includes/Revision.php

   1 <?php
   2
   3 /**
   4  * @todo document
   5  */
   6 class Revision {
   7         protected $mId;
   8         protected $mPage;
   9         protected $mUserText;
  10         protected $mOrigUserText;
  11         protected $mUser;
  12         protected $mMinorEdit;
  13         protected $mTimestamp;
  14         protected $mDeleted;
  15         protected $mSize;
  16         protected $mSha1;
  17         protected $mParentId;
  18         protected $mComment;
  19         protected $mText;
  20         protected $mTextRow;
  21         protected $mTitle;
  22         protected $mCurrent;
  23
  24         const DELETED_TEXT = 1;
  25         const DELETED_COMMENT = 2;
  26         const DELETED_USER = 4;
  27         const DELETED_RESTRICTED = 8;
  28         // Convenience field
  29         const SUPPRESSED_USER = 12;
  30         // Audience options for Revision::getText()
  31         const FOR_PUBLIC = 1;
  32         const FOR_THIS_USER = 2;
  33         const RAW = 3;
  34
  35         /**
  36          * Load a page revision from a given revision ID number.
  37          * Returns null if no such revision can be found.
  38          *
  39          * @param $id Integer
  40          * @return Revision or null
  41          */
  42         public static function newFromId( $id ) {
  43                 return Revision::newFromConds( array( 'rev_id' => intval( $id ) ) );
  44         }
  45
  46         /**
  47          * Load either the current, or a specified, revision
  48          * that's attached to a given title. If not attached
  49          * to that title, will return null.
  50          *
  51          * @param $title Title
  52          * @param $id Integer (optional)
  53          * @return Revision or null
  54          */
  55         public static function newFromTitle( $title, $id = 0 ) {
  56                 $conds = array(
  57                         'page_namespace' => $title->getNamespace(),
  58                         'page_title'     => $title->getDBkey()
  59                 );
  60                 if ( $id ) {
  61                         // Use the specified ID
  62                         $conds['rev_id'] = $id;
  63                 } elseif ( wfGetLB()->getServerCount() > 1 ) {
  64                         // Get the latest revision ID from the master
  65                         $dbw = wfGetDB( DB_MASTER );
  66                         $latest = $dbw->selectField( 'page', 'page_latest', $conds, __METHOD__ );
  67                         if ( $latest === false ) {
  68                                 return null; // page does not exist
  69                         }
  70                         $conds['rev_id'] = $latest;
  71                 } else {
  72                         // Use a join to get the latest revision
  73                         $conds[] = 'rev_id=page_latest';
  74                 }
  75                 return Revision::newFromConds( $conds );
  76         }
  77
  78         /**
  79          * Load either the current, or a specified, revision
  80          * that's attached to a given page ID.
  81          * Returns null if no such revision can be found.
  82          *
  83          * @param $revId Integer
  84          * @param $pageId Integer (optional)
  85          * @return Revision or null
  86          */
  87         public static function newFromPageId( $pageId, $revId = 0 ) {
  88                 $conds = array( 'page_id' => $pageId );
  89                 if ( $revId ) {
  90                         $conds['rev_id'] = $revId;
  91                 } elseif ( wfGetLB()->getServerCount() > 1 ) {
  92                         // Get the latest revision ID from the master
  93                         $dbw = wfGetDB( DB_MASTER );
  94                         $latest = $dbw->selectField( 'page', 'page_latest', $conds, __METHOD__ );
  95                         if ( $latest === false ) {
  96                                 return null; // page does not exist
  97                         }
  98                         $conds['rev_id'] = $latest;
  99                 } else {
 100                         $conds[] = 'rev_id = page_latest';
 101                 }
 102                 return Revision::newFromConds( $conds );
 103         }
 104
 105         /**
 106          * Make a fake revision object from an archive table row. This is queried
 107          * for permissions or even inserted (as in Special:Undelete)
 108          * @todo FIXME: Should be a subclass for RevisionDelete. [TS]
 109          *
 110          * @param $row
 111          * @param $overrides array
 112          *
 113          * @return Revision
 114          */
 115         public static function newFromArchiveRow( $row, $overrides = array() ) {
 116                 $attribs = $overrides + array(
 117                         'page'       => isset( $row->ar_page_id ) ? $row->ar_page_id : null,
 118                         'id'         => isset( $row->ar_rev_id ) ? $row->ar_rev_id : null,
 119                         'comment'    => $row->ar_comment,
 120                         'user'       => $row->ar_user,
 121                         'user_text'  => $row->ar_user_text,
 122                         'timestamp'  => $row->ar_timestamp,
 123                         'minor_edit' => $row->ar_minor_edit,
 124                         'text_id'    => isset( $row->ar_text_id ) ? $row->ar_text_id : null,
 125                         'deleted'    => $row->ar_deleted,
 126                         'len'        => $row->ar_len,
 127                         'sha1'       => isset( $row->ar_sha1 ) ? $row->ar_sha1 : null,
 128                 );
 129                 if ( isset( $row->ar_text ) && !$row->ar_text_id ) {
 130                         // Pre-1.5 ar_text row
 131                         $attribs['text'] = self::getRevisionText( $row, 'ar_' );
 132                         if ( $attribs['text'] === false ) {
 133                                 throw new MWException( 'Unable to load text from archive row (possibly bug 22624)' );
 134                         }
 135                 }
 136                 return new self( $attribs );
 137         }
 138
 139         /**
 140          * @since 1.19
 141          *
 142          * @param $row
 143          * @return Revision
 144          */
 145         public static function newFromRow( $row ) {
 146                 return new self( $row );
 147         }
 148
 149         /**
 150          * Load a page revision from a given revision ID number.
 151          * Returns null if no such revision can be found.
 152          *
 153          * @param $db DatabaseBase
 154          * @param $id Integer
 155          * @return Revision or null
 156          */
 157         public static function loadFromId( $db, $id ) {
 158                 return Revision::loadFromConds( $db, array( 'rev_id' => intval( $id ) ) );
 159         }
 160
 161         /**
 162          * Load either the current, or a specified, revision
 163          * that's attached to a given page. If not attached
 164          * to that page, will return null.
 165          *
 166          * @param $db DatabaseBase
 167          * @param $pageid Integer
 168          * @param $id Integer
 169          * @return Revision or null
 170          */
 171         public static function loadFromPageId( $db, $pageid, $id = 0 ) {
 172                 $conds = array( 'rev_page' => intval( $pageid ), 'page_id'  => intval( $pageid ) );
 173                 if( $id ) {
 174                         $conds['rev_id'] = intval( $id );
 175                 } else {
 176                         $conds[] = 'rev_id=page_latest';
 177                 }
 178                 return Revision::loadFromConds( $db, $conds );
 179         }
 180
 181         /**
 182          * Load either the current, or a specified, revision
 183          * that's attached to a given page. If not attached
 184          * to that page, will return null.
 185          *
 186          * @param $db DatabaseBase
 187          * @param $title Title
 188          * @param $id Integer
 189          * @return Revision or null
 190          */
 191         public static function loadFromTitle( $db, $title, $id = 0 ) {
 192                 if( $id ) {
 193                         $matchId = intval( $id );
 194                 } else {
 195                         $matchId = 'page_latest';
 196                 }
 197                 return Revision::loadFromConds( $db,
 198                         array( "rev_id=$matchId",
 199                                    'page_namespace' => $title->getNamespace(),
 200                                    'page_title'     => $title->getDBkey() )
 201                 );
 202         }
 203
 204         /**
 205          * Load the revision for the given title with the given timestamp.
 206          * WARNING: Timestamps may in some circumstances not be unique,
 207          * so this isn't the best key to use.
 208          *
 209          * @param $db DatabaseBase
 210          * @param $title Title
 211          * @param $timestamp String
 212          * @return Revision or null
 213          */
 214         public static function loadFromTimestamp( $db, $title, $timestamp ) {
 215                 return Revision::loadFromConds( $db,
 216                         array( 'rev_timestamp'  => $db->timestamp( $timestamp ),
 217                                    'page_namespace' => $title->getNamespace(),
 218                                    'page_title'     => $title->getDBkey() )
 219                 );
 220         }
 221
 222         /**
 223          * Given a set of conditions, fetch a revision.
 224          *
 225          * @param $conditions Array
 226          * @return Revision or null
 227          */
 228         public static function newFromConds( $conditions ) {
 229                 $db = wfGetDB( DB_SLAVE );
 230                 $rev = Revision::loadFromConds( $db, $conditions );
 231                 if( is_null( $rev ) && wfGetLB()->getServerCount() > 1 ) {
 232                         $dbw = wfGetDB( DB_MASTER );
 233                         $rev = Revision::loadFromConds( $dbw, $conditions );
 234                 }
 235                 return $rev;
 236         }
 237
 238         /**
 239          * Given a set of conditions, fetch a revision from
 240          * the given database connection.
 241          *
 242          * @param $db DatabaseBase
 243          * @param $conditions Array
 244          * @return Revision or null
 245          */
 246         private static function loadFromConds( $db, $conditions ) {
 247                 $res = Revision::fetchFromConds( $db, $conditions );
 248                 if( $res ) {
 249                         $row = $res->fetchObject();
 250                         if( $row ) {
 251                                 $ret = new Revision( $row );
 252                                 return $ret;
 253                         }
 254                 }
 255                 $ret = null;
 256                 return $ret;
 257         }
 258
 259         /**
 260          * Return a wrapper for a series of database rows to
 261          * fetch all of a given page's revisions in turn.
 262          * Each row can be fed to the constructor to get objects.
 263          *
 264          * @param $title Title
 265          * @return ResultWrapper
 266          */
 267         public static function fetchRevision( $title ) {
 268                 return Revision::fetchFromConds(
 269                         wfGetDB( DB_SLAVE ),
 270                         array( 'rev_id=page_latest',
 271                                    'page_namespace' => $title->getNamespace(),
 272                                    'page_title'     => $title->getDBkey() )
 273                 );
 274         }
 275
 276         /**
 277          * Given a set of conditions, return a ResultWrapper
 278          * which will return matching database rows with the
 279          * fields necessary to build Revision objects.
 280          *
 281          * @param $db DatabaseBase
 282          * @param $conditions Array
 283          * @return ResultWrapper
 284          */
 285         private static function fetchFromConds( $db, $conditions ) {
 286                 $fields = array_merge(
 287                         self::selectFields(),
 288                         self::selectPageFields(),
 289                         self::selectUserFields()
 290                 );
 291                 return $db->select(
 292                         array( 'revision', 'page', 'user' ),
 293                         $fields,
 294                         $conditions,
 295                         __METHOD__,
 296                         array( 'LIMIT' => 1 ),
 297                         array( 'page' => self::pageJoinCond(), 'user' => self::userJoinCond() )
 298                 );
 299         }
 300
 301         /**
 302          * Return the value of a select() JOIN conds array for the user table.
 303          * This will get user table rows for logged-in users.
 304          * @since 1.19
 305          * @return Array
 306          */
 307         public static function userJoinCond() {
 308                 return array( 'LEFT JOIN', array( 'rev_user != 0', 'user_id = rev_user' ) );
 309         }
 310
 311         /**
 312          * Return the value of a select() page conds array for the paeg table.
 313          * This will assure that the revision(s) are not orphaned from live pages.
 314          * @since 1.19
 315          * @return Array
 316          */
 317         public static function pageJoinCond() {
 318                 return array( 'INNER JOIN', array( 'page_id = rev_page' ) );
 319         }
 320
 321         /**
 322          * Return the list of revision fields that should be selected to create
 323          * a new revision.
 324          */
 325         public static function selectFields() {
 326                 return array(
 327                         'rev_id',
 328                         'rev_page',
 329                         'rev_text_id',
 330                         'rev_timestamp',
 331                         'rev_comment',
 332                         'rev_user_text',
 333                         'rev_user',
 334                         'rev_minor_edit',
 335                         'rev_deleted',
 336                         'rev_len',
 337                         'rev_parent_id',
 338                         'rev_sha1'
 339                 );
 340         }
 341
 342         /**
 343          * Return the list of text fields that should be selected to read the
 344          * revision text
 345          */
 346         public static function selectTextFields() {
 347                 return array(
 348                         'old_text',
 349                         'old_flags'
 350                 );
 351         }
 352
 353         /**
 354          * Return the list of page fields that should be selected from page table
 355          */
 356         public static function selectPageFields() {
 357                 return array(
 358                         'page_namespace',
 359                         'page_title',
 360                         'page_latest'
 361                 );
 362         }
 363
 364         /**
 365          * Return the list of user fields that should be selected from user table
 366          */
 367         public static function selectUserFields() {
 368                 return array( 'user_name' );
 369         }
 370
 371         /**
 372          * Constructor
 373          *
 374          * @param $row Mixed: either a database row or an array
 375          * @access private
 376          */
 377         function __construct( $row ) {
 378                 if( is_object( $row ) ) {
 379                         $this->mId        = intval( $row->rev_id );
 380                         $this->mPage      = intval( $row->rev_page );
 381                         $this->mTextId    = intval( $row->rev_text_id );
 382                         $this->mComment   =         $row->rev_comment;
 383                         $this->mUser      = intval( $row->rev_user );
 384                         $this->mMinorEdit = intval( $row->rev_minor_edit );
 385                         $this->mTimestamp =         $row->rev_timestamp;
 386                         $this->mDeleted   = intval( $row->rev_deleted );
 387
 388                         if( !isset( $row->rev_parent_id ) ) {
 389                                 $this->mParentId = is_null( $row->rev_parent_id ) ? null : 0;
 390                         } else {
 391                                 $this->mParentId  = intval( $row->rev_parent_id );
 392                         }
 393
 394                         if( !isset( $row->rev_len ) || is_null( $row->rev_len ) ) {
 395                                 $this->mSize = null;
 396                         } else {
 397                                 $this->mSize = intval( $row->rev_len );
 398                         }
 399
 400                         if ( !isset( $row->rev_sha1 ) ) {
 401                                 $this->mSha1 = null;
 402                         } else {
 403                                 $this->mSha1 = $row->rev_sha1;
 404                         }
 405
 406                         if( isset( $row->page_latest ) ) {
 407                                 $this->mCurrent = ( $row->rev_id == $row->page_latest );
 408                                 $this->mTitle = Title::newFromRow( $row );
 409                         } else {
 410                                 $this->mCurrent = false;
 411                                 $this->mTitle = null;
 412                         }
 413
 414                         // Lazy extraction...
 415                         $this->mText      = null;
 416                         if( isset( $row->old_text ) ) {
 417                                 $this->mTextRow = $row;
 418                         } else {
 419                                 // 'text' table row entry will be lazy-loaded
 420                                 $this->mTextRow = null;
 421                         }
 422
 423                         // Use user_name for users and rev_user_text for IPs...
 424                         $this->mUserText = null; // lazy load if left null
 425                         if ( $this->mUser == 0 ) {
 426                                 $this->mUserText = $row->rev_user_text; // IP user
 427                         } elseif ( isset( $row->user_name ) ) {
 428                                 $this->mUserText = $row->user_name; // logged-in user
 429                         }
 430                         $this->mOrigUserText = $row->rev_user_text;
 431                 } elseif( is_array( $row ) ) {
 432                         // Build a new revision to be saved...
 433                         global $wgUser; // ugh
 434
 435                         $this->mId        = isset( $row['id']         ) ? intval( $row['id']         ) : null;
 436                         $this->mPage      = isset( $row['page']       ) ? intval( $row['page']       ) : null;
 437                         $this->mTextId    = isset( $row['text_id']    ) ? intval( $row['text_id']    ) : null;
 438                         $this->mUserText  = isset( $row['user_text']  ) ? strval( $row['user_text']  ) : $wgUser->getName();
 439                         $this->mUser      = isset( $row['user']       ) ? intval( $row['user']       ) : $wgUser->getId();
 440                         $this->mMinorEdit = isset( $row['minor_edit'] ) ? intval( $row['minor_edit'] ) : 0;
 441                         $this->mTimestamp = isset( $row['timestamp']  ) ? strval( $row['timestamp']  ) : wfTimestampNow();
 442                         $this->mDeleted   = isset( $row['deleted']    ) ? intval( $row['deleted']    ) : 0;
 443                         $this->mSize      = isset( $row['len']        ) ? intval( $row['len']        ) : null;
 444                         $this->mParentId  = isset( $row['parent_id']  ) ? intval( $row['parent_id']  ) : null;
 445                         $this->mSha1      = isset( $row['sha1']  )      ? strval( $row['sha1']  )      : null;
 446
 447                         // Enforce spacing trimming on supplied text
 448                         $this->mComment   = isset( $row['comment']    ) ?  trim( strval( $row['comment'] ) ) : null;
 449                         $this->mText      = isset( $row['text']       ) ? rtrim( strval( $row['text']    ) ) : null;
 450                         $this->mTextRow   = null;
 451
 452                         $this->mTitle     = null; # Load on demand if needed
 453                         $this->mCurrent   = false;
 454                         # If we still have no length, see it we have the text to figure it out
 455                         if ( !$this->mSize ) {
 456                                 $this->mSize = is_null( $this->mText ) ? null : strlen( $this->mText );
 457                         }
 458                         # Same for sha1
 459                         if ( $this->mSha1 === null ) {
 460                                 $this->mSha1 = is_null( $this->mText ) ? null : self::base36Sha1( $this->mText );
 461                         }
 462                 } else {
 463                         throw new MWException( 'Revision constructor passed invalid row format.' );
 464                 }
 465                 $this->mUnpatrolled = null;
 466         }
 467
 468         /**
 469          * Get revision ID
 470          *
 471          * @return Integer
 472          */
 473         public function getId() {
 474                 return $this->mId;
 475         }
 476
 477         /**
 478          * Set the revision ID
 479          *
 480          * @since 1.19
 481          * @param $id Integer
 482          */
 483         public function setId( $id ) {
 484                 $this->mId = $id;
 485         }
 486
 487         /**
 488          * Get text row ID
 489          *
 490          * @return Integer
 491          */
 492         public function getTextId() {
 493                 return $this->mTextId;
 494         }
 495
 496         /**
 497          * Get parent revision ID (the original previous page revision)
 498          *
 499          * @return Integer
 500          */
 501         public function getParentId() {
 502                 return $this->mParentId;
 503         }
 504
 505         /**
 506          * Returns the length of the text in this revision, or null if unknown.
 507          *
 508          * @return Integer
 509          */
 510         public function getSize() {
 511                 return $this->mSize;
 512         }
 513
 514         /**
 515          * Returns the base36 sha1 of the text in this revision, or null if unknown.
 516          *
 517          * @return String
 518          */
 519         public function getSha1() {
 520                 return $this->mSha1;
 521         }
 522
 523         /**
 524          * Returns the title of the page associated with this entry.
 525          *
 526          * @return Title
 527          */
 528         public function getTitle() {
 529                 if( isset( $this->mTitle ) ) {
 530                         return $this->mTitle;
 531                 }
 532                 $dbr = wfGetDB( DB_SLAVE );
 533                 $row = $dbr->selectRow(
 534                         array( 'page', 'revision' ),
 535                         array( 'page_namespace', 'page_title' ),
 536                         array( 'page_id=rev_page',
 537                                    'rev_id' => $this->mId ),
 538                         'Revision::getTitle' );
 539                 if( $row ) {
 540                         $this->mTitle = Title::makeTitle( $row->page_namespace, $row->page_title );
 541                 }
 542                 return $this->mTitle;
 543         }
 544
 545         /**
 546          * Set the title of the revision
 547          *
 548          * @param $title Title
 549          */
 550         public function setTitle( $title ) {
 551                 $this->mTitle = $title;
 552         }
 553
 554         /**
 555          * Get the page ID
 556          *
 557          * @return Integer
 558          */
 559         public function getPage() {
 560                 return $this->mPage;
 561         }
 562
 563         /**
 564          * Fetch revision's user id if it's available to the specified audience.
 565          * If the specified audience does not have access to it, zero will be
 566          * returned.
 567          *
 568          * @param $audience Integer: one of:
 569          *      Revision::FOR_PUBLIC       to be displayed to all users
 570          *      Revision::FOR_THIS_USER    to be displayed to $wgUser
 571          *      Revision::RAW              get the ID regardless of permissions
 572          * @param $user User object to check for, only if FOR_THIS_USER is passed
 573          *              to the $audience parameter
 574          * @return Integer
 575          */
 576         public function getUser( $audience = self::FOR_PUBLIC, User $user = null ) {
 577                 if( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_USER ) ) {
 578                         return 0;
 579                 } elseif( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_USER, $user ) ) {
 580                         return 0;
 581                 } else {
 582                         return $this->mUser;
 583                 }
 584         }
 585
 586         /**
 587          * Fetch revision's user id without regard for the current user's permissions
 588          *
 589          * @return String
 590          */
 591         public function getRawUser() {
 592                 return $this->mUser;
 593         }
 594
 595         /**
 596          * Fetch revision's username if it's available to the specified audience.
 597          * If the specified audience does not have access to the username, an
 598          * empty string will be returned.
 599          *
 600          * @param $audience Integer: one of:
 601          *      Revision::FOR_PUBLIC       to be displayed to all users
 602          *      Revision::FOR_THIS_USER    to be displayed to $wgUser
 603          *      Revision::RAW              get the text regardless of permissions
 604          * @param $user User object to check for, only if FOR_THIS_USER is passed
 605          *              to the $audience parameter
 606          * @return string
 607          */
 608         public function getUserText( $audience = self::FOR_PUBLIC, User $user = null ) {
 609                 if( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_USER ) ) {
 610                         return '';
 611                 } elseif( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_USER, $user ) ) {
 612                         return '';
 613                 } else {
 614                         return $this->getRawUserText();
 615                 }
 616         }
 617
 618         /**
 619          * Fetch revision's username without regard for view restrictions
 620          *
 621          * @return String
 622          */
 623         public function getRawUserText() {
 624                 if ( $this->mUserText === null ) {
 625                         $this->mUserText = User::whoIs( $this->mUser ); // load on demand
 626                         if ( $this->mUserText === false ) {
 627                                 # This shouldn't happen, but it can if the wiki was recovered
 628                                 # via importing revs and there is no user table entry yet.
 629                                 $this->mUserText = $this->mOrigUserText;
 630                         }
 631                 }
 632                 return $this->mUserText;
 633         }
 634
 635         /**
 636          * Fetch revision comment if it's available to the specified audience.
 637          * If the specified audience does not have access to the comment, an
 638          * empty string will be returned.
 639          *
 640          * @param $audience Integer: one of:
 641          *      Revision::FOR_PUBLIC       to be displayed to all users
 642          *      Revision::FOR_THIS_USER    to be displayed to $wgUser
 643          *      Revision::RAW              get the text regardless of permissions
 644          * @param $user User object to check for, only if FOR_THIS_USER is passed
 645          *              to the $audience parameter
 646          * @return String
 647          */
 648         function getComment( $audience = self::FOR_PUBLIC, User $user = null ) {
 649                 if( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_COMMENT ) ) {
 650                         return '';
 651                 } elseif( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_COMMENT, $user ) ) {
 652                         return '';
 653                 } else {
 654                         return $this->mComment;
 655                 }
 656         }
 657
 658         /**
 659          * Fetch revision comment without regard for the current user's permissions
 660          *
 661          * @return String
 662          */
 663         public function getRawComment() {
 664                 return $this->mComment;
 665         }
 666
 667         /**
 668          * @return Boolean
 669          */
 670         public function isMinor() {
 671                 return (bool)$this->mMinorEdit;
 672         }
 673
 674         /**
 675          * @return Integer rcid of the unpatrolled row, zero if there isn't one
 676          */
 677         public function isUnpatrolled() {
 678                 if( $this->mUnpatrolled !== null ) {
 679                         return $this->mUnpatrolled;
 680                 }
 681                 $dbr = wfGetDB( DB_SLAVE );
 682                 $this->mUnpatrolled = $dbr->selectField( 'recentchanges',
 683                         'rc_id',
 684                         array( // Add redundant user,timestamp condition so we can use the existing index
 685                                 'rc_user_text'  => $this->getRawUserText(),
 686                                 'rc_timestamp'  => $dbr->timestamp( $this->getTimestamp() ),
 687                                 'rc_this_oldid' => $this->getId(),
 688                                 'rc_patrolled'  => 0
 689                         ),
 690                         __METHOD__
 691                 );
 692                 return (int)$this->mUnpatrolled;
 693         }
 694
 695         /**
 696          * @param $field int one of DELETED_* bitfield constants
 697          *
 698          * @return Boolean
 699          */
 700         public function isDeleted( $field ) {
 701                 return ( $this->mDeleted & $field ) == $field;
 702         }
 703
 704         /**
 705          * Get the deletion bitfield of the revision
 706          *
 707          * @return int
 708          */
 709         public function getVisibility() {
 710                 return (int)$this->mDeleted;
 711         }
 712
 713         /**
 714          * Fetch revision text if it's available to the specified audience.
 715          * If the specified audience does not have the ability to view this
 716          * revision, an empty string will be returned.
 717          *
 718          * @param $audience Integer: one of:
 719          *      Revision::FOR_PUBLIC       to be displayed to all users
 720          *      Revision::FOR_THIS_USER    to be displayed to $wgUser
 721          *      Revision::RAW              get the text regardless of permissions
 722          * @param $user User object to check for, only if FOR_THIS_USER is passed
 723          *              to the $audience parameter
 724          * @return String
 725          */
 726         public function getText( $audience = self::FOR_PUBLIC, User $user = null ) {
 727                 if( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_TEXT ) ) {
 728                         return '';
 729                 } elseif( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_TEXT, $user ) ) {
 730                         return '';
 731                 } else {
 732                         return $this->getRawText();
 733                 }
 734         }
 735
 736         /**
 737          * Alias for getText(Revision::FOR_THIS_USER)
 738          *
 739          * @deprecated since 1.17
 740          * @return String
 741          */
 742         public function revText() {
 743                 wfDeprecated( __METHOD__, '1.17' );
 744                 return $this->getText( self::FOR_THIS_USER );
 745         }
 746
 747         /**
 748          * Fetch revision text without regard for view restrictions
 749          *
 750          * @return String
 751          */
 752         public function getRawText() {
 753                 if( is_null( $this->mText ) ) {
 754                         // Revision text is immutable. Load on demand:
 755                         $this->mText = $this->loadText();
 756                 }
 757                 return $this->mText;
 758         }
 759
 760         /**
 761          * @return String
 762          */
 763         public function getTimestamp() {
 764                 return wfTimestamp( TS_MW, $this->mTimestamp );
 765         }
 766
 767         /**
 768          * @return Boolean
 769          */
 770         public function isCurrent() {
 771                 return $this->mCurrent;
 772         }
 773
 774         /**
 775          * Get previous revision for this title
 776          *
 777          * @return Revision or null
 778          */
 779         public function getPrevious() {
 780                 if( $this->getTitle() ) {
 781                         $prev = $this->getTitle()->getPreviousRevisionID( $this->getId() );
 782                         if( $prev ) {
 783                                 return Revision::newFromTitle( $this->getTitle(), $prev );
 784                         }
 785                 }
 786                 return null;
 787         }
 788
 789         /**
 790          * Get next revision for this title
 791          *
 792          * @return Revision or null
 793          */
 794         public function getNext() {
 795                 if( $this->getTitle() ) {
 796                         $next = $this->getTitle()->getNextRevisionID( $this->getId() );
 797                         if ( $next ) {
 798                                 return Revision::newFromTitle( $this->getTitle(), $next );
 799                         }
 800                 }
 801                 return null;
 802         }
 803
 804         /**
 805          * Get previous revision Id for this page_id
 806          * This is used to populate rev_parent_id on save
 807          *
 808          * @param $db DatabaseBase
 809          * @return Integer
 810          */
 811         private function getPreviousRevisionId( $db ) {
 812                 if( is_null( $this->mPage ) ) {
 813                         return 0;
 814                 }
 815                 # Use page_latest if ID is not given
 816                 if( !$this->mId ) {
 817                         $prevId = $db->selectField( 'page', 'page_latest',
 818                                 array( 'page_id' => $this->mPage ),
 819                                 __METHOD__ );
 820                 } else {
 821                         $prevId = $db->selectField( 'revision', 'rev_id',
 822                                 array( 'rev_page' => $this->mPage, 'rev_id < ' . $this->mId ),
 823                                 __METHOD__,
 824                                 array( 'ORDER BY' => 'rev_id DESC' ) );
 825                 }
 826                 return intval( $prevId );
 827         }
 828
 829         /**
 830           * Get revision text associated with an old or archive row
 831           * $row is usually an object from wfFetchRow(), both the flags and the text
 832           * field must be included
 833           *
 834           * @param $row Object: the text data
 835           * @param $prefix String: table prefix (default 'old_')
 836           * @return String: text the text requested or false on failure
 837           */
 838         public static function getRevisionText( $row, $prefix = 'old_' ) {
 839                 wfProfileIn( __METHOD__ );
 840
 841                 # Get data
 842                 $textField = $prefix . 'text';
 843                 $flagsField = $prefix . 'flags';
 844
 845                 if( isset( $row->$flagsField ) ) {
 846                         $flags = explode( ',', $row->$flagsField );
 847                 } else {
 848                         $flags = array();
 849                 }
 850
 851                 if( isset( $row->$textField ) ) {
 852                         $text = $row->$textField;
 853                 } else {
 854                         wfProfileOut( __METHOD__ );
 855                         return false;
 856                 }
 857
 858                 # Use external methods for external objects, text in table is URL-only then
 859                 if ( in_array( 'external', $flags ) ) {
 860                         $url = $text;
 861                         $parts = explode( '://', $url, 2 );
 862                         if( count( $parts ) == 1 || $parts[1] == '' ) {
 863                                 wfProfileOut( __METHOD__ );
 864                                 return false;
 865                         }
 866                         $text = ExternalStore::fetchFromURL( $url );
 867                 }
 868
 869                 // If the text was fetched without an error, convert it
 870                 if ( $text !== false ) {
 871                         if( in_array( 'gzip', $flags ) ) {
 872                                 # Deal with optional compression of archived pages.
 873                                 # This can be done periodically via maintenance/compressOld.php, and
 874                                 # as pages are saved if $wgCompressRevisions is set.
 875                                 $text = gzinflate( $text );
 876                         }
 877
 878                         if( in_array( 'object', $flags ) ) {
 879                                 # Generic compressed storage
 880                                 $obj = unserialize( $text );
 881                                 if ( !is_object( $obj ) ) {
 882                                         // Invalid object
 883                                         wfProfileOut( __METHOD__ );
 884                                         return false;
 885                                 }
 886                                 $text = $obj->getText();
 887                         }
 888
 889                         global $wgLegacyEncoding;
 890                         if( $text !== false && $wgLegacyEncoding
 891                                 && !in_array( 'utf-8', $flags ) && !in_array( 'utf8', $flags ) )
 892                         {
 893                                 # Old revisions kept around in a legacy encoding?
 894                                 # Upconvert on demand.
 895                                 # ("utf8" checked for compatibility with some broken
 896                                 #  conversion scripts 2008-12-30)
 897                                 global $wgContLang;
 898                                 $text = $wgContLang->iconv( $wgLegacyEncoding, 'UTF-8', $text );
 899                         }
 900                 }
 901                 wfProfileOut( __METHOD__ );
 902                 return $text;
 903         }
 904
 905         /**
 906          * If $wgCompressRevisions is enabled, we will compress data.
 907          * The input string is modified in place.
 908          * Return value is the flags field: contains 'gzip' if the
 909          * data is compressed, and 'utf-8' if we're saving in UTF-8
 910          * mode.
 911          *
 912          * @param $text Mixed: reference to a text
 913          * @return String
 914          */
 915         public static function compressRevisionText( &$text ) {
 916                 global $wgCompressRevisions;
 917                 $flags = array();
 918
 919                 # Revisions not marked this way will be converted
 920                 # on load if $wgLegacyCharset is set in the future.
 921                 $flags[] = 'utf-8';
 922
 923                 if( $wgCompressRevisions ) {
 924                         if( function_exists( 'gzdeflate' ) ) {
 925                                 $text = gzdeflate( $text );
 926                                 $flags[] = 'gzip';
 927                         } else {
 928                                 wfDebug( "Revision::compressRevisionText() -- no zlib support, not compressing\n" );
 929                         }
 930                 }
 931                 return implode( ',', $flags );
 932         }
 933
 934         /**
 935          * Insert a new revision into the database, returning the new revision ID
 936          * number on success and dies horribly on failure.
 937          *
 938          * @param $dbw DatabaseBase: (master connection)
 939          * @return Integer
 940          */
 941         public function insertOn( $dbw ) {
 942                 global $wgDefaultExternalStore;
 943
 944                 wfProfileIn( __METHOD__ );
 945
 946                 $data = $this->mText;
 947                 $flags = Revision::compressRevisionText( $data );
 948
 949                 # Write to external storage if required
 950                 if( $wgDefaultExternalStore ) {
 951                         // Store and get the URL
 952                         $data = ExternalStore::insertToDefault( $data );
 953                         if( !$data ) {
 954                                 throw new MWException( "Unable to store text to external storage" );
 955                         }
 956                         if( $flags ) {
 957                                 $flags .= ',';
 958                         }
 959                         $flags .= 'external';
 960                 }
 961
 962                 # Record the text (or external storage URL) to the text table
 963                 if( !isset( $this->mTextId ) ) {
 964                         $old_id = $dbw->nextSequenceValue( 'text_old_id_seq' );
 965                         $dbw->insert( 'text',
 966                                 array(
 967                                         'old_id'    => $old_id,
 968                                         'old_text'  => $data,
 969                                         'old_flags' => $flags,
 970                                 ), __METHOD__
 971                         );
 972                         $this->mTextId = $dbw->insertId();
 973                 }
 974
 975                 if ( $this->mComment === null ) $this->mComment = "";
 976
 977                 # Record the edit in revisions
 978                 $rev_id = isset( $this->mId )
 979                         ? $this->mId
 980                         : $dbw->nextSequenceValue( 'revision_rev_id_seq' );
 981                 $dbw->insert( 'revision',
 982                         array(
 983                                 'rev_id'         => $rev_id,
 984                                 'rev_page'       => $this->mPage,
 985                                 'rev_text_id'    => $this->mTextId,
 986                                 'rev_comment'    => $this->mComment,
 987                                 'rev_minor_edit' => $this->mMinorEdit ? 1 : 0,
 988                                 'rev_user'       => $this->mUser,
 989                                 'rev_user_text'  => $this->mUserText,
 990                                 'rev_timestamp'  => $dbw->timestamp( $this->mTimestamp ),
 991                                 'rev_deleted'    => $this->mDeleted,
 992                                 'rev_len'        => $this->mSize,
 993                                 'rev_parent_id'  => is_null( $this->mParentId )
 994                                         ? $this->getPreviousRevisionId( $dbw )
 995                                         : $this->mParentId,
 996                                 'rev_sha1'       => is_null( $this->mSha1 )
 997                                         ? Revision::base36Sha1( $this->mText )
 998                                         : $this->mSha1
 999                         ), __METHOD__
1000                 );
1001
1002                 $this->mId = !is_null( $rev_id ) ? $rev_id : $dbw->insertId();
1003
1004                 wfRunHooks( 'RevisionInsertComplete', array( &$this, $data, $flags ) );
1005
1006                 wfProfileOut( __METHOD__ );
1007                 return $this->mId;
1008         }
1009
1010         /**
1011          * Get the base 36 SHA-1 value for a string of text
1012          * @param $text String
1013          * @return String
1014          */
1015         public static function base36Sha1( $text ) {
1016                 return wfBaseConvert( sha1( $text ), 16, 36, 31 );
1017         }
1018
1019         /**
1020          * Lazy-load the revision's text.
1021          * Currently hardcoded to the 'text' table storage engine.
1022          *
1023          * @return String
1024          */
1025         protected function loadText() {
1026                 wfProfileIn( __METHOD__ );
1027
1028                 // Caching may be beneficial for massive use of external storage
1029                 global $wgRevisionCacheExpiry, $wgMemc;
1030                 $textId = $this->getTextId();
1031                 $key = wfMemcKey( 'revisiontext', 'textid', $textId );
1032                 if( $wgRevisionCacheExpiry ) {
1033                         $text = $wgMemc->get( $key );
1034                         if( is_string( $text ) ) {
1035                                 wfDebug( __METHOD__ . ": got id $textId from cache\n" );
1036                                 wfProfileOut( __METHOD__ );
1037                                 return $text;
1038                         }
1039                 }
1040
1041                 // If we kept data for lazy extraction, use it now...
1042                 if ( isset( $this->mTextRow ) ) {
1043                         $row = $this->mTextRow;
1044                         $this->mTextRow = null;
1045                 } else {
1046                         $row = null;
1047                 }
1048
1049                 if( !$row ) {
1050                         // Text data is immutable; check slaves first.
1051                         $dbr = wfGetDB( DB_SLAVE );
1052                         $row = $dbr->selectRow( 'text',
1053                                 array( 'old_text', 'old_flags' ),
1054                                 array( 'old_id' => $this->getTextId() ),
1055                                 __METHOD__ );
1056                 }
1057
1058                 if( !$row && wfGetLB()->getServerCount() > 1 ) {
1059                         // Possible slave lag!
1060                         $dbw = wfGetDB( DB_MASTER );
1061                         $row = $dbw->selectRow( 'text',
1062                                 array( 'old_text', 'old_flags' ),
1063                                 array( 'old_id' => $this->getTextId() ),
1064                                 __METHOD__ );
1065                 }
1066
1067                 $text = self::getRevisionText( $row );
1068
1069                 # No negative caching -- negative hits on text rows may be due to corrupted slave servers
1070                 if( $wgRevisionCacheExpiry && $text !== false ) {
1071                         $wgMemc->set( $key, $text, $wgRevisionCacheExpiry );
1072                 }
1073
1074                 wfProfileOut( __METHOD__ );
1075
1076                 return $text;
1077         }
1078
1079         /**
1080          * Create a new null-revision for insertion into a page's
1081          * history. This will not re-save the text, but simply refer
1082          * to the text from the previous version.
1083          *
1084          * Such revisions can for instance identify page rename
1085          * operations and other such meta-modifications.
1086          *
1087          * @param $dbw DatabaseBase
1088          * @param $pageId Integer: ID number of the page to read from
1089          * @param $summary String: revision's summary
1090          * @param $minor Boolean: whether the revision should be considered as minor
1091          * @return Revision|null on error
1092          */
1093         public static function newNullRevision( $dbw, $pageId, $summary, $minor ) {
1094                 wfProfileIn( __METHOD__ );
1095
1096                 $current = $dbw->selectRow(
1097                         array( 'page', 'revision' ),
1098                         array( 'page_latest', 'rev_text_id', 'rev_len', 'rev_sha1' ),
1099                         array(
1100                                 'page_id' => $pageId,
1101                                 'page_latest=rev_id',
1102                                 ),
1103                         __METHOD__ );
1104
1105                 if( $current ) {
1106                         $revision = new Revision( array(
1107                                 'page'       => $pageId,
1108                                 'comment'    => $summary,
1109                                 'minor_edit' => $minor,
1110                                 'text_id'    => $current->rev_text_id,
1111                                 'parent_id'  => $current->page_latest,
1112                                 'len'        => $current->rev_len,
1113                                 'sha1'       => $current->rev_sha1
1114                                 ) );
1115                 } else {
1116                         $revision = null;
1117                 }
1118
1119                 wfProfileOut( __METHOD__ );
1120                 return $revision;
1121         }
1122
1123         /**
1124          * Determine if the current user is allowed to view a particular
1125          * field of this revision, if it's marked as deleted.
1126          *
1127          * @param $field Integer:one of self::DELETED_TEXT,
1128          *                              self::DELETED_COMMENT,
1129          *                              self::DELETED_USER
1130          * @param $user User object to check, or null to use $wgUser
1131          * @return Boolean
1132          */
1133         public function userCan( $field, User $user = null ) {
1134                 return self::userCanBitfield( $this->mDeleted, $field, $user );
1135         }
1136
1137         /**
1138          * Determine if the current user is allowed to view a particular
1139          * field of this revision, if it's marked as deleted. This is used
1140          * by various classes to avoid duplication.
1141          *
1142          * @param $bitfield Integer: current field
1143          * @param $field Integer: one of self::DELETED_TEXT = File::DELETED_FILE,
1144          *                               self::DELETED_COMMENT = File::DELETED_COMMENT,
1145          *                               self::DELETED_USER = File::DELETED_USER
1146          * @param $user User object to check, or null to use $wgUser
1147          * @return Boolean
1148          */
1149         public static function userCanBitfield( $bitfield, $field, User $user = null ) {
1150                 if( $bitfield & $field ) { // aspect is deleted
1151                         if ( $bitfield & self::DELETED_RESTRICTED ) {
1152                                 $permission = 'suppressrevision';
1153                         } elseif ( $field & self::DELETED_TEXT ) {
1154                                 $permission = 'deletedtext';
1155                         } else {
1156                                 $permission = 'deletedhistory';
1157                         }
1158                         wfDebug( "Checking for $permission due to $field match on $bitfield\n" );
1159                         if ( $user === null ) {
1160                                 global $wgUser;
1161                                 $user = $wgUser;
1162                         }
1163                         return $user->isAllowed( $permission );
1164                 } else {
1165                         return true;
1166                 }
1167         }
1168
1169         /**
1170          * Get rev_timestamp from rev_id, without loading the rest of the row
1171          *
1172          * @param $title Title
1173          * @param $id Integer
1174          * @return String
1175          */
1176         static function getTimestampFromId( $title, $id ) {
1177                 $dbr = wfGetDB( DB_SLAVE );
1178                 // Casting fix for DB2
1179                 if ( $id == '' ) {
1180                         $id = 0;
1181                 }
1182                 $conds = array( 'rev_id' => $id );
1183                 $conds['rev_page'] = $title->getArticleId();
1184                 $timestamp = $dbr->selectField( 'revision', 'rev_timestamp', $conds, __METHOD__ );
1185                 if ( $timestamp === false && wfGetLB()->getServerCount() > 1 ) {
1186                         # Not in slave, try master
1187                         $dbw = wfGetDB( DB_MASTER );
1188                         $timestamp = $dbw->selectField( 'revision', 'rev_timestamp', $conds, __METHOD__ );
1189                 }
1190                 return wfTimestamp( TS_MW, $timestamp );
1191         }
1192
1193         /**
1194          * Get count of revisions per page...not very efficient
1195          *
1196          * @param $db DatabaseBase
1197          * @param $id Integer: page id
1198          * @return Integer
1199          */
1200         static function countByPageId( $db, $id ) {
1201                 $row = $db->selectRow( 'revision', 'COUNT(*) AS revCount',
1202                         array( 'rev_page' => $id ), __METHOD__ );
1203                 if( $row ) {
1204                         return $row->revCount;
1205                 }
1206                 return 0;
1207         }
1208
1209         /**
1210          * Get count of revisions per page...not very efficient
1211          *
1212          * @param $db DatabaseBase
1213          * @param $title Title
1214          * @return Integer
1215          */
1216         static function countByTitle( $db, $title ) {
1217                 $id = $title->getArticleId();
1218                 if( $id ) {
1219                         return Revision::countByPageId( $db, $id );
1220                 }
1221                 return 0;
1222         }
1223 }