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 SqlDataUpdate {
  29
  30         // @todo: make members protected, but make sure extensions don't break
  31
  32         public $mId,         //!< Page ID of the article linked from
  33                 $mTitle,         //!< Title object of the article linked from
  34                 $mParserOutput,  //!< Parser output
  35                 $mLinks,         //!< Map of title strings to IDs for the links in the document
  36                 $mImages,        //!< DB keys of the images used, in the array key only
  37                 $mTemplates,     //!< Map of title strings to IDs for the template references, including broken ones
  38                 $mExternals,     //!< URLs of external links, array key only
  39                 $mCategories,    //!< Map of category names to sort keys
  40                 $mInterlangs,    //!< Map of language codes to titles
  41                 $mProperties,    //!< Map of arbitrary name to value
  42                 $mRecursive;     //!< Whether to queue jobs for recursive updates
  43
  44         /**
  45          * Constructor
  46          *
  47          * @param $title Title of the page we're updating
  48          * @param $parserOutput ParserOutput: output from a full parse of this page
  49          * @param $recursive Boolean: queue jobs for recursive updates?
  50          */
  51         function __construct( $title, $parserOutput, $recursive = true ) {
  52                 parent::__construct( );
  53
  54                 if ( !( $title instanceof Title ) ) {
  55                         throw new MWException( "The calling convention to LinksUpdate::LinksUpdate() has changed. " .
  56                                 "Please see Article::editUpdates() for an invocation example.\n" );
  57                 }
  58
  59                 if ( !( $parserOutput instanceof ParserOutput ) ) {
  60                         throw new MWException( "The calling convention to LinksUpdate::__construct() has changed. " .
  61                                 "Please see WikiPage::doEditUpdates() for an invocation example.\n" );
  62                 }
  63
  64                 $this->mTitle = $title;
  65                 $this->mId = $title->getArticleID();
  66
  67                 if ( !$this->mId ) {
  68                         throw new MWException( "The Title object did not provide an article ID. Perhaps the page doesn't exist?" );
  69                 }
  70
  71                 $this->mParserOutput = $parserOutput;
  72
  73                 $this->mLinks = $parserOutput->getLinks();
  74                 $this->mImages = $parserOutput->getImages();
  75                 $this->mTemplates = $parserOutput->getTemplates();
  76                 $this->mExternals = $parserOutput->getExternalLinks();
  77                 $this->mCategories = $parserOutput->getCategories();
  78                 $this->mProperties = $parserOutput->getProperties();
  79                 $this->mInterwikis = $parserOutput->getInterwikiLinks();
  80
  81                 # Convert the format of the interlanguage links
  82                 # I didn't want to change it in the ParserOutput, because that array is passed all
  83                 # the way back to the skin, so either a skin API break would be required, or an
  84                 # inefficient back-conversion.
  85                 $ill = $parserOutput->getLanguageLinks();
  86                 $this->mInterlangs = array();
  87                 foreach ( $ill as $link ) {
  88                         list( $key, $title ) = explode( ':', $link, 2 );
  89                         $this->mInterlangs[$key] = $title;
  90                 }
  91
  92                 foreach ( $this->mCategories as &$sortkey ) {
  93                         # If the sortkey is longer then 255 bytes,
  94                         # it truncated by DB, and then doesn't get
  95                         # matched when comparing existing vs current
  96                         # categories, causing bug 25254.
  97                         # Also. substr behaves weird when given "".
  98                         if ( $sortkey !== '' ) {
  99                                 $sortkey = substr( $sortkey, 0, 255 );
 100                         }
 101                 }
 102
 103                 $this->mRecursive = $recursive;
 104
 105                 wfRunHooks( 'LinksUpdateConstructed', array( &$this ) );
 106         }
 107
 108         /**
 109          * Update link tables with outgoing links from an updated article
 110          */
 111         public function doUpdate() {
 112                 global $wgUseDumbLinkUpdate;
 113
 114                 wfRunHooks( 'LinksUpdate', array( &$this ) );
 115                 if ( $wgUseDumbLinkUpdate ) {
 116                         $this->doDumbUpdate();
 117                 } else {
 118                         $this->doIncrementalUpdate();
 119                 }
 120                 wfRunHooks( 'LinksUpdateComplete', array( &$this ) );
 121         }
 122
 123         protected function doIncrementalUpdate() {
 124                 wfProfileIn( __METHOD__ );
 125
 126                 # Page links
 127                 $existing = $this->getExistingLinks();
 128                 $this->incrTableUpdate( 'pagelinks', 'pl', $this->getLinkDeletions( $existing ),
 129                         $this->getLinkInsertions( $existing ) );
 130
 131                 # Image links
 132                 $existing = $this->getExistingImages();
 133
 134                 $imageDeletes = $this->getImageDeletions( $existing );
 135                 $this->incrTableUpdate( 'imagelinks', 'il', $imageDeletes,
 136                         $this->getImageInsertions( $existing ) );
 137
 138                 # Invalidate all image description pages which had links added or removed
 139                 $imageUpdates = $imageDeletes + array_diff_key( $this->mImages, $existing );
 140                 $this->invalidateImageDescriptions( $imageUpdates );
 141
 142                 # External links
 143                 $existing = $this->getExistingExternals();
 144                 $this->incrTableUpdate( 'externallinks', 'el', $this->getExternalDeletions( $existing ),
 145                         $this->getExternalInsertions( $existing ) );
 146
 147                 # Language links
 148                 $existing = $this->getExistingInterlangs();
 149                 $this->incrTableUpdate( 'langlinks', 'll', $this->getInterlangDeletions( $existing ),
 150                         $this->getInterlangInsertions( $existing ) );
 151
 152                 # Inline interwiki links
 153                 $existing = $this->getExistingInterwikis();
 154                 $this->incrTableUpdate( 'iwlinks', 'iwl', $this->getInterwikiDeletions( $existing ),
 155                         $this->getInterwikiInsertions( $existing ) );
 156
 157                 # Template links
 158                 $existing = $this->getExistingTemplates();
 159                 $this->incrTableUpdate( 'templatelinks', 'tl', $this->getTemplateDeletions( $existing ),
 160                         $this->getTemplateInsertions( $existing ) );
 161
 162                 # Category links
 163                 $existing = $this->getExistingCategories();
 164
 165                 $categoryDeletes = $this->getCategoryDeletions( $existing );
 166
 167                 $this->incrTableUpdate( 'categorylinks', 'cl', $categoryDeletes,
 168                         $this->getCategoryInsertions( $existing ) );
 169
 170                 # Invalidate all categories which were added, deleted or changed (set symmetric difference)
 171                 $categoryInserts = array_diff_assoc( $this->mCategories, $existing );
 172                 $categoryUpdates = $categoryInserts + $categoryDeletes;
 173                 $this->invalidateCategories( $categoryUpdates );
 174                 $this->updateCategoryCounts( $categoryInserts, $categoryDeletes );
 175
 176                 # Page properties
 177                 $existing = $this->getExistingProperties();
 178
 179                 $propertiesDeletes = $this->getPropertyDeletions( $existing );
 180
 181                 $this->incrTableUpdate( 'page_props', 'pp', $propertiesDeletes,
 182                         $this->getPropertyInsertions( $existing ) );
 183
 184                 # Invalidate the necessary pages
 185                 $changed = $propertiesDeletes + array_diff_assoc( $this->mProperties, $existing );
 186                 $this->invalidateProperties( $changed );
 187
 188                 # Refresh links of all pages including this page
 189                 # This will be in a separate transaction
 190                 if ( $this->mRecursive ) {
 191                         $this->queueRecursiveJobs();
 192                 }
 193
 194                 wfProfileOut( __METHOD__ );
 195         }
 196
 197         /**
 198          * Link update which clears the previous entries and inserts new ones
 199          * May be slower or faster depending on level of lock contention and write speed of DB
 200          * Also useful where link table corruption needs to be repaired, e.g. in refreshLinks.php
 201          */
 202         protected function doDumbUpdate() {
 203                 wfProfileIn( __METHOD__ );
 204
 205                 # Refresh category pages and image description pages
 206                 $existing = $this->getExistingCategories();
 207                 $categoryInserts = array_diff_assoc( $this->mCategories, $existing );
 208                 $categoryDeletes = array_diff_assoc( $existing, $this->mCategories );
 209                 $categoryUpdates = $categoryInserts + $categoryDeletes;
 210                 $existing = $this->getExistingImages();
 211                 $imageUpdates = array_diff_key( $existing, $this->mImages ) + array_diff_key( $this->mImages, $existing );
 212
 213                 $this->dumbTableUpdate( 'pagelinks',     $this->getLinkInsertions(),     'pl_from' );
 214                 $this->dumbTableUpdate( 'imagelinks',    $this->getImageInsertions(),    'il_from' );
 215                 $this->dumbTableUpdate( 'categorylinks', $this->getCategoryInsertions(), 'cl_from' );
 216                 $this->dumbTableUpdate( 'templatelinks', $this->getTemplateInsertions(), 'tl_from' );
 217                 $this->dumbTableUpdate( 'externallinks', $this->getExternalInsertions(), 'el_from' );
 218                 $this->dumbTableUpdate( 'langlinks',     $this->getInterlangInsertions(),'ll_from' );
 219                 $this->dumbTableUpdate( 'iwlinks',       $this->getInterwikiInsertions(),'iwl_from' );
 220                 $this->dumbTableUpdate( 'page_props',    $this->getPropertyInsertions(), 'pp_page' );
 221
 222                 # Update the cache of all the category pages and image description
 223                 # pages which were changed, and fix the category table count
 224                 $this->invalidateCategories( $categoryUpdates );
 225                 $this->updateCategoryCounts( $categoryInserts, $categoryDeletes );
 226                 $this->invalidateImageDescriptions( $imageUpdates );
 227
 228                 # Refresh links of all pages including this page
 229                 # This will be in a separate transaction
 230                 if ( $this->mRecursive ) {
 231                         $this->queueRecursiveJobs();
 232                 }
 233
 234                 wfProfileOut( __METHOD__ );
 235         }
 236
 237         function queueRecursiveJobs() {
 238                 global $wgUpdateRowsPerJob;
 239                 wfProfileIn( __METHOD__ );
 240
 241                 $cache = $this->mTitle->getBacklinkCache();
 242                 $batches = $cache->partition( 'templatelinks', $wgUpdateRowsPerJob );
 243                 if ( !$batches ) {
 244                         wfProfileOut( __METHOD__ );
 245                         return;
 246                 }
 247                 $jobs = array();
 248                 foreach ( $batches as $batch ) {
 249                         list( $start, $end ) = $batch;
 250                         $params = array(
 251                                 'table' => 'templatelinks',
 252                                 'start' => $start,
 253                                 'end' => $end,
 254                         );
 255                         $jobs[] = new RefreshLinksJob2( $this->mTitle, $params );
 256                 }
 257                 Job::batchInsert( $jobs );
 258
 259                 wfProfileOut( __METHOD__ );
 260         }
 261
 262         /**
 263          * @param $cats
 264          */
 265         function invalidateCategories( $cats ) {
 266                 $this->invalidatePages( NS_CATEGORY, array_keys( $cats ) );
 267         }
 268
 269         /**
 270          * Update all the appropriate counts in the category table.
 271          * @param $added array associative array of category name => sort key
 272          * @param $deleted array associative array of category name => sort key
 273          */
 274         function updateCategoryCounts( $added, $deleted ) {
 275                 $a = WikiPage::factory( $this->mTitle );
 276                 $a->updateCategoryCounts(
 277                         array_keys( $added ), array_keys( $deleted )
 278                 );
 279         }
 280
 281         /**
 282          * @param $images
 283          */
 284         function invalidateImageDescriptions( $images ) {
 285                 $this->invalidatePages( NS_FILE, array_keys( $images ) );
 286         }
 287
 288         /**
 289          * @param $table
 290          * @param $insertions
 291          * @param $fromField
 292          */
 293         private function dumbTableUpdate( $table, $insertions, $fromField ) {
 294                 $this->mDb->delete( $table, array( $fromField => $this->mId ), __METHOD__ );
 295                 if ( count( $insertions ) ) {
 296                         # The link array was constructed without FOR UPDATE, so there may
 297                         # be collisions.  This may cause minor link table inconsistencies,
 298                         # which is better than crippling the site with lock contention.
 299                         $this->mDb->insert( $table, $insertions, __METHOD__, array( 'IGNORE' ) );
 300                 }
 301         }
 302
 303         /**
 304          * Update a table by doing a delete query then an insert query
 305          * @param $table
 306          * @param $prefix
 307          * @param $deletions
 308          * @param $insertions
 309          */
 310         function incrTableUpdate( $table, $prefix, $deletions, $insertions ) {
 311                 if ( $table == 'page_props' ) {
 312                         $fromField = 'pp_page';
 313                 } else {
 314                         $fromField = "{$prefix}_from";
 315                 }
 316                 $where = array( $fromField => $this->mId );
 317                 if ( $table == 'pagelinks' || $table == 'templatelinks' || $table == 'iwlinks' ) {
 318                         if ( $table == 'iwlinks' ) {
 319                                 $baseKey = 'iwl_prefix';
 320                         } else {
 321                                 $baseKey = "{$prefix}_namespace";
 322                         }
 323                         $clause = $this->mDb->makeWhereFrom2d( $deletions, $baseKey, "{$prefix}_title" );
 324                         if ( $clause ) {
 325                                 $where[] = $clause;
 326                         } else {
 327                                 $where = false;
 328                         }
 329                 } else {
 330                         if ( $table == 'langlinks' ) {
 331                                 $toField = 'll_lang';
 332                         } elseif ( $table == 'page_props' ) {
 333                                 $toField = 'pp_propname';
 334                         } else {
 335                                 $toField = $prefix . '_to';
 336                         }
 337                         if ( count( $deletions ) ) {
 338                                 $where[] = "$toField IN (" . $this->mDb->makeList( array_keys( $deletions ) ) . ')';
 339                         } else {
 340                                 $where = false;
 341                         }
 342                 }
 343                 if ( $where ) {
 344                         $this->mDb->delete( $table, $where, __METHOD__ );
 345                 }
 346                 if ( count( $insertions ) ) {
 347                         $this->mDb->insert( $table, $insertions, __METHOD__, 'IGNORE' );
 348                 }
 349         }
 350
 351         /**
 352          * Get an array of pagelinks insertions for passing to the DB
 353          * Skips the titles specified by the 2-D array $existing
 354          * @param $existing array
 355          * @return array
 356          */
 357         private function getLinkInsertions( $existing = array() ) {
 358                 $arr = array();
 359                 foreach( $this->mLinks as $ns => $dbkeys ) {
 360                         $diffs = isset( $existing[$ns] )
 361                                 ? array_diff_key( $dbkeys, $existing[$ns] )
 362                                 : $dbkeys;
 363                         foreach ( $diffs as $dbk => $id ) {
 364                                 $arr[] = array(
 365                                         'pl_from'      => $this->mId,
 366                                         'pl_namespace' => $ns,
 367                                         'pl_title'     => $dbk
 368                                 );
 369                         }
 370                 }
 371                 return $arr;
 372         }
 373
 374         /**
 375          * Get an array of template insertions. Like getLinkInsertions()
 376          * @param $existing array
 377          * @return array
 378          */
 379         private function getTemplateInsertions( $existing = array() ) {
 380                 $arr = array();
 381                 foreach( $this->mTemplates as $ns => $dbkeys ) {
 382                         $diffs = isset( $existing[$ns] ) ? array_diff_key( $dbkeys, $existing[$ns] ) : $dbkeys;
 383                         foreach ( $diffs as $dbk => $id ) {
 384                                 $arr[] = array(
 385                                         'tl_from'      => $this->mId,
 386                                         'tl_namespace' => $ns,
 387                                         'tl_title'     => $dbk
 388                                 );
 389                         }
 390                 }
 391                 return $arr;
 392         }
 393
 394         /**
 395          * Get an array of image insertions
 396          * Skips the names specified in $existing
 397          * @param $existing array
 398          * @return array
 399          */
 400         private function getImageInsertions( $existing = array() ) {
 401                 $arr = array();
 402                 $diffs = array_diff_key( $this->mImages, $existing );
 403                 foreach( $diffs as $iname => $dummy ) {
 404                         $arr[] = array(
 405                                 'il_from' => $this->mId,
 406                                 'il_to'   => $iname
 407                         );
 408                 }
 409                 return $arr;
 410         }
 411
 412         /**
 413          * Get an array of externallinks insertions. Skips the names specified in $existing
 414          * @param $existing array
 415          * @return array
 416          */
 417         private function getExternalInsertions( $existing = array() ) {
 418                 $arr = array();
 419                 $diffs = array_diff_key( $this->mExternals, $existing );
 420                 foreach( $diffs as $url => $dummy ) {
 421                         foreach( wfMakeUrlIndexes( $url ) as $index ) {
 422                                 $arr[] = array(
 423                                         'el_from'   => $this->mId,
 424                                         'el_to'     => $url,
 425                                         'el_index'  => $index,
 426                                 );
 427                         }
 428                 }
 429                 return $arr;
 430         }
 431
 432         /**
 433          * Get an array of category insertions
 434          *
 435          * @param $existing array mapping existing category names to sort keys. If both
 436          * match a link in $this, the link will be omitted from the output
 437          *
 438          * @return array
 439          */
 440         private function getCategoryInsertions( $existing = array() ) {
 441                 global $wgContLang, $wgCategoryCollation;
 442                 $diffs = array_diff_assoc( $this->mCategories, $existing );
 443                 $arr = array();
 444                 foreach ( $diffs as $name => $prefix ) {
 445                         $nt = Title::makeTitleSafe( NS_CATEGORY, $name );
 446                         $wgContLang->findVariantLink( $name, $nt, true );
 447
 448                         if ( $this->mTitle->getNamespace() == NS_CATEGORY ) {
 449                                 $type = 'subcat';
 450                         } elseif ( $this->mTitle->getNamespace() == NS_FILE ) {
 451                                 $type = 'file';
 452                         } else {
 453                                 $type = 'page';
 454                         }
 455
 456                         # Treat custom sortkeys as a prefix, so that if multiple
 457                         # things are forced to sort as '*' or something, they'll
 458                         # sort properly in the category rather than in page_id
 459                         # order or such.
 460                         $sortkey = Collation::singleton()->getSortKey(
 461                                 $this->mTitle->getCategorySortkey( $prefix ) );
 462
 463                         $arr[] = array(
 464                                 'cl_from'    => $this->mId,
 465                                 'cl_to'      => $name,
 466                                 'cl_sortkey' => $sortkey,
 467                                 'cl_timestamp' => $this->mDb->timestamp(),
 468                                 'cl_sortkey_prefix' => $prefix,
 469                                 'cl_collation' => $wgCategoryCollation,
 470                                 'cl_type' => $type,
 471                         );
 472                 }
 473                 return $arr;
 474         }
 475
 476         /**
 477          * Get an array of interlanguage link insertions
 478          *
 479          * @param $existing Array mapping existing language codes to titles
 480          *
 481          * @return array
 482          */
 483         private function getInterlangInsertions( $existing = array() ) {
 484                 $diffs = array_diff_assoc( $this->mInterlangs, $existing );
 485                 $arr = array();
 486                 foreach( $diffs as $lang => $title ) {
 487                         $arr[] = array(
 488                                 'll_from'  => $this->mId,
 489                                 'll_lang'  => $lang,
 490                                 'll_title' => $title
 491                         );
 492                 }
 493                 return $arr;
 494         }
 495
 496         /**
 497          * Get an array of page property insertions
 498          * @param $existing array
 499          * @return array
 500          */
 501         function getPropertyInsertions( $existing = array() ) {
 502                 $diffs = array_diff_assoc( $this->mProperties, $existing );
 503                 $arr = array();
 504                 foreach ( $diffs as $name => $value ) {
 505                         $arr[] = array(
 506                                 'pp_page'      => $this->mId,
 507                                 'pp_propname'  => $name,
 508                                 'pp_value'     => $value,
 509                         );
 510                 }
 511                 return $arr;
 512         }
 513
 514         /**
 515          * Get an array of interwiki insertions for passing to the DB
 516          * Skips the titles specified by the 2-D array $existing
 517          * @param $existing array
 518          * @return array
 519          */
 520         private function getInterwikiInsertions( $existing = array() ) {
 521                 $arr = array();
 522                 foreach( $this->mInterwikis as $prefix => $dbkeys ) {
 523                         $diffs = isset( $existing[$prefix] ) ? array_diff_key( $dbkeys, $existing[$prefix] ) : $dbkeys;
 524                         foreach ( $diffs as $dbk => $id ) {
 525                                 $arr[] = array(
 526                                         'iwl_from'   => $this->mId,
 527                                         'iwl_prefix' => $prefix,
 528                                         'iwl_title'  => $dbk
 529                                 );
 530                         }
 531                 }
 532                 return $arr;
 533         }
 534
 535         /**
 536          * Given an array of existing links, returns those links which are not in $this
 537          * and thus should be deleted.
 538          * @param $existing array
 539          * @return array
 540          */
 541         private function getLinkDeletions( $existing ) {
 542                 $del = array();
 543                 foreach ( $existing as $ns => $dbkeys ) {
 544                         if ( isset( $this->mLinks[$ns] ) ) {
 545                                 $del[$ns] = array_diff_key( $existing[$ns], $this->mLinks[$ns] );
 546                         } else {
 547                                 $del[$ns] = $existing[$ns];
 548                         }
 549                 }
 550                 return $del;
 551         }
 552
 553         /**
 554          * Given an array of existing templates, returns those templates which are not in $this
 555          * and thus should be deleted.
 556          * @param $existing array
 557          * @return array
 558          */
 559         private function getTemplateDeletions( $existing ) {
 560                 $del = array();
 561                 foreach ( $existing as $ns => $dbkeys ) {
 562                         if ( isset( $this->mTemplates[$ns] ) ) {
 563                                 $del[$ns] = array_diff_key( $existing[$ns], $this->mTemplates[$ns] );
 564                         } else {
 565                                 $del[$ns] = $existing[$ns];
 566                         }
 567                 }
 568                 return $del;
 569         }
 570
 571         /**
 572          * Given an array of existing images, returns those images which are not in $this
 573          * and thus should be deleted.
 574          * @param $existing array
 575          * @return array
 576          */
 577         private function getImageDeletions( $existing ) {
 578                 return array_diff_key( $existing, $this->mImages );
 579         }
 580
 581         /**
 582          * Given an array of existing external links, returns those links which are not
 583          * in $this and thus should be deleted.
 584          * @param $existing array
 585          * @return array
 586          */
 587         private function getExternalDeletions( $existing ) {
 588                 return array_diff_key( $existing, $this->mExternals );
 589         }
 590
 591         /**
 592          * Given an array of existing categories, returns those categories which are not in $this
 593          * and thus should be deleted.
 594          * @param $existing array
 595          * @return array
 596          */
 597         private function getCategoryDeletions( $existing ) {
 598                 return array_diff_assoc( $existing, $this->mCategories );
 599         }
 600
 601         /**
 602          * Given an array of existing interlanguage links, returns those links which are not
 603          * in $this and thus should be deleted.
 604          * @param $existing array
 605          * @return array
 606          */
 607         private function getInterlangDeletions( $existing ) {
 608                 return array_diff_assoc( $existing, $this->mInterlangs );
 609         }
 610
 611         /**
 612          * Get array of properties which should be deleted.
 613          * @param $existing array
 614          * @return array
 615          */
 616         function getPropertyDeletions( $existing ) {
 617                 return array_diff_assoc( $existing, $this->mProperties );
 618         }
 619
 620         /**
 621          * Given an array of existing interwiki links, returns those links which are not in $this
 622          * and thus should be deleted.
 623          * @param $existing array
 624          * @return array
 625          */
 626         private function getInterwikiDeletions( $existing ) {
 627                 $del = array();
 628                 foreach ( $existing as $prefix => $dbkeys ) {
 629                         if ( isset( $this->mInterwikis[$prefix] ) ) {
 630                                 $del[$prefix] = array_diff_key( $existing[$prefix], $this->mInterwikis[$prefix] );
 631                         } else {
 632                                 $del[$prefix] = $existing[$prefix];
 633                         }
 634                 }
 635                 return $del;
 636         }
 637
 638         /**
 639          * Get an array of existing links, as a 2-D array
 640          *
 641          * @return array
 642          */
 643         private function getExistingLinks() {
 644                 $res = $this->mDb->select( 'pagelinks', array( 'pl_namespace', 'pl_title' ),
 645                         array( 'pl_from' => $this->mId ), __METHOD__, $this->mOptions );
 646                 $arr = array();
 647                 foreach ( $res as $row ) {
 648                         if ( !isset( $arr[$row->pl_namespace] ) ) {
 649                                 $arr[$row->pl_namespace] = array();
 650                         }
 651                         $arr[$row->pl_namespace][$row->pl_title] = 1;
 652                 }
 653                 return $arr;
 654         }
 655
 656         /**
 657          * Get an array of existing templates, as a 2-D array
 658          *
 659          * @return array
 660          */
 661         private function getExistingTemplates() {
 662                 $res = $this->mDb->select( 'templatelinks', array( 'tl_namespace', 'tl_title' ),
 663                         array( 'tl_from' => $this->mId ), __METHOD__, $this->mOptions );
 664                 $arr = array();
 665                 foreach ( $res as $row ) {
 666                         if ( !isset( $arr[$row->tl_namespace] ) ) {
 667                                 $arr[$row->tl_namespace] = array();
 668                         }
 669                         $arr[$row->tl_namespace][$row->tl_title] = 1;
 670                 }
 671                 return $arr;
 672         }
 673
 674         /**
 675          * Get an array of existing images, image names in the keys
 676          *
 677          * @return array
 678          */
 679         private function getExistingImages() {
 680                 $res = $this->mDb->select( 'imagelinks', array( 'il_to' ),
 681                         array( 'il_from' => $this->mId ), __METHOD__, $this->mOptions );
 682                 $arr = array();
 683                 foreach ( $res as $row ) {
 684                         $arr[$row->il_to] = 1;
 685                 }
 686                 return $arr;
 687         }
 688
 689         /**
 690          * Get an array of existing external links, URLs in the keys
 691          *
 692          * @return array
 693          */
 694         private function getExistingExternals() {
 695                 $res = $this->mDb->select( 'externallinks', array( 'el_to' ),
 696                         array( 'el_from' => $this->mId ), __METHOD__, $this->mOptions );
 697                 $arr = array();
 698                 foreach ( $res as $row ) {
 699                         $arr[$row->el_to] = 1;
 700                 }
 701                 return $arr;
 702         }
 703
 704         /**
 705          * Get an array of existing categories, with the name in the key and sort key in the value.
 706          *
 707          * @return array
 708          */
 709         private function getExistingCategories() {
 710                 $res = $this->mDb->select( 'categorylinks', array( 'cl_to', 'cl_sortkey_prefix' ),
 711                         array( 'cl_from' => $this->mId ), __METHOD__, $this->mOptions );
 712                 $arr = array();
 713                 foreach ( $res as $row ) {
 714                         $arr[$row->cl_to] = $row->cl_sortkey_prefix;
 715                 }
 716                 return $arr;
 717         }
 718
 719         /**
 720          * Get an array of existing interlanguage links, with the language code in the key and the
 721          * title in the value.
 722          *
 723          * @return array
 724          */
 725         private function getExistingInterlangs() {
 726                 $res = $this->mDb->select( 'langlinks', array( 'll_lang', 'll_title' ),
 727                         array( 'll_from' => $this->mId ), __METHOD__, $this->mOptions );
 728                 $arr = array();
 729                 foreach ( $res as $row ) {
 730                         $arr[$row->ll_lang] = $row->ll_title;
 731                 }
 732                 return $arr;
 733         }
 734
 735         /**
 736          * Get an array of existing inline interwiki links, as a 2-D array
 737          * @return array (prefix => array(dbkey => 1))
 738          */
 739         protected function getExistingInterwikis() {
 740                 $res = $this->mDb->select( 'iwlinks', array( 'iwl_prefix', 'iwl_title' ),
 741                         array( 'iwl_from' => $this->mId ), __METHOD__, $this->mOptions );
 742                 $arr = array();
 743                 foreach ( $res as $row ) {
 744                         if ( !isset( $arr[$row->iwl_prefix] ) ) {
 745                                 $arr[$row->iwl_prefix] = array();
 746                         }
 747                         $arr[$row->iwl_prefix][$row->iwl_title] = 1;
 748                 }
 749                 return $arr;
 750         }
 751
 752         /**
 753          * Get an array of existing categories, with the name in the key and sort key in the value.
 754          *
 755          * @return array
 756          */
 757         private function getExistingProperties() {
 758                 $res = $this->mDb->select( 'page_props', array( 'pp_propname', 'pp_value' ),
 759                         array( 'pp_page' => $this->mId ), __METHOD__, $this->mOptions );
 760                 $arr = array();
 761                 foreach ( $res as $row ) {
 762                         $arr[$row->pp_propname] = $row->pp_value;
 763                 }
 764                 return $arr;
 765         }
 766
 767         /**
 768          * Return the title object of the page being updated
 769          * @return Title
 770          */
 771         public function getTitle() {
 772                 return $this->mTitle;
 773         }
 774
 775         /**
 776          * Returns parser output
 777          * @since 1.19
 778          * @return ParserOutput
 779          */
 780         public function getParserOutput() {
 781                 return $this->mParserOutput;
 782         }
 783
 784         /**
 785          * Return the list of images used as generated by the parser
 786          * @return array
 787          */
 788         public function getImages() {
 789                 return $this->mImages;
 790         }
 791
 792         /**
 793          * Invalidate any necessary link lists related to page property changes
 794          * @param $changed
 795          */
 796         private function invalidateProperties( $changed ) {
 797                 global $wgPagePropLinkInvalidations;
 798
 799                 foreach ( $changed as $name => $value ) {
 800                         if ( isset( $wgPagePropLinkInvalidations[$name] ) ) {
 801                                 $inv = $wgPagePropLinkInvalidations[$name];
 802                                 if ( !is_array( $inv ) ) {
 803                                         $inv = array( $inv );
 804                                 }
 805                                 foreach ( $inv as $table ) {
 806                                         $update = new HTMLCacheUpdate( $this->mTitle, $table );
 807                                         $update->doUpdate();
 808                                 }
 809                         }
 810                 }
 811         }
 812 }
 813
 814 /**
 815  * Update object handling the cleanup of links tables after a page was deleted.
 816  **/
 817 class LinksDeletionUpdate extends SqlDataUpdate {
 818
 819         protected $mTitle;     //!< Title the title of page that was deleted
 820
 821         /**
 822          * Constructor
 823          *
 824          * @param $title Title of the page we're updating
 825          * @param $parserOutput ParserOutput: output from a full parse of this page
 826          * @param $recursive Boolean: queue jobs for recursive updates?
 827          */
 828         function __construct( Title $title ) {
 829                 parent::__construct( );
 830
 831                 $this->mTitle = $title;
 832
 833                 if ( !$title->getArticleID() ) {
 834                         throw new MWException( "The Title object did not provide an article ID. Perhaps the page doesn't exist?" );
 835                 }
 836         }
 837
 838         /**
 839          * Do some database updates after deletion
 840          */
 841         public function doUpdate() {
 842                 $title = $this->mTitle;
 843                 $id = $title->getArticleID();
 844
 845                 # Delete restrictions for it
 846                 $this->mDb->delete( 'page_restrictions', array ( 'pr_page' => $id ), __METHOD__ );
 847
 848                 # Fix category table counts
 849                 $cats = array();
 850                 $res = $this->mDb->select( 'categorylinks', 'cl_to', array( 'cl_from' => $id ), __METHOD__ );
 851
 852                 foreach ( $res as $row ) {
 853                         $cats [] = $row->cl_to;
 854                 }
 855
 856                 $this->updateCategoryCounts( array(), $cats );
 857
 858                 # If using cascading deletes, we can skip some explicit deletes
 859                 if ( !$this->mDb->cascadingDeletes() ) {
 860                         $this->mDb->delete( 'revision', array( 'rev_page' => $id ), __METHOD__ );
 861
 862                         # Delete outgoing links
 863                         $this->mDb->delete( 'pagelinks', array( 'pl_from' => $id ), __METHOD__ );
 864                         $this->mDb->delete( 'imagelinks', array( 'il_from' => $id ), __METHOD__ );
 865                         $this->mDb->delete( 'categorylinks', array( 'cl_from' => $id ), __METHOD__ );
 866                         $this->mDb->delete( 'templatelinks', array( 'tl_from' => $id ), __METHOD__ );
 867                         $this->mDb->delete( 'externallinks', array( 'el_from' => $id ), __METHOD__ );
 868                         $this->mDb->delete( 'langlinks', array( 'll_from' => $id ), __METHOD__ );
 869                         $this->mDb->delete( 'iwlinks', array( 'iwl_from' => $id ), __METHOD__ );
 870                         $this->mDb->delete( 'redirect', array( 'rd_from' => $id ), __METHOD__ );
 871                         $this->mDb->delete( 'page_props', array( 'pp_page' => $id ), __METHOD__ );
 872                 }
 873
 874                 # If using cleanup triggers, we can skip some manual deletes
 875                 if ( !$this->mDb->cleanupTriggers() ) {
 876                         # Clean up recentchanges entries...
 877                         $this->mDb->delete( 'recentchanges',
 878                                 array( 'rc_type != ' . RC_LOG,
 879                                         'rc_namespace' => $title->getNamespace(),
 880                                         'rc_title' => $title->getDBkey() ),
 881                                 __METHOD__ );
 882                         $this->mDb->delete( 'recentchanges',
 883                                 array( 'rc_type != ' . RC_LOG, 'rc_cur_id' => $id ),
 884                                 __METHOD__ );
 885                 }
 886         }
 887
 888         /**
 889          * Update all the appropriate counts in the category table.
 890          * @param $added array associative array of category name => sort key
 891          * @param $deleted array associative array of category name => sort key
 892          */
 893         function updateCategoryCounts( $added, $deleted ) {
 894                 $a = WikiPage::factory( $this->mTitle );
 895                 $a->updateCategoryCounts(
 896                         array_keys( $added ), array_keys( $deleted )
 897                 );
 898         }
 899 }