hash: add API to query the key count

Add a new function, rte_hash_count, to return the number of keys that
are currently stored in the hash table. Corresponding test functions are
added into hash_test and hash_multiwriter test.

Signed-off-by: Yipeng Wang <yipeng1.wang@intel.com>
Acked-by: Pablo de Lara <pablo.de.lara.guarch@intel.com>

diff --git a/lib/librte_hash/rte_cuckoo_hash.c b/lib/librte_hash/rte_cuckoo_hash.c
index ee8dc03..f7b86c8 100644 (file)
--- a/lib/librte_hash/rte_cuckoo_hash.c
+++ b/lib/librte_hash/rte_cuckoo_hash.c
@@ -369,6 +369,30 @@ rte_hash_secondary_hash(const hash_sig_t primary_hash)
        return primary_hash ^ ((tag + 1) * alt_bits_xor);
 }
 
+int32_t
+rte_hash_count(const struct rte_hash *h)
+{
+       uint32_t tot_ring_cnt, cached_cnt = 0;
+       uint32_t i, ret;
+
+       if (h == NULL)
+               return -EINVAL;
+
+       if (h->multi_writer_support) {
+               tot_ring_cnt = h->entries + (RTE_MAX_LCORE - 1) *
+                                       (LCORE_CACHE_SIZE - 1);
+               for (i = 0; i < RTE_MAX_LCORE; i++)
+                       cached_cnt += h->local_free_slots[i].len;
+
+               ret = tot_ring_cnt - rte_ring_count(h->free_slots) -
+                                                               cached_cnt;
+       } else {
+               tot_ring_cnt = h->entries;
+               ret = tot_ring_cnt - rte_ring_count(h->free_slots);
+       }
+       return ret;
+}
+
 /* Read write locks implemented using rte_rwlock */
 static inline void
 __hash_rw_writer_lock(const struct rte_hash *h)

diff --git a/lib/librte_hash/rte_hash.h b/lib/librte_hash/rte_hash.h
index ecb49e4..1f1a276 100644 (file)
--- a/lib/librte_hash/rte_hash.h
+++ b/lib/librte_hash/rte_hash.h
@@ -126,6 +126,17 @@ rte_hash_free(struct rte_hash *h);
 void
 rte_hash_reset(struct rte_hash *h);
 
+/**
+ * Return the number of keys in the hash table
+ * @param h
+ *  Hash table to query from
+ * @return
+ *   - -EINVAL if parameters are invalid
+ *   - A value indicating how many keys were inserted in the table.
+ */
+int32_t
+rte_hash_count(const struct rte_hash *h);
+
 /**
  * Add a key-value pair to an existing hash table.
  * This operation is not multi-thread safe

diff --git a/lib/librte_hash/rte_hash_version.map b/lib/librte_hash/rte_hash_version.map
index 52a2576..e216ac8 100644 (file)
--- a/lib/librte_hash/rte_hash_version.map
+++ b/lib/librte_hash/rte_hash_version.map
@@ -45,3 +45,11 @@ DPDK_16.07 {
        rte_hash_get_key_with_position;
 
 } DPDK_2.2;
+
+
+DPDK_18.08 {
+       global:
+
+       rte_hash_count;
+
+} DPDK_16.07;

diff --git a/test/test/test_hash.c b/test/test/test_hash.c
index edf41f5..b3db9fd 100644 (file)
--- a/test/test/test_hash.c
+++ b/test/test/test_hash.c
@@ -1103,6 +1103,7 @@ static int test_average_table_utilization(void)
        unsigned i, j;
        unsigned added_keys, average_keys_added = 0;
        int ret;
+       unsigned int cnt;
 
        printf("\n# Running test to determine average utilization"
               "\n  before adding elements begins to fail\n");
@@ -1121,13 +1122,24 @@ static int test_average_table_utilization(void)
                        for (i = 0; i < ut_params.key_len; i++)
                                simple_key[i] = rte_rand() % 255;
                        ret = rte_hash_add_key(handle, simple_key);
+                       if (ret < 0)
+                               break;
                }
+
                if (ret != -ENOSPC) {
                        printf("Unexpected error when adding keys\n");
                        rte_hash_free(handle);
                        return -1;
                }
 
+               cnt = rte_hash_count(handle);
+               if (cnt != added_keys) {
+                       printf("rte_hash_count returned wrong value %u, %u,"
+                                       "%u\n", j, added_keys, cnt);
+                       rte_hash_free(handle);
+                       return -1;
+               }
+
                average_keys_added += added_keys;
 
                /* Reset the table */

diff --git a/test/test/test_hash_multiwriter.c b/test/test/test_hash_multiwriter.c
index ef5fce3..f182f40 100644 (file)
--- a/test/test/test_hash_multiwriter.c
+++ b/test/test/test_hash_multiwriter.c
@@ -116,6 +116,7 @@ test_hash_multiwriter(void)
 
        uint32_t duplicated_keys = 0;
        uint32_t lost_keys = 0;
+       uint32_t count;
 
        snprintf(name, 32, "test%u", calledCount++);
        hash_params.name = name;
@@ -163,6 +164,13 @@ test_hash_multiwriter(void)
                                 NULL, CALL_MASTER);
        rte_eal_mp_wait_lcore();
 
+       count = rte_hash_count(handle);
+       if (count != rounded_nb_total_tsx_insertion) {
+               printf("rte_hash_count returned wrong value %u, %d\n",
+                               rounded_nb_total_tsx_insertion, count);
+               goto err3;
+       }
+
        while (rte_hash_iterate(handle, &next_key, &next_data, &iter) >= 0) {
                /* Search for the key in the list of keys added .*/
                i = *(const uint32_t *)next_key;