From aa46fa06a0f8aaae9cef60b102d83be8c2d7923a Mon Sep 17 00:00:00 2001
From: Lucas Clemente <lucas@clemente.io>
Date: Fri, 6 May 2016 11:49:32 +0200
Subject: [PATCH] add very basic congestion window implementation

fixes #22
---
 session.go | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/session.go b/session.go
index 93def6a5d..99e0c7ec5 100644
--- a/session.go
+++ b/session.go
@@ -323,6 +323,10 @@ func (s *Session) closeStreamsWithError(err error) {
 }
 
 func (s *Session) sendPacket() error {
+	if !s.congestionAllowsSending() {
+		return nil
+	}
+
 	var controlFrames []frames.Frame
 
 	// check for retransmissions first
@@ -446,3 +450,7 @@ func (s *Session) scheduleSending() {
 	default:
 	}
 }
+
+func (s *Session) congestionAllowsSending() bool {
+	return protocol.ByteCount(s.sentPacketHandler.BytesInFlight()) < 100*protocol.DefaultTCPMSS
+}