Re: Implementing reftable in Git

From: Derrick Stolee <stolee@gmail.com>
Date: May 9, 2018, 14:52 UTC
Message-ID: <059b8daf-c990-aad5-90a4-5ec38c42b7b3@gmail.com>
In-Reply-To: <CAP8UFD0PPZSjBnxCA7ez91vBuatcHKQ+JUWvTD1iHcXzPBjPBg@mail.gmail.com>

On 5/9/2018 10:33 AM, Christian Couder wrote:

Show 8 quoted lines

> Hi,
>
> I might start working on implementing reftable in Git soon.
>
> During the last Git Merge conference last March Stefan talked about
> reftable. In Alex Vandiver's notes [1] it is asked that people
> announce it on the list when they start working on it, and it appears
> that there is a reference implementation in JGit.

Thanks for starting on this! In addition to the performance gains, this will help a lot of users with case-insensitive file systems from getting case-errors on refnames.

Show 16 quoted lines

> Looking it up, there is indeed some documentation [2], code [3], tests
> [4] and other related stuff [5] in the JGit repo. It looks like the
> JGit repo and the reftable code there are licensed under the Eclipse
> Distribution License - v 1.0 [7] which is very similar to the 3-Clause
> BSD License also called Modified BSD License which is GPL compatible
> according to gnu.org [9]. So from a quick look it appears that I
> should be able to port the JGit to Git if I just keep the copyright
> and license header comments in all the related files.
>
> So I think the most straightforward and compatible way to do it would
> be to port the JGit implementation.
>
> Thanks in advance for any suggestion or comment about this.
>
> Reftable was first described by Shawn and then discussed last July on
> the list [6].

The hope is that such a direct port should be possible, but someone else should comment on the porting process.

This is also something that could be created independently based on the documentation you mention. I was planning to attempt that during a hackathon in July, but I'm happy you are able to start earlier (and that you are announcing your intentions). I would be happy to review your patch series, so please keep me posted.

Thanks, -Stolee