closer to flow control

src/lib.rs

@@ -51,6 +51,8 @@ pub enum Frame<T, B = Bytes> {
     Data {
         id: StreamId,
         data: B,
+        /// TODO figure out how to make this a requirement on `B`
+        data_len: usize,
         end_of_stream: bool,
     },
     Trailers {