lib: implement utility function API which does the following

1. listnode_add_sort_nodup - This API adds to list only if no duplicate
    element available in the list. returns true/false
2. list_filter_out_nodes - This API deletes the nodes which satisfy the given
    condition. condition is passed as a func ptr in
    API. This function takes in node data(void ptr).

Signed-off-by: Saravanan K <saravanank@vmware.com>

lib/linklist.c

@@ -92,6 +92,46 @@ void listnode_add_head(struct list *list, void *val)
 	list->count++;
 }
 
+bool listnode_add_sort_nodup(struct list *list, void *val)
+{
+	struct listnode *n;
+	struct listnode *new;
+	int ret;
+
+	assert(val != NULL);
+
+	if (list->cmp) {
+		for (n = list->head; n; n = n->next) {
+			ret = (*list->cmp)(val, n->data);
+			if (ret < 0) {
+				new = listnode_new();
+				new->data = val;
+
+				new->next = n;
+				new->prev = n->prev;
+
+				if (n->prev)
+					n->prev->next = new;
+				else
+					list->head = new;
+				n->prev = new;
+				list->count++;
+				return true;
+			}
+			/* found duplicate return false */
+			if (ret == 0)
+				return false;
+		}
+	}
+
+	new = listnode_new();
+	new->data = val;
+
+	LISTNODE_ATTACH(list, new);
+
+	return true;
+}
+
 void listnode_add_sort(struct list *list, void *val)
 {
 	struct listnode *n;
@@ -242,6 +282,23 @@ void list_delete_all_node(struct list *list)
 	list->count = 0;
 }
 
+void list_filter_out_nodes(struct list *list, bool (*cond)(void *data))
+{
+	struct listnode *node;
+	struct listnode *next;
+	void *data;
+
+	assert(list);
+
+	for (ALL_LIST_ELEMENTS(list, node, next, data)) {
+		if ((cond && cond(data)) || (!cond)) {
+			if (*list->del)
+				(*list->del)(data);
+			list_delete_node(list, node);
+		}
+	}
+}
+
 void list_delete(struct list **list)
 {
 	assert(*list);

lib/linklist.h

@@ -288,6 +288,39 @@ extern void list_delete_node(struct list *list, struct listnode *node);
  */
 extern void list_add_list(struct list *list, struct list *add);
 
+/*
+ * Delete all nodes which satisfy a condition from a list.
+ * Deletes the node if cond function returns true for the node.
+ * If function ptr passed is NULL, it deletes all nodes
+ *
+ * list
+ *    list to operate on
+ * cond
+ *    function pointer which takes node data as input and return TRUE or FALSE
+ */
+
+extern void list_filter_out_nodes(struct list *list, bool (*cond)(void *data));
+
+/*
+ * Insert a new element into a list with insertion sort if there is no
+ * duplicate element present in the list. This assumes the input list is
+ * sorted. If unsorted, it will check for duplicate until it finds out
+ * the position to do insertion sort with the unsorted list.
+ *
+ * If list->cmp is set, this function is used to determine the position to
+ * insert the new element. If it is not set, this function is equivalent to
+ * listnode_add. duplicate element is determined by cmp function returning 0.
+ *
+ * Runtime is O(N).
+ *
+ * list
+ *    list to operate on
+ *
+ * val
+ *    element to add
+ */
+
+extern bool listnode_add_sort_nodup(struct list *list, void *val);
 /* List iteration macro.
  * Usage: for (ALL_LIST_ELEMENTS (...) { ... }
  * It is safe to delete the listnode using this macro.