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Merge branch 'lt/diff-rename'

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* lt/diff-rename:
  optimize diffcore-delta by sorting hash entries.
This commit is contained in:
Shawn O. Pearce 2007-10-18 01:30:19 -04:00
parent 130faabe48 eb4d0e3f45
commit c5d236c70e
1 changed files with 30 additions and 24 deletions
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54
diffcore-delta.c
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@ -46,22 +46,6 @@ struct spanhash_top {
struct spanhash data[FLEX_ARRAY];
};
static struct spanhash *spanhash_find(struct spanhash_top *top,
unsigned int hashval)
{
int sz = 1 << top->alloc_log2;
int bucket = hashval & (sz - 1);
while (1) {
struct spanhash *h = &(top->data[bucket++]);
if (!h->cnt)
return NULL;
if (h->hashval == hashval)
return h;
if (sz <= bucket)
bucket = 0;
}
}
static struct spanhash_top *spanhash_rehash(struct spanhash_top *orig)
{
struct spanhash_top *new;
@ -122,6 +106,20 @@ static struct spanhash_top *add_spanhash(struct spanhash_top *top,
}
}
static int spanhash_cmp(const void *a_, const void *b_)
{
const struct spanhash *a = a_;
const struct spanhash *b = b_;
/* A count of zero compares at the end.. */
if (!a->cnt)
return !b->cnt ? 0 : 1;
if (!b->cnt)
return -1;
return a->hashval < b->hashval ? -1 :
a->hashval > b->hashval ? 1 : 0;
}
static struct spanhash_top *hash_chars(struct diff_filespec *one)
{
int i, n;
@ -158,6 +156,10 @@ static struct spanhash_top *hash_chars(struct diff_filespec *one)
n = 0;
accum1 = accum2 = 0;
}
qsort(hash->data,
1ul << hash->alloc_log2,
sizeof(hash->data[0]),
spanhash_cmp);
return hash;
}
@ -169,7 +171,7 @@ int diffcore_count_changes(struct diff_filespec *src,
unsigned long *src_copied,
unsigned long *literal_added)
{
int i, ssz;
struct spanhash *s, *d;
struct spanhash_top *src_count, *dst_count;
unsigned long sc, la;
@ -190,22 +192,26 @@ int diffcore_count_changes(struct diff_filespec *src,
}
sc = la = 0;
ssz = 1 << src_count->alloc_log2;
for (i = 0; i < ssz; i++) {
struct spanhash *s = &(src_count->data[i]);
struct spanhash *d;
s = src_count->data;
d = dst_count->data;
for (;;) {
unsigned dst_cnt, src_cnt;
if (!s->cnt)
continue;
break; /* we checked all in src */
while (d->cnt) {
if (d->hashval >= s->hashval)
break;
d++;
}
src_cnt = s->cnt;
d = spanhash_find(dst_count, s->hashval);
dst_cnt = d ? d->cnt : 0;
dst_cnt = d->hashval == s->hashval ? d->cnt : 0;
if (src_cnt < dst_cnt) {
la += dst_cnt - src_cnt;
sc += src_cnt;
}
else
sc += dst_cnt;
s++;
}
if (!src_count_p)