1 /*
2  *  Copyright 2011 The WebRTC Project Authors. All rights reserved.
3  *
4  *  Use of this source code is governed by a BSD-style license
5  *  that can be found in the LICENSE file in the root of the source
6  *  tree. An additional intellectual property rights grant can be found
7  *  in the file PATENTS.  All contributing project authors may
8  *  be found in the AUTHORS file in the root of the source tree.
9  */
10 
11 #include <limits.h>
12 
13 #include "webrtc/base/bandwidthsmoother.h"
14 #include "webrtc/base/gunit.h"
15 
16 namespace rtc {
17 
18 static const int kTimeBetweenIncrease = 10;
19 static const double kPercentIncrease = 1.1;
20 static const size_t kSamplesCountToAverage = 2;
21 static const double kMinSampleCountPercent = 1.0;
22 
TEST(BandwidthSmootherTest,TestSampleIncrease)23 TEST(BandwidthSmootherTest, TestSampleIncrease) {
24   BandwidthSmoother mon(1000,  // initial_bandwidth_guess
25                         kTimeBetweenIncrease,
26                         kPercentIncrease,
27                         kSamplesCountToAverage,
28                         kMinSampleCountPercent);
29 
30   int bandwidth_sample = 1000;
31   EXPECT_EQ(bandwidth_sample, mon.get_bandwidth_estimation());
32   bandwidth_sample =
33       static_cast<int>(bandwidth_sample * kPercentIncrease);
34   EXPECT_FALSE(mon.Sample(9, bandwidth_sample));
35   EXPECT_TRUE(mon.Sample(10, bandwidth_sample));
36   EXPECT_EQ(bandwidth_sample, mon.get_bandwidth_estimation());
37   int next_expected_est =
38       static_cast<int>(bandwidth_sample * kPercentIncrease);
39   bandwidth_sample *= 2;
40   EXPECT_TRUE(mon.Sample(20, bandwidth_sample));
41   EXPECT_EQ(next_expected_est, mon.get_bandwidth_estimation());
42 }
43 
TEST(BandwidthSmootherTest,TestSampleIncreaseFromZero)44 TEST(BandwidthSmootherTest, TestSampleIncreaseFromZero) {
45   BandwidthSmoother mon(0,  // initial_bandwidth_guess
46                         kTimeBetweenIncrease,
47                         kPercentIncrease,
48                         kSamplesCountToAverage,
49                         kMinSampleCountPercent);
50 
51   const int kBandwidthSample = 1000;
52   EXPECT_EQ(0, mon.get_bandwidth_estimation());
53   EXPECT_FALSE(mon.Sample(9, kBandwidthSample));
54   EXPECT_TRUE(mon.Sample(10, kBandwidthSample));
55   EXPECT_EQ(kBandwidthSample, mon.get_bandwidth_estimation());
56 }
57 
TEST(BandwidthSmootherTest,TestSampleDecrease)58 TEST(BandwidthSmootherTest, TestSampleDecrease) {
59   BandwidthSmoother mon(1000,  // initial_bandwidth_guess
60                         kTimeBetweenIncrease,
61                         kPercentIncrease,
62                         kSamplesCountToAverage,
63                         kMinSampleCountPercent);
64 
65   const int kBandwidthSample = 999;
66   EXPECT_EQ(1000, mon.get_bandwidth_estimation());
67   EXPECT_FALSE(mon.Sample(1, kBandwidthSample));
68   EXPECT_EQ(1000, mon.get_bandwidth_estimation());
69   EXPECT_TRUE(mon.Sample(2, kBandwidthSample));
70   EXPECT_EQ(kBandwidthSample, mon.get_bandwidth_estimation());
71 }
72 
TEST(BandwidthSmootherTest,TestSampleTooFewSamples)73 TEST(BandwidthSmootherTest, TestSampleTooFewSamples) {
74   BandwidthSmoother mon(1000,  // initial_bandwidth_guess
75                         kTimeBetweenIncrease,
76                         kPercentIncrease,
77                         10,  // 10 samples.
78                         0.5);  // 5 min samples.
79 
80   const int kBandwidthSample = 500;
81   EXPECT_EQ(1000, mon.get_bandwidth_estimation());
82   EXPECT_FALSE(mon.Sample(1, kBandwidthSample));
83   EXPECT_FALSE(mon.Sample(2, kBandwidthSample));
84   EXPECT_FALSE(mon.Sample(3, kBandwidthSample));
85   EXPECT_FALSE(mon.Sample(4, kBandwidthSample));
86   EXPECT_EQ(1000, mon.get_bandwidth_estimation());
87   EXPECT_TRUE(mon.Sample(5, kBandwidthSample));
88   EXPECT_EQ(kBandwidthSample, mon.get_bandwidth_estimation());
89 }
90 
TEST(BandwidthSmootherTest,TestSampleRollover)91 TEST(BandwidthSmootherTest, TestSampleRollover) {
92   const int kHugeBandwidth = 2000000000;  // > INT_MAX/1.1
93   BandwidthSmoother mon(kHugeBandwidth,
94                         kTimeBetweenIncrease,
95                         kPercentIncrease,
96                         kSamplesCountToAverage,
97                         kMinSampleCountPercent);
98 
99   EXPECT_FALSE(mon.Sample(10, INT_MAX));
100   EXPECT_FALSE(mon.Sample(11, INT_MAX));
101   EXPECT_EQ(kHugeBandwidth, mon.get_bandwidth_estimation());
102 }
103 
TEST(BandwidthSmootherTest,TestSampleNegative)104 TEST(BandwidthSmootherTest, TestSampleNegative) {
105   BandwidthSmoother mon(1000,  // initial_bandwidth_guess
106                         kTimeBetweenIncrease,
107                         kPercentIncrease,
108                         kSamplesCountToAverage,
109                         kMinSampleCountPercent);
110 
111   EXPECT_FALSE(mon.Sample(10, -1));
112   EXPECT_FALSE(mon.Sample(11, -1));
113   EXPECT_EQ(1000, mon.get_bandwidth_estimation());
114 }
115 
116 }  // namespace rtc
117