From 50339f96638eed35dac2b673b64cc6f1eb96406c Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Thu, 15 Jan 2009 23:19:57 +0100 Subject: 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 --- include/hash.h | 22 ++++++++-------------- 1 file changed, 8 insertions(+), 14 deletions(-) (limited to 'include/hash.h') diff --git a/include/hash.h b/include/hash.h index 2fb0a27..68d618b 100644 --- a/include/hash.h +++ b/include/hash.h @@ -2,7 +2,6 @@ #define _NF_SET_HASH_H_ #include -#include "slist.h" #include "linux_list.h" #include @@ -15,35 +14,30 @@ struct hashtable { uint32_t limit; uint32_t count; uint32_t initval; - uint32_t datasize; uint32_t (*hash)(const void *data, const struct hashtable *table); int (*compare)(const void *data1, const void *data2); - struct slist_head members[0]; + struct list_head members[0]; }; struct hashtable_node { - struct slist_head head; - char data[0]; + struct list_head head; }; -struct hashtable_node *hashtable_alloc_node(int datasize, void *data); -void hashtable_destroy_node(struct hashtable_node *h); - struct hashtable * -hashtable_create(int hashsize, int limit, int datasize, +hashtable_create(int hashsize, int limit, uint32_t (*hash)(const void *data, const struct hashtable *table), int (*compare)(const void *data1, const void *data2)); void hashtable_destroy(struct hashtable *h); - -void *hashtable_add(struct hashtable *table, void *data); -void *hashtable_find(struct hashtable *table, const void *data); -int hashtable_del(struct hashtable *table, void *data); +int hashtable_hash(const struct hashtable *table, const void *data); +struct hashtable_node *hashtable_find(const struct hashtable *table, const void *data, int id); +int hashtable_add(struct hashtable *table, struct hashtable_node *n, int id); +void hashtable_del(struct hashtable *table, struct hashtable_node *node); int hashtable_flush(struct hashtable *table); int hashtable_iterate(struct hashtable *table, void *data, - int (*iterate)(void *data1, void *data2)); + int (*iterate)(void *data, struct hashtable_node *n)); unsigned int hashtable_counter(const struct hashtable *table); #endif -- cgit v1.2.3