DB_SLAVE );
 313                 $row = $dbr->selectRow(
 314                         array( 'page', 'revision' ),
 315                         array( 'page_namespace', 'page_title' ),
 316                         array( 'page_id=rev_page',
 317                                'rev_id' => $this->mId ),
 318                         'Revision::getTItle' );
 319                 if( $row ) {
 320                         $this->mTitle = Title::makeTitle( $row->page_namespace,
 321                                                            $row->page_title );
 322                 }
 323                 return $this->mTitle;
 324         }
 325
 326         /**
 327          * @return int
 328          */
 329         function getPage() {
 330                 return $this->mPage;
 331         }
 332
 333         /**
 334          * @return int
 335          */
 336         function getUser() {
 337                 return $this->mUser;
 338         }
 339
 340         /**
 341          * @return string
 342          */
 343         function getUserText() {
 344                 return $this->mUserText;
 345         }
 346
 347         /**
 348          * @return string
 349          */
 350         function getComment() {
 351                 return $this->mComment;
 352         }
 353
 354         /**
 355          * @return bool
 356          */
 357         function isMinor() {
 358                 return (bool)$this->mMinorEdit;
 359         }
 360
 361         /**
 362          * @return bool
 363          */
 364         function isDeleted() {
 365                 return (bool)$this->mDeleted;
 366         }
 367
 368         /**
 369          * @return string
 370          */
 371         function getText() {
 372                 if( is_null( $this->mText ) ) {
 373                         // Revision text is immutable. Load on demand:
 374                         $this->mText = $this->loadText();
 375                 }
 376                 return $this->mText;
 377         }
 378
 379         /**
 380          * @return string
 381          */
 382         function getTimestamp() {
 383                 return wfTimestamp(TS_MW, $this->mTimestamp);
 384         }
 385
 386         /**
 387          * @return bool
 388          */
 389         function isCurrent() {
 390                 return $this->mCurrent;
 391         }
 392
 393         /**
 394          * @return Revision
 395          */
 396         function getPrevious() {
 397                 $prev = $this->mTitle->getPreviousRevisionID( $this->mId );
 398                 return Revision::newFromTitle( $this->mTitle, $prev );
 399         }
 400
 401         /**
 402          * @return Revision
 403          */
 404         function getNext() {
 405                 $next = $this->mTitle->getNextRevisionID( $this->mId );
 406                 return Revision::newFromTitle( $this->mTitle, $next );
 407         }
 408         /**#@-*/
 409
 410         /**
 411           * Get revision text associated with an old or archive row
 412           * $row is usually an object from wfFetchRow(), both the flags and the text
 413           * field must be included
 414           * @static
 415           * @param integer $row Id of a row
 416           * @param string $prefix table prefix (default 'old_')
 417           * @return string $text|false the text requested
 418           */
 419         function getRevisionText( $row, $prefix = 'old_' ) {
 420                 $fname = 'Revision::getRevisionText';
 421                 wfProfileIn( $fname );
 422
 423                 # Get data
 424                 $textField = $prefix . 'text';
 425                 $flagsField = $prefix . 'flags';
 426
 427                 if( isset( $row->$flagsField ) ) {
 428                         $flags = explode( ',', $row->$flagsField );
 429                 } else {
 430                         $flags = array();
 431                 }
 432
 433                 if( isset( $row->$textField ) ) {
 434                         $text = $row->$textField;
 435                 } else {
 436                         wfProfileOut( $fname );
 437                         return false;
 438                 }
 439
 440                 # Use external methods for external objects, text in table is URL-only then
 441                 if ( in_array( 'external', $flags ) ) {
 442                         $url=$text;
 443                         @list($proto,$path)=explode('://',$url,2);
 444                         if ($path=="") {
 445                                 wfProfileOut( $fname );
 446                                 return false;
 447                         }
 448                         require_once('ExternalStore.php');
 449                         $text=ExternalStore::fetchFromURL($url);
 450                 }
 451
 452                 if( in_array( 'gzip', $flags ) ) {
 453                         # Deal with optional compression of archived pages.
 454                         # This can be done periodically via maintenance/compressOld.php, and
 455                         # as pages are saved if $wgCompressRevisions is set.
 456                         $text = gzinflate( $text );
 457                 }
 458
 459                 if( in_array( 'object', $flags ) ) {
 460                         # Generic compressed storage
 461                         $obj = unserialize( $text );
 462
 463                         # Bugger, corrupted my test database by double-serializing
 464                         if ( !is_object( $obj ) ) {
 465                                 $obj = unserialize( $obj );
 466                         }
 467
 468                         $text = $obj->getText();
 469                 }
 470
 471                 global $wgLegacyEncoding;
 472                 if( $wgLegacyEncoding && !in_array( 'utf-8', $flags ) ) {
 473                         # Old revisions kept around in a legacy encoding?
 474                         # Upconvert on demand.
 475                         global $wgInputEncoding, $wgContLang;
 476                         $text = $wgContLang->iconv( $wgLegacyEncoding, $wgInputEncoding . '//IGNORE', $text );
 477                 }
 478                 wfProfileOut( $fname );
 479                 return $text;
 480         }
 481
 482         /**
 483          * If $wgCompressRevisions is enabled, we will compress data.
 484          * The input string is modified in place.
 485          * Return value is the flags field: contains 'gzip' if the
 486          * data is compressed, and 'utf-8' if we're saving in UTF-8
 487          * mode.
 488          *
 489          * @static
 490          * @param mixed $text reference to a text
 491          * @return string
 492          */
 493         function compressRevisionText( &$text ) {
 494                 global $wgCompressRevisions;
 495                 $flags = array();
 496
 497                 # Revisions not marked this way will be converted
 498                 # on load if $wgLegacyCharset is set in the future.
 499                 $flags[] = 'utf-8';
 500
 501                 if( $wgCompressRevisions ) {
 502                         if( function_exists( 'gzdeflate' ) ) {
 503                                 $text = gzdeflate( $text );
 504                                 $flags[] = 'gzip';
 505                         } else {
 506                                 wfDebug( "Revision::compressRevisionText() -- no zlib support, not compressing\n" );
 507                         }
 508                 }
 509                 return implode( ',', $flags );
 510         }
 511
 512         /**
 513          * Insert a new revision into the database, returning the new revision ID
 514          * number on success and dies horribly on failure.
 515          *
 516          * @param Database $dbw
 517          * @return int
 518          */
 519         function insertOn( &$dbw ) {
 520                 $fname = 'Revision::insertOn';
 521                 wfProfileIn( $fname );
 522
 523                 $mungedText = $this->mText;
 524                 $flags = Revision::compressRevisionText( $mungedText );
 525
 526                 # Record the text to the text table
 527                 if( !isset( $this->mTextId ) ) {
 528                         $old_id = $dbw->nextSequenceValue( 'text_old_id_val' );
 529                         $dbw->insert( 'text',
 530                                 array(
 531                                         'old_id'    => $old_id,
 532                                         'old_text'  => $mungedText,
 533                                         'old_flags' => $flags,
 534                                 ), $fname
 535                         );
 536                         $this->mTextId = $dbw->insertId();
 537                 }
 538
 539                 # Record the edit in revisions
 540                 $rev_id = isset( $this->mId )
 541                         ? $this->mId
 542                         : $dbw->nextSequenceValue( 'rev_rev_id_val' );
 543                 $dbw->insert( 'revision',
 544                         array(
 545                                 'rev_id'         => $rev_id,
 546                                 'rev_page'       => $this->mPage,
 547                                 'rev_text_id'    => $this->mTextId,
 548                                 'rev_comment'    => $this->mComment,
 549                                 'rev_minor_edit' => $this->mMinorEdit ? 1 : 0,
 550                                 'rev_user'       => $this->mUser,
 551                                 'rev_user_text'  => $this->mUserText,
 552                                 'rev_timestamp'  => $dbw->timestamp( $this->mTimestamp ),
 553                                 'rev_deleted'    => $this->mDeleted,
 554                         ), $fname
 555                 );
 556
 557                 $this->mId = !is_null($rev_id) ? $rev_id : $dbw->insertId();
 558
 559                 wfProfileOut( $fname );
 560                 return $this->mId;
 561         }
 562
 563         /**
 564          * Lazy-load the revision's text.
 565          * Currently hardcoded to the 'text' table storage engine.
 566          *
 567          * @return string
 568          * @access private
 569          */
 570         function loadText() {
 571                 $fname = 'Revision::loadText';
 572                 wfProfileIn( $fname );
 573
 574                 $dbr =& wfGetDB( DB_SLAVE );
 575                 $row = $dbr->selectRow( 'text',
 576                         array( 'old_text', 'old_flags' ),
 577                         array( 'old_id' => $this->getTextId() ),
 578                         $fname);
 579
 580                 if( !$row ) {
 581                         $dbw =& wfGetDB( DB_MASTER );
 582                         $row = $dbw->selectRow( 'text',
 583                                 array( 'old_text', 'old_flags' ),
 584                                 array( 'old_id' => $this->getTextId() ),
 585                                 $fname);
 586                 }
 587
 588                 $text = Revision::getRevisionText( $row );
 589                 wfProfileOut( $fname );
 590
 591                 return $text;
 592         }
 593
 594         /**
 595          * Create a new null-revision for insertion into a page's
 596          * history. This will not re-save the text, but simply refer
 597          * to the text from the previous version.
 598          *
 599          * Such revisions can for instance identify page rename
 600          * operations and other such meta-modifications.
 601          *
 602          * @param Database $dbw
 603          * @param int      $pageId ID number of the page to read from
 604          * @param string   $summary
 605          * @param bool     $minor
 606          * @return Revision
 607          */
 608         function newNullRevision( &$dbw, $pageId, $summary, $minor ) {
 609                 $fname = 'Revision::newNullRevision';
 610                 wfProfileIn( $fname );
 611
 612                 $current = $dbw->selectRow(
 613                         array( 'page', 'revision' ),
 614                         array( 'page_latest', 'rev_text_id' ),
 615                         array(
 616                                 'page_id' => $pageId,
 617                                 'page_latest=rev_id',
 618                                 ),
 619                         $fname );
 620
 621                 if( $current ) {
 622                         $revision = new Revision( array(
 623                                 'page'       => $pageId,
 624                                 'comment'    => $summary,
 625                                 'minor_edit' => $minor,
 626                                 'text_id'    => $current->rev_text_id,
 627                                 ) );
 628                 } else {
 629                         $revision = null;
 630                 }
 631
 632                 wfProfileOut( $fname );
 633                 return $revision;
 634         }
 635
 636 }
 637 ?>