From: "Kristofer Karlsson via GitGitGadget" <gitgitgadget@gmail•com>
To: git@vger•kernel.org
Cc: Kristofer Karlsson <krka@spotify•com>,
Kristofer Karlsson <krka@spotify•com>
Subject: [PATCH 3/3] commit-reach: optimize queue scan in ahead_behind
Date: Sun, 24 May 2026 17:42:20 +0000 [thread overview]
Message-ID: <711a0e2235103489f17ff867439e007abd0e4291.1779644541.git.gitgitgadget@gmail.com> (raw)
In-Reply-To: <pull.2124.git.1779644541.gitgitgadget@gmail.com>
From: Kristofer Karlsson <krka@spotify•com>
Apply the same nonstale_count optimization from the previous commit
to ahead_behind(). This replaces the remaining caller of the O(n)
queue_has_nonstale() scan with an O(1) counter check, allowing
queue_has_nonstale() to be removed.
ahead_behind() already deduplicates queue entries using the PARENT2
flag (via insert_no_dup), so the counter is maintained through
insert_no_dup() and mark_stale() using PARENT2 as the queued_flag.
Signed-off-by: Kristofer Karlsson <krka@spotify•com>
---
commit-reach.c | 27 ++++++++++++---------------
1 file changed, 12 insertions(+), 15 deletions(-)
diff --git a/commit-reach.c b/commit-reach.c
index 356ff52d08..41deb8fc78 100644
--- a/commit-reach.c
+++ b/commit-reach.c
@@ -61,16 +61,6 @@ static void mark_stale(struct commit *c, unsigned queued_flag,
}
}
-static int queue_has_nonstale(struct prio_queue *queue)
-{
- for (size_t i = 0; i < queue->nr; i++) {
- struct commit *commit = queue->array[i].data;
- if (!(commit->object.flags & STALE))
- return 1;
- }
- return 0;
-}
-
/* all input commits in one and twos[] must have been parsed! */
static int paint_down_to_common(struct repository *r,
struct commit *one, int n,
@@ -1051,12 +1041,15 @@ struct commit_list *get_reachable_subset(struct commit **from, size_t nr_from,
define_commit_slab(bit_arrays, struct bitmap *);
static struct bit_arrays bit_arrays;
-static void insert_no_dup(struct prio_queue *queue, struct commit *c)
+static void insert_no_dup(struct prio_queue *queue, struct commit *c,
+ int *nonstale_count)
{
if (c->object.flags & PARENT2)
return;
prio_queue_put(queue, c);
c->object.flags |= PARENT2;
+ if (!(c->object.flags & STALE))
+ (*nonstale_count)++;
}
static struct bitmap *get_bit_array(struct commit *c, int width)
@@ -1082,6 +1075,7 @@ void ahead_behind(struct repository *r,
{
struct prio_queue queue = { .compare = compare_commits_by_gen_then_commit_date };
size_t width = DIV_ROUND_UP(commits_nr, BITS_IN_EWORD);
+ int nonstale_count = 0;
if (!commits_nr || !counts_nr)
return;
@@ -1100,14 +1094,17 @@ void ahead_behind(struct repository *r,
struct bitmap *bitmap = get_bit_array(c, width);
bitmap_set(bitmap, i);
- insert_no_dup(&queue, c);
+ insert_no_dup(&queue, c, &nonstale_count);
}
- while (queue_has_nonstale(&queue)) {
+ while (nonstale_count > 0) {
struct commit *c = prio_queue_get(&queue);
struct commit_list *p;
struct bitmap *bitmap_c = get_bit_array(c, width);
+ if (!(c->object.flags & STALE))
+ nonstale_count--;
+
for (size_t i = 0; i < counts_nr; i++) {
int reach_from_tip = !!bitmap_get(bitmap_c, counts[i].tip_index);
int reach_from_base = !!bitmap_get(bitmap_c, counts[i].base_index);
@@ -1136,9 +1133,9 @@ void ahead_behind(struct repository *r,
* queue is STALE.
*/
if (bitmap_popcount(bitmap_p) == commits_nr)
- p->item->object.flags |= STALE;
+ mark_stale(p->item, PARENT2, &nonstale_count);
- insert_no_dup(&queue, p->item);
+ insert_no_dup(&queue, p->item, &nonstale_count);
}
free_bit_array(c);
--
gitgitgadget
next prev parent reply other threads:[~2026-05-24 17:42 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-24 17:42 [PATCH 0/3] commit-reach: replace queue_has_nonstale with a counter Kristofer Karlsson via GitGitGadget
2026-05-24 17:42 ` [PATCH 1/3] commit-reach: deduplicate queue entries in paint_down_to_common Kristofer Karlsson via GitGitGadget
2026-05-24 23:40 ` Junio C Hamano
2026-05-25 1:43 ` Derrick Stolee
2026-05-25 6:50 ` Kristofer Karlsson
2026-05-25 7:17 ` Junio C Hamano
2026-05-25 7:53 ` Kristofer Karlsson
2026-05-25 10:02 ` Jeff King
2026-05-25 7:01 ` Jeff King
2026-05-25 7:15 ` Jeff King
2026-05-24 17:42 ` [PATCH 2/3] commit-reach: optimize queue scan " Kristofer Karlsson via GitGitGadget
2026-05-25 1:59 ` Derrick Stolee
2026-05-25 8:54 ` Kristofer Karlsson
2026-05-24 17:42 ` Kristofer Karlsson via GitGitGadget [this message]
2026-05-25 7:11 ` [PATCH 3/3] commit-reach: optimize queue scan in ahead_behind Jeff King
2026-05-25 6:47 ` [PATCH 0/3] commit-reach: replace queue_has_nonstale with a counter Jeff King
2026-05-25 7:59 ` Kristofer Karlsson
2026-05-25 8:38 ` Junio C Hamano
2026-05-25 9:55 ` Jeff King
2026-05-25 10:47 ` Kristofer Karlsson
2026-05-25 14:28 ` [PATCH v2 0/3] commit-reach: replace queue_has_nonstale() scan with O(1) tracking Kristofer Karlsson via GitGitGadget
2026-05-25 14:28 ` [PATCH v2 1/3] object.h: fix stale entries in object flag allocation table Kristofer Karlsson via GitGitGadget
2026-05-25 14:28 ` [PATCH v2 2/3] commit-reach: deduplicate queue entries in paint_down_to_common Kristofer Karlsson via GitGitGadget
2026-05-25 22:50 ` Junio C Hamano
2026-05-26 6:57 ` Kristofer Karlsson
2026-05-25 14:28 ` [PATCH v2 3/3] commit-reach: replace queue_has_nonstale() scan with O(1) tracking Kristofer Karlsson via GitGitGadget
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