@matheusbsbs / matheus-bagliano / commits / fbc08ea177

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 <rene.scharfe@lsrfire.ath.cx> Signed-off-by: Junio C Hamano <gitster@pobox.com>

René Scharfe committed Apr 1, 2012 at 00:11 UTC fbc08ea177f8284d10c62ad39de51edb21af88b0

3 files changed +19 -1

commit.c

+15

@@ -361,6 +361,21 @@ struct commit_list *commit_list_insert(struct commit *item, struct commit_list *

361 return new_list;

362 }

363

364 +void commit_list_reverse(struct commit_list **list_p)

365 +{

366 + struct commit_list *prev = NULL, *curr = *list_p, *next;

367 +

368 + if (!list_p)

369 + return;

370 + while (curr) {

371 + next = curr->next;

372 + curr->next = prev;

373 + prev = curr;

374 + curr = next;

375 + }

376 + *list_p = prev;

377 +}

378 +

379 unsigned commit_list_count(const struct commit_list *l)

380 {

381 unsigned c = 0;

commit.h

@@ -57,6 +57,7 @@ unsigned commit_list_count(const struct commit_list *l);

57 struct commit_list *commit_list_insert_by_date(struct commit *item,

58 struct commit_list **list);

59 void commit_list_sort_by_date(struct commit_list **list);

60 +void commit_list_reverse(struct commit_list **list_p);

62 void free_commit_list(struct commit_list *list);

revision.c

+3 -1

@@ -2054,11 +2054,13 @@ int prepare_revision_walk(struct rev_info *revs)

2054 if (commit) {

2055 if (!(commit->object.flags & SEEN)) {

2056 commit->object.flags |= SEEN;

2057 - commit_list_insert_by_date(commit, &revs->commits);

2057 + commit_list_insert(commit, &revs->commits);

2058 }

2059 }

2060 e++;

2061 }

2062 + commit_list_reverse(&revs->commits);

2063 + commit_list_sort_by_date(&revs->commits);

2064 if (!revs->leak_pending)

2065 free(list);

2066