[PATCH v5 09/10] commit-reach: move min_generation check into paint_queue_get()

["Kristofer Karlsson via GitGitGadget" <gitgitgadget@gmail.com>]

From: Kristofer Karlsson <krka@spotify.com>

Consolidate the min_generation termination condition into
paint_queue_get(), alongside the existing stale-entry and
side-exhaustion checks.

Move last_gen into struct paint_state so that
commit_graph_generation() is called exactly once per dequeued commit
and the result is shared across all termination checks and the
monotonicity BUG assertion.

Signed-off-by: Kristofer Karlsson <krka@spotify.com>
---
 commit-reach.c | 31 ++++++++++++++++++-------------
 1 file changed, 18 insertions(+), 13 deletions(-)

diff --git a/commit-reach.c b/commit-reach.c
index 2b9249105c..871d67d07a 100644
--- a/commit-reach.c
+++ b/commit-reach.c
@@ -90,6 +90,8 @@ struct paint_state {
 	size_t parent2_count;
 	size_t mb_candidate_count;
 	int gen_ordered;
+	timestamp_t min_generation;
+	timestamp_t last_gen;
 };
 
 static void paint_count_update(struct paint_state *state,
@@ -139,11 +141,23 @@ static void paint_queue_put(struct paint_state *state,
 static struct commit *paint_queue_get(struct paint_state *state)
 {
 	struct commit *commit = prio_queue_get(&state->queue);
+	timestamp_t generation;
 
 	if (!commit)
 		return NULL;
 
 	commit->object.flags &= ~ENQUEUED;
+	generation = commit_graph_generation(commit);
+
+	if (state->min_generation && generation > state->last_gen)
+		BUG("bad generation skip %"PRItime" > %"PRItime" at %s",
+		    generation, state->last_gen,
+		    oid_to_hex(&commit->object.oid));
+	state->last_gen = generation;
+
+	/* generation cutoff */
+	if (generation < state->min_generation)
+		return NULL;
 
 	if (!state->mb_candidate_count) {
 		/* only stale entries remain */
@@ -153,7 +167,7 @@ static struct commit *paint_queue_get(struct paint_state *state)
 		/* one side is exhausted */
 		if ((!state->parent1_count || !state->parent2_count) &&
 		    state->gen_ordered &&
-		    commit_graph_generation(commit) < GENERATION_NUMBER_INFINITY)
+		    generation < GENERATION_NUMBER_INFINITY)
 			return NULL;
 	}
 
@@ -180,9 +194,10 @@ static int paint_down_to_common(struct repository *r,
 	struct commit *commit;
 	int i;
 	int steps = 0;
-	timestamp_t last_gen = GENERATION_NUMBER_INFINITY;
 	struct commit_list **tail = result;
 
+	state.min_generation = min_generation;
+	state.last_gen = GENERATION_NUMBER_INFINITY;
 	if (!min_generation && !corrected_commit_dates_enabled(r)) {
 		state.queue.compare = compare_commits_by_commit_date;
 		state.gen_ordered = 0;
@@ -201,18 +216,8 @@ static int paint_down_to_common(struct repository *r,
 	while ((commit = paint_queue_get(&state))) {
 		struct commit_list *parents;
 		int flags;
-		timestamp_t generation = commit_graph_generation(commit);
 		steps++;
 
-		if (min_generation && generation > last_gen)
-			BUG("bad generation skip %"PRItime" > %"PRItime" at %s",
-			    generation, last_gen,
-			    oid_to_hex(&commit->object.oid));
-		last_gen = generation;
-
-		if (generation < min_generation)
-			break;
-
 		flags = commit->object.flags & (PARENT1 | PARENT2 | STALE);
 		if (flags == (PARENT1 | PARENT2)) {
 			if (!(commit->object.flags & RESULT)) {
@@ -224,7 +229,7 @@ static int paint_down_to_common(struct repository *r,
 				 * descendant of this one.
 				 */
 				if (!(mb_flags & MERGE_BASE_FIND_ALL) &&
-				    generation < GENERATION_NUMBER_INFINITY)
+				    state.last_gen < GENERATION_NUMBER_INFINITY)
 					break;
 			}
 			/* Mark parents of a found merge stale */
-- 
gitgitgadget