Merge branch 'jk/fetch-pack-many-refs'

Fetching between repositories with many refs employed O(n^2)
algorithm to match up the common objects, which has been corrected.

* jk/fetch-pack-many-refs:
  fetch-pack: avoid quadratic behavior in rev_list_push
  commit.c: make compare_commits_by_commit_date global
  fetch-pack: avoid quadratic list insertion in mark_complete

Author: gitster

commit.c

@@ -581,7 +581,7 @@ static int compare_commits_by_author_date(const void *a_, const void *b_,
 	return 0;
 }
 
-static int compare_commits_by_commit_date(const void *a_, const void *b_, void *unused)
+int compare_commits_by_commit_date(const void *a_, const void *b_, void *unused)
 {
 	const struct commit *a = a_, *b = b_;
 	/* newer commits with larger date first */

commit.h

@@ -254,4 +254,6 @@ extern void print_commit_list(struct commit_list *list,
  */
 extern void check_commit_signature(const struct commit* commit, struct signature_check *sigc);
 
+int compare_commits_by_commit_date(const void *a_, const void *b_, void *unused);
+
 #endif /* COMMIT_H */

fetch-pack.c

@@ -11,6 +11,7 @@
 #include "run-command.h"
 #include "transport.h"
 #include "version.h"
+#include "prio-queue.h"
 
 static int transfer_unpack_limit = -1;
 static int fetch_unpack_limit = -1;
@@ -37,7 +38,7 @@ static int marked;
  */
 #define MAX_IN_VAIN 256
 
-static struct commit_list *rev_list;
+static struct prio_queue rev_list = { compare_commits_by_commit_date };
 static int non_common_revs, multi_ack, use_sideband, allow_tip_sha1_in_want;
 
 static void rev_list_push(struct commit *commit, int mark)
@@ -49,7 +50,7 @@ static void rev_list_push(struct commit *commit, int mark)
 			if (parse_commit(commit))
 				return;
 
-		commit_list_insert_by_date(commit, &rev_list);
+		prio_queue_put(&rev_list, commit);
 
 		if (!(commit->object.flags & COMMON))
 			non_common_revs++;
@@ -122,10 +123,10 @@ static const unsigned char *get_rev(void)
 		unsigned int mark;
 		struct commit_list *parents;
 
-		if (rev_list == NULL || non_common_revs == 0)
+		if (rev_list.nr == 0 || non_common_revs == 0)
 			return NULL;
 
-		commit = rev_list->item;
+		commit = prio_queue_get(&rev_list);
 		if (!commit->object.parsed)
 			parse_commit(commit);
 		parents = commit->parents;
@@ -152,8 +153,6 @@ static const unsigned char *get_rev(void)
 				mark_common(parents->item, 1, 0);
 			parents = parents->next;
 		}
-
-		rev_list = rev_list->next;
 	}
 
 	return commit->object.sha1;
@@ -442,7 +441,7 @@ static int find_common(struct fetch_pack_args *args,
 					in_vain = 0;
 					got_continue = 1;
 					if (ack == ACK_ready) {
-						rev_list = NULL;
+						clear_prio_queue(&rev_list);
 						got_ready = 1;
 					}
 					break;
@@ -505,7 +504,7 @@ static int mark_complete(const char *refname, const unsigned char *sha1, int fla
 		struct commit *commit = (struct commit *)o;
 		if (!(commit->object.flags & COMPLETE)) {
 			commit->object.flags |= COMPLETE;
-			commit_list_insert_by_date(commit, &complete);
+			commit_list_insert(commit, &complete);
 		}
 	}
 	return 0;
@@ -622,6 +621,7 @@ static int everything_local(struct fetch_pack_args *args,
 	if (!args->depth) {
 		for_each_ref(mark_complete, NULL);
 		for_each_alternate_ref(mark_alternate_complete, NULL);
+		commit_list_sort_by_date(&complete);
 		if (cutoff)
 			mark_recent_complete_commits(args, cutoff);
 	}