includes/Revision.php

   1 <?php
   2 /**
   3  * Representation of a page version.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  */
  22
  23 /**
  24  * @todo document
  25  */
  26 class Revision implements IDBAccessObject {
  27         protected $mId;
  28         protected $mPage;
  29         protected $mUserText;
  30         protected $mOrigUserText;
  31         protected $mUser;
  32         protected $mMinorEdit;
  33         protected $mTimestamp;
  34         protected $mDeleted;
  35         protected $mSize;
  36         protected $mSha1;
  37         protected $mParentId;
  38         protected $mComment;
  39         protected $mText;
  40         protected $mTextRow;
  41         protected $mTitle;
  42         protected $mCurrent;
  43
  44         const DELETED_TEXT = 1;
  45         const DELETED_COMMENT = 2;
  46         const DELETED_USER = 4;
  47         const DELETED_RESTRICTED = 8;
  48         // Convenience field
  49         const SUPPRESSED_USER = 12;
  50         // Audience options for accessors
  51         const FOR_PUBLIC = 1;
  52         const FOR_THIS_USER = 2;
  53         const RAW = 3;
  54
  55         /**
  56          * Load a page revision from a given revision ID number.
  57          * Returns null if no such revision can be found.
  58          *
  59          * $flags include:
  60          *      IDBAccessObject::LATEST_READ  : Select the data from the master
  61          *      IDBAccessObject::LOCKING_READ : Select & lock the data from the master
  62          *      IDBAccessObject::AVOID_MASTER : Avoid master queries; data may be stale
  63          *
  64          * @param $id Integer
  65          * @param $flags Integer (optional)
  66          * @return Revision or null
  67          */
  68         public static function newFromId( $id, $flags = 0 ) {
  69                 return self::newFromConds( array( 'rev_id' => intval( $id ) ), $flags );
  70         }
  71
  72         /**
  73          * Load either the current, or a specified, revision
  74          * that's attached to a given title. If not attached
  75          * to that title, will return null.
  76          *
  77          * $flags include:
  78          *      IDBAccessObject::LATEST_READ  : Select the data from the master
  79          *      IDBAccessObject::LOCKING_READ : Select & lock the data from the master
  80          *      IDBAccessObject::AVOID_MASTER : Avoid master queries; data may be stale
  81          *
  82          * @param $title Title
  83          * @param $id Integer (optional)
  84          * @param $flags Integer Bitfield (optional)
  85          * @return Revision or null
  86          */
  87         public static function newFromTitle( $title, $id = 0, $flags = 0 ) {
  88                 $conds = array(
  89                         'page_namespace' => $title->getNamespace(),
  90                         'page_title'     => $title->getDBkey()
  91                 );
  92                 if ( $id ) {
  93                         // Use the specified ID
  94                         $conds['rev_id'] = $id;
  95                 } elseif ( !( $flags & self::AVOID_MASTER ) && wfGetLB()->getServerCount() > 1 ) {
  96                         // Get the latest revision ID from the master
  97                         $dbw = wfGetDB( DB_MASTER );
  98                         $latest = $dbw->selectField( 'page', 'page_latest', $conds, __METHOD__ );
  99                         if ( $latest === false ) {
 100                                 return null; // page does not exist
 101                         }
 102                         $conds['rev_id'] = $latest;
 103                 } else {
 104                         // Use a join to get the latest revision
 105                         $conds[] = 'rev_id=page_latest';
 106                 }
 107                 return self::newFromConds( $conds, $flags );
 108         }
 109
 110         /**
 111          * Load either the current, or a specified, revision
 112          * that's attached to a given page ID.
 113          * Returns null if no such revision can be found.
 114          *
 115          * $flags include:
 116          *      IDBAccessObject::LATEST_READ  : Select the data from the master
 117          *      IDBAccessObject::LOCKING_READ : Select & lock the data from the master
 118          *      IDBAccessObject::AVOID_MASTER : Avoid master queries; data may be stale
 119          *
 120          * @param $revId Integer
 121          * @param $pageId Integer (optional)
 122          * @param $flags Integer Bitfield (optional)
 123          * @return Revision or null
 124          */
 125         public static function newFromPageId( $pageId, $revId = 0, $flags = 0 ) {
 126                 $conds = array( 'page_id' => $pageId );
 127                 if ( $revId ) {
 128                         $conds['rev_id'] = $revId;
 129                 } elseif ( !( $flags & self::AVOID_MASTER ) && wfGetLB()->getServerCount() > 1 ) {
 130                         // Get the latest revision ID from the master
 131                         $dbw = wfGetDB( DB_MASTER );
 132                         $latest = $dbw->selectField( 'page', 'page_latest', $conds, __METHOD__ );
 133                         if ( $latest === false ) {
 134                                 return null; // page does not exist
 135                         }
 136                         $conds['rev_id'] = $latest;
 137                 } else {
 138                         $conds[] = 'rev_id = page_latest';
 139                 }
 140                 return self::newFromConds( $conds, $flags );
 141         }
 142
 143         /**
 144          * Make a fake revision object from an archive table row. This is queried
 145          * for permissions or even inserted (as in Special:Undelete)
 146          * @todo FIXME: Should be a subclass for RevisionDelete. [TS]
 147          *
 148          * @param $row
 149          * @param $overrides array
 150          *
 151          * @return Revision
 152          */
 153         public static function newFromArchiveRow( $row, $overrides = array() ) {
 154                 $attribs = $overrides + array(
 155                         'page'       => isset( $row->ar_page_id ) ? $row->ar_page_id : null,
 156                         'id'         => isset( $row->ar_rev_id ) ? $row->ar_rev_id : null,
 157                         'comment'    => $row->ar_comment,
 158                         'user'       => $row->ar_user,
 159                         'user_text'  => $row->ar_user_text,
 160                         'timestamp'  => $row->ar_timestamp,
 161                         'minor_edit' => $row->ar_minor_edit,
 162                         'text_id'    => isset( $row->ar_text_id ) ? $row->ar_text_id : null,
 163                         'deleted'    => $row->ar_deleted,
 164                         'len'        => $row->ar_len,
 165                         'sha1'       => isset( $row->ar_sha1 ) ? $row->ar_sha1 : null,
 166                 );
 167                 if ( isset( $row->ar_text ) && !$row->ar_text_id ) {
 168                         // Pre-1.5 ar_text row
 169                         $attribs['text'] = self::getRevisionText( $row, 'ar_' );
 170                         if ( $attribs['text'] === false ) {
 171                                 throw new MWException( 'Unable to load text from archive row (possibly bug 22624)' );
 172                         }
 173                 }
 174                 return new self( $attribs );
 175         }
 176
 177         /**
 178          * @since 1.19
 179          *
 180          * @param $row
 181          * @return Revision
 182          */
 183         public static function newFromRow( $row ) {
 184                 return new self( $row );
 185         }
 186
 187         /**
 188          * Load a page revision from a given revision ID number.
 189          * Returns null if no such revision can be found.
 190          *
 191          * @param $db DatabaseBase
 192          * @param $id Integer
 193          * @return Revision or null
 194          */
 195         public static function loadFromId( $db, $id ) {
 196                 return self::loadFromConds( $db, array( 'rev_id' => intval( $id ) ) );
 197         }
 198
 199         /**
 200          * Load either the current, or a specified, revision
 201          * that's attached to a given page. If not attached
 202          * to that page, will return null.
 203          *
 204          * @param $db DatabaseBase
 205          * @param $pageid Integer
 206          * @param $id Integer
 207          * @return Revision or null
 208          */
 209         public static function loadFromPageId( $db, $pageid, $id = 0 ) {
 210                 $conds = array( 'rev_page' => intval( $pageid ), 'page_id'  => intval( $pageid ) );
 211                 if( $id ) {
 212                         $conds['rev_id'] = intval( $id );
 213                 } else {
 214                         $conds[] = 'rev_id=page_latest';
 215                 }
 216                 return self::loadFromConds( $db, $conds );
 217         }
 218
 219         /**
 220          * Load either the current, or a specified, revision
 221          * that's attached to a given page. If not attached
 222          * to that page, will return null.
 223          *
 224          * @param $db DatabaseBase
 225          * @param $title Title
 226          * @param $id Integer
 227          * @return Revision or null
 228          */
 229         public static function loadFromTitle( $db, $title, $id = 0 ) {
 230                 if( $id ) {
 231                         $matchId = intval( $id );
 232                 } else {
 233                         $matchId = 'page_latest';
 234                 }
 235                 return self::loadFromConds( $db,
 236                         array( "rev_id=$matchId",
 237                                    'page_namespace' => $title->getNamespace(),
 238                                    'page_title'     => $title->getDBkey() )
 239                 );
 240         }
 241
 242         /**
 243          * Load the revision for the given title with the given timestamp.
 244          * WARNING: Timestamps may in some circumstances not be unique,
 245          * so this isn't the best key to use.
 246          *
 247          * @param $db DatabaseBase
 248          * @param $title Title
 249          * @param $timestamp String
 250          * @return Revision or null
 251          */
 252         public static function loadFromTimestamp( $db, $title, $timestamp ) {
 253                 return self::loadFromConds( $db,
 254                         array( 'rev_timestamp'  => $db->timestamp( $timestamp ),
 255                                    'page_namespace' => $title->getNamespace(),
 256                                    'page_title'     => $title->getDBkey() )
 257                 );
 258         }
 259
 260         /**
 261          * Given a set of conditions, fetch a revision.
 262          *
 263          * @param $conditions Array
 264          * @param $flags integer (optional)
 265          * @return Revision or null
 266          */
 267         private static function newFromConds( $conditions, $flags = 0 ) {
 268                 $db = wfGetDB( ( $flags & self::LATEST_READ ) ? DB_MASTER : DB_SLAVE );
 269                 $rev = self::loadFromConds( $db, $conditions, $flags );
 270                 if ( is_null( $rev ) && wfGetLB()->getServerCount() > 1 ) {
 271                         if ( !( $flags & self::LATEST_READ ) && !( $flags & self::AVOID_MASTER ) ) {
 272                                 $dbw = wfGetDB( DB_MASTER );
 273                                 $rev = self::loadFromConds( $dbw, $conditions, $flags );
 274                         }
 275                 }
 276                 return $rev;
 277         }
 278
 279         /**
 280          * Given a set of conditions, fetch a revision from
 281          * the given database connection.
 282          *
 283          * @param $db DatabaseBase
 284          * @param $conditions Array
 285          * @param $flags integer (optional)
 286          * @return Revision or null
 287          */
 288         private static function loadFromConds( $db, $conditions, $flags = 0 ) {
 289                 $res = self::fetchFromConds( $db, $conditions, $flags );
 290                 if( $res ) {
 291                         $row = $res->fetchObject();
 292                         if( $row ) {
 293                                 $ret = new Revision( $row );
 294                                 return $ret;
 295                         }
 296                 }
 297                 $ret = null;
 298                 return $ret;
 299         }
 300
 301         /**
 302          * Return a wrapper for a series of database rows to
 303          * fetch all of a given page's revisions in turn.
 304          * Each row can be fed to the constructor to get objects.
 305          *
 306          * @param $title Title
 307          * @return ResultWrapper
 308          */
 309         public static function fetchRevision( $title ) {
 310                 return self::fetchFromConds(
 311                         wfGetDB( DB_SLAVE ),
 312                         array( 'rev_id=page_latest',
 313                                    'page_namespace' => $title->getNamespace(),
 314                                    'page_title'     => $title->getDBkey() )
 315                 );
 316         }
 317
 318         /**
 319          * Given a set of conditions, return a ResultWrapper
 320          * which will return matching database rows with the
 321          * fields necessary to build Revision objects.
 322          *
 323          * @param $db DatabaseBase
 324          * @param $conditions Array
 325          * @param $flags integer (optional)
 326          * @return ResultWrapper
 327          */
 328         private static function fetchFromConds( $db, $conditions, $flags = 0 ) {
 329                 $fields = array_merge(
 330                         self::selectFields(),
 331                         self::selectPageFields(),
 332                         self::selectUserFields()
 333                 );
 334                 $options = array( 'LIMIT' => 1 );
 335                 if ( $flags & self::FOR_UPDATE ) {
 336                         $options[] = 'FOR UPDATE';
 337                 }
 338                 return $db->select(
 339                         array( 'revision', 'page', 'user' ),
 340                         $fields,
 341                         $conditions,
 342                         __METHOD__,
 343                         $options,
 344                         array( 'page' => self::pageJoinCond(), 'user' => self::userJoinCond() )
 345                 );
 346         }
 347
 348         /**
 349          * Return the value of a select() JOIN conds array for the user table.
 350          * This will get user table rows for logged-in users.
 351          * @since 1.19
 352          * @return Array
 353          */
 354         public static function userJoinCond() {
 355                 return array( 'LEFT JOIN', array( 'rev_user != 0', 'user_id = rev_user' ) );
 356         }
 357
 358         /**
 359          * Return the value of a select() page conds array for the paeg table.
 360          * This will assure that the revision(s) are not orphaned from live pages.
 361          * @since 1.19
 362          * @return Array
 363          */
 364         public static function pageJoinCond() {
 365                 return array( 'INNER JOIN', array( 'page_id = rev_page' ) );
 366         }
 367
 368         /**
 369          * Return the list of revision fields that should be selected to create
 370          * a new revision.
 371          * @return array
 372          */
 373         public static function selectFields() {
 374                 return array(
 375                         'rev_id',
 376                         'rev_page',
 377                         'rev_text_id',
 378                         'rev_timestamp',
 379                         'rev_comment',
 380                         'rev_user_text',
 381                         'rev_user',
 382                         'rev_minor_edit',
 383                         'rev_deleted',
 384                         'rev_len',
 385                         'rev_parent_id',
 386                         'rev_sha1'
 387                 );
 388         }
 389
 390         /**
 391          * Return the list of text fields that should be selected to read the
 392          * revision text
 393          * @return array
 394          */
 395         public static function selectTextFields() {
 396                 return array(
 397                         'old_text',
 398                         'old_flags'
 399                 );
 400         }
 401
 402         /**
 403          * Return the list of page fields that should be selected from page table
 404          * @return array
 405          */
 406         public static function selectPageFields() {
 407                 return array(
 408                         'page_namespace',
 409                         'page_title',
 410                         'page_id',
 411                         'page_latest',
 412                         'page_is_redirect',
 413                         'page_len',
 414                 );
 415         }
 416
 417         /**
 418          * Return the list of user fields that should be selected from user table
 419          * @return array
 420          */
 421         public static function selectUserFields() {
 422                 return array( 'user_name' );
 423         }
 424
 425         /**
 426          * Do a batched query to get the parent revision lengths
 427          * @param $db DatabaseBase
 428          * @param $revIds Array
 429          * @return array
 430          */
 431         public static function getParentLengths( $db, array $revIds ) {
 432                 $revLens = array();
 433                 if ( !$revIds ) {
 434                         return $revLens; // empty
 435                 }
 436                 wfProfileIn( __METHOD__ );
 437                 $res = $db->select( 'revision',
 438                         array( 'rev_id', 'rev_len' ),
 439                         array( 'rev_id' => $revIds ),
 440                         __METHOD__ );
 441                 foreach ( $res as $row ) {
 442                         $revLens[$row->rev_id] = $row->rev_len;
 443                 }
 444                 wfProfileOut( __METHOD__ );
 445                 return $revLens;
 446         }
 447
 448         /**
 449          * Constructor
 450          *
 451          * @param $row Mixed: either a database row or an array
 452          * @access private
 453          */
 454         function __construct( $row ) {
 455                 if( is_object( $row ) ) {
 456                         $this->mId        = intval( $row->rev_id );
 457                         $this->mPage      = intval( $row->rev_page );
 458                         $this->mTextId    = intval( $row->rev_text_id );
 459                         $this->mComment   =         $row->rev_comment;
 460                         $this->mUser      = intval( $row->rev_user );
 461                         $this->mMinorEdit = intval( $row->rev_minor_edit );
 462                         $this->mTimestamp =         $row->rev_timestamp;
 463                         $this->mDeleted   = intval( $row->rev_deleted );
 464
 465                         if( !isset( $row->rev_parent_id ) ) {
 466                                 $this->mParentId = is_null( $row->rev_parent_id ) ? null : 0;
 467                         } else {
 468                                 $this->mParentId  = intval( $row->rev_parent_id );
 469                         }
 470
 471                         if( !isset( $row->rev_len ) || is_null( $row->rev_len ) ) {
 472                                 $this->mSize = null;
 473                         } else {
 474                                 $this->mSize = intval( $row->rev_len );
 475                         }
 476
 477                         if ( !isset( $row->rev_sha1 ) ) {
 478                                 $this->mSha1 = null;
 479                         } else {
 480                                 $this->mSha1 = $row->rev_sha1;
 481                         }
 482
 483                         if( isset( $row->page_latest ) ) {
 484                                 $this->mCurrent = ( $row->rev_id == $row->page_latest );
 485                                 $this->mTitle = Title::newFromRow( $row );
 486                         } else {
 487                                 $this->mCurrent = false;
 488                                 $this->mTitle = null;
 489                         }
 490
 491                         // Lazy extraction...
 492                         $this->mText      = null;
 493                         if( isset( $row->old_text ) ) {
 494                                 $this->mTextRow = $row;
 495                         } else {
 496                                 // 'text' table row entry will be lazy-loaded
 497                                 $this->mTextRow = null;
 498                         }
 499
 500                         // Use user_name for users and rev_user_text for IPs...
 501                         $this->mUserText = null; // lazy load if left null
 502                         if ( $this->mUser == 0 ) {
 503                                 $this->mUserText = $row->rev_user_text; // IP user
 504                         } elseif ( isset( $row->user_name ) ) {
 505                                 $this->mUserText = $row->user_name; // logged-in user
 506                         }
 507                         $this->mOrigUserText = $row->rev_user_text;
 508                 } elseif( is_array( $row ) ) {
 509                         // Build a new revision to be saved...
 510                         global $wgUser; // ugh
 511
 512                         $this->mId        = isset( $row['id']         ) ? intval( $row['id']         ) : null;
 513                         $this->mPage      = isset( $row['page']       ) ? intval( $row['page']       ) : null;
 514                         $this->mTextId    = isset( $row['text_id']    ) ? intval( $row['text_id']    ) : null;
 515                         $this->mUserText  = isset( $row['user_text']  ) ? strval( $row['user_text']  ) : $wgUser->getName();
 516                         $this->mUser      = isset( $row['user']       ) ? intval( $row['user']       ) : $wgUser->getId();
 517                         $this->mMinorEdit = isset( $row['minor_edit'] ) ? intval( $row['minor_edit'] ) : 0;
 518                         $this->mTimestamp = isset( $row['timestamp']  ) ? strval( $row['timestamp']  ) : wfTimestampNow();
 519                         $this->mDeleted   = isset( $row['deleted']    ) ? intval( $row['deleted']    ) : 0;
 520                         $this->mSize      = isset( $row['len']        ) ? intval( $row['len']        ) : null;
 521                         $this->mParentId  = isset( $row['parent_id']  ) ? intval( $row['parent_id']  ) : null;
 522                         $this->mSha1      = isset( $row['sha1']  )      ? strval( $row['sha1']  )      : null;
 523
 524                         // Enforce spacing trimming on supplied text
 525                         $this->mComment   = isset( $row['comment']    ) ?  trim( strval( $row['comment'] ) ) : null;
 526                         $this->mText      = isset( $row['text']       ) ? rtrim( strval( $row['text']    ) ) : null;
 527                         $this->mTextRow   = null;
 528
 529                         $this->mTitle     = null; # Load on demand if needed
 530                         $this->mCurrent   = false;
 531                         # If we still have no length, see it we have the text to figure it out
 532                         if ( !$this->mSize ) {
 533                                 $this->mSize = is_null( $this->mText ) ? null : strlen( $this->mText );
 534                         }
 535                         # Same for sha1
 536                         if ( $this->mSha1 === null ) {
 537                                 $this->mSha1 = is_null( $this->mText ) ? null : self::base36Sha1( $this->mText );
 538                         }
 539                 } else {
 540                         throw new MWException( 'Revision constructor passed invalid row format.' );
 541                 }
 542                 $this->mUnpatrolled = null;
 543         }
 544
 545         /**
 546          * Get revision ID
 547          *
 548          * @return Integer|null
 549          */
 550         public function getId() {
 551                 return $this->mId;
 552         }
 553
 554         /**
 555          * Set the revision ID
 556          *
 557          * @since 1.19
 558          * @param $id Integer
 559          */
 560         public function setId( $id ) {
 561                 $this->mId = $id;
 562         }
 563
 564         /**
 565          * Get text row ID
 566          *
 567          * @return Integer|null
 568          */
 569         public function getTextId() {
 570                 return $this->mTextId;
 571         }
 572
 573         /**
 574          * Get parent revision ID (the original previous page revision)
 575          *
 576          * @return Integer|null
 577          */
 578         public function getParentId() {
 579                 return $this->mParentId;
 580         }
 581
 582         /**
 583          * Returns the length of the text in this revision, or null if unknown.
 584          *
 585          * @return Integer|null
 586          */
 587         public function getSize() {
 588                 return $this->mSize;
 589         }
 590
 591         /**
 592          * Returns the base36 sha1 of the text in this revision, or null if unknown.
 593          *
 594          * @return String|null
 595          */
 596         public function getSha1() {
 597                 return $this->mSha1;
 598         }
 599
 600         /**
 601          * Returns the title of the page associated with this entry or null.
 602          *
 603          * Will do a query, when title is not set and id is given.
 604          *
 605          * @return Title|null
 606          */
 607         public function getTitle() {
 608                 if( isset( $this->mTitle ) ) {
 609                         return $this->mTitle;
 610                 }
 611                 if( !is_null( $this->mId ) ) { //rev_id is defined as NOT NULL
 612                         $dbr = wfGetDB( DB_SLAVE );
 613                         $row = $dbr->selectRow(
 614                                 array( 'page', 'revision' ),
 615                                 self::selectPageFields(),
 616                                 array( 'page_id=rev_page',
 617                                            'rev_id' => $this->mId ),
 618                                 __METHOD__ );
 619                         if ( $row ) {
 620                                 $this->mTitle = Title::newFromRow( $row );
 621                         }
 622                 }
 623                 return $this->mTitle;
 624         }
 625
 626         /**
 627          * Set the title of the revision
 628          *
 629          * @param $title Title
 630          */
 631         public function setTitle( $title ) {
 632                 $this->mTitle = $title;
 633         }
 634
 635         /**
 636          * Get the page ID
 637          *
 638          * @return Integer|null
 639          */
 640         public function getPage() {
 641                 return $this->mPage;
 642         }
 643
 644         /**
 645          * Fetch revision's user id if it's available to the specified audience.
 646          * If the specified audience does not have access to it, zero will be
 647          * returned.
 648          *
 649          * @param $audience Integer: one of:
 650          *      Revision::FOR_PUBLIC       to be displayed to all users
 651          *      Revision::FOR_THIS_USER    to be displayed to the given user
 652          *      Revision::RAW              get the ID regardless of permissions
 653          * @param $user User object to check for, only if FOR_THIS_USER is passed
 654          *              to the $audience parameter
 655          * @return Integer
 656          */
 657         public function getUser( $audience = self::FOR_PUBLIC, User $user = null ) {
 658                 if( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_USER ) ) {
 659                         return 0;
 660                 } elseif( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_USER, $user ) ) {
 661                         return 0;
 662                 } else {
 663                         return $this->mUser;
 664                 }
 665         }
 666
 667         /**
 668          * Fetch revision's user id without regard for the current user's permissions
 669          *
 670          * @return String
 671          */
 672         public function getRawUser() {
 673                 return $this->mUser;
 674         }
 675
 676         /**
 677          * Fetch revision's username if it's available to the specified audience.
 678          * If the specified audience does not have access to the username, an
 679          * empty string will be returned.
 680          *
 681          * @param $audience Integer: one of:
 682          *      Revision::FOR_PUBLIC       to be displayed to all users
 683          *      Revision::FOR_THIS_USER    to be displayed to the given user
 684          *      Revision::RAW              get the text regardless of permissions
 685          * @param $user User object to check for, only if FOR_THIS_USER is passed
 686          *              to the $audience parameter
 687          * @return string
 688          */
 689         public function getUserText( $audience = self::FOR_PUBLIC, User $user = null ) {
 690                 if( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_USER ) ) {
 691                         return '';
 692                 } elseif( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_USER, $user ) ) {
 693                         return '';
 694                 } else {
 695                         return $this->getRawUserText();
 696                 }
 697         }
 698
 699         /**
 700          * Fetch revision's username without regard for view restrictions
 701          *
 702          * @return String
 703          */
 704         public function getRawUserText() {
 705                 if ( $this->mUserText === null ) {
 706                         $this->mUserText = User::whoIs( $this->mUser ); // load on demand
 707                         if ( $this->mUserText === false ) {
 708                                 # This shouldn't happen, but it can if the wiki was recovered
 709                                 # via importing revs and there is no user table entry yet.
 710                                 $this->mUserText = $this->mOrigUserText;
 711                         }
 712                 }
 713                 return $this->mUserText;
 714         }
 715
 716         /**
 717          * Fetch revision comment if it's available to the specified audience.
 718          * If the specified audience does not have access to the comment, an
 719          * empty string will be returned.
 720          *
 721          * @param $audience Integer: one of:
 722          *      Revision::FOR_PUBLIC       to be displayed to all users
 723          *      Revision::FOR_THIS_USER    to be displayed to the given user
 724          *      Revision::RAW              get the text regardless of permissions
 725          * @param $user User object to check for, only if FOR_THIS_USER is passed
 726          *              to the $audience parameter
 727          * @return String
 728          */
 729         function getComment( $audience = self::FOR_PUBLIC, User $user = null ) {
 730                 if( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_COMMENT ) ) {
 731                         return '';
 732                 } elseif( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_COMMENT, $user ) ) {
 733                         return '';
 734                 } else {
 735                         return $this->mComment;
 736                 }
 737         }
 738
 739         /**
 740          * Fetch revision comment without regard for the current user's permissions
 741          *
 742          * @return String
 743          */
 744         public function getRawComment() {
 745                 return $this->mComment;
 746         }
 747
 748         /**
 749          * @return Boolean
 750          */
 751         public function isMinor() {
 752                 return (bool)$this->mMinorEdit;
 753         }
 754
 755         /**
 756          * @return Integer rcid of the unpatrolled row, zero if there isn't one
 757          */
 758         public function isUnpatrolled() {
 759                 if( $this->mUnpatrolled !== null ) {
 760                         return $this->mUnpatrolled;
 761                 }
 762                 $dbr = wfGetDB( DB_SLAVE );
 763                 $this->mUnpatrolled = $dbr->selectField( 'recentchanges',
 764                         'rc_id',
 765                         array( // Add redundant user,timestamp condition so we can use the existing index
 766                                 'rc_user_text'  => $this->getRawUserText(),
 767                                 'rc_timestamp'  => $dbr->timestamp( $this->getTimestamp() ),
 768                                 'rc_this_oldid' => $this->getId(),
 769                                 'rc_patrolled'  => 0
 770                         ),
 771                         __METHOD__
 772                 );
 773                 return (int)$this->mUnpatrolled;
 774         }
 775
 776         /**
 777          * @param $field int one of DELETED_* bitfield constants
 778          *
 779          * @return Boolean
 780          */
 781         public function isDeleted( $field ) {
 782                 return ( $this->mDeleted & $field ) == $field;
 783         }
 784
 785         /**
 786          * Get the deletion bitfield of the revision
 787          *
 788          * @return int
 789          */
 790         public function getVisibility() {
 791                 return (int)$this->mDeleted;
 792         }
 793
 794         /**
 795          * Fetch revision text if it's available to the specified audience.
 796          * If the specified audience does not have the ability to view this
 797          * revision, an empty string will be returned.
 798          *
 799          * @param $audience Integer: one of:
 800          *      Revision::FOR_PUBLIC       to be displayed to all users
 801          *      Revision::FOR_THIS_USER    to be displayed to the given user
 802          *      Revision::RAW              get the text regardless of permissions
 803          * @param $user User object to check for, only if FOR_THIS_USER is passed
 804          *              to the $audience parameter
 805          * @return String
 806          */
 807         public function getText( $audience = self::FOR_PUBLIC, User $user = null ) {
 808                 if( $audience == self::FOR_PUBLIC && $this->isDeleted( self::DELETED_TEXT ) ) {
 809                         return '';
 810                 } elseif( $audience == self::FOR_THIS_USER && !$this->userCan( self::DELETED_TEXT, $user ) ) {
 811                         return '';
 812                 } else {
 813                         return $this->getRawText();
 814                 }
 815         }
 816
 817         /**
 818          * Alias for getText(Revision::FOR_THIS_USER)
 819          *
 820          * @deprecated since 1.17
 821          * @return String
 822          */
 823         public function revText() {
 824                 wfDeprecated( __METHOD__, '1.17' );
 825                 return $this->getText( self::FOR_THIS_USER );
 826         }
 827
 828         /**
 829          * Fetch revision text without regard for view restrictions
 830          *
 831          * @return String
 832          */
 833         public function getRawText() {
 834                 if( is_null( $this->mText ) ) {
 835                         // Revision text is immutable. Load on demand:
 836                         $this->mText = $this->loadText();
 837                 }
 838                 return $this->mText;
 839         }
 840
 841         /**
 842          * @return String
 843          */
 844         public function getTimestamp() {
 845                 return wfTimestamp( TS_MW, $this->mTimestamp );
 846         }
 847
 848         /**
 849          * @return Boolean
 850          */
 851         public function isCurrent() {
 852                 return $this->mCurrent;
 853         }
 854
 855         /**
 856          * Get previous revision for this title
 857          *
 858          * @return Revision or null
 859          */
 860         public function getPrevious() {
 861                 if( $this->getTitle() ) {
 862                         $prev = $this->getTitle()->getPreviousRevisionID( $this->getId() );
 863                         if( $prev ) {
 864                                 return self::newFromTitle( $this->getTitle(), $prev );
 865                         }
 866                 }
 867                 return null;
 868         }
 869
 870         /**
 871          * Get next revision for this title
 872          *
 873          * @return Revision or null
 874          */
 875         public function getNext() {
 876                 if( $this->getTitle() ) {
 877                         $next = $this->getTitle()->getNextRevisionID( $this->getId() );
 878                         if ( $next ) {
 879                                 return self::newFromTitle( $this->getTitle(), $next );
 880                         }
 881                 }
 882                 return null;
 883         }
 884
 885         /**
 886          * Get previous revision Id for this page_id
 887          * This is used to populate rev_parent_id on save
 888          *
 889          * @param $db DatabaseBase
 890          * @return Integer
 891          */
 892         private function getPreviousRevisionId( $db ) {
 893                 if( is_null( $this->mPage ) ) {
 894                         return 0;
 895                 }
 896                 # Use page_latest if ID is not given
 897                 if( !$this->mId ) {
 898                         $prevId = $db->selectField( 'page', 'page_latest',
 899                                 array( 'page_id' => $this->mPage ),
 900                                 __METHOD__ );
 901                 } else {
 902                         $prevId = $db->selectField( 'revision', 'rev_id',
 903                                 array( 'rev_page' => $this->mPage, 'rev_id < ' . $this->mId ),
 904                                 __METHOD__,
 905                                 array( 'ORDER BY' => 'rev_id DESC' ) );
 906                 }
 907                 return intval( $prevId );
 908         }
 909
 910         /**
 911           * Get revision text associated with an old or archive row
 912           * $row is usually an object from wfFetchRow(), both the flags and the text
 913           * field must be included
 914           *
 915           * @param $row Object: the text data
 916           * @param $prefix String: table prefix (default 'old_')
 917           * @return String: text the text requested or false on failure
 918           */
 919         public static function getRevisionText( $row, $prefix = 'old_' ) {
 920                 wfProfileIn( __METHOD__ );
 921
 922                 # Get data
 923                 $textField = $prefix . 'text';
 924                 $flagsField = $prefix . 'flags';
 925
 926                 if( isset( $row->$flagsField ) ) {
 927                         $flags = explode( ',', $row->$flagsField );
 928                 } else {
 929                         $flags = array();
 930                 }
 931
 932                 if( isset( $row->$textField ) ) {
 933                         $text = $row->$textField;
 934                 } else {
 935                         wfProfileOut( __METHOD__ );
 936                         return false;
 937                 }
 938
 939                 # Use external methods for external objects, text in table is URL-only then
 940                 if ( in_array( 'external', $flags ) ) {
 941                         $url = $text;
 942                         $parts = explode( '://', $url, 2 );
 943                         if( count( $parts ) == 1 || $parts[1] == '' ) {
 944                                 wfProfileOut( __METHOD__ );
 945                                 return false;
 946                         }
 947                         $text = ExternalStore::fetchFromURL( $url );
 948                 }
 949
 950                 // If the text was fetched without an error, convert it
 951                 if ( $text !== false ) {
 952                         if( in_array( 'gzip', $flags ) ) {
 953                                 # Deal with optional compression of archived pages.
 954                                 # This can be done periodically via maintenance/compressOld.php, and
 955                                 # as pages are saved if $wgCompressRevisions is set.
 956                                 $text = gzinflate( $text );
 957                         }
 958
 959                         if( in_array( 'object', $flags ) ) {
 960                                 # Generic compressed storage
 961                                 $obj = unserialize( $text );
 962                                 if ( !is_object( $obj ) ) {
 963                                         // Invalid object
 964                                         wfProfileOut( __METHOD__ );
 965                                         return false;
 966                                 }
 967                                 $text = $obj->getText();
 968                         }
 969
 970                         global $wgLegacyEncoding;
 971                         if( $text !== false && $wgLegacyEncoding
 972                                 && !in_array( 'utf-8', $flags ) && !in_array( 'utf8', $flags ) )
 973                         {
 974                                 # Old revisions kept around in a legacy encoding?
 975                                 # Upconvert on demand.
 976                                 # ("utf8" checked for compatibility with some broken
 977                                 #  conversion scripts 2008-12-30)
 978                                 global $wgContLang;
 979                                 $text = $wgContLang->iconv( $wgLegacyEncoding, 'UTF-8', $text );
 980                         }
 981                 }
 982                 wfProfileOut( __METHOD__ );
 983                 return $text;
 984         }
 985
 986         /**
 987          * If $wgCompressRevisions is enabled, we will compress data.
 988          * The input string is modified in place.
 989          * Return value is the flags field: contains 'gzip' if the
 990          * data is compressed, and 'utf-8' if we're saving in UTF-8
 991          * mode.
 992          *
 993          * @param $text Mixed: reference to a text
 994          * @return String
 995          */
 996         public static function compressRevisionText( &$text ) {
 997                 global $wgCompressRevisions;
 998                 $flags = array();
 999
1000                 # Revisions not marked this way will be converted
1001                 # on load if $wgLegacyCharset is set in the future.
1002                 $flags[] = 'utf-8';
1003
1004                 if( $wgCompressRevisions ) {
1005                         if( function_exists( 'gzdeflate' ) ) {
1006                                 $text = gzdeflate( $text );
1007                                 $flags[] = 'gzip';
1008                         } else {
1009                                 wfDebug( __METHOD__ . " -- no zlib support, not compressing\n" );
1010                         }
1011                 }
1012                 return implode( ',', $flags );
1013         }
1014
1015         /**
1016          * Insert a new revision into the database, returning the new revision ID
1017          * number on success and dies horribly on failure.
1018          *
1019          * @param $dbw DatabaseBase: (master connection)
1020          * @return Integer
1021          */
1022         public function insertOn( $dbw ) {
1023                 global $wgDefaultExternalStore;
1024
1025                 wfProfileIn( __METHOD__ );
1026
1027                 $data = $this->mText;
1028                 $flags = self::compressRevisionText( $data );
1029
1030                 # Write to external storage if required
1031                 if( $wgDefaultExternalStore ) {
1032                         // Store and get the URL
1033                         $data = ExternalStore::insertToDefault( $data );
1034                         if( !$data ) {
1035                                 throw new MWException( "Unable to store text to external storage" );
1036                         }
1037                         if( $flags ) {
1038                                 $flags .= ',';
1039                         }
1040                         $flags .= 'external';
1041                 }
1042
1043                 # Record the text (or external storage URL) to the text table
1044                 if( !isset( $this->mTextId ) ) {
1045                         $old_id = $dbw->nextSequenceValue( 'text_old_id_seq' );
1046                         $dbw->insert( 'text',
1047                                 array(
1048                                         'old_id'    => $old_id,
1049                                         'old_text'  => $data,
1050                                         'old_flags' => $flags,
1051                                 ), __METHOD__
1052                         );
1053                         $this->mTextId = $dbw->insertId();
1054                 }
1055
1056                 if ( $this->mComment === null ) $this->mComment = "";
1057
1058                 # Record the edit in revisions
1059                 $rev_id = isset( $this->mId )
1060                         ? $this->mId
1061                         : $dbw->nextSequenceValue( 'revision_rev_id_seq' );
1062                 $dbw->insert( 'revision',
1063                         array(
1064                                 'rev_id'         => $rev_id,
1065                                 'rev_page'       => $this->mPage,
1066                                 'rev_text_id'    => $this->mTextId,
1067                                 'rev_comment'    => $this->mComment,
1068                                 'rev_minor_edit' => $this->mMinorEdit ? 1 : 0,
1069                                 'rev_user'       => $this->mUser,
1070                                 'rev_user_text'  => $this->mUserText,
1071                                 'rev_timestamp'  => $dbw->timestamp( $this->mTimestamp ),
1072                                 'rev_deleted'    => $this->mDeleted,
1073                                 'rev_len'        => $this->mSize,
1074                                 'rev_parent_id'  => is_null( $this->mParentId )
1075                                         ? $this->getPreviousRevisionId( $dbw )
1076                                         : $this->mParentId,
1077                                 'rev_sha1'       => is_null( $this->mSha1 )
1078                                         ? self::base36Sha1( $this->mText )
1079                                         : $this->mSha1
1080                         ), __METHOD__
1081                 );
1082
1083                 $this->mId = !is_null( $rev_id ) ? $rev_id : $dbw->insertId();
1084
1085                 wfRunHooks( 'RevisionInsertComplete', array( &$this, $data, $flags ) );
1086
1087                 wfProfileOut( __METHOD__ );
1088                 return $this->mId;
1089         }
1090
1091         /**
1092          * Get the base 36 SHA-1 value for a string of text
1093          * @param $text String
1094          * @return String
1095          */
1096         public static function base36Sha1( $text ) {
1097                 return wfBaseConvert( sha1( $text ), 16, 36, 31 );
1098         }
1099
1100         /**
1101          * Lazy-load the revision's text.
1102          * Currently hardcoded to the 'text' table storage engine.
1103          *
1104          * @return String
1105          */
1106         protected function loadText() {
1107                 wfProfileIn( __METHOD__ );
1108
1109                 // Caching may be beneficial for massive use of external storage
1110                 global $wgRevisionCacheExpiry, $wgMemc;
1111                 $textId = $this->getTextId();
1112                 $key = wfMemcKey( 'revisiontext', 'textid', $textId );
1113                 if( $wgRevisionCacheExpiry ) {
1114                         $text = $wgMemc->get( $key );
1115                         if( is_string( $text ) ) {
1116                                 wfDebug( __METHOD__ . ": got id $textId from cache\n" );
1117                                 wfProfileOut( __METHOD__ );
1118                                 return $text;
1119                         }
1120                 }
1121
1122                 // If we kept data for lazy extraction, use it now...
1123                 if ( isset( $this->mTextRow ) ) {
1124                         $row = $this->mTextRow;
1125                         $this->mTextRow = null;
1126                 } else {
1127                         $row = null;
1128                 }
1129
1130                 if( !$row ) {
1131                         // Text data is immutable; check slaves first.
1132                         $dbr = wfGetDB( DB_SLAVE );
1133                         $row = $dbr->selectRow( 'text',
1134                                 array( 'old_text', 'old_flags' ),
1135                                 array( 'old_id' => $this->getTextId() ),
1136                                 __METHOD__ );
1137                 }
1138
1139                 if( !$row && wfGetLB()->getServerCount() > 1 ) {
1140                         // Possible slave lag!
1141                         $dbw = wfGetDB( DB_MASTER );
1142                         $row = $dbw->selectRow( 'text',
1143                                 array( 'old_text', 'old_flags' ),
1144                                 array( 'old_id' => $this->getTextId() ),
1145                                 __METHOD__ );
1146                 }
1147
1148                 $text = self::getRevisionText( $row );
1149
1150                 # No negative caching -- negative hits on text rows may be due to corrupted slave servers
1151                 if( $wgRevisionCacheExpiry && $text !== false ) {
1152                         $wgMemc->set( $key, $text, $wgRevisionCacheExpiry );
1153                 }
1154
1155                 wfProfileOut( __METHOD__ );
1156
1157                 return $text;
1158         }
1159
1160         /**
1161          * Create a new null-revision for insertion into a page's
1162          * history. This will not re-save the text, but simply refer
1163          * to the text from the previous version.
1164          *
1165          * Such revisions can for instance identify page rename
1166          * operations and other such meta-modifications.
1167          *
1168          * @param $dbw DatabaseBase
1169          * @param $pageId Integer: ID number of the page to read from
1170          * @param $summary String: revision's summary
1171          * @param $minor Boolean: whether the revision should be considered as minor
1172          * @return Revision|null on error
1173          */
1174         public static function newNullRevision( $dbw, $pageId, $summary, $minor ) {
1175                 wfProfileIn( __METHOD__ );
1176
1177                 $current = $dbw->selectRow(
1178                         array( 'page', 'revision' ),
1179                         array( 'page_latest', 'page_namespace', 'page_title',
1180                                 'rev_text_id', 'rev_len', 'rev_sha1' ),
1181                         array(
1182                                 'page_id' => $pageId,
1183                                 'page_latest=rev_id',
1184                                 ),
1185                         __METHOD__ );
1186
1187                 if( $current ) {
1188                         $revision = new Revision( array(
1189                                 'page'       => $pageId,
1190                                 'comment'    => $summary,
1191                                 'minor_edit' => $minor,
1192                                 'text_id'    => $current->rev_text_id,
1193                                 'parent_id'  => $current->page_latest,
1194                                 'len'        => $current->rev_len,
1195                                 'sha1'       => $current->rev_sha1
1196                                 ) );
1197                         $revision->setTitle( Title::makeTitle( $current->page_namespace, $current->page_title ) );
1198                 } else {
1199                         $revision = null;
1200                 }
1201
1202                 wfProfileOut( __METHOD__ );
1203                 return $revision;
1204         }
1205
1206         /**
1207          * Determine if the current user is allowed to view a particular
1208          * field of this revision, if it's marked as deleted.
1209          *
1210          * @param $field Integer:one of self::DELETED_TEXT,
1211          *                              self::DELETED_COMMENT,
1212          *                              self::DELETED_USER
1213          * @param $user User object to check, or null to use $wgUser
1214          * @return Boolean
1215          */
1216         public function userCan( $field, User $user = null ) {
1217                 return self::userCanBitfield( $this->mDeleted, $field, $user );
1218         }
1219
1220         /**
1221          * Determine if the current user is allowed to view a particular
1222          * field of this revision, if it's marked as deleted. This is used
1223          * by various classes to avoid duplication.
1224          *
1225          * @param $bitfield Integer: current field
1226          * @param $field Integer: one of self::DELETED_TEXT = File::DELETED_FILE,
1227          *                               self::DELETED_COMMENT = File::DELETED_COMMENT,
1228          *                               self::DELETED_USER = File::DELETED_USER
1229          * @param $user User object to check, or null to use $wgUser
1230          * @return Boolean
1231          */
1232         public static function userCanBitfield( $bitfield, $field, User $user = null ) {
1233                 if( $bitfield & $field ) { // aspect is deleted
1234                         if ( $bitfield & self::DELETED_RESTRICTED ) {
1235                                 $permission = 'suppressrevision';
1236                         } elseif ( $field & self::DELETED_TEXT ) {
1237                                 $permission = 'deletedtext';
1238                         } else {
1239                                 $permission = 'deletedhistory';
1240                         }
1241                         wfDebug( "Checking for $permission due to $field match on $bitfield\n" );
1242                         if ( $user === null ) {
1243                                 global $wgUser;
1244                                 $user = $wgUser;
1245                         }
1246                         return $user->isAllowed( $permission );
1247                 } else {
1248                         return true;
1249                 }
1250         }
1251
1252         /**
1253          * Get rev_timestamp from rev_id, without loading the rest of the row
1254          *
1255          * @param $title Title
1256          * @param $id Integer
1257          * @return String
1258          */
1259         static function getTimestampFromId( $title, $id ) {
1260                 $dbr = wfGetDB( DB_SLAVE );
1261                 // Casting fix for DB2
1262                 if ( $id == '' ) {
1263                         $id = 0;
1264                 }
1265                 $conds = array( 'rev_id' => $id );
1266                 $conds['rev_page'] = $title->getArticleID();
1267                 $timestamp = $dbr->selectField( 'revision', 'rev_timestamp', $conds, __METHOD__ );
1268                 if ( $timestamp === false && wfGetLB()->getServerCount() > 1 ) {
1269                         # Not in slave, try master
1270                         $dbw = wfGetDB( DB_MASTER );
1271                         $timestamp = $dbw->selectField( 'revision', 'rev_timestamp', $conds, __METHOD__ );
1272                 }
1273                 return wfTimestamp( TS_MW, $timestamp );
1274         }
1275
1276         /**
1277          * Get count of revisions per page...not very efficient
1278          *
1279          * @param $db DatabaseBase
1280          * @param $id Integer: page id
1281          * @return Integer
1282          */
1283         static function countByPageId( $db, $id ) {
1284                 $row = $db->selectRow( 'revision', 'COUNT(*) AS revCount',
1285                         array( 'rev_page' => $id ), __METHOD__ );
1286                 if( $row ) {
1287                         return $row->revCount;
1288                 }
1289                 return 0;
1290         }
1291
1292         /**
1293          * Get count of revisions per page...not very efficient
1294          *
1295          * @param $db DatabaseBase
1296          * @param $title Title
1297          * @return Integer
1298          */
1299         static function countByTitle( $db, $title ) {
1300                 $id = $title->getArticleID();
1301                 if( $id ) {
1302                         return self::countByPageId( $db, $id );
1303                 }
1304                 return 0;
1305         }
1306 }