rev-list --bisect: Fix "halfway" optimization.

If you have 5 commits in the set, commits that reach 2 or 3
commits are at halfway.  If you have 6 commits, only commits
that reach exactly 3 commits are at halfway.  The earlier one is
completely botched the math.

Signed-off-by: Junio C Hamano <junkio@cox.net>
This commit is contained in:
Junio C Hamano 2007-03-23 00:40:54 -07:00
parent 1c2c6112a4
commit 2a4646904a

View File

@ -237,6 +237,27 @@ static int count_interesting_parents(struct commit_list *elem)
return cnt;
}
static inline int halfway(struct commit_list *p, int distance, int nr)
{
/*
* Don't short-cut something we are not going to return!
*/
if (revs.prune_fn && !(p->item->object.flags & TREECHANGE))
return 0;
/*
* 2 and 3 are halfway of 5.
* 3 is halfway of 6 but 2 and 4 are not.
*/
distance *= 2;
switch (distance - nr) {
case -1: case 0: case 1:
return 1;
default:
return 0;
}
}
static struct commit_list *find_bisection_2(struct commit_list *list,
int *reaches, int *all)
{
@ -305,10 +326,9 @@ static struct commit_list *find_bisection_2(struct commit_list *list,
weight_set(p, distance);
/* Does it happen to be at exactly half-way? */
distance *= 2;
if (nr == distance || (nr+1) == distance) {
if (halfway(p, distance, nr)) {
p->next = NULL;
*reaches = weight(p);
*reaches = distance;
free(weights);
return p;
}
@ -330,10 +350,10 @@ static struct commit_list *find_bisection_2(struct commit_list *list,
counted++;
/* Does it happen to be at exactly half-way? */
distance = weight(p) * 2;
if (nr == distance || (nr+1) == distance) {
distance = weight(p);
if (halfway(p, distance, nr)) {
p->next = NULL;
*reaches = weight(p);
*reaches = distance;
free(weights);
return p;
}