add update_storage_stats procedure

db/zm_create.sql.in

@@ -273,10 +273,26 @@ CREATE TABLE `Events_Archived` (
 ) ENGINE=@ZM_MYSQL_ENGINE@;
 
 
-drop trigger if exists event_update_trigger;
+drop procedure if exists update_storage_stats;
 
 delimiter //
 
+create procedure update_storage_stats(IN StorageId smallint(5), IN space BIGINT)
+
+sql security invoker
+
+deterministic
+
+begin
+
+  update Storage set DiskSpace = DiskSpace + space where Id = StorageId;
+
+end;
+
+//
+
+drop trigger if exists event_update_trigger//
+
 CREATE TRIGGER event_update_trigger AFTER UPDATE ON Events 
 FOR EACH ROW
 BEGIN