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