" --header | --pretty\n"
" --abbrev=nr | --no-abbrev\n"
" --abbrev-commit\n"
+" --left-right\n"
" special purpose:\n"
" --bisect\n"
" --bisect-vars"
}
}
-static struct commit_list *find_bisection(struct commit_list *list,
- int *reaches, int *all)
+#define DEBUG_BISECT 0
+
+static inline int weight(struct commit_list *elem)
{
- int nr, closest;
- struct commit_list *p, *best;
+ return *((int*)(elem->item->util));
+}
- nr = 0;
- p = list;
- while (p) {
- if (!revs.prune_fn || (p->item->object.flags & TREECHANGE))
- nr++;
- p = p->next;
- }
- *all = nr;
- closest = 0;
- best = list;
+static inline void weight_set(struct commit_list *elem, int weight)
+{
+ *((int*)(elem->item->util)) = weight;
+}
- for (p = list; p; p = p->next) {
- int distance, reach;
+static int count_interesting_parents(struct commit *commit)
+{
+ struct commit_list *p;
+ int count;
- if (revs.prune_fn && !(p->item->object.flags & TREECHANGE))
+ for (count = 0, p = commit->parents; p; p = p->next) {
+ if (p->item->object.flags & UNINTERESTING)
continue;
-
- distance = reach = count_distance(p);
- clear_distance(list);
- if (nr - distance < distance)
- distance = nr - distance;
- if (distance > closest) {
- best = p;
- *reaches = reach;
- closest = distance;
- }
+ count++;
}
- if (best)
- best->next = NULL;
- return best;
+ return count;
}
-static inline int commit_interesting(struct commit_list *elem)
+static inline int halfway(struct commit_list *p, int distance, int nr)
{
- unsigned flags = elem->item->object.flags;
- if (flags & UNINTERESTING)
+ /*
+ * Don't short-cut something we are not going to return!
+ */
+ if (revs.prune_fn && !(p->item->object.flags & TREECHANGE))
+ return 0;
+ if (DEBUG_BISECT)
+ 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;
- return (!revs.prune_fn || (flags & TREECHANGE));
+ }
}
-static inline int weight(struct commit_list *elem)
+#if !DEBUG_BISECT
+#define show_list(a,b,c,d) do { ; } while (0)
+#else
+static void show_list(const char *debug, int counted, int nr,
+ struct commit_list *list)
{
- return *((int*)(elem->item->util));
-}
+ struct commit_list *p;
-static inline void weight_set(struct commit_list *elem, int weight)
-{
- *((int*)(elem->item->util)) = weight;
-}
+ fprintf(stderr, "%s (%d/%d)\n", debug, counted, nr);
-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++;
+ for (p = list; p; p = p->next) {
+ struct commit_list *pp;
+ struct commit *commit = p->item;
+ unsigned flags = commit->object.flags;
+ enum object_type type;
+ unsigned long size;
+ char *buf = read_sha1_file(commit->object.sha1, &type, &size);
+ char *ep, *sp;
+
+ fprintf(stderr, "%c%c%c ",
+ (flags & TREECHANGE) ? 'T' : ' ',
+ (flags & UNINTERESTING) ? 'U' : ' ',
+ (flags & COUNTED) ? 'C' : ' ');
+ if (commit->util)
+ fprintf(stderr, "%3d", weight(p));
+ else
+ fprintf(stderr, "---");
+ fprintf(stderr, " %.*s", 8, sha1_to_hex(commit->object.sha1));
+ for (pp = commit->parents; pp; pp = pp->next)
+ fprintf(stderr, " %.*s", 8,
+ sha1_to_hex(pp->item->object.sha1));
+
+ sp = strstr(buf, "\n\n");
+ if (sp) {
+ sp += 2;
+ for (ep = sp; *ep && *ep != '\n'; ep++)
+ ;
+ fprintf(stderr, " %.*s", (int)(ep - sp), sp);
+ }
+ fprintf(stderr, "\n");
}
- return cnt;
}
+#endif /* DEBUG_BISECT */
+
+/*
+ * zero or positive weight is the number of interesting commits it can
+ * reach, including itself. Especially, weight = 0 means it does not
+ * reach any tree-changing commits (e.g. just above uninteresting one
+ * but traversal is with pathspec).
+ *
+ * weight = -1 means it has one parent and its distance is yet to
+ * be computed.
+ *
+ * weight = -2 means it has more than one parent and its distance is
+ * unknown. After running count_distance() first, they will get zero
+ * or positive distance.
+ */
-static struct commit_list *find_bisection_2(struct commit_list *list,
- int *reaches, int *all)
+static struct commit_list *find_bisection(struct commit_list *list,
+ int *reaches, int *all)
{
- int n, nr, counted, distance;
- struct commit_list *p, *best;
+ int n, nr, on_list, counted, distance;
+ struct commit_list *p, *best, *next, *last;
int *weights;
- for (nr = 0, p = list; p; p = p->next) {
- if (commit_interesting(p))
+ show_list("bisection 2 entry", 0, 0, list);
+
+ /*
+ * Count the number of total and tree-changing items on the
+ * list, while reversing the list.
+ */
+ for (nr = on_list = 0, last = NULL, p = list;
+ p;
+ p = next) {
+ unsigned flags = p->item->object.flags;
+
+ next = p->next;
+ if (flags & UNINTERESTING)
+ continue;
+ p->next = last;
+ last = p;
+ if (!revs.prune_fn || (flags & TREECHANGE))
nr++;
+ on_list++;
}
+ list = last;
+ show_list("bisection 2 sorted", 0, nr, list);
+
*all = nr;
- weights = xcalloc(nr, sizeof(int*));
+ weights = xcalloc(on_list, 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:
+ struct commit *commit = p->item;
+ unsigned flags = commit->object.flags;
+
+ p->item->util = &weights[n++];
+ switch (count_interesting_parents(commit)) {
+ case 0:
+ if (!revs.prune_fn || (flags & TREECHANGE)) {
weight_set(p, 1);
counted++;
- break;
- case 1:
- weight_set(p, 0);
- break;
- default:
- weight_set(p, -1);
- break;
+ show_list("bisection 2 count one",
+ counted, nr, list);
}
+ /*
+ * otherwise, it is known not to reach any
+ * tree-changing commit and gets weight 0.
+ */
+ break;
+ case 1:
+ weight_set(p, -1);
+ break;
+ default:
+ weight_set(p, -2);
+ break;
}
}
+ show_list("bisection 2 initialize", counted, nr, list);
+
/*
* If you have only one parent in the resulting set
* then you can reach one commit more than that parent
* way, and then fill the blanks using cheaper algorithm.
*/
for (p = list; p; p = p->next) {
- if (!commit_interesting(p))
+ if (p->item->object.flags & UNINTERESTING)
continue;
n = weight(p);
- if (0 <= n)
+ if (n != -2)
continue;
distance = count_distance(p);
- clear_distance(p);
+ clear_distance(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;
}
counted++;
}
+ show_list("bisection 2 count_distance", counted, nr, list);
+
while (counted < nr) {
for (p = list; p; p = p->next) {
struct commit_list *q;
+ unsigned flags = p->item->object.flags;
- if (!commit_interesting(p) || 0 < weight(p))
+ if (0 <= weight(p))
continue;
- for (q = p->item->parents; q; q = q->next)
- if (commit_interesting(q) && 0 < weight(q))
+ for (q = p->item->parents; q; q = q->next) {
+ if (q->item->object.flags & UNINTERESTING)
+ continue;
+ if (0 <= weight(q))
break;
+ }
if (!q)
continue;
- weight_set(p, weight(q)+1);
- counted++;
+
+ /*
+ * weight for p is unknown but q is known.
+ * add one for p itself if p is to be counted,
+ * otherwise inherit it from q directly.
+ */
+ if (!revs.prune_fn || (flags & TREECHANGE)) {
+ weight_set(p, weight(q)+1);
+ counted++;
+ show_list("bisection 2 count one",
+ counted, nr, list);
+ }
+ else
+ weight_set(p, weight(q));
/* 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;
}
}
}
+ show_list("bisection 2 counted all", counted, nr, list);
+
/* Then find the best one */
- counted = 0;
+ counted = -1;
best = list;
for (p = list; p; p = p->next) {
- if (!commit_interesting(p))
+ unsigned flags = p->item->object.flags;
+
+ if (revs.prune_fn && !(flags & TREECHANGE))
continue;
distance = weight(p);
if (nr - distance < distance)
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);
+ revs.commits = find_bisection(revs.commits, &reaches, &all);
if (bisect_show_vars) {
int cnt;
if (!revs.commits)