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Thu, 4 Sep 2025 07:10:17 -0400 (EDT) Received: by mail (OpenSMTPD) with ESMTPSA id f2fb9393 (TLSv1.3:TLS_CHACHA20_POLY1305_SHA256:256:NO); Thu, 4 Sep 2025 11:10:15 +0000 (UTC) Date: Thu, 4 Sep 2025 13:10:07 +0200 From: Patrick Steinhardt To: Junio C Hamano Cc: "brian m. carlson" , Taylor Blau , rsbecker@nexbridge.com, 'Elijah Newren' , 'Kristoffer Haugsbakk' , 'Josh Soref' , git@vger.kernel.org, 'Christian Brabandt' , 'Phillip Wood' , 'Eli Schwartz' , "'Haelwenn (lanodan) Monnier'" , 'Johannes Schindelin' , 'Matthias =?utf-8?B?QcOfaGF1ZXIn?= , 'Sam James' , 'Collin Funk' , 'Mike Hommey' , 'Pierre-Emmanuel Patry' , "'D. Ben Knoble'" , 'Ramsay Jones' , 'Ezekiel Newren' , 'Josh Steadmon' , 'Calvin Wan' Subject: Re: [PATCH v3 02/15] xdiff: introduce rust Message-ID: References: <01f101dc1760$5eef42b0$1ccdc810$@nexbridge.com> Precedence: bulk X-Mailing-List: git@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Wed, Sep 03, 2025 at 03:10:44PM -0700, Junio C Hamano wrote: > Patrick Steinhardt writes: > > Note that I'm not saying that we need to have both a C and Rust > > implementation for everything written in Rust. I don't think that's > > sustainable in any way. But any feature written in Rust should be a > > _new_ feature that can be disabled and that users can live without for > > the time being. > > Yes, if we can find such modular niche, it would be ideal. But how > many areas that we can cleanly plug an optional thing in without > disrupting existing codebase are there? Offhand, all I'd think of > are a new merge backend, a new rebase backend, a transport helper, > or perhaps a new diff-algorithm? Not too many, I guess. If we cannot find anything, an alternative could also be to take a very simple subsystem that doesn't see a lot of changes and convert that to Rust. We'd retain both implementations in that case, which I mentioned is painful because we now have to keep both in sync. But if we say that this is a testballoon, only, and that we don't continue to convert other code until Git 3.0, then that might be fine. "varint.c" could be a good match. It's trivial, only 30 lines of code, and completely standalone. We could still build new and optional functionality via Rust, but I guess it also doesn't hurt to have a test balloon that is part of libgit.a to test interoperability. I'll send patches later today. Patrick