Commit 2821104d authored by Junio C Hamano's avatar Junio C Hamano

diffcore-delta: make the hash a bit denser.

To reduce wasted memory, wait until the hash fills up more
densely before we rehash.  This reduces the working set size a
bit further.
Signed-off-by: default avatarJunio C Hamano <[email protected]>
parent c06c7966
......@@ -25,8 +25,12 @@
*/
/* Wild guess at the initial hash size */
#define INITIAL_HASH_SIZE 10
#define INITIAL_HASH_SIZE 9
#define HASHBASE 65537 /* next_prime(2^16) */
/* We leave more room in smaller hash but do not let it
* grow to have unused hole too much.
*/
#define INITIAL_FREE(sz_log2) ((1<<(sz_log2))*(sz_log2-3)/(sz_log2))
struct spanhash {
unsigned long hashval;
......@@ -38,7 +42,8 @@ struct spanhash_top {
struct spanhash data[FLEX_ARRAY];
};
static struct spanhash *spanhash_find(struct spanhash_top *top, unsigned long hashval)
static struct spanhash *spanhash_find(struct spanhash_top *top,
unsigned long hashval)
{
int sz = 1 << top->alloc_log2;
int bucket = hashval & (sz - 1);
......@@ -62,7 +67,7 @@ static struct spanhash_top *spanhash_rehash(struct spanhash_top *orig)
new = xmalloc(sizeof(*orig) + sizeof(struct spanhash) * sz);
new->alloc_log2 = orig->alloc_log2 + 1;
new->free = osz;
new->free = INITIAL_FREE(new->alloc_log2);
memset(new->data, 0, sizeof(struct spanhash) * sz);
for (i = 0; i < osz; i++) {
struct spanhash *o = &(orig->data[i]);
......@@ -122,7 +127,7 @@ static struct spanhash_top *hash_chars(unsigned char *buf, unsigned long sz)
i = INITIAL_HASH_SIZE;
hash = xmalloc(sizeof(*hash) + sizeof(struct spanhash) * (1<<i));
hash->alloc_log2 = i;
hash->free = (1<<i)/2;
hash->free = INITIAL_FREE(i);
memset(hash->data, 0, sizeof(struct spanhash) * (1<<i));
/* an 8-byte shift register made of accum1 and accum2. New
......
......@@ -307,8 +307,8 @@ void diffcore_rename(struct diff_options *options)
m->score = estimate_similarity(one, two,
minimum_score);
}
free(two->cnt_data);
two->cnt_data = NULL;
/* We do not need the text anymore */
diff_free_filespec_data(two);
dst_cnt++;
}
/* cost matrix sorted by most to least similar pair */
......
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