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From: Jonathan Tan <jonathantanmy@google.com>
To: Taylor Blau <me@ttaylorr.com>
Cc: Jonathan Tan <jonathantanmy@google.com>,
	git@vger.kernel.org, Derrick Stolee <derrickstolee@github.com>,
	Junio C Hamano <gitster@pobox.com>
Subject: Re: [PATCH v5 1/4] gitformat-commit-graph: describe version 2 of BDAT
Date: Thu, 20 Jul 2023 13:20:06 -0700	[thread overview]
Message-ID: <20230720202006.3815802-1-jonathantanmy@google.com> (raw)
In-Reply-To: <ZLgcfvIrV3TapMAp@nand.local>

Taylor Blau <me@ttaylorr.com> writes:
> This is a little beyond the scope of your series, but since we're
> changing the on-disk format here a little bit, I think that it might be
> worth it to consider whether there are any other changes that we'd like
> to perform at the same time.
> 
> One that comes to mind is serializing the `max_changed_paths` value of
> the Bloom filter settings, which is currently hard-coded as a constant,
> c.f. 97ffa4fab50 (commit-graph.c: store maximum changed paths,
> 2020-09-17).
> 
> We always assume that the value there is 512, or the environment
> variable GIT_TEST_BLOOM_SETTINGS_MAX_CHANGED_PATHS, if it is set. But it
> might be nice to write it to disk, since it would allow us to do
> something like:

That's true...I do think it makes sense to either have both
bits_per_entry and max_changed_paths (because if we are reusing Bloom
filters when writing, presumably we would want to make sure that the
existing ones were generated using the same settings), or have neither
(since we don't need them for reading).

Having said that, I am inclined to not change this, so that the offset
calculations are the same for both versions (e.g. in the test tool
too), and as far as I know, we haven't had problems with this. But I can
change it if people want.

> > +	in Probabilistic Verification". Version 1 Bloom filters have a bug that appears
> > +	when char is signed and the repository has path names that have characters >=
> > +	0x80; Git supports reading and writing them, but this ability will be removed
> > +	in a future version of Git.
> 
> Makes sense.
> 
> Thanks,
> Taylor

Thanks for taking a look.

  reply	other threads:[~2023-07-20 20:20 UTC|newest]

Thread overview: 116+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-05-22 21:48 [PATCH 0/2] Changed path filter hash fix and version bump Jonathan Tan
2023-05-22 21:48 ` [PATCH 1/2] t4216: test wrong bloom filter version rejection Jonathan Tan
2023-05-22 21:48 ` [PATCH 2/2] commit-graph: fix murmur3, bump filter ver. to 2 Jonathan Tan
2023-05-23 13:00   ` Derrick Stolee
2023-05-23 23:00     ` Jonathan Tan
2023-05-23 23:51     ` Junio C Hamano
2023-05-24 21:26       ` Jonathan Tan
2023-05-26 13:19         ` Derrick Stolee
2023-05-30 17:26           ` Jonathan Tan
2023-05-23  4:42 ` [PATCH 0/2] Changed path filter hash fix and version bump Junio C Hamano
2023-05-31 23:12 ` [PATCH v2 0/3] " Jonathan Tan
2023-05-31 23:12   ` [PATCH v2 1/3] t4216: test changed path filters with high bit paths Jonathan Tan
2023-05-31 23:12   ` [PATCH v2 2/3] repo-settings: introduce commitgraph.changedPathsVersion Jonathan Tan
2023-05-31 23:12   ` [PATCH v2 3/3] commit-graph: new filter ver. that fixes murmur3 Jonathan Tan
2023-06-03  1:01   ` [PATCH v2 0/3] Changed path filter hash fix and version bump Junio C Hamano
2023-06-03  2:24     ` Junio C Hamano
2023-06-07 16:30       ` Jonathan Tan
2023-06-07 21:37         ` Jonathan Tan
2023-06-08 19:21 ` [PATCH v3 0/4] " Jonathan Tan
2023-06-08 19:21   ` [PATCH v3 1/4] gitformat-commit-graph: describe version 2 of BDAT Jonathan Tan
2023-06-08 19:52     ` Ramsay Jones
2023-06-12 21:26       ` Junio C Hamano
2023-06-08 19:21   ` [PATCH v3 2/4] t4216: test changed path filters with high bit paths Jonathan Tan
2023-06-08 19:21   ` [PATCH v3 3/4] repo-settings: introduce commitgraph.changedPathsVersion Jonathan Tan
2023-06-08 19:21   ` [PATCH v3 4/4] commit-graph: new filter ver. that fixes murmur3 Jonathan Tan
2023-06-08 19:50   ` [PATCH v3 0/4] Changed path filter hash fix and version bump Ramsay Jones
2023-06-09  0:08     ` Jonathan Tan
2023-06-12 21:31     ` Junio C Hamano
2023-06-13 17:16       ` Jonathan Tan
2023-06-13 17:29         ` [PATCH] CodingGuidelines: use octal escapes, not hex Jonathan Tan
2023-06-13 18:16           ` Eric Sunshine
2023-06-13 18:43             ` Jonathan Tan
2023-06-13 19:15               ` Eric Sunshine
2023-06-13 19:29                 ` Junio C Hamano
2023-06-13 19:16         ` [PATCH v3 0/4] Changed path filter hash fix and version bump Junio C Hamano
2023-06-13 17:39 ` [PATCH v4 " Jonathan Tan
2023-06-13 17:39   ` [PATCH v4 1/4] gitformat-commit-graph: describe version 2 of BDAT Jonathan Tan
2023-06-13 21:58     ` Junio C Hamano
2023-06-20 13:22       ` Derrick Stolee
2023-06-21 12:08       ` Taylor Blau
2023-06-22 22:26         ` Jonathan Tan
2023-06-23 13:05           ` Derrick Stolee
2023-06-13 17:39   ` [PATCH v4 2/4] t4216: test changed path filters with high bit paths Jonathan Tan
2023-06-13 17:39   ` [PATCH v4 3/4] repo-settings: introduce commitgraph.changedPathsVersion Jonathan Tan
2023-06-20 13:28     ` Derrick Stolee
2023-06-21 12:14     ` Taylor Blau
2023-06-13 17:39   ` [PATCH v4 4/4] commit-graph: new filter ver. that fixes murmur3 Jonathan Tan
2023-06-20 13:39     ` Derrick Stolee
2023-06-20 18:37       ` Junio C Hamano
2023-06-13 19:21   ` [PATCH v4 0/4] Changed path filter hash fix and version bump Junio C Hamano
2023-06-20 13:43     ` Derrick Stolee
2023-06-20 21:56       ` Jonathan Tan
2023-06-21 12:19       ` Taylor Blau
2023-06-21 17:53         ` Derrick Stolee
2023-06-22 22:27           ` Jonathan Tan
2023-06-23 13:18             ` Derrick Stolee
2023-07-13 21:42 ` [PATCH v5 " Jonathan Tan
2023-07-13 21:42   ` [PATCH v5 1/4] gitformat-commit-graph: describe version 2 of BDAT Jonathan Tan
2023-07-19 17:25     ` Taylor Blau
2023-07-20 20:20       ` Jonathan Tan [this message]
2023-07-21  1:38         ` Taylor Blau
2023-07-13 21:42   ` [PATCH v5 2/4] t4216: test changed path filters with high bit paths Jonathan Tan
2023-07-13 22:50     ` Junio C Hamano
2023-07-19 17:27       ` Taylor Blau
2023-07-19 17:55         ` [PATCH 0/4] commit-graph: avoid looking at Bloom filter data directly Taylor Blau
2023-07-19 17:55           ` [PATCH 1/4] t/helper/test-read-graph.c: extract `dump_graph_info()` Taylor Blau
2023-07-19 17:55           ` [PATCH 2/4] bloom.h: make `load_bloom_filter_from_graph()` public Taylor Blau
2023-07-19 17:55           ` [PATCH 3/4] t/helper/test-read-graph: implement `bloom-filters` mode Taylor Blau
2023-07-19 17:55           ` [PATCH 4/4] fixup! t4216: test changed path filters with high bit paths Taylor Blau
2023-07-19 19:24           ` [PATCH 0/4] commit-graph: avoid looking at Bloom filter data directly Junio C Hamano
2023-07-20 20:22           ` Jonathan Tan
2023-07-13 21:42   ` [PATCH v5 3/4] repo-settings: introduce commitgraph.changedPathsVersion Jonathan Tan
2023-07-19 18:10     ` Taylor Blau
2023-07-20 20:42       ` Jonathan Tan
2023-07-20 21:02         ` Taylor Blau
2023-07-13 21:42   ` [PATCH v5 4/4] commit-graph: new filter ver. that fixes murmur3 Jonathan Tan
2023-07-19 18:24     ` Taylor Blau
2023-07-20 21:27       ` Jonathan Tan
2023-07-26 23:32         ` Taylor Blau
2023-07-13 22:16   ` [PATCH v5 0/4] Changed path filter hash fix and version bump Junio C Hamano
2023-07-13 22:59     ` Junio C Hamano
2023-07-14 18:48     ` Jonathan Tan
2023-07-20 21:46 ` [PATCH v6 0/7] " Jonathan Tan
2023-07-20 21:46   ` [PATCH v6 1/7] gitformat-commit-graph: describe version 2 of BDAT Jonathan Tan
2023-07-20 21:46   ` [PATCH v6 2/7] t/helper/test-read-graph.c: extract `dump_graph_info()` Jonathan Tan
2023-07-26 23:26     ` Taylor Blau
2023-07-20 21:46   ` [PATCH v6 3/7] bloom.h: make `load_bloom_filter_from_graph()` public Jonathan Tan
2023-07-20 21:46   ` [PATCH v6 4/7] t/helper/test-read-graph: implement `bloom-filters` mode Jonathan Tan
2023-07-20 21:46   ` [PATCH v6 5/7] t4216: test changed path filters with high bit paths Jonathan Tan
2023-07-26 23:28     ` Taylor Blau
2023-07-20 21:46   ` [PATCH v6 6/7] repo-settings: introduce commitgraph.changedPathsVersion Jonathan Tan
2023-07-20 21:46   ` [PATCH v6 7/7] commit-graph: new filter ver. that fixes murmur3 Jonathan Tan
2023-07-25 20:52   ` [PATCH v6 0/7] Changed path filter hash fix and version bump Junio C Hamano
2023-07-26 20:39   ` Junio C Hamano
2023-07-27  0:17     ` Taylor Blau
2023-07-27  0:49       ` Junio C Hamano
2023-07-27 17:39         ` Jonathan Tan
2023-07-27 17:56           ` Taylor Blau
2023-07-27 20:53             ` Jonathan Tan
2023-08-01 18:08               ` Taylor Blau
2023-08-01 18:52                 ` Jonathan Tan
2023-08-03  0:01                 ` Taylor Blau
2023-08-03 13:18                   ` Derrick Stolee
2023-08-03 18:45                     ` Taylor Blau
2023-07-27 18:44         ` Junio C Hamano
2023-08-01 18:41 ` [PATCH v7 " Jonathan Tan
2023-08-01 18:41   ` [PATCH v7 1/7] gitformat-commit-graph: describe version 2 of BDAT Jonathan Tan
2023-08-01 18:41   ` [PATCH v7 2/7] t/helper/test-read-graph.c: extract `dump_graph_info()` Jonathan Tan
2023-08-01 18:41   ` [PATCH v7 3/7] bloom.h: make `load_bloom_filter_from_graph()` public Jonathan Tan
2023-08-01 18:41   ` [PATCH v7 4/7] t/helper/test-read-graph: implement `bloom-filters` mode Jonathan Tan
2023-08-01 18:41   ` [PATCH v7 5/7] t4216: test changed path filters with high bit paths Jonathan Tan
2023-08-01 18:41   ` [PATCH v7 6/7] repo-settings: introduce commitgraph.changedPathsVersion Jonathan Tan
2023-08-01 18:41   ` [PATCH v7 7/7] commit-graph: new filter ver. that fixes murmur3 Jonathan Tan
2023-08-01 18:44   ` [PATCH v7 0/7] Changed path filter hash fix and version bump Junio C Hamano
2023-08-01 20:58     ` Taylor Blau
2023-08-01 21:07       ` Junio C Hamano

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