Re: Histogram diff, libgit2 enhancement, libgit2 => git merge (GSOC)

From: Shawn Pearce <spearce@spearce.org>
Date: Mar 20, 2011, 18:06 UTC
Message-ID: <AANLkTi=6z=4m8opfhy9pV1S6ySobSA+WEEESESOJ0MZ4@mail.gmail.com>
In-Reply-To: <op.vsm1yszq2m56ex@localhost.localdomain>

On Sun, Mar 20, 2011 at 03:55, Pavel Raiskup <xraisk00@gmail.com> wrote:

Show 9 quoted lines

> I'd like to ask you for some details about "histogram diff" and "libgit"
> enhancement/git-merge tasks for this year's GSOC.
>
> Histogram diff:
> There is no mentor mentioned in [1]. Does it mean that there is no person
> who can be a mentor for this task or is that assignment possible to be
> mentored by everyone mentioned in other tasks? I'd like to do this task very
> much. After doing a small observing around source code of git/jgit it looks
> feasible for me.

As the original author of HistogramDiff in JGit, and a contributor to C Git... I'm probably the best person to mentor this task. I'm really busy, so I didn't sign up to mentor anything else this year, but I think I would make time for this project.

> There is a goal "Get this feature merged to the upstream git." -- but I have
> one theoretical question -- what if the benchmarking/study of histogram diff
> leads to conclusion that this algorithm will not be useful for upstream?

Then the project doesn't merge. :-)

> Does it mean "fail" in terms of GSOC? I have to think about it even if it
> looks that there should be speedup quite obvious. I don't want to fail
> a priory :).

I don't think so

I think the success of this project is if the code is of the quality that upstream would accept it, and if the final analysis data makes it clear whether or not its worth including. Its probably not worth including if its the same speed as the current Myers diff implementation from libxdiff or slower. But if its 2x faster, its probably worth merging. If the code quality is acceptable to the upstream maintainers.

> [1] https://git.wiki.kernel.org/index.php/SoC2011Ideas

-- 
Shawn.