Git development
 help / color / mirror / Atom feed
From: "Torsten Bögershausen" <tboegi@web.de>
To: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Cc: Johannes Schindelin via GitGitGadget <gitgitgadget@gmail.com>,
	git@vger.kernel.org, Derrick Stolee <stolee@gmail.com>,
	Jeff King <peff@peff.net>
Subject: Re: [PATCH v2 01/11] index-pack, unpack-objects: use size_t for object size
Date: Fri, 8 May 2026 21:09:48 +0200	[thread overview]
Message-ID: <20260508190947.GA25792@tb-raspi4> (raw)
In-Reply-To: <fa39d84b-ddbc-3943-5cca-078fb18db80d@gmx.de>

On Fri, May 08, 2026 at 09:36:53AM +0200, Johannes Schindelin wrote:
> Hi Torsten,
> 
> On Tue, 5 May 2026, Torsten Bögershausen wrote:
> 
> > On Mon, May 04, 2026 at 05:08:18PM +0000, Johannes Schindelin via GitGitGadget wrote:
> > > From: Johannes Schindelin <johannes.schindelin@gmx.de>
> > > 
> > > [...]
> > > @@ -524,7 +524,8 @@ static void *unpack_raw_entry(struct object_entry *obj,
> > >  			      struct object_id *oid)
> > >  {
> > >  	unsigned char *p;
> > > -	unsigned long size, c;
> > > +	size_t size;
> > > +	unsigned long c;
> >
> > Does this look a little bit strange ?
> 
> Good point.
> 
> > p points to an unsigned char (better would be *uint8_t)
> > then it is dereferenced into an "unsigned long".
> > Then it is masked with 0x7f
> > In short: should "c" be declared as uint8_t ?
> 
> Almost. It should be a `size_t`, so that we don't have to cast it when
> shifting it. I'll include a fix in the next iteration.

I think I was not very clear here.
De-referencing a long (or size_t) from any address is something
I would try to avoid:
Some processors do not like to read a 32 or 64 bit value from
an uneven address (and throw an exeption).
x86 processors just handle it, using more than one bus cycle.

In short: Please keep the up-cast and simply read an uint8_t.




  reply	other threads:[~2026-05-08 19:09 UTC|newest]

Thread overview: 60+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-04-28 16:26 [PATCH 0/6] Handle cloning of objects larger than 4GB on Windows Johannes Schindelin via GitGitGadget
2026-04-28 16:26 ` [PATCH 1/6] index-pack, unpack-objects: use size_t for object size Johannes Schindelin via GitGitGadget
2026-04-30 14:13   ` Torsten Bögershausen
2026-05-03 14:46     ` Johannes Schindelin
2026-04-28 16:26 ` [PATCH 2/6] git-zlib: handle data streams larger than 4GB Johannes Schindelin via GitGitGadget
2026-04-28 16:26 ` [PATCH 3/6] odb, packfile: use size_t for streaming object sizes Johannes Schindelin via GitGitGadget
2026-04-28 16:26 ` [PATCH 4/6] delta, packfile: use size_t for delta header sizes Johannes Schindelin via GitGitGadget
2026-04-29 13:28   ` Derrick Stolee
2026-05-03 14:49     ` Johannes Schindelin
2026-04-28 16:26 ` [PATCH 5/6] test-tool: add a helper to synthesize large packfiles Johannes Schindelin via GitGitGadget
2026-04-28 16:26 ` [PATCH 6/6] t5608: add regression test for >4GB object clone Johannes Schindelin via GitGitGadget
2026-04-29 13:34   ` Derrick Stolee
2026-05-01  6:38     ` Jeff King
2026-05-01 13:19       ` Derrick Stolee
2026-05-04 17:07         ` Johannes Schindelin
2026-04-29 13:35 ` [PATCH 0/6] Handle cloning of objects larger than 4GB on Windows Derrick Stolee
2026-05-04 17:08 ` [PATCH v2 00/11] " Johannes Schindelin via GitGitGadget
2026-05-04 17:08   ` [PATCH v2 01/11] index-pack, unpack-objects: use size_t for object size Johannes Schindelin via GitGitGadget
2026-05-05 19:11     ` Torsten Bögershausen
2026-05-08  7:36       ` Johannes Schindelin
2026-05-08 19:09         ` Torsten Bögershausen [this message]
2026-05-10  2:41           ` Junio C Hamano
2026-05-10  9:14             ` Torsten Bögershausen
2026-05-04 17:08   ` [PATCH v2 02/11] git-zlib: handle data streams larger than 4GB Johannes Schindelin via GitGitGadget
2026-05-04 17:08   ` [PATCH v2 03/11] odb, packfile: use size_t for streaming object sizes Johannes Schindelin via GitGitGadget
2026-05-05 19:27     ` Torsten Bögershausen
2026-05-08  7:38       ` Johannes Schindelin
2026-05-04 17:08   ` [PATCH v2 04/11] delta, packfile: use size_t for delta header sizes Johannes Schindelin via GitGitGadget
2026-05-04 17:08   ` [PATCH v2 05/11] test-tool: add a helper to synthesize large packfiles Johannes Schindelin via GitGitGadget
2026-05-04 17:08   ` [PATCH v2 06/11] t5608: add regression test for >4GB object clone Johannes Schindelin via GitGitGadget
2026-05-04 17:08   ` [PATCH v2 07/11] test-tool synthesize: use the unsafe hash for speed Johannes Schindelin via GitGitGadget
2026-05-04 17:08   ` [PATCH v2 08/11] test-tool synthesize: precompute pack for 4 GiB + 1 Johannes Schindelin via GitGitGadget
2026-05-04 18:27     ` Derrick Stolee
2026-05-05 20:54       ` Johannes Schindelin
2026-05-04 17:08   ` [PATCH v2 09/11] test-tool synthesize: add precomputed SHA-256 " Johannes Schindelin via GitGitGadget
2026-05-04 17:08   ` [PATCH v2 10/11] t5608: mark >4GB tests as EXPENSIVE Johannes Schindelin via GitGitGadget
2026-05-04 17:08   ` [PATCH v2 11/11] ci: run expensive tests on push builds to integration branches Johannes Schindelin via GitGitGadget
2026-05-04 18:35     ` Derrick Stolee
2026-05-05 12:56       ` Junio C Hamano
2026-05-05 23:07         ` Junio C Hamano
2026-05-06  8:33           ` Johannes Schindelin
2026-05-07  9:18             ` Junio C Hamano
2026-05-07 10:24               ` Patrick Steinhardt
2026-05-08  2:50         ` Junio C Hamano
2026-05-08  8:16   ` [PATCH v3 00/11] Handle cloning of objects larger than 4GB on Windows Johannes Schindelin via GitGitGadget
2026-05-08  8:16     ` [PATCH v3 01/11] index-pack, unpack-objects: use size_t for object size Johannes Schindelin via GitGitGadget
2026-05-08  8:16     ` [PATCH v3 02/11] git-zlib: handle data streams larger than 4GB Johannes Schindelin via GitGitGadget
2026-05-08  8:16     ` [PATCH v3 03/11] odb, packfile: use size_t for streaming object sizes Johannes Schindelin via GitGitGadget
2026-05-08  8:16     ` [PATCH v3 04/11] delta, packfile: use size_t for delta header sizes Johannes Schindelin via GitGitGadget
2026-05-08  8:16     ` [PATCH v3 05/11] test-tool: add a helper to synthesize large packfiles Johannes Schindelin via GitGitGadget
2026-05-08  8:16     ` [PATCH v3 06/11] t5608: add regression test for >4GB object clone Johannes Schindelin via GitGitGadget
2026-05-08  8:16     ` [PATCH v3 07/11] test-tool synthesize: use the unsafe hash for speed Johannes Schindelin via GitGitGadget
2026-05-08  8:16     ` [PATCH v3 08/11] test-tool synthesize: precompute pack for 4 GiB + 1 Johannes Schindelin via GitGitGadget
2026-05-08  8:16     ` [PATCH v3 09/11] test-tool synthesize: add precomputed SHA-256 " Johannes Schindelin via GitGitGadget
2026-05-08  8:16     ` [PATCH v3 10/11] t5608: mark >4GB tests as EXPENSIVE Johannes Schindelin via GitGitGadget
2026-05-08  8:16     ` [PATCH v3 11/11] ci: run expensive tests on push builds to integration branches Johannes Schindelin via GitGitGadget
2026-05-10 23:51       ` [PATCH] ci: enable EXPENSIVE for contributor builds Junio C Hamano
2026-05-11  7:05         ` Patrick Steinhardt
2026-05-11  8:29           ` Junio C Hamano
2026-05-11 10:02             ` Patrick Steinhardt

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=20260508190947.GA25792@tb-raspi4 \
    --to=tboegi@web.de \
    --cc=Johannes.Schindelin@gmx.de \
    --cc=git@vger.kernel.org \
    --cc=gitgitgadget@gmail.com \
    --cc=peff@peff.net \
    --cc=stolee@gmail.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
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