Fix refs.c;:repack_without_ref() clean-up path
[gitweb.git] / refs.c
diff --git a/refs.c b/refs.c
index 3d4cdd1eb9bda5fe6260d8e7ddba99a4278c3252..aa4c4e0b94585835298ad1785eee77462760e2d6 100644 (file)
--- a/refs.c
+++ b/refs.c
@@ -66,12 +66,42 @@ static struct ref_list *add_ref(const char *name, const unsigned char *sha1,
        return list;
 }
 
-static struct ref_list *get_packed_refs(void)
+/*
+ * Future: need to be in "struct repository"
+ * when doing a full libification.
+ */
+struct cached_refs {
+       char did_loose;
+       char did_packed;
+       struct ref_list *loose;
+       struct ref_list *packed;
+} cached_refs;
+
+static void free_ref_list(struct ref_list *list)
 {
-       static int did_refs = 0;
-       static struct ref_list *refs = NULL;
+       struct ref_list *next;
+       for ( ; list; list = next) {
+               next = list->next;
+               free(list);
+       }
+}
 
-       if (!did_refs) {
+static void invalidate_cached_refs(void)
+{
+       struct cached_refs *ca = &cached_refs;
+
+       if (ca->did_loose && ca->loose)
+               free_ref_list(ca->loose);
+       if (ca->did_packed && ca->packed)
+               free_ref_list(ca->packed);
+       ca->loose = ca->packed = NULL;
+       ca->did_loose = ca->did_packed = 0;
+}
+
+static struct ref_list *get_packed_refs(void)
+{
+       if (!cached_refs.did_packed) {
+               struct ref_list *refs = NULL;
                FILE *f = fopen(git_path("packed-refs"), "r");
                if (f) {
                        struct ref_list *list = NULL;
@@ -86,9 +116,10 @@ static struct ref_list *get_packed_refs(void)
                        fclose(f);
                        refs = list;
                }
-               did_refs = 1;
+               cached_refs.packed = refs;
+               cached_refs.did_packed = 1;
        }
-       return refs;
+       return cached_refs.packed;
 }
 
 static struct ref_list *get_ref_dir(const char *base, struct ref_list *list)
@@ -138,14 +169,11 @@ static struct ref_list *get_ref_dir(const char *base, struct ref_list *list)
 
 static struct ref_list *get_loose_refs(void)
 {
-       static int did_refs = 0;
-       static struct ref_list *refs = NULL;
-
-       if (!did_refs) {
-               refs = get_ref_dir("refs", NULL);
-               did_refs = 1;
+       if (!cached_refs.did_loose) {
+               cached_refs.loose = get_ref_dir("refs", NULL);
+               cached_refs.did_loose = 1;
        }
-       return refs;
+       return cached_refs.loose;
 }
 
 /* We allow "recursive" symbolic refs. Only within reason, though */
@@ -378,32 +406,6 @@ int get_ref_sha1(const char *ref, unsigned char *sha1)
        return read_ref(mkpath("refs/%s", ref), sha1);
 }
 
-int delete_ref(const char *refname, unsigned char *sha1)
-{
-       struct ref_lock *lock;
-       int err, i, ret = 0;
-
-       lock = lock_any_ref_for_update(refname, sha1);
-       if (!lock)
-               return 1;
-       i = strlen(lock->lk->filename) - 5; /* .lock */
-       lock->lk->filename[i] = 0;
-       err = unlink(lock->lk->filename);
-       if (err) {
-               ret = 1;
-               error("unlink(%s) failed: %s",
-                     lock->lk->filename, strerror(errno));
-       }
-       lock->lk->filename[i] = '.';
-
-       err = unlink(lock->log_file);
-       if (err && errno != ENOENT)
-               fprintf(stderr, "warning: unlink(%s) failed: %s",
-                       lock->log_file, strerror(errno));
-
-       return ret;
-}
-
 /*
  * Make sure "ref" is something reasonable to have under ".git/refs/";
  * We do not like it if:
@@ -473,26 +475,116 @@ static struct ref_lock *verify_lock(struct ref_lock *lock,
        return lock;
 }
 
-static struct ref_lock *lock_ref_sha1_basic(const char *ref, const unsigned char *old_sha1)
+static int remove_empty_dir_recursive(char *path, int len)
+{
+       DIR *dir = opendir(path);
+       struct dirent *e;
+       int ret = 0;
+
+       if (!dir)
+               return -1;
+       if (path[len-1] != '/')
+               path[len++] = '/';
+       while ((e = readdir(dir)) != NULL) {
+               struct stat st;
+               int namlen;
+               if ((e->d_name[0] == '.') &&
+                   ((e->d_name[1] == 0) ||
+                    ((e->d_name[1] == '.') && e->d_name[2] == 0)))
+                       continue; /* "." and ".." */
+
+               namlen = strlen(e->d_name);
+               if ((len + namlen < PATH_MAX) &&
+                   strcpy(path + len, e->d_name) &&
+                   !lstat(path, &st) &&
+                   S_ISDIR(st.st_mode) &&
+                   !remove_empty_dir_recursive(path, len + namlen))
+                       continue; /* happy */
+
+               /* path too long, stat fails, or non-directory still exists */
+               ret = -1;
+               break;
+       }
+       closedir(dir);
+       if (!ret) {
+               path[len] = 0;
+               ret = rmdir(path);
+       }
+       return ret;
+}
+
+static int remove_empty_directories(char *file)
+{
+       /* we want to create a file but there is a directory there;
+        * if that is an empty directory (or a directory that contains
+        * only empty directories), remove them.
+        */
+       char path[PATH_MAX];
+       int len = strlen(file);
+
+       if (len >= PATH_MAX) /* path too long ;-) */
+               return -1;
+       strcpy(path, file);
+       return remove_empty_dir_recursive(path, len);
+}
+
+static struct ref_lock *lock_ref_sha1_basic(const char *ref, const unsigned char *old_sha1, int *flag)
 {
        char *ref_file;
        const char *orig_ref = ref;
        struct ref_lock *lock;
        struct stat st;
+       int last_errno = 0;
        int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
 
        lock = xcalloc(1, sizeof(struct ref_lock));
        lock->lock_fd = -1;
 
-       ref = resolve_ref(ref, lock->old_sha1, mustexist, NULL);
+       ref = resolve_ref(ref, lock->old_sha1, mustexist, flag);
+       if (!ref && errno == EISDIR) {
+               /* we are trying to lock foo but we used to
+                * have foo/bar which now does not exist;
+                * it is normal for the empty directory 'foo'
+                * to remain.
+                */
+               ref_file = git_path("%s", orig_ref);
+               if (remove_empty_directories(ref_file)) {
+                       last_errno = errno;
+                       error("there are still refs under '%s'", orig_ref);
+                       goto error_return;
+               }
+               ref = resolve_ref(orig_ref, lock->old_sha1, mustexist, flag);
+       }
        if (!ref) {
-               int last_errno = errno;
+               last_errno = errno;
                error("unable to resolve reference %s: %s",
                        orig_ref, strerror(errno));
-               unlock_ref(lock);
-               errno = last_errno;
-               return NULL;
+               goto error_return;
        }
+       if (is_null_sha1(lock->old_sha1)) {
+               /* The ref did not exist and we are creating it.
+                * Make sure there is no existing ref that is packed
+                * whose name begins with our refname, nor a ref whose
+                * name is a proper prefix of our refname.
+                */
+               int namlen = strlen(ref); /* e.g. 'foo/bar' */
+               struct ref_list *list = get_packed_refs();
+               while (list) {
+                       /* list->name could be 'foo' or 'foo/bar/baz' */
+                       int len = strlen(list->name);
+                       int cmplen = (namlen < len) ? namlen : len;
+                       const char *lead = (namlen < len) ? list->name : ref;
+
+                       if (!strncmp(ref, list->name, cmplen) &&
+                           lead[cmplen] == '/') {
+                               error("'%s' exists; cannot create '%s'",
+                                     list->name, ref);
+                               goto error_return;
+                       }
+                       list = list->next;
+               }
+       }
+
        lock->lk = xcalloc(1, sizeof(struct lock_file));
 
        lock->ref_name = xstrdup(ref);
@@ -500,11 +592,19 @@ static struct ref_lock *lock_ref_sha1_basic(const char *ref, const unsigned char
        ref_file = git_path("%s", ref);
        lock->force_write = lstat(ref_file, &st) && errno == ENOENT;
 
-       if (safe_create_leading_directories(ref_file))
-               die("unable to create directory for %s", ref_file);
+       if (safe_create_leading_directories(ref_file)) {
+               last_errno = errno;
+               error("unable to create directory for %s", ref_file);
+               goto error_return;
+       }
        lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, 1);
 
        return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock;
+
+ error_return:
+       unlock_ref(lock);
+       errno = last_errno;
+       return NULL;
 }
 
 struct ref_lock *lock_ref_sha1(const char *ref, const unsigned char *old_sha1)
@@ -513,12 +613,85 @@ struct ref_lock *lock_ref_sha1(const char *ref, const unsigned char *old_sha1)
        if (check_ref_format(ref))
                return NULL;
        strcpy(refpath, mkpath("refs/%s", ref));
-       return lock_ref_sha1_basic(refpath, old_sha1);
+       return lock_ref_sha1_basic(refpath, old_sha1, NULL);
 }
 
 struct ref_lock *lock_any_ref_for_update(const char *ref, const unsigned char *old_sha1)
 {
-       return lock_ref_sha1_basic(ref, old_sha1);
+       return lock_ref_sha1_basic(ref, old_sha1, NULL);
+}
+
+static struct lock_file packlock;
+
+static int repack_without_ref(const char *refname)
+{
+       struct ref_list *list, *packed_ref_list;
+       int fd;
+       int found = 0;
+
+       packed_ref_list = get_packed_refs();
+       for (list = packed_ref_list; list; list = list->next) {
+               if (!strcmp(refname, list->name)) {
+                       found = 1;
+                       break;
+               }
+       }
+       if (!found)
+               return 0;
+       memset(&packlock, 0, sizeof(packlock));
+       fd = hold_lock_file_for_update(&packlock, git_path("packed-refs"), 0);
+       if (fd < 0)
+               return error("cannot delete '%s' from packed refs", refname);
+
+       for (list = packed_ref_list; list; list = list->next) {
+               char line[PATH_MAX + 100];
+               int len;
+
+               if (!strcmp(refname, list->name))
+                       continue;
+               len = snprintf(line, sizeof(line), "%s %s\n",
+                              sha1_to_hex(list->sha1), list->name);
+               /* this should not happen but just being defensive */
+               if (len > sizeof(line))
+                       die("too long a refname '%s'", list->name);
+               write_or_die(fd, line, len);
+       }
+       return commit_lock_file(&packlock);
+}
+
+int delete_ref(const char *refname, unsigned char *sha1)
+{
+       struct ref_lock *lock;
+       int err, i, ret = 0, flag = 0;
+
+       lock = lock_ref_sha1_basic(refname, sha1, &flag);
+       if (!lock)
+               return 1;
+       if (!(flag & REF_ISPACKED)) {
+               /* loose */
+               i = strlen(lock->lk->filename) - 5; /* .lock */
+               lock->lk->filename[i] = 0;
+               err = unlink(lock->lk->filename);
+               if (err) {
+                       ret = 1;
+                       error("unlink(%s) failed: %s",
+                             lock->lk->filename, strerror(errno));
+               }
+               lock->lk->filename[i] = '.';
+       }
+       /* removing the loose one could have resurrected an earlier
+        * packed one.  Also, if it was not loose we need to repack
+        * without it.
+        */
+       ret |= repack_without_ref(refname);
+
+       err = unlink(lock->log_file);
+       if (err && errno != ENOENT)
+               fprintf(stderr, "warning: unlink(%s) failed: %s",
+                       lock->log_file, strerror(errno));
+       invalidate_cached_refs();
+       unlock_ref(lock);
+       return ret;
 }
 
 void unlock_ref(struct ref_lock *lock)
@@ -601,6 +774,7 @@ int write_ref_sha1(struct ref_lock *lock,
                unlock_ref(lock);
                return -1;
        }
+       invalidate_cached_refs();
        if (log_ref_write(lock, sha1, logmsg) < 0) {
                unlock_ref(lock);
                return -1;