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->mParserOutput = $parserOutput;
  51                 $this->mLinks = $parserOutput->getLinks();
  52                 $this->mImages = $parserOutput->getImages();
  53                 $this->mTemplates = $parserOutput->getTemplates();
  54                 $this->mExternals = $parserOutput->getExternalLinks();
  55                 $this->mCategories = $parserOutput->getCategories();
  56                 $this->mProperties = $parserOutput->getProperties();
  57
  58                 # Convert the format of the interlanguage links
  59                 # I didn't want to change it in the ParserOutput, because that array is passed all
  60                 # the way back to the skin, so either a skin API break would be required, or an
  61                 # inefficient back-conversion.
  62                 $ill = $parserOutput->getLanguageLinks();
  63                 $this->mInterlangs = array();
  64                 foreach ( $ill as $link ) {
  65                         list( $key, $title ) = explode( ':', $link, 2 );
  66                         $this->mInterlangs[$key] = $title;
  67                 }
  68
  69                 $this->mRecursive = $recursive;
  70
  71                 wfRunHooks( 'LinksUpdateConstructed', array( &$this ) );
  72         }
  73
  74         /**
  75          * Update link tables with outgoing links from an updated article
  76          */
  77         function doUpdate() {
  78                 global $wgUseDumbLinkUpdate;
  79
  80                 wfRunHooks( 'LinksUpdate', array( &$this ) );
  81                 if ( $wgUseDumbLinkUpdate ) {
  82                         $this->doDumbUpdate();
  83                 } else {
  84                         $this->doIncrementalUpdate();
  85                 }
  86                 wfRunHooks( 'LinksUpdateComplete', array( &$this ) );
  87
  88         }
  89
  90         function doIncrementalUpdate() {
  91                 wfProfileIn( __METHOD__ );
  92
  93                 # Page links
  94                 $existing = $this->getExistingLinks();
  95                 $this->incrTableUpdate( 'pagelinks', 'pl', $this->getLinkDeletions( $existing ),
  96                         $this->getLinkInsertions( $existing ) );
  97
  98                 # Image links
  99                 $existing = $this->getExistingImages();
 100
 101                 $imageDeletes = $this->getImageDeletions( $existing );
 102                 $imageInserts = $this->getImageInsertions( $existing );
 103                 $this->incrTableUpdate( 'imagelinks', 'il', $imageDeletes, $imageInserts );
 104
 105                 # Invalidate all image description pages which had links added or removed
 106                 $imageUpdates = $imageDeletions + $imageInsertions
 107                 $this->invalidateImageDescriptions( $imageUpdates );
 108
 109                 # External links
 110                 $existing = $this->getExistingExternals();
 111                 $this->incrTableUpdate( 'externallinks', 'el', $this->getExternalDeletions( $existing ),
 112                 $this->getExternalInsertions( $existing ) );
 113
 114                 # Language links
 115                 $existing = $this->getExistingInterlangs();
 116                 $this->incrTableUpdate( 'langlinks', 'll', $this->getInterlangDeletions( $existing ),
 117                         $this->getInterlangInsertions( $existing ) );
 118
 119                 # Template links
 120                 $existing = $this->getExistingTemplates();
 121                 $this->incrTableUpdate( 'templatelinks', 'tl', $this->getTemplateDeletions( $existing ),
 122                         $this->getTemplateInsertions( $existing ) );
 123
 124                 # Category links
 125                 $existing = $this->getExistingCategories();
 126
 127                 $categoryDeletes = $this->getCategoryDeletions( $existing );
 128                 $categoryInserts = $this->getCategoryInsertions( $existing );
 129
 130                 $this->incrTableUpdate( 'categorylinks', 'cl', $categoryDeletes, $categoryInserts );
 131
 132                 # Invalidate all categories which were added, deleted or changed (set symmetric difference)
 133                 $categoryUpdates = $categoryInserts + $categoryDeletes;
 134                 $this->invalidateCategories( $categoryUpdates );
 135                 $this->updateCategoryCounts( $categoryInserts, $categoryDeletes );
 136
 137                 # Page properties
 138                 $existing = $this->getExistingProperties();
 139
 140                 $propertiesDeletes = $this->getPropertiesDeletions( $existing );
 141                 $propertiesInserts = $this->getPropertiesInsertions( $existing );
 142
 143                 $this->incrTableUpdate( 'page_props', 'pp', $propertiesDeletes, $propertiesInserts );
 144
 145                 # Invalidate the necessary pages
 146                 $changed = $propertiesDeletes + $propertiesInserts;
 147                 $this->invalidateProperties( $changed );
 148
 149                 # Refresh links of all pages including this page
 150                 # This will be in a separate transaction
 151                 if ( $this->mRecursive ) {
 152                         $this->queueRecursiveJobs();
 153                 }
 154
 155                 wfProfileOut( __METHOD__ );
 156         }
 157
 158         /**
 159          * Link update which clears the previous entries and inserts new ones
 160          * May be slower or faster depending on level of lock contention and write speed of DB
 161          * Also useful where link table corruption needs to be repaired, e.g. in refreshLinks.php
 162          */
 163         function doDumbUpdate() {
 164                 wfProfileIn( __METHOD__ );
 165
 166                 # Refresh category pages and image description pages
 167                 $existing = $this->getExistingCategories();
 168                 $categoryInserts = array_diff_assoc( $this->mCategories, $existing );
 169                 $categoryDeletes = array_diff_assoc( $existing, $this->mCategoties );
 170                 $categoryUpdates = $categoryInserts + $categoryDeletes;
 171                 $existing = $this->getExistingImages();
 172                 $imageUpdates = array_diff_key( $existing, $this->mImages ) + array_diff_key( $this->mImages, $existing );
 173
 174                 $this->dumbTableUpdate( 'pagelinks',     $this->getLinkInsertions(),     'pl_from' );
 175                 $this->dumbTableUpdate( 'imagelinks',    $this->getImageInsertions(),    'il_from' );
 176                 $this->dumbTableUpdate( 'categorylinks', $this->getCategoryInsertions(), 'cl_from' );
 177                 $this->dumbTableUpdate( 'templatelinks', $this->getTemplateInsertions(), 'tl_from' );
 178                 $this->dumbTableUpdate( 'externallinks', $this->getExternalInsertions(), 'el_from' );
 179                 $this->dumbTableUpdate( 'langlinks',     $this->getInterlangInsertions(),'ll_from' );
 180                 $this->dumbTableUpdate( 'page_props',    $this->getPropertyInsertions(), 'pp_page' );
 181
 182                 # Update the cache of all the category pages and image description
 183                 # pages which were changed, and fix the category table count
 184                 $this->invalidateCategories( $categoryUpdates );
 185                 $this->updateCategoryCounts( $categoryInserts, $categoryDeletes );
 186                 $this->invalidateImageDescriptions( $imageUpdates );
 187
 188                 # Refresh links of all pages including this page
 189                 # This will be in a separate transaction
 190                 if ( $this->mRecursive ) {
 191                         $this->queueRecursiveJobs();
 192                 }
 193
 194                 wfProfileOut( __METHOD__ );
 195         }
 196
 197         function queueRecursiveJobs() {
 198                 wfProfileIn( __METHOD__ );
 199
 200                 $batchSize = 100;
 201                 $dbr = wfGetDB( DB_SLAVE );
 202                 $res = $dbr->select( array( 'templatelinks', 'page' ),
 203                         array( 'page_namespace', 'page_title' ),
 204                         array(
 205                                 'page_id=tl_from',
 206                                 'tl_namespace' => $this->mTitle->getNamespace(),
 207                                 'tl_title' => $this->mTitle->getDBkey()
 208                         ), __METHOD__
 209                 );
 210
 211                 $done = false;
 212                 while ( !$done ) {
 213                         $jobs = array();
 214                         for ( $i = 0; $i < $batchSize; $i++ ) {
 215                                 $row = $dbr->fetchObject( $res );
 216                                 if ( !$row ) {
 217                                         $done = true;
 218                                         break;
 219                                 }
 220                                 $title = Title::makeTitle( $row->page_namespace, $row->page_title );
 221                                 $jobs[] = new RefreshLinksJob( $title, '' );
 222                         }
 223                         Job::batchInsert( $jobs );
 224                 }
 225                 $dbr->freeResult( $res );
 226                 wfProfileOut( __METHOD__ );
 227         }
 228
 229         /**
 230          * Invalidate the cache of a list of pages from a single namespace
 231          *
 232          * @param integer $namespace
 233          * @param array $dbkeys
 234          */
 235         function invalidatePages( $namespace, $dbkeys ) {
 236                 if ( !count( $dbkeys ) ) {
 237                         return;
 238                 }
 239
 240                 /**
 241                  * Determine which pages need to be updated
 242                  * This is necessary to prevent the job queue from smashing the DB with
 243                  * large numbers of concurrent invalidations of the same page
 244                  */
 245                 $now = $this->mDb->timestamp();
 246                 $ids = array();
 247                 $res = $this->mDb->select( 'page', array( 'page_id' ),
 248                         array(
 249                                 'page_namespace' => $namespace,
 250                                 'page_title IN (' . $this->mDb->makeList( $dbkeys ) . ')',
 251                                 'page_touched < ' . $this->mDb->addQuotes( $now )
 252                         ), __METHOD__
 253                 );
 254                 while ( $row = $this->mDb->fetchObject( $res ) ) {
 255                         $ids[] = $row->page_id;
 256                 }
 257                 if ( !count( $ids ) ) {
 258                         return;
 259                 }
 260
 261                 /**
 262                  * Do the update
 263                  * We still need the page_touched condition, in case the row has changed since
 264                  * the non-locking select above.
 265                  */
 266                 $this->mDb->update( 'page', array( 'page_touched' => $now ),
 267                         array(
 268                                 'page_id IN (' . $this->mDb->makeList( $ids ) . ')',
 269                                 'page_touched < ' . $this->mDb->addQuotes( $now )
 270                         ), __METHOD__
 271                 );
 272         }
 273
 274         function invalidateCategories( $cats ) {
 275                 $this->invalidatePages( NS_CATEGORY, array_keys( $cats ) );
 276         }
 277
 278         /**
 279          * Update all the appropriate counts in the category table.
 280          * @param $added associative array of category name => sort key
 281          * @param $deleted associative array of category name => sort key
 282          */
 283         function updateCategoryCounts( $added, $deleted ) {
 284                 $a = new Article($this->mTitle);
 285                 $a->updateCategoryCounts(
 286                         array_keys( $added ), array_keys( $deleted )
 287                 );
 288         }
 289
 290         function invalidateImageDescriptions( $images ) {
 291                 $this->invalidatePages( NS_IMAGE, array_keys( $images ) );
 292         }
 293
 294         function dumbTableUpdate( $table, $insertions, $fromField ) {
 295                 $this->mDb->delete( $table, array( $fromField => $this->mId ), __METHOD__ );
 296                 if ( count( $insertions ) ) {
 297                         # The link array was constructed without FOR UPDATE, so there may
 298                         # be collisions.  This may cause minor link table inconsistencies,
 299                         # which is better than crippling the site with lock contention.
 300                         $this->mDb->insert( $table, $insertions, __METHOD__, array( 'IGNORE' ) );
 301                 }
 302         }
 303
 304         /**
 305          * Make a WHERE clause from a 2-d NS/dbkey array
 306          *
 307          * @param array $arr 2-d array indexed by namespace and DB key
 308          * @param string $prefix Field name prefix, without the underscore
 309          */
 310         function makeWhereFrom2d( &$arr, $prefix ) {
 311                 $lb = new LinkBatch;
 312                 $lb->setArray( $arr );
 313                 return $lb->constructSet( $prefix, $this->mDb );
 314         }
 315
 316         /**
 317          * Update a table by doing a delete query then an insert query
 318          * @private
 319          */
 320         function incrTableUpdate( $table, $prefix, $deletions, $insertions ) {
 321                 if ( $table == 'page_props' ) {
 322                         $fromField = 'pp_page';
 323                 } else {
 324                         $fromField = "{$prefix}_from";
 325                 }
 326                 $where = array( $fromField => $this->mId );
 327                 if ( $table == 'pagelinks' || $table == 'templatelinks' ) {
 328                         $clause = $this->makeWhereFrom2d( $deletions, $prefix );
 329                         if ( $clause ) {
 330                                 $where[] = $clause;
 331                         } else {
 332                                 $where = false;
 333                         }
 334                 } else {
 335                         if ( $table == 'langlinks' ) {
 336                                 $toField = 'll_lang';
 337                         } elseif ( $table == 'page_props' ) {
 338                                 $toField = 'pp_propname';
 339                         } else {
 340                                 $toField = $prefix . '_to';
 341                         }
 342                         if ( count( $deletions ) ) {
 343                                 $where[] = "$toField IN (" . $this->mDb->makeList( array_keys( $deletions ) ) . ')';
 344                         } else {
 345                                 $where = false;
 346                         }
 347                 }
 348                 if ( $where ) {
 349                         $this->mDb->delete( $table, $where, __METHOD__ );
 350                 }
 351                 if ( count( $insertions ) ) {
 352                         $this->mDb->insert( $table, $insertions, __METHOD__, 'IGNORE' );
 353                 }
 354         }
 355
 356
 357         /**
 358          * Get an array of pagelinks insertions for passing to the DB
 359          * Skips the titles specified by the 2-D array $existing
 360          * @private
 361          */
 362         function getLinkInsertions( $existing = array() ) {
 363                 $arr = array();
 364                 foreach( $this->mLinks as $ns => $dbkeys ) {
 365                         # array_diff_key() was introduced in PHP 5.1, there is a compatibility function
 366                         # in GlobalFunctions.php
 367                         $diffs = isset( $existing[$ns] ) ? array_diff_key( $dbkeys, $existing[$ns] ) : $dbkeys;
 368                         foreach ( $diffs as $dbk => $id ) {
 369                                 $arr[] = array(
 370                                         'pl_from'      => $this->mId,
 371                                         'pl_namespace' => $ns,
 372                                         'pl_title'     => $dbk
 373                                 );
 374                         }
 375                 }
 376                 return $arr;
 377         }
 378
 379         /**
 380          * Get an array of template insertions. Like getLinkInsertions()
 381          * @private
 382          */
 383         function getTemplateInsertions( $existing = array() ) {
 384                 $arr = array();
 385                 foreach( $this->mTemplates as $ns => $dbkeys ) {
 386                         $diffs = isset( $existing[$ns] ) ? array_diff_key( $dbkeys, $existing[$ns] ) : $dbkeys;
 387                         foreach ( $diffs as $dbk => $id ) {
 388                                 $arr[] = array(
 389                                         'tl_from'      => $this->mId,
 390                                         'tl_namespace' => $ns,
 391                                         'tl_title'     => $dbk
 392                                 );
 393                         }
 394                 }
 395                 return $arr;
 396         }
 397
 398         /**
 399          * Get an array of image insertions
 400          * Skips the names specified in $existing
 401          * @private
 402          */
 403         function getImageInsertions( $existing = array() ) {
 404                 $arr = array();
 405                 $diffs = array_diff_key( $this->mImages, $existing );
 406                 foreach( $diffs as $iname => $dummy ) {
 407                         $arr[] = array(
 408                                 'il_from' => $this->mId,
 409                                 'il_to'   => $iname
 410                         );
 411                 }
 412                 return $arr;
 413         }
 414
 415         /**
 416          * Get an array of externallinks insertions. Skips the names specified in $existing
 417          * @private
 418          */
 419         function getExternalInsertions( $existing = array() ) {
 420                 $arr = array();
 421                 $diffs = array_diff_key( $this->mExternals, $existing );
 422                 foreach( $diffs as $url => $dummy ) {
 423                         $arr[] = array(
 424                                 'el_from'   => $this->mId,
 425                                 'el_to'     => $url,
 426                                 'el_index'  => wfMakeUrlIndex( $url ),
 427                         );
 428                 }
 429                 return $arr;
 430         }
 431
 432         /**
 433          * Get an array of category insertions
 434          * @param array $existing Array mapping existing category names to sort keys. If both
 435          * match a link in $this, the link will be omitted from the output
 436          * @private
 437          */
 438         function getCategoryInsertions( $existing = array() ) {
 439                 $diffs = array_diff_assoc( $this->mCategories, $existing );
 440                 $arr = array();
 441                 foreach ( $diffs as $name => $sortkey ) {
 442                         $arr[] = array(
 443                                 'cl_from'    => $this->mId,
 444                                 'cl_to'      => $name,
 445                                 'cl_sortkey' => $sortkey,
 446                                 'cl_timestamp' => $this->mDb->timestamp()
 447                         );
 448                 }
 449                 return $arr;
 450         }
 451
 452         /**
 453          * Get an array of interlanguage link insertions
 454          * @param array $existing Array mapping existing language codes to titles
 455          * @private
 456          */
 457         function getInterlangInsertions( $existing = array() ) {
 458             $diffs = array_diff_assoc( $this->mInterlangs, $existing );
 459             $arr = array();
 460             foreach( $diffs as $lang => $title ) {
 461                 $arr[] = array(
 462                     'll_from'  => $this->mId,
 463                     'll_lang'  => $lang,
 464                     'll_title' => $title
 465                 );
 466             }
 467             return $arr;
 468         }
 469
 470         /**
 471          * Get an array of page property insertions
 472          */
 473         function getPropertyInsertions( $existing = array() ) {
 474                 $diffs = array_diff_assoc( $this->mProperties, $existing );
 475                 $arr = array();
 476                 foreach ( $diffs as $name => $value ) {
 477                         $arr[] = array(
 478                                 'pp_page'      => $this->mId,
 479                                 'pp_propname'  => $name,
 480                                 'pp_value'     => $value,
 481                         );
 482                 }
 483                 return $arr;
 484         }
 485
 486
 487         /**
 488          * Given an array of existing links, returns those links which are not in $this
 489          * and thus should be deleted.
 490          * @private
 491          */
 492         function getLinkDeletions( $existing ) {
 493                 $del = array();
 494                 foreach ( $existing as $ns => $dbkeys ) {
 495                         if ( isset( $this->mLinks[$ns] ) ) {
 496                                 $del[$ns] = array_diff_key( $existing[$ns], $this->mLinks[$ns] );
 497                         } else {
 498                                 $del[$ns] = $existing[$ns];
 499                         }
 500                 }
 501                 return $del;
 502         }
 503
 504         /**
 505          * Given an array of existing templates, returns those templates which are not in $this
 506          * and thus should be deleted.
 507          * @private
 508          */
 509         function getTemplateDeletions( $existing ) {
 510                 $del = array();
 511                 foreach ( $existing as $ns => $dbkeys ) {
 512                         if ( isset( $this->mTemplates[$ns] ) ) {
 513                                 $del[$ns] = array_diff_key( $existing[$ns], $this->mTemplates[$ns] );
 514                         } else {
 515                                 $del[$ns] = $existing[$ns];
 516                         }
 517                 }
 518                 return $del;
 519         }
 520
 521         /**
 522          * Given an array of existing images, returns those images which are not in $this
 523          * and thus should be deleted.
 524          * @private
 525          */
 526         function getImageDeletions( $existing ) {
 527                 return array_diff_key( $existing, $this->mImages );
 528         }
 529
 530         /**
 531          * Given an array of existing external links, returns those links which are not
 532          * in $this and thus should be deleted.
 533          * @private
 534          */
 535         function getExternalDeletions( $existing ) {
 536                 return array_diff_key( $existing, $this->mExternals );
 537         }
 538
 539         /**
 540          * Given an array of existing categories, returns those categories which are not in $this
 541          * and thus should be deleted.
 542          * @private
 543          */
 544         function getCategoryDeletions( $existing ) {
 545                 return array_diff_assoc( $existing, $this->mCategories );
 546         }
 547
 548         /**
 549          * Given an array of existing interlanguage links, returns those links which are not
 550          * in $this and thus should be deleted.
 551          * @private
 552          */
 553         function getInterlangDeletions( $existing ) {
 554             return array_diff_assoc( $existing, $this->mInterlangs );
 555         }
 556
 557         /**
 558          * Get array of properties which should be deleted.
 559          * @private
 560          */
 561         function getPropertyDeletions( $existing ) {
 562                 return array_diff_assoc( $existing, $this->mProperties );
 563         }
 564
 565         /**
 566          * Get an array of existing links, as a 2-D array
 567          * @private
 568          */
 569         function getExistingLinks() {
 570                 $res = $this->mDb->select( 'pagelinks', array( 'pl_namespace', 'pl_title' ),
 571                         array( 'pl_from' => $this->mId ), __METHOD__, $this->mOptions );
 572                 $arr = array();
 573                 while ( $row = $this->mDb->fetchObject( $res ) ) {
 574                         if ( !isset( $arr[$row->pl_namespace] ) ) {
 575                                 $arr[$row->pl_namespace] = array();
 576                         }
 577                         $arr[$row->pl_namespace][$row->pl_title] = 1;
 578                 }
 579                 $this->mDb->freeResult( $res );
 580                 return $arr;
 581         }
 582
 583         /**
 584          * Get an array of existing templates, as a 2-D array
 585          * @private
 586          */
 587         function getExistingTemplates() {
 588                 $res = $this->mDb->select( 'templatelinks', array( 'tl_namespace', 'tl_title' ),
 589                         array( 'tl_from' => $this->mId ), __METHOD__, $this->mOptions );
 590                 $arr = array();
 591                 while ( $row = $this->mDb->fetchObject( $res ) ) {
 592                         if ( !isset( $arr[$row->tl_namespace] ) ) {
 593                                 $arr[$row->tl_namespace] = array();
 594                         }
 595                         $arr[$row->tl_namespace][$row->tl_title] = 1;
 596                 }
 597                 $this->mDb->freeResult( $res );
 598                 return $arr;
 599         }
 600
 601         /**
 602          * Get an array of existing images, image names in the keys
 603          * @private
 604          */
 605         function getExistingImages() {
 606                 $res = $this->mDb->select( 'imagelinks', array( 'il_to' ),
 607                         array( 'il_from' => $this->mId ), __METHOD__, $this->mOptions );
 608                 $arr = array();
 609                 while ( $row = $this->mDb->fetchObject( $res ) ) {
 610                         $arr[$row->il_to] = 1;
 611                 }
 612                 $this->mDb->freeResult( $res );
 613                 return $arr;
 614         }
 615
 616         /**
 617          * Get an array of existing external links, URLs in the keys
 618          * @private
 619          */
 620         function getExistingExternals() {
 621                 $res = $this->mDb->select( 'externallinks', array( 'el_to' ),
 622                         array( 'el_from' => $this->mId ), __METHOD__, $this->mOptions );
 623                 $arr = array();
 624                 while ( $row = $this->mDb->fetchObject( $res ) ) {
 625                         $arr[$row->el_to] = 1;
 626                 }
 627                 $this->mDb->freeResult( $res );
 628                 return $arr;
 629         }
 630
 631         /**
 632          * Get an array of existing categories, with the name in the key and sort key in the value.
 633          * @private
 634          */
 635         function getExistingCategories() {
 636                 $res = $this->mDb->select( 'categorylinks', array( 'cl_to', 'cl_sortkey' ),
 637                         array( 'cl_from' => $this->mId ), __METHOD__, $this->mOptions );
 638                 $arr = array();
 639                 while ( $row = $this->mDb->fetchObject( $res ) ) {
 640                         $arr[$row->cl_to] = $row->cl_sortkey;
 641                 }
 642                 $this->mDb->freeResult( $res );
 643                 return $arr;
 644         }
 645
 646         /**
 647          * Get an array of existing interlanguage links, with the language code in the key and the
 648          * title in the value.
 649          * @private
 650          */
 651         function getExistingInterlangs() {
 652                 $res = $this->mDb->select( 'langlinks', array( 'll_lang', 'll_title' ),
 653                         array( 'll_from' => $this->mId ), __METHOD__, $this->mOptions );
 654                 $arr = array();
 655                 while ( $row = $this->mDb->fetchObject( $res ) ) {
 656                         $arr[$row->ll_lang] = $row->ll_title;
 657                 }
 658                 return $arr;
 659         }
 660
 661         /**
 662          * Get an array of existing categories, with the name in the key and sort key in the value.
 663          * @private
 664          */
 665         function getExistingProperties() {
 666                 $res = $this->mDb->select( 'page_props', array( 'pp_propname', 'pp_value' ),
 667                         array( 'pp_page' => $this->mId ), __METHOD__, $this->mOptions );
 668                 $arr = array();
 669                 while ( $row = $this->mDb->fetchObject( $res ) ) {
 670                         $arr[$row->pp_propname] = $row->pp_value;
 671                 }
 672                 $this->mDb->freeResult( $res );
 673                 return $arr;
 674         }
 675
 676
 677         /**
 678          * Return the title object of the page being updated
 679          */
 680         function getTitle() {
 681                 return $this->mTitle;
 682         }
 683
 684         /**
 685          * Invalidate any necessary link lists related to page property changes
 686          */
 687         function invalidateProperties( $changed ) {
 688                 global $wgPagePropLinkInvalidations;
 689
 690                 foreach ( $changed as $name => $value ) {
 691                         if ( isset( $wgPagePropLinkInvalidations[$name] ) ) {
 692                                 $inv = $wgPagePropLinkInvalidations[$name];
 693                                 if ( !is_array( $inv ) ) {
 694                                         $inv = array( $inv );
 695                                 }
 696                                 foreach ( $inv as $table ) {
 697                                         $update = new HTMLCacheUpdate( $this->mTitle, $table );
 698                                         $update->doUpdate();
 699                                 }
 700                         }
 701                 }
 702         }
 703 }