Re: Can I use CRoaring library in Git?

From: Kaartic Sivaraam <kaartic.sivaraam@gmail.com>
Date: Jul 17, 2022, 12:25 UTC
Message-ID: <e574ac20-c287-c395-5bc3-b481d81764c7@gmail.com>
In-Reply-To: <CAPOJW5zNsETYwD=MXCFLn91qaemgooPN-JB1sx7KagkKxOXTnQ@mail.gmail.com>

On 16-07-2022 21:56, Abhradeep Chakraborty wrote:

Show 14 quoted lines

> On Sat, Jul 16, 2022 at 7:50 PM Ævar Arnfjörð Bjarmason
> <avarab@gmail.com> wrote:
>>
>> Another possibility is to get the library to dual-license itself,
>> running "git shortlog -sn" on it it seems it's mainly written by one
>> contributor, with a relatively short tail of others, perhaps they'd be
>> willing to dual-license at the prospect of having git use it?
> 
> Kaartic suggested the same and it seems better than the previous one.
> 
> As a side note, the current EWAH implementation is also relicensed[1]
> to make it compatible with Git. As these two are mainly written by the
> same person, I think he will help us this time also.
>

The EWAH case is a bit different. The original EWAH implementation [ewah-cpp] was in C++. It was then ported to C [ewah-c] by Git contributors [ewah-git]. The ported version has been relicensed under GPLv2 with Deniel Lemire's permission.

The case with CRoaring is that the implementation already exists in C [croaring] and that is the one which is licensed under Apache V2. I'm not sure how relicensing works for already existing code.

I suppose we could enquire Daniel Lemire about using the Apache licensed code for Git. Let's hope for the best.

[[ References ]]

[ewah-cpp]: https://github.com/lemire/EWAHBoolArray

[ewah-c]: https://github.com/vmg/libewok
 [ewah-git]: The initial commit of 'ewah' directory mentions the
    relicensing:

    e1273106f6 (ewah: compressed bitmap implementation, 2013-11-14)

[croaring]: https://github.com/RoaringBitmap/CRoaring

> Thanks!
> 
> [1]  https://github.blog/2015-09-22-counting-objects/#footnote-1

-- Sivaraam