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