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Wed, 7 Oct 2026 01:12:44 -0400 (EDT) Received: by mail (OpenSMTPD) with ESMTPSA id 4b9bb652 (TLSv1.3:TLS_AES_256_GCM_SHA384:256:NO); Wed, 7 Oct 2026 05:12:42 +0000 (UTC) Date: Wed, 7 Oct 2026 07:12:39 +0200 From: Patrick Steinhardt To: Karthik Nayak Cc: git@vger.kernel.org, toon@iotcl.com Subject: Re: [PATCH v3] packed-refs: use `fwrite()` when passing refs verbatim Message-ID: References: <20260930-kn-speedup-packed-refs-v1-1-111cd03d9b0e@gmail.com> <20261006-kn-speedup-packed-refs-v3-1-a1c76b1df9e0@gmail.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 Tue, Oct 06, 2026 at 05:11:57PM -0400, Karthik Nayak wrote: > Patrick Steinhardt writes: > > On Tue, Oct 06, 2026 at 11:18:40AM +0200, Karthik Nayak wrote: > >> diff --git a/refs/packed-backend.c b/refs/packed-backend.c > >> index a73fc6aca7..43ad674cf4 100644 > >> --- a/refs/packed-backend.c > >> +++ b/refs/packed-backend.c > >> @@ -879,6 +879,12 @@ struct packed_ref_iterator { > >> /* The current position in the snapshot's buffer: */ > >> const char *pos; > >> > >> + /* > >> + * Start of the current record, set when advancing `pos`. Used to > >> + * pass records verbatim to `fwrite()`. > >> + */ > >> + const char *record_start; > > > > The way this is written makes you think that `pos == record_start`, and > > thus one wonders why we even need this separate variable in the first > > place. So I assume that we modify `pos` in some cases without modifying > > the new variable at the same point in time. But if so, the above comment > > is not true anymore. > > > > Hmm. I only state that this is 'set _when_ advancing `pos`', Why do you > think that this would mean `pos == record_start`? To me it reads as "whenever we advance `pos`, then we set `record_start`". Which is not the case, we also sometimes advance `pos` without setting it. Patrick