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From: Junio C Hamano <gitster@pobox.com>
To: Jeff King <peff@peff.net>
Cc: Taylor Blau <me@ttaylorr.com>,
	 git@vger.kernel.org,
	 "brian m. carlson" <sandals@crustytoothpaste.net>,
	 Elijah Newren <newren@gmail.com>, Patrick Steinhardt <ps@pks.im>
Subject: Re: [PATCH v3 3/9] finalize_object_file(): implement collision check
Date: Tue, 10 Sep 2024 08:14:27 -0700	[thread overview]
Message-ID: <xmqqr09rmtgs.fsf@gitster.g> (raw)
In-Reply-To: <20240910065333.GF1459778@coredump.intra.peff.net> (Jeff King's message of "Tue, 10 Sep 2024 02:53:33 -0400")

Jeff King <peff@peff.net> writes:

> Now thinking on it more, that view is probably dumb. fstat() is really
> cheap, and byte-wise comparisons are really expensive, so if it has even
> a tiny chance of helping, it might be worth doing.

If we see too many "yikes we need to check for collision" cases,
then yes, but I agree that it should be rare to matter.

> Though again, I'd hope this will trigger pretty rarely in practice,
> because it's probably a sign that we could have skipped work earlier
> (i.e., by realizing we were just going to generate an identical file,
> and not generated it in the first place).

Yes, exactly.

  reply	other threads:[~2024-09-10 15:14 UTC|newest]

Thread overview: 99+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-09-01 16:03 [PATCH 0/4] hash.h: support choosing a separate SHA-1 for non-cryptographic uses Taylor Blau
2024-09-01 16:03 ` [PATCH 1/4] sha1: do not redefine `platform_SHA_CTX` and friends Taylor Blau
2024-09-02 13:41   ` Patrick Steinhardt
2024-09-03 19:34     ` Taylor Blau
2024-09-01 16:03 ` [PATCH 2/4] hash.h: scaffolding for _fast hashing variants Taylor Blau
2024-09-02 13:41   ` Patrick Steinhardt
2024-09-03 17:27     ` Junio C Hamano
2024-09-03 19:52       ` Taylor Blau
2024-09-03 20:47         ` Junio C Hamano
2024-09-03 21:24           ` Taylor Blau
2024-09-04  7:05           ` Patrick Steinhardt
2024-09-04 14:53             ` Junio C Hamano
2024-09-03 19:40     ` Taylor Blau
2024-09-01 16:03 ` [PATCH 3/4] Makefile: allow specifying a SHA-1 for non-cryptographic uses Taylor Blau
2024-09-02 13:41   ` Patrick Steinhardt
2024-09-03 19:43     ` Taylor Blau
2024-09-01 16:03 ` [PATCH 4/4] csum-file.c: use fast SHA-1 implementation when available Taylor Blau
2024-09-02 13:41   ` Patrick Steinhardt
2024-09-03  1:22     ` brian m. carlson
2024-09-03 19:50     ` Taylor Blau
2024-09-02  3:41 ` [PATCH 0/4] hash.h: support choosing a separate SHA-1 for non-cryptographic uses Junio C Hamano
2024-09-03 19:48   ` Taylor Blau
2024-09-03 20:44     ` Junio C Hamano
2024-09-02 14:08 ` brian m. carlson
2024-09-03 19:47   ` Taylor Blau
2024-09-03 22:41     ` Junio C Hamano
2024-09-04 14:01     ` brian m. carlson
2024-09-05 10:37     ` Jeff King
2024-09-05 15:41       ` Junio C Hamano
2024-09-05 16:23         ` Taylor Blau
2024-09-05 16:51           ` Junio C Hamano
2024-09-05 17:04             ` Taylor Blau
2024-09-05 17:51               ` Taylor Blau
2024-09-05 20:21                 ` Taylor Blau
2024-09-05 20:27               ` Jeff King
2024-09-05 21:27                 ` Junio C Hamano
2024-09-05 15:11 ` [PATCH v2 " Taylor Blau
2024-09-05 15:12   ` [PATCH v2 1/4] sha1: do not redefine `platform_SHA_CTX` and friends Taylor Blau
2024-09-05 15:12   ` [PATCH v2 2/4] hash.h: scaffolding for _fast hashing variants Taylor Blau
2024-09-05 15:12   ` [PATCH v2 3/4] Makefile: allow specifying a SHA-1 for non-cryptographic uses Taylor Blau
2024-09-05 15:12   ` [PATCH v2 4/4] csum-file.c: use fast SHA-1 implementation when available Taylor Blau
2024-09-06 19:46 ` [PATCH v3 0/9] hash.h: support choosing a separate SHA-1 for non-cryptographic uses Taylor Blau
2024-09-06 19:46   ` [PATCH v3 1/9] finalize_object_file(): check for name collision before renaming Taylor Blau
2024-09-06 19:46   ` [PATCH v3 2/9] finalize_object_file(): refactor unlink_or_warn() placement Taylor Blau
2024-09-06 19:46   ` [PATCH v3 3/9] finalize_object_file(): implement collision check Taylor Blau
2024-09-06 21:44     ` Junio C Hamano
2024-09-06 21:51       ` Chris Torek
2024-09-10  6:53       ` Jeff King
2024-09-10 15:14         ` Junio C Hamano [this message]
2024-09-16 10:45     ` Patrick Steinhardt
2024-09-16 15:54       ` Taylor Blau
2024-09-16 16:03         ` Taylor Blau
2024-09-17 20:40       ` Junio C Hamano
2024-09-06 19:46   ` [PATCH v3 4/9] pack-objects: use finalize_object_file() to rename pack/idx/etc Taylor Blau
2024-09-06 19:46   ` [PATCH v3 5/9] i5500-git-daemon.sh: use compile-able version of Git without OpenSSL Taylor Blau
2024-09-11  6:10     ` Jeff King
2024-09-11  6:12       ` Jeff King
2024-09-12 20:28         ` Junio C Hamano
2024-09-11 15:28       ` Junio C Hamano
2024-09-11 21:23         ` Jeff King
2024-09-06 19:46   ` [PATCH v3 6/9] sha1: do not redefine `platform_SHA_CTX` and friends Taylor Blau
2024-09-06 19:46   ` [PATCH v3 7/9] hash.h: scaffolding for _fast hashing variants Taylor Blau
2024-09-06 19:46   ` [PATCH v3 8/9] Makefile: allow specifying a SHA-1 for non-cryptographic uses Taylor Blau
2024-09-06 19:46   ` [PATCH v3 9/9] csum-file.c: use fast SHA-1 implementation when available Taylor Blau
2024-09-06 21:50   ` [PATCH v3 0/9] hash.h: support choosing a separate SHA-1 for non-cryptographic uses Junio C Hamano
2024-09-24 17:32 ` [PATCH v4 0/8] " Taylor Blau
2024-09-24 17:32   ` [PATCH v4 1/8] finalize_object_file(): check for name collision before renaming Taylor Blau
2024-09-25 17:02     ` Junio C Hamano
2024-09-24 17:32   ` [PATCH v4 2/8] finalize_object_file(): refactor unlink_or_warn() placement Taylor Blau
2024-09-24 17:32   ` [PATCH v4 3/8] finalize_object_file(): implement collision check Taylor Blau
2024-09-24 20:37     ` Jeff King
2024-09-24 21:59       ` Taylor Blau
2024-09-24 22:20         ` Jeff King
2024-09-25 18:06           ` Taylor Blau
2024-09-24 21:32     ` Junio C Hamano
2024-09-24 22:02       ` Taylor Blau
2024-09-24 17:32   ` [PATCH v4 4/8] pack-objects: use finalize_object_file() to rename pack/idx/etc Taylor Blau
2024-09-24 21:34     ` Junio C Hamano
2024-09-24 17:32   ` [PATCH v4 5/8] sha1: do not redefine `platform_SHA_CTX` and friends Taylor Blau
2024-09-24 17:32   ` [PATCH v4 6/8] hash.h: scaffolding for _unsafe hashing variants Taylor Blau
2024-09-24 17:32   ` [PATCH v4 7/8] Makefile: allow specifying a SHA-1 for non-cryptographic uses Taylor Blau
2024-09-24 17:32   ` [PATCH v4 8/8] csum-file.c: use unsafe SHA-1 implementation when available Taylor Blau
2024-09-24 20:52   ` [PATCH v4 0/8] hash.h: support choosing a separate SHA-1 for non-cryptographic uses Jeff King
2024-09-25 16:58   ` Elijah Newren
2024-09-25 17:11     ` Junio C Hamano
2024-09-25 17:22       ` Taylor Blau
2024-09-25 17:22     ` Taylor Blau
2024-09-26 15:22 ` [PATCH v5 " Taylor Blau
2024-09-26 15:22   ` [PATCH v5 1/8] finalize_object_file(): check for name collision before renaming Taylor Blau
2024-09-26 15:22   ` [PATCH v5 2/8] finalize_object_file(): refactor unlink_or_warn() placement Taylor Blau
2024-09-26 15:22   ` [PATCH v5 3/8] finalize_object_file(): implement collision check Taylor Blau
2024-09-26 15:22   ` [PATCH v5 4/8] pack-objects: use finalize_object_file() to rename pack/idx/etc Taylor Blau
2024-09-26 15:22   ` [PATCH v5 5/8] sha1: do not redefine `platform_SHA_CTX` and friends Taylor Blau
2024-09-26 15:22   ` [PATCH v5 6/8] hash.h: scaffolding for _unsafe hashing variants Taylor Blau
2024-09-26 15:22   ` [PATCH v5 7/8] Makefile: allow specifying a SHA-1 for non-cryptographic uses Taylor Blau
2024-09-26 15:22   ` [PATCH v5 8/8] csum-file.c: use unsafe SHA-1 implementation when available Taylor Blau
2024-09-26 22:47   ` [PATCH v5 0/8] hash.h: support choosing a separate SHA-1 for non-cryptographic uses Elijah Newren
2024-09-27  0:44     ` Junio C Hamano
2024-09-27  3:57   ` Jeff King

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