We save our state by writing out and reading from the three TROVE_handle members, making use of the higher level trove interface.
struct handle_ledger { struct extentlist free_list; struct extentlist recently_freed_list; struct extentlist overflow_list; FILE *backing_store; TROVE_handle free_list_handle; TROVE_handle recently_freed_list_handle; TROVE_handle overflow_list_handle; }