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     protected $mContentModelName;
  24     protected $mContentFormat;
  25     protected $mContent;
  26     protected $mContentHandler;
  27
  28         const DELETED_TEXT = 1;
  29         const DELETED_COMMENT = 2;
  30         const DELETED_USER = 4;
  31         const DELETED_RESTRICTED = 8;
  32         // Convenience field
  33         const SUPPRESSED_USER = 12;
  34         // Audience options for Revision::getText()
  35         const FOR_PUBLIC = 1;
  36         const FOR_THIS_USER = 2;
  37         const RAW = 3;
  38
  39         /**
  40          * Load a page revision from a given revision ID number.
  41          * Returns null if no such revision can be found.
  42          *
  43          * @param $id Integer
  44          * @return Revision or null
  45          */
  46         public static function newFromId( $id ) {
  47                 return Revision::newFromConds( array( 'rev_id' => intval( $id ) ) );
  48         }
  49
  50         /**
  51          * Load either the current, or a specified, revision
  52          * that's attached to a given title. If not attached
  53          * to that title, will return null.
  54          *
  55          * @param $title Title
  56          * @param $id Integer (optional)
  57          * @return Revision or null
  58          */
  59         public static function newFromTitle( $title, $id = 0 ) {
  60                 $conds = array(
  61                         'page_namespace' => $title->getNamespace(),
  62                         'page_title'     => $title->getDBkey()
  63                 );
  64                 if ( $id ) {
  65                         // Use the specified ID
  66                         $conds['rev_id'] = $id;
  67                 } elseif ( wfGetLB()->getServerCount() > 1 ) {
  68                         // Get the latest revision ID from the master
  69                         $dbw = wfGetDB( DB_MASTER );
  70                         $latest = $dbw->selectField( 'page', 'page_latest', $conds, __METHOD__ );
  71                         if ( $latest === false ) {
  72                                 return null; // page does not exist
  73                         }
  74                         $conds['rev_id'] = $latest;
  75                 } else {
  76                         // Use a join to get the latest revision
  77                         $conds[] = 'rev_id=page_latest';
  78                 }
  79                 return Revision::newFromConds( $conds );
  80         }
  81
  82         /**
  83          * Load either the current, or a specified, revision
  84          * that's attached to a given page ID.
  85          * Returns null if no such revision can be found.
  86          *
  87          * @param $revId Integer
  88          * @param $pageId Integer (optional)
  89          * @return Revision or null
  90          */
  91         public static function newFromPageId( $pageId, $revId = 0 ) {
  92                 $conds = array( 'page_id' => $pageId );
  93                 if ( $revId ) {
  94                         $conds['rev_id'] = $revId;
  95                 } elseif ( wfGetLB()->getServerCount() > 1 ) {
  96                         // Get the latest revision ID from the master
  97                         $dbw = wfGetDB( DB_MASTER );
  98                         $latest = $dbw->selectField( 'page', 'page_latest', $conds, __METHOD__ );
  99                         if ( $latest === false ) {
 100                                 return null; // page does not exist
 101                         }
 102                         $conds['rev_id'] = $latest;
 103                 } else {
 104                         $conds[] = 'rev_id = page_latest';
 105                 }
 106                 return Revision::newFromConds( $conds );
 107         }
 108
 109         /**
 110          * Make a fake revision object from an archive table row. This is queried
 111          * for permissions or even inserted (as in Special:Undelete)
 112          * @todo FIXME: Should be a subclass for RevisionDelete. [TS]
 113          *
 114          * @param $row
 115          * @param $overrides array
 116          *
 117          * @return Revision
 118          */
 119         public static function newFromArchiveRow( $row, $overrides = array() ) {
 120                 $attribs = $overrides + array(
 121                         'page'       => isset( $row->ar_page_id ) ? $row->ar_page_id : null,
 122                         'id'         => isset( $row->ar_rev_id ) ? $row->ar_rev_id : null,
 123                         'comment'    => $row->ar_comment,
 124                         'user'       => $row->ar_user,
 125                         'user_text'  => $row->ar_user_text,
 126                         'timestamp'  => $row->ar_timestamp,
 127                         'minor_edit' => $row->ar_minor_edit,
 128                         'text_id'    => isset( $row->ar_text_id ) ? $row->ar_text_id : null,
 129                         'deleted'    => $row->ar_deleted,
 130                         'len'        => $row->ar_len,
 131                         'sha1'       => isset( $row->ar_sha1 ) ? $row->ar_sha1 : null,
 132             'content_model' => isset( $row->ar_content_model ) ? $row->ar_content_model : null,
 133             'content_format'  => isset( $row->ar_content_format ) ? $row->ar_content_format : null,
 134                 );
 135                 if ( isset( $row->ar_text ) && !$row->ar_text_id ) {
 136                         // Pre-1.5 ar_text row
 137                         $attribs['text'] = self::getRevisionText( $row, 'ar_' );
 138                         if ( $attribs['text'] === false ) {
 139                                 throw new MWException( 'Unable to load text from archive row (possibly bug 22624)' );
 140                         }
 141                 }
 142                 return new self( $attribs );
 143         }
 144
 145         /**
 146          * @since 1.19
 147          *
 148          * @param $row
 149          * @return Revision
 150          */
 151         public static function newFromRow( $row ) {
 152                 return new self( $row );
 153         }
 154
 155         /**
 156          * Load a page revision from a given revision ID number.
 157          * Returns null if no such revision can be found.
 158          *
 159          * @param $db DatabaseBase
 160          * @param $id Integer
 161          * @return Revision or null
 162          */
 163         public static function loadFromId( $db, $id ) {
 164                 return Revision::loadFromConds( $db, array( 'rev_id' => intval( $id ) ) );
 165         }
 166
 167         /**
 168          * Load either the current, or a specified, revision
 169          * that's attached to a given page. If not attached
 170          * to that page, will return null.
 171          *
 172          * @param $db DatabaseBase
 173          * @param $pageid Integer
 174          * @param $id Integer
 175          * @return Revision or null
 176          */
 177         public static function loadFromPageId( $db, $pageid, $id = 0 ) {
 178                 $conds = array( 'rev_page' => intval( $pageid ), 'page_id'  => intval( $pageid ) );
 179                 if( $id ) {
 180                         $conds['rev_id'] = intval( $id );
 181                 } else {
 182                         $conds[] = 'rev_id=page_latest';
 183                 }
 184                 return Revision::loadFromConds( $db, $conds );
 185         }
 186
 187         /**
 188          * Load either the current, or a specified, revision
 189          * that's attached to a given page. If not attached
 190          * to that page, will return null.
 191          *
 192          * @param $db DatabaseBase
 193          * @param $title Title
 194          * @param $id Integer
 195          * @return Revision or null
 196          */
 197         public static function loadFromTitle( $db, $title, $id = 0 ) {
 198                 if( $id ) {
 199                         $matchId = intval( $id );
 200                 } else {
 201                         $matchId = 'page_latest';
 202                 }
 203                 return Revision::loadFromConds( $db,
 204                         array( "rev_id=$matchId",
 205                                    'page_namespace' => $title->getNamespace(),
 206                                    'page_title'     => $title->getDBkey() )
 207                 );
 208         }
 209
 210         /**
 211          * Load the revision for the given title with the given timestamp.
 212          * WARNING: Timestamps may in some circumstances not be unique,
 213          * so this isn't the best key to use.
 214          *
 215          * @param $db DatabaseBase
 216          * @param $title Title
 217          * @param $timestamp String
 218          * @return Revision or null
 219          */
 220         public static function loadFromTimestamp( $db, $title, $timestamp ) {
 221                 return Revision::loadFromConds( $db,
 222                         array( 'rev_timestamp'  => $db->timestamp( $timestamp ),
 223                                    'page_namespace' => $title->getNamespace(),
 224                                    'page_title'     => $title->getDBkey() )
 225                 );
 226         }
 227
 228         /**
 229          * Given a set of conditions, fetch a revision.
 230          *
 231          * @param $conditions Array
 232          * @return Revision or null
 233          */
 234         public static function newFromConds( $conditions ) {
 235                 $db = wfGetDB( DB_SLAVE );
 236                 $rev = Revision::loadFromConds( $db, $conditions );
 237                 if( is_null( $rev ) && wfGetLB()->getServerCount() > 1 ) {
 238                         $dbw = wfGetDB( DB_MASTER );
 239                         $rev = Revision::loadFromConds( $dbw, $conditions );
 240                 }
 241                 return $rev;
 242         }
 243
 244         /**
 245          * Given a set of conditions, fetch a revision from
 246          * the given database connection.
 247          *
 248          * @param $db DatabaseBase
 249          * @param $conditions Array
 250          * @return Revision or null
 251          */
 252         private static function loadFromConds( $db, $conditions ) {
 253                 $res = Revision::fetchFromConds( $db, $conditions );
 254                 if( $res ) {
 255                         $row = $res->fetchObject();
 256                         if( $row ) {
 257                                 $ret = new Revision( $row );
 258                                 return $ret;
 259                         }
 260                 }
 261                 $ret = null;
 262                 return $ret;
 263         }
 264
 265         /**
 266          * Return a wrapper for a series of database rows to
 267          * fetch all of a given page's revisions in turn.
 268          * Each row can be fed to the constructor to get objects.
 269          *
 270          * @param $title Title
 271          * @return ResultWrapper
 272          */
 273         public static function fetchRevision( $title ) {
 274                 return Revision::fetchFromConds(
 275                         wfGetDB( DB_SLAVE ),
 276                         array( 'rev_id=page_latest',
 277                                    'page_namespace' => $title->getNamespace(),
 278                                    'page_title'     => $title->getDBkey() )
 279                 );
 280         }
 281
 282         /**
 283          * Given a set of conditions, return a ResultWrapper
 284          * which will return matching database rows with the
 285          * fields necessary to build Revision objects.
 286          *
 287          * @param $db DatabaseBase
 288          * @param $conditions Array
 289          * @return ResultWrapper
 290          */
 291         private static function fetchFromConds( $db, $conditions ) {
 292                 $fields = array_merge(
 293                         self::selectFields(),
 294                         self::selectPageFields(),
 295                         self::selectUserFields()
 296                 );
 297                 return $db->select(
 298                         array( 'revision', 'page', 'user' ),
 299                         $fields,
 300                         $conditions,
 301                         __METHOD__,
 302                         array( 'LIMIT' => 1 ),
 303                         array( 'page' => self::pageJoinCond(), 'user' => self::userJoinCond() )
 304                 );
 305         }
 306
 307         /**
 308          * Return the value of a select() JOIN conds array for the user table.
 309          * This will get user table rows for logged-in users.
 310          * @since 1.19
 311          * @return Array
 312          */
 313         public static function userJoinCond() {
 314                 return array( 'LEFT JOIN', array( 'rev_user != 0', 'user_id = rev_user' ) );
 315         }
 316
 317         /**
 318          * Return the value of a select() page conds array for the paeg table.
 319          * This will assure that the revision(s) are not orphaned from live pages.
 320          * @since 1.19
 321          * @return Array
 322          */
 323         public static function pageJoinCond() {
 324                 return array( 'INNER JOIN', array( 'page_id = rev_page' ) );
 325         }
 326
 327         /**
 328          * Return the list of revision fields that should be selected to create
 329          * a new revision.
 330          */
 331         public static function selectFields() {
 332                 return array(
 333                         'rev_id',
 334                         'rev_page',
 335                         'rev_text_id',
 336                         'rev_timestamp',
 337                         'rev_comment',
 338                         'rev_user_text',
 339                         'rev_user',
 340                         'rev_minor_edit',
 341                         'rev_deleted',
 342                         'rev_len',
 343                         'rev_parent_id',
 344                         'rev_sha1',
 345                         'rev_content_format',
 346                         'rev_content_model'
 347                 );
 348         }
 349
 350         /**
 351          * Return the list of text fields that should be selected to read the
 352          * revision text
 353          */
 354         public static function selectTextFields() {
 355                 return array(
 356                         'old_text',
 357                         'old_flags'
 358                 );
 359         }
 360
 361         /**
 362          * Return the list of page fields that should be selected from page table
 363          */
 364         public static function selectPageFields() {
 365                 return array(
 366                         'page_namespace',
 367                         'page_title',
 368                         'page_id',
 369                         'page_latest'
 370                 );
 371         }
 372
 373         /**
 374          * Return the list of user fields that should be selected from user table
 375          */
 376         public static function selectUserFields() {
 377                 return array( 'user_name' );
 378         }
 379
 380         /**
 381          * Constructor
 382          *
 383          * @param $row Mixed: either a database row or an array
 384          * @access private
 385          */
 386         function __construct( $row ) {
 387                 if( is_object( $row ) ) {
 388                         $this->mId        = intval( $row->rev_id );
 389                         $this->mPage      = intval( $row->rev_page );
 390                         $this->mTextId    = intval( $row->rev_text_id );
 391                         $this->mComment   =         $row->rev_comment;
 392                         $this->mUser      = intval( $row->rev_user );
 393                         $this->mMinorEdit = intval( $row->rev_minor_edit );
 394                         $this->mTimestamp =         $row->rev_timestamp;
 395                         $this->mDeleted   = intval( $row->rev_deleted );
 396
 397                         if( !isset( $row->rev_parent_id ) ) {
 398                                 $this->mParentId = is_null( $row->rev_parent_id ) ? null : 0;
 399                         } else {
 400                                 $this->mParentId  = intval( $row->rev_parent_id );
 401                         }
 402
 403                         if( !isset( $row->rev_len ) || is_null( $row->rev_len ) ) {
 404                                 $this->mSize = null;
 405                         } else {
 406                                 $this->mSize = intval( $row->rev_len );
 407                         }
 408
 409                         if ( !isset( $row->rev_sha1 ) ) {
 410                                 $this->mSha1 = null;
 411                         } else {
 412                                 $this->mSha1 = $row->rev_sha1;
 413                         }
 414
 415                         if( isset( $row->page_latest ) ) {
 416                                 $this->mCurrent = ( $row->rev_id == $row->page_latest );
 417                                 $this->mTitle = Title::newFromRow( $row );
 418                         } else {
 419                                 $this->mCurrent = false;
 420                                 $this->mTitle = null;
 421                         }
 422
 423             if( !isset( $row->rev_content_model ) || is_null( $row->rev_content_model ) ) {
 424                 $this->mContentModelName = null; # determine on demand if needed
 425             } else {
 426                 $this->mContentModelName = strval( $row->rev_content_model );
 427             }
 428
 429             if( !isset( $row->rev_content_format ) || is_null( $row->rev_content_format ) ) {
 430                 $this->mContentFormat = null; # determine on demand if needed
 431             } else {
 432                 $this->mContentFormat = strval( $row->rev_content_format );
 433             }
 434
 435                         // Lazy extraction...
 436                         $this->mText      = null;
 437                         if( isset( $row->old_text ) ) {
 438                                 $this->mTextRow = $row;
 439                         } else {
 440                                 // 'text' table row entry will be lazy-loaded
 441                                 $this->mTextRow = null;
 442                         }
 443
 444                         // Use user_name for users and rev_user_text for IPs...
 445                         $this->mUserText = null; // lazy load if left null
 446                         if ( $this->mUser == 0 ) {
 447                                 $this->mUserText = $row->rev_user_text; // IP user
 448                         } elseif ( isset( $row->user_name ) ) {
 449                                 $this->mUserText = $row->user_name; // logged-in user
 450                         }
 451                         $this->mOrigUserText = $row->rev_user_text;
 452                 } elseif( is_array( $row ) ) {
 453                         // Build a new revision to be saved...
 454                         global $wgUser; // ugh
 455
 456
 457             # if we have a content object, use it to set the model and type
 458             if ( !empty( $row['content'] ) ) {
 459                 if ( !empty( $row['text_id'] ) ) { #FIXME: when is that set? test with external store setup! check out insertOn()
 460                     throw new MWException( "Text already stored in external store (id {$row['text_id']}), can't serialize content object" );
 461                 }
 462
 463                 $row['content_model'] = $row['content']->getModelName();
 464                 # note: mContentFormat is initializes later accordingly
 465                 # note: content is serialized later in this method!
 466                 # also set text to null?
 467             }
 468
 469                         $this->mId        = isset( $row['id']         ) ? intval( $row['id']         ) : null;
 470                         $this->mPage      = isset( $row['page']       ) ? intval( $row['page']       ) : null;
 471                         $this->mTextId    = isset( $row['text_id']    ) ? intval( $row['text_id']    ) : null;
 472                         $this->mUserText  = isset( $row['user_text']  ) ? strval( $row['user_text']  ) : $wgUser->getName();
 473                         $this->mUser      = isset( $row['user']       ) ? intval( $row['user']       ) : $wgUser->getId();
 474                         $this->mMinorEdit = isset( $row['minor_edit'] ) ? intval( $row['minor_edit'] ) : 0;
 475                         $this->mTimestamp = isset( $row['timestamp']  ) ? strval( $row['timestamp']  ) : wfTimestampNow();
 476                         $this->mDeleted   = isset( $row['deleted']    ) ? intval( $row['deleted']    ) : 0;
 477                         $this->mSize      = isset( $row['len']        ) ? intval( $row['len']        ) : null;
 478                         $this->mParentId  = isset( $row['parent_id']  ) ? intval( $row['parent_id']  ) : null;
 479                         $this->mSha1      = isset( $row['sha1']  )      ? strval( $row['sha1']  )      : null;
 480
 481             $this->mContentModelName = isset( $row['content_model']  )  ? strval( $row['content_model'] ) : null;
 482             $this->mContentFormat      = isset( $row['content_format']  )   ? strval( $row['content_format'] ) : null;
 483
 484             if( !isset( $row->rev_content_format ) || is_null( $row->rev_content_format ) ) {
 485                 $this->mContentFormat = null; # determine on demand if needed
 486             } else {
 487                 $this->mContentFormat = $row->rev_content_format;
 488             }
 489
 490                         // Enforce spacing trimming on supplied text
 491                         $this->mComment   = isset( $row['comment']    ) ?  trim( strval( $row['comment'] ) ) : null;
 492                         $this->mText      = isset( $row['text']       ) ? rtrim( strval( $row['text']    ) ) : null;
 493                         $this->mTextRow   = null;
 494
 495                         $this->mTitle     = null; # Load on demand if needed
 496                         $this->mCurrent   = false;
 497                         # If we still have no length, see it we have the text to figure it out
 498                         if ( !$this->mSize ) {
 499                                 $this->mSize = is_null( $this->mText ) ? null : strlen( $this->mText ); #FIXME: do strlen in Content object
 500                         }
 501                         # Same for sha1
 502                         if ( $this->mSha1 === null ) {
 503                                 $this->mSha1 = is_null( $this->mText ) ? null : self::base36Sha1( $this->mText );
 504                         }
 505
 506             $this->getContentModelName(); # force lazy init
 507             $this->getContentFormat();      # force lazy init
 508
 509             # if we have a content object, serialize it, overriding mText
 510             if ( !empty( $row['content'] ) ) {
 511                 $handler = $this->getContentHandler();
 512                 $this->mText = $handler->serialize( $row['content'], $this->getContentFormat() );
 513             }
 514                 } else {
 515                         throw new MWException( 'Revision constructor passed invalid row format.' );
 516                 }
 517                 $this->mUnpatrolled = null;
 518
 519         #FIXME: add patch for ar_content_format, ar_content_model, rev_content_format, rev_content_model to installer
 520         #FIXME: add support for ar_content_format, ar_content_model, rev_content_format, rev_content_model to API
 521         }
 522
 523         /**
 524          * Get revision ID
 525          *
 526          * @return Integer
 527          */
 528         public function getId() {
 529                 return $this->mId;
 530         }
 531
 532         /**
 533          * Set the revision ID
 534          *
 535          * @since 1.19
 536          * @param $id Integer
 537          */
 538         public function setId( $id ) {
 539                 $this->mId = $id;
 540         }
 541
 542         /**
 543          * Get text row ID
 544          *
 545          * @return Integer
 546          */
 547         public function getTextId() {
 548                 return $this->mTextId;
 549         }
 550
 551         /**
 552          * Get parent revision ID (the original previous page revision)
 553          *
 554          * @return Integer
 555          */
 556         public function getParentId() {
 557                 return $this->mParentId;
 558         }
 559
 560         /**
 561          * Returns the length of the text in this revision, or null if unknown.
 562          *
 563          * @return Integer
 564          */
 565         public function getSize() {
 566                 return $this->mSize;
 567         }
 568
 569         /**
 570          * Returns the base36 sha1 of the text in this revision, or null if unknown.
 571          *
 572          * @return String
 573          */
 574         public function getSha1() {
 575                 return $this->mSha1;
 576         }
 577
 578         /**
 579          * Returns the title of the page associated with this entry.
 580          *
 581          * @return Title
 582          */
 583         public function getTitle() {
 584                 if( isset( $this->mTitle ) ) {
 585                         return $this->mTitle;
 586                 }
 587                 $dbr = wfGetDB( DB_SLAVE );
 588                 $row = $dbr->selectRow(
 589                         array( 'page', 'revision' ),
 590                         array( 'page_namespace', 'page_title' ),
 591                         array( 'page_id=rev_page',
 592                                    'rev_id' => $this->mId ),
 593                         'Revision::getTitle' );
 594                 if( $row ) {
 595                         $this->mTitle = Title::makeTitle( $row->page_namespace, $row->page_title );
 596                 }
 597                 return $this->mTitle;
 598         }
 599
 600         /**
 601          * Set the title of the revision
 602          *
 603          * @param $title Title
 604          */
 605         public function setTitle( $title ) {
 606                 $this->mTitle = $title;
 607         }
 608
 609         /**
 610          * Get the page ID
 611          *
 612          * @return Integer
 613          */
 614         public function getPage() {
 615                 return $this->mPage;
 616         }
 617
 618         /**
 619          * Fetch revision's user id if it's available to the specified audience.
 620          * If the specified audience does not have access to it, zero will be
 621          * returned.
 622          *
 623          * @param $audience Integer: one of:
 624          *      Revision::FOR_PUBLIC       to be displayed to all users
 625          *      Revision::FOR_THIS_USER    to be displayed to $wgUser
 626          *      Revision::RAW              get the ID regardless of permissions
 627          * @param $user User object to check for, only if FOR_THIS_USER is passed
 628          *              to the $audience parameter
 629          * @return Integer
 630          */
 631         public function getUser( $audience = self::FOR_PUBLIC, User $user = null ) {
 632                 if( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_USER ) ) {
 633                         return 0;
 634                 } elseif( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_USER, $user ) ) {
 635                         return 0;
 636                 } else {
 637                         return $this->mUser;
 638                 }
 639         }
 640
 641         /**
 642          * Fetch revision's user id without regard for the current user's permissions
 643          *
 644          * @return String
 645          */
 646         public function getRawUser() {
 647                 return $this->mUser;
 648         }
 649
 650         /**
 651          * Fetch revision's username if it's available to the specified audience.
 652          * If the specified audience does not have access to the username, an
 653          * empty string will be returned.
 654          *
 655          * @param $audience Integer: one of:
 656          *      Revision::FOR_PUBLIC       to be displayed to all users
 657          *      Revision::FOR_THIS_USER    to be displayed to $wgUser
 658          *      Revision::RAW              get the text regardless of permissions
 659          * @param $user User object to check for, only if FOR_THIS_USER is passed
 660          *              to the $audience parameter
 661          * @return string
 662          */
 663         public function getUserText( $audience = self::FOR_PUBLIC, User $user = null ) {
 664                 if( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_USER ) ) {
 665                         return '';
 666                 } elseif( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_USER, $user ) ) {
 667                         return '';
 668                 } else {
 669                         return $this->getRawUserText();
 670                 }
 671         }
 672
 673         /**
 674          * Fetch revision's username without regard for view restrictions
 675          *
 676          * @return String
 677          */
 678         public function getRawUserText() {
 679                 if ( $this->mUserText === null ) {
 680                         $this->mUserText = User::whoIs( $this->mUser ); // load on demand
 681                         if ( $this->mUserText === false ) {
 682                                 # This shouldn't happen, but it can if the wiki was recovered
 683                                 # via importing revs and there is no user table entry yet.
 684                                 $this->mUserText = $this->mOrigUserText;
 685                         }
 686                 }
 687                 return $this->mUserText;
 688         }
 689
 690         /**
 691          * Fetch revision comment if it's available to the specified audience.
 692          * If the specified audience does not have access to the comment, an
 693          * empty string will be returned.
 694          *
 695          * @param $audience Integer: one of:
 696          *      Revision::FOR_PUBLIC       to be displayed to all users
 697          *      Revision::FOR_THIS_USER    to be displayed to $wgUser
 698          *      Revision::RAW              get the text regardless of permissions
 699          * @param $user User object to check for, only if FOR_THIS_USER is passed
 700          *              to the $audience parameter
 701          * @return String
 702          */
 703         function getComment( $audience = self::FOR_PUBLIC, User $user = null ) {
 704                 if( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_COMMENT ) ) {
 705                         return '';
 706                 } elseif( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_COMMENT, $user ) ) {
 707                         return '';
 708                 } else {
 709                         return $this->mComment;
 710                 }
 711         }
 712
 713         /**
 714          * Fetch revision comment without regard for the current user's permissions
 715          *
 716          * @return String
 717          */
 718         public function getRawComment() {
 719                 return $this->mComment;
 720         }
 721
 722         /**
 723          * @return Boolean
 724          */
 725         public function isMinor() {
 726                 return (bool)$this->mMinorEdit;
 727         }
 728
 729         /**
 730          * @return Integer rcid of the unpatrolled row, zero if there isn't one
 731          */
 732         public function isUnpatrolled() {
 733                 if( $this->mUnpatrolled !== null ) {
 734                         return $this->mUnpatrolled;
 735                 }
 736                 $dbr = wfGetDB( DB_SLAVE );
 737                 $this->mUnpatrolled = $dbr->selectField( 'recentchanges',
 738                         'rc_id',
 739                         array( // Add redundant user,timestamp condition so we can use the existing index
 740                                 'rc_user_text'  => $this->getRawUserText(),
 741                                 'rc_timestamp'  => $dbr->timestamp( $this->getTimestamp() ),
 742                                 'rc_this_oldid' => $this->getId(),
 743                                 'rc_patrolled'  => 0
 744                         ),
 745                         __METHOD__
 746                 );
 747                 return (int)$this->mUnpatrolled;
 748         }
 749
 750         /**
 751          * @param $field int one of DELETED_* bitfield constants
 752          *
 753          * @return Boolean
 754          */
 755         public function isDeleted( $field ) {
 756                 return ( $this->mDeleted & $field ) == $field;
 757         }
 758
 759         /**
 760          * Get the deletion bitfield of the revision
 761          *
 762          * @return int
 763          */
 764         public function getVisibility() {
 765                 return (int)$this->mDeleted;
 766         }
 767
 768         /**
 769          * Fetch revision text if it's available to the specified audience.
 770          * If the specified audience does not have the ability to view this
 771          * revision, an empty string will be returned.
 772          *
 773          * @param $audience Integer: one of:
 774          *      Revision::FOR_PUBLIC       to be displayed to all users
 775          *      Revision::FOR_THIS_USER    to be displayed to $wgUser
 776          *      Revision::RAW              get the text regardless of permissions
 777          * @param $user User object to check for, only if FOR_THIS_USER is passed
 778          *              to the $audience parameter
 779          * @return String
 780      * @deprectaed in 1.20, use getContent() instead
 781          */
 782         public function getText( $audience = self::FOR_PUBLIC, User $user = null ) { #FIXME: deprecated, replace usage! #FIXME: used a LOT!
 783         wfDeprecated( __METHOD__, '1.20' );
 784
 785         $content = $this->getContent();
 786         return ContentHandler::getContentText( $content ); # returns the raw content text, if applicable
 787         }
 788
 789     /**
 790      * Fetch revision content if it's available to the specified audience.
 791      * If the specified audience does not have the ability to view this
 792      * revision, null will be returned.
 793      *
 794      * @param $audience Integer: one of:
 795      *      Revision::FOR_PUBLIC       to be displayed to all users
 796      *      Revision::FOR_THIS_USER    to be displayed to $wgUser
 797      *      Revision::RAW              get the text regardless of permissions
 798      * @param $user User object to check for, only if FOR_THIS_USER is passed
 799      *              to the $audience parameter
 800      * @return Content
 801      */
 802     public function getContent( $audience = self::FOR_PUBLIC, User $user = null ) {
 803         if( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_TEXT ) ) {
 804             return null;
 805         } elseif( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_TEXT, $user ) ) {
 806             return null;
 807         } else {
 808             return $this->getContentInternal();
 809         }
 810     }
 811
 812         /**
 813          * Alias for getText(Revision::FOR_THIS_USER)
 814          *
 815          * @deprecated since 1.17
 816          * @return String
 817          */
 818         public function revText() {
 819                 wfDeprecated( __METHOD__, '1.17' );
 820                 return $this->getText( self::FOR_THIS_USER );
 821         }
 822
 823         /**
 824          * Fetch revision text without regard for view restrictions
 825          *
 826          * @return String
 827          */
 828         public function getRawText() { #FIXME: deprecated, replace usage!
 829                 return $this->getText( self::RAW );
 830         }
 831
 832     protected function getContentInternal() {
 833         if( is_null( $this->mContent ) ) {
 834             // Revision is immutable. Load on demand:
 835
 836             $handler = $this->getContentHandler();
 837             $format = $this->getContentFormat();
 838
 839             if( is_null( $this->mText ) ) {
 840                 // Load text on demand:
 841                 $this->mText = $this->loadText();
 842             }
 843
 844             $this->mContent = $handler->unserialize( $this->mText, $format );
 845         }
 846
 847         return $this->mContent;
 848     }
 849
 850     public function getContentModelName() {
 851         if ( !$this->mContentModelName ) {
 852             $title = $this->getTitle(); #XXX: never null?
 853             $this->mContentModelName = $title->getContentModelName();
 854         }
 855
 856         return $this->mContentModelName;
 857     }
 858
 859     public function getContentFormat() {
 860         if ( !$this->mContentFormat ) {
 861             $handler = $this->getContentHandler();
 862             $this->mContentFormat = $handler->getDefaultFormat();
 863         }
 864
 865         return $this->mContentFormat;
 866     }
 867
 868     public function getContentHandler() {
 869         if ( !$this->mContentHandler ) {
 870             $m = $this->getModelName();
 871             $this->mContentHandler = ContentHandler::getForModelName( $m );
 872
 873             #XXX: do we need to verify that mContentHandler supports mContentFormat?
 874             #     otherwise, a fixed content format may cause problems on insert.
 875         }
 876
 877         return $this->mContentHandler;
 878     }
 879
 880         /**
 881          * @return String
 882          */
 883         public function getTimestamp() {
 884                 return wfTimestamp( TS_MW, $this->mTimestamp );
 885         }
 886
 887         /**
 888          * @return Boolean
 889          */
 890         public function isCurrent() {
 891                 return $this->mCurrent;
 892         }
 893
 894         /**
 895          * Get previous revision for this title
 896          *
 897          * @return Revision or null
 898          */
 899         public function getPrevious() {
 900                 if( $this->getTitle() ) {
 901                         $prev = $this->getTitle()->getPreviousRevisionID( $this->getId() );
 902                         if( $prev ) {
 903                                 return Revision::newFromTitle( $this->getTitle(), $prev );
 904                         }
 905                 }
 906                 return null;
 907         }
 908
 909         /**
 910          * Get next revision for this title
 911          *
 912          * @return Revision or null
 913          */
 914         public function getNext() {
 915                 if( $this->getTitle() ) {
 916                         $next = $this->getTitle()->getNextRevisionID( $this->getId() );
 917                         if ( $next ) {
 918                                 return Revision::newFromTitle( $this->getTitle(), $next );
 919                         }
 920                 }
 921                 return null;
 922         }
 923
 924         /**
 925          * Get previous revision Id for this page_id
 926          * This is used to populate rev_parent_id on save
 927          *
 928          * @param $db DatabaseBase
 929          * @return Integer
 930          */
 931         private function getPreviousRevisionId( $db ) {
 932                 if( is_null( $this->mPage ) ) {
 933                         return 0;
 934                 }
 935                 # Use page_latest if ID is not given
 936                 if( !$this->mId ) {
 937                         $prevId = $db->selectField( 'page', 'page_latest',
 938                                 array( 'page_id' => $this->mPage ),
 939                                 __METHOD__ );
 940                 } else {
 941                         $prevId = $db->selectField( 'revision', 'rev_id',
 942                                 array( 'rev_page' => $this->mPage, 'rev_id < ' . $this->mId ),
 943                                 __METHOD__,
 944                                 array( 'ORDER BY' => 'rev_id DESC' ) );
 945                 }
 946                 return intval( $prevId );
 947         }
 948
 949         /**
 950           * Get revision text associated with an old or archive row
 951           * $row is usually an object from wfFetchRow(), both the flags and the text
 952           * field must be included
 953           *
 954           * @param $row Object: the text data
 955           * @param $prefix String: table prefix (default 'old_')
 956           * @return String: text the text requested or false on failure
 957           */
 958         public static function getRevisionText( $row, $prefix = 'old_' ) {
 959                 wfProfileIn( __METHOD__ );
 960
 961                 # Get data
 962                 $textField = $prefix . 'text';
 963                 $flagsField = $prefix . 'flags';
 964
 965                 if( isset( $row->$flagsField ) ) {
 966                         $flags = explode( ',', $row->$flagsField );
 967                 } else {
 968                         $flags = array();
 969                 }
 970
 971                 if( isset( $row->$textField ) ) {
 972                         $text = $row->$textField;
 973                 } else {
 974                         wfProfileOut( __METHOD__ );
 975                         return false;
 976                 }
 977
 978                 # Use external methods for external objects, text in table is URL-only then
 979                 if ( in_array( 'external', $flags ) ) {
 980                         $url = $text;
 981                         $parts = explode( '://', $url, 2 );
 982                         if( count( $parts ) == 1 || $parts[1] == '' ) {
 983                                 wfProfileOut( __METHOD__ );
 984                                 return false;
 985                         }
 986                         $text = ExternalStore::fetchFromURL( $url );
 987                 }
 988
 989                 // If the text was fetched without an error, convert it
 990                 if ( $text !== false ) {
 991                         if( in_array( 'gzip', $flags ) ) {
 992                                 # Deal with optional compression of archived pages.
 993                                 # This can be done periodically via maintenance/compressOld.php, and
 994                                 # as pages are saved if $wgCompressRevisions is set.
 995                                 $text = gzinflate( $text );
 996                         }
 997
 998                         if( in_array( 'object', $flags ) ) {
 999                                 # Generic compressed storage
1000                                 $obj = unserialize( $text );
1001                                 if ( !is_object( $obj ) ) {
1002                                         // Invalid object
1003                                         wfProfileOut( __METHOD__ );
1004                                         return false;
1005                                 }
1006                                 $text = $obj->getText();
1007                         }
1008
1009                         global $wgLegacyEncoding;
1010                         if( $text !== false && $wgLegacyEncoding
1011                                 && !in_array( 'utf-8', $flags ) && !in_array( 'utf8', $flags ) )
1012                         {
1013                                 # Old revisions kept around in a legacy encoding?
1014                                 # Upconvert on demand.
1015                                 # ("utf8" checked for compatibility with some broken
1016                                 #  conversion scripts 2008-12-30)
1017                                 global $wgContLang;
1018                                 $text = $wgContLang->iconv( $wgLegacyEncoding, 'UTF-8', $text );
1019                         }
1020                 }
1021                 wfProfileOut( __METHOD__ );
1022                 return $text;
1023         }
1024
1025         /**
1026          * If $wgCompressRevisions is enabled, we will compress data.
1027          * The input string is modified in place.
1028          * Return value is the flags field: contains 'gzip' if the
1029          * data is compressed, and 'utf-8' if we're saving in UTF-8
1030          * mode.
1031          *
1032          * @param $text Mixed: reference to a text
1033          * @return String
1034          */
1035         public static function compressRevisionText( &$text ) {
1036                 global $wgCompressRevisions;
1037                 $flags = array();
1038
1039                 # Revisions not marked this way will be converted
1040                 # on load if $wgLegacyCharset is set in the future.
1041                 $flags[] = 'utf-8';
1042
1043                 if( $wgCompressRevisions ) {
1044                         if( function_exists( 'gzdeflate' ) ) {
1045                                 $text = gzdeflate( $text );
1046                                 $flags[] = 'gzip';
1047                         } else {
1048                                 wfDebug( "Revision::compressRevisionText() -- no zlib support, not compressing\n" );
1049                         }
1050                 }
1051                 return implode( ',', $flags );
1052         }
1053
1054         /**
1055          * Insert a new revision into the database, returning the new revision ID
1056          * number on success and dies horribly on failure.
1057          *
1058          * @param $dbw DatabaseBase: (master connection)
1059          * @return Integer
1060          */
1061         public function insertOn( $dbw ) {
1062                 global $wgDefaultExternalStore;
1063
1064                 wfProfileIn( __METHOD__ );
1065
1066                 $data = $this->mText;
1067                 $flags = Revision::compressRevisionText( $data );
1068
1069                 # Write to external storage if required
1070                 if( $wgDefaultExternalStore ) {
1071                         // Store and get the URL
1072                         $data = ExternalStore::insertToDefault( $data );
1073                         if( !$data ) {
1074                                 throw new MWException( "Unable to store text to external storage" );
1075                         }
1076                         if( $flags ) {
1077                                 $flags .= ',';
1078                         }
1079                         $flags .= 'external';
1080                 }
1081
1082                 # Record the text (or external storage URL) to the text table
1083                 if( !isset( $this->mTextId ) ) {
1084                         $old_id = $dbw->nextSequenceValue( 'text_old_id_seq' );
1085                         $dbw->insert( 'text',
1086                                 array(
1087                                         'old_id'    => $old_id,
1088                                         'old_text'  => $data,
1089                                         'old_flags' => $flags,
1090                                 ), __METHOD__
1091                         );
1092                         $this->mTextId = $dbw->insertId();
1093                 }
1094
1095                 if ( $this->mComment === null ) $this->mComment = "";
1096
1097                 # Record the edit in revisions
1098                 $rev_id = isset( $this->mId )
1099                         ? $this->mId
1100                         : $dbw->nextSequenceValue( 'revision_rev_id_seq' );
1101                 $dbw->insert( 'revision',
1102                         array(
1103                                 'rev_id'         => $rev_id,
1104                                 'rev_page'       => $this->mPage,
1105                                 'rev_text_id'    => $this->mTextId,
1106                                 'rev_comment'    => $this->mComment,
1107                                 'rev_minor_edit' => $this->mMinorEdit ? 1 : 0,
1108                                 'rev_user'       => $this->mUser,
1109                                 'rev_user_text'  => $this->mUserText,
1110                                 'rev_timestamp'  => $dbw->timestamp( $this->mTimestamp ),
1111                                 'rev_deleted'    => $this->mDeleted,
1112                                 'rev_len'        => $this->mSize,
1113                                 'rev_parent_id'  => is_null( $this->mParentId )
1114                                         ? $this->getPreviousRevisionId( $dbw )
1115                                         : $this->mParentId,
1116                                 'rev_sha1'       => is_null( $this->mSha1 )
1117                                         ? Revision::base36Sha1( $this->mText )
1118                                         : $this->mSha1,
1119                 'rev_content_model'       => $this->getContentModelName(),
1120                 'rev_content_format'        => $this->getContentFormat(),
1121                         ), __METHOD__
1122                 );
1123
1124                 $this->mId = !is_null( $rev_id ) ? $rev_id : $dbw->insertId();
1125
1126                 wfRunHooks( 'RevisionInsertComplete', array( &$this, $data, $flags ) );
1127
1128                 wfProfileOut( __METHOD__ );
1129                 return $this->mId;
1130         }
1131
1132         /**
1133          * Get the base 36 SHA-1 value for a string of text
1134          * @param $text String
1135          * @return String
1136          */
1137         public static function base36Sha1( $text ) {
1138                 return wfBaseConvert( sha1( $text ), 16, 36, 31 );
1139         }
1140
1141         /**
1142          * Lazy-load the revision's text.
1143          * Currently hardcoded to the 'text' table storage engine.
1144          *
1145          * @return String
1146          */
1147         protected function loadText() {
1148                 wfProfileIn( __METHOD__ );
1149
1150                 // Caching may be beneficial for massive use of external storage
1151                 global $wgRevisionCacheExpiry, $wgMemc;
1152                 $textId = $this->getTextId();
1153                 $key = wfMemcKey( 'revisiontext', 'textid', $textId );
1154                 if( $wgRevisionCacheExpiry ) {
1155                         $text = $wgMemc->get( $key );
1156                         if( is_string( $text ) ) {
1157                                 wfDebug( __METHOD__ . ": got id $textId from cache\n" );
1158                                 wfProfileOut( __METHOD__ );
1159                                 return $text;
1160                         }
1161                 }
1162
1163                 // If we kept data for lazy extraction, use it now...
1164                 if ( isset( $this->mTextRow ) ) {
1165                         $row = $this->mTextRow;
1166                         $this->mTextRow = null;
1167                 } else {
1168                         $row = null;
1169                 }
1170
1171                 if( !$row ) {
1172                         // Text data is immutable; check slaves first.
1173                         $dbr = wfGetDB( DB_SLAVE );
1174                         $row = $dbr->selectRow( 'text',
1175                                 array( 'old_text', 'old_flags' ),
1176                                 array( 'old_id' => $this->getTextId() ),
1177                                 __METHOD__ );
1178                 }
1179
1180                 if( !$row && wfGetLB()->getServerCount() > 1 ) {
1181                         // Possible slave lag!
1182                         $dbw = wfGetDB( DB_MASTER );
1183                         $row = $dbw->selectRow( 'text',
1184                                 array( 'old_text', 'old_flags' ),
1185                                 array( 'old_id' => $this->getTextId() ),
1186                                 __METHOD__ );
1187                 }
1188
1189                 $text = self::getRevisionText( $row );
1190
1191                 # No negative caching -- negative hits on text rows may be due to corrupted slave servers
1192                 if( $wgRevisionCacheExpiry && $text !== false ) {
1193                         $wgMemc->set( $key, $text, $wgRevisionCacheExpiry );
1194                 }
1195
1196                 wfProfileOut( __METHOD__ );
1197
1198                 return $text;
1199         }
1200
1201         /**
1202          * Create a new null-revision for insertion into a page's
1203          * history. This will not re-save the text, but simply refer
1204          * to the text from the previous version.
1205          *
1206          * Such revisions can for instance identify page rename
1207          * operations and other such meta-modifications.
1208          *
1209          * @param $dbw DatabaseBase
1210          * @param $pageId Integer: ID number of the page to read from
1211          * @param $summary String: revision's summary
1212          * @param $minor Boolean: whether the revision should be considered as minor
1213          * @return Revision|null on error
1214          */
1215         public static function newNullRevision( $dbw, $pageId, $summary, $minor ) {
1216                 wfProfileIn( __METHOD__ );
1217
1218                 $current = $dbw->selectRow(
1219                         array( 'page', 'revision' ),
1220                         array( 'page_latest', 'rev_text_id', 'rev_len', 'rev_sha1',
1221                     'rev_content_model', 'rev_content_format' ),
1222                         array(
1223                                 'page_id' => $pageId,
1224                                 'page_latest=rev_id',
1225                                 ),
1226                         __METHOD__ );
1227
1228                 if( $current ) {
1229                         $revision = new Revision( array(
1230                                 'page'       => $pageId,
1231                                 'comment'    => $summary,
1232                                 'minor_edit' => $minor,
1233                                 'text_id'    => $current->rev_text_id,
1234                                 'parent_id'  => $current->page_latest,
1235                                 'len'        => $current->rev_len,
1236                                 'sha1'       => $current->rev_sha1,
1237                                 'content_model'  => $current->rev_content_model,
1238                                 'content_format'   => $current->rev_content_format
1239                                 ) );
1240                 } else {
1241                         $revision = null;
1242                 }
1243
1244                 wfProfileOut( __METHOD__ );
1245                 return $revision;
1246         }
1247
1248         /**
1249          * Determine if the current user is allowed to view a particular
1250          * field of this revision, if it's marked as deleted.
1251          *
1252          * @param $field Integer:one of self::DELETED_TEXT,
1253          *                              self::DELETED_COMMENT,
1254          *                              self::DELETED_USER
1255          * @param $user User object to check, or null to use $wgUser
1256          * @return Boolean
1257          */
1258         public function userCan( $field, User $user = null ) {
1259                 return self::userCanBitfield( $this->mDeleted, $field, $user );
1260         }
1261
1262         /**
1263          * Determine if the current user is allowed to view a particular
1264          * field of this revision, if it's marked as deleted. This is used
1265          * by various classes to avoid duplication.
1266          *
1267          * @param $bitfield Integer: current field
1268          * @param $field Integer: one of self::DELETED_TEXT = File::DELETED_FILE,
1269          *                               self::DELETED_COMMENT = File::DELETED_COMMENT,
1270          *                               self::DELETED_USER = File::DELETED_USER
1271          * @param $user User object to check, or null to use $wgUser
1272          * @return Boolean
1273          */
1274         public static function userCanBitfield( $bitfield, $field, User $user = null ) {
1275                 if( $bitfield & $field ) { // aspect is deleted
1276                         if ( $bitfield & self::DELETED_RESTRICTED ) {
1277                                 $permission = 'suppressrevision';
1278                         } elseif ( $field & self::DELETED_TEXT ) {
1279                                 $permission = 'deletedtext';
1280                         } else {
1281                                 $permission = 'deletedhistory';
1282                         }
1283                         wfDebug( "Checking for $permission due to $field match on $bitfield\n" );
1284                         if ( $user === null ) {
1285                                 global $wgUser;
1286                                 $user = $wgUser;
1287                         }
1288                         return $user->isAllowed( $permission );
1289                 } else {
1290                         return true;
1291                 }
1292         }
1293
1294         /**
1295          * Get rev_timestamp from rev_id, without loading the rest of the row
1296          *
1297          * @param $title Title
1298          * @param $id Integer
1299          * @return String
1300          */
1301         static function getTimestampFromId( $title, $id ) {
1302                 $dbr = wfGetDB( DB_SLAVE );
1303                 // Casting fix for DB2
1304                 if ( $id == '' ) {
1305                         $id = 0;
1306                 }
1307                 $conds = array( 'rev_id' => $id );
1308                 $conds['rev_page'] = $title->getArticleId();
1309                 $timestamp = $dbr->selectField( 'revision', 'rev_timestamp', $conds, __METHOD__ );
1310                 if ( $timestamp === false && wfGetLB()->getServerCount() > 1 ) {
1311                         # Not in slave, try master
1312                         $dbw = wfGetDB( DB_MASTER );
1313                         $timestamp = $dbw->selectField( 'revision', 'rev_timestamp', $conds, __METHOD__ );
1314                 }
1315                 return wfTimestamp( TS_MW, $timestamp );
1316         }
1317
1318         /**
1319          * Get count of revisions per page...not very efficient
1320          *
1321          * @param $db DatabaseBase
1322          * @param $id Integer: page id
1323          * @return Integer
1324          */
1325         static function countByPageId( $db, $id ) {
1326                 $row = $db->selectRow( 'revision', 'COUNT(*) AS revCount',
1327                         array( 'rev_page' => $id ), __METHOD__ );
1328                 if( $row ) {
1329                         return $row->revCount;
1330                 }
1331                 return 0;
1332         }
1333
1334         /**
1335          * Get count of revisions per page...not very efficient
1336          *
1337          * @param $db DatabaseBase
1338          * @param $title Title
1339          * @return Integer
1340          */
1341         static function countByTitle( $db, $title ) {
1342                 $id = $title->getArticleId();
1343                 if( $id ) {
1344                         return Revision::countByPageId( $db, $id );
1345                 }
1346                 return 0;
1347         }
1348 }