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 use MediaWiki\Linker\LinkTarget;
  23
  24 /**
  25  * @todo document
  26  */
  27 class Revision implements IDBAccessObject {
  28         /** @var int|null */
  29         protected $mId;
  30         /** @var int|null */
  31         protected $mPage;
  32         /** @var string */
  33         protected $mUserText;
  34         /** @var string */
  35         protected $mOrigUserText;
  36         /** @var int */
  37         protected $mUser;
  38         /** @var bool */
  39         protected $mMinorEdit;
  40         /** @var string */
  41         protected $mTimestamp;
  42         /** @var int */
  43         protected $mDeleted;
  44         /** @var int */
  45         protected $mSize;
  46         /** @var string */
  47         protected $mSha1;
  48         /** @var int */
  49         protected $mParentId;
  50         /** @var string */
  51         protected $mComment;
  52         /** @var string */
  53         protected $mText;
  54         /** @var int */
  55         protected $mTextId;
  56         /** @var int */
  57         protected $mUnpatrolled;
  58
  59         /** @var stdClass|null */
  60         protected $mTextRow;
  61
  62         /**  @var null|Title */
  63         protected $mTitle;
  64         /** @var bool */
  65         protected $mCurrent;
  66         /** @var string */
  67         protected $mContentModel;
  68         /** @var string */
  69         protected $mContentFormat;
  70
  71         /** @var Content|null|bool */
  72         protected $mContent;
  73         /** @var null|ContentHandler */
  74         protected $mContentHandler;
  75
  76         /** @var int */
  77         protected $mQueryFlags = 0;
  78         /** @var bool Used for cached values to reload user text and rev_deleted */
  79         protected $mRefreshMutableFields = false;
  80         /** @var string Wiki ID; false means the current wiki */
  81         protected $mWiki = false;
  82
  83         // Revision deletion constants
  84         const DELETED_TEXT = 1;
  85         const DELETED_COMMENT = 2;
  86         const DELETED_USER = 4;
  87         const DELETED_RESTRICTED = 8;
  88         const SUPPRESSED_USER = 12; // convenience
  89
  90         // Audience options for accessors
  91         const FOR_PUBLIC = 1;
  92         const FOR_THIS_USER = 2;
  93         const RAW = 3;
  94
  95         const TEXT_CACHE_GROUP = 'revisiontext:10'; // process cache name and max key count
  96
  97         /**
  98          * Load a page revision from a given revision ID number.
  99          * Returns null if no such revision can be found.
 100          *
 101          * $flags include:
 102          *      Revision::READ_LATEST  : Select the data from the master
 103          *      Revision::READ_LOCKING : Select & lock the data from the master
 104          *
 105          * @param int $id
 106          * @param int $flags (optional)
 107          * @return Revision|null
 108          */
 109         public static function newFromId( $id, $flags = 0 ) {
 110                 return self::newFromConds( [ 'rev_id' => intval( $id ) ], $flags );
 111         }
 112
 113         /**
 114          * Load either the current, or a specified, revision
 115          * that's attached to a given link target. If not attached
 116          * to that link target, will return null.
 117          *
 118          * $flags include:
 119          *      Revision::READ_LATEST  : Select the data from the master
 120          *      Revision::READ_LOCKING : Select & lock the data from the master
 121          *
 122          * @param LinkTarget $linkTarget
 123          * @param int $id (optional)
 124          * @param int $flags Bitfield (optional)
 125          * @return Revision|null
 126          */
 127         public static function newFromTitle( LinkTarget $linkTarget, $id = 0, $flags = 0 ) {
 128                 $conds = [
 129                         'page_namespace' => $linkTarget->getNamespace(),
 130                         'page_title' => $linkTarget->getDBkey()
 131                 ];
 132                 if ( $id ) {
 133                         // Use the specified ID
 134                         $conds['rev_id'] = $id;
 135                         return self::newFromConds( $conds, $flags );
 136                 } else {
 137                         // Use a join to get the latest revision
 138                         $conds[] = 'rev_id=page_latest';
 139                         $db = wfGetDB( ( $flags & self::READ_LATEST ) ? DB_MASTER : DB_REPLICA );
 140                         return self::loadFromConds( $db, $conds, $flags );
 141                 }
 142         }
 143
 144         /**
 145          * Load either the current, or a specified, revision
 146          * that's attached to a given page ID.
 147          * Returns null if no such revision can be found.
 148          *
 149          * $flags include:
 150          *      Revision::READ_LATEST  : Select the data from the master (since 1.20)
 151          *      Revision::READ_LOCKING : Select & lock the data from the master
 152          *
 153          * @param int $pageId
 154          * @param int $revId (optional)
 155          * @param int $flags Bitfield (optional)
 156          * @return Revision|null
 157          */
 158         public static function newFromPageId( $pageId, $revId = 0, $flags = 0 ) {
 159                 $conds = [ 'page_id' => $pageId ];
 160                 if ( $revId ) {
 161                         $conds['rev_id'] = $revId;
 162                         return self::newFromConds( $conds, $flags );
 163                 } else {
 164                         // Use a join to get the latest revision
 165                         $conds[] = 'rev_id = page_latest';
 166                         $db = wfGetDB( ( $flags & self::READ_LATEST ) ? DB_MASTER : DB_REPLICA );
 167                         return self::loadFromConds( $db, $conds, $flags );
 168                 }
 169         }
 170
 171         /**
 172          * Make a fake revision object from an archive table row. This is queried
 173          * for permissions or even inserted (as in Special:Undelete)
 174          * @todo FIXME: Should be a subclass for RevisionDelete. [TS]
 175          *
 176          * @param object $row
 177          * @param array $overrides
 178          *
 179          * @throws MWException
 180          * @return Revision
 181          */
 182         public static function newFromArchiveRow( $row, $overrides = [] ) {
 183                 global $wgContentHandlerUseDB;
 184
 185                 $attribs = $overrides + [
 186                         'page'       => isset( $row->ar_page_id ) ? $row->ar_page_id : null,
 187                         'id'         => isset( $row->ar_rev_id ) ? $row->ar_rev_id : null,
 188                         'comment'    => $row->ar_comment,
 189                         'user'       => $row->ar_user,
 190                         'user_text'  => $row->ar_user_text,
 191                         'timestamp'  => $row->ar_timestamp,
 192                         'minor_edit' => $row->ar_minor_edit,
 193                         'text_id'    => isset( $row->ar_text_id ) ? $row->ar_text_id : null,
 194                         'deleted'    => $row->ar_deleted,
 195                         'len'        => $row->ar_len,
 196                         'sha1'       => isset( $row->ar_sha1 ) ? $row->ar_sha1 : null,
 197                         'content_model'   => isset( $row->ar_content_model ) ? $row->ar_content_model : null,
 198                         'content_format'  => isset( $row->ar_content_format ) ? $row->ar_content_format : null,
 199                 ];
 200
 201                 if ( !$wgContentHandlerUseDB ) {
 202                         unset( $attribs['content_model'] );
 203                         unset( $attribs['content_format'] );
 204                 }
 205
 206                 if ( !isset( $attribs['title'] )
 207                         && isset( $row->ar_namespace )
 208                         && isset( $row->ar_title )
 209                 ) {
 210                         $attribs['title'] = Title::makeTitle( $row->ar_namespace, $row->ar_title );
 211                 }
 212
 213                 if ( isset( $row->ar_text ) && !$row->ar_text_id ) {
 214                         // Pre-1.5 ar_text row
 215                         $attribs['text'] = self::getRevisionText( $row, 'ar_' );
 216                         if ( $attribs['text'] === false ) {
 217                                 throw new MWException( 'Unable to load text from archive row (possibly bug 22624)' );
 218                         }
 219                 }
 220                 return new self( $attribs );
 221         }
 222
 223         /**
 224          * @since 1.19
 225          *
 226          * @param object $row
 227          * @return Revision
 228          */
 229         public static function newFromRow( $row ) {
 230                 return new self( $row );
 231         }
 232
 233         /**
 234          * Load a page revision from a given revision ID number.
 235          * Returns null if no such revision can be found.
 236          *
 237          * @param IDatabase $db
 238          * @param int $id
 239          * @return Revision|null
 240          */
 241         public static function loadFromId( $db, $id ) {
 242                 return self::loadFromConds( $db, [ 'rev_id' => intval( $id ) ] );
 243         }
 244
 245         /**
 246          * Load either the current, or a specified, revision
 247          * that's attached to a given page. If not attached
 248          * to that page, will return null.
 249          *
 250          * @param IDatabase $db
 251          * @param int $pageid
 252          * @param int $id
 253          * @return Revision|null
 254          */
 255         public static function loadFromPageId( $db, $pageid, $id = 0 ) {
 256                 $conds = [ 'rev_page' => intval( $pageid ), 'page_id' => intval( $pageid ) ];
 257                 if ( $id ) {
 258                         $conds['rev_id'] = intval( $id );
 259                 } else {
 260                         $conds[] = 'rev_id=page_latest';
 261                 }
 262                 return self::loadFromConds( $db, $conds );
 263         }
 264
 265         /**
 266          * Load either the current, or a specified, revision
 267          * that's attached to a given page. If not attached
 268          * to that page, will return null.
 269          *
 270          * @param IDatabase $db
 271          * @param Title $title
 272          * @param int $id
 273          * @return Revision|null
 274          */
 275         public static function loadFromTitle( $db, $title, $id = 0 ) {
 276                 if ( $id ) {
 277                         $matchId = intval( $id );
 278                 } else {
 279                         $matchId = 'page_latest';
 280                 }
 281                 return self::loadFromConds( $db,
 282                         [
 283                                 "rev_id=$matchId",
 284                                 'page_namespace' => $title->getNamespace(),
 285                                 'page_title' => $title->getDBkey()
 286                         ]
 287                 );
 288         }
 289
 290         /**
 291          * Load the revision for the given title with the given timestamp.
 292          * WARNING: Timestamps may in some circumstances not be unique,
 293          * so this isn't the best key to use.
 294          *
 295          * @param IDatabase $db
 296          * @param Title $title
 297          * @param string $timestamp
 298          * @return Revision|null
 299          */
 300         public static function loadFromTimestamp( $db, $title, $timestamp ) {
 301                 return self::loadFromConds( $db,
 302                         [
 303                                 'rev_timestamp' => $db->timestamp( $timestamp ),
 304                                 'page_namespace' => $title->getNamespace(),
 305                                 'page_title' => $title->getDBkey()
 306                         ]
 307                 );
 308         }
 309
 310         /**
 311          * Given a set of conditions, fetch a revision
 312          *
 313          * This method is used then a revision ID is qualified and
 314          * will incorporate some basic replica DB/master fallback logic
 315          *
 316          * @param array $conditions
 317          * @param int $flags (optional)
 318          * @return Revision|null
 319          */
 320         private static function newFromConds( $conditions, $flags = 0 ) {
 321                 $db = wfGetDB( ( $flags & self::READ_LATEST ) ? DB_MASTER : DB_REPLICA );
 322
 323                 $rev = self::loadFromConds( $db, $conditions, $flags );
 324                 // Make sure new pending/committed revision are visibile later on
 325                 // within web requests to certain avoid bugs like T93866 and T94407.
 326                 if ( !$rev
 327                         && !( $flags & self::READ_LATEST )
 328                         && wfGetLB()->getServerCount() > 1
 329                         && wfGetLB()->hasOrMadeRecentMasterChanges()
 330                 ) {
 331                         $flags = self::READ_LATEST;
 332                         $db = wfGetDB( DB_MASTER );
 333                         $rev = self::loadFromConds( $db, $conditions, $flags );
 334                 }
 335
 336                 if ( $rev ) {
 337                         $rev->mQueryFlags = $flags;
 338                 }
 339
 340                 return $rev;
 341         }
 342
 343         /**
 344          * Given a set of conditions, fetch a revision from
 345          * the given database connection.
 346          *
 347          * @param IDatabase $db
 348          * @param array $conditions
 349          * @param int $flags (optional)
 350          * @return Revision|null
 351          */
 352         private static function loadFromConds( $db, $conditions, $flags = 0 ) {
 353                 $row = self::fetchFromConds( $db, $conditions, $flags );
 354                 if ( $row ) {
 355                         $rev = new Revision( $row );
 356                         $rev->mWiki = $db->getWikiID();
 357
 358                         return $rev;
 359                 }
 360
 361                 return null;
 362         }
 363
 364         /**
 365          * Return a wrapper for a series of database rows to
 366          * fetch all of a given page's revisions in turn.
 367          * Each row can be fed to the constructor to get objects.
 368          *
 369          * @param LinkTarget $title
 370          * @return ResultWrapper
 371          * @deprecated Since 1.28
 372          */
 373         public static function fetchRevision( LinkTarget $title ) {
 374                 $row = self::fetchFromConds(
 375                         wfGetDB( DB_REPLICA ),
 376                         [
 377                                 'rev_id=page_latest',
 378                                 'page_namespace' => $title->getNamespace(),
 379                                 'page_title' => $title->getDBkey()
 380                         ]
 381                 );
 382
 383                 return new FakeResultWrapper( $row ? [ $row ] : [] );
 384         }
 385
 386         /**
 387          * Given a set of conditions, return a ResultWrapper
 388          * which will return matching database rows with the
 389          * fields necessary to build Revision objects.
 390          *
 391          * @param IDatabase $db
 392          * @param array $conditions
 393          * @param int $flags (optional)
 394          * @return stdClass
 395          */
 396         private static function fetchFromConds( $db, $conditions, $flags = 0 ) {
 397                 $fields = array_merge(
 398                         self::selectFields(),
 399                         self::selectPageFields(),
 400                         self::selectUserFields()
 401                 );
 402                 $options = [];
 403                 if ( ( $flags & self::READ_LOCKING ) == self::READ_LOCKING ) {
 404                         $options[] = 'FOR UPDATE';
 405                 }
 406                 return $db->selectRow(
 407                         [ 'revision', 'page', 'user' ],
 408                         $fields,
 409                         $conditions,
 410                         __METHOD__,
 411                         $options,
 412                         [ 'page' => self::pageJoinCond(), 'user' => self::userJoinCond() ]
 413                 );
 414         }
 415
 416         /**
 417          * Return the value of a select() JOIN conds array for the user table.
 418          * This will get user table rows for logged-in users.
 419          * @since 1.19
 420          * @return array
 421          */
 422         public static function userJoinCond() {
 423                 return [ 'LEFT JOIN', [ 'rev_user != 0', 'user_id = rev_user' ] ];
 424         }
 425
 426         /**
 427          * Return the value of a select() page conds array for the page table.
 428          * This will assure that the revision(s) are not orphaned from live pages.
 429          * @since 1.19
 430          * @return array
 431          */
 432         public static function pageJoinCond() {
 433                 return [ 'INNER JOIN', [ 'page_id = rev_page' ] ];
 434         }
 435
 436         /**
 437          * Return the list of revision fields that should be selected to create
 438          * a new revision.
 439          * @return array
 440          */
 441         public static function selectFields() {
 442                 global $wgContentHandlerUseDB;
 443
 444                 $fields = [
 445                         'rev_id',
 446                         'rev_page',
 447                         'rev_text_id',
 448                         'rev_timestamp',
 449                         'rev_comment',
 450                         'rev_user_text',
 451                         'rev_user',
 452                         'rev_minor_edit',
 453                         'rev_deleted',
 454                         'rev_len',
 455                         'rev_parent_id',
 456                         'rev_sha1',
 457                 ];
 458
 459                 if ( $wgContentHandlerUseDB ) {
 460                         $fields[] = 'rev_content_format';
 461                         $fields[] = 'rev_content_model';
 462                 }
 463
 464                 return $fields;
 465         }
 466
 467         /**
 468          * Return the list of revision fields that should be selected to create
 469          * a new revision from an archive row.
 470          * @return array
 471          */
 472         public static function selectArchiveFields() {
 473                 global $wgContentHandlerUseDB;
 474                 $fields = [
 475                         'ar_id',
 476                         'ar_page_id',
 477                         'ar_rev_id',
 478                         'ar_text',
 479                         'ar_text_id',
 480                         'ar_timestamp',
 481                         'ar_comment',
 482                         'ar_user_text',
 483                         'ar_user',
 484                         'ar_minor_edit',
 485                         'ar_deleted',
 486                         'ar_len',
 487                         'ar_parent_id',
 488                         'ar_sha1',
 489                 ];
 490
 491                 if ( $wgContentHandlerUseDB ) {
 492                         $fields[] = 'ar_content_format';
 493                         $fields[] = 'ar_content_model';
 494                 }
 495                 return $fields;
 496         }
 497
 498         /**
 499          * Return the list of text fields that should be selected to read the
 500          * revision text
 501          * @return array
 502          */
 503         public static function selectTextFields() {
 504                 return [
 505                         'old_text',
 506                         'old_flags'
 507                 ];
 508         }
 509
 510         /**
 511          * Return the list of page fields that should be selected from page table
 512          * @return array
 513          */
 514         public static function selectPageFields() {
 515                 return [
 516                         'page_namespace',
 517                         'page_title',
 518                         'page_id',
 519                         'page_latest',
 520                         'page_is_redirect',
 521                         'page_len',
 522                 ];
 523         }
 524
 525         /**
 526          * Return the list of user fields that should be selected from user table
 527          * @return array
 528          */
 529         public static function selectUserFields() {
 530                 return [ 'user_name' ];
 531         }
 532
 533         /**
 534          * Do a batched query to get the parent revision lengths
 535          * @param IDatabase $db
 536          * @param array $revIds
 537          * @return array
 538          */
 539         public static function getParentLengths( $db, array $revIds ) {
 540                 $revLens = [];
 541                 if ( !$revIds ) {
 542                         return $revLens; // empty
 543                 }
 544                 $res = $db->select( 'revision',
 545                         [ 'rev_id', 'rev_len' ],
 546                         [ 'rev_id' => $revIds ],
 547                         __METHOD__ );
 548                 foreach ( $res as $row ) {
 549                         $revLens[$row->rev_id] = $row->rev_len;
 550                 }
 551                 return $revLens;
 552         }
 553
 554         /**
 555          * Constructor
 556          *
 557          * @param object|array $row Either a database row or an array
 558          * @throws MWException
 559          * @access private
 560          */
 561         function __construct( $row ) {
 562                 if ( is_object( $row ) ) {
 563                         $this->mId = intval( $row->rev_id );
 564                         $this->mPage = intval( $row->rev_page );
 565                         $this->mTextId = intval( $row->rev_text_id );
 566                         $this->mComment = $row->rev_comment;
 567                         $this->mUser = intval( $row->rev_user );
 568                         $this->mMinorEdit = intval( $row->rev_minor_edit );
 569                         $this->mTimestamp = $row->rev_timestamp;
 570                         $this->mDeleted = intval( $row->rev_deleted );
 571
 572                         if ( !isset( $row->rev_parent_id ) ) {
 573                                 $this->mParentId = null;
 574                         } else {
 575                                 $this->mParentId = intval( $row->rev_parent_id );
 576                         }
 577
 578                         if ( !isset( $row->rev_len ) ) {
 579                                 $this->mSize = null;
 580                         } else {
 581                                 $this->mSize = intval( $row->rev_len );
 582                         }
 583
 584                         if ( !isset( $row->rev_sha1 ) ) {
 585                                 $this->mSha1 = null;
 586                         } else {
 587                                 $this->mSha1 = $row->rev_sha1;
 588                         }
 589
 590                         if ( isset( $row->page_latest ) ) {
 591                                 $this->mCurrent = ( $row->rev_id == $row->page_latest );
 592                                 $this->mTitle = Title::newFromRow( $row );
 593                         } else {
 594                                 $this->mCurrent = false;
 595                                 $this->mTitle = null;
 596                         }
 597
 598                         if ( !isset( $row->rev_content_model ) ) {
 599                                 $this->mContentModel = null; # determine on demand if needed
 600                         } else {
 601                                 $this->mContentModel = strval( $row->rev_content_model );
 602                         }
 603
 604                         if ( !isset( $row->rev_content_format ) ) {
 605                                 $this->mContentFormat = null; # determine on demand if needed
 606                         } else {
 607                                 $this->mContentFormat = strval( $row->rev_content_format );
 608                         }
 609
 610                         // Lazy extraction...
 611                         $this->mText = null;
 612                         if ( isset( $row->old_text ) ) {
 613                                 $this->mTextRow = $row;
 614                         } else {
 615                                 // 'text' table row entry will be lazy-loaded
 616                                 $this->mTextRow = null;
 617                         }
 618
 619                         // Use user_name for users and rev_user_text for IPs...
 620                         $this->mUserText = null; // lazy load if left null
 621                         if ( $this->mUser == 0 ) {
 622                                 $this->mUserText = $row->rev_user_text; // IP user
 623                         } elseif ( isset( $row->user_name ) ) {
 624                                 $this->mUserText = $row->user_name; // logged-in user
 625                         }
 626                         $this->mOrigUserText = $row->rev_user_text;
 627                 } elseif ( is_array( $row ) ) {
 628                         // Build a new revision to be saved...
 629                         global $wgUser; // ugh
 630
 631                         # if we have a content object, use it to set the model and type
 632                         if ( !empty( $row['content'] ) ) {
 633                                 // @todo when is that set? test with external store setup! check out insertOn() [dk]
 634                                 if ( !empty( $row['text_id'] ) ) {
 635                                         throw new MWException( "Text already stored in external store (id {$row['text_id']}), " .
 636                                                 "can't serialize content object" );
 637                                 }
 638
 639                                 $row['content_model'] = $row['content']->getModel();
 640                                 # note: mContentFormat is initializes later accordingly
 641                                 # note: content is serialized later in this method!
 642                                 # also set text to null?
 643                         }
 644
 645                         $this->mId = isset( $row['id'] ) ? intval( $row['id'] ) : null;
 646                         $this->mPage = isset( $row['page'] ) ? intval( $row['page'] ) : null;
 647                         $this->mTextId = isset( $row['text_id'] ) ? intval( $row['text_id'] ) : null;
 648                         $this->mUserText = isset( $row['user_text'] )
 649                                 ? strval( $row['user_text'] ) : $wgUser->getName();
 650                         $this->mUser = isset( $row['user'] ) ? intval( $row['user'] ) : $wgUser->getId();
 651                         $this->mMinorEdit = isset( $row['minor_edit'] ) ? intval( $row['minor_edit'] ) : 0;
 652                         $this->mTimestamp = isset( $row['timestamp'] )
 653                                 ? strval( $row['timestamp'] ) : wfTimestampNow();
 654                         $this->mDeleted = isset( $row['deleted'] ) ? intval( $row['deleted'] ) : 0;
 655                         $this->mSize = isset( $row['len'] ) ? intval( $row['len'] ) : null;
 656                         $this->mParentId = isset( $row['parent_id'] ) ? intval( $row['parent_id'] ) : null;
 657                         $this->mSha1 = isset( $row['sha1'] ) ? strval( $row['sha1'] ) : null;
 658
 659                         $this->mContentModel = isset( $row['content_model'] )
 660                                 ? strval( $row['content_model'] ) : null;
 661                         $this->mContentFormat = isset( $row['content_format'] )
 662                                 ? strval( $row['content_format'] ) : null;
 663
 664                         // Enforce spacing trimming on supplied text
 665                         $this->mComment = isset( $row['comment'] ) ? trim( strval( $row['comment'] ) ) : null;
 666                         $this->mText = isset( $row['text'] ) ? rtrim( strval( $row['text'] ) ) : null;
 667                         $this->mTextRow = null;
 668
 669                         $this->mTitle = isset( $row['title'] ) ? $row['title'] : null;
 670
 671                         // if we have a Content object, override mText and mContentModel
 672                         if ( !empty( $row['content'] ) ) {
 673                                 if ( !( $row['content'] instanceof Content ) ) {
 674                                         throw new MWException( '`content` field must contain a Content object.' );
 675                                 }
 676
 677                                 $handler = $this->getContentHandler();
 678                                 $this->mContent = $row['content'];
 679
 680                                 $this->mContentModel = $this->mContent->getModel();
 681                                 $this->mContentHandler = null;
 682
 683                                 $this->mText = $handler->serializeContent( $row['content'], $this->getContentFormat() );
 684                         } elseif ( $this->mText !== null ) {
 685                                 $handler = $this->getContentHandler();
 686                                 $this->mContent = $handler->unserializeContent( $this->mText );
 687                         }
 688
 689                         // If we have a Title object, make sure it is consistent with mPage.
 690                         if ( $this->mTitle && $this->mTitle->exists() ) {
 691                                 if ( $this->mPage === null ) {
 692                                         // if the page ID wasn't known, set it now
 693                                         $this->mPage = $this->mTitle->getArticleID();
 694                                 } elseif ( $this->mTitle->getArticleID() !== $this->mPage ) {
 695                                         // Got different page IDs. This may be legit (e.g. during undeletion),
 696                                         // but it seems worth mentioning it in the log.
 697                                         wfDebug( "Page ID " . $this->mPage . " mismatches the ID " .
 698                                                 $this->mTitle->getArticleID() . " provided by the Title object." );
 699                                 }
 700                         }
 701
 702                         $this->mCurrent = false;
 703
 704                         // If we still have no length, see it we have the text to figure it out
 705                         if ( !$this->mSize && $this->mContent !== null ) {
 706                                 $this->mSize = $this->mContent->getSize();
 707                         }
 708
 709                         // Same for sha1
 710                         if ( $this->mSha1 === null ) {
 711                                 $this->mSha1 = $this->mText === null ? null : self::base36Sha1( $this->mText );
 712                         }
 713
 714                         // force lazy init
 715                         $this->getContentModel();
 716                         $this->getContentFormat();
 717                 } else {
 718                         throw new MWException( 'Revision constructor passed invalid row format.' );
 719                 }
 720                 $this->mUnpatrolled = null;
 721         }
 722
 723         /**
 724          * Get revision ID
 725          *
 726          * @return int|null
 727          */
 728         public function getId() {
 729                 return $this->mId;
 730         }
 731
 732         /**
 733          * Set the revision ID
 734          *
 735          * This should only be used for proposed revisions that turn out to be null edits
 736          *
 737          * @since 1.19
 738          * @param int $id
 739          */
 740         public function setId( $id ) {
 741                 $this->mId = (int)$id;
 742         }
 743
 744         /**
 745          * Set the user ID/name
 746          *
 747          * This should only be used for proposed revisions that turn out to be null edits
 748          *
 749          * @since 1.28
 750          * @param integer $id User ID
 751          * @param string $name User name
 752          */
 753         public function setUserIdAndName( $id, $name ) {
 754                 $this->mUser = (int)$id;
 755                 $this->mUserText = $name;
 756                 $this->mOrigUserText = $name;
 757         }
 758
 759         /**
 760          * Get text row ID
 761          *
 762          * @return int|null
 763          */
 764         public function getTextId() {
 765                 return $this->mTextId;
 766         }
 767
 768         /**
 769          * Get parent revision ID (the original previous page revision)
 770          *
 771          * @return int|null
 772          */
 773         public function getParentId() {
 774                 return $this->mParentId;
 775         }
 776
 777         /**
 778          * Returns the length of the text in this revision, or null if unknown.
 779          *
 780          * @return int|null
 781          */
 782         public function getSize() {
 783                 return $this->mSize;
 784         }
 785
 786         /**
 787          * Returns the base36 sha1 of the text in this revision, or null if unknown.
 788          *
 789          * @return string|null
 790          */
 791         public function getSha1() {
 792                 return $this->mSha1;
 793         }
 794
 795         /**
 796          * Returns the title of the page associated with this entry or null.
 797          *
 798          * Will do a query, when title is not set and id is given.
 799          *
 800          * @return Title|null
 801          */
 802         public function getTitle() {
 803                 if ( $this->mTitle !== null ) {
 804                         return $this->mTitle;
 805                 }
 806                 // rev_id is defined as NOT NULL, but this revision may not yet have been inserted.
 807                 if ( $this->mId !== null ) {
 808                         $dbr = wfGetLB( $this->mWiki )->getConnectionRef( DB_REPLICA, [], $this->mWiki );
 809                         $row = $dbr->selectRow(
 810                                 [ 'page', 'revision' ],
 811                                 self::selectPageFields(),
 812                                 [ 'page_id=rev_page', 'rev_id' => $this->mId ],
 813                                 __METHOD__
 814                         );
 815                         if ( $row ) {
 816                                 // @TODO: better foreign title handling
 817                                 $this->mTitle = Title::newFromRow( $row );
 818                         }
 819                 }
 820
 821                 if ( $this->mWiki === false || $this->mWiki === wfWikiID() ) {
 822                         // Loading by ID is best, though not possible for foreign titles
 823                         if ( !$this->mTitle && $this->mPage !== null && $this->mPage > 0 ) {
 824                                 $this->mTitle = Title::newFromID( $this->mPage );
 825                         }
 826                 }
 827
 828                 return $this->mTitle;
 829         }
 830
 831         /**
 832          * Set the title of the revision
 833          *
 834          * @param Title $title
 835          */
 836         public function setTitle( $title ) {
 837                 $this->mTitle = $title;
 838         }
 839
 840         /**
 841          * Get the page ID
 842          *
 843          * @return int|null
 844          */
 845         public function getPage() {
 846                 return $this->mPage;
 847         }
 848
 849         /**
 850          * Fetch revision's user id if it's available to the specified audience.
 851          * If the specified audience does not have access to it, zero will be
 852          * returned.
 853          *
 854          * @param int $audience One of:
 855          *   Revision::FOR_PUBLIC       to be displayed to all users
 856          *   Revision::FOR_THIS_USER    to be displayed to the given user
 857          *   Revision::RAW              get the ID regardless of permissions
 858          * @param User $user User object to check for, only if FOR_THIS_USER is passed
 859          *   to the $audience parameter
 860          * @return int
 861          */
 862         public function getUser( $audience = self::FOR_PUBLIC, User $user = null ) {
 863                 if ( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_USER ) ) {
 864                         return 0;
 865                 } elseif ( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_USER, $user ) ) {
 866                         return 0;
 867                 } else {
 868                         return $this->mUser;
 869                 }
 870         }
 871
 872         /**
 873          * Fetch revision's user id without regard for the current user's permissions
 874          *
 875          * @return string
 876          * @deprecated since 1.25, use getUser( Revision::RAW )
 877          */
 878         public function getRawUser() {
 879                 wfDeprecated( __METHOD__, '1.25' );
 880                 return $this->getUser( self::RAW );
 881         }
 882
 883         /**
 884          * Fetch revision's username if it's available to the specified audience.
 885          * If the specified audience does not have access to the username, an
 886          * empty string will be returned.
 887          *
 888          * @param int $audience One of:
 889          *   Revision::FOR_PUBLIC       to be displayed to all users
 890          *   Revision::FOR_THIS_USER    to be displayed to the given user
 891          *   Revision::RAW              get the text regardless of permissions
 892          * @param User $user User object to check for, only if FOR_THIS_USER is passed
 893          *   to the $audience parameter
 894          * @return string
 895          */
 896         public function getUserText( $audience = self::FOR_PUBLIC, User $user = null ) {
 897                 $this->loadMutableFields();
 898
 899                 if ( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_USER ) ) {
 900                         return '';
 901                 } elseif ( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_USER, $user ) ) {
 902                         return '';
 903                 } else {
 904                         if ( $this->mUserText === null ) {
 905                                 $this->mUserText = User::whoIs( $this->mUser ); // load on demand
 906                                 if ( $this->mUserText === false ) {
 907                                         # This shouldn't happen, but it can if the wiki was recovered
 908                                         # via importing revs and there is no user table entry yet.
 909                                         $this->mUserText = $this->mOrigUserText;
 910                                 }
 911                         }
 912                         return $this->mUserText;
 913                 }
 914         }
 915
 916         /**
 917          * Fetch revision's username without regard for view restrictions
 918          *
 919          * @return string
 920          * @deprecated since 1.25, use getUserText( Revision::RAW )
 921          */
 922         public function getRawUserText() {
 923                 wfDeprecated( __METHOD__, '1.25' );
 924                 return $this->getUserText( self::RAW );
 925         }
 926
 927         /**
 928          * Fetch revision comment if it's available to the specified audience.
 929          * If the specified audience does not have access to the comment, an
 930          * empty string will be returned.
 931          *
 932          * @param int $audience One of:
 933          *   Revision::FOR_PUBLIC       to be displayed to all users
 934          *   Revision::FOR_THIS_USER    to be displayed to the given user
 935          *   Revision::RAW              get the text regardless of permissions
 936          * @param User $user User object to check for, only if FOR_THIS_USER is passed
 937          *   to the $audience parameter
 938          * @return string
 939          */
 940         function getComment( $audience = self::FOR_PUBLIC, User $user = null ) {
 941                 if ( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_COMMENT ) ) {
 942                         return '';
 943                 } elseif ( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_COMMENT, $user ) ) {
 944                         return '';
 945                 } else {
 946                         return $this->mComment;
 947                 }
 948         }
 949
 950         /**
 951          * Fetch revision comment without regard for the current user's permissions
 952          *
 953          * @return string
 954          * @deprecated since 1.25, use getComment( Revision::RAW )
 955          */
 956         public function getRawComment() {
 957                 wfDeprecated( __METHOD__, '1.25' );
 958                 return $this->getComment( self::RAW );
 959         }
 960
 961         /**
 962          * @return bool
 963          */
 964         public function isMinor() {
 965                 return (bool)$this->mMinorEdit;
 966         }
 967
 968         /**
 969          * @return int Rcid of the unpatrolled row, zero if there isn't one
 970          */
 971         public function isUnpatrolled() {
 972                 if ( $this->mUnpatrolled !== null ) {
 973                         return $this->mUnpatrolled;
 974                 }
 975                 $rc = $this->getRecentChange();
 976                 if ( $rc && $rc->getAttribute( 'rc_patrolled' ) == 0 ) {
 977                         $this->mUnpatrolled = $rc->getAttribute( 'rc_id' );
 978                 } else {
 979                         $this->mUnpatrolled = 0;
 980                 }
 981                 return $this->mUnpatrolled;
 982         }
 983
 984         /**
 985          * Get the RC object belonging to the current revision, if there's one
 986          *
 987          * @param int $flags (optional) $flags include:
 988          *      Revision::READ_LATEST  : Select the data from the master
 989          *
 990          * @since 1.22
 991          * @return RecentChange|null
 992          */
 993         public function getRecentChange( $flags = 0 ) {
 994                 $dbr = wfGetDB( DB_REPLICA );
 995
 996                 list( $dbType, ) = DBAccessObjectUtils::getDBOptions( $flags );
 997
 998                 return RecentChange::newFromConds(
 999                         [
1000                                 'rc_user_text' => $this->getUserText( Revision::RAW ),
1001                                 'rc_timestamp' => $dbr->timestamp( $this->getTimestamp() ),
1002                                 'rc_this_oldid' => $this->getId()
1003                         ],
1004                         __METHOD__,
1005                         $dbType
1006                 );
1007         }
1008
1009         /**
1010          * @param int $field One of DELETED_* bitfield constants
1011          *
1012          * @return bool
1013          */
1014         public function isDeleted( $field ) {
1015                 if ( $this->isCurrent() && $field === self::DELETED_TEXT ) {
1016                         // Current revisions of pages cannot have the content hidden. Skipping this
1017                         // check is very useful for Parser as it fetches templates using newKnownCurrent().
1018                         // Calling getVisibility() in that case triggers a verification database query.
1019                         return false; // no need to check
1020                 }
1021
1022                 return ( $this->getVisibility() & $field ) == $field;
1023         }
1024
1025         /**
1026          * Get the deletion bitfield of the revision
1027          *
1028          * @return int
1029          */
1030         public function getVisibility() {
1031                 $this->loadMutableFields();
1032
1033                 return (int)$this->mDeleted;
1034         }
1035
1036         /**
1037          * Fetch revision text if it's available to the specified audience.
1038          * If the specified audience does not have the ability to view this
1039          * revision, an empty string will be returned.
1040          *
1041          * @param int $audience One of:
1042          *   Revision::FOR_PUBLIC       to be displayed to all users
1043          *   Revision::FOR_THIS_USER    to be displayed to the given user
1044          *   Revision::RAW              get the text regardless of permissions
1045          * @param User $user User object to check for, only if FOR_THIS_USER is passed
1046          *   to the $audience parameter
1047          *
1048          * @deprecated since 1.21, use getContent() instead
1049          * @todo Replace usage in core
1050          * @return string
1051          */
1052         public function getText( $audience = self::FOR_PUBLIC, User $user = null ) {
1053                 ContentHandler::deprecated( __METHOD__, '1.21' );
1054
1055                 $content = $this->getContent( $audience, $user );
1056                 return ContentHandler::getContentText( $content ); # returns the raw content text, if applicable
1057         }
1058
1059         /**
1060          * Fetch revision content if it's available to the specified audience.
1061          * If the specified audience does not have the ability to view this
1062          * revision, null will be returned.
1063          *
1064          * @param int $audience One of:
1065          *   Revision::FOR_PUBLIC       to be displayed to all users
1066          *   Revision::FOR_THIS_USER    to be displayed to $wgUser
1067          *   Revision::RAW              get the text regardless of permissions
1068          * @param User $user User object to check for, only if FOR_THIS_USER is passed
1069          *   to the $audience parameter
1070          * @since 1.21
1071          * @return Content|null
1072          */
1073         public function getContent( $audience = self::FOR_PUBLIC, User $user = null ) {
1074                 if ( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_TEXT ) ) {
1075                         return null;
1076                 } elseif ( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_TEXT, $user ) ) {
1077                         return null;
1078                 } else {
1079                         return $this->getContentInternal();
1080                 }
1081         }
1082
1083         /**
1084          * Get original serialized data (without checking view restrictions)
1085          *
1086          * @since 1.21
1087          * @return string
1088          */
1089         public function getSerializedData() {
1090                 if ( $this->mText === null ) {
1091                         // Revision is immutable. Load on demand.
1092                         $this->mText = $this->loadText();
1093                 }
1094
1095                 return $this->mText;
1096         }
1097
1098         /**
1099          * Gets the content object for the revision (or null on failure).
1100          *
1101          * Note that for mutable Content objects, each call to this method will return a
1102          * fresh clone.
1103          *
1104          * @since 1.21
1105          * @return Content|null The Revision's content, or null on failure.
1106          */
1107         protected function getContentInternal() {
1108                 if ( $this->mContent === null ) {
1109                         $text = $this->getSerializedData();
1110
1111                         if ( $text !== null && $text !== false ) {
1112                                 // Unserialize content
1113                                 $handler = $this->getContentHandler();
1114                                 $format = $this->getContentFormat();
1115
1116                                 $this->mContent = $handler->unserializeContent( $text, $format );
1117                         }
1118                 }
1119
1120                 // NOTE: copy() will return $this for immutable content objects
1121                 return $this->mContent ? $this->mContent->copy() : null;
1122         }
1123
1124         /**
1125          * Returns the content model for this revision.
1126          *
1127          * If no content model was stored in the database, the default content model for the title is
1128          * used to determine the content model to use. If no title is know, CONTENT_MODEL_WIKITEXT
1129          * is used as a last resort.
1130          *
1131          * @return string The content model id associated with this revision,
1132          *     see the CONTENT_MODEL_XXX constants.
1133          **/
1134         public function getContentModel() {
1135                 if ( !$this->mContentModel ) {
1136                         $title = $this->getTitle();
1137                         if ( $title ) {
1138                                 $this->mContentModel = ContentHandler::getDefaultModelFor( $title );
1139                         } else {
1140                                 $this->mContentModel = CONTENT_MODEL_WIKITEXT;
1141                         }
1142
1143                         assert( !empty( $this->mContentModel ) );
1144                 }
1145
1146                 return $this->mContentModel;
1147         }
1148
1149         /**
1150          * Returns the content format for this revision.
1151          *
1152          * If no content format was stored in the database, the default format for this
1153          * revision's content model is returned.
1154          *
1155          * @return string The content format id associated with this revision,
1156          *     see the CONTENT_FORMAT_XXX constants.
1157          **/
1158         public function getContentFormat() {
1159                 if ( !$this->mContentFormat ) {
1160                         $handler = $this->getContentHandler();
1161                         $this->mContentFormat = $handler->getDefaultFormat();
1162
1163                         assert( !empty( $this->mContentFormat ) );
1164                 }
1165
1166                 return $this->mContentFormat;
1167         }
1168
1169         /**
1170          * Returns the content handler appropriate for this revision's content model.
1171          *
1172          * @throws MWException
1173          * @return ContentHandler
1174          */
1175         public function getContentHandler() {
1176                 if ( !$this->mContentHandler ) {
1177                         $model = $this->getContentModel();
1178                         $this->mContentHandler = ContentHandler::getForModelID( $model );
1179
1180                         $format = $this->getContentFormat();
1181
1182                         if ( !$this->mContentHandler->isSupportedFormat( $format ) ) {
1183                                 throw new MWException( "Oops, the content format $format is not supported for "
1184                                         . "this content model, $model" );
1185                         }
1186                 }
1187
1188                 return $this->mContentHandler;
1189         }
1190
1191         /**
1192          * @return string
1193          */
1194         public function getTimestamp() {
1195                 return wfTimestamp( TS_MW, $this->mTimestamp );
1196         }
1197
1198         /**
1199          * @return bool
1200          */
1201         public function isCurrent() {
1202                 return $this->mCurrent;
1203         }
1204
1205         /**
1206          * Get previous revision for this title
1207          *
1208          * @return Revision|null
1209          */
1210         public function getPrevious() {
1211                 if ( $this->getTitle() ) {
1212                         $prev = $this->getTitle()->getPreviousRevisionID( $this->getId() );
1213                         if ( $prev ) {
1214                                 return self::newFromTitle( $this->getTitle(), $prev );
1215                         }
1216                 }
1217                 return null;
1218         }
1219
1220         /**
1221          * Get next revision for this title
1222          *
1223          * @return Revision|null
1224          */
1225         public function getNext() {
1226                 if ( $this->getTitle() ) {
1227                         $next = $this->getTitle()->getNextRevisionID( $this->getId() );
1228                         if ( $next ) {
1229                                 return self::newFromTitle( $this->getTitle(), $next );
1230                         }
1231                 }
1232                 return null;
1233         }
1234
1235         /**
1236          * Get previous revision Id for this page_id
1237          * This is used to populate rev_parent_id on save
1238          *
1239          * @param IDatabase $db
1240          * @return int
1241          */
1242         private function getPreviousRevisionId( $db ) {
1243                 if ( $this->mPage === null ) {
1244                         return 0;
1245                 }
1246                 # Use page_latest if ID is not given
1247                 if ( !$this->mId ) {
1248                         $prevId = $db->selectField( 'page', 'page_latest',
1249                                 [ 'page_id' => $this->mPage ],
1250                                 __METHOD__ );
1251                 } else {
1252                         $prevId = $db->selectField( 'revision', 'rev_id',
1253                                 [ 'rev_page' => $this->mPage, 'rev_id < ' . $this->mId ],
1254                                 __METHOD__,
1255                                 [ 'ORDER BY' => 'rev_id DESC' ] );
1256                 }
1257                 return intval( $prevId );
1258         }
1259
1260         /**
1261          * Get revision text associated with an old or archive row
1262          * $row is usually an object from wfFetchRow(), both the flags and the text
1263          * field must be included.
1264          *
1265          * @param stdClass $row The text data
1266          * @param string $prefix Table prefix (default 'old_')
1267          * @param string|bool $wiki The name of the wiki to load the revision text from
1268          *   (same as the the wiki $row was loaded from) or false to indicate the local
1269          *   wiki (this is the default). Otherwise, it must be a symbolic wiki database
1270          *   identifier as understood by the LoadBalancer class.
1271          * @return string Text the text requested or false on failure
1272          */
1273         public static function getRevisionText( $row, $prefix = 'old_', $wiki = false ) {
1274
1275                 # Get data
1276                 $textField = $prefix . 'text';
1277                 $flagsField = $prefix . 'flags';
1278
1279                 if ( isset( $row->$flagsField ) ) {
1280                         $flags = explode( ',', $row->$flagsField );
1281                 } else {
1282                         $flags = [];
1283                 }
1284
1285                 if ( isset( $row->$textField ) ) {
1286                         $text = $row->$textField;
1287                 } else {
1288                         return false;
1289                 }
1290
1291                 # Use external methods for external objects, text in table is URL-only then
1292                 if ( in_array( 'external', $flags ) ) {
1293                         $url = $text;
1294                         $parts = explode( '://', $url, 2 );
1295                         if ( count( $parts ) == 1 || $parts[1] == '' ) {
1296                                 return false;
1297                         }
1298                         $text = ExternalStore::fetchFromURL( $url, [ 'wiki' => $wiki ] );
1299                 }
1300
1301                 // If the text was fetched without an error, convert it
1302                 if ( $text !== false ) {
1303                         $text = self::decompressRevisionText( $text, $flags );
1304                 }
1305                 return $text;
1306         }
1307
1308         /**
1309          * If $wgCompressRevisions is enabled, we will compress data.
1310          * The input string is modified in place.
1311          * Return value is the flags field: contains 'gzip' if the
1312          * data is compressed, and 'utf-8' if we're saving in UTF-8
1313          * mode.
1314          *
1315          * @param mixed $text Reference to a text
1316          * @return string
1317          */
1318         public static function compressRevisionText( &$text ) {
1319                 global $wgCompressRevisions;
1320                 $flags = [];
1321
1322                 # Revisions not marked this way will be converted
1323                 # on load if $wgLegacyCharset is set in the future.
1324                 $flags[] = 'utf-8';
1325
1326                 if ( $wgCompressRevisions ) {
1327                         if ( function_exists( 'gzdeflate' ) ) {
1328                                 $deflated = gzdeflate( $text );
1329
1330                                 if ( $deflated === false ) {
1331                                         wfLogWarning( __METHOD__ . ': gzdeflate() failed' );
1332                                 } else {
1333                                         $text = $deflated;
1334                                         $flags[] = 'gzip';
1335                                 }
1336                         } else {
1337                                 wfDebug( __METHOD__ . " -- no zlib support, not compressing\n" );
1338                         }
1339                 }
1340                 return implode( ',', $flags );
1341         }
1342
1343         /**
1344          * Re-converts revision text according to it's flags.
1345          *
1346          * @param mixed $text Reference to a text
1347          * @param array $flags Compression flags
1348          * @return string|bool Decompressed text, or false on failure
1349          */
1350         public static function decompressRevisionText( $text, $flags ) {
1351                 if ( in_array( 'gzip', $flags ) ) {
1352                         # Deal with optional compression of archived pages.
1353                         # This can be done periodically via maintenance/compressOld.php, and
1354                         # as pages are saved if $wgCompressRevisions is set.
1355                         $text = gzinflate( $text );
1356
1357                         if ( $text === false ) {
1358                                 wfLogWarning( __METHOD__ . ': gzinflate() failed' );
1359                                 return false;
1360                         }
1361                 }
1362
1363                 if ( in_array( 'object', $flags ) ) {
1364                         # Generic compressed storage
1365                         $obj = unserialize( $text );
1366                         if ( !is_object( $obj ) ) {
1367                                 // Invalid object
1368                                 return false;
1369                         }
1370                         $text = $obj->getText();
1371                 }
1372
1373                 global $wgLegacyEncoding;
1374                 if ( $text !== false && $wgLegacyEncoding
1375                         && !in_array( 'utf-8', $flags ) && !in_array( 'utf8', $flags )
1376                 ) {
1377                         # Old revisions kept around in a legacy encoding?
1378                         # Upconvert on demand.
1379                         # ("utf8" checked for compatibility with some broken
1380                         #  conversion scripts 2008-12-30)
1381                         global $wgContLang;
1382                         $text = $wgContLang->iconv( $wgLegacyEncoding, 'UTF-8', $text );
1383                 }
1384
1385                 return $text;
1386         }
1387
1388         /**
1389          * Insert a new revision into the database, returning the new revision ID
1390          * number on success and dies horribly on failure.
1391          *
1392          * @param IDatabase $dbw (master connection)
1393          * @throws MWException
1394          * @return int
1395          */
1396         public function insertOn( $dbw ) {
1397                 global $wgDefaultExternalStore, $wgContentHandlerUseDB;
1398
1399                 // Not allowed to have rev_page equal to 0, false, etc.
1400                 if ( !$this->mPage ) {
1401                         $title = $this->getTitle();
1402                         if ( $title instanceof Title ) {
1403                                 $titleText = ' for page ' . $title->getPrefixedText();
1404                         } else {
1405                                 $titleText = '';
1406                         }
1407                         throw new MWException( "Cannot insert revision$titleText: page ID must be nonzero" );
1408                 }
1409
1410                 $this->checkContentModel();
1411
1412                 $data = $this->mText;
1413                 $flags = self::compressRevisionText( $data );
1414
1415                 # Write to external storage if required
1416                 if ( $wgDefaultExternalStore ) {
1417                         // Store and get the URL
1418                         $data = ExternalStore::insertToDefault( $data );
1419                         if ( !$data ) {
1420                                 throw new MWException( "Unable to store text to external storage" );
1421                         }
1422                         if ( $flags ) {
1423                                 $flags .= ',';
1424                         }
1425                         $flags .= 'external';
1426                 }
1427
1428                 # Record the text (or external storage URL) to the text table
1429                 if ( $this->mTextId === null ) {
1430                         $old_id = $dbw->nextSequenceValue( 'text_old_id_seq' );
1431                         $dbw->insert( 'text',
1432                                 [
1433                                         'old_id' => $old_id,
1434                                         'old_text' => $data,
1435                                         'old_flags' => $flags,
1436                                 ], __METHOD__
1437                         );
1438                         $this->mTextId = $dbw->insertId();
1439                 }
1440
1441                 if ( $this->mComment === null ) {
1442                         $this->mComment = "";
1443                 }
1444
1445                 # Record the edit in revisions
1446                 $rev_id = $this->mId !== null
1447                         ? $this->mId
1448                         : $dbw->nextSequenceValue( 'revision_rev_id_seq' );
1449                 $row = [
1450                         'rev_id'         => $rev_id,
1451                         'rev_page'       => $this->mPage,
1452                         'rev_text_id'    => $this->mTextId,
1453                         'rev_comment'    => $this->mComment,
1454                         'rev_minor_edit' => $this->mMinorEdit ? 1 : 0,
1455                         'rev_user'       => $this->mUser,
1456                         'rev_user_text'  => $this->mUserText,
1457                         'rev_timestamp'  => $dbw->timestamp( $this->mTimestamp ),
1458                         'rev_deleted'    => $this->mDeleted,
1459                         'rev_len'        => $this->mSize,
1460                         'rev_parent_id'  => $this->mParentId === null
1461                                 ? $this->getPreviousRevisionId( $dbw )
1462                                 : $this->mParentId,
1463                         'rev_sha1'       => $this->mSha1 === null
1464                                 ? Revision::base36Sha1( $this->mText )
1465                                 : $this->mSha1,
1466                 ];
1467
1468                 if ( $wgContentHandlerUseDB ) {
1469                         // NOTE: Store null for the default model and format, to save space.
1470                         // XXX: Makes the DB sensitive to changed defaults.
1471                         // Make this behavior optional? Only in miser mode?
1472
1473                         $model = $this->getContentModel();
1474                         $format = $this->getContentFormat();
1475
1476                         $title = $this->getTitle();
1477
1478                         if ( $title === null ) {
1479                                 throw new MWException( "Insufficient information to determine the title of the "
1480                                         . "revision's page!" );
1481                         }
1482
1483                         $defaultModel = ContentHandler::getDefaultModelFor( $title );
1484                         $defaultFormat = ContentHandler::getForModelID( $defaultModel )->getDefaultFormat();
1485
1486                         $row['rev_content_model'] = ( $model === $defaultModel ) ? null : $model;
1487                         $row['rev_content_format'] = ( $format === $defaultFormat ) ? null : $format;
1488                 }
1489
1490                 $dbw->insert( 'revision', $row, __METHOD__ );
1491
1492                 $this->mId = $rev_id !== null ? $rev_id : $dbw->insertId();
1493
1494                 // Assertion to try to catch T92046
1495                 if ( (int)$this->mId === 0 ) {
1496                         throw new UnexpectedValueException(
1497                                 'After insert, Revision mId is ' . var_export( $this->mId, 1 ) . ': ' .
1498                                         var_export( $row, 1 )
1499                         );
1500                 }
1501
1502                 Hooks::run( 'RevisionInsertComplete', [ &$this, $data, $flags ] );
1503
1504                 return $this->mId;
1505         }
1506
1507         protected function checkContentModel() {
1508                 global $wgContentHandlerUseDB;
1509
1510                 // Note: may return null for revisions that have not yet been inserted
1511                 $title = $this->getTitle();
1512
1513                 $model = $this->getContentModel();
1514                 $format = $this->getContentFormat();
1515                 $handler = $this->getContentHandler();
1516
1517                 if ( !$handler->isSupportedFormat( $format ) ) {
1518                         $t = $title->getPrefixedDBkey();
1519
1520                         throw new MWException( "Can't use format $format with content model $model on $t" );
1521                 }
1522
1523                 if ( !$wgContentHandlerUseDB && $title ) {
1524                         // if $wgContentHandlerUseDB is not set,
1525                         // all revisions must use the default content model and format.
1526
1527                         $defaultModel = ContentHandler::getDefaultModelFor( $title );
1528                         $defaultHandler = ContentHandler::getForModelID( $defaultModel );
1529                         $defaultFormat = $defaultHandler->getDefaultFormat();
1530
1531                         if ( $this->getContentModel() != $defaultModel ) {
1532                                 $t = $title->getPrefixedDBkey();
1533
1534                                 throw new MWException( "Can't save non-default content model with "
1535                                         . "\$wgContentHandlerUseDB disabled: model is $model, "
1536                                         . "default for $t is $defaultModel" );
1537                         }
1538
1539                         if ( $this->getContentFormat() != $defaultFormat ) {
1540                                 $t = $title->getPrefixedDBkey();
1541
1542                                 throw new MWException( "Can't use non-default content format with "
1543                                         . "\$wgContentHandlerUseDB disabled: format is $format, "
1544                                         . "default for $t is $defaultFormat" );
1545                         }
1546                 }
1547
1548                 $content = $this->getContent( Revision::RAW );
1549                 $prefixedDBkey = $title->getPrefixedDBkey();
1550                 $revId = $this->mId;
1551
1552                 if ( !$content ) {
1553                         throw new MWException(
1554                                 "Content of revision $revId ($prefixedDBkey) could not be loaded for validation!"
1555                         );
1556                 }
1557                 if ( !$content->isValid() ) {
1558                         throw new MWException(
1559                                 "Content of revision $revId ($prefixedDBkey) is not valid! Content model is $model"
1560                         );
1561                 }
1562         }
1563
1564         /**
1565          * Get the base 36 SHA-1 value for a string of text
1566          * @param string $text
1567          * @return string
1568          */
1569         public static function base36Sha1( $text ) {
1570                 return Wikimedia\base_convert( sha1( $text ), 16, 36, 31 );
1571         }
1572
1573         /**
1574          * Lazy-load the revision's text.
1575          * Currently hardcoded to the 'text' table storage engine.
1576          *
1577          * @return string|bool The revision's text, or false on failure
1578          */
1579         private function loadText() {
1580                 global $wgRevisionCacheExpiry;
1581
1582                 $cache = ObjectCache::getMainWANInstance();
1583                 if ( $cache->getQoS( $cache::ATTR_EMULATION ) <= $cache::QOS_EMULATION_SQL ) {
1584                         // Do not cache RDBMs blobs in...the RDBMs store
1585                         $ttl = $cache::TTL_UNCACHEABLE;
1586                 } else {
1587                         $ttl = $wgRevisionCacheExpiry ?: $cache::TTL_UNCACHEABLE;
1588                 }
1589
1590                 // No negative caching; negative hits on text rows may be due to corrupted replica DBs
1591                 return $cache->getWithSetCallback(
1592                         $cache->makeKey( 'revisiontext', 'textid', $this->getTextId() ),
1593                         $ttl,
1594                         function () {
1595                                 return $this->fetchText();
1596                         },
1597                         [ 'pcGroup' => self::TEXT_CACHE_GROUP, 'pcTTL' => $cache::TTL_PROC_LONG ]
1598                 );
1599         }
1600
1601         private function fetchText() {
1602                 $textId = $this->getTextId();
1603
1604                 // If we kept data for lazy extraction, use it now...
1605                 if ( $this->mTextRow !== null ) {
1606                         $row = $this->mTextRow;
1607                         $this->mTextRow = null;
1608                 } else {
1609                         $row = null;
1610                 }
1611
1612                 // Callers doing updates will pass in READ_LATEST as usual. Since the text/blob tables
1613                 // do not normally get rows changed around, set READ_LATEST_IMMUTABLE in those cases.
1614                 $flags = $this->mQueryFlags;
1615                 $flags |= DBAccessObjectUtils::hasFlags( $flags, self::READ_LATEST )
1616                         ? self::READ_LATEST_IMMUTABLE
1617                         : 0;
1618
1619                 list( $index, $options, $fallbackIndex, $fallbackOptions ) =
1620                         DBAccessObjectUtils::getDBOptions( $flags );
1621
1622                 if ( !$row ) {
1623                         // Text data is immutable; check replica DBs first.
1624                         $row = wfGetDB( $index )->selectRow(
1625                                 'text',
1626                                 [ 'old_text', 'old_flags' ],
1627                                 [ 'old_id' => $textId ],
1628                                 __METHOD__,
1629                                 $options
1630                         );
1631                 }
1632
1633                 // Fallback to DB_MASTER in some cases if the row was not found
1634                 if ( !$row && $fallbackIndex !== null ) {
1635                         // Use FOR UPDATE if it was used to fetch this revision. This avoids missing the row
1636                         // due to REPEATABLE-READ. Also fallback to the master if READ_LATEST is provided.
1637                         $row = wfGetDB( $fallbackIndex )->selectRow(
1638                                 'text',
1639                                 [ 'old_text', 'old_flags' ],
1640                                 [ 'old_id' => $textId ],
1641                                 __METHOD__,
1642                                 $fallbackOptions
1643                         );
1644                 }
1645
1646                 if ( !$row ) {
1647                         wfDebugLog( 'Revision', "No text row with ID '$textId' (revision {$this->getId()})." );
1648                 }
1649
1650                 $text = self::getRevisionText( $row );
1651                 if ( $row && $text === false ) {
1652                         wfDebugLog( 'Revision', "No blob for text row '$textId' (revision {$this->getId()})." );
1653                 }
1654
1655                 return is_string( $text ) ? $text : false;
1656         }
1657
1658         /**
1659          * Create a new null-revision for insertion into a page's
1660          * history. This will not re-save the text, but simply refer
1661          * to the text from the previous version.
1662          *
1663          * Such revisions can for instance identify page rename
1664          * operations and other such meta-modifications.
1665          *
1666          * @param IDatabase $dbw
1667          * @param int $pageId ID number of the page to read from
1668          * @param string $summary Revision's summary
1669          * @param bool $minor Whether the revision should be considered as minor
1670          * @param User|null $user User object to use or null for $wgUser
1671          * @return Revision|null Revision or null on error
1672          */
1673         public static function newNullRevision( $dbw, $pageId, $summary, $minor, $user = null ) {
1674                 global $wgContentHandlerUseDB, $wgContLang;
1675
1676                 $fields = [ 'page_latest', 'page_namespace', 'page_title',
1677                                                 'rev_text_id', 'rev_len', 'rev_sha1' ];
1678
1679                 if ( $wgContentHandlerUseDB ) {
1680                         $fields[] = 'rev_content_model';
1681                         $fields[] = 'rev_content_format';
1682                 }
1683
1684                 $current = $dbw->selectRow(
1685                         [ 'page', 'revision' ],
1686                         $fields,
1687                         [
1688                                 'page_id' => $pageId,
1689                                 'page_latest=rev_id',
1690                         ],
1691                         __METHOD__,
1692                         [ 'FOR UPDATE' ] // T51581
1693                 );
1694
1695                 if ( $current ) {
1696                         if ( !$user ) {
1697                                 global $wgUser;
1698                                 $user = $wgUser;
1699                         }
1700
1701                         // Truncate for whole multibyte characters
1702                         $summary = $wgContLang->truncate( $summary, 255 );
1703
1704                         $row = [
1705                                 'page'       => $pageId,
1706                                 'user_text'  => $user->getName(),
1707                                 'user'       => $user->getId(),
1708                                 'comment'    => $summary,
1709                                 'minor_edit' => $minor,
1710                                 'text_id'    => $current->rev_text_id,
1711                                 'parent_id'  => $current->page_latest,
1712                                 'len'        => $current->rev_len,
1713                                 'sha1'       => $current->rev_sha1
1714                         ];
1715
1716                         if ( $wgContentHandlerUseDB ) {
1717                                 $row['content_model'] = $current->rev_content_model;
1718                                 $row['content_format'] = $current->rev_content_format;
1719                         }
1720
1721                         $row['title'] = Title::makeTitle( $current->page_namespace, $current->page_title );
1722
1723                         $revision = new Revision( $row );
1724                 } else {
1725                         $revision = null;
1726                 }
1727
1728                 return $revision;
1729         }
1730
1731         /**
1732          * Determine if the current user is allowed to view a particular
1733          * field of this revision, if it's marked as deleted.
1734          *
1735          * @param int $field One of self::DELETED_TEXT,
1736          *                              self::DELETED_COMMENT,
1737          *                              self::DELETED_USER
1738          * @param User|null $user User object to check, or null to use $wgUser
1739          * @return bool
1740          */
1741         public function userCan( $field, User $user = null ) {
1742                 return self::userCanBitfield( $this->getVisibility(), $field, $user );
1743         }
1744
1745         /**
1746          * Determine if the current user is allowed to view a particular
1747          * field of this revision, if it's marked as deleted. This is used
1748          * by various classes to avoid duplication.
1749          *
1750          * @param int $bitfield Current field
1751          * @param int $field One of self::DELETED_TEXT = File::DELETED_FILE,
1752          *                               self::DELETED_COMMENT = File::DELETED_COMMENT,
1753          *                               self::DELETED_USER = File::DELETED_USER
1754          * @param User|null $user User object to check, or null to use $wgUser
1755          * @param Title|null $title A Title object to check for per-page restrictions on,
1756          *                          instead of just plain userrights
1757          * @return bool
1758          */
1759         public static function userCanBitfield( $bitfield, $field, User $user = null,
1760                 Title $title = null
1761         ) {
1762                 if ( $bitfield & $field ) { // aspect is deleted
1763                         if ( $user === null ) {
1764                                 global $wgUser;
1765                                 $user = $wgUser;
1766                         }
1767                         if ( $bitfield & self::DELETED_RESTRICTED ) {
1768                                 $permissions = [ 'suppressrevision', 'viewsuppressed' ];
1769                         } elseif ( $field & self::DELETED_TEXT ) {
1770                                 $permissions = [ 'deletedtext' ];
1771                         } else {
1772                                 $permissions = [ 'deletedhistory' ];
1773                         }
1774                         $permissionlist = implode( ', ', $permissions );
1775                         if ( $title === null ) {
1776                                 wfDebug( "Checking for $permissionlist due to $field match on $bitfield\n" );
1777                                 return call_user_func_array( [ $user, 'isAllowedAny' ], $permissions );
1778                         } else {
1779                                 $text = $title->getPrefixedText();
1780                                 wfDebug( "Checking for $permissionlist on $text due to $field match on $bitfield\n" );
1781                                 foreach ( $permissions as $perm ) {
1782                                         if ( $title->userCan( $perm, $user ) ) {
1783                                                 return true;
1784                                         }
1785                                 }
1786                                 return false;
1787                         }
1788                 } else {
1789                         return true;
1790                 }
1791         }
1792
1793         /**
1794          * Get rev_timestamp from rev_id, without loading the rest of the row
1795          *
1796          * @param Title $title
1797          * @param int $id
1798          * @return string|bool False if not found
1799          */
1800         static function getTimestampFromId( $title, $id, $flags = 0 ) {
1801                 $db = ( $flags & self::READ_LATEST )
1802                         ? wfGetDB( DB_MASTER )
1803                         : wfGetDB( DB_REPLICA );
1804                 // Casting fix for databases that can't take '' for rev_id
1805                 if ( $id == '' ) {
1806                         $id = 0;
1807                 }
1808                 $conds = [ 'rev_id' => $id ];
1809                 $conds['rev_page'] = $title->getArticleID();
1810                 $timestamp = $db->selectField( 'revision', 'rev_timestamp', $conds, __METHOD__ );
1811
1812                 return ( $timestamp !== false ) ? wfTimestamp( TS_MW, $timestamp ) : false;
1813         }
1814
1815         /**
1816          * Get count of revisions per page...not very efficient
1817          *
1818          * @param IDatabase $db
1819          * @param int $id Page id
1820          * @return int
1821          */
1822         static function countByPageId( $db, $id ) {
1823                 $row = $db->selectRow( 'revision', [ 'revCount' => 'COUNT(*)' ],
1824                         [ 'rev_page' => $id ], __METHOD__ );
1825                 if ( $row ) {
1826                         return $row->revCount;
1827                 }
1828                 return 0;
1829         }
1830
1831         /**
1832          * Get count of revisions per page...not very efficient
1833          *
1834          * @param IDatabase $db
1835          * @param Title $title
1836          * @return int
1837          */
1838         static function countByTitle( $db, $title ) {
1839                 $id = $title->getArticleID();
1840                 if ( $id ) {
1841                         return self::countByPageId( $db, $id );
1842                 }
1843                 return 0;
1844         }
1845
1846         /**
1847          * Check if no edits were made by other users since
1848          * the time a user started editing the page. Limit to
1849          * 50 revisions for the sake of performance.
1850          *
1851          * @since 1.20
1852          * @deprecated since 1.24
1853          *
1854          * @param IDatabase|int $db The Database to perform the check on. May be given as a
1855          *        Database object or a database identifier usable with wfGetDB.
1856          * @param int $pageId The ID of the page in question
1857          * @param int $userId The ID of the user in question
1858          * @param string $since Look at edits since this time
1859          *
1860          * @return bool True if the given user was the only one to edit since the given timestamp
1861          */
1862         public static function userWasLastToEdit( $db, $pageId, $userId, $since ) {
1863                 if ( !$userId ) {
1864                         return false;
1865                 }
1866
1867                 if ( is_int( $db ) ) {
1868                         $db = wfGetDB( $db );
1869                 }
1870
1871                 $res = $db->select( 'revision',
1872                         'rev_user',
1873                         [
1874                                 'rev_page' => $pageId,
1875                                 'rev_timestamp > ' . $db->addQuotes( $db->timestamp( $since ) )
1876                         ],
1877                         __METHOD__,
1878                         [ 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 50 ] );
1879                 foreach ( $res as $row ) {
1880                         if ( $row->rev_user != $userId ) {
1881                                 return false;
1882                         }
1883                 }
1884                 return true;
1885         }
1886
1887         /**
1888          * Load a revision based on a known page ID and current revision ID from the DB
1889          *
1890          * This method allows for the use of caching, though accessing anything that normally
1891          * requires permission checks (aside from the text) will trigger a small DB lookup.
1892          * The title will also be lazy loaded, though setTitle() can be used to preload it.
1893          *
1894          * @param IDatabase $db
1895          * @param int $pageId Page ID
1896          * @param int $revId Known current revision of this page
1897          * @return Revision|bool Returns false if missing
1898          * @since 1.28
1899          */
1900         public static function newKnownCurrent( IDatabase $db, $pageId, $revId ) {
1901                 $cache = ObjectCache::getMainWANInstance();
1902                 return $cache->getWithSetCallback(
1903                         // Page/rev IDs passed in from DB to reflect history merges
1904                         $cache->makeGlobalKey( 'revision', $db->getWikiID(), $pageId, $revId ),
1905                         $cache::TTL_WEEK,
1906                         function ( $curValue, &$ttl, array &$setOpts ) use ( $db, $pageId, $revId ) {
1907                                 $setOpts += Database::getCacheSetOptions( $db );
1908
1909                                 $rev = Revision::loadFromPageId( $db, $pageId, $revId );
1910                                 // Reflect revision deletion and user renames
1911                                 if ( $rev ) {
1912                                         $rev->mTitle = null; // mutable; lazy-load
1913                                         $rev->mRefreshMutableFields = true;
1914                                 }
1915
1916                                 return $rev ?: false; // don't cache negatives
1917                         }
1918                 );
1919         }
1920
1921         /**
1922          * For cached revisions, make sure the user name and rev_deleted is up-to-date
1923          */
1924         private function loadMutableFields() {
1925                 if ( !$this->mRefreshMutableFields ) {
1926                         return; // not needed
1927                 }
1928
1929                 $this->mRefreshMutableFields = false;
1930                 $dbr = wfGetLB( $this->mWiki )->getConnectionRef( DB_REPLICA, [], $this->mWiki );
1931                 $row = $dbr->selectRow(
1932                         [ 'revision', 'user' ],
1933                         [ 'rev_deleted', 'user_name' ],
1934                         [ 'rev_id' => $this->mId, 'user_id = rev_user' ],
1935                         __METHOD__
1936                 );
1937                 if ( $row ) { // update values
1938                         $this->mDeleted = (int)$row->rev_deleted;
1939                         $this->mUserText = $row->user_name;
1940                 }
1941         }
1942 }