[thirdparty/git.git] / commit.c

#include "cache.h"
#include "tag.h"
#include "commit.h"

int save_commit_buffer = 1;

struct sort_node
{
	/*
         * the number of children of the associated commit
         * that also occur in the list being sorted.
         */
	unsigned int indegree;

	/*
         * reference to original list item that we will re-use
         * on output.
         */
	struct commit_list * list_item;

};

const char *commit_type = "commit";

enum cmit_fmt get_commit_format(const char *arg)
{
	if (!*arg)
		return CMIT_FMT_DEFAULT;
	if (!strcmp(arg, "=raw"))
		return CMIT_FMT_RAW;
	if (!strcmp(arg, "=medium"))
		return CMIT_FMT_MEDIUM;
	if (!strcmp(arg, "=short"))
		return CMIT_FMT_SHORT;
	if (!strcmp(arg, "=full"))
		return CMIT_FMT_FULL;
	if (!strcmp(arg, "=fuller"))
		return CMIT_FMT_FULLER;
	if (!strcmp(arg, "=oneline"))
		return CMIT_FMT_ONELINE;
	die("invalid --pretty format");
}

static struct commit *check_commit(struct object *obj,
				   const unsigned char *sha1,
				   int quiet)
{
	if (obj->type != commit_type) {
		if (!quiet)
			error("Object %s is a %s, not a commit",
			      sha1_to_hex(sha1), 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) {
		struct commit *ret = xmalloc(sizeof(struct commit));
		memset(ret, 0, sizeof(struct commit));
		created_object(sha1, &ret->object);
		ret->object.type = commit_type;
		return ret;
	}
	if (!obj->type)
		obj->type = commit_type;
	return check_commit(obj, sha1, 0);
}

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

	if (memcmp(buf, "author", 6))
		return 0;
	while (*buf++ != '\n')
		/* nada */;
	if (memcmp(buf, "committer", 9))
		return 0;
	while (*buf++ != '>')
		/* nada */;
	date = strtoul(buf, NULL, 10);
	if (date == ULONG_MAX)
		date = 0;
	return date;
}

static struct commit_graft {
	unsigned char sha1[20];
	int nr_parent;
	unsigned char parent[0][20]; /* more */
} **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 = memcmp(sha1, graft->sha1, 20);
		if (!cmp)
			return mi;
		if (cmp < 0)
			hi = mi;
		else
			lo = mi + 1;
	}
	return -lo - 1;
}

static void prepare_commit_graft(void)
{
	char *graft_file = get_graft_file();
	FILE *fp = fopen(graft_file, "r");
	char buf[1024];
	if (!fp) {
		commit_graft = (struct commit_graft **) "hack";
		return;
	}
	while (fgets(buf, sizeof(buf), fp)) {
		/* The format is just "Commit Parent1 Parent2 ...\n" */
		int len = strlen(buf);
		int i;
		struct commit_graft *graft = NULL;

		if (buf[len-1] == '\n')
			buf[--len] = 0;
		if (buf[0] == '#')
			continue;
		if ((len + 1) % 41) {
		bad_graft_data:
			error("bad graft data: %s", buf);
			free(graft);
			continue;
		}
		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;
		}
		i = commit_graft_pos(graft->sha1);
		if (0 <= i) {
			error("duplicate graft data: %s", buf);
			free(graft);
			continue;
		}
		i = -i - 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 (i < commit_graft_nr)
			memmove(commit_graft + i + 1,
				commit_graft + i,
				(commit_graft_nr - i - 1) *
				sizeof(*commit_graft));
		commit_graft[i] = graft;
	}
	fclose(fp);
}

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

int parse_commit_buffer(struct commit *item, void *buffer, unsigned long size)
{
	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;
	if (memcmp(bufptr, "tree ", 5))
		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\n", 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 (!memcmp(bufptr, "parent ", 7)) {
		struct commit *new_parent;

		if (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);

	if (track_object_refs) {
		unsigned i = 0;
		struct commit_list *p;
		struct object_refs *refs = alloc_object_refs(n_refs);
		if (item->tree)
			refs->ref[i++] = &item->tree->object;
		for (p = item->parents; p; p = p->next)
			refs->ref[i++] = &p->item->object;
		set_object_refs(&item->object, refs);
	}

	return 0;
}

int parse_commit(struct commit *item)
{
	char type[20];
	void *buffer;
	unsigned long size;
	int ret;

	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 (strcmp(type, commit_type)) {
		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;
		parse_commit(commit);
		if (!(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)
{
	struct commit_list *parents;

	parents = commit->parents;
	commit->object.flags &= ~mark;
	while (parents) {
		struct commit *parent = parents->item;
		if (parent && parent->object.parsed &&
		    (parent->object.flags & mark))
			clear_commit_marks(parent, mark);
		parents = parents->next;
	}
}

/*
 * Generic support for pretty-printing the header
 */
static int get_one_line(const char *msg, unsigned long len)
{
	int ret = 0;

	while (len--) {
		char c = *msg++;
		ret++;
		if (c == '\n')
			break;
		if (!c)
			return 0;
	}
	return ret;
}

static int add_user_info(const char *what, enum cmit_fmt fmt, char *buf, const char *line)
{
	char *date;
	int namelen;
	unsigned long time;
	int tz, ret;
	const char *filler = "    ";

	if (fmt == CMIT_FMT_ONELINE)
		return 0;
	date = strchr(line, '>');
	if (!date)
		return 0;
	namelen = ++date - line;
	time = strtoul(date, &date, 10);
	tz = strtol(date, NULL, 10);

	ret = sprintf(buf, "%s: %.*s%.*s\n", what,
		      (fmt == CMIT_FMT_FULLER) ? 4 : 0,
		      filler, namelen, line);
	switch (fmt) {
	case CMIT_FMT_MEDIUM:
		ret += sprintf(buf + ret, "Date:   %s\n", show_date(time, tz));
		break;
	case CMIT_FMT_FULLER:
		ret += sprintf(buf + ret, "%sDate: %s\n", what, show_date(time, tz));
		break;
	default:
		/* notin' */
		break;
	}
	return ret;
}

static int is_empty_line(const char *line, int len)
{
	while (len && isspace(line[len-1]))
		len--;
	return !len;
}

static int add_parent_info(enum cmit_fmt fmt, char *buf, const char *line, int parents)
{
	int offset = 0;

	if (fmt == CMIT_FMT_ONELINE)
		return offset;
	switch (parents) {
	case 1:
		break;
	case 2:
		/* Go back to the previous line: 40 characters of previous parent, and one '\n' */
		offset = sprintf(buf, "Merge: %.40s\n", line-41);
		/* Fallthrough */
	default:
		/* Replace the previous '\n' with a space */
		buf[offset-1] = ' ';
		offset += sprintf(buf + offset, "%.40s\n", line+7);
	}
	return offset;
}

unsigned long pretty_print_commit(enum cmit_fmt fmt, const char *msg, unsigned long len, char *buf, unsigned long space)
{
	int hdr = 1, body = 0;
	unsigned long offset = 0;
	int parents = 0;
	int indent = (fmt == CMIT_FMT_ONELINE) ? 0 : 4;

	for (;;) {
		const char *line = msg;
		int linelen = get_one_line(msg, len);

		if (!linelen)
			break;

		/*
		 * We want some slop for indentation and a possible
		 * final "...". Thus the "+ 20".
		 */
		if (offset + linelen + 20 > space) {
			memcpy(buf + offset, "    ...\n", 8);
			offset += 8;
			break;
		}

		msg += linelen;
		len -= linelen;
		if (hdr) {
			if (linelen == 1) {
				hdr = 0;
				if (fmt != CMIT_FMT_ONELINE)
					buf[offset++] = '\n';
				continue;
			}
			if (fmt == CMIT_FMT_RAW) {
				memcpy(buf + offset, line, linelen);
				offset += linelen;
				continue;
			}
			if (!memcmp(line, "parent ", 7)) {
				if (linelen != 48)
					die("bad parent line in commit");
				offset += add_parent_info(fmt, buf + offset, line, ++parents);
			}

			/*
			 * MEDIUM == DEFAULT shows only author with dates.
			 * FULL shows both authors but not dates.
			 * FULLER shows both authors and dates.
			 */
			if (!memcmp(line, "author ", 7))
				offset += add_user_info("Author", fmt,
							buf + offset,
							line + 7);
			if (!memcmp(line, "committer ", 10) &&
			    (fmt == CMIT_FMT_FULL || fmt == CMIT_FMT_FULLER))
				offset += add_user_info("Commit", fmt,
							buf + offset,
							line + 10);
			continue;
		}

		if (is_empty_line(line, linelen)) {
			if (!body)
				continue;
			if (fmt == CMIT_FMT_SHORT)
				break;
		} else {
			body = 1;
		}

		memset(buf + offset, ' ', indent);
		memcpy(buf + offset + indent, line, linelen);
		offset += linelen + indent;
		if (fmt == CMIT_FMT_ONELINE)
			break;
	}
	if (fmt == CMIT_FMT_ONELINE) {
		/* We do not want the terminating newline */
		if (buf[offset - 1] == '\n')
			offset--;
	}
	else {
		/* Make sure there is an EOLN */
		if (buf[offset - 1] != '\n')
			buf[offset++] = '\n';
	}
	buf[offset] = '\0';
	return offset;
}

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;
}

int count_parents(struct commit * commit)
{
        int count = 0;
        struct commit_list * parents = commit->parents;
        for (count=0;parents; parents=parents->next,count++)
          ;
        return count;
}

/*
 * Performs an in-place topological sort on the list supplied.
 */
void sort_in_topological_order(struct commit_list ** list)
{
	struct commit_list * next = *list;
	struct commit_list * work = NULL, **insert;
	struct commit_list ** pptr = list;
	struct sort_node * nodes;
	struct sort_node * next_nodes;
	int count = 0;

	/* determine the size of the list */
	while (next) {
		next = next->next;
		count++;
	}
	
	if (!count)
		return;
	/* allocate an array to help sort the list */
	nodes = xcalloc(count, sizeof(*nodes));
	/* link the list to the array */
	next_nodes = nodes;
	next=*list;
	while (next) {
		next_nodes->list_item = next;
		next->item->object.util = next_nodes;
		next_nodes++;
		next = next->next;
	}
	/* update the indegree */
	next=*list;
	while (next) {
		struct commit_list * parents = next->item->parents;
		while (parents) {
			struct commit * parent=parents->item;
			struct sort_node * pn = (struct sort_node *)parent->object.util;
			
			if (pn)
				pn->indegree++;
			parents=parents->next;
		}
		next=next->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.
         */
	next=*list;
	insert = &work;
	while (next) {
		struct sort_node * node = (struct sort_node *)next->item->object.util;

		if (node->indegree == 0) {
			insert = &commit_list_insert(next->item, insert)->next;
		}
		next=next->next;
	}
	/* process the list in topological order */
	while (work) {
		struct commit * work_item = pop_commit(&work);
		struct sort_node * work_node = (struct sort_node *)work_item->object.util;
		struct commit_list * parents = work_item->parents;

		while (parents) {
			struct commit * parent=parents->item;
			struct sort_node * pn = (struct sort_node *)parent->object.util;
			
			if (pn) {
				/* 
				 * parents are only enqueued for emission 
                                 * when all their children have been emitted thereby
                                 * guaranteeing topological order.
                                 */
				pn->indegree--;
				if (!pn->indegree) 
					commit_list_insert(parent, &work);
			}
			parents=parents->next;
		}
		/*
                 * work_item is a commit all of whose children
                 * have already been emitted. we can emit it now.
                 */
		*pptr = work_node->list_item;
		pptr = &(*pptr)->next;
		*pptr = NULL;
		work_item->object.util = NULL;
	}
	free(nodes);
}
Commit	Line	Data
8f1d2e6f	1	#include "cache.h"
961784ee	2	#include "tag.h"
175785e5	3	#include "commit.h"
175785e5	4
60ab26de LT	5	int save_commit_buffer = 1;
60ab26de LT	6
ab580ace JS	7	struct sort_node
	8	{
	9	/*
	10	* the number of children of the associated commit
	11	* that also occur in the list being sorted.
	12	*/
	13	unsigned int indegree;
	14
	15	/*
	16	* reference to original list item that we will re-use
	17	* on output.
	18	*/
	19	struct commit_list * list_item;
	20
	21	};
	22
175785e5 DB	23	const char *commit_type = "commit";
175785e5 DB	24
9b66ec04 LT	25	enum cmit_fmt get_commit_format(const char *arg)
	26	{
	27	if (!*arg)
	28	return CMIT_FMT_DEFAULT;
	29	if (!strcmp(arg, "=raw"))
	30	return CMIT_FMT_RAW;
	31	if (!strcmp(arg, "=medium"))
	32	return CMIT_FMT_MEDIUM;
	33	if (!strcmp(arg, "=short"))
	34	return CMIT_FMT_SHORT;
	35	if (!strcmp(arg, "=full"))
	36	return CMIT_FMT_FULL;
ff56fe1c JH	37	if (!strcmp(arg, "=fuller"))
ff56fe1c JH	38	return CMIT_FMT_FULLER;
d87449c5 JH	39	if (!strcmp(arg, "=oneline"))
d87449c5 JH	40	return CMIT_FMT_ONELINE;
9b66ec04 LT	41	die("invalid --pretty format");
	42	}
	43
f76412ed JH	44	static struct commit check_commit(struct object obj,
	45	const unsigned char *sha1,
	46	int quiet)
961784ee LT	47	{
961784ee LT	48	if (obj->type != commit_type) {
f76412ed JH	49	if (!quiet)
	50	error("Object %s is a %s, not a commit",
	51	sha1_to_hex(sha1), obj->type);
961784ee LT	52	return NULL;
	53	}
	54	return (struct commit *) obj;
	55	}
	56
f76412ed JH	57	struct commit lookup_commit_reference_gently(const unsigned char sha1,
f76412ed JH	58	int quiet)
961784ee	59	{
9534f40b	60	struct object *obj = deref_tag(parse_object(sha1), NULL, 0);
961784ee LT	61
	62	if (!obj)
	63	return NULL;
f76412ed JH	64	return check_commit(obj, sha1, quiet);
	65	}
	66
	67	struct commit lookup_commit_reference(const unsigned char sha1)
	68	{
	69	return lookup_commit_reference_gently(sha1, 0);
961784ee LT	70	}
961784ee LT	71
5d6ccf5c	72	struct commit lookup_commit(const unsigned char sha1)
175785e5 DB	73	{
	74	struct object *obj = lookup_object(sha1);
	75	if (!obj) {
812666c8	76	struct commit *ret = xmalloc(sizeof(struct commit));
175785e5 DB	77	memset(ret, 0, sizeof(struct commit));
175785e5 DB	78	created_object(sha1, &ret->object);
d32987be	79	ret->object.type = commit_type;
175785e5 DB	80	return ret;
175785e5 DB	81	}
d1af002d NP	82	if (!obj->type)
d1af002d NP	83	obj->type = commit_type;
f76412ed	84	return check_commit(obj, sha1, 0);
175785e5 DB	85	}
	86
	87	static unsigned long parse_commit_date(const char *buf)
	88	{
	89	unsigned long date;
	90
	91	if (memcmp(buf, "author", 6))
	92	return 0;
	93	while (*buf++ != '\n')
	94	/* nada */;
	95	if (memcmp(buf, "committer", 9))
	96	return 0;
	97	while (*buf++ != '>')
	98	/* nada */;
	99	date = strtoul(buf, NULL, 10);
	100	if (date == ULONG_MAX)
	101	date = 0;
	102	return date;
	103	}
	104
5da5c8f4 JH	105	static struct commit_graft {
	106	unsigned char sha1[20];
	107	int nr_parent;
2c04662d	108	unsigned char parent[0][20]; /* more */
5da5c8f4 JH	109	} **commit_graft;
	110	static int commit_graft_alloc, commit_graft_nr;
	111
	112	static int commit_graft_pos(const unsigned char *sha1)
	113	{
	114	int lo, hi;
	115	lo = 0;
	116	hi = commit_graft_nr;
	117	while (lo < hi) {
	118	int mi = (lo + hi) / 2;
	119	struct commit_graft *graft = commit_graft[mi];
	120	int cmp = memcmp(sha1, graft->sha1, 20);
	121	if (!cmp)
	122	return mi;
	123	if (cmp < 0)
	124	hi = mi;
	125	else
	126	lo = mi + 1;
	127	}
	128	return -lo - 1;
	129	}
	130
	131	static void prepare_commit_graft(void)
	132	{
	133	char *graft_file = get_graft_file();
	134	FILE *fp = fopen(graft_file, "r");
	135	char buf[1024];
	136	if (!fp) {
	137	commit_graft = (struct commit_graft **) "hack";
	138	return;
	139	}
	140	while (fgets(buf, sizeof(buf), fp)) {
	141	/* The format is just "Commit Parent1 Parent2 ...\n" */
	142	int len = strlen(buf);
	143	int i;
	144	struct commit_graft *graft = NULL;
	145
	146	if (buf[len-1] == '\n')
	147	buf[--len] = 0;
	148	if (buf[0] == '#')
	149	continue;
	150	if ((len + 1) % 41) {
	151	bad_graft_data:
	152	error("bad graft data: %s", buf);
	153	free(graft);
	154	continue;
	155	}
	156	i = (len + 1) / 41 - 1;
	157	graft = xmalloc(sizeof(graft) + 20 i);
	158	graft->nr_parent = i;
	159	if (get_sha1_hex(buf, graft->sha1))
	160	goto bad_graft_data;
	161	for (i = 40; i < len; i += 41) {
	162	if (buf[i] != ' ')
	163	goto bad_graft_data;
	164	if (get_sha1_hex(buf + i + 1, graft->parent[i/41]))
	165	goto bad_graft_data;
	166	}
	167	i = commit_graft_pos(graft->sha1);
	168	if (0 <= i) {
	169	error("duplicate graft data: %s", buf);
	170	free(graft);
	171	continue;
	172	}
173	i = -i - 1;
174	if (commit_graft_alloc <= ++commit_graft_nr) {
175	commit_graft_alloc = alloc_nr(commit_graft_alloc);
176	commit_graft = xrealloc(commit_graft,
177	sizeof(commit_graft)
178	commit_graft_alloc);
179	}
180	if (i < commit_graft_nr)
181	memmove(commit_graft + i + 1,
182	commit_graft + i,
183	(commit_graft_nr - i - 1) *
184	sizeof(*commit_graft));
185	commit_graft[i] = graft;
186	}
187	fclose(fp);
188	}
189
190	static struct commit_graft lookup_commit_graft(const unsigned char sha1)
191	{
192	int pos;
193	if (!commit_graft)
194	prepare_commit_graft();
195	pos = commit_graft_pos(sha1);
196	if (pos < 0)
197	return NULL;
198	return commit_graft[pos];
199	}
200
bd2c39f5	201	int parse_commit_buffer(struct commit item, void buffer, unsigned long size)
175785e5	202	{
f7cc77d7	203	char *bufptr = buffer;
175785e5	204	unsigned char parent[20];
6c88be16	205	struct commit_list **pptr;
5da5c8f4	206	struct commit_graft *graft;
27dedf0c	207	unsigned n_refs = 0;
bd2c39f5	208
175785e5 DB	209	if (item->object.parsed)
	210	return 0;
	211	item->object.parsed = 1;
f7cc77d7 LT	212	if (memcmp(bufptr, "tree ", 5))
	213	return error("bogus commit object %s", sha1_to_hex(item->object.sha1));
	214	if (get_sha1_hex(bufptr + 5, parent) < 0)
	215	return error("bad tree pointer in commit %s\n", sha1_to_hex(item->object.sha1));
175785e5	216	item->tree = lookup_tree(parent);
235ac407	217	if (item->tree)
27dedf0c	218	n_refs++;
175785e5	219	bufptr += 46; /* "tree " + "hex sha1" + "\n" */
6c88be16	220	pptr = &item->parents;
5da5c8f4 JH	221
5da5c8f4 JH	222	graft = lookup_commit_graft(item->object.sha1);
f7cc77d7 LT	223	while (!memcmp(bufptr, "parent ", 7)) {
	224	struct commit *new_parent;
	225
	226	if (get_sha1_hex(bufptr + 7, parent) \|\| bufptr[47] != '\n')
	227	return error("bad parents in commit %s", sha1_to_hex(item->object.sha1));
5da5c8f4 JH	228	bufptr += 48;
	229	if (graft)
	230	continue;
f7cc77d7	231	new_parent = lookup_commit(parent);
235ac407	232	if (new_parent) {
6c88be16	233	pptr = &commit_list_insert(new_parent, pptr)->next;
27dedf0c	234	n_refs++;
235ac407	235	}
5da5c8f4 JH	236	}
	237	if (graft) {
	238	int i;
	239	struct commit *new_parent;
	240	for (i = 0; i < graft->nr_parent; i++) {
	241	new_parent = lookup_commit(graft->parent[i]);
	242	if (!new_parent)
	243	continue;
	244	pptr = &commit_list_insert(new_parent, pptr)->next;
27dedf0c	245	n_refs++;
5da5c8f4	246	}
175785e5 DB	247	}
175785e5 DB	248	item->date = parse_commit_date(bufptr);
27dedf0c JH	249
	250	if (track_object_refs) {
	251	unsigned i = 0;
	252	struct commit_list *p;
	253	struct object_refs *refs = alloc_object_refs(n_refs);
	254	if (item->tree)
	255	refs->ref[i++] = &item->tree->object;
	256	for (p = item->parents; p; p = p->next)
	257	refs->ref[i++] = &p->item->object;
	258	set_object_refs(&item->object, refs);
	259	}
	260
175785e5 DB	261	return 0;
	262	}
	263
bd2c39f5 NP	264	int parse_commit(struct commit *item)
	265	{
	266	char type[20];
	267	void *buffer;
	268	unsigned long size;
	269	int ret;
	270
	271	if (item->object.parsed)
	272	return 0;
	273	buffer = read_sha1_file(item->object.sha1, type, &size);
	274	if (!buffer)
	275	return error("Could not read %s",
	276	sha1_to_hex(item->object.sha1));
	277	if (strcmp(type, commit_type)) {
	278	free(buffer);
	279	return error("Object %s not a commit",
	280	sha1_to_hex(item->object.sha1));
	281	}
	282	ret = parse_commit_buffer(item, buffer, size);
60ab26de	283	if (save_commit_buffer && !ret) {
3ff1fbbb LT	284	item->buffer = buffer;
	285	return 0;
	286	}
bd2c39f5 NP	287	free(buffer);
	288	return ret;
	289	}
	290
ac5155ef	291	struct commit_list commit_list_insert(struct commit item, struct commit_list **list_p)
dd97f850	292	{
812666c8	293	struct commit_list *new_list = xmalloc(sizeof(struct commit_list));
dd97f850 DB	294	new_list->item = item;
	295	new_list->next = *list_p;
	296	*list_p = new_list;
ac5155ef	297	return new_list;
dd97f850 DB	298	}
dd97f850 DB	299
175785e5 DB	300	void free_commit_list(struct commit_list *list)
	301	{
	302	while (list) {
	303	struct commit_list *temp = list;
	304	list = temp->next;
	305	free(temp);
	306	}
	307	}
dd97f850	308
f755494c	309	struct commit_list * insert_by_date(struct commit item, struct commit_list *list)
dd97f850 DB	310	{
	311	struct commit_list **pp = list;
	312	struct commit_list *p;
	313	while ((p = *pp) != NULL) {
	314	if (p->item->date < item->date) {
	315	break;
	316	}
	317	pp = &p->next;
	318	}
f755494c	319	return commit_list_insert(item, pp);
dd97f850 DB	320	}
	321
	322
	323	void sort_by_date(struct commit_list **list)
	324	{
	325	struct commit_list *ret = NULL;
	326	while (*list) {
f755494c	327	insert_by_date((*list)->item, &ret);
dd97f850 DB	328	list = (list)->next;
	329	}
	330	*list = ret;
	331	}
	332
58e28af6 DB	333	struct commit pop_most_recent_commit(struct commit_list *list,
58e28af6 DB	334	unsigned int mark)
dd97f850 DB	335	{
	336	struct commit ret = (list)->item;
	337	struct commit_list *parents = ret->parents;
	338	struct commit_list old = list;
	339
	340	list = (list)->next;
	341	free(old);
	342
	343	while (parents) {
4056c091	344	struct commit *commit = parents->item;
58e28af6 DB	345	parse_commit(commit);
	346	if (!(commit->object.flags & mark)) {
	347	commit->object.flags \|= mark;
f755494c	348	insert_by_date(commit, list);
4056c091	349	}
dd97f850 DB	350	parents = parents->next;
	351	}
	352	return ret;
	353	}
e3bc7a3b	354
f8f9c73c JH	355	void clear_commit_marks(struct commit *commit, unsigned int mark)
	356	{
	357	struct commit_list *parents;
	358
	359	parents = commit->parents;
	360	commit->object.flags &= ~mark;
	361	while (parents) {
181dc776 JH	362	struct commit *parent = parents->item;
	363	if (parent && parent->object.parsed &&
	364	(parent->object.flags & mark))
	365	clear_commit_marks(parent, mark);
f8f9c73c JH	366	parents = parents->next;
	367	}
	368	}
	369
e3bc7a3b LT	370	/*
	371	* Generic support for pretty-printing the header
	372	*/
	373	static int get_one_line(const char *msg, unsigned long len)
	374	{
	375	int ret = 0;
	376
	377	while (len--) {
	378	char c = *msg++;
	379	ret++;
	380	if (c == '\n')
	381	break;
	382	if (!c)
	383	return 0;
	384	}
	385	return ret;
	386	}
	387
9b66ec04	388	static int add_user_info(const char what, enum cmit_fmt fmt, char buf, const char *line)
e3bc7a3b LT	389	{
e3bc7a3b LT	390	char *date;
5de36bfe	391	int namelen;
e3bc7a3b	392	unsigned long time;
000182ea	393	int tz, ret;
ff56fe1c	394	const char *filler = " ";
e3bc7a3b	395
d87449c5 JH	396	if (fmt == CMIT_FMT_ONELINE)
d87449c5 JH	397	return 0;
e3bc7a3b LT	398	date = strchr(line, '>');
	399	if (!date)
	400	return 0;
	401	namelen = ++date - line;
	402	time = strtoul(date, &date, 10);
	403	tz = strtol(date, NULL, 10);
	404
ff56fe1c JH	405	ret = sprintf(buf, "%s: %.s%.s\n", what,
	406	(fmt == CMIT_FMT_FULLER) ? 4 : 0,
	407	filler, namelen, line);
	408	switch (fmt) {
	409	case CMIT_FMT_MEDIUM:
000182ea	410	ret += sprintf(buf + ret, "Date: %s\n", show_date(time, tz));
ff56fe1c JH	411	break;
	412	case CMIT_FMT_FULLER:
	413	ret += sprintf(buf + ret, "%sDate: %s\n", what, show_date(time, tz));
	414	break;
	415	default:
	416	/* notin' */
	417	break;
	418	}
000182ea LT	419	return ret;
	420	}
	421
	422	static int is_empty_line(const char *line, int len)
	423	{
	424	while (len && isspace(line[len-1]))
	425	len--;
	426	return !len;
e3bc7a3b LT	427	}
e3bc7a3b LT	428
28342a5d LT	429	static int add_parent_info(enum cmit_fmt fmt, char buf, const char line, int parents)
	430	{
	431	int offset = 0;
d87449c5 JH	432
	433	if (fmt == CMIT_FMT_ONELINE)
	434	return offset;
28342a5d LT	435	switch (parents) {
	436	case 1:
	437	break;
	438	case 2:
	439	/* Go back to the previous line: 40 characters of previous parent, and one '\n' */
	440	offset = sprintf(buf, "Merge: %.40s\n", line-41);
	441	/* Fallthrough */
	442	default:
	443	/* Replace the previous '\n' with a space */
	444	buf[offset-1] = ' ';
	445	offset += sprintf(buf + offset, "%.40s\n", line+7);
	446	}
	447	return offset;
	448	}
	449
000182ea	450	unsigned long pretty_print_commit(enum cmit_fmt fmt, const char msg, unsigned long len, char buf, unsigned long space)
e3bc7a3b	451	{
000182ea	452	int hdr = 1, body = 0;
e3bc7a3b	453	unsigned long offset = 0;
28342a5d	454	int parents = 0;
d87449c5	455	int indent = (fmt == CMIT_FMT_ONELINE) ? 0 : 4;
e3bc7a3b LT	456
	457	for (;;) {
	458	const char *line = msg;
	459	int linelen = get_one_line(msg, len);
	460
	461	if (!linelen)
	462	break;
	463
	464	/*
	465	* We want some slop for indentation and a possible
	466	* final "...". Thus the "+ 20".
	467	*/
	468	if (offset + linelen + 20 > space) {
	469	memcpy(buf + offset, " ...\n", 8);
	470	offset += 8;
	471	break;
	472	}
	473
	474	msg += linelen;
	475	len -= linelen;
e3bc7a3b	476	if (hdr) {
000182ea LT	477	if (linelen == 1) {
000182ea LT	478	hdr = 0;
d87449c5 JH	479	if (fmt != CMIT_FMT_ONELINE)
d87449c5 JH	480	buf[offset++] = '\n';
000182ea LT	481	continue;
	482	}
	483	if (fmt == CMIT_FMT_RAW) {
	484	memcpy(buf + offset, line, linelen);
	485	offset += linelen;
	486	continue;
	487	}
28342a5d LT	488	if (!memcmp(line, "parent ", 7)) {
	489	if (linelen != 48)
	490	die("bad parent line in commit");
	491	offset += add_parent_info(fmt, buf + offset, line, ++parents);
	492	}
ff56fe1c JH	493
	494	/*
	495	* MEDIUM == DEFAULT shows only author with dates.
	496	* FULL shows both authors but not dates.
	497	* FULLER shows both authors and dates.
	498	*/
e3bc7a3b	499	if (!memcmp(line, "author ", 7))
ff56fe1c JH	500	offset += add_user_info("Author", fmt,
	501	buf + offset,
	502	line + 7);
	503	if (!memcmp(line, "committer ", 10) &&
	504	(fmt == CMIT_FMT_FULL \|\| fmt == CMIT_FMT_FULLER))
	505	offset += add_user_info("Commit", fmt,
	506	buf + offset,
	507	line + 10);
e3bc7a3b LT	508	continue;
e3bc7a3b LT	509	}
000182ea LT	510
	511	if (is_empty_line(line, linelen)) {
	512	if (!body)
	513	continue;
	514	if (fmt == CMIT_FMT_SHORT)
	515	break;
	516	} else {
	517	body = 1;
	518	}
d87449c5 JH	519
	520	memset(buf + offset, ' ', indent);
	521	memcpy(buf + offset + indent, line, linelen);
	522	offset += linelen + indent;
	523	if (fmt == CMIT_FMT_ONELINE)
	524	break;
	525	}
	526	if (fmt == CMIT_FMT_ONELINE) {
	527	/* We do not want the terminating newline */
	528	if (buf[offset - 1] == '\n')
	529	offset--;
	530	}
	531	else {
	532	/* Make sure there is an EOLN */
	533	if (buf[offset - 1] != '\n')
	534	buf[offset++] = '\n';
e3bc7a3b	535	}
e3bc7a3b LT	536	buf[offset] = '\0';
	537	return offset;
	538	}
a3437b8c JS	539
	540	struct commit pop_commit(struct commit_list *stack)
	541	{
	542	struct commit_list top = stack;
	543	struct commit *item = top ? top->item : NULL;
	544
	545	if (top) {
	546	*stack = top->next;
	547	free(top);
	548	}
	549	return item;
	550	}
	551
	552	int count_parents(struct commit * commit)
	553	{
	554	int count = 0;
	555	struct commit_list * parents = commit->parents;
	556	for (count=0;parents; parents=parents->next,count++)
	557	;
	558	return count;
	559	}
	560
ab580ace JS	561	/*
	562	* Performs an in-place topological sort on the list supplied.
	563	*/
	564	void sort_in_topological_order(struct commit_list ** list)
	565	{
	566	struct commit_list * next = *list;
2ed02887	567	struct commit_list * work = NULL, **insert;
ab580ace JS	568	struct commit_list ** pptr = list;
	569	struct sort_node * nodes;
	570	struct sort_node * next_nodes;
	571	int count = 0;
	572
	573	/* determine the size of the list */
	574	while (next) {
	575	next = next->next;
	576	count++;
	577	}
7d6fb370 EW	578
	579	if (!count)
	580	return;
ab580ace JS	581	/* allocate an array to help sort the list */
	582	nodes = xcalloc(count, sizeof(*nodes));
	583	/* link the list to the array */
	584	next_nodes = nodes;
	585	next=*list;
	586	while (next) {
	587	next_nodes->list_item = next;
	588	next->item->object.util = next_nodes;
	589	next_nodes++;
	590	next = next->next;
	591	}
	592	/* update the indegree */
	593	next=*list;
	594	while (next) {
	595	struct commit_list * parents = next->item->parents;
	596	while (parents) {
	597	struct commit * parent=parents->item;
	598	struct sort_node * pn = (struct sort_node *)parent->object.util;
	599
	600	if (pn)
	601	pn->indegree++;
	602	parents=parents->next;
	603	}
	604	next=next->next;
	605	}
	606	/*
	607	* find the tips
	608	*
	609	* tips are nodes not reachable from any other node in the list
	610	*
	611	* the tips serve as a starting set for the work queue.
	612	*/
	613	next=*list;
2ed02887	614	insert = &work;
ab580ace JS	615	while (next) {
	616	struct sort_node * node = (struct sort_node *)next->item->object.util;
	617
	618	if (node->indegree == 0) {
2ed02887	619	insert = &commit_list_insert(next->item, insert)->next;
ab580ace JS	620	}
	621	next=next->next;
	622	}
	623	/* process the list in topological order */
	624	while (work) {
	625	struct commit * work_item = pop_commit(&work);
	626	struct sort_node * work_node = (struct sort_node *)work_item->object.util;
	627	struct commit_list * parents = work_item->parents;
	628
	629	while (parents) {
	630	struct commit * parent=parents->item;
	631	struct sort_node * pn = (struct sort_node *)parent->object.util;
	632
	633	if (pn) {
	634	/*
	635	* parents are only enqueued for emission
	636	* when all their children have been emitted thereby
	637	* guaranteeing topological order.
	638	*/
	639	pn->indegree--;
	640	if (!pn->indegree)
	641	commit_list_insert(parent, &work);
	642	}
	643	parents=parents->next;
	644	}
	645	/*
	646	* work_item is a commit all of whose children
	647	* have already been emitted. we can emit it now.
	648	*/
	649	*pptr = work_node->list_item;
	650	pptr = &(*pptr)->next;
	651	*pptr = NULL;
	652	work_item->object.util = NULL;
	653	}
	654	free(nodes);
	655	}