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          * Do a batched query to get the parent revision lengths
 400          * @param $db DatabaseBase
 401          * @param $revIds Array
 402          * @return array
 403          */
 404         public static function getParentLengths( $db, array $revIds ) {
 405                 $revLens = array();
 406                 if ( !$revIds ) {
 407                         return $revLens; // empty
 408                 }
 409                 wfProfileIn( __METHOD__ );
 410                 $res = $db->select( 'revision',
 411                         array( 'rev_id', 'rev_len' ),
 412                         array( 'rev_id' => $revIds ),
 413                         __METHOD__ );
 414                 foreach ( $res as $row ) {
 415                         $revLens[$row->rev_id] = $row->rev_len;
 416                 }
 417                 wfProfileOut( __METHOD__ );
 418                 return $revLens;
 419         }
 420
 421         /**
 422          * Constructor
 423          *
 424          * @param $row Mixed: either a database row or an array
 425          * @access private
 426          */
 427         function __construct( $row ) {
 428                 if( is_object( $row ) ) {
 429                         $this->mId        = intval( $row->rev_id );
 430                         $this->mPage      = intval( $row->rev_page );
 431                         $this->mTextId    = intval( $row->rev_text_id );
 432                         $this->mComment   =         $row->rev_comment;
 433                         $this->mUser      = intval( $row->rev_user );
 434                         $this->mMinorEdit = intval( $row->rev_minor_edit );
 435                         $this->mTimestamp =         $row->rev_timestamp;
 436                         $this->mDeleted   = intval( $row->rev_deleted );
 437
 438                         if( !isset( $row->rev_parent_id ) ) {
 439                                 $this->mParentId = is_null( $row->rev_parent_id ) ? null : 0;
 440                         } else {
 441                                 $this->mParentId  = intval( $row->rev_parent_id );
 442                         }
 443
 444                         if( !isset( $row->rev_len ) || is_null( $row->rev_len ) ) {
 445                                 $this->mSize = null;
 446                         } else {
 447                                 $this->mSize = intval( $row->rev_len );
 448                         }
 449
 450                         if ( !isset( $row->rev_sha1 ) ) {
 451                                 $this->mSha1 = null;
 452                         } else {
 453                                 $this->mSha1 = $row->rev_sha1;
 454                         }
 455
 456                         if( isset( $row->page_latest ) ) {
 457                                 $this->mCurrent = ( $row->rev_id == $row->page_latest );
 458                                 $this->mTitle = Title::newFromRow( $row );
 459                         } else {
 460                                 $this->mCurrent = false;
 461                                 $this->mTitle = null;
 462                         }
 463
 464                         // Lazy extraction...
 465                         $this->mText      = null;
 466                         if( isset( $row->old_text ) ) {
 467                                 $this->mTextRow = $row;
 468                         } else {
 469                                 // 'text' table row entry will be lazy-loaded
 470                                 $this->mTextRow = null;
 471                         }
 472
 473                         // Use user_name for users and rev_user_text for IPs...
 474                         $this->mUserText = null; // lazy load if left null
 475                         if ( $this->mUser == 0 ) {
 476                                 $this->mUserText = $row->rev_user_text; // IP user
 477                         } elseif ( isset( $row->user_name ) ) {
 478                                 $this->mUserText = $row->user_name; // logged-in user
 479                         }
 480                         $this->mOrigUserText = $row->rev_user_text;
 481                 } elseif( is_array( $row ) ) {
 482                         // Build a new revision to be saved...
 483                         global $wgUser; // ugh
 484
 485                         $this->mId        = isset( $row['id']         ) ? intval( $row['id']         ) : null;
 486                         $this->mPage      = isset( $row['page']       ) ? intval( $row['page']       ) : null;
 487                         $this->mTextId    = isset( $row['text_id']    ) ? intval( $row['text_id']    ) : null;
 488                         $this->mUserText  = isset( $row['user_text']  ) ? strval( $row['user_text']  ) : $wgUser->getName();
 489                         $this->mUser      = isset( $row['user']       ) ? intval( $row['user']       ) : $wgUser->getId();
 490                         $this->mMinorEdit = isset( $row['minor_edit'] ) ? intval( $row['minor_edit'] ) : 0;
 491                         $this->mTimestamp = isset( $row['timestamp']  ) ? strval( $row['timestamp']  ) : wfTimestampNow();
 492                         $this->mDeleted   = isset( $row['deleted']    ) ? intval( $row['deleted']    ) : 0;
 493                         $this->mSize      = isset( $row['len']        ) ? intval( $row['len']        ) : null;
 494                         $this->mParentId  = isset( $row['parent_id']  ) ? intval( $row['parent_id']  ) : null;
 495                         $this->mSha1      = isset( $row['sha1']  )      ? strval( $row['sha1']  )      : null;
 496
 497                         // Enforce spacing trimming on supplied text
 498                         $this->mComment   = isset( $row['comment']    ) ?  trim( strval( $row['comment'] ) ) : null;
 499                         $this->mText      = isset( $row['text']       ) ? rtrim( strval( $row['text']    ) ) : null;
 500                         $this->mTextRow   = null;
 501
 502                         $this->mTitle     = null; # Load on demand if needed
 503                         $this->mCurrent   = false;
 504                         # If we still have no length, see it we have the text to figure it out
 505                         if ( !$this->mSize ) {
 506                                 $this->mSize = is_null( $this->mText ) ? null : strlen( $this->mText );
 507                         }
 508                         # Same for sha1
 509                         if ( $this->mSha1 === null ) {
 510                                 $this->mSha1 = is_null( $this->mText ) ? null : self::base36Sha1( $this->mText );
 511                         }
 512                 } else {
 513                         throw new MWException( 'Revision constructor passed invalid row format.' );
 514                 }
 515                 $this->mUnpatrolled = null;
 516         }
 517
 518         /**
 519          * Get revision ID
 520          *
 521          * @return Integer|null
 522          */
 523         public function getId() {
 524                 return $this->mId;
 525         }
 526
 527         /**
 528          * Set the revision ID
 529          *
 530          * @since 1.19
 531          * @param $id Integer
 532          */
 533         public function setId( $id ) {
 534                 $this->mId = $id;
 535         }
 536
 537         /**
 538          * Get text row ID
 539          *
 540          * @return Integer|null
 541          */
 542         public function getTextId() {
 543                 return $this->mTextId;
 544         }
 545
 546         /**
 547          * Get parent revision ID (the original previous page revision)
 548          *
 549          * @return Integer|null
 550          */
 551         public function getParentId() {
 552                 return $this->mParentId;
 553         }
 554
 555         /**
 556          * Returns the length of the text in this revision, or null if unknown.
 557          *
 558          * @return Integer|null
 559          */
 560         public function getSize() {
 561                 return $this->mSize;
 562         }
 563
 564         /**
 565          * Returns the base36 sha1 of the text in this revision, or null if unknown.
 566          *
 567          * @return String|null
 568          */
 569         public function getSha1() {
 570                 return $this->mSha1;
 571         }
 572
 573         /**
 574          * Returns the title of the page associated with this entry or null.
 575          *
 576          * Will do a query, when title is not set and id is given.
 577          *
 578          * @return Title|null
 579          */
 580         public function getTitle() {
 581                 if( isset( $this->mTitle ) ) {
 582                         return $this->mTitle;
 583                 }
 584                 if( !is_null( $this->mId ) ) { //rev_id is defined as NOT NULL
 585                         $dbr = wfGetDB( DB_SLAVE );
 586                         $row = $dbr->selectRow(
 587                                 array( 'page', 'revision' ),
 588                                 self::selectPageFields(),
 589                                 array( 'page_id=rev_page',
 590                                            'rev_id' => $this->mId ),
 591                                 __METHOD__ );
 592                         if ( $row ) {
 593                                 $this->mTitle = Title::newFromRow( $row );
 594                         }
 595                 }
 596                 return $this->mTitle;
 597         }
 598
 599         /**
 600          * Set the title of the revision
 601          *
 602          * @param $title Title
 603          */
 604         public function setTitle( $title ) {
 605                 $this->mTitle = $title;
 606         }
 607
 608         /**
 609          * Get the page ID
 610          *
 611          * @return Integer|null
 612          */
 613         public function getPage() {
 614                 return $this->mPage;
 615         }
 616
 617         /**
 618          * Fetch revision's user id if it's available to the specified audience.
 619          * If the specified audience does not have access to it, zero will be
 620          * returned.
 621          *
 622          * @param $audience Integer: one of:
 623          *      Revision::FOR_PUBLIC       to be displayed to all users
 624          *      Revision::FOR_THIS_USER    to be displayed to the given user
 625          *      Revision::RAW              get the ID regardless of permissions
 626          * @param $user User object to check for, only if FOR_THIS_USER is passed
 627          *              to the $audience parameter
 628          * @return Integer
 629          */
 630         public function getUser( $audience = self::FOR_PUBLIC, User $user = null ) {
 631                 if( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_USER ) ) {
 632                         return 0;
 633                 } elseif( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_USER, $user ) ) {
 634                         return 0;
 635                 } else {
 636                         return $this->mUser;
 637                 }
 638         }
 639
 640         /**
 641          * Fetch revision's user id without regard for the current user's permissions
 642          *
 643          * @return String
 644          */
 645         public function getRawUser() {
 646                 return $this->mUser;
 647         }
 648
 649         /**
 650          * Fetch revision's username if it's available to the specified audience.
 651          * If the specified audience does not have access to the username, an
 652          * empty string will be returned.
 653          *
 654          * @param $audience Integer: one of:
 655          *      Revision::FOR_PUBLIC       to be displayed to all users
 656          *      Revision::FOR_THIS_USER    to be displayed to the given user
 657          *      Revision::RAW              get the text regardless of permissions
 658          * @param $user User object to check for, only if FOR_THIS_USER is passed
 659          *              to the $audience parameter
 660          * @return string
 661          */
 662         public function getUserText( $audience = self::FOR_PUBLIC, User $user = null ) {
 663                 if( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_USER ) ) {
 664                         return '';
 665                 } elseif( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_USER, $user ) ) {
 666                         return '';
 667                 } else {
 668                         return $this->getRawUserText();
 669                 }
 670         }
 671
 672         /**
 673          * Fetch revision's username without regard for view restrictions
 674          *
 675          * @return String
 676          */
 677         public function getRawUserText() {
 678                 if ( $this->mUserText === null ) {
 679                         $this->mUserText = User::whoIs( $this->mUser ); // load on demand
 680                         if ( $this->mUserText === false ) {
 681                                 # This shouldn't happen, but it can if the wiki was recovered
 682                                 # via importing revs and there is no user table entry yet.
 683                                 $this->mUserText = $this->mOrigUserText;
 684                         }
 685                 }
 686                 return $this->mUserText;
 687         }
 688
 689         /**
 690          * Fetch revision comment if it's available to the specified audience.
 691          * If the specified audience does not have access to the comment, an
 692          * empty string will be returned.
 693          *
 694          * @param $audience Integer: one of:
 695          *      Revision::FOR_PUBLIC       to be displayed to all users
 696          *      Revision::FOR_THIS_USER    to be displayed to the given user
 697          *      Revision::RAW              get the text regardless of permissions
 698          * @param $user User object to check for, only if FOR_THIS_USER is passed
 699          *              to the $audience parameter
 700          * @return String
 701          */
 702         function getComment( $audience = self::FOR_PUBLIC, User $user = null ) {
 703                 if( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_COMMENT ) ) {
 704                         return '';
 705                 } elseif( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_COMMENT, $user ) ) {
 706                         return '';
 707                 } else {
 708                         return $this->mComment;
 709                 }
 710         }
 711
 712         /**
 713          * Fetch revision comment without regard for the current user's permissions
 714          *
 715          * @return String
 716          */
 717         public function getRawComment() {
 718                 return $this->mComment;
 719         }
 720
 721         /**
 722          * @return Boolean
 723          */
 724         public function isMinor() {
 725                 return (bool)$this->mMinorEdit;
 726         }
 727
 728         /**
 729          * @return Integer rcid of the unpatrolled row, zero if there isn't one
 730          */
 731         public function isUnpatrolled() {
 732                 if( $this->mUnpatrolled !== null ) {
 733                         return $this->mUnpatrolled;
 734                 }
 735                 $dbr = wfGetDB( DB_SLAVE );
 736                 $this->mUnpatrolled = $dbr->selectField( 'recentchanges',
 737                         'rc_id',
 738                         array( // Add redundant user,timestamp condition so we can use the existing index
 739                                 'rc_user_text'  => $this->getRawUserText(),
 740                                 'rc_timestamp'  => $dbr->timestamp( $this->getTimestamp() ),
 741                                 'rc_this_oldid' => $this->getId(),
 742                                 'rc_patrolled'  => 0
 743                         ),
 744                         __METHOD__
 745                 );
 746                 return (int)$this->mUnpatrolled;
 747         }
 748
 749         /**
 750          * @param $field int one of DELETED_* bitfield constants
 751          *
 752          * @return Boolean
 753          */
 754         public function isDeleted( $field ) {
 755                 return ( $this->mDeleted & $field ) == $field;
 756         }
 757
 758         /**
 759          * Get the deletion bitfield of the revision
 760          *
 761          * @return int
 762          */
 763         public function getVisibility() {
 764                 return (int)$this->mDeleted;
 765         }
 766
 767         /**
 768          * Fetch revision text if it's available to the specified audience.
 769          * If the specified audience does not have the ability to view this
 770          * revision, an empty string will be returned.
 771          *
 772          * @param $audience Integer: one of:
 773          *      Revision::FOR_PUBLIC       to be displayed to all users
 774          *      Revision::FOR_THIS_USER    to be displayed to the given user
 775          *      Revision::RAW              get the text regardless of permissions
 776          * @param $user User object to check for, only if FOR_THIS_USER is passed
 777          *              to the $audience parameter
 778          * @return String
 779          */
 780         public function getText( $audience = self::FOR_PUBLIC, User $user = null ) {
 781                 if( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_TEXT ) ) {
 782                         return '';
 783                 } elseif( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_TEXT, $user ) ) {
 784                         return '';
 785                 } else {
 786                         return $this->getRawText();
 787                 }
 788         }
 789
 790         /**
 791          * Alias for getText(Revision::FOR_THIS_USER)
 792          *
 793          * @deprecated since 1.17
 794          * @return String
 795          */
 796         public function revText() {
 797                 wfDeprecated( __METHOD__, '1.17' );
 798                 return $this->getText( self::FOR_THIS_USER );
 799         }
 800
 801         /**
 802          * Fetch revision text without regard for view restrictions
 803          *
 804          * @return String
 805          */
 806         public function getRawText() {
 807                 if( is_null( $this->mText ) ) {
 808                         // Revision text is immutable. Load on demand:
 809                         $this->mText = $this->loadText();
 810                 }
 811                 return $this->mText;
 812         }
 813
 814         /**
 815          * @return String
 816          */
 817         public function getTimestamp() {
 818                 return wfTimestamp( TS_MW, $this->mTimestamp );
 819         }
 820
 821         /**
 822          * @return Boolean
 823          */
 824         public function isCurrent() {
 825                 return $this->mCurrent;
 826         }
 827
 828         /**
 829          * Get previous revision for this title
 830          *
 831          * @return Revision or null
 832          */
 833         public function getPrevious() {
 834                 if( $this->getTitle() ) {
 835                         $prev = $this->getTitle()->getPreviousRevisionID( $this->getId() );
 836                         if( $prev ) {
 837                                 return Revision::newFromTitle( $this->getTitle(), $prev );
 838                         }
 839                 }
 840                 return null;
 841         }
 842
 843         /**
 844          * Get next revision for this title
 845          *
 846          * @return Revision or null
 847          */
 848         public function getNext() {
 849                 if( $this->getTitle() ) {
 850                         $next = $this->getTitle()->getNextRevisionID( $this->getId() );
 851                         if ( $next ) {
 852                                 return Revision::newFromTitle( $this->getTitle(), $next );
 853                         }
 854                 }
 855                 return null;
 856         }
 857
 858         /**
 859          * Get previous revision Id for this page_id
 860          * This is used to populate rev_parent_id on save
 861          *
 862          * @param $db DatabaseBase
 863          * @return Integer
 864          */
 865         private function getPreviousRevisionId( $db ) {
 866                 if( is_null( $this->mPage ) ) {
 867                         return 0;
 868                 }
 869                 # Use page_latest if ID is not given
 870                 if( !$this->mId ) {
 871                         $prevId = $db->selectField( 'page', 'page_latest',
 872                                 array( 'page_id' => $this->mPage ),
 873                                 __METHOD__ );
 874                 } else {
 875                         $prevId = $db->selectField( 'revision', 'rev_id',
 876                                 array( 'rev_page' => $this->mPage, 'rev_id < ' . $this->mId ),
 877                                 __METHOD__,
 878                                 array( 'ORDER BY' => 'rev_id DESC' ) );
 879                 }
 880                 return intval( $prevId );
 881         }
 882
 883         /**
 884           * Get revision text associated with an old or archive row
 885           * $row is usually an object from wfFetchRow(), both the flags and the text
 886           * field must be included
 887           *
 888           * @param $row Object: the text data
 889           * @param $prefix String: table prefix (default 'old_')
 890           * @return String: text the text requested or false on failure
 891           */
 892         public static function getRevisionText( $row, $prefix = 'old_' ) {
 893                 wfProfileIn( __METHOD__ );
 894
 895                 # Get data
 896                 $textField = $prefix . 'text';
 897                 $flagsField = $prefix . 'flags';
 898
 899                 if( isset( $row->$flagsField ) ) {
 900                         $flags = explode( ',', $row->$flagsField );
 901                 } else {
 902                         $flags = array();
 903                 }
 904
 905                 if( isset( $row->$textField ) ) {
 906                         $text = $row->$textField;
 907                 } else {
 908                         wfProfileOut( __METHOD__ );
 909                         return false;
 910                 }
 911
 912                 # Use external methods for external objects, text in table is URL-only then
 913                 if ( in_array( 'external', $flags ) ) {
 914                         $url = $text;
 915                         $parts = explode( '://', $url, 2 );
 916                         if( count( $parts ) == 1 || $parts[1] == '' ) {
 917                                 wfProfileOut( __METHOD__ );
 918                                 return false;
 919                         }
 920                         $text = ExternalStore::fetchFromURL( $url );
 921                 }
 922
 923                 // If the text was fetched without an error, convert it
 924                 if ( $text !== false ) {
 925                         if( in_array( 'gzip', $flags ) ) {
 926                                 # Deal with optional compression of archived pages.
 927                                 # This can be done periodically via maintenance/compressOld.php, and
 928                                 # as pages are saved if $wgCompressRevisions is set.
 929                                 $text = gzinflate( $text );
 930                         }
 931
 932                         if( in_array( 'object', $flags ) ) {
 933                                 # Generic compressed storage
 934                                 $obj = unserialize( $text );
 935                                 if ( !is_object( $obj ) ) {
 936                                         // Invalid object
 937                                         wfProfileOut( __METHOD__ );
 938                                         return false;
 939                                 }
 940                                 $text = $obj->getText();
 941                         }
 942
 943                         global $wgLegacyEncoding;
 944                         if( $text !== false && $wgLegacyEncoding
 945                                 && !in_array( 'utf-8', $flags ) && !in_array( 'utf8', $flags ) )
 946                         {
 947                                 # Old revisions kept around in a legacy encoding?
 948                                 # Upconvert on demand.
 949                                 # ("utf8" checked for compatibility with some broken
 950                                 #  conversion scripts 2008-12-30)
 951                                 global $wgContLang;
 952                                 $text = $wgContLang->iconv( $wgLegacyEncoding, 'UTF-8', $text );
 953                         }
 954                 }
 955                 wfProfileOut( __METHOD__ );
 956                 return $text;
 957         }
 958
 959         /**
 960          * If $wgCompressRevisions is enabled, we will compress data.
 961          * The input string is modified in place.
 962          * Return value is the flags field: contains 'gzip' if the
 963          * data is compressed, and 'utf-8' if we're saving in UTF-8
 964          * mode.
 965          *
 966          * @param $text Mixed: reference to a text
 967          * @return String
 968          */
 969         public static function compressRevisionText( &$text ) {
 970                 global $wgCompressRevisions;
 971                 $flags = array();
 972
 973                 # Revisions not marked this way will be converted
 974                 # on load if $wgLegacyCharset is set in the future.
 975                 $flags[] = 'utf-8';
 976
 977                 if( $wgCompressRevisions ) {
 978                         if( function_exists( 'gzdeflate' ) ) {
 979                                 $text = gzdeflate( $text );
 980                                 $flags[] = 'gzip';
 981                         } else {
 982                                 wfDebug( "Revision::compressRevisionText() -- no zlib support, not compressing\n" );
 983                         }
 984                 }
 985                 return implode( ',', $flags );
 986         }
 987
 988         /**
 989          * Insert a new revision into the database, returning the new revision ID
 990          * number on success and dies horribly on failure.
 991          *
 992          * @param $dbw DatabaseBase: (master connection)
 993          * @return Integer
 994          */
 995         public function insertOn( $dbw ) {
 996                 global $wgDefaultExternalStore;
 997
 998                 wfProfileIn( __METHOD__ );
 999
1000                 $data = $this->mText;
1001                 $flags = Revision::compressRevisionText( $data );
1002
1003                 # Write to external storage if required
1004                 if( $wgDefaultExternalStore ) {
1005                         // Store and get the URL
1006                         $data = ExternalStore::insertToDefault( $data );
1007                         if( !$data ) {
1008                                 throw new MWException( "Unable to store text to external storage" );
1009                         }
1010                         if( $flags ) {
1011                                 $flags .= ',';
1012                         }
1013                         $flags .= 'external';
1014                 }
1015
1016                 # Record the text (or external storage URL) to the text table
1017                 if( !isset( $this->mTextId ) ) {
1018                         $old_id = $dbw->nextSequenceValue( 'text_old_id_seq' );
1019                         $dbw->insert( 'text',
1020                                 array(
1021                                         'old_id'    => $old_id,
1022                                         'old_text'  => $data,
1023                                         'old_flags' => $flags,
1024                                 ), __METHOD__
1025                         );
1026                         $this->mTextId = $dbw->insertId();
1027                 }
1028
1029                 if ( $this->mComment === null ) $this->mComment = "";
1030
1031                 # Record the edit in revisions
1032                 $rev_id = isset( $this->mId )
1033                         ? $this->mId
1034                         : $dbw->nextSequenceValue( 'revision_rev_id_seq' );
1035                 $dbw->insert( 'revision',
1036                         array(
1037                                 'rev_id'         => $rev_id,
1038                                 'rev_page'       => $this->mPage,
1039                                 'rev_text_id'    => $this->mTextId,
1040                                 'rev_comment'    => $this->mComment,
1041                                 'rev_minor_edit' => $this->mMinorEdit ? 1 : 0,
1042                                 'rev_user'       => $this->mUser,
1043                                 'rev_user_text'  => $this->mUserText,
1044                                 'rev_timestamp'  => $dbw->timestamp( $this->mTimestamp ),
1045                                 'rev_deleted'    => $this->mDeleted,
1046                                 'rev_len'        => $this->mSize,
1047                                 'rev_parent_id'  => is_null( $this->mParentId )
1048                                         ? $this->getPreviousRevisionId( $dbw )
1049                                         : $this->mParentId,
1050                                 'rev_sha1'       => is_null( $this->mSha1 )
1051                                         ? Revision::base36Sha1( $this->mText )
1052                                         : $this->mSha1
1053                         ), __METHOD__
1054                 );
1055
1056                 $this->mId = !is_null( $rev_id ) ? $rev_id : $dbw->insertId();
1057
1058                 wfRunHooks( 'RevisionInsertComplete', array( &$this, $data, $flags ) );
1059
1060                 wfProfileOut( __METHOD__ );
1061                 return $this->mId;
1062         }
1063
1064         /**
1065          * Get the base 36 SHA-1 value for a string of text
1066          * @param $text String
1067          * @return String
1068          */
1069         public static function base36Sha1( $text ) {
1070                 return wfBaseConvert( sha1( $text ), 16, 36, 31 );
1071         }
1072
1073         /**
1074          * Lazy-load the revision's text.
1075          * Currently hardcoded to the 'text' table storage engine.
1076          *
1077          * @return String
1078          */
1079         protected function loadText() {
1080                 wfProfileIn( __METHOD__ );
1081
1082                 // Caching may be beneficial for massive use of external storage
1083                 global $wgRevisionCacheExpiry, $wgMemc;
1084                 $textId = $this->getTextId();
1085                 $key = wfMemcKey( 'revisiontext', 'textid', $textId );
1086                 if( $wgRevisionCacheExpiry ) {
1087                         $text = $wgMemc->get( $key );
1088                         if( is_string( $text ) ) {
1089                                 wfDebug( __METHOD__ . ": got id $textId from cache\n" );
1090                                 wfProfileOut( __METHOD__ );
1091                                 return $text;
1092                         }
1093                 }
1094
1095                 // If we kept data for lazy extraction, use it now...
1096                 if ( isset( $this->mTextRow ) ) {
1097                         $row = $this->mTextRow;
1098                         $this->mTextRow = null;
1099                 } else {
1100                         $row = null;
1101                 }
1102
1103                 if( !$row ) {
1104                         // Text data is immutable; check slaves first.
1105                         $dbr = wfGetDB( DB_SLAVE );
1106                         $row = $dbr->selectRow( 'text',
1107                                 array( 'old_text', 'old_flags' ),
1108                                 array( 'old_id' => $this->getTextId() ),
1109                                 __METHOD__ );
1110                 }
1111
1112                 if( !$row && wfGetLB()->getServerCount() > 1 ) {
1113                         // Possible slave lag!
1114                         $dbw = wfGetDB( DB_MASTER );
1115                         $row = $dbw->selectRow( 'text',
1116                                 array( 'old_text', 'old_flags' ),
1117                                 array( 'old_id' => $this->getTextId() ),
1118                                 __METHOD__ );
1119                 }
1120
1121                 $text = self::getRevisionText( $row );
1122
1123                 # No negative caching -- negative hits on text rows may be due to corrupted slave servers
1124                 if( $wgRevisionCacheExpiry && $text !== false ) {
1125                         $wgMemc->set( $key, $text, $wgRevisionCacheExpiry );
1126                 }
1127
1128                 wfProfileOut( __METHOD__ );
1129
1130                 return $text;
1131         }
1132
1133         /**
1134          * Create a new null-revision for insertion into a page's
1135          * history. This will not re-save the text, but simply refer
1136          * to the text from the previous version.
1137          *
1138          * Such revisions can for instance identify page rename
1139          * operations and other such meta-modifications.
1140          *
1141          * @param $dbw DatabaseBase
1142          * @param $pageId Integer: ID number of the page to read from
1143          * @param $summary String: revision's summary
1144          * @param $minor Boolean: whether the revision should be considered as minor
1145          * @return Revision|null on error
1146          */
1147         public static function newNullRevision( $dbw, $pageId, $summary, $minor ) {
1148                 wfProfileIn( __METHOD__ );
1149
1150                 $current = $dbw->selectRow(
1151                         array( 'page', 'revision' ),
1152                         array( 'page_latest', 'page_namespace', 'page_title',
1153                                 'rev_text_id', 'rev_len', 'rev_sha1' ),
1154                         array(
1155                                 'page_id' => $pageId,
1156                                 'page_latest=rev_id',
1157                                 ),
1158                         __METHOD__ );
1159
1160                 if( $current ) {
1161                         $revision = new Revision( array(
1162                                 'page'       => $pageId,
1163                                 'comment'    => $summary,
1164                                 'minor_edit' => $minor,
1165                                 'text_id'    => $current->rev_text_id,
1166                                 'parent_id'  => $current->page_latest,
1167                                 'len'        => $current->rev_len,
1168                                 'sha1'       => $current->rev_sha1
1169                                 ) );
1170                         $revision->setTitle( Title::makeTitle( $current->page_namespace, $current->page_title ) );
1171                 } else {
1172                         $revision = null;
1173                 }
1174
1175                 wfProfileOut( __METHOD__ );
1176                 return $revision;
1177         }
1178
1179         /**
1180          * Determine if the current user is allowed to view a particular
1181          * field of this revision, if it's marked as deleted.
1182          *
1183          * @param $field Integer:one of self::DELETED_TEXT,
1184          *                              self::DELETED_COMMENT,
1185          *                              self::DELETED_USER
1186          * @param $user User object to check, or null to use $wgUser
1187          * @return Boolean
1188          */
1189         public function userCan( $field, User $user = null ) {
1190                 return self::userCanBitfield( $this->mDeleted, $field, $user );
1191         }
1192
1193         /**
1194          * Determine if the current user is allowed to view a particular
1195          * field of this revision, if it's marked as deleted. This is used
1196          * by various classes to avoid duplication.
1197          *
1198          * @param $bitfield Integer: current field
1199          * @param $field Integer: one of self::DELETED_TEXT = File::DELETED_FILE,
1200          *                               self::DELETED_COMMENT = File::DELETED_COMMENT,
1201          *                               self::DELETED_USER = File::DELETED_USER
1202          * @param $user User object to check, or null to use $wgUser
1203          * @return Boolean
1204          */
1205         public static function userCanBitfield( $bitfield, $field, User $user = null ) {
1206                 if( $bitfield & $field ) { // aspect is deleted
1207                         if ( $bitfield & self::DELETED_RESTRICTED ) {
1208                                 $permission = 'suppressrevision';
1209                         } elseif ( $field & self::DELETED_TEXT ) {
1210                                 $permission = 'deletedtext';
1211                         } else {
1212                                 $permission = 'deletedhistory';
1213                         }
1214                         wfDebug( "Checking for $permission due to $field match on $bitfield\n" );
1215                         if ( $user === null ) {
1216                                 global $wgUser;
1217                                 $user = $wgUser;
1218                         }
1219                         return $user->isAllowed( $permission );
1220                 } else {
1221                         return true;
1222                 }
1223         }
1224
1225         /**
1226          * Get rev_timestamp from rev_id, without loading the rest of the row
1227          *
1228          * @param $title Title
1229          * @param $id Integer
1230          * @return String
1231          */
1232         static function getTimestampFromId( $title, $id ) {
1233                 $dbr = wfGetDB( DB_SLAVE );
1234                 // Casting fix for DB2
1235                 if ( $id == '' ) {
1236                         $id = 0;
1237                 }
1238                 $conds = array( 'rev_id' => $id );
1239                 $conds['rev_page'] = $title->getArticleID();
1240                 $timestamp = $dbr->selectField( 'revision', 'rev_timestamp', $conds, __METHOD__ );
1241                 if ( $timestamp === false && wfGetLB()->getServerCount() > 1 ) {
1242                         # Not in slave, try master
1243                         $dbw = wfGetDB( DB_MASTER );
1244                         $timestamp = $dbw->selectField( 'revision', 'rev_timestamp', $conds, __METHOD__ );
1245                 }
1246                 return wfTimestamp( TS_MW, $timestamp );
1247         }
1248
1249         /**
1250          * Get count of revisions per page...not very efficient
1251          *
1252          * @param $db DatabaseBase
1253          * @param $id Integer: page id
1254          * @return Integer
1255          */
1256         static function countByPageId( $db, $id ) {
1257                 $row = $db->selectRow( 'revision', 'COUNT(*) AS revCount',
1258                         array( 'rev_page' => $id ), __METHOD__ );
1259                 if( $row ) {
1260                         return $row->revCount;
1261                 }
1262                 return 0;
1263         }
1264
1265         /**
1266          * Get count of revisions per page...not very efficient
1267          *
1268          * @param $db DatabaseBase
1269          * @param $title Title
1270          * @return Integer
1271          */
1272         static function countByTitle( $db, $title ) {
1273                 $id = $title->getArticleID();
1274                 if( $id ) {
1275                         return Revision::countByPageId( $db, $id );
1276                 }
1277                 return 0;
1278         }
1279 }