From 885f0063e9962068d381ca5256ca49070bb2480c Mon Sep 17 00:00:00 2001 From: Elijah Newren Date: Sun, 13 Dec 2020 08:04:14 +0000 Subject: [PATCH] merge-ort: avoid repeating fill_tree_descriptor() on the same tree Three-way merges, by their nature, are going to often have two or more trees match at a given subdirectory. We can avoid calling fill_tree_descriptor() on the same tree by checking when these trees match. Noting when various oids match will also be useful in other calculations and optimizations as well. Signed-off-by: Elijah Newren Signed-off-by: Junio C Hamano --- merge-ort.c | 26 ++++++++++++++++++++++---- 1 file changed, 22 insertions(+), 4 deletions(-) diff --git a/merge-ort.c b/merge-ort.c index 4a2c7de6e8ee1b..690c64fe264f0b 100644 --- a/merge-ort.c +++ b/merge-ort.c @@ -223,6 +223,15 @@ static int collect_merge_info_callback(int n, unsigned mbase_null = !(mask & 1); unsigned side1_null = !(mask & 2); unsigned side2_null = !(mask & 4); + unsigned side1_matches_mbase = (!side1_null && !mbase_null && + names[0].mode == names[1].mode && + oideq(&names[0].oid, &names[1].oid)); + unsigned side2_matches_mbase = (!side2_null && !mbase_null && + names[0].mode == names[2].mode && + oideq(&names[0].oid, &names[2].oid)); + unsigned sides_match = (!side1_null && !side2_null && + names[1].mode == names[2].mode && + oideq(&names[1].oid, &names[2].oid)); /* n = 3 is a fundamental assumption. */ if (n != 3) @@ -275,10 +284,19 @@ static int collect_merge_info_callback(int n, newinfo.pathlen = st_add3(newinfo.pathlen, p->pathlen, 1); for (i = MERGE_BASE; i <= MERGE_SIDE2; i++) { - const struct object_id *oid = NULL; - if (dirmask & 1) - oid = &names[i].oid; - buf[i] = fill_tree_descriptor(opt->repo, t + i, oid); + if (i == 1 && side1_matches_mbase) + t[1] = t[0]; + else if (i == 2 && side2_matches_mbase) + t[2] = t[0]; + else if (i == 2 && sides_match) + t[2] = t[1]; + else { + const struct object_id *oid = NULL; + if (dirmask & 1) + oid = &names[i].oid; + buf[i] = fill_tree_descriptor(opt->repo, + t + i, oid); + } dirmask >>= 1; }