[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;

static unsigned int names[256], allocs[256];
static struct commit_name {
	struct commit *commit;
	int prio; /* annotated tag = 2, tag = 1, head = 0 */
	char path[FLEX_ARRAY]; /* more */
} **name_array[256];

static struct commit_name *match(struct commit *cmit)
{
	unsigned char level0 = cmit->object.sha1[0];
	struct commit_name **p = name_array[level0];
	unsigned int hi = names[level0];
	unsigned int lo = 0;

	while (lo < hi) {
		unsigned int mi = (lo + hi) / 2;
		int cmp = hashcmp(p[mi]->commit->object.sha1,
			cmit->object.sha1);
		if (!cmp) {
			while (mi && p[mi - 1]->commit == cmit)
				mi--;
			return p[mi];
		}
		if (cmp > 0)
			hi = mi;
		else
			lo = mi+1;
	}
	return NULL;
}

static void add_to_known_names(const char *path,
			       struct commit *commit,
			       int prio)
{
	int idx;
	int len = strlen(path)+1;
	struct commit_name *name = xmalloc(sizeof(struct commit_name) + len);
	unsigned char m = commit->object.sha1[0];

	name->commit = commit;
	name->prio = prio;
	memcpy(name->path, path, len);
	idx = names[m];
	if (idx >= allocs[m]) {
		allocs[m] = (idx + 50) * 3 / 2;
		name_array[m] = xrealloc(name_array[m],
			allocs[m] * sizeof(*name_array));
	}
	name_array[m][idx] = name;
	names[m] = ++idx;
}

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;
}

static int compare_names(const void *_a, const void *_b)
{
	struct commit_name *a = *(struct commit_name **)_a;
	struct commit_name *b = *(struct commit_name **)_b;
	unsigned long a_date = a->commit->date;
	unsigned long b_date = b->commit->date;
	int cmp = hashcmp(a->commit->object.sha1, b->commit->object.sha1);

	if (cmp)
		return cmp;
	if (a->prio != b->prio)
		return b->prio - a->prio;
	return (a_date > b_date) ? -1 : (a_date == b_date) ? 0 : 1;
}

struct possible_tag {
	struct commit_name *name;
	unsigned long depth;
	unsigned flag_within;
};

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], *min_match;
	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) {
		unsigned int m;
		initialized = 1;
		for_each_ref(get_name, NULL);
		for (m = 0; m < ARRAY_SIZE(name_array); m++)
			qsort(name_array[m], names[m],
				sizeof(*name_array[m]), compare_names);
	}

	n = match(cmit);
	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 = match(c);
		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;
				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;
		}
	}
	free_commit_list(list);

	if (!match_cnt)
		die("cannot describe '%s'", sha1_to_hex(cmit->object.sha1));

	min_match = &all_matches[0];
	for (cur_match = 1; cur_match < match_cnt; cur_match++) {
		struct possible_tag *t = &all_matches[cur_match];
		if (t->depth < min_match->depth
			&& t->name->prio >= min_match->name->prio)
			min_match = t;
	}
	if (debug) {
		for (cur_match = 0; cur_match < match_cnt; cur_match++) {
			struct possible_tag *t = &all_matches[cur_match];
			fprintf(stderr, " %c %8lu %s\n",
				min_match == t ? '*' : ' ',
				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));
		}
	}
	printf("%s-g%s\n", min_match->name->path,
		   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 < 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
c3e3cd4b	19	static unsigned int names[256], allocs[256];
908e5310	20	static struct commit_name {
80dbae03	21	struct commit *commit;
64deb858	22	int prio; /* annotated tag = 2, tag = 1, head = 0 */
5a2282de	23	char path[FLEX_ARRAY]; /* more */
c3e3cd4b	24	} **name_array[256];
908e5310 LT	25
	26	static struct commit_name match(struct commit cmit)
	27	{
910c0d7b SP	28	unsigned char level0 = cmit->object.sha1[0];
	29	struct commit_name **p = name_array[level0];
	30	unsigned int hi = names[level0];
	31	unsigned int lo = 0;
908e5310	32
910c0d7b SP	33	while (lo < hi) {
	34	unsigned int mi = (lo + hi) / 2;
	35	int cmp = hashcmp(p[mi]->commit->object.sha1,
	36	cmit->object.sha1);
	37	if (!cmp) {
	38	while (mi && p[mi - 1]->commit == cmit)
	39	mi--;
	40	return p[mi];
	41	}
	42	if (cmp > 0)
	43	hi = mi;
	44	else
	45	lo = mi+1;
908e5310 LT	46	}
	47	return NULL;
	48	}
	49
64deb858	50	static void add_to_known_names(const char *path,
80dbae03	51	struct commit *commit,
64deb858	52	int prio)
908e5310 LT	53	{
	54	int idx;
	55	int len = strlen(path)+1;
	56	struct commit_name *name = xmalloc(sizeof(struct commit_name) + len);
c3e3cd4b	57	unsigned char m = commit->object.sha1[0];
908e5310 LT	58
908e5310 LT	59	name->commit = commit;
f7122265	60	name->prio = prio;
908e5310	61	memcpy(name->path, path, len);
c3e3cd4b SP	62	idx = names[m];
	63	if (idx >= allocs[m]) {
	64	allocs[m] = (idx + 50) * 3 / 2;
	65	name_array[m] = xrealloc(name_array[m],
	66	allocs[m] * sizeof(*name_array));
908e5310	67	}
c3e3cd4b SP	68	name_array[m][idx] = name;
c3e3cd4b SP	69	names[m] = ++idx;
908e5310 LT	70	}
908e5310 LT	71
8da19775	72	static int get_name(const char path, const unsigned char sha1, int flag, void *cb_data)
908e5310 LT	73	{
908e5310 LT	74	struct commit *commit = lookup_commit_reference_gently(sha1, 1);
64deb858 JH	75	struct object *object;
	76	int prio;
	77
908e5310 LT	78	if (!commit)
908e5310 LT	79	return 0;
64deb858	80	object = parse_object(sha1);
2d9e7c9f JH	81	/* If --all, then any refs are used.
	82	* If --tags, then any tags are used.
	83	* Otherwise only annotated tags are used.
	84	*/
64deb858	85	if (!strncmp(path, "refs/tags/", 10)) {
1974632c	86	if (object->type == OBJ_TAG)
64deb858 JH	87	prio = 2;
	88	else
	89	prio = 1;
	90	}
	91	else
	92	prio = 0;
	93
635d4134	94	if (!all) {
64deb858 JH	95	if (!prio)
	96	return 0;
	97	if (!tags && prio < 2)
635d4134	98	return 0;
635d4134	99	}
64deb858	100	add_to_known_names(all ? path + 5 : path + 10, commit, prio);
908e5310 LT	101	return 0;
	102	}
	103
	104	static int compare_names(const void _a, const void _b)
	105	{
	106	struct commit_name a = (struct commit_name **)_a;
	107	struct commit_name b = (struct commit_name **)_b;
	108	unsigned long a_date = a->commit->date;
	109	unsigned long b_date = b->commit->date;
910c0d7b	110	int cmp = hashcmp(a->commit->object.sha1, b->commit->object.sha1);
64deb858	111
910c0d7b SP	112	if (cmp)
910c0d7b SP	113	return cmp;
64deb858 JH	114	if (a->prio != b->prio)
64deb858 JH	115	return b->prio - a->prio;
908e5310 LT	116	return (a_date > b_date) ? -1 : (a_date == b_date) ? 0 : 1;
	117	}
	118
80dbae03	119	struct possible_tag {
80dbae03 SP	120	struct commit_name *name;
80dbae03 SP	121	unsigned long depth;
8713ab30	122	unsigned flag_within;
80dbae03 SP	123	};
80dbae03 SP	124
554fe20d	125	static void describe(const char *arg, int last_one)
908e5310	126	{
4c34a2c5	127	unsigned char sha1[20];
8713ab30	128	struct commit cmit, gave_up_on = NULL;
908e5310 LT	129	struct commit_list *list;
	130	static int initialized = 0;
	131	struct commit_name *n;
8713ab30 SP	132	struct possible_tag all_matches[MAX_TAGS], *min_match;
	133	unsigned int match_cnt = 0, annotated_cnt = 0, cur_match;
	134	unsigned long seen_commits = 0;
908e5310	135
31fff305 DL	136	if (get_sha1(arg, sha1))
31fff305 DL	137	die("Not a valid object name %s", arg);
4c34a2c5 JH	138	cmit = lookup_commit_reference(sha1);
4c34a2c5 JH	139	if (!cmit)
31fff305	140	die("%s is not a valid '%s' object", arg, commit_type);
4c34a2c5	141
908e5310	142	if (!initialized) {
c3e3cd4b	143	unsigned int m;
908e5310	144	initialized = 1;
cb5d709f	145	for_each_ref(get_name, NULL);
c3e3cd4b SP	146	for (m = 0; m < ARRAY_SIZE(name_array); m++)
	147	qsort(name_array[m], names[m],
	148	sizeof(*name_array[m]), compare_names);
908e5310 LT	149	}
	150
	151	n = match(cmit);
	152	if (n) {
	153	printf("%s\n", n->path);
	154	return;
	155	}
	156
8713ab30 SP	157	if (debug)
	158	fprintf(stderr, "searching to describe %s\n", arg);
	159
908e5310	160	list = NULL;
8713ab30	161	cmit->object.flags = SEEN;
908e5310 LT	162	commit_list_insert(cmit, &list);
908e5310 LT	163	while (list) {
80dbae03	164	struct commit *c = pop_commit(&list);
dccd0c2a	165	struct commit_list *parents = c->parents;
8713ab30	166	seen_commits++;
908e5310 LT	167	n = match(c);
908e5310 LT	168	if (n) {
8713ab30 SP	169	if (match_cnt < max_candidates) {
	170	struct possible_tag *t = &all_matches[match_cnt++];
	171	t->name = n;
	172	t->depth = seen_commits - 1;
	173	t->flag_within = 1u << match_cnt;
	174	c->object.flags \|= t->flag_within;
	175	if (n->prio == 2)
	176	annotated_cnt++;
	177	}
	178	else {
	179	gave_up_on = c;
	180	break;
	181	}
	182	}
	183	for (cur_match = 0; cur_match < match_cnt; cur_match++) {
	184	struct possible_tag *t = &all_matches[cur_match];
	185	if (!(c->object.flags & t->flag_within))
	186	t->depth++;
	187	}
	188	if (annotated_cnt && !list) {
	189	if (debug)
	190	fprintf(stderr, "finished search at %s\n",
	191	sha1_to_hex(c->object.sha1));
	192	break;
dccd0c2a SP	193	}
	194	while (parents) {
	195	struct commit *p = parents->item;
	196	parse_commit(p);
8713ab30	197	if (!(p->object.flags & SEEN))
dccd0c2a	198	insert_by_date(p, &list);
8713ab30	199	p->object.flags \|= c->object.flags;
dccd0c2a	200	parents = parents->next;
80dbae03 SP	201	}
80dbae03 SP	202	}
8713ab30	203	free_commit_list(list);
80dbae03	204
8713ab30	205	if (!match_cnt)
80dbae03 SP	206	die("cannot describe '%s'", sha1_to_hex(cmit->object.sha1));
80dbae03 SP	207
8713ab30 SP	208	min_match = &all_matches[0];
	209	for (cur_match = 1; cur_match < match_cnt; cur_match++) {
	210	struct possible_tag *t = &all_matches[cur_match];
	211	if (t->depth < min_match->depth
	212	&& t->name->prio >= min_match->name->prio)
	213	min_match = t;
	214	}
	215	if (debug) {
	216	for (cur_match = 0; cur_match < match_cnt; cur_match++) {
	217	struct possible_tag *t = &all_matches[cur_match];
	218	fprintf(stderr, " %c %8lu %s\n",
	219	min_match == t ? '*' : ' ',
	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 SP	230	}
	231	printf("%s-g%s\n", min_match->name->path,
	232	find_unique_abbrev(cmit->object.sha1, abbrev));
	233
8713ab30 SP	234	if (!last_one)
8713ab30 SP	235	clear_commit_marks(cmit, -1);
908e5310 LT	236	}
908e5310 LT	237
9a0eaf83	238	int cmd_describe(int argc, const char *argv, const char prefix)
908e5310 LT	239	{
	240	int i;
	241
	242	for (i = 1; i < argc; i++) {
	243	const char *arg = argv[i];
908e5310	244
4c34a2c5 JH	245	if (*arg != '-')
4c34a2c5 JH	246	break;
8713ab30 SP	247	else if (!strcmp(arg, "--debug"))
8713ab30 SP	248	debug = 1;
4c34a2c5	249	else if (!strcmp(arg, "--all"))
908e5310	250	all = 1;
4c34a2c5	251	else if (!strcmp(arg, "--tags"))
2d9e7c9f	252	tags = 1;
4c34a2c5	253	else if (!strncmp(arg, "--abbrev=", 9)) {
2d9e7c9f	254	abbrev = strtoul(arg + 9, NULL, 10);
f7122265	255	if (abbrev < MINIMUM_ABBREV \|\| 40 < abbrev)
2d9e7c9f	256	abbrev = DEFAULT_ABBREV;
2d9e7c9f	257	}
8713ab30 SP	258	else if (!strncmp(arg, "--candidates=", 13)) {
	259	max_candidates = strtoul(arg + 13, NULL, 10);
	260	if (max_candidates < 1)
	261	max_candidates = 1;
	262	else if (max_candidates > MAX_TAGS)
	263	max_candidates = MAX_TAGS;
	264	}
4c34a2c5	265	else
908e5310	266	usage(describe_usage);
908e5310	267	}
4c34a2c5	268
8c599c74	269	save_commit_buffer = 0;
8112894d	270
5b6df8e4	271	if (argc <= i)
fec9ebf1	272	describe("HEAD", 1);
4c34a2c5	273	else
fec9ebf1 JH	274	while (i < argc) {
	275	describe(argv[i], (i == argc - 1));
	276	i++;
	277	}
4c34a2c5	278
908e5310 LT	279	return 0;
908e5310 LT	280	}