Jeremy Katz wrote:
The first thing is that it makes the most sense for the deltas to be
created and stored by koji rather than as a secondary process. This
adds the advantage that they're stored consistently with the packages
and also can be cached rather than recreated every time. It feels
somewhat analagous to me to the current situation with signing.
While I see the semi-parallel with signatures, I'd rather not rush into
adding this to koji. I'd like to have a better understanding of how
these deltas need to be managed.
Do we anticipate Koji actually having a use for the deltas, or would it
just be storing them for other tools?
Can deltarpms be signed independently of the rpms it compares? If so, we
may need to think about tracking these signatures.
How should we deal with the delta/signature interaction? Is there a
quick way to read the target's signature info from the delta (applydelta
-i doesn't seem to report it)? Each rpm in koji can have multiple
signatures, and we would presumably care which signature will be used
for the target rpm in the delta. This leads me to wonder about naming
schemes and api needs.
With signatures, the cached files are tiny, there are unlikely to be
more than a handful of them per rpm, and it is clearly reasonable to
keep them for as long as the rpm is kept. Even deltas for trivial cases
seem to be much larger than a cached signature header, and one can
imagine accumulating a large number of deltas for an rpm. So the
question is, how long should deltas be kept, and what should trigger