From: Junio C Hamano <gitster@pobox•com>
To: Jeff King <peff@peff•net>
Cc: git@vger•kernel.org
Subject: Re: [PATCH 5/5] sha1_file: don't re-scan pack directory for null sha1
Date: Tue, 21 Nov 2017 14:20:19 +0900 [thread overview]
Message-ID: <xmqqwp2ki4x8.fsf@gitster.mtv.corp.google.com> (raw)
In-Reply-To: <20171120203523.c3pt5qi43e24ttqq@sigill.intra.peff.net> (Jeff King's message of "Mon, 20 Nov 2017 15:35:23 -0500")
Jeff King <peff@peff•net> writes:
> This is the minimal fix that addresses the performance issues.
> I'd actually have no problem at all declaring that looking up a null
> sha1 is insane, and having the object-lookup routines simply return "no
> such object" without even doing the loose/pack lookup first.
>
> diff --git a/sha1_file.c b/sha1_file.c
> index 8a7c6b7eba..dde0ad101d 100644
> --- a/sha1_file.c
> +++ b/sha1_file.c
> @@ -1180,6 +1180,9 @@ int sha1_object_info_extended(const unsigned char *sha1, struct object_info *oi,
> if (!sha1_loose_object_info(real, oi, flags))
> return 0;
>
> + if (is_null_sha1(sha1))
> + return -1;
> +
> /* Not a loose object; someone else may have just packed it. */
> if (flags & OBJECT_INFO_QUICK) {
> return -1;
After queuing this series to an earlier part of 'pu' and resolving a
conflict with jh/fsck-promisors topic, I ended up with a code that
rejects 0{40} a lot earlier, before we try to see if a pack entry
for 0{40} exists, even though the patch that is queued on this topic
is more conservative (i.e. the above one).
Perhaps we would want to use the alternate version that declares the
0{40} is a sentinel that signals that there is no such object in
this topic---that would give us a consistent semantics without
having to adjust jh/fsck-promisors when it becomes ready to be
merged.
next prev parent reply other threads:[~2017-11-21 5:20 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-20 20:26 [PATCH 0/5] avoiding pointless pack-directory re-scans Jeff King
2017-11-20 20:26 ` [PATCH 1/5] p5550: factor our nonsense-pack creation Jeff King
2017-11-20 23:55 ` Eric Sunshine
2017-11-21 15:58 ` Jeff King
2017-11-22 0:32 ` Stefan Beller
2017-11-22 22:38 ` Jeff King
2017-11-23 2:41 ` Junio C Hamano
2017-11-23 5:02 ` Jeff King
2017-11-20 20:27 ` [PATCH 2/5] t/perf/lib-pack: use fast-import checkpoint to create packs Jeff King
2017-11-20 20:28 ` [PATCH 3/5] p5551: add a script to test fetch pack-dir rescans Jeff King
2017-11-20 20:29 ` [PATCH 4/5] everything_local: use "quick" object existence check Jeff King
2017-11-20 20:35 ` [PATCH 5/5] sha1_file: don't re-scan pack directory for null sha1 Jeff King
2017-11-20 20:47 ` Stefan Beller
2017-11-20 20:58 ` Jeff King
2017-11-21 2:37 ` Junio C Hamano
2017-11-21 22:57 ` Jeff King
2017-11-22 1:42 ` Junio C Hamano
2017-11-22 22:36 ` Jeff King
2017-11-23 2:35 ` Junio C Hamano
2017-11-24 17:32 ` Jeff King
2017-11-25 3:20 ` Junio C Hamano
2017-11-21 5:20 ` Junio C Hamano [this message]
2017-11-21 23:17 ` Jeff King
2017-11-22 1:49 ` Junio C Hamano
2017-11-22 3:17 ` Jeff King
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