includes/Revision.php

   1 <?php
   2 /**
   3  * Representation of a page version.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  */
  22
  23 /**
  24  * @todo document
  25  */
  26 class Revision {
  27         protected $mId;
  28         protected $mPage;
  29         protected $mUserText;
  30         protected $mOrigUserText;
  31         protected $mUser;
  32         protected $mMinorEdit;
  33         protected $mTimestamp;
  34         protected $mDeleted;
  35         protected $mSize;
  36         protected $mSha1;
  37         protected $mParentId;
  38         protected $mComment;
  39         protected $mText;
  40         protected $mTextRow;
  41         protected $mTitle;
  42         protected $mCurrent;
  43
  44         const DELETED_TEXT = 1;
  45         const DELETED_COMMENT = 2;
  46         const DELETED_USER = 4;
  47         const DELETED_RESTRICTED = 8;
  48         // Convenience field
  49         const SUPPRESSED_USER = 12;
  50         // Audience options for Revision::getText()
  51         const FOR_PUBLIC = 1;
  52         const FOR_THIS_USER = 2;
  53         const RAW = 3;
  54
  55         /**
  56          * Load a page revision from a given revision ID number.
  57          * Returns null if no such revision can be found.
  58          *
  59          * @param $id Integer
  60          * @return Revision or null
  61          */
  62         public static function newFromId( $id ) {
  63                 return Revision::newFromConds( array( 'rev_id' => intval( $id ) ) );
  64         }
  65
  66         /**
  67          * Load either the current, or a specified, revision
  68          * that's attached to a given title. If not attached
  69          * to that title, will return null.
  70          *
  71          * @param $title Title
  72          * @param $id Integer (optional)
  73          * @return Revision or null
  74          */
  75         public static function newFromTitle( $title, $id = 0 ) {
  76                 $conds = array(
  77                         'page_namespace' => $title->getNamespace(),
  78                         'page_title'     => $title->getDBkey()
  79                 );
  80                 if ( $id ) {
  81                         // Use the specified ID
  82                         $conds['rev_id'] = $id;
  83                 } elseif ( wfGetLB()->getServerCount() > 1 ) {
  84                         // Get the latest revision ID from the master
  85                         $dbw = wfGetDB( DB_MASTER );
  86                         $latest = $dbw->selectField( 'page', 'page_latest', $conds, __METHOD__ );
  87                         if ( $latest === false ) {
  88                                 return null; // page does not exist
  89                         }
  90                         $conds['rev_id'] = $latest;
  91                 } else {
  92                         // Use a join to get the latest revision
  93                         $conds[] = 'rev_id=page_latest';
  94                 }
  95                 return Revision::newFromConds( $conds );
  96         }
  97
  98         /**
  99          * Load either the current, or a specified, revision
 100          * that's attached to a given page ID.
 101          * Returns null if no such revision can be found.
 102          *
 103          * @param $revId Integer
 104          * @param $pageId Integer (optional)
 105          * @return Revision or null
 106          */
 107         public static function newFromPageId( $pageId, $revId = 0 ) {
 108                 $conds = array( 'page_id' => $pageId );
 109                 if ( $revId ) {
 110                         $conds['rev_id'] = $revId;
 111                 } elseif ( wfGetLB()->getServerCount() > 1 ) {
 112                         // Get the latest revision ID from the master
 113                         $dbw = wfGetDB( DB_MASTER );
 114                         $latest = $dbw->selectField( 'page', 'page_latest', $conds, __METHOD__ );
 115                         if ( $latest === false ) {
 116                                 return null; // page does not exist
 117                         }
 118                         $conds['rev_id'] = $latest;
 119                 } else {
 120                         $conds[] = 'rev_id = page_latest';
 121                 }
 122                 return Revision::newFromConds( $conds );
 123         }
 124
 125         /**
 126          * Make a fake revision object from an archive table row. This is queried
 127          * for permissions or even inserted (as in Special:Undelete)
 128          * @todo FIXME: Should be a subclass for RevisionDelete. [TS]
 129          *
 130          * @param $row
 131          * @param $overrides array
 132          *
 133          * @return Revision
 134          */
 135         public static function newFromArchiveRow( $row, $overrides = array() ) {
 136                 $attribs = $overrides + array(
 137                         'page'       => isset( $row->ar_page_id ) ? $row->ar_page_id : null,
 138                         'id'         => isset( $row->ar_rev_id ) ? $row->ar_rev_id : null,
 139                         'comment'    => $row->ar_comment,
 140                         'user'       => $row->ar_user,
 141                         'user_text'  => $row->ar_user_text,
 142                         'timestamp'  => $row->ar_timestamp,
 143                         'minor_edit' => $row->ar_minor_edit,
 144                         'text_id'    => isset( $row->ar_text_id ) ? $row->ar_text_id : null,
 145                         'deleted'    => $row->ar_deleted,
 146                         'len'        => $row->ar_len,
 147                         'sha1'       => isset( $row->ar_sha1 ) ? $row->ar_sha1 : null,
 148                 );
 149                 if ( isset( $row->ar_text ) && !$row->ar_text_id ) {
 150                         // Pre-1.5 ar_text row
 151                         $attribs['text'] = self::getRevisionText( $row, 'ar_' );
 152                         if ( $attribs['text'] === false ) {
 153                                 throw new MWException( 'Unable to load text from archive row (possibly bug 22624)' );
 154                         }
 155                 }
 156                 return new self( $attribs );
 157         }
 158
 159         /**
 160          * @since 1.19
 161          *
 162          * @param $row
 163          * @return Revision
 164          */
 165         public static function newFromRow( $row ) {
 166                 return new self( $row );
 167         }
 168
 169         /**
 170          * Load a page revision from a given revision ID number.
 171          * Returns null if no such revision can be found.
 172          *
 173          * @param $db DatabaseBase
 174          * @param $id Integer
 175          * @return Revision or null
 176          */
 177         public static function loadFromId( $db, $id ) {
 178                 return Revision::loadFromConds( $db, array( 'rev_id' => intval( $id ) ) );
 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 $pageid Integer
 188          * @param $id Integer
 189          * @return Revision or null
 190          */
 191         public static function loadFromPageId( $db, $pageid, $id = 0 ) {
 192                 $conds = array( 'rev_page' => intval( $pageid ), 'page_id'  => intval( $pageid ) );
 193                 if( $id ) {
 194                         $conds['rev_id'] = intval( $id );
 195                 } else {
 196                         $conds[] = 'rev_id=page_latest';
 197                 }
 198                 return Revision::loadFromConds( $db, $conds );
 199         }
 200
 201         /**
 202          * Load either the current, or a specified, revision
 203          * that's attached to a given page. If not attached
 204          * to that page, will return null.
 205          *
 206          * @param $db DatabaseBase
 207          * @param $title Title
 208          * @param $id Integer
 209          * @return Revision or null
 210          */
 211         public static function loadFromTitle( $db, $title, $id = 0 ) {
 212                 if( $id ) {
 213                         $matchId = intval( $id );
 214                 } else {
 215                         $matchId = 'page_latest';
 216                 }
 217                 return Revision::loadFromConds( $db,
 218                         array( "rev_id=$matchId",
 219                                    'page_namespace' => $title->getNamespace(),
 220                                    'page_title'     => $title->getDBkey() )
 221                 );
 222         }
 223
 224         /**
 225          * Load the revision for the given title with the given timestamp.
 226          * WARNING: Timestamps may in some circumstances not be unique,
 227          * so this isn't the best key to use.
 228          *
 229          * @param $db DatabaseBase
 230          * @param $title Title
 231          * @param $timestamp String
 232          * @return Revision or null
 233          */
 234         public static function loadFromTimestamp( $db, $title, $timestamp ) {
 235                 return Revision::loadFromConds( $db,
 236                         array( 'rev_timestamp'  => $db->timestamp( $timestamp ),
 237                                    'page_namespace' => $title->getNamespace(),
 238                                    'page_title'     => $title->getDBkey() )
 239                 );
 240         }
 241
 242         /**
 243          * Given a set of conditions, fetch a revision.
 244          *
 245          * @param $conditions Array
 246          * @return Revision or null
 247          */
 248         public static function newFromConds( $conditions ) {
 249                 $db = wfGetDB( DB_SLAVE );
 250                 $rev = Revision::loadFromConds( $db, $conditions );
 251                 if( is_null( $rev ) && wfGetLB()->getServerCount() > 1 ) {
 252                         $dbw = wfGetDB( DB_MASTER );
 253                         $rev = Revision::loadFromConds( $dbw, $conditions );
 254                 }
 255                 return $rev;
 256         }
 257
 258         /**
 259          * Given a set of conditions, fetch a revision from
 260          * the given database connection.
 261          *
 262          * @param $db DatabaseBase
 263          * @param $conditions Array
 264          * @return Revision or null
 265          */
 266         private static function loadFromConds( $db, $conditions ) {
 267                 $res = Revision::fetchFromConds( $db, $conditions );
 268                 if( $res ) {
 269                         $row = $res->fetchObject();
 270                         if( $row ) {
 271                                 $ret = new Revision( $row );
 272                                 return $ret;
 273                         }
 274                 }
 275                 $ret = null;
 276                 return $ret;
 277         }
 278
 279         /**
 280          * Return a wrapper for a series of database rows to
 281          * fetch all of a given page's revisions in turn.
 282          * Each row can be fed to the constructor to get objects.
 283          *
 284          * @param $title Title
 285          * @return ResultWrapper
 286          */
 287         public static function fetchRevision( $title ) {
 288                 return Revision::fetchFromConds(
 289                         wfGetDB( DB_SLAVE ),
 290                         array( 'rev_id=page_latest',
 291                                    'page_namespace' => $title->getNamespace(),
 292                                    'page_title'     => $title->getDBkey() )
 293                 );
 294         }
 295
 296         /**
 297          * Given a set of conditions, return a ResultWrapper
 298          * which will return matching database rows with the
 299          * fields necessary to build Revision objects.
 300          *
 301          * @param $db DatabaseBase
 302          * @param $conditions Array
 303          * @return ResultWrapper
 304          */
 305         private static function fetchFromConds( $db, $conditions ) {
 306                 $fields = array_merge(
 307                         self::selectFields(),
 308                         self::selectPageFields(),
 309                         self::selectUserFields()
 310                 );
 311                 return $db->select(
 312                         array( 'revision', 'page', 'user' ),
 313                         $fields,
 314                         $conditions,
 315                         __METHOD__,
 316                         array( 'LIMIT' => 1 ),
 317                         array( 'page' => self::pageJoinCond(), 'user' => self::userJoinCond() )
 318                 );
 319         }
 320
 321         /**
 322          * Return the value of a select() JOIN conds array for the user table.
 323          * This will get user table rows for logged-in users.
 324          * @since 1.19
 325          * @return Array
 326          */
 327         public static function userJoinCond() {
 328                 return array( 'LEFT JOIN', array( 'rev_user != 0', 'user_id = rev_user' ) );
 329         }
 330
 331         /**
 332          * Return the value of a select() page conds array for the paeg table.
 333          * This will assure that the revision(s) are not orphaned from live pages.
 334          * @since 1.19
 335          * @return Array
 336          */
 337         public static function pageJoinCond() {
 338                 return array( 'INNER JOIN', array( 'page_id = rev_page' ) );
 339         }
 340
 341         /**
 342          * Return the list of revision fields that should be selected to create
 343          * a new revision.
 344          * @return array
 345          */
 346         public static function selectFields() {
 347                 return array(
 348                         'rev_id',
 349                         'rev_page',
 350                         'rev_text_id',
 351                         'rev_timestamp',
 352                         'rev_comment',
 353                         'rev_user_text',
 354                         'rev_user',
 355                         'rev_minor_edit',
 356                         'rev_deleted',
 357                         'rev_len',
 358                         'rev_parent_id',
 359                         'rev_sha1'
 360                 );
 361         }
 362
 363         /**
 364          * Return the list of text fields that should be selected to read the
 365          * revision text
 366          * @return array
 367          */
 368         public static function selectTextFields() {
 369                 return array(
 370                         'old_text',
 371                         'old_flags'
 372                 );
 373         }
 374
 375         /**
 376          * Return the list of page fields that should be selected from page table
 377          * @return array
 378          */
 379         public static function selectPageFields() {
 380                 return array(
 381                         'page_namespace',
 382                         'page_title',
 383                         'page_id',
 384                         'page_latest'
 385                 );
 386         }
 387
 388         /**
 389          * Return the list of user fields that should be selected from user table
 390          * @return array
 391          */
 392         public static function selectUserFields() {
 393                 return array( 'user_name' );
 394         }
 395
 396         /**
 397          * Constructor
 398          *
 399          * @param $row Mixed: either a database row or an array
 400          * @access private
 401          */
 402         function __construct( $row ) {
 403                 if( is_object( $row ) ) {
 404                         $this->mId        = intval( $row->rev_id );
 405                         $this->mPage      = intval( $row->rev_page );
 406                         $this->mTextId    = intval( $row->rev_text_id );
 407                         $this->mComment   =         $row->rev_comment;
 408                         $this->mUser      = intval( $row->rev_user );
 409                         $this->mMinorEdit = intval( $row->rev_minor_edit );
 410                         $this->mTimestamp =         $row->rev_timestamp;
 411                         $this->mDeleted   = intval( $row->rev_deleted );
 412
 413                         if( !isset( $row->rev_parent_id ) ) {
 414                                 $this->mParentId = is_null( $row->rev_parent_id ) ? null : 0;
 415                         } else {
 416                                 $this->mParentId  = intval( $row->rev_parent_id );
 417                         }
 418
 419                         if( !isset( $row->rev_len ) || is_null( $row->rev_len ) ) {
 420                                 $this->mSize = null;
 421                         } else {
 422                                 $this->mSize = intval( $row->rev_len );
 423                         }
 424
 425                         if ( !isset( $row->rev_sha1 ) ) {
 426                                 $this->mSha1 = null;
 427                         } else {
 428                                 $this->mSha1 = $row->rev_sha1;
 429                         }
 430
 431                         if( isset( $row->page_latest ) ) {
 432                                 $this->mCurrent = ( $row->rev_id == $row->page_latest );
 433                                 $this->mTitle = Title::newFromRow( $row );
 434                         } else {
 435                                 $this->mCurrent = false;
 436                                 $this->mTitle = null;
 437                         }
 438
 439                         // Lazy extraction...
 440                         $this->mText      = null;
 441                         if( isset( $row->old_text ) ) {
 442                                 $this->mTextRow = $row;
 443                         } else {
 444                                 // 'text' table row entry will be lazy-loaded
 445                                 $this->mTextRow = null;
 446                         }
 447
 448                         // Use user_name for users and rev_user_text for IPs...
 449                         $this->mUserText = null; // lazy load if left null
 450                         if ( $this->mUser == 0 ) {
 451                                 $this->mUserText = $row->rev_user_text; // IP user
 452                         } elseif ( isset( $row->user_name ) ) {
 453                                 $this->mUserText = $row->user_name; // logged-in user
 454                         }
 455                         $this->mOrigUserText = $row->rev_user_text;
 456                 } elseif( is_array( $row ) ) {
 457                         // Build a new revision to be saved...
 458                         global $wgUser; // ugh
 459
 460                         $this->mId        = isset( $row['id']         ) ? intval( $row['id']         ) : null;
 461                         $this->mPage      = isset( $row['page']       ) ? intval( $row['page']       ) : null;
 462                         $this->mTextId    = isset( $row['text_id']    ) ? intval( $row['text_id']    ) : null;
 463                         $this->mUserText  = isset( $row['user_text']  ) ? strval( $row['user_text']  ) : $wgUser->getName();
 464                         $this->mUser      = isset( $row['user']       ) ? intval( $row['user']       ) : $wgUser->getId();
 465                         $this->mMinorEdit = isset( $row['minor_edit'] ) ? intval( $row['minor_edit'] ) : 0;
 466                         $this->mTimestamp = isset( $row['timestamp']  ) ? strval( $row['timestamp']  ) : wfTimestampNow();
 467                         $this->mDeleted   = isset( $row['deleted']    ) ? intval( $row['deleted']    ) : 0;
 468                         $this->mSize      = isset( $row['len']        ) ? intval( $row['len']        ) : null;
 469                         $this->mParentId  = isset( $row['parent_id']  ) ? intval( $row['parent_id']  ) : null;
 470                         $this->mSha1      = isset( $row['sha1']  )      ? strval( $row['sha1']  )      : null;
 471
 472                         // Enforce spacing trimming on supplied text
 473                         $this->mComment   = isset( $row['comment']    ) ?  trim( strval( $row['comment'] ) ) : null;
 474                         $this->mText      = isset( $row['text']       ) ? rtrim( strval( $row['text']    ) ) : null;
 475                         $this->mTextRow   = null;
 476
 477                         $this->mTitle     = null; # Load on demand if needed
 478                         $this->mCurrent   = false;
 479                         # If we still have no length, see it we have the text to figure it out
 480                         if ( !$this->mSize ) {
 481                                 $this->mSize = is_null( $this->mText ) ? null : strlen( $this->mText );
 482                         }
 483                         # Same for sha1
 484                         if ( $this->mSha1 === null ) {
 485                                 $this->mSha1 = is_null( $this->mText ) ? null : self::base36Sha1( $this->mText );
 486                         }
 487                 } else {
 488                         throw new MWException( 'Revision constructor passed invalid row format.' );
 489                 }
 490                 $this->mUnpatrolled = null;
 491         }
 492
 493         /**
 494          * Get revision ID
 495          *
 496          * @return Integer
 497          */
 498         public function getId() {
 499                 return $this->mId;
 500         }
 501
 502         /**
 503          * Set the revision ID
 504          *
 505          * @since 1.19
 506          * @param $id Integer
 507          */
 508         public function setId( $id ) {
 509                 $this->mId = $id;
 510         }
 511
 512         /**
 513          * Get text row ID
 514          *
 515          * @return Integer
 516          */
 517         public function getTextId() {
 518                 return $this->mTextId;
 519         }
 520
 521         /**
 522          * Get parent revision ID (the original previous page revision)
 523          *
 524          * @return Integer|null
 525          */
 526         public function getParentId() {
 527                 return $this->mParentId;
 528         }
 529
 530         /**
 531          * Returns the length of the text in this revision, or null if unknown.
 532          *
 533          * @return Integer
 534          */
 535         public function getSize() {
 536                 return $this->mSize;
 537         }
 538
 539         /**
 540          * Returns the base36 sha1 of the text in this revision, or null if unknown.
 541          *
 542          * @return String
 543          */
 544         public function getSha1() {
 545                 return $this->mSha1;
 546         }
 547
 548         /**
 549          * Returns the title of the page associated with this entry.
 550          *
 551          * @return Title
 552          */
 553         public function getTitle() {
 554                 if( isset( $this->mTitle ) ) {
 555                         return $this->mTitle;
 556                 }
 557                 $dbr = wfGetDB( DB_SLAVE );
 558                 $row = $dbr->selectRow(
 559                         array( 'page', 'revision' ),
 560                         self::selectPageFields(),
 561                         array( 'page_id=rev_page',
 562                                    'rev_id' => $this->mId ),
 563                         __METHOD__ );
 564                 if ( $row ) {
 565                         $this->mTitle = Title::newFromRow( $row );
 566                 }
 567                 return $this->mTitle;
 568         }
 569
 570         /**
 571          * Set the title of the revision
 572          *
 573          * @param $title Title
 574          */
 575         public function setTitle( $title ) {
 576                 $this->mTitle = $title;
 577         }
 578
 579         /**
 580          * Get the page ID
 581          *
 582          * @return Integer
 583          */
 584         public function getPage() {
 585                 return $this->mPage;
 586         }
 587
 588         /**
 589          * Fetch revision's user id if it's available to the specified audience.
 590          * If the specified audience does not have access to it, zero will be
 591          * returned.
 592          *
 593          * @param $audience Integer: one of:
 594          *      Revision::FOR_PUBLIC       to be displayed to all users
 595          *      Revision::FOR_THIS_USER    to be displayed to $wgUser
 596          *      Revision::RAW              get the ID regardless of permissions
 597          * @param $user User object to check for, only if FOR_THIS_USER is passed
 598          *              to the $audience parameter
 599          * @return Integer
 600          */
 601         public function getUser( $audience = self::FOR_PUBLIC, User $user = null ) {
 602                 if( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_USER ) ) {
 603                         return 0;
 604                 } elseif( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_USER, $user ) ) {
 605                         return 0;
 606                 } else {
 607                         return $this->mUser;
 608                 }
 609         }
 610
 611         /**
 612          * Fetch revision's user id without regard for the current user's permissions
 613          *
 614          * @return String
 615          */
 616         public function getRawUser() {
 617                 return $this->mUser;
 618         }
 619
 620         /**
 621          * Fetch revision's username if it's available to the specified audience.
 622          * If the specified audience does not have access to the username, an
 623          * empty string will be returned.
 624          *
 625          * @param $audience Integer: one of:
 626          *      Revision::FOR_PUBLIC       to be displayed to all users
 627          *      Revision::FOR_THIS_USER    to be displayed to $wgUser
 628          *      Revision::RAW              get the text regardless of permissions
 629          * @param $user User object to check for, only if FOR_THIS_USER is passed
 630          *              to the $audience parameter
 631          * @return string
 632          */
 633         public function getUserText( $audience = self::FOR_PUBLIC, User $user = null ) {
 634                 if( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_USER ) ) {
 635                         return '';
 636                 } elseif( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_USER, $user ) ) {
 637                         return '';
 638                 } else {
 639                         return $this->getRawUserText();
 640                 }
 641         }
 642
 643         /**
 644          * Fetch revision's username without regard for view restrictions
 645          *
 646          * @return String
 647          */
 648         public function getRawUserText() {
 649                 if ( $this->mUserText === null ) {
 650                         $this->mUserText = User::whoIs( $this->mUser ); // load on demand
 651                         if ( $this->mUserText === false ) {
 652                                 # This shouldn't happen, but it can if the wiki was recovered
 653                                 # via importing revs and there is no user table entry yet.
 654                                 $this->mUserText = $this->mOrigUserText;
 655                         }
 656                 }
 657                 return $this->mUserText;
 658         }
 659
 660         /**
 661          * Fetch revision comment if it's available to the specified audience.
 662          * If the specified audience does not have access to the comment, an
 663          * empty string will be returned.
 664          *
 665          * @param $audience Integer: one of:
 666          *      Revision::FOR_PUBLIC       to be displayed to all users
 667          *      Revision::FOR_THIS_USER    to be displayed to $wgUser
 668          *      Revision::RAW              get the text regardless of permissions
 669          * @param $user User object to check for, only if FOR_THIS_USER is passed
 670          *              to the $audience parameter
 671          * @return String
 672          */
 673         function getComment( $audience = self::FOR_PUBLIC, User $user = null ) {
 674                 if( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_COMMENT ) ) {
 675                         return '';
 676                 } elseif( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_COMMENT, $user ) ) {
 677                         return '';
 678                 } else {
 679                         return $this->mComment;
 680                 }
 681         }
 682
 683         /**
 684          * Fetch revision comment without regard for the current user's permissions
 685          *
 686          * @return String
 687          */
 688         public function getRawComment() {
 689                 return $this->mComment;
 690         }
 691
 692         /**
 693          * @return Boolean
 694          */
 695         public function isMinor() {
 696                 return (bool)$this->mMinorEdit;
 697         }
 698
 699         /**
 700          * @return Integer rcid of the unpatrolled row, zero if there isn't one
 701          */
 702         public function isUnpatrolled() {
 703                 if( $this->mUnpatrolled !== null ) {
 704                         return $this->mUnpatrolled;
 705                 }
 706                 $dbr = wfGetDB( DB_SLAVE );
 707                 $this->mUnpatrolled = $dbr->selectField( 'recentchanges',
 708                         'rc_id',
 709                         array( // Add redundant user,timestamp condition so we can use the existing index
 710                                 'rc_user_text'  => $this->getRawUserText(),
 711                                 'rc_timestamp'  => $dbr->timestamp( $this->getTimestamp() ),
 712                                 'rc_this_oldid' => $this->getId(),
 713                                 'rc_patrolled'  => 0
 714                         ),
 715                         __METHOD__
 716                 );
 717                 return (int)$this->mUnpatrolled;
 718         }
 719
 720         /**
 721          * @param $field int one of DELETED_* bitfield constants
 722          *
 723          * @return Boolean
 724          */
 725         public function isDeleted( $field ) {
 726                 return ( $this->mDeleted & $field ) == $field;
 727         }
 728
 729         /**
 730          * Get the deletion bitfield of the revision
 731          *
 732          * @return int
 733          */
 734         public function getVisibility() {
 735                 return (int)$this->mDeleted;
 736         }
 737
 738         /**
 739          * Fetch revision text if it's available to the specified audience.
 740          * If the specified audience does not have the ability to view this
 741          * revision, an empty string will be returned.
 742          *
 743          * @param $audience Integer: one of:
 744          *      Revision::FOR_PUBLIC       to be displayed to all users
 745          *      Revision::FOR_THIS_USER    to be displayed to $wgUser
 746          *      Revision::RAW              get the text regardless of permissions
 747          * @param $user User object to check for, only if FOR_THIS_USER is passed
 748          *              to the $audience parameter
 749          * @return String
 750          */
 751         public function getText( $audience = self::FOR_PUBLIC, User $user = null ) {
 752                 if( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_TEXT ) ) {
 753                         return '';
 754                 } elseif( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_TEXT, $user ) ) {
 755                         return '';
 756                 } else {
 757                         return $this->getRawText();
 758                 }
 759         }
 760
 761         /**
 762          * Alias for getText(Revision::FOR_THIS_USER)
 763          *
 764          * @deprecated since 1.17
 765          * @return String
 766          */
 767         public function revText() {
 768                 wfDeprecated( __METHOD__, '1.17' );
 769                 return $this->getText( self::FOR_THIS_USER );
 770         }
 771
 772         /**
 773          * Fetch revision text without regard for view restrictions
 774          *
 775          * @return String
 776          */
 777         public function getRawText() {
 778                 if( is_null( $this->mText ) ) {
 779                         // Revision text is immutable. Load on demand:
 780                         $this->mText = $this->loadText();
 781                 }
 782                 return $this->mText;
 783         }
 784
 785         /**
 786          * @return String
 787          */
 788         public function getTimestamp() {
 789                 return wfTimestamp( TS_MW, $this->mTimestamp );
 790         }
 791
 792         /**
 793          * @return Boolean
 794          */
 795         public function isCurrent() {
 796                 return $this->mCurrent;
 797         }
 798
 799         /**
 800          * Get previous revision for this title
 801          *
 802          * @return Revision or null
 803          */
 804         public function getPrevious() {
 805                 if( $this->getTitle() ) {
 806                         $prev = $this->getTitle()->getPreviousRevisionID( $this->getId() );
 807                         if( $prev ) {
 808                                 return Revision::newFromTitle( $this->getTitle(), $prev );
 809                         }
 810                 }
 811                 return null;
 812         }
 813
 814         /**
 815          * Get next revision for this title
 816          *
 817          * @return Revision or null
 818          */
 819         public function getNext() {
 820                 if( $this->getTitle() ) {
 821                         $next = $this->getTitle()->getNextRevisionID( $this->getId() );
 822                         if ( $next ) {
 823                                 return Revision::newFromTitle( $this->getTitle(), $next );
 824                         }
 825                 }
 826                 return null;
 827         }
 828
 829         /**
 830          * Get previous revision Id for this page_id
 831          * This is used to populate rev_parent_id on save
 832          *
 833          * @param $db DatabaseBase
 834          * @return Integer
 835          */
 836         private function getPreviousRevisionId( $db ) {
 837                 if( is_null( $this->mPage ) ) {
 838                         return 0;
 839                 }
 840                 # Use page_latest if ID is not given
 841                 if( !$this->mId ) {
 842                         $prevId = $db->selectField( 'page', 'page_latest',
 843                                 array( 'page_id' => $this->mPage ),
 844                                 __METHOD__ );
 845                 } else {
 846                         $prevId = $db->selectField( 'revision', 'rev_id',
 847                                 array( 'rev_page' => $this->mPage, 'rev_id < ' . $this->mId ),
 848                                 __METHOD__,
 849                                 array( 'ORDER BY' => 'rev_id DESC' ) );
 850                 }
 851                 return intval( $prevId );
 852         }
 853
 854         /**
 855           * Get revision text associated with an old or archive row
 856           * $row is usually an object from wfFetchRow(), both the flags and the text
 857           * field must be included
 858           *
 859           * @param $row Object: the text data
 860           * @param $prefix String: table prefix (default 'old_')
 861           * @return String: text the text requested or false on failure
 862           */
 863         public static function getRevisionText( $row, $prefix = 'old_' ) {
 864                 wfProfileIn( __METHOD__ );
 865
 866                 # Get data
 867                 $textField = $prefix . 'text';
 868                 $flagsField = $prefix . 'flags';
 869
 870                 if( isset( $row->$flagsField ) ) {
 871                         $flags = explode( ',', $row->$flagsField );
 872                 } else {
 873                         $flags = array();
 874                 }
 875
 876                 if( isset( $row->$textField ) ) {
 877                         $text = $row->$textField;
 878                 } else {
 879                         wfProfileOut( __METHOD__ );
 880                         return false;
 881                 }
 882
 883                 # Use external methods for external objects, text in table is URL-only then
 884                 if ( in_array( 'external', $flags ) ) {
 885                         $url = $text;
 886                         $parts = explode( '://', $url, 2 );
 887                         if( count( $parts ) == 1 || $parts[1] == '' ) {
 888                                 wfProfileOut( __METHOD__ );
 889                                 return false;
 890                         }
 891                         $text = ExternalStore::fetchFromURL( $url );
 892                 }
 893
 894                 // If the text was fetched without an error, convert it
 895                 if ( $text !== false ) {
 896                         if( in_array( 'gzip', $flags ) ) {
 897                                 # Deal with optional compression of archived pages.
 898                                 # This can be done periodically via maintenance/compressOld.php, and
 899                                 # as pages are saved if $wgCompressRevisions is set.
 900                                 $text = gzinflate( $text );
 901                         }
 902
 903                         if( in_array( 'object', $flags ) ) {
 904                                 # Generic compressed storage
 905                                 $obj = unserialize( $text );
 906                                 if ( !is_object( $obj ) ) {
 907                                         // Invalid object
 908                                         wfProfileOut( __METHOD__ );
 909                                         return false;
 910                                 }
 911                                 $text = $obj->getText();
 912                         }
 913
 914                         global $wgLegacyEncoding;
 915                         if( $text !== false && $wgLegacyEncoding
 916                                 && !in_array( 'utf-8', $flags ) && !in_array( 'utf8', $flags ) )
 917                         {
 918                                 # Old revisions kept around in a legacy encoding?
 919                                 # Upconvert on demand.
 920                                 # ("utf8" checked for compatibility with some broken
 921                                 #  conversion scripts 2008-12-30)
 922                                 global $wgContLang;
 923                                 $text = $wgContLang->iconv( $wgLegacyEncoding, 'UTF-8', $text );
 924                         }
 925                 }
 926                 wfProfileOut( __METHOD__ );
 927                 return $text;
 928         }
 929
 930         /**
 931          * If $wgCompressRevisions is enabled, we will compress data.
 932          * The input string is modified in place.
 933          * Return value is the flags field: contains 'gzip' if the
 934          * data is compressed, and 'utf-8' if we're saving in UTF-8
 935          * mode.
 936          *
 937          * @param $text Mixed: reference to a text
 938          * @return String
 939          */
 940         public static function compressRevisionText( &$text ) {
 941                 global $wgCompressRevisions;
 942                 $flags = array();
 943
 944                 # Revisions not marked this way will be converted
 945                 # on load if $wgLegacyCharset is set in the future.
 946                 $flags[] = 'utf-8';
 947
 948                 if( $wgCompressRevisions ) {
 949                         if( function_exists( 'gzdeflate' ) ) {
 950                                 $text = gzdeflate( $text );
 951                                 $flags[] = 'gzip';
 952                         } else {
 953                                 wfDebug( "Revision::compressRevisionText() -- no zlib support, not compressing\n" );
 954                         }
 955                 }
 956                 return implode( ',', $flags );
 957         }
 958
 959         /**
 960          * Insert a new revision into the database, returning the new revision ID
 961          * number on success and dies horribly on failure.
 962          *
 963          * @param $dbw DatabaseBase: (master connection)
 964          * @return Integer
 965          */
 966         public function insertOn( $dbw ) {
 967                 global $wgDefaultExternalStore;
 968
 969                 wfProfileIn( __METHOD__ );
 970
 971                 $data = $this->mText;
 972                 $flags = Revision::compressRevisionText( $data );
 973
 974                 # Write to external storage if required
 975                 if( $wgDefaultExternalStore ) {
 976                         // Store and get the URL
 977                         $data = ExternalStore::insertToDefault( $data );
 978                         if( !$data ) {
 979                                 throw new MWException( "Unable to store text to external storage" );
 980                         }
 981                         if( $flags ) {
 982                                 $flags .= ',';
 983                         }
 984                         $flags .= 'external';
 985                 }
 986
 987                 # Record the text (or external storage URL) to the text table
 988                 if( !isset( $this->mTextId ) ) {
 989                         $old_id = $dbw->nextSequenceValue( 'text_old_id_seq' );
 990                         $dbw->insert( 'text',
 991                                 array(
 992                                         'old_id'    => $old_id,
 993                                         'old_text'  => $data,
 994                                         'old_flags' => $flags,
 995                                 ), __METHOD__
 996                         );
 997                         $this->mTextId = $dbw->insertId();
 998                 }
 999
1000                 if ( $this->mComment === null ) $this->mComment = "";
1001
1002                 # Record the edit in revisions
1003                 $rev_id = isset( $this->mId )
1004                         ? $this->mId
1005                         : $dbw->nextSequenceValue( 'revision_rev_id_seq' );
1006                 $dbw->insert( 'revision',
1007                         array(
1008                                 'rev_id'         => $rev_id,
1009                                 'rev_page'       => $this->mPage,
1010                                 'rev_text_id'    => $this->mTextId,
1011                                 'rev_comment'    => $this->mComment,
1012                                 'rev_minor_edit' => $this->mMinorEdit ? 1 : 0,
1013                                 'rev_user'       => $this->mUser,
1014                                 'rev_user_text'  => $this->mUserText,
1015                                 'rev_timestamp'  => $dbw->timestamp( $this->mTimestamp ),
1016                                 'rev_deleted'    => $this->mDeleted,
1017                                 'rev_len'        => $this->mSize,
1018                                 'rev_parent_id'  => is_null( $this->mParentId )
1019                                         ? $this->getPreviousRevisionId( $dbw )
1020                                         : $this->mParentId,
1021                                 'rev_sha1'       => is_null( $this->mSha1 )
1022                                         ? Revision::base36Sha1( $this->mText )
1023                                         : $this->mSha1
1024                         ), __METHOD__
1025                 );
1026
1027                 $this->mId = !is_null( $rev_id ) ? $rev_id : $dbw->insertId();
1028
1029                 wfRunHooks( 'RevisionInsertComplete', array( &$this, $data, $flags ) );
1030
1031                 wfProfileOut( __METHOD__ );
1032                 return $this->mId;
1033         }
1034
1035         /**
1036          * Get the base 36 SHA-1 value for a string of text
1037          * @param $text String
1038          * @return String
1039          */
1040         public static function base36Sha1( $text ) {
1041                 return wfBaseConvert( sha1( $text ), 16, 36, 31 );
1042         }
1043
1044         /**
1045          * Lazy-load the revision's text.
1046          * Currently hardcoded to the 'text' table storage engine.
1047          *
1048          * @return String
1049          */
1050         protected function loadText() {
1051                 wfProfileIn( __METHOD__ );
1052
1053                 // Caching may be beneficial for massive use of external storage
1054                 global $wgRevisionCacheExpiry, $wgMemc;
1055                 $textId = $this->getTextId();
1056                 $key = wfMemcKey( 'revisiontext', 'textid', $textId );
1057                 if( $wgRevisionCacheExpiry ) {
1058                         $text = $wgMemc->get( $key );
1059                         if( is_string( $text ) ) {
1060                                 wfDebug( __METHOD__ . ": got id $textId from cache\n" );
1061                                 wfProfileOut( __METHOD__ );
1062                                 return $text;
1063                         }
1064                 }
1065
1066                 // If we kept data for lazy extraction, use it now...
1067                 if ( isset( $this->mTextRow ) ) {
1068                         $row = $this->mTextRow;
1069                         $this->mTextRow = null;
1070                 } else {
1071                         $row = null;
1072                 }
1073
1074                 if( !$row ) {
1075                         // Text data is immutable; check slaves first.
1076                         $dbr = wfGetDB( DB_SLAVE );
1077                         $row = $dbr->selectRow( 'text',
1078                                 array( 'old_text', 'old_flags' ),
1079                                 array( 'old_id' => $this->getTextId() ),
1080                                 __METHOD__ );
1081                 }
1082
1083                 if( !$row && wfGetLB()->getServerCount() > 1 ) {
1084                         // Possible slave lag!
1085                         $dbw = wfGetDB( DB_MASTER );
1086                         $row = $dbw->selectRow( 'text',
1087                                 array( 'old_text', 'old_flags' ),
1088                                 array( 'old_id' => $this->getTextId() ),
1089                                 __METHOD__ );
1090                 }
1091
1092                 $text = self::getRevisionText( $row );
1093
1094                 # No negative caching -- negative hits on text rows may be due to corrupted slave servers
1095                 if( $wgRevisionCacheExpiry && $text !== false ) {
1096                         $wgMemc->set( $key, $text, $wgRevisionCacheExpiry );
1097                 }
1098
1099                 wfProfileOut( __METHOD__ );
1100
1101                 return $text;
1102         }
1103
1104         /**
1105          * Create a new null-revision for insertion into a page's
1106          * history. This will not re-save the text, but simply refer
1107          * to the text from the previous version.
1108          *
1109          * Such revisions can for instance identify page rename
1110          * operations and other such meta-modifications.
1111          *
1112          * @param $dbw DatabaseBase
1113          * @param $pageId Integer: ID number of the page to read from
1114          * @param $summary String: revision's summary
1115          * @param $minor Boolean: whether the revision should be considered as minor
1116          * @return Revision|null on error
1117          */
1118         public static function newNullRevision( $dbw, $pageId, $summary, $minor ) {
1119                 wfProfileIn( __METHOD__ );
1120
1121                 $current = $dbw->selectRow(
1122                         array( 'page', 'revision' ),
1123                         array( 'page_latest', 'page_namespace', 'page_title',
1124                                 'rev_text_id', 'rev_len', 'rev_sha1' ),
1125                         array(
1126                                 'page_id' => $pageId,
1127                                 'page_latest=rev_id',
1128                                 ),
1129                         __METHOD__ );
1130
1131                 if( $current ) {
1132                         $revision = new Revision( array(
1133                                 'page'       => $pageId,
1134                                 'comment'    => $summary,
1135                                 'minor_edit' => $minor,
1136                                 'text_id'    => $current->rev_text_id,
1137                                 'parent_id'  => $current->page_latest,
1138                                 'len'        => $current->rev_len,
1139                                 'sha1'       => $current->rev_sha1
1140                                 ) );
1141                         $revision->setTitle( Title::makeTitle( $current->page_namespace, $current->page_title ) );
1142                 } else {
1143                         $revision = null;
1144                 }
1145
1146                 wfProfileOut( __METHOD__ );
1147                 return $revision;
1148         }
1149
1150         /**
1151          * Determine if the current user is allowed to view a particular
1152          * field of this revision, if it's marked as deleted.
1153          *
1154          * @param $field Integer:one of self::DELETED_TEXT,
1155          *                              self::DELETED_COMMENT,
1156          *                              self::DELETED_USER
1157          * @param $user User object to check, or null to use $wgUser
1158          * @return Boolean
1159          */
1160         public function userCan( $field, User $user = null ) {
1161                 return self::userCanBitfield( $this->mDeleted, $field, $user );
1162         }
1163
1164         /**
1165          * Determine if the current user is allowed to view a particular
1166          * field of this revision, if it's marked as deleted. This is used
1167          * by various classes to avoid duplication.
1168          *
1169          * @param $bitfield Integer: current field
1170          * @param $field Integer: one of self::DELETED_TEXT = File::DELETED_FILE,
1171          *                               self::DELETED_COMMENT = File::DELETED_COMMENT,
1172          *                               self::DELETED_USER = File::DELETED_USER
1173          * @param $user User object to check, or null to use $wgUser
1174          * @return Boolean
1175          */
1176         public static function userCanBitfield( $bitfield, $field, User $user = null ) {
1177                 if( $bitfield & $field ) { // aspect is deleted
1178                         if ( $bitfield & self::DELETED_RESTRICTED ) {
1179                                 $permission = 'suppressrevision';
1180                         } elseif ( $field & self::DELETED_TEXT ) {
1181                                 $permission = 'deletedtext';
1182                         } else {
1183                                 $permission = 'deletedhistory';
1184                         }
1185                         wfDebug( "Checking for $permission due to $field match on $bitfield\n" );
1186                         if ( $user === null ) {
1187                                 global $wgUser;
1188                                 $user = $wgUser;
1189                         }
1190                         return $user->isAllowed( $permission );
1191                 } else {
1192                         return true;
1193                 }
1194         }
1195
1196         /**
1197          * Get rev_timestamp from rev_id, without loading the rest of the row
1198          *
1199          * @param $title Title
1200          * @param $id Integer
1201          * @return String
1202          */
1203         static function getTimestampFromId( $title, $id ) {
1204                 $dbr = wfGetDB( DB_SLAVE );
1205                 // Casting fix for DB2
1206                 if ( $id == '' ) {
1207                         $id = 0;
1208                 }
1209                 $conds = array( 'rev_id' => $id );
1210                 $conds['rev_page'] = $title->getArticleID();
1211                 $timestamp = $dbr->selectField( 'revision', 'rev_timestamp', $conds, __METHOD__ );
1212                 if ( $timestamp === false && wfGetLB()->getServerCount() > 1 ) {
1213                         # Not in slave, try master
1214                         $dbw = wfGetDB( DB_MASTER );
1215                         $timestamp = $dbw->selectField( 'revision', 'rev_timestamp', $conds, __METHOD__ );
1216                 }
1217                 return wfTimestamp( TS_MW, $timestamp );
1218         }
1219
1220         /**
1221          * Get count of revisions per page...not very efficient
1222          *
1223          * @param $db DatabaseBase
1224          * @param $id Integer: page id
1225          * @return Integer
1226          */
1227         static function countByPageId( $db, $id ) {
1228                 $row = $db->selectRow( 'revision', 'COUNT(*) AS revCount',
1229                         array( 'rev_page' => $id ), __METHOD__ );
1230                 if( $row ) {
1231                         return $row->revCount;
1232                 }
1233                 return 0;
1234         }
1235
1236         /**
1237          * Get count of revisions per page...not very efficient
1238          *
1239          * @param $db DatabaseBase
1240          * @param $title Title
1241          * @return Integer
1242          */
1243         static function countByTitle( $db, $title ) {
1244                 $id = $title->getArticleID();
1245                 if( $id ) {
1246                         return Revision::countByPageId( $db, $id );
1247                 }
1248                 return 0;
1249         }
1250 }