Add cache feature

src/lib/cache.c

@@ -1,38 +0,0 @@
-#include "cache.h"
-#include <pthread.h>
-
-struct cache_head {
-	struct hlist_head hash_head;
-	int hash_size;
-	pthread_rwlock_t *rwlock;
-};
-
-struct cache_head *cache_new(int hashsize, void (*item_free)(struct cache_head *head, struct cache_node *node))
-{
-	return NULL;
-}
-
-int cache_add(struct cache_head *head, struct cache_node *node, void *key, int key_len)
-{
-	return 0;
-}
-
-int cache_del(struct cache_node *node)
-{
-	return 0;
-}
-
-struct cache_node *cache_lookup(struct cache_head *head, void *key, int key_len)
-{
-	return 0;
-}
-
-int cache_update(struct cache_head *head, void *key, int key_len)
-{
-	return 0;
-}
-
-void cache_free(struct cache_head *head)
-{
-	return 
-}