includes/Revision.php

   1 <?php
   2
   3 /**
   4  * @todo document
   5  */
   6 class Revision {
   7         const DELETED_TEXT = 1;
   8         const DELETED_COMMENT = 2;
   9         const DELETED_USER = 4;
  10         const DELETED_RESTRICTED = 8;
  11         // Convenience field
  12         const SUPPRESSED_USER = 12;
  13         // Audience options for Revision::getText()
  14         const FOR_PUBLIC = 1;
  15         const FOR_THIS_USER = 2;
  16         const RAW = 3;
  17
  18         /**
  19          * Load a page revision from a given revision ID number.
  20          * Returns null if no such revision can be found.
  21          *
  22          * @param $id Integer
  23          * @return Revision or null
  24          */
  25         public static function newFromId( $id ) {
  26                 return Revision::newFromConds(
  27                         array( 'page_id=rev_page',
  28                                    'rev_id' => intval( $id ) ) );
  29         }
  30
  31         /**
  32          * Load either the current, or a specified, revision
  33          * that's attached to a given title. If not attached
  34          * to that title, will return null.
  35          *
  36          * @param $title Title
  37          * @param $id Integer (optional)
  38          * @return Revision or null
  39          */
  40         public static function newFromTitle( $title, $id = 0 ) {
  41                 $conds = array(
  42                         'page_namespace' => $title->getNamespace(),
  43                         'page_title'     => $title->getDBkey()
  44                 );
  45                 if ( $id ) {
  46                         // Use the specified ID
  47                         $conds['rev_id'] = $id;
  48                 } elseif ( wfGetLB()->getServerCount() > 1 ) {
  49                         // Get the latest revision ID from the master
  50                         $dbw = wfGetDB( DB_MASTER );
  51                         $latest = $dbw->selectField( 'page', 'page_latest', $conds, __METHOD__ );
  52                         if ( $latest === false ) {
  53                                 return null; // page does not exist
  54                         }
  55                         $conds['rev_id'] = $latest;
  56                 } else {
  57                         // Use a join to get the latest revision
  58                         $conds[] = 'rev_id=page_latest';
  59                 }
  60                 $conds[] = 'page_id=rev_page';
  61                 return Revision::newFromConds( $conds );
  62         }
  63
  64         /**
  65          * Load either the current, or a specified, revision
  66          * that's attached to a given page ID.
  67          * Returns null if no such revision can be found.
  68          *
  69          * @param $revId Integer
  70          * @param $pageId Integer (optional)
  71          * @return Revision or null
  72          */
  73         public static function newFromPageId( $pageId, $revId = 0 ) {
  74                 $conds = array( 'page_id' => $pageId );
  75                 if ( $revId ) {
  76                         $conds['rev_id'] = $revId;
  77                 } elseif ( wfGetLB()->getServerCount() > 1 ) {
  78                         // Get the latest revision ID from the master
  79                         $dbw = wfGetDB( DB_MASTER );
  80                         $latest = $dbw->selectField( 'page', 'page_latest', $conds, __METHOD__ );
  81                         if ( $latest === false ) {
  82                                 return null; // page does not exist
  83                         }
  84                         $conds['rev_id'] = $latest;
  85                 } else {
  86                         $conds[] = 'rev_id = page_latest';
  87                 }
  88                 $conds[] = 'page_id=rev_page';
  89                 return Revision::newFromConds( $conds );
  90         }
  91
  92         /**
  93          * Make a fake revision object from an archive table row. This is queried
  94          * for permissions or even inserted (as in Special:Undelete)
  95          * @todo FIXME: Should be a subclass for RevisionDelete. [TS]
  96          *
  97          * @param $row
  98          * @param $overrides array
  99          *
 100          * @return Revision
 101          */
 102         public static function newFromArchiveRow( $row, $overrides = array() ) {
 103                 $attribs = $overrides + array(
 104                         'page'       => isset( $row->ar_page_id ) ? $row->ar_page_id : null,
 105                         'id'         => isset( $row->ar_rev_id ) ? $row->ar_rev_id : null,
 106                         'comment'    => $row->ar_comment,
 107                         'user'       => $row->ar_user,
 108                         'user_text'  => $row->ar_user_text,
 109                         'timestamp'  => $row->ar_timestamp,
 110                         'minor_edit' => $row->ar_minor_edit,
 111                         'text_id'    => isset( $row->ar_text_id ) ? $row->ar_text_id : null,
 112                         'deleted'    => $row->ar_deleted,
 113                         'len'        => $row->ar_len);
 114                 if ( isset( $row->ar_text ) && !$row->ar_text_id ) {
 115                         // Pre-1.5 ar_text row
 116                         $attribs['text'] = self::getRevisionText( $row, 'ar_' );
 117                         if ( $attribs['text'] === false ) {
 118                                 throw new MWException( 'Unable to load text from archive row (possibly bug 22624)' );
 119                         }
 120                 }
 121                 return new self( $attribs );
 122         }
 123
 124         /**
 125          * Load a page revision from a given revision ID number.
 126          * Returns null if no such revision can be found.
 127          *
 128          * @param $db DatabaseBase
 129          * @param $id Integer
 130          * @return Revision or null
 131          */
 132         public static function loadFromId( $db, $id ) {
 133                 return Revision::loadFromConds( $db,
 134                         array( 'page_id=rev_page',
 135                                    'rev_id' => intval( $id ) ) );
 136         }
 137
 138         /**
 139          * Load either the current, or a specified, revision
 140          * that's attached to a given page. If not attached
 141          * to that page, will return null.
 142          *
 143          * @param $db DatabaseBase
 144          * @param $pageid Integer
 145          * @param $id Integer
 146          * @return Revision or null
 147          */
 148         public static function loadFromPageId( $db, $pageid, $id = 0 ) {
 149                 $conds = array( 'page_id=rev_page','rev_page' => intval( $pageid ), 'page_id'=>intval( $pageid ) );
 150                 if( $id ) {
 151                         $conds['rev_id'] = intval( $id );
 152                 } else {
 153                         $conds[] = 'rev_id=page_latest';
 154                 }
 155                 return Revision::loadFromConds( $db, $conds );
 156         }
 157
 158         /**
 159          * Stores the origin wiki of a revision in case it is a foreign wiki
 160          */
 161         function setWikiID( $wikiID ) {
 162                 $this->mWikiID = $wikiID;
 163         }
 164
 165         /**
 166          * Load the current revision of a given page of a foreign wiki.
 167          * The WikiID is stored for further use, such as loadText() and getTimestampFromId()
 168          */
 169         public static function loadFromTitleForeignWiki( $wikiID, $title ) {
 170                 $dbr = wfGetDB( DB_SLAVE, array(), $wikiID );
 171
 172                 $revision = self::loadFromTitle( $dbr, $title );
 173
 174                 if( $revision ) {
 175                         $revision->setWikiID( $wikiID );
 176                 }
 177
 178                 return $revision;
 179
 180         }
 181
 182         /**
 183          * Load either the current, or a specified, revision
 184          * that's attached to a given page. If not attached
 185          * to that page, will return null.
 186          *
 187          * @param $db DatabaseBase
 188          * @param $title Title
 189          * @param $id Integer
 190          * @return Revision or null
 191          */
 192         public static function loadFromTitle( $db, $title, $id = 0 ) {
 193                 if( $id ) {
 194                         $matchId = intval( $id );
 195                 } else {
 196                         $matchId = 'page_latest';
 197                 }
 198                 return Revision::loadFromConds(
 199                         $db,
 200                         array( "rev_id=$matchId",
 201                                    'page_id=rev_page',
 202                                    'page_namespace' => $title->getNamespace(),
 203                                    'page_title'     => $title->getDBkey() ) );
 204         }
 205
 206         /**
 207          * Load the revision for the given title with the given timestamp.
 208          * WARNING: Timestamps may in some circumstances not be unique,
 209          * so this isn't the best key to use.
 210          *
 211          * @param $db DatabaseBase
 212          * @param $title Title
 213          * @param $timestamp String
 214          * @return Revision or null
 215          */
 216         public static function loadFromTimestamp( $db, $title, $timestamp ) {
 217                 return Revision::loadFromConds(
 218                         $db,
 219                         array( 'rev_timestamp'  => $db->timestamp( $timestamp ),
 220                                    'page_id=rev_page',
 221                                    'page_namespace' => $title->getNamespace(),
 222                                    'page_title'     => $title->getDBkey() ) );
 223         }
 224
 225         /**
 226          * Given a set of conditions, fetch a revision.
 227          *
 228          * @param $conditions Array
 229          * @return Revision or null
 230          */
 231         public static function newFromConds( $conditions ) {
 232                 $db = wfGetDB( DB_SLAVE );
 233                 $row = Revision::loadFromConds( $db, $conditions );
 234                 if( is_null( $row ) && wfGetLB()->getServerCount() > 1 ) {
 235                         $dbw = wfGetDB( DB_MASTER );
 236                         $row = Revision::loadFromConds( $dbw, $conditions );
 237                 }
 238                 return $row;
 239         }
 240
 241         /**
 242          * Given a set of conditions, fetch a revision from
 243          * the given database connection.
 244          *
 245          * @param $db DatabaseBase
 246          * @param $conditions Array
 247          * @return Revision or null
 248          */
 249         private static function loadFromConds( $db, $conditions ) {
 250                 $res = Revision::fetchFromConds( $db, $conditions );
 251                 if( $res ) {
 252                         $row = $res->fetchObject();
 253                         $res->free();
 254                         if( $row ) {
 255                                 $ret = new Revision( $row );
 256                                 return $ret;
 257                         }
 258                 }
 259                 $ret = null;
 260                 return $ret;
 261         }
 262
 263         /**
 264          * Return a wrapper for a series of database rows to
 265          * fetch all of a given page's revisions in turn.
 266          * Each row can be fed to the constructor to get objects.
 267          *
 268          * @param $title Title
 269          * @return ResultWrapper
 270          */
 271         public static function fetchRevision( $title ) {
 272                 return Revision::fetchFromConds(
 273                         wfGetDB( DB_SLAVE ),
 274                         array( 'rev_id=page_latest',
 275                                    'page_namespace' => $title->getNamespace(),
 276                                    'page_title'     => $title->getDBkey(),
 277                                    'page_id=rev_page' ) );
 278         }
 279
 280         /**
 281          * Given a set of conditions, return a ResultWrapper
 282          * which will return matching database rows with the
 283          * fields necessary to build Revision objects.
 284          *
 285          * @param $db DatabaseBase
 286          * @param $conditions Array
 287          * @return ResultWrapper
 288          */
 289         private static function fetchFromConds( $db, $conditions ) {
 290                 $fields = self::selectFields();
 291                 $fields[] = 'page_namespace';
 292                 $fields[] = 'page_title';
 293                 $fields[] = 'page_latest';
 294                 return $db->select(
 295                         array( 'page', 'revision' ),
 296                         $fields,
 297                         $conditions,
 298                         __METHOD__,
 299                         array( 'LIMIT' => 1 ) );
 300         }
 301
 302         /**
 303          * Return the list of revision fields that should be selected to create
 304          * a new revision.
 305          */
 306         public static function selectFields() {
 307                 return array(
 308                         'rev_id',
 309                         'rev_page',
 310                         'rev_text_id',
 311                         'rev_timestamp',
 312                         'rev_comment',
 313                         'rev_user_text,'.
 314                         'rev_user',
 315                         'rev_minor_edit',
 316                         'rev_deleted',
 317                         'rev_len',
 318                         'rev_parent_id'
 319                 );
 320         }
 321
 322         /**
 323          * Return the list of text fields that should be selected to read the
 324          * revision text
 325          */
 326         static function selectTextFields() {
 327                 return array(
 328                         'old_text',
 329                         'old_flags'
 330                 );
 331         }
 332
 333         /**
 334          * Return the list of page fields that should be selected from page table
 335          */
 336         static function selectPageFields() {
 337                 return array(
 338                         'page_namespace',
 339                         'page_title',
 340                         'page_latest'
 341                 );
 342         }
 343
 344         /**
 345          * Constructor
 346          *
 347          * @param $row Mixed: either a database row or an array
 348          * @access private
 349          */
 350         function __construct( $row ) {
 351                 if( is_object( $row ) ) {
 352                         $this->mId        = intval( $row->rev_id );
 353                         $this->mPage      = intval( $row->rev_page );
 354                         $this->mTextId    = intval( $row->rev_text_id );
 355                         $this->mComment   =         $row->rev_comment;
 356                         $this->mUserText  =         $row->rev_user_text;
 357                         $this->mUser      = intval( $row->rev_user );
 358                         $this->mMinorEdit = intval( $row->rev_minor_edit );
 359                         $this->mTimestamp =         $row->rev_timestamp;
 360                         $this->mDeleted   = intval( $row->rev_deleted );
 361
 362                         if( !isset( $row->rev_parent_id ) )
 363                                 $this->mParentId = is_null($row->rev_parent_id) ? null : 0;
 364                         else
 365                                 $this->mParentId  = intval( $row->rev_parent_id );
 366
 367                         if( !isset( $row->rev_len ) || is_null( $row->rev_len ) )
 368                                 $this->mSize = null;
 369                         else
 370                                 $this->mSize = intval( $row->rev_len );
 371
 372                         if( isset( $row->page_latest ) ) {
 373                                 $this->mCurrent = ( $row->rev_id == $row->page_latest );
 374                                 $this->mTitle = Title::newFromRow( $row );
 375                         } else {
 376                                 $this->mCurrent = false;
 377                                 $this->mTitle = null;
 378                         }
 379
 380                         // Lazy extraction...
 381                         $this->mText      = null;
 382                         if( isset( $row->old_text ) ) {
 383                                 $this->mTextRow = $row;
 384                         } else {
 385                                 // 'text' table row entry will be lazy-loaded
 386                                 $this->mTextRow = null;
 387                         }
 388                 } elseif( is_array( $row ) ) {
 389                         // Build a new revision to be saved...
 390                         global $wgUser;
 391
 392                         $this->mId        = isset( $row['id']         ) ? intval( $row['id']         ) : null;
 393                         $this->mPage      = isset( $row['page']       ) ? intval( $row['page']       ) : null;
 394                         $this->mTextId    = isset( $row['text_id']    ) ? intval( $row['text_id']    ) : null;
 395                         $this->mUserText  = isset( $row['user_text']  ) ? strval( $row['user_text']  ) : $wgUser->getName();
 396                         $this->mUser      = isset( $row['user']       ) ? intval( $row['user']       ) : $wgUser->getId();
 397                         $this->mMinorEdit = isset( $row['minor_edit'] ) ? intval( $row['minor_edit'] ) : 0;
 398                         $this->mTimestamp = isset( $row['timestamp']  ) ? strval( $row['timestamp']  ) : wfTimestamp( TS_MW );
 399                         $this->mDeleted   = isset( $row['deleted']    ) ? intval( $row['deleted']    ) : 0;
 400                         $this->mSize      = isset( $row['len']        ) ? intval( $row['len']        ) : null;
 401                         $this->mParentId  = isset( $row['parent_id']  ) ? intval( $row['parent_id']  ) : null;
 402
 403                         // Enforce spacing trimming on supplied text
 404                         $this->mComment   = isset( $row['comment']    ) ?  trim( strval( $row['comment'] ) ) : null;
 405                         $this->mText      = isset( $row['text']       ) ? rtrim( strval( $row['text']    ) ) : null;
 406                         $this->mTextRow   = null;
 407
 408                         $this->mTitle     = null; # Load on demand if needed
 409                         $this->mCurrent   = false;
 410                         # If we still have no len_size, see it we have the text to figure it out
 411                         if ( !$this->mSize )
 412                                 $this->mSize      = is_null( $this->mText ) ? null : strlen( $this->mText );
 413                 } else {
 414                         throw new MWException( 'Revision constructor passed invalid row format.' );
 415                 }
 416                 $this->mUnpatrolled = null;
 417                 $this->mWikiID = false;
 418         }
 419
 420         /**
 421          * Get revision ID
 422          *
 423          * @return Integer
 424          */
 425         public function getId() {
 426                 return $this->mId;
 427         }
 428
 429         /**
 430          * Get text row ID
 431          *
 432          * @return Integer
 433          */
 434         public function getTextId() {
 435                 return $this->mTextId;
 436         }
 437
 438         /**
 439          * Get parent revision ID (the original previous page revision)
 440          *
 441          * @return Integer
 442          */
 443         public function getParentId() {
 444                 return $this->mParentId;
 445         }
 446
 447         /**
 448          * Returns the length of the text in this revision, or null if unknown.
 449          *
 450          * @return Integer
 451          */
 452         public function getSize() {
 453                 return $this->mSize;
 454         }
 455
 456         /**
 457          * Returns the title of the page associated with this entry.
 458          *
 459          * @return Title
 460          */
 461         public function getTitle() {
 462                 if( isset( $this->mTitle ) ) {
 463                         return $this->mTitle;
 464                 }
 465                 $dbr = wfGetDB( DB_SLAVE, array(), $this->mWikiID );
 466
 467                 $row = $dbr->selectRow(
 468                         array( 'page', 'revision' ),
 469                         array( 'page_namespace', 'page_title' ),
 470                         array( 'page_id=rev_page',
 471                                    'rev_id' => $this->mId ),
 472                         'Revision::getTitle' );
 473                 if( $row ) {
 474                         $this->mTitle = Title::makeTitle( $row->page_namespace,
 475                                                                                           $row->page_title );
 476                 }
 477                 return $this->mTitle;
 478         }
 479
 480         /**
 481          * Set the title of the revision
 482          *
 483          * @param $title Title
 484          */
 485         public function setTitle( $title ) {
 486                 $this->mTitle = $title;
 487         }
 488
 489         /**
 490          * Get the page ID
 491          *
 492          * @return Integer
 493          */
 494         public function getPage() {
 495                 return $this->mPage;
 496         }
 497
 498         /**
 499          * Fetch revision's user id if it's available to the specified audience.
 500          * If the specified audience does not have access to it, zero will be
 501          * returned.
 502          *
 503          * @param $audience Integer: one of:
 504          *      Revision::FOR_PUBLIC       to be displayed to all users
 505          *      Revision::FOR_THIS_USER    to be displayed to $wgUser
 506          *      Revision::RAW              get the ID regardless of permissions
 507          *
 508          *
 509          * @return Integer
 510          */
 511         public function getUser( $audience = self::FOR_PUBLIC ) {
 512                 if( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_USER ) ) {
 513                         return 0;
 514                 } elseif( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_USER ) ) {
 515                         return 0;
 516                 } else {
 517                         return $this->mUser;
 518                 }
 519         }
 520
 521         /**
 522          * Fetch revision's user id without regard for the current user's permissions
 523          *
 524          * @return String
 525          */
 526         public function getRawUser() {
 527                 return $this->mUser;
 528         }
 529
 530         /**
 531          * Fetch revision's username if it's available to the specified audience.
 532          * If the specified audience does not have access to the username, an
 533          * empty string will be returned.
 534          *
 535          * @param $audience Integer: one of:
 536          *      Revision::FOR_PUBLIC       to be displayed to all users
 537          *      Revision::FOR_THIS_USER    to be displayed to $wgUser
 538          *      Revision::RAW              get the text regardless of permissions
 539          *
 540          * @return string
 541          */
 542         public function getUserText( $audience = self::FOR_PUBLIC ) {
 543                 if( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_USER ) ) {
 544                         return '';
 545                 } elseif( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_USER ) ) {
 546                         return '';
 547                 } else {
 548                         return $this->mUserText;
 549                 }
 550         }
 551
 552         /**
 553          * Fetch revision's username without regard for view restrictions
 554          *
 555          * @return String
 556          */
 557         public function getRawUserText() {
 558                 return $this->mUserText;
 559         }
 560
 561         /**
 562          * Fetch revision comment if it's available to the specified audience.
 563          * If the specified audience does not have access to the comment, an
 564          * empty string will be returned.
 565          *
 566          * @param $audience Integer: one of:
 567          *      Revision::FOR_PUBLIC       to be displayed to all users
 568          *      Revision::FOR_THIS_USER    to be displayed to $wgUser
 569          *      Revision::RAW              get the text regardless of permissions
 570          *
 571          * @return String
 572          */
 573         function getComment( $audience = self::FOR_PUBLIC ) {
 574                 if( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_COMMENT ) ) {
 575                         return '';
 576                 } elseif( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_COMMENT ) ) {
 577                         return '';
 578                 } else {
 579                         return $this->mComment;
 580                 }
 581         }
 582
 583         /**
 584          * Fetch revision comment without regard for the current user's permissions
 585          *
 586          * @return String
 587          */
 588         public function getRawComment() {
 589                 return $this->mComment;
 590         }
 591
 592         /**
 593          * @return Boolean
 594          */
 595         public function isMinor() {
 596                 return (bool)$this->mMinorEdit;
 597         }
 598
 599         /**
 600          * @return Integer rcid of the unpatrolled row, zero if there isn't one
 601          */
 602         public function isUnpatrolled() {
 603                 if( $this->mUnpatrolled !== null ) {
 604                         return $this->mUnpatrolled;
 605                 }
 606                 $dbr = wfGetDB( DB_SLAVE, array(), $this->mWikiID );
 607                 $this->mUnpatrolled = $dbr->selectField( 'recentchanges',
 608                         'rc_id',
 609                         array( // Add redundant user,timestamp condition so we can use the existing index
 610                                 'rc_user_text'  => $this->getRawUserText(),
 611                                 'rc_timestamp'  => $dbr->timestamp( $this->getTimestamp() ),
 612                                 'rc_this_oldid' => $this->getId(),
 613                                 'rc_patrolled'  => 0
 614                         ),
 615                         __METHOD__
 616                 );
 617                 return (int)$this->mUnpatrolled;
 618         }
 619
 620         /**
 621          * int $field one of DELETED_* bitfield constants
 622          *
 623          * @return Boolean
 624          */
 625         public function isDeleted( $field ) {
 626                 return ( $this->mDeleted & $field ) == $field;
 627         }
 628
 629         /**
 630          * Get the deletion bitfield of the revision
 631          */
 632         public function getVisibility() {
 633                 return (int)$this->mDeleted;
 634         }
 635
 636         /**
 637          * Fetch revision text if it's available to the specified audience.
 638          * If the specified audience does not have the ability to view this
 639          * revision, an empty string will be returned.
 640          *
 641          * @param $audience Integer: one of:
 642          *      Revision::FOR_PUBLIC       to be displayed to all users
 643          *      Revision::FOR_THIS_USER    to be displayed to $wgUser
 644          *      Revision::RAW              get the text regardless of permissions
 645          *
 646          * @return String
 647          */
 648         public function getText( $audience = self::FOR_PUBLIC ) {
 649                 if( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_TEXT ) ) {
 650                         return '';
 651                 } elseif( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_TEXT ) ) {
 652                         return '';
 653                 } else {
 654                         return $this->getRawText();
 655                 }
 656         }
 657
 658         /**
 659          * Alias for getText(Revision::FOR_THIS_USER)
 660          *
 661          * @deprecated since 1.17
 662          * @return String
 663          */
 664         public function revText() {
 665                 wfDeprecated( __METHOD__ );
 666                 return $this->getText( self::FOR_THIS_USER );
 667         }
 668
 669         /**
 670          * Fetch revision text without regard for view restrictions
 671          *
 672          * @return String
 673          */
 674         public function getRawText() {
 675                 if( is_null( $this->mText ) ) {
 676                         // Revision text is immutable. Load on demand:
 677                         $this->mText = $this->loadText();
 678                 }
 679                 return $this->mText;
 680         }
 681
 682         /**
 683          * @return String
 684          */
 685         public function getTimestamp() {
 686                 return wfTimestamp( TS_MW, $this->mTimestamp );
 687         }
 688
 689         /**
 690          * @return Boolean
 691          */
 692         public function isCurrent() {
 693                 return $this->mCurrent;
 694         }
 695
 696         /**
 697          * Get previous revision for this title
 698          *
 699          * @return Revision or null
 700          */
 701         public function getPrevious() {
 702                 if( $this->getTitle() ) {
 703                         $prev = $this->getTitle()->getPreviousRevisionID( $this->getId() );
 704                         if( $prev ) {
 705                                 return Revision::newFromTitle( $this->getTitle(), $prev );
 706                         }
 707                 }
 708                 return null;
 709         }
 710
 711         /**
 712          * Get next revision for this title
 713          *
 714          * @return Revision or null
 715          */
 716         public function getNext() {
 717                 if( $this->getTitle() ) {
 718                         $next = $this->getTitle()->getNextRevisionID( $this->getId() );
 719                         if ( $next ) {
 720                                 return Revision::newFromTitle( $this->getTitle(), $next );
 721                         }
 722                 }
 723                 return null;
 724         }
 725
 726         /**
 727          * Get previous revision Id for this page_id
 728          * This is used to populate rev_parent_id on save
 729          *
 730          * @param $db DatabaseBase
 731          * @return Integer
 732          */
 733         private function getPreviousRevisionId( $db ) {
 734                 if( is_null( $this->mPage ) ) {
 735                         return 0;
 736                 }
 737                 # Use page_latest if ID is not given
 738                 if( !$this->mId ) {
 739                         $prevId = $db->selectField( 'page', 'page_latest',
 740                                 array( 'page_id' => $this->mPage ),
 741                                 __METHOD__ );
 742                 } else {
 743                         $prevId = $db->selectField( 'revision', 'rev_id',
 744                                 array( 'rev_page' => $this->mPage, 'rev_id < ' . $this->mId ),
 745                                 __METHOD__,
 746                                 array( 'ORDER BY' => 'rev_id DESC' ) );
 747                 }
 748                 return intval( $prevId );
 749         }
 750
 751         /**
 752           * Get revision text associated with an old or archive row
 753           * $row is usually an object from wfFetchRow(), both the flags and the text
 754           * field must be included
 755           *
 756           * @param $row Object: the text data
 757           * @param $prefix String: table prefix (default 'old_')
 758           * @return String: text the text requested or false on failure
 759           */
 760         public static function getRevisionText( $row, $prefix = 'old_' ) {
 761                 wfProfileIn( __METHOD__ );
 762
 763                 # Get data
 764                 $textField = $prefix . 'text';
 765                 $flagsField = $prefix . 'flags';
 766
 767                 if( isset( $row->$flagsField ) ) {
 768                         $flags = explode( ',', $row->$flagsField );
 769                 } else {
 770                         $flags = array();
 771                 }
 772
 773                 if( isset( $row->$textField ) ) {
 774                         $text = $row->$textField;
 775                 } else {
 776                         wfProfileOut( __METHOD__ );
 777                         return false;
 778                 }
 779
 780                 # Use external methods for external objects, text in table is URL-only then
 781                 if ( in_array( 'external', $flags ) ) {
 782                         $url = $text;
 783                         $parts = explode( '://', $url, 2 );
 784                         if( count( $parts ) == 1 || $parts[1] == '' ) {
 785                                 wfProfileOut( __METHOD__ );
 786                                 return false;
 787                         }
 788                         $text = ExternalStore::fetchFromURL( $url );
 789                 }
 790
 791                 // If the text was fetched without an error, convert it
 792                 if ( $text !== false ) {
 793                         if( in_array( 'gzip', $flags ) ) {
 794                                 # Deal with optional compression of archived pages.
 795                                 # This can be done periodically via maintenance/compressOld.php, and
 796                                 # as pages are saved if $wgCompressRevisions is set.
 797                                 $text = gzinflate( $text );
 798                         }
 799
 800                         if( in_array( 'object', $flags ) ) {
 801                                 # Generic compressed storage
 802                                 $obj = unserialize( $text );
 803                                 if ( !is_object( $obj ) ) {
 804                                         // Invalid object
 805                                         wfProfileOut( __METHOD__ );
 806                                         return false;
 807                                 }
 808                                 $text = $obj->getText();
 809                         }
 810
 811                         global $wgLegacyEncoding;
 812                         if( $text !== false && $wgLegacyEncoding
 813                                 && !in_array( 'utf-8', $flags ) && !in_array( 'utf8', $flags ) )
 814                         {
 815                                 # Old revisions kept around in a legacy encoding?
 816                                 # Upconvert on demand.
 817                                 # ("utf8" checked for compatibility with some broken
 818                                 #  conversion scripts 2008-12-30)
 819                                 global $wgContLang;
 820                                 $text = $wgContLang->iconv( $wgLegacyEncoding, 'UTF-8', $text );
 821                         }
 822                 }
 823                 wfProfileOut( __METHOD__ );
 824                 return $text;
 825         }
 826
 827         /**
 828          * If $wgCompressRevisions is enabled, we will compress data.
 829          * The input string is modified in place.
 830          * Return value is the flags field: contains 'gzip' if the
 831          * data is compressed, and 'utf-8' if we're saving in UTF-8
 832          * mode.
 833          *
 834          * @param $text Mixed: reference to a text
 835          * @return String
 836          */
 837         public static function compressRevisionText( &$text ) {
 838                 global $wgCompressRevisions;
 839                 $flags = array();
 840
 841                 # Revisions not marked this way will be converted
 842                 # on load if $wgLegacyCharset is set in the future.
 843                 $flags[] = 'utf-8';
 844
 845                 if( $wgCompressRevisions ) {
 846                         if( function_exists( 'gzdeflate' ) ) {
 847                                 $text = gzdeflate( $text );
 848                                 $flags[] = 'gzip';
 849                         } else {
 850                                 wfDebug( "Revision::compressRevisionText() -- no zlib support, not compressing\n" );
 851                         }
 852                 }
 853                 return implode( ',', $flags );
 854         }
 855
 856         /**
 857          * Insert a new revision into the database, returning the new revision ID
 858          * number on success and dies horribly on failure.
 859          *
 860          * @param $dbw DatabaseBase: (master connection)
 861          * @return Integer
 862          */
 863         public function insertOn( $dbw ) {
 864                 global $wgDefaultExternalStore;
 865
 866                 wfProfileIn( __METHOD__ );
 867
 868                 $data = $this->mText;
 869                 $flags = Revision::compressRevisionText( $data );
 870
 871                 # Write to external storage if required
 872                 if( $wgDefaultExternalStore ) {
 873                         // Store and get the URL
 874                         $data = ExternalStore::insertToDefault( $data );
 875                         if( !$data ) {
 876                                 throw new MWException( "Unable to store text to external storage" );
 877                         }
 878                         if( $flags ) {
 879                                 $flags .= ',';
 880                         }
 881                         $flags .= 'external';
 882                 }
 883
 884                 # Record the text (or external storage URL) to the text table
 885                 if( !isset( $this->mTextId ) ) {
 886                         $old_id = $dbw->nextSequenceValue( 'text_old_id_seq' );
 887                         $dbw->insert( 'text',
 888                                 array(
 889                                         'old_id'    => $old_id,
 890                                         'old_text'  => $data,
 891                                         'old_flags' => $flags,
 892                                 ), __METHOD__
 893                         );
 894                         $this->mTextId = $dbw->insertId();
 895                 }
 896
 897                 if ( $this->mComment === null ) $this->mComment = "";
 898
 899                 # Record the edit in revisions
 900                 $rev_id = isset( $this->mId )
 901                         ? $this->mId
 902                         : $dbw->nextSequenceValue( 'revision_rev_id_seq' );
 903                 $dbw->insert( 'revision',
 904                         array(
 905                                 'rev_id'         => $rev_id,
 906                                 'rev_page'       => $this->mPage,
 907                                 'rev_text_id'    => $this->mTextId,
 908                                 'rev_comment'    => $this->mComment,
 909                                 'rev_minor_edit' => $this->mMinorEdit ? 1 : 0,
 910                                 'rev_user'       => $this->mUser,
 911                                 'rev_user_text'  => $this->mUserText,
 912                                 'rev_timestamp'  => $dbw->timestamp( $this->mTimestamp ),
 913                                 'rev_deleted'    => $this->mDeleted,
 914                                 'rev_len'        => $this->mSize,
 915                                 'rev_parent_id'  => is_null($this->mParentId) ?
 916                                         $this->getPreviousRevisionId( $dbw ) : $this->mParentId
 917                         ), __METHOD__
 918                 );
 919
 920                 $this->mId = !is_null( $rev_id ) ? $rev_id : $dbw->insertId();
 921
 922                 wfRunHooks( 'RevisionInsertComplete', array( &$this, $data, $flags ) );
 923
 924                 wfProfileOut( __METHOD__ );
 925                 return $this->mId;
 926         }
 927
 928         /**
 929          * Lazy-load the revision's text.
 930          * Currently hardcoded to the 'text' table storage engine.
 931          *
 932          * @return String
 933          */
 934         protected function loadText() {
 935                 wfProfileIn( __METHOD__ );
 936
 937                 // Caching may be beneficial for massive use of external storage
 938                 global $wgRevisionCacheExpiry, $wgMemc;
 939                 $textId = $this->getTextId();
 940                 if( isset( $this->mWikiID ) && $this->mWikiID !== false ) {
 941                         $key = wfForeignMemcKey( $this->mWikiID, null, 'revisiontext', 'textid', $textId );
 942                 } else {
 943                         $key = wfMemcKey( 'revisiontext', 'textid', $textId );
 944                 }
 945                 if( $wgRevisionCacheExpiry ) {
 946                         $text = $wgMemc->get( $key );
 947                         if( is_string( $text ) ) {
 948                                 wfDebug( __METHOD__ . ": got id $textId from cache\n" );
 949                                 wfProfileOut( __METHOD__ );
 950                                 return $text;
 951                         }
 952                 }
 953
 954                 // If we kept data for lazy extraction, use it now...
 955                 if ( isset( $this->mTextRow ) ) {
 956                         $row = $this->mTextRow;
 957                         $this->mTextRow = null;
 958                 } else {
 959                         $row = null;
 960                 }
 961
 962                 if( !$row ) {
 963                         // Text data is immutable; check slaves first.
 964                         $dbr = wfGetDB( DB_SLAVE, array(), $this->mWikiID );
 965                         $row = $dbr->selectRow( 'text',
 966                                 array( 'old_text', 'old_flags' ),
 967                                 array( 'old_id' => $this->getTextId() ),
 968                                 __METHOD__ );
 969                 }
 970
 971                 if( !$row && wfGetLB()->getServerCount() > 1 ) {
 972                         // Possible slave lag!
 973                         $dbw = wfGetDB( DB_MASTER, array(), $this->mWikiID );
 974                         $row = $dbw->selectRow( 'text',
 975                                 array( 'old_text', 'old_flags' ),
 976                                 array( 'old_id' => $this->getTextId() ),
 977                                 __METHOD__ );
 978                 }
 979
 980                 $text = self::getRevisionText( $row );
 981
 982                 # No negative caching -- negative hits on text rows may be due to corrupted slave servers
 983                 if( $wgRevisionCacheExpiry && $text !== false ) {
 984                         $wgMemc->set( $key, $text, $wgRevisionCacheExpiry );
 985                 }
 986
 987                 wfProfileOut( __METHOD__ );
 988
 989                 return $text;
 990         }
 991
 992         /**
 993          * Create a new null-revision for insertion into a page's
 994          * history. This will not re-save the text, but simply refer
 995          * to the text from the previous version.
 996          *
 997          * Such revisions can for instance identify page rename
 998          * operations and other such meta-modifications.
 999          *
1000          * @param $dbw DatabaseBase
1001          * @param $pageId Integer: ID number of the page to read from
1002          * @param $summary String: revision's summary
1003          * @param $minor Boolean: whether the revision should be considered as minor
1004          * @return Revision|null on error
1005          */
1006         public static function newNullRevision( $dbw, $pageId, $summary, $minor ) {
1007                 wfProfileIn( __METHOD__ );
1008
1009                 $current = $dbw->selectRow(
1010                         array( 'page', 'revision' ),
1011                         array( 'page_latest', 'rev_text_id', 'rev_len' ),
1012                         array(
1013                                 'page_id' => $pageId,
1014                                 'page_latest=rev_id',
1015                                 ),
1016                         __METHOD__ );
1017
1018                 if( $current ) {
1019                         $revision = new Revision( array(
1020                                 'page'       => $pageId,
1021                                 'comment'    => $summary,
1022                                 'minor_edit' => $minor,
1023                                 'text_id'    => $current->rev_text_id,
1024                                 'parent_id'  => $current->page_latest,
1025                                 'len'        => $current->rev_len
1026                                 ) );
1027                 } else {
1028                         $revision = null;
1029                 }
1030
1031                 wfProfileOut( __METHOD__ );
1032                 return $revision;
1033         }
1034
1035         /**
1036          * Determine if the current user is allowed to view a particular
1037          * field of this revision, if it's marked as deleted.
1038          *
1039          * @param $field Integer:one of self::DELETED_TEXT,
1040          *                              self::DELETED_COMMENT,
1041          *                              self::DELETED_USER
1042          * @return Boolean
1043          */
1044         public function userCan( $field ) {
1045                 return self::userCanBitfield( $this->mDeleted, $field );
1046         }
1047
1048         /**
1049          * Determine if the current user is allowed to view a particular
1050          * field of this revision, if it's marked as deleted. This is used
1051          * by various classes to avoid duplication.
1052          *
1053          * @param $bitfield Integer: current field
1054          * @param $field Integer: one of self::DELETED_TEXT = File::DELETED_FILE,
1055          *                               self::DELETED_COMMENT = File::DELETED_COMMENT,
1056          *                               self::DELETED_USER = File::DELETED_USER
1057          * @return Boolean
1058          */
1059         public static function userCanBitfield( $bitfield, $field ) {
1060                 if( $bitfield & $field ) { // aspect is deleted
1061                         global $wgUser;
1062                         if ( $bitfield & self::DELETED_RESTRICTED ) {
1063                                 $permission = 'suppressrevision';
1064                         } elseif ( $field & self::DELETED_TEXT ) {
1065                                 $permission = 'deletedtext';
1066                         } else {
1067                                 $permission = 'deletedhistory';
1068                         }
1069                         wfDebug( "Checking for $permission due to $field match on $bitfield\n" );
1070                         return $wgUser->isAllowed( $permission );
1071                 } else {
1072                         return true;
1073                 }
1074         }
1075
1076         /**
1077          * Get rev_timestamp from rev_id, without loading the rest of the row
1078          *
1079          * @param $title Title
1080          * @param $id Integer
1081          * @return String
1082          */
1083         static function getTimestampFromId( $title, $id ) {
1084                 $wikiId = wfWikiID();
1085                 $dbr = wfGetDB( DB_SLAVE, array(), $wikiId );
1086                 // Casting fix for DB2
1087                 if ( $id == '' ) {
1088                         $id = 0;
1089                 }
1090                 $conds = array( 'rev_id' => $id );
1091                 $conds['rev_page'] = $title->getArticleId();
1092                 $timestamp = $dbr->selectField( 'revision', 'rev_timestamp', $conds, __METHOD__ );
1093                 if ( $timestamp === false && wfGetLB()->getServerCount() > 1 ) {
1094                         # Not in slave, try master
1095                         $dbw = wfGetDB( DB_MASTER, array(), $wikiId );
1096                         $timestamp = $dbw->selectField( 'revision', 'rev_timestamp', $conds, __METHOD__ );
1097                 }
1098                 return wfTimestamp( TS_MW, $timestamp );
1099         }
1100
1101         /**
1102          * Get count of revisions per page...not very efficient
1103          *
1104          * @param $db DatabaseBase
1105          * @param $id Integer: page id
1106          * @return Integer
1107          */
1108         static function countByPageId( $db, $id ) {
1109                 $row = $db->selectRow( 'revision', 'COUNT(*) AS revCount',
1110                         array( 'rev_page' => $id ), __METHOD__ );
1111                 if( $row ) {
1112                         return $row->revCount;
1113                 }
1114                 return 0;
1115         }
1116
1117         /**
1118          * Get count of revisions per page...not very efficient
1119          *
1120          * @param $db DatabaseBase
1121          * @param $title Title
1122          * @return Integer
1123          */
1124         static function countByTitle( $db, $title ) {
1125                 $id = $title->getArticleId();
1126                 if( $id ) {
1127                         return Revision::countByPageId( $db, $id );
1128                 }
1129                 return 0;
1130         }
1131 }
1132
1133 /**
1134  * Aliases for backwards compatibility with 1.6
1135  */
1136 define( 'MW_REV_DELETED_TEXT', Revision::DELETED_TEXT );
1137 define( 'MW_REV_DELETED_COMMENT', Revision::DELETED_COMMENT );
1138 define( 'MW_REV_DELETED_USER', Revision::DELETED_USER );
1139 define( 'MW_REV_DELETED_RESTRICTED', Revision::DELETED_RESTRICTED );