includes/LinksUpdate.php

   1 <?php
   2 /**
   3  * Updater for link tracking tables after a page edit.
   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  * @file
  21  */
  22
  23 /**
  24  * See docs/deferred.txt
  25  *
  26  * @todo document (e.g. one-sentence top-level class description).
  27  */
  28 class LinksUpdate extends SecondaryDBDataUpdate {
  29
  30         /**@{{
  31          * @private
  32          */
  33         var $mId,            //!< Page ID of the article linked from
  34                 $mTitle,         //!< Title object of the article linked from
  35                 $mParserOutput,  //!< Whether to queue jobs for recursive update
  36                 $mLinks,         //!< Map of title strings to IDs for the links in the document
  37                 $mImages,        //!< DB keys of the images used, in the array key only
  38                 $mTemplates,     //!< Map of title strings to IDs for the template references, including broken ones
  39                 $mExternals,     //!< URLs of external links, array key only
  40                 $mCategories,    //!< Map of category names to sort keys
  41                 $mInterlangs,    //!< Map of language codes to titles
  42                 $mProperties,    //!< Map of arbitrary name to value
  43                 $mRecursive;     //!< Whether to queue jobs for recursive updates
  44         /**@}}*/
  45
  46         /**
  47          * Constructor
  48          *
  49          * @param $title Title of the page we're updating
  50          * @param $parserOutput ParserOutput: output from a full parse of this page
  51          * @param $recursive Boolean: queue jobs for recursive updates?
  52          */
  53         function __construct( $title, $parserOutput, $recursive = true ) {
  54                 parent::__construct( );
  55
  56                 if ( !is_object( $title ) ) {
  57                         throw new MWException( "The calling convention to LinksUpdate::LinksUpdate() has changed. " .
  58                                 "Please see Article::editUpdates() for an invocation example.\n" );
  59                 }
  60
  61                 if ( !is_object( $parserOutput ) ) {
  62                         throw new MWException( "The calling convention to LinksUpdate::__construct() has changed. " .
  63                                 "Please see WikiPage::doEditUpdates() for an invocation example.\n" );
  64                 }
  65
  66                 $this->mTitle = $title;
  67                 $this->mId = $title->getArticleID();
  68
  69                 $this->mParserOutput = $parserOutput;
  70
  71                 $this->mLinks = $parserOutput->getLinks();
  72                 $this->mImages = $parserOutput->getImages();
  73                 $this->mTemplates = $parserOutput->getTemplates();
  74                 $this->mExternals = $parserOutput->getExternalLinks();
  75                 $this->mCategories = $parserOutput->getCategories();
  76                 $this->mProperties = $parserOutput->getProperties();
  77                 $this->mInterwikis = $parserOutput->getInterwikiLinks();
  78
  79                 # Convert the format of the interlanguage links
  80                 # I didn't want to change it in the ParserOutput, because that array is passed all
  81                 # the way back to the skin, so either a skin API break would be required, or an
  82                 # inefficient back-conversion.
  83                 $ill = $parserOutput->getLanguageLinks();
  84                 $this->mInterlangs = array();
  85                 foreach ( $ill as $link ) {
  86                         list( $key, $title ) = explode( ':', $link, 2 );
  87                         $this->mInterlangs[$key] = $title;
  88                 }
  89
  90                 foreach ( $this->mCategories as &$sortkey ) {
  91                         # If the sortkey is longer then 255 bytes,
  92                         # it truncated by DB, and then doesn't get
  93                         # matched when comparing existing vs current
  94                         # categories, causing bug 25254.
  95                         # Also. substr behaves weird when given "".
  96                         if ( $sortkey !== '' ) {
  97                                 $sortkey = substr( $sortkey, 0, 255 );
  98                         }
  99                 }
 100
 101                 $this->mRecursive = $recursive;
 102
 103                 wfRunHooks( 'LinksUpdateConstructed', array( &$this ) );
 104         }
 105
 106         /**
 107          * Update link tables with outgoing links from an updated article
 108          */
 109         public function doUpdate() {
 110                 global $wgUseDumbLinkUpdate;
 111
 112                 wfRunHooks( 'LinksUpdate', array( &$this ) );
 113                 if ( $wgUseDumbLinkUpdate ) {
 114                         $this->doDumbUpdate();
 115                 } else {
 116                         $this->doIncrementalUpdate();
 117                 }
 118                 wfRunHooks( 'LinksUpdateComplete', array( &$this ) );
 119         }
 120
 121         protected function doIncrementalUpdate() {
 122                 wfProfileIn( __METHOD__ );
 123
 124                 # Page links
 125                 $existing = $this->getExistingLinks();
 126                 $this->incrTableUpdate( 'pagelinks', 'pl', $this->getLinkDeletions( $existing ),
 127                         $this->getLinkInsertions( $existing ) );
 128
 129                 # Image links
 130                 $existing = $this->getExistingImages();
 131
 132                 $imageDeletes = $this->getImageDeletions( $existing );
 133                 $this->incrTableUpdate( 'imagelinks', 'il', $imageDeletes,
 134                         $this->getImageInsertions( $existing ) );
 135
 136                 # Invalidate all image description pages which had links added or removed
 137                 $imageUpdates = $imageDeletes + array_diff_key( $this->mImages, $existing );
 138                 $this->invalidateImageDescriptions( $imageUpdates );
 139
 140                 # External links
 141                 $existing = $this->getExistingExternals();
 142                 $this->incrTableUpdate( 'externallinks', 'el', $this->getExternalDeletions( $existing ),
 143                         $this->getExternalInsertions( $existing ) );
 144
 145                 # Language links
 146                 $existing = $this->getExistingInterlangs();
 147                 $this->incrTableUpdate( 'langlinks', 'll', $this->getInterlangDeletions( $existing ),
 148                         $this->getInterlangInsertions( $existing ) );
 149
 150                 # Inline interwiki links
 151                 $existing = $this->getExistingInterwikis();
 152                 $this->incrTableUpdate( 'iwlinks', 'iwl', $this->getInterwikiDeletions( $existing ),
 153                         $this->getInterwikiInsertions( $existing ) );
 154
 155                 # Template links
 156                 $existing = $this->getExistingTemplates();
 157                 $this->incrTableUpdate( 'templatelinks', 'tl', $this->getTemplateDeletions( $existing ),
 158                         $this->getTemplateInsertions( $existing ) );
 159
 160                 # Category links
 161                 $existing = $this->getExistingCategories();
 162
 163                 $categoryDeletes = $this->getCategoryDeletions( $existing );
 164
 165                 $this->incrTableUpdate( 'categorylinks', 'cl', $categoryDeletes,
 166                         $this->getCategoryInsertions( $existing ) );
 167
 168                 # Invalidate all categories which were added, deleted or changed (set symmetric difference)
 169                 $categoryInserts = array_diff_assoc( $this->mCategories, $existing );
 170                 $categoryUpdates = $categoryInserts + $categoryDeletes;
 171                 $this->invalidateCategories( $categoryUpdates );
 172                 $this->updateCategoryCounts( $categoryInserts, $categoryDeletes );
 173
 174                 # Page properties
 175                 $existing = $this->getExistingProperties();
 176
 177                 $propertiesDeletes = $this->getPropertyDeletions( $existing );
 178
 179                 $this->incrTableUpdate( 'page_props', 'pp', $propertiesDeletes,
 180                         $this->getPropertyInsertions( $existing ) );
 181
 182                 # Invalidate the necessary pages
 183                 $changed = $propertiesDeletes + array_diff_assoc( $this->mProperties, $existing );
 184                 $this->invalidateProperties( $changed );
 185
 186                 # Refresh links of all pages including this page
 187                 # This will be in a separate transaction
 188                 if ( $this->mRecursive ) {
 189                         $this->queueRecursiveJobs();
 190                 }
 191
 192                 wfProfileOut( __METHOD__ );
 193         }
 194
 195         /**
 196          * Link update which clears the previous entries and inserts new ones
 197          * May be slower or faster depending on level of lock contention and write speed of DB
 198          * Also useful where link table corruption needs to be repaired, e.g. in refreshLinks.php
 199          */
 200         protected function doDumbUpdate() {
 201                 wfProfileIn( __METHOD__ );
 202
 203                 # Refresh category pages and image description pages
 204                 $existing = $this->getExistingCategories();
 205                 $categoryInserts = array_diff_assoc( $this->mCategories, $existing );
 206                 $categoryDeletes = array_diff_assoc( $existing, $this->mCategories );
 207                 $categoryUpdates = $categoryInserts + $categoryDeletes;
 208                 $existing = $this->getExistingImages();
 209                 $imageUpdates = array_diff_key( $existing, $this->mImages ) + array_diff_key( $this->mImages, $existing );
 210
 211                 $this->dumbTableUpdate( 'pagelinks',     $this->getLinkInsertions(),     'pl_from' );
 212                 $this->dumbTableUpdate( 'imagelinks',    $this->getImageInsertions(),    'il_from' );
 213                 $this->dumbTableUpdate( 'categorylinks', $this->getCategoryInsertions(), 'cl_from' );
 214                 $this->dumbTableUpdate( 'templatelinks', $this->getTemplateInsertions(), 'tl_from' );
 215                 $this->dumbTableUpdate( 'externallinks', $this->getExternalInsertions(), 'el_from' );
 216                 $this->dumbTableUpdate( 'langlinks',     $this->getInterlangInsertions(),'ll_from' );
 217                 $this->dumbTableUpdate( 'iwlinks',       $this->getInterwikiInsertions(),'iwl_from' );
 218                 $this->dumbTableUpdate( 'page_props',    $this->getPropertyInsertions(), 'pp_page' );
 219
 220                 # Update the cache of all the category pages and image description
 221                 # pages which were changed, and fix the category table count
 222                 $this->invalidateCategories( $categoryUpdates );
 223                 $this->updateCategoryCounts( $categoryInserts, $categoryDeletes );
 224                 $this->invalidateImageDescriptions( $imageUpdates );
 225
 226                 # Refresh links of all pages including this page
 227                 # This will be in a separate transaction
 228                 if ( $this->mRecursive ) {
 229                         $this->queueRecursiveJobs();
 230                 }
 231
 232                 wfProfileOut( __METHOD__ );
 233         }
 234
 235         function queueRecursiveJobs() {
 236                 global $wgUpdateRowsPerJob;
 237                 wfProfileIn( __METHOD__ );
 238
 239                 $cache = $this->mTitle->getBacklinkCache();
 240                 $batches = $cache->partition( 'templatelinks', $wgUpdateRowsPerJob );
 241                 if ( !$batches ) {
 242                         wfProfileOut( __METHOD__ );
 243                         return;
 244                 }
 245                 $jobs = array();
 246                 foreach ( $batches as $batch ) {
 247                         list( $start, $end ) = $batch;
 248                         $params = array(
 249                                 'table' => 'templatelinks',
 250                                 'start' => $start,
 251                                 'end' => $end,
 252                         );
 253                         $jobs[] = new RefreshLinksJob2( $this->mTitle, $params );
 254                 }
 255                 Job::batchInsert( $jobs );
 256
 257                 wfProfileOut( __METHOD__ );
 258         }
 259
 260         /**
 261          * @param $cats
 262          */
 263         function invalidateCategories( $cats ) {
 264                 $this->invalidatePages( NS_CATEGORY, array_keys( $cats ) );
 265         }
 266
 267         /**
 268          * Update all the appropriate counts in the category table.
 269          * @param $added array associative array of category name => sort key
 270          * @param $deleted array associative array of category name => sort key
 271          */
 272         function updateCategoryCounts( $added, $deleted ) {
 273                 $a = WikiPage::factory( $this->mTitle );
 274                 $a->updateCategoryCounts(
 275                         array_keys( $added ), array_keys( $deleted )
 276                 );
 277         }
 278
 279         /**
 280          * @param $images
 281          */
 282         function invalidateImageDescriptions( $images ) {
 283                 $this->invalidatePages( NS_FILE, array_keys( $images ) );
 284         }
 285
 286         /**
 287          * @param $table
 288          * @param $insertions
 289          * @param $fromField
 290          */
 291         private 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          * @param $table
 304          * @param $prefix
 305          * @param $deletions
 306          * @param $insertions
 307          */
 308         function incrTableUpdate( $table, $prefix, $deletions, $insertions ) {
 309                 if ( $table == 'page_props' ) {
 310                         $fromField = 'pp_page';
 311                 } else {
 312                         $fromField = "{$prefix}_from";
 313                 }
 314                 $where = array( $fromField => $this->mId );
 315                 if ( $table == 'pagelinks' || $table == 'templatelinks' || $table == 'iwlinks' ) {
 316                         if ( $table == 'iwlinks' ) {
 317                                 $baseKey = 'iwl_prefix';
 318                         } else {
 319                                 $baseKey = "{$prefix}_namespace";
 320                         }
 321                         $clause = $this->mDb->makeWhereFrom2d( $deletions, $baseKey, "{$prefix}_title" );
 322                         if ( $clause ) {
 323                                 $where[] = $clause;
 324                         } else {
 325                                 $where = false;
 326                         }
 327                 } else {
 328                         if ( $table == 'langlinks' ) {
 329                                 $toField = 'll_lang';
 330                         } elseif ( $table == 'page_props' ) {
 331                                 $toField = 'pp_propname';
 332                         } else {
 333                                 $toField = $prefix . '_to';
 334                         }
 335                         if ( count( $deletions ) ) {
 336                                 $where[] = "$toField IN (" . $this->mDb->makeList( array_keys( $deletions ) ) . ')';
 337                         } else {
 338                                 $where = false;
 339                         }
 340                 }
 341                 if ( $where ) {
 342                         $this->mDb->delete( $table, $where, __METHOD__ );
 343                 }
 344                 if ( count( $insertions ) ) {
 345                         $this->mDb->insert( $table, $insertions, __METHOD__, 'IGNORE' );
 346                 }
 347         }
 348
 349         /**
 350          * Get an array of pagelinks insertions for passing to the DB
 351          * Skips the titles specified by the 2-D array $existing
 352          * @param $existing array
 353          * @return array
 354          */
 355         private function getLinkInsertions( $existing = array() ) {
 356                 $arr = array();
 357                 foreach( $this->mLinks as $ns => $dbkeys ) {
 358                         $diffs = isset( $existing[$ns] )
 359                                 ? array_diff_key( $dbkeys, $existing[$ns] )
 360                                 : $dbkeys;
 361                         foreach ( $diffs as $dbk => $id ) {
 362                                 $arr[] = array(
 363                                         'pl_from'      => $this->mId,
 364                                         'pl_namespace' => $ns,
 365                                         'pl_title'     => $dbk
 366                                 );
 367                         }
 368                 }
 369                 return $arr;
 370         }
 371
 372         /**
 373          * Get an array of template insertions. Like getLinkInsertions()
 374          * @param $existing array
 375          * @return array
 376          */
 377         private function getTemplateInsertions( $existing = array() ) {
 378                 $arr = array();
 379                 foreach( $this->mTemplates as $ns => $dbkeys ) {
 380                         $diffs = isset( $existing[$ns] ) ? array_diff_key( $dbkeys, $existing[$ns] ) : $dbkeys;
 381                         foreach ( $diffs as $dbk => $id ) {
 382                                 $arr[] = array(
 383                                         'tl_from'      => $this->mId,
 384                                         'tl_namespace' => $ns,
 385                                         'tl_title'     => $dbk
 386                                 );
 387                         }
 388                 }
 389                 return $arr;
 390         }
 391
 392         /**
 393          * Get an array of image insertions
 394          * Skips the names specified in $existing
 395          * @param $existing array
 396          * @return array
 397          */
 398         private function getImageInsertions( $existing = array() ) {
 399                 $arr = array();
 400                 $diffs = array_diff_key( $this->mImages, $existing );
 401                 foreach( $diffs as $iname => $dummy ) {
 402                         $arr[] = array(
 403                                 'il_from' => $this->mId,
 404                                 'il_to'   => $iname
 405                         );
 406                 }
 407                 return $arr;
 408         }
 409
 410         /**
 411          * Get an array of externallinks insertions. Skips the names specified in $existing
 412          * @param $existing array
 413          * @return array
 414          */
 415         private function getExternalInsertions( $existing = array() ) {
 416                 $arr = array();
 417                 $diffs = array_diff_key( $this->mExternals, $existing );
 418                 foreach( $diffs as $url => $dummy ) {
 419                         foreach( wfMakeUrlIndexes( $url ) as $index ) {
 420                                 $arr[] = array(
 421                                         'el_from'   => $this->mId,
 422                                         'el_to'     => $url,
 423                                         'el_index'  => $index,
 424                                 );
 425                         }
 426                 }
 427                 return $arr;
 428         }
 429
 430         /**
 431          * Get an array of category insertions
 432          *
 433          * @param $existing array mapping existing category names to sort keys. If both
 434          * match a link in $this, the link will be omitted from the output
 435          *
 436          * @return array
 437          */
 438         private function getCategoryInsertions( $existing = array() ) {
 439                 global $wgContLang, $wgCategoryCollation;
 440                 $diffs = array_diff_assoc( $this->mCategories, $existing );
 441                 $arr = array();
 442                 foreach ( $diffs as $name => $prefix ) {
 443                         $nt = Title::makeTitleSafe( NS_CATEGORY, $name );
 444                         $wgContLang->findVariantLink( $name, $nt, true );
 445
 446                         if ( $this->mTitle->getNamespace() == NS_CATEGORY ) {
 447                                 $type = 'subcat';
 448                         } elseif ( $this->mTitle->getNamespace() == NS_FILE ) {
 449                                 $type = 'file';
 450                         } else {
 451                                 $type = 'page';
 452                         }
 453
 454                         # Treat custom sortkeys as a prefix, so that if multiple
 455                         # things are forced to sort as '*' or something, they'll
 456                         # sort properly in the category rather than in page_id
 457                         # order or such.
 458                         $sortkey = Collation::singleton()->getSortKey(
 459                                 $this->mTitle->getCategorySortkey( $prefix ) );
 460
 461                         $arr[] = array(
 462                                 'cl_from'    => $this->mId,
 463                                 'cl_to'      => $name,
 464                                 'cl_sortkey' => $sortkey,
 465                                 'cl_timestamp' => $this->mDb->timestamp(),
 466                                 'cl_sortkey_prefix' => $prefix,
 467                                 'cl_collation' => $wgCategoryCollation,
 468                                 'cl_type' => $type,
 469                         );
 470                 }
 471                 return $arr;
 472         }
 473
 474         /**
 475          * Get an array of interlanguage link insertions
 476          *
 477          * @param $existing Array mapping existing language codes to titles
 478          *
 479          * @return array
 480          */
 481         private function getInterlangInsertions( $existing = array() ) {
 482                 $diffs = array_diff_assoc( $this->mInterlangs, $existing );
 483                 $arr = array();
 484                 foreach( $diffs as $lang => $title ) {
 485                         $arr[] = array(
 486                                 'll_from'  => $this->mId,
 487                                 'll_lang'  => $lang,
 488                                 'll_title' => $title
 489                         );
 490                 }
 491                 return $arr;
 492         }
 493
 494         /**
 495          * Get an array of page property insertions
 496          * @param $existing array
 497          * @return array
 498          */
 499         function getPropertyInsertions( $existing = array() ) {
 500                 $diffs = array_diff_assoc( $this->mProperties, $existing );
 501                 $arr = array();
 502                 foreach ( $diffs as $name => $value ) {
 503                         $arr[] = array(
 504                                 'pp_page'      => $this->mId,
 505                                 'pp_propname'  => $name,
 506                                 'pp_value'     => $value,
 507                         );
 508                 }
 509                 return $arr;
 510         }
 511
 512         /**
 513          * Get an array of interwiki insertions for passing to the DB
 514          * Skips the titles specified by the 2-D array $existing
 515          * @param $existing array
 516          * @return array
 517          */
 518         private function getInterwikiInsertions( $existing = array() ) {
 519                 $arr = array();
 520                 foreach( $this->mInterwikis as $prefix => $dbkeys ) {
 521                         $diffs = isset( $existing[$prefix] ) ? array_diff_key( $dbkeys, $existing[$prefix] ) : $dbkeys;
 522                         foreach ( $diffs as $dbk => $id ) {
 523                                 $arr[] = array(
 524                                         'iwl_from'   => $this->mId,
 525                                         'iwl_prefix' => $prefix,
 526                                         'iwl_title'  => $dbk
 527                                 );
 528                         }
 529                 }
 530                 return $arr;
 531         }
 532
 533         /**
 534          * Given an array of existing links, returns those links which are not in $this
 535          * and thus should be deleted.
 536          * @param $existing array
 537          * @return array
 538          */
 539         private function getLinkDeletions( $existing ) {
 540                 $del = array();
 541                 foreach ( $existing as $ns => $dbkeys ) {
 542                         if ( isset( $this->mLinks[$ns] ) ) {
 543                                 $del[$ns] = array_diff_key( $existing[$ns], $this->mLinks[$ns] );
 544                         } else {
 545                                 $del[$ns] = $existing[$ns];
 546                         }
 547                 }
 548                 return $del;
 549         }
 550
 551         /**
 552          * Given an array of existing templates, returns those templates which are not in $this
 553          * and thus should be deleted.
 554          * @param $existing array
 555          * @return array
 556          */
 557         private function getTemplateDeletions( $existing ) {
 558                 $del = array();
 559                 foreach ( $existing as $ns => $dbkeys ) {
 560                         if ( isset( $this->mTemplates[$ns] ) ) {
 561                                 $del[$ns] = array_diff_key( $existing[$ns], $this->mTemplates[$ns] );
 562                         } else {
 563                                 $del[$ns] = $existing[$ns];
 564                         }
 565                 }
 566                 return $del;
 567         }
 568
 569         /**
 570          * Given an array of existing images, returns those images which are not in $this
 571          * and thus should be deleted.
 572          * @param $existing array
 573          * @return array
 574          */
 575         private function getImageDeletions( $existing ) {
 576                 return array_diff_key( $existing, $this->mImages );
 577         }
 578
 579         /**
 580          * Given an array of existing external links, returns those links which are not
 581          * in $this and thus should be deleted.
 582          * @param $existing array
 583          * @return array
 584          */
 585         private function getExternalDeletions( $existing ) {
 586                 return array_diff_key( $existing, $this->mExternals );
 587         }
 588
 589         /**
 590          * Given an array of existing categories, returns those categories which are not in $this
 591          * and thus should be deleted.
 592          * @param $existing array
 593          * @return array
 594          */
 595         private function getCategoryDeletions( $existing ) {
 596                 return array_diff_assoc( $existing, $this->mCategories );
 597         }
 598
 599         /**
 600          * Given an array of existing interlanguage links, returns those links which are not
 601          * in $this and thus should be deleted.
 602          * @param $existing array
 603          * @return array
 604          */
 605         private function getInterlangDeletions( $existing ) {
 606                 return array_diff_assoc( $existing, $this->mInterlangs );
 607         }
 608
 609         /**
 610          * Get array of properties which should be deleted.
 611          * @param $existing array
 612          * @return array
 613          */
 614         function getPropertyDeletions( $existing ) {
 615                 return array_diff_assoc( $existing, $this->mProperties );
 616         }
 617
 618         /**
 619          * Given an array of existing interwiki links, returns those links which are not in $this
 620          * and thus should be deleted.
 621          * @param $existing array
 622          * @return array
 623          */
 624         private function getInterwikiDeletions( $existing ) {
 625                 $del = array();
 626                 foreach ( $existing as $prefix => $dbkeys ) {
 627                         if ( isset( $this->mInterwikis[$prefix] ) ) {
 628                                 $del[$prefix] = array_diff_key( $existing[$prefix], $this->mInterwikis[$prefix] );
 629                         } else {
 630                                 $del[$prefix] = $existing[$prefix];
 631                         }
 632                 }
 633                 return $del;
 634         }
 635
 636         /**
 637          * Get an array of existing links, as a 2-D array
 638          *
 639          * @return array
 640          */
 641         private function getExistingLinks() {
 642                 $res = $this->mDb->select( 'pagelinks', array( 'pl_namespace', 'pl_title' ),
 643                         array( 'pl_from' => $this->mId ), __METHOD__, $this->mOptions );
 644                 $arr = array();
 645                 foreach ( $res as $row ) {
 646                         if ( !isset( $arr[$row->pl_namespace] ) ) {
 647                                 $arr[$row->pl_namespace] = array();
 648                         }
 649                         $arr[$row->pl_namespace][$row->pl_title] = 1;
 650                 }
 651                 return $arr;
 652         }
 653
 654         /**
 655          * Get an array of existing templates, as a 2-D array
 656          *
 657          * @return array
 658          */
 659         private function getExistingTemplates() {
 660                 $res = $this->mDb->select( 'templatelinks', array( 'tl_namespace', 'tl_title' ),
 661                         array( 'tl_from' => $this->mId ), __METHOD__, $this->mOptions );
 662                 $arr = array();
 663                 foreach ( $res as $row ) {
 664                         if ( !isset( $arr[$row->tl_namespace] ) ) {
 665                                 $arr[$row->tl_namespace] = array();
 666                         }
 667                         $arr[$row->tl_namespace][$row->tl_title] = 1;
 668                 }
 669                 return $arr;
 670         }
 671
 672         /**
 673          * Get an array of existing images, image names in the keys
 674          *
 675          * @return array
 676          */
 677         private function getExistingImages() {
 678                 $res = $this->mDb->select( 'imagelinks', array( 'il_to' ),
 679                         array( 'il_from' => $this->mId ), __METHOD__, $this->mOptions );
 680                 $arr = array();
 681                 foreach ( $res as $row ) {
 682                         $arr[$row->il_to] = 1;
 683                 }
 684                 return $arr;
 685         }
 686
 687         /**
 688          * Get an array of existing external links, URLs in the keys
 689          *
 690          * @return array
 691          */
 692         private function getExistingExternals() {
 693                 $res = $this->mDb->select( 'externallinks', array( 'el_to' ),
 694                         array( 'el_from' => $this->mId ), __METHOD__, $this->mOptions );
 695                 $arr = array();
 696                 foreach ( $res as $row ) {
 697                         $arr[$row->el_to] = 1;
 698                 }
 699                 return $arr;
 700         }
 701
 702         /**
 703          * Get an array of existing categories, with the name in the key and sort key in the value.
 704          *
 705          * @return array
 706          */
 707         private function getExistingCategories() {
 708                 $res = $this->mDb->select( 'categorylinks', array( 'cl_to', 'cl_sortkey_prefix' ),
 709                         array( 'cl_from' => $this->mId ), __METHOD__, $this->mOptions );
 710                 $arr = array();
 711                 foreach ( $res as $row ) {
 712                         $arr[$row->cl_to] = $row->cl_sortkey_prefix;
 713                 }
 714                 return $arr;
 715         }
 716
 717         /**
 718          * Get an array of existing interlanguage links, with the language code in the key and the
 719          * title in the value.
 720          *
 721          * @return array
 722          */
 723         private function getExistingInterlangs() {
 724                 $res = $this->mDb->select( 'langlinks', array( 'll_lang', 'll_title' ),
 725                         array( 'll_from' => $this->mId ), __METHOD__, $this->mOptions );
 726                 $arr = array();
 727                 foreach ( $res as $row ) {
 728                         $arr[$row->ll_lang] = $row->ll_title;
 729                 }
 730                 return $arr;
 731         }
 732
 733         /**
 734          * Get an array of existing inline interwiki links, as a 2-D array
 735          * @return array (prefix => array(dbkey => 1))
 736          */
 737         protected function getExistingInterwikis() {
 738                 $res = $this->mDb->select( 'iwlinks', array( 'iwl_prefix', 'iwl_title' ),
 739                         array( 'iwl_from' => $this->mId ), __METHOD__, $this->mOptions );
 740                 $arr = array();
 741                 foreach ( $res as $row ) {
 742                         if ( !isset( $arr[$row->iwl_prefix] ) ) {
 743                                 $arr[$row->iwl_prefix] = array();
 744                         }
 745                         $arr[$row->iwl_prefix][$row->iwl_title] = 1;
 746                 }
 747                 return $arr;
 748         }
 749
 750         /**
 751          * Get an array of existing categories, with the name in the key and sort key in the value.
 752          *
 753          * @return array
 754          */
 755         private function getExistingProperties() {
 756                 $res = $this->mDb->select( 'page_props', array( 'pp_propname', 'pp_value' ),
 757                         array( 'pp_page' => $this->mId ), __METHOD__, $this->mOptions );
 758                 $arr = array();
 759                 foreach ( $res as $row ) {
 760                         $arr[$row->pp_propname] = $row->pp_value;
 761                 }
 762                 return $arr;
 763         }
 764
 765         /**
 766          * Return the title object of the page being updated
 767          * @return Title
 768          */
 769         public function getTitle() {
 770                 return $this->mTitle;
 771         }
 772
 773         /**
 774          * Returns parser output
 775          * @since 1.19
 776          * @return ParserOutput
 777          */
 778         public function getParserOutput() {
 779                 return $this->mParserOutput;
 780         }
 781
 782         /**
 783          * Return the list of images used as generated by the parser
 784          * @return array
 785          */
 786         public function getImages() {
 787                 return $this->mImages;
 788         }
 789
 790         /**
 791          * Invalidate any necessary link lists related to page property changes
 792          * @param $changed
 793          */
 794         private function invalidateProperties( $changed ) {
 795                 global $wgPagePropLinkInvalidations;
 796
 797                 foreach ( $changed as $name => $value ) {
 798                         if ( isset( $wgPagePropLinkInvalidations[$name] ) ) {
 799                                 $inv = $wgPagePropLinkInvalidations[$name];
 800                                 if ( !is_array( $inv ) ) {
 801                                         $inv = array( $inv );
 802                                 }
 803                                 foreach ( $inv as $table ) {
 804                                         $update = new HTMLCacheUpdate( $this->mTitle, $table );
 805                                         $update->doUpdate();
 806                                 }
 807                         }
 808                 }
 809         }
 810 }
 811
 812 /**
 813  * Update object handling the cleanup of links tables after a page was deleted.
 814  **/
 815 class LinksDeletionUpdate extends SecondaryDBDataUpdate {
 816
 817         /**@{{
 818          * @private
 819          */
 820         var $mWikiPage;     //!< WikiPage the wikipage that was deleted
 821         /**@}}*/
 822
 823         /**
 824          * Constructor
 825          *
 826          * @param $title Title of the page we're updating
 827          * @param $parserOutput ParserOutput: output from a full parse of this page
 828          * @param $recursive Boolean: queue jobs for recursive updates?
 829          */
 830         function __construct( WikiPage $page ) {
 831                 parent::__construct( );
 832
 833                 $this->mPage = $page;
 834         }
 835
 836         /**
 837          * Do some database updates after deletion
 838          */
 839         public function doUpdate() {
 840                 $title = $this->mPage->getTitle();
 841                 $id = $this->mPage->getId();
 842
 843                 # Delete restrictions for it
 844                 $this->mDb->delete( 'page_restrictions', array ( 'pr_page' => $id ), __METHOD__ );
 845
 846                 # Fix category table counts
 847                 $cats = array();
 848                 $res = $this->mDb->select( 'categorylinks', 'cl_to', array( 'cl_from' => $id ), __METHOD__ );
 849
 850                 foreach ( $res as $row ) {
 851                         $cats [] = $row->cl_to;
 852                 }
 853
 854                 $this->mPage->updateCategoryCounts( array(), $cats );
 855
 856                 # If using cascading deletes, we can skip some explicit deletes
 857                 if ( !$this->mDb->cascadingDeletes() ) {
 858                         $this->mDb->delete( 'revision', array( 'rev_page' => $id ), __METHOD__ );
 859
 860                         # Delete outgoing links
 861                         $this->mDb->delete( 'pagelinks', array( 'pl_from' => $id ), __METHOD__ );
 862                         $this->mDb->delete( 'imagelinks', array( 'il_from' => $id ), __METHOD__ );
 863                         $this->mDb->delete( 'categorylinks', array( 'cl_from' => $id ), __METHOD__ );
 864                         $this->mDb->delete( 'templatelinks', array( 'tl_from' => $id ), __METHOD__ );
 865                         $this->mDb->delete( 'externallinks', array( 'el_from' => $id ), __METHOD__ );
 866                         $this->mDb->delete( 'langlinks', array( 'll_from' => $id ), __METHOD__ );
 867                         $this->mDb->delete( 'iwlinks', array( 'iwl_from' => $id ), __METHOD__ );
 868                         $this->mDb->delete( 'redirect', array( 'rd_from' => $id ), __METHOD__ );
 869                         $this->mDb->delete( 'page_props', array( 'pp_page' => $id ), __METHOD__ );
 870                 }
 871
 872                 # If using cleanup triggers, we can skip some manual deletes
 873                 if ( !$this->mDb->cleanupTriggers() ) {
 874                         # Clean up recentchanges entries...
 875                         $this->mDb->delete( 'recentchanges',
 876                                       array( 'rc_type != ' . RC_LOG,
 877                                            'rc_namespace' => $title->getNamespace(),
 878                                            'rc_title' => $title->getDBkey() ),
 879                                       __METHOD__ );
 880                         $this->mDb->delete( 'recentchanges',
 881                                       array( 'rc_type != ' . RC_LOG, 'rc_cur_id' => $id ),
 882                                       __METHOD__ );
 883                 }
 884         }
 885 }