Subject: Re: [PATCH v2 0/8] ref-filter: ahead/behind counting, faster --merged option

From: Ævar Arnfjörð Bjarmason <[email-masked]>
Date: Wed, 15 Mar 2023 14:22:54 +0100

On Fri, Mar 10 2023, Derrick Stolee via GitGitGadget wrote:

> At $DAYJOB, we have used a custom 'ahead-behind' builtin in our fork of Git
> for lots of reasons. The main goal of the builtin is to compare multiple
> references against a common base reference. The comparison is number of
> commits that are in each side of the symmtric difference of their reachable
> sets. A commit C is "ahead" of a commit B by the number of commits in B..C
> (reachable from C but not reachable from B). Similarly, the commit C is
> "behind" the commit B by the number of commits in C..B (reachable from B but
> not reachable from C).

I have a local change to get rid of the various "the_repository" macros,
which a merge of this in "seen" conflicted with (semantically).

The below patch on top of "seen" will fix it, could you please squash it
in in the appropriate places?

Aside from a desire to get rid of "the_repository" macros this also
makes your own code consistent, i.e. you use repo_clear_commit_marks(),
but then use parse_commit() instead of the repo_parse_commit() in the
same function.

It also makes the new API more future-proof, I don't think we should be
adding new code that implicitly uses "the_repository" to our libraries
if we can help it, much better to pass it down, even if all the current
users are built-in that end up using "the_repository".

diff --git a/builtin/branch.c b/builtin/branch.c
index 21526d9883a..7c7dba839cf 100644
--- a/builtin/branch.c
+++ b/builtin/branch.c
@@ -448,7 +448,7 @@ static void print_ref_list(struct ref_filter *filter, struct ref_sorting *sortin
 	if (verify_ref_format(format))
 		die(_("unable to parse format string"));
 
-	filter_ahead_behind(format, &array);
+	filter_ahead_behind(the_repository, format, &array);
 	ref_array_sort(sorting, &array);
 
 	for (i = 0; i < array.nr; i++) {
diff --git a/builtin/for-each-ref.c b/builtin/for-each-ref.c
index 1cdf8eb5a6b..e097f44e226 100644
--- a/builtin/for-each-ref.c
+++ b/builtin/for-each-ref.c
@@ -102,7 +102,7 @@ int cmd_for_each_ref(int argc, const char **argv, const char *prefix)
 
 	filter.match_as_path = 1;
 	filter_refs(&array, &filter, FILTER_REFS_ALL);
-	filter_ahead_behind(&format, &array);
+	filter_ahead_behind(the_repository, &format, &array);
 
 	ref_array_sort(sorting, &array);
 
diff --git a/builtin/tag.c b/builtin/tag.c
index 8652d5edd47..7e2f686600a 100644
--- a/builtin/tag.c
+++ b/builtin/tag.c
@@ -67,7 +67,7 @@ static int list_tags(struct ref_filter *filter, struct ref_sorting *sorting,
 		die(_("unable to parse format string"));
 	filter->with_commit_tag_algo = 1;
 	filter_refs(&array, filter, FILTER_REFS_TAGS);
-	filter_ahead_behind(format, &array);
+	filter_ahead_behind(the_repository, format, &array);
 	ref_array_sort(sorting, &array);
 
 	for (i = 0; i < array.nr; i++) {
diff --git a/commit-reach.c b/commit-reach.c
index 0abd43801fc..4a2216b8ae0 100644
--- a/commit-reach.c
+++ b/commit-reach.c
@@ -977,8 +977,9 @@ static void free_bit_array(struct commit *c)
 	*bitmap = NULL;
 }
 
-void ahead_behind(struct commit **commits, size_t commits_nr,
-		  struct ahead_behind_count *counts, size_t counts_nr)
+void ahead_behind(struct repository *r, struct commit **commits,
+		  size_t commits_nr, struct ahead_behind_count *counts,
+		  size_t counts_nr)
 {
 	struct prio_queue queue = { compare_commits_by_gen_then_commit_date };
 	size_t width = (commits_nr + BITS_IN_EWORD - 1) / BITS_IN_EWORD;
@@ -1024,7 +1025,7 @@ void ahead_behind(struct commit **commits, size_t commits_nr,
 		for (p = c->parents; p; p = p->next) {
 			struct bitmap *bitmap_p;
 
-			parse_commit(p->item);
+			repo_parse_commit(r, p->item);
 
 			bitmap_p = init_bit_array(p->item, width);
 			bitmap_or(bitmap_p, bitmap_c);
@@ -1039,7 +1040,7 @@ void ahead_behind(struct commit **commits, size_t commits_nr,
 	}
 
 	/* STALE is used here, PARENT2 is used by insert_no_dup(). */
-	repo_clear_commit_marks(the_repository, PARENT2 | STALE);
+	repo_clear_commit_marks(r, PARENT2 | STALE);
 	clear_bit_arrays(&bit_arrays);
 	clear_prio_queue(&queue);
 }
diff --git a/commit-reach.h b/commit-reach.h
index f871b5dcce9..2269fab8261 100644
--- a/commit-reach.h
+++ b/commit-reach.h
@@ -131,7 +131,8 @@ struct ahead_behind_count {
  * Given an array of commits and an array of ahead_behind_count pairs,
  * compute the ahead/behind counts for each pair.
  */
-void ahead_behind(struct commit **commits, size_t commits_nr,
-		  struct ahead_behind_count *counts, size_t counts_nr);
+void ahead_behind(struct repository *r, struct commit **commits,
+		  size_t commits_nr, struct ahead_behind_count *counts,
+		  size_t counts_nr);
 
 #endif
diff --git a/ref-filter.c b/ref-filter.c
index 4125ec3fd3a..cdc054beede 100644
--- a/ref-filter.c
+++ b/ref-filter.c
@@ -2462,7 +2462,7 @@ static void reach_filter(struct ref_array *array,
 	free(to_clear);
 }
 
-void filter_ahead_behind(struct ref_format *format,
+void filter_ahead_behind(struct repository *r, struct ref_format *format,
 			 struct ref_array *array)
 {
 	struct commit **commits;
@@ -2502,7 +2502,7 @@ void filter_ahead_behind(struct ref_format *format,
 		commits_nr++;
 	}
 
-	ahead_behind(commits, commits_nr, array->counts, array->counts_nr);
+	ahead_behind(r, commits, commits_nr, array->counts, array->counts_nr);
 	free(commits);
 }
 
diff --git a/ref-filter.h b/ref-filter.h
index 7e8bff3864e..1a757b49233 100644
--- a/ref-filter.h
+++ b/ref-filter.h
@@ -163,7 +163,7 @@ struct ref_array_item *ref_array_push(struct ref_array *array,
  *
  * If this is not called, then any ahead-behind atoms will be blank.
  */
-void filter_ahead_behind(struct ref_format *format,
+void filter_ahead_behind(struct repository *r, struct ref_format *format,
 			 struct ref_array *array);
 
 #endif /*  REF_FILTER_H  */