includes/LinksUpdate.php

   1 <?php
   2 /**
   3  * See docs/deferred.txt
   4  *
   5  * @todo document (e.g. one-sentence top-level class description).
   6  */
   7 class LinksUpdate {
   8
   9         /**@{{
  10          * @private
  11          */
  12         var $mId,            //!< Page ID of the article linked from
  13                 $mTitle,         //!< Title object of the article linked from
  14                 $mLinks,         //!< Map of title strings to IDs for the links in the document
  15                 $mImages,        //!< DB keys of the images used, in the array key only
  16                 $mTemplates,     //!< Map of title strings to IDs for the template references, including broken ones
  17                 $mExternals,     //!< URLs of external links, array key only
  18                 $mCategories,    //!< Map of category names to sort keys
  19                 $mInterlangs,    //!< Map of language codes to titles
  20                 $mProperties,    //!< Map of arbitrary name to value
  21                 $mDb,            //!< Database connection reference
  22                 $mOptions,       //!< SELECT options to be used (array)
  23                 $mRecursive;     //!< Whether to queue jobs for recursive updates
  24         /**@}}*/
  25
  26         /**
  27          * Constructor
  28          *
  29          * @param Title $title Title of the page we're updating
  30          * @param ParserOutput $parserOutput Output from a full parse of this page
  31          * @param bool $recursive Queue jobs for recursive updates?
  32          */
  33         function LinksUpdate( $title, $parserOutput, $recursive = true ) {
  34                 global $wgAntiLockFlags;
  35
  36                 if ( $wgAntiLockFlags & ALF_NO_LINK_LOCK ) {
  37                         $this->mOptions = array();
  38                 } else {
  39                         $this->mOptions = array( 'FOR UPDATE' );
  40                 }
  41                 $this->mDb = wfGetDB( DB_MASTER );
  42
  43                 if ( !is_object( $title ) ) {
  44                         throw new MWException( "The calling convention to LinksUpdate::LinksUpdate() has changed. " .
  45                                 "Please see Article::editUpdates() for an invocation example.\n" );
  46                 }
  47                 $this->mTitle = $title;
  48                 $this->mId = $title->getArticleID();
  49
  50                 $this->mLinks = $parserOutput->getLinks();
  51                 $this->mImages = $parserOutput->getImages();
  52                 $this->mTemplates = $parserOutput->getTemplates();
  53                 $this->mExternals = $parserOutput->getExternalLinks();
  54                 $this->mCategories = $parserOutput->getCategories();
  55                 $this->mProperties = $parserOutput->getProperties();
  56
  57                 # Convert the format of the interlanguage links
  58                 # I didn't want to change it in the ParserOutput, because that array is passed all
  59                 # the way back to the skin, so either a skin API break would be required, or an
  60                 # inefficient back-conversion.
  61                 $ill = $parserOutput->getLanguageLinks();
  62                 $this->mInterlangs = array();
  63                 foreach ( $ill as $link ) {
  64                         list( $key, $title ) = explode( ':', $link, 2 );
  65                         $this->mInterlangs[$key] = $title;
  66                 }
  67
  68                 $this->mRecursive = $recursive;
  69
  70                 wfRunHooks( 'LinksUpdateConstructed', array( &$this ) );
  71         }
  72
  73         /**
  74          * Update link tables with outgoing links from an updated article
  75          */
  76         function doUpdate() {
  77                 global $wgUseDumbLinkUpdate;
  78
  79                 wfRunHooks( 'LinksUpdate', array( &$this ) );
  80                 if ( $wgUseDumbLinkUpdate ) {
  81                         $this->doDumbUpdate();
  82                 } else {
  83                         $this->doIncrementalUpdate();
  84                 }
  85                 wfRunHooks( 'LinksUpdateComplete', array( &$this ) );
  86
  87         }
  88
  89         function doIncrementalUpdate() {
  90                 wfProfileIn( __METHOD__ );
  91
  92                 # Page links
  93                 $existing = $this->getExistingLinks();
  94                 $this->incrTableUpdate( 'pagelinks', 'pl', $this->getLinkDeletions( $existing ),
  95                         $this->getLinkInsertions( $existing ) );
  96
  97                 # Image links
  98                 $existing = $this->getExistingImages();
  99                 $this->incrTableUpdate( 'imagelinks', 'il', $this->getImageDeletions( $existing ),
 100                         $this->getImageInsertions( $existing ) );
 101
 102                 # Invalidate all image description pages which had links added or removed
 103                 $imageUpdates = array_diff_key( $existing, $this->mImages ) + array_diff_key( $this->mImages, $existing );
 104                 $this->invalidateImageDescriptions( $imageUpdates );
 105
 106                 # External links
 107                 $existing = $this->getExistingExternals();
 108                 $this->incrTableUpdate( 'externallinks', 'el', $this->getExternalDeletions( $existing ),
 109                 $this->getExternalInsertions( $existing ) );
 110
 111                 # Language links
 112                 $existing = $this->getExistingInterlangs();
 113                 $this->incrTableUpdate( 'langlinks', 'll', $this->getInterlangDeletions( $existing ),
 114                         $this->getInterlangInsertions( $existing ) );
 115
 116                 # Template links
 117                 $existing = $this->getExistingTemplates();
 118                 $this->incrTableUpdate( 'templatelinks', 'tl', $this->getTemplateDeletions( $existing ),
 119                         $this->getTemplateInsertions( $existing ) );
 120
 121                 # Category links
 122                 $existing = $this->getExistingCategories();
 123                 $this->incrTableUpdate( 'categorylinks', 'cl', $this->getCategoryDeletions( $existing ),
 124                         $this->getCategoryInsertions( $existing ) );
 125
 126                 # Invalidate all categories which were added, deleted or changed (set symmetric difference)
 127                 $categoryUpdates = array_diff_assoc( $existing, $this->mCategories ) + array_diff_assoc( $this->mCategories, $existing );
 128                 $this->invalidateCategories( $categoryUpdates );
 129
 130                 # Page properties
 131                 $existing = $this->getExistingProperties();
 132                 $this->incrTableUpdate( 'page_props', 'pp', $this->getPropertyDeletions( $existing ),
 133                         $this->getPropertyInsertions( $existing ) );
 134
 135                 # Invalidate the necessary pages
 136                 $changed = array_diff_assoc( $existing, $this->mProperties ) + array_diff_assoc( $this->mProperties, $existing );
 137                 $this->invalidateProperties( $changed );
 138
 139                 # Refresh links of all pages including this page
 140                 # This will be in a separate transaction
 141                 if ( $this->mRecursive ) {
 142                         $this->queueRecursiveJobs();
 143                 }
 144
 145                 wfProfileOut( __METHOD__ );
 146         }
 147
 148         /**
 149          * Link update which clears the previous entries and inserts new ones
 150          * May be slower or faster depending on level of lock contention and write speed of DB
 151          * Also useful where link table corruption needs to be repaired, e.g. in refreshLinks.php
 152          */
 153         function doDumbUpdate() {
 154                 wfProfileIn( __METHOD__ );
 155
 156                 # Refresh category pages and image description pages
 157                 $existing = $this->getExistingCategories();
 158                 $categoryUpdates = array_diff_assoc( $existing, $this->mCategories ) + array_diff_assoc( $this->mCategories, $existing );
 159                 $existing = $this->getExistingImages();
 160                 $imageUpdates = array_diff_key( $existing, $this->mImages ) + array_diff_key( $this->mImages, $existing );
 161
 162                 $this->dumbTableUpdate( 'pagelinks',     $this->getLinkInsertions(),     'pl_from' );
 163                 $this->dumbTableUpdate( 'imagelinks',    $this->getImageInsertions(),    'il_from' );
 164                 $this->dumbTableUpdate( 'categorylinks', $this->getCategoryInsertions(), 'cl_from' );
 165                 $this->dumbTableUpdate( 'templatelinks', $this->getTemplateInsertions(), 'tl_from' );
 166                 $this->dumbTableUpdate( 'externallinks', $this->getExternalInsertions(), 'el_from' );
 167                 $this->dumbTableUpdate( 'langlinks',     $this->getInterlangInsertions(),'ll_from' );
 168                 $this->dumbTableUpdate( 'page_props',    $this->getPropertyInsertions(), 'pp_page' );
 169
 170                 # Update the cache of all the category pages and image description pages which were changed
 171                 $this->invalidateCategories( $categoryUpdates );
 172                 $this->invalidateImageDescriptions( $imageUpdates );
 173
 174                 # Refresh links of all pages including this page
 175                 # This will be in a separate transaction
 176                 if ( $this->mRecursive ) {
 177                         $this->queueRecursiveJobs();
 178                 }
 179
 180                 wfProfileOut( __METHOD__ );
 181         }
 182
 183         function queueRecursiveJobs() {
 184                 wfProfileIn( __METHOD__ );
 185
 186                 $batchSize = 100;
 187                 $dbr = wfGetDB( DB_SLAVE );
 188                 $res = $dbr->select( array( 'templatelinks', 'page' ),
 189                         array( 'page_namespace', 'page_title' ),
 190                         array(
 191                                 'page_id=tl_from',
 192                                 'tl_namespace' => $this->mTitle->getNamespace(),
 193                                 'tl_title' => $this->mTitle->getDBkey()
 194                         ), __METHOD__
 195                 );
 196
 197                 $done = false;
 198                 while ( !$done ) {
 199                         $jobs = array();
 200                         for ( $i = 0; $i < $batchSize; $i++ ) {
 201                                 $row = $dbr->fetchObject( $res );
 202                                 if ( !$row ) {
 203                                         $done = true;
 204                                         break;
 205                                 }
 206                                 $title = Title::makeTitle( $row->page_namespace, $row->page_title );
 207                                 $jobs[] = new RefreshLinksJob( $title, '' );
 208                         }
 209                         Job::batchInsert( $jobs );
 210                 }
 211                 $dbr->freeResult( $res );
 212                 wfProfileOut( __METHOD__ );
 213         }
 214
 215         /**
 216          * Invalidate the cache of a list of pages from a single namespace
 217          *
 218          * @param integer $namespace
 219          * @param array $dbkeys
 220          */
 221         function invalidatePages( $namespace, $dbkeys ) {
 222                 if ( !count( $dbkeys ) ) {
 223                         return;
 224                 }
 225
 226                 /**
 227                  * Determine which pages need to be updated
 228                  * This is necessary to prevent the job queue from smashing the DB with
 229                  * large numbers of concurrent invalidations of the same page
 230                  */
 231                 $now = $this->mDb->timestamp();
 232                 $ids = array();
 233                 $res = $this->mDb->select( 'page', array( 'page_id' ),
 234                         array(
 235                                 'page_namespace' => $namespace,
 236                                 'page_title IN (' . $this->mDb->makeList( $dbkeys ) . ')',
 237                                 'page_touched < ' . $this->mDb->addQuotes( $now )
 238                         ), __METHOD__
 239                 );
 240                 while ( $row = $this->mDb->fetchObject( $res ) ) {
 241                         $ids[] = $row->page_id;
 242                 }
 243                 if ( !count( $ids ) ) {
 244                         return;
 245                 }
 246
 247                 /**
 248                  * Do the update
 249                  * We still need the page_touched condition, in case the row has changed since
 250                  * the non-locking select above.
 251                  */
 252                 $this->mDb->update( 'page', array( 'page_touched' => $now ),
 253                         array(
 254                                 'page_id IN (' . $this->mDb->makeList( $ids ) . ')',
 255                                 'page_touched < ' . $this->mDb->addQuotes( $now )
 256                         ), __METHOD__
 257                 );
 258         }
 259
 260         function invalidateCategories( $cats ) {
 261                 $this->invalidatePages( NS_CATEGORY, array_keys( $cats ) );
 262         }
 263
 264         function invalidateImageDescriptions( $images ) {
 265                 $this->invalidatePages( NS_IMAGE, array_keys( $images ) );
 266         }
 267
 268         function dumbTableUpdate( $table, $insertions, $fromField ) {
 269                 $this->mDb->delete( $table, array( $fromField => $this->mId ), __METHOD__ );
 270                 if ( count( $insertions ) ) {
 271                         # The link array was constructed without FOR UPDATE, so there may be collisions
 272                         # This may cause minor link table inconsistencies, which is better than
 273                         # crippling the site with lock contention.
 274                         $this->mDb->insert( $table, $insertions, __METHOD__, array( 'IGNORE' ) );
 275                 }
 276         }
 277
 278         /**
 279          * Make a WHERE clause from a 2-d NS/dbkey array
 280          *
 281          * @param array $arr 2-d array indexed by namespace and DB key
 282          * @param string $prefix Field name prefix, without the underscore
 283          */
 284         function makeWhereFrom2d( &$arr, $prefix ) {
 285                 $lb = new LinkBatch;
 286                 $lb->setArray( $arr );
 287                 return $lb->constructSet( $prefix, $this->mDb );
 288         }
 289
 290         /**
 291          * Update a table by doing a delete query then an insert query
 292          * @private
 293          */
 294         function incrTableUpdate( $table, $prefix, $deletions, $insertions ) {
 295                 if ( $table == 'page_props' ) {
 296                         $fromField = 'pp_page';
 297                 } else {
 298                         $fromField = "{$prefix}_from";
 299                 }
 300                 $where = array( $fromField => $this->mId );
 301                 if ( $table == 'pagelinks' || $table == 'templatelinks' ) {
 302                         $clause = $this->makeWhereFrom2d( $deletions, $prefix );
 303                         if ( $clause ) {
 304                                 $where[] = $clause;
 305                         } else {
 306                                 $where = false;
 307                         }
 308                 } else {
 309                         if ( $table == 'langlinks' ) {
 310                                 $toField = 'll_lang';
 311                         } elseif ( $table == 'page_props' ) {
 312                                 $toField = 'pp_propname';
 313                         } else {
 314                                 $toField = $prefix . '_to';
 315                         }
 316                         if ( count( $deletions ) ) {
 317                                 $where[] = "$toField IN (" . $this->mDb->makeList( array_keys( $deletions ) ) . ')';
 318                         } else {
 319                                 $where = false;
 320                         }
 321                 }
 322                 if ( $where ) {
 323                         $this->mDb->delete( $table, $where, __METHOD__ );
 324                 }
 325                 if ( count( $insertions ) ) {
 326                         $this->mDb->insert( $table, $insertions, __METHOD__, 'IGNORE' );
 327                 }
 328         }
 329
 330
 331         /**
 332          * Get an array of pagelinks insertions for passing to the DB
 333          * Skips the titles specified by the 2-D array $existing
 334          * @private
 335          */
 336         function getLinkInsertions( $existing = array() ) {
 337                 $arr = array();
 338                 foreach( $this->mLinks as $ns => $dbkeys ) {
 339                         # array_diff_key() was introduced in PHP 5.1, there is a compatibility function
 340                         # in GlobalFunctions.php
 341                         $diffs = isset( $existing[$ns] ) ? array_diff_key( $dbkeys, $existing[$ns] ) : $dbkeys;
 342                         foreach ( $diffs as $dbk => $id ) {
 343                                 $arr[] = array(
 344                                         'pl_from'      => $this->mId,
 345                                         'pl_namespace' => $ns,
 346                                         'pl_title'     => $dbk
 347                                 );
 348                         }
 349                 }
 350                 return $arr;
 351         }
 352
 353         /**
 354          * Get an array of template insertions. Like getLinkInsertions()
 355          * @private
 356          */
 357         function getTemplateInsertions( $existing = array() ) {
 358                 $arr = array();
 359                 foreach( $this->mTemplates as $ns => $dbkeys ) {
 360                         $diffs = isset( $existing[$ns] ) ? array_diff_key( $dbkeys, $existing[$ns] ) : $dbkeys;
 361                         foreach ( $diffs as $dbk => $id ) {
 362                                 $arr[] = array(
 363                                         'tl_from'      => $this->mId,
 364                                         'tl_namespace' => $ns,
 365                                         'tl_title'     => $dbk
 366                                 );
 367                         }
 368                 }
 369                 return $arr;
 370         }
 371
 372         /**
 373          * Get an array of image insertions
 374          * Skips the names specified in $existing
 375          * @private
 376          */
 377         function getImageInsertions( $existing = array() ) {
 378                 $arr = array();
 379                 $diffs = array_diff_key( $this->mImages, $existing );
 380                 foreach( $diffs as $iname => $dummy ) {
 381                         $arr[] = array(
 382                                 'il_from' => $this->mId,
 383                                 'il_to'   => $iname
 384                         );
 385                 }
 386                 return $arr;
 387         }
 388
 389         /**
 390          * Get an array of externallinks insertions. Skips the names specified in $existing
 391          * @private
 392          */
 393         function getExternalInsertions( $existing = array() ) {
 394                 $arr = array();
 395                 $diffs = array_diff_key( $this->mExternals, $existing );
 396                 foreach( $diffs as $url => $dummy ) {
 397                         $arr[] = array(
 398                                 'el_from'   => $this->mId,
 399                                 'el_to'     => $url,
 400                                 'el_index'  => wfMakeUrlIndex( $url ),
 401                         );
 402                 }
 403                 return $arr;
 404         }
 405
 406         /**
 407          * Get an array of category insertions
 408          * @param array $existing Array mapping existing category names to sort keys. If both
 409          * match a link in $this, the link will be omitted from the output
 410          * @private
 411          */
 412         function getCategoryInsertions( $existing = array() ) {
 413                 $diffs = array_diff_assoc( $this->mCategories, $existing );
 414                 $arr = array();
 415                 foreach ( $diffs as $name => $sortkey ) {
 416                         $arr[] = array(
 417                                 'cl_from'    => $this->mId,
 418                                 'cl_to'      => $name,
 419                                 'cl_sortkey' => $sortkey,
 420                                 'cl_timestamp' => $this->mDb->timestamp()
 421                         );
 422                 }
 423                 return $arr;
 424         }
 425
 426         /**
 427          * Get an array of interlanguage link insertions
 428          * @param array $existing Array mapping existing language codes to titles
 429          * @private
 430          */
 431         function getInterlangInsertions( $existing = array() ) {
 432             $diffs = array_diff_assoc( $this->mInterlangs, $existing );
 433             $arr = array();
 434             foreach( $diffs as $lang => $title ) {
 435                 $arr[] = array(
 436                     'll_from'  => $this->mId,
 437                     'll_lang'  => $lang,
 438                     'll_title' => $title
 439                 );
 440             }
 441             return $arr;
 442         }
 443
 444         /**
 445          * Get an array of page property insertions
 446          */
 447         function getPropertyInsertions( $existing = array() ) {
 448                 $diffs = array_diff_assoc( $this->mProperties, $existing );
 449                 $arr = array();
 450                 foreach ( $diffs as $name => $value ) {
 451                         $arr[] = array(
 452                                 'pp_page'      => $this->mId,
 453                                 'pp_propname'  => $name,
 454                                 'pp_value'     => $value,
 455                         );
 456                 }
 457                 return $arr;
 458         }
 459
 460
 461         /**
 462          * Given an array of existing links, returns those links which are not in $this
 463          * and thus should be deleted.
 464          * @private
 465          */
 466         function getLinkDeletions( $existing ) {
 467                 $del = array();
 468                 foreach ( $existing as $ns => $dbkeys ) {
 469                         if ( isset( $this->mLinks[$ns] ) ) {
 470                                 $del[$ns] = array_diff_key( $existing[$ns], $this->mLinks[$ns] );
 471                         } else {
 472                                 $del[$ns] = $existing[$ns];
 473                         }
 474                 }
 475                 return $del;
 476         }
 477
 478         /**
 479          * Given an array of existing templates, returns those templates which are not in $this
 480          * and thus should be deleted.
 481          * @private
 482          */
 483         function getTemplateDeletions( $existing ) {
 484                 $del = array();
 485                 foreach ( $existing as $ns => $dbkeys ) {
 486                         if ( isset( $this->mTemplates[$ns] ) ) {
 487                                 $del[$ns] = array_diff_key( $existing[$ns], $this->mTemplates[$ns] );
 488                         } else {
 489                                 $del[$ns] = $existing[$ns];
 490                         }
 491                 }
 492                 return $del;
 493         }
 494
 495         /**
 496          * Given an array of existing images, returns those images which are not in $this
 497          * and thus should be deleted.
 498          * @private
 499          */
 500         function getImageDeletions( $existing ) {
 501                 return array_diff_key( $existing, $this->mImages );
 502         }
 503
 504         /**
 505          * Given an array of existing external links, returns those links which are not
 506          * in $this and thus should be deleted.
 507          * @private
 508          */
 509         function getExternalDeletions( $existing ) {
 510                 return array_diff_key( $existing, $this->mExternals );
 511         }
 512
 513         /**
 514          * Given an array of existing categories, returns those categories which are not in $this
 515          * and thus should be deleted.
 516          * @private
 517          */
 518         function getCategoryDeletions( $existing ) {
 519                 return array_diff_assoc( $existing, $this->mCategories );
 520         }
 521
 522         /**
 523          * Given an array of existing interlanguage links, returns those links which are not
 524          * in $this and thus should be deleted.
 525          * @private
 526          */
 527         function getInterlangDeletions( $existing ) {
 528             return array_diff_assoc( $existing, $this->mInterlangs );
 529         }
 530
 531         /**
 532          * Get array of properties which should be deleted.
 533          * @private
 534          */
 535         function getPropertyDeletions( $existing ) {
 536                 return array_diff_assoc( $existing, $this->mProperties );
 537         }
 538
 539         /**
 540          * Get an array of existing links, as a 2-D array
 541          * @private
 542          */
 543         function getExistingLinks() {
 544                 $res = $this->mDb->select( 'pagelinks', array( 'pl_namespace', 'pl_title' ),
 545                         array( 'pl_from' => $this->mId ), __METHOD__, $this->mOptions );
 546                 $arr = array();
 547                 while ( $row = $this->mDb->fetchObject( $res ) ) {
 548                         if ( !isset( $arr[$row->pl_namespace] ) ) {
 549                                 $arr[$row->pl_namespace] = array();
 550                         }
 551                         $arr[$row->pl_namespace][$row->pl_title] = 1;
 552                 }
 553                 $this->mDb->freeResult( $res );
 554                 return $arr;
 555         }
 556
 557         /**
 558          * Get an array of existing templates, as a 2-D array
 559          * @private
 560          */
 561         function getExistingTemplates() {
 562                 $res = $this->mDb->select( 'templatelinks', array( 'tl_namespace', 'tl_title' ),
 563                         array( 'tl_from' => $this->mId ), __METHOD__, $this->mOptions );
 564                 $arr = array();
 565                 while ( $row = $this->mDb->fetchObject( $res ) ) {
 566                         if ( !isset( $arr[$row->tl_namespace] ) ) {
 567                                 $arr[$row->tl_namespace] = array();
 568                         }
 569                         $arr[$row->tl_namespace][$row->tl_title] = 1;
 570                 }
 571                 $this->mDb->freeResult( $res );
 572                 return $arr;
 573         }
 574
 575         /**
 576          * Get an array of existing images, image names in the keys
 577          * @private
 578          */
 579         function getExistingImages() {
 580                 $res = $this->mDb->select( 'imagelinks', array( 'il_to' ),
 581                         array( 'il_from' => $this->mId ), __METHOD__, $this->mOptions );
 582                 $arr = array();
 583                 while ( $row = $this->mDb->fetchObject( $res ) ) {
 584                         $arr[$row->il_to] = 1;
 585                 }
 586                 $this->mDb->freeResult( $res );
 587                 return $arr;
 588         }
 589
 590         /**
 591          * Get an array of existing external links, URLs in the keys
 592          * @private
 593          */
 594         function getExistingExternals() {
 595                 $res = $this->mDb->select( 'externallinks', array( 'el_to' ),
 596                         array( 'el_from' => $this->mId ), __METHOD__, $this->mOptions );
 597                 $arr = array();
 598                 while ( $row = $this->mDb->fetchObject( $res ) ) {
 599                         $arr[$row->el_to] = 1;
 600                 }
 601                 $this->mDb->freeResult( $res );
 602                 return $arr;
 603         }
 604
 605         /**
 606          * Get an array of existing categories, with the name in the key and sort key in the value.
 607          * @private
 608          */
 609         function getExistingCategories() {
 610                 $res = $this->mDb->select( 'categorylinks', array( 'cl_to', 'cl_sortkey' ),
 611                         array( 'cl_from' => $this->mId ), __METHOD__, $this->mOptions );
 612                 $arr = array();
 613                 while ( $row = $this->mDb->fetchObject( $res ) ) {
 614                         $arr[$row->cl_to] = $row->cl_sortkey;
 615                 }
 616                 $this->mDb->freeResult( $res );
 617                 return $arr;
 618         }
 619
 620         /**
 621          * Get an array of existing interlanguage links, with the language code in the key and the
 622          * title in the value.
 623          * @private
 624          */
 625         function getExistingInterlangs() {
 626                 $res = $this->mDb->select( 'langlinks', array( 'll_lang', 'll_title' ),
 627                         array( 'll_from' => $this->mId ), __METHOD__, $this->mOptions );
 628                 $arr = array();
 629                 while ( $row = $this->mDb->fetchObject( $res ) ) {
 630                         $arr[$row->ll_lang] = $row->ll_title;
 631                 }
 632                 return $arr;
 633         }
 634
 635         /**
 636          * Get an array of existing categories, with the name in the key and sort key in the value.
 637          * @private
 638          */
 639         function getExistingProperties() {
 640                 $res = $this->mDb->select( 'page_props', array( 'pp_propname', 'pp_value' ),
 641                         array( 'pp_page' => $this->mId ), __METHOD__, $this->mOptions );
 642                 $arr = array();
 643                 while ( $row = $this->mDb->fetchObject( $res ) ) {
 644                         $arr[$row->pp_propname] = $row->pp_value;
 645                 }
 646                 $this->mDb->freeResult( $res );
 647                 return $arr;
 648         }
 649
 650
 651         /**
 652          * Return the title object of the page being updated
 653          */
 654         function getTitle() {
 655                 return $this->mTitle;
 656         }
 657
 658         /**
 659          * Invalidate any necessary link lists related to page property changes
 660          */
 661         function invalidateProperties( $changed ) {
 662                 global $wgPagePropLinkInvalidations;
 663
 664                 foreach ( $changed as $name => $value ) {
 665                         if ( isset( $wgPagePropLinkInvalidations[$name] ) ) {
 666                                 $inv = $wgPagePropLinkInvalidations[$name];
 667                                 if ( !is_array( $inv ) ) {
 668                                         $inv = array( $inv );
 669                                 }
 670                                 foreach ( $inv as $table ) {
 671                                         $update = new HTMLCacheUpdate( $this->mTitle, $table );
 672                                         $update->doUpdate();
 673                                 }
 674                         }
 675                 }
 676         }
 677 }
 678