git/checkout-cache.c

299 строки
6.8 KiB
C

/*
* 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;
}