lib : Yang wrappers

1. To get the parent node
2. To auto delete the parent when last node in list gets deleted

Signed-off-by: VishalDhingra <vdhingra@vmware.com>

1 files changed, 144 insertions, 0 deletions

diff --git a/lib/yang.c b/lib/yang.c
index 0714ddf7bb..db99c0339e 100644
--- a/lib/yang.c
+++ b/lib/yang.c
@@ -749,3 +749,147 @@ void yang_terminate(void)
 
 	ly_ctx_destroy(ly_native_ctx, NULL);
 }
+
+const struct lyd_node *yang_dnode_get_parent(const struct lyd_node *dnode,
+					     const char *name)
+{
+	const struct lyd_node *orig_dnode = dnode;
+
+	while (orig_dnode) {
+		switch (orig_dnode->schema->nodetype) {
+		case LYS_LIST:
+		case LYS_CONTAINER:
+			if (!strcmp(orig_dnode->schema->name, name))
+				return orig_dnode;
+			break;
+		default:
+			break;
+		}
+
+		orig_dnode = orig_dnode->parent;
+	}
+
+	return NULL;
+}
+
+/* API to check if the given node is last node in the list */
+static bool yang_is_last_list_dnode(const struct lyd_node *dnode)
+{
+	return (((dnode->next == NULL)
+	     || (dnode->next
+		 && (strcmp(dnode->next->schema->name, dnode->schema->name)
+		     != 0)))
+	    && dnode->prev
+	    && ((dnode->prev == dnode)
+		|| (strcmp(dnode->prev->schema->name, dnode->schema->name)
+		    != 0)));
+}
+
+/* API to check if the given node is last node in the data tree level */
+static bool yang_is_last_level_dnode(const struct lyd_node *dnode)
+{
+	const struct lyd_node *parent;
+	const struct lys_node_list *snode;
+	const struct lyd_node *key_leaf;
+	uint8_t keys_size;
+
+	switch (dnode->schema->nodetype) {
+	case LYS_LIST:
+		assert(dnode->parent);
+		parent = dnode->parent;
+		snode = (struct lys_node_list *)parent->schema;
+		key_leaf = dnode->prev;
+		for (keys_size = 1; keys_size < snode->keys_size; keys_size++)
+			key_leaf = key_leaf->prev;
+		if (key_leaf->prev == dnode)
+			return true;
+		break;
+	case LYS_CONTAINER:
+		return true;
+	default:
+		break;
+	}
+
+	return false;
+}
+
+
+const struct lyd_node *
+yang_get_subtree_with_no_sibling(const struct lyd_node *dnode)
+{
+	bool parent = true;
+	const struct lyd_node *node;
+	const struct lys_node_container *snode;
+
+	node = dnode;
+	if (node->schema->nodetype != LYS_LIST)
+		return node;
+
+	while (parent) {
+		switch (node->schema->nodetype) {
+		case LYS_CONTAINER:
+			snode = (struct lys_node_container *)node->schema;
+			if ((!snode->presence)
+			    && yang_is_last_level_dnode(node)) {
+				if (node->parent
+				    && (node->parent->schema->module
+					== dnode->schema->module))
+					node = node->parent;
+				else
+					parent = false;
+			} else
+				parent = false;
+			break;
+		case LYS_LIST:
+			if (yang_is_last_list_dnode(node)
+			    && yang_is_last_level_dnode(node)) {
+				if (node->parent
+				    && (node->parent->schema->module
+					== dnode->schema->module))
+					node = node->parent;
+				else
+					parent = false;
+			} else
+				parent = false;
+			break;
+		default:
+			parent = false;
+			break;
+		}
+	}
+	return node;
+}
+
+uint32_t yang_get_list_pos(const struct lyd_node *node)
+{
+	return lyd_list_pos(node);
+}
+
+uint32_t yang_get_list_elements_count(const struct lyd_node *node)
+{
+	unsigned int count;
+	struct lys_node *schema;
+
+	if (!node
+	    || ((node->schema->nodetype != LYS_LIST)
+		&& (node->schema->nodetype != LYS_LEAFLIST))) {
+		return 0;
+	}
+
+	schema = node->schema;
+	count = 0;
+	do {
+		if (node->schema == schema)
+			++count;
+		node = node->next;
+	} while (node);
+	return count;
+}
+
+
+const struct lyd_node *yang_dnode_get_child(const struct lyd_node *dnode)
+{
+	if (dnode)
+		return dnode->child;
+	return NULL;
+}