includes/api/ApiPageSet.php

   1 <?php
   2 /**
   3  *
   4  *
   5  * Created on Sep 24, 2006
   6  *
   7  * Copyright © 2006, 2013 Yuri Astrakhan "<Firstname><Lastname>@gmail.com"
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License along
  20  * with this program; if not, write to the Free Software Foundation, Inc.,
  21  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  22  * http://www.gnu.org/copyleft/gpl.html
  23  *
  24  * @file
  25  */
  26 use MediaWiki\MediaWikiServices;
  27 use Wikimedia\Rdbms\ResultWrapper;
  28
  29 /**
  30  * This class contains a list of pages that the client has requested.
  31  * Initially, when the client passes in titles=, pageids=, or revisions=
  32  * parameter, an instance of the ApiPageSet class will normalize titles,
  33  * determine if the pages/revisions exist, and prefetch any additional page
  34  * data requested.
  35  *
  36  * When a generator is used, the result of the generator will become the input
  37  * for the second instance of this class, and all subsequent actions will use
  38  * the second instance for all their work.
  39  *
  40  * @ingroup API
  41  * @since 1.21 derives from ApiBase instead of ApiQueryBase
  42  */
  43 class ApiPageSet extends ApiBase {
  44         /**
  45          * Constructor flag: The new instance of ApiPageSet will ignore the 'generator=' parameter
  46          * @since 1.21
  47          */
  48         const DISABLE_GENERATORS = 1;
  49
  50         private $mDbSource;
  51         private $mParams;
  52         private $mResolveRedirects;
  53         private $mConvertTitles;
  54         private $mAllowGenerator;
  55
  56         private $mAllPages = []; // [ns][dbkey] => page_id or negative when missing
  57         private $mTitles = [];
  58         private $mGoodAndMissingPages = []; // [ns][dbkey] => page_id or negative when missing
  59         private $mGoodPages = []; // [ns][dbkey] => page_id
  60         private $mGoodTitles = [];
  61         private $mMissingPages = []; // [ns][dbkey] => fake page_id
  62         private $mMissingTitles = [];
  63         /** @var array [fake_page_id] => [ 'title' => $title, 'invalidreason' => $reason ] */
  64         private $mInvalidTitles = [];
  65         private $mMissingPageIDs = [];
  66         private $mRedirectTitles = [];
  67         private $mSpecialTitles = [];
  68         private $mAllSpecials = []; // separate from mAllPages to avoid breaking getAllTitlesByNamespace()
  69         private $mNormalizedTitles = [];
  70         private $mInterwikiTitles = [];
  71         /** @var Title[] */
  72         private $mPendingRedirectIDs = [];
  73         private $mResolvedRedirectTitles = [];
  74         private $mConvertedTitles = [];
  75         private $mGoodRevIDs = [];
  76         private $mLiveRevIDs = [];
  77         private $mDeletedRevIDs = [];
  78         private $mMissingRevIDs = [];
  79         private $mGeneratorData = []; // [ns][dbkey] => data array
  80         private $mFakePageId = -1;
  81         private $mCacheMode = 'public';
  82         private $mRequestedPageFields = [];
  83         /** @var int */
  84         private $mDefaultNamespace = NS_MAIN;
  85         /** @var callable|null */
  86         private $mRedirectMergePolicy;
  87
  88         /**
  89          * Add all items from $values into the result
  90          * @param array $result Output
  91          * @param array $values Values to add
  92          * @param string[] $flags The names of boolean flags to mark this element
  93          * @param string $name If given, name of the value
  94          */
  95         private static function addValues( array &$result, $values, $flags = [], $name = null ) {
  96                 foreach ( $values as $val ) {
  97                         if ( $val instanceof Title ) {
  98                                 $v = [];
  99                                 ApiQueryBase::addTitleInfo( $v, $val );
 100                         } elseif ( $name !== null ) {
 101                                 $v = [ $name => $val ];
 102                         } else {
 103                                 $v = $val;
 104                         }
 105                         foreach ( $flags as $flag ) {
 106                                 $v[$flag] = true;
 107                         }
 108                         $result[] = $v;
 109                 }
 110         }
 111
 112         /**
 113          * @param ApiBase $dbSource Module implementing getDB().
 114          *        Allows PageSet to reuse existing db connection from the shared state like ApiQuery.
 115          * @param int $flags Zero or more flags like DISABLE_GENERATORS
 116          * @param int $defaultNamespace The namespace to use if none is specified by a prefix.
 117          * @since 1.21 accepts $flags instead of two boolean values
 118          */
 119         public function __construct( ApiBase $dbSource, $flags = 0, $defaultNamespace = NS_MAIN ) {
 120                 parent::__construct( $dbSource->getMain(), $dbSource->getModuleName() );
 121                 $this->mDbSource = $dbSource;
 122                 $this->mAllowGenerator = ( $flags & ApiPageSet::DISABLE_GENERATORS ) == 0;
 123                 $this->mDefaultNamespace = $defaultNamespace;
 124
 125                 $this->mParams = $this->extractRequestParams();
 126                 $this->mResolveRedirects = $this->mParams['redirects'];
 127                 $this->mConvertTitles = $this->mParams['converttitles'];
 128         }
 129
 130         /**
 131          * In case execute() is not called, call this method to mark all relevant parameters as used
 132          * This prevents unused parameters from being reported as warnings
 133          */
 134         public function executeDryRun() {
 135                 $this->executeInternal( true );
 136         }
 137
 138         /**
 139          * Populate the PageSet from the request parameters.
 140          */
 141         public function execute() {
 142                 $this->executeInternal( false );
 143         }
 144
 145         /**
 146          * Populate the PageSet from the request parameters.
 147          * @param bool $isDryRun If true, instantiates generator, but only to mark
 148          *    relevant parameters as used
 149          */
 150         private function executeInternal( $isDryRun ) {
 151                 $generatorName = $this->mAllowGenerator ? $this->mParams['generator'] : null;
 152                 if ( isset( $generatorName ) ) {
 153                         $dbSource = $this->mDbSource;
 154                         if ( !$dbSource instanceof ApiQuery ) {
 155                                 // If the parent container of this pageset is not ApiQuery, we must create it to run generator
 156                                 $dbSource = $this->getMain()->getModuleManager()->getModule( 'query' );
 157                         }
 158                         $generator = $dbSource->getModuleManager()->getModule( $generatorName, null, true );
 159                         if ( $generator === null ) {
 160                                 $this->dieWithError( [ 'apierror-badgenerator-unknown', $generatorName ], 'badgenerator' );
 161                         }
 162                         if ( !$generator instanceof ApiQueryGeneratorBase ) {
 163                                 $this->dieWithError( [ 'apierror-badgenerator-notgenerator', $generatorName ], 'badgenerator' );
 164                         }
 165                         // Create a temporary pageset to store generator's output,
 166                         // add any additional fields generator may need, and execute pageset to populate titles/pageids
 167                         $tmpPageSet = new ApiPageSet( $dbSource, ApiPageSet::DISABLE_GENERATORS );
 168                         $generator->setGeneratorMode( $tmpPageSet );
 169                         $this->mCacheMode = $generator->getCacheMode( $generator->extractRequestParams() );
 170
 171                         if ( !$isDryRun ) {
 172                                 $generator->requestExtraData( $tmpPageSet );
 173                         }
 174                         $tmpPageSet->executeInternal( $isDryRun );
 175
 176                         // populate this pageset with the generator output
 177                         if ( !$isDryRun ) {
 178                                 $generator->executeGenerator( $this );
 179
 180                                 // Avoid PHP 7.1 warning of passing $this by reference
 181                                 $apiModule = $this;
 182                                 Hooks::run( 'APIQueryGeneratorAfterExecute', [ &$generator, &$apiModule ] );
 183                         } else {
 184                                 // Prevent warnings from being reported on these parameters
 185                                 $main = $this->getMain();
 186                                 foreach ( $generator->extractRequestParams() as $paramName => $param ) {
 187                                         $main->markParamsUsed( $generator->encodeParamName( $paramName ) );
 188                                 }
 189                         }
 190
 191                         if ( !$isDryRun ) {
 192                                 $this->resolvePendingRedirects();
 193                         }
 194                 } else {
 195                         // Only one of the titles/pageids/revids is allowed at the same time
 196                         $dataSource = null;
 197                         if ( isset( $this->mParams['titles'] ) ) {
 198                                 $dataSource = 'titles';
 199                         }
 200                         if ( isset( $this->mParams['pageids'] ) ) {
 201                                 if ( isset( $dataSource ) ) {
 202                                         $this->dieWithError(
 203                                                 [
 204                                                         'apierror-invalidparammix-cannotusewith',
 205                                                         $this->encodeParamName( 'pageids' ),
 206                                                         $this->encodeParamName( $dataSource )
 207                                                 ],
 208                                                 'multisource'
 209                                         );
 210                                 }
 211                                 $dataSource = 'pageids';
 212                         }
 213                         if ( isset( $this->mParams['revids'] ) ) {
 214                                 if ( isset( $dataSource ) ) {
 215                                         $this->dieWithError(
 216                                                 [
 217                                                         'apierror-invalidparammix-cannotusewith',
 218                                                         $this->encodeParamName( 'revids' ),
 219                                                         $this->encodeParamName( $dataSource )
 220                                                 ],
 221                                                 'multisource'
 222                                         );
 223                                 }
 224                                 $dataSource = 'revids';
 225                         }
 226
 227                         if ( !$isDryRun ) {
 228                                 // Populate page information with the original user input
 229                                 switch ( $dataSource ) {
 230                                         case 'titles':
 231                                                 $this->initFromTitles( $this->mParams['titles'] );
 232                                                 break;
 233                                         case 'pageids':
 234                                                 $this->initFromPageIds( $this->mParams['pageids'] );
 235                                                 break;
 236                                         case 'revids':
 237                                                 if ( $this->mResolveRedirects ) {
 238                                                         $this->addWarning( 'apiwarn-redirectsandrevids' );
 239                                                 }
 240                                                 $this->mResolveRedirects = false;
 241                                                 $this->initFromRevIDs( $this->mParams['revids'] );
 242                                                 break;
 243                                         default:
 244                                                 // Do nothing - some queries do not need any of the data sources.
 245                                                 break;
 246                                 }
 247                         }
 248                 }
 249         }
 250
 251         /**
 252          * Check whether this PageSet is resolving redirects
 253          * @return bool
 254          */
 255         public function isResolvingRedirects() {
 256                 return $this->mResolveRedirects;
 257         }
 258
 259         /**
 260          * Return the parameter name that is the source of data for this PageSet
 261          *
 262          * If multiple source parameters are specified (e.g. titles and pageids),
 263          * one will be named arbitrarily.
 264          *
 265          * @return string|null
 266          */
 267         public function getDataSource() {
 268                 if ( $this->mAllowGenerator && isset( $this->mParams['generator'] ) ) {
 269                         return 'generator';
 270                 }
 271                 if ( isset( $this->mParams['titles'] ) ) {
 272                         return 'titles';
 273                 }
 274                 if ( isset( $this->mParams['pageids'] ) ) {
 275                         return 'pageids';
 276                 }
 277                 if ( isset( $this->mParams['revids'] ) ) {
 278                         return 'revids';
 279                 }
 280
 281                 return null;
 282         }
 283
 284         /**
 285          * Request an additional field from the page table.
 286          * Must be called before execute()
 287          * @param string $fieldName Field name
 288          */
 289         public function requestField( $fieldName ) {
 290                 $this->mRequestedPageFields[$fieldName] = null;
 291         }
 292
 293         /**
 294          * Get the value of a custom field previously requested through
 295          * requestField()
 296          * @param string $fieldName Field name
 297          * @return mixed Field value
 298          */
 299         public function getCustomField( $fieldName ) {
 300                 return $this->mRequestedPageFields[$fieldName];
 301         }
 302
 303         /**
 304          * Get the fields that have to be queried from the page table:
 305          * the ones requested through requestField() and a few basic ones
 306          * we always need
 307          * @return array Array of field names
 308          */
 309         public function getPageTableFields() {
 310                 // Ensure we get minimum required fields
 311                 // DON'T change this order
 312                 $pageFlds = [
 313                         'page_namespace' => null,
 314                         'page_title' => null,
 315                         'page_id' => null,
 316                 ];
 317
 318                 if ( $this->mResolveRedirects ) {
 319                         $pageFlds['page_is_redirect'] = null;
 320                 }
 321
 322                 if ( $this->getConfig()->get( 'ContentHandlerUseDB' ) ) {
 323                         $pageFlds['page_content_model'] = null;
 324                 }
 325
 326                 if ( $this->getConfig()->get( 'PageLanguageUseDB' ) ) {
 327                         $pageFlds['page_lang'] = null;
 328                 }
 329
 330                 foreach ( LinkCache::getSelectFields() as $field ) {
 331                         $pageFlds[$field] = null;
 332                 }
 333
 334                 $pageFlds = array_merge( $pageFlds, $this->mRequestedPageFields );
 335
 336                 return array_keys( $pageFlds );
 337         }
 338
 339         /**
 340          * Returns an array [ns][dbkey] => page_id for all requested titles.
 341          * page_id is a unique negative number in case title was not found.
 342          * Invalid titles will also have negative page IDs and will be in namespace 0
 343          * @return array
 344          */
 345         public function getAllTitlesByNamespace() {
 346                 return $this->mAllPages;
 347         }
 348
 349         /**
 350          * All Title objects provided.
 351          * @return Title[]
 352          */
 353         public function getTitles() {
 354                 return $this->mTitles;
 355         }
 356
 357         /**
 358          * Returns the number of unique pages (not revisions) in the set.
 359          * @return int
 360          */
 361         public function getTitleCount() {
 362                 return count( $this->mTitles );
 363         }
 364
 365         /**
 366          * Returns an array [ns][dbkey] => page_id for all good titles.
 367          * @return array
 368          */
 369         public function getGoodTitlesByNamespace() {
 370                 return $this->mGoodPages;
 371         }
 372
 373         /**
 374          * Title objects that were found in the database.
 375          * @return Title[] Array page_id (int) => Title (obj)
 376          */
 377         public function getGoodTitles() {
 378                 return $this->mGoodTitles;
 379         }
 380
 381         /**
 382          * Returns the number of found unique pages (not revisions) in the set.
 383          * @return int
 384          */
 385         public function getGoodTitleCount() {
 386                 return count( $this->mGoodTitles );
 387         }
 388
 389         /**
 390          * Returns an array [ns][dbkey] => fake_page_id for all missing titles.
 391          * fake_page_id is a unique negative number.
 392          * @return array
 393          */
 394         public function getMissingTitlesByNamespace() {
 395                 return $this->mMissingPages;
 396         }
 397
 398         /**
 399          * Title objects that were NOT found in the database.
 400          * The array's index will be negative for each item
 401          * @return Title[]
 402          */
 403         public function getMissingTitles() {
 404                 return $this->mMissingTitles;
 405         }
 406
 407         /**
 408          * Returns an array [ns][dbkey] => page_id for all good and missing titles.
 409          * @return array
 410          */
 411         public function getGoodAndMissingTitlesByNamespace() {
 412                 return $this->mGoodAndMissingPages;
 413         }
 414
 415         /**
 416          * Title objects for good and missing titles.
 417          * @return array
 418          */
 419         public function getGoodAndMissingTitles() {
 420                 return $this->mGoodTitles + $this->mMissingTitles;
 421         }
 422
 423         /**
 424          * Titles that were deemed invalid by Title::newFromText()
 425          * The array's index will be unique and negative for each item
 426          * @deprecated since 1.26, use self::getInvalidTitlesAndReasons()
 427          * @return string[] Array of strings (not Title objects)
 428          */
 429         public function getInvalidTitles() {
 430                 wfDeprecated( __METHOD__, '1.26' );
 431                 return array_map( function ( $t ) {
 432                         return $t['title'];
 433                 }, $this->mInvalidTitles );
 434         }
 435
 436         /**
 437          * Titles that were deemed invalid by Title::newFromText()
 438          * The array's index will be unique and negative for each item
 439          * @return array[] Array of arrays with 'title' and 'invalidreason' properties
 440          */
 441         public function getInvalidTitlesAndReasons() {
 442                 return $this->mInvalidTitles;
 443         }
 444
 445         /**
 446          * Page IDs that were not found in the database
 447          * @return array Array of page IDs
 448          */
 449         public function getMissingPageIDs() {
 450                 return $this->mMissingPageIDs;
 451         }
 452
 453         /**
 454          * Get a list of redirect resolutions - maps a title to its redirect
 455          * target, as an array of output-ready arrays
 456          * @return Title[]
 457          */
 458         public function getRedirectTitles() {
 459                 return $this->mRedirectTitles;
 460         }
 461
 462         /**
 463          * Get a list of redirect resolutions - maps a title to its redirect
 464          * target. Includes generator data for redirect source when available.
 465          * @param ApiResult $result
 466          * @return array Array of prefixed_title (string) => Title object
 467          * @since 1.21
 468          */
 469         public function getRedirectTitlesAsResult( $result = null ) {
 470                 $values = [];
 471                 foreach ( $this->getRedirectTitles() as $titleStrFrom => $titleTo ) {
 472                         $r = [
 473                                 'from' => strval( $titleStrFrom ),
 474                                 'to' => $titleTo->getPrefixedText(),
 475                         ];
 476                         if ( $titleTo->hasFragment() ) {
 477                                 $r['tofragment'] = $titleTo->getFragment();
 478                         }
 479                         if ( $titleTo->isExternal() ) {
 480                                 $r['tointerwiki'] = $titleTo->getInterwiki();
 481                         }
 482                         if ( isset( $this->mResolvedRedirectTitles[$titleStrFrom] ) ) {
 483                                 $titleFrom = $this->mResolvedRedirectTitles[$titleStrFrom];
 484                                 $ns = $titleFrom->getNamespace();
 485                                 $dbkey = $titleFrom->getDBkey();
 486                                 if ( isset( $this->mGeneratorData[$ns][$dbkey] ) ) {
 487                                         $r = array_merge( $this->mGeneratorData[$ns][$dbkey], $r );
 488                                 }
 489                         }
 490
 491                         $values[] = $r;
 492                 }
 493                 if ( !empty( $values ) && $result ) {
 494                         ApiResult::setIndexedTagName( $values, 'r' );
 495                 }
 496
 497                 return $values;
 498         }
 499
 500         /**
 501          * Get a list of title normalizations - maps a title to its normalized
 502          * version.
 503          * @return array Array of raw_prefixed_title (string) => prefixed_title (string)
 504          */
 505         public function getNormalizedTitles() {
 506                 return $this->mNormalizedTitles;
 507         }
 508
 509         /**
 510          * Get a list of title normalizations - maps a title to its normalized
 511          * version in the form of result array.
 512          * @param ApiResult $result
 513          * @return array Array of raw_prefixed_title (string) => prefixed_title (string)
 514          * @since 1.21
 515          */
 516         public function getNormalizedTitlesAsResult( $result = null ) {
 517                 global $wgContLang;
 518
 519                 $values = [];
 520                 foreach ( $this->getNormalizedTitles() as $rawTitleStr => $titleStr ) {
 521                         $encode = ( $wgContLang->normalize( $rawTitleStr ) !== $rawTitleStr );
 522                         $values[] = [
 523                                 'fromencoded' => $encode,
 524                                 'from' => $encode ? rawurlencode( $rawTitleStr ) : $rawTitleStr,
 525                                 'to' => $titleStr
 526                         ];
 527                 }
 528                 if ( !empty( $values ) && $result ) {
 529                         ApiResult::setIndexedTagName( $values, 'n' );
 530                 }
 531
 532                 return $values;
 533         }
 534
 535         /**
 536          * Get a list of title conversions - maps a title to its converted
 537          * version.
 538          * @return array Array of raw_prefixed_title (string) => prefixed_title (string)
 539          */
 540         public function getConvertedTitles() {
 541                 return $this->mConvertedTitles;
 542         }
 543
 544         /**
 545          * Get a list of title conversions - maps a title to its converted
 546          * version as a result array.
 547          * @param ApiResult $result
 548          * @return array Array of (from, to) strings
 549          * @since 1.21
 550          */
 551         public function getConvertedTitlesAsResult( $result = null ) {
 552                 $values = [];
 553                 foreach ( $this->getConvertedTitles() as $rawTitleStr => $titleStr ) {
 554                         $values[] = [
 555                                 'from' => $rawTitleStr,
 556                                 'to' => $titleStr
 557                         ];
 558                 }
 559                 if ( !empty( $values ) && $result ) {
 560                         ApiResult::setIndexedTagName( $values, 'c' );
 561                 }
 562
 563                 return $values;
 564         }
 565
 566         /**
 567          * Get a list of interwiki titles - maps a title to its interwiki
 568          * prefix.
 569          * @return array Array of raw_prefixed_title (string) => interwiki_prefix (string)
 570          */
 571         public function getInterwikiTitles() {
 572                 return $this->mInterwikiTitles;
 573         }
 574
 575         /**
 576          * Get a list of interwiki titles - maps a title to its interwiki
 577          * prefix as result.
 578          * @param ApiResult $result
 579          * @param bool $iwUrl
 580          * @return array Array of raw_prefixed_title (string) => interwiki_prefix (string)
 581          * @since 1.21
 582          */
 583         public function getInterwikiTitlesAsResult( $result = null, $iwUrl = false ) {
 584                 $values = [];
 585                 foreach ( $this->getInterwikiTitles() as $rawTitleStr => $interwikiStr ) {
 586                         $item = [
 587                                 'title' => $rawTitleStr,
 588                                 'iw' => $interwikiStr,
 589                         ];
 590                         if ( $iwUrl ) {
 591                                 $title = Title::newFromText( $rawTitleStr );
 592                                 $item['url'] = $title->getFullURL( '', false, PROTO_CURRENT );
 593                         }
 594                         $values[] = $item;
 595                 }
 596                 if ( !empty( $values ) && $result ) {
 597                         ApiResult::setIndexedTagName( $values, 'i' );
 598                 }
 599
 600                 return $values;
 601         }
 602
 603         /**
 604          * Get an array of invalid/special/missing titles.
 605          *
 606          * @param array $invalidChecks List of types of invalid titles to include.
 607          *   Recognized values are:
 608          *   - invalidTitles: Titles and reasons from $this->getInvalidTitlesAndReasons()
 609          *   - special: Titles from $this->getSpecialTitles()
 610          *   - missingIds: ids from $this->getMissingPageIDs()
 611          *   - missingRevIds: ids from $this->getMissingRevisionIDs()
 612          *   - missingTitles: Titles from $this->getMissingTitles()
 613          *   - interwikiTitles: Titles from $this->getInterwikiTitlesAsResult()
 614          * @return array Array suitable for inclusion in the response
 615          * @since 1.23
 616          */
 617         public function getInvalidTitlesAndRevisions( $invalidChecks = [ 'invalidTitles',
 618                 'special', 'missingIds', 'missingRevIds', 'missingTitles', 'interwikiTitles' ]
 619         ) {
 620                 $result = [];
 621                 if ( in_array( 'invalidTitles', $invalidChecks ) ) {
 622                         self::addValues( $result, $this->getInvalidTitlesAndReasons(), [ 'invalid' ] );
 623                 }
 624                 if ( in_array( 'special', $invalidChecks ) ) {
 625                         $known = [];
 626                         $unknown = [];
 627                         foreach ( $this->getSpecialTitles() as $title ) {
 628                                 if ( $title->isKnown() ) {
 629                                         $known[] = $title;
 630                                 } else {
 631                                         $unknown[] = $title;
 632                                 }
 633                         }
 634                         self::addValues( $result, $unknown, [ 'special', 'missing' ] );
 635                         self::addValues( $result, $known, [ 'special' ] );
 636                 }
 637                 if ( in_array( 'missingIds', $invalidChecks ) ) {
 638                         self::addValues( $result, $this->getMissingPageIDs(), [ 'missing' ], 'pageid' );
 639                 }
 640                 if ( in_array( 'missingRevIds', $invalidChecks ) ) {
 641                         self::addValues( $result, $this->getMissingRevisionIDs(), [ 'missing' ], 'revid' );
 642                 }
 643                 if ( in_array( 'missingTitles', $invalidChecks ) ) {
 644                         $known = [];
 645                         $unknown = [];
 646                         foreach ( $this->getMissingTitles() as $title ) {
 647                                 if ( $title->isKnown() ) {
 648                                         $known[] = $title;
 649                                 } else {
 650                                         $unknown[] = $title;
 651                                 }
 652                         }
 653                         self::addValues( $result, $unknown, [ 'missing' ] );
 654                         self::addValues( $result, $known, [ 'missing', 'known' ] );
 655                 }
 656                 if ( in_array( 'interwikiTitles', $invalidChecks ) ) {
 657                         self::addValues( $result, $this->getInterwikiTitlesAsResult() );
 658                 }
 659
 660                 return $result;
 661         }
 662
 663         /**
 664          * Get the list of valid revision IDs (requested with the revids= parameter)
 665          * @return array Array of revID (int) => pageID (int)
 666          */
 667         public function getRevisionIDs() {
 668                 return $this->mGoodRevIDs;
 669         }
 670
 671         /**
 672          * Get the list of non-deleted revision IDs (requested with the revids= parameter)
 673          * @return array Array of revID (int) => pageID (int)
 674          */
 675         public function getLiveRevisionIDs() {
 676                 return $this->mLiveRevIDs;
 677         }
 678
 679         /**
 680          * Get the list of revision IDs that were associated with deleted titles.
 681          * @return array Array of revID (int) => pageID (int)
 682          */
 683         public function getDeletedRevisionIDs() {
 684                 return $this->mDeletedRevIDs;
 685         }
 686
 687         /**
 688          * Revision IDs that were not found in the database
 689          * @return array Array of revision IDs
 690          */
 691         public function getMissingRevisionIDs() {
 692                 return $this->mMissingRevIDs;
 693         }
 694
 695         /**
 696          * Revision IDs that were not found in the database as result array.
 697          * @param ApiResult $result
 698          * @return array Array of revision IDs
 699          * @since 1.21
 700          */
 701         public function getMissingRevisionIDsAsResult( $result = null ) {
 702                 $values = [];
 703                 foreach ( $this->getMissingRevisionIDs() as $revid ) {
 704                         $values[$revid] = [
 705                                 'revid' => $revid
 706                         ];
 707                 }
 708                 if ( !empty( $values ) && $result ) {
 709                         ApiResult::setIndexedTagName( $values, 'rev' );
 710                 }
 711
 712                 return $values;
 713         }
 714
 715         /**
 716          * Get the list of titles with negative namespace
 717          * @return Title[]
 718          */
 719         public function getSpecialTitles() {
 720                 return $this->mSpecialTitles;
 721         }
 722
 723         /**
 724          * Returns the number of revisions (requested with revids= parameter).
 725          * @return int Number of revisions.
 726          */
 727         public function getRevisionCount() {
 728                 return count( $this->getRevisionIDs() );
 729         }
 730
 731         /**
 732          * Populate this PageSet from a list of Titles
 733          * @param array $titles Array of Title objects
 734          */
 735         public function populateFromTitles( $titles ) {
 736                 $this->initFromTitles( $titles );
 737         }
 738
 739         /**
 740          * Populate this PageSet from a list of page IDs
 741          * @param array $pageIDs Array of page IDs
 742          */
 743         public function populateFromPageIDs( $pageIDs ) {
 744                 $this->initFromPageIds( $pageIDs );
 745         }
 746
 747         /**
 748          * Populate this PageSet from a rowset returned from the database
 749          *
 750          * Note that the query result must include the columns returned by
 751          * $this->getPageTableFields().
 752          *
 753          * @param IDatabase $db
 754          * @param ResultWrapper $queryResult Query result object
 755          */
 756         public function populateFromQueryResult( $db, $queryResult ) {
 757                 $this->initFromQueryResult( $queryResult );
 758         }
 759
 760         /**
 761          * Populate this PageSet from a list of revision IDs
 762          * @param array $revIDs Array of revision IDs
 763          */
 764         public function populateFromRevisionIDs( $revIDs ) {
 765                 $this->initFromRevIDs( $revIDs );
 766         }
 767
 768         /**
 769          * Extract all requested fields from the row received from the database
 770          * @param stdClass $row Result row
 771          */
 772         public function processDbRow( $row ) {
 773                 // Store Title object in various data structures
 774                 $title = Title::newFromRow( $row );
 775
 776                 LinkCache::singleton()->addGoodLinkObjFromRow( $title, $row );
 777
 778                 $pageId = intval( $row->page_id );
 779                 $this->mAllPages[$row->page_namespace][$row->page_title] = $pageId;
 780                 $this->mTitles[] = $title;
 781
 782                 if ( $this->mResolveRedirects && $row->page_is_redirect == '1' ) {
 783                         $this->mPendingRedirectIDs[$pageId] = $title;
 784                 } else {
 785                         $this->mGoodPages[$row->page_namespace][$row->page_title] = $pageId;
 786                         $this->mGoodAndMissingPages[$row->page_namespace][$row->page_title] = $pageId;
 787                         $this->mGoodTitles[$pageId] = $title;
 788                 }
 789
 790                 foreach ( $this->mRequestedPageFields as $fieldName => &$fieldValues ) {
 791                         $fieldValues[$pageId] = $row->$fieldName;
 792                 }
 793         }
 794
 795         /**
 796          * This method populates internal variables with page information
 797          * based on the given array of title strings.
 798          *
 799          * Steps:
 800          * #1 For each title, get data from `page` table
 801          * #2 If page was not found in the DB, store it as missing
 802          *
 803          * Additionally, when resolving redirects:
 804          * #3 If no more redirects left, stop.
 805          * #4 For each redirect, get its target from the `redirect` table.
 806          * #5 Substitute the original LinkBatch object with the new list
 807          * #6 Repeat from step #1
 808          *
 809          * @param array $titles Array of Title objects or strings
 810          */
 811         private function initFromTitles( $titles ) {
 812                 // Get validated and normalized title objects
 813                 $linkBatch = $this->processTitlesArray( $titles );
 814                 if ( $linkBatch->isEmpty() ) {
 815                         return;
 816                 }
 817
 818                 $db = $this->getDB();
 819                 $set = $linkBatch->constructSet( 'page', $db );
 820
 821                 // Get pageIDs data from the `page` table
 822                 $res = $db->select( 'page', $this->getPageTableFields(), $set,
 823                         __METHOD__ );
 824
 825                 // Hack: get the ns:titles stored in [ ns => [ titles ] ] format
 826                 $this->initFromQueryResult( $res, $linkBatch->data, true ); // process Titles
 827
 828                 // Resolve any found redirects
 829                 $this->resolvePendingRedirects();
 830         }
 831
 832         /**
 833          * Does the same as initFromTitles(), but is based on page IDs instead
 834          * @param array $pageids Array of page IDs
 835          */
 836         private function initFromPageIds( $pageids ) {
 837                 if ( !$pageids ) {
 838                         return;
 839                 }
 840
 841                 $pageids = array_map( 'intval', $pageids ); // paranoia
 842                 $remaining = array_flip( $pageids );
 843
 844                 $pageids = self::getPositiveIntegers( $pageids );
 845
 846                 $res = null;
 847                 if ( !empty( $pageids ) ) {
 848                         $set = [
 849                                 'page_id' => $pageids
 850                         ];
 851                         $db = $this->getDB();
 852
 853                         // Get pageIDs data from the `page` table
 854                         $res = $db->select( 'page', $this->getPageTableFields(), $set,
 855                                 __METHOD__ );
 856                 }
 857
 858                 $this->initFromQueryResult( $res, $remaining, false ); // process PageIDs
 859
 860                 // Resolve any found redirects
 861                 $this->resolvePendingRedirects();
 862         }
 863
 864         /**
 865          * Iterate through the result of the query on 'page' table,
 866          * and for each row create and store title object and save any extra fields requested.
 867          * @param ResultWrapper $res DB Query result
 868          * @param array $remaining Array of either pageID or ns/title elements (optional).
 869          *        If given, any missing items will go to $mMissingPageIDs and $mMissingTitles
 870          * @param bool $processTitles Must be provided together with $remaining.
 871          *        If true, treat $remaining as an array of [ns][title]
 872          *        If false, treat it as an array of [pageIDs]
 873          */
 874         private function initFromQueryResult( $res, &$remaining = null, $processTitles = null ) {
 875                 if ( !is_null( $remaining ) && is_null( $processTitles ) ) {
 876                         ApiBase::dieDebug( __METHOD__, 'Missing $processTitles parameter when $remaining is provided' );
 877                 }
 878
 879                 $usernames = [];
 880                 if ( $res ) {
 881                         foreach ( $res as $row ) {
 882                                 $pageId = intval( $row->page_id );
 883
 884                                 // Remove found page from the list of remaining items
 885                                 if ( isset( $remaining ) ) {
 886                                         if ( $processTitles ) {
 887                                                 unset( $remaining[$row->page_namespace][$row->page_title] );
 888                                         } else {
 889                                                 unset( $remaining[$pageId] );
 890                                         }
 891                                 }
 892
 893                                 // Store any extra fields requested by modules
 894                                 $this->processDbRow( $row );
 895
 896                                 // Need gender information
 897                                 if ( MWNamespace::hasGenderDistinction( $row->page_namespace ) ) {
 898                                         $usernames[] = $row->page_title;
 899                                 }
 900                         }
 901                 }
 902
 903                 if ( isset( $remaining ) ) {
 904                         // Any items left in the $remaining list are added as missing
 905                         if ( $processTitles ) {
 906                                 // The remaining titles in $remaining are non-existent pages
 907                                 $linkCache = LinkCache::singleton();
 908                                 foreach ( $remaining as $ns => $dbkeys ) {
 909                                         foreach ( array_keys( $dbkeys ) as $dbkey ) {
 910                                                 $title = Title::makeTitle( $ns, $dbkey );
 911                                                 $linkCache->addBadLinkObj( $title );
 912                                                 $this->mAllPages[$ns][$dbkey] = $this->mFakePageId;
 913                                                 $this->mMissingPages[$ns][$dbkey] = $this->mFakePageId;
 914                                                 $this->mGoodAndMissingPages[$ns][$dbkey] = $this->mFakePageId;
 915                                                 $this->mMissingTitles[$this->mFakePageId] = $title;
 916                                                 $this->mFakePageId--;
 917                                                 $this->mTitles[] = $title;
 918
 919                                                 // need gender information
 920                                                 if ( MWNamespace::hasGenderDistinction( $ns ) ) {
 921                                                         $usernames[] = $dbkey;
 922                                                 }
 923                                         }
 924                                 }
 925                         } else {
 926                                 // The remaining pageids do not exist
 927                                 if ( !$this->mMissingPageIDs ) {
 928                                         $this->mMissingPageIDs = array_keys( $remaining );
 929                                 } else {
 930                                         $this->mMissingPageIDs = array_merge( $this->mMissingPageIDs, array_keys( $remaining ) );
 931                                 }
 932                         }
 933                 }
 934
 935                 // Get gender information
 936                 $genderCache = MediaWikiServices::getInstance()->getGenderCache();
 937                 $genderCache->doQuery( $usernames, __METHOD__ );
 938         }
 939
 940         /**
 941          * Does the same as initFromTitles(), but is based on revision IDs
 942          * instead
 943          * @param array $revids Array of revision IDs
 944          */
 945         private function initFromRevIDs( $revids ) {
 946                 if ( !$revids ) {
 947                         return;
 948                 }
 949
 950                 $revids = array_map( 'intval', $revids ); // paranoia
 951                 $db = $this->getDB();
 952                 $pageids = [];
 953                 $remaining = array_flip( $revids );
 954
 955                 $revids = self::getPositiveIntegers( $revids );
 956
 957                 if ( !empty( $revids ) ) {
 958                         $tables = [ 'revision', 'page' ];
 959                         $fields = [ 'rev_id', 'rev_page' ];
 960                         $where = [ 'rev_id' => $revids, 'rev_page = page_id' ];
 961
 962                         // Get pageIDs data from the `page` table
 963                         $res = $db->select( $tables, $fields, $where, __METHOD__ );
 964                         foreach ( $res as $row ) {
 965                                 $revid = intval( $row->rev_id );
 966                                 $pageid = intval( $row->rev_page );
 967                                 $this->mGoodRevIDs[$revid] = $pageid;
 968                                 $this->mLiveRevIDs[$revid] = $pageid;
 969                                 $pageids[$pageid] = '';
 970                                 unset( $remaining[$revid] );
 971                         }
 972                 }
 973
 974                 $this->mMissingRevIDs = array_keys( $remaining );
 975
 976                 // Populate all the page information
 977                 $this->initFromPageIds( array_keys( $pageids ) );
 978
 979                 // If the user can see deleted revisions, pull out the corresponding
 980                 // titles from the archive table and include them too. We ignore
 981                 // ar_page_id because deleted revisions are tied by title, not page_id.
 982                 if ( !empty( $this->mMissingRevIDs ) && $this->getUser()->isAllowed( 'deletedhistory' ) ) {
 983                         $remaining = array_flip( $this->mMissingRevIDs );
 984                         $tables = [ 'archive' ];
 985                         $fields = [ 'ar_rev_id', 'ar_namespace', 'ar_title' ];
 986                         $where = [ 'ar_rev_id' => $this->mMissingRevIDs ];
 987
 988                         $res = $db->select( $tables, $fields, $where, __METHOD__ );
 989                         $titles = [];
 990                         foreach ( $res as $row ) {
 991                                 $revid = intval( $row->ar_rev_id );
 992                                 $titles[$revid] = Title::makeTitle( $row->ar_namespace, $row->ar_title );
 993                                 unset( $remaining[$revid] );
 994                         }
 995
 996                         $this->initFromTitles( $titles );
 997
 998                         foreach ( $titles as $revid => $title ) {
 999                                 $ns = $title->getNamespace();
1000                                 $dbkey = $title->getDBkey();
1001
1002                                 // Handle converted titles
1003                                 if ( !isset( $this->mAllPages[$ns][$dbkey] ) &&
1004                                         isset( $this->mConvertedTitles[$title->getPrefixedText()] )
1005                                 ) {
1006                                         $title = Title::newFromText( $this->mConvertedTitles[$title->getPrefixedText()] );
1007                                         $ns = $title->getNamespace();
1008                                         $dbkey = $title->getDBkey();
1009                                 }
1010
1011                                 if ( isset( $this->mAllPages[$ns][$dbkey] ) ) {
1012                                         $this->mGoodRevIDs[$revid] = $this->mAllPages[$ns][$dbkey];
1013                                         $this->mDeletedRevIDs[$revid] = $this->mAllPages[$ns][$dbkey];
1014                                 } else {
1015                                         $remaining[$revid] = true;
1016                                 }
1017                         }
1018
1019                         $this->mMissingRevIDs = array_keys( $remaining );
1020                 }
1021         }
1022
1023         /**
1024          * Resolve any redirects in the result if redirect resolution was
1025          * requested. This function is called repeatedly until all redirects
1026          * have been resolved.
1027          */
1028         private function resolvePendingRedirects() {
1029                 if ( $this->mResolveRedirects ) {
1030                         $db = $this->getDB();
1031                         $pageFlds = $this->getPageTableFields();
1032
1033                         // Repeat until all redirects have been resolved
1034                         // The infinite loop is prevented by keeping all known pages in $this->mAllPages
1035                         while ( $this->mPendingRedirectIDs ) {
1036                                 // Resolve redirects by querying the pagelinks table, and repeat the process
1037                                 // Create a new linkBatch object for the next pass
1038                                 $linkBatch = $this->getRedirectTargets();
1039
1040                                 if ( $linkBatch->isEmpty() ) {
1041                                         break;
1042                                 }
1043
1044                                 $set = $linkBatch->constructSet( 'page', $db );
1045                                 if ( $set === false ) {
1046                                         break;
1047                                 }
1048
1049                                 // Get pageIDs data from the `page` table
1050                                 $res = $db->select( 'page', $pageFlds, $set, __METHOD__ );
1051
1052                                 // Hack: get the ns:titles stored in [ns => array(titles)] format
1053                                 $this->initFromQueryResult( $res, $linkBatch->data, true );
1054                         }
1055                 }
1056         }
1057
1058         /**
1059          * Get the targets of the pending redirects from the database
1060          *
1061          * Also creates entries in the redirect table for redirects that don't
1062          * have one.
1063          * @return LinkBatch
1064          */
1065         private function getRedirectTargets() {
1066                 $titlesToResolve = [];
1067                 $db = $this->getDB();
1068
1069                 $res = $db->select(
1070                         'redirect',
1071                         [
1072                                 'rd_from',
1073                                 'rd_namespace',
1074                                 'rd_fragment',
1075                                 'rd_interwiki',
1076                                 'rd_title'
1077                         ], [ 'rd_from' => array_keys( $this->mPendingRedirectIDs ) ],
1078                         __METHOD__
1079                 );
1080                 foreach ( $res as $row ) {
1081                         $rdfrom = intval( $row->rd_from );
1082                         $from = $this->mPendingRedirectIDs[$rdfrom]->getPrefixedText();
1083                         $to = Title::makeTitle(
1084                                 $row->rd_namespace,
1085                                 $row->rd_title,
1086                                 $row->rd_fragment,
1087                                 $row->rd_interwiki
1088                         );
1089                         $this->mResolvedRedirectTitles[$from] = $this->mPendingRedirectIDs[$rdfrom];
1090                         unset( $this->mPendingRedirectIDs[$rdfrom] );
1091                         if ( $to->isExternal() ) {
1092                                 $this->mInterwikiTitles[$to->getPrefixedText()] = $to->getInterwiki();
1093                         } elseif ( !isset( $this->mAllPages[$to->getNamespace()][$to->getDBkey()] ) ) {
1094                                 $titlesToResolve[] = $to;
1095                         }
1096                         $this->mRedirectTitles[$from] = $to;
1097                 }
1098
1099                 if ( $this->mPendingRedirectIDs ) {
1100                         // We found pages that aren't in the redirect table
1101                         // Add them
1102                         foreach ( $this->mPendingRedirectIDs as $id => $title ) {
1103                                 $page = WikiPage::factory( $title );
1104                                 $rt = $page->insertRedirect();
1105                                 if ( !$rt ) {
1106                                         // What the hell. Let's just ignore this
1107                                         continue;
1108                                 }
1109                                 if ( $rt->isExternal() ) {
1110                                         $this->mInterwikiTitles[$rt->getPrefixedText()] = $rt->getInterwiki();
1111                                 } elseif ( !isset( $this->mAllPages[$rt->getNamespace()][$rt->getDBkey()] ) ) {
1112                                         $titlesToResolve[] = $rt;
1113                                 }
1114                                 $from = $title->getPrefixedText();
1115                                 $this->mResolvedRedirectTitles[$from] = $title;
1116                                 $this->mRedirectTitles[$from] = $rt;
1117                                 unset( $this->mPendingRedirectIDs[$id] );
1118                         }
1119                 }
1120
1121                 return $this->processTitlesArray( $titlesToResolve );
1122         }
1123
1124         /**
1125          * Get the cache mode for the data generated by this module.
1126          * All PageSet users should take into account whether this returns a more-restrictive
1127          * cache mode than the using module itself. For possible return values and other
1128          * details about cache modes, see ApiMain::setCacheMode()
1129          *
1130          * Public caching will only be allowed if *all* the modules that supply
1131          * data for a given request return a cache mode of public.
1132          *
1133          * @param array|null $params
1134          * @return string
1135          * @since 1.21
1136          */
1137         public function getCacheMode( $params = null ) {
1138                 return $this->mCacheMode;
1139         }
1140
1141         /**
1142          * Given an array of title strings, convert them into Title objects.
1143          * Alternatively, an array of Title objects may be given.
1144          * This method validates access rights for the title,
1145          * and appends normalization values to the output.
1146          *
1147          * @param array $titles Array of Title objects or strings
1148          * @return LinkBatch
1149          */
1150         private function processTitlesArray( $titles ) {
1151                 $usernames = [];
1152                 $linkBatch = new LinkBatch();
1153
1154                 foreach ( $titles as $title ) {
1155                         if ( is_string( $title ) ) {
1156                                 try {
1157                                         $titleObj = Title::newFromTextThrow( $title, $this->mDefaultNamespace );
1158                                 } catch ( MalformedTitleException $ex ) {
1159                                         // Handle invalid titles gracefully
1160                                         if ( !isset( $this->mAllPages[0][$title] ) ) {
1161                                                 $this->mAllPages[0][$title] = $this->mFakePageId;
1162                                                 $this->mInvalidTitles[$this->mFakePageId] = [
1163                                                         'title' => $title,
1164                                                         'invalidreason' => $this->getErrorFormatter()->formatException( $ex, [ 'bc' => true ] ),
1165                                                 ];
1166                                                 $this->mFakePageId--;
1167                                         }
1168                                         continue; // There's nothing else we can do
1169                                 }
1170                         } else {
1171                                 $titleObj = $title;
1172                         }
1173                         $unconvertedTitle = $titleObj->getPrefixedText();
1174                         $titleWasConverted = false;
1175                         if ( $titleObj->isExternal() ) {
1176                                 // This title is an interwiki link.
1177                                 $this->mInterwikiTitles[$unconvertedTitle] = $titleObj->getInterwiki();
1178                         } else {
1179                                 // Variants checking
1180                                 global $wgContLang;
1181                                 if ( $this->mConvertTitles &&
1182                                         count( $wgContLang->getVariants() ) > 1 &&
1183                                         !$titleObj->exists()
1184                                 ) {
1185                                         // Language::findVariantLink will modify titleText and titleObj into
1186                                         // the canonical variant if possible
1187                                         $titleText = is_string( $title ) ? $title : $titleObj->getPrefixedText();
1188                                         $wgContLang->findVariantLink( $titleText, $titleObj );
1189                                         $titleWasConverted = $unconvertedTitle !== $titleObj->getPrefixedText();
1190                                 }
1191
1192                                 if ( $titleObj->getNamespace() < 0 ) {
1193                                         // Handle Special and Media pages
1194                                         $titleObj = $titleObj->fixSpecialName();
1195                                         $ns = $titleObj->getNamespace();
1196                                         $dbkey = $titleObj->getDBkey();
1197                                         if ( !isset( $this->mAllSpecials[$ns][$dbkey] ) ) {
1198                                                 $this->mAllSpecials[$ns][$dbkey] = $this->mFakePageId;
1199                                                 $this->mSpecialTitles[$this->mFakePageId] = $titleObj;
1200                                                 $this->mFakePageId--;
1201                                         }
1202                                 } else {
1203                                         // Regular page
1204                                         $linkBatch->addObj( $titleObj );
1205                                 }
1206                         }
1207
1208                         // Make sure we remember the original title that was
1209                         // given to us. This way the caller can correlate new
1210                         // titles with the originally requested when e.g. the
1211                         // namespace is localized or the capitalization is
1212                         // different
1213                         if ( $titleWasConverted ) {
1214                                 $this->mConvertedTitles[$unconvertedTitle] = $titleObj->getPrefixedText();
1215                                 // In this case the page can't be Special.
1216                                 if ( is_string( $title ) && $title !== $unconvertedTitle ) {
1217                                         $this->mNormalizedTitles[$title] = $unconvertedTitle;
1218                                 }
1219                         } elseif ( is_string( $title ) && $title !== $titleObj->getPrefixedText() ) {
1220                                 $this->mNormalizedTitles[$title] = $titleObj->getPrefixedText();
1221                         }
1222
1223                         // Need gender information
1224                         if ( MWNamespace::hasGenderDistinction( $titleObj->getNamespace() ) ) {
1225                                 $usernames[] = $titleObj->getText();
1226                         }
1227                 }
1228                 // Get gender information
1229                 $genderCache = MediaWikiServices::getInstance()->getGenderCache();
1230                 $genderCache->doQuery( $usernames, __METHOD__ );
1231
1232                 return $linkBatch;
1233         }
1234
1235         /**
1236          * Set data for a title.
1237          *
1238          * This data may be extracted into an ApiResult using
1239          * self::populateGeneratorData. This should generally be limited to
1240          * data that is likely to be particularly useful to end users rather than
1241          * just being a dump of everything returned in non-generator mode.
1242          *
1243          * Redirects here will *not* be followed, even if 'redirects' was
1244          * specified, since in the case of multiple redirects we can't know which
1245          * source's data to use on the target.
1246          *
1247          * @param Title $title
1248          * @param array $data
1249          */
1250         public function setGeneratorData( Title $title, array $data ) {
1251                 $ns = $title->getNamespace();
1252                 $dbkey = $title->getDBkey();
1253                 $this->mGeneratorData[$ns][$dbkey] = $data;
1254         }
1255
1256         /**
1257          * Controls how generator data about a redirect source is merged into
1258          * the generator data for the redirect target. When not set no data
1259          * is merged. Note that if multiple titles redirect to the same target
1260          * the order of operations is undefined.
1261          *
1262          * Example to include generated data from redirect in target, prefering
1263          * the data generated for the destination when there is a collision:
1264          * @code
1265          *   $pageSet->setRedirectMergePolicy( function( array $current, array $new ) {
1266          *       return $current + $new;
1267          *   } );
1268          * @endcode
1269          *
1270          * @param callable|null $callable Recieves two array arguments, first the
1271          *  generator data for the redirect target and second the generator data
1272          *  for the redirect source. Returns the resulting generator data to use
1273          *  for the redirect target.
1274          */
1275         public function setRedirectMergePolicy( $callable ) {
1276                 $this->mRedirectMergePolicy = $callable;
1277         }
1278
1279         /**
1280          * Populate the generator data for all titles in the result
1281          *
1282          * The page data may be inserted into an ApiResult object or into an
1283          * associative array. The $path parameter specifies the path within the
1284          * ApiResult or array to find the "pages" node.
1285          *
1286          * The "pages" node itself must be an associative array mapping the page ID
1287          * or fake page ID values returned by this pageset (see
1288          * self::getAllTitlesByNamespace() and self::getSpecialTitles()) to
1289          * associative arrays of page data. Each of those subarrays will have the
1290          * data from self::setGeneratorData() merged in.
1291          *
1292          * Data that was set by self::setGeneratorData() for pages not in the
1293          * "pages" node will be ignored.
1294          *
1295          * @param ApiResult|array &$result
1296          * @param array $path
1297          * @return bool Whether the data fit
1298          */
1299         public function populateGeneratorData( &$result, array $path = [] ) {
1300                 if ( $result instanceof ApiResult ) {
1301                         $data = $result->getResultData( $path );
1302                         if ( $data === null ) {
1303                                 return true;
1304                         }
1305                 } else {
1306                         $data = &$result;
1307                         foreach ( $path as $key ) {
1308                                 if ( !isset( $data[$key] ) ) {
1309                                         // Path isn't in $result, so nothing to add, so everything
1310                                         // "fits"
1311                                         return true;
1312                                 }
1313                                 $data = &$data[$key];
1314                         }
1315                 }
1316                 foreach ( $this->mGeneratorData as $ns => $dbkeys ) {
1317                         if ( $ns === -1 ) {
1318                                 $pages = [];
1319                                 foreach ( $this->mSpecialTitles as $id => $title ) {
1320                                         $pages[$title->getDBkey()] = $id;
1321                                 }
1322                         } else {
1323                                 if ( !isset( $this->mAllPages[$ns] ) ) {
1324                                         // No known titles in the whole namespace. Skip it.
1325                                         continue;
1326                                 }
1327                                 $pages = $this->mAllPages[$ns];
1328                         }
1329                         foreach ( $dbkeys as $dbkey => $genData ) {
1330                                 if ( !isset( $pages[$dbkey] ) ) {
1331                                         // Unknown title. Forget it.
1332                                         continue;
1333                                 }
1334                                 $pageId = $pages[$dbkey];
1335                                 if ( !isset( $data[$pageId] ) ) {
1336                                         // $pageId didn't make it into the result. Ignore it.
1337                                         continue;
1338                                 }
1339
1340                                 if ( $result instanceof ApiResult ) {
1341                                         $path2 = array_merge( $path, [ $pageId ] );
1342                                         foreach ( $genData as $key => $value ) {
1343                                                 if ( !$result->addValue( $path2, $key, $value ) ) {
1344                                                         return false;
1345                                                 }
1346                                         }
1347                                 } else {
1348                                         $data[$pageId] = array_merge( $data[$pageId], $genData );
1349                                 }
1350                         }
1351                 }
1352
1353                 // Merge data generated about redirect titles into the redirect destination
1354                 if ( $this->mRedirectMergePolicy ) {
1355                         foreach ( $this->mResolvedRedirectTitles as $titleFrom ) {
1356                                 $dest = $titleFrom;
1357                                 while ( isset( $this->mRedirectTitles[$dest->getPrefixedText()] ) ) {
1358                                         $dest = $this->mRedirectTitles[$dest->getPrefixedText()];
1359                                 }
1360                                 $fromNs = $titleFrom->getNamespace();
1361                                 $fromDBkey = $titleFrom->getDBkey();
1362                                 $toPageId = $dest->getArticleID();
1363                                 if ( isset( $data[$toPageId] ) &&
1364                                         isset( $this->mGeneratorData[$fromNs][$fromDBkey] )
1365                                 ) {
1366                                         // It is necesary to set both $data and add to $result, if an ApiResult,
1367                                         // to ensure multiple redirects to the same destination are all merged.
1368                                         $data[$toPageId] = call_user_func(
1369                                                 $this->mRedirectMergePolicy,
1370                                                 $data[$toPageId],
1371                                                 $this->mGeneratorData[$fromNs][$fromDBkey]
1372                                         );
1373                                         if ( $result instanceof ApiResult ) {
1374                                                 if ( !$result->addValue( $path, $toPageId, $data[$toPageId], ApiResult::OVERRIDE ) ) {
1375                                                         return false;
1376                                                 }
1377                                         }
1378                                 }
1379                         }
1380                 }
1381
1382                 return true;
1383         }
1384
1385         /**
1386          * Get the database connection (read-only)
1387          * @return Database
1388          */
1389         protected function getDB() {
1390                 return $this->mDbSource->getDB();
1391         }
1392
1393         /**
1394          * Returns the input array of integers with all values < 0 removed
1395          *
1396          * @param array $array
1397          * @return array
1398          */
1399         private static function getPositiveIntegers( $array ) {
1400                 // T27734 API: possible issue with revids validation
1401                 // It seems with a load of revision rows, MySQL gets upset
1402                 // Remove any < 0 integers, as they can't be valid
1403                 foreach ( $array as $i => $int ) {
1404                         if ( $int < 0 ) {
1405                                 unset( $array[$i] );
1406                         }
1407                 }
1408
1409                 return $array;
1410         }
1411
1412         public function getAllowedParams( $flags = 0 ) {
1413                 $result = [
1414                         'titles' => [
1415                                 ApiBase::PARAM_ISMULTI => true,
1416                                 ApiBase::PARAM_HELP_MSG => 'api-pageset-param-titles',
1417                         ],
1418                         'pageids' => [
1419                                 ApiBase::PARAM_TYPE => 'integer',
1420                                 ApiBase::PARAM_ISMULTI => true,
1421                                 ApiBase::PARAM_HELP_MSG => 'api-pageset-param-pageids',
1422                         ],
1423                         'revids' => [
1424                                 ApiBase::PARAM_TYPE => 'integer',
1425                                 ApiBase::PARAM_ISMULTI => true,
1426                                 ApiBase::PARAM_HELP_MSG => 'api-pageset-param-revids',
1427                         ],
1428                         'generator' => [
1429                                 ApiBase::PARAM_TYPE => null,
1430                                 ApiBase::PARAM_HELP_MSG => 'api-pageset-param-generator',
1431                                 ApiBase::PARAM_SUBMODULE_PARAM_PREFIX => 'g',
1432                         ],
1433                         'redirects' => [
1434                                 ApiBase::PARAM_DFLT => false,
1435                                 ApiBase::PARAM_HELP_MSG => $this->mAllowGenerator
1436                                         ? 'api-pageset-param-redirects-generator'
1437                                         : 'api-pageset-param-redirects-nogenerator',
1438                         ],
1439                         'converttitles' => [
1440                                 ApiBase::PARAM_DFLT => false,
1441                                 ApiBase::PARAM_HELP_MSG => [
1442                                         'api-pageset-param-converttitles',
1443                                         [ Message::listParam( LanguageConverter::$languagesWithVariants, 'text' ) ],
1444                                 ],
1445                         ],
1446                 ];
1447
1448                 if ( !$this->mAllowGenerator ) {
1449                         unset( $result['generator'] );
1450                 } elseif ( $flags & ApiBase::GET_VALUES_FOR_HELP ) {
1451                         $result['generator'][ApiBase::PARAM_TYPE] = 'submodule';
1452                         $result['generator'][ApiBase::PARAM_SUBMODULE_MAP] = $this->getGenerators();
1453                 }
1454
1455                 return $result;
1456         }
1457
1458         protected function handleParamNormalization( $paramName, $value, $rawValue ) {
1459                 parent::handleParamNormalization( $paramName, $value, $rawValue );
1460
1461                 if ( $paramName === 'titles' ) {
1462                         // For the 'titles' parameter, we want to split it like ApiBase would
1463                         // and add any changed titles to $this->mNormalizedTitles
1464                         $value = $this->explodeMultiValue( $value, self::LIMIT_SML2 + 1 );
1465                         $l = count( $value );
1466                         $rawValue = $this->explodeMultiValue( $rawValue, $l );
1467                         for ( $i = 0; $i < $l; $i++ ) {
1468                                 if ( $value[$i] !== $rawValue[$i] ) {
1469                                         $this->mNormalizedTitles[$rawValue[$i]] = $value[$i];
1470                                 }
1471                         }
1472                 }
1473         }
1474
1475         private static $generators = null;
1476
1477         /**
1478          * Get an array of all available generators
1479          * @return array
1480          */
1481         private function getGenerators() {
1482                 if ( self::$generators === null ) {
1483                         $query = $this->mDbSource;
1484                         if ( !( $query instanceof ApiQuery ) ) {
1485                                 // If the parent container of this pageset is not ApiQuery,
1486                                 // we must create it to get module manager
1487                                 $query = $this->getMain()->getModuleManager()->getModule( 'query' );
1488                         }
1489                         $gens = [];
1490                         $prefix = $query->getModulePath() . '+';
1491                         $mgr = $query->getModuleManager();
1492                         foreach ( $mgr->getNamesWithClasses() as $name => $class ) {
1493                                 if ( is_subclass_of( $class, 'ApiQueryGeneratorBase' ) ) {
1494                                         $gens[$name] = $prefix . $name;
1495                                 }
1496                         }
1497                         ksort( $gens );
1498                         self::$generators = $gens;
1499                 }
1500
1501                 return self::$generators;
1502         }
1503 }