Re: git-style file storage for .deb

[Phillip Susi <psusi@cfl.rr.com>]

Zenaan Harkness wrote:
> Sorry, what I mean is, separate files, not tarred and gzipped.
>
> This way, when a package is upgraded, only those files which changed
> would have new git-sha1 ref'ed files, files that are the same as before,
> share the same sha ref and are therefore identical and require no extra
> storage.
>
> This is where my thought of inter-distribution shared repositories came
> in - eg distributions sharing the same XOrg release, would have a lot of
> shared files (ie identical files) which would share sha signatures, and
> therefore be the one and the same file in the git repo.
>
> But of course, it would rely on files being stored individually, not
> inside .deb or .rpm packages.
>
> I'm wondering whether someone has the technical know-how to do a
> comparison, eg. between a couple of Debian or other distribution
> versions - as it, how many files are shared for example between say
> Ubuntu 7.10 and 8.04.
>
> There might be more savings to be had for sources, rather than binaries.
> And HTTP download of binaries as individual files might have more
> overhead than downloading as packages. But it might be quicker, since no
> unpacking at other end - does anyone know?

This would mean that the server would have to decompress the pack file, 
undelitfy the file, recompress it, and transmit it to the client, for 
every file in every package.  That load would be several orders of 
magnitude higher than current.

> > It would not be reduced by much and would have a tremendous overhead to 
> > access as a result, which the mirrors could never handle, and it would 
> > break backwards compatibility since http or ftp could no longer be used to 
> > fetch packages.
>
> With an appropriate git config/setup, I'm pretty sure http and ftp
> access is just fine, (my knowledge is relatively limited on this subject
> though).

For http/ftp access to still work, the repository must not be stored in 
packed+pruned form, which negates the space savings you are interested 
in, as well as only allowing access to the current version.  In fact, it 
would use a _lot_ more space than it does now.