Compressing packages with bzip2 instead gzip?

[Mikael Eriksson]

On Fri, Dec 09, 2005 at 03:36:06PM -0200, Carlos Ribeiro wrote:
> On 12/9/05, Mikael Eriksson <mikael_miffe_eriksson at yahoo.se> wrote:
> >
> > On Thu, Dec 08, 2005 at 06:18:00PM -0800, Matt Zimmerman wrote:
> > > On Wed, Dec 07, 2005 at 04:58:28PM +0200, Timo Jyrinki wrote:
> > > > Speaking of language files, those also compress better with bz2 even
> > though they
> > > > are in mo format:
> > > > -rw-r--r--  1 root root 1356095 2005-12-07 16:51 LC_MESSAGES-
> > fi.tar.bz2
> > > > -rw-r--r--  1 root root 1590691 2005-12-07 16:52 LC_MESSAGES-fi.tar.gz
> > > >
> > > > (compressed etch's /usr/share/locale/fi/LC_MESSAGES to get those)
> > >
> > > That's why the language pack .debs are already compressed with bzip2.
> > >
> > A repack of language-pack-gnome-* shows that most would be smallest when
> > compressed with 7z. And the rest is smallest with gzip -9.
> > See the attached file.
> >
> 
> An idea: the compression tests could be done automatically by a 'repacking'
> script on the central repository. It's a computationally intensive task, but
> it could be done in the background. The script would do the following:
> 
> -- get the original .deb
> -- repack the components with a number of different tools
> -- select the smallest ones
> -- generate a new deb file

The script i wrote does everything execpt generate a new deb. 

> 
> Although slow, this is at least an automatic procedure -- something you can
> throw at a server to work over 24x7 day after day, perhaps using otherwise
> unused cycles. The savings in bandwidth (both server side and user side)
> could potentially pay for it. And we would avoid putting one more strain on
> the back of packagers (testing to check which tool compresses better) --
> they could always work with .tar.gz for development.

After running my script on a lot of packages i see a pattern. Really
small debs, ~2000 bytes large benefit most for gzip -9 compression. And
everything else benefits most for 7z compression.

> 
> (After writing I realized that the repacker script can also be distributed
> to do this automatically... but for some reason I believe this is something
> that can be handled by a server in the repository.)
> 
> --
> Carlos Ribeiro
> Consultoria em Projetos
> blog: http://rascunhosrotos.blogspot.com
> blog: http://pythonnotes.blogspot.com
> mail: carribeiro at gmail.com
> mail: carribeiro at yahoo.com

-- 
NP: Nightwish - Wish I Had An Angel