Introduce cowboy_req:set_meta/3 to set request metadata

src/cowboy_req.erl

@@ -49,6 +49,7 @@
 -export([cookies/1]).
 -export([meta/2]).
 -export([meta/3]).
+-export([set_meta/3]).
 
 %% Request body API.
 -export([has_body/1]).
@@ -429,6 +430,15 @@ meta(Name, Req, Default) ->
 		false -> {Default, Req}
 	end.
 
+%% @doc Set metadata information.
+%%
+%% You can use this function to attach information about the request.
+%%
+%% If the value already exists it will be overwritten.
+-spec set_meta(atom(), any(), Req) -> Req when Req::req().
+set_meta(Name, Value, Req=#http_req{meta=Meta}) ->
+	Req#http_req{meta=[{Name, Value}|lists:keydelete(Name, 1, Meta)]}.
+
 %% Request Body API.
 
 %% @doc Return whether the request message has a body.