Re: Libification project (SoC)

From: Rocco Rutte <pdmef@gmx.net>
Date: Mar 16, 2007, 13:09 UTC
Message-ID: <20070316130958.GD1783@peter.daprodeges.fqdn.th-h.de>
In-Reply-To: <Pine.LNX.4.63.0703161251200.22628@wbgn013.biozentrum.uni-wuerzburg.de>

Hi,

* Johannes Schindelin [07-03-16 12:54:52 +0100] wrote:

[...]

>Isn't this an awfully long shot?

>I'd be happy if the libification project resulted

>- in a (static!) libgit.a which can be linked to qgit or similar (being 
>  reentrant, or at least optionally so, and not die()ing all the time), 
>  and

>- which does not fix the API yet (at least for the most parts).

>We _can_ -- once we agree on a stable API -- expose _some_ functions in a 
>libgit.so, but that does not have to be the goal for the first step!

First, I think that would be some cleanup "only" since that basically would mean to

   1) make all functions die()ing return some value and handle it and
   2) wrap all static vars into structures and pass them around

If you don't choose a design before wrapping things up in structures, you'll probably end up having one structure per source file (at least too many structures).

Porting things like qgit to it or writting proper perl/python bindings is wasted time since you'd have to rewrite all of it once you decided which functions to expose and which structures to use (calling the main() routines of builtin's doesn't count as real libifaction, it would rather be a performance improvement only).

I'd simply try to find a rough consensus on the data structures and the 
layer model before starting the project, solve 1), afterwards implement 
2) according to it. While 2) happens it would make sense to try to 
develop perl, python, C and C++ bindings in parallel to find out early 
enough whether the design details chosen are useful for real consumers 
outside the git-* tools.

You could put big fat warnings everywhere that parts of the API which are exposed are heavily unstable and likely subject to change and that programmers using them will have to frequently start over. Once it turns out that all the git-tools and all "reference consumers" work it, you can do some cleanup to get to the final first API version after the libification project is done.

   bye, Rocco

-- 
:wq!