[thirdparty/git.git] / commit.c

#include "cache.h"
#include "tag.h"
#include "commit.h"
#include "pkt-line.h"
#include "utf8.h"
#include "diff.h"
#include "revision.h"

int save_commit_buffer = 1;

const char *commit_type = "commit";

static struct commit *check_commit(struct object *obj,
				   const unsigned char *sha1,
				   int quiet)
{
	if (obj->type != OBJ_COMMIT) {
		if (!quiet)
			error("Object %s is a %s, not a commit",
			      sha1_to_hex(sha1), typename(obj->type));
		return NULL;
	}
	return (struct commit *) obj;
}

struct commit *lookup_commit_reference_gently(const unsigned char *sha1,
					      int quiet)
{
	struct object *obj = deref_tag(parse_object(sha1), NULL, 0);

	if (!obj)
		return NULL;
	return check_commit(obj, sha1, quiet);
}

struct commit *lookup_commit_reference(const unsigned char *sha1)
{
	return lookup_commit_reference_gently(sha1, 0);
}

struct commit *lookup_commit(const unsigned char *sha1)
{
	struct object *obj = lookup_object(sha1);
	if (!obj)
		return create_object(sha1, OBJ_COMMIT, alloc_commit_node());
	if (!obj->type)
		obj->type = OBJ_COMMIT;
	return check_commit(obj, sha1, 0);
}

static unsigned long parse_commit_date(const char *buf, const char *tail)
{
	unsigned long date;
	const char *dateptr;

	if (buf + 6 >= tail)
		return 0;
	if (memcmp(buf, "author", 6))
		return 0;
	while (buf < tail && *buf++ != '\n')
		/* nada */;
	if (buf + 9 >= tail)
		return 0;
	if (memcmp(buf, "committer", 9))
		return 0;
	while (buf < tail && *buf++ != '>')
		/* nada */;
	if (buf >= tail)
		return 0;
	dateptr = buf;
	while (buf < tail && *buf++ != '\n')
		/* nada */;
	if (buf >= tail)
		return 0;
	/* dateptr < buf && buf[-1] == '\n', so strtoul will stop at buf-1 */
	date = strtoul(dateptr, NULL, 10);
	if (date == ULONG_MAX)
		date = 0;
	return date;
}

static struct commit_graft **commit_graft;
static int commit_graft_alloc, commit_graft_nr;

static int commit_graft_pos(const unsigned char *sha1)
{
	int lo, hi;
	lo = 0;
	hi = commit_graft_nr;
	while (lo < hi) {
		int mi = (lo + hi) / 2;
		struct commit_graft *graft = commit_graft[mi];
		int cmp = hashcmp(sha1, graft->sha1);
		if (!cmp)
			return mi;
		if (cmp < 0)
			hi = mi;
		else
			lo = mi + 1;
	}
	return -lo - 1;
}

int register_commit_graft(struct commit_graft *graft, int ignore_dups)
{
	int pos = commit_graft_pos(graft->sha1);

	if (0 <= pos) {
		if (ignore_dups)
			free(graft);
		else {
			free(commit_graft[pos]);
			commit_graft[pos] = graft;
		}
		return 1;
	}
	pos = -pos - 1;
	if (commit_graft_alloc <= ++commit_graft_nr) {
		commit_graft_alloc = alloc_nr(commit_graft_alloc);
		commit_graft = xrealloc(commit_graft,
					sizeof(*commit_graft) *
					commit_graft_alloc);
	}
	if (pos < commit_graft_nr)
		memmove(commit_graft + pos + 1,
			commit_graft + pos,
			(commit_graft_nr - pos - 1) *
			sizeof(*commit_graft));
	commit_graft[pos] = graft;
	return 0;
}

struct commit_graft *read_graft_line(char *buf, int len)
{
	/* The format is just "Commit Parent1 Parent2 ...\n" */
	int i;
	struct commit_graft *graft = NULL;

	if (buf[len-1] == '\n')
		buf[--len] = 0;
	if (buf[0] == '#' || buf[0] == '\0')
		return NULL;
	if ((len + 1) % 41) {
	bad_graft_data:
		error("bad graft data: %s", buf);
		free(graft);
		return NULL;
	}
	i = (len + 1) / 41 - 1;
	graft = xmalloc(sizeof(*graft) + 20 * i);
	graft->nr_parent = i;
	if (get_sha1_hex(buf, graft->sha1))
		goto bad_graft_data;
	for (i = 40; i < len; i += 41) {
		if (buf[i] != ' ')
			goto bad_graft_data;
		if (get_sha1_hex(buf + i + 1, graft->parent[i/41]))
			goto bad_graft_data;
	}
	return graft;
}

int read_graft_file(const char *graft_file)
{
	FILE *fp = fopen(graft_file, "r");
	char buf[1024];
	if (!fp)
		return -1;
	while (fgets(buf, sizeof(buf), fp)) {
		/* The format is just "Commit Parent1 Parent2 ...\n" */
		int len = strlen(buf);
		struct commit_graft *graft = read_graft_line(buf, len);
		if (!graft)
			continue;
		if (register_commit_graft(graft, 1))
			error("duplicate graft data: %s", buf);
	}
	fclose(fp);
	return 0;
}

static void prepare_commit_graft(void)
{
	static int commit_graft_prepared;
	char *graft_file;

	if (commit_graft_prepared)
		return;
	graft_file = get_graft_file();
	read_graft_file(graft_file);
	/* make sure shallows are read */
	is_repository_shallow();
	commit_graft_prepared = 1;
}

struct commit_graft *lookup_commit_graft(const unsigned char *sha1)
{
	int pos;
	prepare_commit_graft();
	pos = commit_graft_pos(sha1);
	if (pos < 0)
		return NULL;
	return commit_graft[pos];
}

int write_shallow_commits(int fd, int use_pack_protocol)
{
	int i, count = 0;
	for (i = 0; i < commit_graft_nr; i++)
		if (commit_graft[i]->nr_parent < 0) {
			const char *hex =
				sha1_to_hex(commit_graft[i]->sha1);
			count++;
			if (use_pack_protocol)
				packet_write(fd, "shallow %s", hex);
			else {
				if (write_in_full(fd, hex,  40) != 40)
					break;
				if (write_in_full(fd, "\n", 1) != 1)
					break;
			}
		}
	return count;
}

int unregister_shallow(const unsigned char *sha1)
{
	int pos = commit_graft_pos(sha1);
	if (pos < 0)
		return -1;
	if (pos + 1 < commit_graft_nr)
		memcpy(commit_graft + pos, commit_graft + pos + 1,
				sizeof(struct commit_graft *)
				* (commit_graft_nr - pos - 1));
	commit_graft_nr--;
	return 0;
}

int parse_commit_buffer(struct commit *item, void *buffer, unsigned long size)
{
	char *tail = buffer;
	char *bufptr = buffer;
	unsigned char parent[20];
	struct commit_list **pptr;
	struct commit_graft *graft;
	unsigned n_refs = 0;

	if (item->object.parsed)
		return 0;
	item->object.parsed = 1;
	tail += size;
	if (tail <= bufptr + 46 || memcmp(bufptr, "tree ", 5) || bufptr[45] != '\n')
		return error("bogus commit object %s", sha1_to_hex(item->object.sha1));
	if (get_sha1_hex(bufptr + 5, parent) < 0)
		return error("bad tree pointer in commit %s",
			     sha1_to_hex(item->object.sha1));
	item->tree = lookup_tree(parent);
	if (item->tree)
		n_refs++;
	bufptr += 46; /* "tree " + "hex sha1" + "\n" */
	pptr = &item->parents;

	graft = lookup_commit_graft(item->object.sha1);
	while (bufptr + 48 < tail && !memcmp(bufptr, "parent ", 7)) {
		struct commit *new_parent;

		if (tail <= bufptr + 48 ||
		    get_sha1_hex(bufptr + 7, parent) ||
		    bufptr[47] != '\n')
			return error("bad parents in commit %s", sha1_to_hex(item->object.sha1));
		bufptr += 48;
		if (graft)
			continue;
		new_parent = lookup_commit(parent);
		if (new_parent) {
			pptr = &commit_list_insert(new_parent, pptr)->next;
			n_refs++;
		}
	}
	if (graft) {
		int i;
		struct commit *new_parent;
		for (i = 0; i < graft->nr_parent; i++) {
			new_parent = lookup_commit(graft->parent[i]);
			if (!new_parent)
				continue;
			pptr = &commit_list_insert(new_parent, pptr)->next;
			n_refs++;
		}
	}
	item->date = parse_commit_date(bufptr, tail);

	return 0;
}

int parse_commit(struct commit *item)
{
	enum object_type type;
	void *buffer;
	unsigned long size;
	int ret;

	if (!item)
		return -1;
	if (item->object.parsed)
		return 0;
	buffer = read_sha1_file(item->object.sha1, &type, &size);
	if (!buffer)
		return error("Could not read %s",
			     sha1_to_hex(item->object.sha1));
	if (type != OBJ_COMMIT) {
		free(buffer);
		return error("Object %s not a commit",
			     sha1_to_hex(item->object.sha1));
	}
	ret = parse_commit_buffer(item, buffer, size);
	if (save_commit_buffer && !ret) {
		item->buffer = buffer;
		return 0;
	}
	free(buffer);
	return ret;
}

struct commit_list *commit_list_insert(struct commit *item, struct commit_list **list_p)
{
	struct commit_list *new_list = xmalloc(sizeof(struct commit_list));
	new_list->item = item;
	new_list->next = *list_p;
	*list_p = new_list;
	return new_list;
}

void free_commit_list(struct commit_list *list)
{
	while (list) {
		struct commit_list *temp = list;
		list = temp->next;
		free(temp);
	}
}

struct commit_list * insert_by_date(struct commit *item, struct commit_list **list)
{
	struct commit_list **pp = list;
	struct commit_list *p;
	while ((p = *pp) != NULL) {
		if (p->item->date < item->date) {
			break;
		}
		pp = &p->next;
	}
	return commit_list_insert(item, pp);
}


void sort_by_date(struct commit_list **list)
{
	struct commit_list *ret = NULL;
	while (*list) {
		insert_by_date((*list)->item, &ret);
		*list = (*list)->next;
	}
	*list = ret;
}

struct commit *pop_most_recent_commit(struct commit_list **list,
				      unsigned int mark)
{
	struct commit *ret = (*list)->item;
	struct commit_list *parents = ret->parents;
	struct commit_list *old = *list;

	*list = (*list)->next;
	free(old);

	while (parents) {
		struct commit *commit = parents->item;
		if (!parse_commit(commit) && !(commit->object.flags & mark)) {
			commit->object.flags |= mark;
			insert_by_date(commit, list);
		}
		parents = parents->next;
	}
	return ret;
}

void clear_commit_marks(struct commit *commit, unsigned int mark)
{
	while (commit) {
		struct commit_list *parents;

		if (!(mark & commit->object.flags))
			return;

		commit->object.flags &= ~mark;

		parents = commit->parents;
		if (!parents)
			return;

		while ((parents = parents->next))
			clear_commit_marks(parents->item, mark);

		commit = commit->parents->item;
	}
}

struct commit *pop_commit(struct commit_list **stack)
{
	struct commit_list *top = *stack;
	struct commit *item = top ? top->item : NULL;

	if (top) {
		*stack = top->next;
		free(top);
	}
	return item;
}

/*
 * Performs an in-place topological sort on the list supplied.
 */
void sort_in_topological_order(struct commit_list ** list, int lifo)
{
	struct commit_list *next, *orig = *list;
	struct commit_list *work, **insert;
	struct commit_list **pptr;

	if (!orig)
		return;
	*list = NULL;

	/* Mark them and clear the indegree */
	for (next = orig; next; next = next->next) {
		struct commit *commit = next->item;
		commit->object.flags |= TOPOSORT;
		commit->indegree = 0;
	}

	/* update the indegree */
	for (next = orig; next; next = next->next) {
		struct commit_list * parents = next->item->parents;
		while (parents) {
			struct commit *parent = parents->item;

			if (parent->object.flags & TOPOSORT)
				parent->indegree++;
			parents = parents->next;
		}
	}

	/*
	 * find the tips
	 *
	 * tips are nodes not reachable from any other node in the list
	 *
	 * the tips serve as a starting set for the work queue.
	 */
	work = NULL;
	insert = &work;
	for (next = orig; next; next = next->next) {
		struct commit *commit = next->item;

		if (!commit->indegree)
			insert = &commit_list_insert(commit, insert)->next;
	}

	/* process the list in topological order */
	if (!lifo)
		sort_by_date(&work);

	pptr = list;
	*list = NULL;
	while (work) {
		struct commit *commit;
		struct commit_list *parents, *work_item;

		work_item = work;
		work = work_item->next;
		work_item->next = NULL;

		commit = work_item->item;
		for (parents = commit->parents; parents ; parents = parents->next) {
			struct commit *parent=parents->item;

			if (!(parent->object.flags & TOPOSORT))
				continue;

			/*
			 * parents are only enqueued for emission
			 * when all their children have been emitted thereby
			 * guaranteeing topological order.
			 */
			if (!--parent->indegree) {
				if (!lifo)
					insert_by_date(parent, &work);
				else
					commit_list_insert(parent, &work);
			}
		}
		/*
		 * work_item is a commit all of whose children
		 * have already been emitted. we can emit it now.
		 */
		commit->object.flags &= ~TOPOSORT;
		*pptr = work_item;
		pptr = &work_item->next;
	}
}

/* merge-base stuff */

/* bits #0..15 in revision.h */
#define PARENT1		(1u<<16)
#define PARENT2		(1u<<17)
#define STALE		(1u<<18)
#define RESULT		(1u<<19)

static const unsigned all_flags = (PARENT1 | PARENT2 | STALE | RESULT);

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

static struct commit_list *merge_bases(struct commit *one, struct commit *two)
{
	struct commit_list *list = NULL;
	struct commit_list *result = NULL;

	if (one == two)
		/* We do not mark this even with RESULT so we do not
		 * have to clean it up.
		 */
		return commit_list_insert(one, &result);

	if (parse_commit(one))
		return NULL;
	if (parse_commit(two))
		return NULL;

	one->object.flags |= PARENT1;
	two->object.flags |= PARENT2;
	insert_by_date(one, &list);
	insert_by_date(two, &list);

	while (interesting(list)) {
		struct commit *commit;
		struct commit_list *parents;
		struct commit_list *n;
		int flags;

		commit = list->item;
		n = list->next;
		free(list);
		list = n;

		flags = commit->object.flags & (PARENT1 | PARENT2 | STALE);
		if (flags == (PARENT1 | PARENT2)) {
			if (!(commit->object.flags & RESULT)) {
				commit->object.flags |= RESULT;
				insert_by_date(commit, &result);
			}
			/* Mark parents of a found merge stale */
			flags |= STALE;
		}
		parents = commit->parents;
		while (parents) {
			struct commit *p = parents->item;
			parents = parents->next;
			if ((p->object.flags & flags) == flags)
				continue;
			if (parse_commit(p))
				return NULL;
			p->object.flags |= flags;
			insert_by_date(p, &list);
		}
	}

	/* Clean up the result to remove stale ones */
	free_commit_list(list);
	list = result; result = NULL;
	while (list) {
		struct commit_list *n = list->next;
		if (!(list->item->object.flags & STALE))
			insert_by_date(list->item, &result);
		free(list);
		list = n;
	}
	return result;
}

struct commit_list *get_merge_bases(struct commit *one,
					struct commit *two, int cleanup)
{
	struct commit_list *list;
	struct commit **rslt;
	struct commit_list *result;
	int cnt, i, j;

	result = merge_bases(one, two);
	if (one == two)
		return result;
	if (!result || !result->next) {
		if (cleanup) {
			clear_commit_marks(one, all_flags);
			clear_commit_marks(two, all_flags);
		}
		return result;
	}

	/* There are more than one */
	cnt = 0;
	list = result;
	while (list) {
		list = list->next;
		cnt++;
	}
	rslt = xcalloc(cnt, sizeof(*rslt));
	for (list = result, i = 0; list; list = list->next)
		rslt[i++] = list->item;
	free_commit_list(result);

	clear_commit_marks(one, all_flags);
	clear_commit_marks(two, all_flags);
	for (i = 0; i < cnt - 1; i++) {
		for (j = i+1; j < cnt; j++) {
			if (!rslt[i] || !rslt[j])
				continue;
			result = merge_bases(rslt[i], rslt[j]);
			clear_commit_marks(rslt[i], all_flags);
			clear_commit_marks(rslt[j], all_flags);
			for (list = result; list; list = list->next) {
				if (rslt[i] == list->item)
					rslt[i] = NULL;
				if (rslt[j] == list->item)
					rslt[j] = NULL;
			}
		}
	}

	/* Surviving ones in rslt[] are the independent results */
	result = NULL;
	for (i = 0; i < cnt; i++) {
		if (rslt[i])
			insert_by_date(rslt[i], &result);
	}
	free(rslt);
	return result;
}

int in_merge_bases(struct commit *commit, struct commit **reference, int num)
{
	struct commit_list *bases, *b;
	int ret = 0;

	if (num == 1)
		bases = get_merge_bases(commit, *reference, 1);
	else
		die("not yet");
	for (b = bases; b; b = b->next) {
		if (!hashcmp(commit->object.sha1, b->item->object.sha1)) {
			ret = 1;
			break;
		}
	}

	free_commit_list(bases);
	return ret;
}
Commit	Line	Data
8f1d2e6f	1	#include "cache.h"
961784ee	2	#include "tag.h"
175785e5	3	#include "commit.h"
ed09aef0	4	#include "pkt-line.h"
52883fbd	5	#include "utf8.h"
199c45bf JH	6	#include "diff.h"
199c45bf JH	7	#include "revision.h"
175785e5	8
60ab26de LT	9	int save_commit_buffer = 1;
60ab26de LT	10
175785e5 DB	11	const char *commit_type = "commit";
175785e5 DB	12
f76412ed JH	13	static struct commit check_commit(struct object obj,
	14	const unsigned char *sha1,
	15	int quiet)
961784ee	16	{
1974632c	17	if (obj->type != OBJ_COMMIT) {
f76412ed JH	18	if (!quiet)
f76412ed JH	19	error("Object %s is a %s, not a commit",
885a86ab	20	sha1_to_hex(sha1), typename(obj->type));
961784ee LT	21	return NULL;
	22	}
	23	return (struct commit *) obj;
	24	}
	25
f76412ed JH	26	struct commit lookup_commit_reference_gently(const unsigned char sha1,
f76412ed JH	27	int quiet)
961784ee	28	{
9534f40b	29	struct object *obj = deref_tag(parse_object(sha1), NULL, 0);
961784ee LT	30
	31	if (!obj)
	32	return NULL;
f76412ed JH	33	return check_commit(obj, sha1, quiet);
	34	}
	35
	36	struct commit lookup_commit_reference(const unsigned char sha1)
	37	{
	38	return lookup_commit_reference_gently(sha1, 0);
961784ee LT	39	}
961784ee LT	40
5d6ccf5c	41	struct commit lookup_commit(const unsigned char sha1)
175785e5 DB	42	{
175785e5 DB	43	struct object *obj = lookup_object(sha1);
100c5f3b LT	44	if (!obj)
100c5f3b LT	45	return create_object(sha1, OBJ_COMMIT, alloc_commit_node());
d1af002d	46	if (!obj->type)
1974632c	47	obj->type = OBJ_COMMIT;
f76412ed	48	return check_commit(obj, sha1, 0);
175785e5 DB	49	}
175785e5 DB	50
0a617799	51	static unsigned long parse_commit_date(const char buf, const char tail)
175785e5 DB	52	{
175785e5 DB	53	unsigned long date;
0a617799	54	const char *dateptr;
175785e5	55
0a617799 MK	56	if (buf + 6 >= tail)
0a617799 MK	57	return 0;
175785e5 DB	58	if (memcmp(buf, "author", 6))
175785e5 DB	59	return 0;
0a617799	60	while (buf < tail && *buf++ != '\n')
175785e5	61	/* nada */;
0a617799 MK	62	if (buf + 9 >= tail)
0a617799 MK	63	return 0;
175785e5 DB	64	if (memcmp(buf, "committer", 9))
175785e5 DB	65	return 0;
0a617799	66	while (buf < tail && *buf++ != '>')
175785e5	67	/* nada */;
0a617799 MK	68	if (buf >= tail)
	69	return 0;
	70	dateptr = buf;
	71	while (buf < tail && *buf++ != '\n')
	72	/* nada */;
	73	if (buf >= tail)
	74	return 0;
	75	/* dateptr < buf && buf[-1] == '\n', so strtoul will stop at buf-1 */
	76	date = strtoul(dateptr, NULL, 10);
175785e5 DB	77	if (date == ULONG_MAX)
	78	date = 0;
	79	return date;
	80	}
	81
5040f17e	82	static struct commit_graft **commit_graft;
5da5c8f4 JH	83	static int commit_graft_alloc, commit_graft_nr;
	84
	85	static int commit_graft_pos(const unsigned char *sha1)
	86	{
	87	int lo, hi;
	88	lo = 0;
	89	hi = commit_graft_nr;
	90	while (lo < hi) {
	91	int mi = (lo + hi) / 2;
	92	struct commit_graft *graft = commit_graft[mi];
a89fccd2	93	int cmp = hashcmp(sha1, graft->sha1);
5da5c8f4 JH	94	if (!cmp)
	95	return mi;
	96	if (cmp < 0)
	97	hi = mi;
	98	else
	99	lo = mi + 1;
	100	}
	101	return -lo - 1;
	102	}
	103
5040f17e JH	104	int register_commit_graft(struct commit_graft *graft, int ignore_dups)
	105	{
	106	int pos = commit_graft_pos(graft->sha1);
a6080a0a	107
5040f17e JH	108	if (0 <= pos) {
	109	if (ignore_dups)
	110	free(graft);
	111	else {
	112	free(commit_graft[pos]);
	113	commit_graft[pos] = graft;
	114	}
	115	return 1;
	116	}
	117	pos = -pos - 1;
	118	if (commit_graft_alloc <= ++commit_graft_nr) {
	119	commit_graft_alloc = alloc_nr(commit_graft_alloc);
	120	commit_graft = xrealloc(commit_graft,
	121	sizeof(commit_graft)
	122	commit_graft_alloc);
	123	}
	124	if (pos < commit_graft_nr)
	125	memmove(commit_graft + pos + 1,
	126	commit_graft + pos,
	127	(commit_graft_nr - pos - 1) *
	128	sizeof(*commit_graft));
	129	commit_graft[pos] = graft;
	130	return 0;
	131	}
	132
	133	struct commit_graft read_graft_line(char buf, int len)
	134	{
	135	/* The format is just "Commit Parent1 Parent2 ...\n" */
	136	int i;
	137	struct commit_graft *graft = NULL;
	138
	139	if (buf[len-1] == '\n')
	140	buf[--len] = 0;
360204c3	141	if (buf[0] == '#' \|\| buf[0] == '\0')
5bc4ce58	142	return NULL;
5040f17e JH	143	if ((len + 1) % 41) {
	144	bad_graft_data:
	145	error("bad graft data: %s", buf);
	146	free(graft);
	147	return NULL;
	148	}
	149	i = (len + 1) / 41 - 1;
	150	graft = xmalloc(sizeof(graft) + 20 i);
	151	graft->nr_parent = i;
	152	if (get_sha1_hex(buf, graft->sha1))
	153	goto bad_graft_data;
	154	for (i = 40; i < len; i += 41) {
	155	if (buf[i] != ' ')
	156	goto bad_graft_data;
	157	if (get_sha1_hex(buf + i + 1, graft->parent[i/41]))
	158	goto bad_graft_data;
	159	}
	160	return graft;
	161	}
	162
	163	int read_graft_file(const char *graft_file)
5da5c8f4	164	{
5da5c8f4 JH	165	FILE *fp = fopen(graft_file, "r");
5da5c8f4 JH	166	char buf[1024];
5040f17e JH	167	if (!fp)
5040f17e JH	168	return -1;
5da5c8f4 JH	169	while (fgets(buf, sizeof(buf), fp)) {
	170	/* The format is just "Commit Parent1 Parent2 ...\n" */
	171	int len = strlen(buf);
5040f17e	172	struct commit_graft *graft = read_graft_line(buf, len);
5bc4ce58 JH	173	if (!graft)
5bc4ce58 JH	174	continue;
5040f17e	175	if (register_commit_graft(graft, 1))
5da5c8f4	176	error("duplicate graft data: %s", buf);
5da5c8f4 JH	177	}
5da5c8f4 JH	178	fclose(fp);
5040f17e JH	179	return 0;
	180	}
	181
	182	static void prepare_commit_graft(void)
	183	{
	184	static int commit_graft_prepared;
	185	char *graft_file;
	186
	187	if (commit_graft_prepared)
	188	return;
	189	graft_file = get_graft_file();
	190	read_graft_file(graft_file);
ed09aef0 JS	191	/* make sure shallows are read */
ed09aef0 JS	192	is_repository_shallow();
5040f17e	193	commit_graft_prepared = 1;
5da5c8f4 JH	194	}
5da5c8f4 JH	195
45163382	196	struct commit_graft lookup_commit_graft(const unsigned char sha1)
5da5c8f4 JH	197	{
5da5c8f4 JH	198	int pos;
5040f17e	199	prepare_commit_graft();
5da5c8f4 JH	200	pos = commit_graft_pos(sha1);
	201	if (pos < 0)
	202	return NULL;
	203	return commit_graft[pos];
	204	}
	205
ed09aef0 JS	206	int write_shallow_commits(int fd, int use_pack_protocol)
	207	{
	208	int i, count = 0;
	209	for (i = 0; i < commit_graft_nr; i++)
	210	if (commit_graft[i]->nr_parent < 0) {
	211	const char *hex =
	212	sha1_to_hex(commit_graft[i]->sha1);
	213	count++;
	214	if (use_pack_protocol)
	215	packet_write(fd, "shallow %s", hex);
	216	else {
93822c22 AW	217	if (write_in_full(fd, hex, 40) != 40)
	218	break;
	219	if (write_in_full(fd, "\n", 1) != 1)
	220	break;
ed09aef0 JS	221	}
	222	}
	223	return count;
	224	}
	225
f53514bc JS	226	int unregister_shallow(const unsigned char *sha1)
	227	{
	228	int pos = commit_graft_pos(sha1);
	229	if (pos < 0)
	230	return -1;
	231	if (pos + 1 < commit_graft_nr)
	232	memcpy(commit_graft + pos, commit_graft + pos + 1,
	233	sizeof(struct commit_graft *)
	234	* (commit_graft_nr - pos - 1));
	235	commit_graft_nr--;
	236	return 0;
	237	}
	238
bd2c39f5	239	int parse_commit_buffer(struct commit item, void buffer, unsigned long size)
175785e5	240	{
3b44f15a	241	char *tail = buffer;
f7cc77d7	242	char *bufptr = buffer;
175785e5	243	unsigned char parent[20];
6c88be16	244	struct commit_list **pptr;
5da5c8f4	245	struct commit_graft *graft;
27dedf0c	246	unsigned n_refs = 0;
bd2c39f5	247
175785e5 DB	248	if (item->object.parsed)
	249	return 0;
	250	item->object.parsed = 1;
3b44f15a	251	tail += size;
0a617799	252	if (tail <= bufptr + 46 \|\| memcmp(bufptr, "tree ", 5) \|\| bufptr[45] != '\n')
f7cc77d7	253	return error("bogus commit object %s", sha1_to_hex(item->object.sha1));
0a617799	254	if (get_sha1_hex(bufptr + 5, parent) < 0)
bd2afde8 JH	255	return error("bad tree pointer in commit %s",
bd2afde8 JH	256	sha1_to_hex(item->object.sha1));
175785e5	257	item->tree = lookup_tree(parent);
235ac407	258	if (item->tree)
27dedf0c	259	n_refs++;
175785e5	260	bufptr += 46; /* "tree " + "hex sha1" + "\n" */
6c88be16	261	pptr = &item->parents;
5da5c8f4 JH	262
5da5c8f4 JH	263	graft = lookup_commit_graft(item->object.sha1);
3b44f15a	264	while (bufptr + 48 < tail && !memcmp(bufptr, "parent ", 7)) {
f7cc77d7 LT	265	struct commit *new_parent;
f7cc77d7 LT	266
3b44f15a JH	267	if (tail <= bufptr + 48 \|\|
	268	get_sha1_hex(bufptr + 7, parent) \|\|
	269	bufptr[47] != '\n')
f7cc77d7	270	return error("bad parents in commit %s", sha1_to_hex(item->object.sha1));
5da5c8f4 JH	271	bufptr += 48;
	272	if (graft)
	273	continue;
f7cc77d7	274	new_parent = lookup_commit(parent);
235ac407	275	if (new_parent) {
6c88be16	276	pptr = &commit_list_insert(new_parent, pptr)->next;
27dedf0c	277	n_refs++;
235ac407	278	}
5da5c8f4 JH	279	}
	280	if (graft) {
	281	int i;
	282	struct commit *new_parent;
	283	for (i = 0; i < graft->nr_parent; i++) {
	284	new_parent = lookup_commit(graft->parent[i]);
	285	if (!new_parent)
	286	continue;
	287	pptr = &commit_list_insert(new_parent, pptr)->next;
27dedf0c	288	n_refs++;
5da5c8f4	289	}
175785e5	290	}
0a617799	291	item->date = parse_commit_date(bufptr, tail);
27dedf0c	292
175785e5 DB	293	return 0;
	294	}
	295
bd2c39f5 NP	296	int parse_commit(struct commit *item)
bd2c39f5 NP	297	{
21666f1a	298	enum object_type type;
bd2c39f5 NP	299	void *buffer;
	300	unsigned long size;
	301	int ret;
	302
9786f68b MK	303	if (!item)
9786f68b MK	304	return -1;
bd2c39f5 NP	305	if (item->object.parsed)
bd2c39f5 NP	306	return 0;
21666f1a	307	buffer = read_sha1_file(item->object.sha1, &type, &size);
bd2c39f5 NP	308	if (!buffer)
	309	return error("Could not read %s",
	310	sha1_to_hex(item->object.sha1));
21666f1a	311	if (type != OBJ_COMMIT) {
bd2c39f5 NP	312	free(buffer);
	313	return error("Object %s not a commit",
	314	sha1_to_hex(item->object.sha1));
	315	}
	316	ret = parse_commit_buffer(item, buffer, size);
60ab26de	317	if (save_commit_buffer && !ret) {
3ff1fbbb LT	318	item->buffer = buffer;
	319	return 0;
	320	}
bd2c39f5 NP	321	free(buffer);
	322	return ret;
	323	}
	324
ac5155ef	325	struct commit_list commit_list_insert(struct commit item, struct commit_list **list_p)
dd97f850	326	{
812666c8	327	struct commit_list *new_list = xmalloc(sizeof(struct commit_list));
dd97f850 DB	328	new_list->item = item;
	329	new_list->next = *list_p;
	330	*list_p = new_list;
ac5155ef	331	return new_list;
dd97f850 DB	332	}
dd97f850 DB	333
175785e5 DB	334	void free_commit_list(struct commit_list *list)
	335	{
	336	while (list) {
	337	struct commit_list *temp = list;
	338	list = temp->next;
	339	free(temp);
	340	}
	341	}
dd97f850	342
f755494c	343	struct commit_list * insert_by_date(struct commit item, struct commit_list *list)
dd97f850 DB	344	{
	345	struct commit_list **pp = list;
	346	struct commit_list *p;
	347	while ((p = *pp) != NULL) {
	348	if (p->item->date < item->date) {
	349	break;
	350	}
	351	pp = &p->next;
	352	}
f755494c	353	return commit_list_insert(item, pp);
dd97f850 DB	354	}
dd97f850 DB	355
a6080a0a	356
dd97f850 DB	357	void sort_by_date(struct commit_list **list)
	358	{
	359	struct commit_list *ret = NULL;
	360	while (*list) {
f755494c	361	insert_by_date((*list)->item, &ret);
dd97f850 DB	362	list = (list)->next;
	363	}
	364	*list = ret;
	365	}
	366
58e28af6 DB	367	struct commit pop_most_recent_commit(struct commit_list *list,
58e28af6 DB	368	unsigned int mark)
dd97f850 DB	369	{
	370	struct commit ret = (list)->item;
	371	struct commit_list *parents = ret->parents;
	372	struct commit_list old = list;
	373
	374	list = (list)->next;
	375	free(old);
	376
	377	while (parents) {
4056c091	378	struct commit *commit = parents->item;
dec38c81	379	if (!parse_commit(commit) && !(commit->object.flags & mark)) {
58e28af6	380	commit->object.flags \|= mark;
f755494c	381	insert_by_date(commit, list);
4056c091	382	}
dd97f850 DB	383	parents = parents->next;
	384	}
	385	return ret;
	386	}
e3bc7a3b	387
f8f9c73c JH	388	void clear_commit_marks(struct commit *commit, unsigned int mark)
f8f9c73c JH	389	{
60fcc2e6 JS	390	while (commit) {
60fcc2e6 JS	391	struct commit_list *parents;
f8f9c73c	392
60fcc2e6 JS	393	if (!(mark & commit->object.flags))
60fcc2e6 JS	394	return;
58ecf5c1	395
60fcc2e6 JS	396	commit->object.flags &= ~mark;
	397
	398	parents = commit->parents;
	399	if (!parents)
	400	return;
	401
	402	while ((parents = parents->next))
	403	clear_commit_marks(parents->item, mark);
	404
	405	commit = commit->parents->item;
f8f9c73c JH	406	}
	407	}
	408
a3437b8c JS	409	struct commit pop_commit(struct commit_list *stack)
	410	{
	411	struct commit_list top = stack;
	412	struct commit *item = top ? top->item : NULL;
	413
	414	if (top) {
	415	*stack = top->next;
	416	free(top);
	417	}
	418	return item;
	419	}
	420
ab580ace JS	421	/*
	422	* Performs an in-place topological sort on the list supplied.
	423	*/
4c8725f1	424	void sort_in_topological_order(struct commit_list ** list, int lifo)
6b6dcfc2	425	{
23c17d4a LT	426	struct commit_list next, orig = *list;
	427	struct commit_list work, *insert;
	428	struct commit_list **pptr;
a6080a0a	429
23c17d4a	430	if (!orig)
7d6fb370	431	return;
23c17d4a LT	432	*list = NULL;
	433
	434	/* Mark them and clear the indegree */
	435	for (next = orig; next; next = next->next) {
	436	struct commit *commit = next->item;
	437	commit->object.flags \|= TOPOSORT;
	438	commit->indegree = 0;
ab580ace	439	}
23c17d4a	440
ab580ace	441	/* update the indegree */
23c17d4a	442	for (next = orig; next; next = next->next) {
ab580ace JS	443	struct commit_list * parents = next->item->parents;
ab580ace JS	444	while (parents) {
23c17d4a	445	struct commit *parent = parents->item;
6b6dcfc2	446
23c17d4a LT	447	if (parent->object.flags & TOPOSORT)
	448	parent->indegree++;
	449	parents = parents->next;
ab580ace	450	}
ab580ace	451	}
23c17d4a	452
a6080a0a	453	/*
674d1727 PH	454	* find the tips
	455	*
	456	* tips are nodes not reachable from any other node in the list
	457	*
	458	* the tips serve as a starting set for the work queue.
	459	*/
23c17d4a	460	work = NULL;
2ed02887	461	insert = &work;
23c17d4a LT	462	for (next = orig; next; next = next->next) {
23c17d4a LT	463	struct commit *commit = next->item;
ab580ace	464
23c17d4a LT	465	if (!commit->indegree)
23c17d4a LT	466	insert = &commit_list_insert(commit, insert)->next;
ab580ace	467	}
4c8725f1	468
ab580ace	469	/* process the list in topological order */
4c8725f1 JH	470	if (!lifo)
4c8725f1 JH	471	sort_by_date(&work);
23c17d4a LT	472
	473	pptr = list;
	474	*list = NULL;
ab580ace	475	while (work) {
23c17d4a LT	476	struct commit *commit;
23c17d4a LT	477	struct commit_list parents, work_item;
ab580ace	478
23c17d4a LT	479	work_item = work;
	480	work = work_item->next;
	481	work_item->next = NULL;
	482
	483	commit = work_item->item;
	484	for (parents = commit->parents; parents ; parents = parents->next) {
	485	struct commit *parent=parents->item;
	486
	487	if (!(parent->object.flags & TOPOSORT))
	488	continue;
	489
	490	/*
	491	* parents are only enqueued for emission
	492	* when all their children have been emitted thereby
	493	* guaranteeing topological order.
	494	*/
	495	if (!--parent->indegree) {
	496	if (!lifo)
	497	insert_by_date(parent, &work);
	498	else
	499	commit_list_insert(parent, &work);
ab580ace	500	}
ab580ace JS	501	}
ab580ace JS	502	/*
674d1727 PH	503	* work_item is a commit all of whose children
	504	* have already been emitted. we can emit it now.
	505	*/
23c17d4a LT	506	commit->object.flags &= ~TOPOSORT;
	507	*pptr = work_item;
	508	pptr = &work_item->next;
ab580ace	509	}
ab580ace	510	}
7c6f8aaf	511
1295228d	512	/* merge-base stuff */
7c6f8aaf	513
577ed5c2 JH	514	/* bits #0..15 in revision.h */
	515	#define PARENT1 (1u<<16)
	516	#define PARENT2 (1u<<17)
	517	#define STALE (1u<<18)
	518	#define RESULT (1u<<19)
7c6f8aaf	519
1295228d JH	520	static const unsigned all_flags = (PARENT1 \| PARENT2 \| STALE \| RESULT);
1295228d JH	521
7c6f8aaf JS	522	static struct commit interesting(struct commit_list list)
	523	{
	524	while (list) {
	525	struct commit *commit = list->item;
	526	list = list->next;
542ccefe	527	if (commit->object.flags & STALE)
7c6f8aaf JS	528	continue;
	529	return commit;
	530	}
	531	return NULL;
	532	}
	533
f3249438	534	static struct commit_list merge_bases(struct commit one, struct commit *two)
7c6f8aaf JS	535	{
	536	struct commit_list *list = NULL;
	537	struct commit_list *result = NULL;
7c6f8aaf	538
f3249438 JH	539	if (one == two)
	540	/* We do not mark this even with RESULT so we do not
	541	* have to clean it up.
	542	*/
	543	return commit_list_insert(one, &result);
7c6f8aaf	544
172947e6 MK	545	if (parse_commit(one))
	546	return NULL;
	547	if (parse_commit(two))
	548	return NULL;
7c6f8aaf	549
f3249438 JH	550	one->object.flags \|= PARENT1;
	551	two->object.flags \|= PARENT2;
	552	insert_by_date(one, &list);
	553	insert_by_date(two, &list);
7c6f8aaf JS	554
7c6f8aaf JS	555	while (interesting(list)) {
f3249438	556	struct commit *commit;
7c6f8aaf	557	struct commit_list *parents;
f3249438 JH	558	struct commit_list *n;
f3249438 JH	559	int flags;
7c6f8aaf	560
f3249438 JH	561	commit = list->item;
	562	n = list->next;
	563	free(list);
	564	list = n;
7c6f8aaf	565
f3249438 JH	566	flags = commit->object.flags & (PARENT1 \| PARENT2 \| STALE);
	567	if (flags == (PARENT1 \| PARENT2)) {
	568	if (!(commit->object.flags & RESULT)) {
	569	commit->object.flags \|= RESULT;
	570	insert_by_date(commit, &result);
	571	}
542ccefe JH	572	/* Mark parents of a found merge stale */
542ccefe JH	573	flags \|= STALE;
7c6f8aaf JS	574	}
	575	parents = commit->parents;
	576	while (parents) {
	577	struct commit *p = parents->item;
	578	parents = parents->next;
	579	if ((p->object.flags & flags) == flags)
	580	continue;
172947e6 MK	581	if (parse_commit(p))
172947e6 MK	582	return NULL;
7c6f8aaf JS	583	p->object.flags \|= flags;
	584	insert_by_date(p, &list);
	585	}
	586	}
	587
f3249438	588	/* Clean up the result to remove stale ones */
1295228d	589	free_commit_list(list);
f3249438 JH	590	list = result; result = NULL;
	591	while (list) {
	592	struct commit_list *n = list->next;
	593	if (!(list->item->object.flags & STALE))
	594	insert_by_date(list->item, &result);
	595	free(list);
	596	list = n;
	597	}
	598	return result;
	599	}
7c6f8aaf	600
f3249438	601	struct commit_list get_merge_bases(struct commit one,
674d1727	602	struct commit *two, int cleanup)
f3249438	603	{
f3249438 JH	604	struct commit_list *list;
	605	struct commit **rslt;
	606	struct commit_list *result;
	607	int cnt, i, j;
	608
	609	result = merge_bases(one, two);
	610	if (one == two)
	611	return result;
	612	if (!result \|\| !result->next) {
	613	if (cleanup) {
	614	clear_commit_marks(one, all_flags);
	615	clear_commit_marks(two, all_flags);
7c6f8aaf	616	}
f3249438	617	return result;
7c6f8aaf JS	618	}
7c6f8aaf JS	619
f3249438 JH	620	/* There are more than one */
	621	cnt = 0;
	622	list = result;
	623	while (list) {
	624	list = list->next;
	625	cnt++;
	626	}
	627	rslt = xcalloc(cnt, sizeof(*rslt));
	628	for (list = result, i = 0; list; list = list->next)
	629	rslt[i++] = list->item;
	630	free_commit_list(result);
	631
	632	clear_commit_marks(one, all_flags);
	633	clear_commit_marks(two, all_flags);
	634	for (i = 0; i < cnt - 1; i++) {
	635	for (j = i+1; j < cnt; j++) {
	636	if (!rslt[i] \|\| !rslt[j])
	637	continue;
	638	result = merge_bases(rslt[i], rslt[j]);
	639	clear_commit_marks(rslt[i], all_flags);
	640	clear_commit_marks(rslt[j], all_flags);
	641	for (list = result; list; list = list->next) {
	642	if (rslt[i] == list->item)
	643	rslt[i] = NULL;
	644	if (rslt[j] == list->item)
	645	rslt[j] = NULL;
	646	}
	647	}
58ecf5c1	648	}
7c6f8aaf	649
f3249438 JH	650	/* Surviving ones in rslt[] are the independent results */
	651	result = NULL;
	652	for (i = 0; i < cnt; i++) {
	653	if (rslt[i])
	654	insert_by_date(rslt[i], &result);
	655	}
	656	free(rslt);
7c6f8aaf JS	657	return result;
7c6f8aaf JS	658	}
2ecd2bbc	659
03840fc3	660	int in_merge_bases(struct commit commit, struct commit *reference, int num)
2ecd2bbc JH	661	{
	662	struct commit_list bases, b;
	663	int ret = 0;
	664
03840fc3 JH	665	if (num == 1)
	666	bases = get_merge_bases(commit, *reference, 1);
	667	else
	668	die("not yet");
2ecd2bbc	669	for (b = bases; b; b = b->next) {
03840fc3	670	if (!hashcmp(commit->object.sha1, b->item->object.sha1)) {
2ecd2bbc JH	671	ret = 1;
	672	break;
	673	}
	674	}
	675
	676	free_commit_list(bases);
	677	return ret;
	678	}