diff options
Diffstat (limited to 'builtin-describe.c')
| -rw-r--r-- | builtin-describe.c | 284 |
1 files changed, 284 insertions, 0 deletions
diff --git a/builtin-describe.c b/builtin-describe.c new file mode 100644 index 0000000000..bcc645622a --- /dev/null +++ b/builtin-describe.c @@ -0,0 +1,284 @@ +#include "cache.h" +#include "commit.h" +#include "tag.h" +#include "refs.h" +#include "builtin.h" + +#define SEEN (1u<<0) +#define MAX_TAGS (FLAG_BITS - 1) + +static const char describe_usage[] = +"git-describe [--all] [--tags] [--abbrev=<n>] <committish>*"; + +static int debug; /* Display lots of verbose info */ +static int all; /* Default to annotated tags only */ +static int tags; /* But allow any tags if --tags is specified */ +static int abbrev = DEFAULT_ABBREV; +static int max_candidates = 10; + +struct commit_name { + int prio; /* annotated tag = 2, tag = 1, head = 0 */ + char path[FLEX_ARRAY]; /* more */ +}; +static const char *prio_names[] = { + "head", "lightweight", "annotated", +}; + +static void add_to_known_names(const char *path, + struct commit *commit, + int prio) +{ + struct commit_name *e = commit->util; + if (!e || e->prio < prio) { + size_t len = strlen(path)+1; + free(e); + e = xmalloc(sizeof(struct commit_name) + len); + e->prio = prio; + memcpy(e->path, path, len); + commit->util = e; + } +} + +static int get_name(const char *path, const unsigned char *sha1, int flag, void *cb_data) +{ + struct commit *commit = lookup_commit_reference_gently(sha1, 1); + struct object *object; + int prio; + + if (!commit) + return 0; + object = parse_object(sha1); + /* If --all, then any refs are used. + * If --tags, then any tags are used. + * Otherwise only annotated tags are used. + */ + if (!strncmp(path, "refs/tags/", 10)) { + if (object->type == OBJ_TAG) + prio = 2; + else + prio = 1; + } + else + prio = 0; + + if (!all) { + if (!prio) + return 0; + if (!tags && prio < 2) + return 0; + } + add_to_known_names(all ? path + 5 : path + 10, commit, prio); + return 0; +} + +struct possible_tag { + struct commit_name *name; + int depth; + int found_order; + unsigned flag_within; +}; + +static int compare_pt(const void *a_, const void *b_) +{ + struct possible_tag *a = (struct possible_tag *)a_; + struct possible_tag *b = (struct possible_tag *)b_; + if (a->name->prio != b->name->prio) + return b->name->prio - a->name->prio; + if (a->depth != b->depth) + return a->depth - b->depth; + if (a->found_order != b->found_order) + return a->found_order - b->found_order; + return 0; +} + +static unsigned long finish_depth_computation( + struct commit_list **list, + struct possible_tag *best) +{ + unsigned long seen_commits = 0; + while (*list) { + struct commit *c = pop_commit(list); + struct commit_list *parents = c->parents; + seen_commits++; + if (c->object.flags & best->flag_within) { + struct commit_list *a = *list; + while (a) { + struct commit *i = a->item; + if (!(i->object.flags & best->flag_within)) + break; + a = a->next; + } + if (!a) + break; + } else + best->depth++; + while (parents) { + struct commit *p = parents->item; + parse_commit(p); + if (!(p->object.flags & SEEN)) + insert_by_date(p, list); + p->object.flags |= c->object.flags; + parents = parents->next; + } + } + return seen_commits; +} + +static void describe(const char *arg, int last_one) +{ + unsigned char sha1[20]; + struct commit *cmit, *gave_up_on = NULL; + struct commit_list *list; + static int initialized = 0; + struct commit_name *n; + struct possible_tag all_matches[MAX_TAGS]; + unsigned int match_cnt = 0, annotated_cnt = 0, cur_match; + unsigned long seen_commits = 0; + + if (get_sha1(arg, sha1)) + die("Not a valid object name %s", arg); + cmit = lookup_commit_reference(sha1); + if (!cmit) + die("%s is not a valid '%s' object", arg, commit_type); + + if (!initialized) { + initialized = 1; + for_each_ref(get_name, NULL); + } + + n = cmit->util; + if (n) { + printf("%s\n", n->path); + return; + } + + if (debug) + fprintf(stderr, "searching to describe %s\n", arg); + + list = NULL; + cmit->object.flags = SEEN; + commit_list_insert(cmit, &list); + while (list) { + struct commit *c = pop_commit(&list); + struct commit_list *parents = c->parents; + seen_commits++; + n = c->util; + if (n) { + if (match_cnt < max_candidates) { + struct possible_tag *t = &all_matches[match_cnt++]; + t->name = n; + t->depth = seen_commits - 1; + t->flag_within = 1u << match_cnt; + t->found_order = match_cnt; + c->object.flags |= t->flag_within; + if (n->prio == 2) + annotated_cnt++; + } + else { + gave_up_on = c; + break; + } + } + for (cur_match = 0; cur_match < match_cnt; cur_match++) { + struct possible_tag *t = &all_matches[cur_match]; + if (!(c->object.flags & t->flag_within)) + t->depth++; + } + if (annotated_cnt && !list) { + if (debug) + fprintf(stderr, "finished search at %s\n", + sha1_to_hex(c->object.sha1)); + break; + } + while (parents) { + struct commit *p = parents->item; + parse_commit(p); + if (!(p->object.flags & SEEN)) + insert_by_date(p, &list); + p->object.flags |= c->object.flags; + parents = parents->next; + } + } + + if (!match_cnt) + die("cannot describe '%s'", sha1_to_hex(cmit->object.sha1)); + + qsort(all_matches, match_cnt, sizeof(all_matches[0]), compare_pt); + + if (gave_up_on) { + insert_by_date(gave_up_on, &list); + seen_commits--; + } + seen_commits += finish_depth_computation(&list, &all_matches[0]); + free_commit_list(list); + + if (debug) { + for (cur_match = 0; cur_match < match_cnt; cur_match++) { + struct possible_tag *t = &all_matches[cur_match]; + fprintf(stderr, " %-11s %8d %s\n", + prio_names[t->name->prio], + t->depth, t->name->path); + } + fprintf(stderr, "traversed %lu commits\n", seen_commits); + if (gave_up_on) { + fprintf(stderr, + "more than %i tags found; listed %i most recent\n" + "gave up search at %s\n", + max_candidates, max_candidates, + sha1_to_hex(gave_up_on->object.sha1)); + } + } + if (abbrev == 0) + printf("%s\n", all_matches[0].name->path ); + else + printf("%s-%d-g%s\n", all_matches[0].name->path, + all_matches[0].depth, + find_unique_abbrev(cmit->object.sha1, abbrev)); + + if (!last_one) + clear_commit_marks(cmit, -1); +} + +int cmd_describe(int argc, const char **argv, const char *prefix) +{ + int i; + + for (i = 1; i < argc; i++) { + const char *arg = argv[i]; + + if (*arg != '-') + break; + else if (!strcmp(arg, "--debug")) + debug = 1; + else if (!strcmp(arg, "--all")) + all = 1; + else if (!strcmp(arg, "--tags")) + tags = 1; + else if (!strncmp(arg, "--abbrev=", 9)) { + abbrev = strtoul(arg + 9, NULL, 10); + if (abbrev != 0 && (abbrev < MINIMUM_ABBREV || 40 < abbrev)) + abbrev = DEFAULT_ABBREV; + } + else if (!strncmp(arg, "--candidates=", 13)) { + max_candidates = strtoul(arg + 13, NULL, 10); + if (max_candidates < 1) + max_candidates = 1; + else if (max_candidates > MAX_TAGS) + max_candidates = MAX_TAGS; + } + else + usage(describe_usage); + } + + save_commit_buffer = 0; + + if (argc <= i) + describe("HEAD", 1); + else + while (i < argc) { + describe(argv[i], (i == argc - 1)); + i++; + } + + return 0; +} |