[PATCH] lib/hash: new feature adding existing key

[PATCH] lib/hash: new feature adding existing key

[Abdullah Ömer Yamaç]

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.yamac@ceng.metu.edu.tr>

---
Cc: Yipeng Wang <yipeng1.wang@intel.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 829b79c89a..cd87d6e4cd 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)
@@ -699,6 +705,8 @@ 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 -EALRDY;
 				/* 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 a399346d02..f8afb4e06d 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

[PATCH] lib/hash: new feature adding existing key

[Abdullah Ömer Yamaç]

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.yamac@ceng.metu.edu.tr>

---
Cc: Yipeng Wang <yipeng1.wang@intel.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 829b79c89a..cd87d6e4cd 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)
@@ -699,6 +705,8 @@ 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 a399346d02..f8afb4e06d 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

Re: [PATCH] lib/hash: new feature adding existing key

[Stephen Hemminger]

On Mon, 13 Mar 2023 07:35:48 +0000
Abdullah Ömer Yamaç <omer.yamac@ceng.metu.edu.tr> wrote:

> 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

This ends up being an ABI change. So needs to wait for 23.11 release

Re: [PATCH] lib/hash: new feature adding existing key

[David Marchand]

On Mon, Mar 13, 2023 at 8:36 AM Abdullah Ömer Yamaç
<omer.yamac@ceng.metu.edu.tr> wrote:
>
> 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.yamac@ceng.metu.edu.tr>

If this patch is still relevant, please rebase it and send a new revision.
Don't forget to copy the library maintainers.


-- 
David Marchand

[PATCH v2] lib/hash: new feature adding existing key

[Abdullah Ömer Yamaç]

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.yamac@ceng.metu.edu.tr>

---
Cc: Yipeng Wang <yipeng1.wang@intel.com>
Cc: Sameh Gobriel <sameh.gobriel@intel.com>
Cc: Bruce Richardson <bruce.richardson@intel.com>
Cc: Vladimir Medvedkin <vladimir.medvedkin@intel.com>
Cc: David Marchand <david.marchand@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

[PATCH v2] lib/hash: new feature adding existing key

[Abdullah Ömer Yamaç]

From: Abdullah Ömer Yamaç <omer.yamac@ceng.metu.edu.tr>

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.yamac@ceng.metu.edu.tr>

---
Cc: Yipeng Wang <yipeng1.wang@intel.com>
Cc: Sameh Gobriel <sameh.gobriel@intel.com>
Cc: Bruce Richardson <bruce.richardson@intel.com>
Cc: Vladimir Medvedkin <vladimir.medvedkin@intel.com>
Cc: David Marchand <david.marchand@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

Re: [PATCH v2] lib/hash: new feature adding existing key

[Thomas Monjalon]

Any review please?
If maintainers agree with the idea, we should announce the ABI change.


23/10/2023 10:29, Abdullah Ömer Yamaç:
> From: Abdullah Ömer Yamaç <omer.yamac@ceng.metu.edu.tr>
> 
> 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.yamac@ceng.metu.edu.tr>
> 
> ---
> Cc: Yipeng Wang <yipeng1.wang@intel.com>
> Cc: Sameh Gobriel <sameh.gobriel@intel.com>
> Cc: Bruce Richardson <bruce.richardson@intel.com>
> Cc: Vladimir Medvedkin <vladimir.medvedkin@intel.com>
> Cc: David Marchand <david.marchand@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.
> 

Re: [PATCH v2] lib/hash: new feature adding existing key

[Stephen Hemminger]

On Fri, 16 Feb 2024 13:43:52 +0100
Thomas Monjalon <thomas@monjalon.net> wrote:

> Any review please?
> If maintainers agree with the idea, we should announce the ABI change.
> 
> 
> 23/10/2023 10:29, Abdullah Ömer Yamaç:
> > From: Abdullah Ömer Yamaç <omer.yamac@ceng.metu.edu.tr>
> > 
> > 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.yamac@ceng.metu.edu.tr>
> > 
> > ---
> > Cc: Yipeng Wang <yipeng1.wang@intel.com>
> > Cc: Sameh Gobriel <sameh.gobriel@intel.com>
> > Cc: Bruce Richardson <bruce.richardson@intel.com>
> > Cc: Vladimir Medvedkin <vladimir.medvedkin@intel.com>
> > Cc: David Marchand <david.marchand@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;

This is buggy, the caller assumes -1 on error in several places.
See:
	ret = search_and_update(h, data, key, prim_bkt, sig);
	if (ret != -1) {
		__hash_rw_writer_unlock(h);
		*ret_val = ret;
		return 1;
	}
These paths would exercised when table had to expand.

Also any new functionality like this would need tests in functional test.