The plan for arbitrarily large files
This plan currently only handles the case that each delta is not stored as diffs. The diffs part is a refinement to come later.
Suppose the file is "foo", the sfile is "SCCS/s.foo".
If the file gets too large, then SCCS/s.foo becomes SCCS/d.foo, which is a directory. In that directory, you will find
SCCS/d.foo/s.foo - this is the delta table graph. SCCS/d.foo/#.foo - serial number # contents