remoting/base/running_average_unittest.cc

   1 // Copyright 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "remoting/base/running_average.h"
   6 #include "testing/gtest/include/gtest/gtest.h"
   7
   8 namespace remoting {
   9
  10 static const int64 kTestValues[] = { 10, 20, 30, 10, 25, 16, 15 };
  11
  12 // Average across a single element, i.e. just return the most recent.
  13 TEST(RunningAverageTest, OneElementWindow) {
  14   RunningAverage running_average(1);
  15   EXPECT_EQ(0, running_average.Average());
  16
  17   for (size_t i = 0; i < arraysize(kTestValues); ++i) {
  18     running_average.Record(kTestValues[i]);
  19     EXPECT_EQ(static_cast<double>(kTestValues[i]), running_average.Average());
  20   }
  21 }
  22
  23 // Average the two most recent elements.
  24 TEST(RunningAverageTest, TwoElementWindow) {
  25   RunningAverage running_average(2);
  26   EXPECT_EQ(0, running_average.Average());
  27
  28   for (size_t i = 0; i < arraysize(kTestValues); ++i) {
  29     running_average.Record(kTestValues[i]);
  30
  31     double expected = kTestValues[i];
  32     if (i > 0)
  33       expected = (expected + kTestValues[i-1]) / 2;
  34
  35     EXPECT_EQ(expected, running_average.Average());
  36   }
  37 }
  38
  39 // Average across all the elements if the window size exceeds the element count.
  40 TEST(RunningAverageTest, LongWindow) {
  41   RunningAverage running_average(arraysize(kTestValues) + 1);
  42   EXPECT_EQ(0, running_average.Average());
  43
  44   for (size_t i = 0; i < arraysize(kTestValues); ++i) {
  45     running_average.Record(kTestValues[i]);
  46
  47     double expected = 0.0;
  48     for (size_t j = 0; j <= i; ++j)
  49       expected += kTestValues[j];
  50     expected /= i + 1;
  51
  52     EXPECT_EQ(expected, running_average.Average());
  53   }
  54 }
  55
  56 }  // namespace remoting