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|null
 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|null
 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|null
 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|null
 543          */
 544         public function getSha1() {
 545                 return $this->mSha1;
 546         }
 547
 548         /**
 549          * Returns the title of the page associated with this entry or null.
 550          *
 551          * Will do a query, when title is not set and id is given.
 552          *
 553          * @return Title|null
 554          */
 555         public function getTitle() {
 556                 if( isset( $this->mTitle ) ) {
 557                         return $this->mTitle;
 558                 }
 559                 if( !is_null( $this->mId ) ) { //rev_id is defined as NOT NULL
 560                         $dbr = wfGetDB( DB_SLAVE );
 561                         $row = $dbr->selectRow(
 562                                 array( 'page', 'revision' ),
 563                                 self::selectPageFields(),
 564                                 array( 'page_id=rev_page',
 565                                            'rev_id' => $this->mId ),
 566                                 __METHOD__ );
 567                         if ( $row ) {
 568                                 $this->mTitle = Title::newFromRow( $row );
 569                         }
 570                 }
 571                 return $this->mTitle;
 572         }
 573
 574         /**
 575          * Set the title of the revision
 576          *
 577          * @param $title Title
 578          */
 579         public function setTitle( $title ) {
 580                 $this->mTitle = $title;
 581         }
 582
 583         /**
 584          * Get the page ID
 585          *
 586          * @return Integer|null
 587          */
 588         public function getPage() {
 589                 return $this->mPage;
 590         }
 591
 592         /**
 593          * Fetch revision's user id if it's available to the specified audience.
 594          * If the specified audience does not have access to it, zero will be
 595          * returned.
 596          *
 597          * @param $audience Integer: one of:
 598          *      Revision::FOR_PUBLIC       to be displayed to all users
 599          *      Revision::FOR_THIS_USER    to be displayed to $wgUser
 600          *      Revision::RAW              get the ID regardless of permissions
 601          * @param $user User object to check for, only if FOR_THIS_USER is passed
 602          *              to the $audience parameter
 603          * @return Integer
 604          */
 605         public function getUser( $audience = self::FOR_PUBLIC, User $user = null ) {
 606                 if( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_USER ) ) {
 607                         return 0;
 608                 } elseif( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_USER, $user ) ) {
 609                         return 0;
 610                 } else {
 611                         return $this->mUser;
 612                 }
 613         }
 614
 615         /**
 616          * Fetch revision's user id without regard for the current user's permissions
 617          *
 618          * @return String
 619          */
 620         public function getRawUser() {
 621                 return $this->mUser;
 622         }
 623
 624         /**
 625          * Fetch revision's username if it's available to the specified audience.
 626          * If the specified audience does not have access to the username, an
 627          * empty string will be returned.
 628          *
 629          * @param $audience Integer: one of:
 630          *      Revision::FOR_PUBLIC       to be displayed to all users
 631          *      Revision::FOR_THIS_USER    to be displayed to $wgUser
 632          *      Revision::RAW              get the text regardless of permissions
 633          * @param $user User object to check for, only if FOR_THIS_USER is passed
 634          *              to the $audience parameter
 635          * @return string
 636          */
 637         public function getUserText( $audience = self::FOR_PUBLIC, User $user = null ) {
 638                 if( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_USER ) ) {
 639                         return '';
 640                 } elseif( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_USER, $user ) ) {
 641                         return '';
 642                 } else {
 643                         return $this->getRawUserText();
 644                 }
 645         }
 646
 647         /**
 648          * Fetch revision's username without regard for view restrictions
 649          *
 650          * @return String
 651          */
 652         public function getRawUserText() {
 653                 if ( $this->mUserText === null ) {
 654                         $this->mUserText = User::whoIs( $this->mUser ); // load on demand
 655                         if ( $this->mUserText === false ) {
 656                                 # This shouldn't happen, but it can if the wiki was recovered
 657                                 # via importing revs and there is no user table entry yet.
 658                                 $this->mUserText = $this->mOrigUserText;
 659                         }
 660                 }
 661                 return $this->mUserText;
 662         }
 663
 664         /**
 665          * Fetch revision comment if it's available to the specified audience.
 666          * If the specified audience does not have access to the comment, an
 667          * empty string will be returned.
 668          *
 669          * @param $audience Integer: one of:
 670          *      Revision::FOR_PUBLIC       to be displayed to all users
 671          *      Revision::FOR_THIS_USER    to be displayed to $wgUser
 672          *      Revision::RAW              get the text regardless of permissions
 673          * @param $user User object to check for, only if FOR_THIS_USER is passed
 674          *              to the $audience parameter
 675          * @return String
 676          */
 677         function getComment( $audience = self::FOR_PUBLIC, User $user = null ) {
 678                 if( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_COMMENT ) ) {
 679                         return '';
 680                 } elseif( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_COMMENT, $user ) ) {
 681                         return '';
 682                 } else {
 683                         return $this->mComment;
 684                 }
 685         }
 686
 687         /**
 688          * Fetch revision comment without regard for the current user's permissions
 689          *
 690          * @return String
 691          */
 692         public function getRawComment() {
 693                 return $this->mComment;
 694         }
 695
 696         /**
 697          * @return Boolean
 698          */
 699         public function isMinor() {
 700                 return (bool)$this->mMinorEdit;
 701         }
 702
 703         /**
 704          * @return Integer rcid of the unpatrolled row, zero if there isn't one
 705          */
 706         public function isUnpatrolled() {
 707                 if( $this->mUnpatrolled !== null ) {
 708                         return $this->mUnpatrolled;
 709                 }
 710                 $dbr = wfGetDB( DB_SLAVE );
 711                 $this->mUnpatrolled = $dbr->selectField( 'recentchanges',
 712                         'rc_id',
 713                         array( // Add redundant user,timestamp condition so we can use the existing index
 714                                 'rc_user_text'  => $this->getRawUserText(),
 715                                 'rc_timestamp'  => $dbr->timestamp( $this->getTimestamp() ),
 716                                 'rc_this_oldid' => $this->getId(),
 717                                 'rc_patrolled'  => 0
 718                         ),
 719                         __METHOD__
 720                 );
 721                 return (int)$this->mUnpatrolled;
 722         }
 723
 724         /**
 725          * @param $field int one of DELETED_* bitfield constants
 726          *
 727          * @return Boolean
 728          */
 729         public function isDeleted( $field ) {
 730                 return ( $this->mDeleted & $field ) == $field;
 731         }
 732
 733         /**
 734          * Get the deletion bitfield of the revision
 735          *
 736          * @return int
 737          */
 738         public function getVisibility() {
 739                 return (int)$this->mDeleted;
 740         }
 741
 742         /**
 743          * Fetch revision text if it's available to the specified audience.
 744          * If the specified audience does not have the ability to view this
 745          * revision, an empty string will be returned.
 746          *
 747          * @param $audience Integer: one of:
 748          *      Revision::FOR_PUBLIC       to be displayed to all users
 749          *      Revision::FOR_THIS_USER    to be displayed to $wgUser
 750          *      Revision::RAW              get the text regardless of permissions
 751          * @param $user User object to check for, only if FOR_THIS_USER is passed
 752          *              to the $audience parameter
 753          * @return String
 754          */
 755         public function getText( $audience = self::FOR_PUBLIC, User $user = null ) {
 756                 if( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_TEXT ) ) {
 757                         return '';
 758                 } elseif( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_TEXT, $user ) ) {
 759                         return '';
 760                 } else {
 761                         return $this->getRawText();
 762                 }
 763         }
 764
 765         /**
 766          * Alias for getText(Revision::FOR_THIS_USER)
 767          *
 768          * @deprecated since 1.17
 769          * @return String
 770          */
 771         public function revText() {
 772                 wfDeprecated( __METHOD__, '1.17' );
 773                 return $this->getText( self::FOR_THIS_USER );
 774         }
 775
 776         /**
 777          * Fetch revision text without regard for view restrictions
 778          *
 779          * @return String
 780          */
 781         public function getRawText() {
 782                 if( is_null( $this->mText ) ) {
 783                         // Revision text is immutable. Load on demand:
 784                         $this->mText = $this->loadText();
 785                 }
 786                 return $this->mText;
 787         }
 788
 789         /**
 790          * @return String
 791          */
 792         public function getTimestamp() {
 793                 return wfTimestamp( TS_MW, $this->mTimestamp );
 794         }
 795
 796         /**
 797          * @return Boolean
 798          */
 799         public function isCurrent() {
 800                 return $this->mCurrent;
 801         }
 802
 803         /**
 804          * Get previous revision for this title
 805          *
 806          * @return Revision or null
 807          */
 808         public function getPrevious() {
 809                 if( $this->getTitle() ) {
 810                         $prev = $this->getTitle()->getPreviousRevisionID( $this->getId() );
 811                         if( $prev ) {
 812                                 return Revision::newFromTitle( $this->getTitle(), $prev );
 813                         }
 814                 }
 815                 return null;
 816         }
 817
 818         /**
 819          * Get next revision for this title
 820          *
 821          * @return Revision or null
 822          */
 823         public function getNext() {
 824                 if( $this->getTitle() ) {
 825                         $next = $this->getTitle()->getNextRevisionID( $this->getId() );
 826                         if ( $next ) {
 827                                 return Revision::newFromTitle( $this->getTitle(), $next );
 828                         }
 829                 }
 830                 return null;
 831         }
 832
 833         /**
 834          * Get previous revision Id for this page_id
 835          * This is used to populate rev_parent_id on save
 836          *
 837          * @param $db DatabaseBase
 838          * @return Integer
 839          */
 840         private function getPreviousRevisionId( $db ) {
 841                 if( is_null( $this->mPage ) ) {
 842                         return 0;
 843                 }
 844                 # Use page_latest if ID is not given
 845                 if( !$this->mId ) {
 846                         $prevId = $db->selectField( 'page', 'page_latest',
 847                                 array( 'page_id' => $this->mPage ),
 848                                 __METHOD__ );
 849                 } else {
 850                         $prevId = $db->selectField( 'revision', 'rev_id',
 851                                 array( 'rev_page' => $this->mPage, 'rev_id < ' . $this->mId ),
 852                                 __METHOD__,
 853                                 array( 'ORDER BY' => 'rev_id DESC' ) );
 854                 }
 855                 return intval( $prevId );
 856         }
 857
 858         /**
 859           * Get revision text associated with an old or archive row
 860           * $row is usually an object from wfFetchRow(), both the flags and the text
 861           * field must be included
 862           *
 863           * @param $row Object: the text data
 864           * @param $prefix String: table prefix (default 'old_')
 865           * @return String: text the text requested or false on failure
 866           */
 867         public static function getRevisionText( $row, $prefix = 'old_' ) {
 868                 wfProfileIn( __METHOD__ );
 869
 870                 # Get data
 871                 $textField = $prefix . 'text';
 872                 $flagsField = $prefix . 'flags';
 873
 874                 if( isset( $row->$flagsField ) ) {
 875                         $flags = explode( ',', $row->$flagsField );
 876                 } else {
 877                         $flags = array();
 878                 }
 879
 880                 if( isset( $row->$textField ) ) {
 881                         $text = $row->$textField;
 882                 } else {
 883                         wfProfileOut( __METHOD__ );
 884                         return false;
 885                 }
 886
 887                 # Use external methods for external objects, text in table is URL-only then
 888                 if ( in_array( 'external', $flags ) ) {
 889                         $url = $text;
 890                         $parts = explode( '://', $url, 2 );
 891                         if( count( $parts ) == 1 || $parts[1] == '' ) {
 892                                 wfProfileOut( __METHOD__ );
 893                                 return false;
 894                         }
 895                         $text = ExternalStore::fetchFromURL( $url );
 896                 }
 897
 898                 // If the text was fetched without an error, convert it
 899                 if ( $text !== false ) {
 900                         if( in_array( 'gzip', $flags ) ) {
 901                                 # Deal with optional compression of archived pages.
 902                                 # This can be done periodically via maintenance/compressOld.php, and
 903                                 # as pages are saved if $wgCompressRevisions is set.
 904                                 $text = gzinflate( $text );
 905                         }
 906
 907                         if( in_array( 'object', $flags ) ) {
 908                                 # Generic compressed storage
 909                                 $obj = unserialize( $text );
 910                                 if ( !is_object( $obj ) ) {
 911                                         // Invalid object
 912                                         wfProfileOut( __METHOD__ );
 913                                         return false;
 914                                 }
 915                                 $text = $obj->getText();
 916                         }
 917
 918                         global $wgLegacyEncoding;
 919                         if( $text !== false && $wgLegacyEncoding
 920                                 && !in_array( 'utf-8', $flags ) && !in_array( 'utf8', $flags ) )
 921                         {
 922                                 # Old revisions kept around in a legacy encoding?
 923                                 # Upconvert on demand.
 924                                 # ("utf8" checked for compatibility with some broken
 925                                 #  conversion scripts 2008-12-30)
 926                                 global $wgContLang;
 927                                 $text = $wgContLang->iconv( $wgLegacyEncoding, 'UTF-8', $text );
 928                         }
 929                 }
 930                 wfProfileOut( __METHOD__ );
 931                 return $text;
 932         }
 933
 934         /**
 935          * If $wgCompressRevisions is enabled, we will compress data.
 936          * The input string is modified in place.
 937          * Return value is the flags field: contains 'gzip' if the
 938          * data is compressed, and 'utf-8' if we're saving in UTF-8
 939          * mode.
 940          *
 941          * @param $text Mixed: reference to a text
 942          * @return String
 943          */
 944         public static function compressRevisionText( &$text ) {
 945                 global $wgCompressRevisions;
 946                 $flags = array();
 947
 948                 # Revisions not marked this way will be converted
 949                 # on load if $wgLegacyCharset is set in the future.
 950                 $flags[] = 'utf-8';
 951
 952                 if( $wgCompressRevisions ) {
 953                         if( function_exists( 'gzdeflate' ) ) {
 954                                 $text = gzdeflate( $text );
 955                                 $flags[] = 'gzip';
 956                         } else {
 957                                 wfDebug( "Revision::compressRevisionText() -- no zlib support, not compressing\n" );
 958                         }
 959                 }
 960                 return implode( ',', $flags );
 961         }
 962
 963         /**
 964          * Insert a new revision into the database, returning the new revision ID
 965          * number on success and dies horribly on failure.
 966          *
 967          * @param $dbw DatabaseBase: (master connection)
 968          * @return Integer
 969          */
 970         public function insertOn( $dbw ) {
 971                 global $wgDefaultExternalStore;
 972
 973                 wfProfileIn( __METHOD__ );
 974
 975                 $data = $this->mText;
 976                 $flags = Revision::compressRevisionText( $data );
 977
 978                 # Write to external storage if required
 979                 if( $wgDefaultExternalStore ) {
 980                         // Store and get the URL
 981                         $data = ExternalStore::insertToDefault( $data );
 982                         if( !$data ) {
 983                                 throw new MWException( "Unable to store text to external storage" );
 984                         }
 985                         if( $flags ) {
 986                                 $flags .= ',';
 987                         }
 988                         $flags .= 'external';
 989                 }
 990
 991                 # Record the text (or external storage URL) to the text table
 992                 if( !isset( $this->mTextId ) ) {
 993                         $old_id = $dbw->nextSequenceValue( 'text_old_id_seq' );
 994                         $dbw->insert( 'text',
 995                                 array(
 996                                         'old_id'    => $old_id,
 997                                         'old_text'  => $data,
 998                                         'old_flags' => $flags,
 999                                 ), __METHOD__
1000                         );
1001                         $this->mTextId = $dbw->insertId();
1002                 }
1003
1004                 if ( $this->mComment === null ) $this->mComment = "";
1005
1006                 # Record the edit in revisions
1007                 $rev_id = isset( $this->mId )
1008                         ? $this->mId
1009                         : $dbw->nextSequenceValue( 'revision_rev_id_seq' );
1010                 $dbw->insert( 'revision',
1011                         array(
1012                                 'rev_id'         => $rev_id,
1013                                 'rev_page'       => $this->mPage,
1014                                 'rev_text_id'    => $this->mTextId,
1015                                 'rev_comment'    => $this->mComment,
1016                                 'rev_minor_edit' => $this->mMinorEdit ? 1 : 0,
1017                                 'rev_user'       => $this->mUser,
1018                                 'rev_user_text'  => $this->mUserText,
1019                                 'rev_timestamp'  => $dbw->timestamp( $this->mTimestamp ),
1020                                 'rev_deleted'    => $this->mDeleted,
1021                                 'rev_len'        => $this->mSize,
1022                                 'rev_parent_id'  => is_null( $this->mParentId )
1023                                         ? $this->getPreviousRevisionId( $dbw )
1024                                         : $this->mParentId,
1025                                 'rev_sha1'       => is_null( $this->mSha1 )
1026                                         ? Revision::base36Sha1( $this->mText )
1027                                         : $this->mSha1
1028                         ), __METHOD__
1029                 );
1030
1031                 $this->mId = !is_null( $rev_id ) ? $rev_id : $dbw->insertId();
1032
1033                 wfRunHooks( 'RevisionInsertComplete', array( &$this, $data, $flags ) );
1034
1035                 wfProfileOut( __METHOD__ );
1036                 return $this->mId;
1037         }
1038
1039         /**
1040          * Get the base 36 SHA-1 value for a string of text
1041          * @param $text String
1042          * @return String
1043          */
1044         public static function base36Sha1( $text ) {
1045                 return wfBaseConvert( sha1( $text ), 16, 36, 31 );
1046         }
1047
1048         /**
1049          * Lazy-load the revision's text.
1050          * Currently hardcoded to the 'text' table storage engine.
1051          *
1052          * @return String
1053          */
1054         protected function loadText() {
1055                 wfProfileIn( __METHOD__ );
1056
1057                 // Caching may be beneficial for massive use of external storage
1058                 global $wgRevisionCacheExpiry, $wgMemc;
1059                 $textId = $this->getTextId();
1060                 $key = wfMemcKey( 'revisiontext', 'textid', $textId );
1061                 if( $wgRevisionCacheExpiry ) {
1062                         $text = $wgMemc->get( $key );
1063                         if( is_string( $text ) ) {
1064                                 wfDebug( __METHOD__ . ": got id $textId from cache\n" );
1065                                 wfProfileOut( __METHOD__ );
1066                                 return $text;
1067                         }
1068                 }
1069
1070                 // If we kept data for lazy extraction, use it now...
1071                 if ( isset( $this->mTextRow ) ) {
1072                         $row = $this->mTextRow;
1073                         $this->mTextRow = null;
1074                 } else {
1075                         $row = null;
1076                 }
1077
1078                 if( !$row ) {
1079                         // Text data is immutable; check slaves first.
1080                         $dbr = wfGetDB( DB_SLAVE );
1081                         $row = $dbr->selectRow( 'text',
1082                                 array( 'old_text', 'old_flags' ),
1083                                 array( 'old_id' => $this->getTextId() ),
1084                                 __METHOD__ );
1085                 }
1086
1087                 if( !$row && wfGetLB()->getServerCount() > 1 ) {
1088                         // Possible slave lag!
1089                         $dbw = wfGetDB( DB_MASTER );
1090                         $row = $dbw->selectRow( 'text',
1091                                 array( 'old_text', 'old_flags' ),
1092                                 array( 'old_id' => $this->getTextId() ),
1093                                 __METHOD__ );
1094                 }
1095
1096                 $text = self::getRevisionText( $row );
1097
1098                 # No negative caching -- negative hits on text rows may be due to corrupted slave servers
1099                 if( $wgRevisionCacheExpiry && $text !== false ) {
1100                         $wgMemc->set( $key, $text, $wgRevisionCacheExpiry );
1101                 }
1102
1103                 wfProfileOut( __METHOD__ );
1104
1105                 return $text;
1106         }
1107
1108         /**
1109          * Create a new null-revision for insertion into a page's
1110          * history. This will not re-save the text, but simply refer
1111          * to the text from the previous version.
1112          *
1113          * Such revisions can for instance identify page rename
1114          * operations and other such meta-modifications.
1115          *
1116          * @param $dbw DatabaseBase
1117          * @param $pageId Integer: ID number of the page to read from
1118          * @param $summary String: revision's summary
1119          * @param $minor Boolean: whether the revision should be considered as minor
1120          * @return Revision|null on error
1121          */
1122         public static function newNullRevision( $dbw, $pageId, $summary, $minor ) {
1123                 wfProfileIn( __METHOD__ );
1124
1125                 $current = $dbw->selectRow(
1126                         array( 'page', 'revision' ),
1127                         array( 'page_latest', 'rev_text_id', 'rev_len', 'rev_sha1' ),
1128                         array(
1129                                 'page_id' => $pageId,
1130                                 'page_latest=rev_id',
1131                                 ),
1132                         __METHOD__ );
1133
1134                 if( $current ) {
1135                         $revision = new Revision( array(
1136                                 'page'       => $pageId,
1137                                 'comment'    => $summary,
1138                                 'minor_edit' => $minor,
1139                                 'text_id'    => $current->rev_text_id,
1140                                 'parent_id'  => $current->page_latest,
1141                                 'len'        => $current->rev_len,
1142                                 'sha1'       => $current->rev_sha1
1143                                 ) );
1144                 } else {
1145                         $revision = null;
1146                 }
1147
1148                 wfProfileOut( __METHOD__ );
1149                 return $revision;
1150         }
1151
1152         /**
1153          * Determine if the current user is allowed to view a particular
1154          * field of this revision, if it's marked as deleted.
1155          *
1156          * @param $field Integer:one of self::DELETED_TEXT,
1157          *                              self::DELETED_COMMENT,
1158          *                              self::DELETED_USER
1159          * @param $user User object to check, or null to use $wgUser
1160          * @return Boolean
1161          */
1162         public function userCan( $field, User $user = null ) {
1163                 return self::userCanBitfield( $this->mDeleted, $field, $user );
1164         }
1165
1166         /**
1167          * Determine if the current user is allowed to view a particular
1168          * field of this revision, if it's marked as deleted. This is used
1169          * by various classes to avoid duplication.
1170          *
1171          * @param $bitfield Integer: current field
1172          * @param $field Integer: one of self::DELETED_TEXT = File::DELETED_FILE,
1173          *                               self::DELETED_COMMENT = File::DELETED_COMMENT,
1174          *                               self::DELETED_USER = File::DELETED_USER
1175          * @param $user User object to check, or null to use $wgUser
1176          * @return Boolean
1177          */
1178         public static function userCanBitfield( $bitfield, $field, User $user = null ) {
1179                 if( $bitfield & $field ) { // aspect is deleted
1180                         if ( $bitfield & self::DELETED_RESTRICTED ) {
1181                                 $permission = 'suppressrevision';
1182                         } elseif ( $field & self::DELETED_TEXT ) {
1183                                 $permission = 'deletedtext';
1184                         } else {
1185                                 $permission = 'deletedhistory';
1186                         }
1187                         wfDebug( "Checking for $permission due to $field match on $bitfield\n" );
1188                         if ( $user === null ) {
1189                                 global $wgUser;
1190                                 $user = $wgUser;
1191                         }
1192                         return $user->isAllowed( $permission );
1193                 } else {
1194                         return true;
1195                 }
1196         }
1197
1198         /**
1199          * Get rev_timestamp from rev_id, without loading the rest of the row
1200          *
1201          * @param $title Title
1202          * @param $id Integer
1203          * @return String
1204          */
1205         static function getTimestampFromId( $title, $id ) {
1206                 $dbr = wfGetDB( DB_SLAVE );
1207                 // Casting fix for DB2
1208                 if ( $id == '' ) {
1209                         $id = 0;
1210                 }
1211                 $conds = array( 'rev_id' => $id );
1212                 $conds['rev_page'] = $title->getArticleID();
1213                 $timestamp = $dbr->selectField( 'revision', 'rev_timestamp', $conds, __METHOD__ );
1214                 if ( $timestamp === false && wfGetLB()->getServerCount() > 1 ) {
1215                         # Not in slave, try master
1216                         $dbw = wfGetDB( DB_MASTER );
1217                         $timestamp = $dbw->selectField( 'revision', 'rev_timestamp', $conds, __METHOD__ );
1218                 }
1219                 return wfTimestamp( TS_MW, $timestamp );
1220         }
1221
1222         /**
1223          * Get count of revisions per page...not very efficient
1224          *
1225          * @param $db DatabaseBase
1226          * @param $id Integer: page id
1227          * @return Integer
1228          */
1229         static function countByPageId( $db, $id ) {
1230                 $row = $db->selectRow( 'revision', 'COUNT(*) AS revCount',
1231                         array( 'rev_page' => $id ), __METHOD__ );
1232                 if( $row ) {
1233                         return $row->revCount;
1234                 }
1235                 return 0;
1236         }
1237
1238         /**
1239          * Get count of revisions per page...not very efficient
1240          *
1241          * @param $db DatabaseBase
1242          * @param $title Title
1243          * @return Integer
1244          */
1245         static function countByTitle( $db, $title ) {
1246                 $id = $title->getArticleID();
1247                 if( $id ) {
1248                         return Revision::countByPageId( $db, $id );
1249                 }
1250                 return 0;
1251         }
1252 }