Merge branch 'kk/prio-queue-get-put-fusion'

The lazy priority queue optimization pattern (deferring actual removal
in 'prio_queue_get()' to allow get+put fusion) has been folded
directly into 'prio_queue' itself, speeding up commit traversal
workflows and simplifying callers.

* kk/prio-queue-get-put-fusion:
  prio-queue: fold lazy_queue into prio_queue for automatic get+put fusion
  prio-queue: rename .nr to .nr_ and add accessor helpers

Author: gitster

builtin/describe.c

@@ -251,56 +251,19 @@ static int compare_pt(const void *a_, const void *b_)
 	return 0;
 }
 
-struct lazy_queue {
-	struct prio_queue queue;
-	bool get_pending;
-};
-
-#define LAZY_QUEUE_INIT { { compare_commits_by_commit_date }, false }
-
-static void *lazy_queue_get(struct lazy_queue *queue)
-{
-	if (queue->get_pending)
-		prio_queue_get(&queue->queue);
-	else
-		queue->get_pending = true;
-	return prio_queue_peek(&queue->queue);
-}
-
-static void lazy_queue_put(struct lazy_queue *queue, void *thing)
-{
-	if (queue->get_pending)
-		prio_queue_replace(&queue->queue, thing);
-	else
-		prio_queue_put(&queue->queue, thing);
-	queue->get_pending = false;
-}
-
-static bool lazy_queue_empty(const struct lazy_queue *queue)
-{
-	return queue->queue.nr == (queue->get_pending ? 1 : 0);
-}
-
-static void lazy_queue_clear(struct lazy_queue *queue)
-{
-	clear_prio_queue(&queue->queue);
-	queue->get_pending = false;
-}
-
-static unsigned long finish_depth_computation(struct lazy_queue *queue,
+static unsigned long finish_depth_computation(struct prio_queue *queue,
 					      struct possible_tag *best)
 {
 	unsigned long seen_commits = 0;
 	struct oidset unflagged = OIDSET_INIT;
+	struct commit *c;
 
-	for (size_t i = queue->get_pending ? 1 : 0; i < queue->queue.nr; i++) {
-		struct commit *commit = queue->queue.array[i].data;
-		if (!(commit->object.flags & best->flag_within))
-			oidset_insert(&unflagged, &commit->object.oid);
+	prio_queue_for_each(queue, c) {
+		if (!(c->object.flags & best->flag_within))
+			oidset_insert(&unflagged, &c->object.oid);
 	}
 
-	while (!lazy_queue_empty(queue)) {
-		struct commit *c = lazy_queue_get(queue);
+	while ((c = prio_queue_get(queue))) {
 		struct commit_list *parents = c->parents;
 		seen_commits++;
 		if (c->object.flags & best->flag_within) {
@@ -316,7 +279,7 @@ static unsigned long finish_depth_computation(struct lazy_queue *queue,
 			repo_parse_commit(the_repository, p);
 			seen = p->object.flags & SEEN;
 			if (!seen)
-				lazy_queue_put(queue, p);
+				prio_queue_put(queue, p);
 			flag_before = p->object.flags & best->flag_within;
 			p->object.flags |= c->object.flags;
 			flag_after = p->object.flags & best->flag_within;
@@ -364,8 +327,8 @@ static void append_suffix(int depth, const struct object_id *oid, struct strbuf
 
 static void describe_commit(struct commit *cmit, struct strbuf *dst)
 {
-	struct commit *gave_up_on = NULL;
-	struct lazy_queue queue = LAZY_QUEUE_INIT;
+	struct commit *c, *gave_up_on = NULL;
+	struct prio_queue queue = { compare_commits_by_commit_date };
 	struct commit_name *n;
 	struct possible_tag all_matches[MAX_TAGS];
 	unsigned int match_cnt = 0, annotated_cnt = 0, cur_match;
@@ -407,9 +370,8 @@ static void describe_commit(struct commit *cmit, struct strbuf *dst)
 	}
 
 	cmit->object.flags = SEEN;
-	lazy_queue_put(&queue, cmit);
-	while (!lazy_queue_empty(&queue)) {
-		struct commit *c = lazy_queue_get(&queue);
+	prio_queue_put(&queue, cmit);
+	while ((c = prio_queue_get(&queue))) {
 		struct commit_list *parents = c->parents;
 		struct commit_name **slot;
 
@@ -443,7 +405,7 @@ static void describe_commit(struct commit *cmit, struct strbuf *dst)
 				t->depth++;
 		}
 		/* Stop if last remaining path already covered by best candidate(s) */
-		if (annotated_cnt && lazy_queue_empty(&queue)) {
+		if (annotated_cnt && !prio_queue_size(&queue)) {
 			int best_depth = INT_MAX;
 			unsigned best_within = 0;
 			for (cur_match = 0; cur_match < match_cnt; cur_match++) {
@@ -466,7 +428,7 @@ static void describe_commit(struct commit *cmit, struct strbuf *dst)
 			struct commit *p = parents->item;
 			repo_parse_commit(the_repository, p);
 			if (!(p->object.flags & SEEN))
-				lazy_queue_put(&queue, p);
+				prio_queue_put(&queue, p);
 			p->object.flags |= c->object.flags;
 			parents = parents->next;
 
@@ -481,7 +443,7 @@ static void describe_commit(struct commit *cmit, struct strbuf *dst)
 			strbuf_add_unique_abbrev(dst, cmit_oid, abbrev);
 			if (suffix)
 				strbuf_addstr(dst, suffix);
-			lazy_queue_clear(&queue);
+			clear_prio_queue(&queue);
 			return;
 		}
 		if (unannotated_cnt)
@@ -497,11 +459,11 @@ static void describe_commit(struct commit *cmit, struct strbuf *dst)
 	QSORT(all_matches, match_cnt, compare_pt);
 
 	if (gave_up_on) {
-		lazy_queue_put(&queue, gave_up_on);
+		prio_queue_put(&queue, gave_up_on);
 		seen_commits--;
 	}
 	seen_commits += finish_depth_computation(&queue, &all_matches[0]);
-	lazy_queue_clear(&queue);
+	clear_prio_queue(&queue);
 
 	if (debug) {
 		static int label_width = -1;

builtin/last-modified.c

@@ -344,6 +344,7 @@ static void process_parent(struct last_modified *lm,
 static int last_modified_run(struct last_modified *lm)
 {
 	int max_count, queue_popped = 0;
+	struct commit *c, *n;
 	struct prio_queue queue = { compare_commits_by_gen_then_commit_date };
 	struct prio_queue not_queue = { compare_commits_by_gen_then_commit_date };
 	struct commit_list *list;
@@ -389,10 +390,9 @@ static int last_modified_run(struct last_modified *lm)
 		}
 	}
 
-	while (queue.nr) {
+	while ((c = prio_queue_get(&queue))) {
 		int parent_i;
 		struct commit_list *p;
-		struct commit *c = prio_queue_get(&queue);
 		struct bitmap *active_c = active_paths_for(lm, c);
 
 		if ((0 <= max_count && max_count < ++queue_popped) ||
@@ -416,9 +416,8 @@ static int last_modified_run(struct last_modified *lm)
 		 */
 		repo_parse_commit(lm->rev.repo, c);
 
-		while (not_queue.nr) {
+		while ((n = prio_queue_get(&not_queue))) {
 			struct commit_list *np;
-			struct commit *n = prio_queue_get(&not_queue);
 
 			repo_parse_commit(lm->rev.repo, n);
 

builtin/show-branch.c

@@ -62,11 +62,10 @@ static const char *get_color_reset_code(void)
 
 static struct commit *interesting(struct prio_queue *queue)
 {
-	for (size_t i = 0; i < queue->nr; i++) {
-		struct commit *commit = queue->array[i].data;
-		if (commit->object.flags & UNINTERESTING)
-			continue;
-		return commit;
+	struct commit *commit;
+	prio_queue_for_each(queue, commit) {
+		if (!(commit->object.flags & UNINTERESTING))
+			return commit;
 	}
 	return NULL;
 }
@@ -228,17 +227,18 @@ static void join_revs(struct prio_queue *queue,
 {
 	int all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
 	int all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
+	struct commit *commit;
 
-	while (queue->nr) {
+	while ((commit = prio_queue_peek(queue))) {
 		struct commit_list *parents;
 		int still_interesting = !!interesting(queue);
-		struct commit *commit = prio_queue_peek(queue);
-		bool get_pending = true;
 		int flags = commit->object.flags & all_mask;
 
 		if (!still_interesting && extra <= 0)
 			break;
 
+		prio_queue_get(queue);
+
 		mark_seen(commit, seen_p);
 		if ((flags & all_revs) == all_revs)
 			flags |= UNINTERESTING;
@@ -254,14 +254,8 @@ static void join_revs(struct prio_queue *queue,
 			if (mark_seen(p, seen_p) && !still_interesting)
 				extra--;
 			p->object.flags |= flags;
-			if (get_pending)
-				prio_queue_replace(queue, p);
-			else
-				prio_queue_put(queue, p);
-			get_pending = false;
+			prio_queue_put(queue, p);
 		}
-		if (get_pending)
-			prio_queue_get(queue);
 	}
 
 	/*

commit-reach.c

@@ -1121,6 +1121,7 @@ void ahead_behind(struct repository *r,
 	struct nonstale_queue queue = {
 		{ .compare = compare_commits_by_gen_then_commit_date }
 	};
+	void *entry;
 	size_t width = DIV_ROUND_UP(commits_nr, BITS_IN_EWORD);
 
 	if (!commits_nr || !counts_nr)
@@ -1186,8 +1187,8 @@ void ahead_behind(struct repository *r,
 
 	/* STALE is used here, PARENT2 is used by insert_no_dup(). */
 	repo_clear_commit_marks(r, PARENT2 | STALE);
-	for (size_t i = 0; i < queue.pq.nr; i++)
-		free_bit_array(queue.pq.array[i].data);
+	prio_queue_for_each(&queue.pq, entry)
+		free_bit_array(entry);
 	clear_bit_arrays(&bit_arrays);
 	clear_nonstale_queue(&queue);
 }
@@ -1320,7 +1321,7 @@ int get_branch_base_for_tip(struct repository *r,
 			    size_t bases_nr)
 {
 	int best_index = -1;
-	struct commit *branch_point = NULL;
+	struct commit *c, *branch_point = NULL;
 	struct prio_queue queue = { compare_commits_by_gen_then_commit_date };
 	int found_missing_gen = 0;
 
@@ -1373,8 +1374,7 @@ int get_branch_base_for_tip(struct repository *r,
 		prio_queue_put(&queue, c);
 	}
 
-	while (queue.nr) {
-		struct commit *c = prio_queue_get(&queue);
+	while ((c = prio_queue_get(&queue))) {
 		int best_for_c = get_best(c);
 		int best_for_p, positive;
 		struct commit *parent;

commit.c

@@ -782,24 +782,17 @@ void commit_list_sort_by_date(struct commit_list **list)
 struct commit *pop_most_recent_commit(struct prio_queue *queue,
 				      unsigned int mark)
 {
-	struct commit *ret = prio_queue_peek(queue);
-	int get_pending = 1;
+	struct commit *ret = prio_queue_get(queue);
 	struct commit_list *parents = ret->parents;
 
 	while (parents) {
 		struct commit *commit = parents->item;
 		if (!repo_parse_commit(the_repository, commit) && !(commit->object.flags & mark)) {
 			commit->object.flags |= mark;
-			if (get_pending)
-				prio_queue_replace(queue, commit);
-			else
-				prio_queue_put(queue, commit);
-			get_pending = 0;
+			prio_queue_put(queue, commit);
 		}
 		parents = parents->next;
 	}
-	if (get_pending)
-		prio_queue_get(queue);
 	return ret;
 }
 

fetch-pack.c

@@ -662,8 +662,8 @@ static int mark_complete_oid(const struct reference *ref, void *cb_data UNUSED)
 static void mark_recent_complete_commits(struct fetch_pack_args *args,
 					 timestamp_t cutoff)
 {
-	while (complete.nr) {
-		struct commit *item = prio_queue_peek(&complete);
+	struct commit *item;
+	while ((item = prio_queue_peek(&complete))) {
 		if (item->date < cutoff)
 			break;
 		print_verbose(args, _("Marking %s as complete"),

negotiator/default.c

@@ -113,10 +113,12 @@ static const struct object_id *get_rev(struct negotiation_state *ns)
 		unsigned int mark;
 		struct commit_list *parents;
 
-		if (ns->rev_list.nr == 0 || ns->non_common_revs == 0)
+		if (ns->non_common_revs == 0)
 			return NULL;
 
 		commit = prio_queue_get(&ns->rev_list);
+		if (!commit)
+			return NULL;
 		repo_parse_commit(the_repository, commit);
 		parents = commit->parents;
 

negotiator/skipping.c

@@ -143,8 +143,7 @@ static int push_parent(struct data *data, struct entry *entry,
 		/*
 		 * Find the existing entry and use it.
 		 */
-		for (size_t i = 0; i < data->rev_list.nr; i++) {
-			parent_entry = data->rev_list.array[i].data;
+		prio_queue_for_each(&data->rev_list, parent_entry) {
 			if (parent_entry->commit == to_push)
 				goto parent_found;
 		}
@@ -181,10 +180,12 @@ static const struct object_id *get_rev(struct data *data)
 		struct commit_list *p;
 		int parent_pushed = 0;
 
-		if (data->rev_list.nr == 0 || data->non_common_revs == 0)
+		if (data->non_common_revs == 0)
 			return NULL;
 
 		entry = prio_queue_get(&data->rev_list);
+		if (!entry)
+			return NULL;
 		commit = entry->commit;
 		commit->object.flags |= POPPED;
 		if (!(commit->object.flags & COMMON))
@@ -253,8 +254,9 @@ static void have_sent(struct fetch_negotiator *n, struct commit *c)
 static void release(struct fetch_negotiator *n)
 {
 	struct data *data = n->data;
-	for (size_t i = 0; i < data->rev_list.nr; i++)
-		free(data->rev_list.array[i].data);
+	void *entry;
+	prio_queue_for_each(&data->rev_list, entry)
+		free(entry);
 	clear_prio_queue(&data->rev_list);
 	FREE_AND_NULL(data);
 }

object-name.c

@@ -1209,7 +1209,7 @@ static int get_oid_oneline(struct repository *r,
 		l->item->object.flags |= ONELINE_SEEN;
 		prio_queue_put(&copy, l->item);
 	}
-	while (copy.nr) {
+	while (prio_queue_size(&copy)) {
 		const char *p, *buf;
 		struct commit *commit;
 		int matches;

pack-bitmap-write.c

@@ -636,6 +636,8 @@ static int fill_bitmap_commit(struct bitmap_writer *writer,
 			      struct bitmap_index *old_bitmap,
 			      const uint32_t *mapping)
 {
+	struct commit *c;
+	struct tree *t;
 	int found;
 	int from_pseudo_merge = commit->object.flags & BITMAP_PSEUDO_MERGE;
 	uint32_t pos;
@@ -650,9 +652,8 @@ static int fill_bitmap_commit(struct bitmap_writer *writer,
 
 	prio_queue_put(queue, commit);
 
-	while (queue->nr) {
+	while ((c = prio_queue_get(queue))) {
 		struct commit_list *p;
-		struct commit *c = prio_queue_get(queue);
 
 		if (old_bitmap && mapping) {
 			struct ewah_bitmap *old;
@@ -740,8 +741,7 @@ static int fill_bitmap_commit(struct bitmap_writer *writer,
 		}
 	}
 
-	while (tree_queue->nr) {
-		struct tree *t = prio_queue_get(tree_queue);
+	while ((t = prio_queue_get(tree_queue))) {
 		int found;
 
 		pos = find_object_pos(writer, &t->object.oid, &found);