[PATCH 06/16] upload-pack: generalize commit date cutoff

["Derrick Stolee via GitGitGadget" <gitgitgadget@xxxxxxxxx>]

From: Derrick Stolee <dstolee@xxxxxxxxxxxxx>

The ok_to_give_up() method uses the commit date as a cutoff to avoid
walking the entire reachble set of commits. Before moving the
reachable() method to commit-reach.c, pull out the dependence on the
global constant 'oldest_have' with a 'min_commit_date' parameter.

Signed-off-by: Derrick Stolee <dstolee@xxxxxxxxxxxxx>
---
 upload-pack.c | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/upload-pack.c b/upload-pack.c
index e7ad7f24b..96298e50e 100644
--- a/upload-pack.c
+++ b/upload-pack.c
@@ -336,7 +336,8 @@ static int got_oid(const char *hex, struct object_id *oid)
 	return 0;
 }
 
-static int reachable(struct commit *from, int with_flag, int assign_flag)
+static int reachable(struct commit *from, int with_flag, int assign_flag,
+		     time_t min_commit_date)
 {
 	struct prio_queue work = { compare_commits_by_commit_date };
 
@@ -354,7 +355,7 @@ static int reachable(struct commit *from, int with_flag, int assign_flag)
 		if (commit->object.flags & REACHABLE)
 			continue;
 		commit->object.flags |= REACHABLE;
-		if (commit->date < oldest_have)
+		if (commit->date < min_commit_date)
 			continue;
 		for (list = commit->parents; list; list = list->next) {
 			struct commit *parent = list->item;
@@ -371,10 +372,12 @@ static int reachable(struct commit *from, int with_flag, int assign_flag)
 /*
  * Determine if every commit in 'from' can reach at least one commit
  * that is marked with 'with_flag'. As we traverse, use 'assign_flag'
- * as a marker for commits that are already visited.
+ * as a marker for commits that are already visited. Do not walk
+ * commits with date below 'min_commit_date'.
  */
 static int can_all_from_reach_with_flag(struct object_array *from,
-					int with_flag, int assign_flag)
+					int with_flag, int assign_flag,
+					time_t min_commit_date)
 {
 	int i;
 
@@ -393,7 +396,8 @@ static int can_all_from_reach_with_flag(struct object_array *from,
 			from->objects[i].item->flags |= assign_flag;
 			continue;
 		}
-		if (!reachable((struct commit *)from_one, with_flag, assign_flag))
+		if (!reachable((struct commit *)from_one, with_flag, assign_flag,
+			       min_commit_date))
 			return 0;
 	}
 	return 1;
@@ -404,7 +408,8 @@ static int ok_to_give_up(void)
 	if (!have_obj.nr)
 		return 0;
 
-	return can_all_from_reach_with_flag(&want_obj, THEY_HAVE, COMMON_KNOWN);
+	return can_all_from_reach_with_flag(&want_obj, THEY_HAVE,
+					    COMMON_KNOWN, oldest_have);
 }
 
 static int get_common_commits(void)
-- 
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