speedup allocation in pack-redundant.c

Reuse discarded nodes of llists

Signed-off-by: Alex Riesen <ariesen@harmanbecker.com>
Signed-off-by: Junio C Hamano <junkio@cox.net>

diff --git a/pack-redundant.c b/pack-redundant.c
index 9851c29..3b91838 100644 (file)
--- a/pack-redundant.c
+++ b/pack-redundant.c
@@ -36,11 +36,31 @@ struct pll {
        size_t pl_size;
 };
 
-static inline void llist_free(struct llist *list)
+static struct llist_item *free_nodes = NULL;
+
+static inline struct llist_item *llist_item_get()
+{
+       struct llist_item *new;
+       if ( free_nodes ) {
+               new = free_nodes;
+               free_nodes = free_nodes->next;
+       } else
+               new = xmalloc(sizeof(struct llist_item));
+
+       return new;
+}
+
+static inline void llist_item_put(struct llist_item *item)
+{
+       item->next = free_nodes;
+       free_nodes = item;
+}
+
+static void llist_free(struct llist *list)
 {
        while((list->back = list->front)) {
                list->front = list->front->next;
-               free(list->back);
+               llist_item_put(list->back);
        }
        free(list);
 }
@@ -62,13 +82,13 @@ static struct llist * llist_copy(struct llist *list)
        if ((ret->size = list->size) == 0)
                return ret;
 
-       new = ret->front = xmalloc(sizeof(struct llist_item));
+       new = ret->front = llist_item_get();
        new->sha1 = list->front->sha1;
 
        old = list->front->next;
        while (old) {
                prev = new;
-               new = xmalloc(sizeof(struct llist_item));
+               new = llist_item_get();
                prev->next = new;
                new->sha1 = old->sha1;
                old = old->next;
@@ -82,7 +102,7 @@ static struct llist * llist_copy(struct llist *list)
 static inline struct llist_item * llist_insert(struct llist *list,
                                        struct llist_item *after, char *sha1)
 {
-       struct llist_item *new = xmalloc(sizeof(struct llist_item));
+       struct llist_item *new = llist_item_get();
        new->sha1 = sha1;
        new->next = NULL;
 
@@ -153,7 +173,7 @@ redo_from_start:
                                prev->next = l->next;
                        if (l == list->back)
                                list->back = prev;
-                       free(l);
+                       llist_item_put(l);
                        list->size--;
                        return prev;
                }