blob: 68a0ae0444d700593198c748a00c9f2b0841bda8 [file] [log] [blame]
/*
* 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;
int max_out_bytes = namelen + st->st_size + 200;
void *out = malloc(max_out_bytes);
void *metadata = malloc(namelen + 200);
void *in = mmap(NULL, st->st_size, PROT_READ, MAP_PRIVATE, fd, 0);
SHA_CTX c;
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", (unsigned long) st->st_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 = st->st_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->ctime.sec = st->st_ctime;
ce->ctime.nsec = st->st_ctim.tv_nsec;
ce->mtime.sec = st->st_mtime;
ce->mtime.nsec = st->st_mtim.tv_nsec;
ce->st_dev = st->st_dev;
ce->st_ino = st->st_ino;
ce->st_uid = st->st_uid;
ce->st_gid = st->st_gid;
}
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->st_mode = st.st_mode;
ce->st_size = st.st_size;
ce->namelen = 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)
{
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 == ce->st_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 length has changed, there's no point in trying
* to refresh the entry - it's not going to match
*/
if (changed & (DATA_CHANGED | MODE_CHANGED))
return NULL;
if (compare_data(ce))
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 (.dircache 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++;
}
}
int main(int argc, char **argv)
{
int i, newfd, entries;
int allow_options = 1;
entries = read_cache();
if (entries < 0) {
perror("cache corrupted");
return -1;
}
newfd = open(".dircache/index.lock", O_RDWR | O_CREAT | O_EXCL, 0600);
if (newfd < 0) {
perror("unable to create new cachefile");
return -1;
}
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;
}
usage("unknown option %s", path);
}
if (!verify_path(path)) {
fprintf(stderr, "Ignoring path %s\n", argv[i]);
continue;
}
if (add_file_to_cache(path)) {
fprintf(stderr, "Unable to add %s to database\n", path);
goto out;
}
}
if (!write_cache(newfd, active_cache, active_nr) && !rename(".dircache/index.lock", ".dircache/index"))
return 0;
out:
unlink(".dircache/index.lock");
return 0;
}