[thirdparty/git.git] / builtin-describe.c

#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;
}
Commit	Line	Data
908e5310 LT	1	#include "cache.h"
908e5310 LT	2	#include "commit.h"
635d4134	3	#include "tag.h"
908e5310	4	#include "refs.h"
9a0eaf83	5	#include "builtin.h"
908e5310	6
8713ab30 SP	7	#define SEEN (1u<<0)
	8	#define MAX_TAGS (FLAG_BITS - 1)
	9
2d9e7c9f JH	10	static const char describe_usage[] =
2d9e7c9f JH	11	"git-describe [--all] [--tags] [--abbrev=<n>] <committish>*";
908e5310	12
8713ab30	13	static int debug; /* Display lots of verbose info */
96f1e58f DR	14	static int all; /* Default to annotated tags only */
96f1e58f DR	15	static int tags; /* But allow any tags if --tags is specified */
2d9e7c9f	16	static int abbrev = DEFAULT_ABBREV;
8713ab30	17	static int max_candidates = 10;
908e5310	18
e7eb5034	19	struct commit_name {
64deb858	20	int prio; /* annotated tag = 2, tag = 1, head = 0 */
5a2282de	21	char path[FLEX_ARRAY]; /* more */
e7eb5034	22	};
cf69fd49 SP	23	static const char *prio_names[] = {
	24	"head", "lightweight", "annotated",
	25	};
908e5310	26
64deb858	27	static void add_to_known_names(const char *path,
80dbae03	28	struct commit *commit,
64deb858	29	int prio)
908e5310	30	{
e7eb5034 SP	31	struct commit_name *e = commit->util;
	32	if (!e \|\| e->prio < prio) {
	33	size_t len = strlen(path)+1;
	34	free(e);
	35	e = xmalloc(sizeof(struct commit_name) + len);
	36	e->prio = prio;
	37	memcpy(e->path, path, len);
	38	commit->util = e;
908e5310	39	}
908e5310 LT	40	}
908e5310 LT	41
8da19775	42	static int get_name(const char path, const unsigned char sha1, int flag, void *cb_data)
908e5310 LT	43	{
908e5310 LT	44	struct commit *commit = lookup_commit_reference_gently(sha1, 1);
64deb858 JH	45	struct object *object;
	46	int prio;
	47
908e5310 LT	48	if (!commit)
908e5310 LT	49	return 0;
64deb858	50	object = parse_object(sha1);
2d9e7c9f JH	51	/* If --all, then any refs are used.
	52	* If --tags, then any tags are used.
	53	* Otherwise only annotated tags are used.
	54	*/
64deb858	55	if (!strncmp(path, "refs/tags/", 10)) {
1974632c	56	if (object->type == OBJ_TAG)
64deb858 JH	57	prio = 2;
	58	else
	59	prio = 1;
	60	}
	61	else
	62	prio = 0;
	63
635d4134	64	if (!all) {
64deb858 JH	65	if (!prio)
	66	return 0;
	67	if (!tags && prio < 2)
635d4134	68	return 0;
635d4134	69	}
64deb858	70	add_to_known_names(all ? path + 5 : path + 10, commit, prio);
908e5310 LT	71	return 0;
	72	}
	73
80dbae03	74	struct possible_tag {
80dbae03	75	struct commit_name *name;
cf69fd49 SP	76	int depth;
cf69fd49 SP	77	int found_order;
8713ab30	78	unsigned flag_within;
80dbae03 SP	79	};
80dbae03 SP	80
cf69fd49 SP	81	static int compare_pt(const void a_, const void b_)
	82	{
	83	struct possible_tag a = (struct possible_tag )a_;
	84	struct possible_tag b = (struct possible_tag )b_;
	85	if (a->name->prio != b->name->prio)
	86	return b->name->prio - a->name->prio;
	87	if (a->depth != b->depth)
	88	return a->depth - b->depth;
	89	if (a->found_order != b->found_order)
	90	return a->found_order - b->found_order;
	91	return 0;
	92	}
	93
1b600e65 SP	94	static unsigned long finish_depth_computation(
	95	struct commit_list **list,
	96	struct possible_tag *best)
	97	{
	98	unsigned long seen_commits = 0;
	99	while (*list) {
	100	struct commit *c = pop_commit(list);
	101	struct commit_list *parents = c->parents;
	102	seen_commits++;
	103	if (c->object.flags & best->flag_within) {
	104	struct commit_list a = list;
	105	while (a) {
	106	struct commit *i = a->item;
	107	if (!(i->object.flags & best->flag_within))
	108	break;
	109	a = a->next;
	110	}
	111	if (!a)
	112	break;
	113	} else
	114	best->depth++;
	115	while (parents) {
	116	struct commit *p = parents->item;
	117	parse_commit(p);
	118	if (!(p->object.flags & SEEN))
	119	insert_by_date(p, list);
	120	p->object.flags \|= c->object.flags;
	121	parents = parents->next;
	122	}
	123	}
	124	return seen_commits;
	125	}
	126
554fe20d	127	static void describe(const char *arg, int last_one)
908e5310	128	{
4c34a2c5	129	unsigned char sha1[20];
8713ab30	130	struct commit cmit, gave_up_on = NULL;
908e5310 LT	131	struct commit_list *list;
	132	static int initialized = 0;
	133	struct commit_name *n;
cf69fd49	134	struct possible_tag all_matches[MAX_TAGS];
8713ab30 SP	135	unsigned int match_cnt = 0, annotated_cnt = 0, cur_match;
8713ab30 SP	136	unsigned long seen_commits = 0;
908e5310	137
31fff305 DL	138	if (get_sha1(arg, sha1))
31fff305 DL	139	die("Not a valid object name %s", arg);
4c34a2c5 JH	140	cmit = lookup_commit_reference(sha1);
4c34a2c5 JH	141	if (!cmit)
31fff305	142	die("%s is not a valid '%s' object", arg, commit_type);
4c34a2c5	143
908e5310 LT	144	if (!initialized) {
908e5310 LT	145	initialized = 1;
cb5d709f	146	for_each_ref(get_name, NULL);
908e5310 LT	147	}
908e5310 LT	148
e7eb5034	149	n = cmit->util;
908e5310 LT	150	if (n) {
	151	printf("%s\n", n->path);
	152	return;
	153	}
	154
8713ab30 SP	155	if (debug)
	156	fprintf(stderr, "searching to describe %s\n", arg);
	157
908e5310	158	list = NULL;
8713ab30	159	cmit->object.flags = SEEN;
908e5310 LT	160	commit_list_insert(cmit, &list);
908e5310 LT	161	while (list) {
80dbae03	162	struct commit *c = pop_commit(&list);
dccd0c2a	163	struct commit_list *parents = c->parents;
8713ab30	164	seen_commits++;
e7eb5034	165	n = c->util;
908e5310	166	if (n) {
8713ab30 SP	167	if (match_cnt < max_candidates) {
	168	struct possible_tag *t = &all_matches[match_cnt++];
	169	t->name = n;
	170	t->depth = seen_commits - 1;
	171	t->flag_within = 1u << match_cnt;
8a8169c0	172	t->found_order = match_cnt;
8713ab30 SP	173	c->object.flags \|= t->flag_within;
	174	if (n->prio == 2)
	175	annotated_cnt++;
	176	}
	177	else {
	178	gave_up_on = c;
	179	break;
	180	}
	181	}
	182	for (cur_match = 0; cur_match < match_cnt; cur_match++) {
	183	struct possible_tag *t = &all_matches[cur_match];
	184	if (!(c->object.flags & t->flag_within))
	185	t->depth++;
	186	}
	187	if (annotated_cnt && !list) {
	188	if (debug)
	189	fprintf(stderr, "finished search at %s\n",
	190	sha1_to_hex(c->object.sha1));
	191	break;
dccd0c2a SP	192	}
	193	while (parents) {
	194	struct commit *p = parents->item;
	195	parse_commit(p);
8713ab30	196	if (!(p->object.flags & SEEN))
dccd0c2a	197	insert_by_date(p, &list);
8713ab30	198	p->object.flags \|= c->object.flags;
dccd0c2a	199	parents = parents->next;
80dbae03 SP	200	}
	201	}
	202
8713ab30	203	if (!match_cnt)
80dbae03 SP	204	die("cannot describe '%s'", sha1_to_hex(cmit->object.sha1));
80dbae03 SP	205
cf69fd49	206	qsort(all_matches, match_cnt, sizeof(all_matches[0]), compare_pt);
1b600e65 SP	207
	208	if (gave_up_on) {
	209	insert_by_date(gave_up_on, &list);
	210	seen_commits--;
	211	}
	212	seen_commits += finish_depth_computation(&list, &all_matches[0]);
	213	free_commit_list(list);
	214
8713ab30 SP	215	if (debug) {
	216	for (cur_match = 0; cur_match < match_cnt; cur_match++) {
	217	struct possible_tag *t = &all_matches[cur_match];
cf69fd49 SP	218	fprintf(stderr, " %-11s %8d %s\n",
cf69fd49 SP	219	prio_names[t->name->prio],
8713ab30 SP	220	t->depth, t->name->path);
	221	}
	222	fprintf(stderr, "traversed %lu commits\n", seen_commits);
	223	if (gave_up_on) {
	224	fprintf(stderr,
	225	"more than %i tags found; listed %i most recent\n"
	226	"gave up search at %s\n",
	227	max_candidates, max_candidates,
	228	sha1_to_hex(gave_up_on->object.sha1));
	229	}
80dbae03	230	}
f127404c AP	231	if (abbrev == 0)
	232	printf("%s\n", all_matches[0].name->path );
	233	else
237fb6ca SP	234	printf("%s-%d-g%s\n", all_matches[0].name->path,
	235	all_matches[0].depth,
	236	find_unique_abbrev(cmit->object.sha1, abbrev));
80dbae03	237
8713ab30 SP	238	if (!last_one)
8713ab30 SP	239	clear_commit_marks(cmit, -1);
908e5310 LT	240	}
908e5310 LT	241
9a0eaf83	242	int cmd_describe(int argc, const char *argv, const char prefix)
908e5310 LT	243	{
	244	int i;
	245
	246	for (i = 1; i < argc; i++) {
	247	const char *arg = argv[i];
908e5310	248
4c34a2c5 JH	249	if (*arg != '-')
4c34a2c5 JH	250	break;
8713ab30 SP	251	else if (!strcmp(arg, "--debug"))
8713ab30 SP	252	debug = 1;
4c34a2c5	253	else if (!strcmp(arg, "--all"))
908e5310	254	all = 1;
4c34a2c5	255	else if (!strcmp(arg, "--tags"))
2d9e7c9f	256	tags = 1;
4c34a2c5	257	else if (!strncmp(arg, "--abbrev=", 9)) {
2d9e7c9f	258	abbrev = strtoul(arg + 9, NULL, 10);
f127404c	259	if (abbrev != 0 && (abbrev < MINIMUM_ABBREV \|\| 40 < abbrev))
2d9e7c9f	260	abbrev = DEFAULT_ABBREV;
2d9e7c9f	261	}
8713ab30 SP	262	else if (!strncmp(arg, "--candidates=", 13)) {
	263	max_candidates = strtoul(arg + 13, NULL, 10);
	264	if (max_candidates < 1)
	265	max_candidates = 1;
	266	else if (max_candidates > MAX_TAGS)
	267	max_candidates = MAX_TAGS;
	268	}
4c34a2c5	269	else
908e5310	270	usage(describe_usage);
908e5310	271	}
4c34a2c5	272
8c599c74	273	save_commit_buffer = 0;
8112894d	274
5b6df8e4	275	if (argc <= i)
fec9ebf1	276	describe("HEAD", 1);
4c34a2c5	277	else
fec9ebf1 JH	278	while (i < argc) {
	279	describe(argv[i], (i == argc - 1));
	280	i++;
	281	}
4c34a2c5	282
908e5310 LT	283	return 0;
908e5310 LT	284	}