[GSoC/RFC] Ideas on git fetch --deepen

[Dongcan Jiang <dongcan.jiang@gmail.com>]

Hi all,

My name is Dongcan Jiang. I am studying for my Master Degree at Peking
University
majoring in Computer Science. I have been using Git to manage my projects
for about half a year. It's really exciting that Git has been helping me make
revision control much more convenient. Therefore, I am very interested in
doing some works for Git in GSoC 2015.

I have submitted my v2 patch on a microproject recently, and I am waiting
for comments on v2 now.

In the meantime, I have been scanning ideas on the git gsoc page and
their related mails. I find that I am interested in most of them, especially
"git fetch --deepen" idea.

Here is my understanding about this idea.

Although "deepen" and "depth" have different behavior, "deepen" can be
achieved by "depth" with some extra calculation. If we know the
distance between "my history bottom" and "your tips", we can set the sum
of "deepen" step and this distance as "depth" step. Then we can reuse
the logics of processing "depth" to complete it.

Take graph in [1] as an example.

>  (upstream)
>   ---o---o---o---A---B
>
>  (you)
>                  A---B

the distance of "my history bottom"(A) and "your tips"(B) is 1, then
"git fetch --deepen=3" can be achieved by "git fetch --depth=4"

However, I am a little worried about whether this idea is enough for a
GSoC project. I hope you can give me some comments and suggestions.

[1] http://article.gmane.org/gmane.comp.version-control.git/212950

Thanks,
Dongcan

-- 
江东灿（Dongcan Jiang）
Team of Search Engine & Web Mining
School of Electronic Engineering & Computer Science
Peking University, Beijing, 100871, P.R.China