[dpdk-dev] hash: add rte_hash_set_cmp_func() function.

  Give user a chance to costomize the hash key compare function.
The default rte_hash_cmp_eq function is set in the rte_hash_create
function, but these builtin ones may not good enough, so the user
may call this to override the default one.

Signed-off-by: Yu Nemo Wenbin <yuwb_bjy@ctbri.com.cn>
---
 lib/librte_hash/rte_cuckoo_hash.c    |  7 +++++--
 lib/librte_hash/rte_hash.h           | 15 +++++++++++++++
 lib/librte_hash/rte_hash_version.map |  1 +
 3 files changed, 21 insertions(+), 2 deletions(-)
  

Hi,

> -----Original Message-----
> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Yu Nemo Wenbin
> Sent: Thursday, November 19, 2015 1:15 AM
> To: dev@dpdk.org
> Subject: [dpdk-dev] [PATCH] hash: add rte_hash_set_cmp_func() function.
> 
> Give user a chance to costomize the hash key compare function.
> The default rte_hash_cmp_eq function is set in the rte_hash_create
> function, but these builtin ones may not good enough, so the user
> may call this to override the default one.

Typos in "costomize" and "may not good" (may not be good)
> 
> Signed-off-by: Yu Nemo Wenbin <yuwb_bjy@ctbri.com.cn>
> ---
>  lib/librte_hash/rte_cuckoo_hash.c    |  7 +++++--
>  lib/librte_hash/rte_hash.h           | 15 +++++++++++++++
>  lib/librte_hash/rte_hash_version.map |  1 +
>  3 files changed, 21 insertions(+), 2 deletions(-)
> 
> diff --git a/lib/librte_hash/rte_cuckoo_hash.c
> b/lib/librte_hash/rte_cuckoo_hash.c
> index 1e970de..71e2419 100644
> --- a/lib/librte_hash/rte_cuckoo_hash.c
> +++ b/lib/librte_hash/rte_cuckoo_hash.c
> @@ -98,8 +98,6 @@ EAL_REGISTER_TAILQ(rte_hash_tailq)
> 
>  #define LCORE_CACHE_SIZE		8
> 
> -typedef int (*rte_hash_cmp_eq_t)(const void *key1, const void *key2,
> size_t key_len);
> -
>  struct lcore_cache {
>  	unsigned len; /**< Cache len */
>  	void *objs[LCORE_CACHE_SIZE]; /**< Cache objects */
> @@ -183,6 +181,11 @@ rte_hash_find_existing(const char *name)
>  	return h;
>  }
> 
> +void rte_hash_set_cmp_func(struct rte_hash *h, rte_hash_cmp_eq_t
> func)
> +{
> +    h->rte_hash_cmp_eq = func;
> +}
> +
>  struct rte_hash *
>  rte_hash_create(const struct rte_hash_parameters *params)
>  {
> diff --git a/lib/librte_hash/rte_hash.h b/lib/librte_hash/rte_hash.h
> index b678766..8378a42 100644
> --- a/lib/librte_hash/rte_hash.h
> +++ b/lib/librte_hash/rte_hash.h
> @@ -66,6 +66,9 @@ typedef uint32_t hash_sig_t;
>  typedef uint32_t (*rte_hash_function)(const void *key, uint32_t key_len,
>  				      uint32_t init_val);
> 
> +/** Type of function used to compare the key. It works like the memcmp()
> */

Remove "the".

> +typedef int (*rte_hash_cmp_eq_t)(const void *key1, const void *key2,
> size_t key_len);
> +
>  /**
>   * Parameters used when creating the hash table.
>   */
> @@ -104,6 +107,18 @@ struct rte_hash *
>  rte_hash_create(const struct rte_hash_parameters *params);
> 
>  /**
> + * Set the rte_hash_set_cmp_func.
> + * Set the new hash compare function if the default one is not suitable
> enough.
> + *
> + * @note Function pointer does not work with multi-process, so don't use
> it
> + * in multi-process mode.
> + *
> + * @param h
> + *   Hash table to reset
> + */
> +void rte_hash_set_cmp_func(struct rte_hash *h, rte_hash_cmp_eq_t
> func);
> +
> +/**
>   * Find an existing hash table object and return a pointer to it.
>   *
>   * @param name
> diff --git a/lib/librte_hash/rte_hash_version.map
> b/lib/librte_hash/rte_hash_version.map
> index 906c8ad..3bc1e2c 100644
> --- a/lib/librte_hash/rte_hash_version.map
> +++ b/lib/librte_hash/rte_hash_version.map
> @@ -30,5 +30,6 @@ DPDK_2.1 {
>  	rte_hash_lookup_data;
>  	rte_hash_lookup_with_hash_data;
>  	rte_hash_reset;
> +	rte_hash_set_cmp_func;
> 
>  } DPDK_2.0;
> --
> 1.9.1

You have to add the new function in a different set (create a new one for 2.2).

Thanks,
Pablo