Let a minimum time interval pass (one bucket size) after initialization before reporting rates (to …

webrtc/base/ratetracker_unittest.cc

 /*
  *  Copyright 2015 The WebRTC Project Authors. All rights reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
 #include "webrtc/base/gunit.h"
 #include "webrtc/base/ratetracker.h"
 
 namespace rtc {
+namespace {
+  const uint32_t kBucketIntervalMs = 100;
+}  // namespace
 
 class RateTrackerForTest : public RateTracker {
  public:
-  RateTrackerForTest() : RateTracker(100u, 10u), time_(0) {}
+  RateTrackerForTest() : RateTracker(kBucketIntervalMs, 10u), time_(0) {}
   virtual uint32_t Time() const { return time_; }
   void AdvanceTime(uint32_t delta) { time_ += delta; }
 
  private:
   uint32_t time_;
 };
 
 TEST(RateTrackerTest, Test30FPS) {
   RateTrackerForTest tracker;
 
@@ skipping 19 matching lines @@
   }
   EXPECT_DOUBLE_EQ(60.0, tracker.ComputeRateForInterval(1000u));
 }
 
 TEST(RateTrackerTest, TestRateTrackerBasics) {
   RateTrackerForTest tracker;
   EXPECT_DOUBLE_EQ(0.0, tracker.ComputeRateForInterval(1000u));
 
   // Add a sample.
   tracker.AddSamples(1234);
-  // Advance the clock by 100 ms.
-  tracker.AdvanceTime(100);
+  // Advance the clock by less than one bucket interval (no rate returned).
+  tracker.AdvanceTime(kBucketIntervalMs - 1);
+  EXPECT_DOUBLE_EQ(0.0, tracker.ComputeRate());
+  // Advance the clock by 100 ms (one bucket interval).
+  tracker.AdvanceTime(1);
   EXPECT_DOUBLE_EQ(12340.0, tracker.ComputeRateForInterval(1000u));
   EXPECT_DOUBLE_EQ(12340.0, tracker.ComputeRate());
   EXPECT_EQ(1234U, tracker.TotalSampleCount());
   EXPECT_DOUBLE_EQ(12340.0, tracker.ComputeTotalRate());
 
   // Repeat.
   tracker.AddSamples(1234);
   tracker.AdvanceTime(100);
   EXPECT_DOUBLE_EQ(12340.0, tracker.ComputeRateForInterval(1000u));
   EXPECT_DOUBLE_EQ(12340.0, tracker.ComputeRate());
@@ skipping 83 matching lines @@
 }
 
 TEST(RateTrackerTest, TestGetUnitSecondsAfterInitialValue) {
   RateTrackerForTest tracker;
   tracker.AddSamples(1234);
   tracker.AdvanceTime(1000);
   EXPECT_DOUBLE_EQ(1234.0, tracker.ComputeRateForInterval(1000u));
 }
 
 }  // namespace rtc