gistfile1.diff

Index: subsites/code/Subsite.php
===================================================================
--- subsites/code/Subsite.php	(revision 100863)
+++ subsites/code/Subsite.php	(working copy)
@@ -74,6 +74,11 @@
 	 */
 	protected static $allowed_themes = array();
 
+	/**
+	 * Memory cache of accessible sites
+	 */
+	private static $_cache_accessible_sites = null;
+
 	static function set_allowed_domains($domain){
 		user_error('Subsite::set_allowed_domains() is deprecated; it is no longer necessary '
 			. 'because users can now enter any domain name', E_USER_NOTICE);
@@ -429,16 +434,23 @@
 	 * @param $mainSiteTitle The label to give to the main site
 	 */
 	function accessible_sites($permCode, $includeMainSite = false, $mainSiteTitle = "Main site", $member = null) {
-		// For 2.3 and 2.4 compatibility
-		$q = defined('Database::USE_ANSI_SQL') ? "\"" : "`";
-
 		// Rationalise member arguments
 		if(!$member) $member = Member::currentUser();
 		if(!$member) return new DataObjectSet();
 		if(!is_object($member)) $member = DataObject::get_by_id('Member', $member);
 
+		// Rationalise permCode argument
 		if(is_array($permCode))	$SQL_codes = "'" . implode("', '", Convert::raw2sql($permCode)) . "'";
 		else $SQL_codes = "'" . Convert::raw2sql($permCode) . "'";
+
+		// For 2.3 and 2.4 compatibility
+		$q = defined('Database::USE_ANSI_SQL') ? "\"" : "`";
+	
+		// Cache handling
+		$cacheKey = $SQL_codes . '-' . $member->ID;
+		if(isset(self::$_cache_accessible_sites[$cacheKey])) {
+			return self::$_cache_accessible_sites[$cacheKey];
+		}
 		
 		$templateClassList = "'" . implode("', '", ClassInfo::subclassesFor("Subsite_Template")) . "'";
 
@@ -497,6 +509,8 @@
 			}
 		}
 
+		self::$_cache_accessible_sites[$cacheKey] = $subsites;
+  
 		return $subsites;
 	}