hash: check if slot is empty with key index

Instead of checking if the current and alternative signatures are 0,
it is faster to check if the key index associated to an entry
is 0, meaning that the slot is empty.

Signed-off-by: Pablo de Lara <pablo.de.lara.guarch@intel.com>
Acked-by: Saikrishna Edupuganti <saikrishna.edupuganti@intel.com>

diff --git a/lib/librte_hash/rte_cuckoo_hash.c b/lib/librte_hash/rte_cuckoo_hash.c
index 32f9f1123c27f79aaeedb76671c2164b675ca04f..4de4422bbd46119185f9c17922650419964d0734 100644 (file)
--- a/lib/librte_hash/rte_cuckoo_hash.c
+++ b/lib/librte_hash/rte_cuckoo_hash.c
@@ -424,7 +424,7 @@ make_space_bucket(const struct rte_hash *h, struct rte_hash_bucket *bkt)
                next_bucket_idx = bkt->signatures[i].alt & h->bucket_bitmask;
                next_bkt[i] = &h->buckets[next_bucket_idx];
                for (j = 0; j < RTE_HASH_BUCKET_ENTRIES; j++) {
-                       if (next_bkt[i]->signatures[j].sig == NULL_SIGNATURE)
+                       if (next_bkt[i]->key_idx[j] == EMPTY_SLOT)
                                break;
                }
 
@@ -610,7 +610,7 @@ __rte_hash_add_key_with_hash(const struct rte_hash *h, const void *key,
 #endif
                for (i = 0; i < RTE_HASH_BUCKET_ENTRIES; i++) {
                        /* Check if slot is available */
-                       if (likely(prim_bkt->signatures[i].sig == NULL_SIGNATURE)) {
+                       if (likely(prim_bkt->key_idx[i] == EMPTY_SLOT)) {
                                prim_bkt->signatures[i].current = sig;
                                prim_bkt->signatures[i].alt = alt_hash;
                                prim_bkt->key_idx[i] = new_idx;
@@ -708,7 +708,7 @@ __rte_hash_lookup_with_hash(const struct rte_hash *h, const void *key,
        /* Check if key is in primary location */
        for (i = 0; i < RTE_HASH_BUCKET_ENTRIES; i++) {
                if (bkt->signatures[i].current == sig &&
-                               bkt->signatures[i].sig != NULL_SIGNATURE) {
+                               bkt->key_idx[i] != EMPTY_SLOT) {
                        k = (struct rte_hash_key *) ((char *)keys +
                                        bkt->key_idx[i] * h->key_entry_size);
                        if (rte_hash_cmp_eq(key, k->key, h) == 0) {
@@ -824,7 +824,7 @@ __rte_hash_del_key_with_hash(const struct rte_hash *h, const void *key,
        /* Check if key is in primary location */
        for (i = 0; i < RTE_HASH_BUCKET_ENTRIES; i++) {
                if (bkt->signatures[i].current == sig &&
-                               bkt->signatures[i].sig != NULL_SIGNATURE) {
+                               bkt->key_idx[i] != EMPTY_SLOT) {
                        k = (struct rte_hash_key *) ((char *)keys +
                                        bkt->key_idx[i] * h->key_entry_size);
                        if (rte_hash_cmp_eq(key, k->key, h) == 0) {
@@ -835,7 +835,7 @@ __rte_hash_del_key_with_hash(const struct rte_hash *h, const void *key,
                                 * substracting the first dummy index
                                 */
                                ret = bkt->key_idx[i] - 1;
-                               bkt->key_idx[i] = 0;
+                               bkt->key_idx[i] = EMPTY_SLOT;
                                return ret;
                        }
                }
@@ -849,7 +849,7 @@ __rte_hash_del_key_with_hash(const struct rte_hash *h, const void *key,
        /* Check if key is in secondary location */
        for (i = 0; i < RTE_HASH_BUCKET_ENTRIES; i++) {
                if (bkt->signatures[i].current == alt_hash &&
-                               bkt->signatures[i].sig != NULL_SIGNATURE) {
+                               bkt->key_idx[i] != EMPTY_SLOT) {
                        k = (struct rte_hash_key *) ((char *)keys +
                                        bkt->key_idx[i] * h->key_entry_size);
                        if (rte_hash_cmp_eq(key, k->key, h) == 0) {
@@ -860,7 +860,7 @@ __rte_hash_del_key_with_hash(const struct rte_hash *h, const void *key,
                                 * substracting the first dummy index
                                 */
                                ret = bkt->key_idx[i] - 1;
-                               bkt->key_idx[i] = 0;
+                               bkt->key_idx[i] = EMPTY_SLOT;
                                return ret;
                        }
                }
@@ -1230,7 +1230,7 @@ rte_hash_iterate(const struct rte_hash *h, const void **key, void **data, uint32
        idx = *next % RTE_HASH_BUCKET_ENTRIES;
 
        /* If current position is empty, go to the next one */
-       while (h->buckets[bucket_idx].signatures[idx].sig == NULL_SIGNATURE) {
+       while (h->buckets[bucket_idx].key_idx[idx] == EMPTY_SLOT) {
                (*next)++;
                /* End of table */
                if (*next == total_entries)

diff --git a/lib/librte_hash/rte_cuckoo_hash.h b/lib/librte_hash/rte_cuckoo_hash.h
index 6c76700faec2a7ff16fd6c725f04b72ae6a2adf0..e290dab9bcf7b75e547f570975e76297ea868b5b 100644 (file)
--- a/lib/librte_hash/rte_cuckoo_hash.h
+++ b/lib/librte_hash/rte_cuckoo_hash.h
@@ -134,6 +134,8 @@ enum add_key_case {
 
 #define NULL_SIGNATURE                 0
 
+#define EMPTY_SLOT                     0
+
 #define KEY_ALIGNMENT                  16
 
 #define LCORE_CACHE_SIZE               64

diff --git a/lib/librte_hash/rte_cuckoo_hash_x86.h b/lib/librte_hash/rte_cuckoo_hash_x86.h
index fa5630b7344581aaff23856f1b334448ecaaf2ba..e16d69cecf93027d62fdbc045f5247fa34f548e7 100644 (file)
--- a/lib/librte_hash/rte_cuckoo_hash_x86.h
+++ b/lib/librte_hash/rte_cuckoo_hash_x86.h
@@ -53,8 +53,7 @@ rte_hash_cuckoo_insert_mw_tm(struct rte_hash_bucket *prim_bkt,
                        */
                        for (i = 0; i < RTE_HASH_BUCKET_ENTRIES; i++) {
                                /* Check if slot is available */
-                               if (likely(prim_bkt->signatures[i].sig ==
-                                               NULL_SIGNATURE)) {
+                               if (likely(prim_bkt->key_idx == EMPTY_SLOT)) {
                                        prim_bkt->signatures[i].current = sig;
                                        prim_bkt->signatures[i].alt = alt_hash;
                                        prim_bkt->key_idx[i] = new_idx;
@@ -171,7 +170,7 @@ rte_hash_cuckoo_make_space_mw_tm(const struct rte_hash *h,
                                        queue + RTE_HASH_BFS_QUEUE_MAX_LEN - 4)) {
                curr_bkt = tail->bkt;
                for (i = 0; i < RTE_HASH_BUCKET_ENTRIES; i++) {
-                       if (curr_bkt->signatures[i].sig == NULL_SIGNATURE) {
+                       if (curr_bkt->key_idx[i] == EMPTY_SLOT) {
                                if (likely(rte_hash_cuckoo_move_insert_mw_tm(h,
                                                tail, i, sig,
                                                alt_hash, new_idx) == 0))