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

/*
 * GIT - The information manager from hell
 *
 * Copyright (C) Linus Torvalds, 2005
 */
#include "cache.h"

/*
 * Default to not allowing changes to the list of files. The
 * tool doesn't actually care, but this makes it harder to add
 * files to the revision control by mistake by doing something
 * like "update-cache *" and suddenly having all the object
 * files be revision controlled.
 */
static int allow_add = 0, allow_remove = 0;

static int index_fd(const char *path, int namelen, struct cache_entry *ce, int fd, struct stat *st)
{
	z_stream stream;
	unsigned long size = st->st_size;
	int max_out_bytes = namelen + size + 200;
	void *out = malloc(max_out_bytes);
	void *metadata = malloc(namelen + 200);
	void *in;
	SHA_CTX c;

	in = "";
	if (size)
		in = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
	close(fd);
	if (!out || (int)(long)in == -1)
		return -1;

	memset(&stream, 0, sizeof(stream));
	deflateInit(&stream, Z_BEST_COMPRESSION);

	/*
	 * ASCII size + nul byte
	 */	
	stream.next_in = metadata;
	stream.avail_in = 1+sprintf(metadata, "blob %lu", size);
	stream.next_out = out;
	stream.avail_out = max_out_bytes;
	while (deflate(&stream, 0) == Z_OK)
		/* nothing */;

	/*
	 * File content
	 */
	stream.next_in = in;
	stream.avail_in = size;
	while (deflate(&stream, Z_FINISH) == Z_OK)
		/*nothing */;

	deflateEnd(&stream);
	
	SHA1_Init(&c);
	SHA1_Update(&c, out, stream.total_out);
	SHA1_Final(ce->sha1, &c);

	return write_sha1_buffer(ce->sha1, out, stream.total_out);
}

/*
 * This only updates the "non-critical" parts of the directory
 * cache, ie the parts that aren't tracked by GIT, and only used
 * to validate the cache.
 */
static void fill_stat_cache_info(struct cache_entry *ce, struct stat *st)
{
	ce->ce_ctime.sec = htonl(st->st_ctime);
	ce->ce_mtime.sec = htonl(st->st_mtime);
#ifdef NSEC
	ce->ce_ctime.nsec = htonl(st->st_ctim.tv_nsec);
	ce->ce_mtime.nsec = htonl(st->st_mtim.tv_nsec);
#endif
	ce->ce_dev = htonl(st->st_dev);
	ce->ce_ino = htonl(st->st_ino);
	ce->ce_uid = htonl(st->st_uid);
	ce->ce_gid = htonl(st->st_gid);
	ce->ce_size = htonl(st->st_size);
}

static int add_file_to_cache(char *path)
{
	int size, namelen;
	struct cache_entry *ce;
	struct stat st;
	int fd;

	fd = open(path, O_RDONLY);
	if (fd < 0) {
		if (errno == ENOENT) {
			if (allow_remove)
				return remove_file_from_cache(path);
		}
		return -1;
	}
	if (fstat(fd, &st) < 0) {
		close(fd);
		return -1;
	}
	namelen = strlen(path);
	size = cache_entry_size(namelen);
	ce = malloc(size);
	memset(ce, 0, size);
	memcpy(ce->name, path, namelen);
	fill_stat_cache_info(ce, &st);
	ce->ce_mode = htonl(st.st_mode);
	ce->ce_namelen = htons(namelen);

	if (index_fd(path, namelen, ce, fd, &st) < 0)
		return -1;

	return add_cache_entry(ce, allow_add);
}

static int match_data(int fd, void *buffer, unsigned long size)
{
	while (size) {
		char compare[1024];
		int ret = read(fd, compare, sizeof(compare));

		if (ret <= 0 || ret > size || memcmp(buffer, compare, ret))
			return -1;
		size -= ret;
		buffer += ret;
	}
	return 0;
}

static int compare_data(struct cache_entry *ce, unsigned long expected_size)
{
	int match = -1;
	int fd = open(ce->name, O_RDONLY);

	if (fd >= 0) {
		void *buffer;
		unsigned long size;
		char type[10];

		buffer = read_sha1_file(ce->sha1, type, &size);
		if (buffer) {
			if (size == expected_size && !strcmp(type, "blob"))
				match = match_data(fd, buffer, size);
			free(buffer);
		}
		close(fd);
	}
	return match;
}

/*
 * "refresh" does not calculate a new sha1 file or bring the
 * cache up-to-date for mode/content changes. But what it
 * _does_ do is to "re-match" the stat information of a file
 * with the cache, so that you can refresh the cache for a
 * file that hasn't been changed but where the stat entry is
 * out of date.
 *
 * For example, you'd want to do this after doing a "read-tree",
 * to link up the stat cache details with the proper files.
 */
static struct cache_entry *refresh_entry(struct cache_entry *ce)
{
	struct stat st;
	struct cache_entry *updated;
	int changed, size;

	if (stat(ce->name, &st) < 0)
		return NULL;

	changed = cache_match_stat(ce, &st);
	if (!changed)
		return ce;

	/*
	 * If the mode has changed, there's no point in trying
	 * to refresh the entry - it's not going to match
	 */
	if (changed & MODE_CHANGED)
		return NULL;

	if (compare_data(ce, st.st_size))
		return NULL;

	size = ce_size(ce);
	updated = malloc(size);
	memcpy(updated, ce, size);
	fill_stat_cache_info(updated, &st);
	return updated;
}

static void refresh_cache(void)
{
	int i;

	for (i = 0; i < active_nr; i++) {
		struct cache_entry *ce = active_cache[i];
		struct cache_entry *new = refresh_entry(ce);

		if (!new) {
			printf("%s: needs update\n", ce->name);
			continue;
		}
		active_cache[i] = new;
	}
}

/*
 * We fundamentally don't like some paths: we don't want
 * dot or dot-dot anywhere, and in fact, we don't even want
 * any other dot-files (.git or anything else). They
 * are hidden, for chist sake.
 *
 * Also, we don't want double slashes or slashes at the
 * end that can make pathnames ambiguous.
 */
static int verify_path(char *path)
{
	char c;

	goto inside;
	for (;;) {
		if (!c)
			return 1;
		if (c == '/') {
inside:
			c = *path++;
			if (c != '/' && c != '.' && c != '\0')
				continue;
			return 0;
		}
		c = *path++;
	}
}

static int remove_lock = 0;

static void remove_lock_file(void)
{
	if (remove_lock)
		unlink(".git/index.lock");
}

int main(int argc, char **argv)
{
	int i, newfd, entries;
	int allow_options = 1;

	newfd = open(".git/index.lock", O_RDWR | O_CREAT | O_EXCL, 0600);
	if (newfd < 0)
		die("unable to create new cachefile");

	atexit(remove_lock_file);
	remove_lock = 1;

	entries = read_cache();
	if (entries < 0)
		die("cache corrupted");

	for (i = 1 ; i < argc; i++) {
		char *path = argv[i];

		if (allow_options && *path == '-') {
			if (!strcmp(path, "--")) {
				allow_options = 0;
				continue;
			}
			if (!strcmp(path, "--add")) {
				allow_add = 1;
				continue;
			}
			if (!strcmp(path, "--remove")) {
				allow_remove = 1;
				continue;
			}
			if (!strcmp(path, "--refresh")) {
				refresh_cache();
				continue;
			}
			die("unknown option %s", path);
		}
		if (!verify_path(path)) {
			fprintf(stderr, "Ignoring path %s\n", argv[i]);
			continue;
		}
		if (add_file_to_cache(path))
			die("Unable to add %s to database", path);
	}
	if (write_cache(newfd, active_cache, active_nr) ||
	    rename(".git/index.lock", ".git/index"))
		die("Unable to write new cachefile");

	remove_lock = 0;
	return 0;
}
Commit	Line	Data
8bc9a0c7 LT	1	/*
	2	* GIT - The information manager from hell
	3	*
	4	* Copyright (C) Linus Torvalds, 2005
	5	*/
e83c5163 LT	6	#include "cache.h"
e83c5163 LT	7
121481ab LT	8	/*
	9	* Default to not allowing changes to the list of files. The
	10	* tool doesn't actually care, but this makes it harder to add
	11	* files to the revision control by mistake by doing something
	12	* like "update-cache *" and suddenly having all the object
	13	* files be revision controlled.
	14	*/
	15	static int allow_add = 0, allow_remove = 0;
	16
e83c5163 LT	17	static int index_fd(const char path, int namelen, struct cache_entry ce, int fd, struct stat *st)
	18	{
	19	z_stream stream;
3607c27f LT	20	unsigned long size = st->st_size;
3607c27f LT	21	int max_out_bytes = namelen + size + 200;
e83c5163 LT	22	void *out = malloc(max_out_bytes);
e83c5163 LT	23	void *metadata = malloc(namelen + 200);
3607c27f	24	void *in;
e83c5163 LT	25	SHA_CTX c;
e83c5163 LT	26
3607c27f LT	27	in = "";
	28	if (size)
	29	in = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
e83c5163 LT	30	close(fd);
	31	if (!out \|\| (int)(long)in == -1)
	32	return -1;
	33
	34	memset(&stream, 0, sizeof(stream));
	35	deflateInit(&stream, Z_BEST_COMPRESSION);
	36
	37	/*
	38	* ASCII size + nul byte
	39	*/
	40	stream.next_in = metadata;
3607c27f	41	stream.avail_in = 1+sprintf(metadata, "blob %lu", size);
e83c5163 LT	42	stream.next_out = out;
	43	stream.avail_out = max_out_bytes;
	44	while (deflate(&stream, 0) == Z_OK)
	45	/* nothing */;
	46
	47	/*
	48	* File content
	49	*/
	50	stream.next_in = in;
3607c27f	51	stream.avail_in = size;
e83c5163 LT	52	while (deflate(&stream, Z_FINISH) == Z_OK)
	53	/nothing /;
	54
	55	deflateEnd(&stream);
	56
	57	SHA1_Init(&c);
	58	SHA1_Update(&c, out, stream.total_out);
	59	SHA1_Final(ce->sha1, &c);
	60
	61	return write_sha1_buffer(ce->sha1, out, stream.total_out);
	62	}
	63
711cf3a0 LT	64	/*
	65	* This only updates the "non-critical" parts of the directory
	66	* cache, ie the parts that aren't tracked by GIT, and only used
	67	* to validate the cache.
	68	*/
	69	static void fill_stat_cache_info(struct cache_entry ce, struct stat st)
	70	{
ccc4feb5 LT	71	ce->ce_ctime.sec = htonl(st->st_ctime);
ccc4feb5 LT	72	ce->ce_mtime.sec = htonl(st->st_mtime);
5ade8628	73	#ifdef NSEC
ccc4feb5 LT	74	ce->ce_ctime.nsec = htonl(st->st_ctim.tv_nsec);
ccc4feb5 LT	75	ce->ce_mtime.nsec = htonl(st->st_mtim.tv_nsec);
5ade8628	76	#endif
ccc4feb5 LT	77	ce->ce_dev = htonl(st->st_dev);
	78	ce->ce_ino = htonl(st->st_ino);
	79	ce->ce_uid = htonl(st->st_uid);
	80	ce->ce_gid = htonl(st->st_gid);
	81	ce->ce_size = htonl(st->st_size);
711cf3a0 LT	82	}
711cf3a0 LT	83
e83c5163 LT	84	static int add_file_to_cache(char *path)
	85	{
	86	int size, namelen;
	87	struct cache_entry *ce;
	88	struct stat st;
	89	int fd;
	90
	91	fd = open(path, O_RDONLY);
	92	if (fd < 0) {
121481ab LT	93	if (errno == ENOENT) {
	94	if (allow_remove)
	95	return remove_file_from_cache(path);
	96	}
e83c5163 LT	97	return -1;
	98	}
	99	if (fstat(fd, &st) < 0) {
	100	close(fd);
	101	return -1;
	102	}
	103	namelen = strlen(path);
	104	size = cache_entry_size(namelen);
	105	ce = malloc(size);
	106	memset(ce, 0, size);
	107	memcpy(ce->name, path, namelen);
711cf3a0	108	fill_stat_cache_info(ce, &st);
ccc4feb5 LT	109	ce->ce_mode = htonl(st.st_mode);
ccc4feb5 LT	110	ce->ce_namelen = htons(namelen);
e83c5163 LT	111
	112	if (index_fd(path, namelen, ce, fd, &st) < 0)
	113	return -1;
	114
121481ab LT	115	return add_cache_entry(ce, allow_add);
	116	}
	117
711cf3a0 LT	118	static int match_data(int fd, void *buffer, unsigned long size)
	119	{
	120	while (size) {
	121	char compare[1024];
	122	int ret = read(fd, compare, sizeof(compare));
	123
	124	if (ret <= 0 \|\| ret > size \|\| memcmp(buffer, compare, ret))
	125	return -1;
	126	size -= ret;
	127	buffer += ret;
	128	}
	129	return 0;
	130	}
	131
32d197f1	132	static int compare_data(struct cache_entry *ce, unsigned long expected_size)
121481ab	133	{
711cf3a0 LT	134	int match = -1;
	135	int fd = open(ce->name, O_RDONLY);
	136
	137	if (fd >= 0) {
	138	void *buffer;
	139	unsigned long size;
	140	char type[10];
	141
	142	buffer = read_sha1_file(ce->sha1, type, &size);
	143	if (buffer) {
32d197f1	144	if (size == expected_size && !strcmp(type, "blob"))
711cf3a0 LT	145	match = match_data(fd, buffer, size);
	146	free(buffer);
	147	}
	148	close(fd);
	149	}
	150	return match;
	151	}
	152
	153	/*
	154	* "refresh" does not calculate a new sha1 file or bring the
	155	* cache up-to-date for mode/content changes. But what it
	156	* _does_ do is to "re-match" the stat information of a file
	157	* with the cache, so that you can refresh the cache for a
	158	* file that hasn't been changed but where the stat entry is
	159	* out of date.
	160	*
	161	* For example, you'd want to do this after doing a "read-tree",
	162	* to link up the stat cache details with the proper files.
	163	*/
	164	static struct cache_entry refresh_entry(struct cache_entry ce)
	165	{
	166	struct stat st;
	167	struct cache_entry *updated;
	168	int changed, size;
	169
	170	if (stat(ce->name, &st) < 0)
	171	return NULL;
	172
	173	changed = cache_match_stat(ce, &st);
	174	if (!changed)
	175	return ce;
	176
121481ab	177	/*
32d197f1	178	* If the mode has changed, there's no point in trying
711cf3a0	179	* to refresh the entry - it's not going to match
121481ab	180	*/
32d197f1	181	if (changed & MODE_CHANGED)
711cf3a0 LT	182	return NULL;
711cf3a0 LT	183
32d197f1	184	if (compare_data(ce, st.st_size))
711cf3a0 LT	185	return NULL;
	186
	187	size = ce_size(ce);
	188	updated = malloc(size);
	189	memcpy(updated, ce, size);
	190	fill_stat_cache_info(updated, &st);
	191	return updated;
121481ab LT	192	}
	193
	194	static void refresh_cache(void)
	195	{
	196	int i;
	197
711cf3a0 LT	198	for (i = 0; i < active_nr; i++) {
	199	struct cache_entry *ce = active_cache[i];
	200	struct cache_entry *new = refresh_entry(ce);
	201
	202	if (!new) {
	203	printf("%s: needs update\n", ce->name);
	204	continue;
	205	}
	206	active_cache[i] = new;
	207	}
e83c5163 LT	208	}
e83c5163 LT	209
e83c5163 LT	210	/*
	211	* We fundamentally don't like some paths: we don't want
	212	* dot or dot-dot anywhere, and in fact, we don't even want
4bb04f21	213	* any other dot-files (.git or anything else). They
e83c5163 LT	214	* are hidden, for chist sake.
	215	*
	216	* Also, we don't want double slashes or slashes at the
aebb2679	217	* end that can make pathnames ambiguous.
e83c5163 LT	218	*/
	219	static int verify_path(char *path)
	220	{
	221	char c;
	222
	223	goto inside;
	224	for (;;) {
	225	if (!c)
	226	return 1;
	227	if (c == '/') {
	228	inside:
	229	c = *path++;
	230	if (c != '/' && c != '.' && c != '\0')
	231	continue;
	232	return 0;
	233	}
	234	c = *path++;
	235	}
	236	}
	237
9614b8dc LT	238	static int remove_lock = 0;
	239
	240	static void remove_lock_file(void)
	241	{
	242	if (remove_lock)
4bb04f21	243	unlink(".git/index.lock");
9614b8dc LT	244	}
9614b8dc LT	245
e83c5163 LT	246	int main(int argc, char **argv)
	247	{
	248	int i, newfd, entries;
121481ab	249	int allow_options = 1;
e83c5163	250
4bb04f21	251	newfd = open(".git/index.lock", O_RDWR \| O_CREAT \| O_EXCL, 0600);
9614b8dc	252	if (newfd < 0)
2de381f9	253	die("unable to create new cachefile");
9614b8dc LT	254
	255	atexit(remove_lock_file);
	256	remove_lock = 1;
	257
e83c5163	258	entries = read_cache();
9614b8dc	259	if (entries < 0)
2de381f9	260	die("cache corrupted");
e83c5163	261
e83c5163 LT	262	for (i = 1 ; i < argc; i++) {
e83c5163 LT	263	char *path = argv[i];
121481ab LT	264
	265	if (allow_options && *path == '-') {
	266	if (!strcmp(path, "--")) {
	267	allow_options = 0;
	268	continue;
	269	}
	270	if (!strcmp(path, "--add")) {
	271	allow_add = 1;
	272	continue;
	273	}
	274	if (!strcmp(path, "--remove")) {
	275	allow_remove = 1;
	276	continue;
	277	}
	278	if (!strcmp(path, "--refresh")) {
	279	refresh_cache();
	280	continue;
	281	}
2de381f9	282	die("unknown option %s", path);
121481ab	283	}
e83c5163 LT	284	if (!verify_path(path)) {
	285	fprintf(stderr, "Ignoring path %s\n", argv[i]);
	286	continue;
	287	}
9614b8dc	288	if (add_file_to_cache(path))
2de381f9	289	die("Unable to add %s to database", path);
e83c5163	290	}
9614b8dc	291	if (write_cache(newfd, active_cache, active_nr) \|\|
4bb04f21	292	rename(".git/index.lock", ".git/index"))
2de381f9	293	die("Unable to write new cachefile");
9614b8dc LT	294
9614b8dc LT	295	remove_lock = 0;
19b2860c	296	return 0;
e83c5163	297	}