Re: [dpdk-dev] [PATCH v3 03/29] graph: implement node operations

["Wang, Xiao W" <xiao.w.wang@intel.com>]

Hi Jerin,

Comment inline.

Best Regards,
Xiao

> -----Original Message-----
> From: dev <dev-bounces@dpdk.org> On Behalf Of jerinj@marvell.com
> Sent: Wednesday, April 1, 2020 3:29 AM
> To: Jerin Jacob <jerinj@marvell.com>; Kiran Kumar K
> <kirankumark@marvell.com>
> Cc: dev@dpdk.org; thomas@monjalon.net; david.marchand@redhat.com;
> mdr@ashroe.eu; mattias.ronnblom@ericsson.com;
> pbhagavatula@marvell.com; ndabilpuram@marvell.com
> Subject: [dpdk-dev] [PATCH v3 03/29] graph: implement node operations
> 
> From: Jerin Jacob <jerinj@marvell.com>
> 
> Adding node-specific API implementation like cloning node, updating
> edges for the node, shrinking edges of a node, retrieving edges of a
> node.
> 
> Signed-off-by: Jerin Jacob <jerinj@marvell.com>
> Signed-off-by: Kiran Kumar K <kirankumark@marvell.com>
> Signed-off-by: Pavan Nikhilesh <pbhagavatula@marvell.com>
> Signed-off-by: Nithin Dabilpuram <ndabilpuram@marvell.com>
> ---
>  lib/librte_graph/graph_private.h       |  10 +
>  lib/librte_graph/node.c                | 269 +++++++++++++++++++++++++
>  lib/librte_graph/rte_graph_version.map |  10 +
>  3 files changed, 289 insertions(+)
> 
> diff --git a/lib/librte_graph/graph_private.h
> b/lib/librte_graph/graph_private.h
> index 8b9ff5292..7ed6d01b6 100644
> --- a/lib/librte_graph/graph_private.h
> +++ b/lib/librte_graph/graph_private.h
> @@ -13,6 +13,16 @@
> 
>  #include "rte_graph.h"
> 
> +
> +#define ID_CHECK(id, id_max)                                                   \
> +	do {                                                                   \
> +		if ((id) >= (id_max)) {                                        \
> +			rte_errno = EINVAL;                                    \
> +			goto fail;                                             \
> +		}                                                              \
> +	} while (0)
> +
> +
[...]
> +char *
> +rte_node_id_to_name(rte_node_t id)
> +{
> +	struct node *node;
> +
> +	NODE_ID_CHECK(id);
> +	STAILQ_FOREACH(node, &node_list, next)
> +		if (node->id == id)
> +			return node->name;
> +
> +fail:
> +	return NULL;
> +}
> +
> +rte_edge_t
> +rte_node_edge_count(rte_node_t id)
> +{
> +	struct node *node;
> +
> +	NODE_ID_CHECK(id);
> +	STAILQ_FOREACH(node, &node_list, next)
> +		if (node->id == id)
> +			return node->nb_edges;
> +fail:
> +	return RTE_EDGE_ID_INVALID;
> +}
> +
> +static rte_edge_t
> +edge_update(struct node *node, struct node *prev, rte_edge_t from,
> +	    const char **next_nodes, rte_edge_t nb_edges)
> +{
> +	rte_edge_t i, max_edges, count = 0;
> +	struct node *new_node;
> +	bool need_realloc;
> +	size_t sz;
> +
> +	if (from == RTE_EDGE_ID_INVALID)
> +		from = node->nb_edges;
> +
> +	/* Don't create hole in next_nodes[] list */
> +	if (from > node->nb_edges) {
> +		rte_errno = ENOMEM;
> +		goto fail;
> +	}
> +
> +	/* Remove me from list */
> +	STAILQ_REMOVE(&node_list, node, node, next);
> +
> +	/* Allocate the storage space for new node if required */
> +	max_edges = from + nb_edges;
> +	need_realloc = max_edges > node->nb_edges;
> +	if (need_realloc) {
> +		sz = sizeof(struct node) + (max_edges *
> RTE_NODE_NAMESIZE);
> +		new_node = realloc(node, sz);
> +		if (new_node == NULL) {
> +			rte_errno = ENOMEM;
> +			goto restore;
> +		} else {
> +			node = new_node;
> +		}
> +	}
> +
> +	/* Update the new nodes name */
> +	for (i = from; i < max_edges; i++, count++) {
> +		if (rte_strscpy(node->next_nodes[i], next_nodes[count],
> +				RTE_NODE_NAMESIZE) < 0) {
> +			rte_errno = E2BIG;
> +			goto restore;
> +		}
> +	}
> +restore:
> +	/* Update the linked list to point new node address in prev node */
> +	if (prev)
> +		STAILQ_INSERT_AFTER(&node_list, prev, node, next);
> +	else
> +		STAILQ_INSERT_HEAD(&node_list, node, next);
> +
> +	if (need_realloc)
> +		node->nb_edges += count;

If the "from" starts from somewhere in the middle of the edges, and also triggers a realloc,
then the new edge number should be: node->nb_edges = max_edges;

> +
> +fail:
> +	return count;