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

#include "cache.h"
#include "commit.h"
#include "tag.h"
#include "refs.h"
#include "builtin.h"
#include "exec_cmd.h"
#include "parse-options.h"

#define SEEN		(1u<<0)
#define MAX_TAGS	(FLAG_BITS - 1)

static const char * const describe_usage[] = {
	"git-describe [options] <committish>*",
	NULL
};

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 (!prefixcmp(path, "refs/tags/")) {
		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 contains = 0;
	struct option options[] = {
		OPT_BOOLEAN(0, "contains",   &contains, "find the tag that comes after the commit"),
		OPT_BOOLEAN(0, "debug",      &debug, "debug search strategy on stderr"),
		OPT_BOOLEAN(0, "all",        &all, "use any ref in .git/refs"),
		OPT_BOOLEAN(0, "tags",       &tags, "use any tag in .git/refs/tags"),
		OPT__ABBREV(&abbrev),
		OPT_INTEGER(0, "candidates", &max_candidates,
					"consider <n> most recent tags (default: 10)"),
		OPT_END(),
	};

	argc = parse_options(argc, argv, options, describe_usage, 0);
	if (max_candidates < 1)
		max_candidates = 1;
	else if (max_candidates > MAX_TAGS)
		max_candidates = MAX_TAGS;

	save_commit_buffer = 0;

	if (contains) {
		const char **args = xmalloc((4 + argc) * sizeof(char*));
		args[0] = "name-rev";
		args[1] = "--name-only";
		args[2] = "--tags";
		memcpy(args + 3, argv, argc * sizeof(char*));
		args[3 + argc] = NULL;
		return cmd_name_rev(3 + argc, args, prefix);
	}

	if (argc == 0) {
		describe("HEAD", 1);
	} else {
		while (argc-- > 0) {
			describe(*argv++, argc == 0);
		}
	}
	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"
23615708	6	#include "exec_cmd.h"
166185be	7	#include "parse-options.h"
908e5310	8
8713ab30 SP	9	#define SEEN (1u<<0)
	10	#define MAX_TAGS (FLAG_BITS - 1)
	11
166185be PH	12	static const char * const describe_usage[] = {
	13	"git-describe [options] <committish>*",
	14	NULL
	15	};
908e5310	16
8713ab30	17	static int debug; /* Display lots of verbose info */
96f1e58f DR	18	static int all; /* Default to annotated tags only */
96f1e58f DR	19	static int tags; /* But allow any tags if --tags is specified */
2d9e7c9f	20	static int abbrev = DEFAULT_ABBREV;
8713ab30	21	static int max_candidates = 10;
908e5310	22
e7eb5034	23	struct commit_name {
64deb858	24	int prio; /* annotated tag = 2, tag = 1, head = 0 */
5a2282de	25	char path[FLEX_ARRAY]; /* more */
e7eb5034	26	};
cf69fd49 SP	27	static const char *prio_names[] = {
	28	"head", "lightweight", "annotated",
	29	};
908e5310	30
64deb858	31	static void add_to_known_names(const char *path,
80dbae03	32	struct commit *commit,
64deb858	33	int prio)
908e5310	34	{
e7eb5034 SP	35	struct commit_name *e = commit->util;
	36	if (!e \|\| e->prio < prio) {
	37	size_t len = strlen(path)+1;
	38	free(e);
	39	e = xmalloc(sizeof(struct commit_name) + len);
	40	e->prio = prio;
	41	memcpy(e->path, path, len);
	42	commit->util = e;
908e5310	43	}
908e5310 LT	44	}
908e5310 LT	45
8da19775	46	static int get_name(const char path, const unsigned char sha1, int flag, void *cb_data)
908e5310 LT	47	{
908e5310 LT	48	struct commit *commit = lookup_commit_reference_gently(sha1, 1);
64deb858 JH	49	struct object *object;
	50	int prio;
	51
908e5310 LT	52	if (!commit)
908e5310 LT	53	return 0;
64deb858	54	object = parse_object(sha1);
2d9e7c9f JH	55	/* If --all, then any refs are used.
	56	* If --tags, then any tags are used.
	57	* Otherwise only annotated tags are used.
	58	*/
cc44c765	59	if (!prefixcmp(path, "refs/tags/")) {
1974632c	60	if (object->type == OBJ_TAG)
64deb858 JH	61	prio = 2;
	62	else
	63	prio = 1;
	64	}
	65	else
	66	prio = 0;
	67
635d4134	68	if (!all) {
64deb858 JH	69	if (!prio)
	70	return 0;
	71	if (!tags && prio < 2)
635d4134	72	return 0;
635d4134	73	}
64deb858	74	add_to_known_names(all ? path + 5 : path + 10, commit, prio);
908e5310 LT	75	return 0;
	76	}
	77
80dbae03	78	struct possible_tag {
80dbae03	79	struct commit_name *name;
cf69fd49 SP	80	int depth;
cf69fd49 SP	81	int found_order;
8713ab30	82	unsigned flag_within;
80dbae03 SP	83	};
80dbae03 SP	84
cf69fd49 SP	85	static int compare_pt(const void a_, const void b_)
	86	{
	87	struct possible_tag a = (struct possible_tag )a_;
	88	struct possible_tag b = (struct possible_tag )b_;
	89	if (a->name->prio != b->name->prio)
	90	return b->name->prio - a->name->prio;
	91	if (a->depth != b->depth)
	92	return a->depth - b->depth;
	93	if (a->found_order != b->found_order)
	94	return a->found_order - b->found_order;
	95	return 0;
	96	}
	97
1b600e65 SP	98	static unsigned long finish_depth_computation(
	99	struct commit_list **list,
	100	struct possible_tag *best)
	101	{
	102	unsigned long seen_commits = 0;
	103	while (*list) {
	104	struct commit *c = pop_commit(list);
	105	struct commit_list *parents = c->parents;
	106	seen_commits++;
	107	if (c->object.flags & best->flag_within) {
	108	struct commit_list a = list;
	109	while (a) {
	110	struct commit *i = a->item;
	111	if (!(i->object.flags & best->flag_within))
	112	break;
	113	a = a->next;
	114	}
	115	if (!a)
	116	break;
	117	} else
	118	best->depth++;
	119	while (parents) {
	120	struct commit *p = parents->item;
	121	parse_commit(p);
	122	if (!(p->object.flags & SEEN))
	123	insert_by_date(p, list);
	124	p->object.flags \|= c->object.flags;
	125	parents = parents->next;
	126	}
	127	}
	128	return seen_commits;
	129	}
	130
554fe20d	131	static void describe(const char *arg, int last_one)
908e5310	132	{
4c34a2c5	133	unsigned char sha1[20];
8713ab30	134	struct commit cmit, gave_up_on = NULL;
908e5310 LT	135	struct commit_list *list;
	136	static int initialized = 0;
	137	struct commit_name *n;
cf69fd49	138	struct possible_tag all_matches[MAX_TAGS];
8713ab30 SP	139	unsigned int match_cnt = 0, annotated_cnt = 0, cur_match;
8713ab30 SP	140	unsigned long seen_commits = 0;
908e5310	141
31fff305 DL	142	if (get_sha1(arg, sha1))
31fff305 DL	143	die("Not a valid object name %s", arg);
4c34a2c5 JH	144	cmit = lookup_commit_reference(sha1);
4c34a2c5 JH	145	if (!cmit)
31fff305	146	die("%s is not a valid '%s' object", arg, commit_type);
4c34a2c5	147
908e5310 LT	148	if (!initialized) {
908e5310 LT	149	initialized = 1;
cb5d709f	150	for_each_ref(get_name, NULL);
908e5310 LT	151	}
908e5310 LT	152
e7eb5034	153	n = cmit->util;
908e5310 LT	154	if (n) {
	155	printf("%s\n", n->path);
	156	return;
	157	}
	158
8713ab30 SP	159	if (debug)
	160	fprintf(stderr, "searching to describe %s\n", arg);
	161
908e5310	162	list = NULL;
8713ab30	163	cmit->object.flags = SEEN;
908e5310 LT	164	commit_list_insert(cmit, &list);
908e5310 LT	165	while (list) {
80dbae03	166	struct commit *c = pop_commit(&list);
dccd0c2a	167	struct commit_list *parents = c->parents;
8713ab30	168	seen_commits++;
e7eb5034	169	n = c->util;
908e5310	170	if (n) {
8713ab30 SP	171	if (match_cnt < max_candidates) {
	172	struct possible_tag *t = &all_matches[match_cnt++];
	173	t->name = n;
	174	t->depth = seen_commits - 1;
	175	t->flag_within = 1u << match_cnt;
8a8169c0	176	t->found_order = match_cnt;
8713ab30 SP	177	c->object.flags \|= t->flag_within;
	178	if (n->prio == 2)
	179	annotated_cnt++;
	180	}
	181	else {
	182	gave_up_on = c;
	183	break;
	184	}
	185	}
	186	for (cur_match = 0; cur_match < match_cnt; cur_match++) {
	187	struct possible_tag *t = &all_matches[cur_match];
	188	if (!(c->object.flags & t->flag_within))
	189	t->depth++;
	190	}
	191	if (annotated_cnt && !list) {
	192	if (debug)
	193	fprintf(stderr, "finished search at %s\n",
	194	sha1_to_hex(c->object.sha1));
	195	break;
dccd0c2a SP	196	}
	197	while (parents) {
	198	struct commit *p = parents->item;
	199	parse_commit(p);
8713ab30	200	if (!(p->object.flags & SEEN))
dccd0c2a	201	insert_by_date(p, &list);
8713ab30	202	p->object.flags \|= c->object.flags;
dccd0c2a	203	parents = parents->next;
80dbae03 SP	204	}
	205	}
	206
8713ab30	207	if (!match_cnt)
80dbae03 SP	208	die("cannot describe '%s'", sha1_to_hex(cmit->object.sha1));
80dbae03 SP	209
cf69fd49	210	qsort(all_matches, match_cnt, sizeof(all_matches[0]), compare_pt);
1b600e65 SP	211
	212	if (gave_up_on) {
	213	insert_by_date(gave_up_on, &list);
	214	seen_commits--;
	215	}
	216	seen_commits += finish_depth_computation(&list, &all_matches[0]);
	217	free_commit_list(list);
	218
8713ab30 SP	219	if (debug) {
	220	for (cur_match = 0; cur_match < match_cnt; cur_match++) {
	221	struct possible_tag *t = &all_matches[cur_match];
cf69fd49 SP	222	fprintf(stderr, " %-11s %8d %s\n",
cf69fd49 SP	223	prio_names[t->name->prio],
8713ab30 SP	224	t->depth, t->name->path);
	225	}
	226	fprintf(stderr, "traversed %lu commits\n", seen_commits);
	227	if (gave_up_on) {
	228	fprintf(stderr,
	229	"more than %i tags found; listed %i most recent\n"
	230	"gave up search at %s\n",
	231	max_candidates, max_candidates,
	232	sha1_to_hex(gave_up_on->object.sha1));
	233	}
80dbae03	234	}
f127404c AP	235	if (abbrev == 0)
	236	printf("%s\n", all_matches[0].name->path );
	237	else
237fb6ca SP	238	printf("%s-%d-g%s\n", all_matches[0].name->path,
	239	all_matches[0].depth,
	240	find_unique_abbrev(cmit->object.sha1, abbrev));
80dbae03	241
8713ab30 SP	242	if (!last_one)
8713ab30 SP	243	clear_commit_marks(cmit, -1);
908e5310 LT	244	}
908e5310 LT	245
9a0eaf83	246	int cmd_describe(int argc, const char *argv, const char prefix)
908e5310	247	{
23615708	248	int contains = 0;
166185be PH	249	struct option options[] = {
	250	OPT_BOOLEAN(0, "contains", &contains, "find the tag that comes after the commit"),
	251	OPT_BOOLEAN(0, "debug", &debug, "debug search strategy on stderr"),
	252	OPT_BOOLEAN(0, "all", &all, "use any ref in .git/refs"),
	253	OPT_BOOLEAN(0, "tags", &tags, "use any tag in .git/refs/tags"),
	254	OPT__ABBREV(&abbrev),
	255	OPT_INTEGER(0, "candidates", &max_candidates,
	256	"consider <n> most recent tags (default: 10)"),
	257	OPT_END(),
	258	};
908e5310	259
166185be PH	260	argc = parse_options(argc, argv, options, describe_usage, 0);
	261	if (max_candidates < 1)
	262	max_candidates = 1;
	263	else if (max_candidates > MAX_TAGS)
	264	max_candidates = MAX_TAGS;
4c34a2c5	265
8c599c74	266	save_commit_buffer = 0;
8112894d	267
23615708	268	if (contains) {
166185be	269	const char *args = xmalloc((4 + argc) sizeof(char*));
23615708 SP	270	args[0] = "name-rev";
	271	args[1] = "--name-only";
	272	args[2] = "--tags";
166185be PH	273	memcpy(args + 3, argv, argc * sizeof(char*));
	274	args[3 + argc] = NULL;
	275	return cmd_name_rev(3 + argc, args, prefix);
23615708 SP	276	}
23615708 SP	277
166185be	278	if (argc == 0) {
fec9ebf1	279	describe("HEAD", 1);
166185be PH	280	} else {
	281	while (argc-- > 0) {
	282	describe(*argv++, argc == 0);
fec9ebf1	283	}
166185be	284	}
908e5310 LT	285	return 0;
908e5310 LT	286	}