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