diff mbox series

[1/2] gc: add tests for --cruft and friends

Message ID 20220803205721.3686361-2-emilyshaffer@google.com (mailing list archive)
State New, archived
Headers show
Series let feature.experimental imply gc.cruftPacks=true | expand

Commit Message

Emily Shaffer Aug. 3, 2022, 8:57 p.m. UTC
In 5b92477f89 (builtin/gc.c: conditionally avoid pruning objects via
loose, 2022-05-20) gc learned to respect '--cruft' and 'gc.cruftPacks'.
'--cruft' is exercised in t5329-pack-objects-cruft.sh, but in a way that
doesn't check whether a lone gc run generates these cruft packs.
'gc.cruftPacks' is never exercised.

Add some tests to exercise these options to gc in the gc test suite.

Signed-off-by: Emily Shaffer <emilyshaffer@google.com>
---
 t/t6500-gc.sh | 36 ++++++++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)

Comments

Junio C Hamano Aug. 3, 2022, 9:56 p.m. UTC | #1
Emily Shaffer <emilyshaffer@google.com> writes:

> In 5b92477f89 (builtin/gc.c: conditionally avoid pruning objects via
> loose, 2022-05-20) gc learned to respect '--cruft' and 'gc.cruftPacks'.
> '--cruft' is exercised in t5329-pack-objects-cruft.sh, but in a way that
> doesn't check whether a lone gc run generates these cruft packs.
> 'gc.cruftPacks' is never exercised.
>
> Add some tests to exercise these options to gc in the gc test suite.
>
> Signed-off-by: Emily Shaffer <emilyshaffer@google.com>
> ---
>  t/t6500-gc.sh | 36 ++++++++++++++++++++++++++++++++++++
>  1 file changed, 36 insertions(+)
>
> diff --git a/t/t6500-gc.sh b/t/t6500-gc.sh
> index cd6c53360d..e4c2c3583d 100755
> --- a/t/t6500-gc.sh
> +++ b/t/t6500-gc.sh
> @@ -202,6 +202,42 @@ test_expect_success 'one of gc.reflogExpire{Unreachable,}=never does not skip "e
>  	grep -E "^trace: (built-in|exec|run_command): git reflog expire --" trace.out
>  '
>  
> +test_expect_success 'gc --cruft generates a cruft pack' '
> +	git init crufts &&
> +	test_when_finished "rm -fr crufts" &&
> +	(
> +		cd crufts &&
> +		test_commit base &&
> +
> +		test_commit --no-tag foo &&
> +		test_commit --no-tag bar &&
> +		git reset HEAD^^ &&
> +
> +		git gc --cruft &&
> +
> +		cruft=$(basename $(ls .git/objects/pack/pack-*.mtimes) .mtimes) &&

What guarantees that we will have one pack-*.mtimes?  

I do not mind if we reliably diagnosed it as an error when "git gc
--cruft" created two cruft packs, but I do mind if this call to
basename receives two files plus .mtimes suffix and misbehaves.

Is the fact that it is accompanied by a .mtimes file the only clue
that a pack is a "cruft" pack?  Given that the usefulness of mtimes
based expiration approach is doubted, do we want to rely on it (and
having to redesign the test)?

I think the right test would be to

 * make a list of all "in use" objects;

 * see if there is one (or more) packfile that does not contain any
   "in use" objects (look at their .idx file).

If all packfiles are packs with objects that are still in use, then
we did not create a cruft pack.

> +		test_path_is_file .git/objects/pack/$cruft.pack

DQuote the whole thing, i.e.

		test_path_is_file ".git/objects/pack/$cruft.pack"
Ævar Arnfjörð Bjarmason Aug. 4, 2022, 7:48 a.m. UTC | #2
On Wed, Aug 03 2022, Emily Shaffer wrote:

> In 5b92477f89 (builtin/gc.c: conditionally avoid pruning objects via
> loose, 2022-05-20) gc learned to respect '--cruft' and 'gc.cruftPacks'.
> '--cruft' is exercised in t5329-pack-objects-cruft.sh, but in a way that
> doesn't check whether a lone gc run generates these cruft packs.
> 'gc.cruftPacks' is never exercised.
>
> Add some tests to exercise these options to gc in the gc test suite.
>
> Signed-off-by: Emily Shaffer <emilyshaffer@google.com>
> ---
>  t/t6500-gc.sh | 36 ++++++++++++++++++++++++++++++++++++
>  1 file changed, 36 insertions(+)
>
> diff --git a/t/t6500-gc.sh b/t/t6500-gc.sh
> index cd6c53360d..e4c2c3583d 100755
> --- a/t/t6500-gc.sh
> +++ b/t/t6500-gc.sh
> @@ -202,6 +202,42 @@ test_expect_success 'one of gc.reflogExpire{Unreachable,}=never does not skip "e
>  	grep -E "^trace: (built-in|exec|run_command): git reflog expire --" trace.out
>  '
>  
> +test_expect_success 'gc --cruft generates a cruft pack' '
> +	git init crufts &&
> +	test_when_finished "rm -fr crufts" &&

Let's "test_when_finished" first, then "git init", the point is to clean
up the directory if we fail.

> +	(
> +		cd crufts &&
> +		test_commit base &&
> +
> +		test_commit --no-tag foo &&
> +		test_commit --no-tag bar &&
> +		git reset HEAD^^ &&
> +
> +		git gc --cruft &&
> +
> +		cruft=$(basename $(ls .git/objects/pack/pack-*.mtimes) .mtimes) &&
> +		test_path_is_file .git/objects/pack/$cruft.pack
> +	)
> +'

...this...

> +test_expect_success 'gc.cruftPacks=true generates a cruft pack' '
> +	git init crufts &&
> +	test_when_finished "rm -fr crufts" &&
> +	(
> +		cd crufts &&
> +		test_commit base &&
> +
> +		test_commit --no-tag foo &&
> +		test_commit --no-tag bar &&
> +		git reset HEAD^^ &&
> +
> +		git -c gc.cruftPacks=true gc &&
> +
> +		cruft=$(basename $(ls .git/objects/pack/pack-*.mtimes) .mtimes) &&
> +		test_path_is_file .git/objects/pack/$cruft.pack
> +	)
> +'
> +

...whole thing seems to be copy/pasted aside from the git options.

If so let's factor this into a trivial helper that invokes git "$@",
then call it with "gc --cruft" and "-c ..."?
Junio C Hamano Aug. 4, 2022, 4:09 p.m. UTC | #3
Ævar Arnfjörð Bjarmason <avarab@gmail.com> writes:

>> +test_expect_success 'gc --cruft generates a cruft pack' '
>> +	git init crufts &&
>> +	test_when_finished "rm -fr crufts" &&
>
> Let's "test_when_finished" first, then "git init", the point is to clean
> up the directory if we fail.

Good advice.

We say "rm -fr" not "rm -r" there because we do not want to see a
failure to remove if "git init" failed before it manages to create
the directory ;-)

>
>> +	(
>> +		cd crufts &&
>> +		test_commit base &&
>> +
>> +		test_commit --no-tag foo &&
>> +		test_commit --no-tag bar &&
>> +		git reset HEAD^^ &&
>> +
>> +		git gc --cruft &&
>> +
>> +		cruft=$(basename $(ls .git/objects/pack/pack-*.mtimes) .mtimes) &&
>> +		test_path_is_file .git/objects/pack/$cruft.pack
>> +	)
>> +'
>
> ...this...
>
>> +test_expect_success 'gc.cruftPacks=true generates a cruft pack' '
>> +	git init crufts &&
>> +	test_when_finished "rm -fr crufts" &&
>> +	(
>> +		cd crufts &&
>> +		test_commit base &&
>> +
>> +		test_commit --no-tag foo &&
>> +		test_commit --no-tag bar &&
>> +		git reset HEAD^^ &&
>> +
>> +		git -c gc.cruftPacks=true gc &&
>> +
>> +		cruft=$(basename $(ls .git/objects/pack/pack-*.mtimes) .mtimes) &&
>> +		test_path_is_file .git/objects/pack/$cruft.pack
>> +	)
>> +'
>> +
>
> ...whole thing seems to be copy/pasted aside from the git options.
>
> If so let's factor this into a trivial helper that invokes git "$@",
> then call it with "gc --cruft" and "-c ..."?

With shell, passing "here is a series of commands to be run in the
middle of a boilerplate sequence" is indeed easy to write, but it
gets harder to follow and quote correctly, which is why I'd rather
not see that pattern overused.

A pair of helper functions, one of which prepares a sample history
to be used, and the other checks if we created one (or more) cruft
packs, may achieve the same conciseness while remaining to be more
readable.  I.e.

    test_when_finished "rm -fr crufts" &&
    git init crufts &&
    (
	cd crufts &&
	prepare_history &&

	git -c gc.cruftPacks=true gc &&

	cruft_packs_exist
    )

perhaps?
diff mbox series

Patch

diff --git a/t/t6500-gc.sh b/t/t6500-gc.sh
index cd6c53360d..e4c2c3583d 100755
--- a/t/t6500-gc.sh
+++ b/t/t6500-gc.sh
@@ -202,6 +202,42 @@  test_expect_success 'one of gc.reflogExpire{Unreachable,}=never does not skip "e
 	grep -E "^trace: (built-in|exec|run_command): git reflog expire --" trace.out
 '
 
+test_expect_success 'gc --cruft generates a cruft pack' '
+	git init crufts &&
+	test_when_finished "rm -fr crufts" &&
+	(
+		cd crufts &&
+		test_commit base &&
+
+		test_commit --no-tag foo &&
+		test_commit --no-tag bar &&
+		git reset HEAD^^ &&
+
+		git gc --cruft &&
+
+		cruft=$(basename $(ls .git/objects/pack/pack-*.mtimes) .mtimes) &&
+		test_path_is_file .git/objects/pack/$cruft.pack
+	)
+'
+
+test_expect_success 'gc.cruftPacks=true generates a cruft pack' '
+	git init crufts &&
+	test_when_finished "rm -fr crufts" &&
+	(
+		cd crufts &&
+		test_commit base &&
+
+		test_commit --no-tag foo &&
+		test_commit --no-tag bar &&
+		git reset HEAD^^ &&
+
+		git -c gc.cruftPacks=true gc &&
+
+		cruft=$(basename $(ls .git/objects/pack/pack-*.mtimes) .mtimes) &&
+		test_path_is_file .git/objects/pack/$cruft.pack
+	)
+'
+
 run_and_wait_for_auto_gc () {
 	# We read stdout from gc for the side effect of waiting until the
 	# background gc process exits, closing its fd 9.  Furthermore, the