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 $id
  37          * @return Revision
  38          * @access public
  39          */
  40         function &newFromTitle( &$title, $id = 0 ) {
  41                 if( $id ) {
  42                         $matchId = IntVal( $id );
  43                 } else {
  44                         $matchId = 'page_latest';
  45                 }
  46                 return Revision::newFromConds(
  47                         array( "rev_id=$matchId",
  48                                'page_id=rev_page',
  49                                'page_namespace' => $title->getNamespace(),
  50                                'page_title'     => $title->getDbkey() ) );
  51         }
  52
  53         /**
  54          * Load either the current, or a specified, revision
  55          * that's attached to a given page. If not attached
  56          * to that page, will return null.
  57          *
  58          * @param Database $db
  59          * @param int $pageid
  60          * @param int $id
  61          * @return Revision
  62          * @access public
  63          */
  64         function &loadFromPageId( &$db, $pageid, $id = 0 ) {
  65                 if( $id ) {
  66                         $matchId = IntVal( $id );
  67                 } else {
  68                         $matchId = 'page_latest';
  69                 }
  70                 return Revision::loadFromConds(
  71                         $db,
  72                         array( "rev_id=$matchId",
  73                                'rev_page' => IntVal( $pageid ),
  74                                'page_id=rev_page' ) );
  75         }
  76
  77         /**
  78          * Given a set of conditions, fetch a revision.
  79          *
  80          * @param array $conditions
  81          * @return Revision
  82          * @static
  83          * @access private
  84          */
  85         function &newFromConds( $conditions ) {
  86                 $db =& wfGetDB( DB_SLAVE );
  87                 return Revision::loadFromConds( $db, $conditions );
  88         }
  89
  90         /**
  91          * Given a set of conditions, fetch a revision from
  92          * the given database connection.
  93          *
  94          * @param Database $db
  95          * @param array $conditions
  96          * @return Revision
  97          * @static
  98          * @access private
  99          */
 100         function &loadFromConds( &$db, $conditions ) {
 101                 $res =& Revision::fetchFromConds( $db, $conditions );
 102                 if( $res ) {
 103                         $row = $res->fetchObject();
 104                         $res->free();
 105                         if( $row ) {
 106                                 return new Revision( $row );
 107                         }
 108                 }
 109                 return null;
 110         }
 111
 112         /**
 113          * Return a wrapper for a series of database rows to
 114          * fetch all of a given page's revisions in turn.
 115          * Each row can be fed to the constructor to get objects.
 116          *
 117          * @param Title $title
 118          * @return ResultWrapper
 119          * @static
 120          * @access public
 121          */
 122         function &fetchAllRevisions( &$title ) {
 123                 return Revision::fetchFromConds(
 124                         wfGetDB( DB_SLAVE ),
 125                         array( 'page_namespace' => $title->getNamespace(),
 126                                'page_title'     => $title->getDbkey(),
 127                                'page_id=rev_page' ) );
 128         }
 129
 130         /**
 131          * Return a wrapper for a series of database rows to
 132          * fetch all of a given page's revisions in turn.
 133          * Each row can be fed to the constructor to get objects.
 134          *
 135          * @param Title $title
 136          * @return ResultWrapper
 137          * @static
 138          * @access public
 139          */
 140         function &fetchRevision( &$title ) {
 141                 return Revision::fetchFromConds(
 142                         wfGetDB( DB_SLAVE ),
 143                         array( 'rev_id=page_latest',
 144                                'page_namespace' => $title->getNamespace(),
 145                                'page_title'     => $title->getDbkey(),
 146                                'page_id=rev_page' ) );
 147         }
 148
 149         /**
 150          * Given a set of conditions, return a ResultWrapper
 151          * which will return matching database rows with the
 152          * fields necessary to build Revision objects.
 153          *
 154          * @param Database $db
 155          * @param array $conditions
 156          * @return ResultWrapper
 157          * @static
 158          * @access private
 159          */
 160         function &fetchFromConds( &$db, $conditions ) {
 161                 $res = $db->select(
 162                         array( 'page', 'revision' ),
 163                         array( 'page_namespace',
 164                                'page_title',
 165                                'page_latest',
 166                                'rev_id',
 167                                'rev_page',
 168                                'rev_text_id',
 169                                'rev_comment',
 170                                'rev_user_text',
 171                                'rev_user',
 172                                'rev_minor_edit',
 173                                'rev_timestamp' ),
 174                         $conditions,
 175                         'Revision::fetchRow' );
 176                 return $db->resultObject( $res );
 177         }
 178
 179         /**
 180          * @param object $row
 181          * @access private
 182          */
 183         function Revision( $row ) {
 184                 if( is_object( $row ) ) {
 185                         $this->mId        = IntVal( $row->rev_id );
 186                         $this->mPage      = IntVal( $row->rev_page );
 187                         $this->mTextId    = IntVal( $row->rev_text_id );
 188                         $this->mComment   =         $row->rev_comment;
 189                         $this->mUserText  =         $row->rev_user_text;
 190                         $this->mUser      = IntVal( $row->rev_user );
 191                         $this->mMinorEdit = IntVal( $row->rev_minor_edit );
 192                         $this->mTimestamp =         $row->rev_timestamp;
 193
 194                         $this->mCurrent   = ( $row->rev_id == $row->page_latest );
 195                         $this->mTitle     = Title::makeTitle( $row->page_namespace,
 196                                                               $row->page_title );
 197
 198                         if( isset( $row->old_text ) ) {
 199                                 $this->mText  = $this->getRevisionText( $row );
 200                         } else {
 201                                 $this->mText  = null;
 202                         }
 203                 } elseif( is_array( $row ) ) {
 204                         // Build a new revision to be saved...
 205                         global $wgUser;
 206
 207                         $this->mId        = isset( $row['id']         ) ? IntVal( $row['id']         ) : null;
 208                         $this->mPage      = isset( $row['page']       ) ? IntVal( $row['page']       ) : null;
 209                         $this->mTextId    = isset( $row['text_id']    ) ? IntVal( $row['text_id']    ) : null;
 210                         $this->mComment   = isset( $row['comment']    ) ? StrVal( $row['comment']    ) : null;
 211                         $this->mUserText  = isset( $row['user_text']  ) ? StrVal( $row['user_text']  ) : $wgUser->getName();
 212                         $this->mUser      = isset( $row['user']       ) ? IntVal( $row['user']       ) : $wgUser->getId();
 213                         $this->mMinorEdit = isset( $row['minor_edit'] ) ? IntVal( $row['minor_edit'] ) : 0;
 214                         $this->mTimestamp = isset( $row['timestamp']  ) ? StrVal( $row['timestamp']  ) : wfTimestamp( TS_MW );
 215                         $this->mText      = isset( $row['text']       ) ? StrVal( $row['text']       ) : null;
 216
 217                         $this->mTitle     = null; # Load on demand if needed
 218                         $this->mCurrent   = false;
 219                 } else {
 220                         wfDebugDieBacktrace( 'Revision constructor passed invalid row format.' );
 221                 }
 222         }
 223
 224         /**#@+
 225          * @access public
 226          */
 227
 228         /**
 229          * @return int
 230          */
 231         function getId() {
 232                 return $this->mId;
 233         }
 234
 235         /**
 236          * @return int
 237          */
 238         function getTextId() {
 239                 return $this->mTextId;
 240         }
 241
 242         /**
 243          * Returns the title of the page associated with this entry.
 244          * @return Title
 245          */
 246         function &getTitle() {
 247                 if( isset( $this->mTitle ) ) {
 248                         return $this->mTitle;
 249                 }
 250                 $dbr =& wfGetDB( DB_SLAVE );
 251                 $row = $dbr->selectRow(
 252                         array( 'page', 'revision' ),
 253                         array( 'page_namespace', 'page_title' ),
 254                         array( 'page_id=rev_page',
 255                                'rev_id' => $this->mId ),
 256                         'Revision::getTItle' );
 257                 if( $row ) {
 258                         $this->mTitle =& Title::makeTitle( $row->page_namespace,
 259                                                            $row->page_title );
 260                 }
 261                 return $this->mTitle;
 262         }
 263
 264         /**
 265          * @return int
 266          */
 267         function getPage() {
 268                 return $this->mPage;
 269         }
 270
 271         /**
 272          * @return int
 273          */
 274         function getUser() {
 275                 return $this->mUser;
 276         }
 277
 278         /**
 279          * @return string
 280          */
 281         function getUserText() {
 282                 return $this->mUserText;
 283         }
 284
 285         /**
 286          * @return string
 287          */
 288         function getComment() {
 289                 return $this->mComment;
 290         }
 291
 292         /**
 293          * @return bool
 294          */
 295         function isMinor() {
 296                 return (bool)$this->mMinorEdit;
 297         }
 298
 299         /**
 300          * @return string
 301          */
 302         function getText() {
 303                 if( is_null( $this->mText ) ) {
 304                         // Revision text is immutable. Load on demand:
 305                         $this->mText = $this->loadText();
 306                 }
 307                 return $this->mText;
 308         }
 309
 310         /**
 311          * @return string
 312          */
 313         function getTimestamp() {
 314                 return $this->mTimestamp;
 315         }
 316
 317         /**
 318          * @return bool
 319          */
 320         function isCurrent() {
 321                 return $this->mCurrent;
 322         }
 323
 324         /**
 325          * @return Revision
 326          */
 327         function &getPrevious() {
 328                 $prev = $this->mTitle->getPreviousRevisionID( $this->mId );
 329                 return Revision::newFromTitle( $this->mTitle, $prev );
 330         }
 331
 332         /**
 333          * @return Revision
 334          */
 335         function &getNext() {
 336                 $next = $this->mTitle->getNextRevisionID( $this->mId );
 337                 return Revision::newFromTitle( $this->mTitle, $next );
 338         }
 339         /**#@-*/
 340
 341         /**
 342           * Get revision text associated with an old or archive row
 343           * $row is usually an object from wfFetchRow(), both the flags and the text
 344           * field must be included
 345           * @static
 346           * @param integer $row Id of a row
 347           * @param string $prefix table prefix (default 'old_')
 348           * @return string $text|false the text requested
 349           */
 350         function getRevisionText( $row, $prefix = 'old_' ) {
 351                 $fname = 'Revision::getRevisionText';
 352                 wfProfileIn( $fname );
 353
 354                 # Get data
 355                 $textField = $prefix . 'text';
 356                 $flagsField = $prefix . 'flags';
 357
 358                 if( isset( $row->$flagsField ) ) {
 359                         $flags = explode( ',', $row->$flagsField );
 360                 } else {
 361                         $flags = array();
 362                 }
 363
 364                 if( isset( $row->$textField ) ) {
 365                         $text = $row->$textField;
 366                 } else {
 367                         wfProfileOut( $fname );
 368                         return false;
 369                 }
 370
 371                 if( in_array( 'gzip', $flags ) ) {
 372                         # Deal with optional compression of archived pages.
 373                         # This can be done periodically via maintenance/compressOld.php, and
 374                         # as pages are saved if $wgCompressRevisions is set.
 375                         $text = gzinflate( $text );
 376                 }
 377
 378                 if( in_array( 'object', $flags ) ) {
 379                         # Generic compressed storage
 380                         $obj = unserialize( $text );
 381
 382                         # Bugger, corrupted my test database by double-serializing
 383                         if ( !is_object( $obj ) ) {
 384                                 $obj = unserialize( $obj );
 385                         }
 386
 387                         $text = $obj->getText();
 388                 }
 389
 390                 global $wgLegacyEncoding;
 391                 if( $wgLegacyEncoding && !in_array( 'utf-8', $flags ) ) {
 392                         # Old revisions kept around in a legacy encoding?
 393                         # Upconvert on demand.
 394                         global $wgInputEncoding, $wgContLang;
 395                         $text = $wgContLang->iconv( $wgLegacyEncoding, $wgInputEncoding, $text );
 396                 }
 397                 wfProfileOut( $fname );
 398                 return $text;
 399         }
 400
 401         /**
 402          * If $wgCompressRevisions is enabled, we will compress data.
 403          * The input string is modified in place.
 404          * Return value is the flags field: contains 'gzip' if the
 405          * data is compressed, and 'utf-8' if we're saving in UTF-8
 406          * mode.
 407          *
 408          * @static
 409          * @param mixed $text reference to a text
 410          * @return string
 411          */
 412         function compressRevisionText( &$text ) {
 413                 global $wgCompressRevisions;
 414                 $flags = array();
 415
 416                 # Revisions not marked this way will be converted
 417                 # on load if $wgLegacyCharset is set in the future.
 418                 $flags[] = 'utf-8';
 419
 420                 if( $wgCompressRevisions ) {
 421                         if( function_exists( 'gzdeflate' ) ) {
 422                                 $text = gzdeflate( $text );
 423                                 $flags[] = 'gzip';
 424                         } else {
 425                                 wfDebug( "Revision::compressRevisionText() -- no zlib support, not compressing\n" );
 426                         }
 427                 }
 428                 return implode( ',', $flags );
 429         }
 430
 431         /**
 432          * Insert a new revision into the database, returning the new revision ID
 433          * number on success and dies horribly on failure.
 434          *
 435          * @param Database $dbw
 436          * @return int
 437          */
 438         function insertOn( &$dbw ) {
 439                 $fname = 'Revision::insertOn';
 440                 wfProfileIn( $fname );
 441
 442                 $mungedText = $this->mText;
 443                 $flags = Revision::compressRevisionText( $mungedText );
 444
 445                 # Record the text to the text table
 446                 if( !isset( $this->mTextId ) ) {
 447                         $old_id = $dbw->nextSequenceValue( 'text_old_id_val' );
 448                         $dbw->insert( 'text',
 449                                 array(
 450                                         'old_id'    => $old_id,
 451                                         'old_text'  => $mungedText,
 452                                         'old_flags' => $flags,
 453                                 ), $fname
 454                         );
 455                         $this->mTextId = $dbw->insertId();
 456                 }
 457
 458                 # Record the edit in revisions
 459                 $rev_id = isset( $this->mId )
 460                         ? $this->mId
 461                         : $dbw->nextSequenceValue( 'rev_rev_id_val' );
 462                 $dbw->insert( 'revision',
 463                         array(
 464                                 'rev_id'         => $rev_id,
 465                                 'rev_page'       => $this->mPage,
 466                                 'rev_text_id'    => $this->mTextId,
 467                                 'rev_comment'    => $this->mComment,
 468                                 'rev_minor_edit' => $this->mMinorEdit ? 1 : 0,
 469                                 'rev_user'       => $this->mUser,
 470                                 'rev_user_text'  => $this->mUserText,
 471                                 'rev_timestamp'  => $dbw->timestamp( $this->mTimestamp ),
 472                         ), $fname
 473                 );
 474
 475                 $this->mId = $dbw->insertId();
 476
 477                 wfProfileOut( $fname );
 478                 return $this->mId;
 479         }
 480
 481         /**
 482          * Lazy-load the revision's text.
 483          * Currently hardcoded to the 'text' table storage engine.
 484          *
 485          * @return string
 486          * @access private
 487          */
 488         function loadText() {
 489                 $fname = 'Revision::loadText';
 490                 wfProfileIn( $fname );
 491
 492                 $dbr =& wfGetDB( DB_SLAVE );
 493                 $row = $dbr->selectRow( 'text',
 494                         array( 'old_text', 'old_flags' ),
 495                         array( 'old_id' => $this->getTextId() ),
 496                         $fname);
 497
 498                 $text = Revision::getRevisionText( $row );
 499                 wfProfileOut( $fname );
 500
 501                 return $text;
 502         }
 503
 504         /**
 505          * Create a new null-revision for insertion into a page's
 506          * history. This will not re-save the text, but simply refer
 507          * to the text from the previous version.
 508          *
 509          * Such revisions can for instance identify page rename
 510          * operations and other such meta-modifications.
 511          *
 512          * @param Database $dbw
 513          * @param int      $pageId ID number of the page to read from
 514          * @param string   $summary
 515          * @param bool     $minor
 516          * @return Revision
 517          */
 518         function &newNullRevision( &$dbw, $pageId, $summary, $minor ) {
 519                 $fname = 'Revision::newNullRevision';
 520                 wfProfileIn( $fname );
 521
 522                 $current = $dbw->selectRow(
 523                         array( 'page', 'revision' ),
 524                         array( 'page_latest', 'rev_text_id' ),
 525                         array(
 526                                 'page_id' => $pageId,
 527                                 'page_latest=rev_id',
 528                                 ),
 529                         $fname );
 530
 531                 if( $current ) {
 532                         $revision = new Revision( array(
 533                                 'page'       => $pageId,
 534                                 'comment'    => $summary,
 535                                 'minor_edit' => $minor,
 536                                 'text_id'    => $current->rev_text_id,
 537                                 ) );
 538                 } else {
 539                         $revision = null;
 540                 }
 541
 542                 wfProfileOut( $fname );
 543                 return $revision;
 544         }
 545
 546 }
 547 ?>