includes/Revision.php

   1 <?php
   2 /**
   3  * @todo document
   4  * @file
   5  */
   6
   7 /**
   8  * @todo document
   9  */
  10 class Revision {
  11         const DELETED_TEXT = 1;
  12         const DELETED_COMMENT = 2;
  13         const DELETED_USER = 4;
  14         const DELETED_RESTRICTED = 8;
  15
  16         // Audience options for Revision::getText()
  17         const FOR_PUBLIC = 1;
  18         const FOR_THIS_USER = 2;
  19         const RAW = 3;
  20
  21         /**
  22          * Load a page revision from a given revision ID number.
  23          * Returns null if no such revision can be found.
  24          *
  25          * @param int $id
  26          * @access public
  27          * @static
  28          */
  29         public static function newFromId( $id ) {
  30                 return Revision::newFromConds(
  31                         array( 'page_id=rev_page',
  32                                'rev_id' => intval( $id ) ) );
  33         }
  34
  35         /**
  36          * Load either the current, or a specified, revision
  37          * that's attached to a given title. If not attached
  38          * to that title, will return null.
  39          *
  40          * @param Title $title
  41          * @param int $id
  42          * @return Revision
  43          */
  44         public static function newFromTitle( $title, $id = 0 ) {
  45                 $conds = array(
  46                         'page_namespace' => $title->getNamespace(),
  47                         'page_title' => $title->getDBkey()
  48                 );
  49                 if ( $id ) {
  50                         // Use the specified ID
  51                         $conds['rev_id'] = $id;
  52                 } elseif ( wfGetLB()->getServerCount() > 1 ) {
  53                         // Get the latest revision ID from the master
  54                         $dbw = wfGetDB( DB_MASTER );
  55                         $latest = $dbw->selectField( 'page', 'page_latest', $conds, __METHOD__ );
  56                         if ( $latest === false ) {
  57                                 // Page does not exist
  58                                 return null;
  59                         }
  60                         $conds['rev_id'] = $latest;
  61                 } else {
  62                         // Use a join to get the latest revision
  63                         $conds[] = 'rev_id=page_latest';
  64                 }
  65                 $conds[] = 'page_id=rev_page';
  66                 return Revision::newFromConds( $conds );
  67         }
  68
  69         /**
  70          * Load a page revision from a given revision ID number.
  71          * Returns null if no such revision can be found.
  72          *
  73          * @param Database $db
  74          * @param int $id
  75          * @access public
  76          * @static
  77          */
  78         public static function loadFromId( $db, $id ) {
  79                 return Revision::loadFromConds( $db,
  80                         array( 'page_id=rev_page',
  81                                'rev_id' => intval( $id ) ) );
  82         }
  83
  84         /**
  85          * Load either the current, or a specified, revision
  86          * that's attached to a given page. If not attached
  87          * to that page, will return null.
  88          *
  89          * @param Database $db
  90          * @param int $pageid
  91          * @param int $id
  92          * @return Revision
  93          * @access public
  94          * @static
  95          */
  96         public static function loadFromPageId( $db, $pageid, $id = 0 ) {
  97                 $conds=array('page_id=rev_page','rev_page'=>intval( $pageid ), 'page_id'=>intval( $pageid ));
  98                 if( $id ) {
  99                         $conds['rev_id']=intval($id);
 100                 } else {
 101                         $conds[]='rev_id=page_latest';
 102                 }
 103                 return Revision::loadFromConds( $db, $conds );
 104         }
 105
 106         /**
 107          * Load either the current, or a specified, revision
 108          * that's attached to a given page. If not attached
 109          * to that page, will return null.
 110          *
 111          * @param Database $db
 112          * @param Title $title
 113          * @param int $id
 114          * @return Revision
 115          * @access public
 116          * @static
 117          */
 118         public static function loadFromTitle( $db, $title, $id = 0 ) {
 119                 if( $id ) {
 120                         $matchId = intval( $id );
 121                 } else {
 122                         $matchId = 'page_latest';
 123                 }
 124                 return Revision::loadFromConds(
 125                         $db,
 126                         array( "rev_id=$matchId",
 127                                'page_id=rev_page',
 128                                'page_namespace' => $title->getNamespace(),
 129                                'page_title'     => $title->getDBkey() ) );
 130         }
 131
 132         /**
 133          * Load the revision for the given title with the given timestamp.
 134          * WARNING: Timestamps may in some circumstances not be unique,
 135          * so this isn't the best key to use.
 136          *
 137          * @param Database $db
 138          * @param Title $title
 139          * @param string $timestamp
 140          * @return Revision
 141          * @access public
 142          * @static
 143          */
 144         public static function loadFromTimestamp( $db, $title, $timestamp ) {
 145                 return Revision::loadFromConds(
 146                         $db,
 147                         array( 'rev_timestamp'  => $db->timestamp( $timestamp ),
 148                                'page_id=rev_page',
 149                                'page_namespace' => $title->getNamespace(),
 150                                'page_title'     => $title->getDBkey() ) );
 151         }
 152
 153         /**
 154          * Given a set of conditions, fetch a revision.
 155          *
 156          * @param array $conditions
 157          * @return Revision
 158          * @access private
 159          * @static
 160          */
 161         private static function newFromConds( $conditions ) {
 162                 $db = wfGetDB( DB_SLAVE );
 163                 $row = Revision::loadFromConds( $db, $conditions );
 164                 if( is_null( $row ) && wfGetLB()->getServerCount() > 1 ) {
 165                         $dbw = wfGetDB( DB_MASTER );
 166                         $row = Revision::loadFromConds( $dbw, $conditions );
 167                 }
 168                 return $row;
 169         }
 170
 171         /**
 172          * Given a set of conditions, fetch a revision from
 173          * the given database connection.
 174          *
 175          * @param Database $db
 176          * @param array $conditions
 177          * @return Revision
 178          * @access private
 179          * @static
 180          */
 181         private static function loadFromConds( $db, $conditions ) {
 182                 $res = Revision::fetchFromConds( $db, $conditions );
 183                 if( $res ) {
 184                         $row = $res->fetchObject();
 185                         $res->free();
 186                         if( $row ) {
 187                                 $ret = new Revision( $row );
 188                                 return $ret;
 189                         }
 190                 }
 191                 $ret = null;
 192                 return $ret;
 193         }
 194
 195         /**
 196          * Return a wrapper for a series of database rows to
 197          * fetch all of a given page's revisions in turn.
 198          * Each row can be fed to the constructor to get objects.
 199          *
 200          * @param Title $title
 201          * @return ResultWrapper
 202          * @access public
 203          * @static
 204          */
 205         public static function fetchAllRevisions( $title ) {
 206                 return Revision::fetchFromConds(
 207                         wfGetDB( DB_SLAVE ),
 208                         array( 'page_namespace' => $title->getNamespace(),
 209                                'page_title'     => $title->getDBkey(),
 210                                'page_id=rev_page' ) );
 211         }
 212
 213         /**
 214          * Return a wrapper for a series of database rows to
 215          * fetch all of a given page's revisions in turn.
 216          * Each row can be fed to the constructor to get objects.
 217          *
 218          * @param Title $title
 219          * @return ResultWrapper
 220          * @access public
 221          * @static
 222          */
 223         public static function fetchRevision( $title ) {
 224                 return Revision::fetchFromConds(
 225                         wfGetDB( DB_SLAVE ),
 226                         array( 'rev_id=page_latest',
 227                                'page_namespace' => $title->getNamespace(),
 228                                'page_title'     => $title->getDBkey(),
 229                                'page_id=rev_page' ) );
 230         }
 231
 232         /**
 233          * Given a set of conditions, return a ResultWrapper
 234          * which will return matching database rows with the
 235          * fields necessary to build Revision objects.
 236          *
 237          * @param Database $db
 238          * @param array $conditions
 239          * @return ResultWrapper
 240          * @access private
 241          * @static
 242          */
 243         private static function fetchFromConds( $db, $conditions ) {
 244                 $fields = self::selectFields();
 245                 $fields[] = 'page_namespace';
 246                 $fields[] = 'page_title';
 247                 $fields[] = 'page_latest';
 248                 $res = $db->select(
 249                         array( 'page', 'revision' ),
 250                         $fields,
 251                         $conditions,
 252                         __METHOD__,
 253                         array( 'LIMIT' => 1 ) );
 254                 $ret = $db->resultObject( $res );
 255                 return $ret;
 256         }
 257
 258         /**
 259          * Return the list of revision fields that should be selected to create
 260          * a new revision.
 261          */
 262         static function selectFields() {
 263                 return array(
 264                         'rev_id',
 265                         'rev_page',
 266                         'rev_text_id',
 267                         'rev_timestamp',
 268                         'rev_comment',
 269                         'rev_user_text,'.
 270                         'rev_user',
 271                         'rev_minor_edit',
 272                         'rev_deleted',
 273                         'rev_len',
 274                         'rev_parent_id'
 275                 );
 276         }
 277
 278         /**
 279          * Return the list of text fields that should be selected to read the
 280          * revision text
 281          */
 282         static function selectTextFields() {
 283                 return array(
 284                         'old_text',
 285                         'old_flags'
 286                 );
 287         }
 288         /**
 289          * Return the list of page fields that should be selected from page table
 290          */
 291         static function selectPageFields() {
 292                 return array(
 293                         'page_namespace',
 294                         'page_title',
 295                         'page_latest'
 296                 );
 297         }
 298
 299         /**
 300          * @param object $row
 301          * @access private
 302          */
 303         function Revision( $row ) {
 304                 if( is_object( $row ) ) {
 305                         $this->mId        = intval( $row->rev_id );
 306                         $this->mPage      = intval( $row->rev_page );
 307                         $this->mTextId    = intval( $row->rev_text_id );
 308                         $this->mComment   =         $row->rev_comment;
 309                         $this->mUserText  =         $row->rev_user_text;
 310                         $this->mUser      = intval( $row->rev_user );
 311                         $this->mMinorEdit = intval( $row->rev_minor_edit );
 312                         $this->mTimestamp =         $row->rev_timestamp;
 313                         $this->mDeleted   = intval( $row->rev_deleted );
 314
 315                         if( !isset( $row->rev_parent_id ) )
 316                                 $this->mParentId = is_null($row->rev_parent_id) ? null : 0;
 317                         else
 318                                 $this->mParentId  = intval( $row->rev_parent_id );
 319
 320                         if( !isset( $row->rev_len ) || is_null( $row->rev_len ) )
 321                                 $this->mSize = null;
 322                         else
 323                                 $this->mSize = intval( $row->rev_len );
 324
 325                         if( isset( $row->page_latest ) ) {
 326                                 $this->mCurrent = ( $row->rev_id == $row->page_latest );
 327                                 $this->mTitle = Title::makeTitle( $row->page_namespace, $row->page_title );
 328                                 $this->mTitle->resetArticleID( $this->mPage );
 329                         } else {
 330                                 $this->mCurrent = false;
 331                                 $this->mTitle = null;
 332                         }
 333
 334                         // Lazy extraction...
 335                         $this->mText      = null;
 336                         if( isset( $row->old_text ) ) {
 337                                 $this->mTextRow = $row;
 338                         } else {
 339                                 // 'text' table row entry will be lazy-loaded
 340                                 $this->mTextRow = null;
 341                         }
 342                 } elseif( is_array( $row ) ) {
 343                         // Build a new revision to be saved...
 344                         global $wgUser;
 345
 346                         $this->mId        = isset( $row['id']         ) ? intval( $row['id']         ) : null;
 347                         $this->mPage      = isset( $row['page']       ) ? intval( $row['page']       ) : null;
 348                         $this->mTextId    = isset( $row['text_id']    ) ? intval( $row['text_id']    ) : null;
 349                         $this->mUserText  = isset( $row['user_text']  ) ? strval( $row['user_text']  ) : $wgUser->getName();
 350                         $this->mUser      = isset( $row['user']       ) ? intval( $row['user']       ) : $wgUser->getId();
 351                         $this->mMinorEdit = isset( $row['minor_edit'] ) ? intval( $row['minor_edit'] ) : 0;
 352                         $this->mTimestamp = isset( $row['timestamp']  ) ? strval( $row['timestamp']  ) : wfTimestamp( TS_MW );
 353                         $this->mDeleted   = isset( $row['deleted']    ) ? intval( $row['deleted']    ) : 0;
 354                         $this->mSize      = isset( $row['len']        ) ? intval( $row['len']        ) : null;
 355                         $this->mParentId  = isset( $row['parent_id']  ) ? intval( $row['parent_id']  ) : null;
 356
 357                         // Enforce spacing trimming on supplied text
 358                         $this->mComment   = isset( $row['comment']    ) ?  trim( strval( $row['comment'] ) ) : null;
 359                         $this->mText      = isset( $row['text']       ) ? rtrim( strval( $row['text']    ) ) : null;
 360                         $this->mTextRow   = null;
 361
 362                         $this->mTitle     = null; # Load on demand if needed
 363                         $this->mCurrent   = false;
 364                         # If we still have no len_size, see it we have the text to figure it out
 365                         if ( !$this->mSize )
 366                                 $this->mSize      = is_null($this->mText) ? null : strlen($this->mText);
 367                 } else {
 368                         throw new MWException( 'Revision constructor passed invalid row format.' );
 369                 }
 370                 $this->mUnpatrolled = NULL;
 371         }
 372
 373         /**#@+
 374          * @access public
 375          */
 376
 377         /**
 378          * Get revision ID
 379          * @return int
 380          */
 381         public function getId() {
 382                 return $this->mId;
 383         }
 384
 385         /**
 386          * Get text row ID
 387          * @return int
 388          */
 389         public function getTextId() {
 390                 return $this->mTextId;
 391         }
 392
 393         /**
 394          * Get parent revision ID (the original previous page revision)
 395          * @return int
 396          */
 397         public function getParentId() {
 398                 return $this->mParentId;
 399         }
 400
 401         /**
 402          * Returns the length of the text in this revision, or null if unknown.
 403          * @return int
 404          */
 405         public function getSize() {
 406                 return $this->mSize;
 407         }
 408
 409         /**
 410          * Returns the title of the page associated with this entry.
 411          * @return Title
 412          */
 413         public function getTitle() {
 414                 if( isset( $this->mTitle ) ) {
 415                         return $this->mTitle;
 416                 }
 417                 $dbr = wfGetDB( DB_SLAVE );
 418                 $row = $dbr->selectRow(
 419                         array( 'page', 'revision' ),
 420                         array( 'page_namespace', 'page_title' ),
 421                         array( 'page_id=rev_page',
 422                                'rev_id' => $this->mId ),
 423                         'Revision::getTitle' );
 424                 if( $row ) {
 425                         $this->mTitle = Title::makeTitle( $row->page_namespace,
 426                                                           $row->page_title );
 427                 }
 428                 return $this->mTitle;
 429         }
 430
 431         /**
 432          * Set the title of the revision
 433          * @param Title $title
 434          */
 435         public function setTitle( $title ) {
 436                 $this->mTitle = $title;
 437         }
 438
 439         /**
 440          * Get the page ID
 441          * @return int
 442          */
 443         public function getPage() {
 444                 return $this->mPage;
 445         }
 446
 447         /**
 448          * Fetch revision's user id if it's available to the specified audience.
 449          * If the specified audience does not have access to it, zero will be
 450          * returned.
 451          *
 452          * @param integer $audience One of:
 453          *      Revision::FOR_PUBLIC       to be displayed to all users
 454          *      Revision::FOR_THIS_USER    to be displayed to $wgUser
 455          *      Revision::RAW              get the ID regardless of permissions
 456          *
 457          *
 458          * @return int
 459          */
 460         public function getUser( $audience = self::FOR_PUBLIC ) {
 461                 if( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_USER ) ) {
 462                         return 0;
 463                 } elseif( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_USER ) ) {
 464                         return 0;
 465                 } else {
 466                         return $this->mUser;
 467                 }
 468         }
 469
 470         /**
 471          * Fetch revision's user id without regard for the current user's permissions
 472          * @return string
 473          */
 474         public function getRawUser() {
 475                 return $this->mUser;
 476         }
 477
 478         /**
 479          * Fetch revision's username if it's available to the specified audience.
 480          * If the specified audience does not have access to the username, an
 481          * empty string will be returned.
 482          *
 483          * @param integer $audience One of:
 484          *      Revision::FOR_PUBLIC       to be displayed to all users
 485          *      Revision::FOR_THIS_USER    to be displayed to $wgUser
 486          *      Revision::RAW              get the text regardless of permissions
 487          *
 488          * @return string
 489          */
 490         public function getUserText( $audience = self::FOR_PUBLIC ) {
 491                 if( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_USER ) ) {
 492                         return "";
 493                 } elseif( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_USER ) ) {
 494                         return "";
 495                 } else {
 496                         return $this->mUserText;
 497                 }
 498         }
 499
 500         /**
 501          * Fetch revision's username without regard for view restrictions
 502          * @return string
 503          */
 504         public function getRawUserText() {
 505                 return $this->mUserText;
 506         }
 507
 508         /**
 509          * Fetch revision comment if it's available to the specified audience.
 510          * If the specified audience does not have access to the comment, an
 511          * empty string will be returned.
 512          *
 513          * @param integer $audience One of:
 514          *      Revision::FOR_PUBLIC       to be displayed to all users
 515          *      Revision::FOR_THIS_USER    to be displayed to $wgUser
 516          *      Revision::RAW              get the text regardless of permissions
 517          *
 518          * @return string
 519          */
 520         function getComment( $audience = self::FOR_PUBLIC ) {
 521                 if( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_COMMENT ) ) {
 522                         return "";
 523                 } elseif( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_COMMENT ) ) {
 524                         return "";
 525                 } else {
 526                         return $this->mComment;
 527                 }
 528         }
 529
 530         /**
 531          * Fetch revision comment without regard for the current user's permissions
 532          * @return string
 533          */
 534         public function getRawComment() {
 535                 return $this->mComment;
 536         }
 537
 538         /**
 539          * @return bool
 540          */
 541         public function isMinor() {
 542                 return (bool)$this->mMinorEdit;
 543         }
 544
 545         /**
 546          * @return int rcid of the unpatrolled row, zero if there isn't one
 547          */
 548         public function isUnpatrolled() {
 549                 if( $this->mUnpatrolled !== NULL ) {
 550                         return $this->mUnpatrolled;
 551                 }
 552                 $dbr = wfGetDB( DB_SLAVE );
 553                 $this->mUnpatrolled = $dbr->selectField( 'recentchanges',
 554                         'rc_id',
 555                         array( // Add redundant user,timestamp condition so we can use the existing index
 556                                 'rc_user_text'  => $this->getRawUserText(),
 557                                 'rc_timestamp'  => $dbr->timestamp( $this->getTimestamp() ),
 558                                 'rc_this_oldid' => $this->getId(),
 559                                 'rc_patrolled'  => 0
 560                         ),
 561                         __METHOD__
 562                 );
 563                 return (int)$this->mUnpatrolled;
 564         }
 565
 566         /**
 567          * int $field one of DELETED_* bitfield constants
 568          * @return bool
 569          */
 570         public function isDeleted( $field ) {
 571                 return ($this->mDeleted & $field) == $field;
 572         }
 573
 574         /**
 575          * Get the deletion bitfield of the revision
 576          */
 577         public function getVisibility() {
 578                 return (int)$this->mDeleted;
 579         }
 580
 581         /**
 582          * Fetch revision text if it's available to the specified audience.
 583          * If the specified audience does not have the ability to view this
 584          * revision, an empty string will be returned.
 585          *
 586          * @param integer $audience One of:
 587          *      Revision::FOR_PUBLIC       to be displayed to all users
 588          *      Revision::FOR_THIS_USER    to be displayed to $wgUser
 589          *      Revision::RAW              get the text regardless of permissions
 590          *
 591          *
 592          * @return string
 593          */
 594         public function getText( $audience = self::FOR_PUBLIC ) {
 595                 if( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_TEXT ) ) {
 596                         return "";
 597                 } elseif( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_TEXT ) ) {
 598                         return "";
 599                 } else {
 600                         return $this->getRawText();
 601                 }
 602         }
 603
 604         /**
 605          * Alias for getText(Revision::FOR_THIS_USER)
 606          */
 607         public function revText() {
 608                 return $this->getText( self::FOR_THIS_USER );
 609         }
 610
 611         /**
 612          * Fetch revision text without regard for view restrictions
 613          * @return string
 614          */
 615         public function getRawText() {
 616                 if( is_null( $this->mText ) ) {
 617                         // Revision text is immutable. Load on demand:
 618                         $this->mText = $this->loadText();
 619                 }
 620                 return $this->mText;
 621         }
 622
 623         /**
 624          * @return string
 625          */
 626         public function getTimestamp() {
 627                 return wfTimestamp(TS_MW, $this->mTimestamp);
 628         }
 629
 630         /**
 631          * @return bool
 632          */
 633         public function isCurrent() {
 634                 return $this->mCurrent;
 635         }
 636
 637         /**
 638          * Get previous revision for this title
 639          * @return Revision
 640          */
 641         public function getPrevious() {
 642                 if( $this->getTitle() ) {
 643                         $prev = $this->getTitle()->getPreviousRevisionID( $this->getId() );
 644                         if( $prev ) {
 645                                 return Revision::newFromTitle( $this->getTitle(), $prev );
 646                         }
 647                 }
 648                 return null;
 649         }
 650
 651         /**
 652          * @return Revision
 653          */
 654         public function getNext() {
 655                 if( $this->getTitle() ) {
 656                         $next = $this->getTitle()->getNextRevisionID( $this->getId() );
 657                         if ( $next ) {
 658                                 return Revision::newFromTitle( $this->getTitle(), $next );
 659                         }
 660                 }
 661                 return null;
 662         }
 663
 664         /**
 665          * Get previous revision Id for this page_id
 666          * This is used to populate rev_parent_id on save
 667          * @param Database $db
 668          * @return int
 669          */
 670         private function getPreviousRevisionId( $db ) {
 671                 if( is_null($this->mPage) ) {
 672                         return 0;
 673                 }
 674                 # Use page_latest if ID is not given
 675                 if( !$this->mId ) {
 676                         $prevId = $db->selectField( 'page', 'page_latest',
 677                                 array( 'page_id' => $this->mPage ),
 678                                 __METHOD__ );
 679                 } else {
 680                         $prevId = $db->selectField( 'revision', 'rev_id',
 681                                 array( 'rev_page' => $this->mPage, 'rev_id < ' . $this->mId ),
 682                                 __METHOD__,
 683                                 array( 'ORDER BY' => 'rev_id DESC' ) );
 684                 }
 685                 return intval($prevId);
 686         }
 687
 688         /**
 689           * Get revision text associated with an old or archive row
 690           * $row is usually an object from wfFetchRow(), both the flags and the text
 691           * field must be included
 692           *
 693           * @param object $row The text data
 694           * @param string $prefix table prefix (default 'old_')
 695           * @return string $text|false the text requested
 696           */
 697         public static function getRevisionText( $row, $prefix = 'old_' ) {
 698                 wfProfileIn( __METHOD__ );
 699
 700                 # Get data
 701                 $textField = $prefix . 'text';
 702                 $flagsField = $prefix . 'flags';
 703
 704                 if( isset( $row->$flagsField ) ) {
 705                         $flags = explode( ',', $row->$flagsField );
 706                 } else {
 707                         $flags = array();
 708                 }
 709
 710                 if( isset( $row->$textField ) ) {
 711                         $text = $row->$textField;
 712                 } else {
 713                         wfProfileOut( __METHOD__ );
 714                         return false;
 715                 }
 716
 717                 # Use external methods for external objects, text in table is URL-only then
 718                 if ( in_array( 'external', $flags ) ) {
 719                         $url=$text;
 720                         @list(/* $proto */,$path)=explode('://',$url,2);
 721                         if ($path=="") {
 722                                 wfProfileOut( __METHOD__ );
 723                                 return false;
 724                         }
 725                         $text=ExternalStore::fetchFromURL($url);
 726                 }
 727
 728                 // If the text was fetched without an error, convert it
 729                 if ( $text !== false ) {
 730                         if( in_array( 'gzip', $flags ) ) {
 731                                 # Deal with optional compression of archived pages.
 732                                 # This can be done periodically via maintenance/compressOld.php, and
 733                                 # as pages are saved if $wgCompressRevisions is set.
 734                                 $text = gzinflate( $text );
 735                         }
 736
 737                         if( in_array( 'object', $flags ) ) {
 738                                 # Generic compressed storage
 739                                 $obj = unserialize( $text );
 740                                 if ( !is_object( $obj ) ) {
 741                                         // Invalid object
 742                                         wfProfileOut( __METHOD__ );
 743                                         return false;
 744                                 }
 745                                 $text = $obj->getText();
 746                         }
 747
 748                         global $wgLegacyEncoding;
 749                         if( $wgLegacyEncoding && !in_array( 'utf-8', $flags ) && !in_array( 'utf8', $flags ) ) {
 750                                 # Old revisions kept around in a legacy encoding?
 751                                 # Upconvert on demand.
 752                                 # ("utf8" checked for compatibility with some broken
 753                                 #  conversion scripts 2008-12-30)
 754                                 global $wgInputEncoding, $wgContLang;
 755                                 $text = $wgContLang->iconv( $wgLegacyEncoding, $wgInputEncoding, $text );
 756                         }
 757                 }
 758                 wfProfileOut( __METHOD__ );
 759                 return $text;
 760         }
 761
 762         /**
 763          * If $wgCompressRevisions is enabled, we will compress data.
 764          * The input string is modified in place.
 765          * Return value is the flags field: contains 'gzip' if the
 766          * data is compressed, and 'utf-8' if we're saving in UTF-8
 767          * mode.
 768          *
 769          * @param mixed $text reference to a text
 770          * @return string
 771          */
 772         public static function compressRevisionText( &$text ) {
 773                 global $wgCompressRevisions;
 774                 $flags = array();
 775
 776                 # Revisions not marked this way will be converted
 777                 # on load if $wgLegacyCharset is set in the future.
 778                 $flags[] = 'utf-8';
 779
 780                 if( $wgCompressRevisions ) {
 781                         if( function_exists( 'gzdeflate' ) ) {
 782                                 $text = gzdeflate( $text );
 783                                 $flags[] = 'gzip';
 784                         } else {
 785                                 wfDebug( "Revision::compressRevisionText() -- no zlib support, not compressing\n" );
 786                         }
 787                 }
 788                 return implode( ',', $flags );
 789         }
 790
 791         /**
 792          * Insert a new revision into the database, returning the new revision ID
 793          * number on success and dies horribly on failure.
 794          *
 795          * @param Database $dbw
 796          * @return int
 797          */
 798         public function insertOn( $dbw ) {
 799                 global $wgDefaultExternalStore;
 800
 801                 wfProfileIn( __METHOD__ );
 802
 803                 $data = $this->mText;
 804                 $flags = Revision::compressRevisionText( $data );
 805
 806                 # Write to external storage if required
 807                 if( $wgDefaultExternalStore ) {
 808                         // Store and get the URL
 809                         $data = ExternalStore::insertToDefault( $data );
 810                         if( !$data ) {
 811                                 throw new MWException( "Unable to store text to external storage" );
 812                         }
 813                         if( $flags ) {
 814                                 $flags .= ',';
 815                         }
 816                         $flags .= 'external';
 817                 }
 818
 819                 # Record the text (or external storage URL) to the text table
 820                 if( !isset( $this->mTextId ) ) {
 821                         $old_id = $dbw->nextSequenceValue( 'text_old_id_val' );
 822                         $dbw->insert( 'text',
 823                                 array(
 824                                         'old_id'    => $old_id,
 825                                         'old_text'  => $data,
 826                                         'old_flags' => $flags,
 827                                 ), __METHOD__
 828                         );
 829                         $this->mTextId = $dbw->insertId();
 830                 }
 831
 832                 # Record the edit in revisions
 833                 $rev_id = isset( $this->mId )
 834                         ? $this->mId
 835                         : $dbw->nextSequenceValue( 'rev_rev_id_val' );
 836                 $dbw->insert( 'revision',
 837                         array(
 838                                 'rev_id'         => $rev_id,
 839                                 'rev_page'       => $this->mPage,
 840                                 'rev_text_id'    => $this->mTextId,
 841                                 'rev_comment'    => $this->mComment,
 842                                 'rev_minor_edit' => $this->mMinorEdit ? 1 : 0,
 843                                 'rev_user'       => $this->mUser,
 844                                 'rev_user_text'  => $this->mUserText,
 845                                 'rev_timestamp'  => $dbw->timestamp( $this->mTimestamp ),
 846                                 'rev_deleted'    => $this->mDeleted,
 847                                 'rev_len'            => $this->mSize,
 848                                 'rev_parent_id'  => is_null($this->mParentId) ?
 849                                         $this->getPreviousRevisionId( $dbw ) : $this->mParentId
 850                         ), __METHOD__
 851                 );
 852
 853                 $this->mId = !is_null($rev_id) ? $rev_id : $dbw->insertId();
 854
 855                 wfRunHooks( 'RevisionInsertComplete', array( &$this, $data, $flags ) );
 856
 857                 wfProfileOut( __METHOD__ );
 858                 return $this->mId;
 859         }
 860
 861         /**
 862          * Lazy-load the revision's text.
 863          * Currently hardcoded to the 'text' table storage engine.
 864          *
 865          * @return string
 866          */
 867         private function loadText() {
 868                 wfProfileIn( __METHOD__ );
 869
 870                 // Caching may be beneficial for massive use of external storage
 871                 global $wgRevisionCacheExpiry, $wgMemc;
 872                 $key = wfMemcKey( 'revisiontext', 'textid', $this->getTextId() );
 873                 if( $wgRevisionCacheExpiry ) {
 874                         $text = $wgMemc->get( $key );
 875                         if( is_string( $text ) ) {
 876                                 wfProfileOut( __METHOD__ );
 877                                 return $text;
 878                         }
 879                 }
 880
 881                 // If we kept data for lazy extraction, use it now...
 882                 if ( isset( $this->mTextRow ) ) {
 883                         $row = $this->mTextRow;
 884                         $this->mTextRow = null;
 885                 } else {
 886                         $row = null;
 887                 }
 888
 889                 if( !$row ) {
 890                         // Text data is immutable; check slaves first.
 891                         $dbr = wfGetDB( DB_SLAVE );
 892                         $row = $dbr->selectRow( 'text',
 893                                 array( 'old_text', 'old_flags' ),
 894                                 array( 'old_id' => $this->getTextId() ),
 895                                 __METHOD__ );
 896                 }
 897
 898                 if( !$row && wfGetLB()->getServerCount() > 1 ) {
 899                         // Possible slave lag!
 900                         $dbw = wfGetDB( DB_MASTER );
 901                         $row = $dbw->selectRow( 'text',
 902                                 array( 'old_text', 'old_flags' ),
 903                                 array( 'old_id' => $this->getTextId() ),
 904                                 __METHOD__ );
 905                 }
 906
 907                 $text = self::getRevisionText( $row );
 908
 909                 # No negative caching -- negative hits on text rows may be due to corrupted slave servers
 910                 if( $wgRevisionCacheExpiry && $text !== false ) {
 911                         $wgMemc->set( $key, $text, $wgRevisionCacheExpiry );
 912                 }
 913
 914                 wfProfileOut( __METHOD__ );
 915
 916                 return $text;
 917         }
 918
 919         /**
 920          * Create a new null-revision for insertion into a page's
 921          * history. This will not re-save the text, but simply refer
 922          * to the text from the previous version.
 923          *
 924          * Such revisions can for instance identify page rename
 925          * operations and other such meta-modifications.
 926          *
 927          * @param Database $dbw
 928          * @param int      $pageId ID number of the page to read from
 929          * @param string   $summary
 930          * @param bool     $minor
 931          * @return Revision
 932          */
 933         public static function newNullRevision( $dbw, $pageId, $summary, $minor ) {
 934                 wfProfileIn( __METHOD__ );
 935
 936                 $current = $dbw->selectRow(
 937                         array( 'page', 'revision' ),
 938                         array( 'page_latest', 'rev_text_id', 'rev_len' ),
 939                         array(
 940                                 'page_id' => $pageId,
 941                                 'page_latest=rev_id',
 942                                 ),
 943                         __METHOD__ );
 944
 945                 if( $current ) {
 946                         $revision = new Revision( array(
 947                                 'page'       => $pageId,
 948                                 'comment'    => $summary,
 949                                 'minor_edit' => $minor,
 950                                 'text_id'    => $current->rev_text_id,
 951                                 'parent_id'  => $current->page_latest,
 952                                 'len'        => $current->rev_len
 953                                 ) );
 954                 } else {
 955                         $revision = null;
 956                 }
 957
 958                 wfProfileOut( __METHOD__ );
 959                 return $revision;
 960         }
 961
 962         /**
 963          * Determine if the current user is allowed to view a particular
 964          * field of this revision, if it's marked as deleted.
 965          * @param int $field one of self::DELETED_TEXT,
 966          *                          self::DELETED_COMMENT,
 967          *                          self::DELETED_USER
 968          * @return bool
 969          */
 970         public function userCan( $field ) {
 971                 if( ( $this->mDeleted & $field ) == $field ) {
 972                         global $wgUser;
 973                         $permission = ( $this->mDeleted & self::DELETED_RESTRICTED ) == self::DELETED_RESTRICTED
 974                                 ? 'suppressrevision'
 975                                 : 'deleterevision';
 976                         wfDebug( "Checking for $permission due to $field match on $this->mDeleted\n" );
 977                         return $wgUser->isAllowed( $permission );
 978                 } else {
 979                         return true;
 980                 }
 981         }
 982
 983
 984         /**
 985          * Get rev_timestamp from rev_id, without loading the rest of the row
 986          * @param Title $title
 987          * @param integer $id
 988          */
 989         static function getTimestampFromId( $title, $id ) {
 990                 $dbr = wfGetDB( DB_SLAVE );
 991                 // Casting fix for DB2
 992                 if ($id == '') {
 993                         $id = 0;
 994                 }
 995                 $conds = array( 'rev_id' => $id );
 996                 $conds['rev_page'] = $title->getArticleId();
 997                 $timestamp = $dbr->selectField( 'revision', 'rev_timestamp', $conds, __METHOD__ );
 998                 if ( $timestamp === false && wfGetLB()->getServerCount() > 1 ) {
 999                         # Not in slave, try master
1000                         $dbw = wfGetDB( DB_MASTER );
1001                         $timestamp = $dbw->selectField( 'revision', 'rev_timestamp', $conds, __METHOD__ );
1002                 }
1003                 return wfTimestamp( TS_MW, $timestamp );
1004         }
1005
1006         /**
1007          * Get count of revisions per page...not very efficient
1008          * @param Database $db
1009          * @param int $id, page id
1010          */
1011         static function countByPageId( $db, $id ) {
1012                 $row = $db->selectRow( 'revision', 'COUNT(*) AS revCount',
1013                         array( 'rev_page' => $id ), __METHOD__ );
1014                 if( $row ) {
1015                         return $row->revCount;
1016                 }
1017                 return 0;
1018         }
1019
1020         /**
1021          * Get count of revisions per page...not very efficient
1022          * @param Database $db
1023          * @param Title $title
1024          */
1025         static function countByTitle( $db, $title ) {
1026                 $id = $title->getArticleId();
1027                 if( $id ) {
1028                         return Revision::countByPageId( $db, $id );
1029                 }
1030                 return 0;
1031         }
1032 }
1033
1034 /**
1035  * Aliases for backwards compatibility with 1.6
1036  */
1037 define( 'MW_REV_DELETED_TEXT', Revision::DELETED_TEXT );
1038 define( 'MW_REV_DELETED_COMMENT', Revision::DELETED_COMMENT );
1039 define( 'MW_REV_DELETED_USER', Revision::DELETED_USER );
1040 define( 'MW_REV_DELETED_RESTRICTED', Revision::DELETED_RESTRICTED );