includes/Revision.php

   1 <?php
   2 /**
   3  * Representation of a page version.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  */
  22
  23 /**
  24  * @todo document
  25  */
  26 class Revision implements IDBAccessObject {
  27         protected $mId;
  28
  29         /**
  30          * @var int|null
  31          */
  32         protected $mPage;
  33         protected $mUserText;
  34         protected $mOrigUserText;
  35         protected $mUser;
  36         protected $mMinorEdit;
  37         protected $mTimestamp;
  38         protected $mDeleted;
  39         protected $mSize;
  40         protected $mSha1;
  41         protected $mParentId;
  42         protected $mComment;
  43         protected $mText;
  44         protected $mTextRow;
  45
  46         /**
  47          * @var null|Title
  48          */
  49         protected $mTitle;
  50         protected $mCurrent;
  51         protected $mContentModel;
  52         protected $mContentFormat;
  53
  54         /**
  55          * @var Content|null|bool
  56          */
  57         protected $mContent;
  58
  59         /**
  60          * @var null|ContentHandler
  61          */
  62         protected $mContentHandler;
  63
  64         /**
  65          * @var int
  66          */
  67         protected $mQueryFlags = 0;
  68
  69         // Revision deletion constants
  70         const DELETED_TEXT = 1;
  71         const DELETED_COMMENT = 2;
  72         const DELETED_USER = 4;
  73         const DELETED_RESTRICTED = 8;
  74         const SUPPRESSED_USER = 12; // convenience
  75
  76         // Audience options for accessors
  77         const FOR_PUBLIC = 1;
  78         const FOR_THIS_USER = 2;
  79         const RAW = 3;
  80
  81         /**
  82          * Load a page revision from a given revision ID number.
  83          * Returns null if no such revision can be found.
  84          *
  85          * $flags include:
  86          *      Revision::READ_LATEST  : Select the data from the master
  87          *      Revision::READ_LOCKING : Select & lock the data from the master
  88          *
  89          * @param $id Integer
  90          * @param $flags Integer (optional)
  91          * @return Revision or null
  92          */
  93         public static function newFromId( $id, $flags = 0 ) {
  94                 return self::newFromConds( array( 'rev_id' => intval( $id ) ), $flags );
  95         }
  96
  97         /**
  98          * Load either the current, or a specified, revision
  99          * that's attached to a given title. If not attached
 100          * to that title, will return null.
 101          *
 102          * $flags include:
 103          *      Revision::READ_LATEST  : Select the data from the master
 104          *      Revision::READ_LOCKING : Select & lock the data from the master
 105          *
 106          * @param $title Title
 107          * @param $id Integer (optional)
 108          * @param $flags Integer Bitfield (optional)
 109          * @return Revision or null
 110          */
 111         public static function newFromTitle( $title, $id = 0, $flags = 0 ) {
 112                 $conds = array(
 113                         'page_namespace' => $title->getNamespace(),
 114                         'page_title' => $title->getDBkey()
 115                 );
 116                 if ( $id ) {
 117                         // Use the specified ID
 118                         $conds['rev_id'] = $id;
 119                         return self::newFromConds( $conds, (int)$flags );
 120                 } else {
 121                         // Use a join to get the latest revision
 122                         $conds[] = 'rev_id=page_latest';
 123                         $db = wfGetDB( ( $flags & self::READ_LATEST ) ? DB_MASTER : DB_SLAVE );
 124                         return self::loadFromConds( $db, $conds, $flags );
 125                 }
 126         }
 127
 128         /**
 129          * Load either the current, or a specified, revision
 130          * that's attached to a given page ID.
 131          * Returns null if no such revision can be found.
 132          *
 133          * $flags include:
 134          *      Revision::READ_LATEST  : Select the data from the master (since 1.20)
 135          *      Revision::READ_LOCKING : Select & lock the data from the master
 136          *
 137          * @param $revId Integer
 138          * @param $pageId Integer (optional)
 139          * @param $flags Integer Bitfield (optional)
 140          * @return Revision or null
 141          */
 142         public static function newFromPageId( $pageId, $revId = 0, $flags = 0 ) {
 143                 $conds = array( 'page_id' => $pageId );
 144                 if ( $revId ) {
 145                         $conds['rev_id'] = $revId;
 146                 } else {
 147                         // Use a join to get the latest revision
 148                         $conds[] = 'rev_id = page_latest';
 149                 }
 150                 return self::newFromConds( $conds, (int)$flags );
 151         }
 152
 153         /**
 154          * Make a fake revision object from an archive table row. This is queried
 155          * for permissions or even inserted (as in Special:Undelete)
 156          * @todo FIXME: Should be a subclass for RevisionDelete. [TS]
 157          *
 158          * @param $row
 159          * @param $overrides array
 160          *
 161          * @throws MWException
 162          * @return Revision
 163          */
 164         public static function newFromArchiveRow( $row, $overrides = array() ) {
 165                 global $wgContentHandlerUseDB;
 166
 167                 $attribs = $overrides + array(
 168                         'page'       => isset( $row->ar_page_id ) ? $row->ar_page_id : null,
 169                         'id'         => isset( $row->ar_rev_id ) ? $row->ar_rev_id : null,
 170                         'comment'    => $row->ar_comment,
 171                         'user'       => $row->ar_user,
 172                         'user_text'  => $row->ar_user_text,
 173                         'timestamp'  => $row->ar_timestamp,
 174                         'minor_edit' => $row->ar_minor_edit,
 175                         'text_id'    => isset( $row->ar_text_id ) ? $row->ar_text_id : null,
 176                         'deleted'    => $row->ar_deleted,
 177                         'len'        => $row->ar_len,
 178                         'sha1'       => isset( $row->ar_sha1 ) ? $row->ar_sha1 : null,
 179                         'content_model'   => isset( $row->ar_content_model ) ? $row->ar_content_model : null,
 180                         'content_format'  => isset( $row->ar_content_format ) ? $row->ar_content_format : null,
 181                 );
 182
 183                 if ( !$wgContentHandlerUseDB ) {
 184                         unset( $attribs['content_model'] );
 185                         unset( $attribs['content_format'] );
 186                 }
 187
 188                 if ( !isset( $attribs['title'] )
 189                         && isset( $row->ar_namespace )
 190                         && isset( $row->ar_title ) ) {
 191
 192                         $attribs['title'] = Title::makeTitle( $row->ar_namespace, $row->ar_title );
 193                 }
 194
 195                 if ( isset( $row->ar_text ) && !$row->ar_text_id ) {
 196                         // Pre-1.5 ar_text row
 197                         $attribs['text'] = self::getRevisionText( $row, 'ar_' );
 198                         if ( $attribs['text'] === false ) {
 199                                 throw new MWException( 'Unable to load text from archive row (possibly bug 22624)' );
 200                         }
 201                 }
 202                 return new self( $attribs );
 203         }
 204
 205         /**
 206          * @since 1.19
 207          *
 208          * @param $row
 209          * @return Revision
 210          */
 211         public static function newFromRow( $row ) {
 212                 return new self( $row );
 213         }
 214
 215         /**
 216          * Load a page revision from a given revision ID number.
 217          * Returns null if no such revision can be found.
 218          *
 219          * @param $db DatabaseBase
 220          * @param $id Integer
 221          * @return Revision or null
 222          */
 223         public static function loadFromId( $db, $id ) {
 224                 return self::loadFromConds( $db, array( 'rev_id' => intval( $id ) ) );
 225         }
 226
 227         /**
 228          * Load either the current, or a specified, revision
 229          * that's attached to a given page. If not attached
 230          * to that page, will return null.
 231          *
 232          * @param $db DatabaseBase
 233          * @param $pageid Integer
 234          * @param $id Integer
 235          * @return Revision or null
 236          */
 237         public static function loadFromPageId( $db, $pageid, $id = 0 ) {
 238                 $conds = array( 'rev_page' => intval( $pageid ), 'page_id' => intval( $pageid ) );
 239                 if ( $id ) {
 240                         $conds['rev_id'] = intval( $id );
 241                 } else {
 242                         $conds[] = 'rev_id=page_latest';
 243                 }
 244                 return self::loadFromConds( $db, $conds );
 245         }
 246
 247         /**
 248          * Load either the current, or a specified, revision
 249          * that's attached to a given page. If not attached
 250          * to that page, will return null.
 251          *
 252          * @param $db DatabaseBase
 253          * @param $title Title
 254          * @param $id Integer
 255          * @return Revision or null
 256          */
 257         public static function loadFromTitle( $db, $title, $id = 0 ) {
 258                 if ( $id ) {
 259                         $matchId = intval( $id );
 260                 } else {
 261                         $matchId = 'page_latest';
 262                 }
 263                 return self::loadFromConds( $db,
 264                         array(
 265                                 "rev_id=$matchId",
 266                                 'page_namespace' => $title->getNamespace(),
 267                                 'page_title' => $title->getDBkey()
 268                         )
 269                 );
 270         }
 271
 272         /**
 273          * Load the revision for the given title with the given timestamp.
 274          * WARNING: Timestamps may in some circumstances not be unique,
 275          * so this isn't the best key to use.
 276          *
 277          * @param $db DatabaseBase
 278          * @param $title Title
 279          * @param $timestamp String
 280          * @return Revision or null
 281          */
 282         public static function loadFromTimestamp( $db, $title, $timestamp ) {
 283                 return self::loadFromConds( $db,
 284                         array(
 285                                 'rev_timestamp' => $db->timestamp( $timestamp ),
 286                                 'page_namespace' => $title->getNamespace(),
 287                                 'page_title' => $title->getDBkey()
 288                         )
 289                 );
 290         }
 291
 292         /**
 293          * Given a set of conditions, fetch a revision.
 294          *
 295          * @param $conditions Array
 296          * @param $flags integer (optional)
 297          * @return Revision or null
 298          */
 299         private static function newFromConds( $conditions, $flags = 0 ) {
 300                 $db = wfGetDB( ( $flags & self::READ_LATEST ) ? DB_MASTER : DB_SLAVE );
 301                 $rev = self::loadFromConds( $db, $conditions, $flags );
 302                 if ( is_null( $rev ) && wfGetLB()->getServerCount() > 1 ) {
 303                         if ( !( $flags & self::READ_LATEST ) ) {
 304                                 $dbw = wfGetDB( DB_MASTER );
 305                                 $rev = self::loadFromConds( $dbw, $conditions, $flags );
 306                         }
 307                 }
 308                 if ( $rev ) {
 309                         $rev->mQueryFlags = $flags;
 310                 }
 311                 return $rev;
 312         }
 313
 314         /**
 315          * Given a set of conditions, fetch a revision from
 316          * the given database connection.
 317          *
 318          * @param $db DatabaseBase
 319          * @param $conditions Array
 320          * @param $flags integer (optional)
 321          * @return Revision or null
 322          */
 323         private static function loadFromConds( $db, $conditions, $flags = 0 ) {
 324                 $res = self::fetchFromConds( $db, $conditions, $flags );
 325                 if ( $res ) {
 326                         $row = $res->fetchObject();
 327                         if ( $row ) {
 328                                 $ret = new Revision( $row );
 329                                 return $ret;
 330                         }
 331                 }
 332                 $ret = null;
 333                 return $ret;
 334         }
 335
 336         /**
 337          * Return a wrapper for a series of database rows to
 338          * fetch all of a given page's revisions in turn.
 339          * Each row can be fed to the constructor to get objects.
 340          *
 341          * @param $title Title
 342          * @return ResultWrapper
 343          */
 344         public static function fetchRevision( $title ) {
 345                 return self::fetchFromConds(
 346                         wfGetDB( DB_SLAVE ),
 347                         array(
 348                                 'rev_id=page_latest',
 349                                 'page_namespace' => $title->getNamespace(),
 350                                 'page_title' => $title->getDBkey()
 351                         )
 352                 );
 353         }
 354
 355         /**
 356          * Given a set of conditions, return a ResultWrapper
 357          * which will return matching database rows with the
 358          * fields necessary to build Revision objects.
 359          *
 360          * @param $db DatabaseBase
 361          * @param $conditions Array
 362          * @param $flags integer (optional)
 363          * @return ResultWrapper
 364          */
 365         private static function fetchFromConds( $db, $conditions, $flags = 0 ) {
 366                 $fields = array_merge(
 367                         self::selectFields(),
 368                         self::selectPageFields(),
 369                         self::selectUserFields()
 370                 );
 371                 $options = array( 'LIMIT' => 1 );
 372                 if ( ( $flags & self::READ_LOCKING ) == self::READ_LOCKING ) {
 373                         $options[] = 'FOR UPDATE';
 374                 }
 375                 return $db->select(
 376                         array( 'revision', 'page', 'user' ),
 377                         $fields,
 378                         $conditions,
 379                         __METHOD__,
 380                         $options,
 381                         array( 'page' => self::pageJoinCond(), 'user' => self::userJoinCond() )
 382                 );
 383         }
 384
 385         /**
 386          * Return the value of a select() JOIN conds array for the user table.
 387          * This will get user table rows for logged-in users.
 388          * @since 1.19
 389          * @return Array
 390          */
 391         public static function userJoinCond() {
 392                 return array( 'LEFT JOIN', array( 'rev_user != 0', 'user_id = rev_user' ) );
 393         }
 394
 395         /**
 396          * Return the value of a select() page conds array for the page table.
 397          * This will assure that the revision(s) are not orphaned from live pages.
 398          * @since 1.19
 399          * @return Array
 400          */
 401         public static function pageJoinCond() {
 402                 return array( 'INNER JOIN', array( 'page_id = rev_page' ) );
 403         }
 404
 405         /**
 406          * Return the list of revision fields that should be selected to create
 407          * a new revision.
 408          * @return array
 409          */
 410         public static function selectFields() {
 411                 global $wgContentHandlerUseDB;
 412
 413                 $fields = array(
 414                         'rev_id',
 415                         'rev_page',
 416                         'rev_text_id',
 417                         'rev_timestamp',
 418                         'rev_comment',
 419                         'rev_user_text',
 420                         'rev_user',
 421                         'rev_minor_edit',
 422                         'rev_deleted',
 423                         'rev_len',
 424                         'rev_parent_id',
 425                         'rev_sha1',
 426                 );
 427
 428                 if ( $wgContentHandlerUseDB ) {
 429                         $fields[] = 'rev_content_format';
 430                         $fields[] = 'rev_content_model';
 431                 }
 432
 433                 return $fields;
 434         }
 435
 436         /**
 437          * Return the list of text fields that should be selected to read the
 438          * revision text
 439          * @return array
 440          */
 441         public static function selectTextFields() {
 442                 return array(
 443                         'old_text',
 444                         'old_flags'
 445                 );
 446         }
 447
 448         /**
 449          * Return the list of page fields that should be selected from page table
 450          * @return array
 451          */
 452         public static function selectPageFields() {
 453                 return array(
 454                         'page_namespace',
 455                         'page_title',
 456                         'page_id',
 457                         'page_latest',
 458                         'page_is_redirect',
 459                         'page_len',
 460                 );
 461         }
 462
 463         /**
 464          * Return the list of user fields that should be selected from user table
 465          * @return array
 466          */
 467         public static function selectUserFields() {
 468                 return array( 'user_name' );
 469         }
 470
 471         /**
 472          * Do a batched query to get the parent revision lengths
 473          * @param $db DatabaseBase
 474          * @param $revIds Array
 475          * @return array
 476          */
 477         public static function getParentLengths( $db, array $revIds ) {
 478                 $revLens = array();
 479                 if ( !$revIds ) {
 480                         return $revLens; // empty
 481                 }
 482                 wfProfileIn( __METHOD__ );
 483                 $res = $db->select( 'revision',
 484                         array( 'rev_id', 'rev_len' ),
 485                         array( 'rev_id' => $revIds ),
 486                         __METHOD__ );
 487                 foreach ( $res as $row ) {
 488                         $revLens[$row->rev_id] = $row->rev_len;
 489                 }
 490                 wfProfileOut( __METHOD__ );
 491                 return $revLens;
 492         }
 493
 494         /**
 495          * Constructor
 496          *
 497          * @param $row Mixed: either a database row or an array
 498          * @throws MWException
 499          * @access private
 500          */
 501         function __construct( $row ) {
 502                 if ( is_object( $row ) ) {
 503                         $this->mId        = intval( $row->rev_id );
 504                         $this->mPage      = intval( $row->rev_page );
 505                         $this->mTextId    = intval( $row->rev_text_id );
 506                         $this->mComment   =         $row->rev_comment;
 507                         $this->mUser      = intval( $row->rev_user );
 508                         $this->mMinorEdit = intval( $row->rev_minor_edit );
 509                         $this->mTimestamp =         $row->rev_timestamp;
 510                         $this->mDeleted   = intval( $row->rev_deleted );
 511
 512                         if ( !isset( $row->rev_parent_id ) ) {
 513                                 $this->mParentId = null;
 514                         } else {
 515                                 $this->mParentId = intval( $row->rev_parent_id );
 516                         }
 517
 518                         if ( !isset( $row->rev_len ) ) {
 519                                 $this->mSize = null;
 520                         } else {
 521                                 $this->mSize = intval( $row->rev_len );
 522                         }
 523
 524                         if ( !isset( $row->rev_sha1 ) ) {
 525                                 $this->mSha1 = null;
 526                         } else {
 527                                 $this->mSha1 = $row->rev_sha1;
 528                         }
 529
 530                         if ( isset( $row->page_latest ) ) {
 531                                 $this->mCurrent = ( $row->rev_id == $row->page_latest );
 532                                 $this->mTitle = Title::newFromRow( $row );
 533                         } else {
 534                                 $this->mCurrent = false;
 535                                 $this->mTitle = null;
 536                         }
 537
 538                         if ( !isset( $row->rev_content_model ) || is_null( $row->rev_content_model ) ) {
 539                                 $this->mContentModel = null; # determine on demand if needed
 540                         } else {
 541                                 $this->mContentModel = strval( $row->rev_content_model );
 542                         }
 543
 544                         if ( !isset( $row->rev_content_format ) || is_null( $row->rev_content_format ) ) {
 545                                 $this->mContentFormat = null; # determine on demand if needed
 546                         } else {
 547                                 $this->mContentFormat = strval( $row->rev_content_format );
 548                         }
 549
 550                         // Lazy extraction...
 551                         $this->mText = null;
 552                         if ( isset( $row->old_text ) ) {
 553                                 $this->mTextRow = $row;
 554                         } else {
 555                                 // 'text' table row entry will be lazy-loaded
 556                                 $this->mTextRow = null;
 557                         }
 558
 559                         // Use user_name for users and rev_user_text for IPs...
 560                         $this->mUserText = null; // lazy load if left null
 561                         if ( $this->mUser == 0 ) {
 562                                 $this->mUserText = $row->rev_user_text; // IP user
 563                         } elseif ( isset( $row->user_name ) ) {
 564                                 $this->mUserText = $row->user_name; // logged-in user
 565                         }
 566                         $this->mOrigUserText = $row->rev_user_text;
 567                 } elseif ( is_array( $row ) ) {
 568                         // Build a new revision to be saved...
 569                         global $wgUser; // ugh
 570
 571                         # if we have a content object, use it to set the model and type
 572                         if ( !empty( $row['content'] ) ) {
 573                                 // @todo when is that set? test with external store setup! check out insertOn() [dk]
 574                                 if ( !empty( $row['text_id'] ) ) {
 575                                         throw new MWException( "Text already stored in external store (id {$row['text_id']}), " .
 576                                                 "can't serialize content object" );
 577                                 }
 578
 579                                 $row['content_model'] = $row['content']->getModel();
 580                                 # note: mContentFormat is initializes later accordingly
 581                                 # note: content is serialized later in this method!
 582                                 # also set text to null?
 583                         }
 584
 585                         $this->mId        = isset( $row['id']         ) ? intval( $row['id']         ) : null;
 586                         $this->mPage      = isset( $row['page']       ) ? intval( $row['page']       ) : null;
 587                         $this->mTextId    = isset( $row['text_id']    ) ? intval( $row['text_id']    ) : null;
 588                         $this->mUserText  = isset( $row['user_text']  ) ? strval( $row['user_text']  ) : $wgUser->getName();
 589                         $this->mUser      = isset( $row['user']       ) ? intval( $row['user']       ) : $wgUser->getId();
 590                         $this->mMinorEdit = isset( $row['minor_edit'] ) ? intval( $row['minor_edit'] ) : 0;
 591                         $this->mTimestamp = isset( $row['timestamp']  ) ? strval( $row['timestamp']  ) : wfTimestampNow();
 592                         $this->mDeleted   = isset( $row['deleted']    ) ? intval( $row['deleted']    ) : 0;
 593                         $this->mSize      = isset( $row['len']        ) ? intval( $row['len']        ) : null;
 594                         $this->mParentId  = isset( $row['parent_id']  ) ? intval( $row['parent_id']  ) : null;
 595                         $this->mSha1      = isset( $row['sha1']  )      ? strval( $row['sha1']  )      : null;
 596
 597                         $this->mContentModel   = isset( $row['content_model']  )  ? strval( $row['content_model'] )  : null;
 598                         $this->mContentFormat  = isset( $row['content_format']  ) ? strval( $row['content_format'] ) : null;
 599
 600                         // Enforce spacing trimming on supplied text
 601                         $this->mComment   = isset( $row['comment']    ) ?  trim( strval( $row['comment'] ) ) : null;
 602                         $this->mText      = isset( $row['text']       ) ? rtrim( strval( $row['text']    ) ) : null;
 603                         $this->mTextRow   = null;
 604
 605                         $this->mTitle     = isset( $row['title']      ) ? $row['title'] : null;
 606
 607                         // if we have a Content object, override mText and mContentModel
 608                         if ( !empty( $row['content'] ) ) {
 609                                 if ( !( $row['content'] instanceof Content ) ) {
 610                                         throw new MWException( '`content` field must contain a Content object.' );
 611                                 }
 612
 613                                 $handler = $this->getContentHandler();
 614                                 $this->mContent = $row['content'];
 615
 616                                 $this->mContentModel = $this->mContent->getModel();
 617                                 $this->mContentHandler = null;
 618
 619                                 $this->mText = $handler->serializeContent( $row['content'], $this->getContentFormat() );
 620                         } elseif ( !is_null( $this->mText ) ) {
 621                                 $handler = $this->getContentHandler();
 622                                 $this->mContent = $handler->unserializeContent( $this->mText );
 623                         }
 624
 625                         // If we have a Title object, make sure it is consistent with mPage.
 626                         if ( $this->mTitle && $this->mTitle->exists() ) {
 627                                 if ( $this->mPage === null ) {
 628                                         // if the page ID wasn't known, set it now
 629                                         $this->mPage = $this->mTitle->getArticleID();
 630                                 } elseif ( $this->mTitle->getArticleID() !== $this->mPage ) {
 631                                         // Got different page IDs. This may be legit (e.g. during undeletion),
 632                                         // but it seems worth mentioning it in the log.
 633                                         wfDebug( "Page ID " . $this->mPage . " mismatches the ID " .
 634                                                 $this->mTitle->getArticleID() . " provided by the Title object." );
 635                                 }
 636                         }
 637
 638                         $this->mCurrent = false;
 639
 640                         // If we still have no length, see it we have the text to figure it out
 641                         if ( !$this->mSize ) {
 642                                 if ( !is_null( $this->mContent ) ) {
 643                                         $this->mSize = $this->mContent->getSize();
 644                                 } else {
 645                                         #NOTE: this should never happen if we have either text or content object!
 646                                         $this->mSize = null;
 647                                 }
 648                         }
 649
 650                         // Same for sha1
 651                         if ( $this->mSha1 === null ) {
 652                                 $this->mSha1 = is_null( $this->mText ) ? null : self::base36Sha1( $this->mText );
 653                         }
 654
 655                         // force lazy init
 656                         $this->getContentModel();
 657                         $this->getContentFormat();
 658                 } else {
 659                         throw new MWException( 'Revision constructor passed invalid row format.' );
 660                 }
 661                 $this->mUnpatrolled = null;
 662         }
 663
 664         /**
 665          * Get revision ID
 666          *
 667          * @return Integer|null
 668          */
 669         public function getId() {
 670                 return $this->mId;
 671         }
 672
 673         /**
 674          * Set the revision ID
 675          *
 676          * @since 1.19
 677          * @param $id Integer
 678          */
 679         public function setId( $id ) {
 680                 $this->mId = $id;
 681         }
 682
 683         /**
 684          * Get text row ID
 685          *
 686          * @return Integer|null
 687          */
 688         public function getTextId() {
 689                 return $this->mTextId;
 690         }
 691
 692         /**
 693          * Get parent revision ID (the original previous page revision)
 694          *
 695          * @return Integer|null
 696          */
 697         public function getParentId() {
 698                 return $this->mParentId;
 699         }
 700
 701         /**
 702          * Returns the length of the text in this revision, or null if unknown.
 703          *
 704          * @return Integer|null
 705          */
 706         public function getSize() {
 707                 return $this->mSize;
 708         }
 709
 710         /**
 711          * Returns the base36 sha1 of the text in this revision, or null if unknown.
 712          *
 713          * @return String|null
 714          */
 715         public function getSha1() {
 716                 return $this->mSha1;
 717         }
 718
 719         /**
 720          * Returns the title of the page associated with this entry or null.
 721          *
 722          * Will do a query, when title is not set and id is given.
 723          *
 724          * @return Title|null
 725          */
 726         public function getTitle() {
 727                 if ( isset( $this->mTitle ) ) {
 728                         return $this->mTitle;
 729                 }
 730                 if ( !is_null( $this->mId ) ) { //rev_id is defined as NOT NULL, but this revision may not yet have been inserted.
 731                         $dbr = wfGetDB( DB_SLAVE );
 732                         $row = $dbr->selectRow(
 733                                 array( 'page', 'revision' ),
 734                                 self::selectPageFields(),
 735                                 array( 'page_id=rev_page',
 736                                         'rev_id' => $this->mId ),
 737                                 __METHOD__ );
 738                         if ( $row ) {
 739                                 $this->mTitle = Title::newFromRow( $row );
 740                         }
 741                 }
 742
 743                 if ( !$this->mTitle && !is_null( $this->mPage ) && $this->mPage > 0 ) {
 744                         $this->mTitle = Title::newFromID( $this->mPage );
 745                 }
 746
 747                 return $this->mTitle;
 748         }
 749
 750         /**
 751          * Set the title of the revision
 752          *
 753          * @param $title Title
 754          */
 755         public function setTitle( $title ) {
 756                 $this->mTitle = $title;
 757         }
 758
 759         /**
 760          * Get the page ID
 761          *
 762          * @return Integer|null
 763          */
 764         public function getPage() {
 765                 return $this->mPage;
 766         }
 767
 768         /**
 769          * Fetch revision's user id if it's available to the specified audience.
 770          * If the specified audience does not have access to it, zero will be
 771          * returned.
 772          *
 773          * @param $audience Integer: one of:
 774          *      Revision::FOR_PUBLIC       to be displayed to all users
 775          *      Revision::FOR_THIS_USER    to be displayed to the given user
 776          *      Revision::RAW              get the ID regardless of permissions
 777          * @param $user User object to check for, only if FOR_THIS_USER is passed
 778          *              to the $audience parameter
 779          * @return Integer
 780          */
 781         public function getUser( $audience = self::FOR_PUBLIC, User $user = null ) {
 782                 if ( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_USER ) ) {
 783                         return 0;
 784                 } elseif ( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_USER, $user ) ) {
 785                         return 0;
 786                 } else {
 787                         return $this->mUser;
 788                 }
 789         }
 790
 791         /**
 792          * Fetch revision's user id without regard for the current user's permissions
 793          *
 794          * @return String
 795          */
 796         public function getRawUser() {
 797                 return $this->mUser;
 798         }
 799
 800         /**
 801          * Fetch revision's username if it's available to the specified audience.
 802          * If the specified audience does not have access to the username, an
 803          * empty string will be returned.
 804          *
 805          * @param $audience Integer: one of:
 806          *      Revision::FOR_PUBLIC       to be displayed to all users
 807          *      Revision::FOR_THIS_USER    to be displayed to the given user
 808          *      Revision::RAW              get the text regardless of permissions
 809          * @param $user User object to check for, only if FOR_THIS_USER is passed
 810          *              to the $audience parameter
 811          * @return string
 812          */
 813         public function getUserText( $audience = self::FOR_PUBLIC, User $user = null ) {
 814                 if ( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_USER ) ) {
 815                         return '';
 816                 } elseif ( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_USER, $user ) ) {
 817                         return '';
 818                 } else {
 819                         return $this->getRawUserText();
 820                 }
 821         }
 822
 823         /**
 824          * Fetch revision's username without regard for view restrictions
 825          *
 826          * @return String
 827          */
 828         public function getRawUserText() {
 829                 if ( $this->mUserText === null ) {
 830                         $this->mUserText = User::whoIs( $this->mUser ); // load on demand
 831                         if ( $this->mUserText === false ) {
 832                                 # This shouldn't happen, but it can if the wiki was recovered
 833                                 # via importing revs and there is no user table entry yet.
 834                                 $this->mUserText = $this->mOrigUserText;
 835                         }
 836                 }
 837                 return $this->mUserText;
 838         }
 839
 840         /**
 841          * Fetch revision comment if it's available to the specified audience.
 842          * If the specified audience does not have access to the comment, an
 843          * empty string will be returned.
 844          *
 845          * @param $audience Integer: one of:
 846          *      Revision::FOR_PUBLIC       to be displayed to all users
 847          *      Revision::FOR_THIS_USER    to be displayed to the given user
 848          *      Revision::RAW              get the text regardless of permissions
 849          * @param $user User object to check for, only if FOR_THIS_USER is passed
 850          *              to the $audience parameter
 851          * @return String
 852          */
 853         function getComment( $audience = self::FOR_PUBLIC, User $user = null ) {
 854                 if ( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_COMMENT ) ) {
 855                         return '';
 856                 } elseif ( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_COMMENT, $user ) ) {
 857                         return '';
 858                 } else {
 859                         return $this->mComment;
 860                 }
 861         }
 862
 863         /**
 864          * Fetch revision comment without regard for the current user's permissions
 865          *
 866          * @return String
 867          */
 868         public function getRawComment() {
 869                 return $this->mComment;
 870         }
 871
 872         /**
 873          * @return Boolean
 874          */
 875         public function isMinor() {
 876                 return (bool)$this->mMinorEdit;
 877         }
 878
 879         /**
 880          * @return integer rcid of the unpatrolled row, zero if there isn't one
 881          */
 882         public function isUnpatrolled() {
 883                 if ( $this->mUnpatrolled !== null ) {
 884                         return $this->mUnpatrolled;
 885                 }
 886                 $rc = $this->getRecentChange();
 887                 if ( $rc && $rc->getAttribute( 'rc_patrolled' ) == 0 ) {
 888                         $this->mUnpatrolled = $rc->getAttribute( 'rc_id' );
 889                 } else {
 890                         $this->mUnpatrolled = 0;
 891                 }
 892                 return $this->mUnpatrolled;
 893         }
 894
 895         /**
 896          * Get the RC object belonging to the current revision, if there's one
 897          *
 898          * @since 1.22
 899          * @return RecentChange|null
 900          */
 901         public function getRecentChange() {
 902                 $dbr = wfGetDB( DB_SLAVE );
 903                 return RecentChange::newFromConds(
 904                         array(
 905                                 'rc_user_text' => $this->getRawUserText(),
 906                                 'rc_timestamp' => $dbr->timestamp( $this->getTimestamp() ),
 907                                 'rc_this_oldid' => $this->getId()
 908                         ),
 909                         __METHOD__
 910                 );
 911         }
 912
 913         /**
 914          * @param int $field one of DELETED_* bitfield constants
 915          *
 916          * @return Boolean
 917          */
 918         public function isDeleted( $field ) {
 919                 return ( $this->mDeleted & $field ) == $field;
 920         }
 921
 922         /**
 923          * Get the deletion bitfield of the revision
 924          *
 925          * @return int
 926          */
 927         public function getVisibility() {
 928                 return (int)$this->mDeleted;
 929         }
 930
 931         /**
 932          * Fetch revision text if it's available to the specified audience.
 933          * If the specified audience does not have the ability to view this
 934          * revision, an empty string will be returned.
 935          *
 936          * @param $audience Integer: one of:
 937          *      Revision::FOR_PUBLIC       to be displayed to all users
 938          *      Revision::FOR_THIS_USER    to be displayed to the given user
 939          *      Revision::RAW              get the text regardless of permissions
 940          * @param $user User object to check for, only if FOR_THIS_USER is passed
 941          *              to the $audience parameter
 942          *
 943          * @deprecated in 1.21, use getContent() instead
 944          * @todo Replace usage in core
 945          * @return String
 946          */
 947         public function getText( $audience = self::FOR_PUBLIC, User $user = null ) {
 948                 ContentHandler::deprecated( __METHOD__, '1.21' );
 949
 950                 $content = $this->getContent( $audience, $user );
 951                 return ContentHandler::getContentText( $content ); # returns the raw content text, if applicable
 952         }
 953
 954         /**
 955          * Fetch revision content if it's available to the specified audience.
 956          * If the specified audience does not have the ability to view this
 957          * revision, null will be returned.
 958          *
 959          * @param $audience Integer: one of:
 960          *      Revision::FOR_PUBLIC       to be displayed to all users
 961          *      Revision::FOR_THIS_USER    to be displayed to $wgUser
 962          *      Revision::RAW              get the text regardless of permissions
 963          * @param $user User object to check for, only if FOR_THIS_USER is passed
 964          *              to the $audience parameter
 965          * @since 1.21
 966          * @return Content|null
 967          */
 968         public function getContent( $audience = self::FOR_PUBLIC, User $user = null ) {
 969                 if ( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_TEXT ) ) {
 970                         return null;
 971                 } elseif ( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_TEXT, $user ) ) {
 972                         return null;
 973                 } else {
 974                         return $this->getContentInternal();
 975                 }
 976         }
 977
 978         /**
 979          * Alias for getText(Revision::FOR_THIS_USER)
 980          *
 981          * @deprecated since 1.17
 982          * @return String
 983          */
 984         public function revText() {
 985                 wfDeprecated( __METHOD__, '1.17' );
 986                 return $this->getText( self::FOR_THIS_USER );
 987         }
 988
 989         /**
 990          * Fetch revision text without regard for view restrictions
 991          *
 992          * @return String
 993          *
 994          * @deprecated since 1.21. Instead, use Revision::getContent( Revision::RAW )
 995          *                         or Revision::getSerializedData() as appropriate.
 996          */
 997         public function getRawText() {
 998                 ContentHandler::deprecated( __METHOD__, "1.21" );
 999                 return $this->getText( self::RAW );
1000         }
1001
1002         /**
1003          * Fetch original serialized data without regard for view restrictions
1004          *
1005          * @since 1.21
1006          * @return String
1007          */
1008         public function getSerializedData() {
1009                 if ( is_null( $this->mText ) ) {
1010                         $this->mText = $this->loadText();
1011                 }
1012
1013                 return $this->mText;
1014         }
1015
1016         /**
1017          * Gets the content object for the revision (or null on failure).
1018          *
1019          * Note that for mutable Content objects, each call to this method will return a
1020          * fresh clone.
1021          *
1022          * @since 1.21
1023          * @return Content|null the Revision's content, or null on failure.
1024          */
1025         protected function getContentInternal() {
1026                 if ( is_null( $this->mContent ) ) {
1027                         // Revision is immutable. Load on demand:
1028                         if ( is_null( $this->mText ) ) {
1029                                 $this->mText = $this->loadText();
1030                         }
1031
1032                         if ( $this->mText !== null && $this->mText !== false ) {
1033                                 // Unserialize content
1034                                 $handler = $this->getContentHandler();
1035                                 $format = $this->getContentFormat();
1036
1037                                 $this->mContent = $handler->unserializeContent( $this->mText, $format );
1038                         } else {
1039                                 $this->mContent = false; // negative caching!
1040                         }
1041                 }
1042
1043                 // NOTE: copy() will return $this for immutable content objects
1044                 return $this->mContent ? $this->mContent->copy() : null;
1045         }
1046
1047         /**
1048          * Returns the content model for this revision.
1049          *
1050          * If no content model was stored in the database, $this->getTitle()->getContentModel() is
1051          * used to determine the content model to use. If no title is know, CONTENT_MODEL_WIKITEXT
1052          * is used as a last resort.
1053          *
1054          * @return String the content model id associated with this revision, see the CONTENT_MODEL_XXX constants.
1055          **/
1056         public function getContentModel() {
1057                 if ( !$this->mContentModel ) {
1058                         $title = $this->getTitle();
1059                         $this->mContentModel = ( $title ? $title->getContentModel() : CONTENT_MODEL_WIKITEXT );
1060
1061                         assert( !empty( $this->mContentModel ) );
1062                 }
1063
1064                 return $this->mContentModel;
1065         }
1066
1067         /**
1068          * Returns the content format for this revision.
1069          *
1070          * If no content format was stored in the database, the default format for this
1071          * revision's content model is returned.
1072          *
1073          * @return String the content format id associated with this revision, see the CONTENT_FORMAT_XXX constants.
1074          **/
1075         public function getContentFormat() {
1076                 if ( !$this->mContentFormat ) {
1077                         $handler = $this->getContentHandler();
1078                         $this->mContentFormat = $handler->getDefaultFormat();
1079
1080                         assert( !empty( $this->mContentFormat ) );
1081                 }
1082
1083                 return $this->mContentFormat;
1084         }
1085
1086         /**
1087          * Returns the content handler appropriate for this revision's content model.
1088          *
1089          * @throws MWException
1090          * @return ContentHandler
1091          */
1092         public function getContentHandler() {
1093                 if ( !$this->mContentHandler ) {
1094                         $model = $this->getContentModel();
1095                         $this->mContentHandler = ContentHandler::getForModelID( $model );
1096
1097                         $format = $this->getContentFormat();
1098
1099                         if ( !$this->mContentHandler->isSupportedFormat( $format ) ) {
1100                                 throw new MWException( "Oops, the content format $format is not supported for this content model, $model" );
1101                         }
1102                 }
1103
1104                 return $this->mContentHandler;
1105         }
1106
1107         /**
1108          * @return String
1109          */
1110         public function getTimestamp() {
1111                 return wfTimestamp( TS_MW, $this->mTimestamp );
1112         }
1113
1114         /**
1115          * @return Boolean
1116          */
1117         public function isCurrent() {
1118                 return $this->mCurrent;
1119         }
1120
1121         /**
1122          * Get previous revision for this title
1123          *
1124          * @return Revision|null
1125          */
1126         public function getPrevious() {
1127                 if ( $this->getTitle() ) {
1128                         $prev = $this->getTitle()->getPreviousRevisionID( $this->getId() );
1129                         if ( $prev ) {
1130                                 return self::newFromTitle( $this->getTitle(), $prev );
1131                         }
1132                 }
1133                 return null;
1134         }
1135
1136         /**
1137          * Get next revision for this title
1138          *
1139          * @return Revision or null
1140          */
1141         public function getNext() {
1142                 if ( $this->getTitle() ) {
1143                         $next = $this->getTitle()->getNextRevisionID( $this->getId() );
1144                         if ( $next ) {
1145                                 return self::newFromTitle( $this->getTitle(), $next );
1146                         }
1147                 }
1148                 return null;
1149         }
1150
1151         /**
1152          * Get previous revision Id for this page_id
1153          * This is used to populate rev_parent_id on save
1154          *
1155          * @param $db DatabaseBase
1156          * @return Integer
1157          */
1158         private function getPreviousRevisionId( $db ) {
1159                 if ( is_null( $this->mPage ) ) {
1160                         return 0;
1161                 }
1162                 # Use page_latest if ID is not given
1163                 if ( !$this->mId ) {
1164                         $prevId = $db->selectField( 'page', 'page_latest',
1165                                 array( 'page_id' => $this->mPage ),
1166                                 __METHOD__ );
1167                 } else {
1168                         $prevId = $db->selectField( 'revision', 'rev_id',
1169                                 array( 'rev_page' => $this->mPage, 'rev_id < ' . $this->mId ),
1170                                 __METHOD__,
1171                                 array( 'ORDER BY' => 'rev_id DESC' ) );
1172                 }
1173                 return intval( $prevId );
1174         }
1175
1176         /**
1177           * Get revision text associated with an old or archive row
1178           * $row is usually an object from wfFetchRow(), both the flags and the text
1179           * field must be included
1180           *
1181           * @param $row Object: the text data
1182           * @param string $prefix table prefix (default 'old_')
1183           * @param string|false $wiki the name of the wiki to load the revision text from
1184           *         (same as the the wiki $row was loaded from) or false to indicate the local
1185           *         wiki (this is the default). Otherwise, it must be a symbolic wiki database
1186           *         identifier as understood by the LoadBalancer class.
1187           * @return String: text the text requested or false on failure
1188           */
1189         public static function getRevisionText( $row, $prefix = 'old_', $wiki = false ) {
1190                 wfProfileIn( __METHOD__ );
1191
1192                 # Get data
1193                 $textField = $prefix . 'text';
1194                 $flagsField = $prefix . 'flags';
1195
1196                 if ( isset( $row->$flagsField ) ) {
1197                         $flags = explode( ',', $row->$flagsField );
1198                 } else {
1199                         $flags = array();
1200                 }
1201
1202                 if ( isset( $row->$textField ) ) {
1203                         $text = $row->$textField;
1204                 } else {
1205                         wfProfileOut( __METHOD__ );
1206                         return false;
1207                 }
1208
1209                 # Use external methods for external objects, text in table is URL-only then
1210                 if ( in_array( 'external', $flags ) ) {
1211                         $url = $text;
1212                         $parts = explode( '://', $url, 2 );
1213                         if ( count( $parts ) == 1 || $parts[1] == '' ) {
1214                                 wfProfileOut( __METHOD__ );
1215                                 return false;
1216                         }
1217                         $text = ExternalStore::fetchFromURL( $url, array( 'wiki' => $wiki ) );
1218                 }
1219
1220                 // If the text was fetched without an error, convert it
1221                 if ( $text !== false ) {
1222                         $text = self::decompressRevisionText( $text, $flags );
1223                 }
1224                 wfProfileOut( __METHOD__ );
1225                 return $text;
1226         }
1227
1228         /**
1229          * If $wgCompressRevisions is enabled, we will compress data.
1230          * The input string is modified in place.
1231          * Return value is the flags field: contains 'gzip' if the
1232          * data is compressed, and 'utf-8' if we're saving in UTF-8
1233          * mode.
1234          *
1235          * @param $text Mixed: reference to a text
1236          * @return String
1237          */
1238         public static function compressRevisionText( &$text ) {
1239                 global $wgCompressRevisions;
1240                 $flags = array();
1241
1242                 # Revisions not marked this way will be converted
1243                 # on load if $wgLegacyCharset is set in the future.
1244                 $flags[] = 'utf-8';
1245
1246                 if ( $wgCompressRevisions ) {
1247                         if ( function_exists( 'gzdeflate' ) ) {
1248                                 $text = gzdeflate( $text );
1249                                 $flags[] = 'gzip';
1250                         } else {
1251                                 wfDebug( __METHOD__ . " -- no zlib support, not compressing\n" );
1252                         }
1253                 }
1254                 return implode( ',', $flags );
1255         }
1256
1257         /**
1258          * Re-converts revision text according to it's flags.
1259          *
1260          * @param $text Mixed: reference to a text
1261          * @param $flags array: compression flags
1262          * @return String|bool decompressed text, or false on failure
1263          */
1264         public static function decompressRevisionText( $text, $flags ) {
1265                 if ( in_array( 'gzip', $flags ) ) {
1266                         # Deal with optional compression of archived pages.
1267                         # This can be done periodically via maintenance/compressOld.php, and
1268                         # as pages are saved if $wgCompressRevisions is set.
1269                         $text = gzinflate( $text );
1270                 }
1271
1272                 if ( in_array( 'object', $flags ) ) {
1273                         # Generic compressed storage
1274                         $obj = unserialize( $text );
1275                         if ( !is_object( $obj ) ) {
1276                                 // Invalid object
1277                                 return false;
1278                         }
1279                         $text = $obj->getText();
1280                 }
1281
1282                 global $wgLegacyEncoding;
1283                 if ( $text !== false && $wgLegacyEncoding
1284                         && !in_array( 'utf-8', $flags ) && !in_array( 'utf8', $flags ) )
1285                 {
1286                         # Old revisions kept around in a legacy encoding?
1287                         # Upconvert on demand.
1288                         # ("utf8" checked for compatibility with some broken
1289                         #  conversion scripts 2008-12-30)
1290                         global $wgContLang;
1291                         $text = $wgContLang->iconv( $wgLegacyEncoding, 'UTF-8', $text );
1292                 }
1293
1294                 return $text;
1295         }
1296
1297         /**
1298          * Insert a new revision into the database, returning the new revision ID
1299          * number on success and dies horribly on failure.
1300          *
1301          * @param $dbw DatabaseBase: (master connection)
1302          * @throws MWException
1303          * @return Integer
1304          */
1305         public function insertOn( $dbw ) {
1306                 global $wgDefaultExternalStore, $wgContentHandlerUseDB;
1307
1308                 wfProfileIn( __METHOD__ );
1309
1310                 $this->checkContentModel();
1311
1312                 $data = $this->mText;
1313                 $flags = self::compressRevisionText( $data );
1314
1315                 # Write to external storage if required
1316                 if ( $wgDefaultExternalStore ) {
1317                         // Store and get the URL
1318                         $data = ExternalStore::insertToDefault( $data );
1319                         if ( !$data ) {
1320                                 wfProfileOut( __METHOD__ );
1321                                 throw new MWException( "Unable to store text to external storage" );
1322                         }
1323                         if ( $flags ) {
1324                                 $flags .= ',';
1325                         }
1326                         $flags .= 'external';
1327                 }
1328
1329                 # Record the text (or external storage URL) to the text table
1330                 if ( !isset( $this->mTextId ) ) {
1331                         $old_id = $dbw->nextSequenceValue( 'text_old_id_seq' );
1332                         $dbw->insert( 'text',
1333                                 array(
1334                                         'old_id' => $old_id,
1335                                         'old_text' => $data,
1336                                         'old_flags' => $flags,
1337                                 ), __METHOD__
1338                         );
1339                         $this->mTextId = $dbw->insertId();
1340                 }
1341
1342                 if ( $this->mComment === null ) {
1343                         $this->mComment = "";
1344                 }
1345
1346                 # Record the edit in revisions
1347                 $rev_id = isset( $this->mId )
1348                         ? $this->mId
1349                         : $dbw->nextSequenceValue( 'revision_rev_id_seq' );
1350                 $row = array(
1351                         'rev_id'         => $rev_id,
1352                         'rev_page'       => $this->mPage,
1353                         'rev_text_id'    => $this->mTextId,
1354                         'rev_comment'    => $this->mComment,
1355                         'rev_minor_edit' => $this->mMinorEdit ? 1 : 0,
1356                         'rev_user'       => $this->mUser,
1357                         'rev_user_text'  => $this->mUserText,
1358                         'rev_timestamp'  => $dbw->timestamp( $this->mTimestamp ),
1359                         'rev_deleted'    => $this->mDeleted,
1360                         'rev_len'        => $this->mSize,
1361                         'rev_parent_id'  => is_null( $this->mParentId )
1362                                 ? $this->getPreviousRevisionId( $dbw )
1363                                 : $this->mParentId,
1364                         'rev_sha1'       => is_null( $this->mSha1 )
1365                                 ? Revision::base36Sha1( $this->mText )
1366                                 : $this->mSha1,
1367                 );
1368
1369                 if ( $wgContentHandlerUseDB ) {
1370                         //NOTE: Store null for the default model and format, to save space.
1371                         //XXX: Makes the DB sensitive to changed defaults. Make this behavior optional? Only in miser mode?
1372
1373                         $model = $this->getContentModel();
1374                         $format = $this->getContentFormat();
1375
1376                         $title = $this->getTitle();
1377
1378                         if ( $title === null ) {
1379                                 wfProfileOut( __METHOD__ );
1380                                 throw new MWException( "Insufficient information to determine the title of the revision's page!" );
1381                         }
1382
1383                         $defaultModel = ContentHandler::getDefaultModelFor( $title );
1384                         $defaultFormat = ContentHandler::getForModelID( $defaultModel )->getDefaultFormat();
1385
1386                         $row['rev_content_model'] = ( $model === $defaultModel ) ? null : $model;
1387                         $row['rev_content_format'] = ( $format === $defaultFormat ) ? null : $format;
1388                 }
1389
1390                 $dbw->insert( 'revision', $row, __METHOD__ );
1391
1392                 $this->mId = !is_null( $rev_id ) ? $rev_id : $dbw->insertId();
1393
1394                 wfRunHooks( 'RevisionInsertComplete', array( &$this, $data, $flags ) );
1395
1396                 wfProfileOut( __METHOD__ );
1397                 return $this->mId;
1398         }
1399
1400         protected function checkContentModel() {
1401                 global $wgContentHandlerUseDB;
1402
1403                 $title = $this->getTitle(); //note: may return null for revisions that have not yet been inserted.
1404
1405                 $model = $this->getContentModel();
1406                 $format = $this->getContentFormat();
1407                 $handler = $this->getContentHandler();
1408
1409                 if ( !$handler->isSupportedFormat( $format ) ) {
1410                         $t = $title->getPrefixedDBkey();
1411
1412                         throw new MWException( "Can't use format $format with content model $model on $t" );
1413                 }
1414
1415                 if ( !$wgContentHandlerUseDB && $title ) {
1416                         // if $wgContentHandlerUseDB is not set, all revisions must use the default content model and format.
1417
1418                         $defaultModel = ContentHandler::getDefaultModelFor( $title );
1419                         $defaultHandler = ContentHandler::getForModelID( $defaultModel );
1420                         $defaultFormat = $defaultHandler->getDefaultFormat();
1421
1422                         if ( $this->getContentModel() != $defaultModel ) {
1423                                 $t = $title->getPrefixedDBkey();
1424
1425                                 throw new MWException( "Can't save non-default content model with \$wgContentHandlerUseDB disabled: "
1426                                                                                 . "model is $model , default for $t is $defaultModel" );
1427                         }
1428
1429                         if ( $this->getContentFormat() != $defaultFormat ) {
1430                                 $t = $title->getPrefixedDBkey();
1431
1432                                 throw new MWException( "Can't use non-default content format with \$wgContentHandlerUseDB disabled: "
1433                                                                                 . "format is $format, default for $t is $defaultFormat" );
1434                         }
1435                 }
1436
1437                 $content = $this->getContent( Revision::RAW );
1438
1439                 if ( !$content || !$content->isValid() ) {
1440                         $t = $title->getPrefixedDBkey();
1441
1442                         throw new MWException( "Content of $t is not valid! Content model is $model" );
1443                 }
1444         }
1445
1446         /**
1447          * Get the base 36 SHA-1 value for a string of text
1448          * @param $text String
1449          * @return String
1450          */
1451         public static function base36Sha1( $text ) {
1452                 return wfBaseConvert( sha1( $text ), 16, 36, 31 );
1453         }
1454
1455         /**
1456          * Lazy-load the revision's text.
1457          * Currently hardcoded to the 'text' table storage engine.
1458          *
1459          * @return String|bool the revision's text, or false on failure
1460          */
1461         protected function loadText() {
1462                 wfProfileIn( __METHOD__ );
1463
1464                 // Caching may be beneficial for massive use of external storage
1465                 global $wgRevisionCacheExpiry, $wgMemc;
1466                 $textId = $this->getTextId();
1467                 $key = wfMemcKey( 'revisiontext', 'textid', $textId );
1468                 if ( $wgRevisionCacheExpiry ) {
1469                         $text = $wgMemc->get( $key );
1470                         if ( is_string( $text ) ) {
1471                                 wfDebug( __METHOD__ . ": got id $textId from cache\n" );
1472                                 wfProfileOut( __METHOD__ );
1473                                 return $text;
1474                         }
1475                 }
1476
1477                 // If we kept data for lazy extraction, use it now...
1478                 if ( isset( $this->mTextRow ) ) {
1479                         $row = $this->mTextRow;
1480                         $this->mTextRow = null;
1481                 } else {
1482                         $row = null;
1483                 }
1484
1485                 if ( !$row ) {
1486                         // Text data is immutable; check slaves first.
1487                         $dbr = wfGetDB( DB_SLAVE );
1488                         $row = $dbr->selectRow( 'text',
1489                                 array( 'old_text', 'old_flags' ),
1490                                 array( 'old_id' => $textId ),
1491                                 __METHOD__ );
1492                 }
1493
1494                 // Fallback to the master in case of slave lag. Also use FOR UPDATE if it was
1495                 // used to fetch this revision to avoid missing the row due to REPEATABLE-READ.
1496                 $forUpdate = ( $this->mQueryFlags & self::READ_LOCKING == self::READ_LOCKING );
1497                 if ( !$row && ( $forUpdate || wfGetLB()->getServerCount() > 1 ) ) {
1498                         $dbw = wfGetDB( DB_MASTER );
1499                         $row = $dbw->selectRow( 'text',
1500                                 array( 'old_text', 'old_flags' ),
1501                                 array( 'old_id' => $textId ),
1502                                 __METHOD__,
1503                                 $forUpdate ? array( 'FOR UPDATE' ) : array() );
1504                 }
1505
1506                 if ( !$row ) {
1507                         wfDebugLog( 'Revision', "No text row with ID '$textId' (revision {$this->getId()})." );
1508                 }
1509
1510                 $text = self::getRevisionText( $row );
1511                 if ( $row && $text === false ) {
1512                         wfDebugLog( 'Revision', "No blob for text row '$textId' (revision {$this->getId()})." );
1513                 }
1514
1515                 # No negative caching -- negative hits on text rows may be due to corrupted slave servers
1516                 if ( $wgRevisionCacheExpiry && $text !== false ) {
1517                         $wgMemc->set( $key, $text, $wgRevisionCacheExpiry );
1518                 }
1519
1520                 wfProfileOut( __METHOD__ );
1521
1522                 return $text;
1523         }
1524
1525         /**
1526          * Create a new null-revision for insertion into a page's
1527          * history. This will not re-save the text, but simply refer
1528          * to the text from the previous version.
1529          *
1530          * Such revisions can for instance identify page rename
1531          * operations and other such meta-modifications.
1532          *
1533          * @param $dbw DatabaseBase
1534          * @param $pageId Integer: ID number of the page to read from
1535          * @param string $summary revision's summary
1536          * @param $minor Boolean: whether the revision should be considered as minor
1537          * @return Revision|null on error
1538          */
1539         public static function newNullRevision( $dbw, $pageId, $summary, $minor ) {
1540                 global $wgContentHandlerUseDB;
1541
1542                 wfProfileIn( __METHOD__ );
1543
1544                 $fields = array( 'page_latest', 'page_namespace', 'page_title',
1545                                                 'rev_text_id', 'rev_len', 'rev_sha1' );
1546
1547                 if ( $wgContentHandlerUseDB ) {
1548                         $fields[] = 'rev_content_model';
1549                         $fields[] = 'rev_content_format';
1550                 }
1551
1552                 $current = $dbw->selectRow(
1553                         array( 'page', 'revision' ),
1554                         $fields,
1555                         array(
1556                                 'page_id' => $pageId,
1557                                 'page_latest=rev_id',
1558                                 ),
1559                         __METHOD__ );
1560
1561                 if ( $current ) {
1562                         $row = array(
1563                                 'page'       => $pageId,
1564                                 'comment'    => $summary,
1565                                 'minor_edit' => $minor,
1566                                 'text_id'    => $current->rev_text_id,
1567                                 'parent_id'  => $current->page_latest,
1568                                 'len'        => $current->rev_len,
1569                                 'sha1'       => $current->rev_sha1
1570                         );
1571
1572                         if ( $wgContentHandlerUseDB ) {
1573                                 $row['content_model'] = $current->rev_content_model;
1574                                 $row['content_format'] = $current->rev_content_format;
1575                         }
1576
1577                         $revision = new Revision( $row );
1578                         $revision->setTitle( Title::makeTitle( $current->page_namespace, $current->page_title ) );
1579                 } else {
1580                         $revision = null;
1581                 }
1582
1583                 wfProfileOut( __METHOD__ );
1584                 return $revision;
1585         }
1586
1587         /**
1588          * Determine if the current user is allowed to view a particular
1589          * field of this revision, if it's marked as deleted.
1590          *
1591          * @param $field Integer:one of self::DELETED_TEXT,
1592          *                              self::DELETED_COMMENT,
1593          *                              self::DELETED_USER
1594          * @param $user User object to check, or null to use $wgUser
1595          * @return Boolean
1596          */
1597         public function userCan( $field, User $user = null ) {
1598                 return self::userCanBitfield( $this->mDeleted, $field, $user );
1599         }
1600
1601         /**
1602          * Determine if the current user is allowed to view a particular
1603          * field of this revision, if it's marked as deleted. This is used
1604          * by various classes to avoid duplication.
1605          *
1606          * @param $bitfield Integer: current field
1607          * @param $field Integer: one of self::DELETED_TEXT = File::DELETED_FILE,
1608          *                               self::DELETED_COMMENT = File::DELETED_COMMENT,
1609          *                               self::DELETED_USER = File::DELETED_USER
1610          * @param $user User object to check, or null to use $wgUser
1611          * @return Boolean
1612          */
1613         public static function userCanBitfield( $bitfield, $field, User $user = null ) {
1614                 if ( $bitfield & $field ) { // aspect is deleted
1615                         if ( $bitfield & self::DELETED_RESTRICTED ) {
1616                                 $permission = 'suppressrevision';
1617                         } elseif ( $field & self::DELETED_TEXT ) {
1618                                 $permission = 'deletedtext';
1619                         } else {
1620                                 $permission = 'deletedhistory';
1621                         }
1622                         wfDebug( "Checking for $permission due to $field match on $bitfield\n" );
1623                         if ( $user === null ) {
1624                                 global $wgUser;
1625                                 $user = $wgUser;
1626                         }
1627                         return $user->isAllowed( $permission );
1628                 } else {
1629                         return true;
1630                 }
1631         }
1632
1633         /**
1634          * Get rev_timestamp from rev_id, without loading the rest of the row
1635          *
1636          * @param $title Title
1637          * @param $id Integer
1638          * @return String
1639          */
1640         static function getTimestampFromId( $title, $id ) {
1641                 $dbr = wfGetDB( DB_SLAVE );
1642                 // Casting fix for databases that can't take '' for rev_id
1643                 if ( $id == '' ) {
1644                         $id = 0;
1645                 }
1646                 $conds = array( 'rev_id' => $id );
1647                 $conds['rev_page'] = $title->getArticleID();
1648                 $timestamp = $dbr->selectField( 'revision', 'rev_timestamp', $conds, __METHOD__ );
1649                 if ( $timestamp === false && wfGetLB()->getServerCount() > 1 ) {
1650                         # Not in slave, try master
1651                         $dbw = wfGetDB( DB_MASTER );
1652                         $timestamp = $dbw->selectField( 'revision', 'rev_timestamp', $conds, __METHOD__ );
1653                 }
1654                 return wfTimestamp( TS_MW, $timestamp );
1655         }
1656
1657         /**
1658          * Get count of revisions per page...not very efficient
1659          *
1660          * @param $db DatabaseBase
1661          * @param $id Integer: page id
1662          * @return Integer
1663          */
1664         static function countByPageId( $db, $id ) {
1665                 $row = $db->selectRow( 'revision', array( 'revCount' => 'COUNT(*)' ),
1666                         array( 'rev_page' => $id ), __METHOD__ );
1667                 if ( $row ) {
1668                         return $row->revCount;
1669                 }
1670                 return 0;
1671         }
1672
1673         /**
1674          * Get count of revisions per page...not very efficient
1675          *
1676          * @param $db DatabaseBase
1677          * @param $title Title
1678          * @return Integer
1679          */
1680         static function countByTitle( $db, $title ) {
1681                 $id = $title->getArticleID();
1682                 if ( $id ) {
1683                         return self::countByPageId( $db, $id );
1684                 }
1685                 return 0;
1686         }
1687
1688         /**
1689          * Check if no edits were made by other users since
1690          * the time a user started editing the page. Limit to
1691          * 50 revisions for the sake of performance.
1692          *
1693          * @since 1.20
1694          *
1695          * @param DatabaseBase|int $db the Database to perform the check on. May be given as a Database object or
1696          *        a database identifier usable with wfGetDB.
1697          * @param int $pageId the ID of the page in question
1698          * @param int $userId the ID of the user in question
1699          * @param string $since look at edits since this time
1700          *
1701          * @return bool True if the given user was the only one to edit since the given timestamp
1702          */
1703         public static function userWasLastToEdit( $db, $pageId, $userId, $since ) {
1704                 if ( !$userId ) {
1705                         return false;
1706                 }
1707
1708                 if ( is_int( $db ) ) {
1709                         $db = wfGetDB( $db );
1710                 }
1711
1712                 $res = $db->select( 'revision',
1713                         'rev_user',
1714                         array(
1715                                 'rev_page' => $pageId,
1716                                 'rev_timestamp > ' . $db->addQuotes( $db->timestamp( $since ) )
1717                         ),
1718                         __METHOD__,
1719                         array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 50 ) );
1720                 foreach ( $res as $row ) {
1721                         if ( $row->rev_user != $userId ) {
1722                                 return false;
1723                         }
1724                 }
1725                 return true;
1726         }
1727 }