Hi Tomas,
> From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of Tomas Vestelind
> Sent: Tuesday, August 12, 2014 10:48 PM
> To: dev at dpdk.org
> Subject: [dpdk-dev] [PATCH] hash: added rte_hash_keys to extract all keys
>
> I added a function which extracts all the configured keys in a hash map.
> This is good to have when debugging and printing data store in hash
> maps.
>
> Signed-off-by: Tomas Vestelind <tomas.vestelind at gmail.com>
> ---
> lib/librte_hash/rte_hash.c | 26 ++++++++++++++++++++++++++
> lib/librte_hash/rte_hash.h | 15 +++++++++++++++
> 2 files changed, 41 insertions(+)
>
> diff --git a/lib/librte_hash/rte_hash.c b/lib/librte_hash/rte_hash.c
> index d02b6b4..2108c4f 100644
> --- a/lib/librte_hash/rte_hash.c
> +++ b/lib/librte_hash/rte_hash.c
> @@ -481,3 +481,29 @@ rte_hash_lookup_bulk(const struct rte_hash *h, const
> void **keys,
>
> return 0;
> }
> +
> +unsigned int
> +rte_hash_keys(const struct rte_hash *h, void *keys)
> +{
> + unsigned int found_keys = 0;
> + unsigned int bucket, entry;
> +
> + /* Go through each bucket and all its entries */
> + for (bucket = 0; bucket < h->num_buckets; bucket++) {
> + const hash_sig_t *sig = get_sig_tbl_bucket(h, bucket);
> +
> + for (entry = 0; entry < h->bucket_entries; entry++) {
> + /* If the signature is valid, find and save the corresponding
> key */
> + if (sig[entry] != NULL_SIGNATURE) {
> + uint8_t *key_bucket = get_key_tbl_bucket(h, bucket);
> + void *key = get_key_from_bucket(h, key_bucket, entry);
> + rte_memcpy(keys, key, h->key_len);
> +
> + keys = (uint8_t* )keys + h->key_len;
> + found_keys++;
> + }
> + }
> + }
I suppose we need to add one extra parameter: keys_size (size of the buffer
provided) and inside the loop check that we wouldn't go beyond it.
Also it would probably helpful to have a function that would return to the user
size of buffer needed to sore all keys from the hash.
What you probably can do: implement a function that would iterate over all
elements in the hash table and for each of them call a callback (taken as an
argument).
Then all these functions and rte_hash_clear() could be implemented on top of it.
Something like:
typedef int (*rte_hash_elem_iter_t)(const struct rte_hash*hash, const void
*key, void *user_arg);
void
rte_hash_elem_iterate(const struct rte_hash *h, rte_hash_key_elem_t iter, void
*arg)
{
...
}
About rte_hash_clear(const struct rte_hash *h) - can't we just do
memset(h->sig_tbl, NULL_SIGNATURE, sig_tbl_size);?
BTW, why it is pointer to the const strucuture if we modifying it?
> +
> + return found_keys;
> +}
> diff --git a/lib/librte_hash/rte_hash.h b/lib/librte_hash/rte_hash.h
> index 2ecaf1a..e0fb28f 100644
> --- a/lib/librte_hash/rte_hash.h
> +++ b/lib/librte_hash/rte_hash.h
> @@ -303,6 +303,21 @@ rte_hash_hash(const struct rte_hash *h, const void *key)
> int
> rte_hash_lookup_bulk(const struct rte_hash *h, const void **keys,
> uint32_t num_keys, int32_t *positions);
> +
> +/**
> + * Copy the hash table keys to the supplied list of keys.
> + * This operation is multi-thread safe.
> + *
> + * @param h
> + * Hash table to look in.
> + * @param keys
> + * A pointer to a list of where keys will be written.
> + * Must be large enough to fit a potentially full hash map.
> + * @return
> + * The number of found keys.
> + */
> +unsigned int
> +rte_hash_keys(const struct rte_hash *h, void *keys);
> #ifdef __cplusplus
> }
> #endif
> --
> 1.7.10.4
