diff options
| -rw-r--r-- | Makefile | 1 | ||||
| -rw-r--r-- | bisect.c | 388 | ||||
| -rw-r--r-- | bisect.h | 8 | ||||
| -rw-r--r-- | builtin-rev-list.c | 388 |
4 files changed, 398 insertions, 387 deletions
@@ -420,6 +420,7 @@ LIB_OBJS += archive-tar.o LIB_OBJS += archive-zip.o LIB_OBJS += attr.o LIB_OBJS += base85.o +LIB_OBJS += bisect.o LIB_OBJS += blob.o LIB_OBJS += branch.o LIB_OBJS += bundle.o diff --git a/bisect.c b/bisect.c new file mode 100644 index 0000000000..27def7dacf --- /dev/null +++ b/bisect.c @@ -0,0 +1,388 @@ +#include "cache.h" +#include "commit.h" +#include "diff.h" +#include "revision.h" +#include "bisect.h" + +/* bits #0-15 in revision.h */ + +#define COUNTED (1u<<16) + +/* + * This is a truly stupid algorithm, but it's only + * used for bisection, and we just don't care enough. + * + * We care just barely enough to avoid recursing for + * non-merge entries. + */ +static int count_distance(struct commit_list *entry) +{ + int nr = 0; + + while (entry) { + struct commit *commit = entry->item; + struct commit_list *p; + + if (commit->object.flags & (UNINTERESTING | COUNTED)) + break; + if (!(commit->object.flags & TREESAME)) + nr++; + commit->object.flags |= COUNTED; + p = commit->parents; + entry = p; + if (p) { + p = p->next; + while (p) { + nr += count_distance(p); + p = p->next; + } + } + } + + return nr; +} + +static void clear_distance(struct commit_list *list) +{ + while (list) { + struct commit *commit = list->item; + commit->object.flags &= ~COUNTED; + list = list->next; + } +} + +#define DEBUG_BISECT 0 + +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 *commit) +{ + 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 count; +} + +static inline int halfway(struct commit_list *p, int nr) +{ + /* + * Don't short-cut something we are not going to return! + */ + if (p->item->object.flags & TREESAME) + 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. + */ + switch (2 * weight(p) - nr) { + case -1: case 0: case 1: + return 1; + default: + return 0; + } +} + +#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) +{ + 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 & TREESAME) ? ' ' : '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 */ + +static struct commit_list *best_bisection(struct commit_list *list, int nr) +{ + struct commit_list *p, *best; + int best_distance = -1; + + best = list; + for (p = list; p; p = p->next) { + int distance; + unsigned flags = p->item->object.flags; + + if (flags & TREESAME) + continue; + distance = weight(p); + if (nr - distance < distance) + distance = nr - distance; + if (distance > best_distance) { + best = p; + best_distance = distance; + } + } + + return best; +} + +struct commit_dist { + struct commit *commit; + int distance; +}; + +static int compare_commit_dist(const void *a_, const void *b_) +{ + struct commit_dist *a, *b; + + a = (struct commit_dist *)a_; + b = (struct commit_dist *)b_; + if (a->distance != b->distance) + return b->distance - a->distance; /* desc sort */ + return hashcmp(a->commit->object.sha1, b->commit->object.sha1); +} + +static struct commit_list *best_bisection_sorted(struct commit_list *list, int nr) +{ + struct commit_list *p; + struct commit_dist *array = xcalloc(nr, sizeof(*array)); + int cnt, i; + + for (p = list, cnt = 0; p; p = p->next) { + int distance; + unsigned flags = p->item->object.flags; + + if (flags & TREESAME) + continue; + distance = weight(p); + if (nr - distance < distance) + distance = nr - distance; + array[cnt].commit = p->item; + array[cnt].distance = distance; + cnt++; + } + qsort(array, cnt, sizeof(*array), compare_commit_dist); + for (p = list, i = 0; i < cnt; i++) { + struct name_decoration *r = xmalloc(sizeof(*r) + 100); + struct object *obj = &(array[i].commit->object); + + sprintf(r->name, "dist=%d", array[i].distance); + r->next = add_decoration(&name_decoration, obj, r); + p->item = array[i].commit; + p = p->next; + } + if (p) + p->next = NULL; + free(array); + return list; +} + +/* + * 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 *do_find_bisection(struct commit_list *list, + int nr, int *weights, + int find_all) +{ + int n, counted; + struct commit_list *p; + + counted = 0; + + for (n = 0, p = list; p; p = p->next) { + struct commit *commit = p->item; + unsigned flags = commit->object.flags; + + p->item->util = &weights[n++]; + switch (count_interesting_parents(commit)) { + case 0: + if (!(flags & TREESAME)) { + weight_set(p, 1); + counted++; + 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 + * 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 (p->item->object.flags & UNINTERESTING) + continue; + if (weight(p) != -2) + continue; + weight_set(p, count_distance(p)); + clear_distance(list); + + /* Does it happen to be at exactly half-way? */ + if (!find_all && halfway(p, nr)) + 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 (0 <= weight(p)) + continue; + 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 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 (!(flags & TREESAME)) { + 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? */ + if (!find_all && halfway(p, nr)) + return p; + } + } + + show_list("bisection 2 counted all", counted, nr, list); + + if (!find_all) + return best_bisection(list, nr); + else + return best_bisection_sorted(list, nr); +} + +struct commit_list *find_bisection(struct commit_list *list, + int *reaches, int *all, + int find_all) +{ + int nr, on_list; + struct commit_list *p, *best, *next, *last; + int *weights; + + 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 (!(flags & TREESAME)) + nr++; + on_list++; + } + list = last; + show_list("bisection 2 sorted", 0, nr, list); + + *all = nr; + weights = xcalloc(on_list, sizeof(*weights)); + + /* Do the real work of finding bisection commit. */ + best = do_find_bisection(list, nr, weights, find_all); + if (best) { + if (!find_all) + best->next = NULL; + *reaches = weight(best); + } + free(weights); + return best; +} + diff --git a/bisect.h b/bisect.h new file mode 100644 index 0000000000..60b2fe1cdc --- /dev/null +++ b/bisect.h @@ -0,0 +1,8 @@ +#ifndef BISECT_H +#define BISECT_H + +extern struct commit_list *find_bisection(struct commit_list *list, + int *reaches, int *all, + int find_all); + +#endif diff --git a/builtin-rev-list.c b/builtin-rev-list.c index 28fe2dc30b..b1e8200d2b 100644 --- a/builtin-rev-list.c +++ b/builtin-rev-list.c @@ -1,20 +1,12 @@ #include "cache.h" -#include "refs.h" -#include "tag.h" #include "commit.h" -#include "tree.h" -#include "blob.h" -#include "tree-walk.h" #include "diff.h" #include "revision.h" #include "list-objects.h" #include "builtin.h" #include "log-tree.h" #include "graph.h" - -/* bits #0-15 in revision.h */ - -#define COUNTED (1u<<16) +#include "bisect.h" static const char rev_list_usage[] = "git rev-list [OPTION] <commit-id>... [ -- paths... ]\n" @@ -195,384 +187,6 @@ static void show_edge(struct commit *commit) printf("-%s\n", sha1_to_hex(commit->object.sha1)); } -/* - * This is a truly stupid algorithm, but it's only - * used for bisection, and we just don't care enough. - * - * We care just barely enough to avoid recursing for - * non-merge entries. - */ -static int count_distance(struct commit_list *entry) -{ - int nr = 0; - - while (entry) { - struct commit *commit = entry->item; - struct commit_list *p; - - if (commit->object.flags & (UNINTERESTING | COUNTED)) - break; - if (!(commit->object.flags & TREESAME)) - nr++; - commit->object.flags |= COUNTED; - p = commit->parents; - entry = p; - if (p) { - p = p->next; - while (p) { - nr += count_distance(p); - p = p->next; - } - } - } - - return nr; -} - -static void clear_distance(struct commit_list *list) -{ - while (list) { - struct commit *commit = list->item; - commit->object.flags &= ~COUNTED; - list = list->next; - } -} - -#define DEBUG_BISECT 0 - -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 *commit) -{ - 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 count; -} - -static inline int halfway(struct commit_list *p, int nr) -{ - /* - * Don't short-cut something we are not going to return! - */ - if (p->item->object.flags & TREESAME) - 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. - */ - switch (2 * weight(p) - nr) { - case -1: case 0: case 1: - return 1; - default: - return 0; - } -} - -#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) -{ - 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 & TREESAME) ? ' ' : '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 */ - -static struct commit_list *best_bisection(struct commit_list *list, int nr) -{ - struct commit_list *p, *best; - int best_distance = -1; - - best = list; - for (p = list; p; p = p->next) { - int distance; - unsigned flags = p->item->object.flags; - - if (flags & TREESAME) - continue; - distance = weight(p); - if (nr - distance < distance) - distance = nr - distance; - if (distance > best_distance) { - best = p; - best_distance = distance; - } - } - - return best; -} - -struct commit_dist { - struct commit *commit; - int distance; -}; - -static int compare_commit_dist(const void *a_, const void *b_) -{ - struct commit_dist *a, *b; - - a = (struct commit_dist *)a_; - b = (struct commit_dist *)b_; - if (a->distance != b->distance) - return b->distance - a->distance; /* desc sort */ - return hashcmp(a->commit->object.sha1, b->commit->object.sha1); -} - -static struct commit_list *best_bisection_sorted(struct commit_list *list, int nr) -{ - struct commit_list *p; - struct commit_dist *array = xcalloc(nr, sizeof(*array)); - int cnt, i; - - for (p = list, cnt = 0; p; p = p->next) { - int distance; - unsigned flags = p->item->object.flags; - - if (flags & TREESAME) - continue; - distance = weight(p); - if (nr - distance < distance) - distance = nr - distance; - array[cnt].commit = p->item; - array[cnt].distance = distance; - cnt++; - } - qsort(array, cnt, sizeof(*array), compare_commit_dist); - for (p = list, i = 0; i < cnt; i++) { - struct name_decoration *r = xmalloc(sizeof(*r) + 100); - struct object *obj = &(array[i].commit->object); - - sprintf(r->name, "dist=%d", array[i].distance); - r->next = add_decoration(&name_decoration, obj, r); - p->item = array[i].commit; - p = p->next; - } - if (p) - p->next = NULL; - free(array); - return list; -} - -/* - * 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 *do_find_bisection(struct commit_list *list, - int nr, int *weights, - int find_all) -{ - int n, counted; - struct commit_list *p; - - counted = 0; - - for (n = 0, p = list; p; p = p->next) { - struct commit *commit = p->item; - unsigned flags = commit->object.flags; - - p->item->util = &weights[n++]; - switch (count_interesting_parents(commit)) { - case 0: - if (!(flags & TREESAME)) { - weight_set(p, 1); - counted++; - 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 - * 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 (p->item->object.flags & UNINTERESTING) - continue; - if (weight(p) != -2) - continue; - weight_set(p, count_distance(p)); - clear_distance(list); - - /* Does it happen to be at exactly half-way? */ - if (!find_all && halfway(p, nr)) - 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 (0 <= weight(p)) - continue; - 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 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 (!(flags & TREESAME)) { - 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? */ - if (!find_all && halfway(p, nr)) - return p; - } - } - - show_list("bisection 2 counted all", counted, nr, list); - - if (!find_all) - return best_bisection(list, nr); - else - return best_bisection_sorted(list, nr); -} - -static struct commit_list *find_bisection(struct commit_list *list, - int *reaches, int *all, - int find_all) -{ - int nr, on_list; - struct commit_list *p, *best, *next, *last; - int *weights; - - 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 (!(flags & TREESAME)) - nr++; - on_list++; - } - list = last; - show_list("bisection 2 sorted", 0, nr, list); - - *all = nr; - weights = xcalloc(on_list, sizeof(*weights)); - - /* Do the real work of finding bisection commit. */ - best = do_find_bisection(list, nr, weights, find_all); - if (best) { - if (!find_all) - best->next = NULL; - *reaches = weight(best); - } - free(weights); - return best; -} - static inline int log2i(int n) { int log2 = 0; |