resourceloader: Set value for getStoreKey in server-side

This change reduces the size of the JavaScript resources.

Change-Id: I850249f910f6275c1b963dc5421ba706ed6e9a56

includes/resourceloader/ResourceLoaderStartUpModule.php

@@ -366,6 +366,16 @@ class ResourceLoaderStartUpModule extends ResourceLoaderModule {
 		return $baseModules;
 	}
 
+	/**
+	 * Get the localStorage key for the entire module store. The key references
+	 * $wgDBname to prevent clashes between wikis under the same web domain.
+	 *
+	 * @return string localStorage item key for JavaScript
+	 */
+	private function getStoreKey() {
+		return 'MediaWikiModuleStore:' . $this->getConfig()->get( 'DBname' );
+	}
+
 	/**
 	 * Get the key on which the JavaScript module cache (mw.loader.store) will vary.
 	 *
@@ -412,6 +422,7 @@ class ResourceLoaderStartUpModule extends ResourceLoaderModule {
 			'$VARS.maxQueryLength' => ResourceLoader::encodeJsonForScript(
 				$conf->get( 'ResourceLoaderMaxQueryLength' )
 			),
+			'$VARS.storeKey' => ResourceLoader::encodeJsonForScript( $this->getStoreKey() ),
 			'$VARS.storeVary' => ResourceLoader::encodeJsonForScript( $this->getStoreVary( $context ) ),
 		];
 		$profilerStubs = [

resources/src/startup/mediawiki.js

@@ -2161,7 +2161,7 @@
 					 * @return {string} localStorage item key
 					 */
 					getStoreKey: function () {
-						return 'MediaWikiModuleStore:' + mw.config.get( 'wgDBname' );
+						return $VARS.storeKey;
 					},
 
 					/**