installer: Add comments to purgeCache()

Change-Id: I791f220b49e3e1c7d6df9ccab7d70ff8a0031ef1

diff --git a/includes/installer/DatabaseUpdater.php b/includes/installer/DatabaseUpdater.php
index 752bc54..a317822 100644 (file)
--- a/includes/installer/DatabaseUpdater.php
+++ b/includes/installer/DatabaseUpdater.php
@@ -988,19 +988,27 @@ abstract class DatabaseUpdater {
        }
 
        /**
-        * Purge the objectcache table
+        * Purge various database caches
         */
        public function purgeCache() {
                global $wgLocalisationCacheConf;
-               # We can't guarantee that the user will be able to use TRUNCATE,
-               # but we know that DELETE is available to us
+               // We can't guarantee that the user will be able to use TRUNCATE,
+               // but we know that DELETE is available to us
                $this->output( "Purging caches..." );
+
+               // ObjectCache
                $this->db->delete( 'objectcache', '*', __METHOD__ );
+
+               // LocalisationCache
                if ( $wgLocalisationCacheConf['manualRecache'] ) {
                        $this->rebuildLocalisationCache();
                }
+
+               // ResourceLoader: Message cache
                $blobStore = new MessageBlobStore();
                $blobStore->clear();
+
+               // ResourceLoader: File-dependency cache
                $this->db->delete( 'module_deps', '*', __METHOD__ );
                $this->output( "done.\n" );
        }