stats: Add stat_item_for_each functions

This commit adds the following functions:

  stat_item_for_each_group     Call a handler for each group
  stat_item_for_each_item      Call a handler for each item of a
                               group

Sponsored-by: On-Waves ehf

include/osmocom/core/stat_item.h

@@ -107,6 +107,20 @@ int stat_item_discard(const struct stat_item *item, int32_t *idx);
 /*! \brief Skip all values of all items and update idx accordingly */
 int stat_item_discard_all(int32_t *idx);
 
+typedef int (*stat_item_handler_t)(
+	struct stat_item_group *, struct stat_item *, void *);
+
+typedef int (*stat_item_group_handler_t)(struct stat_item_group *, void *);
+
+/*! \brief Iteate over all items
+ *  \param[in] handle_item Call-back function, aborts if rc < 0
+ *  \param[in] data Private data handed through to \a handle_item
+ */
+int stat_item_for_each_item(struct stat_item_group *statg,
+	stat_item_handler_t handle_item, void *data);
+
+int stat_item_for_each_group(stat_item_group_handler_t handle_group, void *data);
+
 static inline int32_t stat_item_get_last(const struct stat_item *item)
 {
 	return item->values[item->last_offs].value;

src/stat_item.c

@@ -235,4 +235,34 @@ const struct stat_item *stat_item_get_by_name(
 	return NULL;
 }
 
+int stat_item_for_each_item(struct stat_item_group *statg,
+	stat_item_handler_t handle_item, void *data)
+{
+	int rc = 0;
+	int i;
+
+	for (i = 0; i < statg->desc->num_items; i++) {
+		struct stat_item *item = statg->items[i];
+		rc = handle_item(statg, item, data);
+		if (rc < 0)
+			return rc;
+	}
+
+	return rc;
+}
+
+int stat_item_for_each_group(stat_item_group_handler_t handle_group, void *data)
+{
+	struct stat_item_group *statg;
+	int rc = 0;
+
+	llist_for_each_entry(statg, &stat_item_groups, list) {
+		rc = handle_group(statg, data);
+		if (rc < 0)
+			return rc;
+	}
+
+	return rc;
+}
+
 /*! @} */