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                         'page_is_redirect',
 386                         'page_len',
 387                 );
 388         }
 389
 390         /**
 391          * Return the list of user fields that should be selected from user table
 392          * @return array
 393          */
 394         public static function selectUserFields() {
 395                 return array( 'user_name' );
 396         }
 397
 398         /**
 399          * Constructor
 400          *
 401          * @param $row Mixed: either a database row or an array
 402          * @access private
 403          */
 404         function __construct( $row ) {
 405                 if( is_object( $row ) ) {
 406                         $this->mId        = intval( $row->rev_id );
 407                         $this->mPage      = intval( $row->rev_page );
 408                         $this->mTextId    = intval( $row->rev_text_id );
 409                         $this->mComment   =         $row->rev_comment;
 410                         $this->mUser      = intval( $row->rev_user );
 411                         $this->mMinorEdit = intval( $row->rev_minor_edit );
 412                         $this->mTimestamp =         $row->rev_timestamp;
 413                         $this->mDeleted   = intval( $row->rev_deleted );
 414
 415                         if( !isset( $row->rev_parent_id ) ) {
 416                                 $this->mParentId = is_null( $row->rev_parent_id ) ? null : 0;
 417                         } else {
 418                                 $this->mParentId  = intval( $row->rev_parent_id );
 419                         }
 420
 421                         if( !isset( $row->rev_len ) || is_null( $row->rev_len ) ) {
 422                                 $this->mSize = null;
 423                         } else {
 424                                 $this->mSize = intval( $row->rev_len );
 425                         }
 426
 427                         if ( !isset( $row->rev_sha1 ) ) {
 428                                 $this->mSha1 = null;
 429                         } else {
 430                                 $this->mSha1 = $row->rev_sha1;
 431                         }
 432
 433                         if( isset( $row->page_latest ) ) {
 434                                 $this->mCurrent = ( $row->rev_id == $row->page_latest );
 435                                 $this->mTitle = Title::newFromRow( $row );
 436                         } else {
 437                                 $this->mCurrent = false;
 438                                 $this->mTitle = null;
 439                         }
 440
 441                         // Lazy extraction...
 442                         $this->mText      = null;
 443                         if( isset( $row->old_text ) ) {
 444                                 $this->mTextRow = $row;
 445                         } else {
 446                                 // 'text' table row entry will be lazy-loaded
 447                                 $this->mTextRow = null;
 448                         }
 449
 450                         // Use user_name for users and rev_user_text for IPs...
 451                         $this->mUserText = null; // lazy load if left null
 452                         if ( $this->mUser == 0 ) {
 453                                 $this->mUserText = $row->rev_user_text; // IP user
 454                         } elseif ( isset( $row->user_name ) ) {
 455                                 $this->mUserText = $row->user_name; // logged-in user
 456                         }
 457                         $this->mOrigUserText = $row->rev_user_text;
 458                 } elseif( is_array( $row ) ) {
 459                         // Build a new revision to be saved...
 460                         global $wgUser; // ugh
 461
 462                         $this->mId        = isset( $row['id']         ) ? intval( $row['id']         ) : null;
 463                         $this->mPage      = isset( $row['page']       ) ? intval( $row['page']       ) : null;
 464                         $this->mTextId    = isset( $row['text_id']    ) ? intval( $row['text_id']    ) : null;
 465                         $this->mUserText  = isset( $row['user_text']  ) ? strval( $row['user_text']  ) : $wgUser->getName();
 466                         $this->mUser      = isset( $row['user']       ) ? intval( $row['user']       ) : $wgUser->getId();
 467                         $this->mMinorEdit = isset( $row['minor_edit'] ) ? intval( $row['minor_edit'] ) : 0;
 468                         $this->mTimestamp = isset( $row['timestamp']  ) ? strval( $row['timestamp']  ) : wfTimestampNow();
 469                         $this->mDeleted   = isset( $row['deleted']    ) ? intval( $row['deleted']    ) : 0;
 470                         $this->mSize      = isset( $row['len']        ) ? intval( $row['len']        ) : null;
 471                         $this->mParentId  = isset( $row['parent_id']  ) ? intval( $row['parent_id']  ) : null;
 472                         $this->mSha1      = isset( $row['sha1']  )      ? strval( $row['sha1']  )      : null;
 473
 474                         // Enforce spacing trimming on supplied text
 475                         $this->mComment   = isset( $row['comment']    ) ?  trim( strval( $row['comment'] ) ) : null;
 476                         $this->mText      = isset( $row['text']       ) ? rtrim( strval( $row['text']    ) ) : null;
 477                         $this->mTextRow   = null;
 478
 479                         $this->mTitle     = null; # Load on demand if needed
 480                         $this->mCurrent   = false;
 481                         # If we still have no length, see it we have the text to figure it out
 482                         if ( !$this->mSize ) {
 483                                 $this->mSize = is_null( $this->mText ) ? null : strlen( $this->mText );
 484                         }
 485                         # Same for sha1
 486                         if ( $this->mSha1 === null ) {
 487                                 $this->mSha1 = is_null( $this->mText ) ? null : self::base36Sha1( $this->mText );
 488                         }
 489                 } else {
 490                         throw new MWException( 'Revision constructor passed invalid row format.' );
 491                 }
 492                 $this->mUnpatrolled = null;
 493         }
 494
 495         /**
 496          * Get revision ID
 497          *
 498          * @return Integer|null
 499          */
 500         public function getId() {
 501                 return $this->mId;
 502         }
 503
 504         /**
 505          * Set the revision ID
 506          *
 507          * @since 1.19
 508          * @param $id Integer
 509          */
 510         public function setId( $id ) {
 511                 $this->mId = $id;
 512         }
 513
 514         /**
 515          * Get text row ID
 516          *
 517          * @return Integer|null
 518          */
 519         public function getTextId() {
 520                 return $this->mTextId;
 521         }
 522
 523         /**
 524          * Get parent revision ID (the original previous page revision)
 525          *
 526          * @return Integer|null
 527          */
 528         public function getParentId() {
 529                 return $this->mParentId;
 530         }
 531
 532         /**
 533          * Returns the length of the text in this revision, or null if unknown.
 534          *
 535          * @return Integer|null
 536          */
 537         public function getSize() {
 538                 return $this->mSize;
 539         }
 540
 541         /**
 542          * Returns the base36 sha1 of the text in this revision, or null if unknown.
 543          *
 544          * @return String|null
 545          */
 546         public function getSha1() {
 547                 return $this->mSha1;
 548         }
 549
 550         /**
 551          * Returns the title of the page associated with this entry or null.
 552          *
 553          * Will do a query, when title is not set and id is given.
 554          *
 555          * @return Title|null
 556          */
 557         public function getTitle() {
 558                 if( isset( $this->mTitle ) ) {
 559                         return $this->mTitle;
 560                 }
 561                 if( !is_null( $this->mId ) ) { //rev_id is defined as NOT NULL
 562                         $dbr = wfGetDB( DB_SLAVE );
 563                         $row = $dbr->selectRow(
 564                                 array( 'page', 'revision' ),
 565                                 self::selectPageFields(),
 566                                 array( 'page_id=rev_page',
 567                                            'rev_id' => $this->mId ),
 568                                 __METHOD__ );
 569                         if ( $row ) {
 570                                 $this->mTitle = Title::newFromRow( $row );
 571                         }
 572                 }
 573                 return $this->mTitle;
 574         }
 575
 576         /**
 577          * Set the title of the revision
 578          *
 579          * @param $title Title
 580          */
 581         public function setTitle( $title ) {
 582                 $this->mTitle = $title;
 583         }
 584
 585         /**
 586          * Get the page ID
 587          *
 588          * @return Integer|null
 589          */
 590         public function getPage() {
 591                 return $this->mPage;
 592         }
 593
 594         /**
 595          * Fetch revision's user id if it's available to the specified audience.
 596          * If the specified audience does not have access to it, zero will be
 597          * returned.
 598          *
 599          * @param $audience Integer: one of:
 600          *      Revision::FOR_PUBLIC       to be displayed to all users
 601          *      Revision::FOR_THIS_USER    to be displayed to the given user
 602          *      Revision::RAW              get the ID regardless of permissions
 603          * @param $user User object to check for, only if FOR_THIS_USER is passed
 604          *              to the $audience parameter
 605          * @return Integer
 606          */
 607         public function getUser( $audience = self::FOR_PUBLIC, User $user = null ) {
 608                 if( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_USER ) ) {
 609                         return 0;
 610                 } elseif( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_USER, $user ) ) {
 611                         return 0;
 612                 } else {
 613                         return $this->mUser;
 614                 }
 615         }
 616
 617         /**
 618          * Fetch revision's user id without regard for the current user's permissions
 619          *
 620          * @return String
 621          */
 622         public function getRawUser() {
 623                 return $this->mUser;
 624         }
 625
 626         /**
 627          * Fetch revision's username if it's available to the specified audience.
 628          * If the specified audience does not have access to the username, an
 629          * empty string will be returned.
 630          *
 631          * @param $audience Integer: one of:
 632          *      Revision::FOR_PUBLIC       to be displayed to all users
 633          *      Revision::FOR_THIS_USER    to be displayed to the given user
 634          *      Revision::RAW              get the text regardless of permissions
 635          * @param $user User object to check for, only if FOR_THIS_USER is passed
 636          *              to the $audience parameter
 637          * @return string
 638          */
 639         public function getUserText( $audience = self::FOR_PUBLIC, User $user = null ) {
 640                 if( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_USER ) ) {
 641                         return '';
 642                 } elseif( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_USER, $user ) ) {
 643                         return '';
 644                 } else {
 645                         return $this->getRawUserText();
 646                 }
 647         }
 648
 649         /**
 650          * Fetch revision's username without regard for view restrictions
 651          *
 652          * @return String
 653          */
 654         public function getRawUserText() {
 655                 if ( $this->mUserText === null ) {
 656                         $this->mUserText = User::whoIs( $this->mUser ); // load on demand
 657                         if ( $this->mUserText === false ) {
 658                                 # This shouldn't happen, but it can if the wiki was recovered
 659                                 # via importing revs and there is no user table entry yet.
 660                                 $this->mUserText = $this->mOrigUserText;
 661                         }
 662                 }
 663                 return $this->mUserText;
 664         }
 665
 666         /**
 667          * Fetch revision comment if it's available to the specified audience.
 668          * If the specified audience does not have access to the comment, an
 669          * empty string will be returned.
 670          *
 671          * @param $audience Integer: one of:
 672          *      Revision::FOR_PUBLIC       to be displayed to all users
 673          *      Revision::FOR_THIS_USER    to be displayed to the given user
 674          *      Revision::RAW              get the text regardless of permissions
 675          * @param $user User object to check for, only if FOR_THIS_USER is passed
 676          *              to the $audience parameter
 677          * @return String
 678          */
 679         function getComment( $audience = self::FOR_PUBLIC, User $user = null ) {
 680                 if( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_COMMENT ) ) {
 681                         return '';
 682                 } elseif( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_COMMENT, $user ) ) {
 683                         return '';
 684                 } else {
 685                         return $this->mComment;
 686                 }
 687         }
 688
 689         /**
 690          * Fetch revision comment without regard for the current user's permissions
 691          *
 692          * @return String
 693          */
 694         public function getRawComment() {
 695                 return $this->mComment;
 696         }
 697
 698         /**
 699          * @return Boolean
 700          */
 701         public function isMinor() {
 702                 return (bool)$this->mMinorEdit;
 703         }
 704
 705         /**
 706          * @return Integer rcid of the unpatrolled row, zero if there isn't one
 707          */
 708         public function isUnpatrolled() {
 709                 if( $this->mUnpatrolled !== null ) {
 710                         return $this->mUnpatrolled;
 711                 }
 712                 $dbr = wfGetDB( DB_SLAVE );
 713                 $this->mUnpatrolled = $dbr->selectField( 'recentchanges',
 714                         'rc_id',
 715                         array( // Add redundant user,timestamp condition so we can use the existing index
 716                                 'rc_user_text'  => $this->getRawUserText(),
 717                                 'rc_timestamp'  => $dbr->timestamp( $this->getTimestamp() ),
 718                                 'rc_this_oldid' => $this->getId(),
 719                                 'rc_patrolled'  => 0
 720                         ),
 721                         __METHOD__
 722                 );
 723                 return (int)$this->mUnpatrolled;
 724         }
 725
 726         /**
 727          * @param $field int one of DELETED_* bitfield constants
 728          *
 729          * @return Boolean
 730          */
 731         public function isDeleted( $field ) {
 732                 return ( $this->mDeleted & $field ) == $field;
 733         }
 734
 735         /**
 736          * Get the deletion bitfield of the revision
 737          *
 738          * @return int
 739          */
 740         public function getVisibility() {
 741                 return (int)$this->mDeleted;
 742         }
 743
 744         /**
 745          * Fetch revision text if it's available to the specified audience.
 746          * If the specified audience does not have the ability to view this
 747          * revision, an empty string will be returned.
 748          *
 749          * @param $audience Integer: one of:
 750          *      Revision::FOR_PUBLIC       to be displayed to all users
 751          *      Revision::FOR_THIS_USER    to be displayed to the given user
 752          *      Revision::RAW              get the text regardless of permissions
 753          * @param $user User object to check for, only if FOR_THIS_USER is passed
 754          *              to the $audience parameter
 755          * @return String
 756          */
 757         public function getText( $audience = self::FOR_PUBLIC, User $user = null ) {
 758                 if( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_TEXT ) ) {
 759                         return '';
 760                 } elseif( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_TEXT, $user ) ) {
 761                         return '';
 762                 } else {
 763                         return $this->getRawText();
 764                 }
 765         }
 766
 767         /**
 768          * Alias for getText(Revision::FOR_THIS_USER)
 769          *
 770          * @deprecated since 1.17
 771          * @return String
 772          */
 773         public function revText() {
 774                 wfDeprecated( __METHOD__, '1.17' );
 775                 return $this->getText( self::FOR_THIS_USER );
 776         }
 777
 778         /**
 779          * Fetch revision text without regard for view restrictions
 780          *
 781          * @return String
 782          */
 783         public function getRawText() {
 784                 if( is_null( $this->mText ) ) {
 785                         // Revision text is immutable. Load on demand:
 786                         $this->mText = $this->loadText();
 787                 }
 788                 return $this->mText;
 789         }
 790
 791         /**
 792          * @return String
 793          */
 794         public function getTimestamp() {
 795                 return wfTimestamp( TS_MW, $this->mTimestamp );
 796         }
 797
 798         /**
 799          * @return Boolean
 800          */
 801         public function isCurrent() {
 802                 return $this->mCurrent;
 803         }
 804
 805         /**
 806          * Get previous revision for this title
 807          *
 808          * @return Revision or null
 809          */
 810         public function getPrevious() {
 811                 if( $this->getTitle() ) {
 812                         $prev = $this->getTitle()->getPreviousRevisionID( $this->getId() );
 813                         if( $prev ) {
 814                                 return Revision::newFromTitle( $this->getTitle(), $prev );
 815                         }
 816                 }
 817                 return null;
 818         }
 819
 820         /**
 821          * Get next revision for this title
 822          *
 823          * @return Revision or null
 824          */
 825         public function getNext() {
 826                 if( $this->getTitle() ) {
 827                         $next = $this->getTitle()->getNextRevisionID( $this->getId() );
 828                         if ( $next ) {
 829                                 return Revision::newFromTitle( $this->getTitle(), $next );
 830                         }
 831                 }
 832                 return null;
 833         }
 834
 835         /**
 836          * Get previous revision Id for this page_id
 837          * This is used to populate rev_parent_id on save
 838          *
 839          * @param $db DatabaseBase
 840          * @return Integer
 841          */
 842         private function getPreviousRevisionId( $db ) {
 843                 if( is_null( $this->mPage ) ) {
 844                         return 0;
 845                 }
 846                 # Use page_latest if ID is not given
 847                 if( !$this->mId ) {
 848                         $prevId = $db->selectField( 'page', 'page_latest',
 849                                 array( 'page_id' => $this->mPage ),
 850                                 __METHOD__ );
 851                 } else {
 852                         $prevId = $db->selectField( 'revision', 'rev_id',
 853                                 array( 'rev_page' => $this->mPage, 'rev_id < ' . $this->mId ),
 854                                 __METHOD__,
 855                                 array( 'ORDER BY' => 'rev_id DESC' ) );
 856                 }
 857                 return intval( $prevId );
 858         }
 859
 860         /**
 861           * Get revision text associated with an old or archive row
 862           * $row is usually an object from wfFetchRow(), both the flags and the text
 863           * field must be included
 864           *
 865           * @param $row Object: the text data
 866           * @param $prefix String: table prefix (default 'old_')
 867           * @return String: text the text requested or false on failure
 868           */
 869         public static function getRevisionText( $row, $prefix = 'old_' ) {
 870                 wfProfileIn( __METHOD__ );
 871
 872                 # Get data
 873                 $textField = $prefix . 'text';
 874                 $flagsField = $prefix . 'flags';
 875
 876                 if( isset( $row->$flagsField ) ) {
 877                         $flags = explode( ',', $row->$flagsField );
 878                 } else {
 879                         $flags = array();
 880                 }
 881
 882                 if( isset( $row->$textField ) ) {
 883                         $text = $row->$textField;
 884                 } else {
 885                         wfProfileOut( __METHOD__ );
 886                         return false;
 887                 }
 888
 889                 # Use external methods for external objects, text in table is URL-only then
 890                 if ( in_array( 'external', $flags ) ) {
 891                         $url = $text;
 892                         $parts = explode( '://', $url, 2 );
 893                         if( count( $parts ) == 1 || $parts[1] == '' ) {
 894                                 wfProfileOut( __METHOD__ );
 895                                 return false;
 896                         }
 897                         $text = ExternalStore::fetchFromURL( $url );
 898                 }
 899
 900                 // If the text was fetched without an error, convert it
 901                 if ( $text !== false ) {
 902                         if( in_array( 'gzip', $flags ) ) {
 903                                 # Deal with optional compression of archived pages.
 904                                 # This can be done periodically via maintenance/compressOld.php, and
 905                                 # as pages are saved if $wgCompressRevisions is set.
 906                                 $text = gzinflate( $text );
 907                         }
 908
 909                         if( in_array( 'object', $flags ) ) {
 910                                 # Generic compressed storage
 911                                 $obj = unserialize( $text );
 912                                 if ( !is_object( $obj ) ) {
 913                                         // Invalid object
 914                                         wfProfileOut( __METHOD__ );
 915                                         return false;
 916                                 }
 917                                 $text = $obj->getText();
 918                         }
 919
 920                         global $wgLegacyEncoding;
 921                         if( $text !== false && $wgLegacyEncoding
 922                                 && !in_array( 'utf-8', $flags ) && !in_array( 'utf8', $flags ) )
 923                         {
 924                                 # Old revisions kept around in a legacy encoding?
 925                                 # Upconvert on demand.
 926                                 # ("utf8" checked for compatibility with some broken
 927                                 #  conversion scripts 2008-12-30)
 928                                 global $wgContLang;
 929                                 $text = $wgContLang->iconv( $wgLegacyEncoding, 'UTF-8', $text );
 930                         }
 931                 }
 932                 wfProfileOut( __METHOD__ );
 933                 return $text;
 934         }
 935
 936         /**
 937          * If $wgCompressRevisions is enabled, we will compress data.
 938          * The input string is modified in place.
 939          * Return value is the flags field: contains 'gzip' if the
 940          * data is compressed, and 'utf-8' if we're saving in UTF-8
 941          * mode.
 942          *
 943          * @param $text Mixed: reference to a text
 944          * @return String
 945          */
 946         public static function compressRevisionText( &$text ) {
 947                 global $wgCompressRevisions;
 948                 $flags = array();
 949
 950                 # Revisions not marked this way will be converted
 951                 # on load if $wgLegacyCharset is set in the future.
 952                 $flags[] = 'utf-8';
 953
 954                 if( $wgCompressRevisions ) {
 955                         if( function_exists( 'gzdeflate' ) ) {
 956                                 $text = gzdeflate( $text );
 957                                 $flags[] = 'gzip';
 958                         } else {
 959                                 wfDebug( "Revision::compressRevisionText() -- no zlib support, not compressing\n" );
 960                         }
 961                 }
 962                 return implode( ',', $flags );
 963         }
 964
 965         /**
 966          * Insert a new revision into the database, returning the new revision ID
 967          * number on success and dies horribly on failure.
 968          *
 969          * @param $dbw DatabaseBase: (master connection)
 970          * @return Integer
 971          */
 972         public function insertOn( $dbw ) {
 973                 global $wgDefaultExternalStore;
 974
 975                 wfProfileIn( __METHOD__ );
 976
 977                 $data = $this->mText;
 978                 $flags = Revision::compressRevisionText( $data );
 979
 980                 # Write to external storage if required
 981                 if( $wgDefaultExternalStore ) {
 982                         // Store and get the URL
 983                         $data = ExternalStore::insertToDefault( $data );
 984                         if( !$data ) {
 985                                 throw new MWException( "Unable to store text to external storage" );
 986                         }
 987                         if( $flags ) {
 988                                 $flags .= ',';
 989                         }
 990                         $flags .= 'external';
 991                 }
 992
 993                 # Record the text (or external storage URL) to the text table
 994                 if( !isset( $this->mTextId ) ) {
 995                         $old_id = $dbw->nextSequenceValue( 'text_old_id_seq' );
 996                         $dbw->insert( 'text',
 997                                 array(
 998                                         'old_id'    => $old_id,
 999                                         'old_text'  => $data,
1000                                         'old_flags' => $flags,
1001                                 ), __METHOD__
1002                         );
1003                         $this->mTextId = $dbw->insertId();
1004                 }
1005
1006                 if ( $this->mComment === null ) $this->mComment = "";
1007
1008                 # Record the edit in revisions
1009                 $rev_id = isset( $this->mId )
1010                         ? $this->mId
1011                         : $dbw->nextSequenceValue( 'revision_rev_id_seq' );
1012                 $dbw->insert( 'revision',
1013                         array(
1014                                 'rev_id'         => $rev_id,
1015                                 'rev_page'       => $this->mPage,
1016                                 'rev_text_id'    => $this->mTextId,
1017                                 'rev_comment'    => $this->mComment,
1018                                 'rev_minor_edit' => $this->mMinorEdit ? 1 : 0,
1019                                 'rev_user'       => $this->mUser,
1020                                 'rev_user_text'  => $this->mUserText,
1021                                 'rev_timestamp'  => $dbw->timestamp( $this->mTimestamp ),
1022                                 'rev_deleted'    => $this->mDeleted,
1023                                 'rev_len'        => $this->mSize,
1024                                 'rev_parent_id'  => is_null( $this->mParentId )
1025                                         ? $this->getPreviousRevisionId( $dbw )
1026                                         : $this->mParentId,
1027                                 'rev_sha1'       => is_null( $this->mSha1 )
1028                                         ? Revision::base36Sha1( $this->mText )
1029                                         : $this->mSha1
1030                         ), __METHOD__
1031                 );
1032
1033                 $this->mId = !is_null( $rev_id ) ? $rev_id : $dbw->insertId();
1034
1035                 wfRunHooks( 'RevisionInsertComplete', array( &$this, $data, $flags ) );
1036
1037                 wfProfileOut( __METHOD__ );
1038                 return $this->mId;
1039         }
1040
1041         /**
1042          * Get the base 36 SHA-1 value for a string of text
1043          * @param $text String
1044          * @return String
1045          */
1046         public static function base36Sha1( $text ) {
1047                 return wfBaseConvert( sha1( $text ), 16, 36, 31 );
1048         }
1049
1050         /**
1051          * Lazy-load the revision's text.
1052          * Currently hardcoded to the 'text' table storage engine.
1053          *
1054          * @return String
1055          */
1056         protected function loadText() {
1057                 wfProfileIn( __METHOD__ );
1058
1059                 // Caching may be beneficial for massive use of external storage
1060                 global $wgRevisionCacheExpiry, $wgMemc;
1061                 $textId = $this->getTextId();
1062                 $key = wfMemcKey( 'revisiontext', 'textid', $textId );
1063                 if( $wgRevisionCacheExpiry ) {
1064                         $text = $wgMemc->get( $key );
1065                         if( is_string( $text ) ) {
1066                                 wfDebug( __METHOD__ . ": got id $textId from cache\n" );
1067                                 wfProfileOut( __METHOD__ );
1068                                 return $text;
1069                         }
1070                 }
1071
1072                 // If we kept data for lazy extraction, use it now...
1073                 if ( isset( $this->mTextRow ) ) {
1074                         $row = $this->mTextRow;
1075                         $this->mTextRow = null;
1076                 } else {
1077                         $row = null;
1078                 }
1079
1080                 if( !$row ) {
1081                         // Text data is immutable; check slaves first.
1082                         $dbr = wfGetDB( DB_SLAVE );
1083                         $row = $dbr->selectRow( 'text',
1084                                 array( 'old_text', 'old_flags' ),
1085                                 array( 'old_id' => $this->getTextId() ),
1086                                 __METHOD__ );
1087                 }
1088
1089                 if( !$row && wfGetLB()->getServerCount() > 1 ) {
1090                         // Possible slave lag!
1091                         $dbw = wfGetDB( DB_MASTER );
1092                         $row = $dbw->selectRow( 'text',
1093                                 array( 'old_text', 'old_flags' ),
1094                                 array( 'old_id' => $this->getTextId() ),
1095                                 __METHOD__ );
1096                 }
1097
1098                 $text = self::getRevisionText( $row );
1099
1100                 # No negative caching -- negative hits on text rows may be due to corrupted slave servers
1101                 if( $wgRevisionCacheExpiry && $text !== false ) {
1102                         $wgMemc->set( $key, $text, $wgRevisionCacheExpiry );
1103                 }
1104
1105                 wfProfileOut( __METHOD__ );
1106
1107                 return $text;
1108         }
1109
1110         /**
1111          * Create a new null-revision for insertion into a page's
1112          * history. This will not re-save the text, but simply refer
1113          * to the text from the previous version.
1114          *
1115          * Such revisions can for instance identify page rename
1116          * operations and other such meta-modifications.
1117          *
1118          * @param $dbw DatabaseBase
1119          * @param $pageId Integer: ID number of the page to read from
1120          * @param $summary String: revision's summary
1121          * @param $minor Boolean: whether the revision should be considered as minor
1122          * @return Revision|null on error
1123          */
1124         public static function newNullRevision( $dbw, $pageId, $summary, $minor ) {
1125                 wfProfileIn( __METHOD__ );
1126
1127                 $current = $dbw->selectRow(
1128                         array( 'page', 'revision' ),
1129                         array( 'page_latest', 'page_namespace', 'page_title',
1130                                 'rev_text_id', 'rev_len', 'rev_sha1' ),
1131                         array(
1132                                 'page_id' => $pageId,
1133                                 'page_latest=rev_id',
1134                                 ),
1135                         __METHOD__ );
1136
1137                 if( $current ) {
1138                         $revision = new Revision( array(
1139                                 'page'       => $pageId,
1140                                 'comment'    => $summary,
1141                                 'minor_edit' => $minor,
1142                                 'text_id'    => $current->rev_text_id,
1143                                 'parent_id'  => $current->page_latest,
1144                                 'len'        => $current->rev_len,
1145                                 'sha1'       => $current->rev_sha1
1146                                 ) );
1147                         $revision->setTitle( Title::makeTitle( $current->page_namespace, $current->page_title ) );
1148                 } else {
1149                         $revision = null;
1150                 }
1151
1152                 wfProfileOut( __METHOD__ );
1153                 return $revision;
1154         }
1155
1156         /**
1157          * Determine if the current user is allowed to view a particular
1158          * field of this revision, if it's marked as deleted.
1159          *
1160          * @param $field Integer:one of self::DELETED_TEXT,
1161          *                              self::DELETED_COMMENT,
1162          *                              self::DELETED_USER
1163          * @param $user User object to check, or null to use $wgUser
1164          * @return Boolean
1165          */
1166         public function userCan( $field, User $user = null ) {
1167                 return self::userCanBitfield( $this->mDeleted, $field, $user );
1168         }
1169
1170         /**
1171          * Determine if the current user is allowed to view a particular
1172          * field of this revision, if it's marked as deleted. This is used
1173          * by various classes to avoid duplication.
1174          *
1175          * @param $bitfield Integer: current field
1176          * @param $field Integer: one of self::DELETED_TEXT = File::DELETED_FILE,
1177          *                               self::DELETED_COMMENT = File::DELETED_COMMENT,
1178          *                               self::DELETED_USER = File::DELETED_USER
1179          * @param $user User object to check, or null to use $wgUser
1180          * @return Boolean
1181          */
1182         public static function userCanBitfield( $bitfield, $field, User $user = null ) {
1183                 if( $bitfield & $field ) { // aspect is deleted
1184                         if ( $bitfield & self::DELETED_RESTRICTED ) {
1185                                 $permission = 'suppressrevision';
1186                         } elseif ( $field & self::DELETED_TEXT ) {
1187                                 $permission = 'deletedtext';
1188                         } else {
1189                                 $permission = 'deletedhistory';
1190                         }
1191                         wfDebug( "Checking for $permission due to $field match on $bitfield\n" );
1192                         if ( $user === null ) {
1193                                 global $wgUser;
1194                                 $user = $wgUser;
1195                         }
1196                         return $user->isAllowed( $permission );
1197                 } else {
1198                         return true;
1199                 }
1200         }
1201
1202         /**
1203          * Get rev_timestamp from rev_id, without loading the rest of the row
1204          *
1205          * @param $title Title
1206          * @param $id Integer
1207          * @return String
1208          */
1209         static function getTimestampFromId( $title, $id ) {
1210                 $dbr = wfGetDB( DB_SLAVE );
1211                 // Casting fix for DB2
1212                 if ( $id == '' ) {
1213                         $id = 0;
1214                 }
1215                 $conds = array( 'rev_id' => $id );
1216                 $conds['rev_page'] = $title->getArticleID();
1217                 $timestamp = $dbr->selectField( 'revision', 'rev_timestamp', $conds, __METHOD__ );
1218                 if ( $timestamp === false && wfGetLB()->getServerCount() > 1 ) {
1219                         # Not in slave, try master
1220                         $dbw = wfGetDB( DB_MASTER );
1221                         $timestamp = $dbw->selectField( 'revision', 'rev_timestamp', $conds, __METHOD__ );
1222                 }
1223                 return wfTimestamp( TS_MW, $timestamp );
1224         }
1225
1226         /**
1227          * Get count of revisions per page...not very efficient
1228          *
1229          * @param $db DatabaseBase
1230          * @param $id Integer: page id
1231          * @return Integer
1232          */
1233         static function countByPageId( $db, $id ) {
1234                 $row = $db->selectRow( 'revision', 'COUNT(*) AS revCount',
1235                         array( 'rev_page' => $id ), __METHOD__ );
1236                 if( $row ) {
1237                         return $row->revCount;
1238                 }
1239                 return 0;
1240         }
1241
1242         /**
1243          * Get count of revisions per page...not very efficient
1244          *
1245          * @param $db DatabaseBase
1246          * @param $title Title
1247          * @return Integer
1248          */
1249         static function countByTitle( $db, $title ) {
1250                 $id = $title->getArticleID();
1251                 if( $id ) {
1252                         return Revision::countByPageId( $db, $id );
1253                 }
1254                 return 0;
1255         }
1256 }