diff mbox series

[v2,17/19] t: retire 'GIT_TEST_MULTI_PACK_INDEX_WRITE_BITMAP'

Message ID 23912425bf7c0106ed388f7712e7bb822572fe5d.1721250704.git.me@ttaylorr.com (mailing list archive)
State Superseded
Headers show
Series midx: incremental multi-pack indexes, part one | expand

Commit Message

Taylor Blau July 17, 2024, 9:12 p.m. UTC
Two years ago, commit ff1e653c8e2 (midx: respect
'GIT_TEST_MULTI_PACK_INDEX_WRITE_BITMAP', 2021-08-31) introduced a new
environment variable which caused the test suite to write MIDX bitmaps
after any 'git repack' invocation.

At the time, this was done to help flush out any bugs with MIDX bitmaps
that weren't explicitly covered in the t5326-multi-pack-bitmap.sh
script.

Two years later, that flag has served us well and is no longer providing
meaningful coverage, as the script in t5326 has matured substantially
and covers many more interesting cases than it did back when ff1e653c8e2
was originally written.

Remove the 'GIT_TEST_MULTI_PACK_INDEX_WRITE_BITMAP' environment variable
as it is no longer serving a useful purpose. More importantly, removing
this variable clears the way for us to introduce a new one to help
similarly flush out bugs related to incremental MIDX chains.

Because these incremental MIDX chains are (for now) incompatible with
MIDX bitmaps, we cannot have both.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
---
 builtin/repack.c                  | 12 ++----------
 ci/run-build-and-tests.sh         |  1 -
 midx.h                            |  2 --
 t/README                          |  4 ----
 t/t0410-partial-clone.sh          |  2 --
 t/t5310-pack-bitmaps.sh           |  4 ----
 t/t5319-multi-pack-index.sh       |  3 +--
 t/t5326-multi-pack-bitmaps.sh     |  3 +--
 t/t5327-multi-pack-bitmaps-rev.sh |  5 ++---
 t/t7700-repack.sh                 | 21 +++++++--------------
 10 files changed, 13 insertions(+), 44 deletions(-)

Comments

Jeff King Aug. 1, 2024, 10:46 a.m. UTC | #1
On Wed, Jul 17, 2024 at 05:12:47PM -0400, Taylor Blau wrote:

> Two years ago, commit ff1e653c8e2 (midx: respect
> 'GIT_TEST_MULTI_PACK_INDEX_WRITE_BITMAP', 2021-08-31) introduced a new
> environment variable which caused the test suite to write MIDX bitmaps
> after any 'git repack' invocation.
> 
> At the time, this was done to help flush out any bugs with MIDX bitmaps
> that weren't explicitly covered in the t5326-multi-pack-bitmap.sh
> script.
> 
> Two years later, that flag has served us well and is no longer providing
> meaningful coverage, as the script in t5326 has matured substantially
> and covers many more interesting cases than it did back when ff1e653c8e2
> was originally written.

I do think it could be providing some value still, just because other
scripts may create unusual setups that will exercise the code in
different ways. That said...

> Remove the 'GIT_TEST_MULTI_PACK_INDEX_WRITE_BITMAP' environment variable
> as it is no longer serving a useful purpose. More importantly, removing
> this variable clears the way for us to introduce a new one to help
> similarly flush out bugs related to incremental MIDX chains.
> 
> Because these incremental MIDX chains are (for now) incompatible with
> MIDX bitmaps, we cannot have both.

...if it is one or the other, I think it is better to test the new code.

And I do think that midx bitmap code is less likely to be exercised in
interesting ways by random parts of the test suite (versus something
like GIT_TEST_DEFAULT_HASH, whose effects are pervasive). So I think
this is a good tradeoff.

>  builtin/repack.c                  | 12 ++----------
>  ci/run-build-and-tests.sh         |  1 -
>  midx.h                            |  2 --
>  t/README                          |  4 ----
>  t/t0410-partial-clone.sh          |  2 --
>  t/t5310-pack-bitmaps.sh           |  4 ----
>  t/t5319-multi-pack-index.sh       |  3 +--
>  t/t5326-multi-pack-bitmaps.sh     |  3 +--
>  t/t5327-multi-pack-bitmaps-rev.sh |  5 ++---
>  t/t7700-repack.sh                 | 21 +++++++--------------
>  10 files changed, 13 insertions(+), 44 deletions(-)

Patch looks good.

-Peff
Taylor Blau Aug. 1, 2024, 8:36 p.m. UTC | #2
On Thu, Aug 01, 2024 at 06:46:47AM -0400, Jeff King wrote:
> ...if it is one or the other, I think it is better to test the new code.
>
> And I do think that midx bitmap code is less likely to be exercised in
> interesting ways by random parts of the test suite (versus something
> like GIT_TEST_DEFAULT_HASH, whose effects are pervasive). So I think
> this is a good tradeoff.

Thanks, I appreciate your careful reasoning here.

> Patch looks good.

Thanks also for the review :-).

Thanks,
Taylor
diff mbox series

Patch

diff --git a/builtin/repack.c b/builtin/repack.c
index f0317fa94a..8499bf0e12 100644
--- a/builtin/repack.c
+++ b/builtin/repack.c
@@ -1217,10 +1217,6 @@  int cmd_repack(int argc, const char **argv, const char *prefix)
 		if (!write_midx &&
 		    (!(pack_everything & ALL_INTO_ONE) || !is_bare_repository()))
 			write_bitmaps = 0;
-	} else if (write_bitmaps &&
-		   git_env_bool(GIT_TEST_MULTI_PACK_INDEX, 0) &&
-		   git_env_bool(GIT_TEST_MULTI_PACK_INDEX_WRITE_BITMAP, 0)) {
-		write_bitmaps = 0;
 	}
 	if (pack_kept_objects < 0)
 		pack_kept_objects = write_bitmaps > 0 && !write_midx;
@@ -1518,12 +1514,8 @@  int cmd_repack(int argc, const char **argv, const char *prefix)
 	if (run_update_server_info)
 		update_server_info(0);
 
-	if (git_env_bool(GIT_TEST_MULTI_PACK_INDEX, 0)) {
-		unsigned flags = 0;
-		if (git_env_bool(GIT_TEST_MULTI_PACK_INDEX_WRITE_BITMAP, 0))
-			flags |= MIDX_WRITE_BITMAP | MIDX_WRITE_REV_INDEX;
-		write_midx_file(get_object_directory(), NULL, NULL, flags);
-	}
+	if (git_env_bool(GIT_TEST_MULTI_PACK_INDEX, 0))
+		write_midx_file(get_object_directory(), NULL, NULL, 0);
 
 cleanup:
 	string_list_clear(&names, 1);
diff --git a/ci/run-build-and-tests.sh b/ci/run-build-and-tests.sh
index 98dda42045..e6fd68630c 100755
--- a/ci/run-build-and-tests.sh
+++ b/ci/run-build-and-tests.sh
@@ -25,7 +25,6 @@  linux-TEST-vars)
 	export GIT_TEST_COMMIT_GRAPH=1
 	export GIT_TEST_COMMIT_GRAPH_CHANGED_PATHS=1
 	export GIT_TEST_MULTI_PACK_INDEX=1
-	export GIT_TEST_MULTI_PACK_INDEX_WRITE_BITMAP=1
 	export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=master
 	export GIT_TEST_NO_WRITE_REV_INDEX=1
 	export GIT_TEST_CHECKOUT_WORKERS=2
diff --git a/midx.h b/midx.h
index 9d30935589..3714cad2cc 100644
--- a/midx.h
+++ b/midx.h
@@ -29,8 +29,6 @@  struct bitmapped_pack;
 #define MIDX_LARGE_OFFSET_NEEDED 0x80000000
 
 #define GIT_TEST_MULTI_PACK_INDEX "GIT_TEST_MULTI_PACK_INDEX"
-#define GIT_TEST_MULTI_PACK_INDEX_WRITE_BITMAP \
-	"GIT_TEST_MULTI_PACK_INDEX_WRITE_BITMAP"
 
 struct multi_pack_index {
 	struct multi_pack_index *next;
diff --git a/t/README b/t/README
index d9e0e07506..e8a11926e4 100644
--- a/t/README
+++ b/t/README
@@ -469,10 +469,6 @@  GIT_TEST_MULTI_PACK_INDEX=<boolean>, when true, forces the multi-pack-
 index to be written after every 'git repack' command, and overrides the
 'core.multiPackIndex' setting to true.
 
-GIT_TEST_MULTI_PACK_INDEX_WRITE_BITMAP=<boolean>, when true, sets the
-'--bitmap' option on all invocations of 'git multi-pack-index write',
-and ignores pack-objects' '--write-bitmap-index'.
-
 GIT_TEST_SIDEBAND_ALL=<boolean>, when true, overrides the
 'uploadpack.allowSidebandAll' setting to true, and when false, forces
 fetch-pack to not request sideband-all (even if the server advertises
diff --git a/t/t0410-partial-clone.sh b/t/t0410-partial-clone.sh
index 2c30c86e7b..34bdb3ab1f 100755
--- a/t/t0410-partial-clone.sh
+++ b/t/t0410-partial-clone.sh
@@ -5,8 +5,6 @@  test_description='partial clone'
 . ./test-lib.sh
 . "$TEST_DIRECTORY"/lib-terminal.sh
 
-# missing promisor objects cause repacks which write bitmaps to fail
-GIT_TEST_MULTI_PACK_INDEX_WRITE_BITMAP=0
 # When enabled, some commands will write commit-graphs. This causes fsck
 # to fail when delete_object() is called because fsck will attempt to
 # verify the out-of-sync commit graph.
diff --git a/t/t5310-pack-bitmaps.sh b/t/t5310-pack-bitmaps.sh
index d7fd71360e..a6de7c5764 100755
--- a/t/t5310-pack-bitmaps.sh
+++ b/t/t5310-pack-bitmaps.sh
@@ -5,10 +5,6 @@  test_description='exercise basic bitmap functionality'
 . ./test-lib.sh
 . "$TEST_DIRECTORY"/lib-bitmap.sh
 
-# t5310 deals only with single-pack bitmaps, so don't write MIDX bitmaps in
-# their place.
-GIT_TEST_MULTI_PACK_INDEX_WRITE_BITMAP=0
-
 # Likewise, allow individual tests to control whether or not they use
 # the boundary-based traversal.
 sane_unset GIT_TEST_PACK_USE_BITMAP_BOUNDARY_TRAVERSAL
diff --git a/t/t5319-multi-pack-index.sh b/t/t5319-multi-pack-index.sh
index 10d2a6bf92..6e9ee23398 100755
--- a/t/t5319-multi-pack-index.sh
+++ b/t/t5319-multi-pack-index.sh
@@ -600,8 +600,7 @@  test_expect_success 'repack preserves multi-pack-index when creating packs' '
 compare_results_with_midx "after repack"
 
 test_expect_success 'multi-pack-index and pack-bitmap' '
-	GIT_TEST_MULTI_PACK_INDEX_WRITE_BITMAP=0 \
-		git -c repack.writeBitmaps=true repack -ad &&
+	git -c repack.writeBitmaps=true repack -ad &&
 	git multi-pack-index write &&
 	git rev-list --test-bitmap HEAD
 '
diff --git a/t/t5326-multi-pack-bitmaps.sh b/t/t5326-multi-pack-bitmaps.sh
index 916da389b6..1cb3e3ff08 100755
--- a/t/t5326-multi-pack-bitmaps.sh
+++ b/t/t5326-multi-pack-bitmaps.sh
@@ -4,10 +4,9 @@  test_description='exercise basic multi-pack bitmap functionality'
 . ./test-lib.sh
 . "${TEST_DIRECTORY}/lib-bitmap.sh"
 
-# We'll be writing our own midx and bitmaps, so avoid getting confused by the
+# We'll be writing our own MIDX, so avoid getting confused by the
 # automatic ones.
 GIT_TEST_MULTI_PACK_INDEX=0
-GIT_TEST_MULTI_PACK_INDEX_WRITE_BITMAP=0
 
 # This test exercise multi-pack bitmap functionality where the object order is
 # stored and read from a special chunk within the MIDX, so use the default
diff --git a/t/t5327-multi-pack-bitmaps-rev.sh b/t/t5327-multi-pack-bitmaps-rev.sh
index e65e311cd7..23db949c20 100755
--- a/t/t5327-multi-pack-bitmaps-rev.sh
+++ b/t/t5327-multi-pack-bitmaps-rev.sh
@@ -5,10 +5,9 @@  test_description='exercise basic multi-pack bitmap functionality (.rev files)'
 . ./test-lib.sh
 . "${TEST_DIRECTORY}/lib-bitmap.sh"
 
-# We'll be writing our own midx and bitmaps, so avoid getting confused by the
-# automatic ones.
+# We'll be writing our own MIDX, so avoid getting confused by the automatic
+# ones.
 GIT_TEST_MULTI_PACK_INDEX=0
-GIT_TEST_MULTI_PACK_INDEX_WRITE_BITMAP=0
 
 # Unlike t5326, this test exercise multi-pack bitmap functionality where the
 # object order is stored in a separate .rev file.
diff --git a/t/t7700-repack.sh b/t/t7700-repack.sh
index 127efe99f8..8f34f05087 100755
--- a/t/t7700-repack.sh
+++ b/t/t7700-repack.sh
@@ -70,14 +70,13 @@  test_expect_success 'objects in packs marked .keep are not repacked' '
 
 test_expect_success 'writing bitmaps via command-line can duplicate .keep objects' '
 	# build on $oid, $packid, and .keep state from previous
-	GIT_TEST_MULTI_PACK_INDEX_WRITE_BITMAP=0 git repack -Adbl &&
+	git repack -Adbl &&
 	test_has_duplicate_object true
 '
 
 test_expect_success 'writing bitmaps via config can duplicate .keep objects' '
 	# build on $oid, $packid, and .keep state from previous
-	GIT_TEST_MULTI_PACK_INDEX_WRITE_BITMAP=0 \
-		git -c repack.writebitmaps=true repack -Adl &&
+	git -c repack.writebitmaps=true repack -Adl &&
 	test_has_duplicate_object true
 '
 
@@ -284,8 +283,7 @@  test_expect_success 'repacking fails when missing .pack actually means missing o
 test_expect_success 'bitmaps are created by default in bare repos' '
 	git clone --bare .git bare.git &&
 	rm -f bare.git/objects/pack/*.bitmap &&
-	GIT_TEST_MULTI_PACK_INDEX_WRITE_BITMAP=0 \
-		git -C bare.git repack -ad &&
+	git -C bare.git repack -ad &&
 	bitmap=$(ls bare.git/objects/pack/*.bitmap) &&
 	test_path_is_file "$bitmap"
 '
@@ -296,8 +294,7 @@  test_expect_success 'incremental repack does not complain' '
 '
 
 test_expect_success 'bitmaps can be disabled on bare repos' '
-	GIT_TEST_MULTI_PACK_INDEX_WRITE_BITMAP=0 \
-		git -c repack.writeBitmaps=false -C bare.git repack -ad &&
+	git -c repack.writeBitmaps=false -C bare.git repack -ad &&
 	bitmap=$(ls bare.git/objects/pack/*.bitmap || :) &&
 	test -z "$bitmap"
 '
@@ -308,8 +305,7 @@  test_expect_success 'no bitmaps created if .keep files present' '
 	keep=${pack%.pack}.keep &&
 	test_when_finished "rm -f \"\$keep\"" &&
 	>"$keep" &&
-	GIT_TEST_MULTI_PACK_INDEX_WRITE_BITMAP=0 \
-		git -C bare.git repack -ad 2>stderr &&
+	git -C bare.git repack -ad 2>stderr &&
 	test_must_be_empty stderr &&
 	find bare.git/objects/pack/ -type f -name "*.bitmap" >actual &&
 	test_must_be_empty actual
@@ -320,8 +316,7 @@  test_expect_success 'auto-bitmaps do not complain if unavailable' '
 	blob=$(test-tool genrandom big $((1024*1024)) |
 	       git -C bare.git hash-object -w --stdin) &&
 	git -C bare.git update-ref refs/tags/big $blob &&
-	GIT_TEST_MULTI_PACK_INDEX_WRITE_BITMAP=0 \
-		git -C bare.git repack -ad 2>stderr &&
+	git -C bare.git repack -ad 2>stderr &&
 	test_must_be_empty stderr &&
 	find bare.git/objects/pack -type f -name "*.bitmap" >actual &&
 	test_must_be_empty actual
@@ -342,9 +337,7 @@  test_expect_success 'repacking with a filter works' '
 '
 
 test_expect_success '--filter fails with --write-bitmap-index' '
-	test_must_fail \
-		env GIT_TEST_MULTI_PACK_INDEX_WRITE_BITMAP=0 \
-		git -C bare.git repack -a -d --write-bitmap-index --filter=blob:none
+	test_must_fail git -C bare.git repack -a -d --write-bitmap-index --filter=blob:none
 '
 
 test_expect_success 'repacking with two filters works' '