[thirdparty/git.git] / show-branch.c

#include <stdlib.h>
#include "cache.h"
#include "commit.h"
#include "refs.h"

static const char show_branch_usage[] =
"git-show-branch [--all] [--heads] [--tags] [--more=count] [<refs>...]";

#define UNINTERESTING	01

#define REV_SHIFT	 2
#define MAX_REVS	29 /* should not exceed bits_per_int - REV_SHIFT */

static struct commit *interesting(struct commit_list *list)
{
	while (list) {
		struct commit *commit = list->item;
		list = list->next;
		if (commit->object.flags & UNINTERESTING)
			continue;
		return commit;
	}
	return NULL;
}

static struct commit *pop_one_commit(struct commit_list **list_p)
{
	struct commit *commit;
	struct commit_list *list;
	list = *list_p;
	commit = list->item;
	*list_p = list->next;
	free(list);
	return commit;
}

struct commit_name {
	int head_rev;	/* which head's ancestor? */
	int generation;	/* how many parents away from head_rev */
};

/* Name the commit as nth generation ancestor of head_rev;
 * we count only the first-parent relationship for naming purposes.
 */
static void name_commit(struct commit *commit, int head_rev, int nth)
{
	struct commit_name *name;
	if (!commit->object.util)
		commit->object.util = xmalloc(sizeof(struct commit_name));
	name = commit->object.util;
	name->head_rev = head_rev;
	name->generation = nth;
}

/* Parent is the first parent of the commit.  We may name it
 * as (n+1)th generation ancestor of the same head_rev as
 * commit is nth generation ancestore of, if that generation
 * number is better than the name it already has.
 */
static void name_parent(struct commit *commit, struct commit *parent)
{
	struct commit_name *commit_name = commit->object.util;
	struct commit_name *parent_name = parent->object.util;
	if (!commit_name)
		return;
	if (!parent_name ||
	    commit_name->generation + 1 < parent_name->generation)
		name_commit(parent, commit_name->head_rev,
			    commit_name->generation + 1);
}

static int mark_seen(struct commit *commit, struct commit_list **seen_p)
{
	if (!commit->object.flags) {
		insert_by_date(commit, seen_p);
		return 1;
	}
	return 0;
}

static void join_revs(struct commit_list **list_p,
		      struct commit_list **seen_p,
		      int num_rev, int extra)
{
	int all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
	int all_revs = all_mask & ~((1u << REV_SHIFT) - 1);

	while (*list_p) {
		struct commit_list *parents;
		struct commit *commit = pop_one_commit(list_p);
		int flags = commit->object.flags & all_mask;
		int nth_parent = 0;
		int still_interesting = !!interesting(*list_p);

		if (!still_interesting && extra < 0)
			break;

		mark_seen(commit, seen_p);
		if ((flags & all_revs) == all_revs)
			flags |= UNINTERESTING;
		parents = commit->parents;

		while (parents) {
			struct commit *p = parents->item;
			int this_flag = p->object.flags;
			parents = parents->next;
			nth_parent++;
			if (nth_parent == 1)
				name_parent(commit, p);

			if ((this_flag & flags) == flags)
				continue;
			parse_commit(p);
			if (mark_seen(p, seen_p) && !still_interesting)
				extra--;
			p->object.flags |= flags;
			insert_by_date(p, list_p);
		}
	}
}

static void show_one_commit(struct commit *commit, char **head_name)
{
	char pretty[128], *cp;
	struct commit_name *name = commit->object.util;
	pretty_print_commit(CMIT_FMT_ONELINE, commit->buffer, ~0,
			    pretty, sizeof(pretty));
	if (!strncmp(pretty, "[PATCH] ", 8))
		cp = pretty + 8;
	else
		cp = pretty;
	if (name && head_name) {
		printf("[%s", head_name[name->head_rev]);
		if (name->generation)
			printf("~%d", name->generation);
		printf("] ");
	}
	puts(cp);
}

static char *ref_name[MAX_REVS + 1];
static int ref_name_cnt;

static int append_ref(const char *refname, const unsigned char *sha1)
{
	struct commit *commit = lookup_commit_reference_gently(sha1, 1);
	if (!commit)
		return 0;
	if (MAX_REVS < ref_name_cnt) {
		fprintf(stderr, "warning: ignoring %s; "
			"cannot handle more than %d refs",
			refname, MAX_REVS);
		return 0;
	}
	ref_name[ref_name_cnt++] = strdup(refname);
	ref_name[ref_name_cnt] = NULL;
	return 0;
}

static int append_head_ref(const char *refname, const unsigned char *sha1)
{
	if (strncmp(refname, "refs/heads/", 11))
		return 0;
	return append_ref(refname + 5, sha1);
}

static int append_tag_ref(const char *refname, const unsigned char *sha1)
{
	if (strncmp(refname, "refs/tags/", 10))
		return 0;
	return append_ref(refname + 5, sha1);
}

static void snarf_refs(int head, int tag)
{
	if (head)
		for_each_ref(append_head_ref);
	if (tag)
		for_each_ref(append_tag_ref);
}

static int rev_is_head(char *head_path, int headlen,
		       char *name,
		       unsigned char *head_sha1, unsigned char *sha1)
{
	int namelen;
	if ((!head_path[0]) || memcmp(head_sha1, sha1, 20))
		return 0;
	namelen = strlen(name);
	if ((headlen < namelen) ||
	    memcmp(head_path + headlen - namelen, name, namelen))
		return 0;
	if (headlen == namelen ||
	    head_path[headlen - namelen - 1] == '/')
		return 1;
	return 0;
}

static int show_merge_base(struct commit_list *seen, int num_rev)
{
	int all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
	int all_revs = all_mask & ~((1u << REV_SHIFT) - 1);

	while (seen) {
		struct commit *commit = pop_one_commit(&seen);
		int flags = commit->object.flags & all_mask;
		if (!(flags & UNINTERESTING) &&
		    ((flags & all_revs) == all_revs)) {
			puts(sha1_to_hex(commit->object.sha1));
			return 0;
		}
	}
	return 1;
}

int main(int ac, char **av)
{
	struct commit *rev[MAX_REVS], *commit;
	struct commit_list *list = NULL, *seen = NULL;
	int num_rev, i, extra = 0;
	int all_heads = 0, all_tags = 0;
	char head_path[128];
	int head_path_len;
	unsigned char head_sha1[20];
	int merge_base = 0;
	char **label;

	while (1 < ac && av[1][0] == '-') {
		char *arg = av[1];
		if (!strcmp(arg, "--all"))
			all_heads = all_tags = 1;
		else if (!strcmp(arg, "--heads"))
			all_heads = 1;
		else if (!strcmp(arg, "--tags"))
			all_tags = 1;
		else if (!strcmp(arg, "--more"))
			extra = 1;
		else if (!strncmp(arg, "--more=", 7)) {
			extra = atoi(arg + 7);
			if (extra < 0)
				usage(show_branch_usage);
		}
		else if (!strcmp(arg, "--merge-base"))
			merge_base = 1;
		else
			usage(show_branch_usage);
		ac--; av++;
	}
	ac--; av++;

	if (all_heads + all_tags)
		snarf_refs(all_heads, all_tags);

	while (0 < ac) {
		unsigned char revkey[20];
		if (get_sha1(*av, revkey))
			die("bad sha1 reference %s", *av);
		append_ref(*av, revkey);
		ac--; av++;
	}

	/* If still no revs, then add heads */
	if (!ref_name_cnt)
		snarf_refs(1, 0);

	for (num_rev = 0; ref_name[num_rev]; num_rev++) {
		unsigned char revkey[20];

		if (MAX_REVS <= num_rev)
			die("cannot handle more than %d revs.", MAX_REVS);
		if (get_sha1(ref_name[num_rev], revkey))
			usage(show_branch_usage);
		commit = lookup_commit_reference(revkey);
		if (!commit)
			die("cannot find commit %s (%s)",
			    ref_name[num_rev], revkey);
		parse_commit(commit);
		if (!commit->object.util)
			name_commit(commit, num_rev, 0);
		mark_seen(commit, &seen);

		/* rev#0 uses bit REV_SHIFT, rev#1 uses bit REV_SHIFT+1,
		 * and so on.  REV_SHIFT bits from bit 0 are used for
		 * internal bookkeeping.
		 */
		commit->object.flags |= 1u << (num_rev + REV_SHIFT);
		insert_by_date(commit, &list);
		rev[num_rev] = commit;
	}
	join_revs(&list, &seen, num_rev, extra);

	head_path_len = readlink(".git/HEAD", head_path, sizeof(head_path)-1);
	if ((head_path_len < 0) || get_sha1("HEAD", head_sha1))
		head_path[0] = 0;
	else
		head_path[head_path_len] = 0;

	if (merge_base)
		return show_merge_base(seen, num_rev);

	/* Show list */
	if (1 < num_rev) {
		for (i = 0; i < num_rev; i++) {
			int j;
			int is_head = rev_is_head(head_path,
						  head_path_len,
						  ref_name[i],
						  head_sha1,
						  rev[i]->object.sha1);
			for (j = 0; j < i; j++)
				putchar(' ');
			printf("%c [%s] ", is_head ? '*' : '!', ref_name[i]);
			show_one_commit(rev[i], NULL);
		}
		for (i = 0; i < num_rev; i++)
			putchar('-');
		putchar('\n');
	}

	label = ref_name;
	while (seen) {
		struct commit *commit = pop_one_commit(&seen);
		int this_flag = commit->object.flags;
		static char *obvious[] = { "" };

		if ((this_flag & UNINTERESTING) && (--extra < 0))
			break;
		if (1 < num_rev) {
			for (i = 0; i < num_rev; i++)
				putchar((this_flag & (1u << (i + REV_SHIFT)))
					? '+' : ' ');
			putchar(' ');
		}
		show_one_commit(commit, label);
		if (num_rev == 1)
			label = obvious;
	}
	return 0;
}
Commit	Line	Data
f76412ed JH	1	#include <stdlib.h>
	2	#include "cache.h"
	3	#include "commit.h"
	4	#include "refs.h"
	5
	6	static const char show_branch_usage[] =
	7	"git-show-branch [--all] [--heads] [--tags] [--more=count] [<refs>...]";
	8
	9	#define UNINTERESTING 01
	10
	11	#define REV_SHIFT 2
	12	#define MAX_REVS 29 /* should not exceed bits_per_int - REV_SHIFT */
	13
	14	static struct commit interesting(struct commit_list list)
	15	{
	16	while (list) {
	17	struct commit *commit = list->item;
	18	list = list->next;
	19	if (commit->object.flags & UNINTERESTING)
	20	continue;
	21	return commit;
	22	}
	23	return NULL;
	24	}
	25
	26	static struct commit pop_one_commit(struct commit_list *list_p)
	27	{
	28	struct commit *commit;
	29	struct commit_list *list;
	30	list = *list_p;
	31	commit = list->item;
	32	*list_p = list->next;
	33	free(list);
	34	return commit;
	35	}
	36
	37	struct commit_name {
	38	int head_rev; /* which head's ancestor? */
	39	int generation; /* how many parents away from head_rev */
	40	};
	41
	42	/* Name the commit as nth generation ancestor of head_rev;
	43	* we count only the first-parent relationship for naming purposes.
	44	*/
	45	static void name_commit(struct commit *commit, int head_rev, int nth)
	46	{
	47	struct commit_name *name;
	48	if (!commit->object.util)
	49	commit->object.util = xmalloc(sizeof(struct commit_name));
	50	name = commit->object.util;
	51	name->head_rev = head_rev;
	52	name->generation = nth;
	53	}
	54
	55	/* Parent is the first parent of the commit. We may name it
	56	* as (n+1)th generation ancestor of the same head_rev as
	57	* commit is nth generation ancestore of, if that generation
	58	* number is better than the name it already has.
	59	*/
	60	static void name_parent(struct commit commit, struct commit parent)
	61	{
	62	struct commit_name *commit_name = commit->object.util;
	63	struct commit_name *parent_name = parent->object.util;
	64	if (!commit_name)
65	return;
66	if (!parent_name \|\|
67	commit_name->generation + 1 < parent_name->generation)
68	name_commit(parent, commit_name->head_rev,
69	commit_name->generation + 1);
70	}
71
72	static int mark_seen(struct commit commit, struct commit_list *seen_p)
73	{
74	if (!commit->object.flags) {
75	insert_by_date(commit, seen_p);
76	return 1;
77	}
78	return 0;
79	}
80
81	static void join_revs(struct commit_list **list_p,
82	struct commit_list **seen_p,
83	int num_rev, int extra)
84	{
85	int all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
86	int all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
87
88	while (*list_p) {
89	struct commit_list *parents;
90	struct commit *commit = pop_one_commit(list_p);
91	int flags = commit->object.flags & all_mask;
92	int nth_parent = 0;
93	int still_interesting = !!interesting(*list_p);
94
95	if (!still_interesting && extra < 0)
96	break;
97
98	mark_seen(commit, seen_p);
99	if ((flags & all_revs) == all_revs)
100	flags \|= UNINTERESTING;
101	parents = commit->parents;
102
103	while (parents) {
104	struct commit *p = parents->item;
105	int this_flag = p->object.flags;
106	parents = parents->next;
107	nth_parent++;
108	if (nth_parent == 1)
109	name_parent(commit, p);
110
111	if ((this_flag & flags) == flags)
112	continue;
113	parse_commit(p);
114	if (mark_seen(p, seen_p) && !still_interesting)
115	extra--;
116	p->object.flags \|= flags;
117	insert_by_date(p, list_p);
118	}
119	}
120	}
121
122	static void show_one_commit(struct commit commit, char *head_name)
123	{
124	char pretty[128], *cp;
125	struct commit_name *name = commit->object.util;
126	pretty_print_commit(CMIT_FMT_ONELINE, commit->buffer, ~0,
127	pretty, sizeof(pretty));
128	if (!strncmp(pretty, "[PATCH] ", 8))
129	cp = pretty + 8;
130	else
131	cp = pretty;
132	if (name && head_name) {
133	printf("[%s", head_name[name->head_rev]);
134	if (name->generation)
135	printf("~%d", name->generation);
136	printf("] ");
137	}
138	puts(cp);
139	}
140
141	static char *ref_name[MAX_REVS + 1];
142	static int ref_name_cnt;
143
144	static int append_ref(const char refname, const unsigned char sha1)
145	{
146	struct commit *commit = lookup_commit_reference_gently(sha1, 1);
147	if (!commit)
148	return 0;
149	if (MAX_REVS < ref_name_cnt) {
150	fprintf(stderr, "warning: ignoring %s; "
151	"cannot handle more than %d refs",
152	refname, MAX_REVS);
153	return 0;
154	}
155	ref_name[ref_name_cnt++] = strdup(refname);
156	ref_name[ref_name_cnt] = NULL;
157	return 0;
158	}
159
160	static int append_head_ref(const char refname, const unsigned char sha1)
161	{
162	if (strncmp(refname, "refs/heads/", 11))
163	return 0;
164	return append_ref(refname + 5, sha1);
165	}
166
167	static int append_tag_ref(const char refname, const unsigned char sha1)
168	{
169	if (strncmp(refname, "refs/tags/", 10))
170	return 0;
171	return append_ref(refname + 5, sha1);
172	}
173
174	static void snarf_refs(int head, int tag)
175	{
176	if (head)
177	for_each_ref(append_head_ref);
178	if (tag)
179	for_each_ref(append_tag_ref);
180	}
181
182	static int rev_is_head(char *head_path, int headlen,
183	char *name,
184	unsigned char head_sha1, unsigned char sha1)
185	{
186	int namelen;
187	if ((!head_path[0]) \|\| memcmp(head_sha1, sha1, 20))
188	return 0;
189	namelen = strlen(name);
190	if ((headlen < namelen) \|\|
191	memcmp(head_path + headlen - namelen, name, namelen))
192	return 0;
193	if (headlen == namelen \|\|
194	head_path[headlen - namelen - 1] == '/')
195	return 1;
196	return 0;
197	}
198
199	static int show_merge_base(struct commit_list *seen, int num_rev)
200	{
201	int all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
202	int all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
203
204	while (seen) {
205	struct commit *commit = pop_one_commit(&seen);
206	int flags = commit->object.flags & all_mask;
207	if (!(flags & UNINTERESTING) &&
208	((flags & all_revs) == all_revs)) {
209	puts(sha1_to_hex(commit->object.sha1));
210	return 0;
211	}
212	}
213	return 1;
214	}
215
216	int main(int ac, char **av)
217	{
218	struct commit rev[MAX_REVS], commit;
219	struct commit_list list = NULL, seen = NULL;
220	int num_rev, i, extra = 0;
221	int all_heads = 0, all_tags = 0;
222	char head_path[128];
223	int head_path_len;
224	unsigned char head_sha1[20];
225	int merge_base = 0;
f5e375c9	226	char **label;
f76412ed JH	227
	228	while (1 < ac && av[1][0] == '-') {
	229	char *arg = av[1];
	230	if (!strcmp(arg, "--all"))
	231	all_heads = all_tags = 1;
	232	else if (!strcmp(arg, "--heads"))
	233	all_heads = 1;
	234	else if (!strcmp(arg, "--tags"))
	235	all_tags = 1;
	236	else if (!strcmp(arg, "--more"))
	237	extra = 1;
	238	else if (!strncmp(arg, "--more=", 7)) {
	239	extra = atoi(arg + 7);
	240	if (extra < 0)
	241	usage(show_branch_usage);
	242	}
	243	else if (!strcmp(arg, "--merge-base"))
	244	merge_base = 1;
	245	else
	246	usage(show_branch_usage);
	247	ac--; av++;
	248	}
	249	ac--; av++;
	250
	251	if (all_heads + all_tags)
	252	snarf_refs(all_heads, all_tags);
	253
	254	while (0 < ac) {
	255	unsigned char revkey[20];
	256	if (get_sha1(*av, revkey))
	257	die("bad sha1 reference %s", *av);
	258	append_ref(*av, revkey);
	259	ac--; av++;
	260	}
	261
	262	/* If still no revs, then add heads */
	263	if (!ref_name_cnt)
	264	snarf_refs(1, 0);
	265
	266	for (num_rev = 0; ref_name[num_rev]; num_rev++) {
	267	unsigned char revkey[20];
	268
	269	if (MAX_REVS <= num_rev)
	270	die("cannot handle more than %d revs.", MAX_REVS);
	271	if (get_sha1(ref_name[num_rev], revkey))
	272	usage(show_branch_usage);
	273	commit = lookup_commit_reference(revkey);
	274	if (!commit)
	275	die("cannot find commit %s (%s)",
	276	ref_name[num_rev], revkey);
	277	parse_commit(commit);
	278	if (!commit->object.util)
	279	name_commit(commit, num_rev, 0);
	280	mark_seen(commit, &seen);
	281
	282	/* rev#0 uses bit REV_SHIFT, rev#1 uses bit REV_SHIFT+1,
	283	* and so on. REV_SHIFT bits from bit 0 are used for
	284	* internal bookkeeping.
	285	*/
	286	commit->object.flags \|= 1u << (num_rev + REV_SHIFT);
	287	insert_by_date(commit, &list);
	288	rev[num_rev] = commit;
	289	}
	290	join_revs(&list, &seen, num_rev, extra);
291
292	head_path_len = readlink(".git/HEAD", head_path, sizeof(head_path)-1);
293	if ((head_path_len < 0) \|\| get_sha1("HEAD", head_sha1))
294	head_path[0] = 0;
295	else
296	head_path[head_path_len] = 0;
297
298	if (merge_base)
299	return show_merge_base(seen, num_rev);
300
f5e375c9 JH	301	/* Show list */
f5e375c9 JH	302	if (1 < num_rev) {
f76412ed JH	303	for (i = 0; i < num_rev; i++) {
	304	int j;
	305	int is_head = rev_is_head(head_path,
	306	head_path_len,
	307	ref_name[i],
	308	head_sha1,
	309	rev[i]->object.sha1);
	310	for (j = 0; j < i; j++)
	311	putchar(' ');
	312	printf("%c [%s] ", is_head ? '*' : '!', ref_name[i]);
	313	show_one_commit(rev[i], NULL);
	314	}
f5e375c9 JH	315	for (i = 0; i < num_rev; i++)
	316	putchar('-');
	317	putchar('\n');
	318	}
	319
	320	label = ref_name;
f76412ed JH	321	while (seen) {
	322	struct commit *commit = pop_one_commit(&seen);
	323	int this_flag = commit->object.flags;
f5e375c9 JH	324	static char *obvious[] = { "" };
f5e375c9 JH	325
f76412ed JH	326	if ((this_flag & UNINTERESTING) && (--extra < 0))
f76412ed JH	327	break;
f5e375c9 JH	328	if (1 < num_rev) {
	329	for (i = 0; i < num_rev; i++)
	330	putchar((this_flag & (1u << (i + REV_SHIFT)))
	331	? '+' : ' ');
	332	putchar(' ');
	333	}
	334	show_one_commit(commit, label);
	335	if (num_rev == 1)
	336	label = obvious;
f76412ed JH	337	}
	338	return 0;
	339	}