X-Git-Url: https://scripts.mit.edu/gitweb/autoinstallsdev/mediawiki.git/blobdiff_plain/19e297c21b10b1b8a3acad5e73fc71dcb35db44a..6932310fd58ebef145fa01eb76edf7150284d8ea:/includes/api/ApiQuery.php

diff --git a/includes/api/ApiQuery.php b/includes/api/ApiQuery.php
index ec4da791..31bcc7a7 100644
--- a/includes/api/ApiQuery.php
+++ b/includes/api/ApiQuery.php
@@ -1,10 +1,10 @@
 <?php
 /**
- * API for MediaWiki 1.8+
+ *
  *
  * Created on Sep 7, 2006
  *
- * Copyright © 2006 Yuri Astrakhan <Firstname><Lastname>@gmail.com
+ * Copyright © 2006 Yuri Astrakhan "<Firstname><Lastname>@gmail.com"
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -24,10 +24,7 @@
  * @file
  */
 
-if ( !defined( 'MEDIAWIKI' ) ) {
-	// Eclipse helper - will be ignored in production
-	require_once( 'ApiBase.php' );
-}
+use Wikimedia\Rdbms\IDatabase;
 
 /**
  * This is the main query class. It behaves similar to ApiMain: based on the
@@ -42,105 +39,127 @@ if ( !defined( 'MEDIAWIKI' ) ) {
  */
 class ApiQuery extends ApiBase {
 
-	private $mPropModuleNames, $mListModuleNames, $mMetaModuleNames;
-	private $mPageSet;
-	private $params, $redirects, $convertTitles;
-
-	private $mQueryPropModules = array(
+	/**
+	 * List of Api Query prop modules
+	 * @var array
+	 */
+	private static $QueryPropModules = [
+		'categories' => 'ApiQueryCategories',
+		'categoryinfo' => 'ApiQueryCategoryInfo',
+		'contributors' => 'ApiQueryContributors',
+		'deletedrevisions' => 'ApiQueryDeletedRevisions',
+		'duplicatefiles' => 'ApiQueryDuplicateFiles',
+		'extlinks' => 'ApiQueryExternalLinks',
+		'fileusage' => 'ApiQueryBacklinksprop',
+		'images' => 'ApiQueryImages',
+		'imageinfo' => 'ApiQueryImageInfo',
 		'info' => 'ApiQueryInfo',
-		'revisions' => 'ApiQueryRevisions',
 		'links' => 'ApiQueryLinks',
+		'linkshere' => 'ApiQueryBacklinksprop',
 		'iwlinks' => 'ApiQueryIWLinks',
 		'langlinks' => 'ApiQueryLangLinks',
-		'images' => 'ApiQueryImages',
-		'imageinfo' => 'ApiQueryImageInfo',
+		'pageprops' => 'ApiQueryPageProps',
+		'redirects' => 'ApiQueryBacklinksprop',
+		'revisions' => 'ApiQueryRevisions',
 		'stashimageinfo' => 'ApiQueryStashImageInfo',
 		'templates' => 'ApiQueryLinks',
-		'categories' => 'ApiQueryCategories',
-		'extlinks' => 'ApiQueryExternalLinks',
-		'categoryinfo' => 'ApiQueryCategoryInfo',
-		'duplicatefiles' => 'ApiQueryDuplicateFiles',
-		'pageprops' => 'ApiQueryPageProps',
-	);
+		'transcludedin' => 'ApiQueryBacklinksprop',
+	];
 
-	private $mQueryListModules = array(
-		'allimages' => 'ApiQueryAllimages',
-		'allpages' => 'ApiQueryAllpages',
-		'alllinks' => 'ApiQueryAllLinks',
+	/**
+	 * List of Api Query list modules
+	 * @var array
+	 */
+	private static $QueryListModules = [
 		'allcategories' => 'ApiQueryAllCategories',
+		'alldeletedrevisions' => 'ApiQueryAllDeletedRevisions',
+		'allfileusages' => 'ApiQueryAllLinks',
+		'allimages' => 'ApiQueryAllImages',
+		'alllinks' => 'ApiQueryAllLinks',
+		'allpages' => 'ApiQueryAllPages',
+		'allredirects' => 'ApiQueryAllLinks',
+		'allrevisions' => 'ApiQueryAllRevisions',
+		'mystashedfiles' => 'ApiQueryMyStashedFiles',
+		'alltransclusions' => 'ApiQueryAllLinks',
 		'allusers' => 'ApiQueryAllUsers',
 		'backlinks' => 'ApiQueryBacklinks',
 		'blocks' => 'ApiQueryBlocks',
 		'categorymembers' => 'ApiQueryCategoryMembers',
 		'deletedrevs' => 'ApiQueryDeletedrevs',
 		'embeddedin' => 'ApiQueryBacklinks',
+		'exturlusage' => 'ApiQueryExtLinksUsage',
 		'filearchive' => 'ApiQueryFilearchive',
 		'imageusage' => 'ApiQueryBacklinks',
 		'iwbacklinks' => 'ApiQueryIWBacklinks',
+		'langbacklinks' => 'ApiQueryLangBacklinks',
 		'logevents' => 'ApiQueryLogEvents',
+		'pageswithprop' => 'ApiQueryPagesWithProp',
+		'pagepropnames' => 'ApiQueryPagePropNames',
+		'prefixsearch' => 'ApiQueryPrefixSearch',
+		'protectedtitles' => 'ApiQueryProtectedTitles',
+		'querypage' => 'ApiQueryQueryPage',
+		'random' => 'ApiQueryRandom',
 		'recentchanges' => 'ApiQueryRecentChanges',
 		'search' => 'ApiQuerySearch',
 		'tags' => 'ApiQueryTags',
 		'usercontribs' => 'ApiQueryContributions',
+		'users' => 'ApiQueryUsers',
 		'watchlist' => 'ApiQueryWatchlist',
 		'watchlistraw' => 'ApiQueryWatchlistRaw',
-		'exturlusage' => 'ApiQueryExtLinksUsage',
-		'users' => 'ApiQueryUsers',
-		'random' => 'ApiQueryRandom',
-		'protectedtitles' => 'ApiQueryProtectedTitles',
-	);
+	];
 
-	private $mQueryMetaModules = array(
+	/**
+	 * List of Api Query meta modules
+	 * @var array
+	 */
+	private static $QueryMetaModules = [
+		'allmessages' => 'ApiQueryAllMessages',
+		'authmanagerinfo' => 'ApiQueryAuthManagerInfo',
 		'siteinfo' => 'ApiQuerySiteinfo',
 		'userinfo' => 'ApiQueryUserInfo',
-		'allmessages' => 'ApiQueryAllmessages',
-	);
+		'filerepoinfo' => 'ApiQueryFileRepoInfo',
+		'tokens' => 'ApiQueryTokens',
+	];
 
-	private $mSlaveDB = null;
-	private $mNamedDB = array();
+	/**
+	 * @var ApiPageSet
+	 */
+	private $mPageSet;
 
-	public function __construct( $main, $action ) {
-		parent::__construct( $main, $action );
-
-		// Allow custom modules to be added in LocalSettings.php
-		global $wgAPIPropModules, $wgAPIListModules, $wgAPIMetaModules;
-		self::appendUserModules( $this->mQueryPropModules, $wgAPIPropModules );
-		self::appendUserModules( $this->mQueryListModules, $wgAPIListModules );
-		self::appendUserModules( $this->mQueryMetaModules, $wgAPIMetaModules );
-
-		$this->mPropModuleNames = array_keys( $this->mQueryPropModules );
-		$this->mListModuleNames = array_keys( $this->mQueryListModules );
-		$this->mMetaModuleNames = array_keys( $this->mQueryMetaModules );
-
-		// Allow the entire list of modules at first,
-		// but during module instantiation check if it can be used as a generator.
-		$this->mAllowedGenerators = array_merge( $this->mListModuleNames, $this->mPropModuleNames );
-	}
+	private $mParams;
+	private $mNamedDB = [];
+	private $mModuleMgr;
 
 	/**
-	 * Helper function to append any add-in modules to the list
-	 * @param $modules array Module array
-	 * @param $newModules array Module array to add to $modules
+	 * @param ApiMain $main
+	 * @param string $action
 	 */
-	private static function appendUserModules( &$modules, $newModules ) {
-		if ( is_array( $newModules ) ) {
-			foreach ( $newModules as $moduleName => $moduleClass ) {
-				$modules[$moduleName] = $moduleClass;
-			}
-		}
+	public function __construct( ApiMain $main, $action ) {
+		parent::__construct( $main, $action );
+
+		$this->mModuleMgr = new ApiModuleManager( $this );
+
+		// Allow custom modules to be added in LocalSettings.php
+		$config = $this->getConfig();
+		$this->mModuleMgr->addModules( self::$QueryPropModules, 'prop' );
+		$this->mModuleMgr->addModules( $config->get( 'APIPropModules' ), 'prop' );
+		$this->mModuleMgr->addModules( self::$QueryListModules, 'list' );
+		$this->mModuleMgr->addModules( $config->get( 'APIListModules' ), 'list' );
+		$this->mModuleMgr->addModules( self::$QueryMetaModules, 'meta' );
+		$this->mModuleMgr->addModules( $config->get( 'APIMetaModules' ), 'meta' );
+
+		Hooks::run( 'ApiQuery::moduleManager', [ $this->mModuleMgr ] );
+
+		// Create PageSet that will process titles/pageids/revids/generator
+		$this->mPageSet = new ApiPageSet( $this );
 	}
 
 	/**
-	 * Gets a default slave database connection object
-	 * @return Database
+	 * Overrides to return this instance's module manager.
+	 * @return ApiModuleManager
 	 */
-	public function getDB() {
-		if ( !isset( $this->mSlaveDB ) ) {
-			$this->profileDBIn();
-			$this->mSlaveDB = wfGetDB( DB_SLAVE, 'api' );
-			$this->profileDBOut();
-		}
-		return $this->mSlaveDB;
+	public function getModuleManager() {
+		return $this->mModuleMgr;
 	}
 
 	/**
@@ -148,17 +167,16 @@ class ApiQuery extends ApiBase {
 	 * If no such connection has been requested before, it will be created.
 	 * Subsequent calls with the same $name will return the same connection
 	 * as the first, regardless of the values of $db and $groups
-	 * @param $name string Name to assign to the database connection
-	 * @param $db int One of the DB_* constants
-	 * @param $groups array Query groups
-	 * @return Database
+	 * @param string $name Name to assign to the database connection
+	 * @param int $db One of the DB_* constants
+	 * @param string|string[] $groups Query groups
+	 * @return IDatabase
 	 */
 	public function getNamedDB( $name, $db, $groups ) {
 		if ( !array_key_exists( $name, $this->mNamedDB ) ) {
-			$this->profileDBIn();
 			$this->mNamedDB[$name] = wfGetDB( $db, $groups );
-			$this->profileDBOut();
 		}
+
 		return $this->mNamedDB[$name];
 	}
 
@@ -171,39 +189,13 @@ class ApiQuery extends ApiBase {
 	}
 
 	/**
-	 * Get the array mapping module names to class names
-	 * @return array(modulename => classname)
+	 * @return ApiFormatRaw|null
 	 */
-	function getModules() {
-		return array_merge( $this->mQueryPropModules, $this->mQueryListModules, $this->mQueryMetaModules );
-	}
-
-	/**
-	 * Get whether the specified module is a prop, list or a meta query module
-	 * @param $moduleName string Name of the module to find type for
-	 * @return mixed string or null
-	 */
-	function getModuleType( $moduleName ) {
-		if ( array_key_exists ( $moduleName, $this->mQueryPropModules ) ) {
-			return 'prop';
-		}
-
-		if ( array_key_exists ( $moduleName, $this->mQueryListModules ) ) {
-			return 'list';
-		}
-
-		if ( array_key_exists ( $moduleName, $this->mQueryMetaModules ) ) {
-			return 'meta';
-		}
-
-		return null;
-	}
-
 	public function getCustomPrinter() {
 		// If &exportnowrap is set, use the raw formatter
 		if ( $this->getParameter( 'export' ) &&
-				$this->getParameter( 'exportnowrap' ) )
-		{
+			$this->getParameter( 'exportnowrap' )
+		) {
 			return new ApiFormatRaw( $this->getMain(),
 				$this->getMain()->createPrinterByName( 'xml' ) );
 		} else {
@@ -222,56 +214,75 @@ class ApiQuery extends ApiBase {
 	 * #5 Execute all requested modules
 	 */
 	public function execute() {
-		$this->params = $this->extractRequestParams();
-		$this->redirects = $this->params['redirects'];
-		$this->convertTitles = $this->params['converttitles'];
-
-		// Create PageSet
-		$this->mPageSet = new ApiPageSet( $this, $this->redirects, $this->convertTitles );
+		$this->mParams = $this->extractRequestParams();
 
 		// Instantiate requested modules
-		$modules = array();
-		$this->instantiateModules( $modules, 'prop', $this->mQueryPropModules );
-		$this->instantiateModules( $modules, 'list', $this->mQueryListModules );
-		$this->instantiateModules( $modules, 'meta', $this->mQueryMetaModules );
-
-		$cacheMode = 'public';
-
-		// If given, execute generator to substitute user supplied data with generated data.
-		if ( isset( $this->params['generator'] ) ) {
-			$generator = $this->newGenerator( $this->params['generator'] );
-			$params = $generator->extractRequestParams();
-			$cacheMode = $this->mergeCacheMode( $cacheMode,
-				$generator->getCacheMode( $params ) );
-			$this->executeGeneratorModule( $generator, $modules );
-		} else {
-			// Append custom fields and populate page/revision information
-			$this->addCustomFldsToPageSet( $modules, $this->mPageSet );
+		$allModules = [];
+		$this->instantiateModules( $allModules, 'prop' );
+		$propModules = array_keys( $allModules );
+		$this->instantiateModules( $allModules, 'list' );
+		$this->instantiateModules( $allModules, 'meta' );
+
+		// Filter modules based on continue parameter
+		$continuationManager = new ApiContinuationManager( $this, $allModules, $propModules );
+		$this->setContinuationManager( $continuationManager );
+		$modules = $continuationManager->getRunModules();
+
+		if ( !$continuationManager->isGeneratorDone() ) {
+			// Query modules may optimize data requests through the $this->getPageSet()
+			// object by adding extra fields from the page table.
+			foreach ( $modules as $module ) {
+				$module->requestExtraData( $this->mPageSet );
+			}
+			// Populate page/revision information
 			$this->mPageSet->execute();
+			// Record page information (title, namespace, if exists, etc)
+			$this->outputGeneralPageInfo();
+		} else {
+			$this->mPageSet->executeDryRun();
 		}
 
-		// Record page information (title, namespace, if exists, etc)
-		$this->outputGeneralPageInfo();
+		$cacheMode = $this->mPageSet->getCacheMode();
 
-		// Execute all requested modules.
+		// Execute all unfinished modules
+		/** @var ApiQueryBase $module */
 		foreach ( $modules as $module ) {
 			$params = $module->extractRequestParams();
 			$cacheMode = $this->mergeCacheMode(
 				$cacheMode, $module->getCacheMode( $params ) );
-			$module->profileIn();
 			$module->execute();
-			wfRunHooks( 'APIQueryAfterExecute', array( &$module ) );
-			$module->profileOut();
+			Hooks::run( 'APIQueryAfterExecute', [ &$module ] );
 		}
 
 		// Set the cache mode
 		$this->getMain()->setCacheMode( $cacheMode );
+
+		// Write the continuation data into the result
+		$this->setContinuationManager( null );
+		if ( $this->mParams['rawcontinue'] ) {
+			$data = $continuationManager->getRawNonContinuation();
+			if ( $data ) {
+				$this->getResult()->addValue( null, 'query-noncontinue', $data,
+					ApiResult::ADD_ON_TOP | ApiResult::NO_SIZE_CHECK );
+			}
+			$data = $continuationManager->getRawContinuation();
+			if ( $data ) {
+				$this->getResult()->addValue( null, 'query-continue', $data,
+					ApiResult::ADD_ON_TOP | ApiResult::NO_SIZE_CHECK );
+			}
+		} else {
+			$continuationManager->setContinuationIntoResult( $this->getResult() );
+		}
 	}
 
 	/**
 	 * Update a cache mode string, applying the cache mode of a new module to it.
 	 * The cache mode may increase in the level of privacy, but public modules
 	 * added to private data do not decrease the level of privacy.
+	 *
+	 * @param string $cacheMode
+	 * @param string $modCacheMode
+	 * @return string
 	 */
 	protected function mergeCacheMode( $cacheMode, $modCacheMode ) {
 		if ( $modCacheMode === 'anon-public-user-private' ) {
@@ -283,34 +294,30 @@ class ApiQuery extends ApiBase {
 		} else { // private
 			$cacheMode = 'private';
 		}
-		return $cacheMode;
-	}
 
-	/**
-	 * Query modules may optimize data requests through the $this->getPageSet() object
-	 * by adding extra fields from the page table.
-	 * This function will gather all the extra request fields from the modules.
-	 * @param $modules array of module objects
-	 * @param $pageSet ApiPageSet
-	 */
-	private function addCustomFldsToPageSet( $modules, $pageSet ) {
-		// Query all requested modules.
-		foreach ( $modules as $module ) {
-			$module->requestExtraData( $pageSet );
-		}
+		return $cacheMode;
 	}
 
 	/**
 	 * Create instances of all modules requested by the client
-	 * @param $modules Array to append instantiated modules to
-	 * @param $param string Parameter name to read modules from
-	 * @param $moduleList Array array(modulename => classname)
+	 * @param array $modules To append instantiated modules to
+	 * @param string $param Parameter name to read modules from
 	 */
-	private function instantiateModules( &$modules, $param, $moduleList ) {
-		$list = @$this->params[$param];
-		if ( !is_null ( $list ) ) {
-			foreach ( $list as $moduleName ) {
-				$modules[] = new $moduleList[$moduleName] ( $this, $moduleName );
+	private function instantiateModules( &$modules, $param ) {
+		$wasPosted = $this->getRequest()->wasPosted();
+		if ( isset( $this->mParams[$param] ) ) {
+			foreach ( $this->mParams[$param] as $moduleName ) {
+				$instance = $this->mModuleMgr->getModule( $moduleName, $param );
+				if ( $instance === null ) {
+					ApiBase::dieDebug( __METHOD__, 'Error instantiating module' );
+				}
+				if ( !$wasPosted && $instance->mustBePosted() ) {
+					$this->dieWithErrorOrDebug( [ 'apierror-mustbeposted', $moduleName ] );
+				}
+				// Ignore duplicates. TODO 2.0: die()?
+				if ( !array_key_exists( $moduleName, $modules ) ) {
+					$modules[$moduleName] = $instance;
+				}
 			}
 		}
 	}
@@ -324,375 +331,218 @@ class ApiQuery extends ApiBase {
 		$pageSet = $this->getPageSet();
 		$result = $this->getResult();
 
-		// We don't check for a full result set here because we can't be adding
-		// more than 380K. The maximum revision size is in the megabyte range,
-		// and the maximum result size must be even higher than that.
-
-		// Title normalizations
-		$normValues = array();
-		foreach ( $pageSet->getNormalizedTitles() as $rawTitleStr => $titleStr ) {
-			$normValues[] = array(
-				'from' => $rawTitleStr,
-				'to' => $titleStr
-			);
-		}
-
-		if ( count( $normValues ) ) {
-			$result->setIndexedTagName( $normValues, 'n' );
-			$result->addValue( 'query', 'normalized', $normValues );
-		}
-
-		// Title conversions
-		$convValues = array();
-		foreach ( $pageSet->getConvertedTitles() as $rawTitleStr => $titleStr ) {
-			$convValues[] = array(
-				'from' => $rawTitleStr,
-				'to' => $titleStr
-			);
-		}
-
-		if ( count( $convValues ) ) {
-			$result->setIndexedTagName( $convValues, 'c' );
-			$result->addValue( 'query', 'converted', $convValues );
-		}
+		// We can't really handle max-result-size failure here, but we need to
+		// check anyway in case someone set the limit stupidly low.
+		$fit = true;
 
-		// Interwiki titles
-		$intrwValues = array();
-		foreach ( $pageSet->getInterwikiTitles() as $rawTitleStr => $interwikiStr ) {
-			$intrwValues[] = array(
-				'title' => $rawTitleStr,
-				'iw' => $interwikiStr
-			);
+		$values = $pageSet->getNormalizedTitlesAsResult( $result );
+		if ( $values ) {
+			$fit = $fit && $result->addValue( 'query', 'normalized', $values );
 		}
-
-		if ( count( $intrwValues ) ) {
-			$result->setIndexedTagName( $intrwValues, 'i' );
-			$result->addValue( 'query', 'interwiki', $intrwValues );
+		$values = $pageSet->getConvertedTitlesAsResult( $result );
+		if ( $values ) {
+			$fit = $fit && $result->addValue( 'query', 'converted', $values );
 		}
-
-		// Show redirect information
-		$redirValues = array();
-		foreach ( $pageSet->getRedirectTitles() as $titleStrFrom => $titleStrTo ) {
-			$redirValues[] = array(
-				'from' => strval( $titleStrFrom ),
-				'to' => $titleStrTo
-			);
+		$values = $pageSet->getInterwikiTitlesAsResult( $result, $this->mParams['iwurl'] );
+		if ( $values ) {
+			$fit = $fit && $result->addValue( 'query', 'interwiki', $values );
 		}
-
-		if ( count( $redirValues ) ) {
-			$result->setIndexedTagName( $redirValues, 'r' );
-			$result->addValue( 'query', 'redirects', $redirValues );
+		$values = $pageSet->getRedirectTitlesAsResult( $result );
+		if ( $values ) {
+			$fit = $fit && $result->addValue( 'query', 'redirects', $values );
 		}
-
-		// Missing revision elements
-		$missingRevIDs = $pageSet->getMissingRevisionIDs();
-		if ( count( $missingRevIDs ) ) {
-			$revids = array();
-			foreach ( $missingRevIDs as $revid ) {
-				$revids[$revid] = array(
-					'revid' => $revid
-				);
-			}
-			$result->setIndexedTagName( $revids, 'rev' );
-			$result->addValue( 'query', 'badrevids', $revids );
+		$values = $pageSet->getMissingRevisionIDsAsResult( $result );
+		if ( $values ) {
+			$fit = $fit && $result->addValue( 'query', 'badrevids', $values );
 		}
 
 		// Page elements
-		$pages = array();
+		$pages = [];
 
 		// Report any missing titles
 		foreach ( $pageSet->getMissingTitles() as $fakeId => $title ) {
-			$vals = array();
+			$vals = [];
 			ApiQueryBase::addTitleInfo( $vals, $title );
-			$vals['missing'] = '';
+			$vals['missing'] = true;
+			if ( $title->isKnown() ) {
+				$vals['known'] = true;
+			}
 			$pages[$fakeId] = $vals;
 		}
 		// Report any invalid titles
-		foreach ( $pageSet->getInvalidTitles() as $fakeId => $title ) {
-			$pages[$fakeId] = array( 'title' => $title, 'invalid' => '' );
+		foreach ( $pageSet->getInvalidTitlesAndReasons() as $fakeId => $data ) {
+			$pages[$fakeId] = $data + [ 'invalid' => true ];
 		}
 		// Report any missing page ids
 		foreach ( $pageSet->getMissingPageIDs() as $pageid ) {
-			$pages[$pageid] = array(
+			$pages[$pageid] = [
 				'pageid' => $pageid,
-				'missing' => ''
-			);
+				'missing' => true,
+			];
 		}
 		// Report special pages
+		/** @var Title $title */
 		foreach ( $pageSet->getSpecialTitles() as $fakeId => $title ) {
-			$vals = array();
+			$vals = [];
 			ApiQueryBase::addTitleInfo( $vals, $title );
-			$vals['special'] = '';
-			if ( $title->getNamespace() == NS_SPECIAL &&
-					!SpecialPage::exists( $title->getDbKey() ) ) {
-				$vals['missing'] = '';
-			} elseif ( $title->getNamespace() == NS_MEDIA &&
-					!wfFindFile( $title ) ) {
-				$vals['missing'] = '';
+			$vals['special'] = true;
+			if ( !$title->isKnown() ) {
+				$vals['missing'] = true;
 			}
 			$pages[$fakeId] = $vals;
 		}
 
 		// Output general page information for found titles
 		foreach ( $pageSet->getGoodTitles() as $pageid => $title ) {
-			$vals = array();
+			$vals = [];
 			$vals['pageid'] = $pageid;
 			ApiQueryBase::addTitleInfo( $vals, $title );
 			$pages[$pageid] = $vals;
 		}
 
 		if ( count( $pages ) ) {
-			if ( $this->params['indexpageids'] ) {
-				$pageIDs = array_keys( $pages );
+			$pageSet->populateGeneratorData( $pages );
+			ApiResult::setArrayType( $pages, 'BCarray' );
+
+			if ( $this->mParams['indexpageids'] ) {
+				$pageIDs = array_keys( ApiResult::stripMetadataNonRecursive( $pages ) );
 				// json treats all map keys as strings - converting to match
 				$pageIDs = array_map( 'strval', $pageIDs );
-				$result->setIndexedTagName( $pageIDs, 'id' );
-				$result->addValue( 'query', 'pageids', $pageIDs );
+				ApiResult::setIndexedTagName( $pageIDs, 'id' );
+				$fit = $fit && $result->addValue( 'query', 'pageids', $pageIDs );
 			}
 
-			$result->setIndexedTagName( $pages, 'page' );
-			$result->addValue( 'query', 'pages', $pages );
+			ApiResult::setIndexedTagName( $pages, 'page' );
+			$fit = $fit && $result->addValue( 'query', 'pages', $pages );
+		}
+
+		if ( !$fit ) {
+			$this->dieWithError( 'apierror-badconfig-resulttoosmall', 'badconfig' );
 		}
-		if ( $this->params['export'] ) {
+
+		if ( $this->mParams['export'] ) {
 			$this->doExport( $pageSet, $result );
 		}
 	}
 
 	/**
-	 * @param  $pageSet ApiPageSet Pages to be exported
-	 * @param  $result ApiResult Result to output to
+	 * @param ApiPageSet $pageSet Pages to be exported
+	 * @param ApiResult $result Result to output to
 	 */
-	private function doExport( $pageSet, $result )	{
-		$exportTitles = array();
+	private function doExport( $pageSet, $result ) {
+		$exportTitles = [];
 		$titles = $pageSet->getGoodTitles();
-		if( count( $titles ) ) {
+		if ( count( $titles ) ) {
+			$user = $this->getUser();
+			/** @var Title $title */
 			foreach ( $titles as $title ) {
-				if ( $title->userCanRead() ) {
+				if ( $title->userCan( 'read', $user ) ) {
 					$exportTitles[] = $title;
 				}
 			}
 		}
-		// only export when there are titles
-		if ( !count( $exportTitles ) ) {
-			return;
-		}
 
 		$exporter = new WikiExporter( $this->getDB() );
-		// WikiExporter writes to stdout, so catch its
-		// output with an ob
-		ob_start();
+		$sink = new DumpStringOutput;
+		$exporter->setOutputSink( $sink );
 		$exporter->openStream();
 		foreach ( $exportTitles as $title ) {
 			$exporter->pageByTitle( $title );
 		}
 		$exporter->closeStream();
-		$exportxml = ob_get_contents();
-		ob_end_clean();
 
 		// Don't check the size of exported stuff
 		// It's not continuable, so it would cause more
 		// problems than it'd solve
-		$result->disableSizeCheck();
-		if ( $this->params['exportnowrap'] ) {
+		if ( $this->mParams['exportnowrap'] ) {
 			$result->reset();
 			// Raw formatter will handle this
-			$result->addValue( null, 'text', $exportxml );
-			$result->addValue( null, 'mime', 'text/xml' );
+			$result->addValue( null, 'text', $sink, ApiResult::NO_SIZE_CHECK );
+			$result->addValue( null, 'mime', 'text/xml', ApiResult::NO_SIZE_CHECK );
+			$result->addValue( null, 'filename', 'export.xml', ApiResult::NO_SIZE_CHECK );
 		} else {
-			$r = array();
-			ApiResult::setContent( $r, $exportxml );
-			$result->addValue( 'query', 'export', $r );
+			$result->addValue( 'query', 'export', $sink, ApiResult::NO_SIZE_CHECK );
+			$result->addValue( 'query', ApiResult::META_BC_SUBELEMENTS, [ 'export' ] );
 		}
-		$result->enableSizeCheck();
 	}
 
-	/**
-	 * Create a generator object of the given type and return it
-	 * @param $generatorName string Module name
-	 * @return ApiQueryGeneratorBase
-	 */
-	public function newGenerator( $generatorName ) {
-		// Find class that implements requested generator
-		if ( isset( $this->mQueryListModules[$generatorName] ) ) {
-			$className = $this->mQueryListModules[$generatorName];
-		} elseif ( isset( $this->mQueryPropModules[$generatorName] ) ) {
-			$className = $this->mQueryPropModules[$generatorName];
-		} else {
-			ApiBase::dieDebug( __METHOD__, "Unknown generator=$generatorName" );
-		}
-		$generator = new $className ( $this, $generatorName );
-		if ( !$generator instanceof ApiQueryGeneratorBase ) {
-			$this->dieUsage( "Module $generatorName cannot be used as a generator", 'badgenerator' );
-		}
-		$generator->setGeneratorMode();
-		return $generator;
-	}
-
-	/**
-	 * For generator mode, execute generator, and use its output as new
-	 * ApiPageSet
-	 * @param $generator ApiQueryGeneratorBase Generator Module
-	 * @param $modules array of module objects
-	 */
-	protected function executeGeneratorModule( $generator, $modules ) {
-		// Generator results
-		$resultPageSet = new ApiPageSet( $this, $this->redirects, $this->convertTitles );
-
-		// Add any additional fields modules may need
-		$generator->requestExtraData( $this->mPageSet );
-		$this->addCustomFldsToPageSet( $modules, $resultPageSet );
-
-		// Populate page information with the original user input
-		$this->mPageSet->execute();
-
-		// populate resultPageSet with the generator output
-		$generator->profileIn();
-		$generator->executeGenerator( $resultPageSet );
-		wfRunHooks( 'APIQueryGeneratorAfterExecute', array( &$generator, &$resultPageSet ) );
-		$resultPageSet->finishPageSetGeneration();
-		$generator->profileOut();
-
-		// Swap the resulting pageset back in
-		$this->mPageSet = $resultPageSet;
-	}
-
-	public function getAllowedParams() {
-		return array(
-			'prop' => array(
+	public function getAllowedParams( $flags = 0 ) {
+		$result = [
+			'prop' => [
 				ApiBase::PARAM_ISMULTI => true,
-				ApiBase::PARAM_TYPE => $this->mPropModuleNames
-			),
-			'list' => array(
+				ApiBase::PARAM_TYPE => 'submodule',
+			],
+			'list' => [
 				ApiBase::PARAM_ISMULTI => true,
-				ApiBase::PARAM_TYPE => $this->mListModuleNames
-			),
-			'meta' => array(
+				ApiBase::PARAM_TYPE => 'submodule',
+			],
+			'meta' => [
 				ApiBase::PARAM_ISMULTI => true,
-				ApiBase::PARAM_TYPE => $this->mMetaModuleNames
-			),
-			'generator' => array(
-				ApiBase::PARAM_TYPE => $this->mAllowedGenerators
-			),
-			'redirects' => false,
-			'converttitles' => false,
+				ApiBase::PARAM_TYPE => 'submodule',
+			],
 			'indexpageids' => false,
 			'export' => false,
 			'exportnowrap' => false,
-		);
-	}
-
-	/**
-	 * Override the parent to generate help messages for all available query modules.
-	 * @return string
-	 */
-	public function makeHelpMsg() {
-		$msg = '';
-
-		// Make sure the internal object is empty
-		// (just in case a sub-module decides to optimize during instantiation)
-		$this->mPageSet = null;
-		$this->mAllowedGenerators = array(); // Will be repopulated
-
-		$querySeparator = str_repeat( '--- ', 8 );
-		$moduleSeparator = str_repeat( '*** ', 10 );
-		$msg .= "\n$querySeparator Query: Prop  $querySeparator\n\n";
-		$msg .= $this->makeHelpMsgHelper( $this->mQueryPropModules, 'prop' );
-		$msg .= "\n$querySeparator Query: List  $querySeparator\n\n";
-		$msg .= $this->makeHelpMsgHelper( $this->mQueryListModules, 'list' );
-		$msg .= "\n$querySeparator Query: Meta  $querySeparator\n\n";
-		$msg .= $this->makeHelpMsgHelper( $this->mQueryMetaModules, 'meta' );
-		$msg .= "\n\n$moduleSeparator Modules: continuation  $moduleSeparator\n\n";
-
-		// Perform the base call last because the $this->mAllowedGenerators
-		// will be updated inside makeHelpMsgHelper()
-		// Use parent to make default message for the query module
-		$msg = parent::makeHelpMsg() . $msg;
-
-		return $msg;
-	}
-
-	/**
-	 * For all modules in $moduleList, generate help messages and join them together
-	 * @param $moduleList Array array(modulename => classname)
-	 * @param $paramName string Parameter name
-	 * @return string
-	 */
-	private function makeHelpMsgHelper( $moduleList, $paramName ) {
-		$moduleDescriptions = array();
-
-		foreach ( $moduleList as $moduleName => $moduleClass ) {
-			$module = new $moduleClass ( $this, $moduleName, null );
-
-			$msg = ApiMain::makeHelpMsgHeader( $module, $paramName );
-			$msg2 = $module->makeHelpMsg();
-			if ( $msg2 !== false ) {
-				$msg .= $msg2;
-			}
-			if ( $module instanceof ApiQueryGeneratorBase ) {
-				$this->mAllowedGenerators[] = $moduleName;
-				$msg .= "Generator:\n  This module may be used as a generator\n";
-			}
-			$moduleDescriptions[] = $msg;
+			'iwurl' => false,
+			'continue' => [
+				ApiBase::PARAM_HELP_MSG => 'api-help-param-continue',
+			],
+			'rawcontinue' => false,
+		];
+		if ( $flags ) {
+			$result += $this->getPageSet()->getFinalParams( $flags );
 		}
 
-		return implode( "\n", $moduleDescriptions );
-	}
-
-	/**
-	 * Override to add extra parameters from PageSet
-	 * @return string
-	 */
-	public function makeHelpMsgParameters() {
-		$psModule = new ApiPageSet( $this );
-		return $psModule->makeHelpMsgParameters() . parent::makeHelpMsgParameters();
-	}
-
-	public function shouldCheckMaxlag() {
-		return true;
+		return $result;
 	}
 
-	public function getParamDescription() {
-		return array(
-			'prop' => 'Which properties to get for the titles/revisions/pageids. Module help is available below',
-			'list' => 'Which lists to get. Module help is available below',
-			'meta' => 'Which metadata to get about the site. Module help is available below',
-			'generator' => array( 'Use the output of a list as the input for other prop/list/meta items',
-					'NOTE: generator parameter names must be prefixed with a \'g\', see examples' ),
-			'redirects' => 'Automatically resolve redirects',
-			'converttitles' => array( "Convert titles to other variants if necessary. Only works if the wiki's content language supports variant conversion.",
-					'Languages that support variant conversion include kk, ku, gan, tg, sr, zh' ),
-			'indexpageids' => 'Include an additional pageids section listing all returned page IDs',
-			'export' => 'Export the current revisions of all given or generated pages',
-			'exportnowrap' => 'Return the export XML without wrapping it in an XML result (same format as Special:Export). Can only be used with export',
+	public function isReadMode() {
+		// We need to make an exception for certain meta modules that should be
+		// accessible even without the 'read' right. Restrict the exception as
+		// much as possible: no other modules allowed, and no pageset
+		// parameters either. We do allow the 'rawcontinue' and 'indexpageids'
+		// parameters since frameworks might add these unconditionally and they
+		// can't expose anything here.
+		$this->mParams = $this->extractRequestParams();
+		$params = array_filter(
+			array_diff_key(
+				$this->mParams + $this->getPageSet()->extractRequestParams(),
+				[ 'rawcontinue' => 1, 'indexpageids' => 1 ]
+			)
 		);
-	}
+		if ( array_keys( $params ) !== [ 'meta' ] ) {
+			return true;
+		}
 
-	public function getDescription() {
-		return array(
-			'Query API module allows applications to get needed pieces of data from the MediaWiki databases,',
-			'and is loosely based on the old query.php interface.',
-			'All data modifications will first have to use query to acquire a token to prevent abuse from malicious sites'
-		);
-	}
+		// Ask each module if it requires read mode. Any true => this returns
+		// true.
+		$modules = [];
+		$this->instantiateModules( $modules, 'meta' );
+		foreach ( $modules as $module ) {
+			if ( $module->isReadMode() ) {
+				return true;
+			}
+		}
 
-	public function getPossibleErrors() {
-		return array_merge( parent::getPossibleErrors(), array(
-			array( 'code' => 'badgenerator', 'info' => 'Module $generatorName cannot be used as a generator' ),
-		) );
+		return false;
 	}
 
-	protected function getExamples() {
-		return array(
-			'api.php?action=query&prop=revisions&meta=siteinfo&titles=Main%20Page&rvprop=user|comment',
-			'api.php?action=query&generator=allpages&gapprefix=API/&prop=revisions',
-		);
+	protected function getExamplesMessages() {
+		return [
+			'action=query&prop=revisions&meta=siteinfo&' .
+				'titles=Main%20Page&rvprop=user|comment&continue='
+				=> 'apihelp-query-example-revisions',
+			'action=query&generator=allpages&gapprefix=API/&prop=revisions&continue='
+				=> 'apihelp-query-example-allpages',
+		];
 	}
 
-	public function getVersion() {
-		$psModule = new ApiPageSet( $this );
-		$vers = array();
-		$vers[] = __CLASS__ . ': $Id$';
-		$vers[] = $psModule->getVersion();
-		return $vers;
+	public function getHelpUrls() {
+		return [
+			'https://www.mediawiki.org/wiki/Special:MyLanguage/API:Query',
+			'https://www.mediawiki.org/wiki/Special:MyLanguage/API:Meta',
+			'https://www.mediawiki.org/wiki/Special:MyLanguage/API:Properties',
+			'https://www.mediawiki.org/wiki/Special:MyLanguage/API:Lists',
+		];
 	}
 }