includes/Revision.php

   1 <?php
   2
   3 /**
   4  * @todo document
   5  */
   6 class Revision {
   7         protected $mId;
   8         protected $mPage;
   9         protected $mUserText;
  10         protected $mOrigUserText;
  11         protected $mUser;
  12         protected $mMinorEdit;
  13         protected $mTimestamp;
  14         protected $mDeleted;
  15         protected $mSize;
  16         protected $mParentId;
  17         protected $mComment;
  18         protected $mText;
  19         protected $mTextRow;
  20         protected $mTitle;
  21         protected $mCurrent;
  22
  23         const DELETED_TEXT = 1;
  24         const DELETED_COMMENT = 2;
  25         const DELETED_USER = 4;
  26         const DELETED_RESTRICTED = 8;
  27         // Convenience field
  28         const SUPPRESSED_USER = 12;
  29         // Audience options for Revision::getText()
  30         const FOR_PUBLIC = 1;
  31         const FOR_THIS_USER = 2;
  32         const RAW = 3;
  33
  34         /**
  35          * Load a page revision from a given revision ID number.
  36          * Returns null if no such revision can be found.
  37          *
  38          * @param $id Integer
  39          * @return Revision or null
  40          */
  41         public static function newFromId( $id ) {
  42                 return Revision::newFromConds( array( 'rev_id' => intval( $id ) ) );
  43         }
  44
  45         /**
  46          * Load either the current, or a specified, revision
  47          * that's attached to a given title. If not attached
  48          * to that title, will return null.
  49          *
  50          * @param $title Title
  51          * @param $id Integer (optional)
  52          * @return Revision or null
  53          */
  54         public static function newFromTitle( $title, $id = 0 ) {
  55                 $conds = array(
  56                         'page_namespace' => $title->getNamespace(),
  57                         'page_title'     => $title->getDBkey()
  58                 );
  59                 if ( $id ) {
  60                         // Use the specified ID
  61                         $conds['rev_id'] = $id;
  62                 } elseif ( wfGetLB()->getServerCount() > 1 ) {
  63                         // Get the latest revision ID from the master
  64                         $dbw = wfGetDB( DB_MASTER );
  65                         $latest = $dbw->selectField( 'page', 'page_latest', $conds, __METHOD__ );
  66                         if ( $latest === false ) {
  67                                 return null; // page does not exist
  68                         }
  69                         $conds['rev_id'] = $latest;
  70                 } else {
  71                         // Use a join to get the latest revision
  72                         $conds[] = 'rev_id=page_latest';
  73                 }
  74                 return Revision::newFromConds( $conds );
  75         }
  76
  77         /**
  78          * Load either the current, or a specified, revision
  79          * that's attached to a given page ID.
  80          * Returns null if no such revision can be found.
  81          *
  82          * @param $revId Integer
  83          * @param $pageId Integer (optional)
  84          * @return Revision or null
  85          */
  86         public static function newFromPageId( $pageId, $revId = 0 ) {
  87                 $conds = array( 'page_id' => $pageId );
  88                 if ( $revId ) {
  89                         $conds['rev_id'] = $revId;
  90                 } elseif ( wfGetLB()->getServerCount() > 1 ) {
  91                         // Get the latest revision ID from the master
  92                         $dbw = wfGetDB( DB_MASTER );
  93                         $latest = $dbw->selectField( 'page', 'page_latest', $conds, __METHOD__ );
  94                         if ( $latest === false ) {
  95                                 return null; // page does not exist
  96                         }
  97                         $conds['rev_id'] = $latest;
  98                 } else {
  99                         $conds[] = 'rev_id = page_latest';
 100                 }
 101                 return Revision::newFromConds( $conds );
 102         }
 103
 104         /**
 105          * Make a fake revision object from an archive table row. This is queried
 106          * for permissions or even inserted (as in Special:Undelete)
 107          * @todo FIXME: Should be a subclass for RevisionDelete. [TS]
 108          *
 109          * @param $row
 110          * @param $overrides array
 111          *
 112          * @return Revision
 113          */
 114         public static function newFromArchiveRow( $row, $overrides = array() ) {
 115                 $attribs = $overrides + array(
 116                         'page'       => isset( $row->ar_page_id ) ? $row->ar_page_id : null,
 117                         'id'         => isset( $row->ar_rev_id ) ? $row->ar_rev_id : null,
 118                         'comment'    => $row->ar_comment,
 119                         'user'       => $row->ar_user,
 120                         'user_text'  => $row->ar_user_text,
 121                         'timestamp'  => $row->ar_timestamp,
 122                         'minor_edit' => $row->ar_minor_edit,
 123                         'text_id'    => isset( $row->ar_text_id ) ? $row->ar_text_id : null,
 124                         'deleted'    => $row->ar_deleted,
 125                         'len'        => $row->ar_len
 126                 );
 127                 if ( isset( $row->ar_text ) && !$row->ar_text_id ) {
 128                         // Pre-1.5 ar_text row
 129                         $attribs['text'] = self::getRevisionText( $row, 'ar_' );
 130                         if ( $attribs['text'] === false ) {
 131                                 throw new MWException( 'Unable to load text from archive row (possibly bug 22624)' );
 132                         }
 133                 }
 134                 return new self( $attribs );
 135         }
 136
 137         /**
 138          * @since 1.19
 139          *
 140          * @param $row
 141          * @return Revision
 142          */
 143         public static function newFromRow( $row ) {
 144                 return new self( $row );
 145         }
 146
 147         /**
 148          * Load a page revision from a given revision ID number.
 149          * Returns null if no such revision can be found.
 150          *
 151          * @param $db DatabaseBase
 152          * @param $id Integer
 153          * @return Revision or null
 154          */
 155         public static function loadFromId( $db, $id ) {
 156                 return Revision::loadFromConds( $db, array( 'rev_id' => intval( $id ) ) );
 157         }
 158
 159         /**
 160          * Load either the current, or a specified, revision
 161          * that's attached to a given page. If not attached
 162          * to that page, will return null.
 163          *
 164          * @param $db DatabaseBase
 165          * @param $pageid Integer
 166          * @param $id Integer
 167          * @return Revision or null
 168          */
 169         public static function loadFromPageId( $db, $pageid, $id = 0 ) {
 170                 $conds = array( 'rev_page' => intval( $pageid ), 'page_id'  => intval( $pageid ) );
 171                 if( $id ) {
 172                         $conds['rev_id'] = intval( $id );
 173                 } else {
 174                         $conds[] = 'rev_id=page_latest';
 175                 }
 176                 return Revision::loadFromConds( $db, $conds );
 177         }
 178
 179         /**
 180          * Load either the current, or a specified, revision
 181          * that's attached to a given page. If not attached
 182          * to that page, will return null.
 183          *
 184          * @param $db DatabaseBase
 185          * @param $title Title
 186          * @param $id Integer
 187          * @return Revision or null
 188          */
 189         public static function loadFromTitle( $db, $title, $id = 0 ) {
 190                 if( $id ) {
 191                         $matchId = intval( $id );
 192                 } else {
 193                         $matchId = 'page_latest';
 194                 }
 195                 return Revision::loadFromConds( $db,
 196                         array( "rev_id=$matchId",
 197                                    'page_namespace' => $title->getNamespace(),
 198                                    'page_title'     => $title->getDBkey() )
 199                 );
 200         }
 201
 202         /**
 203          * Load the revision for the given title with the given timestamp.
 204          * WARNING: Timestamps may in some circumstances not be unique,
 205          * so this isn't the best key to use.
 206          *
 207          * @param $db DatabaseBase
 208          * @param $title Title
 209          * @param $timestamp String
 210          * @return Revision or null
 211          */
 212         public static function loadFromTimestamp( $db, $title, $timestamp ) {
 213                 return Revision::loadFromConds( $db,
 214                         array( 'rev_timestamp'  => $db->timestamp( $timestamp ),
 215                                    'page_namespace' => $title->getNamespace(),
 216                                    'page_title'     => $title->getDBkey() )
 217                 );
 218         }
 219
 220         /**
 221          * Given a set of conditions, fetch a revision.
 222          *
 223          * @param $conditions Array
 224          * @return Revision or null
 225          */
 226         public static function newFromConds( $conditions ) {
 227                 $db = wfGetDB( DB_SLAVE );
 228                 $rev = Revision::loadFromConds( $db, $conditions );
 229                 if( is_null( $rev ) && wfGetLB()->getServerCount() > 1 ) {
 230                         $dbw = wfGetDB( DB_MASTER );
 231                         $rev = Revision::loadFromConds( $dbw, $conditions );
 232                 }
 233                 return $rev;
 234         }
 235
 236         /**
 237          * Given a set of conditions, fetch a revision from
 238          * the given database connection.
 239          *
 240          * @param $db DatabaseBase
 241          * @param $conditions Array
 242          * @return Revision or null
 243          */
 244         private static function loadFromConds( $db, $conditions ) {
 245                 $res = Revision::fetchFromConds( $db, $conditions );
 246                 if( $res ) {
 247                         $row = $res->fetchObject();
 248                         if( $row ) {
 249                                 $ret = new Revision( $row );
 250                                 return $ret;
 251                         }
 252                 }
 253                 $ret = null;
 254                 return $ret;
 255         }
 256
 257         /**
 258          * Return a wrapper for a series of database rows to
 259          * fetch all of a given page's revisions in turn.
 260          * Each row can be fed to the constructor to get objects.
 261          *
 262          * @param $title Title
 263          * @return ResultWrapper
 264          */
 265         public static function fetchRevision( $title ) {
 266                 return Revision::fetchFromConds(
 267                         wfGetDB( DB_SLAVE ),
 268                         array( 'rev_id=page_latest',
 269                                    'page_namespace' => $title->getNamespace(),
 270                                    'page_title'     => $title->getDBkey() )
 271                 );
 272         }
 273
 274         /**
 275          * Given a set of conditions, return a ResultWrapper
 276          * which will return matching database rows with the
 277          * fields necessary to build Revision objects.
 278          *
 279          * @param $db DatabaseBase
 280          * @param $conditions Array
 281          * @return ResultWrapper
 282          */
 283         private static function fetchFromConds( $db, $conditions ) {
 284                 $fields = array_merge(
 285                         self::selectFields(),
 286                         self::selectPageFields(),
 287                         self::selectUserFields()
 288                 );
 289                 return $db->select(
 290                         array( 'revision', 'page', 'user' ),
 291                         $fields,
 292                         $conditions,
 293                         __METHOD__,
 294                         array( 'LIMIT' => 1 ),
 295                         array( 'page' => array( 'INNER JOIN', 'page_id = rev_page' ),
 296                                 'user' => array( 'LEFT JOIN', 'rev_user != 0 AND user_id = rev_user' ) )
 297                 );
 298         }
 299
 300         /**
 301          * Return the list of revision fields that should be selected to create
 302          * a new revision.
 303          */
 304         public static function selectFields() {
 305                 return array(
 306                         'rev_id',
 307                         'rev_page',
 308                         'rev_text_id',
 309                         'rev_timestamp',
 310                         'rev_comment',
 311                         'rev_user_text',
 312                         'rev_user',
 313                         'rev_minor_edit',
 314                         'rev_deleted',
 315                         'rev_len',
 316                         'rev_parent_id'
 317                 );
 318         }
 319
 320         /**
 321          * Return the list of text fields that should be selected to read the
 322          * revision text
 323          */
 324         public static function selectTextFields() {
 325                 return array(
 326                         'old_text',
 327                         'old_flags'
 328                 );
 329         }
 330
 331         /**
 332          * Return the list of page fields that should be selected from page table
 333          */
 334         public static function selectPageFields() {
 335                 return array(
 336                         'page_namespace',
 337                         'page_title',
 338                         'page_latest'
 339                 );
 340         }
 341
 342         /**
 343          * Return the list of user fields that should be selected from user table
 344          */
 345         public static function selectUserFields() {
 346                 return array( 'user_name' );
 347         }
 348
 349         /**
 350          * Constructor
 351          *
 352          * @param $row Mixed: either a database row or an array
 353          * @access private
 354          */
 355         function __construct( $row ) {
 356                 if( is_object( $row ) ) {
 357                         $this->mId        = intval( $row->rev_id );
 358                         $this->mPage      = intval( $row->rev_page );
 359                         $this->mTextId    = intval( $row->rev_text_id );
 360                         $this->mComment   =         $row->rev_comment;
 361                         $this->mUser      = intval( $row->rev_user );
 362                         $this->mMinorEdit = intval( $row->rev_minor_edit );
 363                         $this->mTimestamp =         $row->rev_timestamp;
 364                         $this->mDeleted   = intval( $row->rev_deleted );
 365
 366                         if( !isset( $row->rev_parent_id ) ) {
 367                                 $this->mParentId = is_null( $row->rev_parent_id ) ? null : 0;
 368                         } else {
 369                                 $this->mParentId  = intval( $row->rev_parent_id );
 370                         }
 371
 372                         if( !isset( $row->rev_len ) || is_null( $row->rev_len ) ) {
 373                                 $this->mSize = null;
 374                         } else {
 375                                 $this->mSize = intval( $row->rev_len );
 376                         }
 377
 378                         if( isset( $row->page_latest ) ) {
 379                                 $this->mCurrent = ( $row->rev_id == $row->page_latest );
 380                                 $this->mTitle = Title::newFromRow( $row );
 381                         } else {
 382                                 $this->mCurrent = false;
 383                                 $this->mTitle = null;
 384                         }
 385
 386                         // Lazy extraction...
 387                         $this->mText      = null;
 388                         if( isset( $row->old_text ) ) {
 389                                 $this->mTextRow = $row;
 390                         } else {
 391                                 // 'text' table row entry will be lazy-loaded
 392                                 $this->mTextRow = null;
 393                         }
 394
 395                         // Use user_name for users and rev_user_text for IPs...
 396                         $this->mUserText = null; // lazy load if left null
 397                         if ( $this->mUser == 0 ) {
 398                                 $this->mUserText = $row->rev_user_text; // IP user
 399                         } elseif ( isset( $row->user_name ) ) {
 400                                 $this->mUserText = $row->user_name; // logged-in user
 401                         }
 402                         $this->mOrigUserText = $row->rev_user_text;
 403                 } elseif( is_array( $row ) ) {
 404                         // Build a new revision to be saved...
 405                         global $wgUser;
 406
 407                         $this->mId        = isset( $row['id']         ) ? intval( $row['id']         ) : null;
 408                         $this->mPage      = isset( $row['page']       ) ? intval( $row['page']       ) : null;
 409                         $this->mTextId    = isset( $row['text_id']    ) ? intval( $row['text_id']    ) : null;
 410                         $this->mUserText  = isset( $row['user_text']  ) ? strval( $row['user_text']  ) : $wgUser->getName();
 411                         $this->mUser      = isset( $row['user']       ) ? intval( $row['user']       ) : $wgUser->getId();
 412                         $this->mMinorEdit = isset( $row['minor_edit'] ) ? intval( $row['minor_edit'] ) : 0;
 413                         $this->mTimestamp = isset( $row['timestamp']  ) ? strval( $row['timestamp']  ) : wfTimestamp( TS_MW );
 414                         $this->mDeleted   = isset( $row['deleted']    ) ? intval( $row['deleted']    ) : 0;
 415                         $this->mSize      = isset( $row['len']        ) ? intval( $row['len']        ) : null;
 416                         $this->mParentId  = isset( $row['parent_id']  ) ? intval( $row['parent_id']  ) : null;
 417
 418                         // Enforce spacing trimming on supplied text
 419                         $this->mComment   = isset( $row['comment']    ) ?  trim( strval( $row['comment'] ) ) : null;
 420                         $this->mText      = isset( $row['text']       ) ? rtrim( strval( $row['text']    ) ) : null;
 421                         $this->mTextRow   = null;
 422
 423                         $this->mTitle     = null; # Load on demand if needed
 424                         $this->mCurrent   = false;
 425                         # If we still have no len_size, see it we have the text to figure it out
 426                         if ( !$this->mSize ) {
 427                                 $this->mSize      = is_null( $this->mText ) ? null : strlen( $this->mText );
 428                         }
 429                 } else {
 430                         throw new MWException( 'Revision constructor passed invalid row format.' );
 431                 }
 432                 $this->mUnpatrolled = null;
 433         }
 434
 435         /**
 436          * Get revision ID
 437          *
 438          * @return Integer
 439          */
 440         public function getId() {
 441                 return $this->mId;
 442         }
 443
 444         /**
 445          * Get text row ID
 446          *
 447          * @return Integer
 448          */
 449         public function getTextId() {
 450                 return $this->mTextId;
 451         }
 452
 453         /**
 454          * Get parent revision ID (the original previous page revision)
 455          *
 456          * @return Integer
 457          */
 458         public function getParentId() {
 459                 return $this->mParentId;
 460         }
 461
 462         /**
 463          * Returns the length of the text in this revision, or null if unknown.
 464          *
 465          * @return Integer
 466          */
 467         public function getSize() {
 468                 return $this->mSize;
 469         }
 470
 471         /**
 472          * Returns the title of the page associated with this entry.
 473          *
 474          * @return Title
 475          */
 476         public function getTitle() {
 477                 if( isset( $this->mTitle ) ) {
 478                         return $this->mTitle;
 479                 }
 480                 $dbr = wfGetDB( DB_SLAVE );
 481                 $row = $dbr->selectRow(
 482                         array( 'page', 'revision' ),
 483                         array( 'page_namespace', 'page_title' ),
 484                         array( 'page_id=rev_page',
 485                                    'rev_id' => $this->mId ),
 486                         'Revision::getTitle' );
 487                 if( $row ) {
 488                         $this->mTitle = Title::makeTitle( $row->page_namespace, $row->page_title );
 489                 }
 490                 return $this->mTitle;
 491         }
 492
 493         /**
 494          * Set the title of the revision
 495          *
 496          * @param $title Title
 497          */
 498         public function setTitle( $title ) {
 499                 $this->mTitle = $title;
 500         }
 501
 502         /**
 503          * Get the page ID
 504          *
 505          * @return Integer
 506          */
 507         public function getPage() {
 508                 return $this->mPage;
 509         }
 510
 511         /**
 512          * Fetch revision's user id if it's available to the specified audience.
 513          * If the specified audience does not have access to it, zero will be
 514          * returned.
 515          *
 516          * @param $audience Integer: one of:
 517          *      Revision::FOR_PUBLIC       to be displayed to all users
 518          *      Revision::FOR_THIS_USER    to be displayed to $wgUser
 519          *      Revision::RAW              get the ID regardless of permissions
 520          * @param $user User object to check for, only if FOR_THIS_USER is passed
 521          *              to the $audience parameter
 522          * @return Integer
 523          */
 524         public function getUser( $audience = self::FOR_PUBLIC, User $user = null ) {
 525                 if( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_USER ) ) {
 526                         return 0;
 527                 } elseif( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_USER, $user ) ) {
 528                         return 0;
 529                 } else {
 530                         return $this->mUser;
 531                 }
 532         }
 533
 534         /**
 535          * Fetch revision's user id without regard for the current user's permissions
 536          *
 537          * @return String
 538          */
 539         public function getRawUser() {
 540                 return $this->mUser;
 541         }
 542
 543         /**
 544          * Fetch revision's username if it's available to the specified audience.
 545          * If the specified audience does not have access to the username, an
 546          * empty string will be returned.
 547          *
 548          * @param $audience Integer: one of:
 549          *      Revision::FOR_PUBLIC       to be displayed to all users
 550          *      Revision::FOR_THIS_USER    to be displayed to $wgUser
 551          *      Revision::RAW              get the text regardless of permissions
 552          * @param $user User object to check for, only if FOR_THIS_USER is passed
 553          *              to the $audience parameter
 554          * @return string
 555          */
 556         public function getUserText( $audience = self::FOR_PUBLIC, User $user = null ) {
 557                 if( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_USER ) ) {
 558                         return '';
 559                 } elseif( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_USER, $user ) ) {
 560                         return '';
 561                 } else {
 562                         return $this->getRawUserText();
 563                 }
 564         }
 565
 566         /**
 567          * Fetch revision's username without regard for view restrictions
 568          *
 569          * @return String
 570          */
 571         public function getRawUserText() {
 572                 if ( $this->mUserText === null ) {
 573                         $this->mUserText = User::whoIs( $this->mUser ); // load on demand
 574                         if ( $this->mUserText === false ) {
 575                                 # This shouldn't happen, but it can if the wiki was recovered
 576                                 # via importing revs and there is no user table entry yet.
 577                                 $this->mUserText = $this->mOrigUserText;
 578                         }
 579                 }
 580                 return $this->mUserText;
 581         }
 582
 583         /**
 584          * Fetch revision comment if it's available to the specified audience.
 585          * If the specified audience does not have access to the comment, an
 586          * empty string will be returned.
 587          *
 588          * @param $audience Integer: one of:
 589          *      Revision::FOR_PUBLIC       to be displayed to all users
 590          *      Revision::FOR_THIS_USER    to be displayed to $wgUser
 591          *      Revision::RAW              get the text regardless of permissions
 592          * @param $user User object to check for, only if FOR_THIS_USER is passed
 593          *              to the $audience parameter
 594          * @return String
 595          */
 596         function getComment( $audience = self::FOR_PUBLIC, User $user = null ) {
 597                 if( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_COMMENT ) ) {
 598                         return '';
 599                 } elseif( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_COMMENT, $user ) ) {
 600                         return '';
 601                 } else {
 602                         return $this->mComment;
 603                 }
 604         }
 605
 606         /**
 607          * Fetch revision comment without regard for the current user's permissions
 608          *
 609          * @return String
 610          */
 611         public function getRawComment() {
 612                 return $this->mComment;
 613         }
 614
 615         /**
 616          * @return Boolean
 617          */
 618         public function isMinor() {
 619                 return (bool)$this->mMinorEdit;
 620         }
 621
 622         /**
 623          * @return Integer rcid of the unpatrolled row, zero if there isn't one
 624          */
 625         public function isUnpatrolled() {
 626                 if( $this->mUnpatrolled !== null ) {
 627                         return $this->mUnpatrolled;
 628                 }
 629                 $dbr = wfGetDB( DB_SLAVE );
 630                 $this->mUnpatrolled = $dbr->selectField( 'recentchanges',
 631                         'rc_id',
 632                         array( // Add redundant user,timestamp condition so we can use the existing index
 633                                 'rc_user_text'  => $this->getRawUserText(),
 634                                 'rc_timestamp'  => $dbr->timestamp( $this->getTimestamp() ),
 635                                 'rc_this_oldid' => $this->getId(),
 636                                 'rc_patrolled'  => 0
 637                         ),
 638                         __METHOD__
 639                 );
 640                 return (int)$this->mUnpatrolled;
 641         }
 642
 643         /**
 644          * @param $field int one of DELETED_* bitfield constants
 645          *
 646          * @return Boolean
 647          */
 648         public function isDeleted( $field ) {
 649                 return ( $this->mDeleted & $field ) == $field;
 650         }
 651
 652         /**
 653          * Get the deletion bitfield of the revision
 654          *
 655          * @return int
 656          */
 657         public function getVisibility() {
 658                 return (int)$this->mDeleted;
 659         }
 660
 661         /**
 662          * Fetch revision text if it's available to the specified audience.
 663          * If the specified audience does not have the ability to view this
 664          * revision, an empty string will be returned.
 665          *
 666          * @param $audience Integer: one of:
 667          *      Revision::FOR_PUBLIC       to be displayed to all users
 668          *      Revision::FOR_THIS_USER    to be displayed to $wgUser
 669          *      Revision::RAW              get the text regardless of permissions
 670          * @param $user User object to check for, only if FOR_THIS_USER is passed
 671          *              to the $audience parameter
 672          * @return String
 673          */
 674         public function getText( $audience = self::FOR_PUBLIC, User $user = null ) {
 675                 if( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_TEXT ) ) {
 676                         return '';
 677                 } elseif( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_TEXT, $user ) ) {
 678                         return '';
 679                 } else {
 680                         return $this->getRawText();
 681                 }
 682         }
 683
 684         /**
 685          * Alias for getText(Revision::FOR_THIS_USER)
 686          *
 687          * @deprecated since 1.17
 688          * @return String
 689          */
 690         public function revText() {
 691                 wfDeprecated( __METHOD__ );
 692                 return $this->getText( self::FOR_THIS_USER );
 693         }
 694
 695         /**
 696          * Fetch revision text without regard for view restrictions
 697          *
 698          * @return String
 699          */
 700         public function getRawText() {
 701                 if( is_null( $this->mText ) ) {
 702                         // Revision text is immutable. Load on demand:
 703                         $this->mText = $this->loadText();
 704                 }
 705                 return $this->mText;
 706         }
 707
 708         /**
 709          * @return String
 710          */
 711         public function getTimestamp() {
 712                 return wfTimestamp( TS_MW, $this->mTimestamp );
 713         }
 714
 715         /**
 716          * @return Boolean
 717          */
 718         public function isCurrent() {
 719                 return $this->mCurrent;
 720         }
 721
 722         /**
 723          * Get previous revision for this title
 724          *
 725          * @return Revision or null
 726          */
 727         public function getPrevious() {
 728                 if( $this->getTitle() ) {
 729                         $prev = $this->getTitle()->getPreviousRevisionID( $this->getId() );
 730                         if( $prev ) {
 731                                 return Revision::newFromTitle( $this->getTitle(), $prev );
 732                         }
 733                 }
 734                 return null;
 735         }
 736
 737         /**
 738          * Get next revision for this title
 739          *
 740          * @return Revision or null
 741          */
 742         public function getNext() {
 743                 if( $this->getTitle() ) {
 744                         $next = $this->getTitle()->getNextRevisionID( $this->getId() );
 745                         if ( $next ) {
 746                                 return Revision::newFromTitle( $this->getTitle(), $next );
 747                         }
 748                 }
 749                 return null;
 750         }
 751
 752         /**
 753          * Get previous revision Id for this page_id
 754          * This is used to populate rev_parent_id on save
 755          *
 756          * @param $db DatabaseBase
 757          * @return Integer
 758          */
 759         private function getPreviousRevisionId( $db ) {
 760                 if( is_null( $this->mPage ) ) {
 761                         return 0;
 762                 }
 763                 # Use page_latest if ID is not given
 764                 if( !$this->mId ) {
 765                         $prevId = $db->selectField( 'page', 'page_latest',
 766                                 array( 'page_id' => $this->mPage ),
 767                                 __METHOD__ );
 768                 } else {
 769                         $prevId = $db->selectField( 'revision', 'rev_id',
 770                                 array( 'rev_page' => $this->mPage, 'rev_id < ' . $this->mId ),
 771                                 __METHOD__,
 772                                 array( 'ORDER BY' => 'rev_id DESC' ) );
 773                 }
 774                 return intval( $prevId );
 775         }
 776
 777         /**
 778           * Get revision text associated with an old or archive row
 779           * $row is usually an object from wfFetchRow(), both the flags and the text
 780           * field must be included
 781           *
 782           * @param $row Object: the text data
 783           * @param $prefix String: table prefix (default 'old_')
 784           * @return String: text the text requested or false on failure
 785           */
 786         public static function getRevisionText( $row, $prefix = 'old_' ) {
 787                 wfProfileIn( __METHOD__ );
 788
 789                 # Get data
 790                 $textField = $prefix . 'text';
 791                 $flagsField = $prefix . 'flags';
 792
 793                 if( isset( $row->$flagsField ) ) {
 794                         $flags = explode( ',', $row->$flagsField );
 795                 } else {
 796                         $flags = array();
 797                 }
 798
 799                 if( isset( $row->$textField ) ) {
 800                         $text = $row->$textField;
 801                 } else {
 802                         wfProfileOut( __METHOD__ );
 803                         return false;
 804                 }
 805
 806                 # Use external methods for external objects, text in table is URL-only then
 807                 if ( in_array( 'external', $flags ) ) {
 808                         $url = $text;
 809                         $parts = explode( '://', $url, 2 );
 810                         if( count( $parts ) == 1 || $parts[1] == '' ) {
 811                                 wfProfileOut( __METHOD__ );
 812                                 return false;
 813                         }
 814                         $text = ExternalStore::fetchFromURL( $url );
 815                 }
 816
 817                 // If the text was fetched without an error, convert it
 818                 if ( $text !== false ) {
 819                         if( in_array( 'gzip', $flags ) ) {
 820                                 # Deal with optional compression of archived pages.
 821                                 # This can be done periodically via maintenance/compressOld.php, and
 822                                 # as pages are saved if $wgCompressRevisions is set.
 823                                 $text = gzinflate( $text );
 824                         }
 825
 826                         if( in_array( 'object', $flags ) ) {
 827                                 # Generic compressed storage
 828                                 $obj = unserialize( $text );
 829                                 if ( !is_object( $obj ) ) {
 830                                         // Invalid object
 831                                         wfProfileOut( __METHOD__ );
 832                                         return false;
 833                                 }
 834                                 $text = $obj->getText();
 835                         }
 836
 837                         global $wgLegacyEncoding;
 838                         if( $text !== false && $wgLegacyEncoding
 839                                 && !in_array( 'utf-8', $flags ) && !in_array( 'utf8', $flags ) )
 840                         {
 841                                 # Old revisions kept around in a legacy encoding?
 842                                 # Upconvert on demand.
 843                                 # ("utf8" checked for compatibility with some broken
 844                                 #  conversion scripts 2008-12-30)
 845                                 global $wgContLang;
 846                                 $text = $wgContLang->iconv( $wgLegacyEncoding, 'UTF-8', $text );
 847                         }
 848                 }
 849                 wfProfileOut( __METHOD__ );
 850                 return $text;
 851         }
 852
 853         /**
 854          * If $wgCompressRevisions is enabled, we will compress data.
 855          * The input string is modified in place.
 856          * Return value is the flags field: contains 'gzip' if the
 857          * data is compressed, and 'utf-8' if we're saving in UTF-8
 858          * mode.
 859          *
 860          * @param $text Mixed: reference to a text
 861          * @return String
 862          */
 863         public static function compressRevisionText( &$text ) {
 864                 global $wgCompressRevisions;
 865                 $flags = array();
 866
 867                 # Revisions not marked this way will be converted
 868                 # on load if $wgLegacyCharset is set in the future.
 869                 $flags[] = 'utf-8';
 870
 871                 if( $wgCompressRevisions ) {
 872                         if( function_exists( 'gzdeflate' ) ) {
 873                                 $text = gzdeflate( $text );
 874                                 $flags[] = 'gzip';
 875                         } else {
 876                                 wfDebug( "Revision::compressRevisionText() -- no zlib support, not compressing\n" );
 877                         }
 878                 }
 879                 return implode( ',', $flags );
 880         }
 881
 882         /**
 883          * Insert a new revision into the database, returning the new revision ID
 884          * number on success and dies horribly on failure.
 885          *
 886          * @param $dbw DatabaseBase: (master connection)
 887          * @return Integer
 888          */
 889         public function insertOn( $dbw ) {
 890                 global $wgDefaultExternalStore;
 891
 892                 wfProfileIn( __METHOD__ );
 893
 894                 $data = $this->mText;
 895                 $flags = Revision::compressRevisionText( $data );
 896
 897                 # Write to external storage if required
 898                 if( $wgDefaultExternalStore ) {
 899                         // Store and get the URL
 900                         $data = ExternalStore::insertToDefault( $data );
 901                         if( !$data ) {
 902                                 throw new MWException( "Unable to store text to external storage" );
 903                         }
 904                         if( $flags ) {
 905                                 $flags .= ',';
 906                         }
 907                         $flags .= 'external';
 908                 }
 909
 910                 # Record the text (or external storage URL) to the text table
 911                 if( !isset( $this->mTextId ) ) {
 912                         $old_id = $dbw->nextSequenceValue( 'text_old_id_seq' );
 913                         $dbw->insert( 'text',
 914                                 array(
 915                                         'old_id'    => $old_id,
 916                                         'old_text'  => $data,
 917                                         'old_flags' => $flags,
 918                                 ), __METHOD__
 919                         );
 920                         $this->mTextId = $dbw->insertId();
 921                 }
 922
 923                 if ( $this->mComment === null ) $this->mComment = "";
 924
 925                 # Record the edit in revisions
 926                 $rev_id = isset( $this->mId )
 927                         ? $this->mId
 928                         : $dbw->nextSequenceValue( 'revision_rev_id_seq' );
 929                 $dbw->insert( 'revision',
 930                         array(
 931                                 'rev_id'         => $rev_id,
 932                                 'rev_page'       => $this->mPage,
 933                                 'rev_text_id'    => $this->mTextId,
 934                                 'rev_comment'    => $this->mComment,
 935                                 'rev_minor_edit' => $this->mMinorEdit ? 1 : 0,
 936                                 'rev_user'       => $this->mUser,
 937                                 'rev_user_text'  => $this->mUserText,
 938                                 'rev_timestamp'  => $dbw->timestamp( $this->mTimestamp ),
 939                                 'rev_deleted'    => $this->mDeleted,
 940                                 'rev_len'        => $this->mSize,
 941                                 'rev_parent_id'  => is_null($this->mParentId) ?
 942                                         $this->getPreviousRevisionId( $dbw ) : $this->mParentId
 943                         ), __METHOD__
 944                 );
 945
 946                 $this->mId = !is_null( $rev_id ) ? $rev_id : $dbw->insertId();
 947
 948                 wfRunHooks( 'RevisionInsertComplete', array( &$this, $data, $flags ) );
 949
 950                 wfProfileOut( __METHOD__ );
 951                 return $this->mId;
 952         }
 953
 954         /**
 955          * Lazy-load the revision's text.
 956          * Currently hardcoded to the 'text' table storage engine.
 957          *
 958          * @return String
 959          */
 960         protected function loadText() {
 961                 wfProfileIn( __METHOD__ );
 962
 963                 // Caching may be beneficial for massive use of external storage
 964                 global $wgRevisionCacheExpiry, $wgMemc;
 965                 $textId = $this->getTextId();
 966                 $key = wfMemcKey( 'revisiontext', 'textid', $textId );
 967                 if( $wgRevisionCacheExpiry ) {
 968                         $text = $wgMemc->get( $key );
 969                         if( is_string( $text ) ) {
 970                                 wfDebug( __METHOD__ . ": got id $textId from cache\n" );
 971                                 wfProfileOut( __METHOD__ );
 972                                 return $text;
 973                         }
 974                 }
 975
 976                 // If we kept data for lazy extraction, use it now...
 977                 if ( isset( $this->mTextRow ) ) {
 978                         $row = $this->mTextRow;
 979                         $this->mTextRow = null;
 980                 } else {
 981                         $row = null;
 982                 }
 983
 984                 if( !$row ) {
 985                         // Text data is immutable; check slaves first.
 986                         $dbr = wfGetDB( DB_SLAVE );
 987                         $row = $dbr->selectRow( 'text',
 988                                 array( 'old_text', 'old_flags' ),
 989                                 array( 'old_id' => $this->getTextId() ),
 990                                 __METHOD__ );
 991                 }
 992
 993                 if( !$row && wfGetLB()->getServerCount() > 1 ) {
 994                         // Possible slave lag!
 995                         $dbw = wfGetDB( DB_MASTER );
 996                         $row = $dbw->selectRow( 'text',
 997                                 array( 'old_text', 'old_flags' ),
 998                                 array( 'old_id' => $this->getTextId() ),
 999                                 __METHOD__ );
1000                 }
1001
1002                 $text = self::getRevisionText( $row );
1003
1004                 # No negative caching -- negative hits on text rows may be due to corrupted slave servers
1005                 if( $wgRevisionCacheExpiry && $text !== false ) {
1006                         $wgMemc->set( $key, $text, $wgRevisionCacheExpiry );
1007                 }
1008
1009                 wfProfileOut( __METHOD__ );
1010
1011                 return $text;
1012         }
1013
1014         /**
1015          * Create a new null-revision for insertion into a page's
1016          * history. This will not re-save the text, but simply refer
1017          * to the text from the previous version.
1018          *
1019          * Such revisions can for instance identify page rename
1020          * operations and other such meta-modifications.
1021          *
1022          * @param $dbw DatabaseBase
1023          * @param $pageId Integer: ID number of the page to read from
1024          * @param $summary String: revision's summary
1025          * @param $minor Boolean: whether the revision should be considered as minor
1026          * @return Revision|null on error
1027          */
1028         public static function newNullRevision( $dbw, $pageId, $summary, $minor ) {
1029                 wfProfileIn( __METHOD__ );
1030
1031                 $current = $dbw->selectRow(
1032                         array( 'page', 'revision' ),
1033                         array( 'page_latest', 'rev_text_id', 'rev_len' ),
1034                         array(
1035                                 'page_id' => $pageId,
1036                                 'page_latest=rev_id',
1037                                 ),
1038                         __METHOD__ );
1039
1040                 if( $current ) {
1041                         $revision = new Revision( array(
1042                                 'page'       => $pageId,
1043                                 'comment'    => $summary,
1044                                 'minor_edit' => $minor,
1045                                 'text_id'    => $current->rev_text_id,
1046                                 'parent_id'  => $current->page_latest,
1047                                 'len'        => $current->rev_len
1048                                 ) );
1049                 } else {
1050                         $revision = null;
1051                 }
1052
1053                 wfProfileOut( __METHOD__ );
1054                 return $revision;
1055         }
1056
1057         /**
1058          * Determine if the current user is allowed to view a particular
1059          * field of this revision, if it's marked as deleted.
1060          *
1061          * @param $field Integer:one of self::DELETED_TEXT,
1062          *                              self::DELETED_COMMENT,
1063          *                              self::DELETED_USER
1064          * @param $user User object to check, or null to use $wgUser
1065          * @return Boolean
1066          */
1067         public function userCan( $field, User $user = null ) {
1068                 return self::userCanBitfield( $this->mDeleted, $field, $user );
1069         }
1070
1071         /**
1072          * Determine if the current user is allowed to view a particular
1073          * field of this revision, if it's marked as deleted. This is used
1074          * by various classes to avoid duplication.
1075          *
1076          * @param $bitfield Integer: current field
1077          * @param $field Integer: one of self::DELETED_TEXT = File::DELETED_FILE,
1078          *                               self::DELETED_COMMENT = File::DELETED_COMMENT,
1079          *                               self::DELETED_USER = File::DELETED_USER
1080          * @param $user User object to check, or null to use $wgUser
1081          * @return Boolean
1082          */
1083         public static function userCanBitfield( $bitfield, $field, User $user = null ) {
1084                 if( $bitfield & $field ) { // aspect is deleted
1085                         if ( $bitfield & self::DELETED_RESTRICTED ) {
1086                                 $permission = 'suppressrevision';
1087                         } elseif ( $field & self::DELETED_TEXT ) {
1088                                 $permission = 'deletedtext';
1089                         } else {
1090                                 $permission = 'deletedhistory';
1091                         }
1092                         wfDebug( "Checking for $permission due to $field match on $bitfield\n" );
1093                         if ( $user === null ) {
1094                                 global $wgUser;
1095                                 $user = $wgUser;
1096                         }
1097                         return $user->isAllowed( $permission );
1098                 } else {
1099                         return true;
1100                 }
1101         }
1102
1103         /**
1104          * Get rev_timestamp from rev_id, without loading the rest of the row
1105          *
1106          * @param $title Title
1107          * @param $id Integer
1108          * @return String
1109          */
1110         static function getTimestampFromId( $title, $id ) {
1111                 $dbr = wfGetDB( DB_SLAVE );
1112                 // Casting fix for DB2
1113                 if ( $id == '' ) {
1114                         $id = 0;
1115                 }
1116                 $conds = array( 'rev_id' => $id );
1117                 $conds['rev_page'] = $title->getArticleId();
1118                 $timestamp = $dbr->selectField( 'revision', 'rev_timestamp', $conds, __METHOD__ );
1119                 if ( $timestamp === false && wfGetLB()->getServerCount() > 1 ) {
1120                         # Not in slave, try master
1121                         $dbw = wfGetDB( DB_MASTER );
1122                         $timestamp = $dbw->selectField( 'revision', 'rev_timestamp', $conds, __METHOD__ );
1123                 }
1124                 return wfTimestamp( TS_MW, $timestamp );
1125         }
1126
1127         /**
1128          * Get count of revisions per page...not very efficient
1129          *
1130          * @param $db DatabaseBase
1131          * @param $id Integer: page id
1132          * @return Integer
1133          */
1134         static function countByPageId( $db, $id ) {
1135                 $row = $db->selectRow( 'revision', 'COUNT(*) AS revCount',
1136                         array( 'rev_page' => $id ), __METHOD__ );
1137                 if( $row ) {
1138                         return $row->revCount;
1139                 }
1140                 return 0;
1141         }
1142
1143         /**
1144          * Get count of revisions per page...not very efficient
1145          *
1146          * @param $db DatabaseBase
1147          * @param $title Title
1148          * @return Integer
1149          */
1150         static function countByTitle( $db, $title ) {
1151                 $id = $title->getArticleId();
1152                 if( $id ) {
1153                         return Revision::countByPageId( $db, $id );
1154                 }
1155                 return 0;
1156         }
1157 }