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 $mId,            //!< Page ID of the article linked from
  28         $mTitle,         //!< Title object of the article linked from
  29         $mParserOutput,  //!< Whether to queue jobs for recursive update
  30         $mLinks,         //!< Map of title strings to IDs for the links in the document
  31                 $mImages,        //!< DB keys of the images used, in the array key only
  32                 $mTemplates,     //!< Map of title strings to IDs for the template references, including broken ones
  33                 $mExternals,     //!< URLs of external links, array key only
  34                 $mCategories,    //!< Map of category names to sort keys
  35                 $mInterlangs,    //!< Map of language codes to titles
  36                 $mProperties,    //!< Map of arbitrary name to value
  37                 $mRecursive;     //!< Whether to queue jobs for recursive updates
  38         /**@}}*/
  39
  40         /**
  41          * Constructor
  42          *
  43          * @param $title Title of the page we're updating
  44          * @param $parserOutput ParserOutput: output from a full parse of this page
  45          * @param $recursive Boolean: queue jobs for recursive updates?
  46          */
  47         function __construct( $title, $parserOutput, $recursive = true ) {
  48         parent::__construct( );
  49
  50         if ( !is_object( $title ) ) {
  51             throw new MWException( "The calling convention to LinksUpdate::LinksUpdate() has changed. " .
  52                 "Please see Article::editUpdates() for an invocation example.\n" );
  53         }
  54
  55         $this->mTitle = $title;
  56         $this->mId = $title->getArticleID();
  57
  58         $this->mParserOutput = $parserOutput;
  59
  60                 $this->mLinks = $parserOutput->getLinks();
  61                 $this->mImages = $parserOutput->getImages();
  62                 $this->mTemplates = $parserOutput->getTemplates();
  63                 $this->mExternals = $parserOutput->getExternalLinks();
  64                 $this->mCategories = $parserOutput->getCategories();
  65                 $this->mProperties = $parserOutput->getProperties();
  66                 $this->mInterwikis = $parserOutput->getInterwikiLinks();
  67
  68                 # Convert the format of the interlanguage links
  69                 # I didn't want to change it in the ParserOutput, because that array is passed all
  70                 # the way back to the skin, so either a skin API break would be required, or an
  71                 # inefficient back-conversion.
  72                 $ill = $parserOutput->getLanguageLinks();
  73                 $this->mInterlangs = array();
  74                 foreach ( $ill as $link ) {
  75                         list( $key, $title ) = explode( ':', $link, 2 );
  76                         $this->mInterlangs[$key] = $title;
  77                 }
  78
  79                 foreach ( $this->mCategories as &$sortkey ) {
  80                         # If the sortkey is longer then 255 bytes,
  81                         # it truncated by DB, and then doesn't get
  82                         # matched when comparing existing vs current
  83                         # categories, causing bug 25254.
  84                         # Also. substr behaves weird when given "".
  85                         if ( $sortkey !== '' ) {
  86                                 $sortkey = substr( $sortkey, 0, 255 );
  87                         }
  88                 }
  89
  90                 $this->mRecursive = $recursive;
  91
  92                 wfRunHooks( 'LinksUpdateConstructed', array( &$this ) );
  93         }
  94
  95         /**
  96          * Update link tables with outgoing links from an updated article
  97          */
  98         public function doUpdate() {
  99                 global $wgUseDumbLinkUpdate;
 100
 101                 wfRunHooks( 'LinksUpdate', array( &$this ) );
 102                 if ( $wgUseDumbLinkUpdate ) {
 103                         $this->doDumbUpdate();
 104                 } else {
 105                         $this->doIncrementalUpdate();
 106                 }
 107                 wfRunHooks( 'LinksUpdateComplete', array( &$this ) );
 108         }
 109
 110         protected function doIncrementalUpdate() {
 111                 wfProfileIn( __METHOD__ );
 112
 113                 # Page links
 114                 $existing = $this->getExistingLinks();
 115                 $this->incrTableUpdate( 'pagelinks', 'pl', $this->getLinkDeletions( $existing ),
 116                         $this->getLinkInsertions( $existing ) );
 117
 118                 # Image links
 119                 $existing = $this->getExistingImages();
 120
 121                 $imageDeletes = $this->getImageDeletions( $existing );
 122                 $this->incrTableUpdate( 'imagelinks', 'il', $imageDeletes,
 123                         $this->getImageInsertions( $existing ) );
 124
 125                 # Invalidate all image description pages which had links added or removed
 126                 $imageUpdates = $imageDeletes + array_diff_key( $this->mImages, $existing );
 127                 $this->invalidateImageDescriptions( $imageUpdates );
 128
 129                 # External links
 130                 $existing = $this->getExistingExternals();
 131                 $this->incrTableUpdate( 'externallinks', 'el', $this->getExternalDeletions( $existing ),
 132                         $this->getExternalInsertions( $existing ) );
 133
 134                 # Language links
 135                 $existing = $this->getExistingInterlangs();
 136                 $this->incrTableUpdate( 'langlinks', 'll', $this->getInterlangDeletions( $existing ),
 137                         $this->getInterlangInsertions( $existing ) );
 138
 139                 # Inline interwiki links
 140                 $existing = $this->getExistingInterwikis();
 141                 $this->incrTableUpdate( 'iwlinks', 'iwl', $this->getInterwikiDeletions( $existing ),
 142                         $this->getInterwikiInsertions( $existing ) );
 143
 144                 # Template links
 145                 $existing = $this->getExistingTemplates();
 146                 $this->incrTableUpdate( 'templatelinks', 'tl', $this->getTemplateDeletions( $existing ),
 147                         $this->getTemplateInsertions( $existing ) );
 148
 149                 # Category links
 150                 $existing = $this->getExistingCategories();
 151
 152                 $categoryDeletes = $this->getCategoryDeletions( $existing );
 153
 154                 $this->incrTableUpdate( 'categorylinks', 'cl', $categoryDeletes,
 155                         $this->getCategoryInsertions( $existing ) );
 156
 157                 # Invalidate all categories which were added, deleted or changed (set symmetric difference)
 158                 $categoryInserts = array_diff_assoc( $this->mCategories, $existing );
 159                 $categoryUpdates = $categoryInserts + $categoryDeletes;
 160                 $this->invalidateCategories( $categoryUpdates );
 161                 $this->updateCategoryCounts( $categoryInserts, $categoryDeletes );
 162
 163                 # Page properties
 164                 $existing = $this->getExistingProperties();
 165
 166                 $propertiesDeletes = $this->getPropertyDeletions( $existing );
 167
 168                 $this->incrTableUpdate( 'page_props', 'pp', $propertiesDeletes,
 169                         $this->getPropertyInsertions( $existing ) );
 170
 171                 # Invalidate the necessary pages
 172                 $changed = $propertiesDeletes + array_diff_assoc( $this->mProperties, $existing );
 173                 $this->invalidateProperties( $changed );
 174
 175                 # Refresh links of all pages including this page
 176                 # This will be in a separate transaction
 177                 if ( $this->mRecursive ) {
 178                         $this->queueRecursiveJobs();
 179                 }
 180
 181                 wfProfileOut( __METHOD__ );
 182         }
 183
 184         /**
 185          * Link update which clears the previous entries and inserts new ones
 186          * May be slower or faster depending on level of lock contention and write speed of DB
 187          * Also useful where link table corruption needs to be repaired, e.g. in refreshLinks.php
 188          */
 189         protected function doDumbUpdate() {
 190                 wfProfileIn( __METHOD__ );
 191
 192                 # Refresh category pages and image description pages
 193                 $existing = $this->getExistingCategories();
 194                 $categoryInserts = array_diff_assoc( $this->mCategories, $existing );
 195                 $categoryDeletes = array_diff_assoc( $existing, $this->mCategories );
 196                 $categoryUpdates = $categoryInserts + $categoryDeletes;
 197                 $existing = $this->getExistingImages();
 198                 $imageUpdates = array_diff_key( $existing, $this->mImages ) + array_diff_key( $this->mImages, $existing );
 199
 200                 $this->dumbTableUpdate( 'pagelinks',     $this->getLinkInsertions(),     'pl_from' );
 201                 $this->dumbTableUpdate( 'imagelinks',    $this->getImageInsertions(),    'il_from' );
 202                 $this->dumbTableUpdate( 'categorylinks', $this->getCategoryInsertions(), 'cl_from' );
 203                 $this->dumbTableUpdate( 'templatelinks', $this->getTemplateInsertions(), 'tl_from' );
 204                 $this->dumbTableUpdate( 'externallinks', $this->getExternalInsertions(), 'el_from' );
 205                 $this->dumbTableUpdate( 'langlinks',     $this->getInterlangInsertions(),'ll_from' );
 206                 $this->dumbTableUpdate( 'iwlinks',       $this->getInterwikiInsertions(),'iwl_from' );
 207                 $this->dumbTableUpdate( 'page_props',    $this->getPropertyInsertions(), 'pp_page' );
 208
 209                 # Update the cache of all the category pages and image description
 210                 # pages which were changed, and fix the category table count
 211                 $this->invalidateCategories( $categoryUpdates );
 212                 $this->updateCategoryCounts( $categoryInserts, $categoryDeletes );
 213                 $this->invalidateImageDescriptions( $imageUpdates );
 214
 215                 # Refresh links of all pages including this page
 216                 # This will be in a separate transaction
 217                 if ( $this->mRecursive ) {
 218                         $this->queueRecursiveJobs();
 219                 }
 220
 221                 wfProfileOut( __METHOD__ );
 222         }
 223
 224         function queueRecursiveJobs() {
 225                 global $wgUpdateRowsPerJob;
 226                 wfProfileIn( __METHOD__ );
 227
 228                 $cache = $this->mTitle->getBacklinkCache();
 229                 $batches = $cache->partition( 'templatelinks', $wgUpdateRowsPerJob );
 230                 if ( !$batches ) {
 231                         wfProfileOut( __METHOD__ );
 232                         return;
 233                 }
 234                 $jobs = array();
 235                 foreach ( $batches as $batch ) {
 236                         list( $start, $end ) = $batch;
 237                         $params = array(
 238                                 'table' => 'templatelinks',
 239                                 'start' => $start,
 240                                 'end' => $end,
 241                         );
 242                         $jobs[] = new RefreshLinksJob2( $this->mTitle, $params );
 243                 }
 244                 Job::batchInsert( $jobs );
 245
 246                 wfProfileOut( __METHOD__ );
 247         }
 248
 249         /**
 250          * @param $cats
 251          */
 252         function invalidateCategories( $cats ) {
 253                 $this->invalidatePages( NS_CATEGORY, array_keys( $cats ) );
 254         }
 255
 256         /**
 257          * Update all the appropriate counts in the category table.
 258          * @param $added array associative array of category name => sort key
 259          * @param $deleted array associative array of category name => sort key
 260          */
 261         function updateCategoryCounts( $added, $deleted ) {
 262                 $a = WikiPage::factory( $this->mTitle );
 263                 $a->updateCategoryCounts(
 264                         array_keys( $added ), array_keys( $deleted )
 265                 );
 266         }
 267
 268         /**
 269          * @param $images
 270          */
 271         function invalidateImageDescriptions( $images ) {
 272                 $this->invalidatePages( NS_FILE, array_keys( $images ) );
 273         }
 274
 275     /**
 276      * @param $table
 277      * @param $insertions
 278      * @param $fromField
 279      */
 280     private function dumbTableUpdate( $table, $insertions, $fromField ) {
 281         $this->mDb->delete( $table, array( $fromField => $this->mId ), __METHOD__ );
 282         if ( count( $insertions ) ) {
 283             # The link array was constructed without FOR UPDATE, so there may
 284             # be collisions.  This may cause minor link table inconsistencies,
 285             # which is better than crippling the site with lock contention.
 286             $this->mDb->insert( $table, $insertions, __METHOD__, array( 'IGNORE' ) );
 287         }
 288     }
 289
 290         /**
 291          * Update a table by doing a delete query then an insert query
 292          * @param $table
 293          * @param $prefix
 294          * @param $deletions
 295          * @param $insertions
 296          */
 297         function incrTableUpdate( $table, $prefix, $deletions, $insertions ) {
 298                 if ( $table == 'page_props' ) {
 299                         $fromField = 'pp_page';
 300                 } else {
 301                         $fromField = "{$prefix}_from";
 302                 }
 303                 $where = array( $fromField => $this->mId );
 304                 if ( $table == 'pagelinks' || $table == 'templatelinks' || $table == 'iwlinks' ) {
 305                         if ( $table == 'iwlinks' ) {
 306                                 $baseKey = 'iwl_prefix';
 307                         } else {
 308                                 $baseKey = "{$prefix}_namespace";
 309                         }
 310                         $clause = $this->mDb->makeWhereFrom2d( $deletions, $baseKey, "{$prefix}_title" );
 311                         if ( $clause ) {
 312                                 $where[] = $clause;
 313                         } else {
 314                                 $where = false;
 315                         }
 316                 } else {
 317                         if ( $table == 'langlinks' ) {
 318                                 $toField = 'll_lang';
 319                         } elseif ( $table == 'page_props' ) {
 320                                 $toField = 'pp_propname';
 321                         } else {
 322                                 $toField = $prefix . '_to';
 323                         }
 324                         if ( count( $deletions ) ) {
 325                                 $where[] = "$toField IN (" . $this->mDb->makeList( array_keys( $deletions ) ) . ')';
 326                         } else {
 327                                 $where = false;
 328                         }
 329                 }
 330                 if ( $where ) {
 331                         $this->mDb->delete( $table, $where, __METHOD__ );
 332                 }
 333                 if ( count( $insertions ) ) {
 334                         $this->mDb->insert( $table, $insertions, __METHOD__, 'IGNORE' );
 335                 }
 336         }
 337
 338         /**
 339          * Get an array of pagelinks insertions for passing to the DB
 340          * Skips the titles specified by the 2-D array $existing
 341          * @param $existing array
 342          * @return array
 343          */
 344         private function getLinkInsertions( $existing = array() ) {
 345                 $arr = array();
 346                 foreach( $this->mLinks as $ns => $dbkeys ) {
 347                         $diffs = isset( $existing[$ns] )
 348                                 ? array_diff_key( $dbkeys, $existing[$ns] )
 349                                 : $dbkeys;
 350                         foreach ( $diffs as $dbk => $id ) {
 351                                 $arr[] = array(
 352                                         'pl_from'      => $this->mId,
 353                                         'pl_namespace' => $ns,
 354                                         'pl_title'     => $dbk
 355                                 );
 356                         }
 357                 }
 358                 return $arr;
 359         }
 360
 361         /**
 362          * Get an array of template insertions. Like getLinkInsertions()
 363          * @param $existing array
 364          * @return array
 365          */
 366         private function getTemplateInsertions( $existing = array() ) {
 367                 $arr = array();
 368                 foreach( $this->mTemplates as $ns => $dbkeys ) {
 369                         $diffs = isset( $existing[$ns] ) ? array_diff_key( $dbkeys, $existing[$ns] ) : $dbkeys;
 370                         foreach ( $diffs as $dbk => $id ) {
 371                                 $arr[] = array(
 372                                         'tl_from'      => $this->mId,
 373                                         'tl_namespace' => $ns,
 374                                         'tl_title'     => $dbk
 375                                 );
 376                         }
 377                 }
 378                 return $arr;
 379         }
 380
 381         /**
 382          * Get an array of image insertions
 383          * Skips the names specified in $existing
 384          * @param $existing array
 385          * @return array
 386          */
 387         private function getImageInsertions( $existing = array() ) {
 388                 $arr = array();
 389                 $diffs = array_diff_key( $this->mImages, $existing );
 390                 foreach( $diffs as $iname => $dummy ) {
 391                         $arr[] = array(
 392                                 'il_from' => $this->mId,
 393                                 'il_to'   => $iname
 394                         );
 395                 }
 396                 return $arr;
 397         }
 398
 399         /**
 400          * Get an array of externallinks insertions. Skips the names specified in $existing
 401          * @param $existing array
 402          * @return array
 403          */
 404         private function getExternalInsertions( $existing = array() ) {
 405                 $arr = array();
 406                 $diffs = array_diff_key( $this->mExternals, $existing );
 407                 foreach( $diffs as $url => $dummy ) {
 408                         foreach( wfMakeUrlIndexes( $url ) as $index ) {
 409                                 $arr[] = array(
 410                                         'el_from'   => $this->mId,
 411                                         'el_to'     => $url,
 412                                         'el_index'  => $index,
 413                                 );
 414                         }
 415                 }
 416                 return $arr;
 417         }
 418
 419         /**
 420          * Get an array of category insertions
 421          *
 422          * @param $existing array mapping existing category names to sort keys. If both
 423          * match a link in $this, the link will be omitted from the output
 424          *
 425          * @return array
 426          */
 427         private function getCategoryInsertions( $existing = array() ) {
 428                 global $wgContLang, $wgCategoryCollation;
 429                 $diffs = array_diff_assoc( $this->mCategories, $existing );
 430                 $arr = array();
 431                 foreach ( $diffs as $name => $prefix ) {
 432                         $nt = Title::makeTitleSafe( NS_CATEGORY, $name );
 433                         $wgContLang->findVariantLink( $name, $nt, true );
 434
 435                         if ( $this->mTitle->getNamespace() == NS_CATEGORY ) {
 436                                 $type = 'subcat';
 437                         } elseif ( $this->mTitle->getNamespace() == NS_FILE ) {
 438                                 $type = 'file';
 439                         } else {
 440                                 $type = 'page';
 441                         }
 442
 443                         # Treat custom sortkeys as a prefix, so that if multiple
 444                         # things are forced to sort as '*' or something, they'll
 445                         # sort properly in the category rather than in page_id
 446                         # order or such.
 447                         $sortkey = Collation::singleton()->getSortKey(
 448                                 $this->mTitle->getCategorySortkey( $prefix ) );
 449
 450                         $arr[] = array(
 451                                 'cl_from'    => $this->mId,
 452                                 'cl_to'      => $name,
 453                                 'cl_sortkey' => $sortkey,
 454                                 'cl_timestamp' => $this->mDb->timestamp(),
 455                                 'cl_sortkey_prefix' => $prefix,
 456                                 'cl_collation' => $wgCategoryCollation,
 457                                 'cl_type' => $type,
 458                         );
 459                 }
 460                 return $arr;
 461         }
 462
 463         /**
 464          * Get an array of interlanguage link insertions
 465          *
 466          * @param $existing Array mapping existing language codes to titles
 467          *
 468          * @return array
 469          */
 470         private function getInterlangInsertions( $existing = array() ) {
 471                 $diffs = array_diff_assoc( $this->mInterlangs, $existing );
 472                 $arr = array();
 473                 foreach( $diffs as $lang => $title ) {
 474                         $arr[] = array(
 475                                 'll_from'  => $this->mId,
 476                                 'll_lang'  => $lang,
 477                                 'll_title' => $title
 478                         );
 479                 }
 480                 return $arr;
 481         }
 482
 483         /**
 484          * Get an array of page property insertions
 485          * @param $existing array
 486          * @return array
 487          */
 488         function getPropertyInsertions( $existing = array() ) {
 489                 $diffs = array_diff_assoc( $this->mProperties, $existing );
 490                 $arr = array();
 491                 foreach ( $diffs as $name => $value ) {
 492                         $arr[] = array(
 493                                 'pp_page'      => $this->mId,
 494                                 'pp_propname'  => $name,
 495                                 'pp_value'     => $value,
 496                         );
 497                 }
 498                 return $arr;
 499         }
 500
 501         /**
 502          * Get an array of interwiki insertions for passing to the DB
 503          * Skips the titles specified by the 2-D array $existing
 504          * @param $existing array
 505          * @return array
 506          */
 507         private function getInterwikiInsertions( $existing = array() ) {
 508                 $arr = array();
 509                 foreach( $this->mInterwikis as $prefix => $dbkeys ) {
 510                         $diffs = isset( $existing[$prefix] ) ? array_diff_key( $dbkeys, $existing[$prefix] ) : $dbkeys;
 511                         foreach ( $diffs as $dbk => $id ) {
 512                                 $arr[] = array(
 513                                         'iwl_from'   => $this->mId,
 514                                         'iwl_prefix' => $prefix,
 515                                         'iwl_title'  => $dbk
 516                                 );
 517                         }
 518                 }
 519                 return $arr;
 520         }
 521
 522         /**
 523          * Given an array of existing links, returns those links which are not in $this
 524          * and thus should be deleted.
 525          * @param $existing array
 526          * @return array
 527          */
 528         private function getLinkDeletions( $existing ) {
 529                 $del = array();
 530                 foreach ( $existing as $ns => $dbkeys ) {
 531                         if ( isset( $this->mLinks[$ns] ) ) {
 532                                 $del[$ns] = array_diff_key( $existing[$ns], $this->mLinks[$ns] );
 533                         } else {
 534                                 $del[$ns] = $existing[$ns];
 535                         }
 536                 }
 537                 return $del;
 538         }
 539
 540         /**
 541          * Given an array of existing templates, returns those templates which are not in $this
 542          * and thus should be deleted.
 543          * @param $existing array
 544          * @return array
 545          */
 546         private function getTemplateDeletions( $existing ) {
 547                 $del = array();
 548                 foreach ( $existing as $ns => $dbkeys ) {
 549                         if ( isset( $this->mTemplates[$ns] ) ) {
 550                                 $del[$ns] = array_diff_key( $existing[$ns], $this->mTemplates[$ns] );
 551                         } else {
 552                                 $del[$ns] = $existing[$ns];
 553                         }
 554                 }
 555                 return $del;
 556         }
 557
 558         /**
 559          * Given an array of existing images, returns those images which are not in $this
 560          * and thus should be deleted.
 561          * @param $existing array
 562          * @return array
 563          */
 564         private function getImageDeletions( $existing ) {
 565                 return array_diff_key( $existing, $this->mImages );
 566         }
 567
 568         /**
 569          * Given an array of existing external links, returns those links which are not
 570          * in $this and thus should be deleted.
 571          * @param $existing array
 572          * @return array
 573          */
 574         private function getExternalDeletions( $existing ) {
 575                 return array_diff_key( $existing, $this->mExternals );
 576         }
 577
 578         /**
 579          * Given an array of existing categories, returns those categories which are not in $this
 580          * and thus should be deleted.
 581          * @param $existing array
 582          * @return array
 583          */
 584         private function getCategoryDeletions( $existing ) {
 585                 return array_diff_assoc( $existing, $this->mCategories );
 586         }
 587
 588         /**
 589          * Given an array of existing interlanguage links, returns those links which are not
 590          * in $this and thus should be deleted.
 591          * @param $existing array
 592          * @return array
 593          */
 594         private function getInterlangDeletions( $existing ) {
 595                 return array_diff_assoc( $existing, $this->mInterlangs );
 596         }
 597
 598         /**
 599          * Get array of properties which should be deleted.
 600          * @param $existing array
 601          * @return array
 602          */
 603         function getPropertyDeletions( $existing ) {
 604                 return array_diff_assoc( $existing, $this->mProperties );
 605         }
 606
 607         /**
 608          * Given an array of existing interwiki links, returns those links which are not in $this
 609          * and thus should be deleted.
 610          * @param $existing array
 611          * @return array
 612          */
 613         private function getInterwikiDeletions( $existing ) {
 614                 $del = array();
 615                 foreach ( $existing as $prefix => $dbkeys ) {
 616                         if ( isset( $this->mInterwikis[$prefix] ) ) {
 617                                 $del[$prefix] = array_diff_key( $existing[$prefix], $this->mInterwikis[$prefix] );
 618                         } else {
 619                                 $del[$prefix] = $existing[$prefix];
 620                         }
 621                 }
 622                 return $del;
 623         }
 624
 625         /**
 626          * Get an array of existing links, as a 2-D array
 627          *
 628          * @return array
 629          */
 630         private function getExistingLinks() {
 631                 $res = $this->mDb->select( 'pagelinks', array( 'pl_namespace', 'pl_title' ),
 632                         array( 'pl_from' => $this->mId ), __METHOD__, $this->mOptions );
 633                 $arr = array();
 634                 foreach ( $res as $row ) {
 635                         if ( !isset( $arr[$row->pl_namespace] ) ) {
 636                                 $arr[$row->pl_namespace] = array();
 637                         }
 638                         $arr[$row->pl_namespace][$row->pl_title] = 1;
 639                 }
 640                 return $arr;
 641         }
 642
 643         /**
 644          * Get an array of existing templates, as a 2-D array
 645          *
 646          * @return array
 647          */
 648         private function getExistingTemplates() {
 649                 $res = $this->mDb->select( 'templatelinks', array( 'tl_namespace', 'tl_title' ),
 650                         array( 'tl_from' => $this->mId ), __METHOD__, $this->mOptions );
 651                 $arr = array();
 652                 foreach ( $res as $row ) {
 653                         if ( !isset( $arr[$row->tl_namespace] ) ) {
 654                                 $arr[$row->tl_namespace] = array();
 655                         }
 656                         $arr[$row->tl_namespace][$row->tl_title] = 1;
 657                 }
 658                 return $arr;
 659         }
 660
 661         /**
 662          * Get an array of existing images, image names in the keys
 663          *
 664          * @return array
 665          */
 666         private function getExistingImages() {
 667                 $res = $this->mDb->select( 'imagelinks', array( 'il_to' ),
 668                         array( 'il_from' => $this->mId ), __METHOD__, $this->mOptions );
 669                 $arr = array();
 670                 foreach ( $res as $row ) {
 671                         $arr[$row->il_to] = 1;
 672                 }
 673                 return $arr;
 674         }
 675
 676         /**
 677          * Get an array of existing external links, URLs in the keys
 678          *
 679          * @return array
 680          */
 681         private function getExistingExternals() {
 682                 $res = $this->mDb->select( 'externallinks', array( 'el_to' ),
 683                         array( 'el_from' => $this->mId ), __METHOD__, $this->mOptions );
 684                 $arr = array();
 685                 foreach ( $res as $row ) {
 686                         $arr[$row->el_to] = 1;
 687                 }
 688                 return $arr;
 689         }
 690
 691         /**
 692          * Get an array of existing categories, with the name in the key and sort key in the value.
 693          *
 694          * @return array
 695          */
 696         private function getExistingCategories() {
 697                 $res = $this->mDb->select( 'categorylinks', array( 'cl_to', 'cl_sortkey_prefix' ),
 698                         array( 'cl_from' => $this->mId ), __METHOD__, $this->mOptions );
 699                 $arr = array();
 700                 foreach ( $res as $row ) {
 701                         $arr[$row->cl_to] = $row->cl_sortkey_prefix;
 702                 }
 703                 return $arr;
 704         }
 705
 706         /**
 707          * Get an array of existing interlanguage links, with the language code in the key and the
 708          * title in the value.
 709          *
 710          * @return array
 711          */
 712         private function getExistingInterlangs() {
 713                 $res = $this->mDb->select( 'langlinks', array( 'll_lang', 'll_title' ),
 714                         array( 'll_from' => $this->mId ), __METHOD__, $this->mOptions );
 715                 $arr = array();
 716                 foreach ( $res as $row ) {
 717                         $arr[$row->ll_lang] = $row->ll_title;
 718                 }
 719                 return $arr;
 720         }
 721
 722         /**
 723          * Get an array of existing inline interwiki links, as a 2-D array
 724          * @return array (prefix => array(dbkey => 1))
 725          */
 726         protected function getExistingInterwikis() {
 727                 $res = $this->mDb->select( 'iwlinks', array( 'iwl_prefix', 'iwl_title' ),
 728                         array( 'iwl_from' => $this->mId ), __METHOD__, $this->mOptions );
 729                 $arr = array();
 730                 foreach ( $res as $row ) {
 731                         if ( !isset( $arr[$row->iwl_prefix] ) ) {
 732                                 $arr[$row->iwl_prefix] = array();
 733                         }
 734                         $arr[$row->iwl_prefix][$row->iwl_title] = 1;
 735                 }
 736                 return $arr;
 737         }
 738
 739         /**
 740          * Get an array of existing categories, with the name in the key and sort key in the value.
 741          *
 742          * @return array
 743          */
 744         private function getExistingProperties() {
 745                 $res = $this->mDb->select( 'page_props', array( 'pp_propname', 'pp_value' ),
 746                         array( 'pp_page' => $this->mId ), __METHOD__, $this->mOptions );
 747                 $arr = array();
 748                 foreach ( $res as $row ) {
 749                         $arr[$row->pp_propname] = $row->pp_value;
 750                 }
 751                 return $arr;
 752         }
 753
 754     /**
 755      * Return the title object of the page being updated
 756      * @return Title
 757      */
 758     public function getTitle() {
 759         return $this->mTitle;
 760     }
 761
 762     /**
 763      * Returns parser output
 764      * @since 1.19
 765      * @return ParserOutput
 766      */
 767     public function getParserOutput() {
 768         return $this->mParserOutput;
 769     }
 770
 771         /**
 772          * Return the list of images used as generated by the parser
 773          * @return array
 774          */
 775         public function getImages() {
 776                 return $this->mImages;
 777         }
 778
 779         /**
 780          * Invalidate any necessary link lists related to page property changes
 781          * @param $changed
 782          */
 783         private function invalidateProperties( $changed ) {
 784                 global $wgPagePropLinkInvalidations;
 785
 786                 foreach ( $changed as $name => $value ) {
 787                         if ( isset( $wgPagePropLinkInvalidations[$name] ) ) {
 788                                 $inv = $wgPagePropLinkInvalidations[$name];
 789                                 if ( !is_array( $inv ) ) {
 790                                         $inv = array( $inv );
 791                                 }
 792                                 foreach ( $inv as $table ) {
 793                                         $update = new HTMLCacheUpdate( $this->mTitle, $table );
 794                                         $update->doUpdate();
 795                                 }
 796                         }
 797                 }
 798         }
 799 }