In some use cases inserting data with the same key shouldn't be
overwritten. We use a new flag in this patch to disable overwriting
data for the same key.

Signed-off-by: Abdullah Ömer Yamaç <omer.ya...@ceng.metu.edu.tr>

---
Cc: Yipeng Wang <yipeng1.w...@intel.com>
Cc: Sameh Gobriel <sameh.gobr...@intel.com>
Cc: Bruce Richardson <bruce.richard...@intel.com>
Cc: Vladimir Medvedkin <vladimir.medved...@intel.com>
Cc: David Marchand <david.march...@redhat.com>
---
 lib/hash/rte_cuckoo_hash.c | 10 +++++++++-
 lib/hash/rte_cuckoo_hash.h |  2 ++
 lib/hash/rte_hash.h        |  4 ++++
 3 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/lib/hash/rte_cuckoo_hash.c b/lib/hash/rte_cuckoo_hash.c
index 19b23f2a97..fe8f21bee4 100644
--- a/lib/hash/rte_cuckoo_hash.c
+++ b/lib/hash/rte_cuckoo_hash.c
@@ -32,7 +32,8 @@
                                   RTE_HASH_EXTRA_FLAGS_RW_CONCURRENCY | \
                                   RTE_HASH_EXTRA_FLAGS_EXT_TABLE |     \
                                   RTE_HASH_EXTRA_FLAGS_NO_FREE_ON_DEL | \
-                                  RTE_HASH_EXTRA_FLAGS_RW_CONCURRENCY_LF)
+                                  RTE_HASH_EXTRA_FLAGS_RW_CONCURRENCY_LF | \
+                                  
RTE_HASH_EXTRA_FLAGS_DISABLE_UPDATE_EXISTING_KEY)
 
 #define FOR_EACH_BUCKET(CURRENT_BKT, START_BUCKET)                            \
        for (CURRENT_BKT = START_BUCKET;                                      \
@@ -148,6 +149,7 @@ rte_hash_create(const struct rte_hash_parameters *params)
        unsigned int readwrite_concur_support = 0;
        unsigned int writer_takes_lock = 0;
        unsigned int no_free_on_del = 0;
+       unsigned int no_update_data = 0;
        uint32_t *ext_bkt_to_free = NULL;
        uint32_t *tbl_chng_cnt = NULL;
        struct lcore_cache *local_free_slots = NULL;
@@ -216,6 +218,9 @@ rte_hash_create(const struct rte_hash_parameters *params)
                no_free_on_del = 1;
        }
 
+       if (params->extra_flag & 
RTE_HASH_EXTRA_FLAGS_DISABLE_UPDATE_EXISTING_KEY)
+               no_update_data = 1;
+
        /* Store all keys and leave the first entry as a dummy entry for 
lookup_bulk */
        if (use_local_cache)
                /*
@@ -428,6 +433,7 @@ rte_hash_create(const struct rte_hash_parameters *params)
        h->ext_table_support = ext_table_support;
        h->writer_takes_lock = writer_takes_lock;
        h->no_free_on_del = no_free_on_del;
+       h->no_update_data = no_update_data;
        h->readwrite_concur_lf_support = readwrite_concur_lf_support;
 
 #if defined(RTE_ARCH_X86)
@@ -707,6 +713,8 @@ search_and_update(const struct rte_hash *h, void *data, 
const void *key,
                        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) {
+                               if (h->no_update_data == 1)
+                                       return -EINVAL;
                                /* The store to application data at *data
                                 * should not leak after the store to pdata
                                 * in the key store. i.e. pdata is the guard
diff --git a/lib/hash/rte_cuckoo_hash.h b/lib/hash/rte_cuckoo_hash.h
index eb2644f74b..e8b7283ec2 100644
--- a/lib/hash/rte_cuckoo_hash.h
+++ b/lib/hash/rte_cuckoo_hash.h
@@ -193,6 +193,8 @@ struct rte_hash {
        /**< If read-write concurrency support is enabled */
        uint8_t ext_table_support;     /**< Enable extendable bucket table */
        uint8_t no_free_on_del;
+       /**< If update is prohibited on adding same key */
+       uint8_t no_update_data;
        /**< If key index should be freed on calling rte_hash_del_xxx APIs.
         * If this is set, rte_hash_free_key_with_position must be called to
         * free the key index associated with the deleted entry.
diff --git a/lib/hash/rte_hash.h b/lib/hash/rte_hash.h
index 7ecc021111..ca5b4841d2 100644
--- a/lib/hash/rte_hash.h
+++ b/lib/hash/rte_hash.h
@@ -55,6 +55,10 @@ extern "C" {
  */
 #define RTE_HASH_EXTRA_FLAGS_RW_CONCURRENCY_LF 0x20
 
+/** Flag to disable updating data of existing key
+ */
+#define RTE_HASH_EXTRA_FLAGS_DISABLE_UPDATE_EXISTING_KEY 0x40
+
 /**
  * The type of hash value of a key.
  * It should be a value of at least 32bit with fully random pattern.
-- 
2.34.1

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