rculfhash: add unique

[urcu.git] / rculfhash.c

diff --git a/rculfhash.c b/rculfhash.c
index f09f6132aa458103a216be214e011acc5586a410..a5e4d9feed5a0d3ed7ec074727cacb33f9641d23 100644 (file)
--- a/rculfhash.c
+++ b/rculfhash.c
@@ -46,8 +46,8 @@
 #define dbg_printf(args...)
 #endif
 
-#define CHAIN_LEN_TARGET               4
-#define CHAIN_LEN_RESIZE_THRESHOLD     16
+#define CHAIN_LEN_TARGET               1
+#define CHAIN_LEN_RESIZE_THRESHOLD     2
 
 #ifndef max
 #define max(a, b)      ((a) > (b) ? (a) : (b))
@@ -169,7 +169,7 @@ void check_resize(struct rcu_ht *ht, struct rcu_table *t,
 {
        if (chain_len >= CHAIN_LEN_RESIZE_THRESHOLD)
                ht_resize_lazy(ht, t,
-                       log2_u32(chain_len - CHAIN_LEN_TARGET));
+                       log2_u32(chain_len - CHAIN_LEN_TARGET - 1));
 }
 
 static
@@ -205,12 +205,13 @@ unsigned long _uatomic_max(unsigned long *ptr, unsigned long v)
 }
 
 static
-void _ht_add(struct rcu_ht *ht, struct rcu_table *t, struct rcu_ht_node *node)
+int _ht_add(struct rcu_ht *ht, struct rcu_table *t, struct rcu_ht_node *node,
+            int unique)
 {
        struct rcu_ht_node *iter_prev, *iter, *iter_prev_next, *next;
 
        if (!t->size)
-               return;
+               return 0;
        for (;;) {
                uint32_t chain_len = 0;
 
@@ -232,6 +233,12 @@ void _ht_add(struct rcu_ht *ht, struct rcu_table *t, struct rcu_ht_node *node)
                        next = rcu_dereference(clear_flag(iter)->next);
                        if (unlikely(is_removed(next)))
                                continue;
+                       if (unique
+                           && !clear_flag(iter)->dummy
+                           && !ht->compare_fct(node->key, node->key_len,
+                                       clear_flag(iter)->key,
+                                       clear_flag(iter)->key_len))
+                               return -EEXIST;
                        if (clear_flag(iter)->reverse_hash > node->reverse_hash)
                                break;
                        /* Only account for identical reverse hash once */
@@ -250,6 +257,7 @@ void _ht_add(struct rcu_ht *ht, struct rcu_table *t, struct rcu_ht_node *node)
                else
                        break;
        }
+       return 0;
 }
 
 static
@@ -345,7 +353,7 @@ void init_table(struct rcu_ht *ht, struct rcu_table *t,
                t->tbl[i]->dummy = 1;
                t->tbl[i]->hash = i;
                t->tbl[i]->reverse_hash = bit_reverse_ulong(i);
-               _ht_add(ht, t, t->tbl[i]);
+               (void) _ht_add(ht, t, t->tbl[i], 0);
        }
        t->resize_target = t->size = end;
        t->resize_initiated = 0;
@@ -412,7 +420,18 @@ void ht_add(struct rcu_ht *ht, struct rcu_ht_node *node)
        node->reverse_hash = bit_reverse_ulong((unsigned long) node->hash);
 
        t = rcu_dereference(ht->t);
-       _ht_add(ht, t, node);
+       (void) _ht_add(ht, t, node, 0);
+}
+
+int ht_add_unique(struct rcu_ht *ht, struct rcu_ht_node *node)
+{
+       struct rcu_table *t;
+
+       node->hash = ht->hash_fct(node->key, node->key_len, ht->hash_seed);
+       node->reverse_hash = bit_reverse_ulong((unsigned long) node->hash);
+
+       t = rcu_dereference(ht->t);
+       return _ht_add(ht, t, node, 1);
 }
 
 int ht_remove(struct rcu_ht *ht, struct rcu_ht_node *node)