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'       => $row->ar_sha1
 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' => array( 'INNER JOIN', 'page_id = rev_page' ),
 298                                 'user' => array( 'LEFT JOIN', 'rev_user != 0 AND user_id = rev_user' ) )
 299                 );
 300         }
 301
 302         /**
 303          * Return the list of revision fields that should be selected to create
 304          * a new revision.
 305          */
 306         public static function selectFields() {
 307                 return array(
 308                         'rev_id',
 309                         'rev_page',
 310                         'rev_text_id',
 311                         'rev_timestamp',
 312                         'rev_comment',
 313                         'rev_user_text',
 314                         'rev_user',
 315                         'rev_minor_edit',
 316                         'rev_deleted',
 317                         'rev_len',
 318                         'rev_parent_id',
 319                         'rev_sha1'
 320                 );
 321         }
 322
 323         /**
 324          * Return the list of text fields that should be selected to read the
 325          * revision text
 326          */
 327         public static function selectTextFields() {
 328                 return array(
 329                         'old_text',
 330                         'old_flags'
 331                 );
 332         }
 333
 334         /**
 335          * Return the list of page fields that should be selected from page table
 336          */
 337         public static function selectPageFields() {
 338                 return array(
 339                         'page_namespace',
 340                         'page_title',
 341                         'page_latest'
 342                 );
 343         }
 344
 345         /**
 346          * Return the list of user fields that should be selected from user table
 347          */
 348         public static function selectUserFields() {
 349                 return array( 'user_name' );
 350         }
 351
 352         /**
 353          * Constructor
 354          *
 355          * @param $row Mixed: either a database row or an array
 356          * @access private
 357          */
 358         function __construct( $row ) {
 359                 if( is_object( $row ) ) {
 360                         $this->mId        = intval( $row->rev_id );
 361                         $this->mPage      = intval( $row->rev_page );
 362                         $this->mTextId    = intval( $row->rev_text_id );
 363                         $this->mComment   =         $row->rev_comment;
 364                         $this->mUser      = intval( $row->rev_user );
 365                         $this->mMinorEdit = intval( $row->rev_minor_edit );
 366                         $this->mTimestamp =         $row->rev_timestamp;
 367                         $this->mDeleted   = intval( $row->rev_deleted );
 368
 369                         if( !isset( $row->rev_parent_id ) ) {
 370                                 $this->mParentId = is_null( $row->rev_parent_id ) ? null : 0;
 371                         } else {
 372                                 $this->mParentId  = intval( $row->rev_parent_id );
 373                         }
 374
 375                         if( !isset( $row->rev_len ) || is_null( $row->rev_len ) ) {
 376                                 $this->mSize = null;
 377                         } else {
 378                                 $this->mSize = intval( $row->rev_len );
 379                         }
 380
 381                         if ( !isset( $row->rev_sha1 ) ) {
 382                                 $this->mSha1 = null;
 383                         } else {
 384                                 $this->mSha1 = $row->rev_sha1;
 385                         }
 386
 387                         if( isset( $row->page_latest ) ) {
 388                                 $this->mCurrent = ( $row->rev_id == $row->page_latest );
 389                                 $this->mTitle = Title::newFromRow( $row );
 390                         } else {
 391                                 $this->mCurrent = false;
 392                                 $this->mTitle = null;
 393                         }
 394
 395                         // Lazy extraction...
 396                         $this->mText      = null;
 397                         if( isset( $row->old_text ) ) {
 398                                 $this->mTextRow = $row;
 399                         } else {
 400                                 // 'text' table row entry will be lazy-loaded
 401                                 $this->mTextRow = null;
 402                         }
 403
 404                         // Use user_name for users and rev_user_text for IPs...
 405                         $this->mUserText = null; // lazy load if left null
 406                         if ( $this->mUser == 0 ) {
 407                                 $this->mUserText = $row->rev_user_text; // IP user
 408                         } elseif ( isset( $row->user_name ) ) {
 409                                 $this->mUserText = $row->user_name; // logged-in user
 410                         }
 411                         $this->mOrigUserText = $row->rev_user_text;
 412                 } elseif( is_array( $row ) ) {
 413                         // Build a new revision to be saved...
 414                         global $wgUser; // ugh
 415
 416                         $this->mId        = isset( $row['id']         ) ? intval( $row['id']         ) : null;
 417                         $this->mPage      = isset( $row['page']       ) ? intval( $row['page']       ) : null;
 418                         $this->mTextId    = isset( $row['text_id']    ) ? intval( $row['text_id']    ) : null;
 419                         $this->mUserText  = isset( $row['user_text']  ) ? strval( $row['user_text']  ) : $wgUser->getName();
 420                         $this->mUser      = isset( $row['user']       ) ? intval( $row['user']       ) : $wgUser->getId();
 421                         $this->mMinorEdit = isset( $row['minor_edit'] ) ? intval( $row['minor_edit'] ) : 0;
 422                         $this->mTimestamp = isset( $row['timestamp']  ) ? strval( $row['timestamp']  ) : wfTimestamp( TS_MW );
 423                         $this->mDeleted   = isset( $row['deleted']    ) ? intval( $row['deleted']    ) : 0;
 424                         $this->mSize      = isset( $row['len']        ) ? intval( $row['len']        ) : null;
 425                         $this->mParentId  = isset( $row['parent_id']  ) ? intval( $row['parent_id']  ) : null;
 426                         $this->mSha1      = isset( $row['sha1']  )      ? strval( $row['sha1']  )      : null;
 427
 428                         // Enforce spacing trimming on supplied text
 429                         $this->mComment   = isset( $row['comment']    ) ?  trim( strval( $row['comment'] ) ) : null;
 430                         $this->mText      = isset( $row['text']       ) ? rtrim( strval( $row['text']    ) ) : null;
 431                         $this->mTextRow   = null;
 432
 433                         $this->mTitle     = null; # Load on demand if needed
 434                         $this->mCurrent   = false;
 435                         # If we still have no length, see it we have the text to figure it out
 436                         if ( !$this->mSize ) {
 437                                 $this->mSize = is_null( $this->mText ) ? null : strlen( $this->mText );
 438                         }
 439                         # Same for sha1
 440                         if ( $this->mSha1 === null ) {
 441                                 $this->mSha1 = is_null( $this->mText ) ? null : self::base36Sha1( $this->mText );
 442                         }
 443                 } else {
 444                         throw new MWException( 'Revision constructor passed invalid row format.' );
 445                 }
 446                 $this->mUnpatrolled = null;
 447         }
 448
 449         /**
 450          * Get revision ID
 451          *
 452          * @return Integer
 453          */
 454         public function getId() {
 455                 return $this->mId;
 456         }
 457
 458         /**
 459          * Get text row ID
 460          *
 461          * @return Integer
 462          */
 463         public function getTextId() {
 464                 return $this->mTextId;
 465         }
 466
 467         /**
 468          * Get parent revision ID (the original previous page revision)
 469          *
 470          * @return Integer
 471          */
 472         public function getParentId() {
 473                 return $this->mParentId;
 474         }
 475
 476         /**
 477          * Returns the length of the text in this revision, or null if unknown.
 478          *
 479          * @return Integer
 480          */
 481         public function getSize() {
 482                 return $this->mSize;
 483         }
 484
 485         /**
 486          * Returns the base36 sha1 of the text in this revision, or null if unknown.
 487          *
 488          * @return String
 489          */
 490         public function getSha1() {
 491                 return $this->mSha1;
 492         }
 493
 494         /**
 495          * Returns the title of the page associated with this entry.
 496          *
 497          * @return Title
 498          */
 499         public function getTitle() {
 500                 if( isset( $this->mTitle ) ) {
 501                         return $this->mTitle;
 502                 }
 503                 $dbr = wfGetDB( DB_SLAVE );
 504                 $row = $dbr->selectRow(
 505                         array( 'page', 'revision' ),
 506                         array( 'page_namespace', 'page_title' ),
 507                         array( 'page_id=rev_page',
 508                                    'rev_id' => $this->mId ),
 509                         'Revision::getTitle' );
 510                 if( $row ) {
 511                         $this->mTitle = Title::makeTitle( $row->page_namespace, $row->page_title );
 512                 }
 513                 return $this->mTitle;
 514         }
 515
 516         /**
 517          * Set the title of the revision
 518          *
 519          * @param $title Title
 520          */
 521         public function setTitle( $title ) {
 522                 $this->mTitle = $title;
 523         }
 524
 525         /**
 526          * Get the page ID
 527          *
 528          * @return Integer
 529          */
 530         public function getPage() {
 531                 return $this->mPage;
 532         }
 533
 534         /**
 535          * Fetch revision's user id if it's available to the specified audience.
 536          * If the specified audience does not have access to it, zero will be
 537          * returned.
 538          *
 539          * @param $audience Integer: one of:
 540          *      Revision::FOR_PUBLIC       to be displayed to all users
 541          *      Revision::FOR_THIS_USER    to be displayed to $wgUser
 542          *      Revision::RAW              get the ID regardless of permissions
 543          * @param $user User object to check for, only if FOR_THIS_USER is passed
 544          *              to the $audience parameter
 545          * @return Integer
 546          */
 547         public function getUser( $audience = self::FOR_PUBLIC, User $user = null ) {
 548                 if( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_USER ) ) {
 549                         return 0;
 550                 } elseif( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_USER, $user ) ) {
 551                         return 0;
 552                 } else {
 553                         return $this->mUser;
 554                 }
 555         }
 556
 557         /**
 558          * Fetch revision's user id without regard for the current user's permissions
 559          *
 560          * @return String
 561          */
 562         public function getRawUser() {
 563                 return $this->mUser;
 564         }
 565
 566         /**
 567          * Fetch revision's username if it's available to the specified audience.
 568          * If the specified audience does not have access to the username, an
 569          * empty string will be returned.
 570          *
 571          * @param $audience Integer: one of:
 572          *      Revision::FOR_PUBLIC       to be displayed to all users
 573          *      Revision::FOR_THIS_USER    to be displayed to $wgUser
 574          *      Revision::RAW              get the text regardless of permissions
 575          * @param $user User object to check for, only if FOR_THIS_USER is passed
 576          *              to the $audience parameter
 577          * @return string
 578          */
 579         public function getUserText( $audience = self::FOR_PUBLIC, User $user = null ) {
 580                 if( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_USER ) ) {
 581                         return '';
 582                 } elseif( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_USER, $user ) ) {
 583                         return '';
 584                 } else {
 585                         return $this->getRawUserText();
 586                 }
 587         }
 588
 589         /**
 590          * Fetch revision's username without regard for view restrictions
 591          *
 592          * @return String
 593          */
 594         public function getRawUserText() {
 595                 if ( $this->mUserText === null ) {
 596                         $this->mUserText = User::whoIs( $this->mUser ); // load on demand
 597                         if ( $this->mUserText === false ) {
 598                                 # This shouldn't happen, but it can if the wiki was recovered
 599                                 # via importing revs and there is no user table entry yet.
 600                                 $this->mUserText = $this->mOrigUserText;
 601                         }
 602                 }
 603                 return $this->mUserText;
 604         }
 605
 606         /**
 607          * Fetch revision comment if it's available to the specified audience.
 608          * If the specified audience does not have access to the comment, an
 609          * empty string will be returned.
 610          *
 611          * @param $audience Integer: one of:
 612          *      Revision::FOR_PUBLIC       to be displayed to all users
 613          *      Revision::FOR_THIS_USER    to be displayed to $wgUser
 614          *      Revision::RAW              get the text regardless of permissions
 615          * @param $user User object to check for, only if FOR_THIS_USER is passed
 616          *              to the $audience parameter
 617          * @return String
 618          */
 619         function getComment( $audience = self::FOR_PUBLIC, User $user = null ) {
 620                 if( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_COMMENT ) ) {
 621                         return '';
 622                 } elseif( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_COMMENT, $user ) ) {
 623                         return '';
 624                 } else {
 625                         return $this->mComment;
 626                 }
 627         }
 628
 629         /**
 630          * Fetch revision comment without regard for the current user's permissions
 631          *
 632          * @return String
 633          */
 634         public function getRawComment() {
 635                 return $this->mComment;
 636         }
 637
 638         /**
 639          * @return Boolean
 640          */
 641         public function isMinor() {
 642                 return (bool)$this->mMinorEdit;
 643         }
 644
 645         /**
 646          * @return Integer rcid of the unpatrolled row, zero if there isn't one
 647          */
 648         public function isUnpatrolled() {
 649                 if( $this->mUnpatrolled !== null ) {
 650                         return $this->mUnpatrolled;
 651                 }
 652                 $dbr = wfGetDB( DB_SLAVE );
 653                 $this->mUnpatrolled = $dbr->selectField( 'recentchanges',
 654                         'rc_id',
 655                         array( // Add redundant user,timestamp condition so we can use the existing index
 656                                 'rc_user_text'  => $this->getRawUserText(),
 657                                 'rc_timestamp'  => $dbr->timestamp( $this->getTimestamp() ),
 658                                 'rc_this_oldid' => $this->getId(),
 659                                 'rc_patrolled'  => 0
 660                         ),
 661                         __METHOD__
 662                 );
 663                 return (int)$this->mUnpatrolled;
 664         }
 665
 666         /**
 667          * @param $field int one of DELETED_* bitfield constants
 668          *
 669          * @return Boolean
 670          */
 671         public function isDeleted( $field ) {
 672                 return ( $this->mDeleted & $field ) == $field;
 673         }
 674
 675         /**
 676          * Get the deletion bitfield of the revision
 677          *
 678          * @return int
 679          */
 680         public function getVisibility() {
 681                 return (int)$this->mDeleted;
 682         }
 683
 684         /**
 685          * Fetch revision text if it's available to the specified audience.
 686          * If the specified audience does not have the ability to view this
 687          * revision, an empty string will be returned.
 688          *
 689          * @param $audience Integer: one of:
 690          *      Revision::FOR_PUBLIC       to be displayed to all users
 691          *      Revision::FOR_THIS_USER    to be displayed to $wgUser
 692          *      Revision::RAW              get the text regardless of permissions
 693          * @param $user User object to check for, only if FOR_THIS_USER is passed
 694          *              to the $audience parameter
 695          * @return String
 696          */
 697         public function getText( $audience = self::FOR_PUBLIC, User $user = null ) {
 698                 if( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_TEXT ) ) {
 699                         return '';
 700                 } elseif( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_TEXT, $user ) ) {
 701                         return '';
 702                 } else {
 703                         return $this->getRawText();
 704                 }
 705         }
 706
 707         /**
 708          * Alias for getText(Revision::FOR_THIS_USER)
 709          *
 710          * @deprecated since 1.17
 711          * @return String
 712          */
 713         public function revText() {
 714                 wfDeprecated( __METHOD__ );
 715                 return $this->getText( self::FOR_THIS_USER );
 716         }
 717
 718         /**
 719          * Fetch revision text without regard for view restrictions
 720          *
 721          * @return String
 722          */
 723         public function getRawText() {
 724                 if( is_null( $this->mText ) ) {
 725                         // Revision text is immutable. Load on demand:
 726                         $this->mText = $this->loadText();
 727                 }
 728                 return $this->mText;
 729         }
 730
 731         /**
 732          * @return String
 733          */
 734         public function getTimestamp() {
 735                 return wfTimestamp( TS_MW, $this->mTimestamp );
 736         }
 737
 738         /**
 739          * @return Boolean
 740          */
 741         public function isCurrent() {
 742                 return $this->mCurrent;
 743         }
 744
 745         /**
 746          * Get previous revision for this title
 747          *
 748          * @return Revision or null
 749          */
 750         public function getPrevious() {
 751                 if( $this->getTitle() ) {
 752                         $prev = $this->getTitle()->getPreviousRevisionID( $this->getId() );
 753                         if( $prev ) {
 754                                 return Revision::newFromTitle( $this->getTitle(), $prev );
 755                         }
 756                 }
 757                 return null;
 758         }
 759
 760         /**
 761          * Get next revision for this title
 762          *
 763          * @return Revision or null
 764          */
 765         public function getNext() {
 766                 if( $this->getTitle() ) {
 767                         $next = $this->getTitle()->getNextRevisionID( $this->getId() );
 768                         if ( $next ) {
 769                                 return Revision::newFromTitle( $this->getTitle(), $next );
 770                         }
 771                 }
 772                 return null;
 773         }
 774
 775         /**
 776          * Get previous revision Id for this page_id
 777          * This is used to populate rev_parent_id on save
 778          *
 779          * @param $db DatabaseBase
 780          * @return Integer
 781          */
 782         private function getPreviousRevisionId( $db ) {
 783                 if( is_null( $this->mPage ) ) {
 784                         return 0;
 785                 }
 786                 # Use page_latest if ID is not given
 787                 if( !$this->mId ) {
 788                         $prevId = $db->selectField( 'page', 'page_latest',
 789                                 array( 'page_id' => $this->mPage ),
 790                                 __METHOD__ );
 791                 } else {
 792                         $prevId = $db->selectField( 'revision', 'rev_id',
 793                                 array( 'rev_page' => $this->mPage, 'rev_id < ' . $this->mId ),
 794                                 __METHOD__,
 795                                 array( 'ORDER BY' => 'rev_id DESC' ) );
 796                 }
 797                 return intval( $prevId );
 798         }
 799
 800         /**
 801           * Get revision text associated with an old or archive row
 802           * $row is usually an object from wfFetchRow(), both the flags and the text
 803           * field must be included
 804           *
 805           * @param $row Object: the text data
 806           * @param $prefix String: table prefix (default 'old_')
 807           * @return String: text the text requested or false on failure
 808           */
 809         public static function getRevisionText( $row, $prefix = 'old_' ) {
 810                 wfProfileIn( __METHOD__ );
 811
 812                 # Get data
 813                 $textField = $prefix . 'text';
 814                 $flagsField = $prefix . 'flags';
 815
 816                 if( isset( $row->$flagsField ) ) {
 817                         $flags = explode( ',', $row->$flagsField );
 818                 } else {
 819                         $flags = array();
 820                 }
 821
 822                 if( isset( $row->$textField ) ) {
 823                         $text = $row->$textField;
 824                 } else {
 825                         wfProfileOut( __METHOD__ );
 826                         return false;
 827                 }
 828
 829                 # Use external methods for external objects, text in table is URL-only then
 830                 if ( in_array( 'external', $flags ) ) {
 831                         $url = $text;
 832                         $parts = explode( '://', $url, 2 );
 833                         if( count( $parts ) == 1 || $parts[1] == '' ) {
 834                                 wfProfileOut( __METHOD__ );
 835                                 return false;
 836                         }
 837                         $text = ExternalStore::fetchFromURL( $url );
 838                 }
 839
 840                 // If the text was fetched without an error, convert it
 841                 if ( $text !== false ) {
 842                         if( in_array( 'gzip', $flags ) ) {
 843                                 # Deal with optional compression of archived pages.
 844                                 # This can be done periodically via maintenance/compressOld.php, and
 845                                 # as pages are saved if $wgCompressRevisions is set.
 846                                 $text = gzinflate( $text );
 847                         }
 848
 849                         if( in_array( 'object', $flags ) ) {
 850                                 # Generic compressed storage
 851                                 $obj = unserialize( $text );
 852                                 if ( !is_object( $obj ) ) {
 853                                         // Invalid object
 854                                         wfProfileOut( __METHOD__ );
 855                                         return false;
 856                                 }
 857                                 $text = $obj->getText();
 858                         }
 859
 860                         global $wgLegacyEncoding;
 861                         if( $text !== false && $wgLegacyEncoding
 862                                 && !in_array( 'utf-8', $flags ) && !in_array( 'utf8', $flags ) )
 863                         {
 864                                 # Old revisions kept around in a legacy encoding?
 865                                 # Upconvert on demand.
 866                                 # ("utf8" checked for compatibility with some broken
 867                                 #  conversion scripts 2008-12-30)
 868                                 global $wgContLang;
 869                                 $text = $wgContLang->iconv( $wgLegacyEncoding, 'UTF-8', $text );
 870                         }
 871                 }
 872                 wfProfileOut( __METHOD__ );
 873                 return $text;
 874         }
 875
 876         /**
 877          * If $wgCompressRevisions is enabled, we will compress data.
 878          * The input string is modified in place.
 879          * Return value is the flags field: contains 'gzip' if the
 880          * data is compressed, and 'utf-8' if we're saving in UTF-8
 881          * mode.
 882          *
 883          * @param $text Mixed: reference to a text
 884          * @return String
 885          */
 886         public static function compressRevisionText( &$text ) {
 887                 global $wgCompressRevisions;
 888                 $flags = array();
 889
 890                 # Revisions not marked this way will be converted
 891                 # on load if $wgLegacyCharset is set in the future.
 892                 $flags[] = 'utf-8';
 893
 894                 if( $wgCompressRevisions ) {
 895                         if( function_exists( 'gzdeflate' ) ) {
 896                                 $text = gzdeflate( $text );
 897                                 $flags[] = 'gzip';
 898                         } else {
 899                                 wfDebug( "Revision::compressRevisionText() -- no zlib support, not compressing\n" );
 900                         }
 901                 }
 902                 return implode( ',', $flags );
 903         }
 904
 905         /**
 906          * Insert a new revision into the database, returning the new revision ID
 907          * number on success and dies horribly on failure.
 908          *
 909          * @param $dbw DatabaseBase: (master connection)
 910          * @return Integer
 911          */
 912         public function insertOn( $dbw ) {
 913                 global $wgDefaultExternalStore;
 914
 915                 wfProfileIn( __METHOD__ );
 916
 917                 $data = $this->mText;
 918                 $flags = Revision::compressRevisionText( $data );
 919
 920                 # Write to external storage if required
 921                 if( $wgDefaultExternalStore ) {
 922                         // Store and get the URL
 923                         $data = ExternalStore::insertToDefault( $data );
 924                         if( !$data ) {
 925                                 throw new MWException( "Unable to store text to external storage" );
 926                         }
 927                         if( $flags ) {
 928                                 $flags .= ',';
 929                         }
 930                         $flags .= 'external';
 931                 }
 932
 933                 # Record the text (or external storage URL) to the text table
 934                 if( !isset( $this->mTextId ) ) {
 935                         $old_id = $dbw->nextSequenceValue( 'text_old_id_seq' );
 936                         $dbw->insert( 'text',
 937                                 array(
 938                                         'old_id'    => $old_id,
 939                                         'old_text'  => $data,
 940                                         'old_flags' => $flags,
 941                                 ), __METHOD__
 942                         );
 943                         $this->mTextId = $dbw->insertId();
 944                 }
 945
 946                 if ( $this->mComment === null ) $this->mComment = "";
 947
 948                 # Record the edit in revisions
 949                 $rev_id = isset( $this->mId )
 950                         ? $this->mId
 951                         : $dbw->nextSequenceValue( 'revision_rev_id_seq' );
 952                 $dbw->insert( 'revision',
 953                         array(
 954                                 'rev_id'         => $rev_id,
 955                                 'rev_page'       => $this->mPage,
 956                                 'rev_text_id'    => $this->mTextId,
 957                                 'rev_comment'    => $this->mComment,
 958                                 'rev_minor_edit' => $this->mMinorEdit ? 1 : 0,
 959                                 'rev_user'       => $this->mUser,
 960                                 'rev_user_text'  => $this->mUserText,
 961                                 'rev_timestamp'  => $dbw->timestamp( $this->mTimestamp ),
 962                                 'rev_deleted'    => $this->mDeleted,
 963                                 'rev_len'        => $this->mSize,
 964                                 'rev_parent_id'  => is_null( $this->mParentId )
 965                                         ? $this->getPreviousRevisionId( $dbw )
 966                                         : $this->mParentId,
 967                                 'rev_sha1'       => is_null( $this->mSha1 )
 968                                         ? Revision::base36Sha1( $this->mText )
 969                                         : $this->mSha1
 970                         ), __METHOD__
 971                 );
 972
 973                 $this->mId = !is_null( $rev_id ) ? $rev_id : $dbw->insertId();
 974
 975                 wfRunHooks( 'RevisionInsertComplete', array( &$this, $data, $flags ) );
 976
 977                 wfProfileOut( __METHOD__ );
 978                 return $this->mId;
 979         }
 980
 981         /**
 982          * Get the base 36 SHA-1 value for a string of text
 983          * @param $text String
 984          * @return String
 985          */
 986         public static function base36Sha1( $text ) {
 987                 return wfBaseConvert( sha1( $text ), 16, 36, 31 );
 988         }
 989
 990         /**
 991          * Lazy-load the revision's text.
 992          * Currently hardcoded to the 'text' table storage engine.
 993          *
 994          * @return String
 995          */
 996         protected function loadText() {
 997                 wfProfileIn( __METHOD__ );
 998
 999                 // Caching may be beneficial for massive use of external storage
1000                 global $wgRevisionCacheExpiry, $wgMemc;
1001                 $textId = $this->getTextId();
1002                 $key = wfMemcKey( 'revisiontext', 'textid', $textId );
1003                 if( $wgRevisionCacheExpiry ) {
1004                         $text = $wgMemc->get( $key );
1005                         if( is_string( $text ) ) {
1006                                 wfDebug( __METHOD__ . ": got id $textId from cache\n" );
1007                                 wfProfileOut( __METHOD__ );
1008                                 return $text;
1009                         }
1010                 }
1011
1012                 // If we kept data for lazy extraction, use it now...
1013                 if ( isset( $this->mTextRow ) ) {
1014                         $row = $this->mTextRow;
1015                         $this->mTextRow = null;
1016                 } else {
1017                         $row = null;
1018                 }
1019
1020                 if( !$row ) {
1021                         // Text data is immutable; check slaves first.
1022                         $dbr = wfGetDB( DB_SLAVE );
1023                         $row = $dbr->selectRow( 'text',
1024                                 array( 'old_text', 'old_flags' ),
1025                                 array( 'old_id' => $this->getTextId() ),
1026                                 __METHOD__ );
1027                 }
1028
1029                 if( !$row && wfGetLB()->getServerCount() > 1 ) {
1030                         // Possible slave lag!
1031                         $dbw = wfGetDB( DB_MASTER );
1032                         $row = $dbw->selectRow( 'text',
1033                                 array( 'old_text', 'old_flags' ),
1034                                 array( 'old_id' => $this->getTextId() ),
1035                                 __METHOD__ );
1036                 }
1037
1038                 $text = self::getRevisionText( $row );
1039
1040                 # No negative caching -- negative hits on text rows may be due to corrupted slave servers
1041                 if( $wgRevisionCacheExpiry && $text !== false ) {
1042                         $wgMemc->set( $key, $text, $wgRevisionCacheExpiry );
1043                 }
1044
1045                 wfProfileOut( __METHOD__ );
1046
1047                 return $text;
1048         }
1049
1050         /**
1051          * Create a new null-revision for insertion into a page's
1052          * history. This will not re-save the text, but simply refer
1053          * to the text from the previous version.
1054          *
1055          * Such revisions can for instance identify page rename
1056          * operations and other such meta-modifications.
1057          *
1058          * @param $dbw DatabaseBase
1059          * @param $pageId Integer: ID number of the page to read from
1060          * @param $summary String: revision's summary
1061          * @param $minor Boolean: whether the revision should be considered as minor
1062          * @return Revision|null on error
1063          */
1064         public static function newNullRevision( $dbw, $pageId, $summary, $minor ) {
1065                 wfProfileIn( __METHOD__ );
1066
1067                 $current = $dbw->selectRow(
1068                         array( 'page', 'revision' ),
1069                         array( 'page_latest', 'rev_text_id', 'rev_len' ),
1070                         array(
1071                                 'page_id' => $pageId,
1072                                 'page_latest=rev_id',
1073                                 ),
1074                         __METHOD__ );
1075
1076                 if( $current ) {
1077                         $revision = new Revision( array(
1078                                 'page'       => $pageId,
1079                                 'comment'    => $summary,
1080                                 'minor_edit' => $minor,
1081                                 'text_id'    => $current->rev_text_id,
1082                                 'parent_id'  => $current->page_latest,
1083                                 'len'        => $current->rev_len
1084                                 ) );
1085                 } else {
1086                         $revision = null;
1087                 }
1088
1089                 wfProfileOut( __METHOD__ );
1090                 return $revision;
1091         }
1092
1093         /**
1094          * Determine if the current user is allowed to view a particular
1095          * field of this revision, if it's marked as deleted.
1096          *
1097          * @param $field Integer:one of self::DELETED_TEXT,
1098          *                              self::DELETED_COMMENT,
1099          *                              self::DELETED_USER
1100          * @param $user User object to check, or null to use $wgUser
1101          * @return Boolean
1102          */
1103         public function userCan( $field, User $user = null ) {
1104                 return self::userCanBitfield( $this->mDeleted, $field, $user );
1105         }
1106
1107         /**
1108          * Determine if the current user is allowed to view a particular
1109          * field of this revision, if it's marked as deleted. This is used
1110          * by various classes to avoid duplication.
1111          *
1112          * @param $bitfield Integer: current field
1113          * @param $field Integer: one of self::DELETED_TEXT = File::DELETED_FILE,
1114          *                               self::DELETED_COMMENT = File::DELETED_COMMENT,
1115          *                               self::DELETED_USER = File::DELETED_USER
1116          * @param $user User object to check, or null to use $wgUser
1117          * @return Boolean
1118          */
1119         public static function userCanBitfield( $bitfield, $field, User $user = null ) {
1120                 if( $bitfield & $field ) { // aspect is deleted
1121                         if ( $bitfield & self::DELETED_RESTRICTED ) {
1122                                 $permission = 'suppressrevision';
1123                         } elseif ( $field & self::DELETED_TEXT ) {
1124                                 $permission = 'deletedtext';
1125                         } else {
1126                                 $permission = 'deletedhistory';
1127                         }
1128                         wfDebug( "Checking for $permission due to $field match on $bitfield\n" );
1129                         if ( $user === null ) {
1130                                 global $wgUser;
1131                                 $user = $wgUser;
1132                         }
1133                         return $user->isAllowed( $permission );
1134                 } else {
1135                         return true;
1136                 }
1137         }
1138
1139         /**
1140          * Get rev_timestamp from rev_id, without loading the rest of the row
1141          *
1142          * @param $title Title
1143          * @param $id Integer
1144          * @return String
1145          */
1146         static function getTimestampFromId( $title, $id ) {
1147                 $dbr = wfGetDB( DB_SLAVE );
1148                 // Casting fix for DB2
1149                 if ( $id == '' ) {
1150                         $id = 0;
1151                 }
1152                 $conds = array( 'rev_id' => $id );
1153                 $conds['rev_page'] = $title->getArticleId();
1154                 $timestamp = $dbr->selectField( 'revision', 'rev_timestamp', $conds, __METHOD__ );
1155                 if ( $timestamp === false && wfGetLB()->getServerCount() > 1 ) {
1156                         # Not in slave, try master
1157                         $dbw = wfGetDB( DB_MASTER );
1158                         $timestamp = $dbw->selectField( 'revision', 'rev_timestamp', $conds, __METHOD__ );
1159                 }
1160                 return wfTimestamp( TS_MW, $timestamp );
1161         }
1162
1163         /**
1164          * Get count of revisions per page...not very efficient
1165          *
1166          * @param $db DatabaseBase
1167          * @param $id Integer: page id
1168          * @return Integer
1169          */
1170         static function countByPageId( $db, $id ) {
1171                 $row = $db->selectRow( 'revision', 'COUNT(*) AS revCount',
1172                         array( 'rev_page' => $id ), __METHOD__ );
1173                 if( $row ) {
1174                         return $row->revCount;
1175                 }
1176                 return 0;
1177         }
1178
1179         /**
1180          * Get count of revisions per page...not very efficient
1181          *
1182          * @param $db DatabaseBase
1183          * @param $title Title
1184          * @return Integer
1185          */
1186         static function countByTitle( $db, $title ) {
1187                 $id = $title->getArticleId();
1188                 if( $id ) {
1189                         return Revision::countByPageId( $db, $id );
1190                 }
1191                 return 0;
1192         }
1193 }