[thirdparty/git.git] / fsck-cache.c

#include "cache.h"

#include <sys/types.h>
#include <dirent.h>

/*
 * The low 16 bits of the "flags" field shows whether
 * a commit is part of the path to the root for that
 * parent.
 *
 * Bit 16 is an internal flag that we've seen the
 * definition for this rev, and not just seen it as
 * a parent target.
 */
#define MAX_COMMITS (16)
#define marked(rev)	((rev)->flags & 0xffff)
#define SEEN 0x10000
#define USED 0x20000
#define REACHABLE 0x40000

static int show_unreachable = 0;
static int head_supplied = 0;
static unsigned char head_sha1[20];

struct parent {
	struct revision *parent;
	struct parent *next;
};

struct revision {
	unsigned int flags;
	unsigned char sha1[20];
	unsigned long date;
	struct parent *parent;
};

static struct revision **revs;
static int nr_revs, rev_allocs;

static int find_rev(unsigned char *sha1)
{
	int first = 0, last = nr_revs;

	while (first < last) {
		int next = (first + last) / 2;
		struct revision *rev = revs[next];
		int cmp;

		cmp = memcmp(sha1, rev->sha1, 20);
		if (!cmp)
			return next;
		if (cmp < 0) {
			last = next;
			continue;
		}
		first = next+1;
	}
	return -first-1;
}

static struct revision *lookup_rev(unsigned char *sha1)
{
	int pos = find_rev(sha1);
	struct revision *n;

	if (pos >= 0)
		return revs[pos];
	
	pos = -pos-1;

	if (rev_allocs == nr_revs) {
		rev_allocs = alloc_nr(rev_allocs);
		revs = realloc(revs, rev_allocs * sizeof(struct revision *));
	}
	n = malloc(sizeof(struct revision));

	n->flags = 0;
	memcpy(n->sha1, sha1, 20);
	n->parent = NULL;

	/* Insert it into the right place */
	memmove(revs + pos + 1, revs + pos, (nr_revs - pos) * sizeof(struct revision *));
	revs[pos] = n;
	nr_revs++;

	return n;
}

static struct revision *add_relationship(struct revision *rev, unsigned char *needs)
{
	struct revision *parent_rev = lookup_rev(needs);
	struct parent **pp = &rev->parent, *p;

	while ((p = *pp) != NULL) {
		if (p->parent == parent_rev)
			return parent_rev;
		pp = &p->next;
	}

	p = malloc(sizeof(*p));
	p->parent = parent_rev;
	p->next = NULL;
	*pp = p;
	return parent_rev;
}

static void mark_reachable(struct revision *rev)
{
	struct parent *p = rev->parent;

	/* If we've been here already, don't bother */
	if (rev->flags & REACHABLE)
		return;
	rev->flags |= REACHABLE | USED;
	while (p) {
		mark_reachable(p->parent);
		p = p->next;
	}
}

static void check_connectivity(void)
{
	int i;

	if (head_supplied)
		mark_reachable(lookup_rev(head_sha1));

	/* Look up all the requirements, warn about missing objects.. */
	for (i = 0; i < nr_revs; i++) {
		struct revision *rev = revs[i];

		if (show_unreachable && !(rev->flags & REACHABLE)) {
			printf("unreachable %s\n", sha1_to_hex(rev->sha1));
			continue;
		}

		switch (rev->flags & (SEEN | USED)) {
		case 0:
			printf("bad %s\n", sha1_to_hex(rev->sha1));
			break;
		case USED:
			printf("missing %s\n", sha1_to_hex(rev->sha1));
			break;
		case SEEN:
			printf("dangling %s\n", sha1_to_hex(rev->sha1));
			break;
		}
	}
}

static void mark_needs_sha1(unsigned char *parent, const char * tag, unsigned char *child)
{
	struct revision * child_rev = add_relationship(lookup_rev(parent), child);
	child_rev->flags |= USED;
}

static int mark_sha1_seen(unsigned char *sha1, char *tag)
{
	struct revision *rev = lookup_rev(sha1);

	rev->flags |= SEEN;
	return 0;
}

static int fsck_tree(unsigned char *sha1, void *data, unsigned long size)
{
	int warn_old_tree = 1;

	while (size) {
		int len = 1+strlen(data);
		unsigned char *file_sha1 = data + len;
		char *path = strchr(data, ' ');
		unsigned int mode;
		if (size < len + 20 || !path || sscanf(data, "%o", &mode) != 1)
			return -1;

		/* Warn about trees that don't do the recursive thing.. */
		if (warn_old_tree && strchr(path, '/')) {
			fprintf(stderr, "warning: fsck-cache: tree %s has full pathnames in it\n", sha1_to_hex(sha1));
			warn_old_tree = 0;
		}

		data += len + 20;
		size -= len + 20;
		mark_needs_sha1(sha1, S_ISDIR(mode) ? "tree" : "blob", file_sha1);
	}
	return 0;
}

static int fsck_commit(unsigned char *sha1, void *data, unsigned long size)
{
	int parents;
	unsigned char tree_sha1[20];
	unsigned char parent_sha1[20];

	if (memcmp(data, "tree ", 5))
		return -1;
	if (get_sha1_hex(data + 5, tree_sha1) < 0)
		return -1;
	mark_needs_sha1(sha1, "tree", tree_sha1);
	data += 5 + 40 + 1;	/* "tree " + <hex sha1> + '\n' */
	parents = 0;
	while (!memcmp(data, "parent ", 7)) {
		if (get_sha1_hex(data + 7, parent_sha1) < 0)
			return -1;
		mark_needs_sha1(sha1, "commit", parent_sha1);
		data += 7 + 40 + 1; 	/* "parent " + <hex sha1> + '\n' */
		parents++;
	}
	if (!parents)
		printf("root %s\n", sha1_to_hex(sha1));
	return 0;
}

static int fsck_entry(unsigned char *sha1, char *tag, void *data, unsigned long size)
{
	if (!strcmp(tag, "blob")) {
		/* Nothing to check */;
	} else if (!strcmp(tag, "tree")) {
		if (fsck_tree(sha1, data, size) < 0)
			return -1;
	} else if (!strcmp(tag, "commit")) {
		if (fsck_commit(sha1, data, size) < 0)
			return -1;
	} else
		return -1;
	return mark_sha1_seen(sha1, tag);
}

static int fsck_name(char *hex)
{
	unsigned char sha1[20];
	if (!get_sha1_hex(hex, sha1)) {
		unsigned long mapsize;
		void *map = map_sha1_file(sha1, &mapsize);
		if (map) {
			char type[100];
			unsigned long size;
			void *buffer = NULL;
			if (!check_sha1_signature(sha1, map, mapsize))
				buffer = unpack_sha1_file(map, mapsize, type, &size);
			munmap(map, mapsize);
			if (buffer && !fsck_entry(sha1, type, buffer, size))
				return 0;
		}
	}
	return -1;
}

static int fsck_dir(int i, char *path)
{
	DIR *dir = opendir(path);
	struct dirent *de;

	if (!dir) {
		return error("missing sha1 directory '%s'", path);
	}

	while ((de = readdir(dir)) != NULL) {
		char name[100];
		int len = strlen(de->d_name);

		switch (len) {
		case 2:
			if (de->d_name[1] != '.')
				break;
		case 1:
			if (de->d_name[0] != '.')
				break;
			continue;
		case 38:
			sprintf(name, "%02x", i);
			memcpy(name+2, de->d_name, len+1);
			if (!fsck_name(name))
				continue;
		}
		fprintf(stderr, "bad sha1 file: %s/%s\n", path, de->d_name);
	}
	closedir(dir);
	return 0;
}

int main(int argc, char **argv)
{
	int i;
	char *sha1_dir;

	for (i = 1; i < argc; i++) {
		if (!strcmp(argv[i], "--unreachable")) {
			show_unreachable = 1;
			continue;
		}
		if (!get_sha1_hex(argv[i], head_sha1)) {
			head_supplied = 1;
			continue;
		}
		usage("fsck-cache [[--unreachable] <head-sha1>]");
	}
	if (show_unreachable && !head_supplied)
		usage("unable to do reachability checks without a head");

	sha1_dir = getenv(DB_ENVIRONMENT) ? : DEFAULT_DB_ENVIRONMENT;
	for (i = 0; i < 256; i++) {
		static char dir[4096];
		sprintf(dir, "%s/%02x", sha1_dir, i);
		fsck_dir(i, dir);
	}
	check_connectivity();
	return 0;
}
Commit	Line	Data
20222118 LT	1	#include "cache.h"
	2
	3	#include <sys/types.h>
	4	#include <dirent.h>
	5
d9839e03 LT	6	/*
	7	* The low 16 bits of the "flags" field shows whether
	8	* a commit is part of the path to the root for that
	9	* parent.
	10	*
	11	* Bit 16 is an internal flag that we've seen the
	12	* definition for this rev, and not just seen it as
	13	* a parent target.
	14	*/
	15	#define MAX_COMMITS (16)
	16	#define marked(rev) ((rev)->flags & 0xffff)
	17	#define SEEN 0x10000
	18	#define USED 0x20000
	19	#define REACHABLE 0x40000
	20
	21	static int show_unreachable = 0;
	22	static int head_supplied = 0;
	23	static unsigned char head_sha1[20];
	24
	25	struct parent {
	26	struct revision *parent;
	27	struct parent *next;
8ba0bbb2 LT	28	};
8ba0bbb2 LT	29
d9839e03 LT	30	struct revision {
d9839e03 LT	31	unsigned int flags;
8ba0bbb2	32	unsigned char sha1[20];
d9839e03 LT	33	unsigned long date;
d9839e03 LT	34	struct parent *parent;
8ba0bbb2 LT	35	};
8ba0bbb2 LT	36
d9839e03 LT	37	static struct revision **revs;
d9839e03 LT	38	static int nr_revs, rev_allocs;
8ba0bbb2	39
d9839e03	40	static int find_rev(unsigned char *sha1)
8ba0bbb2	41	{
d9839e03	42	int first = 0, last = nr_revs;
8ba0bbb2	43
d9839e03 LT	44	while (first < last) {
	45	int next = (first + last) / 2;
	46	struct revision *rev = revs[next];
	47	int cmp;
8ba0bbb2	48
d9839e03 LT	49	cmp = memcmp(sha1, rev->sha1, 20);
	50	if (!cmp)
	51	return next;
8ba0bbb2 LT	52	if (cmp < 0) {
	53	last = next;
	54	continue;
	55	}
d9839e03 LT	56	first = next+1;
	57	}
	58	return -first-1;
	59	}
	60
	61	static struct revision lookup_rev(unsigned char sha1)
	62	{
	63	int pos = find_rev(sha1);
	64	struct revision *n;
	65
	66	if (pos >= 0)
	67	return revs[pos];
	68
	69	pos = -pos-1;
	70
	71	if (rev_allocs == nr_revs) {
	72	rev_allocs = alloc_nr(rev_allocs);
	73	revs = realloc(revs, rev_allocs * sizeof(struct revision *));
	74	}
	75	n = malloc(sizeof(struct revision));
	76
	77	n->flags = 0;
	78	memcpy(n->sha1, sha1, 20);
	79	n->parent = NULL;
	80
	81	/* Insert it into the right place */
	82	memmove(revs + pos + 1, revs + pos, (nr_revs - pos) * sizeof(struct revision *));
	83	revs[pos] = n;
	84	nr_revs++;
	85
	86	return n;
	87	}
	88
	89	static struct revision add_relationship(struct revision rev, unsigned char *needs)
	90	{
	91	struct revision *parent_rev = lookup_rev(needs);
	92	struct parent *pp = &rev->parent, p;
	93
	94	while ((p = *pp) != NULL) {
	95	if (p->parent == parent_rev)
	96	return parent_rev;
	97	pp = &p->next;
	98	}
	99
	100	p = malloc(sizeof(*p));
	101	p->parent = parent_rev;
	102	p->next = NULL;
	103	*pp = p;
	104	return parent_rev;
	105	}
	106
	107	static void mark_reachable(struct revision *rev)
	108	{
	109	struct parent *p = rev->parent;
	110
2845dbe4 LT	111	/* If we've been here already, don't bother */
	112	if (rev->flags & REACHABLE)
	113	return;
d9839e03 LT	114	rev->flags \|= REACHABLE \| USED;
	115	while (p) {
	116	mark_reachable(p->parent);
	117	p = p->next;
8ba0bbb2	118	}
8ba0bbb2 LT	119	}
	120
	121	static void check_connectivity(void)
	122	{
	123	int i;
	124
d9839e03 LT	125	if (head_supplied)
d9839e03 LT	126	mark_reachable(lookup_rev(head_sha1));
8ba0bbb2 LT	127
8ba0bbb2 LT	128	/* Look up all the requirements, warn about missing objects.. */
d9839e03 LT	129	for (i = 0; i < nr_revs; i++) {
d9839e03 LT	130	struct revision *rev = revs[i];
8ba0bbb2	131
d9839e03 LT	132	if (show_unreachable && !(rev->flags & REACHABLE)) {
d9839e03 LT	133	printf("unreachable %s\n", sha1_to_hex(rev->sha1));
8ba0bbb2	134	continue;
d9839e03	135	}
8ba0bbb2	136
d9839e03 LT	137	switch (rev->flags & (SEEN \| USED)) {
	138	case 0:
	139	printf("bad %s\n", sha1_to_hex(rev->sha1));
	140	break;
	141	case USED:
	142	printf("missing %s\n", sha1_to_hex(rev->sha1));
	143	break;
	144	case SEEN:
	145	printf("dangling %s\n", sha1_to_hex(rev->sha1));
	146	break;
	147	}
8ba0bbb2 LT	148	}
	149	}
	150
	151	static void mark_needs_sha1(unsigned char parent, const char tag, unsigned char *child)
20222118	152	{
d9839e03 LT	153	struct revision * child_rev = add_relationship(lookup_rev(parent), child);
d9839e03 LT	154	child_rev->flags \|= USED;
20222118 LT	155	}
20222118 LT	156
1ea34e36	157	static int mark_sha1_seen(unsigned char sha1, char tag)
20222118	158	{
d9839e03	159	struct revision *rev = lookup_rev(sha1);
8ba0bbb2	160
d9839e03	161	rev->flags \|= SEEN;
1ea34e36	162	return 0;
20222118 LT	163	}
20222118 LT	164
1ea34e36	165	static int fsck_tree(unsigned char sha1, void data, unsigned long size)
20222118	166	{
4e6616ab LT	167	int warn_old_tree = 1;
4e6616ab LT	168
1ea34e36 LT	169	while (size) {
	170	int len = 1+strlen(data);
	171	unsigned char *file_sha1 = data + len;
	172	char *path = strchr(data, ' ');
f768846e LT	173	unsigned int mode;
f768846e LT	174	if (size < len + 20 \|\| !path \|\| sscanf(data, "%o", &mode) != 1)
1ea34e36	175	return -1;
4e6616ab LT	176
	177	/* Warn about trees that don't do the recursive thing.. */
	178	if (warn_old_tree && strchr(path, '/')) {
	179	fprintf(stderr, "warning: fsck-cache: tree %s has full pathnames in it\n", sha1_to_hex(sha1));
	180	warn_old_tree = 0;
	181	}
	182
1ea34e36 LT	183	data += len + 20;
1ea34e36 LT	184	size -= len + 20;
f768846e	185	mark_needs_sha1(sha1, S_ISDIR(mode) ? "tree" : "blob", file_sha1);
1ea34e36	186	}
59c1e249	187	return 0;
1ea34e36 LT	188	}
	189
	190	static int fsck_commit(unsigned char sha1, void data, unsigned long size)
	191	{
16d4d1ba	192	int parents;
1ea34e36 LT	193	unsigned char tree_sha1[20];
	194	unsigned char parent_sha1[20];
	195
	196	if (memcmp(data, "tree ", 5))
	197	return -1;
	198	if (get_sha1_hex(data + 5, tree_sha1) < 0)
	199	return -1;
	200	mark_needs_sha1(sha1, "tree", tree_sha1);
	201	data += 5 + 40 + 1; /* "tree " + <hex sha1> + '\n' */
16d4d1ba	202	parents = 0;
1ea34e36 LT	203	while (!memcmp(data, "parent ", 7)) {
	204	if (get_sha1_hex(data + 7, parent_sha1) < 0)
	205	return -1;
	206	mark_needs_sha1(sha1, "commit", parent_sha1);
	207	data += 7 + 40 + 1; /* "parent " + <hex sha1> + '\n' */
16d4d1ba	208	parents++;
1ea34e36	209	}
16d4d1ba	210	if (!parents)
d9839e03	211	printf("root %s\n", sha1_to_hex(sha1));
59c1e249	212	return 0;
20222118 LT	213	}
	214
	215	static int fsck_entry(unsigned char sha1, char tag, void *data, unsigned long size)
	216	{
1ea34e36	217	if (!strcmp(tag, "blob")) {
20222118	218	/* Nothing to check */;
1ea34e36 LT	219	} else if (!strcmp(tag, "tree")) {
	220	if (fsck_tree(sha1, data, size) < 0)
	221	return -1;
	222	} else if (!strcmp(tag, "commit")) {
	223	if (fsck_commit(sha1, data, size) < 0)
	224	return -1;
	225	} else
20222118 LT	226	return -1;
	227	return mark_sha1_seen(sha1, tag);
	228	}
	229
	230	static int fsck_name(char *hex)
	231	{
	232	unsigned char sha1[20];
	233	if (!get_sha1_hex(hex, sha1)) {
	234	unsigned long mapsize;
	235	void *map = map_sha1_file(sha1, &mapsize);
	236	if (map) {
	237	char type[100];
	238	unsigned long size;
	239	void *buffer = NULL;
	240	if (!check_sha1_signature(sha1, map, mapsize))
	241	buffer = unpack_sha1_file(map, mapsize, type, &size);
	242	munmap(map, mapsize);
	243	if (buffer && !fsck_entry(sha1, type, buffer, size))
	244	return 0;
	245	}
	246	}
	247	return -1;
	248	}
	249
	250	static int fsck_dir(int i, char *path)
	251	{
	252	DIR *dir = opendir(path);
	253	struct dirent *de;
	254
	255	if (!dir) {
2de381f9	256	return error("missing sha1 directory '%s'", path);
20222118 LT	257	}
	258
	259	while ((de = readdir(dir)) != NULL) {
	260	char name[100];
	261	int len = strlen(de->d_name);
	262
	263	switch (len) {
	264	case 2:
	265	if (de->d_name[1] != '.')
	266	break;
	267	case 1:
	268	if (de->d_name[0] != '.')
	269	break;
	270	continue;
	271	case 38:
	272	sprintf(name, "%02x", i);
	273	memcpy(name+2, de->d_name, len+1);
	274	if (!fsck_name(name))
	275	continue;
	276	}
	277	fprintf(stderr, "bad sha1 file: %s/%s\n", path, de->d_name);
	278	}
	279	closedir(dir);
	280	return 0;
	281	}
	282
	283	int main(int argc, char **argv)
	284	{
	285	int i;
	286	char *sha1_dir;
	287
d9839e03 LT	288	for (i = 1; i < argc; i++) {
	289	if (!strcmp(argv[i], "--unreachable")) {
	290	show_unreachable = 1;
	291	continue;
	292	}
	293	if (!get_sha1_hex(argv[i], head_sha1)) {
	294	head_supplied = 1;
	295	continue;
	296	}
	297	usage("fsck-cache [[--unreachable] <head-sha1>]");
	298	}
	299	if (show_unreachable && !head_supplied)
	300	usage("unable to do reachability checks without a head");
	301
20222118 LT	302	sha1_dir = getenv(DB_ENVIRONMENT) ? : DEFAULT_DB_ENVIRONMENT;
	303	for (i = 0; i < 256; i++) {
	304	static char dir[4096];
	305	sprintf(dir, "%s/%02x", sha1_dir, i);
	306	fsck_dir(i, dir);
	307	}
8ba0bbb2	308	check_connectivity();
20222118 LT	309	return 0;
20222118 LT	310	}