delete flow controllers for closed streams

fixes #177

flowcontrol/flow_control_manager.go

@@ -51,6 +51,14 @@ func (f *flowControlManager) NewStream(streamID protocol.StreamID, contributesTo
 	f.contributesToConnectionFlowControl[streamID] = contributesToConnectionFlow
 }
 
+// RemoveStream removes a closed stream from flow control
+func (f *flowControlManager) RemoveStream(streamID protocol.StreamID) {
+	f.mutex.Lock()
+	delete(f.streamFlowController, streamID)
+	delete(f.contributesToConnectionFlowControl, streamID)
+	f.mutex.Unlock()
+}
+
 // UpdateHighestReceived updates the highest received byte offset for a stream
 // it adds the number of additional bytes to connection level flow control
 // streamID must not be 0 here

flowcontrol/flow_control_manager_test.go

@@ -33,6 +33,14 @@ var _ = Describe("Flow Control Manager", func() {
 		})
 	})
 
+	It("removes streams", func() {
+		fcm.NewStream(5, true)
+		Expect(fcm.streamFlowController).To(HaveKey(protocol.StreamID(5)))
+		fcm.RemoveStream(5)
+		Expect(fcm.streamFlowController).ToNot(HaveKey(protocol.StreamID(5)))
+		Expect(fcm.contributesToConnectionFlowControl).ToNot(HaveKey(protocol.StreamID(5)))
+	})
+
 	Context("receiving data", func() {
 		BeforeEach(func() {
 			fcm.NewStream(1, false)

flowcontrol/interface.go

@@ -5,6 +5,7 @@ import "github.com/lucas-clemente/quic-go/protocol"
 // A FlowControlManager manages the flow control
 type FlowControlManager interface {
 	NewStream(streamID protocol.StreamID, contributesToConnectionFlow bool)
+	RemoveStream(streamID protocol.StreamID)
 	// methods needed for receiving data
 	UpdateHighestReceived(streamID protocol.StreamID, byteOffset protocol.ByteCount) error
 	AddBytesRead(streamID protocol.StreamID, n protocol.ByteCount) error