checkout-cache.c - git - Git at Google

 /*
  * Check-out files from the "current cache directory"
  *
  * Copyright (C) 2005 Linus Torvalds
  *
  * Careful: order of argument flags does matter. For example,
  *
  *	git-checkout-cache -a -f file.c
  *
  * Will first check out all files listed in the cache (but not
  * overwrite any old ones), and then force-checkout "file.c" a
  * second time (ie that one _will_ overwrite any old contents
  * with the same filename).
  *
  * Also, just doing "git-checkout-cache" does nothing. You probably
  * meant "git-checkout-cache -a". And if you want to force it, you
  * want "git-checkout-cache -f -a".
  *
  * Intuitiveness is not the goal here. Repeatability is. The
  * reason for the "no arguments means no work" thing is that
  * from scripts you are supposed to be able to do things like
  *
  *	find . -name '*.h' -print0 | xargs -0 git-checkout-cache -f --
  *
  * which will force all existing *.h files to be replaced with
  * their cached copies. If an empty command line implied "all",
  * then this would force-refresh everything in the cache, which
  * was not the point.
  *
  * Oh, and the "--" is just a good idea when you know the rest
  * will be filenames. Just so that you wouldn't have a filename
  * of "-a" causing problems (not possible in the above example,
  * but get used to it in scripting!).
  */
 #include <sys/types.h>
 #include <dirent.h>
 #include "cache.h"

 static int force = 0, quiet = 0, not_new = 0, refresh_cache = 0;
 static const char *base_dir = "";
 static int base_dir_len = 0;

 static void create_directories(const char *path)
 {
 	int len = strlen(path);
 	char *buf = xmalloc(len + 1);
 	const char *slash = path;

 	while ((slash = strchr(slash+1, '/')) != NULL) {
 		len = slash - path;
 		memcpy(buf, path, len);
 		buf[len] = 0;
 		if (mkdir(buf, 0755)) {
 			if (errno == EEXIST) {
 				struct stat st;
 				if (len > base_dir_len && force && !unlink(buf) && !mkdir(buf, 0755))
 					continue;
 				if (!stat(buf, &st) && S_ISDIR(st.st_mode))
 					continue; /* ok */
 			}
 			die("cannot create directory at %s", buf);
 		}
 	}
 	free(buf);
 }

 static void remove_subtree(const char *path)
 {
 	DIR *dir = opendir(path);
 	struct dirent *de;
 	char pathbuf[PATH_MAX];
 	char *name;

 	if (!dir)
 		die("cannot opendir %s", path);
 	strcpy(pathbuf, path);
 	name = pathbuf + strlen(path);
 	*name++ = '/';
 	while ((de = readdir(dir)) != NULL) {
 		struct stat st;
 		if ((de->d_name[0] == '.') &&
 		    ((de->d_name[1] == 0) ||
 		     ((de->d_name[1] == '.') && de->d_name[2] == 0)))
 			continue;
 		strcpy(name, de->d_name);
 		if (lstat(pathbuf, &st))
 			die("cannot lstat %s", pathbuf);
 		if (S_ISDIR(st.st_mode))
 			remove_subtree(pathbuf);
 		else if (unlink(pathbuf))
 			die("cannot unlink %s", pathbuf);
 	}
 	closedir(dir);
 	if (rmdir(path))
 		die("cannot rmdir %s", path);
 }

 static int create_file(const char *path, unsigned int mode)
 {
 	int fd;

 	mode = (mode & 0100) ? 0777 : 0666;
 	create_directories(path);
 	fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
 	if (fd < 0) {
 		if (errno == EISDIR && force) {
 			remove_subtree(path);
 			fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
 		}
 	}
 	return fd;
 }

 static int write_entry(struct cache_entry *ce, const char *path)
 {
 	int fd;
 	void *new;
 	unsigned long size;
 	long wrote;
 	char type[20];
 	char target[1024];

 	new = read_sha1_file(ce->sha1, type, &size);
 	if (!new || strcmp(type, "blob")) {
 		if (new)
 			free(new);
 		return error("git-checkout-cache: unable to read sha1 file of %s (%s)",
 			path, sha1_to_hex(ce->sha1));
 	}
 	switch (ntohl(ce->ce_mode) & S_IFMT) {
 	case S_IFREG:
 		fd = create_file(path, ntohl(ce->ce_mode));
 		if (fd < 0) {
 			free(new);
 			return error("git-checkout-cache: unable to create file %s (%s)",
 				path, strerror(errno));
 		}
 		wrote = write(fd, new, size);
 		close(fd);
 		free(new);
 		if (wrote != size)
 			return error("git-checkout-cache: unable to write file %s", path);
 		break;
 	case S_IFLNK:
 		memcpy(target, new, size);
 		target[size] = '\0';
 		create_directories(path);
 		if (symlink(target, path)) {
 			free(new);
 			return error("git-checkout-cache: unable to create symlink %s (%s)",
 				path, strerror(errno));
 		}
 		free(new);
 		break;
 	default:
 		free(new);
 		return error("git-checkout-cache: unknown file mode for %s", path);
 	}

 	if (refresh_cache) {
 		struct stat st;
 		lstat(ce->name, &st);
 		fill_stat_cache_info(ce, &st);
 	}
 	return 0;
 }

 static int checkout_entry(struct cache_entry *ce)
 {
 	struct stat st;
 	static char path[MAXPATHLEN+1];
 	int len = base_dir_len;

 	memcpy(path, base_dir, len);
 	strcpy(path + len, ce->name);

 	if (!lstat(path, &st)) {
 		unsigned changed = ce_match_stat(ce, &st);
 		if (!changed)
 			return 0;
 		if (!force) {
 			if (!quiet)
 				fprintf(stderr, "git-checkout-cache: %s already exists\n", path);
 			return 0;
 		}

 		/*
 		 * We unlink the old file, to get the new one with the
 		 * right permissions (including umask, which is nasty
 		 * to emulate by hand - much easier to let the system
 		 * just do the right thing)
 		 */
 		unlink(path);
 	} else if (not_new)
 		return 0;
 	return write_entry(ce, path);
 }

 static int checkout_file(const char *name)
 {
 	int pos = cache_name_pos(name, strlen(name));
 	if (pos < 0) {
 		if (!quiet) {
 			pos = -pos - 1;
 			fprintf(stderr,
 				"git-checkout-cache: %s is %s.\n",
 				name,
 				(pos < active_nr &&
 				 !strcmp(active_cache[pos]->name, name)) ?
 				"unmerged" : "not in the cache");
 		}
 		return -1;
 	}
 	return checkout_entry(active_cache[pos]);
 }

 static int checkout_all(void)
 {
 	int i;

 	for (i = 0; i < active_nr ; i++) {
 		struct cache_entry *ce = active_cache[i];
 		if (ce_stage(ce))
 			continue;
 		if (checkout_entry(ce) < 0)
 			return -1;
 	}
 	return 0;
 }

 int main(int argc, char **argv)
 {
 	int i, force_filename = 0;
 	struct cache_file cache_file;
 	int newfd = -1;

 	if (read_cache() < 0) {
 		die("invalid cache");
 	}

 	for (i = 1; i < argc; i++) {
 		const char *arg = argv[i];
 		if (!force_filename) {
 			if (!strcmp(arg, "-a")) {
 				checkout_all();
 				continue;
 			}
 			if (!strcmp(arg, "--")) {
 				force_filename = 1;
 				continue;
 			}
 			if (!strcmp(arg, "-f")) {
 				force = 1;
 				continue;
 			}
 			if (!strcmp(arg, "-q")) {
 				quiet = 1;
 				continue;
 			}
 			if (!strcmp(arg, "-n")) {
 				not_new = 1;
 				continue;
 			}
 			if (!strcmp(arg, "-u")) {
 				refresh_cache = 1;
 				if (newfd < 0)
 					newfd = hold_index_file_for_update
 						(&cache_file,
 						 get_index_file());
 				if (newfd < 0)
 					die("cannot open index.lock file.");
 				continue;
 			}
 			if (!memcmp(arg, "--prefix=", 9)) {
 				base_dir = arg+9;
 				base_dir_len = strlen(base_dir);
 				continue;
 			}
 		}
 		if (base_dir_len) {
 			/* when --prefix is specified we do not
 			 * want to update cache.
 			 */
 			if (refresh_cache) {
 				close(newfd); newfd = -1;
 				rollback_index_file(&cache_file);
 			}
 			refresh_cache = 0;
 		}
 		checkout_file(arg);
 	}

 	if (0 <= newfd &&
 	    (write_cache(newfd, active_cache, active_nr) ||
 	     commit_index_file(&cache_file)))
 		die("Unable to write new cachefile");
 	return 0;
 }
	/*
	* Check-out files from the "current cache directory"
	*
	* Copyright (C) 2005 Linus Torvalds
	*
	* Careful: order of argument flags does matter. For example,
	*
	* git-checkout-cache -a -f file.c
	*
	* Will first check out all files listed in the cache (but not
	* overwrite any old ones), and then force-checkout "file.c" a
	* second time (ie that one _will_ overwrite any old contents
	* with the same filename).
	*
	* Also, just doing "git-checkout-cache" does nothing. You probably
	* meant "git-checkout-cache -a". And if you want to force it, you
	* want "git-checkout-cache -f -a".
	*
	* Intuitiveness is not the goal here. Repeatability is. The
	* reason for the "no arguments means no work" thing is that
	* from scripts you are supposed to be able to do things like
	*
	* find . -name '*.h' -print0 \| xargs -0 git-checkout-cache -f --
	*
	* which will force all existing *.h files to be replaced with
	* their cached copies. If an empty command line implied "all",
	* then this would force-refresh everything in the cache, which
	* was not the point.
	*
	* Oh, and the "--" is just a good idea when you know the rest
	* will be filenames. Just so that you wouldn't have a filename
	* of "-a" causing problems (not possible in the above example,
	* but get used to it in scripting!).
	*/
	#include <sys/types.h>
	#include <dirent.h>
	#include "cache.h"

	static int force = 0, quiet = 0, not_new = 0, refresh_cache = 0;
	static const char *base_dir = "";
	static int base_dir_len = 0;

	static void create_directories(const char *path)
	{
	int len = strlen(path);
	char *buf = xmalloc(len + 1);
	const char *slash = path;

	while ((slash = strchr(slash+1, '/')) != NULL) {
	len = slash - path;
	memcpy(buf, path, len);
	buf[len] = 0;
	if (mkdir(buf, 0755)) {
	if (errno == EEXIST) {
	struct stat st;
	if (len > base_dir_len && force && !unlink(buf) && !mkdir(buf, 0755))
	continue;
	if (!stat(buf, &st) && S_ISDIR(st.st_mode))
	continue; /* ok */
	}
	die("cannot create directory at %s", buf);
	}
	}
	free(buf);
	}

	static void remove_subtree(const char *path)
	{
	DIR *dir = opendir(path);
	struct dirent *de;
	char pathbuf[PATH_MAX];
	char *name;

	if (!dir)
	die("cannot opendir %s", path);
	strcpy(pathbuf, path);
	name = pathbuf + strlen(path);
	*name++ = '/';
	while ((de = readdir(dir)) != NULL) {
	struct stat st;
	if ((de->d_name[0] == '.') &&
	((de->d_name[1] == 0) \|\|
	((de->d_name[1] == '.') && de->d_name[2] == 0)))
	continue;
	strcpy(name, de->d_name);
	if (lstat(pathbuf, &st))
	die("cannot lstat %s", pathbuf);
	if (S_ISDIR(st.st_mode))
	remove_subtree(pathbuf);
	else if (unlink(pathbuf))
	die("cannot unlink %s", pathbuf);
	}
	closedir(dir);
	if (rmdir(path))
	die("cannot rmdir %s", path);
	}

	static int create_file(const char *path, unsigned int mode)
	{
	int fd;

	mode = (mode & 0100) ? 0777 : 0666;
	create_directories(path);
	fd = open(path, O_WRONLY \| O_TRUNC \| O_CREAT, mode);
	if (fd < 0) {
	if (errno == EISDIR && force) {
	remove_subtree(path);
	fd = open(path, O_WRONLY \| O_TRUNC \| O_CREAT, mode);
	}
	}
	return fd;
	}

	static int write_entry(struct cache_entry ce, const char path)
	{
	int fd;
	void *new;
	unsigned long size;
	long wrote;
	char type[20];
	char target[1024];

	new = read_sha1_file(ce->sha1, type, &size);
	if (!new \|\| strcmp(type, "blob")) {
	if (new)
	free(new);
	return error("git-checkout-cache: unable to read sha1 file of %s (%s)",
	path, sha1_to_hex(ce->sha1));
	}
	switch (ntohl(ce->ce_mode) & S_IFMT) {
	case S_IFREG:
	fd = create_file(path, ntohl(ce->ce_mode));
	if (fd < 0) {
	free(new);
	return error("git-checkout-cache: unable to create file %s (%s)",
	path, strerror(errno));
	}
	wrote = write(fd, new, size);
	close(fd);
	free(new);
	if (wrote != size)
	return error("git-checkout-cache: unable to write file %s", path);
	break;
	case S_IFLNK:
	memcpy(target, new, size);
	target[size] = '\0';
	create_directories(path);
	if (symlink(target, path)) {
	free(new);
	return error("git-checkout-cache: unable to create symlink %s (%s)",
	path, strerror(errno));
	}
	free(new);
	break;
	default:
	free(new);
	return error("git-checkout-cache: unknown file mode for %s", path);
	}

	if (refresh_cache) {
	struct stat st;
	lstat(ce->name, &st);
	fill_stat_cache_info(ce, &st);
	}
	return 0;
	}

	static int checkout_entry(struct cache_entry *ce)
	{
	struct stat st;
	static char path[MAXPATHLEN+1];
	int len = base_dir_len;

	memcpy(path, base_dir, len);
	strcpy(path + len, ce->name);

	if (!lstat(path, &st)) {
	unsigned changed = ce_match_stat(ce, &st);
	if (!changed)
	return 0;
	if (!force) {
	if (!quiet)
	fprintf(stderr, "git-checkout-cache: %s already exists\n", path);
	return 0;
	}

	/*
	* We unlink the old file, to get the new one with the
	* right permissions (including umask, which is nasty
	* to emulate by hand - much easier to let the system
	* just do the right thing)
	*/
	unlink(path);
	} else if (not_new)
	return 0;
	return write_entry(ce, path);
	}

	static int checkout_file(const char *name)
	{
	int pos = cache_name_pos(name, strlen(name));
	if (pos < 0) {
	if (!quiet) {
	pos = -pos - 1;
	fprintf(stderr,
	"git-checkout-cache: %s is %s.\n",
	name,
	(pos < active_nr &&
	!strcmp(active_cache[pos]->name, name)) ?
	"unmerged" : "not in the cache");
	}
	return -1;
	}
	return checkout_entry(active_cache[pos]);
	}

	static int checkout_all(void)
	{
	int i;

	for (i = 0; i < active_nr ; i++) {
	struct cache_entry *ce = active_cache[i];
	if (ce_stage(ce))
	continue;
	if (checkout_entry(ce) < 0)
	return -1;
	}
	return 0;
	}

	int main(int argc, char **argv)
	{
	int i, force_filename = 0;
	struct cache_file cache_file;
	int newfd = -1;

	if (read_cache() < 0) {
	die("invalid cache");
	}

	for (i = 1; i < argc; i++) {
	const char *arg = argv[i];
	if (!force_filename) {
	if (!strcmp(arg, "-a")) {
	checkout_all();
	continue;
	}
	if (!strcmp(arg, "--")) {
	force_filename = 1;
	continue;
	}
	if (!strcmp(arg, "-f")) {
	force = 1;
	continue;
	}
	if (!strcmp(arg, "-q")) {
	quiet = 1;
	continue;
	}
	if (!strcmp(arg, "-n")) {
	not_new = 1;
	continue;
	}
	if (!strcmp(arg, "-u")) {
	refresh_cache = 1;
	if (newfd < 0)
	newfd = hold_index_file_for_update
	(&cache_file,
	get_index_file());
	if (newfd < 0)
	die("cannot open index.lock file.");
	continue;
	}
	if (!memcmp(arg, "--prefix=", 9)) {
	base_dir = arg+9;
	base_dir_len = strlen(base_dir);
	continue;
	}
	}
	if (base_dir_len) {
	/* when --prefix is specified we do not
	* want to update cache.
	*/
	if (refresh_cache) {
	close(newfd); newfd = -1;
	rollback_index_file(&cache_file);
	}
	refresh_cache = 0;
	}
	checkout_file(arg);
	}

	if (0 <= newfd &&
	(write_cache(newfd, active_cache, active_nr) \|\|
	commit_index_file(&cache_file)))
	die("Unable to write new cachefile");
	return 0;
	}