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From: benno@bmevers.de
To: junio@pobox.com
Cc: git@vger.kernel.org, spearce@spearce.org, Benno Evers <benno@bmevers.de>
Subject: Re: [PATCH] describe: dont abort too early when searching tags
Date: Tue, 25 Feb 2020 20:07:51 +0100	[thread overview]
Message-ID: <20200225190751.5898-1-benno@bmevers.de> (raw)
In-Reply-To: <xmqq4kvfpv17.fsf@gitster-ct.c.googlers.com>

From: Benno Evers <benno@bmevers.de>

> How much, if any, does this change hurt the performance by forcing
> the code to dig further if there aren't multiple roots?  If there is
> such an unnecessary overhead that degrades performance for the more
> common case, can we improve it further to avoid it?

If there aren't multiple roots, then this should be visiting exactly
the same number of commits as before. This is because in this case, if
we're down to a single branch, the current commit must be an ancestor
of *all* tag candidates so the stopping condition is always true.

It's actually a bit challenging to find good test repositories for
this in the wild, as the big ones that use a merging workflow (like git
itself, the kernel, etc.) usually have so many branches active at any
point in time that the search will only stop when it hits the max number
of candidates. So I might be missing some edge cases. However, for the
"normal" repositories that I tested the number of traversed commits was
always the same before and after the change.
 

  reply	other threads:[~2020-02-25 19:08 UTC|newest]

Thread overview: 34+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-23 12:51 Benno Evers
2020-02-24 20:52 ` Junio C Hamano
2020-02-25 19:07   ` benno [this message]
2020-02-25 20:10     ` Junio C Hamano
2021-02-28 19:54 ` [PATCH 00/10] describe tests: refactor & fix recent broken tests Ævar Arnfjörð Bjarmason
2021-03-09  0:47   ` Junio C Hamano
2021-03-12 23:59   ` Junio C Hamano
2021-04-12 11:21   ` [PATCH v2 0/5] describe test fixes Ævar Arnfjörð Bjarmason
2021-04-12 11:21     ` [PATCH v2 1/5] describe tests: improve test for --work-tree & --dirty Ævar Arnfjörð Bjarmason
2021-04-12 11:21     ` [PATCH v2 2/5] describe tests: refactor away from glob matching Ævar Arnfjörð Bjarmason
2021-04-12 11:21     ` [PATCH v2 3/5] describe tests: don't rely on err.actual from "check_describe" Ævar Arnfjörð Bjarmason
2021-04-12 11:21     ` [PATCH v2 4/5] describe tests: fix nested "test_expect_success" call Ævar Arnfjörð Bjarmason
2021-04-12 11:21     ` [PATCH v2 5/5] describe tests: support -C in "check_describe" Ævar Arnfjörð Bjarmason
2021-04-12 11:33   ` [PATCH v2 0/2] svn tests: trivial "set -e" in main body of test fixes Ævar Arnfjörð Bjarmason
2021-04-12 11:33     ` [PATCH v2 1/2] svn tests: remove legacy re-setup from init-clone test Ævar Arnfjörð Bjarmason
2021-04-12 11:33     ` [PATCH v2 2/2] svn tests: refactor away a "set -e" in test body Ævar Arnfjörð Bjarmason
2021-02-28 19:54 ` [PATCH 01/10] describe tests: improve test for --work-tree & --dirty Ævar Arnfjörð Bjarmason
2021-02-28 19:54 ` [PATCH 02/10] describe tests: refactor away from glob matching Ævar Arnfjörð Bjarmason
2021-03-01 21:26   ` Junio C Hamano
2021-02-28 19:54 ` [PATCH 03/10] describe tests: always assert empty stderr from "describe" Ævar Arnfjörð Bjarmason
2021-03-01 21:32   ` Junio C Hamano
2021-02-28 19:54 ` [PATCH 04/10] test-lib functions: add an --annotated-tag option to "test_commit" Ævar Arnfjörð Bjarmason
2021-03-01 21:41   ` Junio C Hamano
2021-03-02  9:34     ` Ævar Arnfjörð Bjarmason
2021-03-03  6:35       ` Junio C Hamano
2021-02-28 19:54 ` [PATCH 05/10] describe tests: convert setup to use test_commit Ævar Arnfjörð Bjarmason
2021-03-01 21:42   ` Junio C Hamano
2021-02-28 19:54 ` [PATCH 06/10] describe tests: fix nested "test_expect_success" call Ævar Arnfjörð Bjarmason
2021-02-28 19:54 ` [PATCH 07/10] describe tests: support -C in "check_describe" Ævar Arnfjörð Bjarmason
2021-02-28 19:54 ` [PATCH 08/10] svn tests: remove legacy re-setup from init-clone test Ævar Arnfjörð Bjarmason
2021-02-28 19:54 ` [PATCH 09/10] svn tests: refactor away a "set -e" in test body Ævar Arnfjörð Bjarmason
2021-02-28 21:14   ` Eric Wong
2021-02-28 19:54 ` [PATCH 10/10] test-lib: return 1 from test_expect_{success,failure} Ævar Arnfjörð Bjarmason
2021-03-01 21:43   ` Junio C Hamano

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