fn last_record(path: &Path, complete_only: bool) -> Result<(u64, Vec<u8>)>Expand description
path’s last record and the offset where it ends. With complete_only
that is the last newline-ended record, so a record still being written
is passed over; a file with no newline at all is one record either way,
left to the parse to judge. Reads the file’s end, widening the window
until it holds the whole record, however large (a big tool result).