int journal_file_fsprg_evolve(JournalFile *f, uint64_t realtime);
int journal_file_fsprg_seek(JournalFile *f, uint64_t epoch);
int journal_file_fsprg_evolve(JournalFile *f, uint64_t realtime);
int journal_file_fsprg_seek(JournalFile *f, uint64_t epoch);