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authorLinus Torvalds <torvalds@osdl.org>2006-03-15 00:37:57 -0800
committerJunio C Hamano <junkio@cox.net>2006-03-15 00:37:57 -0800
commit3c7ceba4f1e8be1a536dd0e21bc4f422873d08d2 (patch)
tree005c79a7488a4e6f9f31ed81305d43e3734032ac /diffcore-delta.c
parent90bd932c811f4ecd1d8cbceffdf6a69a5ca838b7 (diff)
downloadgit-3c7ceba4f1e8be1a536dd0e21bc4f422873d08d2.tar.gz
diffcore-delta: 64-byte-or-EOL ultrafast replacement.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Diffstat (limited to 'diffcore-delta.c')
-rw-r--r--diffcore-delta.c34
1 files changed, 16 insertions, 18 deletions
diff --git a/diffcore-delta.c b/diffcore-delta.c
index 835d82c993..ceb35c3276 100644
--- a/diffcore-delta.c
+++ b/diffcore-delta.c
@@ -99,7 +99,7 @@ static struct spanhash_top *spanhash_rehash(struct spanhash_top *orig)
}
static struct spanhash_top *add_spanhash(struct spanhash_top *top,
- unsigned long hashval)
+ unsigned long hashval, int cnt)
{
int bucket, lim;
struct spanhash *h;
@@ -110,14 +110,14 @@ static struct spanhash_top *add_spanhash(struct spanhash_top *top,
h = &(top->data[bucket++]);
if (!h->cnt) {
h->hashval = hashval;
- h->cnt = 1;
+ h->cnt = cnt;
top->free--;
if (top->free < 0)
return spanhash_rehash(top);
return top;
}
if (h->hashval == hashval) {
- h->cnt++;
+ h->cnt += cnt;
return top;
}
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)
{
- int i;
+ int i, n;
unsigned long accum1, accum2, hashval;
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);
memset(hash->data, 0, sizeof(struct spanhash) * (1<<i));
- /* an 8-byte shift register made of accum1 and accum2. New
- * bytes come at LSB of accum2, and shifted up to accum1
- */
- for (i = accum1 = accum2 = 0; i < 7; i++, sz--) {
- accum1 = (accum1 << 8) | (accum2 >> 24);
- accum2 = (accum2 << 8) | *buf++;
- }
+ n = 0;
+ accum1 = accum2 = 0;
while (sz) {
- accum1 = (accum1 << 8) | (accum2 >> 24);
- accum2 = (accum2 << 8) | *buf++;
- hashval = (accum1 + accum2 * 0x61) % HASHBASE;
- hash = add_spanhash(hash, hashval);
+ unsigned long c = *buf++;
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;
}
@@ -166,9 +167,6 @@ int diffcore_count_changes(void *src, unsigned long src_size,
struct spanhash_top *src_count, *dst_count;
unsigned long sc, la;
- if (src_size < 8 || dst_size < 8)
- return -1;
-
src_count = dst_count = NULL;
if (src_count_p)
src_count = *src_count_p;