From 726674ac63262b5534536b79cd6779590f6eb447 Mon Sep 17 00:00:00 2001
From: alwu <alwu@mozilla.com>
Date: Mon, 4 Oct 2021 22:30:10 +0000
Subject: [PATCH] Bug 1730020 - part3 : add gtest. r=padenot

Differential Revision: https://phabricator.services.mozilla.com/D126423
---
 dom/media/utils/PerformanceRecorder.cpp       | 24 +++++---
 dom/media/utils/PerformanceRecorder.h         | 16 ++++-
 .../utils/gtest/TestPerformanceRecorder.cpp   | 61 +++++++++++++++++++
 dom/media/utils/gtest/moz.build               | 18 ++++++
 dom/media/utils/moz.build                     |  3 +
 5 files changed, 113 insertions(+), 9 deletions(-)
 create mode 100644 dom/media/utils/gtest/TestPerformanceRecorder.cpp
 create mode 100644 dom/media/utils/gtest/moz.build

diff --git a/dom/media/utils/PerformanceRecorder.cpp b/dom/media/utils/PerformanceRecorder.cpp
index 1ce470921759..162d22cc3f36 100644
--- a/dom/media/utils/PerformanceRecorder.cpp
+++ b/dom/media/utils/PerformanceRecorder.cpp
@@ -29,7 +29,8 @@ const char* StageToStr(PerformanceRecorder::Stage aStage) {
   }
 }
 
-const char* FindMediaResolution(int32_t aHeight) {
+/* static */
+const char* PerformanceRecorder::FindMediaResolution(int32_t aHeight) {
   static const struct {
     const int32_t mH;
     const nsCString mRes;
@@ -52,11 +53,18 @@ const char* FindMediaResolution(int32_t aHeight) {
   return resolution;
 }
 
-static TimeStamp GetCurrentTimeForMeasurement() {
+/* static */
+bool PerformanceRecorder::IsMeasurementEnabled() {
+  return profiler_can_accept_markers() ||
+         PerformanceRecorder::sEnableMeasurementForTesting;
+}
+
+/* static */
+TimeStamp PerformanceRecorder::GetCurrentTimeForMeasurement() {
   // The system call to get the clock is rather expensive on Windows. As we
   // only report the measurement report via markers, if the marker isn't enabled
   // then we won't do any measurement in order to save CPU time.
-  return profiler_can_accept_markers() ? TimeStamp::Now() : TimeStamp();
+  return IsMeasurementEnabled() ? TimeStamp::Now() : TimeStamp();
 }
 
 void PerformanceRecorder::Start() {
@@ -92,13 +100,14 @@ void AppendMediaInfoFlagToName(nsCString& aName, MediaInfoFlag aFlag) {
   }
 }
 
-void PerformanceRecorder::End() {
+float PerformanceRecorder::End() {
+  double elapsedTimeUs = 0.0;
   if (mStartTime && !mStartTime->IsNull()) {
     MOZ_ASSERT(mStage != Stage::Invalid);
-    if (profiler_can_accept_markers()) {
+    if (IsMeasurementEnabled()) {
       const auto now = TimeStamp::Now();
-      const double passedTimeUs = (now - *mStartTime).ToMicroseconds();
-      MOZ_ASSERT(passedTimeUs > 0, "Passed time can't be less than 0!");
+      elapsedTimeUs = (now - *mStartTime).ToMicroseconds();
+      MOZ_ASSERT(elapsedTimeUs >= 0, "Elapsed time can't be less than 0!");
       nsAutoCString name(StageToStr(mStage));
       name.Append(":");
       name.Append(FindMediaResolution(mHeight));
@@ -110,6 +119,7 @@ void PerformanceRecorder::End() {
     }
     Reset();
   }
+  return elapsedTimeUs;
 }
 
 }  // namespace mozilla
diff --git a/dom/media/utils/PerformanceRecorder.h b/dom/media/utils/PerformanceRecorder.h
index 8ee75b630dd9..d6495dffbba3 100644
--- a/dom/media/utils/PerformanceRecorder.h
+++ b/dom/media/utils/PerformanceRecorder.h
@@ -106,15 +106,27 @@ class PerformanceRecorder {
   PerformanceRecorder& operator=(const PerformanceRecorder&) = delete;
 
   void Start();
-  void End();
 
- private:
+  // Return the passed time if it has started and still valid. Otherwise,
+  // return 0.
+  float End();
+
+ protected:
   void Reset();
 
+  static bool IsMeasurementEnabled();
+  static TimeStamp GetCurrentTimeForMeasurement();
+
+  // Return the resolution range for the given height. Eg. V:1080<h<=1440.
+  static const char* FindMediaResolution(int32_t aHeight);
+
   Stage mStage = Stage::Invalid;
   int32_t mHeight;
   MediaInfoFlag mFlag = MediaInfoFlag::None;
   Maybe<TimeStamp> mStartTime;
+
+  // We would enable the measurement on testing.
+  static inline bool sEnableMeasurementForTesting = false;
 };
 
 }  // namespace mozilla
diff --git a/dom/media/utils/gtest/TestPerformanceRecorder.cpp b/dom/media/utils/gtest/TestPerformanceRecorder.cpp
new file mode 100644
index 000000000000..943d62e702e4
--- /dev/null
+++ b/dom/media/utils/gtest/TestPerformanceRecorder.cpp
@@ -0,0 +1,61 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+#include <chrono>
+#include <thread>
+
+#include "PerformanceRecorder.h"
+#include "gtest/gtest.h"
+#include "nsString.h"
+
+using Stage = mozilla::PerformanceRecorder::Stage;
+
+class PerformanceRecorderWrapper : public mozilla::PerformanceRecorder {
+ public:
+  PerformanceRecorderWrapper(Stage aStage, int32_t aHeight)
+      : PerformanceRecorder(aStage, aHeight) {}
+
+  const char* Resolution() const { return FindMediaResolution(mHeight); }
+
+  static void EnableMeasurementOnNonMarkerSituation() {
+    sEnableMeasurementForTesting = true;
+  }
+};
+
+TEST(PerformanceRecorder, TestResolution)
+{
+  static const struct {
+    const int32_t mH;
+    const char* mRes;
+  } resolutions[] = {{0, "A:0"},
+                     {240, "V:0<h<=240"},
+                     {480, "V:240<h<=480"},
+                     {576, "V:480<h<=576"},
+                     {720, "V:576<h<=720"},
+                     {1080, "V:720<h<=1080"},
+                     {1440, "V:1080<h<=1440"},
+                     {2160, "V:1440<h<=2160"},
+                     {4320, "V:h>2160"}};
+
+  const Stage stage = Stage::RequestDecode;
+  for (auto&& res : resolutions) {
+    PerformanceRecorderWrapper w(stage, res.mH);
+    ASSERT_STREQ(w.Resolution(), res.mRes);
+  }
+}
+
+TEST(PerformanceRecorder, TestMoveOperation)
+{
+  PerformanceRecorderWrapper::EnableMeasurementOnNonMarkerSituation();
+
+  const Stage stage = Stage::RequestDecode;
+  const uint32_t resolution = 1080;
+  PerformanceRecorderWrapper w1(stage, resolution);
+  w1.Start();
+  std::this_thread::sleep_for(std::chrono::milliseconds(1));
+
+  // w1 has been moved which won't continue measuring data.
+  PerformanceRecorderWrapper w2(std::move(w1));
+  ASSERT_DOUBLE_EQ(w1.End(), 0.0);
+  ASSERT_TRUE(w2.End() > 0.0);
+}
diff --git a/dom/media/utils/gtest/moz.build b/dom/media/utils/gtest/moz.build
new file mode 100644
index 000000000000..8486f52f738a
--- /dev/null
+++ b/dom/media/utils/gtest/moz.build
@@ -0,0 +1,18 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+UNIFIED_SOURCES += [
+    "TestPerformanceRecorder.cpp",
+]
+
+LOCAL_INCLUDES += [
+    "/dom/media/utils",
+]
+
+FINAL_LIBRARY = "xul-gtest"
+
+if CONFIG["CC_TYPE"] in ("clang", "gcc"):
+    CXXFLAGS += ["-Wno-error=shadow"]
diff --git a/dom/media/utils/moz.build b/dom/media/utils/moz.build
index f9aa10de654c..cc91c79c6477 100644
--- a/dom/media/utils/moz.build
+++ b/dom/media/utils/moz.build
@@ -18,4 +18,7 @@ UNIFIED_SOURCES += [
     "TelemetryProbesReporter.cpp",
 ]
 
+if CONFIG["ENABLE_TESTS"]:
+    DIRS += ["gtest"]
+
 FINAL_LIBRARY = "xul"