Eliminate use of Title object in REST infrastructure

Change-Id: I585f0f23cac5f6dc2a4879f69f7b83828fda3dd3

19 files changed, 407 insertions, 273 deletions

diff --git a/includes/Rest/Entity/SearchResultPageIdentity.php b/includes/Rest/Entity/SearchResultPageIdentity.php
index 5673ea376993..65436c0b9044 100644
--- a/includes/Rest/Entity/SearchResultPageIdentity.php
+++ b/includes/Rest/Entity/SearchResultPageIdentity.php
@@ -1,6 +1,8 @@
 <?php
 namespace MediaWiki\Rest\Entity;
 
+use MediaWiki\Page\PageIdentity;
+
 /**
  * Lightweight interface representing a page identity
  *
@@ -11,8 +13,8 @@ namespace MediaWiki\Rest\Entity;
 interface SearchResultPageIdentity {
 	/**
 	 * The numerical page ID.
-	 * At the moment it is equivalent to Title::getArticleID()
-	 * @see Title::getArticleID()
+	 * At the moment it is equivalent to PageIdentity::getId()
+	 * @see PageIdentity::getId()
 	 *
 	 * @return int
 	 */
@@ -20,8 +22,8 @@ interface SearchResultPageIdentity {
 
 	/**
 	 * Returns the page's namespace number.
-	 * At the moment it is equivalent to Title::getNamespace()
-	 * @see Title::getNamespace()
+	 * At the moment it is equivalent to PageIdentity::getNamespace()
+	 * @see PageIdentity::getNamespace()
 	 *
 	 * @return int
 	 */
@@ -29,8 +31,8 @@ interface SearchResultPageIdentity {
 
 	/**
 	 * Get the page title in DB key form.
-	 * At the moment it is equivalent to Title::getDBkey()
-	 * @see Title::getDBkey()
+	 * At the moment it is equivalent to PageIdentity::getDBkey()
+	 * @see PageIdentity::getDBkey()
 	 *
 	 * @return string
 	 */
diff --git a/includes/Rest/Handler/LanguageLinksHandler.php b/includes/Rest/Handler/LanguageLinksHandler.php
index 7fe7ed73782f..3bdb8f25d9a1 100644
--- a/includes/Rest/Handler/LanguageLinksHandler.php
+++ b/includes/Rest/Handler/LanguageLinksHandler.php
@@ -4,10 +4,11 @@ namespace MediaWiki\Rest\Handler;
 
 use MalformedTitleException;
 use MediaWiki\Languages\LanguageNameUtils;
+use MediaWiki\Page\ExistingPageRecord;
+use MediaWiki\Page\PageLookup;
 use MediaWiki\Rest\LocalizedHttpException;
 use MediaWiki\Rest\Response;
 use MediaWiki\Rest\SimpleHandler;
-use Title;
 use TitleFormatter;
 use TitleParser;
 use Wikimedia\Message\MessageValue;
@@ -36,37 +37,45 @@ class LanguageLinksHandler extends SimpleHandler {
 	/** @var TitleParser */
 	private $titleParser;
 
+	/** @var PageLookup */
+	private $pageLookup;
+
 	/**
-	 * @var Title|bool|null
+	 * @var ExistingPageRecord|false|null
 	 */
-	private $title = null;
+	private $page = false;
 
 	/**
 	 * @param ILoadBalancer $loadBalancer
 	 * @param LanguageNameUtils $languageNameUtils
 	 * @param TitleFormatter $titleFormatter
 	 * @param TitleParser $titleParser
+	 * @param PageLookup $pageLookup
 	 */
 	public function __construct(
 		ILoadBalancer $loadBalancer,
 		LanguageNameUtils $languageNameUtils,
 		TitleFormatter $titleFormatter,
-		TitleParser $titleParser
+		TitleParser $titleParser,
+		PageLookup $pageLookup
 	) {
 		$this->loadBalancer = $loadBalancer;
 		$this->languageNameUtils = $languageNameUtils;
 		$this->titleFormatter = $titleFormatter;
 		$this->titleParser = $titleParser;
+		$this->pageLookup = $pageLookup;
 	}
 
 	/**
-	 * @return Title|bool Title or false if unable to retrieve title
+	 * @return ExistingPageRecord|null
 	 */
-	private function getTitle() {
-		if ( $this->title === null ) {
-			$this->title = Title::newFromText( $this->getValidatedParams()['title'] ) ?? false;
+	private function getPage(): ?ExistingPageRecord {
+		if ( $this->page === false ) {
+			$this->page = $this->pageLookup->getExistingPageByText(
+					$this->getValidatedParams()['title']
+				);
 		}
-		return $this->title;
+		return $this->page;
 	}
 
 	/**
@@ -75,8 +84,8 @@ class LanguageLinksHandler extends SimpleHandler {
 	 * @throws LocalizedHttpException
 	 */
 	public function run( $title ) {
-		$titleObj = $this->getTitle();
-		if ( !$titleObj || !$titleObj->getArticleID() ) {
+		$page = $this->getPage();
+		if ( !$page ) {
 			throw new LocalizedHttpException(
 				new MessageValue( 'rest-nonexistent-title',
 					[ new ScalarParam( ParamType::PLAINTEXT, $title ) ]
@@ -84,7 +93,7 @@ class LanguageLinksHandler extends SimpleHandler {
 				404
 			);
 		}
-		if ( !$this->getAuthority()->authorizeRead( 'read', $titleObj ) ) {
+		if ( !$this->getAuthority()->authorizeRead( 'read', $page ) ) {
 			throw new LocalizedHttpException(
 				new MessageValue( 'rest-permission-denied-title',
 					[ new ScalarParam( ParamType::PLAINTEXT, $title ) ] ),
@@ -93,7 +102,7 @@ class LanguageLinksHandler extends SimpleHandler {
 		}
 
 		return $this->getResponseFactory()
-			->createJson( $this->fetchLinks( $titleObj->getArticleID() ) );
+			->createJson( $this->fetchLinks( $page->getId() ) );
 	}
 
 	private function fetchLinks( $pageId ) {
@@ -138,37 +147,34 @@ class LanguageLinksHandler extends SimpleHandler {
 
 	/**
 	 * @return string|null
-	 * @throws LocalizedHttpException
 	 */
 	protected function getETag(): ?string {
-		$title = $this->getTitle();
-		if ( !$title || !$title->getArticleID() ) {
+		$page = $this->getPage();
+		if ( !$page ) {
 			return null;
 		}
 
 		// XXX: use hash of the rendered HTML?
-		return '"' . $title->getLatestRevID() . '@' . wfTimestamp( TS_MW, $title->getTouched() ) . '"';
+		return '"' . $page->getLatest() . '@' . wfTimestamp( TS_MW, $page->getTouched() ) . '"';
 	}
 
 	/**
 	 * @return string|null
-	 * @throws LocalizedHttpException
 	 */
 	protected function getLastModified(): ?string {
-		$title = $this->getTitle();
-		if ( !$title || !$title->getArticleID() ) {
+		$page = $this->getPage();
+		if ( !$page ) {
 			return null;
 		}
 
-		return $title->getTouched();
+		return $page->getTouched();
 	}
 
 	/**
 	 * @return bool
 	 */
 	protected function hasRepresentation() {
-		$title = $this->getTitle();
-		return $title ? $title->exists() : false;
+		return (bool)$this->getPage();
 	}
 
 }
diff --git a/includes/Rest/Handler/MediaFileHandler.php b/includes/Rest/Handler/MediaFileHandler.php
index e0357621353f..23047af1f3ff 100644
--- a/includes/Rest/Handler/MediaFileHandler.php
+++ b/includes/Rest/Handler/MediaFileHandler.php
@@ -4,11 +4,12 @@ namespace MediaWiki\Rest\Handler;
 
 use File;
 use MediaFileTrait;
+use MediaWiki\Page\ExistingPageRecord;
+use MediaWiki\Page\PageLookup;
 use MediaWiki\Rest\LocalizedHttpException;
 use MediaWiki\Rest\Response;
 use MediaWiki\Rest\SimpleHandler;
 use RepoGroup;
-use Title;
 use User;
 use Wikimedia\Message\MessageValue;
 use Wikimedia\ParamValidator\ParamValidator;
@@ -22,46 +23,53 @@ class MediaFileHandler extends SimpleHandler {
 	/** @var RepoGroup */
 	private $repoGroup;
 
+	/** @var PageLookup */
+	private $pageLookup;
+
 	/**
-	 * @var Title|bool|null
+	 * @var ExistingPageRecord|false|null
 	 */
-	private $title = null;
+	private $page = false;
 
 	/**
-	 * @var File|bool|null
+	 * @var File|false|null
 	 */
-	private $file = null;
+	private $file = false;
 
 	/**
 	 * @param RepoGroup $repoGroup
+	 * @param PageLookup $pageLookup
 	 */
 	public function __construct(
-		RepoGroup $repoGroup
+		RepoGroup $repoGroup,
+		PageLookup $pageLookup
 	) {
 		$this->repoGroup = $repoGroup;
+		$this->pageLookup = $pageLookup;
 	}
 
 	/**
-	 * @return Title|bool Title or false if unable to retrieve title
+	 * @return ExistingPageRecord|null
 	 */
-	private function getTitle() {
-		if ( $this->title === null ) {
-			$this->title =
-				Title::newFromText( $this->getValidatedParams()['title'], NS_FILE ) ?? false;
+	private function getPage(): ?ExistingPageRecord {
+		if ( $this->page === false ) {
+			$this->page = $this->pageLookup->getExistingPageByText(
+					$this->getValidatedParams()['title'], NS_FILE
+				);
 		}
-		return $this->title;
+		return $this->page;
 	}
 
 	/**
-	 * @return File|bool File or false if unable to retrieve file
+	 * @return File|null
 	 */
-	private function getFile() {
-		if ( $this->file === null ) {
-			$title = $this->getTitle();
+	private function getFile(): ?File {
+		if ( $this->file === false ) {
+			$page = $this->getPage();
 			// TODO: make RepoGroup::findFile take Authority
 			$user = User::newFromIdentity( $this->getAuthority()->getUser() );
 			$this->file =
-				$this->repoGroup->findFile( $title, [ 'private' => $user ] ) ?? false;
+				$this->repoGroup->findFile( $page, [ 'private' => $user ] ) ?: null;
 		}
 		return $this->file;
 	}
@@ -72,32 +80,26 @@ class MediaFileHandler extends SimpleHandler {
 	 * @throws LocalizedHttpException
 	 */
 	public function run( $title ) {
-		$titleObj = $this->getTitle();
-		$fileObj = $this->getFile();
+		$page = $this->getPage();
 
-		if ( !$titleObj || !$titleObj->exists() ) {
+		if ( !$page ) {
 			throw new LocalizedHttpException(
-				MessageValue::new( 'rest-nonexistent-title' )->plaintextParams(
-					$titleObj->getPrefixedDBkey()
-				),
+				MessageValue::new( 'rest-nonexistent-title' )->plaintextParams( $title ),
 				404
 			);
 		}
 
-		if ( !$this->getAuthority()->authorizeRead( 'read', $titleObj ) ) {
+		if ( !$this->getAuthority()->authorizeRead( 'read', $page ) ) {
 			throw new LocalizedHttpException(
-				MessageValue::new( 'rest-permission-denied-title' )->plaintextParams(
-					$titleObj->getPrefixedDBkey()
-				),
+				MessageValue::new( 'rest-permission-denied-title' )->plaintextParams( $title ),
 				403
 			);
 		}
 
+		$fileObj = $this->getFile();
 		if ( !$fileObj || !$fileObj->exists() ) {
 			throw new LocalizedHttpException(
-				MessageValue::new( 'rest-cannot-load-file' )->plaintextParams(
-					$titleObj->getPrefixedDBkey()
-				),
+				MessageValue::new( 'rest-cannot-load-file' )->plaintextParams( $title ),
 				404
 			);
 		}
diff --git a/includes/Rest/Handler/MediaLinksHandler.php b/includes/Rest/Handler/MediaLinksHandler.php
index 0c0c41afe101..919140476adb 100644
--- a/includes/Rest/Handler/MediaLinksHandler.php
+++ b/includes/Rest/Handler/MediaLinksHandler.php
@@ -3,11 +3,12 @@
 namespace MediaWiki\Rest\Handler;
 
 use MediaFileTrait;
+use MediaWiki\Page\ExistingPageRecord;
+use MediaWiki\Page\PageLookup;
 use MediaWiki\Rest\LocalizedHttpException;
 use MediaWiki\Rest\Response;
 use MediaWiki\Rest\SimpleHandler;
 use RepoGroup;
-use Title;
 use User;
 use Wikimedia\Message\MessageValue;
 use Wikimedia\ParamValidator\ParamValidator;
@@ -28,31 +29,39 @@ class MediaLinksHandler extends SimpleHandler {
 	/** @var RepoGroup */
 	private $repoGroup;
 
+	/** @var PageLookup */
+	private $pageLookup;
+
 	/**
-	 * @var Title|bool|null
+	 * @var ExistingPageRecord|false|null
 	 */
-	private $title = null;
+	private $page = false;
 
 	/**
 	 * @param ILoadBalancer $loadBalancer
 	 * @param RepoGroup $repoGroup
+	 * @param PageLookup $pageLookup
 	 */
 	public function __construct(
 		ILoadBalancer $loadBalancer,
-		RepoGroup $repoGroup
+		RepoGroup $repoGroup,
+		PageLookup $pageLookup
 	) {
 		$this->loadBalancer = $loadBalancer;
 		$this->repoGroup = $repoGroup;
+		$this->pageLookup = $pageLookup;
 	}
 
 	/**
-	 * @return Title|bool Title or false if unable to retrieve title
+	 * @return ExistingPageRecord|null
 	 */
-	private function getTitle() {
-		if ( $this->title === null ) {
-			$this->title = Title::newFromText( $this->getValidatedParams()['title'] ) ?? false;
+	private function getPage(): ?ExistingPageRecord {
+		if ( $this->page === false ) {
+			$this->page = $this->pageLookup->getExistingPageByText(
+					$this->getValidatedParams()['title']
+				);
 		}
-		return $this->title;
+		return $this->page;
 	}
 
 	/**
@@ -61,15 +70,15 @@ class MediaLinksHandler extends SimpleHandler {
 	 * @throws LocalizedHttpException
 	 */
 	public function run( $title ) {
-		$titleObj = Title::newFromText( $title );
-		if ( !$titleObj || !$titleObj->getArticleID() ) {
+		$page = $this->getPage();
+		if ( !$page ) {
 			throw new LocalizedHttpException(
 				MessageValue::new( 'rest-nonexistent-title' )->plaintextParams( $title ),
 				404
 			);
 		}
 
-		if ( !$this->getAuthority()->authorizeRead( 'read', $titleObj ) ) {
+		if ( !$this->getAuthority()->authorizeRead( 'read', $page ) ) {
 			throw new LocalizedHttpException(
 				MessageValue::new( 'rest-permission-denied-title' )->plaintextParams( $title ),
 				403
@@ -77,7 +86,7 @@ class MediaLinksHandler extends SimpleHandler {
 		}
 
 		// @todo: add continuation if too many links are found
-		$results = $this->getDbResults( $titleObj->getArticleID() );
+		$results = $this->getDbResults( $page->getId() );
 		if ( count( $results ) > self::MAX_NUM_LINKS ) {
 			throw new LocalizedHttpException(
 				MessageValue::new( 'rest-media-too-many-links' )
@@ -166,13 +175,13 @@ class MediaLinksHandler extends SimpleHandler {
 	 * @throws LocalizedHttpException
 	 */
 	protected function getETag(): ?string {
-		$title = $this->getTitle();
-		if ( !$title || !$title->getArticleID() ) {
+		$page = $this->getPage();
+		if ( !$page ) {
 			return null;
 		}
 
 		// XXX: use hash of the rendered HTML?
-		return '"' . $title->getLatestRevID() . '@' . wfTimestamp( TS_MW, $title->getTouched() ) . '"';
+		return '"' . $page->getLatest() . '@' . wfTimestamp( TS_MW, $page->getTouched() ) . '"';
 	}
 
 	/**
@@ -180,19 +189,18 @@ class MediaLinksHandler extends SimpleHandler {
 	 * @throws LocalizedHttpException
 	 */
 	protected function getLastModified(): ?string {
-		$title = $this->getTitle();
-		if ( !$title || !$title->getArticleID() ) {
+		$page = $this->getPage();
+		if ( !$page ) {
 			return null;
 		}
 
-		return $title->getTouched();
+		return $page->getTouched();
 	}
 
 	/**
 	 * @return bool
 	 */
 	protected function hasRepresentation() {
-		$title = $this->getTitle();
-		return $title ? $title->exists() : false;
+		return (bool)$this->getPage();
 	}
 }
diff --git a/includes/Rest/Handler/PageContentHelper.php b/includes/Rest/Handler/PageContentHelper.php
index 6d105b088657..5813409e8b88 100644
--- a/includes/Rest/Handler/PageContentHelper.php
+++ b/includes/Rest/Handler/PageContentHelper.php
@@ -3,6 +3,8 @@
 namespace MediaWiki\Rest\Handler;
 
 use Config;
+use MediaWiki\Page\ExistingPageRecord;
+use MediaWiki\Page\PageLookup;
 use MediaWiki\Permissions\Authority;
 use MediaWiki\Rest\Handler;
 use MediaWiki\Rest\LocalizedHttpException;
@@ -13,14 +15,12 @@ use MediaWiki\Revision\RevisionRecord;
 use MediaWiki\Revision\SlotRecord;
 use MediaWiki\Revision\SuppressedDataException;
 use TextContent;
-use Title;
-use TitleFactory;
 use TitleFormatter;
 use Wikimedia\Message\MessageValue;
 use Wikimedia\ParamValidator\ParamValidator;
 
 /**
- * @since 1.36
+ * @internal for use by core REST infrastructure
  */
 class PageContentHelper {
 	private const MAX_AGE_200 = 5;
@@ -34,8 +34,8 @@ class PageContentHelper {
 	/** @var TitleFormatter */
 	protected $titleFormatter;
 
-	/** @var TitleFactory */
-	protected $titleFactory;
+	/** @var PageLookup */
+	protected $pageLookup;
 
 	/** @var Authority|null */
 	protected $authority = null;
@@ -43,28 +43,28 @@ class PageContentHelper {
 	/** @var string[] */
 	protected $parameters = null;
 
-	/** @var RevisionRecord|bool|null */
-	protected $targetRevision = null;
+	/** @var RevisionRecord|false|null */
+	protected $targetRevision = false;
 
-	/** @var Title|bool|null */
-	protected $titleObject = null;
+	/** @var ExistingPageRecord|false|null */
+	protected $pageRecord = false;
 
 	/**
 	 * @param Config $config
 	 * @param RevisionLookup $revisionLookup
 	 * @param TitleFormatter $titleFormatter
-	 * @param TitleFactory $titleFactory
+	 * @param PageLookup $pageLookup
 	 */
 	public function __construct(
 		Config $config,
 		RevisionLookup $revisionLookup,
 		TitleFormatter $titleFormatter,
-		TitleFactory $titleFactory
+		PageLookup $pageLookup
 	) {
 		$this->config = $config;
 		$this->revisionLookup = $revisionLookup;
 		$this->titleFormatter = $titleFormatter;
-		$this->titleFactory = $titleFactory;
+		$this->pageLookup = $pageLookup;
 	}
 
 	/**
@@ -77,36 +77,38 @@ class PageContentHelper {
 	}
 
 	/**
-	 * @return string|null Title text or null if unable to retrieve title
+	 * @return string|null title text or null if unable to retrieve title
 	 */
 	public function getTitleText(): ?string {
 		return $this->parameters['title'] ?? null;
 	}
 
 	/**
-	 * @return Title|bool Title or false if unable to retrieve title
+	 * @return ExistingPageRecord|null
 	 */
-	public function getTitle() {
-		if ( $this->titleObject === null ) {
+	public function getPage(): ?ExistingPageRecord {
+		if ( $this->pageRecord === false ) {
 			$titleText = $this->getTitleText();
-			$this->titleObject =
-				$this->titleFactory->newFromText( $titleText ) ?? false;
+			if ( !$titleText ) {
+				return null;
+			}
+			$this->pageRecord = $this->pageLookup->getExistingPageByText( $titleText );
 		}
-		return $this->titleObject;
+		return $this->pageRecord;
 	}
 
 	/**
 	 * Returns the target revision. No permission checks are applied.
 	 *
-	 * @return RevisionRecord|bool latest revision or false if unable to retrieve revision
+	 * @return RevisionRecord|null latest revision or null if unable to retrieve revision
 	 */
-	public function getTargetRevision() {
-		if ( $this->targetRevision === null ) {
-			$title = $this->getTitle();
-			if ( $title && $title->getArticleID() ) {
-				$this->targetRevision = $this->revisionLookup->getRevisionByTitle( $title );
+	public function getTargetRevision(): ?RevisionRecord {
+		if ( $this->targetRevision === false ) {
+			$page = $this->getPage();
+			if ( $page ) {
+				$this->targetRevision = $this->revisionLookup->getRevisionByTitle( $page );
 			} else {
-				$this->targetRevision = false;
+				$this->targetRevision = null;
 			}
 		}
 		return $this->targetRevision;
@@ -160,9 +162,8 @@ class PageContentHelper {
 	 * @return bool
 	 */
 	public function isAccessible(): bool {
-		$title = $this->getTitle();
-		return $title && $title->getArticleID()
-			&& $this->authority->probablyCan( 'read', $title );
+		$page = $this->getPage();
+		return $page && $this->authority->probablyCan( 'read', $page );
 	}
 
 	/**
@@ -203,25 +204,26 @@ class PageContentHelper {
 	 * @return bool
 	 */
 	public function hasContent(): bool {
-		$title = $this->getTitle();
-		return $title && $title->getArticleID();
+		return (bool)$this->getPage();
 	}
 
 	/**
 	 * @return array
 	 */
 	public function constructMetadata(): array {
-		$titleObject = $this->getTitle();
+		$page = $this->getPage();
 		$revision = $this->getTargetRevision();
 		return [
-			'id' => $titleObject->getArticleID(),
-			'key' => $this->titleFormatter->getPrefixedDBkey( $titleObject ),
-			'title' => $this->titleFormatter->getPrefixedText( $titleObject ),
+			'id' => $page->getId(),
+			'key' => $this->titleFormatter->getPrefixedDBkey( $page ),
+			'title' => $this->titleFormatter->getPrefixedText( $page ),
 			'latest' => [
 				'id' => $revision->getId(),
 				'timestamp' => wfTimestampOrNull( TS_ISO_8601, $revision->getTimestamp() )
 			],
-			'content_model' => $titleObject->getContentModel(),
+			'content_model' => $this->getTargetRevision()
+				->getSlot( SlotRecord::MAIN, RevisionRecord::RAW )
+				->getModel(),
 			'license' => [
 				'url' => $this->config->get( 'RightsUrl' ),
 				'title' => $this->config->get( 'RightsText' )
@@ -272,7 +274,7 @@ class PageContentHelper {
 			);
 		}
 
-		if ( !$this->authority->authorizeRead( 'read', $this->getTitle() ) ) {
+		if ( !$this->authority->authorizeRead( 'read', $this->getPage() ) ) {
 			throw new LocalizedHttpException(
 				MessageValue::new( 'rest-permission-denied-title' )->plaintextParams( $titleText ),
 				403
diff --git a/includes/Rest/Handler/PageHTMLHandler.php b/includes/Rest/Handler/PageHTMLHandler.php
index d9ba49572216..552f7ae9486e 100644
--- a/includes/Rest/Handler/PageHTMLHandler.php
+++ b/includes/Rest/Handler/PageHTMLHandler.php
@@ -4,14 +4,13 @@ namespace MediaWiki\Rest\Handler;
 
 use Config;
 use LogicException;
-use MediaWiki\Page\WikiPageFactory;
+use MediaWiki\Page\PageLookup;
 use MediaWiki\Parser\ParserCacheFactory;
 use MediaWiki\Rest\LocalizedHttpException;
 use MediaWiki\Rest\Response;
 use MediaWiki\Rest\SimpleHandler;
 use MediaWiki\Rest\StringStream;
 use MediaWiki\Revision\RevisionLookup;
-use TitleFactory;
 use TitleFormatter;
 use Wikimedia\Assert\Assert;
 use Wikimedia\UUID\GlobalIdGenerator;
@@ -35,21 +34,19 @@ class PageHTMLHandler extends SimpleHandler {
 		Config $config,
 		RevisionLookup $revisionLookup,
 		TitleFormatter $titleFormatter,
-		TitleFactory $titleFactory,
 		ParserCacheFactory $parserCacheFactory,
-		WikiPageFactory $wikiPageFactory,
-		GlobalIdGenerator $globalIdGenerator
+		GlobalIdGenerator $globalIdGenerator,
+		PageLookup $pageLookup
 	) {
 		$this->contentHelper = new PageContentHelper(
 			$config,
 			$revisionLookup,
 			$titleFormatter,
-			$titleFactory
+			$pageLookup
 		);
 		$this->htmlHelper = new ParsoidHTMLHelper(
 			$parserCacheFactory->getParserCache( 'parsoid' ),
 			$parserCacheFactory->getRevisionOutputCache( 'parsoid' ),
-			$wikiPageFactory,
 			$globalIdGenerator
 		);
 	}
@@ -57,9 +54,9 @@ class PageHTMLHandler extends SimpleHandler {
 	protected function postValidationSetup() {
 		$this->contentHelper->init( $this->getAuthority(), $this->getValidatedParams() );
 
-		$title = $this->contentHelper->getTitle();
-		if ( $title ) {
-			$this->htmlHelper->init( $title );
+		$page = $this->contentHelper->getPage();
+		if ( $page ) {
+			$this->htmlHelper->init( $page );
 		}
 	}
 
@@ -70,11 +67,11 @@ class PageHTMLHandler extends SimpleHandler {
 	public function run(): Response {
 		$this->contentHelper->checkAccess();
 
-		$titleObj = $this->contentHelper->getTitle();
+		$page = $this->contentHelper->getPage();
 
-		// The call to $this->contentHelper->getTitle() should not return null if
+		// The call to $this->contentHelper->getPage() should not return null if
 		// $this->contentHelper->checkAccess() did not throw.
-		Assert::invariant( $titleObj !== null, 'Title should be known' );
+		Assert::invariant( $page !== null, 'Page should be known' );
 
 		$outputMode = $this->getOutputMode();
 		switch ( $outputMode ) {
diff --git a/includes/Rest/Handler/PageHistoryCountHandler.php b/includes/Rest/Handler/PageHistoryCountHandler.php
index 4eebaee77577..d243214c1d22 100644
--- a/includes/Rest/Handler/PageHistoryCountHandler.php
+++ b/includes/Rest/Handler/PageHistoryCountHandler.php
@@ -3,6 +3,8 @@
 namespace MediaWiki\Rest\Handler;
 
 use ChangeTags;
+use MediaWiki\Page\ExistingPageRecord;
+use MediaWiki\Page\PageLookup;
 use MediaWiki\Permissions\PermissionManager;
 use MediaWiki\Rest\LocalizedHttpException;
 use MediaWiki\Rest\Response;
@@ -12,7 +14,6 @@ use MediaWiki\Revision\RevisionStore;
 use MediaWiki\Storage\NameTableAccessException;
 use MediaWiki\Storage\NameTableStore;
 use MediaWiki\Storage\NameTableStoreFactory;
-use Title;
 use WANObjectCache;
 use Wikimedia\Message\MessageValue;
 use Wikimedia\Message\ParamType;
@@ -54,17 +55,20 @@ class PageHistoryCountHandler extends SimpleHandler {
 	/** @var ILoadBalancer */
 	private $loadBalancer;
 
+	/** @var PageLookup */
+	private $pageLookup;
+
 	/** @var WANObjectCache */
 	private $cache;
 
-	/** @var RevisionRecord|bool */
-	private $revision;
+	/** @var RevisionRecord|false|null */
+	private $revision = false;
 
 	/** @var array */
 	private $lastModifiedTimes;
 
-	/** @var Title */
-	private $titleObject;
+	/** @var ExistingPageRecord|false|null */
+	private $page = false;
 
 	/**
 	 * @param RevisionStore $revisionStore
@@ -72,19 +76,22 @@ class PageHistoryCountHandler extends SimpleHandler {
 	 * @param PermissionManager $permissionManager
 	 * @param ILoadBalancer $loadBalancer
 	 * @param WANObjectCache $cache
+	 * @param PageLookup $pageLookup
 	 */
 	public function __construct(
 		RevisionStore $revisionStore,
 		NameTableStoreFactory $nameTableStoreFactory,
 		PermissionManager $permissionManager,
 		ILoadBalancer $loadBalancer,
-		WANObjectCache $cache
+		WANObjectCache $cache,
+		PageLookup $pageLookup
 	) {
 		$this->revisionStore = $revisionStore;
 		$this->changeTagDefStore = $nameTableStoreFactory->getChangeTagDef();
 		$this->permissionManager = $permissionManager;
 		$this->loadBalancer = $loadBalancer;
 		$this->cache = $cache;
+		$this->pageLookup = $pageLookup;
 	}
 
 	private function normalizeType( $type ) {
@@ -121,7 +128,7 @@ class PageHistoryCountHandler extends SimpleHandler {
 	}
 
 	/**
-	 * @param Title $title the title of the page to load history for
+	 * @param string $title the title of the page to load history for
 	 * @param string $type the validated count type
 	 * @return Response
 	 * @throws LocalizedHttpException
@@ -129,8 +136,8 @@ class PageHistoryCountHandler extends SimpleHandler {
 	public function run( $title, $type ) {
 		$normalizedType = $this->normalizeType( $type );
 		$this->validateParameterCombination( $normalizedType );
-		$titleObj = $this->getTitle();
-		if ( !$titleObj || !$titleObj->getArticleID() ) {
+		$page = $this->getPage();
+		if ( !$page ) {
 			throw new LocalizedHttpException(
 				new MessageValue( 'rest-nonexistent-title',
 					[ new ScalarParam( ParamType::PLAINTEXT, $title ) ]
@@ -139,7 +146,7 @@ class PageHistoryCountHandler extends SimpleHandler {
 			);
 		}
 
-		if ( !$this->getAuthority()->authorizeRead( 'read', $titleObj ) ) {
+		if ( !$this->getAuthority()->authorizeRead( 'read', $page ) ) {
 			throw new LocalizedHttpException(
 				new MessageValue( 'rest-permission-denied-title',
 					[ new ScalarParam( ParamType::PLAINTEXT, $title ) ]
@@ -173,7 +180,7 @@ class PageHistoryCountHandler extends SimpleHandler {
 	 * @throws LocalizedHttpException
 	 */
 	private function getCount( $type ) {
-		$pageId = $this->getTitle()->getArticleID();
+		$pageId = $this->getPage()->getId();
 		switch ( $type ) {
 			case 'anonymous':
 				return $this->getCachedCount( $type,
@@ -261,28 +268,30 @@ class PageHistoryCountHandler extends SimpleHandler {
 	}
 
 	/**
-	 * @return RevisionRecord|bool current revision or false if unable to retrieve revision
+	 * @return RevisionRecord|null current revision or false if unable to retrieve revision
 	 */
-	private function getCurrentRevision() {
-		if ( $this->revision === null ) {
-			$title = $this->getTitle();
-			if ( $title && $title->getArticleID() ) {
-				$this->revision = $this->revisionStore->getKnownCurrentRevision( $title );
+	private function getCurrentRevision(): ?RevisionRecord {
+		if ( $this->revision === false ) {
+			$page = $this->getPage();
+			if ( $page ) {
+				$this->revision = $this->revisionStore->getKnownCurrentRevision( $page ) ?: null;
 			} else {
-				$this->revision = false;
+				$this->revision = null;
 			}
 		}
 		return $this->revision;
 	}
 
 	/**
-	 * @return Title|bool Title or false if unable to retrieve title
+	 * @return ExistingPageRecord|null
 	 */
-	private function getTitle() {
-		if ( $this->titleObject === null ) {
-			$this->titleObject = Title::newFromText( $this->getValidatedParams()['title'] );
+	private function getPage(): ?ExistingPageRecord {
+		if ( $this->page === false ) {
+			$this->page = $this->pageLookup->getExistingPageByText(
+				$this->getValidatedParams()['title']
+			);
 		}
-		return $this->titleObject;
+		return $this->page;
 	}
 
 	/**
@@ -296,6 +305,7 @@ class PageHistoryCountHandler extends SimpleHandler {
 		if ( $lastModifiedTimes ) {
 			return max( array_values( $lastModifiedTimes ) );
 		}
+		return null;
 	}
 
 	/**
@@ -357,8 +367,7 @@ class PageHistoryCountHandler extends SimpleHandler {
 	private function getCachedCount( $type,
 		callable $fetchCount
 	) {
-		$titleObj = $this->getTitle();
-		$pageId = $titleObj->getArticleID();
+		$pageId = $this->getPage()->getId();
 		return $this->cache->getWithSetCallback(
 			$this->cache->makeKey( 'rest', 'pagehistorycount', $pageId, $type ),
 			WANObjectCache::TTL_WEEK,
diff --git a/includes/Rest/Handler/PageHistoryHandler.php b/includes/Rest/Handler/PageHistoryHandler.php
index 57f03e5cb9eb..7dffc4f96474 100644
--- a/includes/Rest/Handler/PageHistoryHandler.php
+++ b/includes/Rest/Handler/PageHistoryHandler.php
@@ -4,6 +4,8 @@ namespace MediaWiki\Rest\Handler;
 
 use ChangeTags;
 use IDBAccessObject;
+use MediaWiki\Page\ExistingPageRecord;
+use MediaWiki\Page\PageLookup;
 use MediaWiki\Permissions\PermissionManager;
 use MediaWiki\Rest\LocalizedHttpException;
 use MediaWiki\Rest\Response;
@@ -13,7 +15,7 @@ use MediaWiki\Revision\RevisionStore;
 use MediaWiki\Storage\NameTableAccessException;
 use MediaWiki\Storage\NameTableStore;
 use MediaWiki\Storage\NameTableStoreFactory;
-use Title;
+use TitleFormatter;
 use Wikimedia\Message\MessageValue;
 use Wikimedia\Message\ParamType;
 use Wikimedia\Message\ScalarParam;
@@ -40,10 +42,16 @@ class PageHistoryHandler extends SimpleHandler {
 	/** @var ILoadBalancer */
 	private $loadBalancer;
 
+	/** @var PageLookup */
+	private $pageLookup;
+
+	/** @var TitleFormatter */
+	private $titleFormatter;
+
 	/**
-	 * @var Title|bool|null
+	 * @var ExistingPageRecord|false|null
 	 */
-	private $title = null;
+	private $page = false;
 
 	/**
 	 * RevisionStore $revisionStore
@@ -52,27 +60,35 @@ class PageHistoryHandler extends SimpleHandler {
 	 * @param NameTableStoreFactory $nameTableStoreFactory
 	 * @param PermissionManager $permissionManager
 	 * @param ILoadBalancer $loadBalancer
+	 * @param PageLookup $pageLookup
+	 * @param TitleFormatter $titleFormatter
 	 */
 	public function __construct(
 		RevisionStore $revisionStore,
 		NameTableStoreFactory $nameTableStoreFactory,
 		PermissionManager $permissionManager,
-		ILoadBalancer $loadBalancer
+		ILoadBalancer $loadBalancer,
+		PageLookup $pageLookup,
+		TitleFormatter $titleFormatter
 	) {
 		$this->revisionStore = $revisionStore;
 		$this->changeTagDefStore = $nameTableStoreFactory->getChangeTagDef();
 		$this->permissionManager = $permissionManager;
 		$this->loadBalancer = $loadBalancer;
+		$this->pageLookup = $pageLookup;
+		$this->titleFormatter = $titleFormatter;
 	}
 
 	/**
-	 * @return Title|bool Title or false if unable to retrieve title
+	 * @return ExistingPageRecord|null
 	 */
-	private function getTitle() {
-		if ( $this->title === null ) {
-			$this->title = Title::newFromText( $this->getValidatedParams()['title'] ) ?? false;
+	private function getPage(): ?ExistingPageRecord {
+		if ( $this->page === false ) {
+			$this->page = $this->pageLookup->getExistingPageByText(
+					$this->getValidatedParams()['title']
+				);
 		}
-		return $this->title;
+		return $this->page;
 	}
 
 	/**
@@ -109,8 +125,8 @@ class PageHistoryHandler extends SimpleHandler {
 			}
 		}
 
-		$titleObj = Title::newFromText( $title );
-		if ( !$titleObj || !$titleObj->getArticleID() ) {
+		$page = $this->getPage();
+		if ( !$page ) {
 			throw new LocalizedHttpException(
 				new MessageValue( 'rest-nonexistent-title',
 					[ new ScalarParam( ParamType::PLAINTEXT, $title ) ]
@@ -118,7 +134,7 @@ class PageHistoryHandler extends SimpleHandler {
 				404
 			);
 		}
-		if ( !$this->getAuthority()->authorizeRead( 'read', $titleObj ) ) {
+		if ( !$this->getAuthority()->authorizeRead( 'read', $page ) ) {
 			throw new LocalizedHttpException(
 				new MessageValue( 'rest-permission-denied-title',
 					[ new ScalarParam( ParamType::PLAINTEXT, $title ) ] ),
@@ -130,7 +146,7 @@ class PageHistoryHandler extends SimpleHandler {
 		if ( $relativeRevId ) {
 			// Confirm the relative revision exists for this page. If so, get its timestamp.
 			$rev = $this->revisionStore->getRevisionByPageId(
-				$titleObj->getArticleID(),
+				$page->getId(),
 				$relativeRevId
 			);
 			if ( !$rev ) {
@@ -154,24 +170,24 @@ class PageHistoryHandler extends SimpleHandler {
 			$ts = 0;
 		}
 
-		$res = $this->getDbResults( $titleObj, $params, $relativeRevId, $ts, $tagIds );
-		$response = $this->processDbResults( $res, $titleObj, $params );
+		$res = $this->getDbResults( $page, $params, $relativeRevId, $ts, $tagIds );
+		$response = $this->processDbResults( $res, $page, $params );
 		return $this->getResponseFactory()->createJson( $response );
 	}
 
 	/**
-	 * @param Title $titleObj title object identifying the page to load history for
+	 * @param ExistingPageRecord $page object identifying the page to load history for
 	 * @param array $params request parameters
 	 * @param int $relativeRevId relative revision id for paging, or zero if none
 	 * @param int $ts timestamp for paging, or zero if none
 	 * @param array $tagIds validated tags ids, or empty array if not needed for this query
 	 * @return IResultWrapper|bool the results, or false if no query was executed
 	 */
-	private function getDbResults( Title $titleObj, array $params, $relativeRevId, $ts, $tagIds ) {
+	private function getDbResults( ExistingPageRecord $page, array $params, $relativeRevId, $ts, $tagIds ) {
 		$dbr = $this->loadBalancer->getConnectionRef( DB_REPLICA );
 		$revQuery = $this->revisionStore->getQueryInfo();
 		$cond = [
-			'rev_page' => $titleObj->getArticleID()
+			'rev_page' => $page->getId()
 		];
 
 		if ( $params['filter'] ) {
@@ -274,11 +290,11 @@ class PageHistoryHandler extends SimpleHandler {
 
 	/**
 	 * @param IResultWrapper|bool $res database results, or false if no query was executed
-	 * @param Title $titleObj title object identifying the page to load history for
+	 * @param ExistingPageRecord $page object identifying the page to load history for
 	 * @param array $params request parameters
 	 * @return array response data
 	 */
-	private function processDbResults( $res, $titleObj, $params ) {
+	private function processDbResults( $res, $page, $params ) {
 		$revisions = [];
 
 		if ( $res ) {
@@ -287,7 +303,7 @@ class PageHistoryHandler extends SimpleHandler {
 				$rev = $this->revisionStore->newRevisionFromRow(
 					$row,
 					IDBAccessObject::READ_NORMAL,
-					$titleObj
+					$page
 				);
 				if ( !$revisions ) {
 					$firstRevId = $row->rev_id;
@@ -383,7 +399,7 @@ class PageHistoryHandler extends SimpleHandler {
 			$queryParts['filter'] = $params['filter'];
 		}
 
-		$pathParams = [ 'title' => $titleObj->getPrefixedDBkey() ];
+		$pathParams = [ 'title' => $this->titleFormatter->getPrefixedDBkey( $page ) ];
 
 		$response['latest'] = $this->getRouteUrl( $pathParams, $queryParts );
 
@@ -434,12 +450,12 @@ class PageHistoryHandler extends SimpleHandler {
 	 * @return string|null
 	 */
 	protected function getETag(): ?string {
-		$title = $this->getTitle();
-		if ( !$title || !$title->getArticleID() ) {
+		$page = $this->getPage();
+		if ( !$page ) {
 			return null;
 		}
 
-		return '"' . $title->getLatestRevID() . '"';
+		return '"' . $page->getLatest() . '"';
 	}
 
 	/**
@@ -448,12 +464,12 @@ class PageHistoryHandler extends SimpleHandler {
 	 * @return string|null
 	 */
 	protected function getLastModified(): ?string {
-		$title = $this->getTitle();
-		if ( !$title || !$title->getArticleID() ) {
+		$page = $this->getPage();
+		if ( !$page ) {
 			return null;
 		}
 
-		$rev = $this->revisionStore->getKnownCurrentRevision( $title );
+		$rev = $this->revisionStore->getKnownCurrentRevision( $page );
 		return $rev->getTimestamp();
 	}
 
@@ -461,7 +477,6 @@ class PageHistoryHandler extends SimpleHandler {
 	 * @return bool
 	 */
 	protected function hasRepresentation() {
-		$title = $this->getTitle();
-		return $title ? $title->exists() : false;
+		return (bool)$this->getPage();
 	}
 }
diff --git a/includes/Rest/Handler/PageSourceHandler.php b/includes/Rest/Handler/PageSourceHandler.php
index 15e028d5570b..c626a2cf4607 100644
--- a/includes/Rest/Handler/PageSourceHandler.php
+++ b/includes/Rest/Handler/PageSourceHandler.php
@@ -4,12 +4,12 @@ namespace MediaWiki\Rest\Handler;
 
 use Config;
 use LogicException;
+use MediaWiki\Page\PageLookup;
+use MediaWiki\Page\PageReference;
 use MediaWiki\Rest\LocalizedHttpException;
 use MediaWiki\Rest\Response;
 use MediaWiki\Rest\SimpleHandler;
 use MediaWiki\Revision\RevisionLookup;
-use Title;
-use TitleFactory;
 use TitleFormatter;
 use Wikimedia\Assert\Assert;
 
@@ -20,6 +20,9 @@ use Wikimedia\Assert\Assert;
  */
 class PageSourceHandler extends SimpleHandler {
 
+	/** @var TitleFormatter */
+	private $titleFormatter;
+
 	/** @var PageContentHelper */
 	private $contentHelper;
 
@@ -27,13 +30,14 @@ class PageSourceHandler extends SimpleHandler {
 		Config $config,
 		RevisionLookup $revisionLookup,
 		TitleFormatter $titleFormatter,
-		TitleFactory $titleFactory
+		PageLookup $pageLookup
 	) {
+		$this->titleFormatter = $titleFormatter;
 		$this->contentHelper = new PageContentHelper(
 			$config,
 			$revisionLookup,
 			$titleFormatter,
-			$titleFactory
+			$pageLookup
 		);
 	}
 
@@ -42,13 +46,13 @@ class PageSourceHandler extends SimpleHandler {
 	}
 
 	/**
-	 * @param Title $title
+	 * @param PageReference $page
 	 * @return string
 	 */
-	private function constructHtmlUrl( Title $title ): string {
+	private function constructHtmlUrl( PageReference $page ): string {
 		return $this->getRouter()->getRouteUrl(
 			'/v1/page/{title}/html',
-			[ 'title' => $title->getPrefixedText() ]
+			[ 'title' => $this->titleFormatter->getPrefixedText( $page ) ]
 		);
 	}
 
@@ -59,17 +63,17 @@ class PageSourceHandler extends SimpleHandler {
 	public function run(): Response {
 		$this->contentHelper->checkAccess();
 
-		$titleObj = $this->contentHelper->getTitle();
+		$page = $this->contentHelper->getPage();
 
-		// The call to $this->contentHelper->getTitle() should not return null if
+		// The call to $this->contentHelper->getPage() should not return null if
 		// $this->contentHelper->checkAccess() did not throw.
-		Assert::invariant( $titleObj !== null, 'Title should be known' );
+		Assert::invariant( $page !== null, 'Page should be known' );
 
 		$outputMode = $this->getOutputMode();
 		switch ( $outputMode ) {
 			case 'bare':
 				$body = $this->contentHelper->constructMetadata();
-				$body['html_url'] = $this->constructHtmlUrl( $titleObj );
+				$body['html_url'] = $this->constructHtmlUrl( $page );
 				break;
 			case 'source':
 				$content = $this->contentHelper->getContent();
diff --git a/includes/Rest/Handler/ParsoidHTMLHelper.php b/includes/Rest/Handler/ParsoidHTMLHelper.php
index 3a880d48f264..4e271281959d 100644
--- a/includes/Rest/Handler/ParsoidHTMLHelper.php
+++ b/includes/Rest/Handler/ParsoidHTMLHelper.php
@@ -22,14 +22,14 @@
 namespace MediaWiki\Rest\Handler;
 
 use MediaWiki\MediaWikiServices;
-use MediaWiki\Page\WikiPageFactory;
+use MediaWiki\Page\PageRecord;
 use MediaWiki\Parser\RevisionOutputCache;
 use MediaWiki\Rest\LocalizedHttpException;
 use MediaWiki\Revision\RevisionRecord;
 use ParserCache;
 use ParserOptions;
 use ParserOutput;
-use Title;
+use TitleValue;
 use Wikimedia\Message\MessageValue;
 use Wikimedia\Parsoid\Config\PageConfig;
 use Wikimedia\Parsoid\Core\ClientError;
@@ -55,14 +55,11 @@ class ParsoidHTMLHelper {
 	/** @var RevisionOutputCache */
 	private $revisionOutputCache;
 
-	/** @var WikiPageFactory */
-	private $wikiPageFactory;
-
 	/** @var GlobalIdGenerator */
 	private $globalIdGenerator;
 
-	/** @var Title|null */
-	private $title = null;
+	/** @var PageRecord|null */
+	private $page = null;
 
 	/** @var Parsoid|null */
 	private $parsoid = null;
@@ -73,27 +70,24 @@ class ParsoidHTMLHelper {
 	/**
 	 * @param ParserCache $parserCache
 	 * @param RevisionOutputCache $revisionOutputCache
-	 * @param WikiPageFactory $wikiPageFactory
 	 * @param GlobalIdGenerator $globalIdGenerator
 	 */
 	public function __construct(
 		ParserCache $parserCache,
 		RevisionOutputCache $revisionOutputCache,
-		WikiPageFactory $wikiPageFactory,
 		GlobalIdGenerator $globalIdGenerator
 	) {
 		$this->parserCache = $parserCache;
-		$this->wikiPageFactory = $wikiPageFactory;
 		$this->globalIdGenerator = $globalIdGenerator;
 		$this->revisionOutputCache = $revisionOutputCache;
 	}
 
 	/**
-	 * @param Title $title
+	 * @param PageRecord $page
 	 * @param RevisionRecord|null $revision
 	 */
-	public function init( Title $title, ?RevisionRecord $revision = null ) {
-		$this->title = $title;
+	public function init( PageRecord $page, ?RevisionRecord $revision = null ) {
+		$this->page = $page;
 		$this->revision = $revision;
 	}
 
@@ -178,9 +172,14 @@ class ParsoidHTMLHelper {
 		// can't report the used options.
 		// Already checked that title/revision exist and accessible.
 		// TODO: make ParsoidPageConfigFactory take a RevisionRecord
+		// TODO: make ParsoidPageConfigFactory take PageReference as well
 		return MediaWikiServices::getInstance()
 			->get( 'ParsoidPageConfigFactory' )
-			->create( $this->title, null, $this->revision ? $this->revision->getId() : null );
+			->create(
+				TitleValue::newFromPage( $this->page ),
+				null,
+				$this->revision ? $this->revision->getId() : null
+			);
 	}
 
 	/**
@@ -188,16 +187,15 @@ class ParsoidHTMLHelper {
 	 * @throws LocalizedHttpException
 	 */
 	public function getHtml(): ParserOutput {
-		$wikiPage = $this->wikiPageFactory->newFromLinkTarget( $this->title );
 		$parserOptions = ParserOptions::newCanonical( 'canonical' );
 
-		$revId = $this->revision ? $this->revision->getId() : $wikiPage->getLatest();
-		$isOld = $revId !== $wikiPage->getLatest();
+		$revId = $this->revision ? $this->revision->getId() : $this->page->getLatest();
+		$isOld = $revId !== $this->page->getLatest();
 
 		if ( $isOld ) {
 			$parserOutput = $this->revisionOutputCache->get( $this->revision, $parserOptions );
 		} else {
-			$parserOutput = $this->parserCache->get( $wikiPage, $parserOptions );
+			$parserOutput = $this->parserCache->get( $this->page, $parserOptions );
 		}
 		if ( $parserOutput ) {
 			return $parserOutput;
@@ -218,7 +216,7 @@ class ParsoidHTMLHelper {
 		if ( $isOld ) {
 			$this->revisionOutputCache->save( $fakeParserOutput, $this->revision, $parserOptions, $now );
 		} else {
-			$this->parserCache->save( $fakeParserOutput, $wikiPage, $parserOptions, $now );
+			$this->parserCache->save( $fakeParserOutput, $this->page, $parserOptions, $now );
 		}
 
 		return $fakeParserOutput;
diff --git a/includes/Rest/Handler/RevisionContentHelper.php b/includes/Rest/Handler/RevisionContentHelper.php
index 1cf186bb2b3b..0165b21c0e0e 100644
--- a/includes/Rest/Handler/RevisionContentHelper.php
+++ b/includes/Rest/Handler/RevisionContentHelper.php
@@ -2,17 +2,17 @@
 
 namespace MediaWiki\Rest\Handler;
 
+use MediaWiki\Page\ExistingPageRecord;
 use MediaWiki\Rest\Handler;
 use MediaWiki\Rest\LocalizedHttpException;
 use MediaWiki\Rest\ResponseInterface;
 use MediaWiki\Revision\RevisionRecord;
 use MediaWiki\Revision\SlotRecord;
-use Title;
 use Wikimedia\Message\MessageValue;
 use Wikimedia\ParamValidator\ParamValidator;
 
 /**
- * @since 1.36
+ * @internal for use by core REST infrastructure
  */
 class RevisionContentHelper extends PageContentHelper {
 
@@ -24,7 +24,7 @@ class RevisionContentHelper extends PageContentHelper {
 	}
 
 	/**
-	 * @return string|null Title text or null if unable to retrieve title
+	 * @return string|null title text or null if unable to retrieve title
 	 */
 	public function getTitleText(): ?string {
 		$revision = $this->getTargetRevision();
@@ -34,25 +34,23 @@ class RevisionContentHelper extends PageContentHelper {
 	}
 
 	/**
-	 * @return Title|bool Title or false if unable to retrieve title
+	 * @return ExistingPageRecord|null
 	 */
-	public function getTitle() {
+	public function getPage(): ?ExistingPageRecord {
 		$revision = $this->getTargetRevision();
-		return $revision
-			? $this->titleFactory->castFromLinkTarget( $revision->getPageAsLinkTarget() )
-			: false;
+		return $revision ? $this->pageLookup->getPageByReference( $revision->getPage() ) : null;
 	}
 
 	/**
-	 * @return RevisionRecord|bool latest revision or false if unable to retrieve revision
+	 * @return RevisionRecord|null latest revision or null if unable to retrieve revision
 	 */
-	public function getTargetRevision() {
-		if ( $this->targetRevision === null ) {
+	public function getTargetRevision(): ?RevisionRecord {
+		if ( $this->targetRevision === false ) {
 			$revId = $this->getRevisionId();
 			if ( $revId ) {
-				$this->targetRevision = $this->revisionLookup->getRevisionById( $revId ) ?: false;
+				$this->targetRevision = $this->revisionLookup->getRevisionById( $revId );
 			} else {
-				$this->targetRevision = false;
+				$this->targetRevision = null;
 			}
 		}
 		return $this->targetRevision;
@@ -101,7 +99,7 @@ class RevisionContentHelper extends PageContentHelper {
 	 * @return array
 	 */
 	public function constructMetadata(): array {
-		$titleObject = $this->getTitle();
+		$page = $this->getPage();
 		$revision = $this->getTargetRevision();
 
 		$mainSlot = $revision->getSlot( SlotRecord::MAIN, RevisionRecord::RAW );
@@ -113,9 +111,9 @@ class RevisionContentHelper extends PageContentHelper {
 			'timestamp' => wfTimestampOrNull( TS_ISO_8601, $revision->getTimestamp() ),
 			'content_model' => $mainSlot->getModel(),
 			'page' => [
-				'id' => $titleObject->getArticleID(),
-				'key' => $this->titleFormatter->getPrefixedDBkey( $titleObject ),
-				'title' => $this->titleFormatter->getPrefixedText( $titleObject ),
+				'id' => $page->getId(),
+				'key' => $this->titleFormatter->getPrefixedDBkey( $page ),
+				'title' => $this->titleFormatter->getPrefixedText( $page ),
 			],
 			'license' => [
 				'url' => $this->config->get( 'RightsUrl' ),
@@ -173,7 +171,7 @@ class RevisionContentHelper extends PageContentHelper {
 			);
 		}
 
-		if ( !$this->authority->authorizeRead( 'read', $this->getTitle() ) ) {
+		if ( !$this->authority->authorizeRead( 'read', $this->getPage() ) ) {
 			throw new LocalizedHttpException(
 				MessageValue::new( 'rest-permission-denied-revision' )->plaintextParams( $revId ),
 				403
diff --git a/includes/Rest/Handler/RevisionHTMLHandler.php b/includes/Rest/Handler/RevisionHTMLHandler.php
index e368d049e28a..f7aa5330c8f1 100644
--- a/includes/Rest/Handler/RevisionHTMLHandler.php
+++ b/includes/Rest/Handler/RevisionHTMLHandler.php
@@ -4,14 +4,13 @@ namespace MediaWiki\Rest\Handler;
 
 use Config;
 use LogicException;
-use MediaWiki\Page\WikiPageFactory;
+use MediaWiki\Page\PageLookup;
 use MediaWiki\Parser\ParserCacheFactory;
 use MediaWiki\Rest\LocalizedHttpException;
 use MediaWiki\Rest\Response;
 use MediaWiki\Rest\SimpleHandler;
 use MediaWiki\Rest\StringStream;
 use MediaWiki\Revision\RevisionLookup;
-use TitleFactory;
 use TitleFormatter;
 use Wikimedia\Assert\Assert;
 use Wikimedia\UUID\GlobalIdGenerator;
@@ -36,21 +35,19 @@ class RevisionHTMLHandler extends SimpleHandler {
 		Config $config,
 		RevisionLookup $revisionLookup,
 		TitleFormatter $titleFormatter,
-		TitleFactory $titleFactory,
 		ParserCacheFactory $parserCacheFactory,
-		WikiPageFactory $wikiPageFactory,
-		GlobalIdGenerator $globalIdGenerator
+		GlobalIdGenerator $globalIdGenerator,
+		PageLookup $pageLookup
 	) {
 		$this->contentHelper = new RevisionContentHelper(
 			$config,
 			$revisionLookup,
 			$titleFormatter,
-			$titleFactory
+			$pageLookup
 		);
 		$this->htmlHelper = new ParsoidHTMLHelper(
 			$parserCacheFactory->getParserCache( 'parsoid' ),
 			$parserCacheFactory->getRevisionOutputCache( 'parsoid' ),
-			$wikiPageFactory,
 			$globalIdGenerator
 		);
 	}
@@ -58,11 +55,11 @@ class RevisionHTMLHandler extends SimpleHandler {
 	protected function postValidationSetup() {
 		$this->contentHelper->init( $this->getAuthority(), $this->getValidatedParams() );
 
-		$title = $this->contentHelper->getTitle();
+		$page = $this->contentHelper->getPage();
 		$revision = $this->contentHelper->getTargetRevision();
 
-		if ( $title && $revision ) {
-			$this->htmlHelper->init( $title, $revision );
+		if ( $page && $revision ) {
+			$this->htmlHelper->init( $page, $revision );
 		}
 	}
 
@@ -73,12 +70,12 @@ class RevisionHTMLHandler extends SimpleHandler {
 	public function run(): Response {
 		$this->contentHelper->checkAccess();
 
-		$titleObj = $this->contentHelper->getTitle();
+		$page = $this->contentHelper->getPage();
 		$revisionRecord = $this->contentHelper->getTargetRevision();
 
-		// The call to $this->contentHelper->getTitle() should not return null if
+		// The call to $this->contentHelper->getPage() should not return null if
 		// $this->contentHelper->checkAccess() did not throw.
-		Assert::invariant( $titleObj !== null, 'Title should be known' );
+		Assert::invariant( $page !== null, 'Page should be known' );
 
 		// The call to $this->contentHelper->getTargetRevision() should not return null if
 		// $this->contentHelper->checkAccess() did not throw.
diff --git a/includes/Rest/Handler/RevisionSourceHandler.php b/includes/Rest/Handler/RevisionSourceHandler.php
index 3071cd0928b1..77040475c752 100644
--- a/includes/Rest/Handler/RevisionSourceHandler.php
+++ b/includes/Rest/Handler/RevisionSourceHandler.php
@@ -4,12 +4,12 @@ namespace MediaWiki\Rest\Handler;
 
 use Config;
 use LogicException;
+use MediaWiki\Page\PageLookup;
 use MediaWiki\Rest\LocalizedHttpException;
 use MediaWiki\Rest\Response;
 use MediaWiki\Rest\SimpleHandler;
 use MediaWiki\Revision\RevisionLookup;
 use MediaWiki\Revision\RevisionRecord;
-use TitleFactory;
 use TitleFormatter;
 
 /**
@@ -26,19 +26,19 @@ class RevisionSourceHandler extends SimpleHandler {
 	 * @param Config $config
 	 * @param RevisionLookup $revisionLookup
 	 * @param TitleFormatter $titleFormatter
-	 * @param TitleFactory $titleFactory
+	 * @param PageLookup $pageLookup
 	 */
 	public function __construct(
 		Config $config,
 		RevisionLookup $revisionLookup,
 		TitleFormatter $titleFormatter,
-		TitleFactory $titleFactory
+		PageLookup $pageLookup
 	) {
 		$this->contentHelper = new RevisionContentHelper(
 			$config,
 			$revisionLookup,
 			$titleFormatter,
-			$titleFactory
+			$pageLookup
 		);
 	}
 
diff --git a/includes/Rest/coreDevelopmentRoutes.json b/includes/Rest/coreDevelopmentRoutes.json
index 385c0b606158..1984e14e2598 100644
--- a/includes/Rest/coreDevelopmentRoutes.json
+++ b/includes/Rest/coreDevelopmentRoutes.json
@@ -42,7 +42,7 @@
 			"MainConfig",
 			"RevisionLookup",
 			"TitleFormatter",
-			"TitleFactory"
+			"PageStore"
 		],
 		"format": "source"
 	},
@@ -53,10 +53,9 @@
 			"MainConfig",
 			"RevisionLookup",
 			"TitleFormatter",
-			"TitleFactory",
 			"ParserCacheFactory",
-			"WikiPageFactory",
-			"GlobalIdGenerator"
+			"GlobalIdGenerator",
+			"PageStore"
 		],
 		"format": "html"
 	},
@@ -67,10 +66,9 @@
 			"MainConfig",
 			"RevisionLookup",
 			"TitleFormatter",
-			"TitleFactory",
 			"ParserCacheFactory",
-			"WikiPageFactory",
-			"GlobalIdGenerator"
+			"GlobalIdGenerator",
+			"PageStore"
 		],
 		"format": "with_html"
 	}
diff --git a/includes/Rest/coreRoutes.json b/includes/Rest/coreRoutes.json
index 321812622fea..28285d02df3c 100644
--- a/includes/Rest/coreRoutes.json
+++ b/includes/Rest/coreRoutes.json
@@ -6,7 +6,9 @@
 			"RevisionStore",
 			"NameTableStoreFactory",
 			"PermissionManager",
-			"DBLoadBalancer"
+			"DBLoadBalancer",
+			"PageStore",
+			"TitleFormatter"
 		]
 	},
 	{
@@ -17,7 +19,8 @@
 			"NameTableStoreFactory",
 			"PermissionManager",
 			"DBLoadBalancer",
-			"MainWANObjectCache"
+			"MainWANObjectCache",
+			"PageStore"
 		]
 	},
 	{
@@ -35,7 +38,7 @@
 			"MainConfig",
 			"RevisionLookup",
 			"TitleFormatter",
-			"TitleFactory"
+			"PageStore"
 		],
 		"format": "bare"
 	},
@@ -66,7 +69,8 @@
 			"DBLoadBalancer",
 			"LanguageNameUtils",
 			"TitleFormatter",
-			"TitleParser"
+			"TitleParser",
+			"PageStore"
 		]
 	},
 	{
@@ -76,7 +80,7 @@
 			"MainConfig",
 			"RevisionLookup",
 			"TitleFormatter",
-			"TitleFactory"
+			"PageStore"
 		],
 		"format": "source"
 	},
@@ -87,7 +91,7 @@
 			"MainConfig",
 			"RevisionLookup",
 			"TitleFormatter",
-			"TitleFactory"
+			"PageStore"
 		],
 		"format": "bare"
 	},
@@ -98,10 +102,9 @@
 			"MainConfig",
 			"RevisionLookup",
 			"TitleFormatter",
-			"TitleFactory",
 			"ParserCacheFactory",
-			"WikiPageFactory",
-			"GlobalIdGenerator"
+			"GlobalIdGenerator",
+			"PageStore"
 		],
 		"format": "html"
 	},
@@ -112,10 +115,9 @@
 			"MainConfig",
 			"RevisionLookup",
 			"TitleFormatter",
-			"TitleFactory",
 			"ParserCacheFactory",
-			"WikiPageFactory",
-			"GlobalIdGenerator"
+			"GlobalIdGenerator",
+			"PageStore"
 		],
 		"format": "with_html"
 	},
@@ -124,14 +126,16 @@
 		"class": "MediaWiki\\Rest\\Handler\\MediaLinksHandler",
 		"services": [
 			"DBLoadBalancer",
-			"RepoGroup"
+			"RepoGroup",
+			"PageStore"
 		]
 	},
 	{
 		"path": "/v1/file/{title}",
 		"class": "MediaWiki\\Rest\\Handler\\MediaFileHandler",
 		"services": [
-			"RepoGroup"
+			"RepoGroup",
+			"PageStore"
 		]
 	},
 	{
diff --git a/includes/ServiceWiring.php b/includes/ServiceWiring.php
index 8884949067cb..4f58f0b9bc15 100644
--- a/includes/ServiceWiring.php
+++ b/includes/ServiceWiring.php
@@ -985,7 +985,8 @@ return [
 		return new PageStoreFactory(
 			$options,
 			$services->getDBLoadBalancerFactory(),
-			$services->getNamespaceInfo()
+			$services->getNamespaceInfo(),
+			$services->getTitleParser()
 		);
 	},
 
diff --git a/includes/page/PageLookup.php b/includes/page/PageLookup.php
index 683047a0b9c5..0caa27a3c664 100644
--- a/includes/page/PageLookup.php
+++ b/includes/page/PageLookup.php
@@ -62,6 +62,40 @@ interface PageLookup extends IDBAccessObject {
 	): ?ExistingPageRecord;
 
 	/**
+	 * Returns a PageIdentity for a given user provided page name text.
+	 *
+	 * @since 1.37
+	 *
+	 * @param string $text
+	 * @param int $defaultNamespace Namespace to assume per default (usually NS_MAIN)
+	 * @param int $queryFlags
+	 *
+	 * @return ProperPageIdentity|null
+	 */
+	public function getPageByText(
+		string $text,
+		int $defaultNamespace = NS_MAIN,
+		int $queryFlags = self::READ_NORMAL
+	): ?ProperPageIdentity;
+
+	/**
+	 * Returns an existing PageRecord for a given user provided page name text.
+	 *
+	 * @since 1.37
+	 *
+	 * @param string $text
+	 * @param int $defaultNamespace Namespace to assume per default (usually NS_MAIN)
+	 * @param int $queryFlags
+	 *
+	 * @return ExistingPageRecord|null
+	 */
+	public function getExistingPageByText(
+		string $text,
+		int $defaultNamespace = NS_MAIN,
+		int $queryFlags = self::READ_NORMAL
+	): ?ExistingPageRecord;
+
+	/**
 	 * Returns the PageRecord of the given page.
 	 * May return $page if that already is a PageRecord.
 	 *
diff --git a/includes/page/PageStore.php b/includes/page/PageStore.php
index d8627a981eef..7674870526f8 100644
--- a/includes/page/PageStore.php
+++ b/includes/page/PageStore.php
@@ -5,11 +5,13 @@ namespace MediaWiki\Page;
 use DBAccessObjectUtils;
 use EmptyIterator;
 use Iterator;
+use MalformedTitleException;
 use MediaWiki\Config\ServiceOptions;
 use MediaWiki\DAO\WikiAwareEntity;
 use MediaWiki\Linker\LinkTarget;
 use NamespaceInfo;
 use stdClass;
+use TitleParser;
 use Wikimedia\Assert\Assert;
 use Wikimedia\Rdbms\IDatabase;
 use Wikimedia\Rdbms\ILoadBalancer;
@@ -31,6 +33,9 @@ class PageStore implements PageLookup {
 	/** @var NamespaceInfo */
 	private $namespaceInfo;
 
+	/** @var TitleParser */
+	private $titleParser;
+
 	/** @var string|false */
 	private $wikiId;
 
@@ -45,12 +50,14 @@ class PageStore implements PageLookup {
 	 * @param ServiceOptions $options
 	 * @param ILoadBalancer $dbLoadBalancer
 	 * @param NamespaceInfo $namespaceInfo
+	 * @param TitleParser $titleParser
 	 * @param false|string $wikiId
 	 */
 	public function __construct(
 		ServiceOptions $options,
 		ILoadBalancer $dbLoadBalancer,
 		NamespaceInfo $namespaceInfo,
+		TitleParser $titleParser,
 		$wikiId = WikiAwareEntity::LOCAL
 	) {
 		$options->assertRequiredOptions( self::CONSTRUCTOR_OPTIONS );
@@ -58,6 +65,7 @@ class PageStore implements PageLookup {
 		$this->options = $options;
 		$this->dbLoadBalancer = $dbLoadBalancer;
 		$this->namespaceInfo = $namespaceInfo;
+		$this->titleParser = $titleParser;
 		$this->wikiId = $wikiId;
 	}
 
@@ -117,6 +125,49 @@ class PageStore implements PageLookup {
 	}
 
 	/**
+	 * @since 1.37
+	 *
+	 * @param string $text
+	 * @param int $defaultNamespace Namespace to assume per default (usually NS_MAIN)
+	 * @param int $queryFlags
+	 *
+	 * @return ProperPageIdentity|null
+	 */
+	public function getPageByText(
+		string $text,
+		int $defaultNamespace = NS_MAIN,
+		int $queryFlags = self::READ_NORMAL
+	): ?ProperPageIdentity {
+		try {
+			$title = $this->titleParser->parseTitle( $text, $defaultNamespace );
+			return $this->getPageForLink( $title, $queryFlags );
+		} catch ( MalformedTitleException $e ) {
+			return null;
+		}
+	}
+
+	/**
+	 * @since 1.37
+	 *
+	 * @param string $text
+	 * @param int $defaultNamespace Namespace to assume per default (usually NS_MAIN)
+	 * @param int $queryFlags
+	 *
+	 * @return ExistingPageRecord|null
+	 */
+	public function getExistingPageByText(
+		string $text,
+		int $defaultNamespace = NS_MAIN,
+		int $queryFlags = self::READ_NORMAL
+	): ?ExistingPageRecord {
+		$pageIdentity = $this->getPageByText( $text, $defaultNamespace, $queryFlags );
+		if ( !$pageIdentity ) {
+			return null;
+		}
+		return $this->getPageByReference( $pageIdentity, $queryFlags );
+	}
+
+	/**
 	 * @param int $pageId
 	 * @param int $queryFlags
 	 *
diff --git a/includes/page/PageStoreFactory.php b/includes/page/PageStoreFactory.php
index 6bff4d472a09..c93dfa6d0d61 100644
--- a/includes/page/PageStoreFactory.php
+++ b/includes/page/PageStoreFactory.php
@@ -5,6 +5,7 @@ namespace MediaWiki\Page;
 use MediaWiki\Config\ServiceOptions;
 use MediaWiki\DAO\WikiAwareEntity;
 use NamespaceInfo;
+use TitleParser;
 use Wikimedia\Rdbms\ILBFactory;
 
 /**
@@ -26,21 +27,27 @@ class PageStoreFactory {
 	/** @var NamespaceInfo */
 	private $namespaceInfo;
 
+	/** @var TitleParser */
+	private $titleParser;
+
 	/**
 	 * @param ServiceOptions $options
 	 * @param ILBFactory $dbLoadBalancerFactory
 	 * @param NamespaceInfo $namespaceInfo
+	 * @param TitleParser $titleParser
 	 */
 	public function __construct(
 		ServiceOptions $options,
 		ILBFactory $dbLoadBalancerFactory,
-		NamespaceInfo $namespaceInfo
+		NamespaceInfo $namespaceInfo,
+		TitleParser $titleParser
 	) {
 		$options->assertRequiredOptions( self::CONSTRUCTOR_OPTIONS );
 
 		$this->options = $options;
 		$this->dbLoadBalancerFactory = $dbLoadBalancerFactory;
 		$this->namespaceInfo = $namespaceInfo;
+		$this->titleParser = $titleParser;
 	}
 
 	/**
@@ -53,6 +60,7 @@ class PageStoreFactory {
 			$this->options,
 			$this->dbLoadBalancerFactory->getMainLB( $wikiId ),
 			$this->namespaceInfo,
+			$this->titleParser,
 			$wikiId
 		);
 	}