Re: [PATCH 3/9] builtin/cat-file: support "blob:none" objects filter

> Implement support for the "blob:none" filter in git-cat-file(1), which
> causes us to omit all blobs.
>
> Signed-off-by: Patrick Steinhardt <ps@pks.im>
> ---
>  Documentation/git-cat-file.adoc |  2 ++
>  builtin/cat-file.c              | 11 ++++++++++-
>  t/t1006-cat-file.sh             | 33 +++++++++++++++++++++++++++++++--
>  3 files changed, 43 insertions(+), 3 deletions(-)
>
> diff --git a/Documentation/git-cat-file.adoc b/Documentation/git-cat-file.adoc
> index 7c1c888079a..c11952d9eca 100644
> --- a/Documentation/git-cat-file.adoc
> +++ b/Documentation/git-cat-file.adoc
> @@ -86,6 +86,8 @@ OPTIONS
>  	Omit objects from the list of printed objects. This can only be used in
>  	combination with one of the batched modes. The '<filter-spec>' may be
>  	one of the following:
> ++
> +The form '--filter=blob:none' omits all blobs.
>

>  --path=<path>::
>  	For use with `--textconv` or `--filters`, to allow specifying an object
> diff --git a/builtin/cat-file.c b/builtin/cat-file.c
> index 723644fbba8..8e5572ba43e 100644
> --- a/builtin/cat-file.c
> +++ b/builtin/cat-file.c
> @@ -472,7 +472,8 @@ static void batch_object_write(const char *obj_name,
>  	if (!data->skip_object_info) {
>  		int ret;
>
> -		if (use_mailmap)
> +		if (use_mailmap ||
> +		    opt->objects_filter.choice == LOFC_BLOB_NONE)

>  			data->info.typep = &data->type;
>
>  		if (pack)
> @@ -492,6 +493,10 @@ static void batch_object_write(const char *obj_name,
>  		switch (opt->objects_filter.choice) {
>  		case LOFC_DISABLED:
>  			break;
> +		case LOFC_BLOB_NONE:
> +			if (data->type == OBJ_BLOB)
> +				return;
> +			break;
>  		default:
>  			BUG("unsupported objects filter");
>  		}
> @@ -1032,6 +1037,10 @@ int cmd_cat_file(int argc,
>  	switch (batch.objects_filter.choice) {
>  	case LOFC_DISABLED:
>  		break;
> +	case LOFC_BLOB_NONE:
> +		if (!batch.enabled)
> +			usage(_("objects filter only supported in batch mode"));
> +		break;
>  	default:
>  		usagef(_("objects filter not supported: '%s'"),
>  		       list_object_filter_config_name(batch.objects_filter.choice));
> diff --git a/t/t1006-cat-file.sh b/t/t1006-cat-file.sh
> index 48840a13561..97533225982 100755
> --- a/t/t1006-cat-file.sh
> +++ b/t/t1006-cat-file.sh
> @@ -1354,7 +1354,22 @@ test_expect_success PERL '--batch-command info is unbuffered by default' '
>  '
>
>  test_expect_success 'setup for objects filter' '
> -	git init repo
> +	git init repo &&
> +	(
> +		# Seed the repository with three different sets of objects:
> +		#
> +		#   - The first set is fully packed and has a bitmap.
> +		#   - The second set is packed, but has no bitmap.
> +		#   - The third set is loose.
> +		#
> +		# This ensures that we cover all these types as expected.
> +		cd repo &&
> +		test_commit first &&
> +		git repack -Adb &&
> +		test_commit second &&
> +		git repack -d &&
> +		test_commit third
> +	)
>  '
>
>  test_expect_success 'objects filter with unknown option' '
> @@ -1365,7 +1380,7 @@ test_expect_success 'objects filter with unknown option' '
>  	test_cmp expect err
>  '
>
> -for option in blob:none blob:limit=1 object:type=tag sparse:oid=1234 tree:1 sparse:path=x
> +for option in blob:limit=1 object:type=tag sparse:oid=1234 tree:1 sparse:path=x
>  do
>  	test_expect_success "objects filter with unsupported option $option" '
>  		case "$option" in
> @@ -1385,4 +1400,18 @@ do
>  	'
>  done
>
> +test_objects_filter () {
> +	filter="$1"
> +
> +	test_expect_success "objects filter: $filter" '
> +		git -C repo cat-file --batch-check="%(objectname)" --batch-all-objects --objects-filter="$filter" >actual &&
> +		sort actual >actual.sorted &&
> +		git -C repo rev-list --objects --no-object-names --all --filter="$filter" --filter-provided-objects >expect &&
> +		sort expect >expect.sorted &&
> +		test_cmp expect.sorted actual.sorted
> +	'
> +}
> +
> +test_objects_filter "blob:none"
> +