pack-objects: enable multi-pack reuse via feature.experimental

Now that multi-pack reuse is supported, enable it via the
feature.experimental configuration in addition to the classic
`pack.allowPackReuse`.

This will allow more users to experiment with the new behavior who might
not otherwise be aware of the existing `pack.allowPackReuse`
configuration option.

The enum with values NO_PACK_REUSE, SINGLE_PACK_REUSE, and
MULTI_PACK_REUSE is defined statically in builtin/pack-objects.c's
compilation unit. We could hoist that enum into a scope visible from the
repository_settings struct, and then use that enum value in
pack-objects. Instead, define a single int that indicates what
pack-objects's default value should be to avoid additional unnecessary
code movement.

Though `feature.experimental` implies `pack.allowPackReuse=multi`, this
can still be overridden by explicitly setting the latter configuration
to either "single" or "false". Tests covering all of these cases are
showin t5332.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Taylor Blau 2024-02-05 17:50:23 -05:00 committed by Junio C Hamano
parent 7c01878eeb
commit 23c1e71369
5 changed files with 23 additions and 0 deletions

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@ -17,6 +17,9 @@ skipping more commits at a time, reducing the number of round trips.
+
* `pack.useBitmapBoundaryTraversal=true` may improve bitmap traversal times by
walking fewer objects.
+
* `pack.allowPackReuse=multi` may improve the time it takes to create a pack by
reusing objects from multiple packs instead of just one.
feature.manyFiles::
Enable config options that optimize for repos with many files in the

View file

@ -4396,6 +4396,8 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
prepare_repo_settings(the_repository);
if (sparse < 0)
sparse = the_repository->settings.pack_use_sparse;
if (the_repository->settings.pack_use_multi_pack_reuse)
allow_pack_reuse = MULTI_PACK_REUSE;
}
reset_pack_idx_option(&pack_idx_opts);

View file

@ -43,6 +43,7 @@ void prepare_repo_settings(struct repository *r)
if (experimental) {
r->settings.fetch_negotiation_algorithm = FETCH_NEGOTIATION_SKIPPING;
r->settings.pack_use_bitmap_boundary_traversal = 1;
r->settings.pack_use_multi_pack_reuse = 1;
}
if (manyfiles) {
r->settings.index_version = 4;

View file

@ -39,6 +39,7 @@ struct repo_settings {
int sparse_index;
int pack_read_reverse_index;
int pack_use_bitmap_boundary_traversal;
int pack_use_multi_pack_reuse;
/*
* Does this repository have core.useReplaceRefs=true (on by

View file

@ -58,6 +58,22 @@ test_expect_success 'preferred pack is reused for single-pack reuse' '
test_pack_objects_reused_all 3 1
'
test_expect_success 'multi-pack reuse is disabled by default' '
test_pack_objects_reused_all 3 1
'
test_expect_success 'feature.experimental implies multi-pack reuse' '
test_config feature.experimental true &&
test_pack_objects_reused_all 6 2
'
test_expect_success 'multi-pack reuse can be disabled with feature.experimental' '
test_config feature.experimental true &&
test_config pack.allowPackReuse single &&
test_pack_objects_reused_all 3 1
'
test_expect_success 'enable multi-pack reuse' '
git config pack.allowPackReuse multi