Re: [dpdk-dev] [RFC v2] lib: add compressdev API

["Verma, Shally" <Shally.Verma@cavium.com>]

> -----Original Message-----
> From: Trahe, Fiona [mailto:fiona.trahe@intel.com]
> Sent: 24 November 2017 22:26
> To: dev@dpdk.org; Verma, Shally <Shally.Verma@cavium.com>
> Cc: Challa, Mahipal <Mahipal.Challa@cavium.com>; Athreya, Narayana
> Prasad <NarayanaPrasad.Athreya@cavium.com>;
> pablo.de.lara.guarch@intel.com; fiona.trahe@intel.com
> Subject: [RFC v2] lib: add compressdev API
> 
> compressdev API
> 
> Signed-off-by: Trahe, Fiona <fiona.trahe@intel.com>
> ---

//snip//

> +unsigned int
> +rte_compressdev_get_header_session_size(void)
> +{
> +	/*
> +	 * Header contains pointers to the private data
> +	 * of all registered drivers
> +	 */
> +	return (sizeof(void *) * nb_drivers);
> +}
> +
> +unsigned int
> +rte_compressdev_get_private_session_size(uint8_t dev_id)
> +{
> +	struct rte_compressdev *dev;
> +	unsigned int header_size = sizeof(void *) * nb_drivers;
> +	unsigned int priv_sess_size;
> +
> +	if (!rte_compressdev_pmd_is_valid_dev(dev_id))
> +		return 0;
> +
> +	dev = rte_compressdev_pmd_get_dev(dev_id);
> +
> +	if (*dev->dev_ops->session_get_size == NULL)
> +		return 0;
> +
> +	priv_sess_size = (*dev->dev_ops->session_get_size)(dev);
> +
> +	/*
> +	 * If size is less than session header size,
> +	 * return the latter, as this guarantees that
> +	 * sessionless operations will work
> +	 */

[Shally] believe this comment need an edit

> +	if (priv_sess_size < header_size)
> +		return header_size;
> +
> +	return priv_sess_size;

[Shally] This doesn't return header_size inclusive which is fine as per API definition. So should application call 
rte_compressdev_get_header_session_size() in case it want to know header_size overhead per session and allocate pool with elt_size = sess_header_size + dev_priv_sz?

> +
> +}
//snip//

Thanks
Shally