Re: [RFC/WIP] Pluggable reference backends

[Junio C Hamano <gitster@pobox.com>]

Jeff King <peff@peff.net> writes:

> On Mon, Mar 10, 2014 at 07:30:45AM -0700, Shawn Pearce wrote:
>
>> > * Store references in a SQLite database, to get correct transaction
>> >   handling.
>> 
>> No to SQLLite in git-core. Using it from JGit requires building
>> SQLLite and a JNI wrapper, which makes JGit significantly less
>> portable. I know SQLLite is pretty amazing, but implementing
>> compatibility with it from JGit will be a big nightmare for us.
>
> That seems like a poor reason not to implement a pluggable feature for
> git-core. If we implement it, then a site using only git-core can take
> advantage of it. Sites with JGit cannot, and would use a different
> pluggable storage mechanism that's supported by both. But if we don't
> implement, it hurts people using only git-core, and it does not help
> sites using JGit at all.

We would need to eventually have at least one backend that we know
will play well with different Git implementations that matter
(namely, git-core, Jgit and libgit2) before the feature can be
widely adopted.

The first backend that is used while the plugging-interface is in
development can be anything and does not have to be one that
eventual ubiquitous one, however; as long as it is something that we
do not mind carrying it forever, along with that final reference
backend.  I take the objection from Shawn only as against making the
sqlite that final one.