From 1daa09d9a833d3969b64e763865a58df56bc3871 Mon Sep 17 00:00:00 2001 From: Junio C Hamano Date: Fri, 23 Mar 2007 17:54:03 -0700 Subject: [PATCH] make the previous optimization work also on path-limited rev-list --bisect The trick is to give a child commit that is not tree-changing the same depth as its parent, so that the depth is propagated properly along strand of pearls. Signed-off-by: Junio C Hamano --- builtin-rev-list.c | 249 +++++++++++++++++++++++++++------------------ 1 file changed, 151 insertions(+), 98 deletions(-) diff --git a/builtin-rev-list.c b/builtin-rev-list.c index 7075548e6..f91685a40 100644 --- a/builtin-rev-list.c +++ b/builtin-rev-list.c @@ -169,51 +169,7 @@ static void clear_distance(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 = 0; - p = list; - while (p) { - if (!revs.prune_fn || (p->item->object.flags & TREECHANGE)) - nr++; - p = p->next; - } - closest = -1; - best = list; - *all = nr; - - for (p = list; p; p = p->next) { - int distance, reach; - - if (revs.prune_fn && !(p->item->object.flags & TREECHANGE)) - 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; - } - } - if (best) - best->next = NULL; - 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)); -} +#define DEBUG_BISECT 0 static inline int weight(struct commit_list *elem) { @@ -225,16 +181,17 @@ 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) +static int count_interesting_parents(struct commit *commit) { - int cnt = 0; - if (!elem->item->parents) - return cnt; - for (elem = elem->item->parents; elem; elem = elem->next) { - if (commit_interesting(elem)) - cnt++; + struct commit_list *p; + int count; + + for (count = 0, p = commit->parents; p; p = p->next) { + if (p->item->object.flags & UNINTERESTING) + continue; + count++; } - return cnt; + return count; } static inline int halfway(struct commit_list *p, int distance, int nr) @@ -244,7 +201,8 @@ static inline int halfway(struct commit_list *p, int distance, int nr) */ 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. @@ -258,49 +216,127 @@ static inline int halfway(struct commit_list *p, int distance, int nr) } } -static struct commit_list *find_bisection_2(struct commit_list *list, - int *reaches, int *all) +#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) { - int n, nr, counted, distance; - struct commit_list *p, *best; + struct commit_list *p; + + fprintf(stderr, "%s (%d/%d)\n", debug, counted, nr); + + 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"); + } +} +#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(struct commit_list *list, + int *reaches, int *all) +{ + 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 @@ -316,13 +352,13 @@ static struct commit_list *find_bisection_2(struct commit_list *list, * 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? */ @@ -335,19 +371,37 @@ static struct commit_list *find_bisection_2(struct commit_list *list, 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); @@ -360,11 +414,15 @@ static struct commit_list *find_bisection_2(struct commit_list *list, } } + 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) @@ -472,12 +530,7 @@ int cmd_rev_list(int argc, const char **argv, const char *prefix) 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) -- 2.30.2