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
8namespace remoting {
9
10static const int64 kTestValues[] = { 10, 20, 30, 10, 25, 16, 15 };
11
12// Average across a single element, i.e. just return the most recent.
13TEST(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.
24TEST(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.
40TEST(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
57