From b7b50572eb4cb34c74a316015b5ec808bdf6afa8 Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Wed, 3 Jan 2018 10:26:50 +0700
Subject: [PATCH] use the timescale factor for flow control tests on CIs

---
 .../flowcontrol/base_flow_controller_test.go  | 20 +++++++++++++++----
 .../connection_flow_controller_test.go        |  2 +-
 .../stream_flow_controller_test.go            |  4 ++--
 3 files changed, 19 insertions(+), 7 deletions(-)

diff --git a/internal/flowcontrol/base_flow_controller_test.go b/internal/flowcontrol/base_flow_controller_test.go
index 71e83cf90..f996a28f4 100644
--- a/internal/flowcontrol/base_flow_controller_test.go
+++ b/internal/flowcontrol/base_flow_controller_test.go
@@ -1,6 +1,8 @@
 package flowcontrol
 
 import (
+	"os"
+	"strconv"
 	"time"
 
 	"github.com/lucas-clemente/quic-go/congestion"
@@ -9,6 +11,16 @@ import (
 	. "github.com/onsi/gomega"
 )
 
+// on the CIs, the timing is a lot less precise, so scale every duration by this factor
+func scaleDuration(t time.Duration) time.Duration {
+	scaleFactor := 1
+	if f, err := strconv.Atoi(os.Getenv("TIMESCALE_FACTOR")); err == nil { // parsing "" errors, so this works fine if the env is not set
+		scaleFactor = f
+	}
+	Expect(scaleFactor).ToNot(BeZero())
+	return time.Duration(scaleFactor) * t
+}
+
 var _ = Describe("Base Flow controller", func() {
 	var controller *baseFlowController
 
@@ -118,7 +130,7 @@ var _ = Describe("Base Flow controller", func() {
 
 			It("increases the window size if read so fast that the window would be consumed in less than 4 RTTs", func() {
 				bytesRead := controller.bytesRead
-				rtt := 200 * time.Millisecond
+				rtt := scaleDuration(20 * time.Millisecond)
 				setRtt(rtt)
 				// consume more than 2/3 of the window...
 				dataRead := receiveWindowSize*2/3 + 1
@@ -139,7 +151,7 @@ var _ = Describe("Base Flow controller", func() {
 				// this test only makes sense if a window update is triggered before half of the window has been consumed
 				Expect(protocol.WindowUpdateThreshold).To(BeNumerically(">", 1/3))
 				bytesRead := controller.bytesRead
-				rtt := 200 * time.Millisecond
+				rtt := scaleDuration(20 * time.Millisecond)
 				setRtt(rtt)
 				// consume more than 2/3 of the window...
 				dataRead := receiveWindowSize*1/3 + 1
@@ -158,7 +170,7 @@ var _ = Describe("Base Flow controller", func() {
 
 			It("doesn't increase the window size if read too slowly", func() {
 				bytesRead := controller.bytesRead
-				rtt := 200 * time.Millisecond
+				rtt := scaleDuration(20 * time.Millisecond)
 				setRtt(rtt)
 				// consume less than 2/3 of the window...
 				dataRead := receiveWindowSize*2/3 - 1
@@ -181,7 +193,7 @@ var _ = Describe("Base Flow controller", func() {
 					controller.epochStartOffset = controller.bytesRead
 					controller.AddBytesRead(controller.receiveWindowSize/2 + 1)
 				}
-				setRtt(200 * time.Millisecond)
+				setRtt(scaleDuration(20 * time.Millisecond))
 				resetEpoch()
 				controller.maybeAdjustWindowSize()
 				Expect(controller.receiveWindowSize).To(Equal(2 * oldWindowSize)) // 2000
diff --git a/internal/flowcontrol/connection_flow_controller_test.go b/internal/flowcontrol/connection_flow_controller_test.go
index b832a5de7..056daf37b 100644
--- a/internal/flowcontrol/connection_flow_controller_test.go
+++ b/internal/flowcontrol/connection_flow_controller_test.go
@@ -63,7 +63,7 @@ var _ = Describe("Connection Flow controller", func() {
 			It("autotunes the window", func() {
 				oldOffset := controller.bytesRead
 				oldWindowSize := controller.receiveWindowSize
-				rtt := 200 * time.Millisecond
+				rtt := scaleDuration(20 * time.Millisecond)
 				setRtt(rtt)
 				controller.epochStartTime = time.Now().Add(-time.Millisecond)
 				controller.epochStartOffset = oldOffset
diff --git a/internal/flowcontrol/stream_flow_controller_test.go b/internal/flowcontrol/stream_flow_controller_test.go
index 79441d2ce..a3ef9dc39 100644
--- a/internal/flowcontrol/stream_flow_controller_test.go
+++ b/internal/flowcontrol/stream_flow_controller_test.go
@@ -184,7 +184,7 @@ var _ = Describe("Stream Flow controller", func() {
 			It("tells the connection flow controller when the window was autotuned", func() {
 				oldOffset := controller.bytesRead
 				controller.contributesToConnection = true
-				setRtt(200 * time.Millisecond)
+				setRtt(scaleDuration(20 * time.Millisecond))
 				controller.epochStartOffset = oldOffset
 				controller.epochStartTime = time.Now().Add(-time.Millisecond)
 				controller.AddBytesRead(55)
@@ -197,7 +197,7 @@ var _ = Describe("Stream Flow controller", func() {
 			It("doesn't tell the connection flow controller if it doesn't contribute", func() {
 				oldOffset := controller.bytesRead
 				controller.contributesToConnection = false
-				setRtt(200 * time.Millisecond)
+				setRtt(scaleDuration(20 * time.Millisecond))
 				controller.epochStartOffset = oldOffset
 				controller.epochStartTime = time.Now().Add(-time.Millisecond)
 				controller.AddBytesRead(55)