From: Timo Tijhof <krinklemail@gmail.com>
Date: Thu, 20 Mar 2014 06:04:48 +0000 (+0100)
Subject: ResourceLoaderStartUpModule: Use hashMtime to detect config changes
X-Git-Tag: 1.31.0-rc.0~16469^2
X-Git-Url: https://git.cyclocoop.org/%27.%24link.%27?a=commitdiff_plain;h=f9a951abc2c1e5a8d8aa361415843875a96d68bd;p=lhc%2Fweb%2Fwiklou.git

ResourceLoaderStartUpModule: Use hashMtime to detect config changes

Changes to the static startup.js file are covered by the file
mtime in #getModifiedTime.

Changes to the module registrations are covered by the max
module mtime loop in #getModifiedTime.

But changes to LocalSettings.php etc. affecting mw.config values
embedded in #getScript aren't traceable. Resort to hashing those
and detecting changes between calls that way.

Without this, changes to mw.config never made it live (not even
after the rebuild every 5 minutes) because of 304 Not Modified
being sent between Apache and Varnish. Changes to config either
didn't matter to front-end right away and made it with the next
deployment that changes a different module, or by touching
startup.js to force a version bump.

Simple third party installs were not affected by this bug as their
settings would only be coming from LocalSettings.php (as opposed
to included files) and $wgInvalidateCacheOnLocalSettingsChange is
true by default.

Bug: 28899
Change-Id: I484166923d97368d95beeb40bb209dec9b849033
---

diff --git a/includes/resourceloader/ResourceLoaderStartUpModule.php b/includes/resourceloader/ResourceLoaderStartUpModule.php
index a551c4ae0d..1e2f65cdbb 100644
--- a/includes/resourceloader/ResourceLoaderStartUpModule.php
+++ b/includes/resourceloader/ResourceLoaderStartUpModule.php
@@ -27,6 +27,7 @@ class ResourceLoaderStartUpModule extends ResourceLoaderModule {
 	/* Protected Members */
 
 	protected $modifiedTime = array();
+	protected $configVars = array();
 	protected $targets = array( 'desktop', 'mobile' );
 
 	/* Protected Methods */
@@ -36,6 +37,12 @@ class ResourceLoaderStartUpModule extends ResourceLoaderModule {
 	 * @return array
 	 */
 	protected function getConfig( $context ) {
+
+		$hash = $context->getHash();
+		if ( isset( $this->configVars[$hash] ) ) {
+			return $this->configVars[$hash];
+		}
+
 		global $wgLoadScript, $wgScript, $wgStylePath, $wgScriptExtension,
 			$wgArticlePath, $wgScriptPath, $wgServer, $wgContLang,
 			$wgVariantArticlePath, $wgActionPaths, $wgVersion,
@@ -106,7 +113,8 @@ class ResourceLoaderStartUpModule extends ResourceLoaderModule {
 
 		wfRunHooks( 'ResourceLoaderGetConfigVars', array( &$vars ) );
 
-		return $vars;
+		$this->configVars[$hash] = $vars;
+		return $this->configVars[$hash];
 	}
 
 	/**
@@ -278,7 +286,8 @@ class ResourceLoaderStartUpModule extends ResourceLoaderModule {
 
 		$time = max(
 			wfTimestamp( TS_UNIX, $wgCacheEpoch ),
-			filemtime( "$IP/resources/startup.js" )
+			filemtime( "$IP/resources/startup.js" ),
+			$this->getHashMtime( $context )
 		);
 
 		// ATTENTION!: Because of the line below, this is not going to cause
@@ -297,6 +306,25 @@ class ResourceLoaderStartUpModule extends ResourceLoaderModule {
 		return $this->modifiedTime[$hash];
 	}
 
+	/**
+	 * Hash of all dynamic data embedded in getScript().
+	 *
+	 * Detect changes to mw.config settings embedded in #getScript (bug 28899).
+	 *
+	 * @param $context ResourceLoaderContext
+	 * @return string: Hash
+	 */
+	public function getModifiedHash( ResourceLoaderContext $context ) {
+		global $wgLegacyJavaScriptGlobals;
+
+		$data = array(
+			'vars' => $this->getConfig( $context ),
+			'wgLegacyJavaScriptGlobals' => $wgLegacyJavaScriptGlobals,
+		);
+
+		return md5( serialize( $data ) );
+	}
+
 	/**
 	 * @return string
 	 */