efficiently store only the changes to that tarball from one day to the next.
For small files, bup's compression won't be as good as xdelta's, but for
anything over a few megabytes in size, bup's compression will actually
-*work*, which is a bit advantage over xdelta.
+*work*, which is a big advantage over xdelta.
How does hashsplitting work? It's deceptively simple. We read through the
file one byte at a time, calculating a rolling checksum of the last 64