[thirdparty/git.git] / shallow.c

#include "cache.h"
#include "tempfile.h"
#include "lockfile.h"
#include "commit.h"
#include "tag.h"
#include "pkt-line.h"
#include "remote.h"
#include "refs.h"
#include "sha1-array.h"
#include "diff.h"
#include "revision.h"
#include "commit-slab.h"

static int is_shallow = -1;
static struct stat_validity shallow_stat;
static char *alternate_shallow_file;

void set_alternate_shallow_file(const char *path, int override)
{
	if (is_shallow != -1)
		die("BUG: is_repository_shallow must not be called before set_alternate_shallow_file");
	if (alternate_shallow_file && !override)
		return;
	free(alternate_shallow_file);
	alternate_shallow_file = xstrdup_or_null(path);
}

int register_shallow(const unsigned char *sha1)
{
	struct commit_graft *graft =
		xmalloc(sizeof(struct commit_graft));
	struct commit *commit = lookup_commit(sha1);

	hashcpy(graft->oid.hash, sha1);
	graft->nr_parent = -1;
	if (commit && commit->object.parsed)
		commit->parents = NULL;
	return register_commit_graft(graft, 0);
}

int is_repository_shallow(void)
{
	FILE *fp;
	char buf[1024];
	const char *path = alternate_shallow_file;

	if (is_shallow >= 0)
		return is_shallow;

	if (!path)
		path = git_path_shallow();
	/*
	 * fetch-pack sets '--shallow-file ""' as an indicator that no
	 * shallow file should be used. We could just open it and it
	 * will likely fail. But let's do an explicit check instead.
	 */
	if (!*path || (fp = fopen(path, "r")) == NULL) {
		stat_validity_clear(&shallow_stat);
		is_shallow = 0;
		return is_shallow;
	}
	stat_validity_update(&shallow_stat, fileno(fp));
	is_shallow = 1;

	while (fgets(buf, sizeof(buf), fp)) {
		unsigned char sha1[20];
		if (get_sha1_hex(buf, sha1))
			die("bad shallow line: %s", buf);
		register_shallow(sha1);
	}
	fclose(fp);
	return is_shallow;
}

struct commit_list *get_shallow_commits(struct object_array *heads, int depth,
		int shallow_flag, int not_shallow_flag)
{
	int i = 0, cur_depth = 0;
	struct commit_list *result = NULL;
	struct object_array stack = OBJECT_ARRAY_INIT;
	struct commit *commit = NULL;
	struct commit_graft *graft;

	while (commit || i < heads->nr || stack.nr) {
		struct commit_list *p;
		if (!commit) {
			if (i < heads->nr) {
				commit = (struct commit *)
					deref_tag(heads->objects[i++].item, NULL, 0);
				if (!commit || commit->object.type != OBJ_COMMIT) {
					commit = NULL;
					continue;
				}
				if (!commit->util)
					commit->util = xmalloc(sizeof(int));
				*(int *)commit->util = 0;
				cur_depth = 0;
			} else {
				commit = (struct commit *)
					stack.objects[--stack.nr].item;
				cur_depth = *(int *)commit->util;
			}
		}
		parse_commit_or_die(commit);
		cur_depth++;
		if ((depth != INFINITE_DEPTH && cur_depth >= depth) ||
		    (is_repository_shallow() && !commit->parents &&
		     (graft = lookup_commit_graft(commit->object.oid.hash)) != NULL &&
		     graft->nr_parent < 0)) {
			commit_list_insert(commit, &result);
			commit->object.flags |= shallow_flag;
			commit = NULL;
			continue;
		}
		commit->object.flags |= not_shallow_flag;
		for (p = commit->parents, commit = NULL; p; p = p->next) {
			if (!p->item->util) {
				int *pointer = xmalloc(sizeof(int));
				p->item->util = pointer;
				*pointer =  cur_depth;
			} else {
				int *pointer = p->item->util;
				if (cur_depth >= *pointer)
					continue;
				*pointer = cur_depth;
			}
			if (p->next)
				add_object_array(&p->item->object,
						NULL, &stack);
			else {
				commit = p->item;
				cur_depth = *(int *)commit->util;
			}
		}
	}

	return result;
}

static void check_shallow_file_for_update(void)
{
	if (is_shallow == -1)
		die("BUG: shallow must be initialized by now");

	if (!stat_validity_check(&shallow_stat, git_path_shallow()))
		die("shallow file has changed since we read it");
}

#define SEEN_ONLY 1
#define VERBOSE   2

struct write_shallow_data {
	struct strbuf *out;
	int use_pack_protocol;
	int count;
	unsigned flags;
};

static int write_one_shallow(const struct commit_graft *graft, void *cb_data)
{
	struct write_shallow_data *data = cb_data;
	const char *hex = oid_to_hex(&graft->oid);
	if (graft->nr_parent != -1)
		return 0;
	if (data->flags & SEEN_ONLY) {
		struct commit *c = lookup_commit(graft->oid.hash);
		if (!c || !(c->object.flags & SEEN)) {
			if (data->flags & VERBOSE)
				printf("Removing %s from .git/shallow\n",
				       oid_to_hex(&c->object.oid));
			return 0;
		}
	}
	data->count++;
	if (data->use_pack_protocol)
		packet_buf_write(data->out, "shallow %s", hex);
	else {
		strbuf_addstr(data->out, hex);
		strbuf_addch(data->out, '\n');
	}
	return 0;
}

static int write_shallow_commits_1(struct strbuf *out, int use_pack_protocol,
				   const struct sha1_array *extra,
				   unsigned flags)
{
	struct write_shallow_data data;
	int i;
	data.out = out;
	data.use_pack_protocol = use_pack_protocol;
	data.count = 0;
	data.flags = flags;
	for_each_commit_graft(write_one_shallow, &data);
	if (!extra)
		return data.count;
	for (i = 0; i < extra->nr; i++) {
		strbuf_addstr(out, sha1_to_hex(extra->sha1[i]));
		strbuf_addch(out, '\n');
		data.count++;
	}
	return data.count;
}

int write_shallow_commits(struct strbuf *out, int use_pack_protocol,
			  const struct sha1_array *extra)
{
	return write_shallow_commits_1(out, use_pack_protocol, extra, 0);
}

static struct tempfile temporary_shallow;

const char *setup_temporary_shallow(const struct sha1_array *extra)
{
	struct strbuf sb = STRBUF_INIT;
	int fd;

	if (write_shallow_commits(&sb, 0, extra)) {
		fd = xmks_tempfile(&temporary_shallow, git_path("shallow_XXXXXX"));

		if (write_in_full(fd, sb.buf, sb.len) != sb.len)
			die_errno("failed to write to %s",
				  get_tempfile_path(&temporary_shallow));
		close_tempfile(&temporary_shallow);
		strbuf_release(&sb);
		return get_tempfile_path(&temporary_shallow);
	}
	/*
	 * is_repository_shallow() sees empty string as "no shallow
	 * file".
	 */
	return get_tempfile_path(&temporary_shallow);
}

void setup_alternate_shallow(struct lock_file *shallow_lock,
			     const char **alternate_shallow_file,
			     const struct sha1_array *extra)
{
	struct strbuf sb = STRBUF_INIT;
	int fd;

	fd = hold_lock_file_for_update(shallow_lock, git_path_shallow(),
				       LOCK_DIE_ON_ERROR);
	check_shallow_file_for_update();
	if (write_shallow_commits(&sb, 0, extra)) {
		if (write_in_full(fd, sb.buf, sb.len) != sb.len)
			die_errno("failed to write to %s",
				  get_lock_file_path(shallow_lock));
		*alternate_shallow_file = get_lock_file_path(shallow_lock);
	} else
		/*
		 * is_repository_shallow() sees empty string as "no
		 * shallow file".
		 */
		*alternate_shallow_file = "";
	strbuf_release(&sb);
}

static int advertise_shallow_grafts_cb(const struct commit_graft *graft, void *cb)
{
	int fd = *(int *)cb;
	if (graft->nr_parent == -1)
		packet_write(fd, "shallow %s\n", oid_to_hex(&graft->oid));
	return 0;
}

void advertise_shallow_grafts(int fd)
{
	if (!is_repository_shallow())
		return;
	for_each_commit_graft(advertise_shallow_grafts_cb, &fd);
}

/*
 * mark_reachable_objects() should have been run prior to this and all
 * reachable commits marked as "SEEN".
 */
void prune_shallow(int show_only)
{
	static struct lock_file shallow_lock;
	struct strbuf sb = STRBUF_INIT;
	int fd;

	if (show_only) {
		write_shallow_commits_1(&sb, 0, NULL, SEEN_ONLY | VERBOSE);
		strbuf_release(&sb);
		return;
	}
	fd = hold_lock_file_for_update(&shallow_lock, git_path_shallow(),
				       LOCK_DIE_ON_ERROR);
	check_shallow_file_for_update();
	if (write_shallow_commits_1(&sb, 0, NULL, SEEN_ONLY)) {
		if (write_in_full(fd, sb.buf, sb.len) != sb.len)
			die_errno("failed to write to %s",
				  get_lock_file_path(&shallow_lock));
		commit_lock_file(&shallow_lock);
	} else {
		unlink(git_path_shallow());
		rollback_lock_file(&shallow_lock);
	}
	strbuf_release(&sb);
}

struct trace_key trace_shallow = TRACE_KEY_INIT(SHALLOW);

/*
 * Step 1, split sender shallow commits into "ours" and "theirs"
 * Step 2, clean "ours" based on .git/shallow
 */
void prepare_shallow_info(struct shallow_info *info, struct sha1_array *sa)
{
	int i;
	trace_printf_key(&trace_shallow, "shallow: prepare_shallow_info\n");
	memset(info, 0, sizeof(*info));
	info->shallow = sa;
	if (!sa)
		return;
	ALLOC_ARRAY(info->ours, sa->nr);
	ALLOC_ARRAY(info->theirs, sa->nr);
	for (i = 0; i < sa->nr; i++) {
		if (has_sha1_file(sa->sha1[i])) {
			struct commit_graft *graft;
			graft = lookup_commit_graft(sa->sha1[i]);
			if (graft && graft->nr_parent < 0)
				continue;
			info->ours[info->nr_ours++] = i;
		} else
			info->theirs[info->nr_theirs++] = i;
	}
}

void clear_shallow_info(struct shallow_info *info)
{
	free(info->ours);
	free(info->theirs);
}

/* Step 4, remove non-existent ones in "theirs" after getting the pack */

void remove_nonexistent_theirs_shallow(struct shallow_info *info)
{
	unsigned char (*sha1)[20] = info->shallow->sha1;
	int i, dst;
	trace_printf_key(&trace_shallow, "shallow: remove_nonexistent_theirs_shallow\n");
	for (i = dst = 0; i < info->nr_theirs; i++) {
		if (i != dst)
			info->theirs[dst] = info->theirs[i];
		if (has_sha1_file(sha1[info->theirs[i]]))
			dst++;
	}
	info->nr_theirs = dst;
}

define_commit_slab(ref_bitmap, uint32_t *);

#define POOL_SIZE (512 * 1024)

struct paint_info {
	struct ref_bitmap ref_bitmap;
	unsigned nr_bits;
	char **pools;
	char *free, *end;
	unsigned pool_count;
};

static uint32_t *paint_alloc(struct paint_info *info)
{
	unsigned nr = (info->nr_bits + 31) / 32;
	unsigned size = nr * sizeof(uint32_t);
	void *p;
	if (!info->pool_count || size > info->end - info->free) {
		if (size > POOL_SIZE)
			die("BUG: pool size too small for %d in paint_alloc()",
			    size);
		info->pool_count++;
		REALLOC_ARRAY(info->pools, info->pool_count);
		info->free = xmalloc(POOL_SIZE);
		info->pools[info->pool_count - 1] = info->free;
		info->end = info->free + POOL_SIZE;
	}
	p = info->free;
	info->free += size;
	return p;
}

/*
 * Given a commit SHA-1, walk down to parents until either SEEN,
 * UNINTERESTING or BOTTOM is hit. Set the id-th bit in ref_bitmap for
 * all walked commits.
 */
static void paint_down(struct paint_info *info, const unsigned char *sha1,
		       int id)
{
	unsigned int i, nr;
	struct commit_list *head = NULL;
	int bitmap_nr = (info->nr_bits + 31) / 32;
	size_t bitmap_size = st_mult(bitmap_nr, sizeof(uint32_t));
	uint32_t *tmp = xmalloc(bitmap_size); /* to be freed before return */
	uint32_t *bitmap = paint_alloc(info);
	struct commit *c = lookup_commit_reference_gently(sha1, 1);
	if (!c)
		return;
	memset(bitmap, 0, bitmap_size);
	bitmap[id / 32] |= (1 << (id % 32));
	commit_list_insert(c, &head);
	while (head) {
		struct commit_list *p;
		struct commit *c = pop_commit(&head);
		uint32_t **refs = ref_bitmap_at(&info->ref_bitmap, c);

		/* XXX check "UNINTERESTING" from pack bitmaps if available */
		if (c->object.flags & (SEEN | UNINTERESTING))
			continue;
		else
			c->object.flags |= SEEN;

		if (*refs == NULL)
			*refs = bitmap;
		else {
			memcpy(tmp, *refs, bitmap_size);
			for (i = 0; i < bitmap_nr; i++)
				tmp[i] |= bitmap[i];
			if (memcmp(tmp, *refs, bitmap_size)) {
				*refs = paint_alloc(info);
				memcpy(*refs, tmp, bitmap_size);
			}
		}

		if (c->object.flags & BOTTOM)
			continue;

		if (parse_commit(c))
			die("unable to parse commit %s",
			    oid_to_hex(&c->object.oid));

		for (p = c->parents; p; p = p->next) {
			uint32_t **p_refs = ref_bitmap_at(&info->ref_bitmap,
							  p->item);
			if (p->item->object.flags & SEEN)
				continue;
			if (*p_refs == NULL || *p_refs == *refs)
				*p_refs = *refs;
			commit_list_insert(p->item, &head);
		}
	}

	nr = get_max_object_index();
	for (i = 0; i < nr; i++) {
		struct object *o = get_indexed_object(i);
		if (o && o->type == OBJ_COMMIT)
			o->flags &= ~SEEN;
	}

	free(tmp);
}

static int mark_uninteresting(const char *refname, const struct object_id *oid,
			      int flags, void *cb_data)
{
	struct commit *commit = lookup_commit_reference_gently(oid->hash, 1);
	if (!commit)
		return 0;
	commit->object.flags |= UNINTERESTING;
	mark_parents_uninteresting(commit);
	return 0;
}

static void post_assign_shallow(struct shallow_info *info,
				struct ref_bitmap *ref_bitmap,
				int *ref_status);
/*
 * Step 6(+7), associate shallow commits with new refs
 *
 * info->ref must be initialized before calling this function.
 *
 * If used is not NULL, it's an array of info->shallow->nr
 * bitmaps. The n-th bit set in the m-th bitmap if ref[n] needs the
 * m-th shallow commit from info->shallow.
 *
 * If used is NULL, "ours" and "theirs" are updated. And if ref_status
 * is not NULL it's an array of ref->nr ints. ref_status[i] is true if
 * the ref needs some shallow commits from either info->ours or
 * info->theirs.
 */
void assign_shallow_commits_to_refs(struct shallow_info *info,
				    uint32_t **used, int *ref_status)
{
	unsigned char (*sha1)[20] = info->shallow->sha1;
	struct sha1_array *ref = info->ref;
	unsigned int i, nr;
	int *shallow, nr_shallow = 0;
	struct paint_info pi;

	trace_printf_key(&trace_shallow, "shallow: assign_shallow_commits_to_refs\n");
	ALLOC_ARRAY(shallow, info->nr_ours + info->nr_theirs);
	for (i = 0; i < info->nr_ours; i++)
		shallow[nr_shallow++] = info->ours[i];
	for (i = 0; i < info->nr_theirs; i++)
		shallow[nr_shallow++] = info->theirs[i];

	/*
	 * Prepare the commit graph to track what refs can reach what
	 * (new) shallow commits.
	 */
	nr = get_max_object_index();
	for (i = 0; i < nr; i++) {
		struct object *o = get_indexed_object(i);
		if (!o || o->type != OBJ_COMMIT)
			continue;

		o->flags &= ~(UNINTERESTING | BOTTOM | SEEN);
	}

	memset(&pi, 0, sizeof(pi));
	init_ref_bitmap(&pi.ref_bitmap);
	pi.nr_bits = ref->nr;

	/*
	 * "--not --all" to cut short the traversal if new refs
	 * connect to old refs. If not (e.g. force ref updates) it'll
	 * have to go down to the current shallow commits.
	 */
	head_ref(mark_uninteresting, NULL);
	for_each_ref(mark_uninteresting, NULL);

	/* Mark potential bottoms so we won't go out of bound */
	for (i = 0; i < nr_shallow; i++) {
		struct commit *c = lookup_commit(sha1[shallow[i]]);
		c->object.flags |= BOTTOM;
	}

	for (i = 0; i < ref->nr; i++)
		paint_down(&pi, ref->sha1[i], i);

	if (used) {
		int bitmap_size = ((pi.nr_bits + 31) / 32) * sizeof(uint32_t);
		memset(used, 0, sizeof(*used) * info->shallow->nr);
		for (i = 0; i < nr_shallow; i++) {
			const struct commit *c = lookup_commit(sha1[shallow[i]]);
			uint32_t **map = ref_bitmap_at(&pi.ref_bitmap, c);
			if (*map)
				used[shallow[i]] = xmemdupz(*map, bitmap_size);
		}
		/*
		 * unreachable shallow commits are not removed from
		 * "ours" and "theirs". The user is supposed to run
		 * step 7 on every ref separately and not trust "ours"
		 * and "theirs" any more.
		 */
	} else
		post_assign_shallow(info, &pi.ref_bitmap, ref_status);

	clear_ref_bitmap(&pi.ref_bitmap);
	for (i = 0; i < pi.pool_count; i++)
		free(pi.pools[i]);
	free(pi.pools);
	free(shallow);
}

struct commit_array {
	struct commit **commits;
	int nr, alloc;
};

static int add_ref(const char *refname, const struct object_id *oid,
		   int flags, void *cb_data)
{
	struct commit_array *ca = cb_data;
	ALLOC_GROW(ca->commits, ca->nr + 1, ca->alloc);
	ca->commits[ca->nr] = lookup_commit_reference_gently(oid->hash, 1);
	if (ca->commits[ca->nr])
		ca->nr++;
	return 0;
}

static void update_refstatus(int *ref_status, int nr, uint32_t *bitmap)
{
	int i;
	if (!ref_status)
		return;
	for (i = 0; i < nr; i++)
		if (bitmap[i / 32] & (1 << (i % 32)))
			ref_status[i]++;
}

/*
 * Step 7, reachability test on "ours" at commit level
 */
static void post_assign_shallow(struct shallow_info *info,
				struct ref_bitmap *ref_bitmap,
				int *ref_status)
{
	unsigned char (*sha1)[20] = info->shallow->sha1;
	struct commit *c;
	uint32_t **bitmap;
	int dst, i, j;
	int bitmap_nr = (info->ref->nr + 31) / 32;
	struct commit_array ca;

	trace_printf_key(&trace_shallow, "shallow: post_assign_shallow\n");
	if (ref_status)
		memset(ref_status, 0, sizeof(*ref_status) * info->ref->nr);

	/* Remove unreachable shallow commits from "theirs" */
	for (i = dst = 0; i < info->nr_theirs; i++) {
		if (i != dst)
			info->theirs[dst] = info->theirs[i];
		c = lookup_commit(sha1[info->theirs[i]]);
		bitmap = ref_bitmap_at(ref_bitmap, c);
		if (!*bitmap)
			continue;
		for (j = 0; j < bitmap_nr; j++)
			if (bitmap[0][j]) {
				update_refstatus(ref_status, info->ref->nr, *bitmap);
				dst++;
				break;
			}
	}
	info->nr_theirs = dst;

	memset(&ca, 0, sizeof(ca));
	head_ref(add_ref, &ca);
	for_each_ref(add_ref, &ca);

	/* Remove unreachable shallow commits from "ours" */
	for (i = dst = 0; i < info->nr_ours; i++) {
		if (i != dst)
			info->ours[dst] = info->ours[i];
		c = lookup_commit(sha1[info->ours[i]]);
		bitmap = ref_bitmap_at(ref_bitmap, c);
		if (!*bitmap)
			continue;
		for (j = 0; j < bitmap_nr; j++)
			if (bitmap[0][j] &&
			    /* Step 7, reachability test at commit level */
			    !in_merge_bases_many(c, ca.nr, ca.commits)) {
				update_refstatus(ref_status, info->ref->nr, *bitmap);
				dst++;
				break;
			}
	}
	info->nr_ours = dst;

	free(ca.commits);
}

/* (Delayed) step 7, reachability test at commit level */
int delayed_reachability_test(struct shallow_info *si, int c)
{
	if (si->need_reachability_test[c]) {
		struct commit *commit = lookup_commit(si->shallow->sha1[c]);

		if (!si->commits) {
			struct commit_array ca;

			memset(&ca, 0, sizeof(ca));
			head_ref(add_ref, &ca);
			for_each_ref(add_ref, &ca);
			si->commits = ca.commits;
			si->nr_commits = ca.nr;
		}

		si->reachable[c] = in_merge_bases_many(commit,
						       si->nr_commits,
						       si->commits);
		si->need_reachability_test[c] = 0;
	}
	return si->reachable[c];
}
Commit	Line	Data
ed09aef0	1	#include "cache.h"
6e122b44	2	#include "tempfile.h"
697cc8ef	3	#include "lockfile.h"
ed09aef0	4	#include "commit.h"
abef3a16	5	#include "tag.h"
3125fe52	6	#include "pkt-line.h"
58babfff NTND	7	#include "remote.h"
	8	#include "refs.h"
	9	#include "sha1-array.h"
	10	#include "diff.h"
	11	#include "revision.h"
	12	#include "commit-slab.h"
ed09aef0 JS	13
ed09aef0 JS	14	static int is_shallow = -1;
0cc77c38	15	static struct stat_validity shallow_stat;
6035d6aa NTND	16	static char *alternate_shallow_file;
6035d6aa NTND	17
069c0532	18	void set_alternate_shallow_file(const char *path, int override)
6035d6aa NTND	19	{
	20	if (is_shallow != -1)
	21	die("BUG: is_repository_shallow must not be called before set_alternate_shallow_file");
069c0532 NTND	22	if (alternate_shallow_file && !override)
069c0532 NTND	23	return;
6035d6aa	24	free(alternate_shallow_file);
8c53f071	25	alternate_shallow_file = xstrdup_or_null(path);
6035d6aa	26	}
ed09aef0 JS	27
	28	int register_shallow(const unsigned char *sha1)
	29	{
	30	struct commit_graft *graft =
	31	xmalloc(sizeof(struct commit_graft));
	32	struct commit *commit = lookup_commit(sha1);
	33
7683e2e6	34	hashcpy(graft->oid.hash, sha1);
ed09aef0 JS	35	graft->nr_parent = -1;
	36	if (commit && commit->object.parsed)
	37	commit->parents = NULL;
	38	return register_commit_graft(graft, 0);
	39	}
	40
f43117a6	41	int is_repository_shallow(void)
ed09aef0 JS	42	{
	43	FILE *fp;
	44	char buf[1024];
6035d6aa	45	const char *path = alternate_shallow_file;
ed09aef0 JS	46
	47	if (is_shallow >= 0)
	48	return is_shallow;
	49
6035d6aa	50	if (!path)
f932729c	51	path = git_path_shallow();
6035d6aa NTND	52	/*
	53	* fetch-pack sets '--shallow-file ""' as an indicator that no
	54	* shallow file should be used. We could just open it and it
	55	* will likely fail. But let's do an explicit check instead.
	56	*/
0cc77c38 JK	57	if (!*path \|\| (fp = fopen(path, "r")) == NULL) {
0cc77c38 JK	58	stat_validity_clear(&shallow_stat);
ed09aef0 JS	59	is_shallow = 0;
	60	return is_shallow;
	61	}
0cc77c38	62	stat_validity_update(&shallow_stat, fileno(fp));
ed09aef0 JS	63	is_shallow = 1;
	64
	65	while (fgets(buf, sizeof(buf), fp)) {
	66	unsigned char sha1[20];
	67	if (get_sha1_hex(buf, sha1))
	68	die("bad shallow line: %s", buf);
	69	register_shallow(sha1);
	70	}
	71	fclose(fp);
	72	return is_shallow;
	73	}
	74
f53514bc JS	75	struct commit_list get_shallow_commits(struct object_array heads, int depth,
f53514bc JS	76	int shallow_flag, int not_shallow_flag)
ed09aef0 JS	77	{
	78	int i = 0, cur_depth = 0;
	79	struct commit_list *result = NULL;
3cd47459	80	struct object_array stack = OBJECT_ARRAY_INIT;
ed09aef0	81	struct commit *commit = NULL;
79d3a236	82	struct commit_graft *graft;
ed09aef0 JS	83
	84	while (commit \|\| i < heads->nr \|\| stack.nr) {
	85	struct commit_list *p;
	86	if (!commit) {
	87	if (i < heads->nr) {
	88	commit = (struct commit *)
abef3a16	89	deref_tag(heads->objects[i++].item, NULL, 0);
affeef12	90	if (!commit \|\| commit->object.type != OBJ_COMMIT) {
ed09aef0 JS	91	commit = NULL;
	92	continue;
	93	}
d64d6c9f AJ	94	if (!commit->util)
	95	commit->util = xmalloc(sizeof(int));
	96	(int )commit->util = 0;
ed09aef0 JS	97	cur_depth = 0;
	98	} else {
	99	commit = (struct commit *)
	100	stack.objects[--stack.nr].item;
	101	cur_depth = (int )commit->util;
	102	}
	103	}
367068e0	104	parse_commit_or_die(commit);
ed09aef0	105	cur_depth++;
79d3a236 NTND	106	if ((depth != INFINITE_DEPTH && cur_depth >= depth) \|\|
79d3a236 NTND	107	(is_repository_shallow() && !commit->parents &&
ed1c9977	108	(graft = lookup_commit_graft(commit->object.oid.hash)) != NULL &&
79d3a236	109	graft->nr_parent < 0)) {
682c7d2f NTND	110	commit_list_insert(commit, &result);
	111	commit->object.flags \|= shallow_flag;
	112	commit = NULL;
	113	continue;
	114	}
	115	commit->object.flags \|= not_shallow_flag;
ed09aef0 JS	116	for (p = commit->parents, commit = NULL; p; p = p->next) {
	117	if (!p->item->util) {
	118	int *pointer = xmalloc(sizeof(int));
	119	p->item->util = pointer;
	120	*pointer = cur_depth;
	121	} else {
	122	int *pointer = p->item->util;
	123	if (cur_depth >= *pointer)
	124	continue;
	125	*pointer = cur_depth;
	126	}
4b796951 MK	127	if (p->next)
	128	add_object_array(&p->item->object,
	129	NULL, &stack);
	130	else {
	131	commit = p->item;
	132	cur_depth = (int )commit->util;
f53514bc	133	}
ed09aef0 JS	134	}
	135	}
	136
	137	return result;
	138	}
6035d6aa	139
167832c2	140	static void check_shallow_file_for_update(void)
6035d6aa	141	{
0cc77c38	142	if (is_shallow == -1)
6035d6aa NTND	143	die("BUG: shallow must be initialized by now");
6035d6aa NTND	144
f932729c	145	if (!stat_validity_check(&shallow_stat, git_path_shallow()))
0cc77c38	146	die("shallow file has changed since we read it");
6035d6aa	147	}
3125fe52	148
eab3296c NTND	149	#define SEEN_ONLY 1
	150	#define VERBOSE 2
	151
3125fe52 NTND	152	struct write_shallow_data {
	153	struct strbuf *out;
	154	int use_pack_protocol;
	155	int count;
eab3296c	156	unsigned flags;
3125fe52 NTND	157	};
	158
	159	static int write_one_shallow(const struct commit_graft graft, void cb_data)
	160	{
	161	struct write_shallow_data *data = cb_data;
7683e2e6	162	const char *hex = oid_to_hex(&graft->oid);
6a3bbb4d NTND	163	if (graft->nr_parent != -1)
6a3bbb4d NTND	164	return 0;
eab3296c	165	if (data->flags & SEEN_ONLY) {
7683e2e6	166	struct commit *c = lookup_commit(graft->oid.hash);
eab3296c NTND	167	if (!c \|\| !(c->object.flags & SEEN)) {
	168	if (data->flags & VERBOSE)
	169	printf("Removing %s from .git/shallow\n",
f2fd0760	170	oid_to_hex(&c->object.oid));
eab3296c NTND	171	return 0;
	172	}
	173	}
3125fe52 NTND	174	data->count++;
	175	if (data->use_pack_protocol)
	176	packet_buf_write(data->out, "shallow %s", hex);
	177	else {
	178	strbuf_addstr(data->out, hex);
	179	strbuf_addch(data->out, '\n');
	180	}
	181	return 0;
	182	}
	183
eab3296c NTND	184	static int write_shallow_commits_1(struct strbuf *out, int use_pack_protocol,
	185	const struct sha1_array *extra,
	186	unsigned flags)
3125fe52 NTND	187	{
3125fe52 NTND	188	struct write_shallow_data data;
1a30f5a2	189	int i;
3125fe52 NTND	190	data.out = out;
	191	data.use_pack_protocol = use_pack_protocol;
	192	data.count = 0;
eab3296c	193	data.flags = flags;
3125fe52	194	for_each_commit_graft(write_one_shallow, &data);
1a30f5a2 NTND	195	if (!extra)
	196	return data.count;
	197	for (i = 0; i < extra->nr; i++) {
	198	strbuf_addstr(out, sha1_to_hex(extra->sha1[i]));
	199	strbuf_addch(out, '\n');
	200	data.count++;
	201	}
3125fe52 NTND	202	return data.count;
	203	}
	204
eab3296c NTND	205	int write_shallow_commits(struct strbuf *out, int use_pack_protocol,
	206	const struct sha1_array *extra)
	207	{
	208	return write_shallow_commits_1(out, use_pack_protocol, extra, 0);
	209	}
	210
6e122b44	211	static struct tempfile temporary_shallow;
0179c945 JK	212
0179c945 JK	213	const char setup_temporary_shallow(const struct sha1_array extra)
08ea65ad NTND	214	{
	215	struct strbuf sb = STRBUF_INIT;
	216	int fd;
	217
1a30f5a2	218	if (write_shallow_commits(&sb, 0, extra)) {
6e122b44	219	fd = xmks_tempfile(&temporary_shallow, git_path("shallow_XXXXXX"));
0179c945	220
08ea65ad NTND	221	if (write_in_full(fd, sb.buf, sb.len) != sb.len)
08ea65ad NTND	222	die_errno("failed to write to %s",
6e122b44 MH	223	get_tempfile_path(&temporary_shallow));
6e122b44 MH	224	close_tempfile(&temporary_shallow);
08ea65ad	225	strbuf_release(&sb);
6e122b44	226	return get_tempfile_path(&temporary_shallow);
08ea65ad NTND	227	}
	228	/*
	229	* is_repository_shallow() sees empty string as "no shallow
	230	* file".
	231	*/
6e122b44	232	return get_tempfile_path(&temporary_shallow);
08ea65ad NTND	233	}
08ea65ad NTND	234
3125fe52	235	void setup_alternate_shallow(struct lock_file *shallow_lock,
1a30f5a2 NTND	236	const char **alternate_shallow_file,
1a30f5a2 NTND	237	const struct sha1_array *extra)
3125fe52 NTND	238	{
	239	struct strbuf sb = STRBUF_INIT;
	240	int fd;
	241
f932729c	242	fd = hold_lock_file_for_update(shallow_lock, git_path_shallow(),
3125fe52	243	LOCK_DIE_ON_ERROR);
78396321	244	check_shallow_file_for_update();
1a30f5a2	245	if (write_shallow_commits(&sb, 0, extra)) {
3125fe52 NTND	246	if (write_in_full(fd, sb.buf, sb.len) != sb.len)
3125fe52 NTND	247	die_errno("failed to write to %s",
b4fb09e4 MH	248	get_lock_file_path(shallow_lock));
b4fb09e4 MH	249	*alternate_shallow_file = get_lock_file_path(shallow_lock);
3125fe52 NTND	250	} else
	251	/*
	252	* is_repository_shallow() sees empty string as "no
	253	* shallow file".
	254	*/
	255	*alternate_shallow_file = "";
	256	strbuf_release(&sb);
	257	}
ad491366 NTND	258
	259	static int advertise_shallow_grafts_cb(const struct commit_graft graft, void cb)
	260	{
	261	int fd = (int )cb;
	262	if (graft->nr_parent == -1)
7683e2e6	263	packet_write(fd, "shallow %s\n", oid_to_hex(&graft->oid));
ad491366 NTND	264	return 0;
	265	}
	266
	267	void advertise_shallow_grafts(int fd)
	268	{
	269	if (!is_repository_shallow())
	270	return;
	271	for_each_commit_graft(advertise_shallow_grafts_cb, &fd);
	272	}
58babfff	273
eab3296c NTND	274	/*
	275	* mark_reachable_objects() should have been run prior to this and all
	276	* reachable commits marked as "SEEN".
	277	*/
	278	void prune_shallow(int show_only)
	279	{
	280	static struct lock_file shallow_lock;
	281	struct strbuf sb = STRBUF_INIT;
	282	int fd;
	283
	284	if (show_only) {
	285	write_shallow_commits_1(&sb, 0, NULL, SEEN_ONLY \| VERBOSE);
	286	strbuf_release(&sb);
	287	return;
	288	}
f932729c	289	fd = hold_lock_file_for_update(&shallow_lock, git_path_shallow(),
eab3296c	290	LOCK_DIE_ON_ERROR);
78396321	291	check_shallow_file_for_update();
eab3296c NTND	292	if (write_shallow_commits_1(&sb, 0, NULL, SEEN_ONLY)) {
	293	if (write_in_full(fd, sb.buf, sb.len) != sb.len)
	294	die_errno("failed to write to %s",
b4fb09e4	295	get_lock_file_path(&shallow_lock));
eab3296c NTND	296	commit_lock_file(&shallow_lock);
eab3296c NTND	297	} else {
f932729c	298	unlink(git_path_shallow());
eab3296c NTND	299	rollback_lock_file(&shallow_lock);
	300	}
	301	strbuf_release(&sb);
	302	}
	303
6aa30857	304	struct trace_key trace_shallow = TRACE_KEY_INIT(SHALLOW);
58babfff NTND	305
	306	/*
	307	* Step 1, split sender shallow commits into "ours" and "theirs"
	308	* Step 2, clean "ours" based on .git/shallow
	309	*/
	310	void prepare_shallow_info(struct shallow_info info, struct sha1_array sa)
	311	{
	312	int i;
6aa30857	313	trace_printf_key(&trace_shallow, "shallow: prepare_shallow_info\n");
58babfff NTND	314	memset(info, 0, sizeof(*info));
	315	info->shallow = sa;
	316	if (!sa)
	317	return;
b32fa95f JK	318	ALLOC_ARRAY(info->ours, sa->nr);
b32fa95f JK	319	ALLOC_ARRAY(info->theirs, sa->nr);
58babfff NTND	320	for (i = 0; i < sa->nr; i++) {
	321	if (has_sha1_file(sa->sha1[i])) {
	322	struct commit_graft *graft;
	323	graft = lookup_commit_graft(sa->sha1[i]);
	324	if (graft && graft->nr_parent < 0)
	325	continue;
	326	info->ours[info->nr_ours++] = i;
	327	} else
	328	info->theirs[info->nr_theirs++] = i;
	329	}
	330	}
	331
	332	void clear_shallow_info(struct shallow_info *info)
	333	{
	334	free(info->ours);
	335	free(info->theirs);
	336	}
	337
	338	/* Step 4, remove non-existent ones in "theirs" after getting the pack */
	339
	340	void remove_nonexistent_theirs_shallow(struct shallow_info *info)
	341	{
	342	unsigned char (*sha1)[20] = info->shallow->sha1;
	343	int i, dst;
6aa30857	344	trace_printf_key(&trace_shallow, "shallow: remove_nonexistent_theirs_shallow\n");
58babfff NTND	345	for (i = dst = 0; i < info->nr_theirs; i++) {
	346	if (i != dst)
	347	info->theirs[dst] = info->theirs[i];
	348	if (has_sha1_file(sha1[info->theirs[i]]))
	349	dst++;
	350	}
	351	info->nr_theirs = dst;
	352	}
	353
8e277383 NTND	354	define_commit_slab(ref_bitmap, uint32_t *);
8e277383 NTND	355
6bc3d8c5 NTND	356	#define POOL_SIZE (512 * 1024)
6bc3d8c5 NTND	357
8e277383 NTND	358	struct paint_info {
	359	struct ref_bitmap ref_bitmap;
	360	unsigned nr_bits;
0afd307a	361	char **pools;
8e277383	362	char free, end;
0afd307a	363	unsigned pool_count;
8e277383 NTND	364	};
	365
	366	static uint32_t paint_alloc(struct paint_info info)
	367	{
	368	unsigned nr = (info->nr_bits + 31) / 32;
	369	unsigned size = nr * sizeof(uint32_t);
	370	void *p;
381aa8e7	371	if (!info->pool_count \|\| size > info->end - info->free) {
f2386c6b NTND	372	if (size > POOL_SIZE)
	373	die("BUG: pool size too small for %d in paint_alloc()",
	374	size);
0afd307a NTND	375	info->pool_count++;
0afd307a NTND	376	REALLOC_ARRAY(info->pools, info->pool_count);
6bc3d8c5	377	info->free = xmalloc(POOL_SIZE);
0afd307a	378	info->pools[info->pool_count - 1] = info->free;
6bc3d8c5	379	info->end = info->free + POOL_SIZE;
8e277383 NTND	380	}
	381	p = info->free;
	382	info->free += size;
	383	return p;
	384	}
	385
	386	/*
	387	* Given a commit SHA-1, walk down to parents until either SEEN,
	388	* UNINTERESTING or BOTTOM is hit. Set the id-th bit in ref_bitmap for
	389	* all walked commits.
	390	*/
	391	static void paint_down(struct paint_info info, const unsigned char sha1,
	392	int id)
	393	{
	394	unsigned int i, nr;
	395	struct commit_list *head = NULL;
	396	int bitmap_nr = (info->nr_bits + 31) / 32;
50a6c8ef	397	size_t bitmap_size = st_mult(bitmap_nr, sizeof(uint32_t));
8e277383 NTND	398	uint32_t tmp = xmalloc(bitmap_size); / to be freed before return */
	399	uint32_t *bitmap = paint_alloc(info);
	400	struct commit *c = lookup_commit_reference_gently(sha1, 1);
	401	if (!c)
	402	return;
	403	memset(bitmap, 0, bitmap_size);
	404	bitmap[id / 32] \|= (1 << (id % 32));
	405	commit_list_insert(c, &head);
	406	while (head) {
	407	struct commit_list *p;
e510ab89	408	struct commit *c = pop_commit(&head);
8e277383 NTND	409	uint32_t **refs = ref_bitmap_at(&info->ref_bitmap, c);
8e277383 NTND	410
8e277383 NTND	411	/* XXX check "UNINTERESTING" from pack bitmaps if available */
	412	if (c->object.flags & (SEEN \| UNINTERESTING))
	413	continue;
	414	else
	415	c->object.flags \|= SEEN;
	416
	417	if (*refs == NULL)
	418	*refs = bitmap;
	419	else {
	420	memcpy(tmp, *refs, bitmap_size);
	421	for (i = 0; i < bitmap_nr; i++)
	422	tmp[i] \|= bitmap[i];
	423	if (memcmp(tmp, *refs, bitmap_size)) {
	424	*refs = paint_alloc(info);
	425	memcpy(*refs, tmp, bitmap_size);
	426	}
	427	}
	428
	429	if (c->object.flags & BOTTOM)
	430	continue;
	431
	432	if (parse_commit(c))
	433	die("unable to parse commit %s",
f2fd0760	434	oid_to_hex(&c->object.oid));
8e277383 NTND	435
	436	for (p = c->parents; p; p = p->next) {
	437	uint32_t **p_refs = ref_bitmap_at(&info->ref_bitmap,
	438	p->item);
	439	if (p->item->object.flags & SEEN)
	440	continue;
	441	if (p_refs == NULL \|\| p_refs == *refs)
	442	p_refs = refs;
	443	commit_list_insert(p->item, &head);
	444	}
	445	}
	446
	447	nr = get_max_object_index();
	448	for (i = 0; i < nr; i++) {
	449	struct object *o = get_indexed_object(i);
	450	if (o && o->type == OBJ_COMMIT)
	451	o->flags &= ~SEEN;
	452	}
	453
	454	free(tmp);
	455	}
	456
580b04ef	457	static int mark_uninteresting(const char refname, const struct object_id oid,
8e277383 NTND	458	int flags, void *cb_data)
8e277383 NTND	459	{
580b04ef	460	struct commit *commit = lookup_commit_reference_gently(oid->hash, 1);
8e277383 NTND	461	if (!commit)
	462	return 0;
	463	commit->object.flags \|= UNINTERESTING;
	464	mark_parents_uninteresting(commit);
	465	return 0;
	466	}
	467
	468	static void post_assign_shallow(struct shallow_info *info,
	469	struct ref_bitmap *ref_bitmap,
	470	int *ref_status);
	471	/*
	472	* Step 6(+7), associate shallow commits with new refs
	473	*
	474	* info->ref must be initialized before calling this function.
	475	*
	476	* If used is not NULL, it's an array of info->shallow->nr
	477	* bitmaps. The n-th bit set in the m-th bitmap if ref[n] needs the
	478	* m-th shallow commit from info->shallow.
	479	*
	480	* If used is NULL, "ours" and "theirs" are updated. And if ref_status
	481	* is not NULL it's an array of ref->nr ints. ref_status[i] is true if
	482	* the ref needs some shallow commits from either info->ours or
	483	* info->theirs.
	484	*/
	485	void assign_shallow_commits_to_refs(struct shallow_info *info,
	486	uint32_t *used, int ref_status)
	487	{
	488	unsigned char (*sha1)[20] = info->shallow->sha1;
	489	struct sha1_array *ref = info->ref;
	490	unsigned int i, nr;
	491	int *shallow, nr_shallow = 0;
	492	struct paint_info pi;
	493
6aa30857	494	trace_printf_key(&trace_shallow, "shallow: assign_shallow_commits_to_refs\n");
b32fa95f	495	ALLOC_ARRAY(shallow, info->nr_ours + info->nr_theirs);
8e277383 NTND	496	for (i = 0; i < info->nr_ours; i++)
	497	shallow[nr_shallow++] = info->ours[i];
	498	for (i = 0; i < info->nr_theirs; i++)
	499	shallow[nr_shallow++] = info->theirs[i];
	500
	501	/*
	502	* Prepare the commit graph to track what refs can reach what
	503	* (new) shallow commits.
	504	*/
	505	nr = get_max_object_index();
	506	for (i = 0; i < nr; i++) {
	507	struct object *o = get_indexed_object(i);
	508	if (!o \|\| o->type != OBJ_COMMIT)
	509	continue;
	510
	511	o->flags &= ~(UNINTERESTING \| BOTTOM \| SEEN);
	512	}
	513
	514	memset(&pi, 0, sizeof(pi));
	515	init_ref_bitmap(&pi.ref_bitmap);
	516	pi.nr_bits = ref->nr;
	517
	518	/*
	519	* "--not --all" to cut short the traversal if new refs
	520	* connect to old refs. If not (e.g. force ref updates) it'll
	521	* have to go down to the current shallow commits.
	522	*/
580b04ef MH	523	head_ref(mark_uninteresting, NULL);
580b04ef MH	524	for_each_ref(mark_uninteresting, NULL);
8e277383 NTND	525
	526	/* Mark potential bottoms so we won't go out of bound */
	527	for (i = 0; i < nr_shallow; i++) {
	528	struct commit *c = lookup_commit(sha1[shallow[i]]);
	529	c->object.flags \|= BOTTOM;
	530	}
	531
	532	for (i = 0; i < ref->nr; i++)
	533	paint_down(&pi, ref->sha1[i], i);
	534
	535	if (used) {
	536	int bitmap_size = ((pi.nr_bits + 31) / 32) * sizeof(uint32_t);
	537	memset(used, 0, sizeof(used) info->shallow->nr);
	538	for (i = 0; i < nr_shallow; i++) {
	539	const struct commit *c = lookup_commit(sha1[shallow[i]]);
	540	uint32_t **map = ref_bitmap_at(&pi.ref_bitmap, c);
	541	if (*map)
	542	used[shallow[i]] = xmemdupz(*map, bitmap_size);
	543	}
	544	/*
	545	* unreachable shallow commits are not removed from
	546	* "ours" and "theirs". The user is supposed to run
	547	* step 7 on every ref separately and not trust "ours"
	548	* and "theirs" any more.
	549	*/
	550	} else
	551	post_assign_shallow(info, &pi.ref_bitmap, ref_status);
	552
	553	clear_ref_bitmap(&pi.ref_bitmap);
0afd307a NTND	554	for (i = 0; i < pi.pool_count; i++)
	555	free(pi.pools[i]);
	556	free(pi.pools);
8e277383 NTND	557	free(shallow);
	558	}
	559
	560	struct commit_array {
	561	struct commit **commits;
	562	int nr, alloc;
	563	};
	564
580b04ef MH	565	static int add_ref(const char refname, const struct object_id oid,
580b04ef MH	566	int flags, void *cb_data)
8e277383 NTND	567	{
	568	struct commit_array *ca = cb_data;
	569	ALLOC_GROW(ca->commits, ca->nr + 1, ca->alloc);
580b04ef	570	ca->commits[ca->nr] = lookup_commit_reference_gently(oid->hash, 1);
8e277383 NTND	571	if (ca->commits[ca->nr])
	572	ca->nr++;
	573	return 0;
	574	}
	575
	576	static void update_refstatus(int ref_status, int nr, uint32_t bitmap)
	577	{
	578	int i;
	579	if (!ref_status)
	580	return;
	581	for (i = 0; i < nr; i++)
	582	if (bitmap[i / 32] & (1 << (i % 32)))
	583	ref_status[i]++;
	584	}
	585
	586	/*
	587	* Step 7, reachability test on "ours" at commit level
	588	*/
	589	static void post_assign_shallow(struct shallow_info *info,
	590	struct ref_bitmap *ref_bitmap,
	591	int *ref_status)
	592	{
	593	unsigned char (*sha1)[20] = info->shallow->sha1;
	594	struct commit *c;
	595	uint32_t **bitmap;
	596	int dst, i, j;
	597	int bitmap_nr = (info->ref->nr + 31) / 32;
	598	struct commit_array ca;
	599
6aa30857	600	trace_printf_key(&trace_shallow, "shallow: post_assign_shallow\n");
8e277383 NTND	601	if (ref_status)
	602	memset(ref_status, 0, sizeof(ref_status) info->ref->nr);
	603
	604	/* Remove unreachable shallow commits from "theirs" */
	605	for (i = dst = 0; i < info->nr_theirs; i++) {
	606	if (i != dst)
	607	info->theirs[dst] = info->theirs[i];
	608	c = lookup_commit(sha1[info->theirs[i]]);
	609	bitmap = ref_bitmap_at(ref_bitmap, c);
	610	if (!*bitmap)
	611	continue;
	612	for (j = 0; j < bitmap_nr; j++)
	613	if (bitmap[0][j]) {
	614	update_refstatus(ref_status, info->ref->nr, *bitmap);
	615	dst++;
	616	break;
	617	}
	618	}
	619	info->nr_theirs = dst;
	620
	621	memset(&ca, 0, sizeof(ca));
580b04ef MH	622	head_ref(add_ref, &ca);
580b04ef MH	623	for_each_ref(add_ref, &ca);
8e277383 NTND	624
	625	/* Remove unreachable shallow commits from "ours" */
	626	for (i = dst = 0; i < info->nr_ours; i++) {
	627	if (i != dst)
	628	info->ours[dst] = info->ours[i];
	629	c = lookup_commit(sha1[info->ours[i]]);
	630	bitmap = ref_bitmap_at(ref_bitmap, c);
	631	if (!*bitmap)
	632	continue;
	633	for (j = 0; j < bitmap_nr; j++)
	634	if (bitmap[0][j] &&
	635	/* Step 7, reachability test at commit level */
	636	!in_merge_bases_many(c, ca.nr, ca.commits)) {
	637	update_refstatus(ref_status, info->ref->nr, *bitmap);
	638	dst++;
	639	break;
	640	}
	641	}
	642	info->nr_ours = dst;
	643
	644	free(ca.commits);
	645	}
0a1bc12b NTND	646
	647	/* (Delayed) step 7, reachability test at commit level */
	648	int delayed_reachability_test(struct shallow_info *si, int c)
	649	{
	650	if (si->need_reachability_test[c]) {
	651	struct commit *commit = lookup_commit(si->shallow->sha1[c]);
	652
	653	if (!si->commits) {
	654	struct commit_array ca;
2b2a5be3	655
0a1bc12b	656	memset(&ca, 0, sizeof(ca));
580b04ef MH	657	head_ref(add_ref, &ca);
580b04ef MH	658	for_each_ref(add_ref, &ca);
0a1bc12b NTND	659	si->commits = ca.commits;
	660	si->nr_commits = ca.nr;
	661	}
	662
	663	si->reachable[c] = in_merge_bases_many(commit,
	664	si->nr_commits,
	665	si->commits);
	666	si->need_reachability_test[c] = 0;
	667	}
	668	return si->reachable[c];
	669	}