From 85daa01f6b80cb6eb14c5f484a6da9f0b1247143 Mon Sep 17 00:00:00 2001 From: Derrick Stolee Date: Fri, 2 Nov 2018 06:14:49 -0700 Subject: [PATCH] remote: make add_missing_tags() linear The add_missing_tags() method currently has quadratic behavior. This is due to a linear number (based on number of tags T) of calls to in_merge_bases_many, which has linear performance (based on number of commits C in the repository). Replace this O(T * C) algorithm with an O(T + C) algorithm by using get_reachable_subset(). We ignore the return list and focus instead on the reachable_flag assigned to the commits we care about, because we need to interact with the tag ref and not just the commit object. Signed-off-by: Derrick Stolee Signed-off-by: Junio C Hamano --- remote.c | 34 +++++++++++++++++++++++++++++++++- 1 file changed, 33 insertions(+), 1 deletion(-) diff --git a/remote.c b/remote.c index 81f4f01b00..b850f2feb3 100644 --- a/remote.c +++ b/remote.c @@ -1205,9 +1205,36 @@ static void add_missing_tags(struct ref *src, struct ref **dst, struct ref ***ds * sent to the other side. */ if (sent_tips.nr) { + const int reachable_flag = 1; + struct commit_list *found_commits; + struct commit **src_commits; + int nr_src_commits = 0, alloc_src_commits = 16; + ALLOC_ARRAY(src_commits, alloc_src_commits); + for_each_string_list_item(item, &src_tag) { struct ref *ref = item->util; + struct commit *commit; + + if (is_null_oid(&ref->new_oid)) + continue; + commit = lookup_commit_reference_gently(the_repository, + &ref->new_oid, + 1); + if (!commit) + /* not pushing a commit, which is not an error */ + continue; + + ALLOC_GROW(src_commits, nr_src_commits + 1, alloc_src_commits); + src_commits[nr_src_commits++] = commit; + } + + found_commits = get_reachable_subset(sent_tips.tip, sent_tips.nr, + src_commits, nr_src_commits, + reachable_flag); + + for_each_string_list_item(item, &src_tag) { struct ref *dst_ref; + struct ref *ref = item->util; struct commit *commit; if (is_null_oid(&ref->new_oid)) @@ -1223,7 +1250,7 @@ static void add_missing_tags(struct ref *src, struct ref **dst, struct ref ***ds * Is this tag, which they do not have, reachable from * any of the commits we are sending? */ - if (!in_merge_bases_many(commit, sent_tips.nr, sent_tips.tip)) + if (!(commit->object.flags & reachable_flag)) continue; /* Add it in */ @@ -1231,7 +1258,12 @@ static void add_missing_tags(struct ref *src, struct ref **dst, struct ref ***ds oidcpy(&dst_ref->new_oid, &ref->new_oid); dst_ref->peer_ref = copy_ref(ref); } + + clear_commit_marks_many(nr_src_commits, src_commits, reachable_flag); + free(src_commits); + free_commit_list(found_commits); } + string_list_clear(&src_tag, 0); free(sent_tips.tip); }