boolean () { //RC: as always, with mapped storage it is tricky to say when it is 'dirty' -- 'cos almost all the // writes go directly to the mapped buffer, and mapped buffer dirty/flush management is up to OS. // We can manage .dirty flag ourself, but it seems an overhead for (almost) nothing -- there are // very few real usages for .isDirty() in mmapped storages. I just define: storage is not dirty // by default: return false; }