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 of the page we're updating
  30          * @param $parserOutput ParserOutput: output from a full parse of this page
  31          * @param $recursive Boolean: 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                 $this->mInterwikis = $parserOutput->getInterwikiLinks();
  58
  59                 # Convert the format of the interlanguage links
  60                 # I didn't want to change it in the ParserOutput, because that array is passed all
  61                 # the way back to the skin, so either a skin API break would be required, or an
  62                 # inefficient back-conversion.
  63                 $ill = $parserOutput->getLanguageLinks();
  64                 $this->mInterlangs = array();
  65                 foreach ( $ill as $link ) {
  66                         list( $key, $title ) = explode( ':', $link, 2 );
  67                         $this->mInterlangs[$key] = $title;
  68                 }
  69
  70                 $this->mRecursive = $recursive;
  71                 $this->mTouchTmplLinks = false;
  72
  73                 wfRunHooks( 'LinksUpdateConstructed', array( &$this ) );
  74         }
  75
  76         /**
  77          * Update link tables with outgoing links from an updated article
  78          */
  79         public function doUpdate() {
  80                 global $wgUseDumbLinkUpdate;
  81
  82                 wfRunHooks( 'LinksUpdate', array( &$this ) );
  83                 if ( $wgUseDumbLinkUpdate ) {
  84                         $this->doDumbUpdate();
  85                 } else {
  86                         $this->doIncrementalUpdate();
  87                 }
  88                 wfRunHooks( 'LinksUpdateComplete', array( &$this ) );
  89         }
  90
  91         protected function doIncrementalUpdate() {
  92                 wfProfileIn( __METHOD__ );
  93
  94                 # Page links
  95                 $existing = $this->getExistingLinks();
  96                 $this->incrTableUpdate( 'pagelinks', 'pl', $this->getLinkDeletions( $existing ),
  97                         $this->getLinkInsertions( $existing ) );
  98
  99                 # Image links
 100                 $existing = $this->getExistingImages();
 101
 102                 $imageDeletes = $this->getImageDeletions( $existing );
 103                 $this->incrTableUpdate( 'imagelinks', 'il', $imageDeletes, $this->getImageInsertions( $existing ) );
 104
 105                 # Invalidate all image description pages which had links added or removed
 106                 $imageUpdates = $imageDeletes + array_diff_key( $this->mImages, $existing );
 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                 # Inline interwiki links
 120                 $existing = $this->getExistingInterwikis();
 121                 $this->incrTableUpdate( 'iwlinks', 'iwl', $this->getInterwikiDeletions( $existing ),
 122                         $this->getInterwikiInsertions( $existing ) );
 123
 124                 # Template links
 125                 $existing = $this->getExistingTemplates();
 126                 $this->incrTableUpdate( 'templatelinks', 'tl', $this->getTemplateDeletions( $existing ),
 127                         $this->getTemplateInsertions( $existing ) );
 128
 129                 # Category links
 130                 $existing = $this->getExistingCategories();
 131
 132                 $categoryDeletes = $this->getCategoryDeletions( $existing );
 133
 134                 $this->incrTableUpdate( 'categorylinks', 'cl', $categoryDeletes, $this->getCategoryInsertions( $existing ) );
 135
 136                 # Invalidate all categories which were added, deleted or changed (set symmetric difference)
 137                 $categoryInserts = array_diff_assoc( $this->mCategories, $existing );
 138                 $categoryUpdates = $categoryInserts + $categoryDeletes;
 139                 $this->invalidateCategories( $categoryUpdates );
 140                 $this->updateCategoryCounts( $categoryInserts, $categoryDeletes );
 141
 142                 # Page properties
 143                 $existing = $this->getExistingProperties();
 144
 145                 $propertiesDeletes = $this->getPropertyDeletions( $existing );
 146
 147                 $this->incrTableUpdate( 'page_props', 'pp', $propertiesDeletes, $this->getPropertyInsertions( $existing ) );
 148
 149                 # Invalidate the necessary pages
 150                 $changed = $propertiesDeletes + array_diff_assoc( $this->mProperties, $existing );
 151                 $this->invalidateProperties( $changed );
 152
 153                 # Refresh links of all pages including this page
 154                 # This will be in a separate transaction
 155                 if ( $this->mRecursive ) {
 156                         $this->queueRecursiveJobs();
 157                 }
 158
 159                 wfProfileOut( __METHOD__ );
 160         }
 161
 162         /**
 163          * Link update which clears the previous entries and inserts new ones
 164          * May be slower or faster depending on level of lock contention and write speed of DB
 165          * Also useful where link table corruption needs to be repaired, e.g. in refreshLinks.php
 166          */
 167         protected function doDumbUpdate() {
 168                 wfProfileIn( __METHOD__ );
 169
 170                 # Refresh category pages and image description pages
 171                 $existing = $this->getExistingCategories();
 172                 $categoryInserts = array_diff_assoc( $this->mCategories, $existing );
 173                 $categoryDeletes = array_diff_assoc( $existing, $this->mCategories );
 174                 $categoryUpdates = $categoryInserts + $categoryDeletes;
 175                 $existing = $this->getExistingImages();
 176                 $imageUpdates = array_diff_key( $existing, $this->mImages ) + array_diff_key( $this->mImages, $existing );
 177
 178                 $this->dumbTableUpdate( 'pagelinks',     $this->getLinkInsertions(),     'pl_from' );
 179                 $this->dumbTableUpdate( 'imagelinks',    $this->getImageInsertions(),    'il_from' );
 180                 $this->dumbTableUpdate( 'categorylinks', $this->getCategoryInsertions(), 'cl_from' );
 181                 $this->dumbTableUpdate( 'templatelinks', $this->getTemplateInsertions(), 'tl_from' );
 182                 $this->dumbTableUpdate( 'externallinks', $this->getExternalInsertions(), 'el_from' );
 183                 $this->dumbTableUpdate( 'langlinks',     $this->getInterlangInsertions(),'ll_from' );
 184                 $this->dumbTableUpdate( 'iwlinks',       $this->getInterwikiInsertions(),'iwl_from' );
 185                 $this->dumbTableUpdate( 'page_props',    $this->getPropertyInsertions(), 'pp_page' );
 186
 187                 # Update the cache of all the category pages and image description
 188                 # pages which were changed, and fix the category table count
 189                 $this->invalidateCategories( $categoryUpdates );
 190                 $this->updateCategoryCounts( $categoryInserts, $categoryDeletes );
 191                 $this->invalidateImageDescriptions( $imageUpdates );
 192
 193                 # Refresh links of all pages including this page
 194                 # This will be in a separate transaction
 195                 if ( $this->mRecursive ) {
 196                         $this->queueRecursiveJobs();
 197                 }
 198
 199                 wfProfileOut( __METHOD__ );
 200         }
 201
 202         function queueRecursiveJobs() {
 203                 global $wgUpdateRowsPerJob;
 204                 wfProfileIn( __METHOD__ );
 205
 206                 $cache = $this->mTitle->getBacklinkCache();
 207                 $batches = $cache->partition( 'templatelinks', $wgUpdateRowsPerJob );
 208                 if ( !$batches ) {
 209                         wfProfileOut( __METHOD__ );
 210                         return;
 211                 }
 212                 $jobs = array();
 213                 foreach ( $batches as $batch ) {
 214                         list( $start, $end ) = $batch;
 215                         $params = array(
 216                                 'start' => $start,
 217                                 'end' => $end,
 218                         );
 219                         $jobs[] = new RefreshLinksJob2( $this->mTitle, $params );
 220                 }
 221                 Job::batchInsert( $jobs );
 222
 223                 wfProfileOut( __METHOD__ );
 224         }
 225
 226         /**
 227          * Invalidate the cache of a list of pages from a single namespace
 228          *
 229          * @param $namespace Integer
 230          * @param $dbkeys Array
 231          */
 232         function invalidatePages( $namespace, $dbkeys ) {
 233                 if ( !count( $dbkeys ) ) {
 234                         return;
 235                 }
 236
 237                 /**
 238                  * Determine which pages need to be updated
 239                  * This is necessary to prevent the job queue from smashing the DB with
 240                  * large numbers of concurrent invalidations of the same page
 241                  */
 242                 $now = $this->mDb->timestamp();
 243                 $ids = array();
 244                 $res = $this->mDb->select( 'page', array( 'page_id' ),
 245                         array(
 246                                 'page_namespace' => $namespace,
 247                                 'page_title IN (' . $this->mDb->makeList( $dbkeys ) . ')',
 248                                 'page_touched < ' . $this->mDb->addQuotes( $now )
 249                         ), __METHOD__
 250                 );
 251                 while ( $row = $this->mDb->fetchObject( $res ) ) {
 252                         $ids[] = $row->page_id;
 253                 }
 254                 if ( !count( $ids ) ) {
 255                         return;
 256                 }
 257
 258                 /**
 259                  * Do the update
 260                  * We still need the page_touched condition, in case the row has changed since
 261                  * the non-locking select above.
 262                  */
 263                 $this->mDb->update( 'page', array( 'page_touched' => $now ),
 264                         array(
 265                                 'page_id IN (' . $this->mDb->makeList( $ids ) . ')',
 266                                 'page_touched < ' . $this->mDb->addQuotes( $now )
 267                         ), __METHOD__
 268                 );
 269         }
 270
 271         function invalidateCategories( $cats ) {
 272                 $this->invalidatePages( NS_CATEGORY, array_keys( $cats ) );
 273         }
 274
 275         /**
 276          * Update all the appropriate counts in the category table.
 277          * @param $added associative array of category name => sort key
 278          * @param $deleted associative array of category name => sort key
 279          */
 280         function updateCategoryCounts( $added, $deleted ) {
 281                 $a = new Article($this->mTitle);
 282                 $a->updateCategoryCounts(
 283                         array_keys( $added ), array_keys( $deleted )
 284                 );
 285         }
 286
 287         function invalidateImageDescriptions( $images ) {
 288                 $this->invalidatePages( NS_FILE, array_keys( $images ) );
 289         }
 290
 291         function dumbTableUpdate( $table, $insertions, $fromField ) {
 292                 $this->mDb->delete( $table, array( $fromField => $this->mId ), __METHOD__ );
 293                 if ( count( $insertions ) ) {
 294                         # The link array was constructed without FOR UPDATE, so there may
 295                         # be collisions.  This may cause minor link table inconsistencies,
 296                         # which is better than crippling the site with lock contention.
 297                         $this->mDb->insert( $table, $insertions, __METHOD__, array( 'IGNORE' ) );
 298                 }
 299         }
 300
 301         /**
 302          * Update a table by doing a delete query then an insert query
 303          * @private
 304          */
 305         function incrTableUpdate( $table, $prefix, $deletions, $insertions ) {
 306                 if ( $table == 'page_props' ) {
 307                         $fromField = 'pp_page';
 308                 } else {
 309                         $fromField = "{$prefix}_from";
 310                 }
 311                 $where = array( $fromField => $this->mId );
 312                 if ( $table == 'pagelinks' || $table == 'templatelinks' || $table == 'iwlinks' ) {
 313                         if ( $table == 'iwlinks' ) {
 314                                 $baseKey = 'iwl_prefix';
 315                         } else {
 316                                 $baseKey = "{$prefix}_namespace";
 317                         }
 318                         $clause = $this->mDb->makeWhereFrom2d( $deletions, $baseKey, "{$prefix}_title" );
 319                         if ( $clause ) {
 320                                 $where[] = $clause;
 321                         } else {
 322                                 $where = false;
 323                         }
 324                 } else {
 325                         if ( $table == 'langlinks' ) {
 326                                 $toField = 'll_lang';
 327                         } elseif ( $table == 'page_props' ) {
 328                                 $toField = 'pp_propname';
 329                         } else {
 330                                 $toField = $prefix . '_to';
 331                         }
 332                         if ( count( $deletions ) ) {
 333                                 $where[] = "$toField IN (" . $this->mDb->makeList( array_keys( $deletions ) ) . ')';
 334                         } else {
 335                                 $where = false;
 336                         }
 337                 }
 338                 if ( $where ) {
 339                         $this->mDb->delete( $table, $where, __METHOD__ );
 340                 }
 341                 if ( count( $insertions ) ) {
 342                         $this->mDb->insert( $table, $insertions, __METHOD__, 'IGNORE' );
 343                 }
 344         }
 345
 346
 347         /**
 348          * Get an array of pagelinks insertions for passing to the DB
 349          * Skips the titles specified by the 2-D array $existing
 350          * @private
 351          */
 352         function getLinkInsertions( $existing = array() ) {
 353                 $arr = array();
 354                 foreach( $this->mLinks as $ns => $dbkeys ) {
 355                         # array_diff_key() was introduced in PHP 5.1, there is a compatibility function
 356                         # in GlobalFunctions.php
 357                         $diffs = isset( $existing[$ns] ) ? array_diff_key( $dbkeys, $existing[$ns] ) : $dbkeys;
 358                         foreach ( $diffs as $dbk => $id ) {
 359                                 $arr[] = array(
 360                                         'pl_from'      => $this->mId,
 361                                         'pl_namespace' => $ns,
 362                                         'pl_title'     => $dbk
 363                                 );
 364                         }
 365                 }
 366                 return $arr;
 367         }
 368
 369         /**
 370          * Get an array of template insertions. Like getLinkInsertions()
 371          * @private
 372          */
 373         function getTemplateInsertions( $existing = array() ) {
 374                 $arr = array();
 375                 foreach( $this->mTemplates as $ns => $dbkeys ) {
 376                         $diffs = isset( $existing[$ns] ) ? array_diff_key( $dbkeys, $existing[$ns] ) : $dbkeys;
 377                         foreach ( $diffs as $dbk => $id ) {
 378                                 $arr[] = array(
 379                                         'tl_from'      => $this->mId,
 380                                         'tl_namespace' => $ns,
 381                                         'tl_title'     => $dbk
 382                                 );
 383                         }
 384                 }
 385                 return $arr;
 386         }
 387
 388         /**
 389          * Get an array of image insertions
 390          * Skips the names specified in $existing
 391          * @private
 392          */
 393         function getImageInsertions( $existing = array() ) {
 394                 $arr = array();
 395                 $diffs = array_diff_key( $this->mImages, $existing );
 396                 foreach( $diffs as $iname => $dummy ) {
 397                         $arr[] = array(
 398                                 'il_from' => $this->mId,
 399                                 'il_to'   => $iname
 400                         );
 401                 }
 402                 return $arr;
 403         }
 404
 405         /**
 406          * Get an array of externallinks insertions. Skips the names specified in $existing
 407          * @private
 408          */
 409         function getExternalInsertions( $existing = array() ) {
 410                 $arr = array();
 411                 $diffs = array_diff_key( $this->mExternals, $existing );
 412                 foreach( $diffs as $url => $dummy ) {
 413                         $arr[] = array(
 414                                 'el_from'   => $this->mId,
 415                                 'el_to'     => $url,
 416                                 'el_index'  => wfMakeUrlIndex( $url ),
 417                         );
 418                 }
 419                 return $arr;
 420         }
 421
 422         /**
 423          * Get an array of category insertions
 424          *
 425          * @param $existing Array mapping existing category names to sort keys. If both
 426          * match a link in $this, the link will be omitted from the output
 427          * @private
 428          */
 429         function getCategoryInsertions( $existing = array() ) {
 430                 global $wgContLang;
 431                 $diffs = array_diff_assoc( $this->mCategories, $existing );
 432                 $arr = array();
 433                 foreach ( $diffs as $name => $sortkey ) {
 434                         $nt = Title::makeTitleSafe( NS_CATEGORY, $name );
 435                         $wgContLang->findVariantLink( $name, $nt, true );
 436                         $arr[] = array(
 437                                 'cl_from'    => $this->mId,
 438                                 'cl_to'      => $name,
 439                                 'cl_sortkey' => $sortkey,
 440                                 'cl_timestamp' => $this->mDb->timestamp()
 441                         );
 442                 }
 443                 return $arr;
 444         }
 445
 446         /**
 447          * Get an array of interlanguage link insertions
 448          *
 449          * @param $existing Array mapping existing language codes to titles
 450          * @private
 451          */
 452         function getInterlangInsertions( $existing = array() ) {
 453             $diffs = array_diff_assoc( $this->mInterlangs, $existing );
 454             $arr = array();
 455             foreach( $diffs as $lang => $title ) {
 456                 $arr[] = array(
 457                     'll_from'  => $this->mId,
 458                     'll_lang'  => $lang,
 459                     'll_title' => $title
 460                 );
 461             }
 462             return $arr;
 463         }
 464
 465         /**
 466          * Get an array of page property insertions
 467          */
 468         function getPropertyInsertions( $existing = array() ) {
 469                 $diffs = array_diff_assoc( $this->mProperties, $existing );
 470                 $arr = array();
 471                 foreach ( $diffs as $name => $value ) {
 472                         $arr[] = array(
 473                                 'pp_page'      => $this->mId,
 474                                 'pp_propname'  => $name,
 475                                 'pp_value'     => $value,
 476                         );
 477                 }
 478                 return $arr;
 479         }
 480
 481         /**
 482          * Get an array of interwiki insertions for passing to the DB
 483          * Skips the titles specified by the 2-D array $existing
 484          * @private
 485          */
 486         function getInterwikiInsertions( $existing = array() ) {
 487                 $arr = array();
 488                 foreach( $this->mInterwikis as $prefix => $dbkeys ) {
 489                         # array_diff_key() was introduced in PHP 5.1, there is a compatibility function
 490                         # in GlobalFunctions.php
 491                         $diffs = isset( $existing[$prefix] ) ? array_diff_key( $dbkeys, $existing[$prefix] ) : $dbkeys;
 492                         foreach ( $diffs as $dbk => $id ) {
 493                                 $arr[] = array(
 494                                         'iwl_from'   => $this->mId,
 495                                         'iwl_prefix' => $prefix,
 496                                         'iwl_title'  => $dbk
 497                                 );
 498                         }
 499                 }
 500                 return $arr;
 501         }
 502
 503
 504
 505         /**
 506          * Given an array of existing links, returns those links which are not in $this
 507          * and thus should be deleted.
 508          * @private
 509          */
 510         function getLinkDeletions( $existing ) {
 511                 $del = array();
 512                 foreach ( $existing as $ns => $dbkeys ) {
 513                         if ( isset( $this->mLinks[$ns] ) ) {
 514                                 $del[$ns] = array_diff_key( $existing[$ns], $this->mLinks[$ns] );
 515                         } else {
 516                                 $del[$ns] = $existing[$ns];
 517                         }
 518                 }
 519                 return $del;
 520         }
 521
 522         /**
 523          * Given an array of existing templates, returns those templates which are not in $this
 524          * and thus should be deleted.
 525          * @private
 526          */
 527         function getTemplateDeletions( $existing ) {
 528                 $del = array();
 529                 foreach ( $existing as $ns => $dbkeys ) {
 530                         if ( isset( $this->mTemplates[$ns] ) ) {
 531                                 $del[$ns] = array_diff_key( $existing[$ns], $this->mTemplates[$ns] );
 532                         } else {
 533                                 $del[$ns] = $existing[$ns];
 534                         }
 535                 }
 536                 return $del;
 537         }
 538
 539         /**
 540          * Given an array of existing images, returns those images which are not in $this
 541          * and thus should be deleted.
 542          * @private
 543          */
 544         function getImageDeletions( $existing ) {
 545                 return array_diff_key( $existing, $this->mImages );
 546         }
 547
 548         /**
 549          * Given an array of existing external links, returns those links which are not
 550          * in $this and thus should be deleted.
 551          * @private
 552          */
 553         function getExternalDeletions( $existing ) {
 554                 return array_diff_key( $existing, $this->mExternals );
 555         }
 556
 557         /**
 558          * Given an array of existing categories, returns those categories which are not in $this
 559          * and thus should be deleted.
 560          * @private
 561          */
 562         function getCategoryDeletions( $existing ) {
 563                 return array_diff_assoc( $existing, $this->mCategories );
 564         }
 565
 566         /**
 567          * Given an array of existing interlanguage links, returns those links which are not
 568          * in $this and thus should be deleted.
 569          * @private
 570          */
 571         function getInterlangDeletions( $existing ) {
 572             return array_diff_assoc( $existing, $this->mInterlangs );
 573         }
 574
 575         /**
 576          * Get array of properties which should be deleted.
 577          * @private
 578          */
 579         function getPropertyDeletions( $existing ) {
 580                 return array_diff_assoc( $existing, $this->mProperties );
 581         }
 582
 583         /**
 584          * Given an array of existing interwiki links, returns those links which are not in $this
 585          * and thus should be deleted.
 586          * @private
 587          */
 588         function getInterwikiDeletions( $existing ) {
 589                 $del = array();
 590                 foreach ( $existing as $prefix => $dbkeys ) {
 591                         if ( isset( $this->mInterwikis[$prefix] ) ) {
 592                                 $del[$prefix] = array_diff_key( $existing[$prefix], $this->mInterwikis[$prefix] );
 593                         } else {
 594                                 $del[$prefix] = $existing[$prefix];
 595                         }
 596                 }
 597                 return $del;
 598         }
 599
 600         /**
 601          * Get an array of existing links, as a 2-D array
 602          * @private
 603          */
 604         function getExistingLinks() {
 605                 $res = $this->mDb->select( 'pagelinks', array( 'pl_namespace', 'pl_title' ),
 606                         array( 'pl_from' => $this->mId ), __METHOD__, $this->mOptions );
 607                 $arr = array();
 608                 while ( $row = $this->mDb->fetchObject( $res ) ) {
 609                         if ( !isset( $arr[$row->pl_namespace] ) ) {
 610                                 $arr[$row->pl_namespace] = array();
 611                         }
 612                         $arr[$row->pl_namespace][$row->pl_title] = 1;
 613                 }
 614                 $this->mDb->freeResult( $res );
 615                 return $arr;
 616         }
 617
 618         /**
 619          * Get an array of existing templates, as a 2-D array
 620          * @private
 621          */
 622         function getExistingTemplates() {
 623                 $res = $this->mDb->select( 'templatelinks', array( 'tl_namespace', 'tl_title' ),
 624                         array( 'tl_from' => $this->mId ), __METHOD__, $this->mOptions );
 625                 $arr = array();
 626                 while ( $row = $this->mDb->fetchObject( $res ) ) {
 627                         if ( !isset( $arr[$row->tl_namespace] ) ) {
 628                                 $arr[$row->tl_namespace] = array();
 629                         }
 630                         $arr[$row->tl_namespace][$row->tl_title] = 1;
 631                 }
 632                 $this->mDb->freeResult( $res );
 633                 return $arr;
 634         }
 635
 636         /**
 637          * Get an array of existing images, image names in the keys
 638          * @private
 639          */
 640         function getExistingImages() {
 641                 $res = $this->mDb->select( 'imagelinks', array( 'il_to' ),
 642                         array( 'il_from' => $this->mId ), __METHOD__, $this->mOptions );
 643                 $arr = array();
 644                 while ( $row = $this->mDb->fetchObject( $res ) ) {
 645                         $arr[$row->il_to] = 1;
 646                 }
 647                 $this->mDb->freeResult( $res );
 648                 return $arr;
 649         }
 650
 651         /**
 652          * Get an array of existing external links, URLs in the keys
 653          * @private
 654          */
 655         function getExistingExternals() {
 656                 $res = $this->mDb->select( 'externallinks', array( 'el_to' ),
 657                         array( 'el_from' => $this->mId ), __METHOD__, $this->mOptions );
 658                 $arr = array();
 659                 while ( $row = $this->mDb->fetchObject( $res ) ) {
 660                         $arr[$row->el_to] = 1;
 661                 }
 662                 $this->mDb->freeResult( $res );
 663                 return $arr;
 664         }
 665
 666         /**
 667          * Get an array of existing categories, with the name in the key and sort key in the value.
 668          * @private
 669          */
 670         function getExistingCategories() {
 671                 $res = $this->mDb->select( 'categorylinks', array( 'cl_to', 'cl_sortkey' ),
 672                         array( 'cl_from' => $this->mId ), __METHOD__, $this->mOptions );
 673                 $arr = array();
 674                 while ( $row = $this->mDb->fetchObject( $res ) ) {
 675                         $arr[$row->cl_to] = $row->cl_sortkey;
 676                 }
 677                 $this->mDb->freeResult( $res );
 678                 return $arr;
 679         }
 680
 681         /**
 682          * Get an array of existing interlanguage links, with the language code in the key and the
 683          * title in the value.
 684          * @private
 685          */
 686         function getExistingInterlangs() {
 687                 $res = $this->mDb->select( 'langlinks', array( 'll_lang', 'll_title' ),
 688                         array( 'll_from' => $this->mId ), __METHOD__, $this->mOptions );
 689                 $arr = array();
 690                 while ( $row = $this->mDb->fetchObject( $res ) ) {
 691                         $arr[$row->ll_lang] = $row->ll_title;
 692                 }
 693                 return $arr;
 694         }
 695
 696         /**
 697          * Get an array of existing inline interwiki links, as a 2-D array
 698          * @return array (prefix => array(dbkey => 1))
 699          */
 700         protected function getExistingInterwikis() {
 701                 $res = $this->mDb->select( 'iwlinks', array( 'iwl_prefix', 'iwl_title' ),
 702                         array( 'iwl_from' => $this->mId ), __METHOD__, $this->mOptions );
 703                 $arr = array();
 704                 while ( $row = $this->mDb->fetchObject( $res ) ) {
 705                         if ( !isset( $arr[$row->iwl_prefix] ) ) {
 706                                 $arr[$row->iwl_prefix] = array();
 707                         }
 708                         $arr[$row->iwl_prefix][$row->iwl_title] = 1;
 709                 }
 710                 $this->mDb->freeResult( $res );
 711                 return $arr;
 712         }
 713
 714         /**
 715          * Get an array of existing categories, with the name in the key and sort key in the value.
 716          * @private
 717          */
 718         function getExistingProperties() {
 719                 $res = $this->mDb->select( 'page_props', array( 'pp_propname', 'pp_value' ),
 720                         array( 'pp_page' => $this->mId ), __METHOD__, $this->mOptions );
 721                 $arr = array();
 722                 while ( $row = $this->mDb->fetchObject( $res ) ) {
 723                         $arr[$row->pp_propname] = $row->pp_value;
 724                 }
 725                 $this->mDb->freeResult( $res );
 726                 return $arr;
 727         }
 728
 729
 730         /**
 731          * Return the title object of the page being updated
 732          */
 733         function getTitle() {
 734                 return $this->mTitle;
 735         }
 736
 737         /**
 738          * Return the list of images used as generated by the parser
 739          */
 740         public function getImages() {
 741                 return $this->mImages;
 742         }
 743
 744         /**
 745          * Invalidate any necessary link lists related to page property changes
 746          */
 747         function invalidateProperties( $changed ) {
 748                 global $wgPagePropLinkInvalidations;
 749
 750                 foreach ( $changed as $name => $value ) {
 751                         if ( isset( $wgPagePropLinkInvalidations[$name] ) ) {
 752                                 $inv = $wgPagePropLinkInvalidations[$name];
 753                                 if ( !is_array( $inv ) ) {
 754                                         $inv = array( $inv );
 755                                 }
 756                                 foreach ( $inv as $table ) {
 757                                         $update = new HTMLCacheUpdate( $this->mTitle, $table );
 758                                         $update->doUpdate();
 759                                 }
 760                         }
 761                 }
 762         }
 763 }