diff options
authorRené Scharfe <>2012-03-31 22:11:01 (GMT)
committerJunio C Hamano <>2012-04-11 15:50:54 (GMT)
commitfbc08ea177f8284d10c62ad39de51edb21af88b0 (patch)
parent46905893b20ac2a044c06a0eecc12425a8405e69 (diff)
revision: insert unsorted, then sort in prepare_revision_walk()
Speed up prepare_revision_walk() by adding commits without sorting to the commit_list and at the end sort the list in one go. Thanks to mergesort() working behind the scenes, this is a lot faster for large numbers of commits than the current insert sort. Also introduce and use commit_list_reverse(), to keep the ordering of commits sharing the same commit date unchanged. That's because commit_list_insert_by_date() sorts commits with descending date, but adds later entries with the same date entries last, while commit_list_insert() always inserts entries at the top. The following commit_list_sort_by_date() keeps the order of entries sharing the same date. Jeff's test case, in a repo with lots of refs, was to run: # make a new commit on top of HEAD, but not yet referenced sha1=`git commit-tree HEAD^{tree} -p HEAD </dev/null` # now do the same "connected" test that receive-pack would do git rev-list --objects $sha1 --not --all With a git.git with a ref for each revision, master needs (best of five): real 0m2.210s user 0m2.188s sys 0m0.016s And with this patch: real 0m0.480s user 0m0.456s sys 0m0.020s Signed-off-by: Rene Scharfe <> Signed-off-by: Junio C Hamano <>
3 files changed, 19 insertions, 1 deletions
diff --git a/commit.c b/commit.c
index b9ce569..0759b2c 100644
--- a/commit.c
+++ b/commit.c
@@ -361,6 +361,21 @@ struct commit_list *commit_list_insert(struct commit *item, struct commit_list *
return new_list;
+void commit_list_reverse(struct commit_list **list_p)
+ struct commit_list *prev = NULL, *curr = *list_p, *next;
+ if (!list_p)
+ return;
+ while (curr) {
+ next = curr->next;
+ curr->next = prev;
+ prev = curr;
+ curr = next;
+ }
+ *list_p = prev;
unsigned commit_list_count(const struct commit_list *l)
unsigned c = 0;
diff --git a/commit.h b/commit.h
index 154c0e3..f8d250d 100644
--- a/commit.h
+++ b/commit.h
@@ -57,6 +57,7 @@ unsigned commit_list_count(const struct commit_list *l);
struct commit_list *commit_list_insert_by_date(struct commit *item,
struct commit_list **list);
void commit_list_sort_by_date(struct commit_list **list);
+void commit_list_reverse(struct commit_list **list_p);
void free_commit_list(struct commit_list *list);
diff --git a/revision.c b/revision.c
index 064e351..a75a1d7 100644
--- a/revision.c
+++ b/revision.c
@@ -2054,11 +2054,13 @@ int prepare_revision_walk(struct rev_info *revs)
if (commit) {
if (!(commit->object.flags & SEEN)) {
commit->object.flags |= SEEN;
- commit_list_insert_by_date(commit, &revs->commits);
+ commit_list_insert(commit, &revs->commits);
+ commit_list_reverse(&revs->commits);
+ commit_list_sort_by_date(&revs->commits);
if (!revs->leak_pending)