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