Idea to prevent those long package listing downloads with apt-get (maybe this should be on debian-devel...)
Maybe I should have posted to debian-devel, but I'm not subscribed and I get enough mail as it is.
I had this idea when I was sitting there watching 768K of package
listing for unstable trickle down my flaky, slow modem connection
at about 1K/sec, paying my 1 pence per minute to British Telecom
when I thought "Why can't I just download what's changed since
last time?".
Now this seems like a great idea, although in practice it's not
that simple, but I think I've thought of a way that would not be
too difficult to do, and could (I think) be relatively easy to
implement (not that I'm up to the job). If the package listing was
archived, say, daily to a Packages-990103.gz file for instance. at
a set time (e.g. midnight GMT or whenever the servers are less
busy on average), and a backlog of diffs between these files kept
for, say, a month, then this would allow apt (assuming local time
and date were correct) to only grab the parts of the listing that
had changed, created by either diff or xdelta and put back
together by something like patch.
This is fine, but what if you want that security fic and don't
want to wait 20 hours for apt to realise it's there? Well, what if
there is also a patch fromt he last archived package listing to
the current package listing. e.g Packages-current.diff.gz. apt or
whatever could then pick up all the necessary patches up to the
last archived packages version, and then save this locally. It
could then create a duplicate to apply the Packages-current.diff
to and remove this as soon as the next archive is made. and start
again. This Packages-current.diff would be recalculated from the
Packages-99whatever.gx file whenever a new package was uploaded or
moved from incoming by the ftp maintainer. The old system would
still be there, available for use by existing tools, just that
these new files would be available for more efficient use by
tools that support this way of working.
Anyway, that was just my twopence while I wait for apt-get update
to do it's job. It was just an idea that is quite simple, yet
seems very long-winded in writing. If someone wants to ridicule me
for putting forward a silly idea, then please do. It was after all
just an idea that crossed my mind.
Aha! apt-get update's finished. Time to hit send.
--
Russell G. Howe <rhowe@mindless.com> -- http://rhowe.8m.com/new/ -- 212.38.66.144
There is is no reason for any individual to have a computer in their home.
-- Ken Olsen (President of Digital Equipment Corporation) 1977
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