" --abbrev=nr | --no-abbrev\n"
" --abbrev-commit\n"
" special purpose:\n"
-" --bisect"
+" --bisect\n"
+" --bisect-vars"
;
static struct rev_info revs;
}
}
-static struct commit_list *find_bisection(struct commit_list *list)
+static struct commit_list *find_bisection(struct commit_list *list,
+ int *reaches, int *all)
{
int nr, closest;
struct commit_list *p, *best;
nr++;
p = p->next;
}
- *all = nr;
- closest = 0;
+ closest = -1;
best = list;
++ *all = nr;
for (p = list; p; p = p->next) {
- int distance;
+ int distance, reach;
if (revs.prune_fn && !(p->item->object.flags & TREECHANGE))
continue;
- distance = count_distance(p);
+ distance = reach = count_distance(p);
clear_distance(list);
if (nr - distance < distance)
distance = nr - distance;
if (distance > closest) {
best = p;
+ *reaches = reach;
closest = distance;
}
}
return best;
}
+static inline int commit_interesting(struct commit_list *elem)
+{
+ unsigned flags = elem->item->object.flags;
+ if (flags & UNINTERESTING)
+ return 0;
+ return (!revs.prune_fn || (flags & TREECHANGE));
+}
+
+static inline int weight(struct commit_list *elem)
+{
+ return *((int*)(elem->item->util));
+}
+
+static inline void weight_set(struct commit_list *elem, int weight)
+{
+ *((int*)(elem->item->util)) = weight;
+}
+
+static int count_interesting_parents(struct commit_list *elem)
+{
+ int cnt = 0;
+ if (!elem->item->parents)
+ return cnt;
+ for (elem = elem->item->parents; elem; elem = elem->next) {
+ if (commit_interesting(elem))
+ cnt++;
+ }
+ return cnt;
+}
+
+static struct commit_list *find_bisection_2(struct commit_list *list,
+ int *reaches, int *all)
+{
+ int n, nr, counted, distance;
+ struct commit_list *p, *best;
+ int *weights;
+
+ for (nr = 0, p = list; p; p = p->next) {
+ if (commit_interesting(p))
+ nr++;
+ }
+ *all = nr;
+ weights = xcalloc(nr, sizeof(int*));
+ counted = 0;
+
+ for (n = 0, p = list; p; p = p->next) {
+ if (!commit_interesting(p))
+ continue;
+ if (commit_interesting(p)) {
+ /*
+ * positive weight is the number of interesting
+ * commits it can reach, including itself.
+ * weight = 0 means it has one parent and
+ * its distance is unknown.
+ * weight < 0 means it has more than one
+ * parent and its distance is unknown.
+ */
+ p->item->util = &weights[n++];
+ switch (count_interesting_parents(p)) {
+ case 0:
+ weight_set(p, 1);
+ counted++;
+ break;
+ case 1:
+ weight_set(p, 0);
+ break;
+ default:
+ weight_set(p, -1);
+ break;
+ }
+ }
+ }
+
+ /*
+ * If you have only one parent in the resulting set
+ * then you can reach one commit more than that parent
+ * can reach. So we do not have to run the expensive
+ * count_distance() for single strand of pearls.
+ *
+ * However, if you have more than one parents, you cannot
+ * just add their distance and one for yourself, since
+ * they usually reach the same ancestor and you would
+ * end up counting them twice that way.
+ *
+ * So we will first count distance of merges the usual
+ * way, and then fill the blanks using cheaper algorithm.
+ */
+ for (p = list; p; p = p->next) {
+ if (!commit_interesting(p))
+ continue;
+ n = weight(p);
+ if (0 <= n)
+ continue;
+ distance = count_distance(p);
+ clear_distance(p);
+ weight_set(p, distance);
+
+ /* Does it happen to be at exactly half-way? */
+ distance *= 2;
+ if (nr == distance || (nr+1) == distance) {
+ p->next = NULL;
+ *reaches = weight(p);
+ free(weights);
+ return p;
+ }
+ counted++;
+ }
+
+ while (counted < nr) {
+ for (p = list; p; p = p->next) {
+ struct commit_list *q;
+
+ if (!commit_interesting(p) || 0 < weight(p))
+ continue;
+ for (q = p->item->parents; q; q = q->next)
+ if (commit_interesting(q) && 0 < weight(q))
+ break;
+ if (!q)
+ continue;
+ weight_set(p, weight(q)+1);
+ counted++;
+
+ /* Does it happen to be at exactly half-way? */
+ distance = weight(p) * 2;
+ if (nr == distance || (nr+1) == distance) {
+ p->next = NULL;
+ *reaches = weight(p);
+ free(weights);
+ return p;
+ }
+ }
+ }
+
+ /* Then find the best one */
+ counted = 0;
+ best = list;
+ for (p = list; p; p = p->next) {
+ if (!commit_interesting(p))
+ continue;
+ distance = weight(p);
+ if (nr - distance < distance)
+ distance = nr - distance;
+ if (distance > counted) {
+ best = p;
+ counted = distance;
+ *reaches = weight(p);
+ }
+ }
+ if (best)
+ best->next = NULL;
+ free(weights);
+ return best;
+}
+
static void read_revisions_from_stdin(struct rev_info *revs)
{
char line[1000];
struct commit_list *list;
int i;
int read_from_stdin = 0;
+ int bisect_show_vars = 0;
git_config(git_default_config);
init_revisions(&revs, prefix);
bisect_list = 1;
continue;
}
+ if (!strcmp(arg, "--bisect-vars")) {
+ bisect_list = 1;
+ bisect_show_vars = 1;
+ continue;
+ }
if (!strcmp(arg, "--stdin")) {
if (read_from_stdin++)
die("--stdin given twice?");
if (revs.tree_objects)
mark_edges_uninteresting(revs.commits, &revs, show_edge);
- if (bisect_list)
- revs.commits = find_bisection(revs.commits);
+ if (bisect_list) {
+ int reaches = reaches, all = all;
+
+ if (!revs.prune_fn)
+ revs.commits = find_bisection_2(revs.commits,
+ &reaches, &all);
+ else
+ revs.commits = find_bisection(revs.commits,
+ &reaches, &all);
+ if (bisect_show_vars) {
+ int cnt;
+ if (!revs.commits)
+ return 1;
+ /*
+ * revs.commits can reach "reaches" commits among
+ * "all" commits. If it is good, then there are
+ * (all-reaches) commits left to be bisected.
+ * On the other hand, if it is bad, then the set
+ * to bisect is "reaches".
+ * A bisect set of size N has (N-1) commits further
+ * to test, as we already know one bad one.
+ */
+ cnt = all-reaches;
+ if (cnt < reaches)
+ cnt = reaches;
+ printf("bisect_rev=%s\n"
+ "bisect_nr=%d\n"
+ "bisect_good=%d\n"
+ "bisect_bad=%d\n"
+ "bisect_all=%d\n",
+ sha1_to_hex(revs.commits->item->object.sha1),
+ cnt - 1,
+ all - reaches - 1,
+ reaches - 1,
+ all);
+ return 0;
+ }
+ }
traverse_commit_list(&revs, show_commit, show_object);