Replace pqueue with code from hashsig heap

I accidentally wrote a separate priority queue implementation when
I was working on file rename detection as part of the file hash
signature calculation code.  To simplify licensing terms, I just
adapted that to a general purpose priority queue and replace the
old priority queue implementation that was borrowed from elsewhere.

This also removes parts of the COPYING document that no longer
apply to libgit2.

1 files changed, 15 insertions, 20 deletions

diff --git a/src/graph.c b/src/graph.c
index f39af5ed5..96fda7add 100644
--- a/src/graph.c
+++ b/src/graph.c
@@ -1,4 +1,3 @@
-
 /*
  * Copyright (C) the libgit2 contributors. All rights reserved.
  *
@@ -13,9 +12,9 @@
 static int interesting(git_pqueue *list, git_commit_list *roots)
 {
 	unsigned int i;
-	/* element 0 isn't used - we need to start at 1 */
-	for (i = 1; i < list->size; i++) {
-		git_commit_list_node *commit = list->d[i];
+
+	for (i = 0; i < git_pqueue_size(list); i++) {
+		git_commit_list_node *commit = git_pqueue_get(list, i);
 		if ((commit->flags & STALE) == 0)
 			return 1;
 	}
@@ -42,7 +41,7 @@ static int mark_parents(git_revwalk *walk, git_commit_list_node *one,
 		return 0;
 	}
 
-	if (git_pqueue_init(&list, 2, git_commit_list_time_cmp) < 0)
+	if (git_pqueue_init(&list, 0, 2, git_commit_list_time_cmp) < 0)
 		return -1;
 
 	if (git_commit_list_parse(walk, one) < 0)
@@ -59,10 +58,9 @@ static int mark_parents(git_revwalk *walk, git_commit_list_node *one,
 
 	/* as long as there are non-STALE commits */
 	while (interesting(&list, roots)) {
-		git_commit_list_node *commit;
+		git_commit_list_node *commit = git_pqueue_pop(&list);
 		int flags;
 
-		commit = git_pqueue_pop(&list);
 		if (commit == NULL)
 			break;
 
@@ -110,16 +108,16 @@ static int ahead_behind(git_commit_list_node *one, git_commit_list_node *two,
 {
 	git_commit_list_node *commit;
 	git_pqueue pq;
-	int i;
+	int error = 0, i;
 	*ahead = 0;
 	*behind = 0;
 
-	if (git_pqueue_init(&pq, 2, git_commit_list_time_cmp) < 0)
+	if (git_pqueue_init(&pq, 0, 2, git_commit_list_time_cmp) < 0)
 		return -1;
-	if (git_pqueue_insert(&pq, one) < 0)
-		goto on_error;
-	if (git_pqueue_insert(&pq, two) < 0)
-		goto on_error;
+
+	if ((error = git_pqueue_insert(&pq, one)) < 0 ||
+		(error = git_pqueue_insert(&pq, two)) < 0)
+		goto done;
 
 	while ((commit = git_pqueue_pop(&pq)) != NULL) {
 		if (commit->flags & RESULT ||
@@ -132,18 +130,15 @@ static int ahead_behind(git_commit_list_node *one, git_commit_list_node *two,
 
 		for (i = 0; i < commit->out_degree; i++) {
 			git_commit_list_node *p = commit->parents[i];
-			if (git_pqueue_insert(&pq, p) < 0)
-				return -1;
+			if ((error = git_pqueue_insert(&pq, p)) < 0)
+				goto done;
 		}
 		commit->flags |= RESULT;
 	}
 
+done:
 	git_pqueue_free(&pq);
-	return 0;
-
-on_error:
-	git_pqueue_free(&pq);
-	return -1;
+	return error;
 }
 
 int git_graph_ahead_behind(size_t *ahead, size_t *behind, git_repository *repo,