[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 compare_ref_name(const void *a_, const void *b_)
{
	const char * const*a = a_, * const*b = b_;
	return strcmp(*a, *b);
}

static void sort_ref_range(int bottom, int top)
{
	qsort(ref_name + bottom, top - bottom, sizeof(ref_name[0]),
	      compare_ref_name);
}

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 + 11, 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) {
		int orig_cnt = ref_name_cnt;
		for_each_ref(append_head_ref);
		sort_ref_range(orig_cnt, ref_name_cnt);
	}
	if (tag) {
		int orig_cnt = ref_name_cnt;
		for_each_ref(append_tag_ref);
		sort_ref_range(orig_cnt, ref_name_cnt);
	}
}

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
628894b2 JH	144	static int compare_ref_name(const void a_, const void b_)
	145	{
	146	const char * consta = a_, const*b = b_;
	147	return strcmp(a, b);
	148	}
	149
	150	static void sort_ref_range(int bottom, int top)
	151	{
	152	qsort(ref_name + bottom, top - bottom, sizeof(ref_name[0]),
	153	compare_ref_name);
	154	}
	155
f76412ed JH	156	static int append_ref(const char refname, const unsigned char sha1)
	157	{
	158	struct commit *commit = lookup_commit_reference_gently(sha1, 1);
	159	if (!commit)
	160	return 0;
	161	if (MAX_REVS < ref_name_cnt) {
	162	fprintf(stderr, "warning: ignoring %s; "
	163	"cannot handle more than %d refs",
	164	refname, MAX_REVS);
	165	return 0;
	166	}
	167	ref_name[ref_name_cnt++] = strdup(refname);
	168	ref_name[ref_name_cnt] = NULL;
	169	return 0;
	170	}
	171
	172	static int append_head_ref(const char refname, const unsigned char sha1)
	173	{
	174	if (strncmp(refname, "refs/heads/", 11))
	175	return 0;
628894b2	176	return append_ref(refname + 11, sha1);
f76412ed JH	177	}
	178
	179	static int append_tag_ref(const char refname, const unsigned char sha1)
	180	{
	181	if (strncmp(refname, "refs/tags/", 10))
	182	return 0;
	183	return append_ref(refname + 5, sha1);
	184	}
	185
	186	static void snarf_refs(int head, int tag)
	187	{
628894b2 JH	188	if (head) {
628894b2 JH	189	int orig_cnt = ref_name_cnt;
f76412ed	190	for_each_ref(append_head_ref);
628894b2 JH	191	sort_ref_range(orig_cnt, ref_name_cnt);
	192	}
	193	if (tag) {
	194	int orig_cnt = ref_name_cnt;
f76412ed	195	for_each_ref(append_tag_ref);
628894b2 JH	196	sort_ref_range(orig_cnt, ref_name_cnt);
628894b2 JH	197	}
f76412ed JH	198	}
	199
	200	static int rev_is_head(char *head_path, int headlen,
	201	char *name,
	202	unsigned char head_sha1, unsigned char sha1)
	203	{
	204	int namelen;
	205	if ((!head_path[0]) \|\| memcmp(head_sha1, sha1, 20))
	206	return 0;
	207	namelen = strlen(name);
	208	if ((headlen < namelen) \|\|
	209	memcmp(head_path + headlen - namelen, name, namelen))
	210	return 0;
	211	if (headlen == namelen \|\|
	212	head_path[headlen - namelen - 1] == '/')
	213	return 1;
	214	return 0;
	215	}
	216
	217	static int show_merge_base(struct commit_list *seen, int num_rev)
	218	{
	219	int all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
	220	int all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
	221
	222	while (seen) {
	223	struct commit *commit = pop_one_commit(&seen);
	224	int flags = commit->object.flags & all_mask;
	225	if (!(flags & UNINTERESTING) &&
	226	((flags & all_revs) == all_revs)) {
	227	puts(sha1_to_hex(commit->object.sha1));
	228	return 0;
	229	}
	230	}
	231	return 1;
	232	}
	233
	234	int main(int ac, char **av)
	235	{
	236	struct commit rev[MAX_REVS], commit;
	237	struct commit_list list = NULL, seen = NULL;
	238	int num_rev, i, extra = 0;
	239	int all_heads = 0, all_tags = 0;
	240	char head_path[128];
	241	int head_path_len;
	242	unsigned char head_sha1[20];
	243	int merge_base = 0;
f5e375c9	244	char **label;
f76412ed JH	245
	246	while (1 < ac && av[1][0] == '-') {
	247	char *arg = av[1];
	248	if (!strcmp(arg, "--all"))
	249	all_heads = all_tags = 1;
	250	else if (!strcmp(arg, "--heads"))
	251	all_heads = 1;
	252	else if (!strcmp(arg, "--tags"))
	253	all_tags = 1;
	254	else if (!strcmp(arg, "--more"))
	255	extra = 1;
	256	else if (!strncmp(arg, "--more=", 7)) {
	257	extra = atoi(arg + 7);
	258	if (extra < 0)
	259	usage(show_branch_usage);
	260	}
	261	else if (!strcmp(arg, "--merge-base"))
	262	merge_base = 1;
	263	else
	264	usage(show_branch_usage);
	265	ac--; av++;
	266	}
	267	ac--; av++;
	268
	269	if (all_heads + all_tags)
	270	snarf_refs(all_heads, all_tags);
	271
	272	while (0 < ac) {
	273	unsigned char revkey[20];
	274	if (get_sha1(*av, revkey))
	275	die("bad sha1 reference %s", *av);
	276	append_ref(*av, revkey);
	277	ac--; av++;
	278	}
	279
	280	/* If still no revs, then add heads */
	281	if (!ref_name_cnt)
	282	snarf_refs(1, 0);
	283
	284	for (num_rev = 0; ref_name[num_rev]; num_rev++) {
	285	unsigned char revkey[20];
	286
	287	if (MAX_REVS <= num_rev)
	288	die("cannot handle more than %d revs.", MAX_REVS);
	289	if (get_sha1(ref_name[num_rev], revkey))
	290	usage(show_branch_usage);
	291	commit = lookup_commit_reference(revkey);
	292	if (!commit)
	293	die("cannot find commit %s (%s)",
	294	ref_name[num_rev], revkey);
	295	parse_commit(commit);
	296	if (!commit->object.util)
	297	name_commit(commit, num_rev, 0);
	298	mark_seen(commit, &seen);
	299
	300	/* rev#0 uses bit REV_SHIFT, rev#1 uses bit REV_SHIFT+1,
	301	* and so on. REV_SHIFT bits from bit 0 are used for
	302	* internal bookkeeping.
	303	*/
	304	commit->object.flags \|= 1u << (num_rev + REV_SHIFT);
	305	insert_by_date(commit, &list);
	306	rev[num_rev] = commit;
	307	}
	308	join_revs(&list, &seen, num_rev, extra);
309
310	head_path_len = readlink(".git/HEAD", head_path, sizeof(head_path)-1);
311	if ((head_path_len < 0) \|\| get_sha1("HEAD", head_sha1))
312	head_path[0] = 0;
313	else
314	head_path[head_path_len] = 0;
315
316	if (merge_base)
317	return show_merge_base(seen, num_rev);
318
f5e375c9 JH	319	/* Show list */
f5e375c9 JH	320	if (1 < num_rev) {
f76412ed JH	321	for (i = 0; i < num_rev; i++) {
	322	int j;
	323	int is_head = rev_is_head(head_path,
	324	head_path_len,
	325	ref_name[i],
	326	head_sha1,
	327	rev[i]->object.sha1);
	328	for (j = 0; j < i; j++)
	329	putchar(' ');
	330	printf("%c [%s] ", is_head ? '*' : '!', ref_name[i]);
	331	show_one_commit(rev[i], NULL);
	332	}
f5e375c9 JH	333	for (i = 0; i < num_rev; i++)
	334	putchar('-');
	335	putchar('\n');
	336	}
	337
	338	label = ref_name;
f76412ed JH	339	while (seen) {
	340	struct commit *commit = pop_one_commit(&seen);
	341	int this_flag = commit->object.flags;
f5e375c9 JH	342	static char *obvious[] = { "" };
f5e375c9 JH	343
f76412ed JH	344	if ((this_flag & UNINTERESTING) && (--extra < 0))
f76412ed JH	345	break;
f5e375c9 JH	346	if (1 < num_rev) {
	347	for (i = 0; i < num_rev; i++)
	348	putchar((this_flag & (1u << (i + REV_SHIFT)))
	349	? '+' : ' ');
	350	putchar(' ');
	351	}
	352	show_one_commit(commit, label);
	353	if (num_rev == 1)
	354	label = obvious;
f76412ed JH	355	}
	356	return 0;
	357	}