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 $mSha1;
  17         protected $mParentId;
  18         protected $mComment;
  19         protected $mText;
  20         protected $mTextRow;
  21         protected $mTitle;
  22         protected $mCurrent;
  23
  24         const DELETED_TEXT = 1;
  25         const DELETED_COMMENT = 2;
  26         const DELETED_USER = 4;
  27         const DELETED_RESTRICTED = 8;
  28         // Convenience field
  29         const SUPPRESSED_USER = 12;
  30         // Audience options for Revision::getText()
  31         const FOR_PUBLIC = 1;
  32         const FOR_THIS_USER = 2;
  33         const RAW = 3;
  34
  35         /**
  36          * Load a page revision from a given revision ID number.
  37          * Returns null if no such revision can be found.
  38          *
  39          * @param $id Integer
  40          * @return Revision or null
  41          */
  42         public static function newFromId( $id ) {
  43                 return Revision::newFromConds( array( 'rev_id' => intval( $id ) ) );
  44         }
  45
  46         /**
  47          * Load either the current, or a specified, revision
  48          * that's attached to a given title. If not attached
  49          * to that title, will return null.
  50          *
  51          * @param $title Title
  52          * @param $id Integer (optional)
  53          * @return Revision or null
  54          */
  55         public static function newFromTitle( $title, $id = 0 ) {
  56                 $conds = array(
  57                         'page_namespace' => $title->getNamespace(),
  58                         'page_title'     => $title->getDBkey()
  59                 );
  60                 if ( $id ) {
  61                         // Use the specified ID
  62                         $conds['rev_id'] = $id;
  63                 } elseif ( wfGetLB()->getServerCount() > 1 ) {
  64                         // Get the latest revision ID from the master
  65                         $dbw = wfGetDB( DB_MASTER );
  66                         $latest = $dbw->selectField( 'page', 'page_latest', $conds, __METHOD__ );
  67                         if ( $latest === false ) {
  68                                 return null; // page does not exist
  69                         }
  70                         $conds['rev_id'] = $latest;
  71                 } else {
  72                         // Use a join to get the latest revision
  73                         $conds[] = 'rev_id=page_latest';
  74                 }
  75                 return Revision::newFromConds( $conds );
  76         }
  77
  78         /**
  79          * Load either the current, or a specified, revision
  80          * that's attached to a given page ID.
  81          * Returns null if no such revision can be found.
  82          *
  83          * @param $revId Integer
  84          * @param $pageId Integer (optional)
  85          * @return Revision or null
  86          */
  87         public static function newFromPageId( $pageId, $revId = 0 ) {
  88                 $conds = array( 'page_id' => $pageId );
  89                 if ( $revId ) {
  90                         $conds['rev_id'] = $revId;
  91                 } elseif ( wfGetLB()->getServerCount() > 1 ) {
  92                         // Get the latest revision ID from the master
  93                         $dbw = wfGetDB( DB_MASTER );
  94                         $latest = $dbw->selectField( 'page', 'page_latest', $conds, __METHOD__ );
  95                         if ( $latest === false ) {
  96                                 return null; // page does not exist
  97                         }
  98                         $conds['rev_id'] = $latest;
  99                 } else {
 100                         $conds[] = 'rev_id = page_latest';
 101                 }
 102                 return Revision::newFromConds( $conds );
 103         }
 104
 105         /**
 106          * Make a fake revision object from an archive table row. This is queried
 107          * for permissions or even inserted (as in Special:Undelete)
 108          * @todo FIXME: Should be a subclass for RevisionDelete. [TS]
 109          *
 110          * @param $row
 111          * @param $overrides array
 112          *
 113          * @return Revision
 114          */
 115         public static function newFromArchiveRow( $row, $overrides = array() ) {
 116                 $attribs = $overrides + array(
 117                         'page'       => isset( $row->ar_page_id ) ? $row->ar_page_id : null,
 118                         'id'         => isset( $row->ar_rev_id ) ? $row->ar_rev_id : null,
 119                         'comment'    => $row->ar_comment,
 120                         'user'       => $row->ar_user,
 121                         'user_text'  => $row->ar_user_text,
 122                         'timestamp'  => $row->ar_timestamp,
 123                         'minor_edit' => $row->ar_minor_edit,
 124                         'text_id'    => isset( $row->ar_text_id ) ? $row->ar_text_id : null,
 125                         'deleted'    => $row->ar_deleted,
 126                         'len'        => $row->ar_len,
 127                         'sha1'       => isset( $row->ar_sha1 ) ? $row->ar_sha1 : null,
 128                 );
 129                 if ( isset( $row->ar_text ) && !$row->ar_text_id ) {
 130                         // Pre-1.5 ar_text row
 131                         $attribs['text'] = self::getRevisionText( $row, 'ar_' );
 132                         if ( $attribs['text'] === false ) {
 133                                 throw new MWException( 'Unable to load text from archive row (possibly bug 22624)' );
 134                         }
 135                 }
 136                 return new self( $attribs );
 137         }
 138
 139         /**
 140          * @since 1.19
 141          *
 142          * @param $row
 143          * @return Revision
 144          */
 145         public static function newFromRow( $row ) {
 146                 return new self( $row );
 147         }
 148
 149         /**
 150          * Load a page revision from a given revision ID number.
 151          * Returns null if no such revision can be found.
 152          *
 153          * @param $db DatabaseBase
 154          * @param $id Integer
 155          * @return Revision or null
 156          */
 157         public static function loadFromId( $db, $id ) {
 158                 return Revision::loadFromConds( $db, array( 'rev_id' => intval( $id ) ) );
 159         }
 160
 161         /**
 162          * Load either the current, or a specified, revision
 163          * that's attached to a given page. If not attached
 164          * to that page, will return null.
 165          *
 166          * @param $db DatabaseBase
 167          * @param $pageid Integer
 168          * @param $id Integer
 169          * @return Revision or null
 170          */
 171         public static function loadFromPageId( $db, $pageid, $id = 0 ) {
 172                 $conds = array( 'rev_page' => intval( $pageid ), 'page_id'  => intval( $pageid ) );
 173                 if( $id ) {
 174                         $conds['rev_id'] = intval( $id );
 175                 } else {
 176                         $conds[] = 'rev_id=page_latest';
 177                 }
 178                 return Revision::loadFromConds( $db, $conds );
 179         }
 180
 181         /**
 182          * Load either the current, or a specified, revision
 183          * that's attached to a given page. If not attached
 184          * to that page, will return null.
 185          *
 186          * @param $db DatabaseBase
 187          * @param $title Title
 188          * @param $id Integer
 189          * @return Revision or null
 190          */
 191         public static function loadFromTitle( $db, $title, $id = 0 ) {
 192                 if( $id ) {
 193                         $matchId = intval( $id );
 194                 } else {
 195                         $matchId = 'page_latest';
 196                 }
 197                 return Revision::loadFromConds( $db,
 198                         array( "rev_id=$matchId",
 199                                    'page_namespace' => $title->getNamespace(),
 200                                    'page_title'     => $title->getDBkey() )
 201                 );
 202         }
 203
 204         /**
 205          * Load the revision for the given title with the given timestamp.
 206          * WARNING: Timestamps may in some circumstances not be unique,
 207          * so this isn't the best key to use.
 208          *
 209          * @param $db DatabaseBase
 210          * @param $title Title
 211          * @param $timestamp String
 212          * @return Revision or null
 213          */
 214         public static function loadFromTimestamp( $db, $title, $timestamp ) {
 215                 return Revision::loadFromConds( $db,
 216                         array( 'rev_timestamp'  => $db->timestamp( $timestamp ),
 217                                    'page_namespace' => $title->getNamespace(),
 218                                    'page_title'     => $title->getDBkey() )
 219                 );
 220         }
 221
 222         /**
 223          * Given a set of conditions, fetch a revision.
 224          *
 225          * @param $conditions Array
 226          * @return Revision or null
 227          */
 228         public static function newFromConds( $conditions ) {
 229                 $db = wfGetDB( DB_SLAVE );
 230                 $rev = Revision::loadFromConds( $db, $conditions );
 231                 if( is_null( $rev ) && wfGetLB()->getServerCount() > 1 ) {
 232                         $dbw = wfGetDB( DB_MASTER );
 233                         $rev = Revision::loadFromConds( $dbw, $conditions );
 234                 }
 235                 return $rev;
 236         }
 237
 238         /**
 239          * Given a set of conditions, fetch a revision from
 240          * the given database connection.
 241          *
 242          * @param $db DatabaseBase
 243          * @param $conditions Array
 244          * @return Revision or null
 245          */
 246         private static function loadFromConds( $db, $conditions ) {
 247                 $res = Revision::fetchFromConds( $db, $conditions );
 248                 if( $res ) {
 249                         $row = $res->fetchObject();
 250                         if( $row ) {
 251                                 $ret = new Revision( $row );
 252                                 return $ret;
 253                         }
 254                 }
 255                 $ret = null;
 256                 return $ret;
 257         }
 258
 259         /**
 260          * Return a wrapper for a series of database rows to
 261          * fetch all of a given page's revisions in turn.
 262          * Each row can be fed to the constructor to get objects.
 263          *
 264          * @param $title Title
 265          * @return ResultWrapper
 266          */
 267         public static function fetchRevision( $title ) {
 268                 return Revision::fetchFromConds(
 269                         wfGetDB( DB_SLAVE ),
 270                         array( 'rev_id=page_latest',
 271                                    'page_namespace' => $title->getNamespace(),
 272                                    'page_title'     => $title->getDBkey() )
 273                 );
 274         }
 275
 276         /**
 277          * Given a set of conditions, return a ResultWrapper
 278          * which will return matching database rows with the
 279          * fields necessary to build Revision objects.
 280          *
 281          * @param $db DatabaseBase
 282          * @param $conditions Array
 283          * @return ResultWrapper
 284          */
 285         private static function fetchFromConds( $db, $conditions ) {
 286                 $fields = array_merge(
 287                         self::selectFields(),
 288                         self::selectPageFields(),
 289                         self::selectUserFields()
 290                 );
 291                 return $db->select(
 292                         array( 'revision', 'page', 'user' ),
 293                         $fields,
 294                         $conditions,
 295                         __METHOD__,
 296                         array( 'LIMIT' => 1 ),
 297                         array( 'page' => self::pageJoinCond(), 'user' => self::userJoinCond() )
 298                 );
 299         }
 300
 301         /**
 302          * Return the value of a select() JOIN conds array for the user table.
 303          * This will get user table rows for logged-in users.
 304          * @since 1.19
 305          * @return Array
 306          */
 307         public static function userJoinCond() {
 308                 return array( 'LEFT JOIN', array( 'rev_user != 0', 'user_id = rev_user' ) );
 309         }
 310
 311         /**
 312          * Return the value of a select() page conds array for the paeg table.
 313          * This will assure that the revision(s) are not orphaned from live pages.
 314          * @since 1.19
 315          * @return Array
 316          */
 317         public static function pageJoinCond() {
 318                 return array( 'INNER JOIN', array( 'page_id = rev_page' ) );
 319         }
 320
 321         /**
 322          * Return the list of revision fields that should be selected to create
 323          * a new revision.
 324          */
 325         public static function selectFields() {
 326                 return array(
 327                         'rev_id',
 328                         'rev_page',
 329                         'rev_text_id',
 330                         'rev_timestamp',
 331                         'rev_comment',
 332                         'rev_user_text',
 333                         'rev_user',
 334                         'rev_minor_edit',
 335                         'rev_deleted',
 336                         'rev_len',
 337                         'rev_parent_id',
 338                         'rev_sha1'
 339                 );
 340         }
 341
 342         /**
 343          * Return the list of text fields that should be selected to read the
 344          * revision text
 345          */
 346         public static function selectTextFields() {
 347                 return array(
 348                         'old_text',
 349                         'old_flags'
 350                 );
 351         }
 352
 353         /**
 354          * Return the list of page fields that should be selected from page table
 355          */
 356         public static function selectPageFields() {
 357                 return array(
 358                         'page_namespace',
 359                         'page_title',
 360                         'page_latest'
 361                 );
 362         }
 363
 364         /**
 365          * Return the list of user fields that should be selected from user table
 366          */
 367         public static function selectUserFields() {
 368                 return array( 'user_name' );
 369         }
 370
 371         /**
 372          * Constructor
 373          *
 374          * @param $row Mixed: either a database row or an array
 375          * @access private
 376          */
 377         function __construct( $row ) {
 378                 if( is_object( $row ) ) {
 379                         $this->mId        = intval( $row->rev_id );
 380                         $this->mPage      = intval( $row->rev_page );
 381                         $this->mTextId    = intval( $row->rev_text_id );
 382                         $this->mComment   =         $row->rev_comment;
 383                         $this->mUser      = intval( $row->rev_user );
 384                         $this->mMinorEdit = intval( $row->rev_minor_edit );
 385                         $this->mTimestamp =         $row->rev_timestamp;
 386                         $this->mDeleted   = intval( $row->rev_deleted );
 387
 388                         if( !isset( $row->rev_parent_id ) ) {
 389                                 $this->mParentId = is_null( $row->rev_parent_id ) ? null : 0;
 390                         } else {
 391                                 $this->mParentId  = intval( $row->rev_parent_id );
 392                         }
 393
 394                         if( !isset( $row->rev_len ) || is_null( $row->rev_len ) ) {
 395                                 $this->mSize = null;
 396                         } else {
 397                                 $this->mSize = intval( $row->rev_len );
 398                         }
 399
 400                         if ( !isset( $row->rev_sha1 ) ) {
 401                                 $this->mSha1 = null;
 402                         } else {
 403                                 $this->mSha1 = $row->rev_sha1;
 404                         }
 405
 406                         if( isset( $row->page_latest ) ) {
 407                                 $this->mCurrent = ( $row->rev_id == $row->page_latest );
 408                                 $this->mTitle = Title::newFromRow( $row );
 409                         } else {
 410                                 $this->mCurrent = false;
 411                                 $this->mTitle = null;
 412                         }
 413
 414                         // Lazy extraction...
 415                         $this->mText      = null;
 416                         if( isset( $row->old_text ) ) {
 417                                 $this->mTextRow = $row;
 418                         } else {
 419                                 // 'text' table row entry will be lazy-loaded
 420                                 $this->mTextRow = null;
 421                         }
 422
 423                         // Use user_name for users and rev_user_text for IPs...
 424                         $this->mUserText = null; // lazy load if left null
 425                         if ( $this->mUser == 0 ) {
 426                                 $this->mUserText = $row->rev_user_text; // IP user
 427                         } elseif ( isset( $row->user_name ) ) {
 428                                 $this->mUserText = $row->user_name; // logged-in user
 429                         }
 430                         $this->mOrigUserText = $row->rev_user_text;
 431                 } elseif( is_array( $row ) ) {
 432                         // Build a new revision to be saved...
 433                         global $wgUser; // ugh
 434
 435                         $this->mId        = isset( $row['id']         ) ? intval( $row['id']         ) : null;
 436                         $this->mPage      = isset( $row['page']       ) ? intval( $row['page']       ) : null;
 437                         $this->mTextId    = isset( $row['text_id']    ) ? intval( $row['text_id']    ) : null;
 438                         $this->mUserText  = isset( $row['user_text']  ) ? strval( $row['user_text']  ) : $wgUser->getName();
 439                         $this->mUser      = isset( $row['user']       ) ? intval( $row['user']       ) : $wgUser->getId();
 440                         $this->mMinorEdit = isset( $row['minor_edit'] ) ? intval( $row['minor_edit'] ) : 0;
 441                         $this->mTimestamp = isset( $row['timestamp']  ) ? strval( $row['timestamp']  ) : wfTimestampNow();
 442                         $this->mDeleted   = isset( $row['deleted']    ) ? intval( $row['deleted']    ) : 0;
 443                         $this->mSize      = isset( $row['len']        ) ? intval( $row['len']        ) : null;
 444                         $this->mParentId  = isset( $row['parent_id']  ) ? intval( $row['parent_id']  ) : null;
 445                         $this->mSha1      = isset( $row['sha1']  )      ? strval( $row['sha1']  )      : null;
 446
 447                         // Enforce spacing trimming on supplied text
 448                         $this->mComment   = isset( $row['comment']    ) ?  trim( strval( $row['comment'] ) ) : null;
 449                         $this->mText      = isset( $row['text']       ) ? rtrim( strval( $row['text']    ) ) : null;
 450                         $this->mTextRow   = null;
 451
 452                         $this->mTitle     = null; # Load on demand if needed
 453                         $this->mCurrent   = false;
 454                         # If we still have no length, see it we have the text to figure it out
 455                         if ( !$this->mSize ) {
 456                                 $this->mSize = is_null( $this->mText ) ? null : strlen( $this->mText );
 457                         }
 458                         # Same for sha1
 459                         if ( $this->mSha1 === null ) {
 460                                 $this->mSha1 = is_null( $this->mText ) ? null : self::base36Sha1( $this->mText );
 461                         }
 462                 } else {
 463                         throw new MWException( 'Revision constructor passed invalid row format.' );
 464                 }
 465                 $this->mUnpatrolled = null;
 466         }
 467
 468         /**
 469          * Get revision ID
 470          *
 471          * @return Integer
 472          */
 473         public function getId() {
 474                 return $this->mId;
 475         }
 476
 477         /**
 478          * Get text row ID
 479          *
 480          * @return Integer
 481          */
 482         public function getTextId() {
 483                 return $this->mTextId;
 484         }
 485
 486         /**
 487          * Get parent revision ID (the original previous page revision)
 488          *
 489          * @return Integer
 490          */
 491         public function getParentId() {
 492                 return $this->mParentId;
 493         }
 494
 495         /**
 496          * Returns the length of the text in this revision, or null if unknown.
 497          *
 498          * @return Integer
 499          */
 500         public function getSize() {
 501                 return $this->mSize;
 502         }
 503
 504         /**
 505          * Returns the base36 sha1 of the text in this revision, or null if unknown.
 506          *
 507          * @return String
 508          */
 509         public function getSha1() {
 510                 return $this->mSha1;
 511         }
 512
 513         /**
 514          * Returns the title of the page associated with this entry.
 515          *
 516          * @return Title
 517          */
 518         public function getTitle() {
 519                 if( isset( $this->mTitle ) ) {
 520                         return $this->mTitle;
 521                 }
 522                 $dbr = wfGetDB( DB_SLAVE );
 523                 $row = $dbr->selectRow(
 524                         array( 'page', 'revision' ),
 525                         array( 'page_namespace', 'page_title' ),
 526                         array( 'page_id=rev_page',
 527                                    'rev_id' => $this->mId ),
 528                         'Revision::getTitle' );
 529                 if( $row ) {
 530                         $this->mTitle = Title::makeTitle( $row->page_namespace, $row->page_title );
 531                 }
 532                 return $this->mTitle;
 533         }
 534
 535         /**
 536          * Set the title of the revision
 537          *
 538          * @param $title Title
 539          */
 540         public function setTitle( $title ) {
 541                 $this->mTitle = $title;
 542         }
 543
 544         /**
 545          * Get the page ID
 546          *
 547          * @return Integer
 548          */
 549         public function getPage() {
 550                 return $this->mPage;
 551         }
 552
 553         /**
 554          * Fetch revision's user id if it's available to the specified audience.
 555          * If the specified audience does not have access to it, zero will be
 556          * returned.
 557          *
 558          * @param $audience Integer: one of:
 559          *      Revision::FOR_PUBLIC       to be displayed to all users
 560          *      Revision::FOR_THIS_USER    to be displayed to $wgUser
 561          *      Revision::RAW              get the ID regardless of permissions
 562          * @param $user User object to check for, only if FOR_THIS_USER is passed
 563          *              to the $audience parameter
 564          * @return Integer
 565          */
 566         public function getUser( $audience = self::FOR_PUBLIC, User $user = null ) {
 567                 if( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_USER ) ) {
 568                         return 0;
 569                 } elseif( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_USER, $user ) ) {
 570                         return 0;
 571                 } else {
 572                         return $this->mUser;
 573                 }
 574         }
 575
 576         /**
 577          * Fetch revision's user id without regard for the current user's permissions
 578          *
 579          * @return String
 580          */
 581         public function getRawUser() {
 582                 return $this->mUser;
 583         }
 584
 585         /**
 586          * Fetch revision's username if it's available to the specified audience.
 587          * If the specified audience does not have access to the username, an
 588          * empty string will be returned.
 589          *
 590          * @param $audience Integer: one of:
 591          *      Revision::FOR_PUBLIC       to be displayed to all users
 592          *      Revision::FOR_THIS_USER    to be displayed to $wgUser
 593          *      Revision::RAW              get the text regardless of permissions
 594          * @param $user User object to check for, only if FOR_THIS_USER is passed
 595          *              to the $audience parameter
 596          * @return string
 597          */
 598         public function getUserText( $audience = self::FOR_PUBLIC, User $user = null ) {
 599                 if( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_USER ) ) {
 600                         return '';
 601                 } elseif( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_USER, $user ) ) {
 602                         return '';
 603                 } else {
 604                         return $this->getRawUserText();
 605                 }
 606         }
 607
 608         /**
 609          * Fetch revision's username without regard for view restrictions
 610          *
 611          * @return String
 612          */
 613         public function getRawUserText() {
 614                 if ( $this->mUserText === null ) {
 615                         $this->mUserText = User::whoIs( $this->mUser ); // load on demand
 616                         if ( $this->mUserText === false ) {
 617                                 # This shouldn't happen, but it can if the wiki was recovered
 618                                 # via importing revs and there is no user table entry yet.
 619                                 $this->mUserText = $this->mOrigUserText;
 620                         }
 621                 }
 622                 return $this->mUserText;
 623         }
 624
 625         /**
 626          * Fetch revision comment if it's available to the specified audience.
 627          * If the specified audience does not have access to the comment, an
 628          * empty string will be returned.
 629          *
 630          * @param $audience Integer: one of:
 631          *      Revision::FOR_PUBLIC       to be displayed to all users
 632          *      Revision::FOR_THIS_USER    to be displayed to $wgUser
 633          *      Revision::RAW              get the text regardless of permissions
 634          * @param $user User object to check for, only if FOR_THIS_USER is passed
 635          *              to the $audience parameter
 636          * @return String
 637          */
 638         function getComment( $audience = self::FOR_PUBLIC, User $user = null ) {
 639                 if( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_COMMENT ) ) {
 640                         return '';
 641                 } elseif( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_COMMENT, $user ) ) {
 642                         return '';
 643                 } else {
 644                         return $this->mComment;
 645                 }
 646         }
 647
 648         /**
 649          * Fetch revision comment without regard for the current user's permissions
 650          *
 651          * @return String
 652          */
 653         public function getRawComment() {
 654                 return $this->mComment;
 655         }
 656
 657         /**
 658          * @return Boolean
 659          */
 660         public function isMinor() {
 661                 return (bool)$this->mMinorEdit;
 662         }
 663
 664         /**
 665          * @return Integer rcid of the unpatrolled row, zero if there isn't one
 666          */
 667         public function isUnpatrolled() {
 668                 if( $this->mUnpatrolled !== null ) {
 669                         return $this->mUnpatrolled;
 670                 }
 671                 $dbr = wfGetDB( DB_SLAVE );
 672                 $this->mUnpatrolled = $dbr->selectField( 'recentchanges',
 673                         'rc_id',
 674                         array( // Add redundant user,timestamp condition so we can use the existing index
 675                                 'rc_user_text'  => $this->getRawUserText(),
 676                                 'rc_timestamp'  => $dbr->timestamp( $this->getTimestamp() ),
 677                                 'rc_this_oldid' => $this->getId(),
 678                                 'rc_patrolled'  => 0
 679                         ),
 680                         __METHOD__
 681                 );
 682                 return (int)$this->mUnpatrolled;
 683         }
 684
 685         /**
 686          * @param $field int one of DELETED_* bitfield constants
 687          *
 688          * @return Boolean
 689          */
 690         public function isDeleted( $field ) {
 691                 return ( $this->mDeleted & $field ) == $field;
 692         }
 693
 694         /**
 695          * Get the deletion bitfield of the revision
 696          *
 697          * @return int
 698          */
 699         public function getVisibility() {
 700                 return (int)$this->mDeleted;
 701         }
 702
 703         /**
 704          * Fetch revision text if it's available to the specified audience.
 705          * If the specified audience does not have the ability to view this
 706          * revision, an empty string will be returned.
 707          *
 708          * @param $audience Integer: one of:
 709          *      Revision::FOR_PUBLIC       to be displayed to all users
 710          *      Revision::FOR_THIS_USER    to be displayed to $wgUser
 711          *      Revision::RAW              get the text regardless of permissions
 712          * @param $user User object to check for, only if FOR_THIS_USER is passed
 713          *              to the $audience parameter
 714          * @return String
 715          */
 716         public function getText( $audience = self::FOR_PUBLIC, User $user = null ) {
 717                 if( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_TEXT ) ) {
 718                         return '';
 719                 } elseif( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_TEXT, $user ) ) {
 720                         return '';
 721                 } else {
 722                         return $this->getRawText();
 723                 }
 724         }
 725
 726         /**
 727          * Alias for getText(Revision::FOR_THIS_USER)
 728          *
 729          * @deprecated since 1.17
 730          * @return String
 731          */
 732         public function revText() {
 733                 wfDeprecated( __METHOD__, '1.17' );
 734                 return $this->getText( self::FOR_THIS_USER );
 735         }
 736
 737         /**
 738          * Fetch revision text without regard for view restrictions
 739          *
 740          * @return String
 741          */
 742         public function getRawText() {
 743                 if( is_null( $this->mText ) ) {
 744                         // Revision text is immutable. Load on demand:
 745                         $this->mText = $this->loadText();
 746                 }
 747                 return $this->mText;
 748         }
 749
 750         /**
 751          * @return String
 752          */
 753         public function getTimestamp() {
 754                 return wfTimestamp( TS_MW, $this->mTimestamp );
 755         }
 756
 757         /**
 758          * @return Boolean
 759          */
 760         public function isCurrent() {
 761                 return $this->mCurrent;
 762         }
 763
 764         /**
 765          * Get previous revision for this title
 766          *
 767          * @return Revision or null
 768          */
 769         public function getPrevious() {
 770                 if( $this->getTitle() ) {
 771                         $prev = $this->getTitle()->getPreviousRevisionID( $this->getId() );
 772                         if( $prev ) {
 773                                 return Revision::newFromTitle( $this->getTitle(), $prev );
 774                         }
 775                 }
 776                 return null;
 777         }
 778
 779         /**
 780          * Get next revision for this title
 781          *
 782          * @return Revision or null
 783          */
 784         public function getNext() {
 785                 if( $this->getTitle() ) {
 786                         $next = $this->getTitle()->getNextRevisionID( $this->getId() );
 787                         if ( $next ) {
 788                                 return Revision::newFromTitle( $this->getTitle(), $next );
 789                         }
 790                 }
 791                 return null;
 792         }
 793
 794         /**
 795          * Get previous revision Id for this page_id
 796          * This is used to populate rev_parent_id on save
 797          *
 798          * @param $db DatabaseBase
 799          * @return Integer
 800          */
 801         private function getPreviousRevisionId( $db ) {
 802                 if( is_null( $this->mPage ) ) {
 803                         return 0;
 804                 }
 805                 # Use page_latest if ID is not given
 806                 if( !$this->mId ) {
 807                         $prevId = $db->selectField( 'page', 'page_latest',
 808                                 array( 'page_id' => $this->mPage ),
 809                                 __METHOD__ );
 810                 } else {
 811                         $prevId = $db->selectField( 'revision', 'rev_id',
 812                                 array( 'rev_page' => $this->mPage, 'rev_id < ' . $this->mId ),
 813                                 __METHOD__,
 814                                 array( 'ORDER BY' => 'rev_id DESC' ) );
 815                 }
 816                 return intval( $prevId );
 817         }
 818
 819         /**
 820           * Get revision text associated with an old or archive row
 821           * $row is usually an object from wfFetchRow(), both the flags and the text
 822           * field must be included
 823           *
 824           * @param $row Object: the text data
 825           * @param $prefix String: table prefix (default 'old_')
 826           * @return String: text the text requested or false on failure
 827           */
 828         public static function getRevisionText( $row, $prefix = 'old_' ) {
 829                 wfProfileIn( __METHOD__ );
 830
 831                 # Get data
 832                 $textField = $prefix . 'text';
 833                 $flagsField = $prefix . 'flags';
 834
 835                 if( isset( $row->$flagsField ) ) {
 836                         $flags = explode( ',', $row->$flagsField );
 837                 } else {
 838                         $flags = array();
 839                 }
 840
 841                 if( isset( $row->$textField ) ) {
 842                         $text = $row->$textField;
 843                 } else {
 844                         wfProfileOut( __METHOD__ );
 845                         return false;
 846                 }
 847
 848                 # Use external methods for external objects, text in table is URL-only then
 849                 if ( in_array( 'external', $flags ) ) {
 850                         $url = $text;
 851                         $parts = explode( '://', $url, 2 );
 852                         if( count( $parts ) == 1 || $parts[1] == '' ) {
 853                                 wfProfileOut( __METHOD__ );
 854                                 return false;
 855                         }
 856                         $text = ExternalStore::fetchFromURL( $url );
 857                 }
 858
 859                 // If the text was fetched without an error, convert it
 860                 if ( $text !== false ) {
 861                         if( in_array( 'gzip', $flags ) ) {
 862                                 # Deal with optional compression of archived pages.
 863                                 # This can be done periodically via maintenance/compressOld.php, and
 864                                 # as pages are saved if $wgCompressRevisions is set.
 865                                 $text = gzinflate( $text );
 866                         }
 867
 868                         if( in_array( 'object', $flags ) ) {
 869                                 # Generic compressed storage
 870                                 $obj = unserialize( $text );
 871                                 if ( !is_object( $obj ) ) {
 872                                         // Invalid object
 873                                         wfProfileOut( __METHOD__ );
 874                                         return false;
 875                                 }
 876                                 $text = $obj->getText();
 877                         }
 878
 879                         global $wgLegacyEncoding;
 880                         if( $text !== false && $wgLegacyEncoding
 881                                 && !in_array( 'utf-8', $flags ) && !in_array( 'utf8', $flags ) )
 882                         {
 883                                 # Old revisions kept around in a legacy encoding?
 884                                 # Upconvert on demand.
 885                                 # ("utf8" checked for compatibility with some broken
 886                                 #  conversion scripts 2008-12-30)
 887                                 global $wgContLang;
 888                                 $text = $wgContLang->iconv( $wgLegacyEncoding, 'UTF-8', $text );
 889                         }
 890                 }
 891                 wfProfileOut( __METHOD__ );
 892                 return $text;
 893         }
 894
 895         /**
 896          * If $wgCompressRevisions is enabled, we will compress data.
 897          * The input string is modified in place.
 898          * Return value is the flags field: contains 'gzip' if the
 899          * data is compressed, and 'utf-8' if we're saving in UTF-8
 900          * mode.
 901          *
 902          * @param $text Mixed: reference to a text
 903          * @return String
 904          */
 905         public static function compressRevisionText( &$text ) {
 906                 global $wgCompressRevisions;
 907                 $flags = array();
 908
 909                 # Revisions not marked this way will be converted
 910                 # on load if $wgLegacyCharset is set in the future.
 911                 $flags[] = 'utf-8';
 912
 913                 if( $wgCompressRevisions ) {
 914                         if( function_exists( 'gzdeflate' ) ) {
 915                                 $text = gzdeflate( $text );
 916                                 $flags[] = 'gzip';
 917                         } else {
 918                                 wfDebug( "Revision::compressRevisionText() -- no zlib support, not compressing\n" );
 919                         }
 920                 }
 921                 return implode( ',', $flags );
 922         }
 923
 924         /**
 925          * Insert a new revision into the database, returning the new revision ID
 926          * number on success and dies horribly on failure.
 927          *
 928          * @param $dbw DatabaseBase: (master connection)
 929          * @return Integer
 930          */
 931         public function insertOn( $dbw ) {
 932                 global $wgDefaultExternalStore;
 933
 934                 wfProfileIn( __METHOD__ );
 935
 936                 $data = $this->mText;
 937                 $flags = Revision::compressRevisionText( $data );
 938
 939                 # Write to external storage if required
 940                 if( $wgDefaultExternalStore ) {
 941                         // Store and get the URL
 942                         $data = ExternalStore::insertToDefault( $data );
 943                         if( !$data ) {
 944                                 throw new MWException( "Unable to store text to external storage" );
 945                         }
 946                         if( $flags ) {
 947                                 $flags .= ',';
 948                         }
 949                         $flags .= 'external';
 950                 }
 951
 952                 # Record the text (or external storage URL) to the text table
 953                 if( !isset( $this->mTextId ) ) {
 954                         $old_id = $dbw->nextSequenceValue( 'text_old_id_seq' );
 955                         $dbw->insert( 'text',
 956                                 array(
 957                                         'old_id'    => $old_id,
 958                                         'old_text'  => $data,
 959                                         'old_flags' => $flags,
 960                                 ), __METHOD__
 961                         );
 962                         $this->mTextId = $dbw->insertId();
 963                 }
 964
 965                 if ( $this->mComment === null ) $this->mComment = "";
 966
 967                 # Record the edit in revisions
 968                 $rev_id = isset( $this->mId )
 969                         ? $this->mId
 970                         : $dbw->nextSequenceValue( 'revision_rev_id_seq' );
 971                 $dbw->insert( 'revision',
 972                         array(
 973                                 'rev_id'         => $rev_id,
 974                                 'rev_page'       => $this->mPage,
 975                                 'rev_text_id'    => $this->mTextId,
 976                                 'rev_comment'    => $this->mComment,
 977                                 'rev_minor_edit' => $this->mMinorEdit ? 1 : 0,
 978                                 'rev_user'       => $this->mUser,
 979                                 'rev_user_text'  => $this->mUserText,
 980                                 'rev_timestamp'  => $dbw->timestamp( $this->mTimestamp ),
 981                                 'rev_deleted'    => $this->mDeleted,
 982                                 'rev_len'        => $this->mSize,
 983                                 'rev_parent_id'  => is_null( $this->mParentId )
 984                                         ? $this->getPreviousRevisionId( $dbw )
 985                                         : $this->mParentId,
 986                                 'rev_sha1'       => is_null( $this->mSha1 )
 987                                         ? Revision::base36Sha1( $this->mText )
 988                                         : $this->mSha1
 989                         ), __METHOD__
 990                 );
 991
 992                 $this->mId = !is_null( $rev_id ) ? $rev_id : $dbw->insertId();
 993
 994                 wfRunHooks( 'RevisionInsertComplete', array( &$this, $data, $flags ) );
 995
 996                 wfProfileOut( __METHOD__ );
 997                 return $this->mId;
 998         }
 999
1000         /**
1001          * Get the base 36 SHA-1 value for a string of text
1002          * @param $text String
1003          * @return String
1004          */
1005         public static function base36Sha1( $text ) {
1006                 return wfBaseConvert( sha1( $text ), 16, 36, 31 );
1007         }
1008
1009         /**
1010          * Lazy-load the revision's text.
1011          * Currently hardcoded to the 'text' table storage engine.
1012          *
1013          * @return String
1014          */
1015         protected function loadText() {
1016                 wfProfileIn( __METHOD__ );
1017
1018                 // Caching may be beneficial for massive use of external storage
1019                 global $wgRevisionCacheExpiry, $wgMemc;
1020                 $textId = $this->getTextId();
1021                 $key = wfMemcKey( 'revisiontext', 'textid', $textId );
1022                 if( $wgRevisionCacheExpiry ) {
1023                         $text = $wgMemc->get( $key );
1024                         if( is_string( $text ) ) {
1025                                 wfDebug( __METHOD__ . ": got id $textId from cache\n" );
1026                                 wfProfileOut( __METHOD__ );
1027                                 return $text;
1028                         }
1029                 }
1030
1031                 // If we kept data for lazy extraction, use it now...
1032                 if ( isset( $this->mTextRow ) ) {
1033                         $row = $this->mTextRow;
1034                         $this->mTextRow = null;
1035                 } else {
1036                         $row = null;
1037                 }
1038
1039                 if( !$row ) {
1040                         // Text data is immutable; check slaves first.
1041                         $dbr = wfGetDB( DB_SLAVE );
1042                         $row = $dbr->selectRow( 'text',
1043                                 array( 'old_text', 'old_flags' ),
1044                                 array( 'old_id' => $this->getTextId() ),
1045                                 __METHOD__ );
1046                 }
1047
1048                 if( !$row && wfGetLB()->getServerCount() > 1 ) {
1049                         // Possible slave lag!
1050                         $dbw = wfGetDB( DB_MASTER );
1051                         $row = $dbw->selectRow( 'text',
1052                                 array( 'old_text', 'old_flags' ),
1053                                 array( 'old_id' => $this->getTextId() ),
1054                                 __METHOD__ );
1055                 }
1056
1057                 $text = self::getRevisionText( $row );
1058
1059                 # No negative caching -- negative hits on text rows may be due to corrupted slave servers
1060                 if( $wgRevisionCacheExpiry && $text !== false ) {
1061                         $wgMemc->set( $key, $text, $wgRevisionCacheExpiry );
1062                 }
1063
1064                 wfProfileOut( __METHOD__ );
1065
1066                 return $text;
1067         }
1068
1069         /**
1070          * Create a new null-revision for insertion into a page's
1071          * history. This will not re-save the text, but simply refer
1072          * to the text from the previous version.
1073          *
1074          * Such revisions can for instance identify page rename
1075          * operations and other such meta-modifications.
1076          *
1077          * @param $dbw DatabaseBase
1078          * @param $pageId Integer: ID number of the page to read from
1079          * @param $summary String: revision's summary
1080          * @param $minor Boolean: whether the revision should be considered as minor
1081          * @return Revision|null on error
1082          */
1083         public static function newNullRevision( $dbw, $pageId, $summary, $minor ) {
1084                 wfProfileIn( __METHOD__ );
1085
1086                 $current = $dbw->selectRow(
1087                         array( 'page', 'revision' ),
1088                         array( 'page_latest', 'rev_text_id', 'rev_len', 'rev_sha1' ),
1089                         array(
1090                                 'page_id' => $pageId,
1091                                 'page_latest=rev_id',
1092                                 ),
1093                         __METHOD__ );
1094
1095                 if( $current ) {
1096                         $revision = new Revision( array(
1097                                 'page'       => $pageId,
1098                                 'comment'    => $summary,
1099                                 'minor_edit' => $minor,
1100                                 'text_id'    => $current->rev_text_id,
1101                                 'parent_id'  => $current->page_latest,
1102                                 'len'        => $current->rev_len,
1103                                 'sha1'       => $current->rev_sha1
1104                                 ) );
1105                 } else {
1106                         $revision = null;
1107                 }
1108
1109                 wfProfileOut( __METHOD__ );
1110                 return $revision;
1111         }
1112
1113         /**
1114          * Determine if the current user is allowed to view a particular
1115          * field of this revision, if it's marked as deleted.
1116          *
1117          * @param $field Integer:one of self::DELETED_TEXT,
1118          *                              self::DELETED_COMMENT,
1119          *                              self::DELETED_USER
1120          * @param $user User object to check, or null to use $wgUser
1121          * @return Boolean
1122          */
1123         public function userCan( $field, User $user = null ) {
1124                 return self::userCanBitfield( $this->mDeleted, $field, $user );
1125         }
1126
1127         /**
1128          * Determine if the current user is allowed to view a particular
1129          * field of this revision, if it's marked as deleted. This is used
1130          * by various classes to avoid duplication.
1131          *
1132          * @param $bitfield Integer: current field
1133          * @param $field Integer: one of self::DELETED_TEXT = File::DELETED_FILE,
1134          *                               self::DELETED_COMMENT = File::DELETED_COMMENT,
1135          *                               self::DELETED_USER = File::DELETED_USER
1136          * @param $user User object to check, or null to use $wgUser
1137          * @return Boolean
1138          */
1139         public static function userCanBitfield( $bitfield, $field, User $user = null ) {
1140                 if( $bitfield & $field ) { // aspect is deleted
1141                         if ( $bitfield & self::DELETED_RESTRICTED ) {
1142                                 $permission = 'suppressrevision';
1143                         } elseif ( $field & self::DELETED_TEXT ) {
1144                                 $permission = 'deletedtext';
1145                         } else {
1146                                 $permission = 'deletedhistory';
1147                         }
1148                         wfDebug( "Checking for $permission due to $field match on $bitfield\n" );
1149                         if ( $user === null ) {
1150                                 global $wgUser;
1151                                 $user = $wgUser;
1152                         }
1153                         return $user->isAllowed( $permission );
1154                 } else {
1155                         return true;
1156                 }
1157         }
1158
1159         /**
1160          * Get rev_timestamp from rev_id, without loading the rest of the row
1161          *
1162          * @param $title Title
1163          * @param $id Integer
1164          * @return String
1165          */
1166         static function getTimestampFromId( $title, $id ) {
1167                 $dbr = wfGetDB( DB_SLAVE );
1168                 // Casting fix for DB2
1169                 if ( $id == '' ) {
1170                         $id = 0;
1171                 }
1172                 $conds = array( 'rev_id' => $id );
1173                 $conds['rev_page'] = $title->getArticleId();
1174                 $timestamp = $dbr->selectField( 'revision', 'rev_timestamp', $conds, __METHOD__ );
1175                 if ( $timestamp === false && wfGetLB()->getServerCount() > 1 ) {
1176                         # Not in slave, try master
1177                         $dbw = wfGetDB( DB_MASTER );
1178                         $timestamp = $dbw->selectField( 'revision', 'rev_timestamp', $conds, __METHOD__ );
1179                 }
1180                 return wfTimestamp( TS_MW, $timestamp );
1181         }
1182
1183         /**
1184          * Get count of revisions per page...not very efficient
1185          *
1186          * @param $db DatabaseBase
1187          * @param $id Integer: page id
1188          * @return Integer
1189          */
1190         static function countByPageId( $db, $id ) {
1191                 $row = $db->selectRow( 'revision', 'COUNT(*) AS revCount',
1192                         array( 'rev_page' => $id ), __METHOD__ );
1193                 if( $row ) {
1194                         return $row->revCount;
1195                 }
1196                 return 0;
1197         }
1198
1199         /**
1200          * Get count of revisions per page...not very efficient
1201          *
1202          * @param $db DatabaseBase
1203          * @param $title Title
1204          * @return Integer
1205          */
1206         static function countByTitle( $db, $title ) {
1207                 $id = $title->getArticleId();
1208                 if( $id ) {
1209                         return Revision::countByPageId( $db, $id );
1210                 }
1211                 return 0;
1212         }
1213 }