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          * Make a fake revision object from an archive table row. This is queried
  71          * for permissions or even inserted (as in Special:Undelete)
  72          * @fixme: should be a subclass for RevisionDelete. [TS]
  73          */
  74         public static function newFromArchiveRow( $row, $overrides = array() ) {
  75                 $attribs = $overrides + array(
  76                         'page'       => isset( $row->page_id ) ? $row->page_id : null,
  77                         'id'         => isset( $row->ar_rev_id ) ? $row->ar_rev_id : null,
  78                         'comment'    => $row->ar_comment,
  79                         'user'       => $row->ar_user,
  80                         'user_text'  => $row->ar_user_text,
  81                         'timestamp'  => $row->ar_timestamp,
  82                         'minor_edit' => $row->ar_minor_edit,
  83                         'text_id'    => isset( $row->ar_text_id ) ? $row->ar_text_id : null,
  84                         'deleted'    => $row->ar_deleted,
  85                         'len'        => $row->ar_len);
  86                 if ( isset( $row->ar_text ) && !$row->ar_text_id ) {
  87                         // Pre-1.5 ar_text row
  88                         $attribs['text'] = $row->ar_text;
  89                 }
  90                 return new self( $attribs );
  91         }
  92
  93         /**
  94          * Load a page revision from a given revision ID number.
  95          * Returns null if no such revision can be found.
  96          *
  97          * @param Database $db
  98          * @param int $id
  99          * @access public
 100          * @static
 101          */
 102         public static function loadFromId( $db, $id ) {
 103                 return Revision::loadFromConds( $db,
 104                         array( 'page_id=rev_page',
 105                                'rev_id' => intval( $id ) ) );
 106         }
 107
 108         /**
 109          * Load either the current, or a specified, revision
 110          * that's attached to a given page. If not attached
 111          * to that page, will return null.
 112          *
 113          * @param Database $db
 114          * @param int $pageid
 115          * @param int $id
 116          * @return Revision
 117          * @access public
 118          * @static
 119          */
 120         public static function loadFromPageId( $db, $pageid, $id = 0 ) {
 121                 $conds=array('page_id=rev_page','rev_page'=>intval( $pageid ), 'page_id'=>intval( $pageid ));
 122                 if( $id ) {
 123                         $conds['rev_id']=intval($id);
 124                 } else {
 125                         $conds[]='rev_id=page_latest';
 126                 }
 127                 return Revision::loadFromConds( $db, $conds );
 128         }
 129
 130         /**
 131          * Load either the current, or a specified, revision
 132          * that's attached to a given page. If not attached
 133          * to that page, will return null.
 134          *
 135          * @param Database $db
 136          * @param Title $title
 137          * @param int $id
 138          * @return Revision
 139          * @access public
 140          * @static
 141          */
 142         public static function loadFromTitle( $db, $title, $id = 0 ) {
 143                 if( $id ) {
 144                         $matchId = intval( $id );
 145                 } else {
 146                         $matchId = 'page_latest';
 147                 }
 148                 return Revision::loadFromConds(
 149                         $db,
 150                         array( "rev_id=$matchId",
 151                                'page_id=rev_page',
 152                                'page_namespace' => $title->getNamespace(),
 153                                'page_title'     => $title->getDBkey() ) );
 154         }
 155
 156         /**
 157          * Load the revision for the given title with the given timestamp.
 158          * WARNING: Timestamps may in some circumstances not be unique,
 159          * so this isn't the best key to use.
 160          *
 161          * @param Database $db
 162          * @param Title $title
 163          * @param string $timestamp
 164          * @return Revision
 165          * @access public
 166          * @static
 167          */
 168         public static function loadFromTimestamp( $db, $title, $timestamp ) {
 169                 return Revision::loadFromConds(
 170                         $db,
 171                         array( 'rev_timestamp'  => $db->timestamp( $timestamp ),
 172                                'page_id=rev_page',
 173                                'page_namespace' => $title->getNamespace(),
 174                                'page_title'     => $title->getDBkey() ) );
 175         }
 176
 177         /**
 178          * Given a set of conditions, fetch a revision.
 179          *
 180          * @param array $conditions
 181          * @return Revision
 182          * @access private
 183          * @static
 184          */
 185         private static function newFromConds( $conditions ) {
 186                 $db = wfGetDB( DB_SLAVE );
 187                 $row = Revision::loadFromConds( $db, $conditions );
 188                 if( is_null( $row ) && wfGetLB()->getServerCount() > 1 ) {
 189                         $dbw = wfGetDB( DB_MASTER );
 190                         $row = Revision::loadFromConds( $dbw, $conditions );
 191                 }
 192                 return $row;
 193         }
 194
 195         /**
 196          * Given a set of conditions, fetch a revision from
 197          * the given database connection.
 198          *
 199          * @param Database $db
 200          * @param array $conditions
 201          * @return Revision
 202          * @access private
 203          * @static
 204          */
 205         private static function loadFromConds( $db, $conditions ) {
 206                 $res = Revision::fetchFromConds( $db, $conditions );
 207                 if( $res ) {
 208                         $row = $res->fetchObject();
 209                         $res->free();
 210                         if( $row ) {
 211                                 $ret = new Revision( $row );
 212                                 return $ret;
 213                         }
 214                 }
 215                 $ret = null;
 216                 return $ret;
 217         }
 218
 219         /**
 220          * Return a wrapper for a series of database rows to
 221          * fetch all of a given page's revisions in turn.
 222          * Each row can be fed to the constructor to get objects.
 223          *
 224          * @param Title $title
 225          * @return ResultWrapper
 226          * @access public
 227          * @static
 228          */
 229         public static function fetchRevision( $title ) {
 230                 return Revision::fetchFromConds(
 231                         wfGetDB( DB_SLAVE ),
 232                         array( 'rev_id=page_latest',
 233                                'page_namespace' => $title->getNamespace(),
 234                                'page_title'     => $title->getDBkey(),
 235                                'page_id=rev_page' ) );
 236         }
 237
 238         /**
 239          * Given a set of conditions, return a ResultWrapper
 240          * which will return matching database rows with the
 241          * fields necessary to build Revision objects.
 242          *
 243          * @param Database $db
 244          * @param array $conditions
 245          * @return ResultWrapper
 246          * @access private
 247          * @static
 248          */
 249         private static function fetchFromConds( $db, $conditions ) {
 250                 $fields = self::selectFields();
 251                 $fields[] = 'page_namespace';
 252                 $fields[] = 'page_title';
 253                 $fields[] = 'page_latest';
 254                 $res = $db->select(
 255                         array( 'page', 'revision' ),
 256                         $fields,
 257                         $conditions,
 258                         __METHOD__,
 259                         array( 'LIMIT' => 1 ) );
 260                 $ret = $db->resultObject( $res );
 261                 return $ret;
 262         }
 263
 264         /**
 265          * Return the list of revision fields that should be selected to create
 266          * a new revision.
 267          */
 268         static function selectFields() {
 269                 return array(
 270                         'rev_id',
 271                         'rev_page',
 272                         'rev_text_id',
 273                         'rev_timestamp',
 274                         'rev_comment',
 275                         'rev_user_text,'.
 276                         'rev_user',
 277                         'rev_minor_edit',
 278                         'rev_deleted',
 279                         'rev_len',
 280                         'rev_parent_id'
 281                 );
 282         }
 283
 284         /**
 285          * Return the list of text fields that should be selected to read the
 286          * revision text
 287          */
 288         static function selectTextFields() {
 289                 return array(
 290                         'old_text',
 291                         'old_flags'
 292                 );
 293         }
 294         /**
 295          * Return the list of page fields that should be selected from page table
 296          */
 297         static function selectPageFields() {
 298                 return array(
 299                         'page_namespace',
 300                         'page_title',
 301                         'page_latest'
 302                 );
 303         }
 304
 305         /**
 306          * @param object $row
 307          * @access private
 308          */
 309         function Revision( $row ) {
 310                 if( is_object( $row ) ) {
 311                         $this->mId        = intval( $row->rev_id );
 312                         $this->mPage      = intval( $row->rev_page );
 313                         $this->mTextId    = intval( $row->rev_text_id );
 314                         $this->mComment   =         $row->rev_comment;
 315                         $this->mUserText  =         $row->rev_user_text;
 316                         $this->mUser      = intval( $row->rev_user );
 317                         $this->mMinorEdit = intval( $row->rev_minor_edit );
 318                         $this->mTimestamp =         $row->rev_timestamp;
 319                         $this->mDeleted   = intval( $row->rev_deleted );
 320
 321                         if( !isset( $row->rev_parent_id ) )
 322                                 $this->mParentId = is_null($row->rev_parent_id) ? null : 0;
 323                         else
 324                                 $this->mParentId  = intval( $row->rev_parent_id );
 325
 326                         if( !isset( $row->rev_len ) || is_null( $row->rev_len ) )
 327                                 $this->mSize = null;
 328                         else
 329                                 $this->mSize = intval( $row->rev_len );
 330
 331                         if( isset( $row->page_latest ) ) {
 332                                 $this->mCurrent = ( $row->rev_id == $row->page_latest );
 333                                 $this->mTitle = Title::makeTitle( $row->page_namespace, $row->page_title );
 334                                 $this->mTitle->resetArticleID( $this->mPage );
 335                         } else {
 336                                 $this->mCurrent = false;
 337                                 $this->mTitle = null;
 338                         }
 339
 340                         // Lazy extraction...
 341                         $this->mText      = null;
 342                         if( isset( $row->old_text ) ) {
 343                                 $this->mTextRow = $row;
 344                         } else {
 345                                 // 'text' table row entry will be lazy-loaded
 346                                 $this->mTextRow = null;
 347                         }
 348                 } elseif( is_array( $row ) ) {
 349                         // Build a new revision to be saved...
 350                         global $wgUser;
 351
 352                         $this->mId        = isset( $row['id']         ) ? intval( $row['id']         ) : null;
 353                         $this->mPage      = isset( $row['page']       ) ? intval( $row['page']       ) : null;
 354                         $this->mTextId    = isset( $row['text_id']    ) ? intval( $row['text_id']    ) : null;
 355                         $this->mUserText  = isset( $row['user_text']  ) ? strval( $row['user_text']  ) : $wgUser->getName();
 356                         $this->mUser      = isset( $row['user']       ) ? intval( $row['user']       ) : $wgUser->getId();
 357                         $this->mMinorEdit = isset( $row['minor_edit'] ) ? intval( $row['minor_edit'] ) : 0;
 358                         $this->mTimestamp = isset( $row['timestamp']  ) ? strval( $row['timestamp']  ) : wfTimestamp( TS_MW );
 359                         $this->mDeleted   = isset( $row['deleted']    ) ? intval( $row['deleted']    ) : 0;
 360                         $this->mSize      = isset( $row['len']        ) ? intval( $row['len']        ) : null;
 361                         $this->mParentId  = isset( $row['parent_id']  ) ? intval( $row['parent_id']  ) : null;
 362
 363                         // Enforce spacing trimming on supplied text
 364                         $this->mComment   = isset( $row['comment']    ) ?  trim( strval( $row['comment'] ) ) : null;
 365                         $this->mText      = isset( $row['text']       ) ? rtrim( strval( $row['text']    ) ) : null;
 366                         $this->mTextRow   = null;
 367
 368                         $this->mTitle     = null; # Load on demand if needed
 369                         $this->mCurrent   = false;
 370                         # If we still have no len_size, see it we have the text to figure it out
 371                         if ( !$this->mSize )
 372                                 $this->mSize      = is_null($this->mText) ? null : strlen($this->mText);
 373                 } else {
 374                         throw new MWException( 'Revision constructor passed invalid row format.' );
 375                 }
 376                 $this->mUnpatrolled = NULL;
 377         }
 378
 379         /**#@+
 380          * @access public
 381          */
 382
 383         /**
 384          * Get revision ID
 385          * @return int
 386          */
 387         public function getId() {
 388                 return $this->mId;
 389         }
 390
 391         /**
 392          * Get text row ID
 393          * @return int
 394          */
 395         public function getTextId() {
 396                 return $this->mTextId;
 397         }
 398
 399         /**
 400          * Get parent revision ID (the original previous page revision)
 401          * @return int
 402          */
 403         public function getParentId() {
 404                 return $this->mParentId;
 405         }
 406
 407         /**
 408          * Returns the length of the text in this revision, or null if unknown.
 409          * @return int
 410          */
 411         public function getSize() {
 412                 return $this->mSize;
 413         }
 414
 415         /**
 416          * Returns the title of the page associated with this entry.
 417          * @return Title
 418          */
 419         public function getTitle() {
 420                 if( isset( $this->mTitle ) ) {
 421                         return $this->mTitle;
 422                 }
 423                 $dbr = wfGetDB( DB_SLAVE );
 424                 $row = $dbr->selectRow(
 425                         array( 'page', 'revision' ),
 426                         array( 'page_namespace', 'page_title' ),
 427                         array( 'page_id=rev_page',
 428                                'rev_id' => $this->mId ),
 429                         'Revision::getTitle' );
 430                 if( $row ) {
 431                         $this->mTitle = Title::makeTitle( $row->page_namespace,
 432                                                           $row->page_title );
 433                 }
 434                 return $this->mTitle;
 435         }
 436
 437         /**
 438          * Set the title of the revision
 439          * @param Title $title
 440          */
 441         public function setTitle( $title ) {
 442                 $this->mTitle = $title;
 443         }
 444
 445         /**
 446          * Get the page ID
 447          * @return int
 448          */
 449         public function getPage() {
 450                 return $this->mPage;
 451         }
 452
 453         /**
 454          * Fetch revision's user id if it's available to the specified audience.
 455          * If the specified audience does not have access to it, zero will be
 456          * returned.
 457          *
 458          * @param integer $audience One of:
 459          *      Revision::FOR_PUBLIC       to be displayed to all users
 460          *      Revision::FOR_THIS_USER    to be displayed to $wgUser
 461          *      Revision::RAW              get the ID regardless of permissions
 462          *
 463          *
 464          * @return int
 465          */
 466         public function getUser( $audience = self::FOR_PUBLIC ) {
 467                 if( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_USER ) ) {
 468                         return 0;
 469                 } elseif( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_USER ) ) {
 470                         return 0;
 471                 } else {
 472                         return $this->mUser;
 473                 }
 474         }
 475
 476         /**
 477          * Fetch revision's user id without regard for the current user's permissions
 478          * @return string
 479          */
 480         public function getRawUser() {
 481                 return $this->mUser;
 482         }
 483
 484         /**
 485          * Fetch revision's username if it's available to the specified audience.
 486          * If the specified audience does not have access to the username, an
 487          * empty string will be returned.
 488          *
 489          * @param integer $audience One of:
 490          *      Revision::FOR_PUBLIC       to be displayed to all users
 491          *      Revision::FOR_THIS_USER    to be displayed to $wgUser
 492          *      Revision::RAW              get the text regardless of permissions
 493          *
 494          * @return string
 495          */
 496         public function getUserText( $audience = self::FOR_PUBLIC ) {
 497                 if( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_USER ) ) {
 498                         return "";
 499                 } elseif( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_USER ) ) {
 500                         return "";
 501                 } else {
 502                         return $this->mUserText;
 503                 }
 504         }
 505
 506         /**
 507          * Fetch revision's username without regard for view restrictions
 508          * @return string
 509          */
 510         public function getRawUserText() {
 511                 return $this->mUserText;
 512         }
 513
 514         /**
 515          * Fetch revision comment if it's available to the specified audience.
 516          * If the specified audience does not have access to the comment, an
 517          * empty string will be returned.
 518          *
 519          * @param integer $audience One of:
 520          *      Revision::FOR_PUBLIC       to be displayed to all users
 521          *      Revision::FOR_THIS_USER    to be displayed to $wgUser
 522          *      Revision::RAW              get the text regardless of permissions
 523          *
 524          * @return string
 525          */
 526         function getComment( $audience = self::FOR_PUBLIC ) {
 527                 if( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_COMMENT ) ) {
 528                         return "";
 529                 } elseif( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_COMMENT ) ) {
 530                         return "";
 531                 } else {
 532                         return $this->mComment;
 533                 }
 534         }
 535
 536         /**
 537          * Fetch revision comment without regard for the current user's permissions
 538          * @return string
 539          */
 540         public function getRawComment() {
 541                 return $this->mComment;
 542         }
 543
 544         /**
 545          * @return bool
 546          */
 547         public function isMinor() {
 548                 return (bool)$this->mMinorEdit;
 549         }
 550
 551         /**
 552          * @return int rcid of the unpatrolled row, zero if there isn't one
 553          */
 554         public function isUnpatrolled() {
 555                 if( $this->mUnpatrolled !== NULL ) {
 556                         return $this->mUnpatrolled;
 557                 }
 558                 $dbr = wfGetDB( DB_SLAVE );
 559                 $this->mUnpatrolled = $dbr->selectField( 'recentchanges',
 560                         'rc_id',
 561                         array( // Add redundant user,timestamp condition so we can use the existing index
 562                                 'rc_user_text'  => $this->getRawUserText(),
 563                                 'rc_timestamp'  => $dbr->timestamp( $this->getTimestamp() ),
 564                                 'rc_this_oldid' => $this->getId(),
 565                                 'rc_patrolled'  => 0
 566                         ),
 567                         __METHOD__
 568                 );
 569                 return (int)$this->mUnpatrolled;
 570         }
 571
 572         /**
 573          * int $field one of DELETED_* bitfield constants
 574          * @return bool
 575          */
 576         public function isDeleted( $field ) {
 577                 return ($this->mDeleted & $field) == $field;
 578         }
 579
 580         /**
 581          * Get the deletion bitfield of the revision
 582          */
 583         public function getVisibility() {
 584                 return (int)$this->mDeleted;
 585         }
 586
 587         /**
 588          * Fetch revision text if it's available to the specified audience.
 589          * If the specified audience does not have the ability to view this
 590          * revision, an empty string will be returned.
 591          *
 592          * @param integer $audience One of:
 593          *      Revision::FOR_PUBLIC       to be displayed to all users
 594          *      Revision::FOR_THIS_USER    to be displayed to $wgUser
 595          *      Revision::RAW              get the text regardless of permissions
 596          *
 597          *
 598          * @return string
 599          */
 600         public function getText( $audience = self::FOR_PUBLIC ) {
 601                 if( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_TEXT ) ) {
 602                         return "";
 603                 } elseif( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_TEXT ) ) {
 604                         return "";
 605                 } else {
 606                         return $this->getRawText();
 607                 }
 608         }
 609
 610         /**
 611          * Alias for getText(Revision::FOR_THIS_USER)
 612          */
 613         public function revText() {
 614                 return $this->getText( self::FOR_THIS_USER );
 615         }
 616
 617         /**
 618          * Fetch revision text without regard for view restrictions
 619          * @return string
 620          */
 621         public function getRawText() {
 622                 if( is_null( $this->mText ) ) {
 623                         // Revision text is immutable. Load on demand:
 624                         $this->mText = $this->loadText();
 625                 }
 626                 return $this->mText;
 627         }
 628
 629         /**
 630          * @return string
 631          */
 632         public function getTimestamp() {
 633                 return wfTimestamp(TS_MW, $this->mTimestamp);
 634         }
 635
 636         /**
 637          * @return bool
 638          */
 639         public function isCurrent() {
 640                 return $this->mCurrent;
 641         }
 642
 643         /**
 644          * Get previous revision for this title
 645          * @return Revision
 646          */
 647         public function getPrevious() {
 648                 if( $this->getTitle() ) {
 649                         $prev = $this->getTitle()->getPreviousRevisionID( $this->getId() );
 650                         if( $prev ) {
 651                                 return Revision::newFromTitle( $this->getTitle(), $prev );
 652                         }
 653                 }
 654                 return null;
 655         }
 656
 657         /**
 658          * @return Revision
 659          */
 660         public function getNext() {
 661                 if( $this->getTitle() ) {
 662                         $next = $this->getTitle()->getNextRevisionID( $this->getId() );
 663                         if ( $next ) {
 664                                 return Revision::newFromTitle( $this->getTitle(), $next );
 665                         }
 666                 }
 667                 return null;
 668         }
 669
 670         /**
 671          * Get previous revision Id for this page_id
 672          * This is used to populate rev_parent_id on save
 673          * @param Database $db
 674          * @return int
 675          */
 676         private function getPreviousRevisionId( $db ) {
 677                 if( is_null($this->mPage) ) {
 678                         return 0;
 679                 }
 680                 # Use page_latest if ID is not given
 681                 if( !$this->mId ) {
 682                         $prevId = $db->selectField( 'page', 'page_latest',
 683                                 array( 'page_id' => $this->mPage ),
 684                                 __METHOD__ );
 685                 } else {
 686                         $prevId = $db->selectField( 'revision', 'rev_id',
 687                                 array( 'rev_page' => $this->mPage, 'rev_id < ' . $this->mId ),
 688                                 __METHOD__,
 689                                 array( 'ORDER BY' => 'rev_id DESC' ) );
 690                 }
 691                 return intval($prevId);
 692         }
 693
 694         /**
 695           * Get revision text associated with an old or archive row
 696           * $row is usually an object from wfFetchRow(), both the flags and the text
 697           * field must be included
 698           *
 699           * @param object $row The text data
 700           * @param string $prefix table prefix (default 'old_')
 701           * @return string $text|false the text requested
 702           */
 703         public static function getRevisionText( $row, $prefix = 'old_' ) {
 704                 wfProfileIn( __METHOD__ );
 705
 706                 # Get data
 707                 $textField = $prefix . 'text';
 708                 $flagsField = $prefix . 'flags';
 709
 710                 if( isset( $row->$flagsField ) ) {
 711                         $flags = explode( ',', $row->$flagsField );
 712                 } else {
 713                         $flags = array();
 714                 }
 715
 716                 if( isset( $row->$textField ) ) {
 717                         $text = $row->$textField;
 718                 } else {
 719                         wfProfileOut( __METHOD__ );
 720                         return false;
 721                 }
 722
 723                 # Use external methods for external objects, text in table is URL-only then
 724                 if ( in_array( 'external', $flags ) ) {
 725                         $url=$text;
 726                         @list(/* $proto */,$path)=explode('://',$url,2);
 727                         if ($path=="") {
 728                                 wfProfileOut( __METHOD__ );
 729                                 return false;
 730                         }
 731                         $text=ExternalStore::fetchFromURL($url);
 732                 }
 733
 734                 // If the text was fetched without an error, convert it
 735                 if ( $text !== false ) {
 736                         if( in_array( 'gzip', $flags ) ) {
 737                                 # Deal with optional compression of archived pages.
 738                                 # This can be done periodically via maintenance/compressOld.php, and
 739                                 # as pages are saved if $wgCompressRevisions is set.
 740                                 $text = gzinflate( $text );
 741                         }
 742
 743                         if( in_array( 'object', $flags ) ) {
 744                                 # Generic compressed storage
 745                                 $obj = unserialize( $text );
 746                                 if ( !is_object( $obj ) ) {
 747                                         // Invalid object
 748                                         wfProfileOut( __METHOD__ );
 749                                         return false;
 750                                 }
 751                                 $text = $obj->getText();
 752                         }
 753
 754                         global $wgLegacyEncoding;
 755                         if( $wgLegacyEncoding && !in_array( 'utf-8', $flags ) && !in_array( 'utf8', $flags ) ) {
 756                                 # Old revisions kept around in a legacy encoding?
 757                                 # Upconvert on demand.
 758                                 # ("utf8" checked for compatibility with some broken
 759                                 #  conversion scripts 2008-12-30)
 760                                 global $wgInputEncoding, $wgContLang;
 761                                 $text = $wgContLang->iconv( $wgLegacyEncoding, $wgInputEncoding, $text );
 762                         }
 763                 }
 764                 wfProfileOut( __METHOD__ );
 765                 return $text;
 766         }
 767
 768         /**
 769          * If $wgCompressRevisions is enabled, we will compress data.
 770          * The input string is modified in place.
 771          * Return value is the flags field: contains 'gzip' if the
 772          * data is compressed, and 'utf-8' if we're saving in UTF-8
 773          * mode.
 774          *
 775          * @param mixed $text reference to a text
 776          * @return string
 777          */
 778         public static function compressRevisionText( &$text ) {
 779                 global $wgCompressRevisions;
 780                 $flags = array();
 781
 782                 # Revisions not marked this way will be converted
 783                 # on load if $wgLegacyCharset is set in the future.
 784                 $flags[] = 'utf-8';
 785
 786                 if( $wgCompressRevisions ) {
 787                         if( function_exists( 'gzdeflate' ) ) {
 788                                 $text = gzdeflate( $text );
 789                                 $flags[] = 'gzip';
 790                         } else {
 791                                 wfDebug( "Revision::compressRevisionText() -- no zlib support, not compressing\n" );
 792                         }
 793                 }
 794                 return implode( ',', $flags );
 795         }
 796
 797         /**
 798          * Insert a new revision into the database, returning the new revision ID
 799          * number on success and dies horribly on failure.
 800          *
 801          * @param Database $dbw
 802          * @return int
 803          */
 804         public function insertOn( $dbw ) {
 805                 global $wgDefaultExternalStore;
 806
 807                 wfProfileIn( __METHOD__ );
 808
 809                 $data = $this->mText;
 810                 $flags = Revision::compressRevisionText( $data );
 811
 812                 # Write to external storage if required
 813                 if( $wgDefaultExternalStore ) {
 814                         // Store and get the URL
 815                         $data = ExternalStore::insertToDefault( $data );
 816                         if( !$data ) {
 817                                 throw new MWException( "Unable to store text to external storage" );
 818                         }
 819                         if( $flags ) {
 820                                 $flags .= ',';
 821                         }
 822                         $flags .= 'external';
 823                 }
 824
 825                 # Record the text (or external storage URL) to the text table
 826                 if( !isset( $this->mTextId ) ) {
 827                         $old_id = $dbw->nextSequenceValue( 'text_old_id_val' );
 828                         $dbw->insert( 'text',
 829                                 array(
 830                                         'old_id'    => $old_id,
 831                                         'old_text'  => $data,
 832                                         'old_flags' => $flags,
 833                                 ), __METHOD__
 834                         );
 835                         $this->mTextId = $dbw->insertId();
 836                 }
 837
 838                 # Record the edit in revisions
 839                 $rev_id = isset( $this->mId )
 840                         ? $this->mId
 841                         : $dbw->nextSequenceValue( 'rev_rev_id_val' );
 842                 $dbw->insert( 'revision',
 843                         array(
 844                                 'rev_id'         => $rev_id,
 845                                 'rev_page'       => $this->mPage,
 846                                 'rev_text_id'    => $this->mTextId,
 847                                 'rev_comment'    => $this->mComment,
 848                                 'rev_minor_edit' => $this->mMinorEdit ? 1 : 0,
 849                                 'rev_user'       => $this->mUser,
 850                                 'rev_user_text'  => $this->mUserText,
 851                                 'rev_timestamp'  => $dbw->timestamp( $this->mTimestamp ),
 852                                 'rev_deleted'    => $this->mDeleted,
 853                                 'rev_len'            => $this->mSize,
 854                                 'rev_parent_id'  => is_null($this->mParentId) ?
 855                                         $this->getPreviousRevisionId( $dbw ) : $this->mParentId
 856                         ), __METHOD__
 857                 );
 858
 859                 $this->mId = !is_null($rev_id) ? $rev_id : $dbw->insertId();
 860
 861                 wfRunHooks( 'RevisionInsertComplete', array( &$this, $data, $flags ) );
 862
 863                 wfProfileOut( __METHOD__ );
 864                 return $this->mId;
 865         }
 866
 867         /**
 868          * Lazy-load the revision's text.
 869          * Currently hardcoded to the 'text' table storage engine.
 870          *
 871          * @return string
 872          */
 873         protected function loadText() {
 874                 wfProfileIn( __METHOD__ );
 875
 876                 // Caching may be beneficial for massive use of external storage
 877                 global $wgRevisionCacheExpiry, $wgMemc;
 878                 $textId = $this->getTextId();
 879                 $key = wfMemcKey( 'revisiontext', 'textid', $textId );
 880                 if( $wgRevisionCacheExpiry ) {
 881                         $text = $wgMemc->get( $key );
 882                         if( is_string( $text ) ) {
 883                                 wfDebug( __METHOD__. ": got id $textId from cache\n" );
 884                                 wfProfileOut( __METHOD__ );
 885                                 return $text;
 886                         }
 887                 }
 888
 889                 // If we kept data for lazy extraction, use it now...
 890                 if ( isset( $this->mTextRow ) ) {
 891                         $row = $this->mTextRow;
 892                         $this->mTextRow = null;
 893                 } else {
 894                         $row = null;
 895                 }
 896
 897                 if( !$row ) {
 898                         // Text data is immutable; check slaves first.
 899                         $dbr = wfGetDB( DB_SLAVE );
 900                         $row = $dbr->selectRow( 'text',
 901                                 array( 'old_text', 'old_flags' ),
 902                                 array( 'old_id' => $this->getTextId() ),
 903                                 __METHOD__ );
 904                 }
 905
 906                 if( !$row && wfGetLB()->getServerCount() > 1 ) {
 907                         // Possible slave lag!
 908                         $dbw = wfGetDB( DB_MASTER );
 909                         $row = $dbw->selectRow( 'text',
 910                                 array( 'old_text', 'old_flags' ),
 911                                 array( 'old_id' => $this->getTextId() ),
 912                                 __METHOD__ );
 913                 }
 914
 915                 $text = self::getRevisionText( $row );
 916
 917                 # No negative caching -- negative hits on text rows may be due to corrupted slave servers
 918                 if( $wgRevisionCacheExpiry && $text !== false ) {
 919                         $wgMemc->set( $key, $text, $wgRevisionCacheExpiry );
 920                 }
 921
 922                 wfProfileOut( __METHOD__ );
 923
 924                 return $text;
 925         }
 926
 927         /**
 928          * Create a new null-revision for insertion into a page's
 929          * history. This will not re-save the text, but simply refer
 930          * to the text from the previous version.
 931          *
 932          * Such revisions can for instance identify page rename
 933          * operations and other such meta-modifications.
 934          *
 935          * @param Database $dbw
 936          * @param int      $pageId ID number of the page to read from
 937          * @param string   $summary
 938          * @param bool     $minor
 939          * @return Revision
 940          */
 941         public static function newNullRevision( $dbw, $pageId, $summary, $minor ) {
 942                 wfProfileIn( __METHOD__ );
 943
 944                 $current = $dbw->selectRow(
 945                         array( 'page', 'revision' ),
 946                         array( 'page_latest', 'rev_text_id', 'rev_len' ),
 947                         array(
 948                                 'page_id' => $pageId,
 949                                 'page_latest=rev_id',
 950                                 ),
 951                         __METHOD__ );
 952
 953                 if( $current ) {
 954                         $revision = new Revision( array(
 955                                 'page'       => $pageId,
 956                                 'comment'    => $summary,
 957                                 'minor_edit' => $minor,
 958                                 'text_id'    => $current->rev_text_id,
 959                                 'parent_id'  => $current->page_latest,
 960                                 'len'        => $current->rev_len
 961                                 ) );
 962                 } else {
 963                         $revision = null;
 964                 }
 965
 966                 wfProfileOut( __METHOD__ );
 967                 return $revision;
 968         }
 969
 970         /**
 971          * Determine if the current user is allowed to view a particular
 972          * field of this revision, if it's marked as deleted.
 973          * @param int $field one of self::DELETED_TEXT,
 974          *                          self::DELETED_COMMENT,
 975          *                          self::DELETED_USER
 976          * @return bool
 977          */
 978         public function userCan( $field ) {
 979                 if( ( $this->mDeleted & $field ) == $field ) {
 980                         global $wgUser;
 981                         $permission = ( $this->mDeleted & self::DELETED_RESTRICTED ) == self::DELETED_RESTRICTED
 982                                 ? 'suppressrevision'
 983                                 : 'deleterevision';
 984                         wfDebug( "Checking for $permission due to $field match on $this->mDeleted\n" );
 985                         return $wgUser->isAllowed( $permission );
 986                 } else {
 987                         return true;
 988                 }
 989         }
 990
 991
 992         /**
 993          * Get rev_timestamp from rev_id, without loading the rest of the row
 994          * @param Title $title
 995          * @param integer $id
 996          */
 997         static function getTimestampFromId( $title, $id ) {
 998                 $dbr = wfGetDB( DB_SLAVE );
 999                 // Casting fix for DB2
1000                 if ($id == '') {
1001                         $id = 0;
1002                 }
1003                 $conds = array( 'rev_id' => $id );
1004                 $conds['rev_page'] = $title->getArticleId();
1005                 $timestamp = $dbr->selectField( 'revision', 'rev_timestamp', $conds, __METHOD__ );
1006                 if ( $timestamp === false && wfGetLB()->getServerCount() > 1 ) {
1007                         # Not in slave, try master
1008                         $dbw = wfGetDB( DB_MASTER );
1009                         $timestamp = $dbw->selectField( 'revision', 'rev_timestamp', $conds, __METHOD__ );
1010                 }
1011                 return wfTimestamp( TS_MW, $timestamp );
1012         }
1013
1014         /**
1015          * Get count of revisions per page...not very efficient
1016          * @param Database $db
1017          * @param int $id, page id
1018          */
1019         static function countByPageId( $db, $id ) {
1020                 $row = $db->selectRow( 'revision', 'COUNT(*) AS revCount',
1021                         array( 'rev_page' => $id ), __METHOD__ );
1022                 if( $row ) {
1023                         return $row->revCount;
1024                 }
1025                 return 0;
1026         }
1027
1028         /**
1029          * Get count of revisions per page...not very efficient
1030          * @param Database $db
1031          * @param Title $title
1032          */
1033         static function countByTitle( $db, $title ) {
1034                 $id = $title->getArticleId();
1035                 if( $id ) {
1036                         return Revision::countByPageId( $db, $id );
1037                 }
1038                 return 0;
1039         }
1040 }
1041
1042 /**
1043  * Aliases for backwards compatibility with 1.6
1044  */
1045 define( 'MW_REV_DELETED_TEXT', Revision::DELETED_TEXT );
1046 define( 'MW_REV_DELETED_COMMENT', Revision::DELETED_COMMENT );
1047 define( 'MW_REV_DELETED_USER', Revision::DELETED_USER );
1048 define( 'MW_REV_DELETED_RESTRICTED', Revision::DELETED_RESTRICTED );