includes/LinksUpdate.php

   1 <?php
   2 /**
   3  * See docs/deferred.txt
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @todo document (e.g. one-sentence top-level class description).
  21  */
  22 class LinksUpdate extends SecondaryDBDataUpdate {
  23
  24         /**@{{
  25          * @private
  26          */
  27         var $mLinks,         //!< Map of title strings to IDs for the links in the document
  28                 $mImages,        //!< DB keys of the images used, in the array key only
  29                 $mTemplates,     //!< Map of title strings to IDs for the template references, including broken ones
  30                 $mExternals,     //!< URLs of external links, array key only
  31                 $mCategories,    //!< Map of category names to sort keys
  32                 $mInterlangs,    //!< Map of language codes to titles
  33                 $mProperties,    //!< Map of arbitrary name to value
  34                 $mRecursive;     //!< Whether to queue jobs for recursive updates
  35         /**@}}*/
  36
  37         /**
  38          * Constructor
  39          *
  40          * @param $title Title of the page we're updating
  41          * @param $parserOutput ParserOutput: output from a full parse of this page
  42          * @param $recursive Boolean: queue jobs for recursive updates?
  43          */
  44         function __construct( $title, $parserOutput, $recursive = true ) {
  45         if ( !is_object( $title ) ) {
  46             throw new MWException( "The calling convention to LinksUpdate::LinksUpdate() has changed. " .
  47                 "Please see Article::editUpdates() for an invocation example.\n" );
  48         }
  49
  50         parent::__construct( $title, $parserOutput );
  51
  52                 $this->mLinks = $parserOutput->getLinks();
  53                 $this->mImages = $parserOutput->getImages();
  54                 $this->mTemplates = $parserOutput->getTemplates();
  55                 $this->mExternals = $parserOutput->getExternalLinks();
  56                 $this->mCategories = $parserOutput->getCategories();
  57                 $this->mProperties = $parserOutput->getProperties();
  58                 $this->mInterwikis = $parserOutput->getInterwikiLinks();
  59
  60                 # Convert the format of the interlanguage links
  61                 # I didn't want to change it in the ParserOutput, because that array is passed all
  62                 # the way back to the skin, so either a skin API break would be required, or an
  63                 # inefficient back-conversion.
  64                 $ill = $parserOutput->getLanguageLinks();
  65                 $this->mInterlangs = array();
  66                 foreach ( $ill as $link ) {
  67                         list( $key, $title ) = explode( ':', $link, 2 );
  68                         $this->mInterlangs[$key] = $title;
  69                 }
  70
  71                 foreach ( $this->mCategories as &$sortkey ) {
  72                         # If the sortkey is longer then 255 bytes,
  73                         # it truncated by DB, and then doesn't get
  74                         # matched when comparing existing vs current
  75                         # categories, causing bug 25254.
  76                         # Also. substr behaves weird when given "".
  77                         if ( $sortkey !== '' ) {
  78                                 $sortkey = substr( $sortkey, 0, 255 );
  79                         }
  80                 }
  81
  82                 $this->mRecursive = $recursive;
  83
  84                 wfRunHooks( 'LinksUpdateConstructed', array( &$this ) );
  85         }
  86
  87         /**
  88          * Update link tables with outgoing links from an updated article
  89          */
  90         public function doUpdate() {
  91                 global $wgUseDumbLinkUpdate;
  92
  93                 wfRunHooks( 'LinksUpdate', array( &$this ) );
  94                 if ( $wgUseDumbLinkUpdate ) {
  95                         $this->doDumbUpdate();
  96                 } else {
  97                         $this->doIncrementalUpdate();
  98                 }
  99                 wfRunHooks( 'LinksUpdateComplete', array( &$this ) );
 100         }
 101
 102         protected function doIncrementalUpdate() {
 103                 wfProfileIn( __METHOD__ );
 104
 105                 # Page links
 106                 $existing = $this->getExistingLinks();
 107                 $this->incrTableUpdate( 'pagelinks', 'pl', $this->getLinkDeletions( $existing ),
 108                         $this->getLinkInsertions( $existing ) );
 109
 110                 # Image links
 111                 $existing = $this->getExistingImages();
 112
 113                 $imageDeletes = $this->getImageDeletions( $existing );
 114                 $this->incrTableUpdate( 'imagelinks', 'il', $imageDeletes,
 115                         $this->getImageInsertions( $existing ) );
 116
 117                 # Invalidate all image description pages which had links added or removed
 118                 $imageUpdates = $imageDeletes + array_diff_key( $this->mImages, $existing );
 119                 $this->invalidateImageDescriptions( $imageUpdates );
 120
 121                 # External links
 122                 $existing = $this->getExistingExternals();
 123                 $this->incrTableUpdate( 'externallinks', 'el', $this->getExternalDeletions( $existing ),
 124                         $this->getExternalInsertions( $existing ) );
 125
 126                 # Language links
 127                 $existing = $this->getExistingInterlangs();
 128                 $this->incrTableUpdate( 'langlinks', 'll', $this->getInterlangDeletions( $existing ),
 129                         $this->getInterlangInsertions( $existing ) );
 130
 131                 # Inline interwiki links
 132                 $existing = $this->getExistingInterwikis();
 133                 $this->incrTableUpdate( 'iwlinks', 'iwl', $this->getInterwikiDeletions( $existing ),
 134                         $this->getInterwikiInsertions( $existing ) );
 135
 136                 # Template links
 137                 $existing = $this->getExistingTemplates();
 138                 $this->incrTableUpdate( 'templatelinks', 'tl', $this->getTemplateDeletions( $existing ),
 139                         $this->getTemplateInsertions( $existing ) );
 140
 141                 # Category links
 142                 $existing = $this->getExistingCategories();
 143
 144                 $categoryDeletes = $this->getCategoryDeletions( $existing );
 145
 146                 $this->incrTableUpdate( 'categorylinks', 'cl', $categoryDeletes,
 147                         $this->getCategoryInsertions( $existing ) );
 148
 149                 # Invalidate all categories which were added, deleted or changed (set symmetric difference)
 150                 $categoryInserts = array_diff_assoc( $this->mCategories, $existing );
 151                 $categoryUpdates = $categoryInserts + $categoryDeletes;
 152                 $this->invalidateCategories( $categoryUpdates );
 153                 $this->updateCategoryCounts( $categoryInserts, $categoryDeletes );
 154
 155                 # Page properties
 156                 $existing = $this->getExistingProperties();
 157
 158                 $propertiesDeletes = $this->getPropertyDeletions( $existing );
 159
 160                 $this->incrTableUpdate( 'page_props', 'pp', $propertiesDeletes,
 161                         $this->getPropertyInsertions( $existing ) );
 162
 163                 # Invalidate the necessary pages
 164                 $changed = $propertiesDeletes + array_diff_assoc( $this->mProperties, $existing );
 165                 $this->invalidateProperties( $changed );
 166
 167                 # Refresh links of all pages including this page
 168                 # This will be in a separate transaction
 169                 if ( $this->mRecursive ) {
 170                         $this->queueRecursiveJobs();
 171                 }
 172
 173                 wfProfileOut( __METHOD__ );
 174         }
 175
 176         /**
 177          * Link update which clears the previous entries and inserts new ones
 178          * May be slower or faster depending on level of lock contention and write speed of DB
 179          * Also useful where link table corruption needs to be repaired, e.g. in refreshLinks.php
 180          */
 181         protected function doDumbUpdate() {
 182                 wfProfileIn( __METHOD__ );
 183
 184                 # Refresh category pages and image description pages
 185                 $existing = $this->getExistingCategories();
 186                 $categoryInserts = array_diff_assoc( $this->mCategories, $existing );
 187                 $categoryDeletes = array_diff_assoc( $existing, $this->mCategories );
 188                 $categoryUpdates = $categoryInserts + $categoryDeletes;
 189                 $existing = $this->getExistingImages();
 190                 $imageUpdates = array_diff_key( $existing, $this->mImages ) + array_diff_key( $this->mImages, $existing );
 191
 192                 $this->dumbTableUpdate( 'pagelinks',     $this->getLinkInsertions(),     'pl_from' );
 193                 $this->dumbTableUpdate( 'imagelinks',    $this->getImageInsertions(),    'il_from' );
 194                 $this->dumbTableUpdate( 'categorylinks', $this->getCategoryInsertions(), 'cl_from' );
 195                 $this->dumbTableUpdate( 'templatelinks', $this->getTemplateInsertions(), 'tl_from' );
 196                 $this->dumbTableUpdate( 'externallinks', $this->getExternalInsertions(), 'el_from' );
 197                 $this->dumbTableUpdate( 'langlinks',     $this->getInterlangInsertions(),'ll_from' );
 198                 $this->dumbTableUpdate( 'iwlinks',       $this->getInterwikiInsertions(),'iwl_from' );
 199                 $this->dumbTableUpdate( 'page_props',    $this->getPropertyInsertions(), 'pp_page' );
 200
 201                 # Update the cache of all the category pages and image description
 202                 # pages which were changed, and fix the category table count
 203                 $this->invalidateCategories( $categoryUpdates );
 204                 $this->updateCategoryCounts( $categoryInserts, $categoryDeletes );
 205                 $this->invalidateImageDescriptions( $imageUpdates );
 206
 207                 # Refresh links of all pages including this page
 208                 # This will be in a separate transaction
 209                 if ( $this->mRecursive ) {
 210                         $this->queueRecursiveJobs();
 211                 }
 212
 213                 wfProfileOut( __METHOD__ );
 214         }
 215
 216         function queueRecursiveJobs() {
 217                 global $wgUpdateRowsPerJob;
 218                 wfProfileIn( __METHOD__ );
 219
 220                 $cache = $this->mTitle->getBacklinkCache();
 221                 $batches = $cache->partition( 'templatelinks', $wgUpdateRowsPerJob );
 222                 if ( !$batches ) {
 223                         wfProfileOut( __METHOD__ );
 224                         return;
 225                 }
 226                 $jobs = array();
 227                 foreach ( $batches as $batch ) {
 228                         list( $start, $end ) = $batch;
 229                         $params = array(
 230                                 'table' => 'templatelinks',
 231                                 'start' => $start,
 232                                 'end' => $end,
 233                         );
 234                         $jobs[] = new RefreshLinksJob2( $this->mTitle, $params );
 235                 }
 236                 Job::batchInsert( $jobs );
 237
 238                 wfProfileOut( __METHOD__ );
 239         }
 240
 241         /**
 242          * @param $cats
 243          */
 244         function invalidateCategories( $cats ) {
 245                 $this->invalidatePages( NS_CATEGORY, array_keys( $cats ) );
 246         }
 247
 248         /**
 249          * Update all the appropriate counts in the category table.
 250          * @param $added array associative array of category name => sort key
 251          * @param $deleted array associative array of category name => sort key
 252          */
 253         function updateCategoryCounts( $added, $deleted ) {
 254                 $a = WikiPage::factory( $this->mTitle );
 255                 $a->updateCategoryCounts(
 256                         array_keys( $added ), array_keys( $deleted )
 257                 );
 258         }
 259
 260         /**
 261          * @param $images
 262          */
 263         function invalidateImageDescriptions( $images ) {
 264                 $this->invalidatePages( NS_FILE, array_keys( $images ) );
 265         }
 266
 267     /**
 268      * @param $table
 269      * @param $insertions
 270      * @param $fromField
 271      */
 272     private function dumbTableUpdate( $table, $insertions, $fromField ) {
 273         $this->mDb->delete( $table, array( $fromField => $this->mId ), __METHOD__ );
 274         if ( count( $insertions ) ) {
 275             # The link array was constructed without FOR UPDATE, so there may
 276             # be collisions.  This may cause minor link table inconsistencies,
 277             # which is better than crippling the site with lock contention.
 278             $this->mDb->insert( $table, $insertions, __METHOD__, array( 'IGNORE' ) );
 279         }
 280     }
 281
 282         /**
 283          * Update a table by doing a delete query then an insert query
 284          * @param $table
 285          * @param $prefix
 286          * @param $deletions
 287          * @param $insertions
 288          */
 289         function incrTableUpdate( $table, $prefix, $deletions, $insertions ) {
 290                 if ( $table == 'page_props' ) {
 291                         $fromField = 'pp_page';
 292                 } else {
 293                         $fromField = "{$prefix}_from";
 294                 }
 295                 $where = array( $fromField => $this->mId );
 296                 if ( $table == 'pagelinks' || $table == 'templatelinks' || $table == 'iwlinks' ) {
 297                         if ( $table == 'iwlinks' ) {
 298                                 $baseKey = 'iwl_prefix';
 299                         } else {
 300                                 $baseKey = "{$prefix}_namespace";
 301                         }
 302                         $clause = $this->mDb->makeWhereFrom2d( $deletions, $baseKey, "{$prefix}_title" );
 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          * Get an array of pagelinks insertions for passing to the DB
 332          * Skips the titles specified by the 2-D array $existing
 333          * @param $existing array
 334          * @return array
 335          */
 336         private function getLinkInsertions( $existing = array() ) {
 337                 $arr = array();
 338                 foreach( $this->mLinks as $ns => $dbkeys ) {
 339                         $diffs = isset( $existing[$ns] )
 340                                 ? array_diff_key( $dbkeys, $existing[$ns] )
 341                                 : $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          * @param $existing array
 356          * @return array
 357          */
 358         private function getTemplateInsertions( $existing = array() ) {
 359                 $arr = array();
 360                 foreach( $this->mTemplates as $ns => $dbkeys ) {
 361                         $diffs = isset( $existing[$ns] ) ? array_diff_key( $dbkeys, $existing[$ns] ) : $dbkeys;
 362                         foreach ( $diffs as $dbk => $id ) {
 363                                 $arr[] = array(
 364                                         'tl_from'      => $this->mId,
 365                                         'tl_namespace' => $ns,
 366                                         'tl_title'     => $dbk
 367                                 );
 368                         }
 369                 }
 370                 return $arr;
 371         }
 372
 373         /**
 374          * Get an array of image insertions
 375          * Skips the names specified in $existing
 376          * @param $existing array
 377          * @return array
 378          */
 379         private function getImageInsertions( $existing = array() ) {
 380                 $arr = array();
 381                 $diffs = array_diff_key( $this->mImages, $existing );
 382                 foreach( $diffs as $iname => $dummy ) {
 383                         $arr[] = array(
 384                                 'il_from' => $this->mId,
 385                                 'il_to'   => $iname
 386                         );
 387                 }
 388                 return $arr;
 389         }
 390
 391         /**
 392          * Get an array of externallinks insertions. Skips the names specified in $existing
 393          * @param $existing array
 394          * @return array
 395          */
 396         private function getExternalInsertions( $existing = array() ) {
 397                 $arr = array();
 398                 $diffs = array_diff_key( $this->mExternals, $existing );
 399                 foreach( $diffs as $url => $dummy ) {
 400                         foreach( wfMakeUrlIndexes( $url ) as $index ) {
 401                                 $arr[] = array(
 402                                         'el_from'   => $this->mId,
 403                                         'el_to'     => $url,
 404                                         'el_index'  => $index,
 405                                 );
 406                         }
 407                 }
 408                 return $arr;
 409         }
 410
 411         /**
 412          * Get an array of category insertions
 413          *
 414          * @param $existing array mapping existing category names to sort keys. If both
 415          * match a link in $this, the link will be omitted from the output
 416          *
 417          * @return array
 418          */
 419         private function getCategoryInsertions( $existing = array() ) {
 420                 global $wgContLang, $wgCategoryCollation;
 421                 $diffs = array_diff_assoc( $this->mCategories, $existing );
 422                 $arr = array();
 423                 foreach ( $diffs as $name => $prefix ) {
 424                         $nt = Title::makeTitleSafe( NS_CATEGORY, $name );
 425                         $wgContLang->findVariantLink( $name, $nt, true );
 426
 427                         if ( $this->mTitle->getNamespace() == NS_CATEGORY ) {
 428                                 $type = 'subcat';
 429                         } elseif ( $this->mTitle->getNamespace() == NS_FILE ) {
 430                                 $type = 'file';
 431                         } else {
 432                                 $type = 'page';
 433                         }
 434
 435                         # Treat custom sortkeys as a prefix, so that if multiple
 436                         # things are forced to sort as '*' or something, they'll
 437                         # sort properly in the category rather than in page_id
 438                         # order or such.
 439                         $sortkey = Collation::singleton()->getSortKey(
 440                                 $this->mTitle->getCategorySortkey( $prefix ) );
 441
 442                         $arr[] = array(
 443                                 'cl_from'    => $this->mId,
 444                                 'cl_to'      => $name,
 445                                 'cl_sortkey' => $sortkey,
 446                                 'cl_timestamp' => $this->mDb->timestamp(),
 447                                 'cl_sortkey_prefix' => $prefix,
 448                                 'cl_collation' => $wgCategoryCollation,
 449                                 'cl_type' => $type,
 450                         );
 451                 }
 452                 return $arr;
 453         }
 454
 455         /**
 456          * Get an array of interlanguage link insertions
 457          *
 458          * @param $existing Array mapping existing language codes to titles
 459          *
 460          * @return array
 461          */
 462         private function getInterlangInsertions( $existing = array() ) {
 463                 $diffs = array_diff_assoc( $this->mInterlangs, $existing );
 464                 $arr = array();
 465                 foreach( $diffs as $lang => $title ) {
 466                         $arr[] = array(
 467                                 'll_from'  => $this->mId,
 468                                 'll_lang'  => $lang,
 469                                 'll_title' => $title
 470                         );
 471                 }
 472                 return $arr;
 473         }
 474
 475         /**
 476          * Get an array of page property insertions
 477          * @param $existing array
 478          * @return array
 479          */
 480         function getPropertyInsertions( $existing = array() ) {
 481                 $diffs = array_diff_assoc( $this->mProperties, $existing );
 482                 $arr = array();
 483                 foreach ( $diffs as $name => $value ) {
 484                         $arr[] = array(
 485                                 'pp_page'      => $this->mId,
 486                                 'pp_propname'  => $name,
 487                                 'pp_value'     => $value,
 488                         );
 489                 }
 490                 return $arr;
 491         }
 492
 493         /**
 494          * Get an array of interwiki insertions for passing to the DB
 495          * Skips the titles specified by the 2-D array $existing
 496          * @param $existing array
 497          * @return array
 498          */
 499         private function getInterwikiInsertions( $existing = array() ) {
 500                 $arr = array();
 501                 foreach( $this->mInterwikis as $prefix => $dbkeys ) {
 502                         $diffs = isset( $existing[$prefix] ) ? array_diff_key( $dbkeys, $existing[$prefix] ) : $dbkeys;
 503                         foreach ( $diffs as $dbk => $id ) {
 504                                 $arr[] = array(
 505                                         'iwl_from'   => $this->mId,
 506                                         'iwl_prefix' => $prefix,
 507                                         'iwl_title'  => $dbk
 508                                 );
 509                         }
 510                 }
 511                 return $arr;
 512         }
 513
 514         /**
 515          * Given an array of existing links, returns those links which are not in $this
 516          * and thus should be deleted.
 517          * @param $existing array
 518          * @return array
 519          */
 520         private function getLinkDeletions( $existing ) {
 521                 $del = array();
 522                 foreach ( $existing as $ns => $dbkeys ) {
 523                         if ( isset( $this->mLinks[$ns] ) ) {
 524                                 $del[$ns] = array_diff_key( $existing[$ns], $this->mLinks[$ns] );
 525                         } else {
 526                                 $del[$ns] = $existing[$ns];
 527                         }
 528                 }
 529                 return $del;
 530         }
 531
 532         /**
 533          * Given an array of existing templates, returns those templates which are not in $this
 534          * and thus should be deleted.
 535          * @param $existing array
 536          * @return array
 537          */
 538         private function getTemplateDeletions( $existing ) {
 539                 $del = array();
 540                 foreach ( $existing as $ns => $dbkeys ) {
 541                         if ( isset( $this->mTemplates[$ns] ) ) {
 542                                 $del[$ns] = array_diff_key( $existing[$ns], $this->mTemplates[$ns] );
 543                         } else {
 544                                 $del[$ns] = $existing[$ns];
 545                         }
 546                 }
 547                 return $del;
 548         }
 549
 550         /**
 551          * Given an array of existing images, returns those images which are not in $this
 552          * and thus should be deleted.
 553          * @param $existing array
 554          * @return array
 555          */
 556         private function getImageDeletions( $existing ) {
 557                 return array_diff_key( $existing, $this->mImages );
 558         }
 559
 560         /**
 561          * Given an array of existing external links, returns those links which are not
 562          * in $this and thus should be deleted.
 563          * @param $existing array
 564          * @return array
 565          */
 566         private function getExternalDeletions( $existing ) {
 567                 return array_diff_key( $existing, $this->mExternals );
 568         }
 569
 570         /**
 571          * Given an array of existing categories, returns those categories which are not in $this
 572          * and thus should be deleted.
 573          * @param $existing array
 574          * @return array
 575          */
 576         private function getCategoryDeletions( $existing ) {
 577                 return array_diff_assoc( $existing, $this->mCategories );
 578         }
 579
 580         /**
 581          * Given an array of existing interlanguage links, returns those links which are not
 582          * in $this and thus should be deleted.
 583          * @param $existing array
 584          * @return array
 585          */
 586         private function getInterlangDeletions( $existing ) {
 587                 return array_diff_assoc( $existing, $this->mInterlangs );
 588         }
 589
 590         /**
 591          * Get array of properties which should be deleted.
 592          * @param $existing array
 593          * @return array
 594          */
 595         function getPropertyDeletions( $existing ) {
 596                 return array_diff_assoc( $existing, $this->mProperties );
 597         }
 598
 599         /**
 600          * Given an array of existing interwiki links, returns those links which are not in $this
 601          * and thus should be deleted.
 602          * @param $existing array
 603          * @return array
 604          */
 605         private function getInterwikiDeletions( $existing ) {
 606                 $del = array();
 607                 foreach ( $existing as $prefix => $dbkeys ) {
 608                         if ( isset( $this->mInterwikis[$prefix] ) ) {
 609                                 $del[$prefix] = array_diff_key( $existing[$prefix], $this->mInterwikis[$prefix] );
 610                         } else {
 611                                 $del[$prefix] = $existing[$prefix];
 612                         }
 613                 }
 614                 return $del;
 615         }
 616
 617         /**
 618          * Get an array of existing links, as a 2-D array
 619          *
 620          * @return array
 621          */
 622         private function getExistingLinks() {
 623                 $res = $this->mDb->select( 'pagelinks', array( 'pl_namespace', 'pl_title' ),
 624                         array( 'pl_from' => $this->mId ), __METHOD__, $this->mOptions );
 625                 $arr = array();
 626                 foreach ( $res as $row ) {
 627                         if ( !isset( $arr[$row->pl_namespace] ) ) {
 628                                 $arr[$row->pl_namespace] = array();
 629                         }
 630                         $arr[$row->pl_namespace][$row->pl_title] = 1;
 631                 }
 632                 return $arr;
 633         }
 634
 635         /**
 636          * Get an array of existing templates, as a 2-D array
 637          *
 638          * @return array
 639          */
 640         private function getExistingTemplates() {
 641                 $res = $this->mDb->select( 'templatelinks', array( 'tl_namespace', 'tl_title' ),
 642                         array( 'tl_from' => $this->mId ), __METHOD__, $this->mOptions );
 643                 $arr = array();
 644                 foreach ( $res as $row ) {
 645                         if ( !isset( $arr[$row->tl_namespace] ) ) {
 646                                 $arr[$row->tl_namespace] = array();
 647                         }
 648                         $arr[$row->tl_namespace][$row->tl_title] = 1;
 649                 }
 650                 return $arr;
 651         }
 652
 653         /**
 654          * Get an array of existing images, image names in the keys
 655          *
 656          * @return array
 657          */
 658         private function getExistingImages() {
 659                 $res = $this->mDb->select( 'imagelinks', array( 'il_to' ),
 660                         array( 'il_from' => $this->mId ), __METHOD__, $this->mOptions );
 661                 $arr = array();
 662                 foreach ( $res as $row ) {
 663                         $arr[$row->il_to] = 1;
 664                 }
 665                 return $arr;
 666         }
 667
 668         /**
 669          * Get an array of existing external links, URLs in the keys
 670          *
 671          * @return array
 672          */
 673         private function getExistingExternals() {
 674                 $res = $this->mDb->select( 'externallinks', array( 'el_to' ),
 675                         array( 'el_from' => $this->mId ), __METHOD__, $this->mOptions );
 676                 $arr = array();
 677                 foreach ( $res as $row ) {
 678                         $arr[$row->el_to] = 1;
 679                 }
 680                 return $arr;
 681         }
 682
 683         /**
 684          * Get an array of existing categories, with the name in the key and sort key in the value.
 685          *
 686          * @return array
 687          */
 688         private function getExistingCategories() {
 689                 $res = $this->mDb->select( 'categorylinks', array( 'cl_to', 'cl_sortkey_prefix' ),
 690                         array( 'cl_from' => $this->mId ), __METHOD__, $this->mOptions );
 691                 $arr = array();
 692                 foreach ( $res as $row ) {
 693                         $arr[$row->cl_to] = $row->cl_sortkey_prefix;
 694                 }
 695                 return $arr;
 696         }
 697
 698         /**
 699          * Get an array of existing interlanguage links, with the language code in the key and the
 700          * title in the value.
 701          *
 702          * @return array
 703          */
 704         private function getExistingInterlangs() {
 705                 $res = $this->mDb->select( 'langlinks', array( 'll_lang', 'll_title' ),
 706                         array( 'll_from' => $this->mId ), __METHOD__, $this->mOptions );
 707                 $arr = array();
 708                 foreach ( $res as $row ) {
 709                         $arr[$row->ll_lang] = $row->ll_title;
 710                 }
 711                 return $arr;
 712         }
 713
 714         /**
 715          * Get an array of existing inline interwiki links, as a 2-D array
 716          * @return array (prefix => array(dbkey => 1))
 717          */
 718         protected function getExistingInterwikis() {
 719                 $res = $this->mDb->select( 'iwlinks', array( 'iwl_prefix', 'iwl_title' ),
 720                         array( 'iwl_from' => $this->mId ), __METHOD__, $this->mOptions );
 721                 $arr = array();
 722                 foreach ( $res as $row ) {
 723                         if ( !isset( $arr[$row->iwl_prefix] ) ) {
 724                                 $arr[$row->iwl_prefix] = array();
 725                         }
 726                         $arr[$row->iwl_prefix][$row->iwl_title] = 1;
 727                 }
 728                 return $arr;
 729         }
 730
 731         /**
 732          * Get an array of existing categories, with the name in the key and sort key in the value.
 733          *
 734          * @return array
 735          */
 736         private function getExistingProperties() {
 737                 $res = $this->mDb->select( 'page_props', array( 'pp_propname', 'pp_value' ),
 738                         array( 'pp_page' => $this->mId ), __METHOD__, $this->mOptions );
 739                 $arr = array();
 740                 foreach ( $res as $row ) {
 741                         $arr[$row->pp_propname] = $row->pp_value;
 742                 }
 743                 return $arr;
 744         }
 745
 746         /**
 747          * Return the list of images used as generated by the parser
 748          * @return array
 749          */
 750         public function getImages() {
 751                 return $this->mImages;
 752         }
 753
 754         /**
 755          * Invalidate any necessary link lists related to page property changes
 756          * @param $changed
 757          */
 758         private function invalidateProperties( $changed ) {
 759                 global $wgPagePropLinkInvalidations;
 760
 761                 foreach ( $changed as $name => $value ) {
 762                         if ( isset( $wgPagePropLinkInvalidations[$name] ) ) {
 763                                 $inv = $wgPagePropLinkInvalidations[$name];
 764                                 if ( !is_array( $inv ) ) {
 765                                         $inv = array( $inv );
 766                                 }
 767                                 foreach ( $inv as $table ) {
 768                                         $update = new HTMLCacheUpdate( $this->mTitle, $table );
 769                                         $update->doUpdate();
 770                                 }
 771                         }
 772                 }
 773         }
 774 }