[gentoo-soc] rfc: reducing the time of "Calculating dependencies" phase project.

[Александр Берсенев]

Hello,

my name is Alexander Bersenev, I am postgraduate of Institute of
Mathematics
and Mechanics(Russia).
I want to propose a project for GSoC 2013 and ask what do you think about
it.

In short: I want to reduce the "Calculating dependencies" phase of emerge.

On my notebook "emerge -pv bash" command takes 40 secs to calculate a deps.
If I launch it again, it take about 40 secs again(a have a lot of RAM, so
there was no HDD usage).

Of course, quick cprofile profiling showed no places to optimize because
such optimizations already have been made.

The main idea is add some caching layers(more high-level, than in
/usr/portage/metadata/md5-cache/). The main goal is to find and eliminate
repeated computations between "emerge" runs.

As part of work I plan to examine approaches of other pkg managers(yum,
aptitude).

I heard from Donnie Berkholz in IRC about pkgcore project. He said it works
faster in practice. But it has some problems with EAPI5 support.

What is better: actualize a pkgcore code or try to dig into portage? Or it
is
the bad ideas at all?

----
Some info about me:
- github: https://github.com/alexbers/
- twitter: https://twitter.com/alex_bers
- I was participated in GSoC 2011 with Autodep(auto dependency checker)
project.
- I administer ~250 nodes cluster in Institute of Mathematics and Mechanics
- I use Gentoo as my primary OS since 2007.
- I interested in computer security. Participated in Defcon CTF(Las Vegas)
  and in Nuit du Hack CTF(Paris, won 4000 euro) as member of Hackerdom
team.
  Also we organize RuCTF and RuCTFE annual competitions, which likely are
  the biggest in Russia(http://ructf.org/index.en.html).

----

Best,
Alexander Bersenev