Subject: [PATCH 10/11] object: try 3-way cuckoo

From: Junio C Hamano <[email-masked]>
Date: Thu, 11 Aug 2011 10:53:15 -0700

Signed-off-by: Junio C Hamano <[email-masked]>
---
../+v/48b49262cd2d0d64696b489fe5bdfa8efb9180f5/git-pack-objects
Counting objects: 2139209, done.
30.68user 2.26system 0:33.05elapsed 99%CPU (0avgtext+0avgdata 3660832maxresident)k
0inputs+0outputs (0major+421963minor)pagefaults 0swaps
Counting objects: 2139209, done.
30.76user 2.26system 0:33.12elapsed 99%CPU (0avgtext+0avgdata 3660480maxresident)k
0inputs+0outputs (0major+421941minor)pagefaults 0swaps
Counting objects: 2139209, done.
30.74user 2.33system 0:33.18elapsed 99%CPU (0avgtext+0avgdata 3661696maxresident)k
0inputs+0outputs (0major+422017minor)pagefaults 0swaps
---
 object.c |   15 ++++-----------
 1 files changed, 4 insertions(+), 11 deletions(-)

diff --git a/object.c b/object.c
index caced56..18e6bcf 100644
--- a/object.c
+++ b/object.c
@@ -49,20 +49,18 @@ struct object *get_indexed_object(unsigned int idx)
 struct object *lookup_object(const unsigned char *sha1)
 {
 	struct object *obj;
-	unsigned int hashval[4];
+	unsigned int hashval[3];
 
 	if (!obj_hash)
 		return NULL;
 
-	memcpy(hashval, sha1, 16);
+	memcpy(hashval, sha1, 12);
 	if ((obj = obj_hash[H(hashval, 0)]) && !hashcmp(sha1, obj->sha1))
 		return obj;
 	if ((obj = obj_hash[H(hashval, 1)]) && !hashcmp(sha1, obj->sha1))
 		return obj;
 	if ((obj = obj_hash[H(hashval, 2)]) && !hashcmp(sha1, obj->sha1))
 		return obj;
-	if ((obj = obj_hash[H(hashval, 3)]) && !hashcmp(sha1, obj->sha1))
-		return obj;
 	return NULL;
 }
 
@@ -82,9 +80,9 @@ static struct object *insert_obj_hash(struct object *obj)
 	for (loop = obj_hash_size / 2; 0 <= loop; loop--) {
 		struct object *tmp_obj;
 		unsigned int ix;
-		unsigned int hashval[4];
+		unsigned int hashval[3];
 
-		memcpy(hashval, obj->sha1, 16);
+		memcpy(hashval, obj->sha1, 12);
 		ix = H(hashval, 0);
 		if (!obj_hash[ix]) {
 			obj_hash[ix] = obj;
@@ -96,11 +94,6 @@ static struct object *insert_obj_hash(struct object *obj)
 			return NULL;
 		}
 		ix = H(hashval, 2);
-		if (!obj_hash[ix]) {
-			obj_hash[ix] = obj;
-			return NULL;
-		}
-		ix = H(hashval, 3);
 		tmp_obj = obj_hash[ix];
 		obj_hash[ix] = obj;
 		if (!tmp_obj)
-- 
1.7.6.433.g1421f