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