src: rework of the hash-cache infrastructure

Currently, the caching system is implemented in a two layer
architecture: hashtable (inner layer) and cache (upper layer).
This patch reworks the hash-cache infrastructure to solve some
initial design problems to make it more flexible, the main strong
points of this patch are:

* Memory handling is done in the cache layer, not in the inner
hashtable layer. This removes one of the main dependencies between
the hashtable and the cache classes.
* Remove excessive encapsulation: the former cache used to hide a
lot of details of the inner hashtable implementation.
* Fix over-hashing of some operations: lookup-delete-add required
three hash calculations. Similarly, the update-or-add operation
required two hash calculations. Now, we calculate the hash once
and re-use the value how many times as we need.

This patch simplifies the caching system. As a result, we save ~130
lines of code. Small code means and less complexity means less
chance to have bugs.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/include/sync.h b/include/sync.h
index fc06c93..60c9fae 100644
--- a/include/sync.h
+++ b/include/sync.h
@@ -2,7 +2,7 @@
 #define _SYNC_HOOKS_H_
 
 struct nethdr;
-struct us_conntrack;
+struct cache_object;
 
 struct sync_mode {
 	int internal_cache_flags;
@@ -14,7 +14,7 @@ struct sync_mode {
 	void (*kill)(void);
 	int  (*local)(int fd, int type, void *data);
 	int  (*recv)(const struct nethdr *net);
-	void (*send)(struct nethdr *net, struct us_conntrack *u);
+	void (*send)(struct nethdr *net, struct cache_object *obj);
 	void (*run)(void);
 };