Designing a faster index format GSoC 2012

Hi

I'm a third year computer engineering major wanting to participate at
GSoC 2012 working on the Git project of designing a faster index
format.
I was hoping if someone could give some pointers on where to begin.
I've already started looking around and found some files that I think
are important <add.c, read-cache.c, index-format.txt>.
Is there something I'm missing or that you think I should also check out?
Any pointer would be greatly appreciated.

Thank you.