diff mbox series

[2/3] pack-object: simplify --filter handling

Message ID 59abb8d2-e8e6-7423-ead8-49382293aaa6@web.de (mailing list archive)
State Superseded
Headers show
Series pack-objects: fix and simplify --filter handling | expand

Commit Message

René Scharfe Nov. 12, 2022, 10:44 a.m. UTC 
pack-objects uses OPT_PARSE_LIST_OBJECTS_FILTER_INIT() to initialize the
a rev_info struct lazily before populating its filter member using the
--filter option values.  It tracks whether the initialization is needed
using the .have_revs member of the callback data.

There is a better way: Use a stand-alone list_objects_filter_options
struct and build a rev_info struct with its .filter member after option
parsing.  This allows using the simpler OPT_PARSE_LIST_OBJECTS_FILTER()
and getting rid of the extra callback mechanism.

Signed-off-by: René Scharfe <l.s.r@web.de>
---
 builtin/pack-objects.c | 28 ++++++----------------------
 1 file changed, 6 insertions(+), 22 deletions(-)

--
2.38.1

Comments

Ævar Arnfjörð Bjarmason Nov. 12, 2022, 11:45 a.m. UTC | #1 
On Sat, Nov 12 2022, René Scharfe wrote:

> pack-objects uses OPT_PARSE_LIST_OBJECTS_FILTER_INIT() to initialize the
> a rev_info struct lazily before populating its filter member using the
> --filter option values.  It tracks whether the initialization is needed
> using the .have_revs member of the callback data.
>
> There is a better way: Use a stand-alone list_objects_filter_options
> struct and build a rev_info struct with its .filter member after option
> parsing.  This allows using the simpler OPT_PARSE_LIST_OBJECTS_FILTER()
> and getting rid of the extra callback mechanism.

I haven't gone through the history again, but as I recall this used to
be outside of "struct rev_info", then (I think I did, as part of a leak
fix) it was put there, and now it's still there, but we make a copy of
it, then copy it into the "rev_info" struct again.

Maybe we've finally reached the right trade-off here, but it would help
to discuss some of those past commits, why those arrangements were
wrong, and why this is finally the right one...
Jeff King Nov. 12, 2022, 5:02 p.m. UTC | #2 
On Sat, Nov 12, 2022 at 11:44:50AM +0100, René Scharfe wrote:

> pack-objects uses OPT_PARSE_LIST_OBJECTS_FILTER_INIT() to initialize the
> a rev_info struct lazily before populating its filter member using the
> --filter option values.  It tracks whether the initialization is needed
> using the .have_revs member of the callback data.
> 
> There is a better way: Use a stand-alone list_objects_filter_options
> struct and build a rev_info struct with its .filter member after option
> parsing.  This allows using the simpler OPT_PARSE_LIST_OBJECTS_FILTER()
> and getting rid of the extra callback mechanism.

That seems like a reasonable fix (and I think we do it elsewhere). But I
wonder if it wouldn't be simpler to just unconditionally initialize the
rev_info in cmd_pack_objects(), and then unconditionally release it.
True, we _might_ not use it if we are receiving objects directly over
stdin, but I don't think initializing it is particularly costly.

And then we don't have to worry about whether it's valid (it always is),
or about copying between two representations of the filter (there's only
one).

-Peff
Jeff King Nov. 13, 2022, 4:49 p.m. UTC | #3 
On Sat, Nov 12, 2022 at 12:02:58PM -0500, Jeff King wrote:

> > There is a better way: Use a stand-alone list_objects_filter_options
> > struct and build a rev_info struct with its .filter member after option
> > parsing.  This allows using the simpler OPT_PARSE_LIST_OBJECTS_FILTER()
> > and getting rid of the extra callback mechanism.
> 
> That seems like a reasonable fix (and I think we do it elsewhere). But I
> wonder if it wouldn't be simpler to just unconditionally initialize the
> rev_info in cmd_pack_objects(), and then unconditionally release it.
> True, we _might_ not use it if we are receiving objects directly over
> stdin, but I don't think initializing it is particularly costly.
> 
> And then we don't have to worry about whether it's valid (it always is),
> or about copying between two representations of the filter (there's only
> one).

Just to make sure I wasn't telling you absolute garbage, I sketched this
out quickly, so sharing it below (to illustrate, or maybe to save you 5
minutes if you want to go that direction).

If you do stick with copying the filter spec, yet another option is that
the rev_info variable could move back into get_object_list(), and we
could just pass in the filter_options. It was only moved out in
80f6de4f5b (pack-objects: move revs out of get_object_list(),
2022-03-22) so that we could parse --filter directly into it.

That's probably approaching bikeshed territory, and I'm happy enough
either way, but it keeps the outer cmd_pack_objects() to the absolute
minimum of what it needs to see.

-Peff

-- >8 --
diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c
index c702c09dd4..cadc2be35f 100644
--- a/builtin/pack-objects.c
+++ b/builtin/pack-objects.c
@@ -4149,22 +4149,6 @@ static int option_parse_cruft_expiration(const struct option *opt,
 	return 0;
 }
 
-struct po_filter_data {
-	unsigned have_revs:1;
-	struct rev_info revs;
-};
-
-static struct list_objects_filter_options *po_filter_revs_init(void *value)
-{
-	struct po_filter_data *data = value;
-
-	if (!data->have_revs)
-		repo_init_revisions(the_repository, &data->revs, NULL);
-	data->have_revs = 1;
-
-	return &data->revs.filter;
-}
-
 int cmd_pack_objects(int argc, const char **argv, const char *prefix)
 {
 	int use_internal_rev_list = 0;
@@ -4175,7 +4159,7 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
 	int rev_list_index = 0;
 	int stdin_packs = 0;
 	struct string_list keep_pack_list = STRING_LIST_INIT_NODUP;
-	struct po_filter_data pfd = { .have_revs = 0 };
+	struct rev_info revs;
 
 	struct option pack_objects_options[] = {
 		OPT_SET_INT('q', "quiet", &progress,
@@ -4266,7 +4250,7 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
 			      &write_bitmap_index,
 			      N_("write a bitmap index if possible"),
 			      WRITE_BITMAP_QUIET, PARSE_OPT_HIDDEN),
-		OPT_PARSE_LIST_OBJECTS_FILTER_INIT(&pfd, po_filter_revs_init),
+		OPT_PARSE_LIST_OBJECTS_FILTER(&revs.filter),
 		OPT_CALLBACK_F(0, "missing", NULL, N_("action"),
 		  N_("handling for missing objects"), PARSE_OPT_NONEG,
 		  option_parse_missing_action),
@@ -4297,6 +4281,8 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
 	if (git_env_bool(GIT_TEST_WRITE_REV_INDEX, 0))
 		pack_idx_opts.flags |= WRITE_REV;
 
+	repo_init_revisions(the_repository, &revs, NULL);
+
 	progress = isatty(2);
 	argc = parse_options(argc, argv, prefix, pack_objects_options,
 			     pack_usage, 0);
@@ -4386,7 +4372,7 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
 	if (!rev_list_all || !rev_list_reflog || !rev_list_index)
 		unpack_unreachable_expiration = 0;
 
-	if (pfd.have_revs && pfd.revs.filter.choice) {
+	if (revs.filter.choice) {
 		if (!pack_to_stdout)
 			die(_("cannot use --filter without --stdout"));
 		if (stdin_packs)
@@ -4473,16 +4459,10 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
 		read_cruft_objects();
 	} else if (!use_internal_rev_list) {
 		read_object_list_from_stdin();
-	} else if (pfd.have_revs) {
-		get_object_list(&pfd.revs, rp.nr, rp.v);
-		release_revisions(&pfd.revs);
 	} else {
-		struct rev_info revs;
-
-		repo_init_revisions(the_repository, &revs, NULL);
 		get_object_list(&revs, rp.nr, rp.v);
-		release_revisions(&revs);
 	}
+	release_revisions(&revs);
 	cleanup_preferred_base();
 	if (include_tag && nr_result)
 		for_each_tag_ref(add_ref_tag, NULL);
René Scharfe Nov. 13, 2022, 5:31 p.m. UTC | #4 
Am 12.11.22 um 18:02 schrieb Jeff King:
> On Sat, Nov 12, 2022 at 11:44:50AM +0100, René Scharfe wrote:
>
>> pack-objects uses OPT_PARSE_LIST_OBJECTS_FILTER_INIT() to initialize the
>> a rev_info struct lazily before populating its filter member using the
>> --filter option values.  It tracks whether the initialization is needed
>> using the .have_revs member of the callback data.
>>
>> There is a better way: Use a stand-alone list_objects_filter_options
>> struct and build a rev_info struct with its .filter member after option
>> parsing.  This allows using the simpler OPT_PARSE_LIST_OBJECTS_FILTER()
>> and getting rid of the extra callback mechanism.
>
> That seems like a reasonable fix (and I think we do it elsewhere). But I
> wonder if it wouldn't be simpler to just unconditionally initialize the
> rev_info in cmd_pack_objects(), and then unconditionally release it.
> True, we _might_ not use it if we are receiving objects directly over
> stdin, but I don't think initializing it is particularly costly.
>
> And then we don't have to worry about whether it's valid (it always is),
> or about copying between two representations of the filter (there's only
> one).

Indeed that's even simpler and what we had before 5cb28270a1
(pack-objects: lazily set up "struct rev_info", don't leak, 2022-03-28).

René
diff mbox series

Patch

diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c
index c702c09dd4..30023bcebb 100644
--- a/builtin/pack-objects.c
+++ b/builtin/pack-objects.c
@@ -4149,22 +4149,6 @@  static int option_parse_cruft_expiration(const struct option *opt,
 	return 0;
 }

-struct po_filter_data {
-	unsigned have_revs:1;
-	struct rev_info revs;
-};
-
-static struct list_objects_filter_options *po_filter_revs_init(void *value)
-{
-	struct po_filter_data *data = value;
-
-	if (!data->have_revs)
-		repo_init_revisions(the_repository, &data->revs, NULL);
-	data->have_revs = 1;
-
-	return &data->revs.filter;
-}
-
 int cmd_pack_objects(int argc, const char **argv, const char *prefix)
 {
 	int use_internal_rev_list = 0;
@@ -4175,7 +4159,8 @@  int cmd_pack_objects(int argc, const char **argv, const char *prefix)
 	int rev_list_index = 0;
 	int stdin_packs = 0;
 	struct string_list keep_pack_list = STRING_LIST_INIT_NODUP;
-	struct po_filter_data pfd = { .have_revs = 0 };
+	struct list_objects_filter_options filter_options =
+		LIST_OBJECTS_FILTER_INIT;

 	struct option pack_objects_options[] = {
 		OPT_SET_INT('q', "quiet", &progress,
@@ -4266,7 +4251,7 @@  int cmd_pack_objects(int argc, const char **argv, const char *prefix)
 			      &write_bitmap_index,
 			      N_("write a bitmap index if possible"),
 			      WRITE_BITMAP_QUIET, PARSE_OPT_HIDDEN),
-		OPT_PARSE_LIST_OBJECTS_FILTER_INIT(&pfd, po_filter_revs_init),
+		OPT_PARSE_LIST_OBJECTS_FILTER(&filter_options),
 		OPT_CALLBACK_F(0, "missing", NULL, N_("action"),
 		  N_("handling for missing objects"), PARSE_OPT_NONEG,
 		  option_parse_missing_action),
@@ -4386,7 +4371,7 @@  int cmd_pack_objects(int argc, const char **argv, const char *prefix)
 	if (!rev_list_all || !rev_list_reflog || !rev_list_index)
 		unpack_unreachable_expiration = 0;

-	if (pfd.have_revs && pfd.revs.filter.choice) {
+	if (filter_options.choice) {
 		if (!pack_to_stdout)
 			die(_("cannot use --filter without --stdout"));
 		if (stdin_packs)
@@ -4473,16 +4458,15 @@  int cmd_pack_objects(int argc, const char **argv, const char *prefix)
 		read_cruft_objects();
 	} else if (!use_internal_rev_list) {
 		read_object_list_from_stdin();
-	} else if (pfd.have_revs) {
-		get_object_list(&pfd.revs, rp.nr, rp.v);
-		release_revisions(&pfd.revs);
 	} else {
 		struct rev_info revs;

 		repo_init_revisions(the_repository, &revs, NULL);
+		list_objects_filter_copy(&revs.filter, &filter_options);
 		get_object_list(&revs, rp.nr, rp.v);
 		release_revisions(&revs);
 	}
+	list_objects_filter_release(&filter_options);
 	cleanup_preferred_base();
 	if (include_tag && nr_result)
 		for_each_tag_ref(add_ref_tag, NULL);