The more we probe alternative slots, the more expensive average
look-up gets, while it helps reduce the load factor of the hash
table.
Signed-off-by: Junio C Hamano <gitster@xxxxxxxxx>
---
../+v/6bb99816f5676ed5ddb6922363b7470a7e8c61f7/git-pack-objects
Counting objects: 2139209, done.
31.09user 2.05system 0:33.25elapsed 99%CPU (0avgtext+0avgdata 3135840maxresident)k
0inputs+0outputs (0major+290849minor)pagefaults 0swaps
Counting objects: 2139209, done.
31.12user 2.14system 0:33.37elapsed 99%CPU (0avgtext+0avgdata 3136128maxresident)k
0inputs+0outputs (0major+290866minor)pagefaults 0swaps
Counting objects: 2139209, done.
31.17user 2.01system 0:33.29elapsed 99%CPU (0avgtext+0avgdata 3136512maxresident)k
0inputs+0outputs (0major+290890minor)pagefaults 0swaps
---
object.c | 15 ++++-----------
1 files changed, 4 insertions(+), 11 deletions(-)
diff --git a/object.c b/object.c
index c777520..caced56 100644
--- a/object.c
+++ b/object.c
@@ -49,12 +49,12 @@ struct object *get_indexed_object(unsigned int idx)
struct object *lookup_object(const unsigned char *sha1)
{
struct object *obj;
- unsigned int hashval[5];
+ unsigned int hashval[4];
if (!obj_hash)
return NULL;
- memcpy(hashval, sha1, 20);
+ memcpy(hashval, sha1, 16);
if ((obj = obj_hash[H(hashval, 0)]) && !hashcmp(sha1, obj->sha1))
return obj;
if ((obj = obj_hash[H(hashval, 1)]) && !hashcmp(sha1, obj->sha1))
@@ -63,8 +63,6 @@ struct object *lookup_object(const unsigned char *sha1)
return obj;
if ((obj = obj_hash[H(hashval, 3)]) && !hashcmp(sha1, obj->sha1))
return obj;
- if ((obj = obj_hash[H(hashval, 4)]) && !hashcmp(sha1, obj->sha1))
- return obj;
return NULL;
}
@@ -84,9 +82,9 @@ 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[5];
+ unsigned int hashval[4];
- memcpy(hashval, obj->sha1, 20);
+ memcpy(hashval, obj->sha1, 16);
ix = H(hashval, 0);
if (!obj_hash[ix]) {
obj_hash[ix] = obj;
@@ -103,11 +101,6 @@ static struct object *insert_obj_hash(struct object *obj)
return NULL;
}
ix = H(hashval, 3);
- if (!obj_hash[ix]) {
- obj_hash[ix] = obj;
- return NULL;
- }
- ix = H(hashval, 4);
tmp_obj = obj_hash[ix];
obj_hash[ix] = obj;
if (!tmp_obj)
--
1.7.6.433.g1421f
--
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