git-commit-vandalism/fsck-cache.c
Junio C Hamano ae7c0c92c0 Git-prune-script loses blobs referenced from an uncommitted cache.
(updated from the version posted to GIT mailing list).

When a new blob is registered with update-cache, and before the cache
is written as a tree and committed, git-fsck-cache will find the blob
unreachable.  This patch adds a new flag, "--cache" to git-fsck-cache,
with which it keeps such blobs from considered "unreachable".

The git-prune-script is updated to use this new flag.  At the same time
it adds .git/refs/*/* to the set of default locations to look for heads,
which should be consistent with expectations from Cogito users.

Without this fix, "diff-cache -p --cached" after git-prune-script has
pruned the blob object will fail mysteriously and git-write-tree would
also fail.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2005-05-04 01:33:33 -07:00

345 lines
7.2 KiB
C

#include <sys/types.h>
#include <dirent.h>
#include "cache.h"
#include "commit.h"
#include "tree.h"
#include "blob.h"
#include "tag.h"
#define REACHABLE 0x0001
static int show_root = 0;
static int show_tags = 0;
static int show_unreachable = 0;
static int keep_cache_objects = 0;
static unsigned char head_sha1[20];
static void check_connectivity(void)
{
int i;
/* Look up all the requirements, warn about missing objects.. */
for (i = 0; i < nr_objs; i++) {
struct object *obj = objs[i];
struct object_list *refs;
if (!obj->parsed) {
printf("missing %s %s\n", obj->type, sha1_to_hex(obj->sha1));
continue;
}
for (refs = obj->refs; refs; refs = refs->next) {
if (refs->item->parsed)
continue;
printf("broken link from %7s %s\n",
obj->type, sha1_to_hex(obj->sha1));
printf(" to %7s %s\n",
refs->item->type, sha1_to_hex(refs->item->sha1));
}
/* Don't bother with tag reachability. */
if (obj->type == tag_type)
continue;
if (show_unreachable && !(obj->flags & REACHABLE)) {
printf("unreachable %s %s\n", obj->type, sha1_to_hex(obj->sha1));
continue;
}
if (!obj->used) {
printf("dangling %s %s\n", obj->type,
sha1_to_hex(obj->sha1));
}
}
}
/*
* The entries in a tree are ordered in the _path_ order,
* which means that a directory entry is ordered by adding
* a slash to the end of it.
*
* So a directory called "a" is ordered _after_ a file
* called "a.c", because "a/" sorts after "a.c".
*/
static int verify_ordered(struct tree_entry_list *a, struct tree_entry_list *b)
{
int len1 = strlen(a->name);
int len2 = strlen(b->name);
int len = len1 < len2 ? len1 : len2;
unsigned char c1, c2;
int cmp;
cmp = memcmp(a->name, b->name, len);
if (cmp < 0)
return 0;
if (cmp > 0)
return -1;
/*
* Ok, the first <len> characters are the same.
* Now we need to order the next one, but turn
* a '\0' into a '/' for a directory entry.
*/
c1 = a->name[len];
c2 = b->name[len];
if (!c1 && a->directory)
c1 = '/';
if (!c2 && b->directory)
c2 = '/';
return c1 < c2 ? 0 : -1;
}
static int fsck_tree(struct tree *item)
{
int has_full_path = 0;
struct tree_entry_list *entry, *last;
last = NULL;
for (entry = item->entries; entry; entry = entry->next) {
if (strchr(entry->name, '/'))
has_full_path = 1;
if (last) {
if (verify_ordered(last, entry) < 0) {
fprintf(stderr, "tree %s not ordered\n",
sha1_to_hex(item->object.sha1));
return -1;
}
}
last = entry;
}
if (has_full_path) {
fprintf(stderr, "warning: fsck-cache: tree %s "
"has full pathnames in it\n",
sha1_to_hex(item->object.sha1));
}
return 0;
}
static int fsck_commit(struct commit *commit)
{
if (!commit->tree)
return -1;
if (!commit->parents && show_root)
printf("root %s\n", sha1_to_hex(commit->object.sha1));
if (!commit->date)
printf("bad commit date in %s\n",
sha1_to_hex(commit->object.sha1));
return 0;
}
static int fsck_tag(struct tag *tag)
{
struct object *tagged = tag->tagged;
if (!tagged) {
printf("bad object in tag %s\n", sha1_to_hex(tag->object.sha1));
return -1;
}
if (!show_tags)
return 0;
printf("tagged %s %s", tagged->type, sha1_to_hex(tagged->sha1));
printf(" (%s) in %s\n", tag->tag, sha1_to_hex(tag->object.sha1));
return 0;
}
static int fsck_sha1(unsigned char *sha1)
{
struct object *obj = parse_object(sha1);
if (!obj)
return -1;
if (obj->type == blob_type)
return 0;
if (obj->type == tree_type)
return fsck_tree((struct tree *) obj);
if (obj->type == commit_type)
return fsck_commit((struct commit *) obj);
if (obj->type == tag_type)
return fsck_tag((struct tag *) obj);
return -1;
}
/*
* This is the sorting chunk size: make it reasonably
* big so that we can sort well..
*/
#define MAX_SHA1_ENTRIES (1024)
struct sha1_entry {
unsigned long ino;
unsigned char sha1[20];
};
static struct {
unsigned long nr;
struct sha1_entry *entry[MAX_SHA1_ENTRIES];
} sha1_list;
static int ino_compare(const void *_a, const void *_b)
{
const struct sha1_entry *a = _a, *b = _b;
unsigned long ino1 = a->ino, ino2 = b->ino;
return ino1 < ino2 ? -1 : ino1 > ino2 ? 1 : 0;
}
static void fsck_sha1_list(void)
{
int i, nr = sha1_list.nr;
qsort(sha1_list.entry, nr, sizeof(struct sha1_entry *), ino_compare);
for (i = 0; i < nr; i++) {
struct sha1_entry *entry = sha1_list.entry[i];
unsigned char *sha1 = entry->sha1;
sha1_list.entry[i] = NULL;
if (fsck_sha1(sha1) < 0)
fprintf(stderr, "bad sha1 entry '%s'\n", sha1_to_hex(sha1));
free(entry);
}
sha1_list.nr = 0;
}
static void add_sha1_list(unsigned char *sha1, unsigned long ino)
{
struct sha1_entry *entry = xmalloc(sizeof(*entry));
int nr;
entry->ino = ino;
memcpy(entry->sha1, sha1, 20);
nr = sha1_list.nr;
if (nr == MAX_SHA1_ENTRIES) {
fsck_sha1_list();
nr = 0;
}
sha1_list.entry[nr] = entry;
sha1_list.nr = ++nr;
}
static int fsck_dir(int i, char *path)
{
DIR *dir = opendir(path);
struct dirent *de;
if (!dir) {
return error("missing sha1 directory '%s'", path);
}
while ((de = readdir(dir)) != NULL) {
char name[100];
unsigned char sha1[20];
int len = strlen(de->d_name);
switch (len) {
case 2:
if (de->d_name[1] != '.')
break;
case 1:
if (de->d_name[0] != '.')
break;
continue;
case 38:
sprintf(name, "%02x", i);
memcpy(name+2, de->d_name, len+1);
if (get_sha1_hex(name, sha1) < 0)
break;
add_sha1_list(sha1, de->d_ino);
continue;
}
fprintf(stderr, "bad sha1 file: %s/%s\n", path, de->d_name);
}
closedir(dir);
return 0;
}
int main(int argc, char **argv)
{
int i, heads;
char *sha1_dir;
for (i = 1; i < argc; i++) {
const char *arg = argv[i];
if (!strcmp(arg, "--unreachable")) {
show_unreachable = 1;
continue;
}
if (!strcmp(arg, "--tags")) {
show_tags = 1;
continue;
}
if (!strcmp(arg, "--root")) {
show_root = 1;
continue;
}
if (!strcmp(arg, "--cache")) {
keep_cache_objects = 1;
continue;
}
if (*arg == '-')
usage("fsck-cache [--tags] [[--unreachable] [--cache] <head-sha1>*]");
}
sha1_dir = getenv(DB_ENVIRONMENT) ? : DEFAULT_DB_ENVIRONMENT;
for (i = 0; i < 256; i++) {
static char dir[4096];
sprintf(dir, "%s/%02x", sha1_dir, i);
fsck_dir(i, dir);
}
fsck_sha1_list();
heads = 0;
for (i = 1; i < argc; i++) {
const char *arg = argv[i];
if (*arg == '-')
continue;
if (!get_sha1(arg, head_sha1)) {
struct commit *commit = lookup_commit(head_sha1);
struct object *obj;
/* Error is printed by lookup_commit(). */
if (!commit)
continue;
obj = &commit->object;
obj->used = 1;
mark_reachable(obj, REACHABLE);
heads++;
continue;
}
error("expected sha1, got %s", arg);
}
if (keep_cache_objects) {
int i;
read_cache();
for (i = 0; i < active_nr; i++) {
struct blob *blob = lookup_blob(active_cache[i]->sha1);
struct object *obj;
if (!blob)
continue;
obj = &blob->object;
obj->used = 1;
mark_reachable(obj, REACHABLE);
}
}
if (!heads && !keep_cache_objects) {
if (show_unreachable) {
fprintf(stderr, "unable to do reachability without a head nor --cache\n");
show_unreachable = 0;
}
if (!heads)
fprintf(stderr, "expect dangling commits - potential heads - due to lack of head information\n");
}
check_connectivity();
return 0;
}