update-cache.c - jrn/git - Git at Google

 /*
  * 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 "git-update-cache *" and suddenly having all the object
  * files be revision controlled.
  */
 static int allow_add = 0, allow_remove = 0, allow_replace = 0, not_new = 0, quiet = 0, info_only = 0;
 static int force_remove;

 /* Three functions to allow overloaded pointer return; see linux/err.h */
 static inline void *ERR_PTR(long error)
 {
 	return (void *) error;
 }

 static inline long PTR_ERR(const void *ptr)
 {
 	return (long) ptr;
 }

 static inline long IS_ERR(const void *ptr)
 {
 	return (unsigned long)ptr > (unsigned long)-1000L;
 }

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

 	status = lstat(path, &st);
 	if (status < 0 || S_ISDIR(st.st_mode)) {
 		/* When we used to have "path" and now we want to add
 		 * "path/file", we need a way to remove "path" before
 		 * being able to add "path/file".  However,
 		 * "git-update-cache --remove path" would not work.
 		 * --force-remove can be used but this is more user
 		 * friendly, especially since we can do the opposite
 		 * case just fine without --force-remove.
 		 */
 		if (status == 0 || (errno == ENOENT || errno == ENOTDIR)) {
 			if (allow_remove)
 				return remove_file_from_cache(path);
 		}
 		return error("open(\"%s\"): %s", path, strerror(errno));
 	}
 	namelen = strlen(path);
 	size = cache_entry_size(namelen);
 	ce = xmalloc(size);
 	memset(ce, 0, size);
 	memcpy(ce->name, path, namelen);
 	fill_stat_cache_info(ce, &st);
 	ce->ce_mode = create_ce_mode(st.st_mode);
 	ce->ce_flags = htons(namelen);
 	switch (st.st_mode & S_IFMT) {
 	case S_IFREG:
 		fd = open(path, O_RDONLY);
 		if (fd < 0)
 			return -1;
 		if (index_fd(ce->sha1, fd, &st, !info_only, NULL) < 0)
 			return -1;
 		break;
 	case S_IFLNK:
 		target = xmalloc(st.st_size+1);
 		if (readlink(path, target, st.st_size+1) != st.st_size) {
 			free(target);
 			return -1;
 		}
 		if (info_only) {
 			unsigned char hdr[50];
 			int hdrlen;
 			write_sha1_file_prepare(target, st.st_size, "blob",
 						ce->sha1, hdr, &hdrlen);
 		} else if (write_sha1_file(target, st.st_size, "blob", ce->sha1))
 			return -1;
 		free(target);
 		break;
 	default:
 		return -1;
 	}
 	option = allow_add ? ADD_CACHE_OK_TO_ADD : 0;
 	option |= allow_replace ? ADD_CACHE_OK_TO_REPLACE : 0;
 	return add_cache_entry(ce, option);
 }

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

 	if (fd >= 0) {
 		unsigned char sha1[20];
 		if (!index_fd(sha1, fd, st, 0, NULL))
 			match = memcmp(sha1, ce->sha1, 20);
 		close(fd);
 	}
 	return match;
 }

 static int compare_link(struct cache_entry *ce, unsigned long expected_size)
 {
 	int match = -1;
 	char *target;
 	void *buffer;
 	unsigned long size;
 	char type[10];
 	int len;

 	target = xmalloc(expected_size);
 	len = readlink(ce->name, target, expected_size);
 	if (len != expected_size) {
 		free(target);
 		return -1;
 	}
 	buffer = read_sha1_file(ce->sha1, type, &size);
 	if (!buffer) {
 		free(target);
 		return -1;
 	}
 	if (size == expected_size)
 		match = memcmp(buffer, target, size);
 	free(buffer);
 	free(target);
 	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 "git-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 (lstat(ce->name, &st) < 0)
 		return ERR_PTR(-errno);

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

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

 	switch (st.st_mode & S_IFMT) {
 	case S_IFREG:
 		if (compare_data(ce, &st))
 			return ERR_PTR(-EINVAL);
 		break;
 	case S_IFLNK:
 		if (compare_link(ce, st.st_size))
 			return ERR_PTR(-EINVAL);
 		break;
 	default:
 		return ERR_PTR(-EINVAL);
 	}

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

 static int refresh_cache(void)
 {
 	int i;
 	int has_errors = 0;

 	for (i = 0; i < active_nr; i++) {
 		struct cache_entry *ce, *new;
 		ce = active_cache[i];
 		if (ce_stage(ce)) {
 			printf("%s: needs merge\n", ce->name);
 			has_errors = 1;
 			while ((i < active_nr) &&
 			       ! strcmp(active_cache[i]->name, ce->name))
 				i++;
 			i--;
 			continue;
 		}

 		new = refresh_entry(ce);
 		if (IS_ERR(new)) {
 			if (not_new && PTR_ERR(new) == -ENOENT)
 				continue;
 			if (quiet)
 				continue;
 			printf("%s: needs update\n", ce->name);
 			has_errors = 1;
 			continue;
 		}
 		active_cache_changed = 1;
 		/* You can NOT just free active_cache[i] here, since it
 		 * might not be necessarily malloc()ed but can also come
 		 * from mmap(). */
 		active_cache[i] = new;
 	}
 	return has_errors;
 }

 /*
  * We fundamentally don't like some paths: we don't want
  * dot or dot-dot anywhere, and for obvious reasons don't
  * want to recurse into ".git" either.
  *
  * Also, we don't want double slashes or slashes at the
  * end that can make pathnames ambiguous.
  */
 static int verify_dotfile(const char *rest)
 {
 	/*
 	 * The first character was '.', but that
 	 * has already been discarded, we now test
 	 * the rest.
 	 */
 	switch (*rest) {
 	/* "." is not allowed */
 	case '\0': case '/':
 		return 0;

 	/*
 	 * ".git" followed by  NUL or slash is bad. This
 	 * shares the path end test with the ".." case.
 	 */
 	case 'g':
 		if (rest[1] != 'i')
 			break;
 		if (rest[2] != 't')
 			break;
 		rest += 2;
 	/* fallthrough */
 	case '.':
 		if (rest[1] == '\0' || rest[1] == '/')
 			return 0;
 	}
 	return 1;
 }

 static int verify_path(char *path)
 {
 	char c;

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

 static int add_cacheinfo(char *arg1, char *arg2, char *arg3)
 {
 	int size, len, option;
 	unsigned int mode;
 	unsigned char sha1[20];
 	struct cache_entry *ce;

 	if (sscanf(arg1, "%o", &mode) != 1)
 		return -1;
 	if (get_sha1_hex(arg2, sha1))
 		return -1;
 	if (!verify_path(arg3))
 		return -1;

 	len = strlen(arg3);
 	size = cache_entry_size(len);
 	ce = xmalloc(size);
 	memset(ce, 0, size);

 	memcpy(ce->sha1, sha1, 20);
 	memcpy(ce->name, arg3, len);
 	ce->ce_flags = htons(len);
 	ce->ce_mode = create_ce_mode(mode);
 	option = allow_add ? ADD_CACHE_OK_TO_ADD : 0;
 	option |= allow_replace ? ADD_CACHE_OK_TO_REPLACE : 0;
 	return add_cache_entry(ce, option);
 }

 static struct cache_file cache_file;

 int main(int argc, char **argv)
 {
 	int i, newfd, entries, has_errors = 0;
 	int allow_options = 1;
 	const char *prefix = setup_git_directory();

 	newfd = hold_index_file_for_update(&cache_file, get_index_file());
 	if (newfd < 0)
 		die("unable to create new cachefile");

 	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, "-q")) {
 				quiet = 1;
 				continue;
 			}
 			if (!strcmp(path, "--add")) {
 				allow_add = 1;
 				continue;
 			}
 			if (!strcmp(path, "--replace")) {
 				allow_replace = 1;
 				continue;
 			}
 			if (!strcmp(path, "--remove")) {
 				allow_remove = 1;
 				continue;
 			}
 			if (!strcmp(path, "--refresh")) {
 				has_errors |= refresh_cache();
 				continue;
 			}
 			if (!strcmp(path, "--cacheinfo")) {
 				if (i+3 >= argc)
 					die("git-update-cache: --cacheinfo <mode> <sha1> <path>");
 				if (add_cacheinfo(argv[i+1], argv[i+2], argv[i+3]))
 					die("git-update-cache: --cacheinfo cannot add %s", argv[i+3]);
 				i += 3;
 				continue;
 			}
 			if (!strcmp(path, "--info-only")) {
 				info_only = 1;
 				continue;
 			}
 			if (!strcmp(path, "--force-remove")) {
 				force_remove = 1;
 				continue;
 			}

 			if (!strcmp(path, "--ignore-missing")) {
 				not_new = 1;
 				continue;
 			}
 			die("unknown option %s", path);
 		}
 		path = prefix_path(prefix, prefix ? strlen(prefix) : 0, path);
 		if (!verify_path(path)) {
 			fprintf(stderr, "Ignoring path %s\n", argv[i]);
 			continue;
 		}
 		if (force_remove) {
 			if (remove_file_from_cache(path))
 				die("git-update-cache: --force-remove cannot remove %s", path);
 			continue;
 		}
 		if (add_file_to_cache(path))
 			die("Unable to add %s to database", path);
 	}
 	if (write_cache(newfd, active_cache, active_nr) ||
 	    commit_index_file(&cache_file))
 		die("Unable to write new cachefile");

 	return has_errors ? 1 : 0;
 }
	/*
	* 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 "git-update-cache *" and suddenly having all the object
	* files be revision controlled.
	*/
	static int allow_add = 0, allow_remove = 0, allow_replace = 0, not_new = 0, quiet = 0, info_only = 0;
	static int force_remove;

	/* Three functions to allow overloaded pointer return; see linux/err.h */
	static inline void *ERR_PTR(long error)
	{
	return (void *) error;
	}

	static inline long PTR_ERR(const void *ptr)
	{
	return (long) ptr;
	}

	static inline long IS_ERR(const void *ptr)
	{
	return (unsigned long)ptr > (unsigned long)-1000L;
	}

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

	status = lstat(path, &st);
	if (status < 0 \|\| S_ISDIR(st.st_mode)) {
	/* When we used to have "path" and now we want to add
	* "path/file", we need a way to remove "path" before
	* being able to add "path/file". However,
	* "git-update-cache --remove path" would not work.
	* --force-remove can be used but this is more user
	* friendly, especially since we can do the opposite
	* case just fine without --force-remove.
	*/
	if (status == 0 \|\| (errno == ENOENT \|\| errno == ENOTDIR)) {
	if (allow_remove)
	return remove_file_from_cache(path);
	}
	return error("open(\"%s\"): %s", path, strerror(errno));
	}
	namelen = strlen(path);
	size = cache_entry_size(namelen);
	ce = xmalloc(size);
	memset(ce, 0, size);
	memcpy(ce->name, path, namelen);
	fill_stat_cache_info(ce, &st);
	ce->ce_mode = create_ce_mode(st.st_mode);
	ce->ce_flags = htons(namelen);
	switch (st.st_mode & S_IFMT) {
	case S_IFREG:
	fd = open(path, O_RDONLY);
	if (fd < 0)
	return -1;
	if (index_fd(ce->sha1, fd, &st, !info_only, NULL) < 0)
	return -1;
	break;
	case S_IFLNK:
	target = xmalloc(st.st_size+1);
	if (readlink(path, target, st.st_size+1) != st.st_size) {
	free(target);
	return -1;
	}
	if (info_only) {
	unsigned char hdr[50];
	int hdrlen;
	write_sha1_file_prepare(target, st.st_size, "blob",
	ce->sha1, hdr, &hdrlen);
	} else if (write_sha1_file(target, st.st_size, "blob", ce->sha1))
	return -1;
	free(target);
	break;
	default:
	return -1;
	}
	option = allow_add ? ADD_CACHE_OK_TO_ADD : 0;
	option \|= allow_replace ? ADD_CACHE_OK_TO_REPLACE : 0;
	return add_cache_entry(ce, option);
	}

	static int compare_data(struct cache_entry ce, struct stat st)
	{
	int match = -1;
	int fd = open(ce->name, O_RDONLY);

	if (fd >= 0) {
	unsigned char sha1[20];
	if (!index_fd(sha1, fd, st, 0, NULL))
	match = memcmp(sha1, ce->sha1, 20);
	close(fd);
	}
	return match;
	}

	static int compare_link(struct cache_entry *ce, unsigned long expected_size)
	{
	int match = -1;
	char *target;
	void *buffer;
	unsigned long size;
	char type[10];
	int len;

	target = xmalloc(expected_size);
	len = readlink(ce->name, target, expected_size);
	if (len != expected_size) {
	free(target);
	return -1;
	}
	buffer = read_sha1_file(ce->sha1, type, &size);
	if (!buffer) {
	free(target);
	return -1;
	}
	if (size == expected_size)
	match = memcmp(buffer, target, size);
	free(buffer);
	free(target);
	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 "git-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 (lstat(ce->name, &st) < 0)
	return ERR_PTR(-errno);

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

	/*
	* If the mode or type has changed, there's no point in trying
	* to refresh the entry - it's not going to match
	*/
	if (changed & (MODE_CHANGED \| TYPE_CHANGED))
	return ERR_PTR(-EINVAL);

	switch (st.st_mode & S_IFMT) {
	case S_IFREG:
	if (compare_data(ce, &st))
	return ERR_PTR(-EINVAL);
	break;
	case S_IFLNK:
	if (compare_link(ce, st.st_size))
	return ERR_PTR(-EINVAL);
	break;
	default:
	return ERR_PTR(-EINVAL);
	}

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

	static int refresh_cache(void)
	{
	int i;
	int has_errors = 0;

	for (i = 0; i < active_nr; i++) {
	struct cache_entry ce, new;
	ce = active_cache[i];
	if (ce_stage(ce)) {
	printf("%s: needs merge\n", ce->name);
	has_errors = 1;
	while ((i < active_nr) &&
	! strcmp(active_cache[i]->name, ce->name))
	i++;
	i--;
	continue;
	}

	new = refresh_entry(ce);
	if (IS_ERR(new)) {
	if (not_new && PTR_ERR(new) == -ENOENT)
	continue;
	if (quiet)
	continue;
	printf("%s: needs update\n", ce->name);
	has_errors = 1;
	continue;
	}
	active_cache_changed = 1;
	/* You can NOT just free active_cache[i] here, since it
	* might not be necessarily malloc()ed but can also come
	* from mmap(). */
	active_cache[i] = new;
	}
	return has_errors;
	}

	/*
	* We fundamentally don't like some paths: we don't want
	* dot or dot-dot anywhere, and for obvious reasons don't
	* want to recurse into ".git" either.
	*
	* Also, we don't want double slashes or slashes at the
	* end that can make pathnames ambiguous.
	*/
	static int verify_dotfile(const char *rest)
	{
	/*
	* The first character was '.', but that
	* has already been discarded, we now test
	* the rest.
	*/
	switch (*rest) {
	/* "." is not allowed */
	case '\0': case '/':
	return 0;

	/*
	* ".git" followed by NUL or slash is bad. This
	* shares the path end test with the ".." case.
	*/
	case 'g':
	if (rest[1] != 'i')
	break;
	if (rest[2] != 't')
	break;
	rest += 2;
	/* fallthrough */
	case '.':
	if (rest[1] == '\0' \|\| rest[1] == '/')
	return 0;
	}
	return 1;
	}

	static int verify_path(char *path)
	{
	char c;

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

	static int add_cacheinfo(char arg1, char arg2, char *arg3)
	{
	int size, len, option;
	unsigned int mode;
	unsigned char sha1[20];
	struct cache_entry *ce;

	if (sscanf(arg1, "%o", &mode) != 1)
	return -1;
	if (get_sha1_hex(arg2, sha1))
	return -1;
	if (!verify_path(arg3))
	return -1;

	len = strlen(arg3);
	size = cache_entry_size(len);
	ce = xmalloc(size);
	memset(ce, 0, size);

	memcpy(ce->sha1, sha1, 20);
	memcpy(ce->name, arg3, len);
	ce->ce_flags = htons(len);
	ce->ce_mode = create_ce_mode(mode);
	option = allow_add ? ADD_CACHE_OK_TO_ADD : 0;
	option \|= allow_replace ? ADD_CACHE_OK_TO_REPLACE : 0;
	return add_cache_entry(ce, option);
	}

	static struct cache_file cache_file;

	int main(int argc, char **argv)
	{
	int i, newfd, entries, has_errors = 0;
	int allow_options = 1;
	const char *prefix = setup_git_directory();

	newfd = hold_index_file_for_update(&cache_file, get_index_file());
	if (newfd < 0)
	die("unable to create new cachefile");

	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, "-q")) {
	quiet = 1;
	continue;
	}
	if (!strcmp(path, "--add")) {
	allow_add = 1;
	continue;
	}
	if (!strcmp(path, "--replace")) {
	allow_replace = 1;
	continue;
	}
	if (!strcmp(path, "--remove")) {
	allow_remove = 1;
	continue;
	}
	if (!strcmp(path, "--refresh")) {
	has_errors \|= refresh_cache();
	continue;
	}
	if (!strcmp(path, "--cacheinfo")) {
	if (i+3 >= argc)
	die("git-update-cache: --cacheinfo <mode> <sha1> <path>");
	if (add_cacheinfo(argv[i+1], argv[i+2], argv[i+3]))
	die("git-update-cache: --cacheinfo cannot add %s", argv[i+3]);
	i += 3;
	continue;
	}
	if (!strcmp(path, "--info-only")) {
	info_only = 1;
	continue;
	}
	if (!strcmp(path, "--force-remove")) {
	force_remove = 1;
	continue;
	}

	if (!strcmp(path, "--ignore-missing")) {
	not_new = 1;
	continue;
	}
	die("unknown option %s", path);
	}
	path = prefix_path(prefix, prefix ? strlen(prefix) : 0, path);
	if (!verify_path(path)) {
	fprintf(stderr, "Ignoring path %s\n", argv[i]);
	continue;
	}
	if (force_remove) {
	if (remove_file_from_cache(path))
	die("git-update-cache: --force-remove cannot remove %s", path);
	continue;
	}
	if (add_file_to_cache(path))
	die("Unable to add %s to database", path);
	}
	if (write_cache(newfd, active_cache, active_nr) \|\|
	commit_index_file(&cache_file))
	die("Unable to write new cachefile");

	return has_errors ? 1 : 0;
	}