Add rte_hash_replace_key_data() and rte_hash_replace_key_with_hash_data() which behave like their add_key_data counterparts but return the previous data pointer via an output parameter. On fresh insert, *old_data is set to NULL.
When the caller provides old_data, no automatic RCU deferred free is performed: the caller takes ownership of the old pointer and is responsible for freeing it. Signed-off-by: Robin Jarry <[email protected]> --- app/test/test_hash.c | 80 ++++++++++++++++++++++++++ doc/guides/rel_notes/release_26_03.rst | 6 ++ lib/hash/rte_cuckoo_hash.c | 42 ++++++++++++-- lib/hash/rte_hash.h | 67 +++++++++++++++++++++ 4 files changed, 189 insertions(+), 6 deletions(-) diff --git a/app/test/test_hash.c b/app/test/test_hash.c index 56a7779e09b9..fcc02ea31205 100644 --- a/app/test/test_hash.c +++ b/app/test/test_hash.c @@ -2473,6 +2473,83 @@ test_hash_rcu_qsbr_replace_auto_free(void) return ret; } +/* + * Test rte_hash_replace_key_data (explicit replace, no RCU). + * - Add key with data pointer (void *)1. + * - Replace same key with data (void *)2, verify old_data == (void *)1. + * - Lookup and verify data == (void *)2. + * - Replace with a new key (not yet inserted), verify old_data == NULL. + */ +static int +test_hash_replace_key_data(void) +{ + struct rte_hash_parameters params = { + .name = "test_replace_key_data", + .entries = 64, + .key_len = sizeof(uint32_t), + .hash_func = NULL, + .hash_func_init_val = 0, + .socket_id = SOCKET_ID_ANY, + }; + struct rte_hash *hash; + void *old_data = NULL; + void *data = NULL; + uint32_t key1 = 42; + uint32_t key2 = 99; + int ret = -1; + + printf("\n# Running replace key data test\n"); + + hash = rte_hash_create(¶ms); + if (hash == NULL) { + printf("hash creation failed\n"); + goto end; + } + + /* Add key with data = (void *)1 */ + ret = rte_hash_add_key_data(hash, &key1, (void *)(uintptr_t)1); + if (ret != 0) { + printf("failed to add key (ret=%d)\n", ret); + goto end; + } + + /* Replace same key with data = (void *)2 */ + ret = rte_hash_replace_key_data(hash, &key1, (void *)(uintptr_t)2, &old_data); + if (ret != 0) { + printf("failed to replace key (ret=%d)\n", ret); + goto end; + } + if (old_data != (void *)(uintptr_t)1) { + printf("old_data should be 0x1 but is %p\n", old_data); + goto end; + } + + /* Lookup and verify data == (void *)2 */ + ret = rte_hash_lookup_data(hash, &key1, &data); + if (ret < 0 || data != (void *)(uintptr_t)2) { + printf("lookup returned wrong data %p (ret=%d)\n", data, ret); + goto end; + } + + /* Replace with a new key (not yet inserted) */ + old_data = (void *)(uintptr_t)0xdeadbeef; + ret = rte_hash_replace_key_data(hash, &key2, (void *)(uintptr_t)3, &old_data); + if (ret != 0) { + printf("failed to insert new key via replace (ret=%d)\n", ret); + goto end; + } + if (old_data != NULL) { + printf("old_data should be NULL on fresh insert but is %p\n", + old_data); + goto end; + } + +end: + rte_hash_free(hash); + + return ret; +} + /* * Do all unit and performance tests. */ @@ -2557,6 +2634,9 @@ test_hash(void) if (test_hash_rcu_qsbr_replace_auto_free() < 0) return -1; + if (test_hash_replace_key_data() < 0) + return -1; + return 0; } diff --git a/doc/guides/rel_notes/release_26_03.rst b/doc/guides/rel_notes/release_26_03.rst index 693034bcb0d2..73418523809c 100644 --- a/doc/guides/rel_notes/release_26_03.rst +++ b/doc/guides/rel_notes/release_26_03.rst @@ -93,6 +93,12 @@ New Features ``rte_hash_add_key_data`` now automatically defers freeing the old data pointer on key overwrite via the RCU defer queue. +* **Added hash replace API.** + + Added ``rte_hash_replace_key_data`` and ``rte_hash_replace_key_with_hash_data`` + functions that return the previous data pointer on key overwrite, letting the + caller manage its lifecycle. + Removed Items ------------- diff --git a/lib/hash/rte_cuckoo_hash.c b/lib/hash/rte_cuckoo_hash.c index f487b3b725dd..cf957de55288 100644 --- a/lib/hash/rte_cuckoo_hash.c +++ b/lib/hash/rte_cuckoo_hash.c @@ -1106,7 +1106,7 @@ __hash_rcu_auto_free_old_data(const struct rte_hash *h, void *old_data_val) static inline int32_t __rte_hash_add_key_with_hash(const struct rte_hash *h, const void *key, - hash_sig_t sig, void *data) + hash_sig_t sig, void *data, void **old_data) { uint16_t short_sig; uint32_t prim_bucket_idx, sec_bucket_idx; @@ -1305,7 +1305,9 @@ __rte_hash_add_key_with_hash(const struct rte_hash *h, const void *key, return slot_id - 1; overwrite: - if (saved_old_data != NULL) + if (old_data != NULL) + *old_data = saved_old_data; + else if (saved_old_data != NULL) __hash_rcu_auto_free_old_data(h, saved_old_data); return ret; @@ -1321,7 +1323,7 @@ rte_hash_add_key_with_hash(const struct rte_hash *h, const void *key, hash_sig_t sig) { RETURN_IF_TRUE(((h == NULL) || (key == NULL)), -EINVAL); - return __rte_hash_add_key_with_hash(h, key, sig, 0); + return __rte_hash_add_key_with_hash(h, key, sig, 0, NULL); } RTE_EXPORT_SYMBOL(rte_hash_add_key) @@ -1329,7 +1331,7 @@ int32_t rte_hash_add_key(const struct rte_hash *h, const void *key) { RETURN_IF_TRUE(((h == NULL) || (key == NULL)), -EINVAL); - return __rte_hash_add_key_with_hash(h, key, rte_hash_hash(h, key), 0); + return __rte_hash_add_key_with_hash(h, key, rte_hash_hash(h, key), 0, NULL); } RTE_EXPORT_SYMBOL(rte_hash_add_key_with_hash_data) @@ -1340,7 +1342,7 @@ rte_hash_add_key_with_hash_data(const struct rte_hash *h, int ret; RETURN_IF_TRUE(((h == NULL) || (key == NULL)), -EINVAL); - ret = __rte_hash_add_key_with_hash(h, key, sig, data); + ret = __rte_hash_add_key_with_hash(h, key, sig, data, NULL); if (ret >= 0) return 0; else @@ -1355,13 +1357,41 @@ rte_hash_add_key_data(const struct rte_hash *h, const void *key, void *data) RETURN_IF_TRUE(((h == NULL) || (key == NULL)), -EINVAL); - ret = __rte_hash_add_key_with_hash(h, key, rte_hash_hash(h, key), data); + ret = __rte_hash_add_key_with_hash(h, key, rte_hash_hash(h, key), data, NULL); if (ret >= 0) return 0; else return ret; } +RTE_EXPORT_EXPERIMENTAL_SYMBOL(rte_hash_replace_key_with_hash_data, 26.03) +int +rte_hash_replace_key_with_hash_data(const struct rte_hash *h, + const void *key, hash_sig_t sig, + void *data, void **old_data) +{ + int ret; + + RETURN_IF_TRUE(((h == NULL) || (key == NULL) || + (old_data == NULL)), -EINVAL); + + *old_data = NULL; + ret = __rte_hash_add_key_with_hash(h, key, sig, data, old_data); + if (ret >= 0) + return 0; + else + return ret; +} + +RTE_EXPORT_EXPERIMENTAL_SYMBOL(rte_hash_replace_key_data, 26.03) +int +rte_hash_replace_key_data(const struct rte_hash *h, const void *key, + void *data, void **old_data) +{ + return rte_hash_replace_key_with_hash_data(h, key, + rte_hash_hash(h, key), data, old_data); +} + /* Search one bucket to find the match key - uses rw lock */ static inline int32_t search_one_bucket_l(const struct rte_hash *h, const void *key, diff --git a/lib/hash/rte_hash.h b/lib/hash/rte_hash.h index e33f0aea0f5e..4a328c51501c 100644 --- a/lib/hash/rte_hash.h +++ b/lib/hash/rte_hash.h @@ -279,6 +279,73 @@ int32_t rte_hash_add_key_with_hash_data(const struct rte_hash *h, const void *key, hash_sig_t sig, void *data); +/** + * Replace a key-value pair in an existing hash table, returning the previous + * data pointer associated with the key. If the key does not exist, it is + * inserted and *old_data is set to NULL. + * + * This operation is not multi-thread safe and should only be called from one + * thread by default. Thread safety can be enabled by setting flag during table + * creation. + * + * When old_data is provided, no automatic RCU deferred free is performed on + * overwrite; the caller takes ownership of the old pointer and is responsible + * for freeing it (e.g. via RCU). + * + * @param h + * Hash table to add the key to. + * @param key + * Key to add to the hash table. + * @param data + * Data to add to the hash table. + * @param old_data + * Output: on overwrite, set to the previous data pointer. + * On fresh insert, set to NULL. + * @return + * - 0 if added/replaced successfully + * - -EINVAL if the parameters are invalid. + * - -ENOSPC if there is no space in the hash for this key. + */ +__rte_experimental +int +rte_hash_replace_key_data(const struct rte_hash *h, const void *key, + void *data, void **old_data); + +/** + * Replace a key-value pair with a pre-computed hash value in an existing hash + * table, returning the previous data pointer associated with the key. If the + * key does not exist, it is inserted and *old_data is set to NULL. + * + * This operation is not multi-thread safe and should only be called from one + * thread by default. Thread safety can be enabled by setting flag during table + * creation. + * + * When old_data is provided, no automatic RCU deferred free is performed on + * overwrite; the caller takes ownership of the old pointer and is responsible + * for freeing it (e.g. via RCU). + * + * @param h + * Hash table to add the key to. + * @param key + * Key to add to the hash table. + * @param sig + * Precomputed hash value for 'key' + * @param data + * Data to add to the hash table. + * @param old_data + * Output: on overwrite, set to the previous data pointer. + * On fresh insert, set to NULL. + * @return + * - 0 if added/replaced successfully + * - -EINVAL if the parameters are invalid. + * - -ENOSPC if there is no space in the hash for this key. + */ +__rte_experimental +int +rte_hash_replace_key_with_hash_data(const struct rte_hash *h, + const void *key, hash_sig_t sig, + void *data, void **old_data); + /** * Add a key to an existing hash table. This operation is not multi-thread safe * and should only be called from one thread by default. -- 2.53.0
