From: Derrick Stolee <stolee@gmail•com>
To: Patrick Steinhardt <ps@pks•im>,
Derrick Stolee via GitGitGadget <gitgitgadget@gmail•com>
Cc: git@vger•kernel.org, gitster@pobox•com, me@ttaylorr•com
Subject: Re: [PATCH v2 4/6] midx-write: use uint32_t for preferred_pack_idx
Date: Fri, 5 Sep 2025 15:05:42 -0400 [thread overview]
Message-ID: <4c6468d6-02c1-4c79-8ec7-4d250341ca81@gmail.com> (raw)
In-Reply-To: <aLgVOa96grWC3G0Q@pks.im>
On 9/3/2025 6:15 AM, Patrick Steinhardt wrote:
> On Sat, Aug 30, 2025 at 09:23:25PM +0000, Derrick Stolee via GitGitGadget wrote:
>> From: Derrick Stolee <stolee@gmail•com>
>>
>> midx-write.c has the DISABLE_SIGN_COMPARE_WARNINGS macro defined for a
>> few reasons, but the biggest one is the use of a signed
>> preferred_pack_idx member inside the write_midx_context struct. The code
>> currently uses -1 to indicate an unset preferred pack but pack int ids
>> are normally handled as uint32_t. There are also a few loops that search
>> for the preferred pack by name and those iterators will need updates to
>> uint32_t in the next change.
>>
>> For now, replace the use of -1 with a 'NO_PREFERRED_PACK' macro and an
>> equality check. The macro stores the max value of a uint32_t, so we
>> cannot store a preferred pack that appears last in a list of 2^32 total
>> packs, but that's expected to be unreasonable already. This improves the
>> range from 2^31 already.
>
> Tiny nit: the last sentence reads a bit funny. Maybe something like
> this?
>
> Furthermore, with this change we end up extending the range from
> 2^31 possible packs to 2^32-1.
That is better.
>> @@ -1040,7 +1042,9 @@ static int write_midx_internal(struct repository *r, const char *object_dir,
>> struct hashfile *f = NULL;
>> struct lock_file lk;
>> struct tempfile *incr;
>> - struct write_midx_context ctx = { 0 };
>> + struct write_midx_context ctx = {
>> + .preferred_pack_idx = NO_PREFERRED_PACK,
>> + };
>> int bitmapped_packs_concat_len = 0;
>> int pack_name_concat_len = 0;
>> int dropped_packs = 0;
>
> Why is this change needed? We didn't previously initialize
> `.preferred_pack_idx = -1` either.
I think the previous lack of initialization was incorrect. It happened
to work because it became initialized to -1 later _or_ its value of
zero was implicitly used when searching for a preferred pack.
I thought it prudent to set this value as the default instead of
implying that the 0th packfile was preferred.
Thanks,
-Stolee
next prev parent reply other threads:[~2025-09-05 19:05 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-08-28 17:39 [PATCH 0/5] midx-write: fix segfault and do several cleanups Derrick Stolee via GitGitGadget
2025-08-28 17:39 ` [PATCH 1/5] midx-write: only load initialized packs Derrick Stolee via GitGitGadget
2025-08-28 20:19 ` Junio C Hamano
2025-08-29 1:20 ` Taylor Blau
2025-08-30 14:33 ` Derrick Stolee
2025-08-28 17:39 ` [PATCH 2/5] midx-write: put failing response value back Derrick Stolee via GitGitGadget
2025-08-28 20:45 ` Junio C Hamano
2025-08-29 1:26 ` Taylor Blau
2025-08-28 17:39 ` [PATCH 3/5] midx-write: use cleanup when incremental midx fails Derrick Stolee via GitGitGadget
2025-08-28 20:51 ` Junio C Hamano
2025-08-29 1:29 ` Taylor Blau
2025-08-30 14:44 ` Derrick Stolee
2025-08-28 17:39 ` [PATCH 4/5] midx-write: use uint32_t for preferred_pack_idx Derrick Stolee via GitGitGadget
2025-08-28 20:58 ` Junio C Hamano
2025-08-29 1:35 ` Taylor Blau
2025-08-28 17:39 ` [PATCH 5/5] midx-write: reenable signed comparison errors Derrick Stolee via GitGitGadget
2025-08-28 21:01 ` Junio C Hamano
2025-08-29 1:35 ` Taylor Blau
2025-08-29 1:36 ` [PATCH 0/5] midx-write: fix segfault and do several cleanups Taylor Blau
2025-08-30 21:23 ` [PATCH v2 0/6] " Derrick Stolee via GitGitGadget
2025-08-30 21:23 ` [PATCH v2 1/6] midx-write: only load initialized packs Derrick Stolee via GitGitGadget
2025-09-03 10:14 ` Patrick Steinhardt
2025-09-05 18:58 ` Derrick Stolee
2025-08-30 21:23 ` [PATCH v2 2/6] midx-write: put failing response value back Derrick Stolee via GitGitGadget
2025-09-03 10:15 ` Patrick Steinhardt
2025-09-05 19:03 ` Derrick Stolee
2025-08-30 21:23 ` [PATCH v2 3/6] midx-write: use cleanup when incremental midx fails Derrick Stolee via GitGitGadget
2025-09-03 10:15 ` Patrick Steinhardt
2025-08-30 21:23 ` [PATCH v2 4/6] midx-write: use uint32_t for preferred_pack_idx Derrick Stolee via GitGitGadget
2025-09-03 10:15 ` Patrick Steinhardt
2025-09-05 19:05 ` Derrick Stolee [this message]
2025-08-30 21:23 ` [PATCH v2 5/6] midx-write: reenable signed comparison errors Derrick Stolee via GitGitGadget
2025-09-03 10:15 ` Patrick Steinhardt
2025-08-30 21:23 ` [PATCH v2 6/6] midx-write: simplify error cases Derrick Stolee via GitGitGadget
2025-09-03 10:15 ` Patrick Steinhardt
2025-09-03 18:43 ` Junio C Hamano
2025-09-05 19:26 ` [PATCH v3 0/6] midx-write: fix segfault and do several cleanups Derrick Stolee via GitGitGadget
2025-09-05 19:26 ` [PATCH v3 1/6] midx-write: only load initialized packs Derrick Stolee via GitGitGadget
2025-09-05 19:26 ` [PATCH v3 2/6] midx-write: put failing response value back Derrick Stolee via GitGitGadget
2025-09-05 19:26 ` [PATCH v3 3/6] midx-write: use cleanup when incremental midx fails Derrick Stolee via GitGitGadget
2025-09-05 19:26 ` [PATCH v3 4/6] midx-write: use uint32_t for preferred_pack_idx Derrick Stolee via GitGitGadget
2025-09-05 19:26 ` [PATCH v3 5/6] midx-write: reenable signed comparison errors Derrick Stolee via GitGitGadget
2025-09-05 19:26 ` [PATCH v3 6/6] midx-write: simplify error cases Derrick Stolee via GitGitGadget
2025-09-05 19:38 ` [PATCH v3 0/6] midx-write: fix segfault and do several cleanups Junio C Hamano
2025-09-05 19:57 ` Derrick Stolee
2025-09-11 23:13 ` Taylor Blau
2025-09-11 23:44 ` Junio C Hamano
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=4c6468d6-02c1-4c79-8ec7-4d250341ca81@gmail.com \
--to=stolee@gmail$(echo .)com \
--cc=git@vger$(echo .)kernel.org \
--cc=gitgitgadget@gmail$(echo .)com \
--cc=gitster@pobox$(echo .)com \
--cc=me@ttaylorr$(echo .)com \
--cc=ps@pks$(echo .)im \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox