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 $mTextId;
  45
  46         /**
  47          * @var stdClass|null
  48          */
  49         protected $mTextRow;
  50
  51         /**
  52          * @var null|Title
  53          */
  54         protected $mTitle;
  55         protected $mCurrent;
  56         protected $mContentModel;
  57         protected $mContentFormat;
  58
  59         /**
  60          * @var Content|null|bool
  61          */
  62         protected $mContent;
  63
  64         /**
  65          * @var null|ContentHandler
  66          */
  67         protected $mContentHandler;
  68
  69         /**
  70          * @var int
  71          */
  72         protected $mQueryFlags = 0;
  73
  74         // Revision deletion constants
  75         const DELETED_TEXT = 1;
  76         const DELETED_COMMENT = 2;
  77         const DELETED_USER = 4;
  78         const DELETED_RESTRICTED = 8;
  79         const SUPPRESSED_USER = 12; // convenience
  80
  81         // Audience options for accessors
  82         const FOR_PUBLIC = 1;
  83         const FOR_THIS_USER = 2;
  84         const RAW = 3;
  85
  86         /**
  87          * Load a page revision from a given revision ID number.
  88          * Returns null if no such revision can be found.
  89          *
  90          * $flags include:
  91          *      Revision::READ_LATEST  : Select the data from the master
  92          *      Revision::READ_LOCKING : Select & lock the data from the master
  93          *
  94          * @param int $id
  95          * @param int $flags (optional)
  96          * @return Revision|null
  97          */
  98         public static function newFromId( $id, $flags = 0 ) {
  99                 return self::newFromConds( array( 'rev_id' => intval( $id ) ), $flags );
 100         }
 101
 102         /**
 103          * Load either the current, or a specified, revision
 104          * that's attached to a given title. If not attached
 105          * to that title, will return null.
 106          *
 107          * $flags include:
 108          *      Revision::READ_LATEST  : Select the data from the master
 109          *      Revision::READ_LOCKING : Select & lock the data from the master
 110          *
 111          * @param Title $title
 112          * @param int $id (optional)
 113          * @param int $flags Bitfield (optional)
 114          * @return Revision|null
 115          */
 116         public static function newFromTitle( $title, $id = 0, $flags = 0 ) {
 117                 $conds = array(
 118                         'page_namespace' => $title->getNamespace(),
 119                         'page_title' => $title->getDBkey()
 120                 );
 121                 if ( $id ) {
 122                         // Use the specified ID
 123                         $conds['rev_id'] = $id;
 124                         return self::newFromConds( $conds, (int)$flags );
 125                 } else {
 126                         // Use a join to get the latest revision
 127                         $conds[] = 'rev_id=page_latest';
 128                         $db = wfGetDB( ( $flags & self::READ_LATEST ) ? DB_MASTER : DB_SLAVE );
 129                         return self::loadFromConds( $db, $conds, $flags );
 130                 }
 131         }
 132
 133         /**
 134          * Load either the current, or a specified, revision
 135          * that's attached to a given page ID.
 136          * Returns null if no such revision can be found.
 137          *
 138          * $flags include:
 139          *      Revision::READ_LATEST  : Select the data from the master (since 1.20)
 140          *      Revision::READ_LOCKING : Select & lock the data from the master
 141          *
 142          * @param int $pageId
 143          * @param int $revId (optional)
 144          * @param int $flags Bitfield (optional)
 145          * @return Revision|null
 146          */
 147         public static function newFromPageId( $pageId, $revId = 0, $flags = 0 ) {
 148                 $conds = array( 'page_id' => $pageId );
 149                 if ( $revId ) {
 150                         $conds['rev_id'] = $revId;
 151                 } else {
 152                         // Use a join to get the latest revision
 153                         $conds[] = 'rev_id = page_latest';
 154                 }
 155                 return self::newFromConds( $conds, (int)$flags );
 156         }
 157
 158         /**
 159          * Make a fake revision object from an archive table row. This is queried
 160          * for permissions or even inserted (as in Special:Undelete)
 161          * @todo FIXME: Should be a subclass for RevisionDelete. [TS]
 162          *
 163          * @param object $row
 164          * @param array $overrides
 165          *
 166          * @throws MWException
 167          * @return Revision
 168          */
 169         public static function newFromArchiveRow( $row, $overrides = array() ) {
 170                 global $wgContentHandlerUseDB;
 171
 172                 $attribs = $overrides + array(
 173                         'page'       => isset( $row->ar_page_id ) ? $row->ar_page_id : null,
 174                         'id'         => isset( $row->ar_rev_id ) ? $row->ar_rev_id : null,
 175                         'comment'    => $row->ar_comment,
 176                         'user'       => $row->ar_user,
 177                         'user_text'  => $row->ar_user_text,
 178                         'timestamp'  => $row->ar_timestamp,
 179                         'minor_edit' => $row->ar_minor_edit,
 180                         'text_id'    => isset( $row->ar_text_id ) ? $row->ar_text_id : null,
 181                         'deleted'    => $row->ar_deleted,
 182                         'len'        => $row->ar_len,
 183                         'sha1'       => isset( $row->ar_sha1 ) ? $row->ar_sha1 : null,
 184                         'content_model'   => isset( $row->ar_content_model ) ? $row->ar_content_model : null,
 185                         'content_format'  => isset( $row->ar_content_format ) ? $row->ar_content_format : null,
 186                 );
 187
 188                 if ( !$wgContentHandlerUseDB ) {
 189                         unset( $attribs['content_model'] );
 190                         unset( $attribs['content_format'] );
 191                 }
 192
 193                 if ( !isset( $attribs['title'] )
 194                         && isset( $row->ar_namespace )
 195                         && isset( $row->ar_title ) ) {
 196
 197                         $attribs['title'] = Title::makeTitle( $row->ar_namespace, $row->ar_title );
 198                 }
 199
 200                 if ( isset( $row->ar_text ) && !$row->ar_text_id ) {
 201                         // Pre-1.5 ar_text row
 202                         $attribs['text'] = self::getRevisionText( $row, 'ar_' );
 203                         if ( $attribs['text'] === false ) {
 204                                 throw new MWException( 'Unable to load text from archive row (possibly bug 22624)' );
 205                         }
 206                 }
 207                 return new self( $attribs );
 208         }
 209
 210         /**
 211          * @since 1.19
 212          *
 213          * @param object $row
 214          * @return Revision
 215          */
 216         public static function newFromRow( $row ) {
 217                 return new self( $row );
 218         }
 219
 220         /**
 221          * Load a page revision from a given revision ID number.
 222          * Returns null if no such revision can be found.
 223          *
 224          * @param DatabaseBase $db
 225          * @param int $id
 226          * @return Revision|null
 227          */
 228         public static function loadFromId( $db, $id ) {
 229                 return self::loadFromConds( $db, array( 'rev_id' => intval( $id ) ) );
 230         }
 231
 232         /**
 233          * Load either the current, or a specified, revision
 234          * that's attached to a given page. If not attached
 235          * to that page, will return null.
 236          *
 237          * @param DatabaseBase $db
 238          * @param int $pageid
 239          * @param int $id
 240          * @return Revision|null
 241          */
 242         public static function loadFromPageId( $db, $pageid, $id = 0 ) {
 243                 $conds = array( 'rev_page' => intval( $pageid ), 'page_id' => intval( $pageid ) );
 244                 if ( $id ) {
 245                         $conds['rev_id'] = intval( $id );
 246                 } else {
 247                         $conds[] = 'rev_id=page_latest';
 248                 }
 249                 return self::loadFromConds( $db, $conds );
 250         }
 251
 252         /**
 253          * Load either the current, or a specified, revision
 254          * that's attached to a given page. If not attached
 255          * to that page, will return null.
 256          *
 257          * @param DatabaseBase $db
 258          * @param Title $title
 259          * @param int $id
 260          * @return Revision|null
 261          */
 262         public static function loadFromTitle( $db, $title, $id = 0 ) {
 263                 if ( $id ) {
 264                         $matchId = intval( $id );
 265                 } else {
 266                         $matchId = 'page_latest';
 267                 }
 268                 return self::loadFromConds( $db,
 269                         array(
 270                                 "rev_id=$matchId",
 271                                 'page_namespace' => $title->getNamespace(),
 272                                 'page_title' => $title->getDBkey()
 273                         )
 274                 );
 275         }
 276
 277         /**
 278          * Load the revision for the given title with the given timestamp.
 279          * WARNING: Timestamps may in some circumstances not be unique,
 280          * so this isn't the best key to use.
 281          *
 282          * @param DatabaseBase $db
 283          * @param Title $title
 284          * @param string $timestamp
 285          * @return Revision|null
 286          */
 287         public static function loadFromTimestamp( $db, $title, $timestamp ) {
 288                 return self::loadFromConds( $db,
 289                         array(
 290                                 'rev_timestamp' => $db->timestamp( $timestamp ),
 291                                 'page_namespace' => $title->getNamespace(),
 292                                 'page_title' => $title->getDBkey()
 293                         )
 294                 );
 295         }
 296
 297         /**
 298          * Given a set of conditions, fetch a revision.
 299          *
 300          * @param array $conditions
 301          * @param int $flags (optional)
 302          * @return Revision|null
 303          */
 304         private static function newFromConds( $conditions, $flags = 0 ) {
 305                 $db = wfGetDB( ( $flags & self::READ_LATEST ) ? DB_MASTER : DB_SLAVE );
 306                 $rev = self::loadFromConds( $db, $conditions, $flags );
 307                 if ( $rev === null && wfGetLB()->getServerCount() > 1 ) {
 308                         if ( !( $flags & self::READ_LATEST ) ) {
 309                                 $dbw = wfGetDB( DB_MASTER );
 310                                 $rev = self::loadFromConds( $dbw, $conditions, $flags );
 311                         }
 312                 }
 313                 if ( $rev ) {
 314                         $rev->mQueryFlags = $flags;
 315                 }
 316                 return $rev;
 317         }
 318
 319         /**
 320          * Given a set of conditions, fetch a revision from
 321          * the given database connection.
 322          *
 323          * @param DatabaseBase $db
 324          * @param array $conditions
 325          * @param int $flags (optional)
 326          * @return Revision|null
 327          */
 328         private static function loadFromConds( $db, $conditions, $flags = 0 ) {
 329                 $res = self::fetchFromConds( $db, $conditions, $flags );
 330                 if ( $res ) {
 331                         $row = $res->fetchObject();
 332                         if ( $row ) {
 333                                 $ret = new Revision( $row );
 334                                 return $ret;
 335                         }
 336                 }
 337                 $ret = null;
 338                 return $ret;
 339         }
 340
 341         /**
 342          * Return a wrapper for a series of database rows to
 343          * fetch all of a given page's revisions in turn.
 344          * Each row can be fed to the constructor to get objects.
 345          *
 346          * @param Title $title
 347          * @return ResultWrapper
 348          */
 349         public static function fetchRevision( $title ) {
 350                 return self::fetchFromConds(
 351                         wfGetDB( DB_SLAVE ),
 352                         array(
 353                                 'rev_id=page_latest',
 354                                 'page_namespace' => $title->getNamespace(),
 355                                 'page_title' => $title->getDBkey()
 356                         )
 357                 );
 358         }
 359
 360         /**
 361          * Given a set of conditions, return a ResultWrapper
 362          * which will return matching database rows with the
 363          * fields necessary to build Revision objects.
 364          *
 365          * @param DatabaseBase $db
 366          * @param array $conditions
 367          * @param int $flags (optional)
 368          * @return ResultWrapper
 369          */
 370         private static function fetchFromConds( $db, $conditions, $flags = 0 ) {
 371                 $fields = array_merge(
 372                         self::selectFields(),
 373                         self::selectPageFields(),
 374                         self::selectUserFields()
 375                 );
 376                 $options = array( 'LIMIT' => 1 );
 377                 if ( ( $flags & self::READ_LOCKING ) == self::READ_LOCKING ) {
 378                         $options[] = 'FOR UPDATE';
 379                 }
 380                 return $db->select(
 381                         array( 'revision', 'page', 'user' ),
 382                         $fields,
 383                         $conditions,
 384                         __METHOD__,
 385                         $options,
 386                         array( 'page' => self::pageJoinCond(), 'user' => self::userJoinCond() )
 387                 );
 388         }
 389
 390         /**
 391          * Return the value of a select() JOIN conds array for the user table.
 392          * This will get user table rows for logged-in users.
 393          * @since 1.19
 394          * @return array
 395          */
 396         public static function userJoinCond() {
 397                 return array( 'LEFT JOIN', array( 'rev_user != 0', 'user_id = rev_user' ) );
 398         }
 399
 400         /**
 401          * Return the value of a select() page conds array for the page table.
 402          * This will assure that the revision(s) are not orphaned from live pages.
 403          * @since 1.19
 404          * @return array
 405          */
 406         public static function pageJoinCond() {
 407                 return array( 'INNER JOIN', array( 'page_id = rev_page' ) );
 408         }
 409
 410         /**
 411          * Return the list of revision fields that should be selected to create
 412          * a new revision.
 413          * @return array
 414          */
 415         public static function selectFields() {
 416                 global $wgContentHandlerUseDB;
 417
 418                 $fields = array(
 419                         'rev_id',
 420                         'rev_page',
 421                         'rev_text_id',
 422                         'rev_timestamp',
 423                         'rev_comment',
 424                         'rev_user_text',
 425                         'rev_user',
 426                         'rev_minor_edit',
 427                         'rev_deleted',
 428                         'rev_len',
 429                         'rev_parent_id',
 430                         'rev_sha1',
 431                 );
 432
 433                 if ( $wgContentHandlerUseDB ) {
 434                         $fields[] = 'rev_content_format';
 435                         $fields[] = 'rev_content_model';
 436                 }
 437
 438                 return $fields;
 439         }
 440
 441         /**
 442          * Return the list of revision fields that should be selected to create
 443          * a new revision from an archive row.
 444          * @return array
 445          */
 446         public static function selectArchiveFields() {
 447                 global $wgContentHandlerUseDB;
 448                 $fields = array(
 449                         'ar_id',
 450                         'ar_page_id',
 451                         'ar_rev_id',
 452                         'ar_text',
 453                         'ar_text_id',
 454                         'ar_timestamp',
 455                         'ar_comment',
 456                         'ar_user_text',
 457                         'ar_user',
 458                         'ar_minor_edit',
 459                         'ar_deleted',
 460                         'ar_len',
 461                         'ar_parent_id',
 462                         'ar_sha1',
 463                 );
 464
 465                 if ( $wgContentHandlerUseDB ) {
 466                         $fields[] = 'ar_content_format';
 467                         $fields[] = 'ar_content_model';
 468                 }
 469                 return $fields;
 470         }
 471
 472         /**
 473          * Return the list of text fields that should be selected to read the
 474          * revision text
 475          * @return array
 476          */
 477         public static function selectTextFields() {
 478                 return array(
 479                         'old_text',
 480                         'old_flags'
 481                 );
 482         }
 483
 484         /**
 485          * Return the list of page fields that should be selected from page table
 486          * @return array
 487          */
 488         public static function selectPageFields() {
 489                 return array(
 490                         'page_namespace',
 491                         'page_title',
 492                         'page_id',
 493                         'page_latest',
 494                         'page_is_redirect',
 495                         'page_len',
 496                 );
 497         }
 498
 499         /**
 500          * Return the list of user fields that should be selected from user table
 501          * @return array
 502          */
 503         public static function selectUserFields() {
 504                 return array( 'user_name' );
 505         }
 506
 507         /**
 508          * Do a batched query to get the parent revision lengths
 509          * @param DatabaseBase $db
 510          * @param array $revIds
 511          * @return array
 512          */
 513         public static function getParentLengths( $db, array $revIds ) {
 514                 $revLens = array();
 515                 if ( !$revIds ) {
 516                         return $revLens; // empty
 517                 }
 518                 wfProfileIn( __METHOD__ );
 519                 $res = $db->select( 'revision',
 520                         array( 'rev_id', 'rev_len' ),
 521                         array( 'rev_id' => $revIds ),
 522                         __METHOD__ );
 523                 foreach ( $res as $row ) {
 524                         $revLens[$row->rev_id] = $row->rev_len;
 525                 }
 526                 wfProfileOut( __METHOD__ );
 527                 return $revLens;
 528         }
 529
 530         /**
 531          * Constructor
 532          *
 533          * @param object|array $row Either a database row or an array
 534          * @throws MWException
 535          * @access private
 536          */
 537         function __construct( $row ) {
 538                 if ( is_object( $row ) ) {
 539                         $this->mId = intval( $row->rev_id );
 540                         $this->mPage = intval( $row->rev_page );
 541                         $this->mTextId = intval( $row->rev_text_id );
 542                         $this->mComment = $row->rev_comment;
 543                         $this->mUser = intval( $row->rev_user );
 544                         $this->mMinorEdit = intval( $row->rev_minor_edit );
 545                         $this->mTimestamp = $row->rev_timestamp;
 546                         $this->mDeleted = intval( $row->rev_deleted );
 547
 548                         if ( !isset( $row->rev_parent_id ) ) {
 549                                 $this->mParentId = null;
 550                         } else {
 551                                 $this->mParentId = intval( $row->rev_parent_id );
 552                         }
 553
 554                         if ( !isset( $row->rev_len ) ) {
 555                                 $this->mSize = null;
 556                         } else {
 557                                 $this->mSize = intval( $row->rev_len );
 558                         }
 559
 560                         if ( !isset( $row->rev_sha1 ) ) {
 561                                 $this->mSha1 = null;
 562                         } else {
 563                                 $this->mSha1 = $row->rev_sha1;
 564                         }
 565
 566                         if ( isset( $row->page_latest ) ) {
 567                                 $this->mCurrent = ( $row->rev_id == $row->page_latest );
 568                                 $this->mTitle = Title::newFromRow( $row );
 569                         } else {
 570                                 $this->mCurrent = false;
 571                                 $this->mTitle = null;
 572                         }
 573
 574                         if ( !isset( $row->rev_content_model ) ) {
 575                                 $this->mContentModel = null; # determine on demand if needed
 576                         } else {
 577                                 $this->mContentModel = strval( $row->rev_content_model );
 578                         }
 579
 580                         if ( !isset( $row->rev_content_format ) ) {
 581                                 $this->mContentFormat = null; # determine on demand if needed
 582                         } else {
 583                                 $this->mContentFormat = strval( $row->rev_content_format );
 584                         }
 585
 586                         // Lazy extraction...
 587                         $this->mText = null;
 588                         if ( isset( $row->old_text ) ) {
 589                                 $this->mTextRow = $row;
 590                         } else {
 591                                 // 'text' table row entry will be lazy-loaded
 592                                 $this->mTextRow = null;
 593                         }
 594
 595                         // Use user_name for users and rev_user_text for IPs...
 596                         $this->mUserText = null; // lazy load if left null
 597                         if ( $this->mUser == 0 ) {
 598                                 $this->mUserText = $row->rev_user_text; // IP user
 599                         } elseif ( isset( $row->user_name ) ) {
 600                                 $this->mUserText = $row->user_name; // logged-in user
 601                         }
 602                         $this->mOrigUserText = $row->rev_user_text;
 603                 } elseif ( is_array( $row ) ) {
 604                         // Build a new revision to be saved...
 605                         global $wgUser; // ugh
 606
 607                         # if we have a content object, use it to set the model and type
 608                         if ( !empty( $row['content'] ) ) {
 609                                 // @todo when is that set? test with external store setup! check out insertOn() [dk]
 610                                 if ( !empty( $row['text_id'] ) ) {
 611                                         throw new MWException( "Text already stored in external store (id {$row['text_id']}), " .
 612                                                 "can't serialize content object" );
 613                                 }
 614
 615                                 $row['content_model'] = $row['content']->getModel();
 616                                 # note: mContentFormat is initializes later accordingly
 617                                 # note: content is serialized later in this method!
 618                                 # also set text to null?
 619                         }
 620
 621                         $this->mId = isset( $row['id'] ) ? intval( $row['id'] ) : null;
 622                         $this->mPage = isset( $row['page'] ) ? intval( $row['page'] ) : null;
 623                         $this->mTextId = isset( $row['text_id'] ) ? intval( $row['text_id'] ) : null;
 624                         $this->mUserText = isset( $row['user_text'] )
 625                                 ? strval( $row['user_text'] ) : $wgUser->getName();
 626                         $this->mUser = isset( $row['user'] ) ? intval( $row['user'] ) : $wgUser->getId();
 627                         $this->mMinorEdit = isset( $row['minor_edit'] ) ? intval( $row['minor_edit'] ) : 0;
 628                         $this->mTimestamp = isset( $row['timestamp'] )
 629                                 ? strval( $row['timestamp'] ) : wfTimestampNow();
 630                         $this->mDeleted = isset( $row['deleted'] ) ? intval( $row['deleted'] ) : 0;
 631                         $this->mSize = isset( $row['len'] ) ? intval( $row['len'] ) : null;
 632                         $this->mParentId = isset( $row['parent_id'] ) ? intval( $row['parent_id'] ) : null;
 633                         $this->mSha1 = isset( $row['sha1'] ) ? strval( $row['sha1'] ) : null;
 634
 635                         $this->mContentModel = isset( $row['content_model'] )
 636                                 ? strval( $row['content_model'] ) : null;
 637                         $this->mContentFormat = isset( $row['content_format'] )
 638                                 ? strval( $row['content_format'] ) : null;
 639
 640                         // Enforce spacing trimming on supplied text
 641                         $this->mComment = isset( $row['comment'] ) ? trim( strval( $row['comment'] ) ) : null;
 642                         $this->mText = isset( $row['text'] ) ? rtrim( strval( $row['text'] ) ) : null;
 643                         $this->mTextRow = null;
 644
 645                         $this->mTitle = isset( $row['title'] ) ? $row['title'] : null;
 646
 647                         // if we have a Content object, override mText and mContentModel
 648                         if ( !empty( $row['content'] ) ) {
 649                                 if ( !( $row['content'] instanceof Content ) ) {
 650                                         throw new MWException( '`content` field must contain a Content object.' );
 651                                 }
 652
 653                                 $handler = $this->getContentHandler();
 654                                 $this->mContent = $row['content'];
 655
 656                                 $this->mContentModel = $this->mContent->getModel();
 657                                 $this->mContentHandler = null;
 658
 659                                 $this->mText = $handler->serializeContent( $row['content'], $this->getContentFormat() );
 660                         } elseif ( $this->mText !== null ) {
 661                                 $handler = $this->getContentHandler();
 662                                 $this->mContent = $handler->unserializeContent( $this->mText );
 663                         }
 664
 665                         // If we have a Title object, make sure it is consistent with mPage.
 666                         if ( $this->mTitle && $this->mTitle->exists() ) {
 667                                 if ( $this->mPage === null ) {
 668                                         // if the page ID wasn't known, set it now
 669                                         $this->mPage = $this->mTitle->getArticleID();
 670                                 } elseif ( $this->mTitle->getArticleID() !== $this->mPage ) {
 671                                         // Got different page IDs. This may be legit (e.g. during undeletion),
 672                                         // but it seems worth mentioning it in the log.
 673                                         wfDebug( "Page ID " . $this->mPage . " mismatches the ID " .
 674                                                 $this->mTitle->getArticleID() . " provided by the Title object." );
 675                                 }
 676                         }
 677
 678                         $this->mCurrent = false;
 679
 680                         // If we still have no length, see it we have the text to figure it out
 681                         if ( !$this->mSize && $this->mContent !== null ) {
 682                                 $this->mSize = $this->mContent->getSize();
 683                         }
 684
 685                         // Same for sha1
 686                         if ( $this->mSha1 === null ) {
 687                                 $this->mSha1 = $this->mText === null ? null : self::base36Sha1( $this->mText );
 688                         }
 689
 690                         // force lazy init
 691                         $this->getContentModel();
 692                         $this->getContentFormat();
 693                 } else {
 694                         throw new MWException( 'Revision constructor passed invalid row format.' );
 695                 }
 696                 $this->mUnpatrolled = null;
 697         }
 698
 699         /**
 700          * Get revision ID
 701          *
 702          * @return int|null
 703          */
 704         public function getId() {
 705                 return $this->mId;
 706         }
 707
 708         /**
 709          * Set the revision ID
 710          *
 711          * @since 1.19
 712          * @param int $id
 713          */
 714         public function setId( $id ) {
 715                 $this->mId = $id;
 716         }
 717
 718         /**
 719          * Get text row ID
 720          *
 721          * @return int|null
 722          */
 723         public function getTextId() {
 724                 return $this->mTextId;
 725         }
 726
 727         /**
 728          * Get parent revision ID (the original previous page revision)
 729          *
 730          * @return int|null
 731          */
 732         public function getParentId() {
 733                 return $this->mParentId;
 734         }
 735
 736         /**
 737          * Returns the length of the text in this revision, or null if unknown.
 738          *
 739          * @return int|null
 740          */
 741         public function getSize() {
 742                 return $this->mSize;
 743         }
 744
 745         /**
 746          * Returns the base36 sha1 of the text in this revision, or null if unknown.
 747          *
 748          * @return string|null
 749          */
 750         public function getSha1() {
 751                 return $this->mSha1;
 752         }
 753
 754         /**
 755          * Returns the title of the page associated with this entry or null.
 756          *
 757          * Will do a query, when title is not set and id is given.
 758          *
 759          * @return Title|null
 760          */
 761         public function getTitle() {
 762                 if ( $this->mTitle !== null ) {
 763                         return $this->mTitle;
 764                 }
 765                 //rev_id is defined as NOT NULL, but this revision may not yet have been inserted.
 766                 if ( $this->mId !== null ) {
 767                         $dbr = wfGetDB( DB_SLAVE );
 768                         $row = $dbr->selectRow(
 769                                 array( 'page', 'revision' ),
 770                                 self::selectPageFields(),
 771                                 array( 'page_id=rev_page',
 772                                         'rev_id' => $this->mId ),
 773                                 __METHOD__ );
 774                         if ( $row ) {
 775                                 $this->mTitle = Title::newFromRow( $row );
 776                         }
 777                 }
 778
 779                 if ( !$this->mTitle && $this->mPage !== null && $this->mPage > 0 ) {
 780                         $this->mTitle = Title::newFromID( $this->mPage );
 781                 }
 782
 783                 return $this->mTitle;
 784         }
 785
 786         /**
 787          * Set the title of the revision
 788          *
 789          * @param Title $title
 790          */
 791         public function setTitle( $title ) {
 792                 $this->mTitle = $title;
 793         }
 794
 795         /**
 796          * Get the page ID
 797          *
 798          * @return int|null
 799          */
 800         public function getPage() {
 801                 return $this->mPage;
 802         }
 803
 804         /**
 805          * Fetch revision's user id if it's available to the specified audience.
 806          * If the specified audience does not have access to it, zero will be
 807          * returned.
 808          *
 809          * @param int $audience One of:
 810          *   Revision::FOR_PUBLIC       to be displayed to all users
 811          *   Revision::FOR_THIS_USER    to be displayed to the given user
 812          *   Revision::RAW              get the ID regardless of permissions
 813          * @param User $user User object to check for, only if FOR_THIS_USER is passed
 814          *   to the $audience parameter
 815          * @return int
 816          */
 817         public function getUser( $audience = self::FOR_PUBLIC, User $user = null ) {
 818                 if ( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_USER ) ) {
 819                         return 0;
 820                 } elseif ( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_USER, $user ) ) {
 821                         return 0;
 822                 } else {
 823                         return $this->mUser;
 824                 }
 825         }
 826
 827         /**
 828          * Fetch revision's user id without regard for the current user's permissions
 829          *
 830          * @return string
 831          */
 832         public function getRawUser() {
 833                 return $this->mUser;
 834         }
 835
 836         /**
 837          * Fetch revision's username if it's available to the specified audience.
 838          * If the specified audience does not have access to the username, an
 839          * empty string will be returned.
 840          *
 841          * @param int $audience One of:
 842          *   Revision::FOR_PUBLIC       to be displayed to all users
 843          *   Revision::FOR_THIS_USER    to be displayed to the given user
 844          *   Revision::RAW              get the text regardless of permissions
 845          * @param User $user User object to check for, only if FOR_THIS_USER is passed
 846          *   to the $audience parameter
 847          * @return string
 848          */
 849         public function getUserText( $audience = self::FOR_PUBLIC, User $user = null ) {
 850                 if ( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_USER ) ) {
 851                         return '';
 852                 } elseif ( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_USER, $user ) ) {
 853                         return '';
 854                 } else {
 855                         return $this->getRawUserText();
 856                 }
 857         }
 858
 859         /**
 860          * Fetch revision's username without regard for view restrictions
 861          *
 862          * @return string
 863          */
 864         public function getRawUserText() {
 865                 if ( $this->mUserText === null ) {
 866                         $this->mUserText = User::whoIs( $this->mUser ); // load on demand
 867                         if ( $this->mUserText === false ) {
 868                                 # This shouldn't happen, but it can if the wiki was recovered
 869                                 # via importing revs and there is no user table entry yet.
 870                                 $this->mUserText = $this->mOrigUserText;
 871                         }
 872                 }
 873                 return $this->mUserText;
 874         }
 875
 876         /**
 877          * Fetch revision comment if it's available to the specified audience.
 878          * If the specified audience does not have access to the comment, an
 879          * empty string will be returned.
 880          *
 881          * @param int $audience One of:
 882          *   Revision::FOR_PUBLIC       to be displayed to all users
 883          *   Revision::FOR_THIS_USER    to be displayed to the given user
 884          *   Revision::RAW              get the text regardless of permissions
 885          * @param User $user User object to check for, only if FOR_THIS_USER is passed
 886          *   to the $audience parameter
 887          * @return string
 888          */
 889         function getComment( $audience = self::FOR_PUBLIC, User $user = null ) {
 890                 if ( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_COMMENT ) ) {
 891                         return '';
 892                 } elseif ( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_COMMENT, $user ) ) {
 893                         return '';
 894                 } else {
 895                         return $this->mComment;
 896                 }
 897         }
 898
 899         /**
 900          * Fetch revision comment without regard for the current user's permissions
 901          *
 902          * @return string
 903          */
 904         public function getRawComment() {
 905                 return $this->mComment;
 906         }
 907
 908         /**
 909          * @return bool
 910          */
 911         public function isMinor() {
 912                 return (bool)$this->mMinorEdit;
 913         }
 914
 915         /**
 916          * @return int Rcid of the unpatrolled row, zero if there isn't one
 917          */
 918         public function isUnpatrolled() {
 919                 if ( $this->mUnpatrolled !== null ) {
 920                         return $this->mUnpatrolled;
 921                 }
 922                 $rc = $this->getRecentChange();
 923                 if ( $rc && $rc->getAttribute( 'rc_patrolled' ) == 0 ) {
 924                         $this->mUnpatrolled = $rc->getAttribute( 'rc_id' );
 925                 } else {
 926                         $this->mUnpatrolled = 0;
 927                 }
 928                 return $this->mUnpatrolled;
 929         }
 930
 931         /**
 932          * Get the RC object belonging to the current revision, if there's one
 933          *
 934          * @since 1.22
 935          * @return RecentChange|null
 936          */
 937         public function getRecentChange() {
 938                 $dbr = wfGetDB( DB_SLAVE );
 939                 return RecentChange::newFromConds(
 940                         array(
 941                                 'rc_user_text' => $this->getRawUserText(),
 942                                 'rc_timestamp' => $dbr->timestamp( $this->getTimestamp() ),
 943                                 'rc_this_oldid' => $this->getId()
 944                         ),
 945                         __METHOD__
 946                 );
 947         }
 948
 949         /**
 950          * @param int $field One of DELETED_* bitfield constants
 951          *
 952          * @return bool
 953          */
 954         public function isDeleted( $field ) {
 955                 return ( $this->mDeleted & $field ) == $field;
 956         }
 957
 958         /**
 959          * Get the deletion bitfield of the revision
 960          *
 961          * @return int
 962          */
 963         public function getVisibility() {
 964                 return (int)$this->mDeleted;
 965         }
 966
 967         /**
 968          * Fetch revision text if it's available to the specified audience.
 969          * If the specified audience does not have the ability to view this
 970          * revision, an empty string will be returned.
 971          *
 972          * @param int $audience One of:
 973          *   Revision::FOR_PUBLIC       to be displayed to all users
 974          *   Revision::FOR_THIS_USER    to be displayed to the given user
 975          *   Revision::RAW              get the text regardless of permissions
 976          * @param User $user User object to check for, only if FOR_THIS_USER is passed
 977          *   to the $audience parameter
 978          *
 979          * @deprecated since 1.21, use getContent() instead
 980          * @todo Replace usage in core
 981          * @return string
 982          */
 983         public function getText( $audience = self::FOR_PUBLIC, User $user = null ) {
 984                 ContentHandler::deprecated( __METHOD__, '1.21' );
 985
 986                 $content = $this->getContent( $audience, $user );
 987                 return ContentHandler::getContentText( $content ); # returns the raw content text, if applicable
 988         }
 989
 990         /**
 991          * Fetch revision content if it's available to the specified audience.
 992          * If the specified audience does not have the ability to view this
 993          * revision, null will be returned.
 994          *
 995          * @param int $audience One of:
 996          *   Revision::FOR_PUBLIC       to be displayed to all users
 997          *   Revision::FOR_THIS_USER    to be displayed to $wgUser
 998          *   Revision::RAW              get the text regardless of permissions
 999          * @param User $user User object to check for, only if FOR_THIS_USER is passed
1000          *   to the $audience parameter
1001          * @since 1.21
1002          * @return Content|null
1003          */
1004         public function getContent( $audience = self::FOR_PUBLIC, User $user = null ) {
1005                 if ( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_TEXT ) ) {
1006                         return null;
1007                 } elseif ( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_TEXT, $user ) ) {
1008                         return null;
1009                 } else {
1010                         return $this->getContentInternal();
1011                 }
1012         }
1013
1014         /**
1015          * Fetch revision text without regard for view restrictions
1016          *
1017          * @return string
1018          *
1019          * @deprecated since 1.21. Instead, use Revision::getContent( Revision::RAW )
1020          *                         or Revision::getSerializedData() as appropriate.
1021          */
1022         public function getRawText() {
1023                 ContentHandler::deprecated( __METHOD__, "1.21" );
1024                 return $this->getText( self::RAW );
1025         }
1026
1027         /**
1028          * Fetch original serialized data without regard for view restrictions
1029          *
1030          * @since 1.21
1031          * @return string
1032          */
1033         public function getSerializedData() {
1034                 if ( $this->mText === null ) {
1035                         $this->mText = $this->loadText();
1036                 }
1037
1038                 return $this->mText;
1039         }
1040
1041         /**
1042          * Gets the content object for the revision (or null on failure).
1043          *
1044          * Note that for mutable Content objects, each call to this method will return a
1045          * fresh clone.
1046          *
1047          * @since 1.21
1048          * @return Content|null The Revision's content, or null on failure.
1049          */
1050         protected function getContentInternal() {
1051                 if ( $this->mContent === null ) {
1052                         // Revision is immutable. Load on demand:
1053                         if ( $this->mText === null ) {
1054                                 $this->mText = $this->loadText();
1055                         }
1056
1057                         if ( $this->mText !== null && $this->mText !== false ) {
1058                                 // Unserialize content
1059                                 $handler = $this->getContentHandler();
1060                                 $format = $this->getContentFormat();
1061
1062                                 $this->mContent = $handler->unserializeContent( $this->mText, $format );
1063                         }
1064                 }
1065
1066                 // NOTE: copy() will return $this for immutable content objects
1067                 return $this->mContent ? $this->mContent->copy() : null;
1068         }
1069
1070         /**
1071          * Returns the content model for this revision.
1072          *
1073          * If no content model was stored in the database, $this->getTitle()->getContentModel() is
1074          * used to determine the content model to use. If no title is know, CONTENT_MODEL_WIKITEXT
1075          * is used as a last resort.
1076          *
1077          * @return string The content model id associated with this revision,
1078          *     see the CONTENT_MODEL_XXX constants.
1079          **/
1080         public function getContentModel() {
1081                 if ( !$this->mContentModel ) {
1082                         $title = $this->getTitle();
1083                         $this->mContentModel = ( $title ? $title->getContentModel() : CONTENT_MODEL_WIKITEXT );
1084
1085                         assert( !empty( $this->mContentModel ) );
1086                 }
1087
1088                 return $this->mContentModel;
1089         }
1090
1091         /**
1092          * Returns the content format for this revision.
1093          *
1094          * If no content format was stored in the database, the default format for this
1095          * revision's content model is returned.
1096          *
1097          * @return string The content format id associated with this revision,
1098          *     see the CONTENT_FORMAT_XXX constants.
1099          **/
1100         public function getContentFormat() {
1101                 if ( !$this->mContentFormat ) {
1102                         $handler = $this->getContentHandler();
1103                         $this->mContentFormat = $handler->getDefaultFormat();
1104
1105                         assert( !empty( $this->mContentFormat ) );
1106                 }
1107
1108                 return $this->mContentFormat;
1109         }
1110
1111         /**
1112          * Returns the content handler appropriate for this revision's content model.
1113          *
1114          * @throws MWException
1115          * @return ContentHandler
1116          */
1117         public function getContentHandler() {
1118                 if ( !$this->mContentHandler ) {
1119                         $model = $this->getContentModel();
1120                         $this->mContentHandler = ContentHandler::getForModelID( $model );
1121
1122                         $format = $this->getContentFormat();
1123
1124                         if ( !$this->mContentHandler->isSupportedFormat( $format ) ) {
1125                                 throw new MWException( "Oops, the content format $format is not supported for "
1126                                         . "this content model, $model" );
1127                         }
1128                 }
1129
1130                 return $this->mContentHandler;
1131         }
1132
1133         /**
1134          * @return string
1135          */
1136         public function getTimestamp() {
1137                 return wfTimestamp( TS_MW, $this->mTimestamp );
1138         }
1139
1140         /**
1141          * @return bool
1142          */
1143         public function isCurrent() {
1144                 return $this->mCurrent;
1145         }
1146
1147         /**
1148          * Get previous revision for this title
1149          *
1150          * @return Revision|null
1151          */
1152         public function getPrevious() {
1153                 if ( $this->getTitle() ) {
1154                         $prev = $this->getTitle()->getPreviousRevisionID( $this->getId() );
1155                         if ( $prev ) {
1156                                 return self::newFromTitle( $this->getTitle(), $prev );
1157                         }
1158                 }
1159                 return null;
1160         }
1161
1162         /**
1163          * Get next revision for this title
1164          *
1165          * @return Revision|null
1166          */
1167         public function getNext() {
1168                 if ( $this->getTitle() ) {
1169                         $next = $this->getTitle()->getNextRevisionID( $this->getId() );
1170                         if ( $next ) {
1171                                 return self::newFromTitle( $this->getTitle(), $next );
1172                         }
1173                 }
1174                 return null;
1175         }
1176
1177         /**
1178          * Get previous revision Id for this page_id
1179          * This is used to populate rev_parent_id on save
1180          *
1181          * @param DatabaseBase $db
1182          * @return int
1183          */
1184         private function getPreviousRevisionId( $db ) {
1185                 if ( $this->mPage === null ) {
1186                         return 0;
1187                 }
1188                 # Use page_latest if ID is not given
1189                 if ( !$this->mId ) {
1190                         $prevId = $db->selectField( 'page', 'page_latest',
1191                                 array( 'page_id' => $this->mPage ),
1192                                 __METHOD__ );
1193                 } else {
1194                         $prevId = $db->selectField( 'revision', 'rev_id',
1195                                 array( 'rev_page' => $this->mPage, 'rev_id < ' . $this->mId ),
1196                                 __METHOD__,
1197                                 array( 'ORDER BY' => 'rev_id DESC' ) );
1198                 }
1199                 return intval( $prevId );
1200         }
1201
1202         /**
1203          * Get revision text associated with an old or archive row
1204          * $row is usually an object from wfFetchRow(), both the flags and the text
1205          * field must be included.
1206          *
1207          * @param stdClass $row The text data
1208          * @param string $prefix Table prefix (default 'old_')
1209          * @param string|bool $wiki The name of the wiki to load the revision text from
1210          *   (same as the the wiki $row was loaded from) or false to indicate the local
1211          *   wiki (this is the default). Otherwise, it must be a symbolic wiki database
1212          *   identifier as understood by the LoadBalancer class.
1213          * @return string Text the text requested or false on failure
1214          */
1215         public static function getRevisionText( $row, $prefix = 'old_', $wiki = false ) {
1216                 wfProfileIn( __METHOD__ );
1217
1218                 # Get data
1219                 $textField = $prefix . 'text';
1220                 $flagsField = $prefix . 'flags';
1221
1222                 if ( isset( $row->$flagsField ) ) {
1223                         $flags = explode( ',', $row->$flagsField );
1224                 } else {
1225                         $flags = array();
1226                 }
1227
1228                 if ( isset( $row->$textField ) ) {
1229                         $text = $row->$textField;
1230                 } else {
1231                         wfProfileOut( __METHOD__ );
1232                         return false;
1233                 }
1234
1235                 # Use external methods for external objects, text in table is URL-only then
1236                 if ( in_array( 'external', $flags ) ) {
1237                         $url = $text;
1238                         $parts = explode( '://', $url, 2 );
1239                         if ( count( $parts ) == 1 || $parts[1] == '' ) {
1240                                 wfProfileOut( __METHOD__ );
1241                                 return false;
1242                         }
1243                         $text = ExternalStore::fetchFromURL( $url, array( 'wiki' => $wiki ) );
1244                 }
1245
1246                 // If the text was fetched without an error, convert it
1247                 if ( $text !== false ) {
1248                         $text = self::decompressRevisionText( $text, $flags );
1249                 }
1250                 wfProfileOut( __METHOD__ );
1251                 return $text;
1252         }
1253
1254         /**
1255          * If $wgCompressRevisions is enabled, we will compress data.
1256          * The input string is modified in place.
1257          * Return value is the flags field: contains 'gzip' if the
1258          * data is compressed, and 'utf-8' if we're saving in UTF-8
1259          * mode.
1260          *
1261          * @param mixed $text Reference to a text
1262          * @return string
1263          */
1264         public static function compressRevisionText( &$text ) {
1265                 global $wgCompressRevisions;
1266                 $flags = array();
1267
1268                 # Revisions not marked this way will be converted
1269                 # on load if $wgLegacyCharset is set in the future.
1270                 $flags[] = 'utf-8';
1271
1272                 if ( $wgCompressRevisions ) {
1273                         if ( function_exists( 'gzdeflate' ) ) {
1274                                 $text = gzdeflate( $text );
1275                                 $flags[] = 'gzip';
1276                         } else {
1277                                 wfDebug( __METHOD__ . " -- no zlib support, not compressing\n" );
1278                         }
1279                 }
1280                 return implode( ',', $flags );
1281         }
1282
1283         /**
1284          * Re-converts revision text according to it's flags.
1285          *
1286          * @param mixed $text Reference to a text
1287          * @param array $flags Compression flags
1288          * @return string|bool Decompressed text, or false on failure
1289          */
1290         public static function decompressRevisionText( $text, $flags ) {
1291                 if ( in_array( 'gzip', $flags ) ) {
1292                         # Deal with optional compression of archived pages.
1293                         # This can be done periodically via maintenance/compressOld.php, and
1294                         # as pages are saved if $wgCompressRevisions is set.
1295                         $text = gzinflate( $text );
1296                 }
1297
1298                 if ( in_array( 'object', $flags ) ) {
1299                         # Generic compressed storage
1300                         $obj = unserialize( $text );
1301                         if ( !is_object( $obj ) ) {
1302                                 // Invalid object
1303                                 return false;
1304                         }
1305                         $text = $obj->getText();
1306                 }
1307
1308                 global $wgLegacyEncoding;
1309                 if ( $text !== false && $wgLegacyEncoding
1310                         && !in_array( 'utf-8', $flags ) && !in_array( 'utf8', $flags )
1311                 ) {
1312                         # Old revisions kept around in a legacy encoding?
1313                         # Upconvert on demand.
1314                         # ("utf8" checked for compatibility with some broken
1315                         #  conversion scripts 2008-12-30)
1316                         global $wgContLang;
1317                         $text = $wgContLang->iconv( $wgLegacyEncoding, 'UTF-8', $text );
1318                 }
1319
1320                 return $text;
1321         }
1322
1323         /**
1324          * Insert a new revision into the database, returning the new revision ID
1325          * number on success and dies horribly on failure.
1326          *
1327          * @param DatabaseBase $dbw (master connection)
1328          * @throws MWException
1329          * @return int
1330          */
1331         public function insertOn( $dbw ) {
1332                 global $wgDefaultExternalStore, $wgContentHandlerUseDB;
1333
1334                 wfProfileIn( __METHOD__ );
1335
1336                 $this->checkContentModel();
1337
1338                 $data = $this->mText;
1339                 $flags = self::compressRevisionText( $data );
1340
1341                 # Write to external storage if required
1342                 if ( $wgDefaultExternalStore ) {
1343                         // Store and get the URL
1344                         $data = ExternalStore::insertToDefault( $data );
1345                         if ( !$data ) {
1346                                 wfProfileOut( __METHOD__ );
1347                                 throw new MWException( "Unable to store text to external storage" );
1348                         }
1349                         if ( $flags ) {
1350                                 $flags .= ',';
1351                         }
1352                         $flags .= 'external';
1353                 }
1354
1355                 # Record the text (or external storage URL) to the text table
1356                 if ( $this->mTextId === null ) {
1357                         $old_id = $dbw->nextSequenceValue( 'text_old_id_seq' );
1358                         $dbw->insert( 'text',
1359                                 array(
1360                                         'old_id' => $old_id,
1361                                         'old_text' => $data,
1362                                         'old_flags' => $flags,
1363                                 ), __METHOD__
1364                         );
1365                         $this->mTextId = $dbw->insertId();
1366                 }
1367
1368                 if ( $this->mComment === null ) {
1369                         $this->mComment = "";
1370                 }
1371
1372                 # Record the edit in revisions
1373                 $rev_id = $this->mId !== null
1374                         ? $this->mId
1375                         : $dbw->nextSequenceValue( 'revision_rev_id_seq' );
1376                 $row = array(
1377                         'rev_id'         => $rev_id,
1378                         'rev_page'       => $this->mPage,
1379                         'rev_text_id'    => $this->mTextId,
1380                         'rev_comment'    => $this->mComment,
1381                         'rev_minor_edit' => $this->mMinorEdit ? 1 : 0,
1382                         'rev_user'       => $this->mUser,
1383                         'rev_user_text'  => $this->mUserText,
1384                         'rev_timestamp'  => $dbw->timestamp( $this->mTimestamp ),
1385                         'rev_deleted'    => $this->mDeleted,
1386                         'rev_len'        => $this->mSize,
1387                         'rev_parent_id'  => $this->mParentId === null
1388                                 ? $this->getPreviousRevisionId( $dbw )
1389                                 : $this->mParentId,
1390                         'rev_sha1'       => $this->mSha1 === null
1391                                 ? Revision::base36Sha1( $this->mText )
1392                                 : $this->mSha1,
1393                 );
1394
1395                 if ( $wgContentHandlerUseDB ) {
1396                         //NOTE: Store null for the default model and format, to save space.
1397                         //XXX: Makes the DB sensitive to changed defaults.
1398                         // Make this behavior optional? Only in miser mode?
1399
1400                         $model = $this->getContentModel();
1401                         $format = $this->getContentFormat();
1402
1403                         $title = $this->getTitle();
1404
1405                         if ( $title === null ) {
1406                                 wfProfileOut( __METHOD__ );
1407                                 throw new MWException( "Insufficient information to determine the title of the "
1408                                         . "revision's page!" );
1409                         }
1410
1411                         $defaultModel = ContentHandler::getDefaultModelFor( $title );
1412                         $defaultFormat = ContentHandler::getForModelID( $defaultModel )->getDefaultFormat();
1413
1414                         $row['rev_content_model'] = ( $model === $defaultModel ) ? null : $model;
1415                         $row['rev_content_format'] = ( $format === $defaultFormat ) ? null : $format;
1416                 }
1417
1418                 $dbw->insert( 'revision', $row, __METHOD__ );
1419
1420                 $this->mId = $rev_id !== null ? $rev_id : $dbw->insertId();
1421
1422                 wfRunHooks( 'RevisionInsertComplete', array( &$this, $data, $flags ) );
1423
1424                 wfProfileOut( __METHOD__ );
1425                 return $this->mId;
1426         }
1427
1428         protected function checkContentModel() {
1429                 global $wgContentHandlerUseDB;
1430
1431                 $title = $this->getTitle(); //note: may return null for revisions that have not yet been inserted.
1432
1433                 $model = $this->getContentModel();
1434                 $format = $this->getContentFormat();
1435                 $handler = $this->getContentHandler();
1436
1437                 if ( !$handler->isSupportedFormat( $format ) ) {
1438                         $t = $title->getPrefixedDBkey();
1439
1440                         throw new MWException( "Can't use format $format with content model $model on $t" );
1441                 }
1442
1443                 if ( !$wgContentHandlerUseDB && $title ) {
1444                         // if $wgContentHandlerUseDB is not set,
1445                         // all revisions must use the default content model and format.
1446
1447                         $defaultModel = ContentHandler::getDefaultModelFor( $title );
1448                         $defaultHandler = ContentHandler::getForModelID( $defaultModel );
1449                         $defaultFormat = $defaultHandler->getDefaultFormat();
1450
1451                         if ( $this->getContentModel() != $defaultModel ) {
1452                                 $t = $title->getPrefixedDBkey();
1453
1454                                 throw new MWException( "Can't save non-default content model with "
1455                                         . "\$wgContentHandlerUseDB disabled: model is $model, "
1456                                         . "default for $t is $defaultModel" );
1457                         }
1458
1459                         if ( $this->getContentFormat() != $defaultFormat ) {
1460                                 $t = $title->getPrefixedDBkey();
1461
1462                                 throw new MWException( "Can't use non-default content format with "
1463                                         . "\$wgContentHandlerUseDB disabled: format is $format, "
1464                                         . "default for $t is $defaultFormat" );
1465                         }
1466                 }
1467
1468                 $content = $this->getContent( Revision::RAW );
1469
1470                 if ( !$content || !$content->isValid() ) {
1471                         $t = $title->getPrefixedDBkey();
1472
1473                         throw new MWException( "Content of $t is not valid! Content model is $model" );
1474                 }
1475         }
1476
1477         /**
1478          * Get the base 36 SHA-1 value for a string of text
1479          * @param string $text
1480          * @return string
1481          */
1482         public static function base36Sha1( $text ) {
1483                 return wfBaseConvert( sha1( $text ), 16, 36, 31 );
1484         }
1485
1486         /**
1487          * Lazy-load the revision's text.
1488          * Currently hardcoded to the 'text' table storage engine.
1489          *
1490          * @return string|bool The revision's text, or false on failure
1491          */
1492         protected function loadText() {
1493                 wfProfileIn( __METHOD__ );
1494
1495                 // Caching may be beneficial for massive use of external storage
1496                 global $wgRevisionCacheExpiry, $wgMemc;
1497                 $textId = $this->getTextId();
1498                 $key = wfMemcKey( 'revisiontext', 'textid', $textId );
1499                 if ( $wgRevisionCacheExpiry ) {
1500                         $text = $wgMemc->get( $key );
1501                         if ( is_string( $text ) ) {
1502                                 wfDebug( __METHOD__ . ": got id $textId from cache\n" );
1503                                 wfProfileOut( __METHOD__ );
1504                                 return $text;
1505                         }
1506                 }
1507
1508                 // If we kept data for lazy extraction, use it now...
1509                 if ( $this->mTextRow !== null ) {
1510                         $row = $this->mTextRow;
1511                         $this->mTextRow = null;
1512                 } else {
1513                         $row = null;
1514                 }
1515
1516                 if ( !$row ) {
1517                         // Text data is immutable; check slaves first.
1518                         $dbr = wfGetDB( DB_SLAVE );
1519                         $row = $dbr->selectRow( 'text',
1520                                 array( 'old_text', 'old_flags' ),
1521                                 array( 'old_id' => $textId ),
1522                                 __METHOD__ );
1523                 }
1524
1525                 // Fallback to the master in case of slave lag. Also use FOR UPDATE if it was
1526                 // used to fetch this revision to avoid missing the row due to REPEATABLE-READ.
1527                 $forUpdate = ( $this->mQueryFlags & self::READ_LOCKING == self::READ_LOCKING );
1528                 if ( !$row && ( $forUpdate || wfGetLB()->getServerCount() > 1 ) ) {
1529                         $dbw = wfGetDB( DB_MASTER );
1530                         $row = $dbw->selectRow( 'text',
1531                                 array( 'old_text', 'old_flags' ),
1532                                 array( 'old_id' => $textId ),
1533                                 __METHOD__,
1534                                 $forUpdate ? array( 'FOR UPDATE' ) : array() );
1535                 }
1536
1537                 if ( !$row ) {
1538                         wfDebugLog( 'Revision', "No text row with ID '$textId' (revision {$this->getId()})." );
1539                 }
1540
1541                 $text = self::getRevisionText( $row );
1542                 if ( $row && $text === false ) {
1543                         wfDebugLog( 'Revision', "No blob for text row '$textId' (revision {$this->getId()})." );
1544                 }
1545
1546                 # No negative caching -- negative hits on text rows may be due to corrupted slave servers
1547                 if ( $wgRevisionCacheExpiry && $text !== false ) {
1548                         $wgMemc->set( $key, $text, $wgRevisionCacheExpiry );
1549                 }
1550
1551                 wfProfileOut( __METHOD__ );
1552
1553                 return $text;
1554         }
1555
1556         /**
1557          * Create a new null-revision for insertion into a page's
1558          * history. This will not re-save the text, but simply refer
1559          * to the text from the previous version.
1560          *
1561          * Such revisions can for instance identify page rename
1562          * operations and other such meta-modifications.
1563          *
1564          * @param DatabaseBase $dbw
1565          * @param int $pageId ID number of the page to read from
1566          * @param string $summary Revision's summary
1567          * @param bool $minor Whether the revision should be considered as minor
1568          * @param User|null $user User object to use or null for $wgUser
1569          * @return Revision|null Revision or null on error
1570          */
1571         public static function newNullRevision( $dbw, $pageId, $summary, $minor, $user = null ) {
1572                 global $wgContentHandlerUseDB;
1573
1574                 wfProfileIn( __METHOD__ );
1575
1576                 $fields = array( 'page_latest', 'page_namespace', 'page_title',
1577                                                 'rev_text_id', 'rev_len', 'rev_sha1' );
1578
1579                 if ( $wgContentHandlerUseDB ) {
1580                         $fields[] = 'rev_content_model';
1581                         $fields[] = 'rev_content_format';
1582                 }
1583
1584                 $current = $dbw->selectRow(
1585                         array( 'page', 'revision' ),
1586                         $fields,
1587                         array(
1588                                 'page_id' => $pageId,
1589                                 'page_latest=rev_id',
1590                                 ),
1591                         __METHOD__ );
1592
1593                 if ( $current ) {
1594                         if ( !$user ) {
1595                                 global $wgUser;
1596                                 $user = $wgUser;
1597                         }
1598
1599                         $row = array(
1600                                 'page'       => $pageId,
1601                                 'user_text'  => $user->getName(),
1602                                 'user'       => $user->getId(),
1603                                 'comment'    => $summary,
1604                                 'minor_edit' => $minor,
1605                                 'text_id'    => $current->rev_text_id,
1606                                 'parent_id'  => $current->page_latest,
1607                                 'len'        => $current->rev_len,
1608                                 'sha1'       => $current->rev_sha1
1609                         );
1610
1611                         if ( $wgContentHandlerUseDB ) {
1612                                 $row['content_model'] = $current->rev_content_model;
1613                                 $row['content_format'] = $current->rev_content_format;
1614                         }
1615
1616                         $revision = new Revision( $row );
1617                         $revision->setTitle( Title::makeTitle( $current->page_namespace, $current->page_title ) );
1618                 } else {
1619                         $revision = null;
1620                 }
1621
1622                 wfProfileOut( __METHOD__ );
1623                 return $revision;
1624         }
1625
1626         /**
1627          * Determine if the current user is allowed to view a particular
1628          * field of this revision, if it's marked as deleted.
1629          *
1630          * @param int $field One of self::DELETED_TEXT,
1631          *                              self::DELETED_COMMENT,
1632          *                              self::DELETED_USER
1633          * @param User|null $user User object to check, or null to use $wgUser
1634          * @return bool
1635          */
1636         public function userCan( $field, User $user = null ) {
1637                 return self::userCanBitfield( $this->mDeleted, $field, $user );
1638         }
1639
1640         /**
1641          * Determine if the current user is allowed to view a particular
1642          * field of this revision, if it's marked as deleted. This is used
1643          * by various classes to avoid duplication.
1644          *
1645          * @param int $bitfield Current field
1646          * @param int $field One of self::DELETED_TEXT = File::DELETED_FILE,
1647          *                               self::DELETED_COMMENT = File::DELETED_COMMENT,
1648          *                               self::DELETED_USER = File::DELETED_USER
1649          * @param User|null $user User object to check, or null to use $wgUser
1650          * @param Title|null $title A Title object to check for per-page restrictions on,
1651          *                          instead of just plain userrights
1652          * @return bool
1653          */
1654         public static function userCanBitfield( $bitfield, $field, User $user = null,
1655                 Title $title = null
1656         ) {
1657                 if ( $bitfield & $field ) { // aspect is deleted
1658                         if ( $user === null ) {
1659                                 global $wgUser;
1660                                 $user = $wgUser;
1661                         }
1662                         if ( $bitfield & self::DELETED_RESTRICTED ) {
1663                                 $permissions = array( 'suppressrevision', 'viewsuppressed' );
1664                         } elseif ( $field & self::DELETED_TEXT ) {
1665                                 $permissions = array( 'deletedtext' );
1666                         } else {
1667                                 $permissions = array( 'deletedhistory' );
1668                         }
1669                         $permissionlist = implode( ', ', $permissions );
1670                         if ( $title === null ) {
1671                                 wfDebug( "Checking for $permissionlist due to $field match on $bitfield\n" );
1672                                 return call_user_func_array( array( $user, 'isAllowedAny' ), $permissions );
1673                         } else {
1674                                 $text = $title->getPrefixedText();
1675                                 wfDebug( "Checking for $permissionlist on $text due to $field match on $bitfield\n" );
1676                                 foreach ( $permissions as $perm ) {
1677                                         if ( $title->userCan( $perm, $user ) ) {
1678                                                 return true;
1679                                         }
1680                                 }
1681                                 return false;
1682                         }
1683                 } else {
1684                         return true;
1685                 }
1686         }
1687
1688         /**
1689          * Get rev_timestamp from rev_id, without loading the rest of the row
1690          *
1691          * @param Title $title
1692          * @param int $id
1693          * @return string
1694          */
1695         static function getTimestampFromId( $title, $id ) {
1696                 $dbr = wfGetDB( DB_SLAVE );
1697                 // Casting fix for databases that can't take '' for rev_id
1698                 if ( $id == '' ) {
1699                         $id = 0;
1700                 }
1701                 $conds = array( 'rev_id' => $id );
1702                 $conds['rev_page'] = $title->getArticleID();
1703                 $timestamp = $dbr->selectField( 'revision', 'rev_timestamp', $conds, __METHOD__ );
1704                 if ( $timestamp === false && wfGetLB()->getServerCount() > 1 ) {
1705                         # Not in slave, try master
1706                         $dbw = wfGetDB( DB_MASTER );
1707                         $timestamp = $dbw->selectField( 'revision', 'rev_timestamp', $conds, __METHOD__ );
1708                 }
1709                 return wfTimestamp( TS_MW, $timestamp );
1710         }
1711
1712         /**
1713          * Get count of revisions per page...not very efficient
1714          *
1715          * @param DatabaseBase $db
1716          * @param int $id Page id
1717          * @return int
1718          */
1719         static function countByPageId( $db, $id ) {
1720                 $row = $db->selectRow( 'revision', array( 'revCount' => 'COUNT(*)' ),
1721                         array( 'rev_page' => $id ), __METHOD__ );
1722                 if ( $row ) {
1723                         return $row->revCount;
1724                 }
1725                 return 0;
1726         }
1727
1728         /**
1729          * Get count of revisions per page...not very efficient
1730          *
1731          * @param DatabaseBase $db
1732          * @param Title $title
1733          * @return int
1734          */
1735         static function countByTitle( $db, $title ) {
1736                 $id = $title->getArticleID();
1737                 if ( $id ) {
1738                         return self::countByPageId( $db, $id );
1739                 }
1740                 return 0;
1741         }
1742
1743         /**
1744          * Check if no edits were made by other users since
1745          * the time a user started editing the page. Limit to
1746          * 50 revisions for the sake of performance.
1747          *
1748          * @since 1.20
1749          * @deprecated since 1.24
1750          *
1751          * @param DatabaseBase|int $db The Database to perform the check on. May be given as a
1752          *        Database object or a database identifier usable with wfGetDB.
1753          * @param int $pageId The ID of the page in question
1754          * @param int $userId The ID of the user in question
1755          * @param string $since Look at edits since this time
1756          *
1757          * @return bool True if the given user was the only one to edit since the given timestamp
1758          */
1759         public static function userWasLastToEdit( $db, $pageId, $userId, $since ) {
1760                 if ( !$userId ) {
1761                         return false;
1762                 }
1763
1764                 if ( is_int( $db ) ) {
1765                         $db = wfGetDB( $db );
1766                 }
1767
1768                 $res = $db->select( 'revision',
1769                         'rev_user',
1770                         array(
1771                                 'rev_page' => $pageId,
1772                                 'rev_timestamp > ' . $db->addQuotes( $db->timestamp( $since ) )
1773                         ),
1774                         __METHOD__,
1775                         array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 50 ) );
1776                 foreach ( $res as $row ) {
1777                         if ( $row->rev_user != $userId ) {
1778                                 return false;
1779                         }
1780                 }
1781                 return true;
1782         }
1783 }