Refactor parts of in_delta_base_cache/cache_or_unpack_entry

The delta base cache lookup and test were shared.  Refactor them;
we'll need both parts again.  Also, we'll use the clearing routine
later.

Signed-off-by: Thomas Rast <trast@student.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/sha1_file.c b/sha1_file.c
index 71877a75fd05a9d11432d50fb86bb60765201529..fb0506ea9e4751ac45124256ca9ecb7b65e07b9c 100644 (file)
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -1756,32 +1756,51 @@ static unsigned long pack_entry_hash(struct packed_git *p, off_t base_offset)
        return hash % MAX_DELTA_CACHE;
 }
 
-static int in_delta_base_cache(struct packed_git *p, off_t base_offset)
+static struct delta_base_cache_entry *
+get_delta_base_cache_entry(struct packed_git *p, off_t base_offset)
 {
        unsigned long hash = pack_entry_hash(p, base_offset);
-       struct delta_base_cache_entry *ent = delta_base_cache + hash;
+       return delta_base_cache + hash;
+}
+
+static int eq_delta_base_cache_entry(struct delta_base_cache_entry *ent,
+                                    struct packed_git *p, off_t base_offset)
+{
        return (ent->data && ent->p == p && ent->base_offset == base_offset);
 }
 
+static int in_delta_base_cache(struct packed_git *p, off_t base_offset)
+{
+       struct delta_base_cache_entry *ent;
+       ent = get_delta_base_cache_entry(p, base_offset);
+       return eq_delta_base_cache_entry(ent, p, base_offset);
+}
+
+static void clear_delta_base_cache_entry(struct delta_base_cache_entry *ent)
+{
+       ent->data = NULL;
+       ent->lru.next->prev = ent->lru.prev;
+       ent->lru.prev->next = ent->lru.next;
+       delta_base_cached -= ent->size;
+}
+
 static void *cache_or_unpack_entry(struct packed_git *p, off_t base_offset,
        unsigned long *base_size, enum object_type *type, int keep_cache)
 {
+       struct delta_base_cache_entry *ent;
        void *ret;
-       unsigned long hash = pack_entry_hash(p, base_offset);
-       struct delta_base_cache_entry *ent = delta_base_cache + hash;
 
-       ret = ent->data;
-       if (!ret || ent->p != p || ent->base_offset != base_offset)
+       ent = get_delta_base_cache_entry(p, base_offset);
+
+       if (!eq_delta_base_cache_entry(ent, p, base_offset))
                return unpack_entry(p, base_offset, type, base_size);
 
-       if (!keep_cache) {
-               ent->data = NULL;
-               ent->lru.next->prev = ent->lru.prev;
-               ent->lru.prev->next = ent->lru.next;
-               delta_base_cached -= ent->size;
-       } else {
+       ret = ent->data;
+
+       if (!keep_cache)
+               clear_delta_base_cache_entry(ent);
+       else
                ret = xmemdupz(ent->data, ent->size);
-       }
        *type = ent->type;
        *base_size = ent->size;
        return ret;