includes/Revision.php

   1 <?php
   2 /**
   3  * Representation of a page version.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  */
  22
  23 /**
  24  * @todo document
  25  */
  26 class Revision implements IDBAccessObject {
  27         protected $mId;
  28
  29         /**
  30          * @var int|null
  31          */
  32         protected $mPage;
  33         protected $mUserText;
  34         protected $mOrigUserText;
  35         protected $mUser;
  36         protected $mMinorEdit;
  37         protected $mTimestamp;
  38         protected $mDeleted;
  39         protected $mSize;
  40         protected $mSha1;
  41         protected $mParentId;
  42         protected $mComment;
  43         protected $mText;
  44         protected $mTextId;
  45
  46         /**
  47          * @var stdClass|null
  48          */
  49         protected $mTextRow;
  50
  51         /**
  52          * @var null|Title
  53          */
  54         protected $mTitle;
  55         protected $mCurrent;
  56         protected $mContentModel;
  57         protected $mContentFormat;
  58
  59         /**
  60          * @var Content|null|bool
  61          */
  62         protected $mContent;
  63
  64         /**
  65          * @var null|ContentHandler
  66          */
  67         protected $mContentHandler;
  68
  69         /**
  70          * @var int
  71          */
  72         protected $mQueryFlags = 0;
  73
  74         // Revision deletion constants
  75         const DELETED_TEXT = 1;
  76         const DELETED_COMMENT = 2;
  77         const DELETED_USER = 4;
  78         const DELETED_RESTRICTED = 8;
  79         const SUPPRESSED_USER = 12; // convenience
  80
  81         // Audience options for accessors
  82         const FOR_PUBLIC = 1;
  83         const FOR_THIS_USER = 2;
  84         const RAW = 3;
  85
  86         /**
  87          * Load a page revision from a given revision ID number.
  88          * Returns null if no such revision can be found.
  89          *
  90          * $flags include:
  91          *      Revision::READ_LATEST  : Select the data from the master
  92          *      Revision::READ_LOCKING : Select & lock the data from the master
  93          *
  94          * @param int $id
  95          * @param int $flags (optional)
  96          * @return Revision|null
  97          */
  98         public static function newFromId( $id, $flags = 0 ) {
  99                 return self::newFromConds( array( 'rev_id' => intval( $id ) ), $flags );
 100         }
 101
 102         /**
 103          * Load either the current, or a specified, revision
 104          * that's attached to a given title. If not attached
 105          * to that title, will return null.
 106          *
 107          * $flags include:
 108          *      Revision::READ_LATEST  : Select the data from the master
 109          *      Revision::READ_LOCKING : Select & lock the data from the master
 110          *
 111          * @param Title $title
 112          * @param int $id (optional)
 113          * @param int $flags Bitfield (optional)
 114          * @return Revision|null
 115          */
 116         public static function newFromTitle( $title, $id = 0, $flags = 0 ) {
 117                 $conds = array(
 118                         'page_namespace' => $title->getNamespace(),
 119                         'page_title' => $title->getDBkey()
 120                 );
 121                 if ( $id ) {
 122                         // Use the specified ID
 123                         $conds['rev_id'] = $id;
 124                         return self::newFromConds( $conds, (int)$flags );
 125                 } else {
 126                         // Use a join to get the latest revision
 127                         $conds[] = 'rev_id=page_latest';
 128                         $db = wfGetDB( ( $flags & self::READ_LATEST ) ? DB_MASTER : DB_SLAVE );
 129                         return self::loadFromConds( $db, $conds, $flags );
 130                 }
 131         }
 132
 133         /**
 134          * Load either the current, or a specified, revision
 135          * that's attached to a given page ID.
 136          * Returns null if no such revision can be found.
 137          *
 138          * $flags include:
 139          *      Revision::READ_LATEST  : Select the data from the master (since 1.20)
 140          *      Revision::READ_LOCKING : Select & lock the data from the master
 141          *
 142          * @param int $pageId
 143          * @param int $revId (optional)
 144          * @param int $flags Bitfield (optional)
 145          * @return Revision|null
 146          */
 147         public static function newFromPageId( $pageId, $revId = 0, $flags = 0 ) {
 148                 $conds = array( 'page_id' => $pageId );
 149                 if ( $revId ) {
 150                         $conds['rev_id'] = $revId;
 151                 } else {
 152                         // Use a join to get the latest revision
 153                         $conds[] = 'rev_id = page_latest';
 154                 }
 155                 return self::newFromConds( $conds, (int)$flags );
 156         }
 157
 158         /**
 159          * Make a fake revision object from an archive table row. This is queried
 160          * for permissions or even inserted (as in Special:Undelete)
 161          * @todo FIXME: Should be a subclass for RevisionDelete. [TS]
 162          *
 163          * @param object $row
 164          * @param array $overrides
 165          *
 166          * @throws MWException
 167          * @return Revision
 168          */
 169         public static function newFromArchiveRow( $row, $overrides = array() ) {
 170                 global $wgContentHandlerUseDB;
 171
 172                 $attribs = $overrides + array(
 173                         'page'       => isset( $row->ar_page_id ) ? $row->ar_page_id : null,
 174                         'id'         => isset( $row->ar_rev_id ) ? $row->ar_rev_id : null,
 175                         'comment'    => $row->ar_comment,
 176                         'user'       => $row->ar_user,
 177                         'user_text'  => $row->ar_user_text,
 178                         'timestamp'  => $row->ar_timestamp,
 179                         'minor_edit' => $row->ar_minor_edit,
 180                         'text_id'    => isset( $row->ar_text_id ) ? $row->ar_text_id : null,
 181                         'deleted'    => $row->ar_deleted,
 182                         'len'        => $row->ar_len,
 183                         'sha1'       => isset( $row->ar_sha1 ) ? $row->ar_sha1 : null,
 184                         'content_model'   => isset( $row->ar_content_model ) ? $row->ar_content_model : null,
 185                         'content_format'  => isset( $row->ar_content_format ) ? $row->ar_content_format : null,
 186                 );
 187
 188                 if ( !$wgContentHandlerUseDB ) {
 189                         unset( $attribs['content_model'] );
 190                         unset( $attribs['content_format'] );
 191                 }
 192
 193                 if ( !isset( $attribs['title'] )
 194                         && isset( $row->ar_namespace )
 195                         && isset( $row->ar_title ) ) {
 196
 197                         $attribs['title'] = Title::makeTitle( $row->ar_namespace, $row->ar_title );
 198                 }
 199
 200                 if ( isset( $row->ar_text ) && !$row->ar_text_id ) {
 201                         // Pre-1.5 ar_text row
 202                         $attribs['text'] = self::getRevisionText( $row, 'ar_' );
 203                         if ( $attribs['text'] === false ) {
 204                                 throw new MWException( 'Unable to load text from archive row (possibly bug 22624)' );
 205                         }
 206                 }
 207                 return new self( $attribs );
 208         }
 209
 210         /**
 211          * @since 1.19
 212          *
 213          * @param object $row
 214          * @return Revision
 215          */
 216         public static function newFromRow( $row ) {
 217                 return new self( $row );
 218         }
 219
 220         /**
 221          * Load a page revision from a given revision ID number.
 222          * Returns null if no such revision can be found.
 223          *
 224          * @param DatabaseBase $db
 225          * @param int $id
 226          * @return Revision|null
 227          */
 228         public static function loadFromId( $db, $id ) {
 229                 return self::loadFromConds( $db, array( 'rev_id' => intval( $id ) ) );
 230         }
 231
 232         /**
 233          * Load either the current, or a specified, revision
 234          * that's attached to a given page. If not attached
 235          * to that page, will return null.
 236          *
 237          * @param DatabaseBase $db
 238          * @param int $pageid
 239          * @param int $id
 240          * @return Revision|null
 241          */
 242         public static function loadFromPageId( $db, $pageid, $id = 0 ) {
 243                 $conds = array( 'rev_page' => intval( $pageid ), 'page_id' => intval( $pageid ) );
 244                 if ( $id ) {
 245                         $conds['rev_id'] = intval( $id );
 246                 } else {
 247                         $conds[] = 'rev_id=page_latest';
 248                 }
 249                 return self::loadFromConds( $db, $conds );
 250         }
 251
 252         /**
 253          * Load either the current, or a specified, revision
 254          * that's attached to a given page. If not attached
 255          * to that page, will return null.
 256          *
 257          * @param DatabaseBase $db
 258          * @param Title $title
 259          * @param int $id
 260          * @return Revision|null
 261          */
 262         public static function loadFromTitle( $db, $title, $id = 0 ) {
 263                 if ( $id ) {
 264                         $matchId = intval( $id );
 265                 } else {
 266                         $matchId = 'page_latest';
 267                 }
 268                 return self::loadFromConds( $db,
 269                         array(
 270                                 "rev_id=$matchId",
 271                                 'page_namespace' => $title->getNamespace(),
 272                                 'page_title' => $title->getDBkey()
 273                         )
 274                 );
 275         }
 276
 277         /**
 278          * Load the revision for the given title with the given timestamp.
 279          * WARNING: Timestamps may in some circumstances not be unique,
 280          * so this isn't the best key to use.
 281          *
 282          * @param DatabaseBase $db
 283          * @param Title $title
 284          * @param string $timestamp
 285          * @return Revision|null
 286          */
 287         public static function loadFromTimestamp( $db, $title, $timestamp ) {
 288                 return self::loadFromConds( $db,
 289                         array(
 290                                 'rev_timestamp' => $db->timestamp( $timestamp ),
 291                                 'page_namespace' => $title->getNamespace(),
 292                                 'page_title' => $title->getDBkey()
 293                         )
 294                 );
 295         }
 296
 297         /**
 298          * Given a set of conditions, fetch a revision.
 299          *
 300          * @param array $conditions
 301          * @param int $flags (optional)
 302          * @return Revision|null
 303          */
 304         private static function newFromConds( $conditions, $flags = 0 ) {
 305                 $db = wfGetDB( ( $flags & self::READ_LATEST ) ? DB_MASTER : DB_SLAVE );
 306                 $rev = self::loadFromConds( $db, $conditions, $flags );
 307                 if ( $rev === null && wfGetLB()->getServerCount() > 1 ) {
 308                         if ( !( $flags & self::READ_LATEST ) ) {
 309                                 $dbw = wfGetDB( DB_MASTER );
 310                                 $rev = self::loadFromConds( $dbw, $conditions, $flags );
 311                         }
 312                 }
 313                 if ( $rev ) {
 314                         $rev->mQueryFlags = $flags;
 315                 }
 316                 return $rev;
 317         }
 318
 319         /**
 320          * Given a set of conditions, fetch a revision from
 321          * the given database connection.
 322          *
 323          * @param DatabaseBase $db
 324          * @param array $conditions
 325          * @param int $flags (optional)
 326          * @return Revision|null
 327          */
 328         private static function loadFromConds( $db, $conditions, $flags = 0 ) {
 329                 $res = self::fetchFromConds( $db, $conditions, $flags );
 330                 if ( $res ) {
 331                         $row = $res->fetchObject();
 332                         if ( $row ) {
 333                                 $ret = new Revision( $row );
 334                                 return $ret;
 335                         }
 336                 }
 337                 $ret = null;
 338                 return $ret;
 339         }
 340
 341         /**
 342          * Return a wrapper for a series of database rows to
 343          * fetch all of a given page's revisions in turn.
 344          * Each row can be fed to the constructor to get objects.
 345          *
 346          * @param Title $title
 347          * @return ResultWrapper
 348          */
 349         public static function fetchRevision( $title ) {
 350                 return self::fetchFromConds(
 351                         wfGetDB( DB_SLAVE ),
 352                         array(
 353                                 'rev_id=page_latest',
 354                                 'page_namespace' => $title->getNamespace(),
 355                                 'page_title' => $title->getDBkey()
 356                         )
 357                 );
 358         }
 359
 360         /**
 361          * Given a set of conditions, return a ResultWrapper
 362          * which will return matching database rows with the
 363          * fields necessary to build Revision objects.
 364          *
 365          * @param DatabaseBase $db
 366          * @param array $conditions
 367          * @param int $flags (optional)
 368          * @return ResultWrapper
 369          */
 370         private static function fetchFromConds( $db, $conditions, $flags = 0 ) {
 371                 $fields = array_merge(
 372                         self::selectFields(),
 373                         self::selectPageFields(),
 374                         self::selectUserFields()
 375                 );
 376                 $options = array( 'LIMIT' => 1 );
 377                 if ( ( $flags & self::READ_LOCKING ) == self::READ_LOCKING ) {
 378                         $options[] = 'FOR UPDATE';
 379                 }
 380                 return $db->select(
 381                         array( 'revision', 'page', 'user' ),
 382                         $fields,
 383                         $conditions,
 384                         __METHOD__,
 385                         $options,
 386                         array( 'page' => self::pageJoinCond(), 'user' => self::userJoinCond() )
 387                 );
 388         }
 389
 390         /**
 391          * Return the value of a select() JOIN conds array for the user table.
 392          * This will get user table rows for logged-in users.
 393          * @since 1.19
 394          * @return array
 395          */
 396         public static function userJoinCond() {
 397                 return array( 'LEFT JOIN', array( 'rev_user != 0', 'user_id = rev_user' ) );
 398         }
 399
 400         /**
 401          * Return the value of a select() page conds array for the page table.
 402          * This will assure that the revision(s) are not orphaned from live pages.
 403          * @since 1.19
 404          * @return array
 405          */
 406         public static function pageJoinCond() {
 407                 return array( 'INNER JOIN', array( 'page_id = rev_page' ) );
 408         }
 409
 410         /**
 411          * Return the list of revision fields that should be selected to create
 412          * a new revision.
 413          * @return array
 414          */
 415         public static function selectFields() {
 416                 global $wgContentHandlerUseDB;
 417
 418                 $fields = array(
 419                         'rev_id',
 420                         'rev_page',
 421                         'rev_text_id',
 422                         'rev_timestamp',
 423                         'rev_comment',
 424                         'rev_user_text',
 425                         'rev_user',
 426                         'rev_minor_edit',
 427                         'rev_deleted',
 428                         'rev_len',
 429                         'rev_parent_id',
 430                         'rev_sha1',
 431                 );
 432
 433                 if ( $wgContentHandlerUseDB ) {
 434                         $fields[] = 'rev_content_format';
 435                         $fields[] = 'rev_content_model';
 436                 }
 437
 438                 return $fields;
 439         }
 440
 441         /**
 442          * Return the list of revision fields that should be selected to create
 443          * a new revision from an archive row.
 444          * @return array
 445          */
 446         public static function selectArchiveFields() {
 447                 global $wgContentHandlerUseDB;
 448                 $fields = array(
 449                         'ar_id',
 450                         'ar_page_id',
 451                         'ar_rev_id',
 452                         'ar_text',
 453                         'ar_text_id',
 454                         'ar_timestamp',
 455                         'ar_comment',
 456                         'ar_user_text',
 457                         'ar_user',
 458                         'ar_minor_edit',
 459                         'ar_deleted',
 460                         'ar_len',
 461                         'ar_parent_id',
 462                         'ar_sha1',
 463                 );
 464
 465                 if ( $wgContentHandlerUseDB ) {
 466                         $fields[] = 'ar_content_format';
 467                         $fields[] = 'ar_content_model';
 468                 }
 469                 return $fields;
 470         }
 471
 472         /**
 473          * Return the list of text fields that should be selected to read the
 474          * revision text
 475          * @return array
 476          */
 477         public static function selectTextFields() {
 478                 return array(
 479                         'old_text',
 480                         'old_flags'
 481                 );
 482         }
 483
 484         /**
 485          * Return the list of page fields that should be selected from page table
 486          * @return array
 487          */
 488         public static function selectPageFields() {
 489                 return array(
 490                         'page_namespace',
 491                         'page_title',
 492                         'page_id',
 493                         'page_latest',
 494                         'page_is_redirect',
 495                         'page_len',
 496                 );
 497         }
 498
 499         /**
 500          * Return the list of user fields that should be selected from user table
 501          * @return array
 502          */
 503         public static function selectUserFields() {
 504                 return array( 'user_name' );
 505         }
 506
 507         /**
 508          * Do a batched query to get the parent revision lengths
 509          * @param DatabaseBase $db
 510          * @param array $revIds
 511          * @return array
 512          */
 513         public static function getParentLengths( $db, array $revIds ) {
 514                 $revLens = array();
 515                 if ( !$revIds ) {
 516                         return $revLens; // empty
 517                 }
 518                 $res = $db->select( 'revision',
 519                         array( 'rev_id', 'rev_len' ),
 520                         array( 'rev_id' => $revIds ),
 521                         __METHOD__ );
 522                 foreach ( $res as $row ) {
 523                         $revLens[$row->rev_id] = $row->rev_len;
 524                 }
 525                 return $revLens;
 526         }
 527
 528         /**
 529          * Constructor
 530          *
 531          * @param object|array $row Either a database row or an array
 532          * @throws MWException
 533          * @access private
 534          */
 535         function __construct( $row ) {
 536                 if ( is_object( $row ) ) {
 537                         $this->mId = intval( $row->rev_id );
 538                         $this->mPage = intval( $row->rev_page );
 539                         $this->mTextId = intval( $row->rev_text_id );
 540                         $this->mComment = $row->rev_comment;
 541                         $this->mUser = intval( $row->rev_user );
 542                         $this->mMinorEdit = intval( $row->rev_minor_edit );
 543                         $this->mTimestamp = $row->rev_timestamp;
 544                         $this->mDeleted = intval( $row->rev_deleted );
 545
 546                         if ( !isset( $row->rev_parent_id ) ) {
 547                                 $this->mParentId = null;
 548                         } else {
 549                                 $this->mParentId = intval( $row->rev_parent_id );
 550                         }
 551
 552                         if ( !isset( $row->rev_len ) ) {
 553                                 $this->mSize = null;
 554                         } else {
 555                                 $this->mSize = intval( $row->rev_len );
 556                         }
 557
 558                         if ( !isset( $row->rev_sha1 ) ) {
 559                                 $this->mSha1 = null;
 560                         } else {
 561                                 $this->mSha1 = $row->rev_sha1;
 562                         }
 563
 564                         if ( isset( $row->page_latest ) ) {
 565                                 $this->mCurrent = ( $row->rev_id == $row->page_latest );
 566                                 $this->mTitle = Title::newFromRow( $row );
 567                         } else {
 568                                 $this->mCurrent = false;
 569                                 $this->mTitle = null;
 570                         }
 571
 572                         if ( !isset( $row->rev_content_model ) ) {
 573                                 $this->mContentModel = null; # determine on demand if needed
 574                         } else {
 575                                 $this->mContentModel = strval( $row->rev_content_model );
 576                         }
 577
 578                         if ( !isset( $row->rev_content_format ) ) {
 579                                 $this->mContentFormat = null; # determine on demand if needed
 580                         } else {
 581                                 $this->mContentFormat = strval( $row->rev_content_format );
 582                         }
 583
 584                         // Lazy extraction...
 585                         $this->mText = null;
 586                         if ( isset( $row->old_text ) ) {
 587                                 $this->mTextRow = $row;
 588                         } else {
 589                                 // 'text' table row entry will be lazy-loaded
 590                                 $this->mTextRow = null;
 591                         }
 592
 593                         // Use user_name for users and rev_user_text for IPs...
 594                         $this->mUserText = null; // lazy load if left null
 595                         if ( $this->mUser == 0 ) {
 596                                 $this->mUserText = $row->rev_user_text; // IP user
 597                         } elseif ( isset( $row->user_name ) ) {
 598                                 $this->mUserText = $row->user_name; // logged-in user
 599                         }
 600                         $this->mOrigUserText = $row->rev_user_text;
 601                 } elseif ( is_array( $row ) ) {
 602                         // Build a new revision to be saved...
 603                         global $wgUser; // ugh
 604
 605                         # if we have a content object, use it to set the model and type
 606                         if ( !empty( $row['content'] ) ) {
 607                                 // @todo when is that set? test with external store setup! check out insertOn() [dk]
 608                                 if ( !empty( $row['text_id'] ) ) {
 609                                         throw new MWException( "Text already stored in external store (id {$row['text_id']}), " .
 610                                                 "can't serialize content object" );
 611                                 }
 612
 613                                 $row['content_model'] = $row['content']->getModel();
 614                                 # note: mContentFormat is initializes later accordingly
 615                                 # note: content is serialized later in this method!
 616                                 # also set text to null?
 617                         }
 618
 619                         $this->mId = isset( $row['id'] ) ? intval( $row['id'] ) : null;
 620                         $this->mPage = isset( $row['page'] ) ? intval( $row['page'] ) : null;
 621                         $this->mTextId = isset( $row['text_id'] ) ? intval( $row['text_id'] ) : null;
 622                         $this->mUserText = isset( $row['user_text'] )
 623                                 ? strval( $row['user_text'] ) : $wgUser->getName();
 624                         $this->mUser = isset( $row['user'] ) ? intval( $row['user'] ) : $wgUser->getId();
 625                         $this->mMinorEdit = isset( $row['minor_edit'] ) ? intval( $row['minor_edit'] ) : 0;
 626                         $this->mTimestamp = isset( $row['timestamp'] )
 627                                 ? strval( $row['timestamp'] ) : wfTimestampNow();
 628                         $this->mDeleted = isset( $row['deleted'] ) ? intval( $row['deleted'] ) : 0;
 629                         $this->mSize = isset( $row['len'] ) ? intval( $row['len'] ) : null;
 630                         $this->mParentId = isset( $row['parent_id'] ) ? intval( $row['parent_id'] ) : null;
 631                         $this->mSha1 = isset( $row['sha1'] ) ? strval( $row['sha1'] ) : null;
 632
 633                         $this->mContentModel = isset( $row['content_model'] )
 634                                 ? strval( $row['content_model'] ) : null;
 635                         $this->mContentFormat = isset( $row['content_format'] )
 636                                 ? strval( $row['content_format'] ) : null;
 637
 638                         // Enforce spacing trimming on supplied text
 639                         $this->mComment = isset( $row['comment'] ) ? trim( strval( $row['comment'] ) ) : null;
 640                         $this->mText = isset( $row['text'] ) ? rtrim( strval( $row['text'] ) ) : null;
 641                         $this->mTextRow = null;
 642
 643                         $this->mTitle = isset( $row['title'] ) ? $row['title'] : null;
 644
 645                         // if we have a Content object, override mText and mContentModel
 646                         if ( !empty( $row['content'] ) ) {
 647                                 if ( !( $row['content'] instanceof Content ) ) {
 648                                         throw new MWException( '`content` field must contain a Content object.' );
 649                                 }
 650
 651                                 $handler = $this->getContentHandler();
 652                                 $this->mContent = $row['content'];
 653
 654                                 $this->mContentModel = $this->mContent->getModel();
 655                                 $this->mContentHandler = null;
 656
 657                                 $this->mText = $handler->serializeContent( $row['content'], $this->getContentFormat() );
 658                         } elseif ( $this->mText !== null ) {
 659                                 $handler = $this->getContentHandler();
 660                                 $this->mContent = $handler->unserializeContent( $this->mText );
 661                         }
 662
 663                         // If we have a Title object, make sure it is consistent with mPage.
 664                         if ( $this->mTitle && $this->mTitle->exists() ) {
 665                                 if ( $this->mPage === null ) {
 666                                         // if the page ID wasn't known, set it now
 667                                         $this->mPage = $this->mTitle->getArticleID();
 668                                 } elseif ( $this->mTitle->getArticleID() !== $this->mPage ) {
 669                                         // Got different page IDs. This may be legit (e.g. during undeletion),
 670                                         // but it seems worth mentioning it in the log.
 671                                         wfDebug( "Page ID " . $this->mPage . " mismatches the ID " .
 672                                                 $this->mTitle->getArticleID() . " provided by the Title object." );
 673                                 }
 674                         }
 675
 676                         $this->mCurrent = false;
 677
 678                         // If we still have no length, see it we have the text to figure it out
 679                         if ( !$this->mSize && $this->mContent !== null ) {
 680                                 $this->mSize = $this->mContent->getSize();
 681                         }
 682
 683                         // Same for sha1
 684                         if ( $this->mSha1 === null ) {
 685                                 $this->mSha1 = $this->mText === null ? null : self::base36Sha1( $this->mText );
 686                         }
 687
 688                         // force lazy init
 689                         $this->getContentModel();
 690                         $this->getContentFormat();
 691                 } else {
 692                         throw new MWException( 'Revision constructor passed invalid row format.' );
 693                 }
 694                 $this->mUnpatrolled = null;
 695         }
 696
 697         /**
 698          * Get revision ID
 699          *
 700          * @return int|null
 701          */
 702         public function getId() {
 703                 return $this->mId;
 704         }
 705
 706         /**
 707          * Set the revision ID
 708          *
 709          * @since 1.19
 710          * @param int $id
 711          */
 712         public function setId( $id ) {
 713                 $this->mId = $id;
 714         }
 715
 716         /**
 717          * Get text row ID
 718          *
 719          * @return int|null
 720          */
 721         public function getTextId() {
 722                 return $this->mTextId;
 723         }
 724
 725         /**
 726          * Get parent revision ID (the original previous page revision)
 727          *
 728          * @return int|null
 729          */
 730         public function getParentId() {
 731                 return $this->mParentId;
 732         }
 733
 734         /**
 735          * Returns the length of the text in this revision, or null if unknown.
 736          *
 737          * @return int|null
 738          */
 739         public function getSize() {
 740                 return $this->mSize;
 741         }
 742
 743         /**
 744          * Returns the base36 sha1 of the text in this revision, or null if unknown.
 745          *
 746          * @return string|null
 747          */
 748         public function getSha1() {
 749                 return $this->mSha1;
 750         }
 751
 752         /**
 753          * Returns the title of the page associated with this entry or null.
 754          *
 755          * Will do a query, when title is not set and id is given.
 756          *
 757          * @return Title|null
 758          */
 759         public function getTitle() {
 760                 if ( $this->mTitle !== null ) {
 761                         return $this->mTitle;
 762                 }
 763                 //rev_id is defined as NOT NULL, but this revision may not yet have been inserted.
 764                 if ( $this->mId !== null ) {
 765                         $dbr = wfGetDB( DB_SLAVE );
 766                         $row = $dbr->selectRow(
 767                                 array( 'page', 'revision' ),
 768                                 self::selectPageFields(),
 769                                 array( 'page_id=rev_page',
 770                                         'rev_id' => $this->mId ),
 771                                 __METHOD__ );
 772                         if ( $row ) {
 773                                 $this->mTitle = Title::newFromRow( $row );
 774                         }
 775                 }
 776
 777                 if ( !$this->mTitle && $this->mPage !== null && $this->mPage > 0 ) {
 778                         $this->mTitle = Title::newFromID( $this->mPage );
 779                 }
 780
 781                 return $this->mTitle;
 782         }
 783
 784         /**
 785          * Set the title of the revision
 786          *
 787          * @param Title $title
 788          */
 789         public function setTitle( $title ) {
 790                 $this->mTitle = $title;
 791         }
 792
 793         /**
 794          * Get the page ID
 795          *
 796          * @return int|null
 797          */
 798         public function getPage() {
 799                 return $this->mPage;
 800         }
 801
 802         /**
 803          * Fetch revision's user id if it's available to the specified audience.
 804          * If the specified audience does not have access to it, zero will be
 805          * returned.
 806          *
 807          * @param int $audience One of:
 808          *   Revision::FOR_PUBLIC       to be displayed to all users
 809          *   Revision::FOR_THIS_USER    to be displayed to the given user
 810          *   Revision::RAW              get the ID regardless of permissions
 811          * @param User $user User object to check for, only if FOR_THIS_USER is passed
 812          *   to the $audience parameter
 813          * @return int
 814          */
 815         public function getUser( $audience = self::FOR_PUBLIC, User $user = null ) {
 816                 if ( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_USER ) ) {
 817                         return 0;
 818                 } elseif ( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_USER, $user ) ) {
 819                         return 0;
 820                 } else {
 821                         return $this->mUser;
 822                 }
 823         }
 824
 825         /**
 826          * Fetch revision's user id without regard for the current user's permissions
 827          *
 828          * @return string
 829          * @deprecated since 1.25, use getUser( Revision::RAW )
 830          */
 831         public function getRawUser() {
 832                 wfDeprecated( __METHOD__, '1.25' );
 833                 return $this->getUser( self::RAW );
 834         }
 835
 836         /**
 837          * Fetch revision's username if it's available to the specified audience.
 838          * If the specified audience does not have access to the username, an
 839          * empty string will be returned.
 840          *
 841          * @param int $audience One of:
 842          *   Revision::FOR_PUBLIC       to be displayed to all users
 843          *   Revision::FOR_THIS_USER    to be displayed to the given user
 844          *   Revision::RAW              get the text regardless of permissions
 845          * @param User $user User object to check for, only if FOR_THIS_USER is passed
 846          *   to the $audience parameter
 847          * @return string
 848          */
 849         public function getUserText( $audience = self::FOR_PUBLIC, User $user = null ) {
 850                 if ( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_USER ) ) {
 851                         return '';
 852                 } elseif ( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_USER, $user ) ) {
 853                         return '';
 854                 } else {
 855                         if ( $this->mUserText === null ) {
 856                                 $this->mUserText = User::whoIs( $this->mUser ); // load on demand
 857                                 if ( $this->mUserText === false ) {
 858                                         # This shouldn't happen, but it can if the wiki was recovered
 859                                         # via importing revs and there is no user table entry yet.
 860                                         $this->mUserText = $this->mOrigUserText;
 861                                 }
 862                         }
 863                         return $this->mUserText;
 864                 }
 865         }
 866
 867         /**
 868          * Fetch revision's username without regard for view restrictions
 869          *
 870          * @return string
 871          * @deprecated since 1.25, use getUserText( Revision::RAW )
 872          */
 873         public function getRawUserText() {
 874                 wfDeprecated( __METHOD__, '1.25' );
 875                 return $this->getUserText( self::RAW );
 876         }
 877
 878         /**
 879          * Fetch revision comment if it's available to the specified audience.
 880          * If the specified audience does not have access to the comment, an
 881          * empty string will be returned.
 882          *
 883          * @param int $audience One of:
 884          *   Revision::FOR_PUBLIC       to be displayed to all users
 885          *   Revision::FOR_THIS_USER    to be displayed to the given user
 886          *   Revision::RAW              get the text regardless of permissions
 887          * @param User $user User object to check for, only if FOR_THIS_USER is passed
 888          *   to the $audience parameter
 889          * @return string
 890          */
 891         function getComment( $audience = self::FOR_PUBLIC, User $user = null ) {
 892                 if ( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_COMMENT ) ) {
 893                         return '';
 894                 } elseif ( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_COMMENT, $user ) ) {
 895                         return '';
 896                 } else {
 897                         return $this->mComment;
 898                 }
 899         }
 900
 901         /**
 902          * Fetch revision comment without regard for the current user's permissions
 903          *
 904          * @return string
 905          * @deprecated since 1.25, use getComment( Revision::RAW )
 906          */
 907         public function getRawComment() {
 908                 wfDeprecated( __METHOD__, '1.25' );
 909                 return $this->getComment( self::RAW );
 910         }
 911
 912         /**
 913          * @return bool
 914          */
 915         public function isMinor() {
 916                 return (bool)$this->mMinorEdit;
 917         }
 918
 919         /**
 920          * @return int Rcid of the unpatrolled row, zero if there isn't one
 921          */
 922         public function isUnpatrolled() {
 923                 if ( $this->mUnpatrolled !== null ) {
 924                         return $this->mUnpatrolled;
 925                 }
 926                 $rc = $this->getRecentChange();
 927                 if ( $rc && $rc->getAttribute( 'rc_patrolled' ) == 0 ) {
 928                         $this->mUnpatrolled = $rc->getAttribute( 'rc_id' );
 929                 } else {
 930                         $this->mUnpatrolled = 0;
 931                 }
 932                 return $this->mUnpatrolled;
 933         }
 934
 935         /**
 936          * Get the RC object belonging to the current revision, if there's one
 937          *
 938          * @since 1.22
 939          * @return RecentChange|null
 940          */
 941         public function getRecentChange() {
 942                 $dbr = wfGetDB( DB_SLAVE );
 943                 return RecentChange::newFromConds(
 944                         array(
 945                                 'rc_user_text' => $this->getUserText( Revision::RAW ),
 946                                 'rc_timestamp' => $dbr->timestamp( $this->getTimestamp() ),
 947                                 'rc_this_oldid' => $this->getId()
 948                         ),
 949                         __METHOD__
 950                 );
 951         }
 952
 953         /**
 954          * @param int $field One of DELETED_* bitfield constants
 955          *
 956          * @return bool
 957          */
 958         public function isDeleted( $field ) {
 959                 return ( $this->mDeleted & $field ) == $field;
 960         }
 961
 962         /**
 963          * Get the deletion bitfield of the revision
 964          *
 965          * @return int
 966          */
 967         public function getVisibility() {
 968                 return (int)$this->mDeleted;
 969         }
 970
 971         /**
 972          * Fetch revision text if it's available to the specified audience.
 973          * If the specified audience does not have the ability to view this
 974          * revision, an empty string will be returned.
 975          *
 976          * @param int $audience One of:
 977          *   Revision::FOR_PUBLIC       to be displayed to all users
 978          *   Revision::FOR_THIS_USER    to be displayed to the given user
 979          *   Revision::RAW              get the text regardless of permissions
 980          * @param User $user User object to check for, only if FOR_THIS_USER is passed
 981          *   to the $audience parameter
 982          *
 983          * @deprecated since 1.21, use getContent() instead
 984          * @todo Replace usage in core
 985          * @return string
 986          */
 987         public function getText( $audience = self::FOR_PUBLIC, User $user = null ) {
 988                 ContentHandler::deprecated( __METHOD__, '1.21' );
 989
 990                 $content = $this->getContent( $audience, $user );
 991                 return ContentHandler::getContentText( $content ); # returns the raw content text, if applicable
 992         }
 993
 994         /**
 995          * Fetch revision content if it's available to the specified audience.
 996          * If the specified audience does not have the ability to view this
 997          * revision, null will be returned.
 998          *
 999          * @param int $audience One of:
1000          *   Revision::FOR_PUBLIC       to be displayed to all users
1001          *   Revision::FOR_THIS_USER    to be displayed to $wgUser
1002          *   Revision::RAW              get the text regardless of permissions
1003          * @param User $user User object to check for, only if FOR_THIS_USER is passed
1004          *   to the $audience parameter
1005          * @since 1.21
1006          * @return Content|null
1007          */
1008         public function getContent( $audience = self::FOR_PUBLIC, User $user = null ) {
1009                 if ( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_TEXT ) ) {
1010                         return null;
1011                 } elseif ( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_TEXT, $user ) ) {
1012                         return null;
1013                 } else {
1014                         return $this->getContentInternal();
1015                 }
1016         }
1017
1018         /**
1019          * Fetch revision text without regard for view restrictions
1020          *
1021          * @return string
1022          *
1023          * @deprecated since 1.21. Instead, use Revision::getContent( Revision::RAW )
1024          *                         or Revision::getSerializedData() as appropriate.
1025          */
1026         public function getRawText() {
1027                 ContentHandler::deprecated( __METHOD__, "1.21" );
1028                 return $this->getText( self::RAW );
1029         }
1030
1031         /**
1032          * Fetch original serialized data without regard for view restrictions
1033          *
1034          * @since 1.21
1035          * @return string
1036          */
1037         public function getSerializedData() {
1038                 if ( $this->mText === null ) {
1039                         $this->mText = $this->loadText();
1040                 }
1041
1042                 return $this->mText;
1043         }
1044
1045         /**
1046          * Gets the content object for the revision (or null on failure).
1047          *
1048          * Note that for mutable Content objects, each call to this method will return a
1049          * fresh clone.
1050          *
1051          * @since 1.21
1052          * @return Content|null The Revision's content, or null on failure.
1053          */
1054         protected function getContentInternal() {
1055                 if ( $this->mContent === null ) {
1056                         // Revision is immutable. Load on demand:
1057                         if ( $this->mText === null ) {
1058                                 $this->mText = $this->loadText();
1059                         }
1060
1061                         if ( $this->mText !== null && $this->mText !== false ) {
1062                                 // Unserialize content
1063                                 $handler = $this->getContentHandler();
1064                                 $format = $this->getContentFormat();
1065
1066                                 $this->mContent = $handler->unserializeContent( $this->mText, $format );
1067                         }
1068                 }
1069
1070                 // NOTE: copy() will return $this for immutable content objects
1071                 return $this->mContent ? $this->mContent->copy() : null;
1072         }
1073
1074         /**
1075          * Returns the content model for this revision.
1076          *
1077          * If no content model was stored in the database, $this->getTitle()->getContentModel() is
1078          * used to determine the content model to use. If no title is know, CONTENT_MODEL_WIKITEXT
1079          * is used as a last resort.
1080          *
1081          * @return string The content model id associated with this revision,
1082          *     see the CONTENT_MODEL_XXX constants.
1083          **/
1084         public function getContentModel() {
1085                 if ( !$this->mContentModel ) {
1086                         $title = $this->getTitle();
1087                         $this->mContentModel = ( $title ? $title->getContentModel() : CONTENT_MODEL_WIKITEXT );
1088
1089                         assert( !empty( $this->mContentModel ) );
1090                 }
1091
1092                 return $this->mContentModel;
1093         }
1094
1095         /**
1096          * Returns the content format for this revision.
1097          *
1098          * If no content format was stored in the database, the default format for this
1099          * revision's content model is returned.
1100          *
1101          * @return string The content format id associated with this revision,
1102          *     see the CONTENT_FORMAT_XXX constants.
1103          **/
1104         public function getContentFormat() {
1105                 if ( !$this->mContentFormat ) {
1106                         $handler = $this->getContentHandler();
1107                         $this->mContentFormat = $handler->getDefaultFormat();
1108
1109                         assert( !empty( $this->mContentFormat ) );
1110                 }
1111
1112                 return $this->mContentFormat;
1113         }
1114
1115         /**
1116          * Returns the content handler appropriate for this revision's content model.
1117          *
1118          * @throws MWException
1119          * @return ContentHandler
1120          */
1121         public function getContentHandler() {
1122                 if ( !$this->mContentHandler ) {
1123                         $model = $this->getContentModel();
1124                         $this->mContentHandler = ContentHandler::getForModelID( $model );
1125
1126                         $format = $this->getContentFormat();
1127
1128                         if ( !$this->mContentHandler->isSupportedFormat( $format ) ) {
1129                                 throw new MWException( "Oops, the content format $format is not supported for "
1130                                         . "this content model, $model" );
1131                         }
1132                 }
1133
1134                 return $this->mContentHandler;
1135         }
1136
1137         /**
1138          * @return string
1139          */
1140         public function getTimestamp() {
1141                 return wfTimestamp( TS_MW, $this->mTimestamp );
1142         }
1143
1144         /**
1145          * @return bool
1146          */
1147         public function isCurrent() {
1148                 return $this->mCurrent;
1149         }
1150
1151         /**
1152          * Get previous revision for this title
1153          *
1154          * @return Revision|null
1155          */
1156         public function getPrevious() {
1157                 if ( $this->getTitle() ) {
1158                         $prev = $this->getTitle()->getPreviousRevisionID( $this->getId() );
1159                         if ( $prev ) {
1160                                 return self::newFromTitle( $this->getTitle(), $prev );
1161                         }
1162                 }
1163                 return null;
1164         }
1165
1166         /**
1167          * Get next revision for this title
1168          *
1169          * @return Revision|null
1170          */
1171         public function getNext() {
1172                 if ( $this->getTitle() ) {
1173                         $next = $this->getTitle()->getNextRevisionID( $this->getId() );
1174                         if ( $next ) {
1175                                 return self::newFromTitle( $this->getTitle(), $next );
1176                         }
1177                 }
1178                 return null;
1179         }
1180
1181         /**
1182          * Get previous revision Id for this page_id
1183          * This is used to populate rev_parent_id on save
1184          *
1185          * @param DatabaseBase $db
1186          * @return int
1187          */
1188         private function getPreviousRevisionId( $db ) {
1189                 if ( $this->mPage === null ) {
1190                         return 0;
1191                 }
1192                 # Use page_latest if ID is not given
1193                 if ( !$this->mId ) {
1194                         $prevId = $db->selectField( 'page', 'page_latest',
1195                                 array( 'page_id' => $this->mPage ),
1196                                 __METHOD__ );
1197                 } else {
1198                         $prevId = $db->selectField( 'revision', 'rev_id',
1199                                 array( 'rev_page' => $this->mPage, 'rev_id < ' . $this->mId ),
1200                                 __METHOD__,
1201                                 array( 'ORDER BY' => 'rev_id DESC' ) );
1202                 }
1203                 return intval( $prevId );
1204         }
1205
1206         /**
1207          * Get revision text associated with an old or archive row
1208          * $row is usually an object from wfFetchRow(), both the flags and the text
1209          * field must be included.
1210          *
1211          * @param stdClass $row The text data
1212          * @param string $prefix Table prefix (default 'old_')
1213          * @param string|bool $wiki The name of the wiki to load the revision text from
1214          *   (same as the the wiki $row was loaded from) or false to indicate the local
1215          *   wiki (this is the default). Otherwise, it must be a symbolic wiki database
1216          *   identifier as understood by the LoadBalancer class.
1217          * @return string Text the text requested or false on failure
1218          */
1219         public static function getRevisionText( $row, $prefix = 'old_', $wiki = false ) {
1220
1221                 # Get data
1222                 $textField = $prefix . 'text';
1223                 $flagsField = $prefix . 'flags';
1224
1225                 if ( isset( $row->$flagsField ) ) {
1226                         $flags = explode( ',', $row->$flagsField );
1227                 } else {
1228                         $flags = array();
1229                 }
1230
1231                 if ( isset( $row->$textField ) ) {
1232                         $text = $row->$textField;
1233                 } else {
1234                         return false;
1235                 }
1236
1237                 # Use external methods for external objects, text in table is URL-only then
1238                 if ( in_array( 'external', $flags ) ) {
1239                         $url = $text;
1240                         $parts = explode( '://', $url, 2 );
1241                         if ( count( $parts ) == 1 || $parts[1] == '' ) {
1242                                 return false;
1243                         }
1244                         $text = ExternalStore::fetchFromURL( $url, array( 'wiki' => $wiki ) );
1245                 }
1246
1247                 // If the text was fetched without an error, convert it
1248                 if ( $text !== false ) {
1249                         $text = self::decompressRevisionText( $text, $flags );
1250                 }
1251                 return $text;
1252         }
1253
1254         /**
1255          * If $wgCompressRevisions is enabled, we will compress data.
1256          * The input string is modified in place.
1257          * Return value is the flags field: contains 'gzip' if the
1258          * data is compressed, and 'utf-8' if we're saving in UTF-8
1259          * mode.
1260          *
1261          * @param mixed $text Reference to a text
1262          * @return string
1263          */
1264         public static function compressRevisionText( &$text ) {
1265                 global $wgCompressRevisions;
1266                 $flags = array();
1267
1268                 # Revisions not marked this way will be converted
1269                 # on load if $wgLegacyCharset is set in the future.
1270                 $flags[] = 'utf-8';
1271
1272                 if ( $wgCompressRevisions ) {
1273                         if ( function_exists( 'gzdeflate' ) ) {
1274                                 $text = gzdeflate( $text );
1275                                 $flags[] = 'gzip';
1276                         } else {
1277                                 wfDebug( __METHOD__ . " -- no zlib support, not compressing\n" );
1278                         }
1279                 }
1280                 return implode( ',', $flags );
1281         }
1282
1283         /**
1284          * Re-converts revision text according to it's flags.
1285          *
1286          * @param mixed $text Reference to a text
1287          * @param array $flags Compression flags
1288          * @return string|bool Decompressed text, or false on failure
1289          */
1290         public static function decompressRevisionText( $text, $flags ) {
1291                 if ( in_array( 'gzip', $flags ) ) {
1292                         # Deal with optional compression of archived pages.
1293                         # This can be done periodically via maintenance/compressOld.php, and
1294                         # as pages are saved if $wgCompressRevisions is set.
1295                         $text = gzinflate( $text );
1296                 }
1297
1298                 if ( in_array( 'object', $flags ) ) {
1299                         # Generic compressed storage
1300                         $obj = unserialize( $text );
1301                         if ( !is_object( $obj ) ) {
1302                                 // Invalid object
1303                                 return false;
1304                         }
1305                         $text = $obj->getText();
1306                 }
1307
1308                 global $wgLegacyEncoding;
1309                 if ( $text !== false && $wgLegacyEncoding
1310                         && !in_array( 'utf-8', $flags ) && !in_array( 'utf8', $flags )
1311                 ) {
1312                         # Old revisions kept around in a legacy encoding?
1313                         # Upconvert on demand.
1314                         # ("utf8" checked for compatibility with some broken
1315                         #  conversion scripts 2008-12-30)
1316                         global $wgContLang;
1317                         $text = $wgContLang->iconv( $wgLegacyEncoding, 'UTF-8', $text );
1318                 }
1319
1320                 return $text;
1321         }
1322
1323         /**
1324          * Insert a new revision into the database, returning the new revision ID
1325          * number on success and dies horribly on failure.
1326          *
1327          * @param DatabaseBase $dbw (master connection)
1328          * @throws MWException
1329          * @return int
1330          */
1331         public function insertOn( $dbw ) {
1332                 global $wgDefaultExternalStore, $wgContentHandlerUseDB;
1333
1334                 $this->checkContentModel();
1335
1336                 $data = $this->mText;
1337                 $flags = self::compressRevisionText( $data );
1338
1339                 # Write to external storage if required
1340                 if ( $wgDefaultExternalStore ) {
1341                         // Store and get the URL
1342                         $data = ExternalStore::insertToDefault( $data );
1343                         if ( !$data ) {
1344                                 throw new MWException( "Unable to store text to external storage" );
1345                         }
1346                         if ( $flags ) {
1347                                 $flags .= ',';
1348                         }
1349                         $flags .= 'external';
1350                 }
1351
1352                 # Record the text (or external storage URL) to the text table
1353                 if ( $this->mTextId === null ) {
1354                         $old_id = $dbw->nextSequenceValue( 'text_old_id_seq' );
1355                         $dbw->insert( 'text',
1356                                 array(
1357                                         'old_id' => $old_id,
1358                                         'old_text' => $data,
1359                                         'old_flags' => $flags,
1360                                 ), __METHOD__
1361                         );
1362                         $this->mTextId = $dbw->insertId();
1363                 }
1364
1365                 if ( $this->mComment === null ) {
1366                         $this->mComment = "";
1367                 }
1368
1369                 # Record the edit in revisions
1370                 $rev_id = $this->mId !== null
1371                         ? $this->mId
1372                         : $dbw->nextSequenceValue( 'revision_rev_id_seq' );
1373                 $row = array(
1374                         'rev_id'         => $rev_id,
1375                         'rev_page'       => $this->mPage,
1376                         'rev_text_id'    => $this->mTextId,
1377                         'rev_comment'    => $this->mComment,
1378                         'rev_minor_edit' => $this->mMinorEdit ? 1 : 0,
1379                         'rev_user'       => $this->mUser,
1380                         'rev_user_text'  => $this->mUserText,
1381                         'rev_timestamp'  => $dbw->timestamp( $this->mTimestamp ),
1382                         'rev_deleted'    => $this->mDeleted,
1383                         'rev_len'        => $this->mSize,
1384                         'rev_parent_id'  => $this->mParentId === null
1385                                 ? $this->getPreviousRevisionId( $dbw )
1386                                 : $this->mParentId,
1387                         'rev_sha1'       => $this->mSha1 === null
1388                                 ? Revision::base36Sha1( $this->mText )
1389                                 : $this->mSha1,
1390                 );
1391
1392                 if ( $wgContentHandlerUseDB ) {
1393                         //NOTE: Store null for the default model and format, to save space.
1394                         //XXX: Makes the DB sensitive to changed defaults.
1395                         // Make this behavior optional? Only in miser mode?
1396
1397                         $model = $this->getContentModel();
1398                         $format = $this->getContentFormat();
1399
1400                         $title = $this->getTitle();
1401
1402                         if ( $title === null ) {
1403                                 throw new MWException( "Insufficient information to determine the title of the "
1404                                         . "revision's page!" );
1405                         }
1406
1407                         $defaultModel = ContentHandler::getDefaultModelFor( $title );
1408                         $defaultFormat = ContentHandler::getForModelID( $defaultModel )->getDefaultFormat();
1409
1410                         $row['rev_content_model'] = ( $model === $defaultModel ) ? null : $model;
1411                         $row['rev_content_format'] = ( $format === $defaultFormat ) ? null : $format;
1412                 }
1413
1414                 $dbw->insert( 'revision', $row, __METHOD__ );
1415
1416                 $this->mId = $rev_id !== null ? $rev_id : $dbw->insertId();
1417
1418                 Hooks::run( 'RevisionInsertComplete', array( &$this, $data, $flags ) );
1419
1420                 return $this->mId;
1421         }
1422
1423         protected function checkContentModel() {
1424                 global $wgContentHandlerUseDB;
1425
1426                 $title = $this->getTitle(); //note: may return null for revisions that have not yet been inserted.
1427
1428                 $model = $this->getContentModel();
1429                 $format = $this->getContentFormat();
1430                 $handler = $this->getContentHandler();
1431
1432                 if ( !$handler->isSupportedFormat( $format ) ) {
1433                         $t = $title->getPrefixedDBkey();
1434
1435                         throw new MWException( "Can't use format $format with content model $model on $t" );
1436                 }
1437
1438                 if ( !$wgContentHandlerUseDB && $title ) {
1439                         // if $wgContentHandlerUseDB is not set,
1440                         // all revisions must use the default content model and format.
1441
1442                         $defaultModel = ContentHandler::getDefaultModelFor( $title );
1443                         $defaultHandler = ContentHandler::getForModelID( $defaultModel );
1444                         $defaultFormat = $defaultHandler->getDefaultFormat();
1445
1446                         if ( $this->getContentModel() != $defaultModel ) {
1447                                 $t = $title->getPrefixedDBkey();
1448
1449                                 throw new MWException( "Can't save non-default content model with "
1450                                         . "\$wgContentHandlerUseDB disabled: model is $model, "
1451                                         . "default for $t is $defaultModel" );
1452                         }
1453
1454                         if ( $this->getContentFormat() != $defaultFormat ) {
1455                                 $t = $title->getPrefixedDBkey();
1456
1457                                 throw new MWException( "Can't use non-default content format with "
1458                                         . "\$wgContentHandlerUseDB disabled: format is $format, "
1459                                         . "default for $t is $defaultFormat" );
1460                         }
1461                 }
1462
1463                 $content = $this->getContent( Revision::RAW );
1464
1465                 if ( !$content || !$content->isValid() ) {
1466                         $t = $title->getPrefixedDBkey();
1467
1468                         throw new MWException( "Content of $t is not valid! Content model is $model" );
1469                 }
1470         }
1471
1472         /**
1473          * Get the base 36 SHA-1 value for a string of text
1474          * @param string $text
1475          * @return string
1476          */
1477         public static function base36Sha1( $text ) {
1478                 return wfBaseConvert( sha1( $text ), 16, 36, 31 );
1479         }
1480
1481         /**
1482          * Lazy-load the revision's text.
1483          * Currently hardcoded to the 'text' table storage engine.
1484          *
1485          * @return string|bool The revision's text, or false on failure
1486          */
1487         protected function loadText() {
1488
1489                 // Caching may be beneficial for massive use of external storage
1490                 global $wgRevisionCacheExpiry, $wgMemc;
1491                 $textId = $this->getTextId();
1492                 $key = wfMemcKey( 'revisiontext', 'textid', $textId );
1493                 if ( $wgRevisionCacheExpiry ) {
1494                         $text = $wgMemc->get( $key );
1495                         if ( is_string( $text ) ) {
1496                                 wfDebug( __METHOD__ . ": got id $textId from cache\n" );
1497                                 return $text;
1498                         }
1499                 }
1500
1501                 // If we kept data for lazy extraction, use it now...
1502                 if ( $this->mTextRow !== null ) {
1503                         $row = $this->mTextRow;
1504                         $this->mTextRow = null;
1505                 } else {
1506                         $row = null;
1507                 }
1508
1509                 if ( !$row ) {
1510                         // Text data is immutable; check slaves first.
1511                         $dbr = wfGetDB( DB_SLAVE );
1512                         $row = $dbr->selectRow( 'text',
1513                                 array( 'old_text', 'old_flags' ),
1514                                 array( 'old_id' => $textId ),
1515                                 __METHOD__ );
1516                 }
1517
1518                 // Fallback to the master in case of slave lag. Also use FOR UPDATE if it was
1519                 // used to fetch this revision to avoid missing the row due to REPEATABLE-READ.
1520                 $forUpdate = ( $this->mQueryFlags & self::READ_LOCKING == self::READ_LOCKING );
1521                 if ( !$row && ( $forUpdate || wfGetLB()->getServerCount() > 1 ) ) {
1522                         $dbw = wfGetDB( DB_MASTER );
1523                         $row = $dbw->selectRow( 'text',
1524                                 array( 'old_text', 'old_flags' ),
1525                                 array( 'old_id' => $textId ),
1526                                 __METHOD__,
1527                                 $forUpdate ? array( 'FOR UPDATE' ) : array() );
1528                 }
1529
1530                 if ( !$row ) {
1531                         wfDebugLog( 'Revision', "No text row with ID '$textId' (revision {$this->getId()})." );
1532                 }
1533
1534                 $text = self::getRevisionText( $row );
1535                 if ( $row && $text === false ) {
1536                         wfDebugLog( 'Revision', "No blob for text row '$textId' (revision {$this->getId()})." );
1537                 }
1538
1539                 # No negative caching -- negative hits on text rows may be due to corrupted slave servers
1540                 if ( $wgRevisionCacheExpiry && $text !== false ) {
1541                         $wgMemc->set( $key, $text, $wgRevisionCacheExpiry );
1542                 }
1543
1544                 return $text;
1545         }
1546
1547         /**
1548          * Create a new null-revision for insertion into a page's
1549          * history. This will not re-save the text, but simply refer
1550          * to the text from the previous version.
1551          *
1552          * Such revisions can for instance identify page rename
1553          * operations and other such meta-modifications.
1554          *
1555          * @param DatabaseBase $dbw
1556          * @param int $pageId ID number of the page to read from
1557          * @param string $summary Revision's summary
1558          * @param bool $minor Whether the revision should be considered as minor
1559          * @param User|null $user User object to use or null for $wgUser
1560          * @return Revision|null Revision or null on error
1561          */
1562         public static function newNullRevision( $dbw, $pageId, $summary, $minor, $user = null ) {
1563                 global $wgContentHandlerUseDB;
1564
1565                 $fields = array( 'page_latest', 'page_namespace', 'page_title',
1566                                                 'rev_text_id', 'rev_len', 'rev_sha1' );
1567
1568                 if ( $wgContentHandlerUseDB ) {
1569                         $fields[] = 'rev_content_model';
1570                         $fields[] = 'rev_content_format';
1571                 }
1572
1573                 $current = $dbw->selectRow(
1574                         array( 'page', 'revision' ),
1575                         $fields,
1576                         array(
1577                                 'page_id' => $pageId,
1578                                 'page_latest=rev_id',
1579                                 ),
1580                         __METHOD__ );
1581
1582                 if ( $current ) {
1583                         if ( !$user ) {
1584                                 global $wgUser;
1585                                 $user = $wgUser;
1586                         }
1587
1588                         $row = array(
1589                                 'page'       => $pageId,
1590                                 'user_text'  => $user->getName(),
1591                                 'user'       => $user->getId(),
1592                                 'comment'    => $summary,
1593                                 'minor_edit' => $minor,
1594                                 'text_id'    => $current->rev_text_id,
1595                                 'parent_id'  => $current->page_latest,
1596                                 'len'        => $current->rev_len,
1597                                 'sha1'       => $current->rev_sha1
1598                         );
1599
1600                         if ( $wgContentHandlerUseDB ) {
1601                                 $row['content_model'] = $current->rev_content_model;
1602                                 $row['content_format'] = $current->rev_content_format;
1603                         }
1604
1605                         $revision = new Revision( $row );
1606                         $revision->setTitle( Title::makeTitle( $current->page_namespace, $current->page_title ) );
1607                 } else {
1608                         $revision = null;
1609                 }
1610
1611                 return $revision;
1612         }
1613
1614         /**
1615          * Determine if the current user is allowed to view a particular
1616          * field of this revision, if it's marked as deleted.
1617          *
1618          * @param int $field One of self::DELETED_TEXT,
1619          *                              self::DELETED_COMMENT,
1620          *                              self::DELETED_USER
1621          * @param User|null $user User object to check, or null to use $wgUser
1622          * @return bool
1623          */
1624         public function userCan( $field, User $user = null ) {
1625                 return self::userCanBitfield( $this->mDeleted, $field, $user );
1626         }
1627
1628         /**
1629          * Determine if the current user is allowed to view a particular
1630          * field of this revision, if it's marked as deleted. This is used
1631          * by various classes to avoid duplication.
1632          *
1633          * @param int $bitfield Current field
1634          * @param int $field One of self::DELETED_TEXT = File::DELETED_FILE,
1635          *                               self::DELETED_COMMENT = File::DELETED_COMMENT,
1636          *                               self::DELETED_USER = File::DELETED_USER
1637          * @param User|null $user User object to check, or null to use $wgUser
1638          * @param Title|null $title A Title object to check for per-page restrictions on,
1639          *                          instead of just plain userrights
1640          * @return bool
1641          */
1642         public static function userCanBitfield( $bitfield, $field, User $user = null,
1643                 Title $title = null
1644         ) {
1645                 if ( $bitfield & $field ) { // aspect is deleted
1646                         if ( $user === null ) {
1647                                 global $wgUser;
1648                                 $user = $wgUser;
1649                         }
1650                         if ( $bitfield & self::DELETED_RESTRICTED ) {
1651                                 $permissions = array( 'suppressrevision', 'viewsuppressed' );
1652                         } elseif ( $field & self::DELETED_TEXT ) {
1653                                 $permissions = array( 'deletedtext' );
1654                         } else {
1655                                 $permissions = array( 'deletedhistory' );
1656                         }
1657                         $permissionlist = implode( ', ', $permissions );
1658                         if ( $title === null ) {
1659                                 wfDebug( "Checking for $permissionlist due to $field match on $bitfield\n" );
1660                                 return call_user_func_array( array( $user, 'isAllowedAny' ), $permissions );
1661                         } else {
1662                                 $text = $title->getPrefixedText();
1663                                 wfDebug( "Checking for $permissionlist on $text due to $field match on $bitfield\n" );
1664                                 foreach ( $permissions as $perm ) {
1665                                         if ( $title->userCan( $perm, $user ) ) {
1666                                                 return true;
1667                                         }
1668                                 }
1669                                 return false;
1670                         }
1671                 } else {
1672                         return true;
1673                 }
1674         }
1675
1676         /**
1677          * Get rev_timestamp from rev_id, without loading the rest of the row
1678          *
1679          * @param Title $title
1680          * @param int $id
1681          * @return string
1682          */
1683         static function getTimestampFromId( $title, $id ) {
1684                 $dbr = wfGetDB( DB_SLAVE );
1685                 // Casting fix for databases that can't take '' for rev_id
1686                 if ( $id == '' ) {
1687                         $id = 0;
1688                 }
1689                 $conds = array( 'rev_id' => $id );
1690                 $conds['rev_page'] = $title->getArticleID();
1691                 $timestamp = $dbr->selectField( 'revision', 'rev_timestamp', $conds, __METHOD__ );
1692                 if ( $timestamp === false && wfGetLB()->getServerCount() > 1 ) {
1693                         # Not in slave, try master
1694                         $dbw = wfGetDB( DB_MASTER );
1695                         $timestamp = $dbw->selectField( 'revision', 'rev_timestamp', $conds, __METHOD__ );
1696                 }
1697                 return wfTimestamp( TS_MW, $timestamp );
1698         }
1699
1700         /**
1701          * Get count of revisions per page...not very efficient
1702          *
1703          * @param DatabaseBase $db
1704          * @param int $id Page id
1705          * @return int
1706          */
1707         static function countByPageId( $db, $id ) {
1708                 $row = $db->selectRow( 'revision', array( 'revCount' => 'COUNT(*)' ),
1709                         array( 'rev_page' => $id ), __METHOD__ );
1710                 if ( $row ) {
1711                         return $row->revCount;
1712                 }
1713                 return 0;
1714         }
1715
1716         /**
1717          * Get count of revisions per page...not very efficient
1718          *
1719          * @param DatabaseBase $db
1720          * @param Title $title
1721          * @return int
1722          */
1723         static function countByTitle( $db, $title ) {
1724                 $id = $title->getArticleID();
1725                 if ( $id ) {
1726                         return self::countByPageId( $db, $id );
1727                 }
1728                 return 0;
1729         }
1730
1731         /**
1732          * Check if no edits were made by other users since
1733          * the time a user started editing the page. Limit to
1734          * 50 revisions for the sake of performance.
1735          *
1736          * @since 1.20
1737          * @deprecated since 1.24
1738          *
1739          * @param DatabaseBase|int $db The Database to perform the check on. May be given as a
1740          *        Database object or a database identifier usable with wfGetDB.
1741          * @param int $pageId The ID of the page in question
1742          * @param int $userId The ID of the user in question
1743          * @param string $since Look at edits since this time
1744          *
1745          * @return bool True if the given user was the only one to edit since the given timestamp
1746          */
1747         public static function userWasLastToEdit( $db, $pageId, $userId, $since ) {
1748                 if ( !$userId ) {
1749                         return false;
1750                 }
1751
1752                 if ( is_int( $db ) ) {
1753                         $db = wfGetDB( $db );
1754                 }
1755
1756                 $res = $db->select( 'revision',
1757                         'rev_user',
1758                         array(
1759                                 'rev_page' => $pageId,
1760                                 'rev_timestamp > ' . $db->addQuotes( $db->timestamp( $since ) )
1761                         ),
1762                         __METHOD__,
1763                         array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 50 ) );
1764                 foreach ( $res as $row ) {
1765                         if ( $row->rev_user != $userId ) {
1766                                 return false;
1767                         }
1768                 }
1769                 return true;
1770         }
1771 }