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Merge branch 'lt/diff' into next 

* lt/diff:
  diffcore-delta: 64-byte-or-EOL ultrafast replacement.
maint
Junio C Hamano 2006-03-15 00:38:47 -08:00
parent cf1e6d1ec5 3c7ceba4f1
commit d09a0a3cb8
1 changed files with 16 additions and 18 deletions
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34
diffcore-delta.c
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@ -99,7 +99,7 @@ static struct spanhash_top *spanhash_rehash(struct spanhash_top *orig)
} }


static struct spanhash_top *add_spanhash(struct spanhash_top *top, static struct spanhash_top *add_spanhash(struct spanhash_top *top,
unsigned long hashval) unsigned long hashval, int cnt)
{ {
int bucket, lim; int bucket, lim;
struct spanhash *h; struct spanhash *h;
@ -110,14 +110,14 @@ static struct spanhash_top *add_spanhash(struct spanhash_top *top,
h = &(top->data[bucket++]); h = &(top->data[bucket++]);
if (!h->cnt) { if (!h->cnt) {
h->hashval = hashval; h->hashval = hashval;
h->cnt = 1; h->cnt = cnt;
top->free--; top->free--;
if (top->free < 0) if (top->free < 0)
return spanhash_rehash(top); return spanhash_rehash(top);
return top; return top;
} }
if (h->hashval == hashval) { if (h->hashval == hashval) {
h->cnt++; h->cnt += cnt;
return top; return top;
} }
if (lim <= bucket) if (lim <= bucket)
@ -127,7 +127,7 @@ static struct spanhash_top *add_spanhash(struct spanhash_top *top,


static struct spanhash_top *hash_chars(unsigned char *buf, unsigned long sz) static struct spanhash_top *hash_chars(unsigned char *buf, unsigned long sz)
{ {
int i; int i, n;
unsigned long accum1, accum2, hashval; unsigned long accum1, accum2, hashval;
struct spanhash_top *hash; struct spanhash_top *hash;


@ -137,19 +137,20 @@ static struct spanhash_top *hash_chars(unsigned char *buf, unsigned long sz)
hash->free = INITIAL_FREE(i); hash->free = INITIAL_FREE(i);
memset(hash->data, 0, sizeof(struct spanhash) * (1<<i)); memset(hash->data, 0, sizeof(struct spanhash) * (1<<i));


/* an 8-byte shift register made of accum1 and accum2. New n = 0;
* bytes come at LSB of accum2, and shifted up to accum1 accum1 = accum2 = 0;
*/
for (i = accum1 = accum2 = 0; i < 7; i++, sz--) {
accum1 = (accum1 << 8) | (accum2 >> 24);
accum2 = (accum2 << 8) | *buf++;
}
while (sz) { while (sz) {
accum1 = (accum1 << 8) | (accum2 >> 24); unsigned long c = *buf++;
accum2 = (accum2 << 8) | *buf++;
hashval = (accum1 + accum2 * 0x61) % HASHBASE;
hash = add_spanhash(hash, hashval);
sz--; sz--;
accum1 = (accum1 << 7) | (accum2 >> 25);
accum2 = (accum2 << 7) | (accum1 >> 25);
accum1 += c;
if (++n < 64 && c != '\n')
continue;
hashval = (accum1 + accum2 * 0x61) % HASHBASE;
hash = add_spanhash(hash, hashval, n);
n = 0;
accum1 = accum2 = 0;
} }
return hash; return hash;
} }
@ -166,9 +167,6 @@ int diffcore_count_changes(void *src, unsigned long src_size,
struct spanhash_top *src_count, *dst_count; struct spanhash_top *src_count, *dst_count;
unsigned long sc, la; unsigned long sc, la;


if (src_size < 8 || dst_size < 8)
return -1;

src_count = dst_count = NULL; src_count = dst_count = NULL;
if (src_count_p) if (src_count_p)
src_count = *src_count_p; src_count = *src_count_p;