Re: Why article numbers?

[Simon Josefsson <jas@extundo.com>]

kai.grossjohann@uni-duisburg.de (Kai Großjohann) writes:

> Yeah.  What I think should happen is a renumbering.  For the cache,
> renumbering is actually easier, most of the time: just renumber the
> cached articles to start at 1, and you'll be fine in most cases.

What if there is an article with number 1 on the server?  (But see
below too.)

> The copies in the agent are a thornier issue.  I think it would not
> be good to just delete them: they will then be fetched again from the
> server, which is a waste of bandwidth that we wanted to avoid by
> using the agent in the first place...

Yes, although that is an optimization.  Deleting them would at least
make things correct.

> If you have an index of the local copies by message id, then you
> could just ask the server for the headers (NOV) and then search for
> articles mentioned there by message id.  That tells you which number
> to use locally, and then there could be some articles that aren't
> found on the server -- we want to delete them I think.

Yes.

> Maybe the cache should be treated a little bit like a separate
> backend, kind of like nnvirtual does it, at least conceptually.  I
> think it would be best to just decouple the numbers used in the cache
> totally from the numbers used on the server.  This leads to problems
> when the cached articles are still on the server, but oh, well.

This sounds like a good idea.  So conceptually there is a nncache
which contains the articles you put into it with `*', and the nncache
groups mirror all your normal groups.  And when you enter a group it
is like entering a nnvirtual that contains the nncache group and the
real group.

OTOH it sounds like work, and might expose other unwanted behaviour,
so I'm not sure if it is worth the time to really implement it like
this...