fetch-pack: avoid quadratic behavior in remove_duplicates

We remove duplicate entries from the list of refs we are
fed in fetch-pack. The original algorithm is quadratic over
the number of refs, but since the list is now guaranteed to
be sorted, we can do it in linear time.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Jeff King 2012-05-21 18:17:20 -04:00 committed by Junio C Hamano
parent 443596850f
commit 7db8d5370f

View File

@ -834,21 +834,12 @@ static int remove_duplicates(int nr_heads, char **heads)
{ {
int src, dst; int src, dst;
for (src = dst = 0; src < nr_heads; src++) { if (!nr_heads)
/* If heads[src] is different from any of return 0;
* heads[0..dst], push it in.
*/ for (src = dst = 1; src < nr_heads; src++)
int i; if (strcmp(heads[src], heads[dst-1]))
for (i = 0; i < dst; i++) { heads[dst++] = heads[src];
if (!strcmp(heads[i], heads[src]))
break;
}
if (i < dst)
continue;
if (src != dst)
heads[dst] = heads[src];
dst++;
}
return dst; return dst;
} }