WIP: send flow control

src/frame/mod.rs

@@ -1,7 +1,7 @@
 use hpack;
 use error::{ConnectionError, Reason};
 
-use bytes::Bytes;
+use bytes::{Bytes, Buf};
 
 use std::fmt;
 
@@ -78,6 +78,18 @@ impl<T> Frame<T> {
     }
 }
 
+impl<T: Buf> Frame<T> {
+    /// Returns the length of the frame as it applies to flow control.
+    pub fn flow_len(&self) -> usize {
+        use self::Frame::*;
+
+        match *self {
+            Data(ref frame) => frame.payload().remaining(),
+            _ => 0,
+        }
+    }
+}
+
 impl<T> fmt::Debug for Frame<T> {
     fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
         use self::Frame::*;