includes/Revision.php

   1 <?php
   2 /**
   3  * Representation of a page version.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  */
  22
  23 /**
  24  * @todo document
  25  */
  26 class Revision implements IDBAccessObject {
  27         protected $mId;
  28
  29         /**
  30          * @var int|null
  31          */
  32         protected $mPage;
  33         protected $mUserText;
  34         protected $mOrigUserText;
  35         protected $mUser;
  36         protected $mMinorEdit;
  37         protected $mTimestamp;
  38         protected $mDeleted;
  39         protected $mSize;
  40         protected $mSha1;
  41         protected $mParentId;
  42         protected $mComment;
  43         protected $mText;
  44         protected $mTextId;
  45
  46         /**
  47          * @var stdClass|null
  48          */
  49         protected $mTextRow;
  50
  51         /**
  52          * @var null|Title
  53          */
  54         protected $mTitle;
  55         protected $mCurrent;
  56         protected $mContentModel;
  57         protected $mContentFormat;
  58
  59         /**
  60          * @var Content|null|bool
  61          */
  62         protected $mContent;
  63
  64         /**
  65          * @var null|ContentHandler
  66          */
  67         protected $mContentHandler;
  68
  69         /**
  70          * @var int
  71          */
  72         protected $mQueryFlags = 0;
  73
  74         // Revision deletion constants
  75         const DELETED_TEXT = 1;
  76         const DELETED_COMMENT = 2;
  77         const DELETED_USER = 4;
  78         const DELETED_RESTRICTED = 8;
  79         const SUPPRESSED_USER = 12; // convenience
  80
  81         // Audience options for accessors
  82         const FOR_PUBLIC = 1;
  83         const FOR_THIS_USER = 2;
  84         const RAW = 3;
  85
  86         /**
  87          * Load a page revision from a given revision ID number.
  88          * Returns null if no such revision can be found.
  89          *
  90          * $flags include:
  91          *      Revision::READ_LATEST  : Select the data from the master
  92          *      Revision::READ_LOCKING : Select & lock the data from the master
  93          *
  94          * @param int $id
  95          * @param int $flags (optional)
  96          * @return Revision|null
  97          */
  98         public static function newFromId( $id, $flags = 0 ) {
  99                 return self::newFromConds( array( 'rev_id' => intval( $id ) ), $flags );
 100         }
 101
 102         /**
 103          * Load either the current, or a specified, revision
 104          * that's attached to a given title. If not attached
 105          * to that title, will return null.
 106          *
 107          * $flags include:
 108          *      Revision::READ_LATEST  : Select the data from the master
 109          *      Revision::READ_LOCKING : Select & lock the data from the master
 110          *
 111          * @param Title $title
 112          * @param int $id (optional)
 113          * @param int $flags Bitfield (optional)
 114          * @return Revision|null
 115          */
 116         public static function newFromTitle( $title, $id = 0, $flags = 0 ) {
 117                 $conds = array(
 118                         'page_namespace' => $title->getNamespace(),
 119                         'page_title' => $title->getDBkey()
 120                 );
 121                 if ( $id ) {
 122                         // Use the specified ID
 123                         $conds['rev_id'] = $id;
 124                         return self::newFromConds( $conds, $flags );
 125                 } else {
 126                         // Use a join to get the latest revision
 127                         $conds[] = 'rev_id=page_latest';
 128                         $db = wfGetDB( ( $flags & self::READ_LATEST ) ? DB_MASTER : DB_SLAVE );
 129                         return self::loadFromConds( $db, $conds, $flags );
 130                 }
 131         }
 132
 133         /**
 134          * Load either the current, or a specified, revision
 135          * that's attached to a given page ID.
 136          * Returns null if no such revision can be found.
 137          *
 138          * $flags include:
 139          *      Revision::READ_LATEST  : Select the data from the master (since 1.20)
 140          *      Revision::READ_LOCKING : Select & lock the data from the master
 141          *
 142          * @param int $pageId
 143          * @param int $revId (optional)
 144          * @param int $flags Bitfield (optional)
 145          * @return Revision|null
 146          */
 147         public static function newFromPageId( $pageId, $revId = 0, $flags = 0 ) {
 148                 $conds = array( 'page_id' => $pageId );
 149                 if ( $revId ) {
 150                         $conds['rev_id'] = $revId;
 151                         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 = array() ) {
 172                 global $wgContentHandlerUseDB;
 173
 174                 $attribs = $overrides + array(
 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 DatabaseBase $db
 227          * @param int $id
 228          * @return Revision|null
 229          */
 230         public static function loadFromId( $db, $id ) {
 231                 return self::loadFromConds( $db, array( '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 DatabaseBase $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 = array( '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 DatabaseBase $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( $db,
 271                         array(
 272                                 "rev_id=$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 DatabaseBase $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                         array(
 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 DatabaseBase $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                         array(
 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 DatabaseBase $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 = array( 'LIMIT' => 1 );
 390                 if ( ( $flags & self::READ_LOCKING ) == self::READ_LOCKING ) {
 391                         $options[] = 'FOR UPDATE';
 392                 }
 393                 return $db->select(
 394                         array( 'revision', 'page', 'user' ),
 395                         $fields,
 396                         $conditions,
 397                         __METHOD__,
 398                         $options,
 399                         array( '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 array( 'LEFT JOIN', array( '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 array( 'INNER JOIN', array( '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 = array(
 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 = array(
 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 array(
 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 array(
 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 array( 'user_name' );
 518         }
 519
 520         /**
 521          * Do a batched query to get the parent revision lengths
 522          * @param DatabaseBase $db
 523          * @param array $revIds
 524          * @return array
 525          */
 526         public static function getParentLengths( $db, array $revIds ) {
 527                 $revLens = array();
 528                 if ( !$revIds ) {
 529                         return $revLens; // empty
 530                 }
 531                 $res = $db->select( 'revision',
 532                         array( 'rev_id', 'rev_len' ),
 533                         array( '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                                 array( 'page', 'revision' ),
 781                                 self::selectPageFields(),
 782                                 array( '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          * @since 1.22
 952          * @return RecentChange|null
 953          */
 954         public function getRecentChange() {
 955                 $dbr = wfGetDB( DB_SLAVE );
 956                 return RecentChange::newFromConds(
 957                         array(
 958                                 'rc_user_text' => $this->getUserText( Revision::RAW ),
 959                                 'rc_timestamp' => $dbr->timestamp( $this->getTimestamp() ),
 960                                 'rc_this_oldid' => $this->getId()
 961                         ),
 962                         __METHOD__
 963                 );
 964         }
 965
 966         /**
 967          * @param int $field One of DELETED_* bitfield constants
 968          *
 969          * @return bool
 970          */
 971         public function isDeleted( $field ) {
 972                 return ( $this->mDeleted & $field ) == $field;
 973         }
 974
 975         /**
 976          * Get the deletion bitfield of the revision
 977          *
 978          * @return int
 979          */
 980         public function getVisibility() {
 981                 return (int)$this->mDeleted;
 982         }
 983
 984         /**
 985          * Fetch revision text if it's available to the specified audience.
 986          * If the specified audience does not have the ability to view this
 987          * revision, an empty string will be returned.
 988          *
 989          * @param int $audience One of:
 990          *   Revision::FOR_PUBLIC       to be displayed to all users
 991          *   Revision::FOR_THIS_USER    to be displayed to the given user
 992          *   Revision::RAW              get the text regardless of permissions
 993          * @param User $user User object to check for, only if FOR_THIS_USER is passed
 994          *   to the $audience parameter
 995          *
 996          * @deprecated since 1.21, use getContent() instead
 997          * @todo Replace usage in core
 998          * @return string
 999          */
1000         public function getText( $audience = self::FOR_PUBLIC, User $user = null ) {
1001                 ContentHandler::deprecated( __METHOD__, '1.21' );
1002
1003                 $content = $this->getContent( $audience, $user );
1004                 return ContentHandler::getContentText( $content ); # returns the raw content text, if applicable
1005         }
1006
1007         /**
1008          * Fetch revision content if it's available to the specified audience.
1009          * If the specified audience does not have the ability to view this
1010          * revision, null will be returned.
1011          *
1012          * @param int $audience One of:
1013          *   Revision::FOR_PUBLIC       to be displayed to all users
1014          *   Revision::FOR_THIS_USER    to be displayed to $wgUser
1015          *   Revision::RAW              get the text regardless of permissions
1016          * @param User $user User object to check for, only if FOR_THIS_USER is passed
1017          *   to the $audience parameter
1018          * @since 1.21
1019          * @return Content|null
1020          */
1021         public function getContent( $audience = self::FOR_PUBLIC, User $user = null ) {
1022                 if ( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_TEXT ) ) {
1023                         return null;
1024                 } elseif ( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_TEXT, $user ) ) {
1025                         return null;
1026                 } else {
1027                         return $this->getContentInternal();
1028                 }
1029         }
1030
1031         /**
1032          * Fetch revision text without regard for view restrictions
1033          *
1034          * @return string
1035          *
1036          * @deprecated since 1.21. Instead, use Revision::getContent( Revision::RAW )
1037          *                         or Revision::getSerializedData() as appropriate.
1038          */
1039         public function getRawText() {
1040                 ContentHandler::deprecated( __METHOD__, "1.21" );
1041                 return $this->getText( self::RAW );
1042         }
1043
1044         /**
1045          * Fetch original serialized data without regard for view restrictions
1046          *
1047          * @since 1.21
1048          * @return string
1049          */
1050         public function getSerializedData() {
1051                 if ( $this->mText === null ) {
1052                         $this->mText = $this->loadText();
1053                 }
1054
1055                 return $this->mText;
1056         }
1057
1058         /**
1059          * Gets the content object for the revision (or null on failure).
1060          *
1061          * Note that for mutable Content objects, each call to this method will return a
1062          * fresh clone.
1063          *
1064          * @since 1.21
1065          * @return Content|null The Revision's content, or null on failure.
1066          */
1067         protected function getContentInternal() {
1068                 if ( $this->mContent === null ) {
1069                         // Revision is immutable. Load on demand:
1070                         if ( $this->mText === null ) {
1071                                 $this->mText = $this->loadText();
1072                         }
1073
1074                         if ( $this->mText !== null && $this->mText !== false ) {
1075                                 // Unserialize content
1076                                 $handler = $this->getContentHandler();
1077                                 $format = $this->getContentFormat();
1078
1079                                 $this->mContent = $handler->unserializeContent( $this->mText, $format );
1080                         }
1081                 }
1082
1083                 // NOTE: copy() will return $this for immutable content objects
1084                 return $this->mContent ? $this->mContent->copy() : null;
1085         }
1086
1087         /**
1088          * Returns the content model for this revision.
1089          *
1090          * If no content model was stored in the database, $this->getTitle()->getContentModel() is
1091          * used to determine the content model to use. If no title is know, CONTENT_MODEL_WIKITEXT
1092          * is used as a last resort.
1093          *
1094          * @return string The content model id associated with this revision,
1095          *     see the CONTENT_MODEL_XXX constants.
1096          **/
1097         public function getContentModel() {
1098                 if ( !$this->mContentModel ) {
1099                         $title = $this->getTitle();
1100                         $this->mContentModel = ( $title ? $title->getContentModel() : CONTENT_MODEL_WIKITEXT );
1101
1102                         assert( !empty( $this->mContentModel ) );
1103                 }
1104
1105                 return $this->mContentModel;
1106         }
1107
1108         /**
1109          * Returns the content format for this revision.
1110          *
1111          * If no content format was stored in the database, the default format for this
1112          * revision's content model is returned.
1113          *
1114          * @return string The content format id associated with this revision,
1115          *     see the CONTENT_FORMAT_XXX constants.
1116          **/
1117         public function getContentFormat() {
1118                 if ( !$this->mContentFormat ) {
1119                         $handler = $this->getContentHandler();
1120                         $this->mContentFormat = $handler->getDefaultFormat();
1121
1122                         assert( !empty( $this->mContentFormat ) );
1123                 }
1124
1125                 return $this->mContentFormat;
1126         }
1127
1128         /**
1129          * Returns the content handler appropriate for this revision's content model.
1130          *
1131          * @throws MWException
1132          * @return ContentHandler
1133          */
1134         public function getContentHandler() {
1135                 if ( !$this->mContentHandler ) {
1136                         $model = $this->getContentModel();
1137                         $this->mContentHandler = ContentHandler::getForModelID( $model );
1138
1139                         $format = $this->getContentFormat();
1140
1141                         if ( !$this->mContentHandler->isSupportedFormat( $format ) ) {
1142                                 throw new MWException( "Oops, the content format $format is not supported for "
1143                                         . "this content model, $model" );
1144                         }
1145                 }
1146
1147                 return $this->mContentHandler;
1148         }
1149
1150         /**
1151          * @return string
1152          */
1153         public function getTimestamp() {
1154                 return wfTimestamp( TS_MW, $this->mTimestamp );
1155         }
1156
1157         /**
1158          * @return bool
1159          */
1160         public function isCurrent() {
1161                 return $this->mCurrent;
1162         }
1163
1164         /**
1165          * Get previous revision for this title
1166          *
1167          * @return Revision|null
1168          */
1169         public function getPrevious() {
1170                 if ( $this->getTitle() ) {
1171                         $prev = $this->getTitle()->getPreviousRevisionID( $this->getId() );
1172                         if ( $prev ) {
1173                                 return self::newFromTitle( $this->getTitle(), $prev );
1174                         }
1175                 }
1176                 return null;
1177         }
1178
1179         /**
1180          * Get next revision for this title
1181          *
1182          * @return Revision|null
1183          */
1184         public function getNext() {
1185                 if ( $this->getTitle() ) {
1186                         $next = $this->getTitle()->getNextRevisionID( $this->getId() );
1187                         if ( $next ) {
1188                                 return self::newFromTitle( $this->getTitle(), $next );
1189                         }
1190                 }
1191                 return null;
1192         }
1193
1194         /**
1195          * Get previous revision Id for this page_id
1196          * This is used to populate rev_parent_id on save
1197          *
1198          * @param DatabaseBase $db
1199          * @return int
1200          */
1201         private function getPreviousRevisionId( $db ) {
1202                 if ( $this->mPage === null ) {
1203                         return 0;
1204                 }
1205                 # Use page_latest if ID is not given
1206                 if ( !$this->mId ) {
1207                         $prevId = $db->selectField( 'page', 'page_latest',
1208                                 array( 'page_id' => $this->mPage ),
1209                                 __METHOD__ );
1210                 } else {
1211                         $prevId = $db->selectField( 'revision', 'rev_id',
1212                                 array( 'rev_page' => $this->mPage, 'rev_id < ' . $this->mId ),
1213                                 __METHOD__,
1214                                 array( 'ORDER BY' => 'rev_id DESC' ) );
1215                 }
1216                 return intval( $prevId );
1217         }
1218
1219         /**
1220          * Get revision text associated with an old or archive row
1221          * $row is usually an object from wfFetchRow(), both the flags and the text
1222          * field must be included.
1223          *
1224          * @param stdClass $row The text data
1225          * @param string $prefix Table prefix (default 'old_')
1226          * @param string|bool $wiki The name of the wiki to load the revision text from
1227          *   (same as the the wiki $row was loaded from) or false to indicate the local
1228          *   wiki (this is the default). Otherwise, it must be a symbolic wiki database
1229          *   identifier as understood by the LoadBalancer class.
1230          * @return string Text the text requested or false on failure
1231          */
1232         public static function getRevisionText( $row, $prefix = 'old_', $wiki = false ) {
1233
1234                 # Get data
1235                 $textField = $prefix . 'text';
1236                 $flagsField = $prefix . 'flags';
1237
1238                 if ( isset( $row->$flagsField ) ) {
1239                         $flags = explode( ',', $row->$flagsField );
1240                 } else {
1241                         $flags = array();
1242                 }
1243
1244                 if ( isset( $row->$textField ) ) {
1245                         $text = $row->$textField;
1246                 } else {
1247                         return false;
1248                 }
1249
1250                 # Use external methods for external objects, text in table is URL-only then
1251                 if ( in_array( 'external', $flags ) ) {
1252                         $url = $text;
1253                         $parts = explode( '://', $url, 2 );
1254                         if ( count( $parts ) == 1 || $parts[1] == '' ) {
1255                                 return false;
1256                         }
1257                         $text = ExternalStore::fetchFromURL( $url, array( 'wiki' => $wiki ) );
1258                 }
1259
1260                 // If the text was fetched without an error, convert it
1261                 if ( $text !== false ) {
1262                         $text = self::decompressRevisionText( $text, $flags );
1263                 }
1264                 return $text;
1265         }
1266
1267         /**
1268          * If $wgCompressRevisions is enabled, we will compress data.
1269          * The input string is modified in place.
1270          * Return value is the flags field: contains 'gzip' if the
1271          * data is compressed, and 'utf-8' if we're saving in UTF-8
1272          * mode.
1273          *
1274          * @param mixed $text Reference to a text
1275          * @return string
1276          */
1277         public static function compressRevisionText( &$text ) {
1278                 global $wgCompressRevisions;
1279                 $flags = array();
1280
1281                 # Revisions not marked this way will be converted
1282                 # on load if $wgLegacyCharset is set in the future.
1283                 $flags[] = 'utf-8';
1284
1285                 if ( $wgCompressRevisions ) {
1286                         if ( function_exists( 'gzdeflate' ) ) {
1287                                 $deflated = gzdeflate( $text );
1288
1289                                 if ( $deflated === false ) {
1290                                         wfLogWarning( __METHOD__ . ': gzdeflate() failed' );
1291                                 } else {
1292                                         $text = $deflated;
1293                                         $flags[] = 'gzip';
1294                                 }
1295                         } else {
1296                                 wfDebug( __METHOD__ . " -- no zlib support, not compressing\n" );
1297                         }
1298                 }
1299                 return implode( ',', $flags );
1300         }
1301
1302         /**
1303          * Re-converts revision text according to it's flags.
1304          *
1305          * @param mixed $text Reference to a text
1306          * @param array $flags Compression flags
1307          * @return string|bool Decompressed text, or false on failure
1308          */
1309         public static function decompressRevisionText( $text, $flags ) {
1310                 if ( in_array( 'gzip', $flags ) ) {
1311                         # Deal with optional compression of archived pages.
1312                         # This can be done periodically via maintenance/compressOld.php, and
1313                         # as pages are saved if $wgCompressRevisions is set.
1314                         $text = gzinflate( $text );
1315
1316                         if ( $text === false ) {
1317                                 wfLogWarning( __METHOD__ . ': gzinflate() failed' );
1318                                 return false;
1319                         }
1320                 }
1321
1322                 if ( in_array( 'object', $flags ) ) {
1323                         # Generic compressed storage
1324                         $obj = unserialize( $text );
1325                         if ( !is_object( $obj ) ) {
1326                                 // Invalid object
1327                                 return false;
1328                         }
1329                         $text = $obj->getText();
1330                 }
1331
1332                 global $wgLegacyEncoding;
1333                 if ( $text !== false && $wgLegacyEncoding
1334                         && !in_array( 'utf-8', $flags ) && !in_array( 'utf8', $flags )
1335                 ) {
1336                         # Old revisions kept around in a legacy encoding?
1337                         # Upconvert on demand.
1338                         # ("utf8" checked for compatibility with some broken
1339                         #  conversion scripts 2008-12-30)
1340                         global $wgContLang;
1341                         $text = $wgContLang->iconv( $wgLegacyEncoding, 'UTF-8', $text );
1342                 }
1343
1344                 return $text;
1345         }
1346
1347         /**
1348          * Insert a new revision into the database, returning the new revision ID
1349          * number on success and dies horribly on failure.
1350          *
1351          * @param DatabaseBase $dbw (master connection)
1352          * @throws MWException
1353          * @return int
1354          */
1355         public function insertOn( $dbw ) {
1356                 global $wgDefaultExternalStore, $wgContentHandlerUseDB;
1357
1358                 $this->checkContentModel();
1359
1360                 $data = $this->mText;
1361                 $flags = self::compressRevisionText( $data );
1362
1363                 # Write to external storage if required
1364                 if ( $wgDefaultExternalStore ) {
1365                         // Store and get the URL
1366                         $data = ExternalStore::insertToDefault( $data );
1367                         if ( !$data ) {
1368                                 throw new MWException( "Unable to store text to external storage" );
1369                         }
1370                         if ( $flags ) {
1371                                 $flags .= ',';
1372                         }
1373                         $flags .= 'external';
1374                 }
1375
1376                 # Record the text (or external storage URL) to the text table
1377                 if ( $this->mTextId === null ) {
1378                         $old_id = $dbw->nextSequenceValue( 'text_old_id_seq' );
1379                         $dbw->insert( 'text',
1380                                 array(
1381                                         'old_id' => $old_id,
1382                                         'old_text' => $data,
1383                                         'old_flags' => $flags,
1384                                 ), __METHOD__
1385                         );
1386                         $this->mTextId = $dbw->insertId();
1387                 }
1388
1389                 if ( $this->mComment === null ) {
1390                         $this->mComment = "";
1391                 }
1392
1393                 # Record the edit in revisions
1394                 $rev_id = $this->mId !== null
1395                         ? $this->mId
1396                         : $dbw->nextSequenceValue( 'revision_rev_id_seq' );
1397                 $row = array(
1398                         'rev_id'         => $rev_id,
1399                         'rev_page'       => $this->mPage,
1400                         'rev_text_id'    => $this->mTextId,
1401                         'rev_comment'    => $this->mComment,
1402                         'rev_minor_edit' => $this->mMinorEdit ? 1 : 0,
1403                         'rev_user'       => $this->mUser,
1404                         'rev_user_text'  => $this->mUserText,
1405                         'rev_timestamp'  => $dbw->timestamp( $this->mTimestamp ),
1406                         'rev_deleted'    => $this->mDeleted,
1407                         'rev_len'        => $this->mSize,
1408                         'rev_parent_id'  => $this->mParentId === null
1409                                 ? $this->getPreviousRevisionId( $dbw )
1410                                 : $this->mParentId,
1411                         'rev_sha1'       => $this->mSha1 === null
1412                                 ? Revision::base36Sha1( $this->mText )
1413                                 : $this->mSha1,
1414                 );
1415
1416                 if ( $wgContentHandlerUseDB ) {
1417                         //NOTE: Store null for the default model and format, to save space.
1418                         //XXX: Makes the DB sensitive to changed defaults.
1419                         // Make this behavior optional? Only in miser mode?
1420
1421                         $model = $this->getContentModel();
1422                         $format = $this->getContentFormat();
1423
1424                         $title = $this->getTitle();
1425
1426                         if ( $title === null ) {
1427                                 throw new MWException( "Insufficient information to determine the title of the "
1428                                         . "revision's page!" );
1429                         }
1430
1431                         $defaultModel = ContentHandler::getDefaultModelFor( $title );
1432                         $defaultFormat = ContentHandler::getForModelID( $defaultModel )->getDefaultFormat();
1433
1434                         $row['rev_content_model'] = ( $model === $defaultModel ) ? null : $model;
1435                         $row['rev_content_format'] = ( $format === $defaultFormat ) ? null : $format;
1436                 }
1437
1438                 $dbw->insert( 'revision', $row, __METHOD__ );
1439
1440                 $this->mId = $rev_id !== null ? $rev_id : $dbw->insertId();
1441
1442                 // Assertion to try to catch T92046
1443                 if ( (int)$this->mId === 0 ) {
1444                         throw new UnexpectedValueException(
1445                                 'After insert, Revision mId is ' . var_export( $this->mId, 1 ) . ': ' .
1446                                         var_export( $row, 1 )
1447                         );
1448                 }
1449
1450                 Hooks::run( 'RevisionInsertComplete', array( &$this, $data, $flags ) );
1451
1452                 return $this->mId;
1453         }
1454
1455         protected function checkContentModel() {
1456                 global $wgContentHandlerUseDB;
1457
1458                 $title = $this->getTitle(); //note: may return null for revisions that have not yet been inserted.
1459
1460                 $model = $this->getContentModel();
1461                 $format = $this->getContentFormat();
1462                 $handler = $this->getContentHandler();
1463
1464                 if ( !$handler->isSupportedFormat( $format ) ) {
1465                         $t = $title->getPrefixedDBkey();
1466
1467                         throw new MWException( "Can't use format $format with content model $model on $t" );
1468                 }
1469
1470                 if ( !$wgContentHandlerUseDB && $title ) {
1471                         // if $wgContentHandlerUseDB is not set,
1472                         // all revisions must use the default content model and format.
1473
1474                         $defaultModel = ContentHandler::getDefaultModelFor( $title );
1475                         $defaultHandler = ContentHandler::getForModelID( $defaultModel );
1476                         $defaultFormat = $defaultHandler->getDefaultFormat();
1477
1478                         if ( $this->getContentModel() != $defaultModel ) {
1479                                 $t = $title->getPrefixedDBkey();
1480
1481                                 throw new MWException( "Can't save non-default content model with "
1482                                         . "\$wgContentHandlerUseDB disabled: model is $model, "
1483                                         . "default for $t is $defaultModel" );
1484                         }
1485
1486                         if ( $this->getContentFormat() != $defaultFormat ) {
1487                                 $t = $title->getPrefixedDBkey();
1488
1489                                 throw new MWException( "Can't use non-default content format with "
1490                                         . "\$wgContentHandlerUseDB disabled: format is $format, "
1491                                         . "default for $t is $defaultFormat" );
1492                         }
1493                 }
1494
1495                 $content = $this->getContent( Revision::RAW );
1496
1497                 if ( !$content || !$content->isValid() ) {
1498                         $t = $title->getPrefixedDBkey();
1499
1500                         throw new MWException( "Content of $t is not valid! Content model is $model" );
1501                 }
1502         }
1503
1504         /**
1505          * Get the base 36 SHA-1 value for a string of text
1506          * @param string $text
1507          * @return string
1508          */
1509         public static function base36Sha1( $text ) {
1510                 return wfBaseConvert( sha1( $text ), 16, 36, 31 );
1511         }
1512
1513         /**
1514          * Lazy-load the revision's text.
1515          * Currently hardcoded to the 'text' table storage engine.
1516          *
1517          * @return string|bool The revision's text, or false on failure
1518          */
1519         protected function loadText() {
1520                 // Caching may be beneficial for massive use of external storage
1521                 global $wgRevisionCacheExpiry, $wgMemc;
1522
1523                 $textId = $this->getTextId();
1524                 $key = wfMemcKey( 'revisiontext', 'textid', $textId );
1525                 if ( $wgRevisionCacheExpiry ) {
1526                         $text = $wgMemc->get( $key );
1527                         if ( is_string( $text ) ) {
1528                                 wfDebug( __METHOD__ . ": got id $textId from cache\n" );
1529                                 return $text;
1530                         }
1531                 }
1532
1533                 // If we kept data for lazy extraction, use it now...
1534                 if ( $this->mTextRow !== null ) {
1535                         $row = $this->mTextRow;
1536                         $this->mTextRow = null;
1537                 } else {
1538                         $row = null;
1539                 }
1540
1541                 if ( !$row ) {
1542                         // Text data is immutable; check slaves first.
1543                         $dbr = wfGetDB( DB_SLAVE );
1544                         $row = $dbr->selectRow( 'text',
1545                                 array( 'old_text', 'old_flags' ),
1546                                 array( 'old_id' => $textId ),
1547                                 __METHOD__ );
1548                 }
1549
1550                 // Fallback to the master in case of slave lag. Also use FOR UPDATE if it was
1551                 // used to fetch this revision to avoid missing the row due to REPEATABLE-READ.
1552                 $forUpdate = ( $this->mQueryFlags & self::READ_LOCKING == self::READ_LOCKING );
1553                 if ( !$row && ( $forUpdate || wfGetLB()->getServerCount() > 1 ) ) {
1554                         $dbw = wfGetDB( DB_MASTER );
1555                         $row = $dbw->selectRow( 'text',
1556                                 array( 'old_text', 'old_flags' ),
1557                                 array( 'old_id' => $textId ),
1558                                 __METHOD__,
1559                                 $forUpdate ? array( 'FOR UPDATE' ) : array() );
1560                 }
1561
1562                 if ( !$row ) {
1563                         wfDebugLog( 'Revision', "No text row with ID '$textId' (revision {$this->getId()})." );
1564                 }
1565
1566                 $text = self::getRevisionText( $row );
1567                 if ( $row && $text === false ) {
1568                         wfDebugLog( 'Revision', "No blob for text row '$textId' (revision {$this->getId()})." );
1569                 }
1570
1571                 # No negative caching -- negative hits on text rows may be due to corrupted slave servers
1572                 if ( $wgRevisionCacheExpiry && $text !== false ) {
1573                         $wgMemc->set( $key, $text, $wgRevisionCacheExpiry );
1574                 }
1575
1576                 return $text;
1577         }
1578
1579         /**
1580          * Create a new null-revision for insertion into a page's
1581          * history. This will not re-save the text, but simply refer
1582          * to the text from the previous version.
1583          *
1584          * Such revisions can for instance identify page rename
1585          * operations and other such meta-modifications.
1586          *
1587          * @param DatabaseBase $dbw
1588          * @param int $pageId ID number of the page to read from
1589          * @param string $summary Revision's summary
1590          * @param bool $minor Whether the revision should be considered as minor
1591          * @param User|null $user User object to use or null for $wgUser
1592          * @return Revision|null Revision or null on error
1593          */
1594         public static function newNullRevision( $dbw, $pageId, $summary, $minor, $user = null ) {
1595                 global $wgContentHandlerUseDB, $wgContLang;
1596
1597                 $fields = array( 'page_latest', 'page_namespace', 'page_title',
1598                                                 'rev_text_id', 'rev_len', 'rev_sha1' );
1599
1600                 if ( $wgContentHandlerUseDB ) {
1601                         $fields[] = 'rev_content_model';
1602                         $fields[] = 'rev_content_format';
1603                 }
1604
1605                 $current = $dbw->selectRow(
1606                         array( 'page', 'revision' ),
1607                         $fields,
1608                         array(
1609                                 'page_id' => $pageId,
1610                                 'page_latest=rev_id',
1611                                 ),
1612                         __METHOD__ );
1613
1614                 if ( $current ) {
1615                         if ( !$user ) {
1616                                 global $wgUser;
1617                                 $user = $wgUser;
1618                         }
1619
1620                         // Truncate for whole multibyte characters
1621                         $summary = $wgContLang->truncate( $summary, 255 );
1622
1623                         $row = array(
1624                                 'page'       => $pageId,
1625                                 'user_text'  => $user->getName(),
1626                                 'user'       => $user->getId(),
1627                                 'comment'    => $summary,
1628                                 'minor_edit' => $minor,
1629                                 'text_id'    => $current->rev_text_id,
1630                                 'parent_id'  => $current->page_latest,
1631                                 'len'        => $current->rev_len,
1632                                 'sha1'       => $current->rev_sha1
1633                         );
1634
1635                         if ( $wgContentHandlerUseDB ) {
1636                                 $row['content_model'] = $current->rev_content_model;
1637                                 $row['content_format'] = $current->rev_content_format;
1638                         }
1639
1640                         $revision = new Revision( $row );
1641                         $revision->setTitle( Title::makeTitle( $current->page_namespace, $current->page_title ) );
1642                 } else {
1643                         $revision = null;
1644                 }
1645
1646                 return $revision;
1647         }
1648
1649         /**
1650          * Determine if the current user is allowed to view a particular
1651          * field of this revision, if it's marked as deleted.
1652          *
1653          * @param int $field One of self::DELETED_TEXT,
1654          *                              self::DELETED_COMMENT,
1655          *                              self::DELETED_USER
1656          * @param User|null $user User object to check, or null to use $wgUser
1657          * @return bool
1658          */
1659         public function userCan( $field, User $user = null ) {
1660                 return self::userCanBitfield( $this->mDeleted, $field, $user );
1661         }
1662
1663         /**
1664          * Determine if the current user is allowed to view a particular
1665          * field of this revision, if it's marked as deleted. This is used
1666          * by various classes to avoid duplication.
1667          *
1668          * @param int $bitfield Current field
1669          * @param int $field One of self::DELETED_TEXT = File::DELETED_FILE,
1670          *                               self::DELETED_COMMENT = File::DELETED_COMMENT,
1671          *                               self::DELETED_USER = File::DELETED_USER
1672          * @param User|null $user User object to check, or null to use $wgUser
1673          * @param Title|null $title A Title object to check for per-page restrictions on,
1674          *                          instead of just plain userrights
1675          * @return bool
1676          */
1677         public static function userCanBitfield( $bitfield, $field, User $user = null,
1678                 Title $title = null
1679         ) {
1680                 if ( $bitfield & $field ) { // aspect is deleted
1681                         if ( $user === null ) {
1682                                 global $wgUser;
1683                                 $user = $wgUser;
1684                         }
1685                         if ( $bitfield & self::DELETED_RESTRICTED ) {
1686                                 $permissions = array( 'suppressrevision', 'viewsuppressed' );
1687                         } elseif ( $field & self::DELETED_TEXT ) {
1688                                 $permissions = array( 'deletedtext' );
1689                         } else {
1690                                 $permissions = array( 'deletedhistory' );
1691                         }
1692                         $permissionlist = implode( ', ', $permissions );
1693                         if ( $title === null ) {
1694                                 wfDebug( "Checking for $permissionlist due to $field match on $bitfield\n" );
1695                                 return call_user_func_array( array( $user, 'isAllowedAny' ), $permissions );
1696                         } else {
1697                                 $text = $title->getPrefixedText();
1698                                 wfDebug( "Checking for $permissionlist on $text due to $field match on $bitfield\n" );
1699                                 foreach ( $permissions as $perm ) {
1700                                         if ( $title->userCan( $perm, $user ) ) {
1701                                                 return true;
1702                                         }
1703                                 }
1704                                 return false;
1705                         }
1706                 } else {
1707                         return true;
1708                 }
1709         }
1710
1711         /**
1712          * Get rev_timestamp from rev_id, without loading the rest of the row
1713          *
1714          * @param Title $title
1715          * @param int $id
1716          * @return string|bool False if not found
1717          */
1718         static function getTimestampFromId( $title, $id, $flags = 0 ) {
1719                 $db = ( $flags & self::READ_LATEST )
1720                         ? wfGetDB( DB_MASTER )
1721                         : wfGetDB( DB_SLAVE );
1722                 // Casting fix for databases that can't take '' for rev_id
1723                 if ( $id == '' ) {
1724                         $id = 0;
1725                 }
1726                 $conds = array( 'rev_id' => $id );
1727                 $conds['rev_page'] = $title->getArticleID();
1728                 $timestamp = $db->selectField( 'revision', 'rev_timestamp', $conds, __METHOD__ );
1729
1730                 return ( $timestamp !== false ) ? wfTimestamp( TS_MW, $timestamp ) : false;
1731         }
1732
1733         /**
1734          * Get count of revisions per page...not very efficient
1735          *
1736          * @param DatabaseBase $db
1737          * @param int $id Page id
1738          * @return int
1739          */
1740         static function countByPageId( $db, $id ) {
1741                 $row = $db->selectRow( 'revision', array( 'revCount' => 'COUNT(*)' ),
1742                         array( 'rev_page' => $id ), __METHOD__ );
1743                 if ( $row ) {
1744                         return $row->revCount;
1745                 }
1746                 return 0;
1747         }
1748
1749         /**
1750          * Get count of revisions per page...not very efficient
1751          *
1752          * @param DatabaseBase $db
1753          * @param Title $title
1754          * @return int
1755          */
1756         static function countByTitle( $db, $title ) {
1757                 $id = $title->getArticleID();
1758                 if ( $id ) {
1759                         return self::countByPageId( $db, $id );
1760                 }
1761                 return 0;
1762         }
1763
1764         /**
1765          * Check if no edits were made by other users since
1766          * the time a user started editing the page. Limit to
1767          * 50 revisions for the sake of performance.
1768          *
1769          * @since 1.20
1770          * @deprecated since 1.24
1771          *
1772          * @param DatabaseBase|int $db The Database to perform the check on. May be given as a
1773          *        Database object or a database identifier usable with wfGetDB.
1774          * @param int $pageId The ID of the page in question
1775          * @param int $userId The ID of the user in question
1776          * @param string $since Look at edits since this time
1777          *
1778          * @return bool True if the given user was the only one to edit since the given timestamp
1779          */
1780         public static function userWasLastToEdit( $db, $pageId, $userId, $since ) {
1781                 if ( !$userId ) {
1782                         return false;
1783                 }
1784
1785                 if ( is_int( $db ) ) {
1786                         $db = wfGetDB( $db );
1787                 }
1788
1789                 $res = $db->select( 'revision',
1790                         'rev_user',
1791                         array(
1792                                 'rev_page' => $pageId,
1793                                 'rev_timestamp > ' . $db->addQuotes( $db->timestamp( $since ) )
1794                         ),
1795                         __METHOD__,
1796                         array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 50 ) );
1797                 foreach ( $res as $row ) {
1798                         if ( $row->rev_user != $userId ) {
1799                                 return false;
1800                         }
1801                 }
1802                 return true;
1803         }
1804 }