includes/specialpage/QueryPage.php

   1 <?php
   2 /**
   3  * Base code for "query" special pages.
   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  * @ingroup SpecialPage
  22  */
  23
  24 use MediaWiki\MediaWikiServices;
  25 use Wikimedia\Rdbms\IResultWrapper;
  26 use Wikimedia\Rdbms\IDatabase;
  27 use Wikimedia\Rdbms\DBError;
  28
  29 /**
  30  * This is a class for doing query pages; since they're almost all the same,
  31  * we factor out some of the functionality into a superclass, and let
  32  * subclasses derive from it.
  33  * @ingroup SpecialPage
  34  */
  35 abstract class QueryPage extends SpecialPage {
  36         /** @var bool Whether or not we want plain listoutput rather than an ordered list */
  37         protected $listoutput = false;
  38
  39         /** @var int The offset and limit in use, as passed to the query() function */
  40         protected $offset = 0;
  41
  42         /** @var int */
  43         protected $limit = 0;
  44
  45         /**
  46          * The number of rows returned by the query. Reading this variable
  47          * only makes sense in functions that are run after the query has been
  48          * done, such as preprocessResults() and formatRow().
  49          *
  50          * @var int
  51          */
  52         protected $numRows;
  53
  54         /**
  55          * @var string|null
  56          */
  57         protected $cachedTimestamp = null;
  58
  59         /**
  60          * @var bool Whether to show prev/next links
  61          */
  62         protected $shownavigation = true;
  63
  64         /**
  65          * Get a list of query page classes and their associated special pages,
  66          * for periodic updates.
  67          *
  68          * DO NOT CHANGE THIS LIST without testing that
  69          * maintenance/updateSpecialPages.php still works.
  70          *
  71          * @return string[][]
  72          */
  73         public static function getPages() {
  74                 static $qp = null;
  75
  76                 if ( $qp === null ) {
  77                         // QueryPage subclass, Special page name
  78                         $qp = [
  79                                 [ AncientPagesPage::class, 'Ancientpages' ],
  80                                 [ BrokenRedirectsPage::class, 'BrokenRedirects' ],
  81                                 [ DeadendPagesPage::class, 'Deadendpages' ],
  82                                 [ DoubleRedirectsPage::class, 'DoubleRedirects' ],
  83                                 [ FileDuplicateSearchPage::class, 'FileDuplicateSearch' ],
  84                                 [ ListDuplicatedFilesPage::class, 'ListDuplicatedFiles' ],
  85                                 [ LinkSearchPage::class, 'LinkSearch' ],
  86                                 [ ListredirectsPage::class, 'Listredirects' ],
  87                                 [ LonelyPagesPage::class, 'Lonelypages' ],
  88                                 [ LongPagesPage::class, 'Longpages' ],
  89                                 [ MediaStatisticsPage::class, 'MediaStatistics' ],
  90                                 [ MIMEsearchPage::class, 'MIMEsearch' ],
  91                                 [ MostcategoriesPage::class, 'Mostcategories' ],
  92                                 [ MostimagesPage::class, 'Mostimages' ],
  93                                 [ MostinterwikisPage::class, 'Mostinterwikis' ],
  94                                 [ MostlinkedCategoriesPage::class, 'Mostlinkedcategories' ],
  95                                 [ MostlinkedTemplatesPage::class, 'Mostlinkedtemplates' ],
  96                                 [ MostlinkedPage::class, 'Mostlinked' ],
  97                                 [ MostrevisionsPage::class, 'Mostrevisions' ],
  98                                 [ FewestrevisionsPage::class, 'Fewestrevisions' ],
  99                                 [ ShortPagesPage::class, 'Shortpages' ],
 100                                 [ UncategorizedCategoriesPage::class, 'Uncategorizedcategories' ],
 101                                 [ UncategorizedPagesPage::class, 'Uncategorizedpages' ],
 102                                 [ UncategorizedImagesPage::class, 'Uncategorizedimages' ],
 103                                 [ UncategorizedTemplatesPage::class, 'Uncategorizedtemplates' ],
 104                                 [ UnusedCategoriesPage::class, 'Unusedcategories' ],
 105                                 [ UnusedimagesPage::class, 'Unusedimages' ],
 106                                 [ WantedCategoriesPage::class, 'Wantedcategories' ],
 107                                 [ WantedFilesPage::class, 'Wantedfiles' ],
 108                                 [ WantedPagesPage::class, 'Wantedpages' ],
 109                                 [ WantedTemplatesPage::class, 'Wantedtemplates' ],
 110                                 [ UnwatchedpagesPage::class, 'Unwatchedpages' ],
 111                                 [ UnusedtemplatesPage::class, 'Unusedtemplates' ],
 112                                 [ WithoutInterwikiPage::class, 'Withoutinterwiki' ],
 113                         ];
 114                         Hooks::run( 'wgQueryPages', [ &$qp ] );
 115                 }
 116
 117                 return $qp;
 118         }
 119
 120         /**
 121          * A mutator for $this->listoutput;
 122          *
 123          * @param bool $bool
 124          */
 125         function setListoutput( $bool ) {
 126                 $this->listoutput = $bool;
 127         }
 128
 129         /**
 130          * Subclasses return an SQL query here, formatted as an array with the
 131          * following keys:
 132          *    tables => Table(s) for passing to Database::select()
 133          *    fields => Field(s) for passing to Database::select(), may be *
 134          *    conds => WHERE conditions
 135          *    options => options
 136          *    join_conds => JOIN conditions
 137          *
 138          * Note that the query itself should return the following three columns:
 139          * 'namespace', 'title', and 'value'. 'value' is used for sorting.
 140          *
 141          * These may be stored in the querycache table for expensive queries,
 142          * and that cached data will be returned sometimes, so the presence of
 143          * extra fields can't be relied upon. The cached 'value' column will be
 144          * an integer; non-numeric values are useful only for sorting the
 145          * initial query (except if they're timestamps, see usesTimestamps()).
 146          *
 147          * Don't include an ORDER or LIMIT clause, they will be added.
 148          *
 149          * If this function is not overridden or returns something other than
 150          * an array, getSQL() will be used instead. This is for backwards
 151          * compatibility only and is strongly deprecated.
 152          * @return array
 153          * @since 1.18
 154          */
 155         public function getQueryInfo() {
 156                 return null;
 157         }
 158
 159         /**
 160          * For back-compat, subclasses may return a raw SQL query here, as a string.
 161          * This is strongly deprecated; getQueryInfo() should be overridden instead.
 162          * @throws MWException
 163          * @return string
 164          */
 165         function getSQL() {
 166                 /* Implement getQueryInfo() instead */
 167                 throw new MWException( "Bug in a QueryPage: doesn't implement getQueryInfo() nor "
 168                         . "getQuery() properly" );
 169         }
 170
 171         /**
 172          * Subclasses return an array of fields to order by here. Don't append
 173          * DESC to the field names, that'll be done automatically if
 174          * sortDescending() returns true.
 175          * @return string[]
 176          * @since 1.18
 177          */
 178         function getOrderFields() {
 179                 return [ 'value' ];
 180         }
 181
 182         /**
 183          * Does this query return timestamps rather than integers in its
 184          * 'value' field? If true, this class will convert 'value' to a
 185          * UNIX timestamp for caching.
 186          * NOTE: formatRow() may get timestamps in TS_MW (mysql), TS_DB (pgsql)
 187          *       or TS_UNIX (querycache) format, so be sure to always run them
 188          *       through wfTimestamp()
 189          * @return bool
 190          * @since 1.18
 191          */
 192         public function usesTimestamps() {
 193                 return false;
 194         }
 195
 196         /**
 197          * Override to sort by increasing values
 198          *
 199          * @return bool
 200          */
 201         function sortDescending() {
 202                 return true;
 203         }
 204
 205         /**
 206          * Is this query expensive (for some definition of expensive)? Then we
 207          * don't let it run in miser mode. $wgDisableQueryPages causes all query
 208          * pages to be declared expensive. Some query pages are always expensive.
 209          *
 210          * @return bool
 211          */
 212         public function isExpensive() {
 213                 return $this->getConfig()->get( 'DisableQueryPages' );
 214         }
 215
 216         /**
 217          * Is the output of this query cacheable? Non-cacheable expensive pages
 218          * will be disabled in miser mode and will not have their results written
 219          * to the querycache table.
 220          * @return bool
 221          * @since 1.18
 222          */
 223         public function isCacheable() {
 224                 return true;
 225         }
 226
 227         /**
 228          * Whether or not the output of the page in question is retrieved from
 229          * the database cache.
 230          *
 231          * @return bool
 232          */
 233         public function isCached() {
 234                 return $this->isExpensive() && $this->getConfig()->get( 'MiserMode' );
 235         }
 236
 237         /**
 238          * Sometime we don't want to build rss / atom feeds.
 239          *
 240          * @return bool
 241          */
 242         function isSyndicated() {
 243                 return true;
 244         }
 245
 246         /**
 247          * Formats the results of the query for display. The skin is the current
 248          * skin; you can use it for making links. The result is a single row of
 249          * result data. You should be able to grab SQL results off of it.
 250          * If the function returns false, the line output will be skipped.
 251          * @param Skin $skin
 252          * @param object $result Result row
 253          * @return string|bool String or false to skip
 254          */
 255         abstract function formatResult( $skin, $result );
 256
 257         /**
 258          * The content returned by this function will be output before any result
 259          *
 260          * @return string
 261          */
 262         function getPageHeader() {
 263                 return '';
 264         }
 265
 266         /**
 267          * Outputs some kind of an informative message (via OutputPage) to let the
 268          * user know that the query returned nothing and thus there's nothing to
 269          * show.
 270          *
 271          * @since 1.26
 272          */
 273         protected function showEmptyText() {
 274                 $this->getOutput()->addWikiMsg( 'specialpage-empty' );
 275         }
 276
 277         /**
 278          * If using extra form wheely-dealies, return a set of parameters here
 279          * as an associative array. They will be encoded and added to the paging
 280          * links (prev/next/lengths).
 281          *
 282          * @return array
 283          */
 284         function linkParameters() {
 285                 return [];
 286         }
 287
 288         /**
 289          * Clear the cache and save new results
 290          *
 291          * @param int|bool $limit Limit for SQL statement
 292          * @param bool $ignoreErrors Whether to ignore database errors
 293          * @throws DBError|Exception
 294          * @return bool|int
 295          */
 296         public function recache( $limit, $ignoreErrors = true ) {
 297                 if ( !$this->isCacheable() ) {
 298                         return 0;
 299                 }
 300
 301                 $fname = static::class . '::recache';
 302                 $dbw = wfGetDB( DB_MASTER );
 303                 if ( !$dbw ) {
 304                         return false;
 305                 }
 306
 307                 try {
 308                         # Do query
 309                         $res = $this->reallyDoQuery( $limit, false );
 310                         $num = false;
 311                         if ( $res ) {
 312                                 $num = $res->numRows();
 313                                 # Fetch results
 314                                 $vals = [];
 315                                 foreach ( $res as $row ) {
 316                                         if ( isset( $row->value ) ) {
 317                                                 if ( $this->usesTimestamps() ) {
 318                                                         $value = wfTimestamp( TS_UNIX,
 319                                                                 $row->value );
 320                                                 } else {
 321                                                         $value = intval( $row->value ); // T16414
 322                                                 }
 323                                         } else {
 324                                                 $value = 0;
 325                                         }
 326
 327                                         $vals[] = [
 328                                                 'qc_type' => $this->getName(),
 329                                                 'qc_namespace' => $row->namespace,
 330                                                 'qc_title' => $row->title,
 331                                                 'qc_value' => $value
 332                                         ];
 333                                 }
 334
 335                                 $dbw->doAtomicSection(
 336                                         __METHOD__,
 337                                         function ( IDatabase $dbw, $fname ) use ( $vals ) {
 338                                                 # Clear out any old cached data
 339                                                 $dbw->delete( 'querycache',
 340                                                         [ 'qc_type' => $this->getName() ],
 341                                                         $fname
 342                                                 );
 343                                                 # Save results into the querycache table on the master
 344                                                 if ( count( $vals ) ) {
 345                                                         $dbw->insert( 'querycache', $vals, $fname );
 346                                                 }
 347                                                 # Update the querycache_info record for the page
 348                                                 $dbw->delete( 'querycache_info',
 349                                                         [ 'qci_type' => $this->getName() ],
 350                                                         $fname
 351                                                 );
 352                                                 $dbw->insert( 'querycache_info',
 353                                                         [ 'qci_type' => $this->getName(),
 354                                                                 'qci_timestamp' => $dbw->timestamp() ],
 355                                                         $fname
 356                                                 );
 357                                         }
 358                                 );
 359                         }
 360                 } catch ( DBError $e ) {
 361                         if ( !$ignoreErrors ) {
 362                                 throw $e; // report query error
 363                         }
 364                         $num = false; // set result to false to indicate error
 365                 }
 366
 367                 return $num;
 368         }
 369
 370         /**
 371          * Get a DB connection to be used for slow recache queries
 372          * @return IDatabase
 373          */
 374         function getRecacheDB() {
 375                 return wfGetDB( DB_REPLICA, [ $this->getName(), 'QueryPage::recache', 'vslow' ] );
 376         }
 377
 378         /**
 379          * Run the query and return the result
 380          * @param int|bool $limit Numerical limit or false for no limit
 381          * @param int|bool $offset Numerical offset or false for no offset
 382          * @return IResultWrapper
 383          * @since 1.18
 384          */
 385         public function reallyDoQuery( $limit, $offset = false ) {
 386                 $fname = static::class . '::reallyDoQuery';
 387                 $dbr = $this->getRecacheDB();
 388                 $query = $this->getQueryInfo();
 389                 $order = $this->getOrderFields();
 390
 391                 if ( $this->sortDescending() ) {
 392                         foreach ( $order as &$field ) {
 393                                 $field .= ' DESC';
 394                         }
 395                 }
 396
 397                 if ( is_array( $query ) ) {
 398                         $tables = isset( $query['tables'] ) ? (array)$query['tables'] : [];
 399                         $fields = isset( $query['fields'] ) ? (array)$query['fields'] : [];
 400                         $conds = isset( $query['conds'] ) ? (array)$query['conds'] : [];
 401                         $options = isset( $query['options'] ) ? (array)$query['options'] : [];
 402                         $join_conds = isset( $query['join_conds'] ) ? (array)$query['join_conds'] : [];
 403
 404                         if ( $order ) {
 405                                 $options['ORDER BY'] = $order;
 406                         }
 407
 408                         if ( $limit !== false ) {
 409                                 $options['LIMIT'] = intval( $limit );
 410                         }
 411
 412                         if ( $offset !== false ) {
 413                                 $options['OFFSET'] = intval( $offset );
 414                         }
 415
 416                         $res = $dbr->select( $tables, $fields, $conds, $fname,
 417                                         $options, $join_conds
 418                         );
 419                 } else {
 420                         // Old-fashioned raw SQL style, deprecated
 421                         $sql = $this->getSQL();
 422                         $sql .= ' ORDER BY ' . implode( ', ', $order );
 423                         $sql = $dbr->limitResult( $sql, $limit, $offset );
 424                         $res = $dbr->query( $sql, $fname );
 425                 }
 426
 427                 return $res;
 428         }
 429
 430         /**
 431          * Somewhat deprecated, you probably want to be using execute()
 432          * @param int|bool $offset
 433          * @param int|bool $limit
 434          * @return IResultWrapper
 435          */
 436         public function doQuery( $offset = false, $limit = false ) {
 437                 if ( $this->isCached() && $this->isCacheable() ) {
 438                         return $this->fetchFromCache( $limit, $offset );
 439                 } else {
 440                         return $this->reallyDoQuery( $limit, $offset );
 441                 }
 442         }
 443
 444         /**
 445          * Fetch the query results from the query cache
 446          * @param int|bool $limit Numerical limit or false for no limit
 447          * @param int|bool $offset Numerical offset or false for no offset
 448          * @return IResultWrapper
 449          * @since 1.18
 450          */
 451         public function fetchFromCache( $limit, $offset = false ) {
 452                 $dbr = wfGetDB( DB_REPLICA );
 453                 $options = [];
 454
 455                 if ( $limit !== false ) {
 456                         $options['LIMIT'] = intval( $limit );
 457                 }
 458
 459                 if ( $offset !== false ) {
 460                         $options['OFFSET'] = intval( $offset );
 461                 }
 462
 463                 $order = $this->getCacheOrderFields();
 464                 if ( $this->sortDescending() ) {
 465                         foreach ( $order as &$field ) {
 466                                 $field .= " DESC";
 467                         }
 468                 }
 469                 if ( $order ) {
 470                         $options['ORDER BY'] = $order;
 471                 }
 472
 473                 return $dbr->select( 'querycache',
 474                                 [ 'qc_type',
 475                                 'namespace' => 'qc_namespace',
 476                                 'title' => 'qc_title',
 477                                 'value' => 'qc_value' ],
 478                                 [ 'qc_type' => $this->getName() ],
 479                                 __METHOD__,
 480                                 $options
 481                 );
 482         }
 483
 484         /**
 485          * Return the order fields for fetchFromCache. Default is to always use
 486          * "ORDER BY value" which was the default prior to this function.
 487          * @return array
 488          * @since 1.29
 489          */
 490         function getCacheOrderFields() {
 491                 return [ 'value' ];
 492         }
 493
 494         /**
 495          * @return string
 496          */
 497         public function getCachedTimestamp() {
 498                 if ( is_null( $this->cachedTimestamp ) ) {
 499                         $dbr = wfGetDB( DB_REPLICA );
 500                         $fname = static::class . '::getCachedTimestamp';
 501                         $this->cachedTimestamp = $dbr->selectField( 'querycache_info', 'qci_timestamp',
 502                                 [ 'qci_type' => $this->getName() ], $fname );
 503                 }
 504                 return $this->cachedTimestamp;
 505         }
 506
 507         /**
 508          * Returns limit and offset, as returned by $this->getRequest()->getLimitOffset().
 509          * Subclasses may override this to further restrict or modify limit and offset.
 510          *
 511          * @note Restricts the offset parameter, as most query pages have inefficient paging
 512          *
 513          * Its generally expected that the returned limit will not be 0, and the returned
 514          * offset will be less than the max results.
 515          *
 516          * @since 1.26
 517          * @return int[] list( $limit, $offset )
 518          */
 519         protected function getLimitOffset() {
 520                 list( $limit, $offset ) = $this->getRequest()->getLimitOffset();
 521                 if ( $this->getConfig()->get( 'MiserMode' ) ) {
 522                         $maxResults = $this->getMaxResults();
 523                         // Can't display more than max results on a page
 524                         $limit = min( $limit, $maxResults );
 525                         // Can't skip over more than the end of $maxResults
 526                         $offset = min( $offset, $maxResults + 1 );
 527                 }
 528                 return [ $limit, $offset ];
 529         }
 530
 531         /**
 532          * What is limit to fetch from DB
 533          *
 534          * Used to make it appear the DB stores less results then it actually does
 535          * @param int $uiLimit Limit from UI
 536          * @param int $uiOffset Offset from UI
 537          * @return int Limit to use for DB (not including extra row to see if at end)
 538          */
 539         protected function getDBLimit( $uiLimit, $uiOffset ) {
 540                 $maxResults = $this->getMaxResults();
 541                 if ( $this->getConfig()->get( 'MiserMode' ) ) {
 542                         $limit = min( $uiLimit + 1, $maxResults - $uiOffset );
 543                         return max( $limit, 0 );
 544                 } else {
 545                         return $uiLimit + 1;
 546                 }
 547         }
 548
 549         /**
 550          * Get max number of results we can return in miser mode.
 551          *
 552          * Most QueryPage subclasses use inefficient paging, so limit the max amount we return
 553          * This matters for uncached query pages that might otherwise accept an offset of 3 million
 554          *
 555          * @since 1.27
 556          * @return int
 557          */
 558         protected function getMaxResults() {
 559                 // Max of 10000, unless we store more than 10000 in query cache.
 560                 return max( $this->getConfig()->get( 'QueryCacheLimit' ), 10000 );
 561         }
 562
 563         /**
 564          * This is the actual workhorse. It does everything needed to make a
 565          * real, honest-to-gosh query page.
 566          * @param string|null $par
 567          */
 568         public function execute( $par ) {
 569                 $user = $this->getUser();
 570                 if ( !$this->userCanExecute( $user ) ) {
 571                         $this->displayRestrictionError();
 572                         return;
 573                 }
 574
 575                 $this->setHeaders();
 576                 $this->outputHeader();
 577
 578                 $out = $this->getOutput();
 579
 580                 if ( $this->isCached() && !$this->isCacheable() ) {
 581                         $out->addWikiMsg( 'querypage-disabled' );
 582                         return;
 583                 }
 584
 585                 $out->setSyndicated( $this->isSyndicated() );
 586
 587                 if ( $this->limit == 0 && $this->offset == 0 ) {
 588                         list( $this->limit, $this->offset ) = $this->getLimitOffset();
 589                 }
 590                 $dbLimit = $this->getDBLimit( $this->limit, $this->offset );
 591                 // @todo Use doQuery()
 592                 if ( !$this->isCached() ) {
 593                         # select one extra row for navigation
 594                         $res = $this->reallyDoQuery( $dbLimit, $this->offset );
 595                 } else {
 596                         # Get the cached result, select one extra row for navigation
 597                         $res = $this->fetchFromCache( $dbLimit, $this->offset );
 598                         if ( !$this->listoutput ) {
 599                                 # Fetch the timestamp of this update
 600                                 $ts = $this->getCachedTimestamp();
 601                                 $lang = $this->getLanguage();
 602                                 $maxResults = $lang->formatNum( $this->getConfig()->get( 'QueryCacheLimit' ) );
 603
 604                                 if ( $ts ) {
 605                                         $updated = $lang->userTimeAndDate( $ts, $user );
 606                                         $updateddate = $lang->userDate( $ts, $user );
 607                                         $updatedtime = $lang->userTime( $ts, $user );
 608                                         $out->addMeta( 'Data-Cache-Time', $ts );
 609                                         $out->addJsConfigVars( 'dataCacheTime', $ts );
 610                                         $out->addWikiMsg( 'perfcachedts', $updated, $updateddate, $updatedtime, $maxResults );
 611                                 } else {
 612                                         $out->addWikiMsg( 'perfcached', $maxResults );
 613                                 }
 614
 615                                 # If updates on this page have been disabled, let the user know
 616                                 # that the data set won't be refreshed for now
 617                                 if ( is_array( $this->getConfig()->get( 'DisableQueryPageUpdate' ) )
 618                                         && in_array( $this->getName(), $this->getConfig()->get( 'DisableQueryPageUpdate' ) )
 619                                 ) {
 620                                         $out->wrapWikiMsg(
 621                                                 "<div class=\"mw-querypage-no-updates\">\n$1\n</div>",
 622                                                 'querypage-no-updates'
 623                                         );
 624                                 }
 625                         }
 626                 }
 627
 628                 $this->numRows = $res->numRows();
 629
 630                 $dbr = $this->getRecacheDB();
 631                 $this->preprocessResults( $dbr, $res );
 632
 633                 $out->addHTML( Xml::openElement( 'div', [ 'class' => 'mw-spcontent' ] ) );
 634
 635                 # Top header and navigation
 636                 if ( $this->shownavigation ) {
 637                         $out->addHTML( $this->getPageHeader() );
 638                         if ( $this->numRows > 0 ) {
 639                                 $out->addHTML( $this->msg( 'showingresultsinrange' )->numParams(
 640                                         min( $this->numRows, $this->limit ), # do not show the one extra row, if exist
 641                                         $this->offset + 1, ( min( $this->numRows, $this->limit ) + $this->offset ) )->parseAsBlock() );
 642                                 # Disable the "next" link when we reach the end
 643                                 $miserMaxResults = $this->getConfig()->get( 'MiserMode' )
 644                                         && ( $this->offset + $this->limit >= $this->getMaxResults() );
 645                                 $atEnd = ( $this->numRows <= $this->limit ) || $miserMaxResults;
 646                                 $paging = $this->buildPrevNextNavigation( $this->offset,
 647                                         $this->limit, $this->linkParameters(), $atEnd, $par );
 648                                 $out->addHTML( '<p>' . $paging . '</p>' );
 649                         } else {
 650                                 # No results to show, so don't bother with "showing X of Y" etc.
 651                                 # -- just let the user know and give up now
 652                                 $this->showEmptyText();
 653                                 $out->addHTML( Xml::closeElement( 'div' ) );
 654                                 return;
 655                         }
 656                 }
 657
 658                 # The actual results; specialist subclasses will want to handle this
 659                 # with more than a straight list, so we hand them the info, plus
 660                 # an OutputPage, and let them get on with it
 661                 $this->outputResults( $out,
 662                         $this->getSkin(),
 663                         $dbr, # Should use a ResultWrapper for this
 664                         $res,
 665                         min( $this->numRows, $this->limit ), # do not format the one extra row, if exist
 666                         $this->offset );
 667
 668                 # Repeat the paging links at the bottom
 669                 if ( $this->shownavigation ) {
 670                         $out->addHTML( '<p>' . $paging . '</p>' );
 671                 }
 672
 673                 $out->addHTML( Xml::closeElement( 'div' ) );
 674         }
 675
 676         /**
 677          * Format and output report results using the given information plus
 678          * OutputPage
 679          *
 680          * @param OutputPage $out OutputPage to print to
 681          * @param Skin $skin User skin to use
 682          * @param IDatabase $dbr Database (read) connection to use
 683          * @param IResultWrapper $res Result pointer
 684          * @param int $num Number of available result rows
 685          * @param int $offset Paging offset
 686          */
 687         protected function outputResults( $out, $skin, $dbr, $res, $num, $offset ) {
 688                 if ( $num > 0 ) {
 689                         $html = [];
 690                         if ( !$this->listoutput ) {
 691                                 $html[] = $this->openList( $offset );
 692                         }
 693
 694                         # $res might contain the whole 1,000 rows, so we read up to
 695                         # $num [should update this to use a Pager]
 696                         for ( $i = 0; $i < $num && $row = $res->fetchObject(); $i++ ) {
 697                                 $line = $this->formatResult( $skin, $row );
 698                                 if ( $line ) {
 699                                         $html[] = $this->listoutput
 700                                                 ? $line
 701                                                 : "<li>{$line}</li>\n";
 702                                 }
 703                         }
 704
 705                         if ( !$this->listoutput ) {
 706                                 $html[] = $this->closeList();
 707                         }
 708
 709                         $html = $this->listoutput
 710                                 ? MediaWikiServices::getInstance()->getContentLanguage()->listToText( $html )
 711                                 : implode( '', $html );
 712
 713                         $out->addHTML( $html );
 714                 }
 715         }
 716
 717         /**
 718          * @param int $offset
 719          * @return string
 720          */
 721         function openList( $offset ) {
 722                 return "\n<ol start='" . ( $offset + 1 ) . "' class='special'>\n";
 723         }
 724
 725         /**
 726          * @return string
 727          */
 728         function closeList() {
 729                 return "</ol>\n";
 730         }
 731
 732         /**
 733          * Do any necessary preprocessing of the result object.
 734          * @param IDatabase $db
 735          * @param IResultWrapper $res
 736          */
 737         function preprocessResults( $db, $res ) {
 738         }
 739
 740         /**
 741          * Creates a new LinkBatch object, adds all pages from the passed ResultWrapper (MUST include
 742          * title and optional the namespace field) and executes the batch. This operation will pre-cache
 743          * LinkCache information like page existence and information for stub color and redirect hints.
 744          *
 745          * @param IResultWrapper $res The ResultWrapper object to process. Needs to include the title
 746          *  field and namespace field, if the $ns parameter isn't set.
 747          * @param null $ns Use this namespace for the given titles in the ResultWrapper object,
 748          *  instead of the namespace value of $res.
 749          */
 750         protected function executeLBFromResultWrapper( IResultWrapper $res, $ns = null ) {
 751                 if ( !$res->numRows() ) {
 752                         return;
 753                 }
 754
 755                 $batch = new LinkBatch;
 756                 foreach ( $res as $row ) {
 757                         $batch->add( $ns ?? $row->namespace, $row->title );
 758                 }
 759                 $batch->execute();
 760
 761                 $res->seek( 0 );
 762         }
 763 }