Implement an iterator for `struct str_map'

src/common.c

@@ -566,6 +566,16 @@ struct str_map
 	void (*free) (void *);              ///< Callback to destruct the payload
 };
 
+// As long as you don't remove the current entry, you can modify the map.
+// Use `link' directly to access the data.
+
+struct str_map_iter
+{
+	struct str_map *map;                ///< The map we're iterating
+	size_t next_index;                  ///< Next table index to search
+	struct str_map_link *link;          ///< Current link
+};
+
 #define STR_MAP_MIN_ALLOC 16
 
 typedef void (*str_map_free_func) (void *);
@@ -598,6 +608,29 @@ str_map_free (struct str_map *self)
 	self->map = NULL;
 }
 
+static void
+str_map_iter_init (struct str_map_iter *self, struct str_map *map)
+{
+	self->map = map;
+	self->next_index = 0;
+	self->link = NULL;
+}
+
+static bool
+str_map_iter_next (struct str_map_iter *self)
+{
+	struct str_map *map = self->map;
+	if (self->link)
+		self->link = self->link->next;
+	while (!self->link)
+	{
+		if (self->next_index >= map->len)
+			return false;
+		self->link = map->map[self->next_index++];
+	}
+	return true;
+}
+
 static uint64_t
 str_map_hash (const char *s, size_t len)
 {