From: Emily Shaffer <nasamuffin@google.com>
To: Taylor Blau <me@ttaylorr.com>
Cc: Git List <git@vger.kernel.org>, Jonathan Nieder <jrn@google.com>,
Jose Lopes <jabolopes@google.com>,
Aleksandr Mikhailov <avmikhailov@google.com>
Subject: Re: Proposal/Discussion: Turning parts of Git into libraries
Date: Tue, 21 Feb 2023 14:27:47 -0800 [thread overview]
Message-ID: <CAJoAoZm+bS3pT_DOaQfafW6dyV=m3ZUs=oxNZ_sKdfFO7uxM9A@mail.gmail.com> (raw)
In-Reply-To: <Y/UXBw3Y9YnXUBIN@nand.local>
On Tue, Feb 21, 2023 at 11:10 AM Taylor Blau <me@ttaylorr.com> wrote:
>
> On Fri, Feb 17, 2023 at 01:12:23PM -0800, Emily Shaffer wrote:
> > This turned out pretty long-winded, so a quick summary before I dive in:
> >
> > - We want to compile parts of Git as independent libraries
> > - We want to do it by making incremental code quality improvements to Git
> > - Let's avoid promising stability of the interfaces of those libraries
> > - We think it'll let Git do cool stuff like unit tests and allowing
> > purpose-built plugins
> > - Hopefully by example we can convince the rest of the project to join
> > in the effort
>
> Like others, I am less interested in the VFS-specific components you
> mention here, but I suspect that is just one particular instance of
> something that would be benefited by making git internals exposed via a
> linkable library.
>
> I don't have objections to things like reducing our usage of globals,
> making fewer internal functions die() when they encounter an error, and
> so on. But like Junio, I suspect that this is definitely an instance of
> a "devil's in the details" kind of problem.
>
> That's definitely my main concern: that this turns out to be much more
> complicated than imagined and that we leave the codebase in a worse
> state without much to show.
Yeah, I'm really hoping we don't end up with ugly half-changes too.
Some examples of "partial credit" that I'd be happy with:
- Fewer internal libraries relying on globals like
the_repository/the_index/etc (we've already started this effort,
libification or no)
- An "ugly" library interface becoming clearer and easier to use (and
internal callers updated)
- Figuring out an "error reporting type" that works well for us
There are some things that *are* ugly, for example, calling a library
via a vtable. But I do feel comfortable waiting to introduce that kind
of thing until we really need it, at which point I suspect we'll have
already made some successful strides with libification in general.
It's not so great to just trust me to say "I promise not to make ugly
changes" - I'd appreciate the community's help pushing back if we
propose doing something in an untidy way without clear justification.
> A lesser version of that outcome would be
> that we cause a lot of churn in the tree with not much to show either.
I'm actually not so concerned about this! The "churn", as I see it,
comes in the form of code cleanup that already makes Git more
understandable for Git hackers. We do spend some time on that now, as
a project, but I wouldn't be unhappy if we spent even more :)
>
> So I think we'd want to see some more concrete examples with clear
> benefits to gauge whether this is a worthwhile direction. I think that
> strbuf.h is too trivial an example to demonstrate anything useful. Being
> able to extract config.h into its own library so that another non-Git
> program could link against it and implement 'git config'-like
> functionality would be much more interesting.
Sure - I'm also looking forward to seeing it.
Thanks for your thoughtful reply.
- Emily
next prev parent reply other threads:[~2023-02-21 22:28 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-02-17 21:12 Proposal/Discussion: Turning parts of Git into libraries Emily Shaffer
2023-02-17 21:21 ` brian m. carlson
2023-02-17 21:38 ` Emily Shaffer
2023-02-17 22:41 ` brian m. carlson
2023-02-17 22:49 ` Emily Shaffer
2023-02-22 19:34 ` Jeff King
2023-02-24 20:31 ` Emily Shaffer
2023-02-24 21:41 ` Jeff King
2023-02-24 22:59 ` Junio C Hamano
2023-02-17 22:04 ` rsbecker
2023-02-17 22:48 ` brian m. carlson
2023-02-17 22:57 ` Junio C Hamano
2023-02-18 1:59 ` demerphq
2023-02-18 10:36 ` Phillip Wood
2023-03-23 23:22 ` Felipe Contreras
2023-03-23 23:30 ` rsbecker
2023-03-23 23:34 ` Felipe Contreras
2023-03-23 23:42 ` rsbecker
2023-03-23 23:55 ` Felipe Contreras
2023-03-24 19:27 ` rsbecker
2023-03-24 21:21 ` Felipe Contreras
2023-03-24 22:06 ` rsbecker
2023-03-24 22:29 ` Felipe Contreras
2023-02-21 21:42 ` Emily Shaffer
2023-02-22 0:22 ` Junio C Hamano
2023-02-18 4:05 ` Elijah Newren
2023-02-21 22:06 ` Emily Shaffer
2023-02-22 8:23 ` Elijah Newren
2023-02-22 19:25 ` Jeff King
2023-02-21 19:09 ` Taylor Blau
2023-02-21 22:27 ` Emily Shaffer [this message]
2023-02-22 1:44 ` Victoria Dye
2023-02-25 1:48 ` Jonathan Tan
2023-02-22 14:55 ` Derrick Stolee
2023-02-24 21:06 ` Emily Shaffer
2023-03-23 23:37 ` Felipe Contreras
2023-03-23 23:44 ` rsbecker
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