split the flow controller in stream and connection flow controller

internal/flowcontrol/stream_flow_controller_test.go

@@ -0,0 +1,83 @@
+package flowcontrol
+
+import (
+	"github.com/lucas-clemente/quic-go/congestion"
+	"github.com/lucas-clemente/quic-go/internal/protocol"
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+)
+
+var _ = Describe("Stream Flow controller", func() {
+	var controller *streamFlowController
+
+	BeforeEach(func() {
+		controller = &streamFlowController{}
+		controller.rttStats = &congestion.RTTStats{}
+	})
+
+	Context("Constructor", func() {
+		rttStats := &congestion.RTTStats{}
+
+		It("sets the send and receive windows", func() {
+			receiveWindow := protocol.ByteCount(2000)
+			maxReceiveWindow := protocol.ByteCount(3000)
+			sendWindow := protocol.ByteCount(4000)
+
+			fc := newStreamFlowController(5, true, receiveWindow, maxReceiveWindow, sendWindow, rttStats)
+			Expect(fc.streamID).To(Equal(protocol.StreamID(5)))
+			Expect(fc.receiveWindow).To(Equal(receiveWindow))
+			Expect(fc.maxReceiveWindowIncrement).To(Equal(maxReceiveWindow))
+			Expect(fc.sendWindow).To(Equal(sendWindow))
+		})
+
+		It("says if it contributes to connection-level flow control", func() {
+			fc := newStreamFlowController(1, false, protocol.MaxByteCount, protocol.MaxByteCount, protocol.MaxByteCount, rttStats)
+			Expect(fc.ContributesToConnection()).To(BeFalse())
+			fc = newStreamFlowController(5, true, protocol.MaxByteCount, protocol.MaxByteCount, protocol.MaxByteCount, rttStats)
+			Expect(fc.ContributesToConnection()).To(BeTrue())
+		})
+	})
+
+	Context("receive flow control", func() {
+		var receiveWindow protocol.ByteCount = 10000
+		var receiveWindowIncrement protocol.ByteCount = 600
+
+		BeforeEach(func() {
+			controller.receiveWindow = receiveWindow
+			controller.receiveWindowIncrement = receiveWindowIncrement
+		})
+
+		It("updates the highestReceived", func() {
+			controller.highestReceived = 1337
+			increment, err := controller.UpdateHighestReceived(1338)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(increment).To(Equal(protocol.ByteCount(1338 - 1337)))
+			Expect(controller.highestReceived).To(Equal(protocol.ByteCount(1338)))
+		})
+
+		It("does not decrease the highestReceived", func() {
+			controller.highestReceived = 1337
+			increment, err := controller.UpdateHighestReceived(1000)
+			Expect(err).To(MatchError(ErrReceivedSmallerByteOffset))
+			Expect(increment).To(BeZero())
+			Expect(controller.highestReceived).To(Equal(protocol.ByteCount(1337)))
+		})
+
+		It("does not error when setting the same byte offset", func() {
+			controller.highestReceived = 1337
+			increment, err := controller.UpdateHighestReceived(1337)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(increment).To(BeZero())
+		})
+
+		It("detects a flow control violation", func() {
+			controller.UpdateHighestReceived(receiveWindow + 1)
+			Expect(controller.CheckFlowControlViolation()).To(BeTrue())
+		})
+
+		It("does not give a flow control violation when using the window completely", func() {
+			controller.UpdateHighestReceived(receiveWindow)
+			Expect(controller.CheckFlowControlViolation()).To(BeFalse())
+		})
+	})
+})