Re: [msysGit] Re: [RFH] GSoC 2015 application

[Christian Couder <christian.couder@gmail.com>]

On Wed, Feb 25, 2015 at 9:44 AM, Johannes Schindelin
<johannes.schindelin@gmx.de> wrote:
> Hi Matthieu,
>
> On 2015-02-25 00:56, Matthieu Moy wrote:
>> Johannes Schindelin <johannes.schindelin@gmx.de> writes:
>>
>>> On 2015-02-24 19:25, Junio C Hamano wrote:
>>>> On Tue, Feb 24, 2015 at 9:32 AM, Matthieu Moy
>>>> <Matthieu.Moy@grenoble-inp.fr> wrote:
>>>>> About the proposal:
>>>>>
>>>>>   The idea of this project is to dive into the Git source code and
>>>>>   convert, say, git-add--interactive.perl and/or git stash into proper C
>>>>>   code, making it a so-called "built-in".
>>>>>
>>>>> My advice would be to try converting several small scripts, and avoid
>>>>> targetting a big one....
>>>>> add--interactive and stash are relatively complex beasts, perhaps
>>>>> git-pull.sh would be easier to start with.
>>>>
>>>> Yeah, I think that is a very good suggestion.
>>>
>>> Well, git-pull.sh is really small. I did not want to give the impression that the Git project is giving out freebies. But I have no objection to change it if you open that PR.
>>
>> To get an idea, I counted the lines of code written by the student I
>> mentored last year:
>>
>> $ git log --author tanayabh@gmail.com -p | diffstat -s
>>  43 files changed, 1225 insertions(+), 367 deletions(-)
>>
>> I would consider this GSoC as "average" (i.e. not exceptionnally good,
>> but certainly not a bad one either), so you may hope for more, but you
>> should not _expect_ much more IMHO.
>>
>> In comparison:
>>
>> $ wc -l git-add--interactive.perl
>> 1654 git-add--interactive.perl
>> $ wc -l git-stash.sh
>> 617 git-stash.sh

There is also:

$ wc -l git-bisect.sh
528 git-bisect.sh

And there is already builtin/bisect--helper.c that can be used to
convert step by step shell code to C. I can mentor or co-mentor this
convertion by the way, but that would conflict with the other bisect
related GSoC project if a student takes it.

>> I'd expect a rewrite in C to at least double the number of lines of
>> code, so rewriting git-stash would mean writting at least as many lines
>> of code as the GSoC above. git-add--interactive.perl would be rather far
>> above.
>
> Sure. You're right, I was thinking too big.
>
>> But my point was not to convert _only_ git-pull.sh, but to have a GSoC
>> starting with this one and plan more. Then, depending on how it goes,
>> you can adjust the target.
>
> That's excellent advice.

Yeah!

>> This all depends on what you intend to do if the student does not finish
>> the job. If you're going to do the rewrite yourself anyway, then having
>> the student do even half of it is good already. If you're not going to
>> finish the job by yourself, then a 95%-done-rewrite means a piece of
>> code posted on the mailing list and never merged (and a lot of time
>> wasted).
>
> Well, all of this is academic at this point.

Yeah, but it's still worth keeping in many parts of our collective mind :-)

> Let's see whether we get accepted, and then, if a student finds this project compelling enough.
>
> If both things happen, I will definitely heed your advice and encourage the student to start with some script that is easily converted, to "get her feet wet".

Great!

Thanks,
Christian.