Convert UserCache to a service

Bug: T253061
Change-Id: Id951177712648dc5ac684ae38097a0e9f3e12c7a

includes/MediaWikiServices.php

@@ -109,6 +109,7 @@ use TitleFactory;
 use TitleFormatter;
 use TitleParser;
 use UploadRevisionImporter;
+use UserCache;
 use VirtualRESTServiceClient;
 use WANObjectCache;
 use WatchedItemQueryService;
@@ -1340,6 +1341,14 @@ class MediaWikiServices extends ServiceContainer {
 		return $this->getService( 'UploadRevisionImporter' );
 	}
 
+	/**
+	 * @since 1.36
+	 * @return UserCache
+	 */
+	public function getUserCache() : UserCache {
+		return $this->getService( 'UserCache' );
+	}
+
 	/**
 	 * @since 1.35
 	 * @return UserEditTracker

includes/ServiceWiring.php

@@ -1336,6 +1336,14 @@ return [
 		);
 	},
 
+	'UserCache' => function ( MediaWikiServices $services ) : UserCache {
+		return new UserCache(
+			LoggerFactory::getInstance( 'UserCache' ),
+			$services->getDBLoadBalancer(),
+			$services->getLinkBatchFactory()
+		);
+	},
+
 	'UserEditTracker' => function ( MediaWikiServices $services ) : UserEditTracker {
 		$jobQueueGroup = JobQueueGroup::singleton();
 

includes/cache/UserCache.php

@@ -21,6 +21,11 @@
  * @ingroup Cache
  */
 
+use MediaWiki\Cache\LinkBatchFactory;
+use MediaWiki\MediaWikiServices;
+use Psr\Log\LoggerInterface;
+use Wikimedia\Rdbms\ILoadBalancer;
+
 /**
  * @since 1.20
  */
@@ -28,19 +33,37 @@ class UserCache {
 	protected $cache = []; // (uid => property => value)
 	protected $typesCached = []; // (uid => cache type => 1)
 
+	/** @var LoggerInterface */
+	private $logger;
+
+	/** @var LinkBatchFactory */
+	private $linkBatchFactory;
+
+	/** @var ILoadBalancer */
+	private $loadBalancer;
+
 	/**
 	 * @return UserCache
 	 */
 	public static function singleton() {
-		static $instance = null;
-		if ( $instance === null ) {
-			$instance = new self();
-		}
-
-		return $instance;
+		return MediaWikiServices::getInstance()->getUserCache();
 	}
 
-	protected function __construct() {
+	/**
+	 * Uses dependency injection since 1.36
+	 *
+	 * @param LoggerInterface $logger
+	 * @param ILoadBalancer $loadBalancer
+	 * @param LinkBatchFactory $linkBatchFactory
+	 */
+	public function __construct(
+		LoggerInterface $logger,
+		ILoadBalancer $loadBalancer,
+		LinkBatchFactory $linkBatchFactory
+	) {
+		$this->logger = $logger;
+		$this->loadBalancer = $loadBalancer;
+		$this->linkBatchFactory = $linkBatchFactory;
 	}
 
 	/**
@@ -52,7 +75,13 @@ class UserCache {
 	 */
 	public function getProp( $userId, $prop ) {
 		if ( !isset( $this->cache[$userId][$prop] ) ) {
-			wfDebug( __METHOD__ . ": querying DB for prop '$prop' for user ID '$userId'." );
+			$this->logger->debug(
+				'Querying DB for prop {prop} for user ID {userId}',
+				[
+					'prop' => $prop,
+					'userId' => $userId,
+				]
+			);
 			$this->doQuery( [ $userId ] ); // cache miss
 		}
 
@@ -97,7 +126,7 @@ class UserCache {
 
 		// Lookup basic info for users not yet loaded...
 		if ( count( $usersToQuery ) ) {
-			$dbr = wfGetDB( DB_REPLICA );
+			$dbr = $this->loadBalancer->getConnection( DB_REPLICA );
 			$tables = [ 'user', 'actor' ];
 			$conds = [ 'user_id' => $usersToQuery ];
 			$fields = [ 'user_name', 'user_real_name', 'user_registration', 'user_id', 'actor_id' ];
@@ -121,7 +150,7 @@ class UserCache {
 			}
 		}
 
-		$lb = new LinkBatch();
+		$lb = $this->linkBatchFactory->newLinkBatch();
 		foreach ( $usersToCheck as $userId => $name ) {
 			if ( $this->queryNeeded( $userId, 'userpage', $options ) ) {
 				$lb->add( NS_USER, $name );