We use hash value to determine the range of the object
and use cds_lfht_lookup_fct to lookup them.

Signed-off-by: Lai Jiangshan <[email protected]>
---
 rculfhash.c            |    8 ++++----
 tests/test_urcu_hash.c |   25 ++++++++++++++++++++++---
 urcu/rculfhash.h       |    4 +++-
 3 files changed, 29 insertions(+), 8 deletions(-)

diff --git a/rculfhash.c b/rculfhash.c
index d1a1766..29054cd 100644
--- a/rculfhash.c
+++ b/rculfhash.c
@@ -1391,14 +1391,14 @@ struct cds_lfht *_cds_lfht_new(cds_lfht_hash_fct 
hash_fct,
        return ht;
 }
 
-void cds_lfht_lookup(struct cds_lfht *ht, void *key, size_t key_len,
+void cds_lfht_lookup(struct cds_lfht *ht, unsigned long hash,
+               cds_lfht_lookup_fct match, void *arg,
                struct cds_lfht_iter *iter)
 {
        struct cds_lfht_node *node, *next, *dummy_node;
        struct _cds_lfht_node *lookup;
-       unsigned long hash, reverse_hash, size;
+       unsigned long reverse_hash, size;
 
-       hash = ht->hash_fct(key, key_len, ht->hash_seed);
        reverse_hash = bit_reverse_ulong(hash);
 
        size = rcu_dereference(ht->t.size);
@@ -1421,7 +1421,7 @@ void cds_lfht_lookup(struct cds_lfht *ht, void *key, 
size_t key_len,
                if (caa_likely(!is_removed(next))
                    && !is_dummy(next)
                    && node->p.reverse_hash == reverse_hash
-                   && caa_likely(!ht->compare_fct(node->key, node->key_len, 
key, key_len))) {
+                   && caa_likely(match(node, arg))) {
                                break;
                }
                node = clear_flag(next);
diff --git a/tests/test_urcu_hash.c b/tests/test_urcu_hash.c
index e28c14a..4c45573 100644
--- a/tests/test_urcu_hash.c
+++ b/tests/test_urcu_hash.c
@@ -41,6 +41,8 @@
 #define DEFAULT_MIN_ALLOC_SIZE 1
 #define DEFAULT_RAND_POOL      1000000
 
+#define TEST_HASH_SEED 0x42UL
+
 /* Make this big enough to include the POWER5+ L3 cacheline size of 256B */
 #define CACHE_LINE_SIZE 4096
 
@@ -419,6 +421,23 @@ unsigned long test_compare(void *key1, size_t key1_len,
                return 1;
 }
 
+static
+int test_match(struct cds_lfht_node *node, void *arg)
+{
+       return !test_compare(node->key, node->key_len,
+                       arg, sizeof(unsigned long));
+}
+
+static
+void cds_lfht_test_lookup(struct cds_lfht *ht, void *key, size_t key_len,
+               struct cds_lfht_iter *iter)
+{
+       assert(key_len == sizeof(unsigned long));
+
+       cds_lfht_lookup(ht, test_hash(key, key_len, TEST_HASH_SEED),
+                       test_match, key, iter);
+}
+
 void *thr_count(void *arg)
 {
        printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
@@ -479,7 +498,7 @@ void *thr_reader(void *_count)
 
        for (;;) {
                rcu_read_lock();
-               cds_lfht_lookup(test_ht,
+               cds_lfht_test_lookup(test_ht,
                        (void *)(((unsigned long) rand_r(&rand_lookup) % 
lookup_pool_size) + lookup_pool_offset),
                        sizeof(void *), &iter);
                node = cds_lfht_iter_get_test_node(&iter);
@@ -574,7 +593,7 @@ void *thr_writer(void *_count)
                } else {
                        /* May delete */
                        rcu_read_lock();
-                       cds_lfht_lookup(test_ht,
+                       cds_lfht_test_lookup(test_ht,
                                (void *)(((unsigned long) rand_r(&rand_lookup) 
% write_pool_size) + write_pool_offset),
                                sizeof(void *), &iter);
                        ret = cds_lfht_del(test_ht, &iter);
@@ -932,7 +951,7 @@ int main(int argc, char **argv)
         * thread from the point of view of resize.
         */
        rcu_register_thread();
-       test_ht = cds_lfht_new(test_hash, test_compare, 0x42UL,
+       test_ht = cds_lfht_new(test_hash, test_compare, TEST_HASH_SEED,
                        init_hash_size, min_hash_alloc_size,
                        (opt_auto_resize ? CDS_LFHT_AUTO_RESIZE : 0) |
                        CDS_LFHT_ACCOUNTING, NULL);
diff --git a/urcu/rculfhash.h b/urcu/rculfhash.h
index f4f3373..b56fe56 100644
--- a/urcu/rculfhash.h
+++ b/urcu/rculfhash.h
@@ -86,6 +86,7 @@ typedef unsigned long (*cds_lfht_hash_fct)(void *key, size_t 
length,
                                        unsigned long seed);
 typedef unsigned long (*cds_lfht_compare_fct)(void *key1, size_t key1_len,
                                        void *key2, size_t key2_len);
+typedef int (*cds_lfht_lookup_fct)(struct cds_lfht_node *node, void *arg);
 
 /*
  * cds_lfht_node_init - initialize a hash table node
@@ -203,7 +204,8 @@ void cds_lfht_count_nodes(struct cds_lfht *ht,
  * Call with rcu_read_lock held.
  * Threads calling this API need to be registered RCU read-side threads.
  */
-void cds_lfht_lookup(struct cds_lfht *ht, void *key, size_t key_len,
+void cds_lfht_lookup(struct cds_lfht *ht, unsigned long hash,
+               cds_lfht_lookup_fct match, void *arg,
                struct cds_lfht_iter *iter);
 
 /*
-- 
1.7.4.4


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