refs: minor restructuring of cached refs data.

Once we read packed and loose refs, for_each_ref() and friends
kept using them even after write_ref_sha1() and delete_ref()
changed the refs.  This adds invalidate_cached_refs() as a way
to flush the cached information.

Signed-off-by: Junio C Hamano <junkio@cox.net>

diff --git a/refs.c b/refs.c
index b433c0c2d09e1ba363bd9c10f7144f089dd66b70..6ee5f96943d59243871c4158c06795e978bb8d8d 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)
+{
+       struct ref_list *next;
+       for ( ; list; list = next) {
+               next = list->next;
+               free(list);
+       }
+}
+
+static void invalidate_cached_refs(void)
 {
-       static int did_refs = 0;
-       static struct ref_list *refs = NULL;
+       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;
+}
 
-       if (!did_refs) {
+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 */
@@ -401,6 +429,7 @@ int delete_ref(const char *refname, unsigned char *sha1)
                fprintf(stderr, "warning: unlink(%s) failed: %s",
                        lock->log_file, strerror(errno));
 
+       invalidate_cached_refs();
        return ret;
 }
 
@@ -665,6 +694,7 @@ 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;